KR102074008B1 - Processes to produce short cut microfibers - Google Patents

Abstract

(A) contacting the short-cut multicomponent fibers having a length of less than 25 mm with the heated aqueous stream in the mixing zone to produce a short-cut multicomponent microfiber slurry; (B) directing the short-cut multicomponent microfiber slurry, and optionally, a heated aqueous stream to a fiber open zone to remove a portion of the water dispersible sulfopolyester to produce an open microfiber slurry; And (C) directing the opened microfiber slurry to a first solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream.

Description

PROCESSES TO PRODUCE SHORT CUT MICROFIBERS

The present invention relates to water dispersible fibers and fiber articles comprising sulfopolyesters. The invention also relates to multicomponent fibers comprising sulfopolyesters, and microdenier fibers and fibrous articles made therefrom. The invention also relates to a process for producing water dispersible multicomponent fibers and microdenier fibers and to articles made therefrom.

This application claims priority to US Provisional Application Nos. 61 / 592,854, 61 / 592,867, 61 / 592,917, and 61 / 592,974, filed January 31, 2012, the disclosures of which are incorporated herein by reference. The references are incorporated herein by reference to the extent that they do not conflict with the description.

Fibers, melt blown webs, and other melt spun fiber articles have been made from thermoplastic polymers such as poly (propylene), polyamides, and polyesters. One common use of these fibers and textile articles is, in particular, wipes, feminine hygiene articles, infant diapers, adult incontinence briefs, hospital / surgical and other medical disposable protective fabrics and layers, geotextiles Nonwovens in personal care articles, such as industrial wipes, and filter media. Unfortunately, personal care articles made from conventional thermoplastic polymers are difficult to dispose of and are usually disposed of in landfills. One promising alternative disposal method is to make these items or their components "washable", ie, suitable for public sewage systems. The use of water dispersible or water soluble materials also improves recyclability and recycling of personal care articles. The various thermoplastic polymers currently used in personal care articles are not inherently water dispersible or water soluble and thus do not produce articles that can be easily dismantled and disposed of or easily recycled to sewage systems.

The need for flushable personal care articles has necessitated fibers, nonwovens and other fibrous articles with varying water-reactivity. Various solutions to address this need are described, for example, in US Pat. Nos. 6,548,592, 6,552,162, 5,281,306, 5,292,581, 5,935,880 and 5,509,913; US Patent Application Nos. 09 / 775,312 and 09 / 752,017; And PCT International Patent Publication WO 01/666666 A2. However, these solutions have several disadvantages and fail to provide a fibrous article, such as a fiber or nonwoven, with a satisfactory balance of tensile strength, absorbency, flexibility and performance properties such as fabric integrity under wet or dry conditions.

For example, a typical nonwoven technique is based on depositing fibers treated with a resin-bonded adhesive in various directions to produce a web with strong integrity and other desirable properties. However, the resulting assembly generally has poor water-reactivity and is not suitable for flushable applications. The presence of the binder may also cause undesirable properties of the final article such as reduced sheet wetting, increased stiffness, blocking and higher manufacturing costs. It is also difficult to produce binders that exhibit adequate wet strength during use but disperse rapidly upon disposal. Thus, nonwoven assemblies using such binders may be slowly disintegrated under ambient conditions or may have less than adequate wet strength properties in the presence of body fluids. To address this problem, pH and ion-sensitive water dispersible binders, such as lattice containing acrylic or methacrylic acid with or without salts are known and are described, for example, in US Pat. No. 6,548,592 B1. . However, ion concentrations and pH levels in public sewage and residential purification systems can vary widely depending on geographic location and may not be sufficient for the binder to be soluble and dispersed. In this case, the fibrous article may close the drain pipe or the sewer branch pipe without dismantling after disposal.

Multicomponent fibers containing water dispersible components and thermoplastic water non-dispersible components are described, for example, in US Pat. Nos. 5,916,678, 5,405,698, 4,966,808, 5,525,282, 5,366,804, and 5,486,418. For example, these multicomponent fibers may be shaped, such as for example islands-in-the-sea, sheath core, side-by-side or segmented pie shapes, or It may be a bicomponent fiber having an engineered cross section. Water or a dilute alkaline solution can be added to the multicomponent fiber to dissolve the water dispersible component, leaving the water non-dispersible component as a separate, independent fiber of extremely small fineness. However, polymers with good water dispersibility often impart stickiness to the resultant multicomponent fibers, causing the fibers to stick to, block or fuse with each other during winding or after days of storage, especially under high temperature and high humidity conditions. To prevent fusion, fatty acids or oil based finishes are often applied to the fiber surface. Also, as described, for example, in US Pat. No. 6,171,685, large amounts of pigments or fillers are sometimes added to the water dispersible polymer to prevent fusing of the fibers. Such oil finishes, pigments and fillers require additional processing steps and can impart undesirable properties to the final fiber. Many water dispersible polymers also require alkaline solutions to remove them, which can cause degradation of other polymer components of the fiber, such as, for example, reductions in intrinsic viscosity, toughness and melt strength. In addition, some water-dispersible polymers cannot tolerate exposure to water during high pressure hydroentanglement and are therefore not suitable for the production of nonwoven webs and nonwovens.

Alternatively, the water dispersible component can serve as a binder for the thermoplastic fibers in the nonwoven web. Upon exposure to water, the fiber-fiber bonds separate so that the nonwoven web loses its integrity and breaks down into individual fibers. However, the thermoplastic fiber components of these nonwoven webs are not water dispersible and remain in the aqueous medium and must eventually be removed from the municipal wastewater treatment plant. High pressure weaving can be used to produce degradable nonwovens with or without very low levels of binder (less than 5% by weight) added to hold the fibers together. Although these fabrics can be dismantled upon disposal, they often use fibers that are not water-soluble or water-dispersible and can cause entanglement and blockage in sewage systems. Any added water dispersible binder should also be minimally affected by high pressure weaving and should not form gelatinous formation or crosslinking, thereby contributing to fabric handling or sewage related problems.

Several water soluble or water dispersible polymers may be available but are typically not applicable to melt blown fiber manufacturing processes or melt spinning. Polymers such as polyvinyl alcohol, polyvinyl pyrrolidone and polyacrylic acid cannot be melt processed due to thermal decomposition occurring at temperatures below those at which suitable melt viscosities are achieved. High molecular weight polyethylene oxides may have suitable thermal stability, but provide a high viscosity solution at the polymer interface to slow down the dissolution. Water dispersible sulfopolyesters are described, for example, in US Pat. Nos. 6,171,685, 5,543,488, 5,853,701, 4,304,901, 6,211,309, 5,570,605, 6,428,900, and 3,779,993. Typical sulfopolyesters, however, are low molecular weight thermoplastics that are brittle and lack flexibility to withstand winding operations to obtain rolls of unbreakable or unbreakable material. Sulfopolyesters may also exhibit blocking or fusion during processing into films or fibers, and may require the use of oil finishes or large amounts of pigments or fillers to avoid this. Low molecular weight polyethylene oxide (more commonly known as polyethylene glycol) is a weak / fragile polymer that does not have the physical properties required for fiber applications. There is an alternative to making fibers from known water soluble polymers via solution techniques, but the added complexity of removing solvents (especially water) adds to the manufacturing cost.

Accordingly, there is a need for water dispersible fibers and fiber articles made therefrom that exhibit fabric integrity in the presence of appropriate tensile strength, absorbency, flexibility, and moisture, especially when exposed to human body fluids. There is also a need for a fibrous article that does not require a binder and is completely dispersed or dissolved in a residential or municipal sewage system. Possible uses include melt blown webs, spunbonded fabrics, high pressure woven fabrics, dry-laid nonwovens, bicomponent fiber components, adhesion promoting layers, binders for cellulose, flushable nonwovens and films , Soluble binder fibers, protective layers, and carriers for the active ingredient that are released or dissolved in water. There is also a need for a multicomponent fiber having water dispersible components that are easily removed by hot water at neutral or slightly acidic pH without exhibiting excessive blocking or fusion of the filaments during spinning operations and are suitable for high-pressure weaving processes for producing nonwovens. Other fiber materials that are extrudable and melt spun are possible.

The inventors have unexpectedly discovered that flexible water dispersible fibers can be produced from sulfopolyester. Therefore, the present invention

(A) (i) one or more dicarboxylic acid residues; (ii) at least one having at least about 4 to about 40 mole percent, based on the total repeat units, of two functional groups attached to an aromatic or cycloaliphatic ring, which is hydroxyl, carboxyl, or a combination thereof, and one or more sulfonate groups Sulfomonomer residues; (iii) at least 25 mole percent, based on total diol residues, are poly (ethylene glycol) having a structure of H- (OCH ₂ -CH ₂ ) _n -OH, where n is an integer from 2 to about 500 One or more diol residues; And (iv) a glass transition temperature of at least 25 ° C. comprising branched monomer residues having from 0 to about 25 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof. Sulfopolyester with (Tg);

(B) optionally, a water dispersible polymer blended with the sulfopolyester; And

(C) optionally, a water non-dispersible polymer blended with the sulfopolyester, provided that the blend is an immiscible blend

It includes, and provides a water dispersible fiber containing less than 10% by weight pigment or filler based on the total weight of the fiber.

The fibers of the present invention can be monocomponent fibers that are readily dispersed or dissolved in water and can be prepared by melt-blowing or melt-spinning. The fibers can be made from a single sulfopolyester or blends of sulfopolyesters with water dispersible or water non-dispersible polymers. Thus, the fibers of the present invention may optionally comprise a water dispersible polymer blended with sulfopolyester. In addition, the fibers may optionally comprise a water non-dispersible polymer blended with sulfopolyester, provided that the blend is an immiscible blend. The present invention also includes a fibrous article comprising the water dispersible fibers of the present invention. Thus, the fibers of the present invention can be used to produce a variety of fibrous articles, which are water dispersible or flushable, such as yarns, melt-blown webs, spunbond webs and nonwovens. The staple fibers of the invention can also be blended with natural or synthetic fibers in paper, nonwoven webs, and textile yarns.

Another aspect of the invention

(A) (i) about 50 to about 96 mole percent of one or more isophthalic or terephthalic acid residues based on total acid residues; (ii) about 4 to about 30 mole percent sodiosulfoisophthalic acid residues based on total acid residues; (iii) at least 25 mole percent, based on total diol residues, are poly (ethylene glycol) having a structure of H- (OCH ₂ -CH ₂ ) _n -OH, where n is an integer from 2 to about 500 One or more diol residues; (iv) a glass transition temperature of at least 25 ° C., comprising branched monomer residues having from 0 to about 20 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof; Sulfopolyester with Tg);

(B) optionally, a first water dispersible polymer blended with the sulfopolyester; And

(C) optionally, a water non-dispersible polymer blended with the sulfopolyester to form an immiscible blend

And less than 10% by weight of pigment or filler, based on the total weight of the fiber.

The water dispersible fibrous articles of the present invention include, for example, personal care articles such as wipes, gauze, tissues, diapers, training pants, sanitary napkins, bandages, wound care and surgical dressings. In addition to being water dispersible, the fiber articles of the present invention are flushable, ie compatible with residential and municipal sewage systems and suitable for disposal in such sewage systems.

The present invention also provides a multicomponent fiber comprising a water dispersible sulfopolyester and at least one water non-dispersible polymer. The fibers have a geometric form designed to exist as compartments in which the water non-dispersible polymers are substantially isolated from each other by intervening sulfopolyesters, the sulfopolyesters being a binder to the water non-dispersible compartments or It acts as a surrounding matrix. Accordingly, another aspect of the present invention

(A) (i) one or more dicarboxylic acid residues; (ii) at least one having at least about 4 to about 40 mole percent, based on the total repeat units, of two functional groups attached to an aromatic or cycloaliphatic ring, which is hydroxyl, carboxyl, or a combination thereof, and one or more sulfonate groups Sulfomonomer residues; (iii) at least 25 mole percent, based on total diol residues, are poly (ethylene glycol) having a structure of H- (OCH ₂ -CH ₂ ) _n -OH, where n is an integer from 2 to about 500 One or more diol residues; And (iv) a glass transition temperature of at least 57 ° C. comprising branched monomer residues having from 0 to about 25 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof. Water dispersible sulfopolyester having (Tg); And

(B) a plurality of segments comprising at least one water non-dispersible polymer that is immiscible with the sulfopolyester, the compartments being substantially isolated from each other by the sulfopolyester intervening between the compartments Plural compartments

It is a multi-component fiber having a molded cross section, including.

The sulfopolyester has a glass transition temperature of at least 57 ° C., which greatly reduces the blocking and fusion of the fibers during winding and long term storage. The sulfopolyester can be removed by contacting the multicomponent fiber with water, leaving the water non-dispersible compartment as microdenier fibers. Thus, the present invention also

(A) (i) about 50 to about 96 mole percent of one or more isophthalic or terephthalic acid residues based on total acid residues; (ii) about 4 to about 30 mole percent sodiosulfoisophthalic acid residues based on total acid residues; (iii) at least 25 mole percent, based on total diol residues, are poly (ethylene glycol) having a structure of H- (OCH ₂ -CH ₂ ) _n -OH, where n is an integer from 2 to about 500 One or more diol residues; And (iv) branched monomer residues having from 0 to about 20 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof, and having a glass transition temperature of 57 ° C. or higher ( Spinning a water dispersible sulfopolyester having Tg) and at least one water non-dispersible polymer that is immiscible with the sulfopolyester into a multicomponent fiber, wherein the fiber comprises a water non-dispersible polymer Having a plurality of compartments, said compartments being substantially isolated from one another by sulfopolyesters intervening between the compartments; And

(B) contacting the multicomponent fiber with water to remove the sulfopolyester to produce microdenier fibers

It also provides a method for producing microdenier fibers.

The water non-dispersible polymer may be biodisintegratable as determined by DIN standard 54900 and / or may be biodegradable as determined by ASTM standard method D6340-98. The multicomponent fibers may also be used to make fibrous articles, such as yarns, fabrics, melt-blown webs, spun-bonding webs or nonwovens (which may include one or more layers of fibres). A fibrous article having multicomponent fibers may then be contacted with water to produce a fibrous article containing microdenier fibers.

Accordingly, another aspect of the present invention

(A) (i) about 50 to about 96 mole percent of one or more isophthalic or terephthalic acid residues based on total acid residues; (ii) about 4 to about 30 mole percent sodiosulfoisophthalic acid residues based on total acid residues; (iii) at least 25 mole percent, based on total diol residues, are poly (ethylene glycol) having a structure of H- (OCH ₂ -CH ₂ ) _n -OH, where n is an integer from 2 to about 500 One or more diol residues; And (iv) branched monomer residues having from 0 to about 20 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof, and having a glass transition temperature of 57 ° C. or higher ( Spinning a water dispersible sulfopolyester having Tg) and at least one water non-dispersible polymer that is immiscible with the sulfopolyester into a multicomponent fiber, wherein the fiber comprises a water non-dispersible polymer Having a plurality of compartments, said compartments being substantially isolated from one another by sulfopolyesters intervening between the compartments;

(B) overlapping the multicomponent fibers of step (A) to produce a nonwoven web; And

(C) contacting the nonwoven web with water to remove the sulfopolyester to produce a microdenier fiber web.

It includes, a method for producing a microdenier fiber web.

The invention also

(A) (i) (a) one or more dicarboxylic acid residues; (b) about 4 to about 40 mole percent, based on the total repeat units, of two functional groups attached to an aromatic or cycloaliphatic ring, which is hydroxyl, carboxyl, or a combination thereof, and one or more metal sulfonate groups Sulfomonomer residues; (c) at least 20 mole percent, based on the total diol residues, are poly (ethylene glycol) having a structure of H— (OCH ₂ —CH ₂ ) _n —OH, wherein n is an integer from 2 to about 500 One or more diol residues; And (d) a glass transition temperature of at least 25 ° C. comprising branched monomer residues having from 0 to about 25 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof. Sulfopolyester with (Tg);

(ii) optionally, a water dispersible polymer blended with the sulfopolyester; And

(iii) optionally, a water non-dispersible polymer blended with the sulfopolyester to produce an immiscible blend

Heating the water dispersible polymer composition comprising a pigment or filler based on the total weight of the polymer composition to a temperature above its pour point;

(B) melt spinning the filament; And

(C) overlapping the filaments of step (B) to create a nonwoven web

It also provides a method for producing a water dispersible nonwoven comprising a.

In another aspect of the invention,

(A) shows a melt viscosity of less than about 12,000 poise, measured at 240 ° C. at a strain rate of 1 radian / second, and less than about 25 mole percent of one or more sulfomonomer residues based on the total moles of diacid or diol residues; One or more water dispersible sulfopolyesters; And

(B) a plurality of microfiber domains comprising at least one water non-dispersible polymer that is immiscible with the sulfopolyester, wherein the domains are substantially isolated from each other by sulfopolyesters intervening between the domains; Multiple microfiber domains

There is provided a multicomponent fiber having a shaped cross section.

In another aspect of the invention,

(A) at least one water dispersible sulfopolyester; And

(B) a plurality of domains comprising at least one water non-dispersible polymer that is immiscible with the sulfopolyester, wherein the domains are substantially isolated from each other by sulfopolyesters intervening between the domains; domain

A multicomponent extrudates having a shaped cross section are provided, comprising

The extrudate can then be melt drawn at a rate of about 2000 m / min or more.

In another aspect of the invention, a method of making a multicomponent fiber having a molded cross section comprising spinning at least one water dispersible sulfopolyester and at least one water non-dispersible polymer that is immiscible with the sulfopolyester. Is provided,

Wherein the multicomponent fiber has a plurality of domains comprising a water non-dispersible polymer, which domains are substantially isolated from each other by sulfopolyesters intervening between the domains, wherein the water dispersible sulfopolyester is 1 radian A melt viscosity of less than about 12,000 poise as measured at 240 ° C. at a strain rate of per second and comprises less than about 25 mole percent of one or more sulfomonomer residues based on the total moles of diacid or diol residues.

In another aspect of the invention,

Extruding at least one water dispersible sulfopolyester and at least one water non-dispersible polymer that is immiscible with the sulfopolyester to produce a multicomponent extrudates, wherein the multicomponent extrudates are non-dispersible Having a plurality of domains comprising a polymer, said domains being substantially isolated from each other by said sulfopolyester intervening between said domains, and

Melt drawing the multicomponent extrudates at a rate of at least about 2000 m / min to produce multicomponent fibers

Provided is a method of making a multicomponent fiber having a molded cross section, including.

In another aspect, the present invention

(A) spinning at least one water dispersible sulfopolyester and at least one water non-dispersible polymer immiscible with the water dispersible sulfopolyester into a multicomponent fiber, wherein the multicomponent fiber is water non-dispersible Having a plurality of domains comprising a polymer, said domains being substantially isolated from each other by sulfopolyesters intervening between the domains, said water dispersible sulfopolyesters measured at 240 ° C. at a strain rate of 1 radian / second Exhibiting a melt viscosity of less than about 12,000 poise and comprising less than about 25 mole percent of one or more sulfomonomer residues based on the total moles of diacid or diol residues, and

(B) contacting the multicomponent fiber with water to remove the water dispersible sulfopolyester to produce microdenier fibers of the water non-dispersible polymer (s).

It provides a microdenier fiber manufacturing method comprising a.

In another aspect, the present invention

(A) extruding at least one water dispersible sulfopolyester and at least one water non-dispersible polymer immiscible with the water dispersible sulfopolyester to produce a multicomponent extrudate, wherein the multicomponent extrudates are -Having a plurality of domains comprising a dispersible polymer, said domains being substantially isolated from each other by sulfopolyesters intervening between the domains;

(B) melt drawing the multicomponent extrudates at a rate of at least about 2000 m / min to produce multicomponent fibers; And

(C) contacting the multicomponent fiber with water to remove the water dispersible sulfopolyester to produce microdenier fibers of the water non-dispersible polymer (s).

It provides a microdenier fiber manufacturing method comprising a.

In another aspect of the invention,

(A) spinning at least one water dispersible sulfopolyester and at least one water non-dispersible polymer that is immiscible with the sulfopolyester into a multicomponent fiber, wherein the multicomponent fiber comprises a water non-dispersible polymer Wherein the domains are substantially isolated from each other by water dispersible sulfopolyesters intervening between the domains, wherein the water dispersible sulfopolyesters are about when measured at 240 ° C. at a strain rate of 1 radian / second. Having a melt viscosity of less than 12,000 poise and comprising less than about 25 mole percent of one or more sulfomonomer residues based on the total moles of diacid or diol residues;

(B) collecting the multicomponent fibers of step (A) to produce a nonwoven web; And

(C) contacting the nonwoven web with water to remove sulfopolyester to produce a microdenier fiber web.

Provided is a method of producing a microdenier fiber web.

In another aspect of the invention,

(A) extruding at least one water dispersible sulfopolyester and at least one water non-dispersible polymer that is immiscible with the sulfopolyester to produce a multicomponent extrudate, wherein the multicomponent extrudates are water non-minute Having a plurality of domains comprising an acidic polymer, said domains being substantially isolated from each other by sulfopolyesters intervening between the domains;

(B) melt drawing the multicomponent extrudates at a speed of at least about 2000 m / min to produce multicomponent fibers;

(C) collecting the multicomponent fibers of step (B) to produce a nonwoven web; And

(D) contacting the nonwoven web with water to remove the sulfopolyester to produce a microdenier fiber web

Provided is a method of producing a microdenier fiber web.

In another embodiment of the invention,

(A) cutting the multicomponent fibers into cut multicomponent fibers;

(B) contacting the fiber-containing feedstock comprising the cut multicomponent fibers with water to produce a fiber mixing slurry;

(C) heating the fiber mixing slurry to produce a heated fiber mixing slurry;

(D) optionally, mixing the fiber mixing slurry in a shear zone;

(E) removing at least a portion of the sulfopolyester from the chopped multicomponent fibers to produce a slurry mixture comprising a sulfopolyester dispersion and chopped water non-dispersible polymer microfibers; And

(F) separating the chopped water non-dispersible polymer microfibers from the slurry mixture

Provided is a method of making a cleaved water non-dispersible polymer microfiber.

In another embodiment of the present invention, a cleaved water non-dispersible polymer microfiber comprising at least one water non-dispersible polymer is provided, wherein the cleaved water non-dispersible polymer microfiber is less than 5 microns. It has an equivalent diameter of and a length of less than 25 mm.

In another embodiment of the present invention, there is provided a method of making a nonwoven article from the water non-dispersible polymer microfibers, the method

(A) providing a water non-dispersible polymer microfiber made from multicomponent fibers; And

(B) manufacturing a nonwoven article using a wet-laid process or a dry-laminate process

It includes.

In another embodiment of the present invention, a method of preparing a microfiber product stream is provided. This way

(A) contacting short-cut multicomponent fibers having a length of less than 25 mm with an aqueous stream heated in the fiber open zone to remove a portion of the water dispersible sulfopolyester to produce an open microfiber slurry, wherein The short-cut multicomponent fiber comprises at least one water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer that is immiscible with the water dispersible sulfopolyester, wherein the heated aqueous stream is at least 40 ° C., Said open microfiber slurry comprises water, microfibers and water dispersible sulfopolyester; And

(B) sending the open microfiber slurry to a first solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream, wherein the first mother liquor stream comprises water and a water dispersible sulfopolyester. , step

It includes.

In another embodiment of the present invention, a method of preparing a microfiber product stream is provided, the method of

(A) contacting short-cut multicomponent fibers having a length of less than 25 mm with an aqueous stream heated in the fiber open zone to remove a portion of the water dispersible sulfopolyester to produce an open microfiber slurry, wherein The short-cut multicomponent fiber comprises at least one water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer that is immiscible with the water dispersible sulfopolyester, wherein the heated aqueous stream is at least 40 ° C., Said open microfiber slurry comprises water non-dispersible polymer microfibers, water dispersible sulfopolyester and water; And

(B) sending the open microfiber slurry to a first solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream, wherein the first mother liquor stream comprises water and a water dispersible sulfopolyester. , step

It includes.

In another embodiment of the present invention, a method of preparing a microfiber product stream is provided, the method of

(A) contacting short-cut multicomponent fibers having a length of less than 25 mm with an aqueous stream treated in a fiber slurry zone to produce a short-cut multicomponent fiber slurry, wherein the short-cut multicomponent fibers are one At least one water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer incompatible with the water dispersible sulfopolyester, wherein the treated aqueous stream is at a temperature of at least 40 ° C .;

(B) contacting the short-cut multicomponent fiber slurry and the heated aqueous stream in a fiber open zone to remove a portion of the water dispersible sulfopolyester to produce an open microfiber slurry, wherein the open micro The fiber slurry comprises water non-dispersible polymer microfibers, water dispersible sulfopolyester and water; And

(C) directing the open microfiber slurry to a first solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream, wherein the first mother liquor stream comprises water and a water dispersible sulfopolyester. , step

It includes.

In another embodiment of the present invention, another method of preparing a microfiber product stream is provided, which method

(A) contacting a short-cut multicomponent fiber having a length of less than 25 mm in a mixing zone with a heated aqueous stream to produce a short-cut multicomponent fiber slurry, wherein the short-cut multicomponent fiber is at least one A water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer that is incompatible with the water dispersible sulfopolyester, wherein the heated aqueous stream is at a temperature of at least 40 ° C .;

(B) sending the short-cut multicomponent fiber slurry, and optionally, a heated aqueous stream, to an open fiber zone to remove a portion of the water dispersible sulfopolyester to produce an open microfiber slurry, wherein Wherein the open microfiber slurry comprises water non-dispersible polymer microfibers, water dispersible sulfopolyester and water; And

(C) directing the open microfiber slurry to a first solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream, wherein the first mother liquor stream comprises water and a water dispersible sulfopolyester. , step

It includes.

In another embodiment of the present invention, another method of preparing a microfiber product stream is provided, which method

(A) contacting a short-cut multicomponent fiber having a length of less than 25 mm in the fiber slurry zone with a treated aqueous stream to produce a short-cut multicomponent fiber slurry, wherein the short-cut multicomponent fiber is one At least one water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer incompatible with the water dispersible sulfopolyester, wherein the treated aqueous stream is at a temperature of at least 40 ° C .;

(B) contacting the short-cut multicomponent fiber slurry with a heated aqueous stream in a mixing zone to produce a heated multicomponent fiber slurry;

(C) sending the heated multicomponent fiber slurry to a fiber open zone to remove a portion of the water dispersible sulfopolyester to produce an open microfiber slurry; And

(D) sending the open microfiber slurry to a first solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream, wherein the first mother liquor stream comprises water and a water dispersible sulfopolyester. , step

It includes.

In another embodiment of the present invention, a method of separating a first mother liquor stream is provided. The method includes sending a first mother liquor stream to a second solid-liquid separation zone to produce a second wet cake stream and a second mother liquor stream, wherein the second mother liquor stream comprises water and water dispersible sulfopolyester. And the second wet cake stream comprises water non-dispersible polymer microfibers.

In another embodiment of the present invention, a method for recovering sulfopolyester is provided. This way,

(A) sending a second mother liquor stream to the first concentration zone to produce a first polymer concentrate stream and a first recovered water stream; And

(B) optionally, directing the first recovered water stream to a fiber open zone

It includes.

1A, 1B, and 1C are cross-sectional views of three differently constructed fibers that illustrate how to determine various measurements, particularly related to the size and shape of the fibers.
2 illustrates an embodiment of the invention in which a microfiber product stream is produced in a one stage open zone.
3A and 3B illustrate an embodiment of the present invention in which a microfiber product stream is produced in a two stage open zone.
4 illustrates an embodiment of the invention in which a microfiber product stream is produced in a three stage open zone.
5 illustrates an embodiment of a method of cutting multicomponent fibers to produce short-cut multicomponent fibers.
6A illustrates an embodiment of an open zone that includes a pipe.
6B illustrates an embodiment of an open zone that includes a continuous stirred tank.
6C illustrates an embodiment of an open zone that includes more than one continuous stirred tank.
7A and 7B illustrate an embodiment of a first solid-liquid separation zone.
8 shows the change in solids in the first mother liquor recovered from the open process of Example 36. FIG.
9 shows the results of performing a 37 INS bicomponent fiber opening process according to Example 38.
FIG. 10 shows the sulfopolyester content in the first mother liquor in the open process according to Example 39 as a function of treatment time.
11 shows the sulfopolyester removal rate in the open process according to Comparative Example 40.
12 shows sulfopolyester removal profiles for fiber openings according to Comparative Example 41. FIG.

The present invention provides water dispersible fibers and fibrous articles that exhibit fabric integrity in the presence of tensile strength, absorbency, flexibility, and moisture, especially when exposed to human body fluids. The fibers and fibrous articles of the present invention do not require the presence of oils, waxes or fatty acid finishes, or the use of large amounts (typically 10% by weight or more) of pigments or fillers to prevent blocking or fusion of the fibers during processing. Do not. In addition, fiber articles made from the novel fibers of the present invention do not require a binder and are readily dispersed or dissolved in household or public sewage systems.

In a comprehensive embodiment, the invention is a water dispersible fiber comprising a sulfopolyester having a glass transition temperature (Tg) of at least 25 ° C., wherein the sulfopolyester is

(A) at least one dicarboxylic acid residue;

(B) one or more having from about 4 to about 40 mole percent, based on the total repeat units, of two functional groups attached to an aromatic or cycloaliphatic ring (which is hydroxyl, carboxyl, or a combination thereof) and one or more sulfonate groups Sulfomonomer residues;

(C) at least 25 mole%, based on the total diol residues, are poly (ethylene glycol) having a structure of H— (OCH ₂ —CH ₂ ) _n —OH, wherein n is an integer from 2 to about 500 One or more diol residues; And

(D) branched monomer residues having from 0 to about 25 mole percent, based on the total repeat units, of at least three functional groups, which are hydroxyl, carboxyl, or a combination thereof

It provides a water-dispersible fiber comprising a.

The fibers of the present invention may optionally comprise a water dispersible polymer blended with a sulfopolyester and optionally include a water non-dispersible polymer blended with a sulfopolyester, provided that the blend is an immiscible blend. Can be. The present invention also includes fiber articles comprising these fibers and may include personal care articles such as wipes, gauze, tissues, diapers, adult incontinence briefs, training pants, sanitary napkins, bandages and surgical dressings. The fibrous article may have one or more absorbent fibrous layers.

The fibers of the present invention may be monocomponent fibers, bicomponent fibers or multicomponent fibers. For example, the fibers of the present invention can be made by melt spinning a single sulfopolyester or sulfopolyester blend and include staple fibers, single filament fibers, and multiple filament fibers with molded cross sections. The present invention also provides multicomponent fibers, such as those described, for example, in US Pat. No. 5,916,678, which have shaped or engineered transverse geometries such as, for example, “sea charts”, sheath-core, parallel or divided pie shapes. It can be prepared by separately extruding sulfopolyester and one or more water non-dispersible polymers that are immiscible with the sulfopolyester via spinneret. The sulfopolyester can later be removed by dissolving the interfacial layer or pie compartment, leaving smaller filaments or microdenier fibers of the water non-dispersible polymer (s). These water non-dispersible polymer fibers have a much smaller fiber size than the multicomponent fibers prior to removing the sulfopolyester. For example, sulfopolyester and water non-dispersible polymers may be fed to a polymer distribution system that introduces the polymer into a divided spinneret plate. The polymer follows a separate path to the fiber spinneret and is divided into a plurality of parts along the diameter to spinneret holes that provide the sheath-core type of fiber, including two concentric circular holes, to form parallel fibers. Are provided in a circular spinneret hole to provide. Alternatively, the immiscible water dispersible sulfopolyester and the water non-dispersible polymer may be introduced separately into the spinneret having a plurality of radial channels to produce a multicomponent fiber having divided pie cross sections. Typically, sulfopolyesters form a "shell" component of the shell core shape. In the fiber cross section having a plurality of compartments, the water non-dispersible compartments are typically substantially isolated from one another by sulfopolyester. Alternatively, the fiber having cross-sectional shape even if the sulfopolyester and water non-dispersible polymer are melted in separate extruders and the polymer is flowed into one spinneret having a plurality of distribution flow paths in the form of small thin tubes or compartments. By providing the multicomponent fiber can be produced. Examples of such spinnerets are described in US Pat. No. 5,366,804. In the present invention, sulfopolyesters typically form the "sea" component and the water non-dispersible polymers form the "island" component.

Unless otherwise indicated, all numbers expressing quantities of components, properties such as molecular weight, reaction conditions, and the like, used in the description and claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following description and appended claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, each numerical parameter should be inferred in light of the significant number reported and also by applying conventional approximation techniques. Also, the ranges mentioned in this specification and claims are intended to specifically cover the entire range, not just the termination value (s). For example, the ranges referred to as 0 to 10 are, for example, all integers between 0 and 10, such as 1, 2, 3, 4, etc., all prime numbers between 0 and 10, for example 1.5, 2.3, 4.57, 6.1113, etc. And end values 0 and 10. In addition, the ranges associated with chemical substituents such as, for example, "C1 to C5 hydrocarbons" are intended to specifically include and disclose C1 and C5 hydrocarbons as well as C2, C3 and C4 hydrocarbons.

Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors which inevitably result from standard deviations found in individual test measurements.

Monocomponent fibers and fibrous articles of the present invention are water dispersible and are typically fully dispersed at room temperature. Higher water temperatures can be used to accelerate their dispersion or removal rate from nonwoven or multicomponent fibers. The term "water dispersible", as used herein with reference to monocomponent fibers and fibrous articles made from monocomponent fibers, refers to the terms "water-dissipatable", "water-dissolvable", "water-soluble" , Synonymous with "water-dispellable", "water-soluble", "water-removable", "water-soluble" and "hydrodispersible", and are fibers or fibrous articles By this action of water it is meant to be dispersed or dissolved therein. The term “dispersed”, “dispersible”, “dissipated” or “dissipative” refers to an amount of deionized water (eg, 100) sufficient to form a coarse suspension or slurry of fibers or fibrous articles at about 60 ° C. within 5 days. A plurality of scattered pieces distributed throughout the medium such that no noticeable filaments are recovered from the medium when the water or the fibrous article is removed, such as by filtration or evaporation, Means dissolution, dissolution or separation into particles. Thus, as used herein, “water dispersible” refers to the simple disassembly of an assembly of entangled or bonded, but non-aqueous or non-dispersible fibers (in this case, the fiber assembly can simply be divided out of water and recovered by removal of water). Producing a slurry of fibers in water). In the context of the present invention, both of these terms refer to the action of water or mixtures of water and water-miscible cosolvents on the sulfopolyesters described herein. Examples of such water-miscible cosolvents include alcohols, ketones, glycol ethers, esters, and the like. The term is intended to include the state in which the sulfopolyester is dissolved to produce a true solution and the state in which the sulfopolyester is dispersed in an aqueous medium. Often, due to the statistical nature of the sulfopolyester composition, a single sulfopolyester sample may have a soluble fraction and a dispersed fraction when placed in an aqueous medium.

Similarly, the term "water dispersible" as used herein in connection with sulfopolyester as a component of a multicomponent fiber or fibrous article is also referred to as the terms "water-dispersible", "water-dissolvable", "water-soluble", Synonymous with "water-monoplastic", "water-soluble", "water-removable", "aqueous-soluble" and "aqueous-dispersible", and the sulfopolyester component is sufficiently removed from the multicomponent fiber by the action of water and It is intended to mean that it can disperse or dissolve to release and separate the water non-dispersible fibers contained therein. The terms "dispersed", "dispersible", "dissipated" or "dissipative" refer to an amount of deionized water sufficient to form a loose suspension or slurry of the fiber or fibrous article at about 60 ° C within 5 days. 100: 1 water: fiber, by weight), means that the sulfopolyester component is dissolved, disassembled, or separated from the multicomponent fiber, leaving a plurality of microdenier fibers from the water non-dispersible compartment.

The term “compartment” or “domain” or “zone” when used to describe a molded cross section of a multicomponent fiber refers to a compartment within a cross section comprising a water non-dispersible polymer, which domain or compartment is a compartment or domain. It is substantially isolated from each other by water dispersible sulfopolyester intervening therebetween. As used herein, the term "substantially isolated" means that the compartments or domains are separated from each other so that upon removal of the sulfopolyester, the compartments or domains can form individual fibers. The partitions or domains or zones may be of similar size and shape, or of varying sizes and shapes. Again, the compartments or domains or zones can be arranged in any shape. These sections or domains or zones are "substantially continuous" along the length of the multicomponent extrudates or fibers. The term "substantially continuous" means continuous along the length of at least 10 cm of the multicomponent fiber. The compartments, domains or zones of the multicomponent fiber produce water non-dispersible polymer microfibers when the water dispersible sulfopolyester is removed.

As mentioned in the detailed description, the shaped cross section of the multicomponent fiber can be in the form of, for example, a sheath-core, sea island, divided pie, hollow divided pie, off-centered divided pie and the like.

The water dispersible fibers of the present invention are made from polyesters, more specifically sulfopolyesters comprising dicarboxylic acid monomer residues, sulfomonomer residues, diol monomer residues and repeating units. Sulfomonomers may be dicarboxylic acids, diols or hydroxycarboxylic acids. Thus, as used herein, the term “monomer residue” refers to a dicarboxylic acid, diol or hydroxycarboxylic acid residue. As used herein, "repeating unit" means an organic structure having two monomer residues bonded through a carbonyloxy group. The sulfopolyesters of the present invention contain substantially equimolar amounts of acid residues (100 mol%) and diol residues (100 mol%) reacting at substantially the same ratio such that the total moles of repeat units are 100 mol%. Thus, the mole percentages provided in the description can be based on the total moles of acid residues, the total moles of diol residues, or the total moles of repeat units. For example, sulfopolyesters containing 30 mole percent sulfomonomers, which may be dicarboxylic acids, diols, or hydroxycarboxylic acids, based on total repeat units, have sulfopolyesters in a total of 100 mole percent repeat units. It contains 30 mol% of sulfomonomers. Thus, there are 30 moles of sulfomonomer residues in every 100 moles of repeating unit. Similarly, sulfopolyesters containing 30 mole percent dicarboxylic acid sulfomonomers based on total acid residues means that the sulfopolyester contains 30 mole percent sulfomonomers in a total of 100 mole percent acid residues. In this case, therefore, there are 30 moles of sulfomonomer residues in every 100 moles of acid residues.

The sulfopolyesters described herein are at least about 0.1 dL / g, preferably about about as measured in a 60/40 parts by weight solution of phenol / tetrachloroethane solvent at 25 ° C. at a concentration of about 0.5 g of sulfopolyester in 100 mL of solvent. Intrinsic viscosity (abbreviated herein as "Ih.V.") greater than 0.2 to 0.3 dL / g, most preferably about 0.3 dL / g. The term "polyester" as used herein encompasses both "homopolyester" and "copolyester" and means a synthetic polymer prepared by polycondensation of a bifunctional carboxylic acid with a bifunctional hydroxyl compound. As used herein, the term “sulfopolyester” means any polyester that includes sulfomonomers. Typically, the difunctional carboxylic acid is a dicarboxylic acid and the difunctional hydroxyl compound is a dihydric alcohol such as, for example, glycols and diols. Alternatively, the bifunctional carboxylic acid can be, for example, a hydroxy carboxylic acid such as p-hydroxybenzoic acid, and the bifunctional hydroxyl compound can be an aromatic nucleus (eg hydroquinone) with two hydroxy substituents. As used herein, the term “residue” means any organic structure that is incorporated into a polymer via a polycondensation reaction that includes the corresponding monomers. Thus, the dicarboxylic acid residues may be derived from dicarboxylic acid monomers or their associated acid halides, esters, salts, anhydrides or mixtures thereof. Thus, the term dicarboxylic acid as used herein refers to dicarboxylic acids useful in polycondensation processes with diols for preparing high molecular weight polyesters, and the acid halides, esters, semi-esters, salts, semi-salts, anhydrides associated therewith. And any derivative of dicarboxylic acids, including mixed anhydrides or mixtures thereof.

The sulfopolyesters of the invention comprise one or more dicarboxylic acid residues. Depending on the type and concentration of sulfomonomer, the dicarboxylic acid residue may comprise about 60 to about 100 mole percent acid residue. Other examples of concentration ranges of dicarboxylic acid residues are from about 60 to about 95 mole percent, and from about 70 to about 95 mole percent. Examples of dicarboxylic acids that may be used include aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, aromatic dicarboxylic acids, or mixtures of two or more of these acids. Thus, suitable dicarboxylic acids include succinic acid; Glutaric acid; Adipic acid; Azelaic acid; Sebacic acid; Fumaric acid; Maleic acid; Itaconic acid; 1,3-cyclohexanedicarboxylic acid; 1,4-cyclohexanedicarboxylic acid; Diglycolic acid; 2,5-norbornene dicarboxylic acid; Phthalic acid; Terephthalic acid; 1,4-naphthalenedicarboxylic acid; 2,5-naphthalenedicarboxylic acid; Diphenic acid; 4,4'-oxydibenzoic acid; 4,4'-sulfonyldibenzoic acid and isophthalic acid, but are not limited to these. Preferred dicarboxylic acid residues are isophthalic acid, terephthalic acid and 1,4-cyclohexanedicarboxylic acid, or dimethyl terephthalate, dimethyl isophthalate and dimethyl-1,4-cyclohexanedicarboxylate, when diesters are used Isophthalic acid and terephthalic acid residues are particularly preferred. Although dicarboxylic acid methyl esters are the most preferred embodiments, it is also acceptable to include higher alkyl esters such as ethyl, propyl, isopropyl, butyl and the like. In addition, aromatic esters, in particular phenyl, may also be used.

Sulfopolyesters comprise from about 4 to about 40 mole percent, based on the total repeat units, of at least one sulfomonomer residue having two functional groups and at least one sulfonate group attached to an aromatic or cycloaliphatic ring, wherein the functional groups Hydroxyl, carboxyl, or a combination thereof. Further examples of concentration ranges of sulfomonomer residues are from about 4 to about 35 mole percent, about 8 to about 30 mole percent, and about 8 to about 25 mole percent, based on total repeat units. The sulfomonomer may be a dicarboxylic acid or ester thereof containing a sulfonate group, a diol containing a sulfonate group, or a hydroxy acid containing a sulfonate group. The term "sulfonate" refers to a salt of sulfonic acid having the structure of "-SO ₃ N", where M is the cation of the sulfonate salt. The cation of the sulfonate salt may be a metal ion such as Li ⁺ , Na ⁺ , K ⁺ , Mg ⁺⁺ , Ca ⁺⁺ , Ni ⁺⁺ , Fe ⁺⁺ and the like. Alternatively, the cation of the sulfonate salt may be non-metallic, such as for example the nitrogen containing base described in US Pat. No. 4,304,901. Nitrogen-based cations are derived from nitrogen-containing bases which may be aliphatic, cycloaliphatic or aromatic compounds. Examples of such nitrogen containing bases include ammonia, dimethylethanolamine, diethanolamine, triethanolamine, pyridine, morpholine and piperidine. Since monomers containing nitrogen-based sulfonate salts are typically not thermally stable at the conditions necessary to prepare the polymer in the melt, the process of the present invention for preparing sulfopolyesters containing nitrogen-based sulfonate salt groups is an alkali metal salt. A polymer containing the required amount of sulfonate groups in the form is dispersed, dissipated or dissolved in water and then the alkali metal cations are exchanged for nitrogen-based cations.

When monovalent alkali metal ions are used as the cations of the sulfonate salts, the resulting sulfopolyester can be completely dispersed in water at a rate of dispersion that depends on the content of sulfomonomers in the polymer, the temperature of the water, the surface area / thickness of the sulfopolyester, and the like. have. When divalent metal ions are used, the resulting sulfopolyester is not easily dispersed by cold water but more easily by hot water. More than one counterion may be used in a single polymer composition, which may provide a means to trim or fine-tune the water-reactivity of the resulting article. Examples of sulfomonomer residues include sulfonate salt groups such as benzene; naphthalene; Diphenyl; Oxydiphenyl; Sulfonyldiphenyl; And aromatic acid nuclei such as methylenediphenyl, or such as cyclohexyl; Cyclopentyl; Cyclobutyl; Cycloheptyl; And monomer residues attached to an alicyclic ring such as cyclooctyl. Another example of a sulfomonomer residue that can be used in the present invention is a metal sulfonate salt of sulfophthalic acid, sulfoteterphthalic acid, sulfoisophthalic acid or a combination thereof. Other examples of sulfomonomers that can be used are 5-sodiosulfoisophthalic acid and its esters. When sulfomonomer residues are derived from 5-sodiosulfoisophthalic acid, typical sulfomonomer concentration ranges are from about 4 to about 35 mole percent, from about 8 to about 30 mole percent, and about 8 based on the total moles of acid residues. To 25 mol%.

Sulfomonomers used in the preparation of sulfopolyesters are known compounds and can be prepared using methods well known in the art. For example, a sulfonomer having a sulfonate group attached to an aromatic ring may be sulfonated with an fuming sulfuric acid to give the corresponding sulfonic acid, followed by reaction with a metal oxide or base (e.g. sodium acetate) to produce a sulfonate salt. It can be prepared by. Procedures for preparing various sulfomonomers are described, for example, in US Pat. Nos. 3,779,993, 3,018,272 and 3,528,947.

Polyesters can also be prepared using, for example, sodium sulfonate salts and ion-exchange methods that replace sodium with different ions (eg, zinc) when the polymer is in a dispersed form. This type of ion exchange procedure is typically superior to preparing polymers having divalent salts, since sodium salts are usually more soluble in the polymer reactant melt-phase.

Sulfopolyesters include one or more diol moieties that may include aliphatic, cycloaliphatic, and aralkyl glycols. Alicyclic diols such as 1,3- and 1,4-cyclohexanedimethanol can exist as their pure cis or trans isomers, or as a mixture of cis isomers and trans isomers. The term "diol" as used herein is synonymous with the term "glycol" and means any dihydric alcohol. Examples of diols include ethylene glycol; Diethylene glycol; Triethylene glycol; Polyethylene glycol; 1,3-propanediol; 2,4-dimethyl-2-ethylhexane-1,3-diol; 2,2-dimethyl-1,3-propanediol; 2-ethyl-2-butyl-1,3-propanediol; 2-ethyl-2-isobutyl-1,3-propanediol; 1,3-butanediol; 1,4-butanediol; 1,5-pentanediol; 1,6-hexanediol; 2,2,4-trimethyl-1,6-hexanediol; Thiodiethanol; 1,2-cyclohexanedimethanol; 1,3-cyclohexanedimethanol; 1,4-cyclohexanedimethanol; 2,2,4,4-tetramethyl-1,3-cyclobutanediol; p-xylylenediol or combinations of one or more of these glycols, but are not limited to these.

The diol moiety is a poly (ethylene glycol) moiety having a structure of H— (OCH ₂ —CH ₂ ) _n —OH, wherein n is an integer from 2 to about 500, based on the total diol moiety. About 100 mol%. Non-limiting examples of low molecular weight polyethylene glycols, for example n of 2 to 6, are diethylene glycol, triethylene glycol and tetraethylene glycol. Of these low molecular weight glycols, diethylene glycol and triethylene glycol are most preferred. High molecular weight polyethylene glycols (abbreviated herein as "PEG") where n is from 7 to about 500 are CARBOWAX® registered as Dow Chemical Company (formerly Union Carbide) products. Trademark) known on the market. Typically, PEG is used in combination with other diols such as, for example, diethylene glycol or ethylene glycol. Based on the value of n in the range of 6 to 500, the molecular weight can be from 300 to about 22,000 g / mol. Molecular weight and mole% are inversely proportional to each other, specifically, as the molecular weight increases, the mole% decreases to obtain the defined hydrophilicity. For example, as an example of this concept, PEG with a molecular weight of 1000 may constitute up to 10 mole percent of the total diol while PEG with a molecular weight of 10,000 is typically at a level of less than 1 mole percent of the total diol. Incorporation is contemplated.

Certain dimers, trimers and tetramer diols can be produced in situ because of side reactions that can be controlled by changing process conditions. For example, various amounts of diethylene glycol, triethylene glycol and tetraethylene glycol can be produced from ethylene glycol by acid-promoted dehydration reactions which are readily generated when the polycondensation reaction is carried out under acidic conditions. Buffer solutions, well known to those skilled in the art, can be added to the reaction mixture to delay these side reactions. However, additional composition ranges are possible if buffers are excluded and dimerization, trimerization and tetramerization reactions proceed.

The sulfopolyesters of the present invention may comprise from 0 to about 25 mole percent, based on total repeat units, of branched monomer residues having three or more functional groups that are hydroxyl, carboxyl, or a combination thereof. Non-limiting examples of branched monomers include 1,1,1-trimethylol propane, 1,1,1-trimethylol ethane, glycerine, pentaerythritol, erythritol, pentitol, dipentaerythritol , Sorbitol, trimellitic anhydride, pyromellitic dianhydride, dimethylol propionic acid or a combination thereof. Further examples of branching monomer concentration ranges are 0 to about 20 mole percent and 0 to about 10 mole percent. The presence of branched monomers can result in a number of possible advantages for the sulfopolyesters of the present invention, including but not limited to the ability to modify rheology, solubility and tensile properties. For example, at constant molecular weight, branched sulfopolyesters have higher concentrations of end groups that can facilitate crosslinking reactions after polymerization as compared to linear analogs. However, if the concentration of the branching agent is high, the sulfopolyester may be easy to gel.

The sulfopolyesters used in the fibers of the present invention have glass transition temperatures of 25 ° C. or higher (herein, as measured on dry polymers) using standard techniques such as differential scanning calorimetry (“DSC”), which are well known to those skilled in the art. Abbreviated as "Tg"). The Tg of the sulfopolyester of the present invention is measured using a “dry polymer”, ie a polymer sample from which foreign or absorbed water is removed by heating the polymer to about 200 ° C. and returning the sample to room temperature. Typically, a first heat scan is performed to heat the sample to a temperature higher than the vaporization temperature of the water, and the sample is held at that temperature until the vaporization of the water absorbed by the polymer is complete (indicated by the large and wide endotherm), The sample is cooled to room temperature and the sulfopolyester is dried in a DSC apparatus by performing a second heat scan to measure Tg. Further examples of the glass transition temperature represented by the sulfopolyester are at least 30 ° C, at least 35 ° C, at least 40 ° C, at least 50 ° C, at least 60 ° C, at least 65 ° C, at least 80 ° C, and at least 90 ° C. While other Tg is possible, typical glass transition temperatures of the dry sulfopolyester of the present invention are about 30 ° C, about 48 ° C, about 55 ° C, about 65 ° C, about 70 ° C, about 75 ° C, about 85 ° C, and about 90 ℃.

The novel fibers of the present invention consist essentially of, or consist of, the sulfopolyesters described above. However, in other embodiments, the sulfopolyesters of the present invention may be a single polyester or may be blended with one or more supplemental polymers to modify the properties of the resulting fiber. The supplemental polymer may or may not be water dispersible, depending on the application, and may or may not be compatible with sulfopolyester. If the supplemental polymer is water non-dispersible, it is preferred that the blend with sulfopolyester is immiscible. As used herein, the term “miscible” is intended to mean that the blend has a single homogeneous amorphous phase as indicated by the Tg based on a single composition. For example, as illustrated in US Pat. No. 6,211,309, a first polymer that is miscible with the second polymer can be used to “plasticize” the second polymer. In contrast, the term “immiscibility” as used herein refers to a blend that exhibits two or more randomly mixed phases and exhibits more than one Tg. Some polymers are immiscible but compatible with sulfopolyesters. Further comprehensive descriptions of miscible and immiscible polymer blends and various analytical techniques for determining their characteristics are given in Polymer. Blends Volumes 1 and 2, Editing Paul and Bucknell, 2000, John Wiley & Sons, Inc.

Non-limiting examples of water dispersible polymers that can be blended with sulfopolyesters include polymethacrylic acid, polyvinyl pyrrolidone, polyethylene-acrylic acid copolymers, polyvinyl methyl ether, polyvinyl alcohol, polyethylene oxide, hydroxy propyl cellulose , Hydroxypropyl methyl cellulose, methyl cellulose, ethyl hydroxyethyl cellulose, isopropyl cellulose, methyl ether starch, polyacrylamide, poly (N-vinyl caprolactam), polyethyl oxazoline, poly (2-isopropyl-2 Oxazoline), polyvinyl methyl oxazolidone, water dispersible sulfopolyester, polyvinyl methyl oxazolidinone, poly (2,4-dimethyl-6-triazinylethylene) and ethylene oxide-propylene oxide copolymers . Examples of water non-dispersible polymers that can be blended with sulfopolyesters include polyolefins such as homopolymers and copolymers of polyethylene and polypropylene; Poly (ethylene terephthalate); Poly (butylene terephthalate); Polyamides such as nylon-6; Polylactide; Caprolactone; Eastar Bio® (poly (tetramethylene adipate-co-terephthalate), product of Eastman Chemical Company); Polycarbonate; Polyurethane; And polyvinyl chlorides.

In accordance with the present invention, blends of more than one sulfopolyester can be used to control the end-use properties of the resulting fiber or fibrous article, such as a nonwoven or nonwoven web. The blend of one or more sulfopolyesters has a Tg of at least 25 ° C. for water dispersible monocomponent fibers and at least 57 ° C. for multicomponent fibers. Thus, blending can also be used to change the processing characteristics of the sulfopolyester to facilitate the manufacture of nonwovens. In another example, an immiscible blend of polypropylene and sulfopolyester may provide a conventional nonwoven web that is cleaved and completely dispersed in water since no true solubility is needed. For this latter example, the desired performance is the physical properties of the polypropylene while the sulfopolyester is only a bystander during the actual use of the article or otherwise the sulfopolyester is removed and removed before the final form of the article is used. Related to maintaining.

Sulfopolyesters and supplemental polymers may be blended in a batch, semicontinuous or continuous process. Prior to melt-spinning the fibers, small batches can be readily prepared in any high intensity mixing apparatus well known to those skilled in the art, such as a Banbury mixer. The components may also be blended in solution in a suitable solvent. Melt blending methods include blending sulfopolyester and supplemental polymer at a temperature sufficient to melt the polymer. The blend can be cooled and pelletized for further use, or the melt blend can be melt spun in the form of fibers directly from this melted blend. As used herein, the term “melt” includes, but is not limited to, softening polyester. For melt mixing methods commonly known in the polymer art, see Mixing and Compounding of Polymers (Manas-Zozorwo and Tadmer Edit, Carl Hanser Verlag Publisher, 1994, New York, NY).

The present invention also relates to a water dispersible fiber comprising a sulfopolyester having a glass transition temperature (Tg) of 25 ° C. or more, wherein the sulfopolyester is

(A) about 50 to about 96 mole percent of one or more isophthalic or terephthalic acid residues based on total acid residues;

(B) about 4 to about 30 mole percent sodiosulfoisophthalic acid residues based on the total acid residues;

(C) at least 25 mole%, based on the total diol residues, are poly (ethylene glycol) having a structure of H— (OCH ₂ —CH ₂ ) _n —OH, wherein n is an integer from 2 to about 500 One or more diol residues;

(D) 0 to about 20 mole percent, based on the total repeat units, of the branched monomer residues having at least three functional groups which are hydroxyl, carboxyl, or a combination thereof

It provides a water-dispersible fiber comprising a.

As previously described, the fibers comprise a first water dispersible polymer blended with sulfopolyester; And optionally a water non-dispersible polymer blended with sulfopolyester such that the blend is an immiscible blend. The fibers of the present invention contain less than 10%, less than 8%, or less than 6% by weight of the pigment or filler based on the total weight of the fiber. The first water dispersible polymer is as described above. The sulfopolyester should have a glass transition temperature (Tg) of at least 25 ° C, but for example about 35 ° C, about 48 ° C, about 55 ° C, about 65 ° C, about 70 ° C, about 75 ° C, about 85 ° C and about 90 It may have a Tg of ℃. The sulfopolyester may contain other concentrations of isophthalic acid residues, such as about 60 to about 95 mole percent, and about 75 to about 95 mole percent. Further examples of isophthalic acid residue concentrations are about 70 to about 85 mole percent, about 85 to about 95 mole percent, and about 90 to about 95 mole percent. The sulfopolyester may also comprise about 25 to about 95 mole percent diethylene glycol residues. Further examples of diethylene glycol residue concentration ranges include about 50 to about 95 mole percent, about 70 to about 95 mole percent, and about 75 to about 95 mole percent. Sulfopolyesters may also include ethylene glycol residues and / or 1,4-cyclohexanedimethanol (abbreviated herein as "CHDM") residues. Typical concentration ranges for CHDM residues are from about 10 to about 75 mole percent, about 25 to about 65 mole percent, and about 40 to about 60 mole percent. Typical concentration ranges for ethylene glycol moieties are about 10 to about 75 mole percent, about 25 to about 65 mole percent, and about 40 to about 60 mole percent. In other embodiments, the sulfopolyester comprises about 75 to about 96 mole percent isophthalic acid residues and about 25 to about 95 mole percent diethylene glycol residues.

The sulfopolyesters of the present invention are readily prepared from suitable dicarboxylic acids, esters, anhydrides or salts, sulfomonomers, and suitable diols or diol mixtures using typical polycondensation reaction conditions. They can be produced by continuous, semi-continuous and batch operations and can utilize a variety of reactor types. Examples of suitable reactor types include, but are not limited to, stirred tanks, continuous stirred tanks, slurries, tubulars, wiping-films, drop films or extrusion reactors. As used herein, the term "continuous" means a process in which the introduction of the reactants and the recovery of the product occur simultaneously in an uninterrupted manner. "Continuous" means that the process is substantially or completely continuous in operation, in contrast to a "batch" process. "Continuous" does not mean to prohibit in any way normal interruptions to the continuity of the process, for example due to start-up, reactor maintenance or planned shutdown periods. As used herein, the term "batch" process refers to a process in which all reactants are added to a reactor and then no material is fed to or removed from the reactor during processing according to the desired reaction procedure. The term "semi-continuous" means a process in which some of the reactants are added at the start of the process and the remaining reactants are fed continuously as the reaction proceeds. Alternatively, the semi-continuous process may also include a process similar to the batch process where all reactants are added at the start of the process, except that one or more of the products are continuously removed as the reaction proceeds. For economic reasons, the process is also advantageously continuous in order to produce an excellent color of the polymer, since the appearance may deteriorate if the sulfopolyester stays in the reactor at elevated temperatures for too long time (if this is acceptable). Proceed as a food process.

The sulfopolyesters of the present invention are prepared by procedures known to those skilled in the art. Although other processes are known and may be used as described, for example, in US Pat. Nos. 3,018,272, 3,075,952 and 3,033,822, most often sulfomonomers are added directly to the reaction mixture from which the polymer is prepared. . Conventional polyester polymerization conditions may be used to carry out the reaction of the sulfomonomer, diol component and dicarboxylic acid component. For example, when preparing sulfopolyesters by ester exchange reactions, ie from the ester form of the dicarboxylic acid component, the reaction process may comprise two steps. In the first step, the diol component and the dicarboxylic acid component, such as, for example, dimethyl isophthalate, are elevated at a temperature of about 0.0 to about 414 kPa gauge (60 pounds per square inch, "psig"), typically at about 150 to about 250 ° C. In the reaction for about 0.5 to about 8 hours. Preferably, the temperature of the transesterification reaction is from about 180 to about 230 ° C. for about 1 to about 4 hours, and the preferred pressure range is from about 103 kPa gauge (15 psig) to about 276 kPa gauge (40 psig). Thereafter, the reaction product is heated under high temperature and reduced pressure to form a sulfopolyester while removing the diol, which is easily vaporized under these conditions and removed from the system. This second step or polycondensation step is usually carried out at high vacuum at about 230 to about 350 ° C., preferably at about 250 to about 310 ° C. and most preferably at about 260 to about 290 ° C. The polymer is held for about 0.1 to about 6 hours, or preferably about 0.2 to about 2 hours, until a polymer having it is obtained. The polycondensation step may be carried out under reduced pressure of about 53 kPa (400 Torr) to about 0.013 kPa (0.1 Torr). Stirring or appropriate conditions are used in both steps to ensure proper heat transfer and surface regeneration of the reaction mixture. The reaction of the two stages is facilitated by suitable catalysts such as, for example, alkoxy titanium compounds, alkali metal hydroxides and alcoholates, salts of organic carboxylic acids, alkyl tin compounds, metal oxides and the like. A three step preparation procedure similar to that described in US Pat. No. 5,290,631 can also be used, especially when using mixed monomer feeds of acid and ester.

In order to ensure that the reaction of the diol component with the dicarboxylic acid component by the ester exchange reaction mechanism is completed, it is preferable to use about 1.05 to about 2.5 moles of the diol component per mole of the dicarboxylic acid component. However, those skilled in the art will appreciate that the ratio of the diol component to the dicarboxylic acid component is usually determined by the design of the reactor in which the reaction process is carried out.

In the preparation of sulfopolyesters by direct esterification, ie from the acid form of the dicarboxylic acid component, the sulfopolyester is produced by reacting a mixture of dicarboxylic acid or dicarboxylic acid with a mixture of diol component or diol component. The reaction is carried out at a pressure of about 7 kPa gauge (1 psig) to about 1379 kPa gauge (200 psig), preferably less than 689 kPa (100 psig), so that a low molecular weight linear or branched sulfopolyester having an average degree of polymerization of about 1.4 to about 10 To produce the product. The temperature used during the direct esterification reaction is typically about 180 to about 280 ° C, more preferably about 220 to about 270 ° C. Subsequently, this low molecular weight polymer can be polymerized by a polycondensation reaction.

The water dispersible multicomponent fibers and short-cut fibers, fibrous articles of the present invention may also contain other conventional additives and components that do not adversely affect their end use. For example, fillers, surface friction modifiers, light stabilizers, heat stabilizers, extrusion aids, antistatic agents, colorants, dyes, pigments, fluorescent brighteners, antibacterial agents, anti-counterfeiting markers, hydrophobicity enhancers, hydrophilicity enhancers, viscosity modifiers, slips Agents, additives such as tougheners, adhesion promoters and the like can be used.

The fibers and fibrous articles of the present invention do not require the presence of additives such as pigments, fillers, oils, waxes or fatty acid finishes to prevent blocking or fusion of the fibers during processing. The term "blocking or fusion" as used herein is understood to mean that the fibers or fiber articles are blocked together or fused together in a mass such that the fibers cannot be processed or used for their intended purpose. Blocking and fusion may occur during processing of the fiber or fibrous article or during storage over a period of days or weeks, which deteriorates under high temperature and high humidity conditions.

In one embodiment of the present invention, the fibers and fibrous articles contain less than 10% by weight of such antiblocking additives, based on the total weight of the fibers or fibrous articles. For example, fibers and fibrous articles may contain less than 10% by weight of pigments or fillers. In other embodiments, the fibers and fibrous articles may contain less than 9 weight percent, less than 5 weight percent, less than 3 weight percent, less than 1 weight percent and 0 weight percent pigment or filler based on the total weight of the fibers. Colorants, sometimes called toners, may be added to impart the desired neutral color tone and / or brightness to the sulfopolyester. If colored fibers are desired, pigments or colorants may be included in the sulfopolyester reaction mixture during the reaction of the diol monomers with the dicarboxylic acid monomers, or they may be melt blended with the preformed sulfopolyesters. A preferred method of including a colorant is to use a colorant having a thermally stable organic colored compound having reactive groups such that the colorant is copolymerized with and incorporated into the sulfopolyester to improve the color tone of the sulfopolyester. For example, colorants such as dyes having reactive hydroxyl groups and / or carboxyl groups, including but not limited to blue and red substituted anthraquinones, can be copolymerized into the polymer chain. When dyes are used as colorants, they can be added to the copolyester reaction step after ester exchange or direct esterification.

For the purposes of the present invention, the term "fiber" refers to a high aspect ratio polymeric object that can be made into a two-dimensional or three-dimensional article, such as a woven or nonwoven. In the context of the present invention, the term "fiber" is synonymous with "fibers" and is intended to mean one or more fibers. The fibers of the present invention may be monocomponent fibers, bicomponent fibers or multicomponent fibers. As used herein, the term “monocomponent fiber” is intended to mean a fiber made by melt spinning a single sulfopolyester, a blend of one or more sulfopolyesters, or a blend of one or more sulfopolyesters and one or more additional polymers, and staples Fibers, single filament fibers and multiple filament fibers. "Single component" is synonymous with the term "monocomponent" and includes "biconstituent" or "multiconstituent" fibers and is made from two or more polymers extruded from the same extruder as a blend Say. Monocomponent or mixed bicomponent fibers do not have a variety of polymer components arranged in discrete zones that are relatively uniformly positioned across the cross section of the fiber, and the various polymers produce fibrils or protofibrils that start and end randomly. Instead, they are usually not continuous along the entire length of the fiber. Thus, the term "monocomponent" is not intended to exclude fibers produced from one polymer or blends of one or more polymers to which small amounts of additives may be added for coloring, antistatic properties, lubricity, hydrophilicity, and the like.

In contrast, as used herein, the term “multicomponent fiber” refers to one that melts two or more fiber forming polymers in separate extruders and flows the resulting multiple polymer into one spinneret having a plurality of distribution flow paths and spun together It is intended to mean the fiber produced by forming a fiber of. Multicomponent fibers are also sometimes called conjugate or bicomponent fibers. The polymer is arranged in separate compartments or zones positioned substantially constant across the cross section of the conjugate fiber and extends continuously along the length of the conjugate fiber. The shape of such multicomponent fibers may be, for example, a sheath / core arrangement in which one polymer is surrounded by another, or may be in a parallel arrangement, a pi arrangement or a “seaweed” arrangement. For example, multicomponent fibers may be prepared by separately extruding the sulfopolyester and one or more water non-dispersible polymers through a spinneret having a molded or engineered transverse geometry, such as a “sea chart” or divided pie shape. . Monocomponent fibers are typically staple fibers, single filament fibers or multifilament fibers having a molded cross section or a round cross section. Most fiber forms are heat cured. The fibers can include various antioxidants, pigments and additives described herein.

Single filament fibers are generally about 15 to about 8000 denier / filament (abbreviated herein as "d / f"). The novel fibers of the present invention typically have a d / f value of about 40 to about 5000. Single filaments may be in the form of monocomponent or multicomponent fibers. The multifilament fibers of the present invention preferably have a size of about 1.5 μm for melt blown webs, about 0.5 to about 50 d / f for staple fibers and about 5000 d / f or less for single filament fibers. Multifilament fibers can also be used as yarns and tows that are crimped or un crimped. The fibers used in meltblown webs and melt spun fabrics can be made in microdenier sizes. The term "microdenier" as used herein is intended to mean a d / f value of 1 d / f or less. For example, the microdenier fibers of the present invention typically have d / f values of 1 or less, 0.5 or less, or 0.1 or less. Nanofibers can also be produced by electrostatic spinning.

As described above, sulfopolyesters are also advantageous for the production of bicomponent and multicomponent fibers having shaped cross sections. The inventors have found that sulfopolyesters or blends of sulfopolyesters having a glass transition temperature (Tg) of at least 57 ° C. are particularly useful for multicomponent fibers to prevent blocking and fusion of the fibers during spinning and winding. Therefore, the present invention

(A) (i) one or more dicarboxylic acid residues; (ii) at least one having at least about 4 to about 40 mole percent, based on the total repeat units, of two functional groups attached to an aromatic or cycloaliphatic ring, which is hydroxyl, carboxyl, or a combination thereof, and one or more sulfonate groups Sulfomonomer residues; (iii) at least 25 mole% of the total diol residues are poly (ethylene glycol) having a structure of H— (OCH ₂ —CH ₂ ) _n —OH, wherein n is an integer from 2 to about 500 Diol residues; And (iv) a glass transition temperature of at least 57 ° C. comprising branched monomer residues having from 0 to about 25 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof. Water dispersible sulfopolyester having (Tg); And

(B) a plurality of compartments comprising one or more water non-dispersible polymers immiscible with sulfopolyesters, the plurality of compartments being substantially isolated from one another by sulfopolyesters intervening between the compartments;

A multicomponent fiber having a shaped cross section is provided, optionally wherein the fiber has an island-in-sea or divided pie cross section and contains less than 10% by weight of pigment or filler based on the total weight of the fiber.

Dicarboxylic acids, diols, sulfopolyesters, sulfomonomers and branched monomer residues are as previously described for other embodiments of the present invention. In the case of multicomponent fibers, it is advantageous for the sulfopolyester to have a Tg of at least 57 ° C. Other examples of glass transition temperatures that the sulfopolyester or sulfopolyester blends of the multicomponent fibers of the present invention can exhibit include at least 60 ° C, at least 65 ° C, at least 70 ° C, at least 75 ° C, at least 80 ° C, at least 85 ° C, and It is 90 degreeC or more. In addition, in order to obtain sulfopolyesters having a Tg of 57 ° C. or higher, blends of one or more sulfopolyesters can be used in various proportions to obtain sulfopolyester blends having the desired Tg. The Tg of the sulfopolyester blend can be calculated by using the weighted average of the Tg of the sulfopolyester component. For example, a sulfopolyester having a Tg of 48 ° C. may be blended with another sulfopolyester having a Tg of 65 ° C. in a 27:75 weight: weight ratio to provide a sulfopolyester blend having a Tg of about 61 ° C. have.

In another embodiment of the invention, the water dispersible sulfopolyester of the multicomponent fiber provides properties that allow one or more of the following:

(A) causing the multicomponent fibers to be spun to the desired low denier;

(B) sulfopolyester in these multicomponent fibers is resistant to removal during high pressure weaving of the web produced from the fibers, but is effectively removed at elevated temperature after high pressure weaving;

(C) The multicomponent fiber is thermoset to give a stable and strong fabric.

Surprising and unexpected results have been achieved in pursuing these objectives using sulfopolyesters having specific melt viscosities and levels of sulfomonomer residues.

Therefore, in this embodiment of the present invention,

(A) at least one water dispersible sulfopolyester; And

(B) a plurality of domains comprising one or more water non-dispersible polymers immiscible with sulfopolyesters, the plurality of domains being substantially isolated from one another by sulfopolyesters in which the domains intervene between the domains;

A multicomponent fiber having a shaped cross section is provided, wherein the fiber has a spun denier of less than about 6 denier / filament, and the water dispersible sulfopolyester is measured at a strain rate of 1 radian / second at 240 ° C. And a melt viscosity of less than about 12,000 poise and comprises less than about 25 mole percent of one or more sulfomonomer residues based on the total moles of diacid or diol residues.

The sulfopolyesters used in these multicomponent fibers typically have a melt viscosity of less than about 12,000 poise. Preferably, the melt viscosity of the sulfopolyester is less than 10,000 poise, more preferably less than 6,000 poise and most preferably less than 4,000 poise when measured at 240 ° C. at a strain rate of 1 radian / second. In another embodiment, the sulfopolyester has a melt viscosity of about 1000 to 12000 poise, more preferably 2000 to 6000 poise, most preferably 2500 to 4000 poise as measured at a strain rate of 240 ° C. and 1 radian / sec. Indicates. Before determining the viscosity, the samples are dried in a vacuum oven at 60 ° C. for 2 days. Melt viscosity is measured in a viscometer using a 25 mm diameter parallel plate structure with 1 mm spacing. A dynamic frequency sweep is operated at a strain rate of 1 to 400 radians / second and a 10% strain width. The viscosity is then measured at 240 ° C. and strain rate of 1 radian / second.

The level of sulfomonomer residues in sulfopolyester polymers for use in accordance with this aspect of the invention is generally less than about 25 mol%, preferably less than 20 mol% (percentage of total diacid or diol residues in sulfopolyester). Reported as). More preferably, this level is about 4 to about 20 mol%, even more preferably about 5 to about 12 mol%, most preferably about 7 to about 10 mol%. Sulfomonomers for use in the present invention preferably have two functional groups and one or more sulfonate groups attached to an aromatic or cycloaliphatic ring, wherein the functional groups are hydroxyl, carboxyl or combinations thereof. Sodiosulfo-isophthalic acid monomers are particularly preferred.

In addition to the sulfomonomers already described, the sulfopolyester preferably comprises at least one dicarboxylic acid residue, at least 25 mole% of the total diol residues H- (OCH ₂ -CH ₂ ) _n -OH, wherein n is from 2 to about At least one diol moiety that is a poly (ethylene glycol) having a structure of 0) and from 0 to about 20 mole percent, based on the total repeat units, of at least 3 functional groups (which are hydroxyl, carboxyl, or a combination thereof) Branched monomer residues having:

In a particularly preferred embodiment, the sulfopolyester comprises about 80 to 96 mole% dicarboxylic acid residues, about 4 to about 20 mole% sulfomonomer residues and 100 mole% diol residues (200 mole% in total, Ie 100 mole% diacid and 100 mole% diol). More specifically, the dicarboxylic acid portion of the sulfopolyester comprises about 60 to 80 mole percent of terephthalic acid, about 0 to 30 mole percent of isophthalic acid and about 4 to 20 mole percent of 5-sodiosulfoisophthalic acid (5-SSIPA). Include. The diol portion comprises about 0-50 mole percent diethylene glycol and about 50-100 mole percent ethylene glycol. Exemplary combinations according to this embodiment of the invention are described below.

The water non-dispersible component of the multicomponent fiber may comprise any of the water non-dispersible polymers described herein. The fibers can be spun according to any of the methods described herein. However, the improved rheological properties of the multicomponent fibers according to this aspect of the invention provide improved drawing speeds. When the sulfopolyester and water non-dispersible polymer are extruded to produce a multicomponent extrudate, at least about 2000 m / min, more preferably at least about 3000 m / min, even more preferred using any of the methods disclosed herein. Preferably, the multicomponent extrudate can be melted drawn at a speed of at least about 4000 m / min, most preferably at least about 4500 m / min to produce multicomponent fibers. Without wishing to be bound by any particular theory, melt drawing the multicomponent extrudate at this rate results in at least some oriented crystallinity in the water non-dispersible component in the multicomponent fiber. This oriented crystallinity can increase the dimensional stability of nonwoven materials made from multicomponent fibers during subsequent processing.

Another advantage of the multicomponent extrudates is that they can be melt drawn into multicomponent fibers having less than 6 denier / filament spinneriers. Other ranges of multicomponent fiber sizes include less than 4 denier / filament, and less than 2.5 denier / filament spun denier.

Thus, in another embodiment of the present invention,

(A) at least one water dispersible sulfopolyester; And

(B) a plurality of domains comprising one or more water non-dispersible polymers immiscible with sulfopolyesters, the plurality of domains being substantially isolated from one another by sulfopolyesters in which the domains intervene between the domains;

A multicomponent extrudate having a shaped cross section is provided, wherein the extrudate can be melt drawn at a speed of about 2000 m / min or more.

The multicomponent fiber comprises a plurality of compartments or domains of one or more water non-dispersible polymers that are immiscible with sulfopolyesters, wherein the compartments or domains are substantially substantially mutually spaced by sulfopolyesters intervening between the compartments or domains. Is isolated. As used herein, the term “substantially isolated” is intended to mean that the compartments or domains may be spaced apart from one another so that the compartments or domains can form individual fibers upon removal of the sulfopolyester. For example, the compartments or domains may be in contact with each other, such as in a split pie shape, for example, but may be divided by impact or when the sulfopolyester is removed.

The weight ratio of sulfopolyester to water non-dispersible polymer component in the multicomponent fibers of the present invention is generally from about 60:40 to about 2:98, or in other instances from about 50:50 to about 5:95. Typically, sulfopolyester accounts for up to 50% by weight of the total weight of the multicomponent fiber.

The compartments or domains of the multicomponent fiber may comprise one or more water non-dispersible polymers. Examples of water non-dispersible polymers that can be used in the compartments of multicomponent fibers include, but are not limited to, polyolefins, polyesters, polyamides, polylactides, polycaprolactones, polycarbonates, polyurethanes, and polyvinyl chlorides. It is not limited. For example, the water non-dispersible polymers include poly (ethylene) terephthalate, poly (butylene) terephthalate, poly (cyclohexylene) cyclohexanedicarboxylate, poly (cyclohexylene) terephthalate, poly (tri Methylene) terephthalate and the like. In another example, the water non-dispersible polymer may be biodegradable as determined by DIN standard 54900 and / or biodegradable as determined by ASTM standard method D6340-98. Examples of biodegradable polyesters and polyester blends are disclosed in US Pat. Nos. 5,599,858, 5,580,911, 5,446,079, and 5,559,171. The term "biodegradable" as used herein in connection with the water non-dispersible polymers of the present invention refers to, for example, ASTM standard method D6340-98 (heading "radioactive in aqueous or composting environments) under environmental influences such as composting environments. It is understood that it means degradation at an appropriate and apparent reference period defined by " standard test methods for determining aerobic biodegradation of labeled plastic materials ". The water non-dispersible polymers of the present invention may also be "biodegradable", meaning that the polymers are readily degraded in a composting environment as defined, for example, by DIN standard 54900. For example, biodegradable polymers initially lose molecular weight in the environment by the action of heat, water, air, microorganisms and other factors. This reduction in molecular weight leads to loss of physical properties (toughness) and often fiber breakage. If the molecular weight of the polymer is low enough, then the monomers and oligomers are assimilated by the microorganisms. In an aerobic environment, these monomers or oligomers are ultimately oxidized to CO ₂ , H ₂ O and new cellular biological resources. In an anaerobic environment, monomers or oligomers are ultimately converted to CO ₂ , H ₂ , acetate, methane and cell biomass.

For example, the water non-dispersible polymer may be an aliphatic-aromatic polyester (abbreviated herein as "AAPE"). As used herein, the term "aliphatic-aromatic polyester" means a polyester comprising a mixture of residues from aliphatic or cycloaliphatic dicarboxylic acids or diols and aromatic dicarboxylic acids or diols. The term "non-aromatic" as used herein in connection with the dicarboxylic acid and diol monomers of the present invention means that the carboxyl or hydroxyl groups of the monomer are not linked through the aromatic nucleus. For example, adipic acid does not contain an aromatic nucleus in its main chain, ie the chain of carbon atoms connecting the carboxylic acid groups, and thus is "non-aromatic". In contrast, the term “aromatic” means that dicarboxylic acids or diols contain aromatic nuclei in the main chain, for example terephthalic acid or 2,6-naphthalene dicarboxylic acid. Thus, "non-aromatic" is, for example, essentially saturated or paraffinic, unsaturated (ie, containing non-aromatic carbon-carbon double bonds), or acetylene (ie, containing carbon-carbon triple bonds) It is intended to include both aliphatic and cycloaliphatic structures such as diols and dicarboxylic acids containing as straight chain or branched or cyclic arrangements of the constituent carbon atoms which may be. Thus, in connection with the description and claims of the present invention, non-aromatics are intended to include linear and branched chain structures (referred to herein as "aliphatic") and cyclic structures (referred to herein as "alicyclic"). do. However, the term "non-aromatic" is not intended to exclude any aromatic substituents that may be attached to aliphatic or cycloaliphatic diols or dicarboxylic acids. In the present invention, difunctional carboxylic acids are typically aliphatic dicarboxylic acids such as adipic acid, or aromatic dicarboxylic acids such as terephthalic acid. The bifunctional hydroxyl compound can be, for example, an alicyclic diol such as 1,4-cyclohexanedimethanol, such as linear or branched aliphatic diols such as 1,4-butanediol, or an aromatic diol such as hydroquinone .

AAPE includes one or more substituted or unsubstituted linear or branched diols (aliphatic diols containing 2 to about 8 carbon atoms, polyalkylene ether glycols containing 2 to 8 carbon atoms and about 4 to about 12 Linear or branched random copolyesters and / or chain extended copolyesters containing a moiety selected from cycloaliphatic diols containing 2 carbon atoms. Substituted diols typically comprise from 1 to about 4 substituents independently selected from halo, C ₆ -C ₁₀ aryl and C ₁ -C ₄ alkoxy. Examples of diols that may be used are ethylene glycol, diethylene glycol, propylene glycol, 1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 1,3-butanediol , 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, polyethylene glycol, diethylene glycol, 2,2,4-trimethyl-1,6-hexanediol, Thio-diethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol, triethylene glycol and tetraethylene glycol Preferred diols include, but are not limited to, 1,4-butanediol, 1,3-propanediol, ethylene glycol, 1,6-hexanediol, diethylene glycol or 1,4 At least one diol selected from cyclohexanedimethanol. AAPE is also selected from aliphatic dicarboxylic acids containing from 2 to about 12 carbon atoms and alicyclic acids containing from about 5 to about 10 carbon atoms, based on the total moles of diacid residues Also included are diacid residues containing one or more substituted or unsubstituted linear or branched non-aromatic dicarboxylic acid residues. Substituted non-aromatic dicarboxylic acids typically contain 1 to about 4 substituents selected from halo, C ₆ -C ₁₀ aryl and C ₁ -C ₄ alkoxy. Non-limiting examples of non-aromatic diacids include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, fumaric acid, 2,2-dimethyl glutaric acid, suberic acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, diglycolic acid, itaconic acid, maleic acid and 2,5-norbornene dicarboxylic acid. In addition to non-aromatic dicarboxylic acids, AAPE includes from about 1 to about 65 mole percent, based on the total moles of diacid residues, of one or more substituted or unsubstituted aromatic dicarboxylic acid residues containing 6 to about 10 carbon atoms. do. When substituted aromatic dicarboxylic acids are used, they typically contain from 1 to about 4 substituents selected from halo, C ₆ -C ₁₀ aryl and C ₁ -C ₄ alkoxy. Non-limiting examples of aromatic dicarboxylic acids that can be used in the AAPE of the present invention are terephthalic acid, isophthalic acid, salts of 5-sulfoisophthalic acid and 2,6-naphthalenedicarboxylic acid. More preferably, the non-aromatic dicarboxylic acid comprises adipic acid, the aromatic dicarboxylic acid comprises terephthalic acid, and the diol comprises 1,4-butanediol.

Other compositions possible for AAPE of the present invention are prepared from the following mole percent of the following diols and dicarboxylic acids (or their polyester-forming equivalents such as diesters) based on 100 mole percent of the diacid component and 100 mole percent of the diol component will be:

(1) glutaric acid (about 30 to about 75%); Terephthalic acid (about 25 to about 70%); 1,4-butanediol (about 90 to 100%); And modified diols (0 to about 10%);

(2) succinic acid (about 30 to about 95%); Terephthalic acid (about 5 to about 70%); 1,4-butanediol (about 90 to 100%); And modified diols (0 to about 10%); And

(3) adipic acid (about 30 to about 75%); Terephthalic acid (about 25 to about 70%); 1,4-butanediol (about 90 to 100%); And modified diols (0 to about 10%).

Modified diols are preferably selected from 1,4-cyclohexanedimethanol, triethylene glycol, polyethylene glycol and neopentyl glycol. Most preferred AAPEs are linear, branched or chain extended comprising from about 50 to about 60 mole percent adipic acid residues, from about 40 to about 50 mole percent terephthalic acid residues, and at least 95 mole percent of 1,4-butanediol residues. Copolyester. Even more preferably, the adipic acid residues comprise about 55 to about 60 mole percent, the terephthalic acid residues make up about 40 to about 45 mole percent, and the diol residues are about 95 moles of 1,4-butanediol residues. Contains% Such compositions are commercially available from Eastman Chemical Company, Kingsport, Tenn., Under the tradename Eastar Bio (R) Copolyester and from BASF Corporation under the trade name ECOFLEX (R).

Additional specific examples of preferred AAPEs include (a) 50 mole percent glutaric acid residues, 50 mole percent terephthalic acid residues and 100 mole percent 1,4-butanediol residues, (b) 60 mole percent glutaric acid residues, terephthalic acid residues 40 Poly (tetra) containing mole% and 100 mole% of 1,4-butanediol residues, or (c) 40 mole% glutaric acid residues, 60 mole% terephthalic acid residues and 100 mole% 1,4-butanediol residues Methylene glutarate-co-terephthalate); (a) 85 mole percent succinic acid residues, 15 mole percent terephthalic acid residues and 100 mole percent 1,4-butanediol residues, or (b) 70 mole percent succinic acid residues, 30 mole percent terephthalic acid residues and 1,4-butane Poly (tetramethylene-succinate-co-terephthalate) containing 100 mol% diol residues; Poly (ethylene succinate-co-terephthalate) containing 70 mol% of succinic residue, 30 mol% of terephthalic acid residue and 100 mol% of ethylene glycol residue; And (a) 85 mole percent adipic acid residues, 15 mole percent terephthalic acid residues and 100 mole percent 1,4-butanediol residues, or (b) 55 mole percent adipic acid residues, 45 mole percent terephthalic acid residues and 1, Poly (tetramethylene adipate-co-terephthalate) containing 100 mol% of 4-butanediol residues.

AAPE preferably comprises about 10 to about 1,000, preferably about 15 to about 600 repeat units. AAPE is from about 0.4 to about 2.0 dL / g, more preferably from about 0.7 to as measured at 25 ° C. using a concentration of 0.5 g of copolyester in 100 ml of a 60/40 (by weight) solution of phenol / tetrachloroethane. It may have an inherent viscosity of about 1.6 dL / g.

AAPE may optionally contain branching agent residues. The mole percent range of the branching agent ranges from about 0 to about 2 mole percent, preferably about, based on the total moles of diacid or diol residues (depending on whether the branching agent contains a carboxyl group or a hydroxyl group) 0.1 to about 1 mol%, most preferably about 0.1 to about 0.5 mol%. The branching agent preferably has a weight average molecular weight of about 50 to about 5000, more preferably about 92 to about 3000 and a functionality of about 3 to about 6. Branching agents are, for example, esterified residues of polyols having 3 to 6 hydroxyl groups, polycarboxylic acids having 3 or 4 carboxyl groups (or ester-forming equivalent groups), or 3 to 6 hydroxyl groups in total And hydroxy acids having carboxyl groups. It is also possible to branch AAAA by adding peroxide during reactive extrusion.

Each compartment of the water non-dispersible polymer may be different from each other in fineness and may be arranged in any shaped or engineered cross-sectional form known to those skilled in the art. For example, using sulfopolyesters and water non-dispersible polymers such as parallel, "seattle", divided pies, other splittable shapes, shells / cores or other forms known to those skilled in the art. It is possible to produce bicomponent fibers with engineered geometries. Other multicomponent shapes are also possible. One side of the parallel, "sea" or "pie," may subsequently be removed to produce very fine fibers. Methods of making bicomponent fibers are well known to those skilled in the art. In bicomponent fibers, the sulfopolyester fibers of the present invention may be present in an amount of about 10 to about 90% by weight, and are generally used in the skin portion of the skin / core fibers. Other components can be, for example, poly (ethylene) terephthalate, poly (butylene) terephthalate, poly (trimethylene) terephthalate, polylactide and the like, as well as a wide variety of other polymeric materials such as polyolefins, cellulose esters and polyamides. Typically, when a water-insoluble or water non-dispersible polymer is used, the resulting bicomponent or multicomponent fiber is not completely water dispersible. Parallel combinations with significantly different thermal shrinkage rates can be used to cause spiral crimping. If crimping is required, tooth or press crimping is typically suitable for many applications. If the second polymer component is present in the shell / core shaped core, this core may be optionally stabilized.

Compared to the caustic soda-containing solution that is sometimes required to remove other water dispersible polymers from the multicomponent fibers, the sulfopolyester may be "even" because it only requires neutral or weakly acidic (ie, "soft" water) to disperse. It is particularly useful for fibers having a "or" split pie "cross section. The term "soft water" used in this disclosure, means (the equivalent of one grain CaCO ₃ / gallon was 17.1 ppm) water has a grain / gallon of 5 or less as CaCO _3.

Another aspect of the invention

(A) (i) about 50 to about 96 mole percent of one or more isophthalic or terephthalic acid residues based on total acid residues; (ii) about 4 to about 30 mole percent sodiosulfoisophthalic acid residues based on total acid residues; (iii) at least 25 mole percent, based on total diol residues, are poly (ethylene glycol) having a structure of H- (OCH ₂ -CH ₂ ) _n -OH, where n is an integer from 2 to about 500 One or more diol residues; And (iv) branched monomer residues having from 0 to about 20 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof, and having a glass transition temperature of 57 ° C. or higher ( Water dispersible sulfopolyester with Tg); And

(B) a plurality of compartments comprising one or more water non-dispersible polymers immiscible with sulfopolyesters, the plurality of compartments being substantially isolated from one another by sulfopolyesters intervening between the compartments

It is a multicomponent fiber comprising a.

In one embodiment, the multicomponent fiber has an island-in-sea or split pie cross-section and contains less than 10% by weight of pigment or filler based on the total weight of the fiber.

The dicarboxylic acids, diols, sulfopolyesters, sulfomonomers, branched monomer residues and water non-dispersible polymers are as previously described. In the case of the multicomponent fiber, it is advantageous for the sulfopolyester to have a Tg of at least 57 ° C. The sulfopolyester may be a single sulfopolyester or a blend of one or more sulfopolyester polymers. Other examples of glass transition temperatures that the sulfopolyester or sulfopolyester blends can represent are at least 65 ° C, at least 70 ° C, at least 75 ° C, at least 85 ° C, and at least 90 ° C. For example, the sulfopolyester may comprise about 75 to about 96 mole percent of one or more isophthalic or terephthalic acid residues and about 25 to about 95 mole percent of diethylene glycol residues. As described above, examples of water non-dispersible polymers are polyolefins, polyesters, polyamides, polylactides, polycaprolactones, polycarbonates, polyurethanes and polyvinyl chlorides. In addition, the water non-dispersible polymer may be biodegradable or biodegradable. For example, the water non-dispersible polymer may be an aliphatic-aromatic polyester as already described.

The novel multicomponent fibers of the present invention can be produced by a variety of methods known to those skilled in the art. Therefore, the present invention

(A) at least one dicarboxylic acid residue;

(B) one or more having from about 4 to about 40 mole percent, based on the total repeat units, of two functional groups attached to an aromatic or cycloaliphatic ring (which is hydroxyl, carboxyl, or a combination thereof) and one or more sulfonate groups Sulfomonomer residues;

(C) at least 25 mole% of the total diol residues are poly (ethylene glycol) having a structure of H— (OCH ₂ —CH ₂ ) _n —OH, wherein n is an integer from 2 to about 500 Diol residues; And

(D) branched monomer residues having from 0 to about 25 mole percent, based on the total repeat units, of at least three functional groups, which are hydroxyl, carboxyl, or a combination thereof

A water dispersible sulfopolyester having a glass transition temperature (Tg) of 57 ° C. or more, and

One or more water non-dispersible polymers immiscible with the sulfopolyester

Spinning a fiber into a fiber, the fiber having a plurality of compartments comprising a water non-dispersible polymer, the compartments being between the compartments. Are substantially isolated from each other by sulfopolyesters intervening in one embodiment, the fibers contain less than 10% by weight of pigment or filler based on the total weight of the fibers. For example, small sections or thin strands in which the sulfopolyester and one or more water non-dispersible polymers are melted in separate extruders and the water non-dispersible polymer components are substantially isolated from each other by the intervention of sulfopolyester. Multicomponent fibers can be prepared by flowing the individual polymers into one spinneret or extrusion die having a plurality of dispensing flow paths to form. The cross section of such fibers can be, for example, a divided pie arrangement or a sea island arrangement. In another example, the sulfopolyester and one or more water non-dispersible polymers are fed separately into the spinneret spinneret, followed by a "core" in which the water non-dispersible polymer is substantially surrounded by a sulfopolyester "shell" polymer. Extruded into a sheath-core form to form. In the case of such concentric fibers, the hole supplying the "core" polymer is at the center of the spinneret outlet, and the flow conditions of the core polymer fluid are tightly adjusted to maintain the concentricity of the two components upon spinning. The spinneret of the spinneret can be modified to obtain different core and / or sheath shapes within the fiber cross section. In another example, (1) the water dispersible sulfopolyester and the water non-dispersible polymer are co-extruded separately through the spinneret and the separate polymer streams converge at substantially the same rate to combine under the surface of the spinneret. By parallel coalescing as a stream, or (2) separately feeding the two polymer streams through a spinneret converging at substantially the same rate at the surface of the spinneret, in parallel coalescing as a combined stream at the surface of the spinneret, It is possible to produce multicomponent fibers having a shape. In both cases, the speed of each polymer stream at the point of coalescence is determined by its weighing pump speed, number of spinnerets and size of spinneret.

The dicarboxylic acids, diols, sulfopolyesters, sulfomonomers, branched monomer residues and water non-dispersible polymers are as previously described. The sulfopolyester has a glass transition temperature of at least 57 ° C. Further examples of glass transition temperatures that may be represented by the sulfopolyester or sulfopolyester blends are at least 65 ° C, at least 70 ° C, at least 75 ° C, at least 85 ° C, and at least 90 ° C. In one example, the sulfopolyester comprises from about 50 to about 96 mole percent of one or more isophthalic or terephthalic acid residues based on total acid residues; And from about 4 to about 30 mole percent sodiosulfoisophthalic acid residues based on the total acid residues; And branched monomer residues having from 0 to about 20 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof. In another example, the sulfopolyester may comprise about 75 to about 96 mole percent of one or more isophthalic or terephthalic acid residues and about 25 to about 95 mole percent of diethylene glycol residues. As described above, examples of water non-dispersible polymers are polyolefins, polyesters, polyamides, polylactides, polycaprolactones, polycarbonates, polyurethanes and polyvinyl chlorides. In addition, the water non-dispersible polymer may be biodegradable or biodegradable. For example, the water non-dispersible polymer may be an aliphatic-aromatic polyester as already described. Examples of shaped cross sections include, but are not limited to, parallel, sheath-core, split pie or ribbon (striped) structures.

In another embodiment of the present invention, it has a shaped cross section comprising spinning one or more water dispersible sulfopolyesters and one or more water non-dispersible polymers that are incompatible with sulfopolyesters to produce multicomponent fibers. A method of making the component fibers is provided wherein the multicomponent fibers have a plurality of domains comprising a water non-dispersible polymer, the domains being substantially isolated from one another by sulfopolyesters intervening between the domains, The water dispersible sulfopolyester has a melt viscosity of less than about 12,000 poise as measured at a strain rate of 1 radian / second at 240 ° C., and the sulfopolyester is about 25 mole percent based on the total moles of diacid or diol residues Less than one sulfomonomer residue. In another embodiment, the multicomponent fiber has a spun denier of less than about 6 denier / filament.

Sulfopolyesters and water non-dispersible polymers used in these multicomponent fibers have already been discussed in the present description.

In another embodiment of the invention,

(A) extruding at least one water dispersible sulfopolyester and at least one water non-dispersible polymer that is immiscible with the sulfopolyester to produce a multicomponent extrudates, wherein the multicomponent extrudates are -Having a plurality of domains comprising a dispersible polymer, said domains being substantially isolated from one another by said sulfopolyester intervening between said domains, and

(B) melt drawing the multicomponent extrudates at a rate of at least about 2000 m / min to produce multicomponent fibers

Provided is a method of making a multicomponent fiber having a molded cross section, including.

In addition, the present invention also includes the step of melt drawing the multicomponent extrudates at a speed of at least about 2000 m / min, more preferably at least about 3000 m / min, most preferably at least 4500 m / min. It is a feature of.

Typically, upon exiting the spinneret, the fiber is quenched with an orthogonal flow of air, where the fiber solidifies. In this step, various finishes and sizing agents can be applied to the fibers. The cooled fiber is typically subsequently drawn and wound on a winding spool. Other additives such as emulsifiers, antistatics, antimicrobials, antifoams, lubricants, heat stabilizers, UV stabilizers and the like can be incorporated into the final treatment in an effective amount.

Optionally, the drawn fibers can be textured and wound to produce bulky continuous filaments. This one-step technique is known in the art as spin-draw-texturing. Other embodiments include flat filament (untextured) yarns or chopped staple fibers that are not crimped or crimped.

The sulfopolyester can later be removed by dissolving the interfacial layer or pie compartment and leaving smaller filaments or microdenier fibers of the water non-dispersible polymer (s). Therefore, the present invention

(A) (i) about 50 to about 96 mole percent of one or more isophthalic or terephthalic acid residues based on total acid residues; (ii) about 4 to about 30 mole percent sodiosulfoisophthalic acid residues based on total acid residues; (iii) at least 25 mole percent, based on total diol residues, are poly (ethylene glycol) having a structure of H- (OCH ₂ -CH ₂ ) _n -OH, where n is an integer from 2 to about 500 One or more diol residues; And (iv) branched monomer residues having from 0 to about 20 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof, and having a glass transition temperature of 57 ° C. or higher ( Spinning a water dispersible sulfopolyester having Tg) and at least one water non-dispersible polymer that is immiscible with the sulfopolyester into a multicomponent fiber, wherein the fiber is a plurality of fibers comprising a water non-dispersible polymer Having two compartments, said compartments being substantially isolated from one another by sulfopolyester intervening between the compartments; And

(B) contacting the multicomponent fiber with water to remove sulfopolyester to produce microdenier fibers

It provides a microdenier fiber manufacturing method comprising a.

In another embodiment, the multicomponent fiber contains less than 10 weight percent pigment or filler based on the total weight of the fiber.

Typically, the sulfopolyester is dissipated or dissolved by contacting the multicomponent fiber with water at about 25 to about 100 ° C., preferably at about 50 to about 80 ° C. for about 10 to about 600 seconds. After removal of the sulfopolyester, the remaining microfibers have an average fineness of 1 d / f or less, typically 0.5 d / f or less, more typically 0.1 d / f or less.

Typical uses of these remaining water non-dispersible polymer microfibers include artificial leather, suede, wipes and filter media. Filter media made from these microfibers can be used to filter air or liquids. Filter media for liquids include, but are not limited to, water, body fluids, solvents, and hydrocarbons. The ionic nature of sulfopolyesters advantageously results in poor "solubility" in saline media such as body fluids. This property is desirable for personal care articles and cleaning wipes that may be washed in a sewage system or otherwise discarded. The selected sulfopolyester was also used as a dispersant in the dye bath and also as a contaminant re-deposition inhibitor during the wash cycle.

In another embodiment of the invention,

Spinning at least one water dispersible sulfopolyester and at least one water non-dispersible polymer that is immiscible with the water dispersible sulfopolyester into a multicomponent fiber, wherein the multicomponent fiber comprises the water non-dispersible polymer Wherein the domains are substantially isolated from each other by sulfopolyesters intervening between the domains, and the water dispersible sulfopolyester is measured at a strain rate of 1 radian / second at 240 ° C. Having a melt viscosity of less than aze and comprising less than about 25 mole percent of one or more sulfomonomer residues based on the total moles of diacid or diol residues;

Contacting the multicomponent fiber with water to remove the water dispersible sulfopolyester to produce microdenier fibers

Provided is a method for producing microdenier fibers.

In one embodiment, the multicomponent fiber has a spun denier of less than about 6 denier / filament.

In another embodiment of the invention,

(A) extruding at least one water dispersible sulfopolyester and at least one water non-dispersible polymer immiscible with the water dispersible sulfopolyester to produce a multicomponent extrudate, wherein the multicomponent extrudates are Having a plurality of domains comprising a water non-dispersible polymer, said domains being substantially isolated from one another by said sulfopolyester intervening between said domains;

(B) melt drawing the multicomponent extrudates at a speed of at least about 2000 m / min to produce multicomponent fibers; And

(C) preparing the microdenier fibers by contacting the multicomponent fibers with water to remove the water dispersible sulfopolyester.

Provided is a method for producing microdenier fibers.

The multicomponent extrudates may be melt drawn at a speed of at least about 2000 m / min, more preferably at least about 3000 m / min and most preferably at least 4500 m / min.

Such sulfomonomers and sulfopolyesters suitable for use according to the invention are described above.

In one embodiment, the water used to remove the sulfopolyester from the multicomponent fiber is at a temperature above room temperature. In other embodiments, the water used to remove the sulfopolyester is at least about 45 ° C, at least about 60 ° C or at least about 80 ° C.

In another embodiment of the present invention, another method for producing cut water non-dispersible polymer microfibers is provided. The method is

(A) cutting the multicomponent fibers into cut multicomponent fibers;

(B) contacting the fiber-containing feedstock comprising the cut multicomponent fibers with water to produce a fiber mixing slurry;

(C) heating the fiber mixing slurry to produce a heated fiber mixing slurry;

(D) optionally, mixing the fiber mixing slurry in a shear zone;

(E) removing at least a portion of the sulfopolyester from the cut multicomponent fiber to produce a slurry mixture comprising a sulfopolyester dispersion and water non-dispersible polymer microfibers; And

(F) separating the chopped water non-dispersible polymer microfibers from the slurry mixture

It includes.

The multicomponent fiber can be cut into any length that can be used to make a nonwoven article. In one embodiment of the present invention, the multicomponent fiber can be cut to a length ranging from about 1 mm to about 50 mm. In other embodiments, the multicomponent fiber has about 1 mm to about 25 mm, about 1 mm to about 20 mm, about 1 mm to about 15 mm, about 1 mm to about 10 mm, about 1 mm to about 6 mm, It can be cut to a length ranging from about 1 mm to about 5 mm, about 1 mm to about 5 mm. In another embodiment, the cut multicomponent fibers are cut to a length of less than about 25 mm, less than about 20 mm, less than about 15 mm, less than about 10 mm, or less than about 5 mm. In another aspect of the invention, the multicomponent fiber can be cut into a mixture of various lengths.

The term "staple fiber" as used in the present disclosure is used to define a fiber cut to a length greater than 25 mm to about 50 mm. The term "short-cut fiber" is used to define a fiber cut to a length of about 25 mm or less.

The fiber-containing feedstock may include any other type of fiber useful for the manufacture of nonwoven articles. In one embodiment, the fiber-containing feedstock further comprises one or more fibers selected from the group consisting of cellulose fiber pulp, glass fibers, polyester fibers, nylon fibers, polyolefin fibers, rayon fibers, and cellulose ester fibers. can do.

The fiber-containing feedstock is mixed with water to produce a fiber mixing slurry. Preferably, the water used may be soft water or deionized water to facilitate removal of the water dispersible sulfopolyester. Training is defined above in the present disclosure. In one embodiment of the present invention, one or more water softeners may be used to facilitate the removal of the water dispersible sulfopolyester from the multicomponent fiber. Any water softener known in the art can be used. In one embodiment, the water softener is a chelating agent or a calcium ion sequestrant. Applicable chelating agents or calcium ion sequestrants are compounds which contain a plurality of carboxylic acid groups per molecule, wherein the carboxylic acid groups are separated by 2 to 6 atoms in the molecular structure of the chelating agent. Tetrasodium ethylene diamine tetraacetic acid (EDTA) is an example of the most common chelating agent, containing four carboxylic acid groups per molecular structure, separated into three atoms between adjacent carboxylic acid groups. Sodium polyacrylic acid salts are examples of calcium blockers containing carboxylic acid groups separated by two atoms between carboxylic acid groups. The sodium salt of maleic acid or succinic acid is an example of the most basic chelating compound. Further examples of applicable chelating agents include a plurality of carboxylic acid groups per molecular structure, wherein the carboxylic acid groups are separated by the required distance (2 to 6 atomic units), so that divalent or polyvalent cations (eg calcium) and To cause preferred steric interactions of the chelating agent, wherein the chelating agent is preferentially bound to divalent or polyvalent cations. Such compounds include, for example, diethylenetriaminepentaacetic acid; Diethylenetriamine-N, N, N ', N', N "-pentaacetic acid; pentenoic acid; N, N-bis (2- (bis- (carboxymethyl) amino) ethyl) -glycine; diethylenetriamine Pentaacetic acid; [[(carboxymethyl) imino] bis (ethylenenitrilo)]-tetra-acetic acid; edetic acid; ethylenedinitriletetraacetic acid; EDTA, free base; EDTA, free acid; ethylenediamine-N, N, N ', N'-tetraacetic acid; hampen; versen; N, N'-1,2-ethane diylbis- (N- (carboxymethyl) glycine); ethylenediamine tetra-acetic acid; N, N -Bis (carboxymethyl) glycine, triglycol amic acid, trilon A, α, α ', α "-trimethylaminetricarboxylic acid; Tri (carboxymethyl) amine; Aminotriacetic acid; Hampshire NTA acid; Nitrilo-2,2 ', 2 "-triacetic acid; teatriplex i; nitrilotriacetic acid; and mixtures thereof.

The required amount of water softener depends on the hardness of the water used in terms of Ca ⁺⁺ and other polyvalent ions.

The fiber mixing slurry is heated to produce a heated fiber mixing slurry. The temperature is sufficient to remove a portion of the sulfopolyester from the multicomponent fiber. In one embodiment of the present invention, the fiber mixing slurry is heated to a temperature in the range of about 50 to about 100 ° C. Other temperature ranges range from about 70 to about 100 ° C, from about 80 to about 100 ° C, and from about 90 to about 100 ° C.

Optionally, the fiber mixing slurry is mixed in shear zones. The degree of mixing is sufficient to isolate and remove the water dispersible sulfopolyester from the multicomponent fiber and to separate the water non-dispersible polymer microfibers. In one embodiment of the invention, 90% of the sulfopolyester is removed. In another embodiment 95% of the sulfopolyester is removed and in another embodiment more than 98% of the sulfopolyester is removed. The shear zone may include any type of equipment capable of providing the shearing action required to isolate and remove the water dispersible sulfopolyester from the multicomponent fiber and to separate the water non-dispersible polymer microfibers. Examples of such equipment include, but are not limited to, pulpers and refiners.

After contact with water and heating, the water dispersible sulfopolyester in the multicomponent fiber is isolated and separated from the water non-dispersible polymer microfibers, resulting in a slurry mixture comprising the sulfopolyester dispersion and the water non-dispersible polymer microfibers. Create The cleaved water non-dispersible polymer microfibers can then be separated from the sulfopolyester dispersion by any means known in the art. For example, the slurry mixture can be passed through separation equipment such as screens and filters. Optionally, the water non-dispersible polymer microfibers can be washed once or several times to remove larger amounts of water dispersible sulfopolyester.

Removal of the water dispersible sulfopolyester can be determined by physical observation of the slurry mixture. The water used to clean the water non-dispersible polymer microfibers is transparent if the water dispersible sulfopolyester is mainly removed. In addition, if the water dispersible sulfopolyester is still removed, the water used to clean the water non-dispersible polymer microfibers may be milky. In addition, if the water dispersible sulfopolyester remains on the water non-dispersible polymer microfibers, the microfibers may be somewhat tacky and adhesive.

The water dispersible sulfopolyester can be recovered from the sulfopolyester dispersion by any method known in the art.

In another embodiment of the present invention, a water non-dispersible polymer microfiber comprising at least one water non-dispersible polymer is provided, wherein the water non-dispersible polymer microfiber has an equivalent diameter of less than 5 microns. (equivalent diameter) and a length of less than 25 mm. The water non-dispersible polymer microfibers are prepared by the microfiber manufacturing method described above. In another embodiment of the present invention, the water non-dispersible polymer microfibers have an equivalent diameter of less than 3 microns and a length of less than 25 mm. In another embodiment of the invention, the water non-dispersible polymer microfibers have an equivalent diameter of less than 5 microns or less than 3 microns. In other embodiments of the invention, the water non-dispersible polymer microfibers have a length of less than 21 mm, less than 10 mm, less than 6.5 mm, and less than 3.5 mm. The domains or compartments in the multicomponent fiber once separated produce water non-dispersible polymer microfibers.

The present invention also includes fiber articles comprising the water dispersible fibers, multicomponent fibers, microdenier fibers or water non-dispersible polymer microfibers described above. The term "fiber article" is understood to mean any article having or resembling a fiber. Non-limiting examples of fibrous articles include multicomponent fibers, yarns, cords, tapes, fabrics, meltblown webs, spunbond webs, thermally bonded webs, high pressure woven webs, nonwoven webs and nonwovens, and combinations thereof; Such as multi-layered nonwovens, laminates and composites from these fibers, gauze, bandages, diapers, training pants, tampons, surgical gowns and masks, sanitary napkins and the like. Fiber articles may also include replacement inserts for various personal care and cleaning articles. The fibrous articles of the present invention may be bonded, laminated, attached to, or used with such other materials that may or may not be water dispersible. The fibrous article, for example a nonwoven layer, can be bonded to a backing of a flexible plastic film or a water non-dispersible material (eg, polyethylene). Such an assembly can be used, for example, as a component of a disposable diaper. Fiber articles can also be made by overblowing the fibers onto other substrates to produce a very colorful combination of engineered melt blown, spunbond films or membrane structures.

Textile articles of the present invention include nonwovens and nonwoven webs. Nonwovens are defined as fabrics made directly from the fibrous web without weaving or knitting operations. The Textile Institute defines nonwovens as textile structures made directly from fibers, not yarns. These fabrics are usually bonded using a variety of techniques, including but not limited to adhesive interlocking, needling or fluid jet entanglement, thermal bonding, and stitching, thereby providing a reinforced gum oil web or batt. From or from continuous filaments. For example, the multicomponent fibers of the present invention may be formed into a fabric by any known fabric forming process. The resulting fabric or web can be converted to a microdenier fiber web by applying sufficient force to split the multicomponent fibers, or by contacting the web with water to remove the sulfopolyester and leave the remaining microdenier fibers. .

In another embodiment of the invention,

(A) (i) about 50 to about 96 mole percent of one or more isophthalic or terephthalic acid residues based on total acid residues; (ii) about 4 to about 30 mole percent sodiosulfoisophthalic acid residues based on total acid residues; (iii) at least 25 mole percent, based on total diol residues, are poly (ethylene glycol) having a structure of H- (OCH ₂ -CH ₂ ) _n -OH, where n is an integer from 2 to about 500 One or more diol residues; And (iv) branched monomer residues having from 0 to about 20 mole percent, based on the total repeat units, of at least 3 functional groups, which are hydroxyl, carboxyl, or a combination thereof, and having a glass transition temperature of 57 ° C. or higher ( Spinning a water dispersible sulfopolyester having Tg) and at least one water non-dispersible polymer that is immiscible with the sulfopolyester into a multicomponent fiber, wherein the multicomponent fiber comprises a water non-dispersible polymer Having a plurality of compartments, said compartments being substantially isolated from one another by sulfopolyesters intervening between the compartments;

(B) overlapping the multicomponent fibers of step (A) to produce a nonwoven web; And

(C) contacting the nonwoven web with water to remove sulfopolyester to produce a microdenier fiber web.

It provides a method of producing a microdenier fiber web, including.

In another embodiment of the present invention, the multicomponent fiber used contains less than 10% by weight of pigment or filler based on the total weight of the fiber.

In another embodiment of the invention,

(A) spinning at least one water dispersible sulfopolyester and at least one water non-dispersible polymer that is immiscible with the sulfopolyester into a multicomponent fiber, wherein the multicomponent fiber is formed of a water non-dispersible polymer Wherein the domains are substantially isolated from each other by the sulfopolyester intervening between the domains, and the water dispersible sulfopolyester can be measured at a strain rate of 1 radian / second at 240 ° C. Exhibiting a melt viscosity of less than about 12,000 poise and comprising less than about 25 mole percent of one or more sulfomonomer residues based on the total moles of diacid or diol residues;

(B) collecting the multicomponent fibers of step (A) to produce a nonwoven web; And

(C) contacting the nonwoven web with water to remove the sulfopolyester to produce a microdenier fiber web.

Provided is a method of producing a microdenier fiber web.

In another embodiment of the invention, the multicomponent fiber used has a spun denier of less than about 6 denier / filament.

In another embodiment of the invention,

(A) extruding at least one water dispersible sulfopolyester and at least one water non-dispersible polymer immiscible with the water dispersible sulfopolyester to produce a multicomponent extrudate, wherein the multicomponent extrudates are Having a plurality of domains comprising a water non-dispersible polymer, said domains being substantially isolated from each other by said water dispersible sulfopolyester intervening between domains;

(B) melt drawing the multicomponent extrudates at a speed of at least about 2000 m / min to produce multicomponent fibers;

(C) collecting the multicomponent fibers of step (B) to produce a nonwoven web; And

(D) contacting the nonwoven web with water to remove the sulfopolyester to produce a microdenier fiber web

Provided is a method of producing a microdenier fiber web.

The method also preferably comprises a high pressure weaving of the multicomponent fibers of the nonwoven web prior to step (C). In one embodiment of the invention, the high water pressure weaving step results in less than about 20%, less than 15% or less than 10% by weight of the sulfopolyester contained in the multicomponent fiber. In pursuit of the purpose of reducing the loss of sulfopolyester during high-pressure weaving, the water used during this process is preferably less than about 45 ° C, more preferably less than about 35 ° C, most preferably less than about 30 ° C. Has a temperature of. In one embodiment of the present invention, it is desirable for the water used during high pressure weaving to minimize the loss of sulfopolyester from the multicomponent fiber as close to room temperature as possible. In contrast, the removal of the sulfopolyester polymer during step (C) may preferably be carried out using water having a temperature of at least about 45 ° C., more preferably at least about 60 ° C., most preferably at least about 80 ° C.

Before the step (C) after the high-pressure weaving, a thermosetting step can be performed on the nonwoven web, including heating the nonwoven web to at least about 100 ° C., more preferably at least about 120 ° C. The thermal curing step helps to relax the internal fiber stress and produce a dimensional stable fabric product. When the heat curable material is reheated to the heated temperature during the heat curing step, it is preferred that it exhibits a surface area shrinkage of less than about 5% of its original surface area. More preferably, the shrinkage is less than about 2% of the original surface area and most preferably the shrinkage is less than about 1%.

The sulfopolyesters used for the multicomponent fibers may be any of those described herein. In one embodiment, the sulfopolyester has a melt viscosity of less than about 6000 poise as measured at a strain rate of 1 radian / sec at 240 ° C. and contains less than about 12 moles of one or more sulfomonomer residues based on total repeat units. Include. These types of sulfopolyesters are already described herein.

In addition, the process of the present invention is preferably multicomponent fiber at a fiber speed of at least 2000 m / min, more preferably at least about 3000 m / min, even more preferably at least about 4000 m / min and most preferably at least about 5000 m / min. It includes the step of drawing.

In another embodiment of the present invention, nonwoven articles comprising water non-dispersible polymer microfibers can be made. Nonwoven articles comprising water non-dispersible polymer microfibers are made by a method selected from the group consisting of a dry-lamination process and a wet-lamination process. Methods for producing water non-dispersible polymer microfibers and multicomponent fibers are described herein above.

In one embodiment of the invention, at least 1% of water non-dispersible polymer microfibers are contained in the nonwoven article. Other amounts of the water non-dispersible polymer microfibers contained in the nonwoven article are at least 10%, at least 25% and at least 50%.

In another aspect of the invention, the nonwoven article may further comprise one or more other fibers. The other fibers may be any known in the art depending on the type of nonwoven article to be made. In one embodiment of the present invention, the other fibers may be selected from the group consisting of cellulose fiber pulp, glass fibers, polyester fibers, nylon fibers, polyolefin fibers, rayon fibers, cellulose ester fibers, and mixtures thereof. .

The nonwoven article may further comprise one or more additives. Additives include, but are not limited to, starch, fillers, and binders. Other additives are mentioned in other sections herein.

In general, methods for making this nonwoven article from water non-dispersible microfibers made from multicomponent fibers can be divided into the following groups: dry-laminated webs, wet-laminated webs, and combinations between these processes or Combination of these processes with other nonwoven processes.

Generally, dry-laminated nonwoven articles are made with staple fiber processing machines designed to handle fibers in a dry state. This includes mechanical processes such as carding, aerodynamics, and other air-lamination paths. This category also includes nonwoven articles made from filaments in the form of tows, fabrics composed of staple fibers, and stitched filaments or yards (ie, stitched nonwovens). Carding is a process of disentangling, washing, and intermixing fibers to produce a web for further processing into a nonwoven article. The process aligns the fibers that are fixed to each other as webs primarily by mechanical entangling and fiber-fiber friction. Cards (eg, rolled cards) generally consist of one or more main cylinders, rollers, or stationary tops, one or more doffers, or various combinations of these major components. A carding operation is a combination or operation of water non-dispersible microfibers between the positions of a card on a series of interoperable card rollers. Types of cards include roller cards, wool cards, cotton cards and random cards. Garnets may also be used to align these fibers.

Multicomponent fibers cut in a dry-lamination process may be water non-dispersible polymer microfibers may also be aligned by air-lamination. These fibers are sent to a collector, which can be a flat conveyor or drum by air current.

Extruded-formed webs can also be made from the multicomponent fibers of the present invention. Examples include spin-bonded and melt blown. Extrusion techniques are used to produce spin-bonded, melt-blown and porous-film nonwoven articles. This nonwoven article is made with a machine related to polymer extrusion methods such as melt-spinning, film casting and extrusion coating. The nonwoven article is then contacted with water to remove the water dispersible sulfopolyester, producing a nonwoven article comprising water non-dispersible polymer microfibers.

In a spin-bonding process, water dispersible sulfopolyesters and water non-dispersible polymers are formed by extruding multicomponent filaments, orienting them as bundles or groupings, laminating them on a transport screen and interlocking them. Convert directly to fabric. The interlocking can be carried out by thermal fusion, mechanical entanglement, high-pressure weaving, chemical binders or a combination of these processes.

Melt blown fabrics are also prepared directly from water dispersible sulfopolyesters and water non-dispersible polymers. The polymer is melted and extruded. As the melt passes through the extrusion orifice, it is blown into the air at high temperature. The air stream dilutes and solidifies the molten polymer. The multicomponent fiber can then be separated from the air stream as a web and compressed between heated rolls.

Combined spin-bond and melt-bond processes can also be used to make nonwoven articles.

Wet lamination processes include the use of papermaking techniques to produce nonwoven articles. Such nonwoven articles are made by pumping slurry into machinery associated with pulp fibrosis (eg hammer mills) and slurry into continuous screens designed to handle paper, such as short fibers in a fluid.

In one embodiment of the wet lamination process, the water non-dispersible polymer microfibers are suspended in water, transferred from the forming screen to the forming unit where the water is drained, and the fibers are placed on the screen wire.

In another embodiment of the wet lamination process, the water non-dispersible polymer microfibers are formed at a rate of 1,500 meters / minute at the beginning of the hydraulic former in a dewatering module (eg, suction box, foil, and curture). It is dehydrated on wire mesh or sheave that rotates at high speed. The sheet is dehydrated to a solids content of about 20-30%. The sheet can then be pressed and dried.

In another embodiment of the wet-lamination process,

(A) optionally, washing the water non-dispersible polymer microfibers comprising the water non-dispersible synthetic polymer with water;

(B) adding water to the water non-dispersible polymer microfibers to form a water non-dispersible polymer microfiber slurry;

(C) optionally, adding other fibers and / or additives to the water non-dispersible polymer microfiber slurry; And

(D) transferring the water non-dispersible polymer microfiber slurry to a wet-laid nonwoven zone to produce a nonwoven article.

Provided is a process comprising a.

In step (A), the number of washes depends on the specific use chosen for the water non-dispersible polymer microfibers. In step (B), sufficient water is added to the ribbon fibers to allow them to migrate to the wet-laid nonwoven zone.

The wet-laid nonwoven zone includes any device known in the art that can produce a wet-laid nonwoven article. In one embodiment of the invention, the wet-laid nonwoven zone includes one or more screens, meshes, or sieves to remove water from the water non-dispersible polymer microfiber slurry.

In another embodiment of the wet-lamination process,

(A) contacting the chopped multicomponent fiber with water to remove a portion of the water dispersible sulfopolyester to form a water non-dispersible polymer microfiber slurry comprising a water non-dispersible polymer microfiber and a water dispersible sulfopolyester. Generating;

(B) optionally, washing the water non-dispersible polymer microfibers with water;

(C) optionally, adding other fibers and / or additives to the water dispersible polymer slurry; And

(D) transferring the water non-dispersible polymer microfiber containing slurry into a wet-laid nonwoven zone to produce a nonwoven article.

Provided is a process comprising a.

In another embodiment of the present invention, the water non-dispersible microfiber slurry is mixed before moving to the wet-laid nonwoven zone.

Web-bonding processes may also be used to make nonwoven articles. This process can be divided into chemical and physical processes. Chemical bonding refers to bonding fibers and / or fibrous webs together using aqueous and solvent based polymers. The binder can be applied by saturation, impregnation, spraying, printing or application as a foam. Physical bonding processes include thermal processes such as calendaring and hot-air bonding, and mechanical processes such as needling and high-pressure weaving. A needling or needle-punching process interlocks the fibers by physically moving some of the fibers from a nearly horizontal position to a nearly vertical position. Needle-punching may be performed by a needleloom. The needle room generally includes a web-feeding mechanism, a needle beam including a needle board holding the needle, a striper plate, a bed plate and a fabric winding machine.

Stitch-bonding is a method of mechanical bonding that interlocks a fibrous web using yarns or using yarns without yarns. Examples of stitch-bonding machines include, but are not limited to, Maliwatt, Arachne, Malivlies, and Arababe.

Nonwoven articles may include: 1) mechanical fiber binding and interlocking into a web or mat; 2) various techniques for fusing fibers, including the use of binder fibers that utilize the thermoplastic properties of certain polymers and polymer blends; 3) the use of binding resins such as starch, casein, cellulose derivatives, or synthetic resins such as acrylic latex or urethanes; 4) powder adhesive binders; Or 5) held together by a combination thereof. The fibers are often deposited in a random manner, but orientation in one direction is possible and then joined using one of the methods described above.

The fibrous articles of the present invention may also include one or more layers of water dispersible fibers, multicomponent fibers, or microdenier fibers. The fiber layer may be one or more nonwoven layers, loosely bonded overlapping fibers, or a combination thereof. Textile articles may also include child care articles such as infant diapers; Training pants for children; Adult care articles such as adult diapers and adult incontinence pads; Female care articles such as female sanitary napkins, panty liners, and tampons; wife; Fiber-containing cleaning articles; Medical and surgical care articles such as medical wipes, tissues, gauze, examination bed covers, surgical masks, gowns, bandages, and wound dressings; textile; Personal care and health care articles, including but not limited to elastomeric yarns, wipes, tapes, other protective barriers, and packaging materials. Fibrous articles may be used to absorb liquids or may be pre-wetted with various liquid compositions and used to convey the composition to a surface. Non-limiting examples of liquid compositions include wetting agents; detergent; Skin care articles such as cosmetics, ointments, drugs, softeners, and fragrances. The fibrous article may also include various powders and particulates to improve absorbency or as a delivery vehicle. Examples of powders and particulates include but are not limited to talc, starch, various water absorbing, water dispersible, or water swellable polymers such as superabsorbent polymers, sulfopolyesters, and poly (vinyl alcohol), silica, pigments, and microcapsules. It doesn't work. In addition, additives may be present as required for the particular use, but are not required. Examples of additives include oxidative stabilizers, UV absorbers, colorants, pigments, opacifiers, light brighteners, fillers, nucleating agents, plasticizers, viscosity modifiers, surface modifiers, antibacterial agents, bactericides, low temperature fluidity inhibitors, branching agents, And catalysts.

In addition to being water dispersible, the aforementioned fiber articles may be flushable. The term "washable" herein means that it can be discarded in a conventional toilet and introduced into a local sewage or residential purification system without causing obstruction or blockage in the toilet or sewage system.

The fibrous article may also comprise a water dispersible film comprising a second water dispersible polymer. The second water dispersible polymer may be the same as or different from the aforementioned water dispersible polymer used in the fibers and fibrous articles of the present invention. Thus, in one embodiment, for example, the second water dispersible polymer may be an additional sulfopolyester comprising the following (A) to (D):

(A) about 50 to about 96 mole percent, based on total acid residues, of at least one isophthalic acid or terephthalic acid residue;

(B) about 4 to about 30 mole percent sodiosulfoisophthalic acid residues based on total acid residues;

(C) at least 15 mole%, based on the total diol residues, is a poly (ethylene glycol) having a structure of H— (OCH ₂ —CH ₂ ) _n —OH, wherein n is an integer ranging from 2 to about 500; One or more residues;

(D) from 0 to about 20 mole percent, based on total repeat units, of branched monomer residues having at least three functional groups which are hydroxyl, carboxyl, or a combination thereof.

The additional sulfopolyester may be blended with one or more auxiliary polymers described above to modify the properties of the resulting fibrous article. The auxiliary polymer may or may not be water dispersible, depending on the application. The copolymer may be miscible or immiscible with the additional sulfopolyester.

Additional sulfopolyesters may contain other concentrations of isophthalic acid residues, for example from about 60 to about 95 mole percent, and from about 75 to about 95 mole percent. Further examples of isophthalic acid residue concentration ranges are from about 70 to about 85 mol%, from about 85 to about 95 mol% and from about 90 to about 95 mol%. The additional sulfopolyester may also include about 25 to about 95 mole percent diethylene glycol moiety. Additional examples of diethylene glycol moiety concentration ranges include about 50 to about 95 mole percent, about 70 to about 95 mole percent, and about 75 to about 95 mole percent. Additional sulfopolyesters may also include ethylene glycol and / or 1,4-cyclohexanedimethanol residues. Typical concentration ranges for CHDM residues are from about 10 to about 75 mol%, from about 25 to about 65 mol%, and from about 40 to about 60 mol%. Typical concentration ranges for ethylene glycol moieties are about 10 to about 75 mole percent, about 25 to about 65 mole percent, and about 40 to about 60 mole percent. In another embodiment, the additional sulfopolyester comprises about 75 to about 96 mole percent isophthalic acid residues and about 25 to about 95 mole percent diethylene glycol residues.

According to the invention, the sulfopolyester film component of the fiber article can be prepared as a single layer or a multilayer film. Monolayer films can be produced by conventional casting techniques. The multilayer film can be produced by a conventional lamination method or the like. The film can be a conventional thickness, but the overall thickness is usually about 2 to about 50 mils.

The film-containing fiber article may include one or more water dispersible fiber layers as described above. The fiber layer may be one or more nonwoven layers, a layer of loosely bonded overlapping fibers, or a combination thereof. In addition, the film-containing fiber articles may include personal and health care articles as described herein above.

As mentioned above, the fibrous article may also include various powders and particulates to improve absorbency or as a delivery vehicle. Therefore, in one embodiment, the fibrous article of the present invention comprises a powder comprising a third water dispersible polymer, which may be the same as or different from the water dispersible polymer component described above. Other examples of powders and particulates include talc, starch, various water absorbing, water dispersible, or water swellable polymers such as poly (acrylonitrile), sulfopolyesters, and poly (vinyl alcohol), silica, pigments, and microcapsules. Including but not limited to.

The novel fibers and fibrous articles of the present invention have many possible uses in addition to those mentioned above. One novel use involves melt blowing a film or nonwoven onto a flat, curved, or shaped surface to provide a protective layer. This layer provides surface protection for durable equipment during shipment. At the destination, before using the equipment, the outer layer of sulfopolyester can be washed off. Additional embodiments of this general use concept may include a personal care article that provides a temporary barrier layer for garments or covers for some reusable or limited use. For military use, the activated carbon and chemical absorbent may be sprayed just prior to the collector onto a tapered filament pattern such that the melt blown matrix adheres to the exposed surface in its entirety. The chemical absorbent can even be changed by melt blowing on another layer in the front operating area when a threat occurs.

The main advantage inherent in sulfopolyesters is the ease of removing or recovering the polymer from the aqueous dispersion via flocculation or precipitation by addition of ionic moieties (such as salts). Other methods can also be used, such as pH adjustment, nonsolvent addition, freezing and the like. Thus, a fibrous article, such as an external wear protection garment, can be safely handled in a much smaller volume for potentially acceptable procedures such as incineration, even if the polymer becomes hazardous waste even after successful use of the protective barrier.

Undissolved or dried sulfopolyesters include fluff pulp, cotton, acrylic, rayon, lyocell, PLA (polylactide), cellulose acetate, cellulose acetate propionate, poly (ethylene) Terephthalate, poly (butylene) terephthalate, poly (trimethylene) terephthalate, poly (cyclohexylene) terephthalate, copolyester, polyamide (nylon), stainless steel, aluminum, treated polyolefin, PAN (poly Acrylonitrile), and polycarbonates, and are known to form strong adhesive bonds with a wide range of substrates. Therefore, the nonwovens of the present invention can be used as laminating adhesives or binders that can be bonded by known techniques such as thermal, radio wave (RF), microwave, and ultrasonic methods. The application of sulfopolyesters to enable RF activation has been disclosed in a number of recent patents. Therefore, the novel nonwovens of the present invention may have bifunctional or even multifunctional properties in addition to adhesive applications. For example, the nonwoven fabric of the present invention can yield disposable baby diapers that act as a water-reactive adhesive as well as the fluid care component of the final assembly.

In addition, the present invention,

(A) at least one dicarboxylic acid residue;

(ii) about 4 to about 40 mole percent, based on total repeat units, of sulfomonomer residues having at least one metal sulfonate group attached to an aromatic or cycloaliphatic ring and two functional groups that are hydroxyl, carboxyl, or a combination thereof One or more;

(iii) a die wherein at least 20 mole%, based on the total diol residues, are poly (ethylene glycol) having a structure of H- (OCH ₂ -CH ₂ ) _n -OH, wherein n is an integer ranging from 2 to about 500 One or more residues; And

(iv) from 0 to about 25 mole percent, based on total repeat units, of branched monomer residues having at least three functional groups that are hydroxyl, carboxyl, or a combination thereof

Heating the water dispersible polymer composition comprising a pigment or filler based on the total weight of the polymer composition to a temperature above its pour point; And

(B) melt spinning the filament

It provides a method of producing a water-dispersible fiber, including. As detailed herein above, the water dispersible polymer may optionally be blended with sulfopolyester. In addition, the water non-dispersible polymer may optionally be blended with sulfopolyester to form a blend that is an immiscible blend. As used herein, the term "flow point" means the temperature at which the viscosity of the polymer composition allows extrusion or other forms of processing through a spinneret or extrusion die. Dicarboxylic acid residues may comprise from about 60 to about 100 mole% of acid residues, depending on the type and concentration of sulfomonomer. Other examples of concentration ranges of dicarboxylic acid residues are from about 60 mol% to about 95 mol% and from about 70 mol% to about 95 mol%. Preferred dicarboxylic acid residues are isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid, or dimethyl terephthalate, dimethyl isophthalate, and dimethyl-1,4-cyclohexanedicarboxyl when diesters are used Rate, and isophthalic acid and terephthalic acid residues are particularly preferred.

The sulfomonomer may be a dicarboxylic acid or ester thereof containing a sulfonate group, a diol containing a sulfonate group, or a hydroxy acid containing a sulfonate group. Further examples of concentration ranges of sulfomonomer residues are from about 4 to about 25 mole percent, from about 4 to about 20 mole percent, from about 4 to about 15 mole percent, and from about 4 to about 10 mole percent, based on total repeat units. The cation of the sulfonate salt may be a metal ion such as Li ⁺ , Na ⁺ , K ⁺ , Mg ⁺⁺ , Ca ⁺⁺ , Ni ⁺⁺ , Fe ⁺⁺ and the like. Alternatively, the cation of the sulfonate salt may be nonmetallic, such as the nitrogenous base as described above. Examples of sulfomonomer residues that can be used in the process of the invention are sulfophthalic acid, sulfoterephthalic acid, metal sulfonate salts of sulfoisophthalic acid, or combinations thereof. Another example of a sulfomonomer that can be used is 5-sodiosulfoisophthalic acid or its esters. When sulfomonomer residues are derived from 5-sodiosulfoisophthalic acid, typical sulfomonomer concentration ranges are from about 4 to about 35 mole percent, from about 8 to about 30 mole percent, and from about 10 to 25 mole based on total acid residues. %to be.

The sulfopolyesters of the invention comprise one or more diol moieties that may include aliphatic, cycloaliphatic, and aralkyl glycols. Alicyclic diols such as 1,3- and 1,4-cyclohexanedimethanol may exist as their pure cis or trans isomers or as a mixture of cis and trans isomers. For example, non-limiting examples of low molecular weight polyethylene glycols with n of 2 to 6 are diethylene glycol, triethylene glycol, and tetraethylene glycol. Of these low molecular weight glycols, diethylene and triethylene glycol are most preferred. The sulfopolyester may optionally include branching monomers. Examples of branched monomers are as described herein above. Further examples of branching monomer concentration ranges are 0 to about 20 mol% and 0 to about 10 mol%. The sulfopolyesters of the novel process of the invention have a T _g of at least 25 ° C. Further examples of glass transition temperatures represented by sulfopolyesters are at least 30 ° C, at least 35 ° C, at least 40 ° C, at least 50 ° C, at least 60 ° C, at least 65 ° C, at least 80 ° C, and at least 90 ° C. Although other T _g is possible, typical glass transition temperatures of the dry sulfopolyester of the present invention are about 30 ° C, about 48 ° C, about 55 ° C, about 65 ° C, about 70 ° C, about 75 ° C, about 85 ° C, and about 90 ° C.

Water dispersible fibers are produced by a melt blowing process. The polymer is melted in the extruder and pushed through the die. The extrudate exiting the die is rapidly tapered to ultrafine diameters by hot, high velocity air. Fiber orientation, cooling rate, glass transition temperature (T _g ), and crystallization rate are important because they affect the viscosity and processing properties of the polymer while the extrudate is thinning. The filaments are collected on a renewable surface such as moving belts, cylindrical drums, rotary mandrels and the like. Predrying of pellets (if required), extruder zone temperature, melt temperature, screw design, processing speed, air temperature, air flow (speed), die air gap and setback, nose tip hole size, die temperature, die at The die-to-collector (DCP), quenching environment, collector speed, and post-treatment are all factors that affect article characteristics such as filament diameter, basis weight, web thickness, pore size, softness, and shrinkage. In addition, high velocity air can be used to move the filament in a somewhat random fashion so that extensive interlacing occurs. When the moving belt moves under the die, the nonwoven can be manufactured by a combination of overlapping laydown, mechanical cohesiveness, and thermal bonding of the filaments. Overblowing onto another substrate, such as a spin-bonded or backing layer, is also possible. When the filament is wound on a rotating mandrel, a cylindrical article is formed. Water dispersible fiber lay-down can also be made by a spin-bonding process.

Thus, the present invention also provides

(A) at least one dicarboxylic acid residue;

(ii) about 4 to about 40 mole percent, based on total repeat units, of sulfomonomer residues having at least one metal sulfonate group attached to an aromatic or cycloaliphatic ring and two functional groups that are hydroxyl, carboxyl, or a combination thereof One or more;

(iii) a die wherein at least 20 mole%, based on the total diol residues, are poly (ethylene glycol) having a structure of H- (OCH ₂ -CH ₂ ) _n -OH, wherein n is an integer ranging from 2 to about 500 One or more residues; And

(iv) from 0 to about 25 mole percent, based on total repeat units, of branched monomer residues having at least three functional groups that are hydroxyl, carboxyl, or a combination thereof

Water dispersible polymer composition, wherein the sulfopolyester has a glass transition temperature (T _g ) of at least 25 ° C .; the polymer composition contains less than 10% by weight of pigment or filler, based on the total weight of the polymer composition. Heating to a temperature above its pour point;

(B) melt-spinning the filaments; And

(C) overlapping and collecting the filaments of step (B) to form a nonwoven fabric

It provides a method for producing a water dispersible nonwoven comprising a.

As detailed herein above, the water dispersible polymer can optionally be blended with sulfopolyester. In addition, the non-water dispersible polymer may optionally be blended with sulfopolyester to form a blend that is an immiscible blend. Dicarboxylic acids, sulfomonomers, and branched monomer residues are as described above. The sulfopolyester has a T _g of at least 25 ° C. Further examples of glass transition temperatures represented by sulfopolyesters are at least 30 ° C, at least 35 ° C, at least 40 ° C, at least 50 ° C, at least 60 ° C, at least 65 ° C, at least 80 ° C, and at least 90 ° C. Although other T _g is possible, typical glass transition temperatures of the dry sulfopolyester of the present invention are about 30 ° C, about 48 ° C, about 55 ° C, about 65 ° C, about 70 ° C, about 75 ° C, about 85 ° C, and about 90 ° C.

In certain embodiments of the invention, a water-wet microfiber product (wet wrap) prepared after cutting, washing, and excess water dehydration of the multicomponent fiber is directly subjected to a wet-laid nonwoven process (ie, without further drying). Used. Direct use of the wet wrap product in the wet-laid nonwoven process saves significant energy and equipment costs by avoiding the need for complete drying of the wet wrap. When the wet wrap production facility is located away from the wet-laid nonwoven manufacturing facility, the wet wrap can be packaged and transported from the wet wrap production site to the nonwoven production site. Such wet wrap compositions are described in detail immediately below.

One embodiment of the invention relates to a wet wrap composition comprising water and a plurality of synthetic fibers. The water may make up at least 50, 55 or 60 weight percent and / or up to 90, 85 or 80 weight percent of the wet wrap composition. The synthetic fibers may comprise at least 10, 15, or 20 weight percent and / or up to 50, 45, or 40 weight percent of the wet wrap composition. The water and the synthetic fibers may combine to make up at least 95, 98, or 99 weight percent of the wet wrap composition. The synthetic fibers may have a length of 0.25, 0.5 or 1 mm or more and / or 25, 10 or 2 mm or less. The synthetic fibers may have a minimum transverse dimension of at least 0.1, 0.5 or 0.75 microns and / or at most 10, 5 or 2 microns.

As used herein, “minimum transverse dimension” is defined as the minimum dimension of a fiber measured perpendicular to the fiber's extension axis by an external caliper method. As used herein, "maximum transverse dimension" is defined as the maximum dimension of a fiber measured perpendicular to the fiber's elongation axis by an external caliper method. 1A, 1B, and 1C show how these dimensions can be measured at various fiber cross sections. 1A, 1B and 1C, "TD _minimum " is the minimum transverse dimension and "TD _maximum " is the maximum transverse dimension. As used herein, the "external caliper method" is a method of measuring the external dimension of a fiber, wherein the measured dimension is the distance between two parallel lines on the same plane, and the fiber is located between these two parallel lines, each parallel line of the fiber It is generally in contact with the outer surface of the fiber on the opposite side. All fiber dimensions provided herein (eg, length, minimum transverse dimension and maximum transverse dimension) are average dimensions of the fibers belonging to the specified group.

The wet wrap composition may further comprise a fiber finishing composition in an amount of at least 10, 50, or 100 ppmw and / or up to 1,000, 500, 250 ppmw. In an embodiment, the fiber finishing composition may comprise oils, waxes and / or fatty acids. In another embodiment, the fiber finishing composition may comprise natural fatty acids and / or natural oils. In another embodiment, the fiber finishing composition comprises mineral oil, stearate ester, sorbitan ester, and / or palm oil. In another embodiment, the fiber finishing composition comprises mineral oil.

The wet wrap composition may comprise at least 0.001, 0.01, or 0.1 weight percent, and / or up to 5, 2, or 1 weight percent water dispersible polymer. In an embodiment, the water dispersible polymer may comprise one or more sulfopolyesters. Such sulfopolyesters have been described herein above.

The sulfopolyester is

(A) at least one residue of a dicarboxylic acid comprising terephthalic acid and isophthalic acid, from about 50 to about 96% based on total acid residues,

(B) about 4 to about 40 mole percent, based on total acid residues, sulfomonomer residues having at least one sulfonate group attached to an aromatic or cycloaliphatic ring and two functional groups that are hydroxyl, carboxyl, or a combination thereof One or more, and

(C) at least one diol residue

It includes.

The sulfopolyester has a glass transition temperature (Tg) of at least 40 ° C. or at least 50 ° C., measured at a concentration of 0.5 g of sulfopolyester in 40 ° C. and 100 ml of solvent in a 60/40 parts by weight solution of phenol / tetrachloroethane solvent. It has an inherent viscosity of at least 0.2 dL / g and may have a melt viscosity of less than about 12,000, 8,000 or 6,000 poise as measured at 1 rad / sec strain at 240 ° C.

The water non-dispersible synthetic polymers of the wet wrap compositions include polyolefins, polyesters, copolyesters, polyamides, polylactides, polycaprolactones, polycarbonates, polyurethanes, cellulose esters, acrylics, polyvinyl chlorides, and their It can be selected from the group consisting of blends. In one embodiment, the water non-dispersible synthetic polymer is selected from the group consisting of polyethylene terephthalate homopolymer, polyethylene terephthalate copolymer, polybutylene terephthalate, polypropylene terephthalate, nylon 6, nylon 66 and blends thereof do.

Wet wrap compositions can be prepared by a method comprising the following steps (A)-(D):

(A) preparing a multicomponent fiber having less than 15 dpf spun denier, comprising at least one water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer that is incompatible with the water dispersible sulfopolyester;

(B) cutting the multicomponent fibers into chopped multicomponent fibers having a length of less than 25 mm;

(C) contacting the chopped multicomponent fiber with water to remove sulfopolyester, thereby producing a synthetic fiber slurry in a sulfopolyester dispersion comprising at least a portion of water and sulfopolyester; And

(D) preparing a wet wrap composition by removing at least a portion of the sulfopolyester dispersion from the slurry.

As discussed above, the wet wrap composition can be used directly in a wet-lamination process to produce a nonwoven article. To use the wet wrap during the wet-lamination process, the wet wrap composition is shipped from the manufacturing location to the wet-laid nonwoven zone. The wet wrap composition may be mixed with additional fibers immediately before the wet-laid nonwoven zone and / or the wet-laminate. The additional fibers may be selected from the group consisting of cellulose fiber pulp, inorganic fibers, polyester fibers, nylon fibers, lyocell fibers, polyolefin fibers, rayon fibers, cellulose ester fibers and combinations thereof.

As part of the wet-lamination process, the wet wrap composition may be mixed with dilution water upstream immediately before the wet-laid nonwoven zone and / or the wet-laid nonwoven zone. The dilution water and the wet wrap may be mixed in an amount of 50, 75, 90 or 95 parts by weight or more per dilution water of the wet wrap.

In another embodiment of the present invention, a method of making a microfiber product stream is provided, as shown in FIGS. 2, 3A, 3B, and 4. Multicomponent fibers are as already mentioned herein. Further disclosures relating to multicomponent fibers are provided in the following patents and patent applications: US Pat. No. 6,989,193; 7,635,745; 7,902,094; 7,892,993; 7,687,143; And US Patent Application 12 / 199,304; 12 / 909,574; 13 / 273,692; 13 / 273,648; 13 / 273,710; 13 / 273,720; 13 / 273,929, 13 / 273,937; 13 / 273,727, 13 / 273,737; 13 / 273,745; 13 / 273,749; 12 / 966,502; 12 / 966,507; 12 / 975,450; 12 / 975,452; 12 / 975,456; 13 / 053,615; 13 / 352,362; 13 / 433,812; 13 / 433,854; 61 / 471,259; 61 / 472,964; And 61 / 558,744. The above documents are incorporated herein by reference to the extent that they do not contradict what is stated herein.

The terms “wet wrap” and “microfiber product stream” will be used interchangeably herein.

In one embodiment of the present invention shown in FIG. 2, a method of preparing a microfiber product stream is provided. This way

(A) Short-cut multicomponent fibers 101 having a length of less than 25 mm are contacted with an aqueous stream 801 heated in the fiber open zone 400 to remove a portion of the water dispersible sulfopolyester and open the microfibers. Producing a slurry 401, wherein the short-cut multicomponent fiber comprises at least one water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer that is immiscible with the water dispersible sulfopolyester, The heated aqueous stream 801 is at a temperature of at least 40 ° C., and wherein the open microfiber slurry 401 comprises water, microfibers and water dispersible sulfopolyester; And

(B) sending the open microfiber slurry 401 to a first solid-liquid separation zone 500 to produce a microfiber product stream 503 and a first mother liquor stream 501, wherein the first mother liquor Stream 501 comprises water and water dispersible sulfopolyester

It includes.

In this embodiment of the present invention, the fiber slurry zone 200, the mixing zone 300 and the fiber open zone 400 as shown in FIG. 4 are combined in one unit operation in the open process zone 1100. Open process zone 1100 includes fiber open zone 400.

The treated aqueous stream 103 used in this method can be generated by sending the aqueous stream 102 to the aqueous treatment band 1000 to produce the treated aqueous stream 103. The aqueous stream contains water. In embodiments of the invention, the monovalent metal cations in the treated aqueous stream 103 may be less than about 1000 ppm, less than about 500 ppm, less than about 100 ppm, or less than about 50 ppm by weight. Removal of divalent and polyvalent metal cations from aqueous stream 102 is one function of aqueous treatment zone 1000. In other embodiments of the invention, the concentrations of divalent and polyvalent metal cations are less than about 50 ppm by weight, less than about 25 ppm by weight, less than about 10 ppm by weight, or less than about 5 ppm by weight. The temperature of stream 103 may range from groundwater temperature to about 40 ° C.

Treatment of aqueous stream 102 in aqueous treatment zone 1000 may be accomplished by any method known in the art. In one embodiment, aqueous treatment zone 1000 includes distillation equipment that generates steam and condenses to produce treated aqueous stream 103. In another embodiment, water can be sent to the reverse osmosis membrane separation zone to remove monovalent and divalent metal cations from the water to produce the treated aqueous stream 103. In another embodiment, water is sent to the ion exchange resin to produce a treated aqueous stream 103 having an acceptable low concentration of metal ions. In another embodiment, water is sent to a commercial softening device to produce a treated aqueous stream 103 having acceptable low concentrations of divalent and polyvalent metal ions. It should be understood that any combination of these water treatment options may be used to achieve the required treated water characteristics.

The treated aqueous stream 103 can be sent to any desired location in the process. In one embodiment, a portion of stream 103 is sent to first solid-liquid separation zone 500 to serve as a wash liquor for solids contained in cloth wash liquor and / or first solid-liquid separation zone 500. .

In one embodiment, at least a portion of the treated aqueous stream 103 is sent to heat exchanger zone 800 to produce a heated aqueous stream. One function of the heat exchanger zone 800 is to produce a heated aqueous stream 801 at a specific controlled temperature.

In one embodiment, stream 800, which may be supplied to heat exchanger zone 800, is treated aqueous stream 103 and second mother liquor stream 601. In another embodiment, stream 800, which may be supplied to heat exchanger zone 800, is treated aqueous stream 103, part of first recovered water stream 703, first mother liquor stream 501. And a portion of the second mother liquor stream 601.

Apparatus known in the art for regulating the temperature of stream 801, such as but not limited to any heat exchanger utilizing a stream used to provide a portion of the required energy, used to provide a portion of the required energy Any heat exchanger using a heat transfer fluid, any heat exchanger using an electrical heating element used to provide some of the required energy, and steam is condensed and the condensate mixed with water supplied to the heat exchanger zone 800 Any vessel or tank using direct steam injection can be used. The multicomponent fiber stream 90 is sent to the fiber cut zone 100 to produce a cut multicomponent fiber stream 101. Multicomponent fibers may have any multicomponent structure known in the art. Multicomponent fibers include water dispersible sulfopolyesters and water non-dispersible polymers as described herein above.

Any device known in the art can be used to cut the multicomponent fiber stream 90 to produce the cut multicomponent fiber stream 101. In one embodiment, the length of the cut fibers in the cut multicomponent fiber stream 101 is less than about 50 mm. In other embodiments, the length of the cut fibers in the cut multicomponent fiber stream 101 is less than about 25 mm, less than about 20 mm, less than about 15 mm, less than about 10 mm, less than about 5 mm, or about 2.5 mm. Is less than.

A portion of the cut multicomponent fiber stream 101 and the heated treated aqueous stream 801 is directed to the fiber open zone 400 to produce an open microfiber slurry 401. One function of the fiber open zone 400 is to separate the water dispersible polymer from the cut multicomponent fibers so that at least a portion of the water non-dispersible polymer microfibers are separated from the cut multicomponent fiber fibers to open the micro It is to be suspended in the fiber slurry (401). In another embodiment of the present invention, about 50 to about 100 weight percent of the water non-dispersible polymer microfibers contained in the cut multicomponent fiber slurry 201 is contained in the open microfiber slurry 401. It is suspended as a non-dispersible polymer microfiber and is no longer part of the cut multicomponent fiber. In other embodiments, about 75 to about 100 weight percent, about 90 to about 100 weight percent, or about 95 to about 100 weight percent of the water non-dispersible polymer microfibers contained in the cut multicomponent fiber stream 201. Is suspended in the open microfiber slurry 401 as a water non-dispersible polymer microfiber and no longer part of the cut multicomponent fiber.

The diameter or denier of the starting cut multicomponent fiber in stream 201 affects the degree of separation of the water dispersible sulfopolyester from the multicomponent fiber in the fiber open zone 400. Typical multicomponent fiber types generally have diameters in the range of about 12 microns to about 20 microns. Useful multicomponent fibers can have larger starting diameters of diameter sizes of at least about 40 microns. The time required to separate the desired amount of water dispersible sulfopolyester from the chopped multicomponent fibers increases with increasing diameter of the chopped multicomponent fibers in stream 201.

In this embodiment of the present invention, the fiber slurry zone 200, the mixing zone 300 and the fiber open zone 400 as shown in FIG. 4 are combined to achieve one unit operation as shown in FIG. 2. . In this embodiment, the cut multicomponent fiber stream 101 is sent directly to a single unit operation where it is mixed with the heated aqueous stream 801 in the fiber open region 400. For example, in a single batch mixing device in which the chopped multicomponent fiber stream 101 and the heated aqueous stream 801 are added directly to the fiber open zone 400, opening or washing of the chopped multicomponent fiber is achieved. There is a batch mixing device. The fiber open zone may comprise one or more mixing tanks. In this embodiment, the combined functionality of the zones 200, 300 and 400 can be achieved in the continuous stirred tank reactor shown in FIG. 5B aoc FIG. 5C. In this embodiment, the combined functionality of the zones 200, 300, and 400 is a function of the residence time, temperature, and mixing shear forces required for the proper functioning of the zones 200, 300, and 400. It can be achieved in any batch or continuous mixing device that can achieve the requirements.

The residence time, temperature and shear forces in the fiber open zone 400 also affect the degree of separation of the water dispersible sulfopolyester from the cut multicomponent fiber. Conditions affecting the open process in the fiber open zone 400 include residence time, slurry temperature and shear force, where water temperature in the fiber open zone 400, range of residence time, degree of shear applied, The extent to which the dispersible polymer microfibers are separated and suspended in the continuous aqueous phase of the open microfiber slurry 401 is governed by the need to separate the water dispersible sulfopolyester from the starting multicomponent fiber.

The residence time, temperature and shear forces in the fiber open zone 400 affect the degree of separation of the water dispersible sulfopolyester from the cut multicomponent fiber. The temperature of the fiber open zone 400 may range from about 55 to about 100 ° C, about 60 to about 90 ° C, or about 65 to about 80 ° C. The residence time in the fiber open zone 400 may range from about 5 minutes to about 10 seconds, from about 3 minutes to about 20 seconds, or from about 2 minutes to about 30 seconds. Sufficient mixing is maintained in the fiber open zone 400 to maintain suspension of the cleaved water non-dispersible polymer microfibers to minimize sedimentation of the cleaved microfibers. In another embodiment of the present invention, the mass per unit time of cut water non-dispersible polymer microfibers in fiber open zone 400 is the mass per unit time of water non-dispersible polymer microfibers entering the zone 400. Less than about 5% of the amount of water non-dispersible polymer microfibers entering the zone 400, or less than about 3% of the mass per unit time of water non-dispersible polymer microfibers entering the zone 400, or Less than about 1% of mass per unit time.

Fiber opening in fiber opening zone 400 may be achieved in any device that may allow for acceptable residence time, temperature, and mixing range. Examples of suitable devices include, but are not limited to, stirred batch tanks as shown in FIGS. 6B and 6C, continuous stirred tank reactors, and flows sufficient to minimize solids settling out of the slurry as shown in FIG. 6A. Pipes are included. One example of a unit operation to achieve fiber opening in the fiber open zone 400 is a plug flow reactor, where the heated multicomponent fiber slurry 301 is a zone 400 plug flow device, typically circular Sent to pipe or conduit. The residence time of the material in the plug flow device is calculated by dividing the filled volume in the device by the volume flow rate in the device. The mass velocity in the device is defined as the cross sectional area of the flow channel divided by the volumetric flow of liquid through the device.

In another embodiment of the present invention, the fiber open zone 400 may have a material flow rate in the pipe in the range of 0.1 to about 20 ft / sec, 0.2 to about 10 ft / sec, or about 0.5 to about 5 ft / sec. It may include pipes or conduits. In the case of a flow of fluid or slurry in a pipe or conduit, the Reynolds number is a dimensionless number that is useful for describing turbulence or motion of irregular fluid eddy currents for both direction and time. For flow in a pipe or tube, the Reynolds number is generally defined as:

Where

D _H Is the hydraulic diameter L of the pipe in m;

Q is the volumetric flow rate (m ³ / s),

A is the pipe cross section (m ² ),

υ is the average velocity of the object relative to the fluid in m / s,

μ is the dynamic viscosity of the fluid (Pa · s or N · s / m ² or kg / (m · s)),

v is the dynamic viscosity (v = μ / ρ) (m ² / s),

ρ is the density of the fluid (kg / m ³ ).

For flows in pipes of diameter D , experimental observation shows that for fully developed flows, laminar flow occurs when Re _D is less than 2000, and turbulent flow occurs when Re _D is more than 4000. . Between 2300 and 4000, laminar and turbulent flows are possible ("transition" flows), depending on other factors, such as pipe roughness and flow uniformity.

The fiber open zone 400 may include pipes or conduits to facilitate the opening process, and the Reynolds number of flows through the pipes or conduits in the fiber open zone 400 may be about 2,100 to about 6,000, about 3,000. To about 6,000, or about 3,500 to about 6,000. In other embodiments, the fiber open zone 400 may comprise a pipe or conduit to facilitate the opening process, wherein the Reynolds number of the flow through the pipe or conduit is at least 2,500, at least about 3,500 or at least about 4,000 to be.

The fiber open zone 400 includes a pipe or conduit with a mixing device inserted in the pipe or conduit. The device may comprise an in-line mixing device. The in-line mixing device may be a static mixer without moving parts. In another embodiment, the in-line mixing device comprises a movable portion. Without limitation, such elements are mechanical devices for the purpose of imparting more mixing energy to the heated multicomponent fiber slurry 301, rather than being achieved by flow through the pipe. The device can be inserted at the beginning of the pipe section used as the fiber open zone, at the end of the pipe section, or anywhere in the pipe flow path.

An open fiber slurry stream 401 comprising water non-dispersible polymer microfibers, water and water dispersible sulfopolyester is sent to the first solid-liquid separation zone 500 to send the microfibers and the first mother liquor stream 501. A microfiber product stream 503 can be produced. In one embodiment, the first mother liquor stream 501 comprises water and a water dispersible sulfopolyester.

The weight percent of solids in the open fiber slurry stream 401 can range from about 0.1 to about 20 weight percent, from about 0.3 to about 10 weight percent, from about 0.3 to about 5 weight percent, or from about 0.3 to about 2.5 weight percent. .

 The weight percent of solids in the microfiber product stream 503 may range from about 10 to about 65 weight percent, about 15 to about 50 weight percent, about 25 to about 45 weight percent, or about 30 to about 40 weight percent.

Separating the microfiber product stream 503 from the open fiber slurry stream 401 may be accomplished by any method known in the art. In one embodiment, a wash stream 103 comprising water is sent to the first solid-liquid separation zone 500. The wash stream 103 may be used to wash the microfiber product stream in the filter cloth media in the first solid-liquid separation zone 500 and / or in the first solid-liquid separation zone 500 to produce a liquor stream 502. Up to 100% by weight of the fraction of the liquor stream 502 can be combined with the open fiber slurry stream 401 prior to entering the first solid-liquid separation zone 500. Up to 100% by weight of the fraction of the liquor stream 502 can be sent to the second solid-liquid separation zone 600. The tax liquor stream 502 may contain microfibers. In one embodiment, the g of microfiber mass passing through the filter media with openings of 200 microns or less in the first solid-liquid separation zone 500 ranges from about 1 to 2 g per cm ² of filter area. In another embodiment of the present invention, the filter openings of the filter media in the first solid-liquid separation zone 500 may range from about 43 microns to 3000 microns, about 100 microns to 2000 microns, or about 500 microns to 2000 microns.

Separating the microfiber product stream from the open microfiber slurry in the first solid-liquid separation zone 500 may be accomplished by one or several solid-liquid separation devices. Separation in the first solid-liquid separation zone 500 may be accomplished by a solid-liquid separation device or apparatuses operated in batch and / or continuously. Suitable solid-liquid separation devices in the first solid-liquid separation zone 500 may include, but are not limited to, one of the following: perforated basket centrifuge, continuous vacuum belt filter, batch vacuum nutschfilter, batch perforated Sedimentation tanks, twin wire dewatering devices, continuous horizontal belt filters with compression zones, non-vibrating inclined screen devices with wedge wire filter media, continuous vacuum drum filters, dewatering conveyor belts and the like.

In one embodiment, the first solid-liquid separation zone 500 includes a twin wire dewatering device where an open fiber slurry stream 401 is sent to the tapering gap between a pair of moving filter cloths moving in the same direction. . In the first zone of the twin wire dewatering device, water is drained from the open fiber slurry stream 401 due to gravity and from every narrow gap between the two moving filter cloths. In the downstream zone of the twin wire dewatering device, the two filter cloths and the microfiber material between these two filter cloths are compressed one or more times to mechanically reduce the moisture in the microfiber material. In one embodiment, mechanical dehydration is achieved by passing the two filter cloths and the contained microfiber material through one or more sets of rollers that exert a compressive force on the two filter cloths and the microfiber material therebetween. In another embodiment, mechanical dewatering is accomplished by passing the two filter cloths and the microfiber material through one or more sets of pressure rollers.

In another embodiment of the present invention, the force exerted by mechanical dehydration for each set of pressure rollers ranges from about 25 to about 300 lb per linear inch of filter media width, from about 50 to about 200 per linear inch of filter media width. lb range, or about 70 to about 125 lb per linear inch of filter media width. The microfiber product stream 503 is withdrawn from the twin wire dehydrator as the two filter cloths are separated and divided in the solid discharge zone of the twin wire dehydrator. The thickness of the ejected microfiber material may range from about 0.2 to about 1.5 inches, from about 0.3 to about 1.25 inches, or from about 0.4 to about 1 inch. In one embodiment, the tax stream comprising water is continuously applied to the filter media. In another embodiment, a tax stream comprising water is periodically applied to the filter media.

In another embodiment, the first solid-liquid separation zone 500 includes a belt filter device that includes a gravity drainage zone and a pressurized dewatering zone, as illustrated in FIG. 7. The open microfiber slurry 401 is directed to a tapering gap between a pair of moving filter cloths moving in the same direction, which first passes through the gravity drainage zone and then in a tortuous arrangement of rollers as shown in FIG. 6B. It passes through the included pressurized dehydration zone or press zone. As the belt is fed through the roller, water escapes from the solid. In this process, when the belt passes through the final roller pair, the filter cloth is separated and solids are discharged from the belt filter device.

In another embodiment of the present invention, at least a portion of the water contained in the first mother liquor stream 501 comprising water and the water dispersible sulfopolyester is recovered and recycled. The first mother liquor stream 501 may be recycled to the first solid-liquid separation zone 500. Depending on the efficiency of the first solid-liquid separation zone in the removal of water non-dispersible polymer microfibers, the first mother liquor stream 501 may be a fiber open zone 400, or a heat exchanger zone prior to entering the zone 400. Recycled to 800. The first mother liquor stream 501 may contain a small amount of solids, including water non-dispersible polymer microfibers due to breakthrough and cloth cleaning. In one embodiment, g of water non-dispersible polymer microfiber material passing through the filter media in the first solid separation zone having an opening of 2000 microns or less ranges from about 1 to about 2 g per cm ² of filter area. . Before sending the first mother liquor stream 501 to the first concentration zone 700 and the heat exchange zone 800, in which water non-dispersible polymer microfiber solids may be collected and accumulated negatively. It is desirable to minimize the water non-dispersible polymer microfibers in the stream 501.

The second solid-liquid separation zone 600 removes at least a portion of the water non-dispersible polymer microfiber solids present in the first mother liquor stream 501 so that the second wet cake comprises water non-dispersible microfibers. Function to produce a stream 602 and a second mother liquor stream 601 comprising water and water dispersible sulfopolyester.

In one embodiment, second mother liquor stream 601 is directed to first enrichment zone 700 and / or heat exchanger zone 800, with second mother liquor stream 601 directed to first enrichment zone 700. Weight percent) may range from 0 to 100% and the remainder of the stream is sent to heat exchanger zone 800. The second mother liquor stream 601 may be recycled to the fiber open zone 400, or to the heat exchanger zone 800 prior to being sent to the zone 400. The amount of water dispersible sulfopolyester in the second mother liquor stream sent to the fiber open zone 400 is about 0.01 to about 7 weight percent, or about 0.1 to about 7 weight percent, based on the weight percent of the second mother liquor stream. 0.2 to about 5 weight percent, or about 0.3 to about 3 weight percent.

Any portion of the second mother liquor stream 601 sent to the first concentration zone may be subjected to a separation process to obtain a first recovered water stream 703 and a first polymer concentrate stream 702 enriched in water dispersible sulfopolyester. Resulting in the weight percent of water dispersible sulfopolyester in the first polymer concentrate stream 702 may range from about 5 to about 85 weight percent, from about 10 to about 65 weight percent, or from about 15 to about 45 weight percent. have. The first recovered water stream 703 may be recycled to the fiber open zone 400, or to the heat exchanger zone 800 prior to being sent to the zone 400. The amount of water dispersible sulfopolyester in the second mother liquor stream sent to the fiber open zone 400 is from about 0.01 to about 7 weight percent, or from about 0.1 to about 7 weight percent, based on the weight percent of the second mother liquor stream. 0.2 to about 5 weight percent, or about 0.3 to about 3 weight percent.

Water may be removed from the second mother liquor stream 601 in the first concentration zone 700 by any method known in the art to produce the first polymer concentrated stream 702. In one embodiment, the removal of water comprises an evaporation process by boiling water in a batch or continuous evaporation apparatus. For example, one or more thin film evaporators can be used for this purpose. In another embodiment, membrane technology including nanofiltration media can be used to produce the first polymer concentrate stream 702. In another embodiment, a process including an extraction device can be used to extract the water dispersible polymer from the second mother liquor stream 601 and produce a first polymer concentrate stream 702. The combination of evaporation, membrane and extraction steps may be used to separate the water dispersible polymer from the second mother liquor stream 601 and produce a first polymer concentrate stream 702. The first polymer concentrate stream 702 may then be discharged out of the process.

In one embodiment, first polymer concentrate stream 702 is sent to second concentration zone 900 such that molten polymer stream 903 comprising a water dispersible sulfopolyester, wherein the weight percent of polymer is about 95 to about 100%) and water to produce a vapor stream 902. In one embodiment, the stream 903 comprises a water dispersible sulfopolyester. Suitable devices for the second concentration zone 900 include any device known in the art that can supply an aqueous dispersion of water dispersible polymer and can produce 95% to 100% water dispersible polymer stream 903. . This embodiment includes feeding an aqueous dispersion of the water dispersible sulfopolyester polymer into the second concentration zone 900. The temperature of the feed stream is typically below 100 ° C.

In one embodiment, the second enrichment zone 900 is characterized by at least one device characterized by a jacketed tubular shell containing a rotating transport screw, wherein the transport screw is heated with heat transfer fluid or steam. Both transport and high shear mixing elements). The jacket or shell is vented to remove steam. The shell jacket can be banded to enable other temperature set points along the length of the device. During continuous operation, the first polymer concentrate stream 702 comprises water and water dispersible sulfopolyester, and is fed continuously to the second concentration zone 900. Within the device, there are at least three distinct and different forms of material during steady state. In the device the material first exists as an aqueous dispersion of the water dispersible sulfopolyester polymer. As the aqueous dispersion of sulfopolyester polymer moves through the device, the water evaporates due to the heat of the jacket and internal screws. When enough water has evaporated, the material is in a second form comprising a viscous plug at a temperature below the melting point of the sulfopolyester polymer. The aqueous dispersion cannot flow past this viscous plug and is confined to the first aqueous dispersion zone of the device. Due to the heat of the jacket, the heat of the internally heated screw, and the heat due to the mixed shear forces of this highly viscous plug material, substantially all of the water present in this location is evaporated and the temperature is reached until the melting temperature of the sulfoester is reached. Ascending, a third final physical form of the material comprising the molten sulfopolyester polymer is produced in the device. The molten sulfopolyester polymer then exits the apparatus through an extrusion die and is typically cooled and cut into pellets in any manner known in the art. It is to be understood that the apparatus for the second enrichment zone 900 described above can also be operated in a batch fashion, where a continuous mixture of viscous plug material and finally sulfopolyester melt, starting with an aqueous dispersion, throughout the length of the apparatus Three different physical forms of the above-mentioned substances occur in sequence at different times.

In one embodiment, the steam generated in the second concentration zone 900 may be condensed and sent to the heat exchanger zone 800 and / or discarded and / or sent to the wash stream 103. In another embodiment, the condensed vapor stream 902 comprising water vapor may be sent to the heat exchanger zone 800 to provide at least some of the energy needed to produce the temperature required for the stream 801. The molten polymer stream 903 comprising the water dispersible polymer comprising sulfopolyester in the molten phase may be cooled and chopped into pellets by any method known in the art.

Impurities may be introduced into the process and concentrated in the water recovered and recycled. One or more purge streams 603 and 701 may be used to adjust the concentration of impurities in the second mother liquor 601 and the first recovered water stream 701 to an acceptable level. In one embodiment, a portion of the second mother liquor stream 601 may be isolated and purged from the process. In one embodiment, a portion of the first recovered water stream 701 may be isolated and purged from the process.

In another embodiment of the present invention, a method of preparing a microfiber product stream is provided as shown in FIG. 3A. This way

(A) contacting the treated aqueous stream 103 with a short-cut multicomponent fiber 101 having a length of less than 25 mm in the fiber slurry zone 200 to produce a short-cut multicomponent fiber slurry 201. Wherein the short-cut multicomponent fiber 101 comprises at least one water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer immiscible with the water dispersible sulfopolyester, wherein the treated aqueous stream 103 is a temperature of at least 40 ° C .;

(B) contacting the short-cut multicomponent fiber slurry 201 and the heated aqueous stream 801 in a fiber open zone 400 to remove a portion of the water dispersible sulfopolyester to open the microfiber slurry 401. ), Wherein the open microfiber slurry comprises water non-dispersible polymer microfibers, water dispersible sulfopolyester and water; And

(C) sending the open microfiber slurry 401 to a first solid-liquid separation zone 500 to produce a microfiber product stream 503 and a first mother liquor stream 501, wherein the first mother liquor Stream 501 comprises water and water dispersible sulfopolyester

It includes.

In this embodiment of the present invention, the mixing zone 300 and the fiber open zone 400 as shown in FIG. 4 are combined in one unit operation in the open process zone 1100. Open process zone 1100 includes a fiber slurry zone 200 and a fiber open zone 400.

The treated aqueous stream 103 for use in this method can be generated by sending the aqueous stream 102 to the aqueous treatment band 1000 to produce the treated aqueous stream 103. The aqueous stream contains water. In embodiments of the invention, the monovalent metal cations in the treated aqueous stream 103 may be less than about 1000 ppm, less than about 500 ppm, less than about 100 ppm, or less than about 50 ppm by weight. Removal of divalent and polyvalent metal cations from aqueous stream 102 is one function of aqueous treatment zone 1000. In other embodiments of the invention, the concentrations of divalent and polyvalent metal cations are less than about 50 ppm by weight, less than about 25 ppm by weight, less than about 10 ppm by weight, or less than about 5 ppm by weight. The temperature of stream 103 may range from groundwater temperature to about 40 ° C.

Treatment of aqueous stream 102 in aqueous treatment zone 1000 may be accomplished by any method known in the art. In one embodiment, aqueous treatment zone 1000 includes distillation equipment that generates steam and condenses to produce treated aqueous stream 103. In another embodiment, water can be sent to the reverse osmosis membrane separation zone to remove monovalent and divalent metal cations from the water to produce the treated aqueous stream 103. In another embodiment, water is sent to the ion exchange resin to produce a treated aqueous stream 103 having an acceptable low concentration of metal ions. In another embodiment, water is sent to a commercial softening device to produce a treated aqueous stream 103 having acceptable low concentrations of divalent and polyvalent metal ions. It should be understood that any combination of these water treatment options may be used to achieve the required treated water characteristics.

The treated aqueous stream 103 can be sent to any location needed in the process. In one embodiment, a portion of stream 103 is sent to first solid-liquid separation zone 500 to serve as a wash liquor for solids contained in cloth wash liquor and / or first solid-liquid separation zone 500. .

In one embodiment, at least a portion of the treated aqueous stream 103 is sent to heat exchanger zone 800. In another embodiment, at least a portion of the treated aqueous stream 103 is sent to the fiber slurry zone 200. In another embodiment, at least a portion of the treated aqueous stream 103 is sent to the heat exchanger zone 800 and at least a portion of the treated aqueous stream 103 is sent to the fiber slurry zone 200. One function of the heat exchanger zone 800 is to produce a heated aqueous stream 801 at a specific controlled temperature.

In one embodiment, stream 800, which may be supplied to heat exchanger zone 800, is treated aqueous stream 103 and second mother liquor stream 601. In another embodiment, stream 800, which may be supplied to heat exchanger zone 800, comprises treated aqueous stream 103, first recovered water stream 703, first mother liquor stream 501, and Two mother liquor streams 601.

Apparatus known in the art for regulating the temperature of stream 801, such as but not limited to any heat exchanger utilizing a stream used to provide a portion of the required energy, used to provide a portion of the required energy Any heat exchanger using a heat transfer fluid, any heat exchanger using an electrical heating element used to provide some of the required energy, and steam is condensed and the condensate mixed with water supplied to the heat exchanger zone 800 Any vessel or tank using direct steam injection can be used. The multicomponent fiber stream 90 is sent to the fiber cut zone 100 to produce a cut multicomponent fiber stream 101. Multicomponent fibers may have any multicomponent structure known in the art. Multicomponent fibers include water dispersible sulfopolyesters and water non-dispersible polymers as described herein above.

Any device known in the art can be used to cut the multicomponent fiber stream 90 to produce the cut multicomponent fiber stream 101. In one embodiment, the length of the cut fibers in the cut multicomponent fiber stream 101 is less than about 50 mm. In other embodiments, the length of the cut fibers in the cut multicomponent fiber stream 101 is less than about 25 mm, less than about 20 mm, less than about 15 mm, less than about 10 mm, less than about 5 mm, or about 2.5 mm. Is less than.

A portion of the chopped multicomponent fiber stream 101 and a heated treated aqueous stream 801 is sent to the fiber slurry zone 200 to produce a chopped multicomponent fiber slurry 201 comprising water and chopped multicomponent fibers. Create In one embodiment, the weight percent of the chopped microfibers in the chopped multicomponent fiber slurry 201 is from about 35 wt% to about 1 wt%, from about 25 wt% to about 1 wt%, from about 15 wt% to about 1 weight percent, or about 7 weight percent to about 1 weight percent.

The temperature of the chopped multicomponent fiber slurry 201 may range from about 5 to about 45 ° C, about 10 to about 35 ° C, or about 10 to about 25 ° C. In one embodiment, fiber slurry zone 200 comprises a tank with sufficient agitation to produce a suspension in a continuous aqueous phase of chopped multicomponent fibers.

Any device known in the art to be suitable for mixing solids with water and maintaining a suspension in the continuous aqueous phase of the resulting chopped multicomponent fibers may be used in the fiber slurry zone 200. Fiber slurry zone 200 may include a batch or continuous mixing device operated in a continuous or batch mode. Appropriate devices for use in the fiber slurry zone 200 include, but are not limited to, a hydro-pulpator, a continuous stirred tank reactor, and a tank with agitation operated in batch mode.

The chopped multicomponent fiber slurry 201 may then be sent to the fiber open zone 400. One function of the fiber open zone 400 is to separate the water dispersible polymer from the cut multicomponent fibers so that at least a portion of the water non-dispersible polymer microfibers are separated from the cut multicomponent fiber fibers to open the micro It is to be suspended in the fiber slurry (401). In another embodiment of the present invention, about 50 to about 100 weight percent of the water non-dispersible polymer microfibers contained in the chopped multicomponent fiber slurry 201 is contained in the open microfiber slurry 401. It is suspended as a non-dispersible polymer microfiber and is no longer part of the cut multicomponent fiber. In other embodiments, about 75 to about 100 weight percent, about 90 to about 100 weight percent, or about 95 to about 100 weight percent of the water non-dispersible polymer microfibers contained in the cut multicomponent fiber stream 201. Is suspended in the open microfiber slurry 401 as a water non-dispersible polymer microfiber and is no longer part of the cut multicomponent fiber.

The diameter or denier of the starting cut multicomponent fiber in stream 201 affects the degree of separation of the water dispersible sulfopolyester from the multicomponent fiber in the fiber open zone 400. Typical multicomponent fiber types generally have diameters in the range of about 12 microns to about 20 microns. Useful multicomponent fibers can have larger starting diameters of diameter sizes of at least about 40 microns. The time required to separate the desired amount of water dispersible sulfopolyester from the chopped multicomponent fibers increases with increasing diameter of the chopped multicomponent fibers in stream 201.

The residence time, temperature and shear forces in the fiber open zone 400 also affect the degree of separation of the water dispersible sulfopolyester from the cut multicomponent fiber. Conditions affecting the open process in the fiber open zone 400 include residence time, slurry temperature and shear force, where water temperature in the fiber open zone 400, range of residence time, degree of shear applied, -The dispersion polymer microfibers are dependent upon the need to separate the water dispersible sulfopolyester from the starting multicomponent fiber to a degree sufficient to be separated and suspended in the continuous aqueous phase of the open microfiber slurry 401.

The residence time, temperature and shear forces in the fiber open zone 400 affect the degree of separation of the water dispersible sulfopolyester from the cut multicomponent fiber. The temperature of the fiber open zone 400 may range from about 55 to about 100 ° C, about 60 to about 90 ° C, or about 65 to about 80 ° C. The residence time in the fiber open zone 400 may range from about 5 minutes to about 10 seconds, from about 3 minutes to about 20 seconds, or from about 2 minutes to about 30 seconds. Sufficient mixing is maintained in the fiber open zone 400 to maintain suspension of the cleaved water non-dispersible polymer microfibers to minimize sedimentation of the cleaved microfibers. In another embodiment of the present invention, the mass per unit time of cut water non-dispersible polymer microfibers in fiber open zone 400 is the mass per unit time of water non-dispersible polymer microfibers entering the zone 400. Less than about 5% of the amount of water non-dispersible polymer microfibers entering the zone 400, or less than about 3% of the mass per unit time of water non-dispersible polymer microfibers entering the zone 400, or Less than about 1% of mass per unit time.

Fiber opening in fiber opening zone 400 may be achieved in any device that may allow for acceptable residence time, temperature, and mixing range. Examples of suitable devices include, but are not limited to, stirred batch tanks as shown in FIGS. 6B and 6C, continuous stirred tank reactors, and flows sufficient to minimize solids settling out of the slurry as shown in FIG. 6A. Pipes are included. One example of a unit operation to achieve fiber opening in the fiber open zone 400 is a plug flow reactor, where the heated multicomponent fiber slurry 301 is a zone 400 plug flow device, typically circular Sent to pipe or conduit. The residence time of the material in the plug flow device is calculated by dividing the filled volume in the device by the volume flow rate in the device. The mass velocity in the device is defined as the cross sectional area of the flow channel divided by the volumetric flow of liquid through the device.

In another embodiment of the present invention, the fiber open zone 400 may have a material flow rate in the pipe in the range of 0.1 to about 20 ft / sec, 0.2 to about 10 ft / sec, or about 0.5 to about 5 ft / sec. It may include pipes or conduits. For the flow of a fluid or slurry in a pipe or conduit, the Reynolds number is a dimensionless number that is useful for describing turbulence or movement of irregular fluid vortices for both direction and time. For flow in a pipe or tube, the Reynolds number is generally defined as:

Where

D _H Is the hydraulic diameter L of the pipe in m;

Q is the volumetric flow rate (m ³ / s),

A is the pipe cross section (m ² ),

υ is the average velocity of the object relative to the fluid in m / s,

μ is the dynamic viscosity of the fluid (Pa · s or N · s / m ² or kg / (m · s)),

v is the dynamic viscosity (v = μ / ρ) (m ² / s),

ρ is the density of the fluid (kg / m ³ ).

For flow in a pipe of diameter D , experimental observation shows that for fully developed flow a laminar flow occurs when Re _D is less than 2000 and a turbulent flow occurs when Re _D is greater than 4000. Between 2300 and 4000, laminar and turbulent flows are possible ("transition" flows), depending on other factors, such as pipe roughness and flow uniformity.

The fiber open zone 400 may include pipes or conduits to facilitate the opening process, and the Reynolds number of flows through the pipes or conduits in the fiber open zone 400 may be about 2,100 to about 6,000, about 3,000. To about 6,000, or about 3,500 to about 6,000. In other embodiments, the fiber open zone 400 may comprise a pipe or conduit to facilitate the opening process, wherein the Reynolds number of the flow through the pipe or conduit is at least 2,500, at least about 3,500 or at least about 4,000 to be.

The fiber open zone 400 includes a pipe or conduit with a mixing device inserted in the pipe or conduit. The device may comprise an in-line mixing device. The in-line mixing device may be a static mixer without moving parts. In another embodiment, the in-line mixing device comprises a movable portion. Without limitation, such elements are mechanical devices for the purpose of imparting more mixing energy to the heated multicomponent fiber slurry 301, rather than being achieved by flow through the pipe. The device can be inserted at the beginning of the pipe section used as the fiber open zone, at the end of the pipe section, or anywhere in the pipe flow path.

An open fiber slurry stream 401 comprising water non-dispersible polymer microfibers, water and water dispersible sulfopolyester is sent to the first solid-liquid separation zone 500 to send the microfibers and the first mother liquor stream 501. A microfiber product stream 503 can be produced. In one embodiment, the first mother liquor stream 501 comprises water and a water dispersible sulfopolyester.

The weight percent of solids in the open fiber slurry stream 401 can range from about 0.1 to about 20 weight percent, from about 0.3 to about 10 weight percent, from about 0.3 to about 5 weight percent, or from about 0.3 to about 2.5 weight percent. .

 The weight percent of solids in the microfiber product stream 503 may range from about 10 to about 65 weight percent, about 15 to about 50 weight percent, about 25 to about 45 weight percent, or about 30 to about 40 weight percent.

Separating the microfiber product stream 503 from the open fiber slurry stream 401 may be accomplished by any method known in the art. In one embodiment, a wash stream 103 comprising water is sent to the first solid-liquid separation zone 500. The wash stream 103 may be used to wash the microfiber product stream in the filter cloth media in the first solid-liquid separation zone 500 and / or in the first solid-liquid separation zone 500 to produce a liquor stream 502. Up to 100% by weight of the fraction of the liquor stream 502 can be combined with the open fiber slurry stream 401 prior to entering the first solid-liquid separation zone 500. Up to 100% by weight of the fraction of the liquor stream 502 can be sent to the second solid-liquid separation zone 600. The tax liquor stream 502 may contain microfibers. In one embodiment, the g of microfiber mass passing through the filter media with openings of 200 microns or less in the first solid-liquid separation zone 500 ranges from about 1 to 2 g per cm ² of filter area. In another embodiment of the present invention, the filter openings of the filter media in the first solid-liquid separation zone 500 may range from about 43 microns to 3000 microns, about 100 microns to 2000 microns, or about 500 microns to 2000 microns.

Separating the microfiber product stream from the open microfiber slurry in the first solid-liquid separation zone 500 may be accomplished by one or several solid-liquid separation devices. Separation in the first solid-liquid separation zone 500 may be accomplished by a solid-liquid separation device or apparatuses operated in batch and / or continuously. Suitable solid-liquid separation devices in the first solid-liquid separation zone 500 may include, but are not limited to, one of the following: perforated basket centrifuge, continuous vacuum belt filter, batch vacuum nutschfilter, batch perforated Sedimentation tanks, twin wire dewatering devices, continuous horizontal belt filters with compression zones, non-vibrating inclined screen devices with wedge wire filter media, continuous vacuum drum filters, dewatering conveyor belts and the like.

In one embodiment, the first solid-liquid separation zone 500 includes a twin wire dewatering device where an open fiber slurry stream 401 is sent to the tapering gap between a pair of moving filter cloths moving in the same direction. . In the first zone of the twin wire dewatering device, water is drained from the open fiber slurry stream 401 due to gravity and from every narrow gap between the two moving filter cloths. In the downstream zone of the twin wire dewatering device, the two filter cloths and the microfiber material between these two filter cloths are compressed one or more times to mechanically reduce the moisture in the microfiber material. In one embodiment, mechanical dehydration is achieved by passing the two filter cloths and the contained microfiber material through one or more sets of rollers that exert a compressive force on the two filter cloths and the microfiber material therebetween. In another embodiment, mechanical dewatering is accomplished by passing the two filter cloths and the microfiber material through one or more sets of pressure rollers.

In another embodiment of the present invention, the force exerted by mechanical dehydration for each set of pressure rollers ranges from about 25 to about 300 lb per linear inch of filter media width, from about 50 to about 200 per linear inch of filter media width. lb range, or about 70 to about 125 lb per linear inch of filter media width. The microfiber product stream 503 is withdrawn from the twin wire dehydrator as the two filter cloths are separated and divided in the solid discharge zone of the twin wire dehydrator. The thickness of the ejected microfiber material may range from about 0.2 to about 1.5 inches, from about 0.3 to about 1.25 inches, or from about 0.4 to about 1 inch. In one embodiment, the tax stream comprising water is continuously applied to the filter media. In another embodiment, a tax stream comprising water is periodically applied to the filter media.

In another embodiment, the first solid-liquid separation zone 500 includes a belt filter device that includes a gravity drainage zone and a pressurized dewatering zone, as illustrated in FIG. 7. The open microfiber slurry 401 is directed to a tapering gap between a pair of moving filter cloths moving in the same direction, which first passes through the gravity drainage zone and then in a tortuous arrangement of rollers as shown in FIG. 6B. It passes through the included pressurized dehydration zone or press zone. As the belt is fed through the roller, water escapes from the solid. In this process, when the belt passes through the final roller pair, the filter cloth is separated and solids are discharged from the belt filter device.

In another embodiment of the present invention, at least a portion of the water contained in the first mother liquor stream 501 comprising water and the water dispersible sulfopolyester is recovered and recycled. The first mother liquor stream 501 may be recycled to the first solid-liquid separation zone 500. Depending on the efficiency of the first solid-liquid separation zone in the removal of water non-dispersible polymer microfibers, the first mother liquor stream 501 may be a fiber open zone 400, or a heat exchanger zone prior to entering the zone 400. Recycled to 800. The first mother liquor stream 501 may contain a small amount of solids comprising water non-dispersible polymer microfibers due to penetration and cloth cleaning. In one embodiment, g of water non-dispersible polymer microfiber material passing through the filter media in the first solid separation zone having an opening of 2000 microns or less ranges from about 1 to about 2 g per cm ² of filter area. . Before sending the first mother liquor stream 501 to the first concentration zone 700 and the heat exchange zone 800, in which water non-dispersible polymer microfiber solids may be collected and accumulated negatively. It is desirable to minimize the water non-dispersible polymer microfibers in the stream 501.

The second solid-liquid separation zone 600 removes at least a portion of the water non-dispersible polymer microfiber solids present in the first mother liquor stream 501 so that the second wet cake comprises water non-dispersible microfibers. Function to produce a stream 602 and a second mother liquor stream 601 comprising water and water dispersible sulfopolyester.

In one embodiment, second mother liquor stream 601 is directed to first enrichment zone 700 and / or heat exchanger zone 800, with second mother liquor stream 601 directed to first enrichment zone 700. Weight percent) may range from 0 to 100% and the remainder of the stream is sent to heat exchanger zone 800. The second mother liquor stream 601 may be recycled to the fiber open zone 400, or to the heat exchanger zone 800 prior to being sent to the zone 400. The amount of water dispersible sulfopolyester in the second mother liquor stream sent to the fiber open zone 400 is about 0.01 to about 7 weight percent, or about 0.1 to about 7 weight percent, based on the weight percent of the second mother liquor stream. 0.2 to about 5 weight percent, or about 0.3 to about 3 weight percent.

Any portion of the second mother liquor stream 601 sent to the first concentration zone may be subjected to a separation process to obtain a first recovered water stream 703 and a first polymer concentrate stream 702 enriched in water dispersible sulfopolyester. Resulting in the weight percent of water dispersible sulfopolyester in the first polymer concentrate stream 702 may range from about 5 to about 85 weight percent, from about 10 to about 65 weight percent, or from about 15 to about 45 weight percent. have. The first recovered water stream 703 may be recycled to the fiber slurry zone 200, the fiber open zone 400, or to the heat exchanger zone 800 before being sent to the zone 200 and / or 400. have. The amount of water dispersible sulfopolyester in the second mother liquor stream sent to the fiber open zone 400 is from about 0.01 to about 7 weight percent, or from about 0.1 to about 7 weight percent, based on the weight percent of the second mother liquor stream. 0.2 to about 5 weight percent, or about 0.3 to about 3 weight percent.

Water may be removed from the second mother liquor stream 601 in the first concentration zone 700 by any method known in the art to produce the first polymer concentrated stream 702. In one embodiment, the removal of water comprises an evaporation process by boiling water in a batch or continuous evaporation apparatus. For example, one or more thin film evaporators can be used for this purpose.

In another embodiment, membrane technology including nanofiltration media can be used to produce the first polymer concentrate stream 702. In another embodiment, a process including an extraction device can be used to extract the water dispersible polymer from the second mother liquor stream 601 and produce a first polymer concentrate stream 702. The combination of evaporation, membrane and extraction steps may be used to separate the water dispersible polymer from the second mother liquor stream 601 and produce a first polymer concentrate stream 702. The first polymer concentrate stream 702 may then be discharged out of the process.

In one embodiment, first polymer concentrate stream 702 is sent to second concentration zone 900 such that molten polymer stream 903 comprising a water dispersible sulfopolyester, wherein the weight percent of polymer is about 95 to about 100%) and water to produce a vapor stream 902. In one embodiment, the stream 903 comprises a water dispersible sulfopolyester. Suitable devices for the second concentration zone 900 include any device known in the art that can supply an aqueous dispersion of water dispersible polymer and can produce 95% to 100% water dispersible polymer stream 903. . This embodiment includes feeding an aqueous dispersion of the water dispersible sulfopolyester polymer into the second concentration zone 900. The temperature of the feed stream is typically below 100 ° C.

In one embodiment, the second enrichment zone 900 is characterized by at least one device characterized by a jacketed tubular shell containing a rotating transport screw, wherein the transport screw is heated with heat transfer fluid or steam. Both transport and high shear mixing elements). The jacket or shell is vented to remove steam. The shell jacket can be banded to enable other temperature set points along the length of the device. During continuous operation, the first polymer concentrate stream 702 comprises water and water dispersible sulfopolyester, and is fed continuously to the second concentration zone 900. Within the device, there are at least three distinct and different forms of material during steady state. In the device the material first exists as an aqueous dispersion of the water dispersible sulfopolyester polymer. As the aqueous dispersion of sulfopolyester polymer moves through the device, the water evaporates due to the heat of the jacket and internal screws. When enough water has evaporated, the material is in a second form comprising a viscous plug at a temperature below the melting point of the sulfopolyester polymer. The aqueous dispersion cannot flow past this viscous plug and is confined to the first aqueous dispersion zone of the device. Due to the heat of the jacket, the heat of the internally heated screw, and the heat due to the mixed shear forces of this highly viscous plug material, substantially all of the water present in this location is evaporated and the temperature is reached until the melting temperature of the sulfoester is reached. Ascending, a third final physical form of the material comprising the molten sulfopolyester polymer is produced in the device. The molten sulfopolyester polymer then exits the apparatus through an extrusion die and is typically cooled and cut into pellets in any manner known in the art. It is to be understood that the apparatus for the second enrichment zone 900 described above can also be operated in a batch fashion, where a continuous mixture of viscous plug material and finally sulfopolyester melt, starting with an aqueous dispersion, throughout the length of the apparatus Three different physical forms of the above-mentioned substances occur in sequence at different times.

In one embodiment, the steam generated in the second concentration zone 900 may be condensed and sent to the heat exchanger zone 800 and / or discarded and / or sent to the wash stream 103. In another embodiment, the condensed vapor stream 902 comprising water vapor may be sent to the heat exchanger zone 800 to provide at least some of the energy needed to produce the temperature required for the stream 801. The molten polymer stream 903 comprising the water dispersible polymer comprising sulfopolyester in the molten phase may be cooled and chopped into pellets by any method known in the art.

Impurities may be introduced into the process and concentrated in the water recovered and recycled. One or more purge streams 603 and 701 may be used to adjust the concentration of impurities in the second mother liquor 601 and the first recovered water stream 701 to an acceptable level. In one embodiment, a portion of the second mother liquor stream 601 may be isolated and purged from the process. In one embodiment, a portion of the first recovered water stream 701 may be isolated and purged from the process.

In another embodiment of the present invention, a method of preparing a microfiber product stream is provided as shown in FIG. 3B. This way

(A) contacting the short-cut multicomponent fiber 101 having a length of less than 25 mm in the mixing zone with the heated aqueous stream 801 to produce a short-cut multicomponent fiber slurry 301, wherein Short-cut multicomponent fiber 101 comprises at least one water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer that is immiscible with the water dispersible sulfopolyester, wherein the heated aqueous stream is at least 40 ° C. Temperature;

(B) directing the short-cut multicomponent fiber slurry 301, and optionally, heated aqueous stream 801, to the fiber open zone 400 to remove a portion of the water dispersible sulfopolyester to open the micro Creating a fiber slurry 401, wherein the open microfiber slurry 401 comprises water non-dispersible polymer microfibers, water dispersible sulfopolyester and water; And

(C) sending the open microfiber slurry 401 to a first solid-liquid separation zone 500 to produce a microfiber product stream 503 and a first mother liquor stream 501, wherein the first mother liquor Stream 501 comprises water and water dispersible sulfopolyester

It includes.

In this embodiment of the present invention as shown in FIG. 3B, the fiber slurry zone 200 and the fiber mixing zone 300 are combined in one unit operation in the open process zone 1100. Open process zone 1100 includes a mixed zone 200 and a fiber open zone 400.

The treated aqueous stream 103 for use in this method can be generated by sending the aqueous stream 102 to the aqueous treatment band 1000 to produce the treated aqueous stream 103. The aqueous stream contains water. In embodiments of the invention, the monovalent metal cations in the treated aqueous stream 103 may be less than about 1000 ppm, less than about 500 ppm, less than about 100 ppm, or less than about 50 ppm by weight. Removal of divalent and polyvalent metal cations from aqueous stream 102 is one function of aqueous treatment zone 1000. In other embodiments of the invention, the concentrations of divalent and polyvalent metal cations are less than about 50 ppm by weight, less than about 25 ppm by weight, less than about 10 ppm by weight, or less than about 5 ppm by weight. The temperature of stream 103 may range from groundwater temperature to about 40 ° C.

Treatment of aqueous stream 102 in aqueous treatment zone 1000 may be accomplished by any method known in the art. In one embodiment, aqueous treatment zone 1000 includes distillation equipment that generates steam and condenses to produce treated aqueous stream 103. In another embodiment, water can be sent to the reverse osmosis membrane separation zone to remove monovalent and divalent metal cations from the water to produce the treated aqueous stream 103. In another embodiment, water is sent to the ion exchange resin to produce a treated aqueous stream 103 having an acceptable low concentration of metal ions. In another embodiment, water is sent to a commercial softening device to produce a treated aqueous stream 103 having acceptable low concentrations of divalent and polyvalent metal ions. It should be understood that any combination of these water treatment options may be used to achieve the required treated water characteristics.

The treated aqueous stream 103 can be sent to any location needed in the process. In one embodiment, a portion of stream 103 is sent to first solid-liquid separation zone 500 to serve as a wash liquor for solids contained in cloth wash liquor and / or first solid-liquid separation zone 500. .

In one embodiment, at least a portion of the treated aqueous stream 103 is sent to heat exchanger zone 800. In another embodiment, at least a portion of the treated aqueous stream 103 is sent to the mixing zone 300. In another embodiment, at least a portion of the treated aqueous stream 103 is sent to heat exchanger zone 800 and at least a portion of the treated aqueous stream 103 is sent to mixed zone 300. One function of the heat exchanger zone 800 is to produce a heated aqueous stream 801 at a specific controlled temperature.

In one embodiment, the streams that may be supplied to the heat exchanger zone 800 are treated aqueous stream 103 and second mother liquor stream 601. In another embodiment, stream 800, which may be supplied to heat exchanger zone 800, comprises treated aqueous stream 103, first recovered water stream 703, first mother liquor stream 501, and Two mother liquor streams 601.

Any device known in the art for regulating the temperature of stream 801, such as, but not limited to, any heat exchanger utilizing a stream used to provide a portion of the required energy, to provide a portion of the required energy Any heat exchanger using heat transfer fluid used, any heat exchanger using an electrical heating element used to provide some of the required energy, and water condensed and the condensate supplied to heat exchanger zone 800 Any vessel or tank using direct steam injection to be mixed may be used. The multicomponent fiber stream 90 is sent to the fiber cut zone 100 to produce a cut multicomponent fiber stream 101. Multicomponent fibers may have any multicomponent structure known in the art. Multicomponent fibers include water dispersible sulfopolyesters and water non-dispersible polymers as described herein above.

Any device known in the art can be used to cut the multicomponent fiber stream 90 to produce the cut multicomponent fiber stream 101. In one embodiment, the length of the cut fibers in the cut multicomponent fiber stream 101 is less than about 50 mm. In other embodiments, the length of the cut fibers in the cut multicomponent fiber stream 101 is less than about 25 mm, less than about 20 mm, less than about 15 mm, less than about 10 mm, less than about 5 mm, or about 2.5 mm. Is less than.

A portion of the chopped multicomponent fiber stream 101 and the heated treated aqueous stream 801 is sent to the mixing zone 300 to produce a heated multicomponent fiber slurry 301 comprising water and chopped multicomponent fibers. Create

The temperature of the heated multicomponent fiber slurry 301 is such as to separate the water non-dispersible polymer portion of the cut multicomponent fiber from the water non-dispersible polymer portion of the cut multicomponent fiber in the fiber open region 400. affect. In another embodiment of the present invention, the temperature of the heated multicomponent fiber slurry 301 may range from about 55 to about 100 ° C, about 60 to about 90 ° C, or about 65 to about 80 ° C.

The weight percent of the cut microfibers in the heated multicomponent fiber slurry 301 can be controlled. In other embodiments, the weight percent of the cut microfibers in the heated multicomponent fiber slurry 301 is from about 10 wt% to about 0.1 wt%, from about 5 wt% to about 0.2 wt%, from about 3 wt% to about 0.3 wt% %, Or from about 2% to about 0.4% by weight.

Any device known in the art that can mix the heated aqueous stream 801 with the chopped multicomponent fiber 101 can be used for the mixing zone 300. Suitable devices include both continuous and batch mixing devices. In one embodiment, a mixing device suitable for mixing zone 300 includes a tank and a stirrer. In another embodiment, a suitable mixing device comprises a pipe or conduit.

In other embodiments, a mixing device suitable for mixing zone 300 is a pipe or conduit with a diameter such that the velocity in the conduit is sufficient to mix the cut multicomponent fiber slurry 201 and the heated aqueous stream 801. Wherein less than about 2 weight percent, less than about 1 weight percent, or less than about 0.5 weight percent of the cut multicomponent material introduced per minute into the conduit is sedimented and accumulated in the conduit.

The heated multicomponent fiber slurry 301 may then be sent to the fiber open zone 400. One function of the fiber open zone 400 is to separate the water dispersible polymer from the cut multicomponent fibers so that at least a portion of the water non-dispersible polymer microfibers are separated from the cut multicomponent fiber fibers to open the micro It is to be suspended in the fiber slurry (401). In another embodiment of the present invention, about 50 to about 100 weight percent of the water non-dispersible polymer microfibers contained in the chopped multicomponent fiber slurry 201 is contained in the open microfiber slurry 401. It is suspended as a non-dispersible polymer microfiber and is no longer part of the cut multicomponent fiber. In other embodiments, about 75 to about 100 weight percent, about 90 to about 100 weight percent, or about 95 to about 100 weight percent of the water non-dispersible polymer microfibers contained in the cut multicomponent fiber stream 201. Is suspended in the open microfiber slurry 401 as a water non-dispersible polymer microfiber and no longer part of the cut multicomponent fiber.

The diameter or denier of the starting cut multicomponent fiber in stream 201 affects the degree of separation of the water dispersible sulfopolyester from the multicomponent fiber in the fiber open zone 400. Typical multicomponent fiber types generally have diameters in the range of about 12 microns to about 20 microns. Useful multicomponent fibers can have larger starting diameters of diameter sizes of at least about 40 microns. The time required to separate the desired amount of water dispersible sulfopolyester from the chopped multicomponent fibers increases with increasing diameter of the chopped multicomponent fibers in stream 201.

The residence time, temperature and shear forces in the fiber open zone 400 also affect the degree of separation of the water dispersible sulfopolyester from the cut multicomponent fiber. Conditions affecting the open process in the fiber open zone 400 include residence time, temperature and shear force, where the water temperature in the fiber open zone 400, the range of residence time, and the degree of shear applied, It is dictated by the need to separate the water dispersible sulfopolyester from the starting multicomponent fiber to a degree sufficient to dispersible polymer microfibers separate and suspended in the continuous aqueous phase of the open microfiber slurry 401.

The residence time, temperature and shear forces in the fiber open zone 400 affect the degree of separation of the water dispersible sulfopolyester from the cut multicomponent fiber. The temperature of the fiber open zone 400 may range from about 55 to about 100 ° C, about 60 to about 90 ° C, or about 65 to about 80 ° C. The residence time in the fiber open zone 400 may range from about 5 minutes to about 10 seconds, from about 3 minutes to about 20 seconds, or from about 2 minutes to about 30 seconds. Sufficient mixing is maintained in the fiber open zone 400 to maintain suspension of the cleaved water non-dispersible polymer microfibers to minimize sedimentation of the cleaved microfibers. In another embodiment of the present invention, the mass per unit time of cut water non-dispersible polymer microfibers in fiber open zone 400 is the mass per unit time of water non-dispersible polymer microfibers entering the zone 400. Less than about 5% of the amount of water non-dispersible polymer microfibers entering the zone 400, or less than about 3% of the mass per unit time of water non-dispersible polymer microfibers entering the zone 400, or Less than about 1% of mass per unit time.

Fiber opening in fiber opening zone 400 may be achieved in any device that may allow for acceptable residence time, temperature, and mixing range. Examples of suitable devices include, but are not limited to, stirred batch tanks as shown in FIGS. 6B and 6C, continuous stirred tank reactors, and flows sufficient to minimize solids settling out of the slurry as shown in FIG. 6A. Pipes are included. One example of a unit operation to achieve fiber opening in the fiber open zone 400 is a plug flow reactor, where the heated multicomponent fiber slurry 301 is a zone 400 plug flow device, typically circular Sent to pipe or conduit. The residence time of the material in the plug flow device is calculated by dividing the filled volume in the device by the volume flow rate in the device. The mass velocity in the device is defined as the cross sectional area of the flow channel divided by the volumetric flow of liquid through the device.

In another embodiment of the present invention, the fiber open zone 400 may have a material flow rate in the pipe in the range of 0.1 to about 20 ft / sec, 0.2 to about 10 ft / sec, or about 0.5 to about 5 ft / sec. It may include pipes or conduits. For the flow of a fluid or slurry in a pipe or conduit, the Reynolds number is a dimensionless number that is useful for describing turbulence or movement of irregular fluid vortices for both direction and time. For flow in a pipe or tube, the Reynolds number is generally defined as:

Where

D _H Is the hydraulic diameter L of the pipe in m;

Q is the volumetric flow rate (m ³ / s),

A is the pipe cross section (m ² ),

υ is the average velocity of the object relative to the fluid in m / s,

μ is the dynamic viscosity of the fluid (Pa · s or N · s / m ² or kg / (m · s)),

v is the dynamic viscosity (v = μ / ρ) (m ² / s),

ρ is the density of the fluid (kg / m ³ ).

For flow in a pipe of diameter D , experimental observation shows that for fully developed flow a laminar flow occurs when Re _D is less than 2000 and a turbulent flow occurs when Re _D is greater than 4000. Between 2300 and 4000, laminar and turbulent flows are possible ("transition" flows), depending on other factors, such as pipe roughness and flow uniformity.

The fiber open zone 400 may include pipes or conduits to facilitate the opening process, and the Reynolds number of flows through the pipes or conduits in the fiber open zone 400 may be about 2,100 to about 6,000, about 3,000. To about 6,000, or about 3,500 to about 6,000. In other embodiments, the fiber open zone 400 may comprise a pipe or conduit to facilitate the opening process, wherein the Reynolds number of the flow through the pipe or conduit is at least 2,500, at least about 3,500 or at least about 4,000 to be.

The fiber open zone 400 includes a pipe or conduit with a mixing device inserted in the pipe or conduit. The device may comprise an in-line mixing device. The in-line mixing device may be a static mixer without moving parts. In another embodiment, the in-line mixing device comprises a movable portion. Without limitation, such elements are mechanical devices for the purpose of imparting more mixing energy to the heated multicomponent fiber slurry 301, rather than being achieved by flow through the pipe. The device can be inserted at the beginning of the pipe section used as the fiber open zone, at the end of the pipe section, or anywhere in the pipe flow path.

An open fiber slurry stream 401 comprising water non-dispersible polymer microfibers, water and water dispersible sulfopolyester is sent to the first solid-liquid separation zone 500 to send the microfibers and the first mother liquor stream 501. A microfiber product stream 503 can be produced. In one embodiment, the first mother liquor stream 501 comprises water and a water dispersible sulfopolyester.

The weight percent of solids in the open fiber slurry stream 401 can range from about 0.1 to about 20 weight percent, from about 0.3 to about 10 weight percent, from about 0.3 to about 5 weight percent, or from about 0.3 to about 2.5 weight percent. .

 The weight percent of solids in the microfiber product stream 503 may range from about 10 to about 65 weight percent, about 15 to about 50 weight percent, about 25 to about 45 weight percent, or about 30 to about 40 weight percent.

Separating the microfiber product stream 503 from the open fiber slurry stream 401 may be accomplished by any method known in the art. In one embodiment, a wash stream 103 comprising water is sent to the first solid-liquid separation zone 500. The wash stream 103 may be used to wash the microfiber product stream in the filter cloth media in the first solid-liquid separation zone 500 and / or in the first solid-liquid separation zone 500 to produce a liquor stream 502. Up to 100% by weight of the fraction of the liquor stream 502 can be combined with the open fiber slurry stream 401 prior to entering the first solid-liquid separation zone 500. Up to 100% by weight of the fraction of the liquor stream 502 can be sent to the second solid-liquid separation zone 600. The tax liquor stream 502 may contain microfibers. In one embodiment, the g of microfiber mass passing through the filter media with openings of 200 microns or less in the first solid-liquid separation zone 500 ranges from about 1 to 2 g per cm ² of filter area. In another embodiment of the present invention, the filter openings of the filter media in the first solid-liquid separation zone 500 may range from about 43 microns to 3000 microns, about 100 microns to 2000 microns, or about 500 microns to 2000 microns.

Separating the microfiber product stream from the open microfiber slurry in the first solid-liquid separation zone 500 may be accomplished by one or several solid-liquid separation devices. Separation in the first solid-liquid separation zone 500 may be accomplished by a solid-liquid separation device or apparatuses operated in batch and / or continuously. Suitable solid-liquid separation devices in the first solid-liquid separation zone 500 may include, but are not limited to, one of the following: perforated basket centrifuge, continuous vacuum belt filter, batch vacuum nutschfilter, batch perforated Sedimentation tanks, twin wire dewatering devices, continuous horizontal belt filters with compression zones, non-vibrating inclined screen devices with wedge wire filter media, continuous vacuum drum filters, dewatering conveyor belts and the like.

In one embodiment, the first solid-liquid separation zone 500 includes a twin wire dewatering device where an open fiber slurry stream 401 is sent to the tapering gap between a pair of moving filter cloths moving in the same direction. . In the first zone of the twin wire dewatering device, water is drained from the open fiber slurry stream 401 due to gravity and from every narrow gap between the two moving filter cloths. In the downstream zone of the twin wire dewatering device, the two filter cloths and the microfiber material between these two filter cloths are compressed one or more times to mechanically reduce the moisture in the microfiber material. In one embodiment, mechanical dehydration is achieved by passing the two filter cloths and the contained microfiber material through one or more sets of rollers that exert a compressive force on the two filter cloths and the microfiber material therebetween. In another embodiment, mechanical dewatering is accomplished by passing the two filter cloths and the microfiber material through one or more sets of pressure rollers and a fixed surface.

In other embodiments of the invention, the force exerted by mechanical dehydration ranges from about 25 to about 300 lbs per linear inch of filter media width, from about 50 to about 200 lbs per linear inch of filter media width, or filter media It may range from about 70 to about 125 lbs per linear inch of width. The microfiber product stream 503 is withdrawn from the twin wire dehydrator as the two filter cloths are separated and divided in the solid discharge zone of the twin wire dehydrator. The thickness of the ejected microfiber material may range from about 0.2 to about 1.5 inches, from about 0.3 to about 1.25 inches, or from about 0.4 to about 1 inch. In one embodiment, the tax stream comprising water is continuously applied to the filter media. In another embodiment, a tax stream comprising water is periodically applied to the filter media.

In another embodiment, the first solid-liquid separation zone 500 includes a belt filter device that includes a gravity drainage zone and a pressurized dewatering zone, as illustrated in FIG. 7. The open microfiber slurry 401 is directed to a tapering gap between a pair of moving filter cloths moving in the same direction, which first passes through the gravity drainage zone and then in a tortuous arrangement of rollers as shown in FIG. 6B. It passes through the included pressurized dehydration zone or press zone. As the belt is fed through the roller, water escapes from the solid. In this process, when the belt passes through the final roller pair, the filter cloth is separated and solids are discharged from the belt filter device.

In another embodiment of the present invention, at least a portion of the water contained in the first mother liquor stream 501 comprising water and the water dispersible sulfopolyester is recovered and recycled. The first mother liquor stream 501 may be recycled to the first solid-liquid separation zone 500. Depending on the efficiency of the first solid-liquid separation zone in the removal of water non-dispersible polymer microfibers, the first mother liquor stream 501 may be divided into a fiber slurry zone 200, a mixing zone 300, and an open fiber zone 400. Or may be recycled to the heat exchanger zone 800 prior to entering the zones 200, 300 and / or 400. The first mother liquor stream 501 may contain a small amount of solids comprising water non-dispersible polymer microfibers due to penetration and cloth cleaning. In one embodiment, g of water non-dispersible polymer microfiber material passing through the filter media in the first solid separation zone having an opening of 2000 microns or less ranges from about 1 to about 2 g per cm ² of filter area. . Before sending the first mother liquor stream 501 to the first concentration zone 700 and the heat exchange zone 800, in which water non-dispersible polymer microfiber solids may be collected and accumulated negatively. It is desirable to minimize the water non-dispersible polymer microfibers in the stream 501.

The second solid-liquid separation zone 600 removes at least a portion of the water non-dispersible polymer microfiber solids present in the first mother liquor stream 501 so that the second wet cake comprises water non-dispersible microfibers. Function to produce a stream 602 and a second mother liquor stream 601 comprising water and water dispersible sulfopolyester.

In one embodiment, second mother liquor stream 601 is directed to first enrichment zone 700 and / or heat exchanger zone 800, with second mother liquor stream 601 directed to first enrichment zone 700. Weight percent) may range from 0 to 100% and the remainder of the stream is sent to heat exchanger zone 800. The second mother liquor stream 601 is a heat exchanger prior to entering the fiber slurry zone 200, the mixing zone 300, the fiber open zone 400, or the zones 200, 300 and / or 400. May be recycled to the band 800. The amount of water dispersible sulfopolyester in the second mother liquor stream sent to the fiber open zone 400 is about 0.01 to about 7 weight percent, or about 0.1 to about 7 weight percent, based on the weight percent of the second mother liquor stream. 0.2 to about 5 weight percent, or about 0.3 to about 3 weight percent.

Any portion of the second mother liquor stream 601 sent to the first concentration zone may be subjected to a separation process to obtain a first recovered water stream 703 and a first polymer concentrate stream 702 enriched in water dispersible sulfopolyester. Resulting in the weight percent of water dispersible sulfopolyester in the first polymer concentrate stream 702 may range from about 5 to about 85 weight percent, from about 10 to about 65 weight percent, or from about 15 to about 45 weight percent. have. The first recovered water stream 703 is prior to entering the fiber slurry zone 200, the mixing zone 300, the fiber open zone 400, or the zones 200, 300 and / or 400. May be recycled to the heat exchanger zone 800. The amount of water dispersible sulfopolyester in the second mother liquor stream sent to the fiber open zone 400 is from about 0.01 to about 7 weight percent, or from about 0.1 to about 7 weight percent, based on the weight percent of the second mother liquor stream. 0.2 to about 5 weight percent, or about 0.3 to about 3 weight percent.

Water may be removed from the second mother liquor stream 601 in the first concentration zone 700 by any method known in the art to produce the first polymer concentrated stream 702. In one embodiment, the removal of water comprises an evaporation process by boiling water in a batch or continuous evaporation apparatus. For example, one or more thin film evaporators can be used for this purpose. In another embodiment, membrane technology including nanofiltration media can be used to produce the first polymer concentrate stream 702. In another embodiment, a process including an extraction device can be used to extract the water dispersible polymer from the second mother liquor stream 601 and produce a first polymer concentrate stream 702. The combination of evaporation, membrane and extraction steps may be used to separate the water dispersible polymer from the second mother liquor stream 601 and produce a first polymer concentrate stream 702. The first polymer concentrate stream 702 may then be discharged out of the process.

In one embodiment, first polymer concentrate stream 702 is sent to second concentration zone 900 such that molten polymer stream 903 comprising a water dispersible sulfopolyester, wherein the weight percent of polymer is about 95 to about 100%) and water to produce a vapor stream 902. In one embodiment, the stream 903 comprises a water dispersible sulfopolyester. Suitable devices for the second concentration zone 900 include any device known in the art that can supply an aqueous dispersion of water dispersible polymer and can produce 95% to 100% water dispersible polymer stream 903. . This embodiment includes feeding an aqueous dispersion of the water dispersible sulfopolyester polymer into the second concentration zone 900. The temperature of the feed stream is typically below 100 ° C.

In one embodiment, the second enrichment zone 900 is characterized by at least one device characterized by a jacketed tubular shell containing a rotating transport screw, wherein the transport screw is heated with heat transfer fluid or steam. Both transport and high shear mixing elements). The jacket or shell is vented to remove steam. The shell jacket can be banded to enable other temperature set points along the length of the device. During continuous operation, the first polymer concentrate stream 702 comprises water and water dispersible sulfopolyester, and is fed continuously to the second concentration zone 900. Within the device, there are at least three distinct and different forms of material during steady state. In the device the material first exists as an aqueous dispersion of the water dispersible sulfopolyester polymer. As the aqueous dispersion of sulfopolyester polymer moves through the device, the water evaporates due to the heat of the jacket and internal screws. When enough water has evaporated, the material is in a second form comprising a viscous plug at a temperature below the melting point of the sulfopolyester polymer. The aqueous dispersion cannot flow past this viscous plug and is confined to the first aqueous dispersion zone of the device. Due to the heat of the jacket, the heat of the internally heated screw, and the heat due to the mixed shear forces of this highly viscous plug material, substantially all of the water present in this location is evaporated and the temperature is reached until the melting temperature of the sulfoester is reached. Ascending, a third final physical form of the material comprising the molten sulfopolyester polymer is produced in the device. The molten sulfopolyester polymer then exits the apparatus through an extrusion die and is typically cooled and cut into pellets in any manner known in the art. It is to be understood that the apparatus for the second enrichment zone 900 described above can also be operated in a batch fashion, where a continuous mixture of viscous plug material and finally sulfopolyester melt, starting with an aqueous dispersion, throughout the length of the apparatus Three different physical forms of the above-mentioned substances occur in sequence at different times.

In one embodiment, the steam generated in the second concentration zone 900 may be condensed and sent to the heat exchanger zone 800 and / or discarded and / or sent to the wash stream 103. In another embodiment, the condensed vapor stream 902 comprising water vapor may be sent to the heat exchanger zone 800 to provide at least some of the energy needed to produce the temperature required for the stream 801. The molten polymer stream 903 comprising the water dispersible polymer comprising sulfopolyester in the molten phase may be cooled and chopped into pellets by any method known in the art.

Impurities may be introduced into the process and concentrated in the water recovered and recycled. One or more purge streams 603 and 701 may be used to adjust the concentration of impurities in the second mother liquor 601 and the first recovered water stream 701 to an acceptable level. In one embodiment, a portion of the second mother liquor stream 601 may be isolated and purged from the process. In one embodiment, a portion of the first recovered water stream 701 may be isolated and purged from the process.

In another embodiment of the present invention, as shown in FIG. 4, another method of preparing a microfiber product stream is provided. This way

(A) contacting the short-cut multicomponent fiber 101 having a length of less than 25 mm with the aqueous stream 103 treated in the fiber slurry zone 200 to produce a short-cut multicomponent fiber slurry 201. Wherein the short-cut multicomponent fiber 101 comprises at least one water dispersible sulfopolyester and at least one water non-dispersible synthetic polymer that is immiscible with the water dispersible sulfopolyester and wherein the treated aqueous stream Is a temperature of at least 40 ° C .;

(B) contacting the short-cut multicomponent fiber slurry 201 with a heated aqueous stream 801 in a mixing zone 300 to produce a heated multicomponent fiber slurry 301;

(C) sending the heated multicomponent fiber slurry 301 to a fiber open zone 400 to remove a portion of the water dispersible sulfopolyester to produce an open microfiber slurry 401; And

(D) sending the open microfiber slurry 401 to a first solid-liquid separation zone 500 to produce a microfiber product stream 503 and a first mother liquor stream 501, wherein the first mother liquor Stream 501 comprises water and water dispersible sulfopolyester

It includes.

In this embodiment of the present invention as shown in FIG. 4, the open process zone 1100 includes a fiber slurry zone 200, a mixing zone 300 and a fiber opening zone 400.

The treated aqueous stream 103 for use in this method can be generated by sending the aqueous stream 102 to the aqueous treatment band 1000 to produce the treated aqueous stream 103. The aqueous stream contains water. In embodiments of the invention, the monovalent metal cations in the treated aqueous stream 103 may be less than about 1000 ppm, less than about 500 ppm, less than about 100 ppm, or less than about 50 ppm by weight. Removal of divalent and polyvalent metal cations from aqueous stream 102 is one function of aqueous treatment zone 1000. In other embodiments of the invention, the concentrations of divalent and polyvalent metal cations are less than about 50 ppm by weight, less than about 25 ppm by weight, less than about 10 ppm by weight, or less than about 5 ppm by weight. The temperature of stream 103 may range from groundwater temperature to about 40 ° C.

Treatment of aqueous stream 102 in aqueous treatment zone 1000 may be accomplished by any method known in the art. In one embodiment, aqueous treatment zone 1000 includes distillation equipment that generates steam and condenses to produce treated aqueous stream 103. In another embodiment, water can be sent to the reverse osmosis membrane separation zone to remove monovalent and divalent metal cations from the water to produce the treated aqueous stream 103. In another embodiment, water is sent to the ion exchange resin to produce a treated aqueous stream 103 having an acceptable low concentration of metal ions. In another embodiment, water is sent to a commercial softening device to produce a treated aqueous stream 103 having acceptable low concentrations of divalent and polyvalent metal ions. It should be understood that any combination of these water treatment options may be used to achieve the required treated water characteristics.

The treated aqueous stream 103 can be sent to any location needed in the process. In one embodiment, a portion of stream 103 is sent to first solid-liquid separation zone 500 to serve as a wash liquor for solids contained in cloth wash liquor and / or first solid-liquid separation zone 500. .

In one embodiment, at least a portion of the treated aqueous stream 103 is sent to heat exchanger zone 800. In another embodiment, at least a portion of the treated aqueous stream 103 is sent to the fiber slurry zone 200. In another embodiment, at least a portion of the treated aqueous stream 103 is sent to the heat exchanger zone 800 and at least a portion of the treated aqueous stream 103 is sent to the fiber slurry zone 200. One function of the heat exchanger zone 800 is to produce a heated aqueous stream 801 at a specific controlled temperature.

In one embodiment, the streams that may be supplied to the heat exchanger zone 800 are treated aqueous stream 103 and second mother liquor stream 601. In another embodiment, the streams that may be supplied to the heat exchanger zone 800 include the treated aqueous stream 103, the first recovered water stream 703, the first mother liquor stream 501, and the second mother liquor stream. 601.

Any device known in the art for regulating the temperature of stream 801, such as, but not limited to, any heat exchanger utilizing a stream used to provide a portion of the required energy, to provide a portion of the required energy Any heat exchanger using heat transfer fluid used, any heat exchanger using an electrical heating element used to provide some of the required energy, and water condensed and the condensate supplied to heat exchanger zone 800 Any vessel or tank using direct steam injection to be mixed may be used.

The multicomponent fiber stream 90 is sent to the fiber cut zone 100 to produce a cut multicomponent fiber stream 101. Multicomponent fibers may have any multicomponent structure known in the art. Multicomponent fibers include water dispersible sulfopolyesters and water non-dispersible polymers as described herein above.

Any device known in the art can be used to cut the multicomponent fiber stream 90 to produce the cut multicomponent fiber stream 101. In one embodiment, the length of the cut fibers in the cut multicomponent fiber stream 101 is less than about 50 mm. In other embodiments, the length of the cut fibers in the cut multicomponent fiber stream 101 is less than about 25 mm, less than about 20 mm, less than about 15 mm, less than about 10 mm, less than about 5 mm, or about 2.5 mm. Is less than.

A portion of the chopped multicomponent fiber stream 101 and a heated treated aqueous stream 801 is sent to the fiber slurry zone 200 to produce a chopped multicomponent fiber slurry 201 comprising water and chopped multicomponent fibers. Create In one embodiment, the weight percent of the chopped microfibers in the chopped multicomponent fiber slurry 201 is from about 35 wt% to about 1 wt%, from about 25 wt% to about 1 wt%, from about 15 wt% to about 1 weight percent, or about 7 weight percent to about 1 weight percent.

The temperature of the chopped multicomponent fiber slurry 201 may range from about 5 to about 45 ° C, about 10 to about 35 ° C, or about 10 to about 25 ° C. In one embodiment, fiber slurry zone 200 comprises a tank with sufficient agitation to produce a suspension in a continuous aqueous phase of chopped multicomponent fibers.

Any device known in the art to be suitable for mixing solids with water and maintaining a suspension in the continuous aqueous phase of the resulting chopped multicomponent fibers may be used in the fiber slurry zone 200. Fiber slurry zone 200 may include a batch or continuous mixing device operated in a continuous or batch mode. Appropriate devices for use in the fiber slurry zone 200 include, but are not limited to, a hydro-pulpator, a continuous stirred tank reactor, and a tank with agitation operated in batch mode.

The chopped multicomponent fiber slurry 201 and the heated aqueous stream 801 are then sent to the mixing zone 300 to combine to produce a heated multicomponent fiber slurry 301. The temperature of the heated multicomponent fiber slurry 301 is such as to separate the water non-dispersible polymer portion of the cut multicomponent fiber from the water non-dispersible polymer portion of the cut multicomponent fiber in the fiber open region 400. affect. In another embodiment of the present invention, the temperature of the heated multicomponent fiber slurry 301 may range from about 55 to about 100 ° C, about 60 to about 90 ° C, or about 65 to about 80 ° C.

The weight percent of the cut microfibers in the heated multicomponent fiber slurry 301 can be controlled. In other embodiments, the weight percent of the cut microfibers in the heated multicomponent fiber slurry 301 is from about 10 wt% to about 0.1 wt%, from about 5 wt% to about 0.2 wt%, from about 3 wt% to about 0.3 wt% %, Or from about 2% to about 0.4% by weight.

Any device known in the art that can mix the heated aqueous stream 801 with the cut multicomponent fiber slurry 201 can be used in the mixing zone 300. Suitable devices include both continuous and batch mixing devices. In one embodiment, a mixing device suitable for mixing zone 300 includes a tank and a stirrer. In another embodiment, a suitable mixing device comprises a pipe or conduit.

In other embodiments, a mixing device suitable for mixing zone 300 is a pipe or conduit with a diameter such that the velocity in the conduit is sufficient to mix the cut multicomponent fiber slurry 201 and the heated aqueous stream 801. Wherein less than about 2 weight percent, less than about 1 weight percent, or less than about 0.5 weight percent of the cut multicomponent material introduced per minute into the conduit is sedimented and accumulated in the conduit.

The heated multicomponent fiber slurry 301 may then be sent to the fiber open zone 400. One function of the fiber open zone 400 is to separate the water dispersible polymer from the cut multicomponent fibers so that at least a portion of the water non-dispersible polymer microfibers are separated from the cut multicomponent fiber fibers to open the micro It is to be suspended in the fiber slurry (401). In another embodiment of the present invention, about 50 to about 100 weight percent of the water non-dispersible polymer microfibers contained in the chopped multicomponent fiber slurry 201 is contained in the open microfiber slurry 401. It is suspended as a non-dispersible polymer microfiber and is no longer part of the cut multicomponent fiber. In other embodiments, about 75 to about 100 weight percent, about 90 to about 100 weight percent, or about 95 to about 100 weight percent of the water non-dispersible polymer microfibers contained in the cut multicomponent fiber stream 201. Is suspended in the open microfiber slurry 401 as a water non-dispersible polymer microfiber and no longer part of the cut multicomponent fiber.

The diameter or denier of the starting cut multicomponent fiber in stream 201 affects the degree of separation of the water dispersible sulfopolyester from the multicomponent fiber in the fiber open zone 400. Typical multicomponent fiber types generally have diameters in the range of about 12 microns to about 20 microns. Useful multicomponent fibers can have larger starting diameters of diameter sizes of at least about 40 microns. The time required to separate the desired amount of water dispersible sulfopolyester from the chopped multicomponent fibers increases with increasing diameter of the chopped multicomponent fibers in stream 201.

The residence time, temperature and shear forces in the fiber open zone 400 also affect the degree of separation of the water dispersible sulfopolyester from the cut multicomponent fiber. Conditions affecting the open process in the fiber open zone 400 include residence time, slurry temperature and shear force, where water temperature in the fiber open zone 400, range of residence time, degree of shear applied, The extent to which the dispersible polymer microfibers are separated and suspended in the continuous aqueous phase of the open microfiber slurry 401 is governed by the need to separate the water dispersible sulfopolyester from the starting multicomponent fiber.

The residence time, temperature and shear forces in the fiber open zone 400 affect the degree of separation of the water dispersible sulfopolyester from the cut multicomponent fiber. The temperature of the fiber open zone 400 may range from about 55 to about 100 ° C, about 60 to about 90 ° C, or about 65 to about 80 ° C. The residence time in the fiber open zone 400 may range from about 5 minutes to about 10 seconds, from about 3 minutes to about 20 seconds, or from about 2 minutes to about 30 seconds. Sufficient mixing is maintained in the fiber open zone 400 to maintain suspension of the cleaved water non-dispersible polymer microfibers to minimize sedimentation of the cleaved microfibers. In another embodiment of the present invention, the mass per unit time of cut water non-dispersible polymer microfibers in fiber open zone 400 is the mass per unit time of water non-dispersible polymer microfibers entering the zone 400. Less than about 5% of the amount of water non-dispersible polymer microfibers entering the zone 400, or less than about 3% of the mass per unit time of water non-dispersible polymer microfibers entering the zone 400, or Less than about 1% of mass per unit time.

Fiber opening in fiber opening zone 400 may be achieved in any device that may allow for acceptable residence time, temperature, and mixing range. Examples of suitable devices include, but are not limited to, stirred batch tanks as shown in FIGS. 6B and 6C, continuous stirred tank reactors, and flows sufficient to minimize solids settling out of the slurry as shown in FIG. 6A. Pipes are included. One example of a unit operation to achieve fiber opening in the fiber open zone 400 is a plug flow reactor, where the heated multicomponent fiber slurry 301 is a zone 400 plug flow device, typically circular Sent to pipe or conduit. The residence time of the material in the plug flow device is calculated by dividing the filled volume in the device by the volume flow rate in the device. The mass velocity in the device is defined as the cross sectional area of the flow channel divided by the volumetric flow of liquid through the device.

In another embodiment of the present invention, the fiber open zone 400 may have a material flow rate in the pipe in the range of 0.1 to about 20 ft / sec, 0.2 to about 10 ft / sec, or about 0.5 to about 5 ft / sec. It may include pipes or conduits. For the flow of a fluid or slurry in a pipe or conduit, the Reynolds number is a dimensionless number that is useful for describing turbulence or movement of irregular fluid vortices for both direction and time. For flow in a pipe or tube, the Reynolds number is generally defined as:

Where

D _H Is the hydraulic diameter L of the pipe in m;

Q is the volumetric flow rate (m ³ / s),

A is the pipe cross section (m ² ),

υ is the average velocity of the object relative to the fluid in m / s,

μ is the dynamic viscosity of the fluid (Pa · s or N · s / m ² or kg / (m · s)),

v is the dynamic viscosity (v = μ / ρ) (m ² / s),

ρ is the density of the fluid (kg / m ³ ).

For flow in a pipe of diameter D , experimental observation shows that for fully developed flow a laminar flow occurs when Re _D is less than 2000 and a turbulent flow occurs when Re _D is greater than 4000. Between 2300 and 4000, laminar and turbulent flows are possible ("transition" flows), depending on other factors, such as pipe roughness and flow uniformity.

The fiber open zone 400 may include pipes or conduits to facilitate the opening process, and the Reynolds number of flows through the pipes or conduits in the fiber open zone 400 may be about 2,100 to about 6,000, about 3,000. To about 6,000, or about 3,500 to about 6,000. In other embodiments, the fiber open zone 400 may comprise a pipe or conduit to facilitate the opening process, wherein the Reynolds number of the flow through the pipe or conduit is at least 2,500, at least about 3,500 or at least about 4,000 to be.

The fiber open zone 400 includes a pipe or conduit with a mixing device inserted in the pipe or conduit. The device may comprise an in-line mixing device. The in-line mixing device may be a static mixer without moving parts. In another embodiment, the in-line mixing device comprises a movable portion. Without limitation, such elements are mechanical devices for the purpose of imparting more mixing energy to the heated multicomponent fiber slurry 301, rather than being achieved by flow through the pipe. The device can be inserted at the beginning of the pipe section used as the fiber open zone, at the end of the pipe section, or anywhere in the pipe flow path.

An open fiber slurry stream 401 comprising water non-dispersible polymer microfibers, water and water dispersible sulfopolyester is sent to the first solid-liquid separation zone 500 to send the microfibers and the first mother liquor stream 501. A microfiber product stream 503 can be produced. In one embodiment, the first mother liquor stream 501 comprises water and a water dispersible sulfopolyester.

The weight percent of solids in the open fiber slurry stream 401 can range from about 0.1 to about 20 weight percent, from about 0.3 to about 10 weight percent, from about 0.3 to about 5 weight percent, or from about 0.3 to about 2.5 weight percent. .

 The weight percent of solids in the microfiber product stream 503 may range from about 10 to about 65 weight percent, about 15 to about 50 weight percent, about 25 to about 45 weight percent, or about 30 to about 40 weight percent.

Separating the microfiber product stream 503 from the open fiber slurry stream 401 may be accomplished by any method known in the art. In one embodiment, a wash stream 103 comprising water is sent to the first solid-liquid separation zone 500. The wash stream 103 may be used to wash the microfiber product stream in the filter cloth media in the first solid-liquid separation zone 500 and / or in the first solid-liquid separation zone 500 to produce a liquor stream 502. Up to 100% by weight of the fraction of the liquor stream 502 can be combined with the open fiber slurry stream 401 prior to entering the first solid-liquid separation zone 500. Up to 100% by weight of the fraction of the liquor stream 502 can be sent to the second solid-liquid separation zone 600. The tax liquor stream 502 may contain microfibers. In one embodiment, the g of microfiber mass passing through the filter media with openings of 200 microns or less in the first solid-liquid separation zone 500 ranges from about 1 to 2 g per cm ² of filter area. In another embodiment of the present invention, the filter openings of the filter media in the first solid-liquid separation zone 500 may range from about 43 microns to 3000 microns, about 100 microns to 2000 microns, or about 500 microns to 2000 microns.

Separating the microfiber product stream from the open microfiber slurry in the first solid-liquid separation zone 500 may be accomplished by one or several solid-liquid separation devices. Separation in the first solid-liquid separation zone 500 may be accomplished by a solid-liquid separation device or apparatuses operated in batch and / or continuously. Suitable solid-liquid separation devices in the first solid-liquid separation zone 500 may include, but are not limited to, one of the following: perforated basket centrifuge, continuous vacuum belt filter, batch vacuum nutschfilter, batch perforated Sedimentation tanks, twin wire dewatering devices, continuous horizontal belt filters with compression zones, non-vibrating inclined screen devices with wedge wire filter media, continuous vacuum drum filters, dewatering conveyor belts and the like.

In one embodiment, the first solid-liquid separation zone 500 includes a twin wire dewatering device where an open fiber slurry stream 401 is sent to the tapering gap between a pair of moving filter cloths moving in the same direction. . In the first zone of the twin wire dewatering device, water is drained from the open fiber slurry stream 401 due to gravity and from every narrow gap between the two moving filter cloths. In the downstream zone of the twin wire dewatering device, the two filter cloths and the microfiber material between these two filter cloths are compressed one or more times to mechanically reduce the moisture in the microfiber material. In one embodiment, mechanical dehydration is achieved by passing the two filter cloths and the contained microfiber material through one or more sets of rollers that exert a compressive force on the two filter cloths and the microfiber material therebetween. In another embodiment, mechanical dewatering is accomplished by passing the two filter cloths and the microfiber material through one or more sets of pressure rollers.

In another embodiment of the present invention, the force exerted by mechanical dehydration for each set of pressure rollers ranges from about 25 to about 300 lb per linear inch of filter media width, from about 50 to about 200 per linear inch of filter media width. lb range, or about 70 to about 125 lb per linear inch of filter media width. The microfiber product stream 503 is withdrawn from the twin wire dehydrator as the two filter cloths are separated and divided in the solid discharge zone of the twin wire dehydrator. The thickness of the ejected microfiber material may range from about 0.2 to about 1.5 inches, from about 0.3 to about 1.25 inches, or from about 0.4 to about 1 inch. In one embodiment, the tax stream comprising water is continuously applied to the filter media. In another embodiment, a tax stream comprising water is periodically applied to the filter media.

In another embodiment, the first solid-liquid separation zone 500 includes a belt filter device that includes a gravity drainage zone and a pressurized dewatering zone, as illustrated in FIG. 7. The open microfiber slurry 401 is directed to a tapering gap between a pair of moving filter cloths moving in the same direction, which first passes through the gravity drainage zone and then in a tortuous arrangement of rollers as shown in FIG. 6B. It passes through the included pressurized dehydration zone or press zone. As the belt is fed through the roller, water escapes from the solid. In this process, when the belt passes through the final roller pair, the filter cloth is separated and solids are discharged from the belt filter device.

In another embodiment of the present invention, at least a portion of the water contained in the first mother liquor stream 501 comprising water and the water dispersible sulfopolyester is recovered and recycled. The first mother liquor stream 501 may be recycled to the first solid-liquid separation zone 500. Depending on the efficiency of the first solid-liquid separation zone in the removal of water non-dispersible polymer microfibers, the first mother liquor stream 501 may be divided into a fiber slurry zone 200, a mixing zone 300, and an open fiber zone 400. Or may be recycled to the heat exchanger zone 800 prior to entering the zones 200, 300 and / or 400. The first mother liquor stream 501 may contain a small amount of solids comprising water non-dispersible polymer microfibers due to penetration and cloth cleaning. In one embodiment, g of water non-dispersible polymer microfiber material passing through the filter media in the first solid separation zone having an opening of 2000 microns or less ranges from about 1 to about 2 g per cm ² of filter area. . Before sending the first mother liquor stream 501 to the first concentration zone 700 and the heat exchange zone 800, in which water non-dispersible polymer microfiber solids may be collected and accumulated negatively. It is desirable to minimize the water non-dispersible polymer microfibers in the stream 501.

The second solid-liquid separation zone 600 removes at least a portion of the water non-dispersible polymer microfiber solids present in the first mother liquor stream 501 so that the second wet cake comprises water non-dispersible microfibers. Function to produce a stream 602 and a second mother liquor stream 601 comprising water and water dispersible sulfopolyester.

In one embodiment, second mother liquor stream 601 is directed to first enrichment zone 700 and / or heat exchanger zone 800, with second mother liquor stream 601 directed to first enrichment zone 700. Weight percent) may range from 0 to 100% and the remainder of the stream is sent to heat exchanger zone 800. The second mother liquor stream 601 is a heat exchanger zone prior to entering the fiber slurry zone 200, mixing zone 300, fiber opening zone 400, or zones 200, 300 and / or 400. Recycled to 800. The amount of water dispersible sulfopolyester in the second mother liquor stream sent to the fiber open zone 400 is about 0.01 to about 7 weight percent, or about 0.1 to about 7 weight percent, based on the weight percent of the second mother liquor stream. 0.2 to about 5 weight percent, or about 0.3 to about 3 weight percent.

Any portion of the second mother liquor stream 601 sent to the first concentration zone may be subjected to a separation process to obtain a first recovered water stream 703 and a first polymer concentrate stream 702 enriched in water dispersible sulfopolyester. Resulting in the weight percent of water dispersible sulfopolyester in the first polymer concentrate stream 702 may range from about 5 to about 85 weight percent, from about 10 to about 65 weight percent, or from about 15 to about 45 weight percent. have. The first recovered water stream 703 is heat exchanged prior to entering the fiber slurry zone 200, the mixing zone 300, the fiber open zone 400, or the zones 200, 300 and / or 400. The baseband 800 may be recycled. The amount of water dispersible sulfopolyester in the second mother liquor stream sent to the fiber open zone 400 is from about 0.01 to about 7 weight percent, or from about 0.1 to about 7 weight percent, based on the weight percent of the second mother liquor stream. 0.2 to about 5 weight percent, or about 0.3 to about 3 weight percent.

Water may be removed from the second mother liquor stream 601 in the first concentration zone 700 by any method known in the art to produce the first polymer concentrated stream 702. In one embodiment, the removal of water comprises an evaporation process by boiling water in a batch or continuous evaporation apparatus. For example, one or more thin film evaporators can be used for this purpose. In another embodiment, membrane technology including nanofiltration media can be used to produce the first polymer concentrate stream 702. In another embodiment, a process including an extraction device can be used to extract the water dispersible polymer from the second mother liquor stream 601 and produce a first polymer concentrate stream 702. The combination of evaporation, membrane and extraction steps may be used to separate the water dispersible polymer from the second mother liquor stream 601 and produce a first polymer concentrate stream 702. The first polymer concentrate stream 702 may then be discharged out of the process.

In one embodiment, first polymer concentrate stream 702 is sent to second concentration zone 900 such that molten polymer stream 903 comprising a water dispersible sulfopolyester, wherein the weight percent of polymer is about 95 to about 100%) and water to produce a vapor stream 902. In one embodiment, the stream 903 comprises a water dispersible sulfopolyester. Suitable devices for the second concentration zone 900 include any device known in the art that can supply an aqueous dispersion of water dispersible polymer and can produce 95% to 100% water dispersible polymer stream 903. . This embodiment includes feeding an aqueous dispersion of the water dispersible sulfopolyester polymer into the second concentration zone 900. The temperature of the feed stream is typically below 100 ° C.

In one embodiment, the second enrichment zone 900 is characterized by at least one device characterized by a jacketed tubular shell containing a rotating transport screw, wherein the transport screw is heated with heat transfer fluid or steam. Both transport and high shear mixing elements). The jacket or shell is vented to remove steam. The shell jacket can be banded to enable other temperature set points along the length of the device. During continuous operation, the first polymer concentrate stream 702 comprises water and water dispersible sulfopolyester, and is fed continuously to the second concentration zone 900. Within the device, there are at least three distinct and different forms of material during steady state. In the device the material first exists as an aqueous dispersion of the water dispersible sulfopolyester polymer. As the aqueous dispersion of sulfopolyester polymer moves through the device, the water evaporates due to the heat of the jacket and internal screws. When enough water has evaporated, the material is in a second form comprising a viscous plug at a temperature below the melting point of the sulfopolyester polymer. The aqueous dispersion cannot flow past this viscous plug and is confined to the first aqueous dispersion zone of the device. Due to the heat of the jacket, the heat of the internally heated screw, and the heat due to the mixed shear forces of this highly viscous plug material, substantially all of the water present in this location is evaporated and the temperature is reached until the melting temperature of the sulfoester is reached. Ascending, a third final physical form of the material comprising the molten sulfopolyester polymer is produced in the device. The molten sulfopolyester polymer then exits the apparatus through an extrusion die and is typically cooled and cut into pellets in any manner known in the art. It is to be understood that the apparatus for the second enrichment zone 900 described above can also be operated in a batch fashion, where a continuous mixture of viscous plug material and finally sulfopolyester melt, starting with an aqueous dispersion, throughout the length of the apparatus Three different physical forms of the above-mentioned substances occur in sequence at different times.

In one embodiment, the steam generated in the second concentration zone 900 may be condensed and sent to the heat exchanger zone 800 and / or discarded and / or sent to the wash stream 103. In another embodiment, the condensed vapor stream 902 comprising water vapor may be sent to the heat exchanger zone 800 to provide at least some of the energy needed to produce the temperature required for the stream 801. The molten polymer stream 903 comprising the water dispersible polymer comprising sulfopolyester in the molten phase may be cooled and chopped into pellets by any method known in the art.

Impurities may be introduced into the process and concentrated in the water recovered and recycled. One or more purge streams 603 and 701 may be used to adjust the concentration of impurities in the second mother liquor 601 and the first recovered water stream 701 to an acceptable level. In one embodiment, a portion of the second mother liquor stream 601 may be isolated and purged from the process. In one embodiment, a portion of the first recovered water stream 701 may be isolated and purged from the process.

The invention is further illustrated by the following examples.

EXAMPLE

All pellet samples were pre-dried for at least 12 hours at room temperature under vacuum. Dispersion times listed in Table 3 are for complete dispersion or dissolution of the nonwoven sample. The abbreviation "CE" used in Tables 2 and 3 means "Comparative Example."

Example  One

76 mol% of isophthalic acid, 24 mol% of sodiosulfoisophthalic acid, 76 mol% of diethylene glycol, and 24 mol% of 1,4-cyclohexanedimethanol and 0.29 of Ih.V. And sulfopolyester having a Tg of 48 ° C., melt blown onto a cylindrical collector through a nominal 6-inch die (30 holes / inch in a sample piece) using the conditions described in Table 1. I was. No interleafing paper was needed. A flexible, easy to handle flexible web that did not block during roll winding operations was obtained. Physical properties are provided in Table 2. Small pieces of nonwoven (1 "x 3") readily disperse in both room temperature (RT) and water at 50 ° C with only a slight shaking, as shown by the data in Table 3.

[Table 1] Melt Blowing Conditions

Table 2 Physical Properties of Nonwovens

Table 3 Dispersibility of Nonwovens

Example  2

89 mol% of isophthalic acid, 11 mol% of sodiosulfoisophthalic acid, 72 mol% of diethylene glycol and 28 mol% of ethylene glycol; And sulfopolyester having a Tg of 35 ° C. was melt blown through a 6-inch die using conditions similar to those in Table 1. A flexible, easy to handle flexible web that did not block during roll winding operations was obtained. Physical properties are provided in Table 2. Small pieces (1 "x 2") of the nonwovens were readily fully dispersed at 50 ° C and 80 ° C, and at room temperature (23 ° C) a longer time was required for the fabric to be fully dispersed as shown by the data in Table 3. .

It has been found that the compositions of Examples 1 and 2 can be top blown onto other nonwoven substrates. It can also be condensed and enclosed in a molded or contoured form used in place of a conventional web collector. Thus, a circular “roving” or plug form of the web can be obtained.

Comparative example ( CE ) 1 to 3

89 mol% of isophthalic acid, 11 mol% of sodiosulfoisophthalic acid, 72 mol% of diethylene glycol and 28 mol% of ethylene glycol; And pellets of sulfopolyester having a Tg of 35 ° C. were combined with polypropylene (Basell PF 008) pellets in the following two component ratios (based on weight percent):

75 PP: 25 sulfopolyester (Example 3)

50 PP: 50 sulfopolyester (Example 4)

25 PP: 75 sulfopolyester (Example 5)

PP had an MFR (melt flow rate) of 800. Melt blow operations were performed on a line equipped with a 24-inch wide die to obtain an easy-to-handle flexible flexible nonblocking web with the physical properties provided in Table 2. Small pieces of nonwoven (1 "x 4") were easily disassembled as reported in Table 3. However, none of the fibers were completely water dispersible because of the insoluble polypropylene component.

Example  3

A circular piece (4 "diameter) of the nonwoven fabric prepared in Example 2 was used as the adhesive layer between two cotton fabric sheets. By applying a pressure of 35 psig at 200 ° C. for 30 seconds using a Hannifin melt press. Two cotton sheets were fused together The resulting assembly showed a very strong bond strength The cotton substrate was chopped before the bond or bond was broken A similar result was obtained with other cellulose and PET polyester substrates. Strong bonding was also generated by the technique.

Comparative example  4

PP (Exxon 3356G) with an MFR of 1200 was melt blown using a 24 "die to obtain a flexible nonwoven that was easily unblocked from the roll without blocking. Small pieces (1" x 4 ") No reaction was seen when soaked in water at RT or 50 ° C. for 15 minutes (ie there was no dissolution or basis weight loss).

Example  4

Monocomponent fiber of sulfopolyester containing 82 mol% of isophthalic acid, 18 mol% of sodiosulfoisophthalic acid, 54 mol% of diethylene glycol and 46 mol% of 1,4-cyclohexanedimethanol and having a Tg of 55 ° C Was melt spun at a melt temperature of 245 ° C. (473 ° F.) in a lab staple spinning line. The spinning denier was about 8 d / f. There was some blocking in the take-up tube, but the 10-filament strand was easily dissolved in 10-19 seconds in unbleached demineralized water at 82 ° C. and pH 5-6.

Example  5

Sulfopolyester and isophthalic acid 91 containing 82 mole percent isophthalic acid, 18 mole percent sodium sulfoisophthalic acid, 54 mole percent diethylene glycol and 46 mole percent 1,4-cyclohexanedimethanol (Tg at 55 ° C) Blend of sulfopolyester (75:25) containing mol%, 9 mol% of sodiosulfoisophthalic acid, 25 mol% of diethylene glycol and 75 mol% of 1,4-cyclohexanedimethanol (Tg at 65 ° C) The monocomponent fibers obtained from were melt spun in each lab staple spinning line. The blend has a Tg of 57 ° C., calculated by taking the weighted average of the Tg of the component sulfopolyesters. The 10-filament strand showed no blocking on the take-up tube and readily dissolved in 20-43 seconds in undepressurized demineralized water at 82 ° C. and pH 5-6.

Example  6

The blend described in Example 5 was co-spun with PET to obtain a bicomponent islands-in-the-sea fiber. A shape was obtained in which the sulfopolyester “sea” was 20% by weight fiber containing 80% by weight PET “island”. Spin yarn elongation was 190% immediately after spinning. No blocking appeared because the yarn was satisfactorily released from the bobbin and processed one week after spinning. In subsequent work, the “sea” was dissolved by passing the yarn through a soft bath at 88 ° C., leaving only a fine PET filament.

Example  7

This putative example illustrates the possible use of the multicomponent and microdenier fibers of the present invention for the production of specialty paper. The blend described in Example 5 was co-spun with PET to give a bicomponent islands-in-the-sea fiber. The fiber contains about 35% by weight sulfopolyester "sea" component and about 65% by weight PET "island". The un crimped fibers are cut to length of 1/8 inch. In simulated papermaking, these short cut bicomponent fibers are added to the regeneration operation. By removing the sulfopolyester “sea” from the shaken aqueous slurry, the microdenier PET fibers are released into the mix. At comparable weights, microdenier PET fibers (“islands”) are more effective at increasing paper tensile strength than addition of coarse PET fibers.

Comparative example  8

108 islands in sea structure in a radial bond line using a 24 "wide bicomponent spinneret die from Hills Inc. of Melbourne, Florida, with die holes totaling multicomponent fibers in the die plate. The two extruders were connected to a melt pump, and the melt pump was again connected to the inlets for the two components of the fiber spinning die.The main extruder (A) was used to control the flow of Eastman F61HC PET polyester. Weighing was connected to an inlet to create island domains in the islands' fiber cross-section structure.The extrusion zone was set to melt PET entering the die at 285 ° C. The co-extruder (B) had an inherent viscosity of about 0.35 and a rheometric dynamic analyzer (Rheometric Dynamic Analyzer) RDAII (Rheometrics Inc., Piscataway, NJ) Flow Meter at 240 ° C Eastman from Eastman Chemical Company, Kingsport, Tenn., Having a melt viscosity of about 15,000 poises measured at a shear rate of 1 radian / sec and 9,700 poises at a shear rate of 240 ° C. and 100 radians / second. The AQ 55S sulfopolyester was processed Before the melt viscosity measurements were taken, the samples were dried for 2 days in a vacuum oven at 60 ° C. Viscosity tests were performed using a 25 mm diameter parallel plate configuration set at 1 mm intervals. Frequency sweeps were performed at a strain rate range of 1 to 400 radians / sec and a 10% strain width, and then the viscosity was measured at strain rates of 240 ° C. and 1 radian / sec.Sulfopoly used in subsequent examples after this procedure The viscosity of the ester material was determined The coextruder melts the AQ 55S polymer and feeds it to the spinneret die at a melt temperature of 255 ° C. Two polymers were produced as bicomponent extrudates by extrusion at a processing rate of 0.6 g / hole / min The volume ratio of PET to AQ 55S in the bicomponent extrudates produced a 60/40 and 70/30 ratio. To adjust.

The bicomponent extrudates were melt drawn using an inhaler device to produce bicomponent fibers. Air flow through the inhaler chamber pulled down the generated fibers. The amount of air flowing down through the inhaler assembly was controlled by the pressure of the air entering the inhaler. In this example, the maximum pressure of air used for the inhaler to melt draw the bicomponent extrudates was 25 psi. If greater than this value, because the melt draw rate imposed on the bicomponent extrudates is greater than the inherent durability of the bicomponent extrudates, the airflow through the inhaler destroyed the extrudate during this melt draw spinning process. The bicomponent fibers were laid down into a nonwoven web having a fabric weight of 95 g / m ² (gsm). The evaluation of bicomponent fibers in this nonwoven web by optical microscopy shows that although PET is present as islands in the center of the fiber structure, the PET islands around the outer periphery of the bicomponent fibers are almost agglomerated so that almost all of the PEE polymer around the circumference of the fiber It has been shown to form a continuous ring, which is undesirable. Microscopy found that the diameter of the bicomponent fibers in the nonwoven web is typically 15-19 microns, corresponding to an average fiber spinning denier of about 2.5 denier / filament (dpf). This gives a melt drawn fiber speed of about 2160 m / min. Spinning denier is defined as the denier of fiber (weight in g of 9000 meters length) obtained by the melt extrusion and melt drawing steps. Changes in the bicomponent fiber diameters showed nonuniformity in the spin-draw of the fibers.

Nonwoven web samples were conditioned at 120 ° C. for 5 minutes in a forced-air oven. The heat treated web exhibited significant shrinkage, with the area of the nonwoven web reduced to about 12% of the initial area of the web before heating. Without wishing to be bound by any theory, because of the high molecular weight and melt viscosity of the AQ 55S sulfopolyesters used in the fibers, the bicomponent extrudates melt draw to the extent necessary to cause deformation-induced crystallization of the PET compartment in the fibers. Could not be. As a result, AQ 55S sulfopolyesters having this specific intrinsic and melt viscosity could not be tolerated because the bicomponent extrudates could not be melt melted uniformly to the desired fine denier.

Example  8

Sulfopolyester polymers with the same chemical composition as commercially available Eastman AQ55S polymers were produced, but the molecular weight was adjusted to lower values characterized by an intrinsic viscosity of about 0.25. The melt viscosity of this polymer was 3300 poise when measured at 240 ° C. and shear rate of 1 radian / second.

Example  9

Binary compression with a 16-compartmented pie structure using a bicomponent spinneret die, a Hills Incorporated (Melbourne, Florida) article with a total of 2222 die holes in a 24-inch wide die plate on a spinning bond installation Water was prepared. Two extruders were used to melt both polymers and feed them to the spinneret die. The main extruder (A) was fed to the Eastman F61HC PET polyester melt and connected to the inlet to form domain or compartment slices in the divided pie cross-sectional structure. The extrusion zone was set to melt PET entering the spinneret die at 285 ° C. The co-extruder (B) melted and fed the sulfopolyester polymer of Example 8. The coextruder was set to extrude the sulfopolyester polymer into the spinneret die at a melt temperature of 225 ° C. Except for the melt viscosity of the spinneret die and the sulfopolyester polymer used, the procedure used in this example was the same as in Comparative Example 8. The melt throughput per hole was 0.6 gm / min. The volume ratio of PET to sulfopolyester in the bicomponent extrudates was set to 70/30, representing a weight ratio of about 70/30.

The bicomponent extrudate was melt drawn using the same inhaler as used in Comparative Example 8 to produce bicomponent fibers. First, the inlet air to the inhaler was set to 25 psi, the fibers had a spin denier of about 2.0, and the bicomponent fibers exhibited a uniform diameter profile of about 14 to 15 microns. The air to the inhaler was increased to a maximum available pressure of 45 psi without breaking the melt extrudate during the melt draw. Using 45 psi of air, the bicomponent extrudates were melt drawn down to a fiber spinning denier of about 1.2 and the bicomponent fibers exhibited a diameter of 11 to 12 microns when viewed under a microscope. The speed during the melt draw process was calculated to be about 4500 m / min. While not wishing to be bound by any theory, it is believed that at the melt draw rate approaching this rate, strain induced crystallization of PET begins to occur during the melt draw process. As indicated above, it is desirable to form some oriented crystallinity in the PET fiber sections during the fiber melt drawing process to make the nonwoven web more dimensionally stable during subsequent processing.

Bicomponent fibers were laminated to a nonwoven web having a weight of 140 g / m ² (gsm) using an inhaler air pressure of 45 psi. The shrinkage of the nonwoven web was measured by conditioning the material for 5 minutes at 120 ° C. in a forced-air oven. This example shows a significant reduction in shrinkage compared to the fibers and fabrics of Comparative Example 8.

This nonwoven web with 140 gsm fabric weight was immersed in a static deionized water bath at various temperatures for 5 minutes. The immersed nonwoven web was dried, and the weight loss due to immersion in deionized water at various temperatures was measured as shown in Table 4 below.

TABLE 4

The sulfopolyester dissipated very easily in deionized water at about 25 ° C. Sulfopolyester removal from the bicomponent fibers of the nonwoven web is indicated by% weight loss. Above 33 ° C., extensive or complete removal of sulfopolyester from bicomponent fibers was observed. When high pressure weaving is used to produce nonwoven webs of these bicomponent fibers comprising the present sulfopolyester of Example 8, the sulfopolyester polymer may be extensively or It is expected to be completely removed. If it is desired that little sulfopolyester polymer is to be removed from these bicomponent fibers during the high pressure weaving step, a low water temperature of less than about 25 ° C. should be used.

Example  10

Sulfopolyester polymers were prepared with the following diacid and diol compositions: a disperse composition (71 mole percent terephthalic acid, 20 mole percent isophthalic acid and 9 mole percent 5- (sodiosulfo) isophthalic acid) and a diol composition (ethylene glycol 60 Mole% and 40 mole% diethylene glycol). Sulfopolyesters were prepared by high temperature polyesterification under vacuum. The esterification conditions were adjusted to produce sulfopolyesters having an intrinsic viscosity of about 0.31. The melt viscosity of this sulfopolyester was determined to be about 3000 to 4000 poise at 240 ° C. and shear rate of 1 radian / second.

Example  11

The sulfopolyester polymer of Example 10 was spun into bicomponent split pie fibers and nonwoven webs following the same procedure as described in Example 9. The main extruder (A) fed Eastman F61HC PET polyester melt to form larger compartment slices of the split pie structure. The extrusion zone was set to melt PET entering the spinneret die at 285 ° C. The co-extruder (B) processed the sulfopolyester polymer of Example 10 fed to the spinneret die at a melt temperature of 255 ° C. The melt throughput rate per hole was 0.6 gm / min. The volume ratio of PET to sulfopolyester in the bicomponent extrudates was set to 70/30, representing a weight ratio of about 70/30. The cross section of the bicomponent extrudates had wedge-shaped domains of PET and sulfopolyester polymers separating these domains.

The bicomponent extrudates were melt drawn to produce the bicomponent fibers using the same inhaler assembly as used in Comparative Example 8. The maximum air pressure that could be used as the inhaler without breaking the bicomponent fiber during drawing was 45 psi. 45 psi of air was used to melt draw down the bicomponent extrudates to produce a bicomponent fiber having a spinning denier of about 1.2, which exhibited a diameter of about 11 to 12 microns when viewed under a microscope. It was. The speed during the melt draw process was calculated to be about 4500 m / min.

The bicomponent fibers were laminated to nonwoven webs having a weight of 140 gsm and 110 gsm. The shrinkage of the web was measured by conditioning the material for 5 minutes at 120 ° C. in a forced-air oven. The area of the nonwoven web after shrinking was about 29% of the starting area of the web.

Microscopic examination of the cross section of the fibers drawn from the melt drawn fibers and the nonwoven webs showed very good split pie structures with clearly defined individual compartments and similar sizes and shapes. The PET compartments were completely separated from each other, resulting in eight separate PET monocomponent fibers having a pi-slice shape after removing the sulfopolyester from the bicomponent fibers.

A nonwoven web with a fabric weight of 110 gsm was immersed in a static deionized water bath at various temperatures for 8 minutes. The percentage of weight loss due to drying of the immersed nonwoven web and immersing in deionized water at various temperatures was shown in Table 5 below.

TABLE 5

The sulfopolyester polymer readily dissipated in deionized water at temperatures above about 46 ° C., and removal of the sulfopolyester polymer from the fiber was very broad or complete at temperatures above 51 ° C. as shown by weight loss. A weight loss of about 30% was indicative of complete removal of the sulfopolyester from the bicomponent fibers of the nonwoven web. When processing this nonwoven web of bicomponent fibers comprising this sulfopolyester using high pressure weaving, it is expected that the polymer will not be removed extensively by high pressure woven spray water with a water temperature below 40 ° C.

Example  12

The nonwoven web of Example 11 having a basis weight of 140 gsm and 110 gsm was woven high pressure using a high pressure weaving device manufactured by Fleissner, GmbH (Egelsbach, Germany). The machine has a total of five high-pressure weaving stations, where three sets of spray water contacted the top of the nonwoven web and two sets of spray water contacted the opposite side of the nonwoven web. The water jet contained a series of micropores of about 100 microns in diameter engineered into a two foot wide jet strip. The spray water pressure was set to 60 bar (jet strip # 1), 190 bar (jet strip # 2 and 3) and 230 bar (jet strip # 4 and 5). During the high water pressure weaving process, the spray water temperature was found to be about 40-45 ° C. The nonwovens present in the high pressure weaving device were tightly bonded together. The continuous fibers were entangled together to produce a high pressure woven nonwoven with high tear resistance when drawn in both directions.

The high-pressure woven nonwoven was then secured onto a tenter frame comprising a rigid rectangular frame with a series of pins around it. The fabric was pinned to a pin to limit the shrinkage of the fabric when it was heated. A frame equipped with fabric samples was placed in a forced-air oven for 3 minutes at 130 ° C. to thermoset the fabric while limited. After thermosetting, the conditioned fabric was cut into specimens of measured size and the specimens were conditioned at 130 ° C. without limitation by the tenter frame. After the conditioning, the dimensions of the high-pressure woven nonwovens were measured, and only a minimum shrinkage (diameter decrease of less than 0.5%) was observed. It has been evident that thermal curing of the high pressure woven nonwoven is sufficient to produce a dimensional stability nonwoven.

After heat curing as described above, the high pressure woven nonwoven was washed in deionized water at 90 ° C. to remove the sulfopolyester polymer and leave a PET monocomponent fiber compartment on the high pressure woven fabric. After repeated washings, the dried fabric showed a weight loss of about 26%. Washing the nonwoven prior to high pressure weaving resulted in a weight loss of 31.3%. Thus, the high pressure weaving process removes some of the sulfopolyester from the nonwoven web, but this amount is relatively small. In order to reduce the amount of sulfopolyester removed during high pressure weaving, the high pressure woven spray water temperature must be lowered below 40 ° C.

The sulfopolyester of Example 10 was found to provide segmented pie fibers with good compartmental distribution (water non-dispersible polymer compartments produce individual fibers of similar size and shape after removal of sulfopolyester polymers). . The rheology of the sulfopolyester was suitable to melt draw bicomponent extrudates at high speed to achieve fine denier bicomponent fibers having a low spinning denier of about 1.0. These bicomponent fibers could be laminated to nonwoven webs, which were woven high pressure without significant loss of sulfopolyester polymer to produce nonwovens. The nonwovens produced by the high pressure weaving of the nonwoven webs exhibited high strength and were thermally cured at temperatures above about 120 ° C. to produce nonwovens with excellent dimensional stability. The sulfopolyester polymer was removed from the high pressure woven nonwoven in the washing step. The result is a strong nonwoven article with lighter fabric weight and much greater flexibility and soft feel. The monocomponent PET fibers of this nonwoven article had a wedge shape and exhibited an average denier of about 0.1.

Example  13

Sulfopolyester polymers were prepared with the following diacid and diol compositions: diacid compositions (69 mole percent terephthalic acid, 22.5 mole percent isophthalic acid and 8.5 mole percent 5- (sodiosulfo) isophthalic acid) and diol composition (65 mole percent) Ethylene glycol and 35 mole% diethylene glycol). Sulfopolyesters were prepared by high temperature polyesterification under vacuum. The esterification conditions were adjusted to produce sulfopolyesters having an intrinsic viscosity of about 0.33. The melt viscosity of this sulfopolyester was determined to be in the range of about 3000 to 4000 poise at 240 ° C. and shear rate of 1 radian / second.

Example  14

The sulfopolyester polymer of Example 13 was spun into a bicomponent islands (with 16 islands) cross-sectional shape in a spin bond line. The main extruder (A) fed Eastman F61HC PET polyester melt to produce islands of islands structure. The extrusion zone was set to melt PET entering the spinneret at about 290 ° C. The co-extruder (B) processed the sulfopolyester polymer of Example 13 fed to the spinneret die at a melt temperature of about 260 ° C. The volume ratio of PET to sulfopolyester in the bicomponent extrudates was set to 70/30, representing a weight ratio of about 70/30. The melt processing rate through the spinneret was 0.6 g / hole / min. The cross section of the bicomponent extrudates had a rounded PET island domain from which the sulfopolyester polymer separated.

The bicomponent extrudates were melt drawn using an inhaler assembly. The maximum pressure of air available to the inhaler was 50 psi without breaking the bicomponent fibers during melt draw. Using 50 psi of air, the bicomponent extrudates were melted down to yield bicomponent fibers having a spin denier of about 1.4, which showed a diameter of about 12 microns when viewed under a microscope. The speed during the drawing process was calculated to be about 3900 m / min.

Example 15

The sulfopolyester polymer of Example 13 was spun into bicomponent islands-in-the-sea cross-section fibers with 64 island fibers using a bicomponent extrusion line. The primary extruder fed Eastman F61HC polyester melt to form islands in the islands-in-sea fiber cross-sectional structure. The secondary extruder fed the sulfopolyester polymer melt to form seas in the islands-in-sea bicomponent fibers. The intrinsic viscosity of the polyester was 0.61 dL / g and the melt viscosity of the dry sulfopolyester was about 7000 poise measured at 240 ° C. and 1 rad / sec strain using the melt viscosity measurement procedure described above. The islands-in-sea bicomponent fibers were made using a spinneret with 198 holes and a throughput rate of 0.85 gm / min / hole. The polymer ratio between "island" polyester and "sea" sulfopolyester was 65% vs. 35%. The bicomponent fiber was spun using an extrusion temperature of 280 ° C for the polyester component and an extrusion temperature of 260 ° C for the sulfopolyester component. The bicomponent fiber contained a number of filaments (198 filaments) and melt spun at a rate of about 530 meters / minute to form a filament having a nominal d / f of about 14. A 24 wt% finish solution of PT 769 finish from Goulston Technologies was applied to the bicomponent fiber using a kiss roll applicator. The filaments of the bicomponent fibers are then drawn in line using a set of two godet rolls heated to 90 ° C. and 130 ° C., respectively, and drawn to a final draw roll operated at a speed of about 1750 meters / minute. A filament draw ratio of 3.3X was provided to form a stretched islands-in-sea bicomponent filament having an average diameter of about 4.5 nominal d / f or about 25 microns. The filaments consisted of polyester microdenier fiber “islands” having an average diameter of about 2.5 microns.

Example 16

The stretched islands-in-sea bicomponent fibers of Example 15 were cut into short length fibers of 3.2 millimeters and 6.4 millimeters cut length, thereby producing short length bicomponent fibers having a 64 islands islands cross-sectional structure. The short-cut bicomponent fibers consisted of "island" of polyester and "sea" of water dispersible sulfopolyester polymer. The cross-sectional distribution of islands and seas was essentially consistent along the length of these short-cut bicomponent fibers.

Example 17

The drawn islands-in-sea bicomponent fibers of Example 15 were immersed in soft water for about 24 hours and then cut into short length fibers of 3.2 millimeters and 6.4 millimeters cut length. The water dispersible sulfopolyester was at least partially emulsified before cutting into short length fibers. Thus, partial separation of the islands from the sea component is achieved, thereby producing partially emulsified short island island bicomponent fibers.

Example 18

The short-cut length islands-in-sea bicomponent fibers of Example 16 were washed with soft water at 80 ° C. to remove the water dispersible sulfopolyester “sea” component, thereby forming the polyester micros that were the “island” component of the bicomponent fiber. The fiber was released. The washed polyester microfibers were washed with soft water at 25 ° C. to essentially remove most of the “sea” component. Optical microscopy of the washed polyester microfibers showed an average diameter of about 2.5 microns and lengths of 3.2 and 6.4 millimeters.

Example 19

The short-cut length of partially emulsified islands-in-sea bicomponent fibers of Example 17 were washed with soft water at 80 ° C. to remove the water dispersible sulfopolyester “sea” component, thereby forming the polyester that was the “island” component of the fiber. Microfibers were released. The washed polyester microfibers were washed with soft water at 25 ° C. to essentially remove most of the “sea” component. Optical microscopic observation of the washed polyester microfibers revealed polyester microfibers with an average diameter of 2.5 microns and lengths of 3.2 and 6.4 millimeters.

Comparative Example 20

Wet-laminated hand sheets were prepared using the following procedure. 7.5 gm of Alba Southern Southern Bleached Softwood Kraft (SBSK) manufactured by International Paper, Memphis, Tenn., And 188 gm of room temperature water are placed in a 1000 ml pulp mill and Pulping at 7000 rpm produced a pulped mixture. This pulped mixture was transferred to an 8 liter metal beaker with 7312 gm of room temperature water to produce a pulp slurry of about 0.1% consistency (7500 gm water and 7.5 gm fibrous material). This pulp slurry was shaken for 60 seconds using a high speed impeller mixer. The procedure for preparing a hand sheet from this pulp slurry is as follows. The pulp slurry was poured into a 25 centimeter by 30 centimeter hand sheet mold with continued stirring. The drop valve was pulled and the pulp fibers flowed out on the screen to form a hand seat. A 750 g / m ² (gsm) blotter paper was placed on top of the formed hand sheet and the blotter paper was flattened onto the hand sheet. The screen frame was raised and turned over on a transparent release paper for 10 minutes. The screen was lifted vertically from the formed hand sheet. Two 750 gsm blotter paper were placed on top of the formed hand sheet. The hand sheet was dried with three blotter papers at about 88 ° C. for 15 minutes using a Norwood Dryer. One blotter paper was removed so that one blotter paper remained on each side of the hand sheet. The hand sheet was dried at 65 ° C. for 15 minutes using a Williams Dryer. The hand sheet was then also dried using a 40 kg dry press for 12 to 24 hours. The blotter paper was removed to obtain a dry hand sheet sample. The hand sheet was trimmed to 21.6 centimeters by 27.9 centimeters dimensions for testing.

Comparative Example 21

Wet-laminated hand sheets were prepared using the following procedure. Alba-Cell Southern Bleached Softwood Craft (SBSK) from 7.5 gm of International Paper, Memphis, Tenn., Pre-gelatinized quaternary cationic, manufactured from Avebe, Foxgm, Netherlands, of 0.3 gm. A pulped mixture was prepared by placing potato starch Solvitose N, and 188 gm of room temperature water in a 1000 ml pulp maker and pulping at 7000 rpm for 30 seconds. This pulped mixture was transferred to an 8 liter metal beaker with 7312 gm of room temperature water to make a concentration of about 0.1% (7500 gm water and 7.5 gm fibrous material) to prepare a pulp slurry. This pulp slurry was shaken for 60 seconds using a high speed impeller mixer. The rest of the procedure for making a hand sheet from this pulp slurry is as in Example 20.

Example 22

Wet-laminated hand sheets were prepared using the following procedure. Albacell Southern Bleached Softwood Craft (SBSK) manufactured from 6.0 gm of International Paper, Memphis, Tenn., Pre-gelatinized quaternary cationic potato starch made from Abebe, 0.3 gm of Foxhole, Netherlands. A fiber mixture slurry was prepared by placing sorbitol N, 1.5 gm of 3.2 millimeter cut length islands-in-sea fibers, and 188 gm of room temperature water in a 1000 ml pulp maker and pulping at 7000 rpm for 30 seconds. This fiber mixture slurry was heated to 82 ° C. for 10 seconds to emulsify and remove the water dispersible sulfopolyester component in the islands-in-sea fibers to release polyester microfibers. The fiber mixture slurry was then modified to produce a sulfopolyester dispersion comprising a sulfopolyester and a microfiber-containing mixture comprising pulp fibers and polyester microfibers. The microfiber-containing mixture was also washed with 500 gm of room temperature water to also remove the water dispersible sulfopolyester from the microfiber-containing mixture. This microfiber-containing mixture was transferred to an 8 liter metal beaker with 7312 gm of room temperature water to make a concentration of about 0.1% (7500 gm water and 7.5 gm fibrous material) to prepare a microfiber-containing slurry. This microfiber-containing slurry was shaken for 60 seconds using a high speed impeller mixer. The rest of the procedure for making a hand sheet from this microfiber-containing slurry is as in Example 20.

Comparative Example 23

Wet-laminated hand sheets were prepared using the following procedure. 7.5 gm of MicroStrand 475-106 microglass fiber, available from Johns Manville, Denver, CO, pre-gelatinized quaternary cation made from Abebe, 0.3 gm of Foxhole, The Netherlands A glass fiber mixture was prepared by placing sorbitol N, a raw potato starch, and 188 gm of room temperature water in a 1000 ml pulp maker and pulping at 7000 rpm for 30 seconds. This glass fiber mixture was transferred to an 8 liter metal beaker with 7312 gm of room temperature water to make a concentration of about 0.1% (7500 gm water and 7.5 gm fibrous material) to make a glass fiber slurry. This glass fiber slurry was shaken for 60 seconds using a high speed impeller mixer. The rest of the procedure for making a hand sheet from this glass fiber slurry is as in Example 20.

Example 24

Wet-laminated hand sheets were prepared using the following procedure. 3.8 gm of MicroStrand 475-106 micro glass fibers available from Jones Manville, Denver, Colorado, USA, 3.2 mm cut length sea island fibers of Example 16 of 3.8 gm, 0.3 mm of Abbe, Holland, Holland A fiber mixture slurry was prepared by placing sorbitos N, a pre-gelatinized quaternary cationic potato starch, and 188 gm of room temperature water prepared in a 1000 ml pulp maker and pulping at 7000 rpm for 30 seconds. The fiber mixture slurry was heated to 82 ° C. for 10 seconds to emulsify and remove the water dispersible sulfopolyester component in the bicomponent fibers to release polyester microfibers. The fiber mixture slurry was then modified to produce a sulfopolyester dispersion comprising a sulfopolyester and a microfiber-containing mixture comprising glass microfibers and polyester microfibers. The microfiber-containing mixture was also washed with 500 gm of room temperature water to remove sulfopolyester from the microfiber-containing mixture as well. This microfiber-containing mixture was transferred to an 8 liter metal beaker with 7312 gm of room temperature water to make a concentration of about 0.1% (7500 gm water and 7.5 gm fibrous material) to prepare a microfiber-containing slurry. This microfiber-containing slurry was shaken for 60 seconds using a high speed impeller mixer. The rest of the procedure for making a hand sheet from this microfiber-containing slurry is as in Example 20.

Example 25

Wet-laminated hand sheets were prepared using the following procedure. 1000 ml pulp of 3.2 gm cut length islands-in-the-sea fiber of 7.5 gm of Example 16, sorbitos N, a pre-gelatinized quaternary cationic potato starch made from Abbe, 0.3 gm of Foxhole, Netherlands, and 188 gm of room temperature water The fiber mixture slurry was prepared by placing in a maker and pulping at 7000 rpm for 30 seconds. This fiber mixture slurry was heated to 82 ° C. for 10 seconds to emulsify and remove the water dispersible sulfopolyester component in the islands-in-sea fibers to release polyester microfibers. The fiber mixture slurry was then deformed to produce sulfopolyester dispersions and polyester microfibers. The sulfopolyester dispersion consisted of water dispersible sulfopolyester. The polyester microfibers were washed with 500 gm of room temperature water to also remove sulfopolyester from the polyester microfibers. The polyester microfibers were transferred to an 8 liter metal beaker with 7312 gm of room temperature water to a concentration of about 0.1% (7500 gm water and 7.5 gm fibrous material) to prepare a microfiber slurry. This microfiber slurry was shaken for 60 seconds using a high speed impeller mixer. The rest of the procedure for making a hand sheet from this microfiber slurry is as in Example 20.

The hand sheet samples of Examples 20-25 were tested and the properties are provided in Table 6 below.

TABLE 6

The hand sheet basis weight is determined by weighing the hand sheet and calculating it in gram weight per square meter (gsm). Hand sheet thickness was measured using the Ono Sokki EG-233 thickness gauge and reported in millimeter thickness. Density was calculated as gram weight per cubic centimeter. Porosity was measured using a Grainer porosity manometer with a 1.9 × 1.9 cm square aperture head and a 100 cc capacity. The porosity was measured using an Instron ModelTM on six 30 mm x 105 mm test strips with 100 cc of water. The average of six measurements was reported for each example. From the above test data, it can be observed that by adding the polyester microfiber of the present invention, a significant improvement in the tensile properties of the wet-laid fibrous structure is obtained.

Example 26

The sulfopolyester polymer of Example 13 was spun into bicomponent islands-in-the-sea cross-section fibers with 37 island fibers using a bicomponent extrusion line. The primary extruder fed Eastman F61HC polyester to form "islands" in the islands cross-sectional structure. The secondary extruder supplied the water dispersible sulfopolyester polymer to form "sea" in the island-in-sea bicomponent fibers. The inherent viscosity of the polyester was 0.61 dL / g and the melt viscosity of the dry sulfopolyester was about 7000 poise measured at 240 ° C. and 1 rad / sec strain using the melt viscosity measurement procedure described above. This islands-in-sea bicomponent fiber was prepared using a spinneret with 72 holes and a throughput rate of 1.15 gm / min / hole. The polymer ratio between "island" polyester and "sea" sulfopolyester was 2 to 1. This bicomponent fiber was spun using an extrusion temperature of 280 ° C for the polyester component and an extrusion temperature of 255 ° C for the water dispersible sulfopolyester component. This bicomponent fiber contained a large number of filaments (198 filaments) and was melt spun at a rate of about 530 meters / minute to form filaments with a nominal d / f of 19.5. A 24 wt% finish solution of PT 769 finish from Goulston Technologies was applied to the bicomponent fiber using a kiss roll applicator. The filaments of the bicomponent fibers are then drawn in a row using two sets of goblet rolls heated to 95 ° C. and 130 ° C., respectively, and drawn to a final draw roll operated at a speed of about 1750 meters / minute, to about 3.3 ×. The filament draw ratio was provided to form a stretched islands-in-sea bicomponent filament having a nominal d / f of about 5.9 or an average diameter of about 29 microns. The filaments consisted of polyester microfiber "islands" having an average diameter of about 3.9 microns.

Example 27

The drawn islands-in-sea bicomponent fibers of Example 26 were cut into short length bicomponent fibers of 3.2 millimeters and 6.4 millimeters cut length, thereby producing short length fibers having 37 islands-in-sea cross-sectional structures. The fibers consisted of "islands" of polyester and "sea" of water dispersible sulfopolyester polymers. The cross-sectional distribution of "island" and "sea" was essentially consistent along the length of the bicomponent fiber.

Example 28

The short-cut length islands-in-sea fibers of Example 27 were washed with soft water at 80 ° C. to remove the water dispersible sulfopolyester “sea” component, thereby removing the polyester microfibers that were the “island” component of the bicomponent fiber. Released. The washed polyester microfibers were washed with soft water at 25 ° C. to essentially remove most of the “sea” component. The washed polyester microfibers were observed under an optical microscope and had an average diameter of about 3.9 microns and lengths of 3.2 and 6.4 millimeters.

Example 29

The sulfopolyester polymer of Example 13 was spun into bicomponent islands-in-the-sea cross-section fibers with 37 island fibers using a bicomponent extrusion line. The primary extruder fed polyester to form "islands" in the islands-in-sea fiber cross-sectional structure. The secondary extruder supplied the water dispersible sulfopolyester polymer to form "sea" in the island-in-sea bicomponent fibers. The intrinsic viscosity of the polyester was 0.52 dL / g and the melt viscosity of the dry water dispersible sulfopolyester was about 3500 poise as measured at 240 ° C. and 1 rad / sec strain using the melt viscosity measurement procedure described above. The islands-in-sea bicomponent fibers were made using two spinnerets with 175 holes each and a throughput rate of 1.0 gm / min / hole. The polymer ratio between "island" polyester and "sea" sulfopolyester was 70% to 30%. This bicomponent fiber was spun using an extrusion temperature of 280 ° C for the polyester component and an extrusion temperature of 255 ° C for the sulfopolyester component. This bicomponent fiber contained a number of filaments (350 filaments) and was melt spun at a rate of about 1000 meters / minute using a winding roll heated to 100 ° C., yielding an average of about 9 nominal d / f and about 36 microns. A filament having a fiber diameter was formed. A 24 wt% finish solution of PT 769 finish was applied to the bicomponent fiber using a kiss roll applicator. After combining the filaments of the bicomponent fibers, they were drawn at 3.0x on a draw line at a draw roll speed of 100 m / min and a temperature of 38 ° C. to draw stretched sea islands with an average d / f of about 3 and an average diameter of about 20 microns Minute filaments formed. The elongated islands-in-sea bicomponent fibers were cut into short length fibers of about 6.4 millimeters in length. The short length islands-in-sea bicomponent fibers consisted of polyester microfiber “islands” with an average diameter of about 2.8 microns.

Example 30

The short-cut length islands-in-sea bicomponent fibers of Example 29 were washed with soft water at 80 ° C. to remove the water dispersible sulfopolyester “sea” component, thereby removing the polyester microfibers that were the “island” component of the fiber. Released. The washed polyester microfibers were washed with soft water at 25 ° C. to essentially remove most of the “sea” component. Optical microscopic observation of the washed fibers showed polyester microfibers of average diameter of about 2.8 microns and about 6.4 millimeters in length.

Example 31

Wet-laminated microfiber raw hand sheets were prepared using the following procedure. The 3.2 millimeter cut length islands-in-sea bicomponent fibers of 56.3 gm of Example 16, sorbitos N, a pre-gelatinized quaternary cationic potato starch made from Abbe, 2.3 gm of Foxhole, and 1410 gm of room temperature water Fiber slurry was prepared by placing in a 2 liter beaker. The fiber slurry was stirred. About 352 ml, an amount of 1/4 of this fiber slurry, was placed in a 1000 ml pulp maker and pulped at 7000 rpm for 30 seconds. The fiber slurry was heated to 82 ° C. for 10 seconds to emulsify to remove the water dispersible sulfopolyester component in the bicomponent fiber and to release the polyester microfibers. The fiber slurry was then deformed to produce sulfopolyester dispersions and polyester microfibers. The polyester microfibers were washed with 500 gm of room temperature water to further remove sulfopolyester from the polyester microfibers. Sufficient room temperature water was added to make 352 ml of microfiber slurry. This microfiber slurry was repulped at 7000 rpm for 30 seconds. This microfiber was transferred to an 8 liter metal beaker. The remaining three quarters of the fiber slurry were similarly pulped, washed, rinsed, repulped and transferred to an 8 liter metal beaker. Thereafter, 6090 gm of room temperature water was added to produce a concentration of about 0.49% (7500 gm water and 36.6 gm polyester microfiber) to prepare a microfiber slurry. This microfiber slurry was shaken for 60 seconds using a high speed impeller mixer. The rest of the procedure for making a hand sheet from this microfiber slurry is as in Example 20. The microfiber raw hand sheet having a basis weight of about 490 gsm consisted of polyester microfibers of average diameter of about 2.5 microns and average length of about 3.2 millimeters.

Example 32

Wet-laminated hand sheets were prepared using the following procedure. 1000 ml of 7.5 gm of polyester microfiber raw material hand sheet of Example 31, sorbitos N, a pre-gelatinized quaternary cationic potato starch made from Abebe, 0.3 gm of Foxhole, Netherlands, and room temperature water of 188 gm Placed in a pulp maker and pulped at 7000 rpm for 30 seconds. The microfibers were transferred to an 8 liter metal beaker with 7312 gm of room temperature water to make a concentration of about 0.1% (7500 gm water and 7.5 gm fibrous material) to prepare a microfiber slurry. This microfiber slurry was shaken for 60 seconds using a high speed impeller mixer. The rest of the procedure for making a hand sheet from this slurry is as in Example 20. A 100 gsm wet-laminated hand sheet of polyester microfibers having an average diameter of about 2.5 microns was obtained.

Example 33

The islands-in-sea bicomponent fiber of Example 6.4 millimeter cut length was washed at 80 ° C. with soft water to remove the water dispersible sulfopolyester “sea” component, whereby the polyester micro was the “island” component of the bicomponent fiber. The fiber was released. The washed polyester microfibers were washed with soft water at 25 ° C. to essentially remove most of the “sea” component. Optical microscopic observation of the washed polyester microfibers showed an average diameter of about 2.5 microns and a length of 6.4 millimeters.

Example 34

Ethylenediamine tetraacetic acid from Sigma-Aldrich Company, Atlanta, Georgia, USA, about 1% by weight of the short-cut length of island-in-sea bicomponent fibers of Examples 16, 27, and 29 Tetra sodium salt (Na ₄ EDTA) is washed separately at 80 ° C. using soft water containing about 1% by weight of bicomponent fibers to remove the water dispersible sulfopolyester “sea” component, thereby providing bicomponent fibers. The polyester microfibers that were the "island" component of were released. Adding one or more softeners such as Na ₄ EDTA aids in the removal of the water dispersible sulfopolyester polymer from the islands-in-sea bicomponent fiber. The washed polyester microfibers were washed with soft water at 25 ° C. to essentially remove most of the “sea” component. Observation of the washed polyester microfibers under an optical microscope revealed excellent release and separation of the polyester microfibers. The use of water softeners such as Na ₄ EDTA in water prevents Ca ⁺⁺ ion exchange of sulfopolyesters, which can adversely affect the water dispersibility of sulfopolyesters. Typical soft water may contain Ca ⁺⁺ ion concentrations of up to 15 ppm. The softening water used in the processes described herein has an essentially zero concentration of Ca ⁺⁺ and other polyvalent ions, or alternatively uses a sufficient amount of softener such as Na ₄ EDTA to bind this Ca ++ ion and other polyvalent ions. It is desirable to. This polyester microfiber can be used to make a wet-laminated sheet using the procedure of the above-described embodiment.

Example 35

The short-cut length islands-in-sea bicomponent fibers of Example 16 and Example 27 were treated separately using the following procedure. Solbitose N, a pre-gelatinized quaternary cationic potato starch made from Abbe, 17 grams of Foxhole, Netherlands, was added to distilled water. After the starch was completely dissolved or hydrolyzed, 429 grams of short-cut islands-in-sea bicomponent fibers were slowly added to the distilled water to prepare a fiber slurry. The Williams rotary Continuous Feed Refiner (5 inch diameter) was turned on to refine or mix the fiber slurry to provide sufficient shearing action to separate the water dispersible sulfopolyester from the polyester microfibers. The contents of the raw chests were poured into a 24 liter stainless steel container and the lid was tightly closed. The stainless steel vessel was placed on a propane cooker and heated until the fiber slurry began to boil at about 97 ° C. to remove the sulfopolyester component in the island's fiber and release the polyester microfibers. After the fiber slurry reached the boiling point, it was shaken with a manual shake paddle. The contents of the stainless steel vessel were poured into a 27 inch by 15 inch by 6 inch deep Fall Bottom Knuche with a 30 mesh screen to make sulfopolyester dispersions and polyester microfibers. The sulfopolyester dispersion consisted of water and water dispersible sulfopolyester. The polyester microfibers were washed at 17 ° C. with 10 liters of soft water for 15 seconds in Knuche, and pressed to remove excess water.

20 grams of polyester microfibers (based on dry fibers) was added to 2000 ml of water at 70 ° C. and using a 2 liter 3000 rpm 3/4 horsepower hydropulper manufactured by Hermann Manufacturing Company. Shaking for 3 minutes (9,000 revolutions) yielded a microfiber slurry at 1% concentration. A handsheet was prepared using the procedure described above in Example 20.

Observation of the handsheet with light microscopy and scanning electron microscopy showed good separation and formation of polyester microfibers.

Example 36

This example is a two-component extruded to form 4.5 denier / filament fibers (each filament having a 37 PET island comprising Eastman F-61HC polyester and a sea fraction comprising Eastman sulfopolyester polymer) Relates to the opening of islands-in-the-sea fibers. The ratio of polyester component to sulfopolyester sea component was 70 PET / 30 sulfopolyester. The fibers were made using a two-component islands-in-the-sea spin pack made by Hills Inc. (Melbourne, FL). Extrusion and stretching conditions were adjusted to achieve a nominal 22 micron total starting fiber targeting individual islands with an average diameter of 2.0 microns. Elongated yarns were prepared and cut into 1.5 mm long staple fibers. The bicomponent fibers were cut to a total length of 1.5 mm to produce cut bicomponent fibers, which were used after evaluation to produce open microfibers containing individual 3.0 microns of individual PET islands.

The bicomponent fiber comprising 37 INS filaments cut to 1.5 mm length was opened by a batch open process to remove the sulfopolyester sea component, a binder that holds the 37 PET islands together in the cut bicomponent fiber. In the open process of Example 36, a 20 kg load of deionized water was added to a 10 gallon laboratory hydropulping machine (Adirondack Machinery Co.) and low pressure steam was added while stirring at a 30% speed setpoint. Heated to ° C. When the deionized water reached 79 ° C., 400 g of 37 INS chopped bicomponent fibers were quickly added to the stirred water, all the chopped bicomponent fibers were added and the timer started to run. After 10 seconds of agitation, a nominal 400 cc open microfiber slurry sample was recovered and immediately screened using a colander to contain sulfopolyester polymer, which was removed during contact for 10 seconds in 79 ° C. water. The microfiber product was quickly separated from the first mother liquor. The microfiber product sample was pressed against the screen to dehydrate the microfiber product to a water content of about 20-25%. After 20 second mixing time, 60 second mixing time, and 120 second mixing time, samples were recovered from the hydropulping machine, and each sample was similarly screened to recover the first mother liquor separated from the microfiber product.

The degree of removal of the sulfopolyester sea component was evaluated by measuring the solids content of the first mother liquor recovered from each of the four test samples. In this process, the percent solids level of the final sample taken after a long 120 second contact time indicates a condition in which the largest amount of sulfopolyester is removed from the starting cut bicomponent fiber with near quantitative removal. The solids content of each sample was determined by measuring the weight (+/- 0.001 g) of a 3 inch by 5 inch aluminum pan and then adding 100.0 g of the first mother liquor sample containing the removed sulfopolyester. Water was boiled off using a hot plate at medium speed to prevent liquid from bumping out of the pan. After removing almost all the water on the hot plate, a sample pan containing polymer residue is added to a uniform moisture content by placing the pan in a forced air oven at 180 ° C. for 5 minutes to adjust the residue to a uniform moisture content. Dried over. The pan was weighed again (+/- 0.001 g) and the weight of the residue was calculated by subtracting the starting pan weight. The solids content was calculated by dividing the residue weight by the starting sample weight.

The change in solids in the first mother liquor recovered from the open process of Example 36 is shown in FIG. 8.

After quantitative removal of the sulfopolyester polymer from the chopped multicomponent fiber, the solid residue in the first mother liquor will not increase. The test results showed a minimal increase in the solids content of the recovered first mother liquor after recovering the first 10 second sample. The difference in the solids level of the sample recovered at 20, 60, and 120 seconds is within the test error range. After only 10 seconds of contact at 79 ° C. water, the removal efficiency was 95% or within 5% of the level of removal considered quantitative. In Example 36, the sulfopolyester sea component was effectively removed from 4.5 dpf 37 INS cleaved bicomponent fibers using a contact time of 15 seconds or less in water stirred at 79 ° C.

Example 37

The process of Example 36 was repeated, increasing the rate setpoint of the Adirondac hydropulping machine from 30% to 80% to improve the mixing of 37 INS cut bicomponent fibers in deionized water heated to 79 ° C. . A sulfopolyester removal profile similar to that of FIG. 1 was observed where the solid% value of the initial 10 second sample was within the test accuracy of the later solids value, indicating a quantitative sulfopolyester removal rate after 10 seconds contact time at 79 ° C.

Example 38

The 37 INS bicomponent fiber opening process was changed in the same manner as in Example 36, by changing the temperature of the deionized water in contact with the cleaved bicomponent fibers to 74 ° C. or 5 ° C. below the temperature used in Example 36. Was performed.

The results are shown in FIG. 9.

Samples recovered at 20, 60, and 120 seconds showed a solids content consistent with the quantitative removal of sulfopolyester from the cut bicomponent fibers. Even when contacted for 10 seconds in 74 ° C. water, sulfopolyester removal was within 5% of quantitative removal, indicating that at 74 ° C. the sea component was quickly removed from the cut bicomponent fibers.

Example 39

The cleaved bicomponent fiber of Example 36, with 37 INS configuration and 4.5 dpf fineness, was opened in a manner similar to that described in Example 36, with the agitation of the hydropulping machine set to a 50% set point and opening stage The temperature of the deionized water used for was reduced to 68 ° C. Samples were collected after 15 seconds, 30 seconds, 60 seconds, and 120 seconds of bicomponent fibers cut at a stirred 68 ° C. temperature. For the first mother liquor recovered from each sample, the sulfopolyester content was analyzed by measuring the solids content using the method described in Example 36. The sulfopolyester content in the first mother liquor is shown in FIG. 10 as a function of treatment time. The time required for the solid level to reach asymptotes (sulfopolyester removal approaches quantitative levels) is an indication of the rate of the open phase.

At 68 ° C., quantitative removal of the sulfopolyester sea component was achieved after 60 seconds or more of contact time in 68 ° C. water, but removal after a short time (15 seconds) was far from quantitative removal, and only 30 seconds later approach quantitative removal. It was. In comparison, Examples 36-38 showed nearly quantitative sulfopolyester sea component removal in samples taken after a 10 second contact time (where water temperatures in these samples were higher than in Example 39). Example 39 shows that when a longer fiber / hydrothermal contact time is applied at 68 ° C. to 60 seconds or more, the bicomponent fiber opening process is more effective but the sea component is incompletely removed at shorter treatment times.

Comparative Example 40

The bicomponent fiber opening process was performed in the same manner as in Example 36, but the temperature of the deionized water used during the opening process was further reduced to 63 ° C. Samples were recovered after 15, 30, 60, and 120 seconds, and the solid components were analyzed for the first mother liquor recovered from each sample to determine the amount and opening efficiency of the removed sulfopolyester. The sulfopolyester removal rate is shown in FIG. 11. The results in FIG. 11 show slower removal behavior of the sulfopolyester sea component.

About two thirds of the sulfopolyester sea component was removed from the cut bicomponent fiber after 15 seconds contact time and about 85% after 30 seconds contact. At 60 second contact time the removal level was high but not quantitative. At 63 ° C., an open time of more than 2 minutes was required to remove the sea component from the cut bicomponent fiber to a quantitatively considered removal level. The main effect of the open process is to remove the sea component at a level considered to be quantitative, and in this regard, the slow removal rate measured in Comparative Example 40, on a commercial scale, comprises a cleavage comprising sulfopolyester as a removable component. It was shown to be a slower opening condition to open the bicomponent fibers. In Comparative Example 40, the agitation setpoint was 30%, and higher agitation or turbulence levels during the opening process can reduce the time required to perform quantitative opening, and a reduction in mixing energy can slow the opening process and sulfopolyester It may take much longer to completely remove the components.

The removal rates described in this example and all previous examples are based on chopped bicomponent fibers comprising sulfopolyester as removable components. If the removable component is replaced with a polymer type that can be removed (dissolved or emulsified) more easily or more difficultly into the water phase, the opening temperature will vary depending on the nature of the removable polymer. These examples are provided to illustrate the removal properties of bicomponent fibers containing a particular type of removable sulfopolyester polymer, but in terms of the open conditions they are suitable for bicomponent fibers comprising other types of removable polymers. It does not mean that it is limited.

Comparative Example 41

In Comparative Example 41, the same process as described in Example 36 was used, but sufficient CaCl ₂ was added to the deionized water load to add Ca ⁺² cation to the aqueous phase at 20 ppm by weight, and the temperature of the open process was 77 ° C. The sulfopolyester removal profile for fiber opening under these conditions is shown in FIG. 12.

When compared to Examples 36 and 37 performed with deionized water at similar open temperatures, the sulfopolyester removal rate in Comparative Example 41 was much slower. In the previous two examples, almost quantitative sulfopolyester removal was recorded after a contact time of about 10 seconds in deionized water at 79 ° C. In Comparative Example 41, only about 90% of removal was achieved after 30 seconds with similar stirring levels.

Compared with the removal properties in Examples 36, 37, and 38, the sulfopolyester removal properties in Comparative Example 41 are slower, with only about 90% of removal measured after 30 seconds in Comparative Example 41, whereas the previous run In the examples almost quantitative clearance was measured after 10-15 seconds. The removal properties of Comparative Example 41 were similar to those measured for Comparative Example 40, which was run at an open temperature lower than 14 ° C. but using deionized water without hard cations (FIG. 11). Comparative Example 41 is provided to show that the hardness of the water used in the open process greatly influences the contact time and temperature required to open the bicomponent fiber comprising the water dispersible sulfopolyester component, and 20 ppm Ca ^{+ 2} Hardness is borderline and higher levels can slow or disable complete fiber opening.

Example 42

continuity Two-component  Fiber opening process

Previous Examples 36-39 illustrate the use of a batch type opening process to remove the water dispersible polymer fraction from the bicomponent fiber. In commercial manufacturing, continuous type processes are generally used because continuous operation provides higher efficiency. The main improvement in efficiency is due to the batch load of the overall batch cycle and the omission of the batch discharge step, which eliminates significant process time during the batch cycle and also achieves the same yield using smaller equipment sizes.

There are two main types of continuous operation applicable to the open process of bicomponent fibers consisting of removing or extracting the water dispersible polymer from the water non-dispersible polymer fiber material into the aqueous phase. A first type of process involves removing open microfiber slurries from the stirred tank at the same mass flow rate while adding water and chopped multicomponent fibers to the stirred tank at a constant rate and at a constant feed rate in the stirred tank. A continuous stirred tank reactor (CSTR) capable of maintaining a constant level of chopped multicomponent fiber slurry.

A disadvantage of the CSTR is the residence time distribution of the cut multicomponent fibers inside the stirred tank during the process. In a batch type process, all products are processed for a nominally equal amount of time during the batch cycle between the end of the load phase and the start of the discharge phase. In the CSTR, the chopped multicomponent fibers applied to the stirred tank are mixed with the material treated for various lengths of time in the tank, and the material discharged from the tank includes the microfibers treated inside the tank for various lengths of time. The amount of time the microfibers stay inside the tank during the CSTR opening process is defined by the statistical mean, and the center point of the statistical mean is the average time the microfiber material stays inside the tank. This statistical mean residence time (RT) at which the microfibers stay inside the stirred tank is defined by the equation RT = V _t / Q, where V _t is the total volume of liquid contained in the stirred tank and Q is continuous The volume of liquid exiting the tank during operation.

The problem with CSTRs for continuous operation is that, based on this statistical distribution, some of the cut multicomponent fibers applied to the tank stay inside for only a short period of time (which may be insufficient for full fiber opening), and the distribution At the other end of the part of the cut multicomponent fiber for a much longer time than the target average RT in the tank, during which time small diameter microfibers can be mechanically damaged by prolonged excessive mixing inside the tank. Is to stay.

For this reason, another method for continuous fiber opening processes is the plug flow process commonly used for chemical treatment. In this type of process, fluid is applied to a process vessel at a constant rate, and each element of fluid applied to the vessel moves through the vessel at the same nominal speed so that all elements of the fluid are inside the vessel for a nominally equivalent amount of time. It can be contained in. Compared with CSTR, the plug flow opening process presents problems with the cut multicomponent fiber portion remaining inside the process vessel for an insufficient time to fully open and the fiber portion staying in the tank for an excessive time causing mechanical damage to the microfibers. May be omitted.

In one embodiment of the plug flow opening process for bicomponent fibers, the plug flow vessel may be a long pipe section, wherein a hot aqueous multicomponent fiber slurry is applied at one end of the pipe section at a constant volume flow rate and multicomponent After the fiber slurry passes through the pipe at a nominal constant flow rate and after the residence time inside the pipe (defined as the total volume contained within the process pipe divided by the volume flow rate of the multicomponent fiber slurry entering the process pipe) The multicomponent fiber slurry exits the other end of the process pipe.

Common plug flow Two-component  Fiber opening process

Several examples of a continuous plug flow process are provided for opening a cut multicomponent fiber comprising a water dispersible sulfopolyester phase (which is removed from the cut multicomponent fiber during the open process). Certain process steps in the overall plug flow operation can fall into the following categories:

1) a process for preparing a concentrated cold cut multicomponent fiber slurry from the cut multicomponent fibers,

2) producing a hot treated aqueous stream for mixing with cold cut multicomponent fiber slurries,

3) a combination process of streams (1) and (2) for producing a hot multicomponent fiber slurry,

4) a process of opening the fibers as the hot multicomponent fiber slurry 3 flows into the plug flow through the process pipe to produce an open microfiber slurry, and

5) Separating the microfiber product stream from an open microfiber slurry containing the removed sulfopolyester polymer using a screen filtration device.

A more detailed description of each of these specific process steps is provided below.

1) Preparation of cold cut multicomponent fiber slurries from cut multicomponent fibers

Tap water containing a nominal 25 ppm hard cation was passed through a softener to reduce the concentration of hard cations to less than 1 ppm. Soft water of about 18 ° C. was continuously metered to a stirred tank containing a 10 gallon fluid level at a target flow rate maintaining a constant fluid level in the stirred tank. The chopped multicomponent fibers of Example 36 were successively added to the well stirred mixture tank at a constant rate and rate relative to the flow, resulting in a cold chopped multicomponent fiber slurry containing the chopped multicomponent fibers at a target concentration. . Pump the cold cut multicomponent fiber slurry of the cut multicomponent fibers out of the cold slurry mixture tank using a variable speed centrifugal pump to pump out the cold cut multicomponent fiber slurry, the cold slurry mixture tank Pumped at the same rate as the components were fed into the mixture tank to maintain a constant level at.

The operating principle of the cold slurry processing step is that the hard cations are provided in such a way that the agitation provided is sufficient to prevent the cut multicomponent fibers from settling in the mixture tank while maintaining the cut multicomponent fibers in suspension. It is to disperse the cut multi-component fiber into cold water containing a low concentration of. Both the water temperature and the residence time of the chopped multicomponent fiber in the cold slurry tank are designed to prevent significant sulfopolyester removal in the cold slurry tank and to minimize mechanical damage to the fibers in the tank.

2) Preparation of Hot Treated Aqueous Stream for Fiber Opening Process

Deionized water was metered into the injector of a steam heated tubular heat exchanger using a micro-adjustable flow controller to maintain a constant hot water flow at the target rate. Steam was applied to the heat exchanger to heat the deionized water stream to an outlet temperature of 96-98 ° C. at the target flow rate. Hot deionized water exiting the heat exchanger was sent to a mixing tee and combined with the cold cut multicomponent fiber slurry stream described above.

3) Combination of hot water stream and cold fiber slurry stream

The hot water stream (2) and the cold cut multicomponent fiber slurry stream (1) are continuously combined using only turbulence to homogeneously mix the two streams and combine the combined streams of the fiber open compartment (1 1/2) outside the mixing tee. The two streams were combined in a 1 1/2 inch pipe tee by continuously flowing through an inch schedule 40 CPVC pipe. The ratio of hot water (98 ° C.) to cold cut multicomponent fiber slurry (18 ° C.) is such that the temperature of the combined stream causes rapid opening or removal of the sulfopolyester polymer from the cut multicomponent fiber. It was chosen to be high enough. The target temperature for the combined stream was in the range of nominal 70-80 ° C. to allow sulfopolyester to flow rapidly through the 1 1/2 inch pipe opening device.

4) Fiber opening at plug flow through 1 1/2 inch pipe device

The opening device consisted of five 10 foot sections of 1 1/2 inch CPVC pipe, with a total flow length of 55 feet from the inlet to the outlet. An internal pipe volume of 0.78 ft ³ was calculated. A typical flow rate of the combined fiber slurry stream is about 1.1 ft ³ / min, which corresponds to a nominal residence time of 40 seconds as the combined fiber slurry flowing through the plug flow opening device.

An example is provided in which the length of the plug flow pipe section extends to a total length of 110 feet to obtain a total residence time of 80 seconds during the fiber opening step.

5) open microfiber recovery

Baskets 18 inches in diameter and 12 inches high were made of perforated steel sheet metal with 3/16 inch perforations. The holes are small enough so that the microfiber product leaving the opening stage cannot pass and the process water is discharged. The effluent from the 1 1/2 inch pipe opening device is sent directly to the basket, allowing the first mother liquor containing sulfopolyester to be discharged and recover the wet cake comprising open PET microfibers.

The continuous opening of the 37 islands-in-sea bicomponent fiber was performed by applying the general plug flow bicomponent fiber opening process described above to the cut bicomponent fibers of Example 36. In this example, a crude tap water of 18 ° C. was passed through a softening unit to remove less than 1 ppm of light cations and soft water at about 2.3 gallons in a stirred tank containing pretreated water at a nominal 12 gallon liquid level. A cold cut bicomponent fiber slurry was produced by metering in at / pm (gpm) or nominal 9 kg / min. When cold water was applied to the tank, a variable speed centrifugal pump with a 4 inch impeller was pumped from the bottom of the tank to the mixing tee and plug flow pipe sections of the open stage, to maintain a constant tank level. The speed of the pump was adjusted such that liquid was pumped out of the tank at the nominal 2.3 gpm rate as when added.

When water was added to the tank, the 37 INS chopped bicomponent fibers of Example 36 were continuously added to the liquid in the mixing tank at a rate of 325 g / min through the port at the top of the tank while providing sufficient agitation to the bicomponent fiber slurry in the tank. The applied cut bicomponent fibers were maintained in suspension inside the tank and prevented from settling. The concentration of the cut multicomponent fibers in the cold multicomponent fiber slurry during the continuous operation reached a steady state slurry concentration of about 3.5% by weight fibers in water.

The hot water stream for the process of Example 42 was generated using a Pic heater device, where it was decanted at a nominal rate of 6 gpm or 22 kg / min via a micro-adjustable flow control device to the inlet of the steam-heated heat exchanger. Ionized water was metered in. The outlet temperature of the deionized water leaving the heat exchanger was adjusted to 97 ° C. by a temperature controller that regulates the steam pressure on the jacket of the heat exchanger to control the outlet temperature.

The hot water stream exiting the Pic heater flowed into the inlet of the mixing tee where it merged with the flow stream from the cold binary fiber slurry tank and then passed through a plug flow contact device. The combined total flow of the hot water stream and the cold binary fiber slurry stream was 8.3 gpm or 31 kg / min. The hot water stream made up about 71% by weight of the combined stream. The temperature of the combined stream exiting the mixing tee was measured at 75 ° C. and the outlet temperature was controlled by the individual temperature of each stream and the relative proportion of the streams in the mixing tee joining. Likewise, the concentration of chopped bicomponent fibers in the combined stream was reduced from 3.5% in cold slurry to 1.0% in the combined stream, based on the proportion of each individual stream before mixing.

The combined fiber slurry stream containing 1.0 wt% of the chopped bicomponent fibers at 75 ° C. was sent to the inlet of the plug flow opening device. The plug flow opening device consisted of five sections of 1 1/2 inch Schedule 40 CPVC pipe with a total flow length of 55 feet. The average plug flow rate through which the chopped bicomponent fiber slurry passed through the pipe section was calculated to be 1.2 ft / sec, and the average residence time of the chopped bicomponent fiber slurry in the plug flow zone was 45 under the flow conditions applied in Example 42. It was calculated to be seconds. The calculation of the Reynolds number for the pipe flow under these conditions indicates that the mixing energy obtained by the turbulence flows in a turbulent fashion that helps remove sulfopolyester polymer from the cleaved bicomponent fibers to create an open microfiber slurry. Determine if it exists. The process requirement of this example was to essentially remove quantitatively the sulfopolyester from the bicomponent precursor fiber within a 45 second contact time inside the pipe section.

Microfibers were filtered from an open microfiber slurry exiting the plug flow contact zone using a basket filter with 3/16 inch perforation (40% of surface area). Compared to the microfibers of Examples 36 to 38, the microfibers of Example 42 were filtered less effectively in terms of the fine fibers passing through the filter and the slower permeation rate. This result was due to the less entanglement of the microfibers while flowing in the plug flow zone of Example 42. Turbulent mixing in Example 42 may cause the microfibers to deform and entangle to a lesser extent than the vigorous stirring in the previous example, and the microfiber of Example 42 may require a dewatering screen with smaller openings.

The texture of the microfibers of Example 42 varied dramatically in the texture of the bicomponent fibers cut from the starting 1.5 mm. The texture of the starting wet chopped bicomponent fibers was very rough and sandy. The texture of the filtered microfiber of Example 42 was smooth to the extent that it was sticky, indicating that the fiber properties changed dramatically.

The microfibers of Example 42 were redispersed in additional water and diluted slightly to apply to microscope slides for characterization. Microscopy confirmed that the microfibers of Example 42 were very fine fibers with a nominal fiber diameter of about 3 microns (which corresponds to the starting diameter of the starting PET island domain in the 37 islands cut bicomponent fiber).

Microscopic examination confirmed the evidence that there was little residual sea material binding the 3 micron island fibers together in the resulting fibers. Incompletely open fibers comprising several island fibrils bound together by residual sea material incompletely removed during the process of Example 42 resulted in only a small fraction.

The microfiber of Example 42 by redispersing the filtered microfiber product to 0.02% solid fiber concentration in water and converting this diluted fiber solution into a paper hand sheet sample using a standard 6.25 inch diameter TAPPI sheet forming apparatus. Was evaluated. Comparative tests were performed using microfibers opened in the batch open process described in Examples 36-38. The microfiber of Example 42 converts the redisperse dilution fiber slurry into paper-like products by a high dilution formation technique using a conventional 6.25 inch diameter TAPPI sheet forming apparatus and process characteristics when redispersed into a low water solid slurry. Both were found to be qualitatively equivalent to the fibers opened by the batch process, both in terms of sheet properties.

Example 43

In Example 43, the process of Example 42 was carried out, but the rate of addition of the chopped bicomponent fibers to the cold slurry tank was increased from 325 g / min to 475 g / min, which increased the solids level in the cold slurry stream by 3.5 Corresponding to an increase from 5.0% by weight. The nominal concentration of chopped bicomponent fibers in the hot slurry entering the plug flow pipe section was 1.5% by weight. Increased cleaved bicomponent fiber levels in both the cold slurry zone and the combined hot slurry zone caused no notable process difficulties compared to the process of Example 42.

The microfibers of Example 43 were characterized in the same manner as described in Example 42, with the degree of opening when redispersed with dilute fiber slurries and when converted to sheet samples by conventional high dilution paper forming techniques. And functionally equivalent in terms of subsequent behavior.

Example 44

In Example 44, the process of Example 42 was carried out, wherein the flow rate of cold water for the cold slurry tank was reduced from 2.3 gpm to about 2.0 gpm, and the flow rate of 97 ° C. water from the Pic heater to the mixing tee from 6.0 gpm to 7.2 gpm. Increased. By providing a change in the ratio of the hot water stream to the cold water stream, the temperature of the combined streams was increased from 75 ° C. in Example 42 to 80 ° C. in Example 44. The chopped bicomponent fibers were added to the cold slurry tank at about 320 g / min, corresponding to 4.0 wt% of the chopped bicomponent fibers concentration in the cold bicomponent fiber slurry stream. After the joining process, the concentration of chopped bicomponent fibers in the combined stream exiting the mixing tee was 0.90 wt%.

Compared to the microfibers of Examples 42 and 43, the microfibers of Example 44, due to the higher degree of entanglement in the flow through the 1 1/2 inch pipe at the higher temperatures of Example 44 compared to Examples 42 and 43, Filtered better. Microscopic examination of the microfibers of Example 44 showed that the microfibers consisted of fine fibrils having a nominal 3 micron diameter (corresponding to the starting diameter of the island domain in the island-in-sea cut bicomponent fiber).

The microfibers of Example 44 were redispersed in water at high dilution in the manner described in Example 42 and converted to sheet samples. The properties of the microfibers of Example 44 were found to be qualitatively equivalent to those of the microfibers of Example 42 opened at lower temperatures with the same plug flow opening process.

Example 45

The process of Example 44 was repeated but the length of the 1 1/2 inch plug flow pipe section used for contacting the cut bicomponent fibers with hot water was increased to 110 feet. In the process of Example 45, the effective residence time at 80 ° C. of the combined bicomponent fiber slurries was doubled to about 90 seconds. Filtration of the microfibers was very effective and similar to the behavior identified in Example 44. Microscopic examination of the microfibers of Example 45 showed that the microfibers consist essentially of individual fine fibrils having a nominal 3 micron diameter. The high magnification dilution sheet formation test of the product of Example 45 in the same manner as in Example 44 did not show any significant difference in behavior.

In Example 45, increasing the residence time in the plug flow pipe section of the apparatus used in Examples 42-45 did not show a significant improvement compared to the less residence time used in Examples 42-44. The residence time of 45 seconds in these examples was sufficient to remove the sulfopolyester sea polymer to a degree sufficient to cause the cleaved bicomponent fibers to open, due to the high temperatures used during the open process of Examples 42-44. If process advantages are realized in carrying out the open process at the lowest possible temperature necessary for the effective removal of the water dispersible sulfopolyester polymer from the chopped bicomponent fibers, the use of longer plug flow contact times as performed in Example 45 It can provide greater benefits than shown in the examples.

Claims (18)

(A) contacting a short-cut multicomponent fiber having a length of less than 25 mm in a mixing zone with a heated aqueous stream to produce a short-cut multicomponent fiber slurry, wherein the short-cut multicomponent fiber is at least one A water dispersible sulfopolyester and at least one water non-dispersible polymer that is incompatible with the water dispersible sulfopolyester, wherein the heated aqueous stream is at a temperature of at least 40 ° C .;
(B) mixing the short-cut multicomponent fiber slurry and the heated aqueous stream for a time sufficient to remove a portion of the water dispersible sulfopolyester in a fiber open zone to open at a temperature ranging from 55 ° C. to 100 ° C. Producing a microfiber slurry, wherein the open microfiber slurry comprises water non-dispersible polymer microfibers, water dispersible sulfopolyester and water, wherein the weight percent of solids in the open microfiber slurry is 0.1%. Weight percent to 20 weight percent, the water non-dispersible polymer microfibers have a minimum transverse dimension of less than 10 microns,
At least 50 weight percent of the water non-dispersible polymer microfibers are suspended in the open microfiber slurry;
(C) directing the open microfiber slurry to a first solid-liquid separation zone to produce a microfiber product stream and a first mother liquor stream, wherein the first mother liquor stream comprises water and a water dispersible sulfopolyester. , step; And
(D) directing at least a portion of the first mother liquor stream to a second solid-liquid separation zone to produce a second wet cake stream and a second mother liquor stream, wherein the second mother liquor stream is adapted to produce water and water dispersible sulfopolyester. And wherein the second wet cake stream comprises microfibers
Comprising a microfiber product stream. delete The method of claim 1,
And the short-cut multicomponent fiber has a length of less than 5 mm. The method of claim 1,
The heated aqueous stream comprises a treated aqueous stream generated by sending an untreated aqueous stream to an aqueous treatment zone,
The treated aqueous stream contains less than 50 ppm of divalent and polyvalent cations,
Sending the treated aqueous stream to a heat exchanger zone to produce a heated aqueous stream. The method of claim 1,
Wherein the mixing zone comprises one or more pieces of equipment selected from the group consisting of a continuous stirred tank reactor, an agitated batch tank and a pipe. The method of claim 1,
And wherein said heated multicomponent fiber slurry in said mixing zone has chopped multicomponent fibers ranging from 10% to 1% by weight. The method of claim 1,
Wherein the fiber open zone comprises one or more equipment selected from the group consisting of a mixing tank, a stirred batch tank, a plug flow reactor, a pipe, and a continuous stirred tank reactor. The method of claim 1,
Wherein the temperature of the open microfiber slurry in the fiber open zone ranges from 55 ° C. to 100 ° C. delete The method of claim 1,
The first solid-liquid separation zone is continuously horizontal with perforated basket centrifuge, continuous vacuum belt filter, batch vacuum nutschfilter, batch perforated sedimentation tank, twin wire dewatering device, compression zone And at least one piece of equipment selected from the group consisting of a belt filter, a non-vibrating tilted screen device with wedge wire filter media, a continuous vacuum drum filter, and a dewatering conveyor belt. The method of claim 1,
The weight percent solids in the microfiber product stream ranges from 10 weight percent to 65 weight percent. The method of claim 1,
At least a portion of the first mother liquor stream
(A) said mixed band,
(B) the fiber open zone,
(C) a heat exchange zone for producing the heated aqueous stream, wherein at least a portion of the heated aqueous stream is directed to the fiber open zone and / or to the mixed zone, and / or
(D) the first solid-liquid separation zone
Including additional sending. delete The method of claim 1,
Sending at least a portion of the second mother liquor stream to a first concentration zone to produce a first polymer concentrate stream and a first recovered water stream. The method of claim 1,
At least a portion of the second mother liquor stream
(A) said mixed band,
(B) the fiber open zone,
(C) a heat exchange zone for producing the heated aqueous stream, wherein at least a portion of the heated aqueous stream is directed to the fiber open zone and / or to the mixed zone, and / or
(D) a wash stream, said first solid-liquid separation zone
Including additional sending. The method of claim 14,
And purging the first mother liquor stream, the second mother liquor stream and / or the first recovered water stream from the method for reuse or sending to a wastewater treatment system. The method of claim 14,
The first recovered water stream
(A) said mixed band,
(B) the fiber open zone,
(C) a heat exchange zone for producing the heated aqueous stream, wherein at least a portion of the heated aqueous stream is directed to the fiber open zone and / or to the mixed zone, and / or
(D) a wash stream, said first solid-liquid separation zone
Including additional sending. The method of claim 14,
Sending at least a portion of the first polymer concentrate stream to a second concentration zone to produce a vapor stream and a molten polymer stream.

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