JP2920567B2 - Bicomponent fiber manufacturing method - Google Patents

Description

The present invention relates to a dyeable thermoplastic bicomponent fiber and a method for producing the same. These bicomponent fibers comprise: (a) a first component comprising a high performance thermoplastic polymer of polyester; and
(B) From a polymer blend of linear low-density polyethylene (LLDPE) or high-density polyethylene (HDPE) with succinic or succinic anhydride groups as grafting groups and non-grafted linear low-density polyethylene (LLDPE) By contacting the second component under thermal bonding conditions. Bicomponent fibers are defined as (a) and (b) in the form of round, oval, trilobal, triangular, canine bone, flat or hollow shapes and sheath / core or adjoining fibers; It can be manufactured by co-extrusion. The bicomponent fibers can be coextruded using meltblowing, spin bonding or staple fiber manufacturing methods. The present invention also relates to a process for producing high performance fibers using the dyeable thermoplastic bicomponent fibers of the present invention as binder fibers.

Various olefin fibers are well known in the prior art, i.e., fibers in which the fiber-forming substance is at least 85% by weight of ethylene, propylene, or other olefin single long chain synthetic fibers. The mechanical properties of such fibers are generally largely related to the morphology of the polymer, especially the molecular coordination and crystallinity. Crystalline polypropylene fibers and filaments are commercial items and have been used in products such as ropes, nonwovens and woven fabrics. Polypropylene is known to exist as atactic (very amorphous), syndiotactic (very crystalline), and isotactic (also very crystalline). Highly crystalline polypropylene (PP), including both isotactic and syndiotactic, has been found to be widely accepted for some applications in the form of fibers.

Other types of polyolefins suitably formed on fibers include ethylene polymers such as linear high density polyethylene (HDPE) [density 0.941-0.965 g / cc] and linear medium density polyethylene (LLDPE) [low density polyethylene ( LDPE)
And having a density in the range of linear medium density polyethylene (LMDPE), in other words having a density of 0.91 g / cc to 0.94 g / cc]
Is mentioned. The density of linear ethylene polymer is ASTM D
Measured according to -792 and defined as ASTM D-1248. These polymers are made using coordination catalysts and are commonly known as linear polymers due to the substantial absence of polymerized polymer branches pendent from the main polymer backbone. LLDPE is a linear low density ethylene polymer, ethylene alkene per molecule from 3 to 12 carbon atoms (C ₃ -C _12), more typically 4-8 carbon atoms (C ₄ -C ₈ ) With a small amount of an α, β-ethylenically unsaturated alkene having LLDPE
Has the strength, crystallinity, and extendability normally found in HDPE homopolymers, although it contains short side chains branched by pendant side chains, derived from alkene comonomers, and exhibits the properties of low density polyethylene such as strength and low modulus. Holds a lot of sex and practically. In contrast, polyethylenes made using free radical initiators such as peroxides are highly branched, known as low density polyethylene (LDPE), and sometimes as high pressure polyethylene (HPPE) and ICI type polyethylene. Yields a modified polyethylene. Due to improper morphology, notable long chain branching, and the associated high melt elasticity, LDPE is difficult to fiber and has inferior properties compared to LLDPE, HDPE and PP fibers.

For example, one use of some fibers, such as vinyl chloride, low melting polyester and polyvinyl acetate, is to use such fibers as a binder and convert such fibers to high performance natural and / or constituent fibers, For example, by blending with polyester (eg, polyethylene terephthalate (PET) or polybutylene terephthalate (PBT)), polyamide, cellulose (eg, cotton), modified cellulose (eg, rayon), wool, etc., such fibers are brought near the melting point of the binder fibers To thermally weld the binder fibers to the high performance fibers. This method has found particular use in nonwoven fabrics made from high performance fibers, which tend to separate easily in the fabric without binder fibers. However, since olefin fibers do not have a reactive field, the bonding of olefin fibers to high performance fibers depends on the formation of microspheres or beads of olefin fibers, and the high performance fibers Is encapsulated. Moreover, it is difficult to achieve a suitable thermal bond in this way, since the non-polar olefin fibers impair the wettability of the polar high performance fibers.

Another problem that hinders the acceptability of olefin fibers is the lack of dyeability. Olefin fibers are inherently difficult to dye. This is because there is no place where the dye molecules are particularly sucked. That is, there are no hydrogen-bonding or ionic groups, and staining can only occur by Van der Waals forces. Typically, such fibers are colored by adding a pigment to the pre-extruded polyolefin melt, and much effort has been directed to coloring techniques that disperse dyes in the polyolefin fibers. This was unsuccessful. Because of poor light fastness, poor fastness to dye cleaning, low color build-up, hardness, continuous production variation, poor uniformity, loss of fiber strength, and the need for large equipment.

Bicomponent fibers are typically produced commercially by melt spinning. In this method, each molten polymer is extruded from a die, such as a spinning hole, followed by stretching of the molten extrudate, solidification of the extrudate by heat transfer to the surrounding fluid medium, and winding of the solid extrudate. Melt spinning also includes cold drawing, heat treatment, hand treatment and / or cutting. An important aspect of melt spinning is the alignment of the pyrimer molecules by drawing the polymer in the molten state as it exits the spinning hole. In the standard terms of the fiber and filament industry, the terms used herein are given the following definitions:

"Monofilament" (also known as "monofil") refers to an individual strand of 15 or more, usually 30 or more denier.

"Fine denier fiber" or "filament"
Less than a denier strand.

"Multifilament" (or "Multifill")
Refers to a simultaneously produced fine denier filament spun into a fiber bundle generally containing at least three, preferably at least 15 to 100 fibers, which can be hundreds or thousands of filaments.

"Extruded strand" refers to an extrudate produced by passing through an orifice, such as a pirmer die.

"Bicomponent fiber" refers to a fiber that contains two polymers each in a continuous phase, for example, in sequential contact or in a sheath / core configuration.

"Bicomponent staple fibers" refers to fine denier strands that have been formed into staple lengths of about 1 to 8 inches (2.5 to 25 cm) and have been cut to staple lengths.

The bicomponent fibers, extruded strands and bicomponent staple fibers can be of any shape convenient for the intended end use, such as round, trilobal, triangular, dogbone, flat or hollow. sell. The morphology of these bicomponent fibers or staples can be symmetric (eg, sheath / core or adjacently in contact) or their asymmetric (eg, moon / circle configuration within elliptical fibers). It is possible.

Literature on fibers and filaments, including artificial thermoplastics, is, for example, as follows, which are hereby incorporated by reference.

(A) Encyclupedia of Polymer Science and Tec
hnology , Intercience, New York, vol.6 (1967) .pp505-
555 and vol.9 (1968), pp403-440: (b) Kirk-Othmer Eneyclupedia of Cahemical Te
chnology , vol.16 for “Olefin Fibers”, John Wiley an
d Sons. New York, 1981.3rd edition: (c) Man Made and Fiber and Textile Diction
ary , Celanese Corporation: (d) Fundamentals of Fiber Formation-The Science
of Fiber Spinning and Drawing, Adrezij Ziabcki, Joh
n Wiley and Sons, London / New York, 1976: (e) Man Made Fibers, by RW Moncrieff, John Miley
and Sons, London / New York, 1975.

U.S. Pat.
No. 4,644,045 and European Patent Application No. 87304728.6. The former US patent describes a spin bonded nonwoven of LLDPE with a critical combination of crystal%, conical die melt flow, die swelling, the relationship between die swelling and melt index, and polymer uniformity. The European patent application describes a non-woven fabric made of heat-coupled bicomponent filaments having an LLDPE sheath and a polyethylene terephthalate core.

CA91: 22388p (1978) comprises a graft copolymer of polypropylene and ethylene-maleic anhydride, 50: 5
A fiber spun at a ratio of 0 and stretched by 300% at 100 ° C, and a bulky nonwoven fabric obtained by blending the drawn fiber and rayon at a weight ratio of 40:60, carding and heating at 145 ° C are described. Have been. However, polypropylene is disadvantageous for certain applications due to its relatively high melting point (145 ° C.) and to impart a relatively poor hand to fabrics made therefrom. Poor hand is indicated by a relatively rough and inflexible fabric as opposed to a smooth and flexible fabric.

U.S. Pat.No. 4,684,576 discloses a blend of maleic or maleic anhydride grafted HDPE with other olefin polymers to produce succinic or succinic anhydride groups along the polymer chain, e.g., extrusion of articles. It is described for use as an adhesive in coatings, as an adhesive layer in films and wrappers, as an intermediate layer in wires and cables, and other similar applications. U.S. Pat.Nos. 4,460,632, 4,394,485, and 4,230,83 that describe adhesive blends, including HDPE grafted with unsaturated carboxylic acids, primarily for laminated structures.
0 and UK Patent Application Nos. 2,081,723 and 2,113,696
No.

Under thermal bonding conditions, (a) a first component, which is a high performance thermoplastic polymer made of polyester, and (b) a second component, which is olefinic and forms at least a portion of the fiber surface.
A method for producing a thermoplastic bicomponent fiber by contacting the components, comprising: (b) a linear low density polyethylene (LLDPE) or a high density polyethylene having pendant succinic or succinic anhydride groups as graft groups. (HDP
A process has now been discovered for the production of thermoplastic bicomponent fibers, which comprises a polymer blend of E) and non-grafted linear low density polyethylene (LLDPE), thereby rendering the fibers dyeable. . These novel dyeable thermoplastic bicomponent fibers have excellent hand, relatively low melting or bonding temperature, excellent adhesion, excellent dyeability, and excellent adhesion of the components of the bicomponent fiber diagram. The bicomponent fibers have a (a) and (b) symmetrical or asymmetrical sheath / core or sequential contact configuration and a round, oval, trilobal,
It can be manufactured by co-extrusion into fibers having a square, dogbone, flat or hollow configuration. Component (a) is a polyester (eg, polyethylene terephthalate or polybutylene terephthalate)
It is. Component (b) is a grafted LLDPE or grafted HDPE having pendant succinic or succinic anhydride groups
And a non-grafted LLDPE polymer blend. Bicomponent fibers can be produced by melt blowing, spunbond or staple production techniques.

In a further aspect of the present invention, the dyeable thermoplastic bicomponent fibers of the present invention used as binder fibers are blended with high performance fibers, and the fibrous mixture is heated to thermally convert the binder fibers into high performance fibers. A method is provided for bonding high performance natural and / or synthetic fibers, such as polyester (eg, PET or PBT), modified cellulose (eg, rayon), wool, etc., by welding.

In still yet another aspect, at least one component comprising (a) a first component comprising at least one high performance thermoplastic polymer; and (b) at least one having pendant succinic or succinic anhydride groups contacted under thermal bonding conditions. A dyeable thermoplastic bicomponent fiber comprising one type of grafted linear ethylene polymer is provided.

The linear ethylene polymer used for grafting is linear
HDPE and / or LLDPE. Linear HDCPE before grafting
Can be about 0.94 to 0.97 g / cc, but typically about
0.945 to 0.965 g / cc. In contrast, before grafting
The density of the LLDPE can be between about 0.88 and 0.94 g / cc, but is typically between about 0.91 and 0.94 g / cc. Typically linear HDPE and LL
DPE has approximately the same density before and after grafting, which depends on the properties of certain linear ethylene polymers, graft level,
It may vary depending on the conditions of the grafting and the like. The linear ethylene polymer before grafting, measured at 190 ° C / 2.16 kg,
It has a melt index of 0.1 to about 1000 g / 10 minutes, but is typically smaller than after grafting. For example, 25MI grafted to a level of about 1% by weight maleic anhydride (MAH)
And a linear HDPE with a density of 0.955 g / cc
With MI of 6-18g / 10min. The melt index herein is a value measured according to ASTM D1238 condition 190 ° C./2.16 kg (also known as condition “E”). The MI of the non-grafted linear ethylene polymer used for grafting depends on the particular melt spinning method used and whether the grafted linear ethylene polymer is used alone or in a blend with another linear ethylene polymer It is selected depending on whether it is done or not.

Grafting of the succinic or succinic anhydride groups can be accomplished by methods known in the art, which generally include reacting in a mixed state with a heated polymer, generally using a peroxide or free radical initiator to promote grafting. Done. Maleic acid and maleic anhydride compounds are known in the art as having olefinic unsaturation fields conjugated to acid groups. Fumaric acid, an isomer of maleic acid, is also conjugated to release water and rearranges upon heating to maleic anhydride, so that it can be operated in the present invention. Grafting can occur in these materials in the presence of oxygen, air, hydroperoxides or other free radical initiators, or when the mixture of monomer and polymer is kept under conditions of high shear and heat. Can be carried out in the substantial absence of A convenient method for producing a graft polymer is a method using an extruder, but a Brabender mixer, a Banbury mixer, a roll mill and the like can also be used for producing a graft polymer. It is preferred to use a twin screw devolatilizing cold extruder (e.g. Werner-Pfleiger twin screw extruder) where maleic acid or maleic anhydride is mixed with a linear ethylene polymer at the melting temperature;
It is reacted to form a graft polymer, which is extruded.

The anhydride or acid groups of the graft polymer generally comprise from about 0.001 to about 10 weight of the graft polymer, preferably
1 to about 5% by weight, and particularly preferably 0.1 to about 1% by weight
Is configured. The graft polymer is characterized by the presence of vertical succinic groups or succinic anhydride groups along the polymer chain, which is described in European Patent Application No. 88116222.6 (EP Publication 03
In contrast to the carboxylic acid groups obtained by bulk copolymerization of α, β-ethylenically unsaturated carboxylic acids, for example acrylic acid and ethylene, as described in 11860A2). Grafted linear HDPE is a preferred grafted linear ethylene polymer.

The polymer blend may preferably comprise from about 0.5 to about 99.5% by weight of the grafted linear ethylene polymer, more preferably from about 1 to 50% by weight of the grafted linear ethylene polymer, and in particular Preferably, it may contain about 2 to 15% by weight of the grafted linear ethylene polymer. The pyrimer blends can also include conventional additives such as dyes, pigments, antioxidants, UV stabilizers, etc. and / or relatively small amounts of other fiber-forming polymers. However, other fiber-forming polymers may be LLDP as the melting point of the blend or as a polymer blend component.
It does not significantly alter the improved hand obtained for fabrics containing fibers using E.

LLDPE is at least a small amount of C ₃ -C ₂ olefinically unsaturated alkene to be used as non-grafted component as a component of a grafted linear ethylene polymer or dyed thermoplastic bicomponent fibers, preferably C ₄ -C ₈ Contains olefinically unsaturated alkenes. 1-octene is particularly preferred. The alkene comprises about 0.5 to about 30% by weight of LLDPE, preferably about 1 to
It comprises about 20% by weight, and most preferably about 2 to about 15% by weight.

The grafted linear ethylene polymer (eg, grafted linear HDPE) and the non-grafted linear ethylene polymer (non-grafted LLDPE) can be blended together by melt blending or dry blending prior to extrusion. Dry blending of the grafted and non-grafted linear ethylene polymer pellets prior to extrusion has similar melt indices for the blend components, and generally involves blending such blend components prior to extrusion. Where there is no advantage, it is generally preferred. Melt blending can be carried out using a conventional blending apparatus, for example, a mixing extruder, a Brabender mixer, a Banbury mixer, a roll mill, or the like.

A high performance thermoplastic polymer useful as such as the second component of the dyeable thermoplastic bicomponent fibers of the present invention is a polyester (eg, PET or PBT). High performance thermoplastic polymers can be used as a component of the bicomponent fiber. This is accomplished by contacting a high performance thermoplastic polymer with a grafted linear ethylene polymer under the thermal bonding conditions encountered when coextruding bicomponent fibers using a bicomponent staple fiber die. Done. The high performance polymer may be either a component in a sheath / core form or a component in sequential contact. The high performance thermoplastic polymer can be selected to provide bicomponent fiber stiffness, especially when the grafted linear ethylene polymer is a polymer blend of grafted linear HDPE blended with non-grafted LLDPE. Additionally, the high performance thermoplastic polymer used to make the bicomponent fibers of the present invention can be the same polymer used to make the high performance fibers blended with the bicomponent fibers.

Extrusion of the polymer through the die to make the fibers is performed using conventional equipment such as extruders, gear pumps, and the like. Preferably, another extruder is used, which feeds the gear pump and another stream of molten polymer to the die. The grafted linear polymer or polymer blend is preferably mixed in the mixing zone of the extruder and / or in a mixing mixer, for example upstream of a gear pump, to obtain a more uniform distribution of the polymer components.

After extrusion through the die, the fiber is wound in solid form on a godet or another winding surface. In the process for producing bicomponent staple fibers, the fibers are wound onto a godet that stretches the fibers in proportion to the speed of the winding godet. In spin bonding (spunbonding), fibers are collected in a jet, such as an air gun, and blown onto a winding surface, such as a roller or moving belt. In the melt-blown method, air is sprayed onto the surface of a spinneret which serves to simultaneously elongate and cool the fibers as they accumulate on the winding surface of the cooling air passage. Regardless of the type of melt spinning method used, it is important that the fibers be partially melt drawn in the molten state, ie, before solidification occurs. At least some stretching is required to align the polymer molecules and obtain good strength. It is generally not sufficient to solidify the fiber without noticeable stretching before winding. The fine strands produced thereby may be difficult to cold stretch due to their low strength, i.e. stretch in the solid state at a temperature below the melting point of the polymer. On the other hand, when the fibers are drawn to the molten state, the resulting strands can be cold drawn more easily due to the improved strength imparted by the melt drawing.

Depending on the spinneret die diameter and spinning speed, about
Melt drawing up to 1: 1000, preferably about 1:10 to about 1: 200,
Particularly preferably, a melt stretching of 1:20 to 1: 100 can be used.

When using a two-component staple manufacturing method, it may be desirable to cold stretch the strands with conventional stretching equipment, such as a sequential godet at different speeds. The strands can also be heat treated or annealed by using a heated godet. The strands can also be staples by crimping and cutting the strands. In the spin-bonding or air-jet method, the cold drawing and texturing of the solidified strand takes place in the air jet and by the impact of the winding surface, respectively. Similar telistearing is performed with a cooling fluid in a melt-blown process. The cooling fluid is in a state of shearing the molten strand, and can also randomly describe the fibers before solidification.

The bicomponent fibers produced by the above method also form part of the present invention. The bicomponent fibers are generally fine denier filaments in the range of less than 15 denier or fractional denier, preferably in the range of 1 to 10 denier, depending on the desired properties of the fiber and the specific use of the fiber.

The bicomponent fibers of the present invention have a wide variety of potential uses. For example, bicomponent fibers can be formed into a bat and heat treated into a woven fabric by calendering on a heated embossing roller. The bat can also be thermally bonded, such as by infrared, ultrasonic, or the like, into a high loft fabric. The fibers can also be used in conventional textile processing such as carding, sizing, weaving and the like. Fabrics made from the bicomponent fibers of the present invention can also be heat treated to alter the properties of the resulting fabric.

In a preferred embodiment of the present invention, the bicomponent fibers produced by the process of the present invention are used to convert high performance natural or synthetic fibers such as polyamide, polyester, silk, cellulose (eg, cotton), wool, modified cellulose (eg, rayon and acetate), and the like. To be used as a binder fiber. The bicomponent fibers of the present invention have particular advantages as binder fibers. Due to adhesion to high performance fibers, dyeability enhanced by acid groups in the grafted linear ethylene polymer component, and a relatively low melting point (or melting range) compared to high performance fibers. The proportion of the binder fibers of the present invention used in mixing with the high performance fibers in the fiber blend will vary depending on the desired use and capacity of the resulting fiber mixture and / or the resulting fabric. About 5 to about 9 per 100 parts by weight of the binder fiber / high performance fiber mixture
It is preferred to use 5 parts by weight of binder fiber, more preferably about 5 to about 50 parts by weight, particularly preferably 5 to about 50 parts by weight.
It is preferred to use 15 parts by weight of binder fibers.

Some important considerations are needed in making nonwovens from the bicomponent binder fibers / high performance fibers of the present invention. If the binder fibers are in the form of staples, there must be no melting of the fibers when they are cut into staples and the crimp applied to the binder fibers is high to obtain a good distribution of the fibers. Should be sufficient to blend with performance fibers.

The ability of component (b) to adhere to component (a) is the most important consideration in cutting bicomponent staple fibers. When the bicomponent staple fiber is cut and one of the two components (eg, the core of the bicomponent fiber) protrudes from the cutting edge, the fiber causes irritation when it is near the skin.
This irritation is particularly pronounced when the core component is a high performance fiber such as PET. With non-grafted linear ethylene polymer
When each PET is made into a sheath / core bicomponent fiber and cut into short staple fibers, the PET core protrudes beyond the cutting edge. The enhanced adhesion of the grafted linear ethylene polymer component to the PET component used to make the dyeable thermoplastic bicomponent fibers of the present invention reduces PET protruding beyond the fiber after cutting, thus reducing woven and The fiber blend makes access to the skin more comfortable.

The ability of bicomponent binder fibers to adhere to high performance fibers is another important consideration. Adhesion and dyeability can be improved by changing the acid content of the binder fiber, or by changing the grafting level of maleic or maleic anhydride of the grafted linear ethylene polymer, or by changing the non-grafted linear in the bicomponent binder fiber. It can generally be adjusted by the proportion of the grafted linear ethylene polymer blended with the ethylene polymer. In a typical non-woven fabric obtained by thermally bonding high-performance fibers with a bicomponent binder fiber, the ability of the binder fibers to bond to the high-performance fibers greatly increases the thermal bonding of the high-performance fibers bonded by the binder fibers. Dependent.
In a typical prior art nonwoven fabric using binder fibers, the binder fibers are bonded to the high performance fibers to form globules and encapsulate the high performance fibers by at least partial melting. The binder fibers of the present invention enhance the nonwoven fabric by providing a large bond of the binder fibers to the high performance fibers. Using the binder fibers of the present invention, it is also possible to obtain a thermal bond of the binder fibers to the high-performance fibers by means of partial melting and contact bonding in which the bicomponent binder fibers retain their fibrous form; It is characterized in that the number of small balls or beads generated by the melting of the low melting point component of the component binder fiber is reduced.

It is also important that one component of the bicomponent binder fiber has a relatively wide melting range or thermal bonding window. It is especially important when hot calendering is used to obtain a thermal bond of the nonwoven or woven fabric. A good indication of the melting point range or thermal coupling window is the difference between the Vicat softening point and the peak melting point as measured by a scanning differential calorimeter (DSC). The narrow melting range represents a difficult target for the operation of a bonding device such as a calender roll, and even small temperature fluctuations in the bonding device can produce poor results between the bicomponent binder fiber and the high performance fiber. May bring. If a temperature that is too low is used, the bicomponent fibers will not melt sufficiently. On the other hand, if too high a temperature is used, one component of the bicomponent binder fiber will completely melt and exit the high performance fiber batt. Therefore, a wide melting range is desirable so that partial melting of one component of the bicomponent binder fiber material can be achieved without complete melting. For proper thermal bonding, a melting point range of at least 7.5 ° C is desirable, preferably a minimum of 10 ° C.
A sufficiently wide melting point range to provide a binding window of ° C. is desirable.

Another important feature of bicomponent fibers is that when melted in a device such as a calender roll, one of the components has sufficient melt viscosity and is retained in the fiber matrix and does not easily flow out of it It is. An important advantage of the bicomponent fiber binder of the present invention is that one component is non-grafted
It generally has a higher melt viscosity than a fabric consisting of LLDPE and / or non-grafted linear HDPE.
In addition to using calender rolls, other bonding techniques such as hot air, infrared heaters, etc. can also be used to obtain the bonding of the binder fibers of the present invention.

The thermoplastic bicomponent fibers of the present invention can be dyed by contacting with a water-soluble ionic dye, preferably a water-soluble cationic dye in a suitable medium.

The present invention will be described more specifically with reference to the following examples, but these examples are for illustrative purposes only and do not limit the present invention.

Example 1 Linear HDP with MI of about 25 g / 10 min and density of 0.955 g / cc
E Ethylene / propylene copolymers ("base" polymers) were heated to a temperature of 225 ° C (about 180 ° C to about 25 ° C) using a Werner Pflider twin screw devolatilizing cold extruder.
Extrusion with maleic anhydride (3 lb / hr) and dicumyl peroxide (0.3 lb / hr) at an average melting point of 0 ° C). The final concentration of maleic anhydride is about 1% by weight.
(Measured by titration) and has an MI of about 16-18 g / min. This is referred to as the MAH-grafted linear HDPE concentrate.

Using a 6 inch Farrell twin mill, blend 250 g of sample. From a 5% MAH grafted linear HDPE concentrate in various LLDPE resins, a 50% MAH grafted linear HDPE
It has a composition ranging up to concentrates. These blends
At least one other component is useful as at least one component in a bicomponent fiber when it is a high performance polymer component, such as PBT or PET.

Example 2 25 g / 10 min MI before grafting and 0.955 g / c before grafting
10% of grafted HDPE (ethylene / propylene copolymer) with a density of c and containing 1% by weight of succinic groups
Is blended with 90% of ungrafted LLDPE (ethylene / octene copolymer, 18 g / 10 min MI, density of 0.930 g / cc) to produce a polymer blend containing about 0.1% by weight succinic groups. This polymer blend is then used as a sheath during the bicomponent staple fiber spinning operation (the core is
PET). The sheath / core bicomponent fiber was blended with other high performance fibers, such as PET or cellulose, to make a batt and bonded in an oven. It can be seen that these bats are well bonded and have good physical integrity.

Example 3 Linear HDPE (ethylene-propylene copolymer, 25 g / 10
Min, density of 0.955 g / cc) with maleic acid to give succinic groups along the polymer chain. A portion of the grafted linear HDPE is then mixed with various amounts of non-grafted LL
DPE (ethylene-octene copolymer, 18g / 10min MI,
0.930 g / cc density)
Produce polymer blends containing 5%, 0.1%, 0.15%, 0.2% and 0.4% succinic acid. These grafted linear
A sample of HDPE / LLDPE polymer blend is co-extruded with PET to obtain a sequentially contacting fibrous material. The adhesion between the fibers in the thermal bonding batt of this fiber material is clearly better than that obtained for comparison by using the same linear HDPE and LLDPE without grafted acid groups. The highest thermal bond batt strength is obtained when using bicomponent fibers having a succinic acid level of about 0.1% by weight.

Example 4 Linear HDPE (ethylene-propylene copolymer, 25 g / 10
Min, a density of 0.955 g / cc) is crafted with maleic anhydride to provide about 1% by weight of succinic anhydride groups along the polymer chain. A portion of the grafted linear HDPE is blended with various amounts of non-grafted LLDPE (ethylene octene copolymer, 18 g / 10 min MI, 0.930 g / cc density) to give 0.05%, 0.1% by weight, respectively. %, 0.15%, 0.2%
And a polymer blend containing 0.5% succinic groups. Polymer blends of grafted linear HDPE and non-grafted LLDPE can be extruded as a sheath layer in a two component spinning system using PET as the core layer. The resulting thermally bonded fabric has a higher bonded fiber strength than that obtained as a non-grafted linear ethylene polymer as the sheath resin.

Example 5 LLDPE (ethylene / octene copolymer, 18 g / 10 min M
I, a density of 0.930 g / cc), in the presence of one drop of didecyldimethylammonium chloride used as a wetting agent.
When treated with Basic Violet (a basic dye also known as crystal violet) at 15 ° C for 15 minutes, it does not accept the dye. Enough LLDP grafted with maleic anhydride
When blended with E to give a polymer blend having about 0.15% by weight of succinic anhydride, the resulting polymer blend stains blue / purple when processed as described above. The dye does not leach easily, even when placed in boiling water for 10-15 minutes. Other water-soluble cationic dyes (ie, dyes that are typically referred to in the industry as "basic dyes") can be used to dye the novel bicomponent fibers of the present invention as well.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Visor, John O. 77566, Texas, USA Lake Jackson Anyway 105 Apartment # 902 (72) Inventor Finlayson, Marcolm F. Texas, United States 77008 Houston East 12 1/2 Street 731 (56) References JP-A-54-30929 (JP, A) JP-A-61-201015 (JP, A) JP-A-1-192856 (JP, A) JP-A-48-20833 (JP, A) A) JP-A-55-152812 (JP, A) European Publication 465203 (EP, A1) (58) Fields investigated (Int. Cl. ⁶ , DB name) D01F 8/04-8/16 D04H 1/54

Claims (7)

(57) [Claims] 1. A first component which is a high-performance thermoplastic polymer consisting of (a) polyester under the conditions of thermal bonding, and (b)
A second polymer blend of linear low density polyethylene (LLDPE) or high density polyethylene (HDPE) with succinic or succinic anhydride groups as grafting groups and non-grafted linear low density polyethylene (LLDPE) A method for producing a dyeable thermoplastic bicomponent fiber, comprising producing a thermoplastic bicomponent fiber by bringing a component into contact with at least a part of the second component so as to form a fiber surface. 2. A bicomponent fiber comprising (a) and (b) having a round, oval, trilobal, triangular, dogbone, flat or hollow shape and symmetric or asymmetric. The method of claim 1, wherein the method is produced by co-extrusion into fibers having a sheath / core or parallel configuration. 3. The method of claim 2 wherein the bicomponent fibers have a round shape and a sheath / core configuration. 4. A polymer blend of (a) polyethylene terephthalate or polybutylene terephthalate, and (b) a grafted linear high density polyethylene (HDPE) and a non-grafted linear low density polyethylene (LLDPE). The method of claim 1. 5. The method of claim 2 wherein the fibers are melt blown and produced under spunbond or staple fiber manufacturing conditions. 6. A method for bonding high performance fibers by blending high performance fibers with binder fibers, heating the fiber mixture to near the melting point of the binder fibers, and thermally bonding the binder fibers to the high performance fibers. A method comprising using the dyeable thermoplastic bicomponent fiber produced by the method according to claim 1 as the fiber. 7. The method according to claim 6, wherein the high-performance fiber is polyester, polyamide, cellulose or wool or a mixture thereof.