WO2023112895A1 - Fibre d'alcool polyvinylique et procédé de production d'une telle fibre - Google Patents

Fibre d'alcool polyvinylique et procédé de production d'une telle fibre Download PDF

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Publication number
WO2023112895A1
WO2023112895A1 PCT/JP2022/045689 JP2022045689W WO2023112895A1 WO 2023112895 A1 WO2023112895 A1 WO 2023112895A1 JP 2022045689 W JP2022045689 W JP 2022045689W WO 2023112895 A1 WO2023112895 A1 WO 2023112895A1
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Prior art keywords
polyvinyl alcohol
degree
fiber
saponification
mol
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PCT/JP2022/045689
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English (en)
Japanese (ja)
Inventor
蘭 廣谷
聡 小泉
宣広 古賀
拓哉 辻本
Original Assignee
株式会社クラレ
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Priority to CN202280082465.9A priority Critical patent/CN118401713A/zh
Priority to JP2023567777A priority patent/JPWO2023112895A1/ja
Publication of WO2023112895A1 publication Critical patent/WO2023112895A1/fr

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    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
    • D01F6/28—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
    • D01F6/34—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from copolymers obtained by reactions only involving carbon-to-carbon unsaturated bonds comprising unsaturated alcohols, acetals or ketals as the major constituent
    • D—TEXTILES; PAPER
    • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
    • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
    • D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
    • D01F6/44—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds as major constituent with other polymers or low-molecular-weight compounds
    • D01F6/50—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from mixtures of polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds as major constituent with other polymers or low-molecular-weight compounds of polyalcohols, polyacetals or polyketals
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
    • D04H3/005—Synthetic yarns or filaments
    • D04H3/007—Addition polymers

Definitions

  • the present invention relates to polyvinyl alcohol fibers containing polyvinyl alcohol with different degrees of saponification, long-fiber nonwoven fabrics made of the fibers, and methods for producing the fibers or long-fiber nonwoven fabrics. More specifically, the present invention relates to a polyvinyl alcohol fiber containing ethylene-modified polyvinyl alcohol and a polyvinyl alcohol having a saponification degree within a specific range, a long fiber nonwoven fabric made of the fiber, and a melt-spun fiber and a long fiber made of the fiber. The present invention relates to a method for producing a fibrous nonwoven fabric.
  • polyvinyl alcohol fibers In polyvinyl alcohol fibers, the hydroxyl groups in the polyvinyl alcohol molecules form intramolecular and intermolecular hydrogen bonds, and these bonds are extremely strong. Therefore, the polyvinyl alcohol fiber has high strength and excellent mechanical strength. Taking advantage of such excellent mechanical strength, polyvinyl alcohol fibers are used in a wide range of applications such as packaging, wound dressings, and textile materials.
  • polyvinyl alcohol fibers are also highly soluble in water and are useful as water-soluble fibers or water-soluble packaging materials. Since such water-soluble fibers or water-soluble packaging materials are dissolved in water, they have a small impact on the environment when discarded, and are expected to be used in a wider range of applications.
  • Polyvinyl alcohol fibers are usually manufactured by a wet spinning method in which they are dissolved in a solvent and then spun.
  • a wet spinning method uses a solvent, etc.
  • a process for removing the solvent is required, and the manufacturing process may become complicated. be.
  • trace amounts of solvent may remain on the fibers, which may need to be removed when the fibers are discarded.
  • the melt spinning method does not use a solvent, the step of removing the solvent is omitted, and the solvent does not remain on the fibers. Therefore, it is desired to develop a polyvinyl alcohol suitable for melt spinning rather than wet spinning.
  • Ethylene-modified polyvinyl alcohol has been proposed as one of polyvinyl alcohols suitable for the melt spinning method (for example, Patent Documents 1 and 2).
  • Patent Document 1 describes a melt-spinnable resin having a degree of polymerization of 200 to 500, a degree of saponification of 90 to 99.99 mol%, and a molar fraction of the central hydroxyl group of the triad of hydroxyl groups in the triad notation with respect to the vinyl alcohol unit.
  • Fibers are disclosed in proportions of 0.0003 to 1 part by weight.
  • Patent Document 2 discloses a thermoplastic polyvinyl alcohol fiber containing polyvinyl alcohol having a 1,2-glycol bond content of 1.8 mol % to 3.5 mol % as at least one component.
  • JP-A-2000-234214 Japanese Patent Application Laid-Open No. 2001-248014
  • the ethylene-modified polyvinyl alcohol described in these documents needs to have a high degree of saponification in order to improve melt spinnability.
  • the secondary workability of fibers made of ethylene-modified polyvinyl alcohol with a high degree of saponification tends to be lower than that of polyvinyl alcohol that is not ethylene-modified.
  • ethylene-modified polyvinyl alcohol with a high degree of saponification has a lower solubility in water, especially in low-temperature water, and its water solubility decreases when it is made into fibers. Therefore, it may be necessary to treat with high-temperature water at the time of disposal.
  • An object of the present invention is to provide polyvinyl alcohol fibers which are excellent in secondary workability and water solubility, particularly in water solubility at low temperatures, and long-fiber nonwoven fabrics comprising the fibers.
  • the present inventors have found that a polyvinyl alcohol fiber containing two types of polyvinyl alcohol and a long-fiber nonwoven fabric made of the fiber have improved secondary workability and solubility in water, and have completed the present invention. Arrived.
  • the present invention relates to a polyvinyl alcohol fiber containing polyvinyl alcohol A having a degree of saponification of 90 mol % or more and an ethylene modification rate of 4 to 15 mol %, and polyvinyl alcohol B having a degree of saponification satisfying the following formula (1).
  • ⁇ A represents the degree of saponification of polyvinyl alcohol A
  • ⁇ B represents the degree of saponification of polyvinyl alcohol B.
  • [2] The polyvinyl alcohol fiber according to [1] above, wherein the difference between the melting point and the decomposition temperature is 40° C. or more; [3] The polyvinyl alcohol fiber according to [1] or [2], wherein the polyvinyl alcohol A has a polymerization degree of 200 to 600; and [4] The polyvinyl alcohol fiber according to any one of [1] to [3], wherein the polyvinyl alcohol B has a degree of polymerization of 200 to 600; [5] The polyvinyl alcohol fiber according to any one of [1] to [4], wherein the degree of saponification of the polyvinyl alcohol B is 80 mol% or more; [6] The polyvinyl alcohol fiber according to any one of [1] to [5], which contains 15% by mass or more and 95% by mass or less of the polyvinyl alcohol B, with the total mass of the polyvinyl alcohol A and the polyvinyl alcohol B being 100% by mass. , and
  • the present invention [8] A composition containing polyvinyl alcohol A having a degree of saponification of 90 mol% or more and an ethylene modification rate of 4 to 15 mol% and polyvinyl alcohol B having a degree of saponification satisfying the following formula (2) is melted and discharged from a nozzle.
  • ⁇ A represents the degree of saponification of polyvinyl alcohol A
  • ⁇ B represents the degree of saponification of polyvinyl alcohol B.
  • the present invention [9] A long-fiber nonwoven fabric made of the polyvinyl alcohol fiber according to any one of [1] to [7], [10] A method for producing a long-fiber nonwoven fabric by depositing the polyvinyl alcohol fibers according to any one of [1] to [7] to form a nonwoven web, Regarding.
  • polyvinyl alcohol fibers and long-fiber nonwoven fabrics having excellent secondary workability and solubility in water, particularly low-temperature water solubility, and methods for producing the polyvinyl alcohol fibers and long-fiber nonwoven fabrics are provided. be done.
  • Polyvinyl alcohol A in the present invention is an ethylene-modified polyvinyl alcohol having a degree of saponification of 90 mol % or more and an ethylene modification rate of 4 to 15 mol %.
  • ethylene-modified polyvinyl alcohol include ethylene-vinyl alcohol copolymers obtained by saponifying ethylene-vinyl ester copolymers obtained by copolymerizing ethylene and vinyl esters.
  • the ethylene-vinyl alcohol copolymer may be an ethylene-vinyl alcohol copolymer obtained by saponifying ethylene, a monomer other than ethylene that can be copolymerized with a vinyl ester as described later, and a copolymer with a vinyl ester.
  • the ethylene-modified polyvinyl alcohol may be a so-called polyvinyl acetal resin obtained by cross-linking some hydroxyl groups of the ethylene-vinyl alcohol copolymer with aldehydes such as formalin, butyraldehyde and benzaldehyde.
  • aldehydes such as formalin, butyraldehyde and benzaldehyde.
  • ethylene-vinyl alcohol copolymers are preferred from the viewpoint of lowering the melting point and improving strength.
  • One or two or more of the vinyl esters may be used for the production of the ethylene-modified polyvinyl alcohol, and it is preferable to use one vinyl ester.
  • vinyl esters include vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate, vinyl valerate, vinyl laurate, vinyl stearate, vinyl benzoate, vinyl pivalate, and vinyl versatate. Among these, vinyl acetate is preferred.
  • Examples of monomers copolymerizable with the vinyl ester include olefins having 3 to 30 carbon atoms such as propylene, 1-butene, and isobutene; acrylic acid or salts thereof; methyl acrylate, ethyl acrylate, and n-propyl acrylate.
  • the degree of saponification of polyvinyl alcohol A is 90 mol% or more.
  • the degree of saponification is preferably 95 mol% or more, more preferably 98 mol% or more, from the viewpoint of the mechanical strength of the resulting polyvinyl alcohol fiber.
  • the degree of saponification is usually 100 mol % or less, preferably 99.5 mol % or less, more preferably 99 mol % or less.
  • the degree of saponification of polyvinyl alcohol A is the ratio of the number of moles of vinyl alcohol units to the total number of moles of structural units that can be converted to vinyl alcohol units by saponification, typically vinyl ester monomer units and vinyl alcohol units. (mol %).
  • the degree of saponification of polyvinyl alcohol can be measured according to JIS K 6726-1994.
  • the ethylene modification rate of polyvinyl alcohol A is 4 to 15 mol % from the viewpoint of water solubility and strength.
  • the ethylene modification rate is the ratio of structural units derived from ethylene to all structural units, assuming that all structural units constituting polyvinyl alcohol A are 100 mol %.
  • the ethylene modification rate is preferably 12 mol % or less, more preferably 9 mol % or less, based on the number of moles of all structural units constituting the vinyl ester polymer. From the viewpoint of strength, the ethylene modification rate is preferably 6 mol% or more, more preferably 7 mol% or more.
  • the ethylene modification rate can be obtained, for example, from 1 H-NMR of an ethylene-vinyl ester copolymer that is a precursor or a re-esterification product of ethylene-modified polyvinyl alcohol. Specifically, the peak derived from the backbone methylene of the vinyl ester in the range of 4.7 to 5.2 ppm and the ethylene and vinyl ester and copolymerizable with vinyl ester in the range of 0.8 to 1.6 ppm. The ethylene modification rate can be determined using peaks derived from main chain methylene of other monomers.
  • the difference between the melting point and the decomposition temperature of the polyvinyl alcohol A is preferably 40° C. or more from the viewpoint of melt spinnability.
  • the difference between the melting point and the decomposition temperature of the polyvinyl alcohol A is more preferably 50°C or more.
  • the upper limit of the difference between the melting point and the decomposition temperature of the polyvinyl alcohol A is not particularly limited, but is preferably 150°C or less. From the viewpoint of melt spinnability, the melting point of the polyvinyl alcohol A is preferably 180° C. or higher, more preferably 190° C. or higher.
  • the melting point of the polyvinyl alcohol A is preferably 220° C. or less, more preferably 210° C. or less, from the viewpoint of secondary workability when made into fibers.
  • the decomposition temperature of the polyvinyl alcohol A is preferably 250° C. or higher, more preferably 260° C. or higher, from the viewpoint of melt spinnability.
  • the upper limit of the decomposition temperature of polyvinyl alcohol A is not particularly limited, but is preferably 350° C. or less.
  • the melting point is the peak temperature of the main endothermic peak observed by differential scanning calorimeter (DSC), and the decomposition temperature is the thermogravimetric decrease of 3% when the temperature is raised at a rate of 10°C/min in thermogravimetry (TG). temperature.
  • the degree of polymerization (viscosity average degree of polymerization) of polyvinyl alcohol A is preferably 600 or less, more preferably 500 or less. If the degree of polymerization is too high, the melt viscosity may be too high and the polymer may not be extruded from the spinning nozzle.
  • the degree of polymerization is preferably 200 or more, more preferably 300 or more, from the viewpoint of suppressing deterioration of spinnability during spinning and adhesion between fibers, and maintaining mechanical performance and quality of fibers and fiber structures.
  • Polyvinyl alcohol B in the present invention is a polyvinyl alcohol whose degree of saponification satisfies the following formula (1). 0 ⁇ A ⁇ B ⁇ 20 (1) However, in the formula (1), ⁇ A represents the degree of saponification of polyvinyl alcohol A, and ⁇ B represents the degree of saponification of polyvinyl alcohol B.
  • the degree of saponification of polyvinyl alcohol B preferably satisfies the following formula (4) from the viewpoint of the secondary processability and water solubility of the obtained fiber. 0 ⁇ A ⁇ B ⁇ 15 (4) However, in the above formula (4), ⁇ A and ⁇ B have the same meanings as above.
  • the degree of saponification of polyvinyl alcohol B satisfies the above formula (4), and is preferably 80 mol% or more, more preferably 85 mol% or more, from the viewpoint of secondary processability and water solubility of the resulting fiber.
  • the degree of saponification of polyvinyl alcohol B is as described above, the degree of saponification of polyvinyl alcohol A is preferably 95 mol % or more, more preferably 98 mol % or more.
  • Polyvinyl alcohol B may be an ethylene-modified polyvinyl alcohol similar to polyvinyl alcohol A, or a saponified product of the vinyl ester polymer. It may also be a copolymer of a vinyl ester and a copolymerizable monomer.
  • vinyl esters and monomers copolymerizable with vinyl esters include ethylene and the same vinyl esters and monomers as the vinyl esters and monomers exemplified for polyvinyl alcohol A, and preferred vinyl esters and monomers are also the same as above.
  • Polyvinyl alcohol B is preferably ethylene-unmodified polyvinyl alcohol that has a degree of saponification that satisfies the above formula (1) and is not modified with ethylene.
  • the ethylene non-modified polyvinyl alcohol includes polyvinyl alcohol which is a saponified product of the above-mentioned vinyl ester polymer or polyvinyl alcohol which is a saponified product of a copolymer of a monomer other than ethylene and a vinyl ester which is copolymerizable with the above-mentioned vinyl ester. .
  • polyvinyl alcohol which is a saponified product of the vinyl ester polymer is preferable.
  • vinyl esters and monomers copolymerizable with vinyl esters include the same vinyl esters and monomers as the vinyl esters and monomers exemplified for polyvinyl alcohol A, and preferred vinyl esters and monomers are also the same as above except for ethylene. .
  • the difference between the melting point and decomposition temperature of polyvinyl alcohol B is preferably 40° C. or more from the viewpoint of melt spinnability.
  • the difference between the melting point and the decomposition temperature of the polyvinyl alcohol B is more preferably 50°C or more. If the difference between the melting point and the decomposition temperature of the polyvinyl alcohol B is at least the lower limit, the melt spinnability is excellent.
  • the upper limit of the difference between the melting point and the decomposition temperature of polyvinyl alcohol B is not particularly limited, but is preferably 150°C or less. From the viewpoint of melt spinnability, the melting point of the polyvinyl alcohol B is preferably 170° C. or higher, more preferably 180° C. or higher.
  • the melting point of the polyvinyl alcohol B is preferably 200° C. or lower, more preferably 190° C. or lower, from the viewpoint of secondary processing when made into fibers.
  • the decomposition temperature of the polyvinyl alcohol B is preferably 250° C. or higher, more preferably 260° C. or higher, from the viewpoint of melt spinnability.
  • the decomposition temperature of polyvinyl alcohol B is not particularly limited, but is preferably 350° C. or lower.
  • the degree of polymerization (viscosity average degree of polymerization) of polyvinyl alcohol B is preferably 600 or less, more preferably 500 or less. If the degree of polymerization is too high, the melt viscosity may be too high and the polymer may not be extruded from the spinning nozzle.
  • the degree of polymerization is preferably 200 or more, more preferably 300 or more, from the viewpoint of suppressing deterioration of spinnability and adhesion between fibers and maintaining mechanical performance and quality of fibers and fiber structures.
  • the polyvinyl alcohol fiber of the present invention contains the polyvinyl alcohol A and the polyvinyl alcohol B.
  • the polyvinyl alcohol fiber of the present invention preferably contains 15% by mass or more and 95% by mass or less of the polyvinyl alcohol B, with the total mass of the polyvinyl alcohol A and the polyvinyl alcohol B being 100% by mass.
  • the content of polyvinyl alcohol B is more preferably 30% by mass or more and 80% by mass or less, where the total mass of polyvinyl alcohol A and polyvinyl alcohol B is 100% by mass.
  • the melting point of the polyvinyl alcohol fiber of the present invention is preferably 190° C. or higher and 210° C. or lower from the viewpoint of secondary workability.
  • the upper limit of the melting point is more preferably 208°C or lower, and even more preferably 205°C or lower.
  • the difference between the melting point and the decomposition temperature of the polyvinyl alcohol fiber is preferably 40° C. or higher, more preferably 50° C. or higher, and even more preferably 60° C. or higher, from the viewpoint of secondary workability.
  • the melting point and decomposition temperature of the polyvinyl alcohol fiber can be obtained by measuring the fiber obtained by spinning from polyvinyl alcohol A and polyvinyl alcohol B by the method described later by the method described above. By adjusting the ethylene modification rate and saponification degree of polyvinyl alcohol A and the saponification degree and content of polyvinyl alcohol B within the above ranges, the melting point and decomposition temperature of the resulting fiber can be set within the above ranges.
  • the tensile strength of the polyvinyl alcohol fiber of the present invention is preferably 1 cN/dtex or more, more preferably 3 cN/dtex or more.
  • the upper limit of the tensile strength is not particularly limited, it is usually 25 cN/dtex or less.
  • the tensile strength of the polyvinyl alcohol fiber can be adjusted to a desired level by controlling the drawing conditions such as the drawing temperature and draw ratio in the fiber production method described below.
  • the melting temperature of the polyvinyl alcohol fiber of the present invention in water is preferably as low as possible, and is preferably 70° C. or lower, more preferably 50° C. or lower, and even more preferably 30° C. or lower from the viewpoint of reducing environmental load. From the viewpoint of fiber handling, the temperature is preferably 5°C or higher.
  • the fusing temperature is the temperature at which a load of 2 mg/dtex is applied to a fiber with a length of 100 mm, held in water, and the water temperature is raised at a rate of 2° C./min.
  • the melting temperature can be adjusted to the desired melting temperature by adjusting the ethylene modification rate of the polyvinyl alcohol A, the ratio of the polyvinyl alcohol B, the degree of saponification of the polyvinyl alcohol A or the polyvinyl alcohol B, etc. within the above ranges. can do.
  • the polyvinyl alcohol fiber of the present invention preferably has a degree of crystallinity of 50% or less, more preferably 40% or less. From the viewpoint of fiberization and mechanical strength, it is preferably 15% or more, more preferably 25% or more.
  • the degree of crystallinity of the fiber can be controlled by the degree of polymerization, the degree of saponification of the polyvinyl alcohol A and the polyvinyl alcohol B, the type and content of functional groups, and the like.
  • the crystallinity of fibers can be obtained by the following method.
  • the polyvinyl alcohol fiber of the present invention contains commonly used plasticizers, cross-linking agents, antioxidants, stabilizers, lubricants, processing aids, antistatic agents, colorants, impact resistance aids and foaming agents.
  • Various additives may be added.
  • the total amount of the polyvinyl alcohol A and the polyvinyl alcohol B in the polyvinyl alcohol fiber is preferably 60% by mass or more, more preferably 70 to 99% by mass.
  • the polyvinyl alcohol fiber of the present invention can be produced by any of wet spinning, dry spinning, and melt spinning, but the melt spinning is preferred from the viewpoint of simplification of the spinning process and reduction of environmental load by not using solvents during the process. preferable.
  • the melt spinning method polyvinyl alcohol as a raw material is melted, and the yarn discharged from the spinning nozzle is taken up and spun.
  • the melt-spinning method also includes a melt-blowing method or a spunbond method in which fibers discharged from a spinning nozzle are directly formed into a sheet. The meltblowing method is preferred because it provides a nonwoven fabric with fine fibers and fine mesh.
  • the polyvinyl alcohol fiber of the present invention contains the polyvinyl alcohol A and the polyvinyl alcohol B
  • a composition containing predetermined amounts of the polyvinyl alcohol A and the polyvinyl alcohol B may be prepared in advance, and the composition may be melt-spun.
  • the polyvinyl alcohol A and the polyvinyl alcohol B may be separately melted and then combined when discharged from a spinning nozzle to form a single fiber.
  • the composition containing both polyvinyl alcohols may be taken out by a melt kneader and then melt-spun or melted in the melt-spinning machine.
  • the content of the polyvinyl alcohol A and the polyvinyl alcohol B in the polyvinyl alcohol fiber is set to a predetermined amount by controlling the extrusion rate and the like. can be done.
  • the melting temperature is higher than the melting temperature of polyvinyl alcohol and lower than the decomposition temperature. More preferably, it melts at a temperature higher than the melting temperature of polyvinyl alcohol by 10°C or more and lower than the decomposition temperature by 20°C or more. In the present invention, the melting temperature may be higher than the melting temperature of the higher one of the polyvinyl alcohol A and the polyvinyl alcohol B and lower than the decomposition temperature of the lower one of the polyvinyl alcohol A and the polyvinyl alcohol B, which is 220°C. It is preferable to melt in the range of 240° C. or more.
  • the temperature of the spinning nozzle when discharging from the spinning nozzle is 10° C. or more higher than the melting temperature of polyvinyl alcohol.
  • it may be discharged at a temperature higher than the melting temperature of the higher one of the polyvinyl alcohol A and the polyvinyl alcohol B and lower than a temperature higher than the melting temperature by 10° C. or more, and the discharge is in the range of 230° C. or more and 240° C. or less. preferably.
  • the yarn discharged from the spinning nozzle may be taken as it is without being drawn, or may be drawn continuously. Stretching is performed at a temperature higher than the glass transition point (Tg) of polyvinyl alcohol, and at a temperature higher than the higher Tg of polyvinyl alcohol A and polyvinyl alcohol B, whichever is higher.
  • Tg glass transition point
  • the draw ratio is preferably 2 times or more, more preferably 3 times or more, from the viewpoint of the strength of the resulting fiber.
  • the drawing is usually performed by hot drawing, and the hot drawing may be performed using hot air, a hot plate, a hot roller, a water bath, or the like.
  • the stretching temperature is usually about 70 to 100°C.
  • a non-contact type heater such as a heating tube, it is preferable to set the temperature condition at a higher temperature of about 110 to 150°C.
  • the cross section of the fiber can be circular, hollow, or irregular, depending on the shape of the spinning nozzle.
  • a perfect circle is preferable from the point of process passability in fiberization and weaving.
  • the fineness of the single fiber of the polyvinyl alcohol fiber of the present invention is not particularly limited, the fineness is preferably 0.01 dtex or more, more preferably 0.1 dtex or more, and still more preferably 0.2 dtex or more.
  • the fineness is preferably 1000 dtex or less, more preferably 100 dtex or less, and even more preferably 10 dtex or less.
  • a fineness of 0.1 to 1000 dtex, particularly 0.2 to 100 dtex, further 0.5 to 10 dtex can be widely used.
  • a simple substantially circular fiber is preferable to a complicated shape from the viewpoints of water dispersibility, product homogeneity, and the like.
  • the polyvinyl alcohol fiber of the present invention is excellent in various performances such as mechanical performance such as strength, and is also excellent in water solubility, so all kinds of fiber structures can be obtained by using said fiber.
  • it can be processed into cut fibers, filaments, spun yarns, fabrics such as woven or knitted fabrics or dry non-woven fabrics, and fiber structures such as ropes and cords.
  • such a fabric may be formed into a desired shape.
  • other fibers may be used in combination, but from the viewpoint of efficiently obtaining the effects of the present invention, the fiber structure should be 40% by mass or more, further 60% by mass or more, particularly 80 to 100% by mass.
  • the other fibers include water-soluble fibers, water-insoluble fibers and polyvinyl alcohol fibers other than those of the present invention. It may also be used in combination with other materials such as metals or films.
  • the fiber length of the polyvinyl alcohol fiber of the present invention may be appropriately set depending on the application.
  • the fiber length is preferably about 1 to 100 mm. preferable.
  • the obtained short fibers can be made into a nonwoven fabric by a dry method.
  • the polyvinyl alcohol fiber of the present invention is used as a long fiber to form a long-fiber nonwoven fabric, the fiber length may be from several meters to several hundred meters.
  • a spunbonding method is used in which the long fibers obtained by the above method are spread and deposited on a collecting surface to form a nonwoven web, which is then partially pressure-bonded and wound. And it can be made into a nonwoven fabric by a meltblowing method.
  • polyvinyl alcohol fiber and the fiber structure of the present invention can be used for all purposes, they are particularly suitable for use as a process aid for textile products and as a base fabric for chemical lace embroidery, taking advantage of their water-solubility and secondary processability. can.
  • the fiber structure of the present invention is used as an embroidery base fabric, it is preferable to use at least a fabric from the viewpoint of mechanical performance.
  • the basis weight of such fabric is preferably 50 g/m 2 or more, particularly 100 g/m 2 or more from the viewpoint of mechanical performance, and 300 g/m 2 or less, further preferably 200 g/m 2 or less from the viewpoint of production efficiency. It is preferable to have In terms of mechanical performance, the breaking length of the fabric is preferably 2.5 N/25 mm or more, more preferably 2.6 N/25 mm or more.
  • a dry-laid nonwoven fabric obtained by treating a fiber web in terms of feel, flexibility, and the like.
  • a method for producing a dry-laid nonwoven fabric for example, a polyvinyl alcohol-based fiber filament or the like is opened by a repulsive action due to triboelectrification, or crimped or cut staples are opened with a card or the like to form a web, and the web is formed.
  • a preferred method is thermal bonding using a hot air dryer at 150°C to 200°C.
  • Another method for producing a dry nonwoven fabric is, for example, a method of producing a nonwoven fabric by entangling by needle punching.
  • a method of producing a nonwoven fabric by entangling by needle punching by using a known needle punch machine and adjusting conditions such as needle density, needle type, needle depth, and number of punches according to the properties of the fiber, a dry-laid nonwoven fabric with excellent strength and flexibility can be produced. can.
  • entanglement may be optimized through multiple needle punch machines.
  • x indicates that no nonwoven fabric was obtained
  • ⁇ indicates that a nonwoven fabric with a basis weight of about 40 g/m 2 is obtained, and has a breaking strength of 3.0 N/25 mm or less, and exceeds 3.0 N/25 mm.
  • the item was marked as ⁇ .
  • Example 1 As polyvinyl alcohol A, 90% by mass of polyvinyl alcohol having a degree of saponification of 98.5 mol%, a degree of polymerization of 380, and an ethylene modification rate of 8 mol%; % by mass to prepare a polyvinyl alcohol composition.
  • the resulting polyvinyl alcohol composition was spun by a melt spinning machine at 230° C. through a round-hole nozzle.
  • the spun raw yarn was dry-heat drawn at a draw ratio of 2.7 times using a hot air oven to obtain a multifilament of 50 dtex/24 filaments.
  • the spinnability was good without interruption for 6 hours, and the drawability was good with no single filament breakage or agglutination.
  • Example 2 to 9 A polyvinyl alcohol fiber was obtained in the same manner as in Example 1, except that the ratio of polyvinyl alcohol A and polyvinyl alcohol B was changed as shown in Table 1. Table 1 shows the results.
  • Polyvinyl alcohol A is 70% by mass of polyvinyl alcohol with a saponification degree of 98.5 mol%, a polymerization degree of 380, and an ethylene modification rate of 8 mol%
  • polyvinyl alcohol B is 30% of polyvinyl alcohol with a saponification degree of 80 mol% and a polymerization degree of 300.
  • a polyvinyl alcohol fiber was obtained in the same manner as in Example 1, except that the polyvinyl alcohol composition was prepared by mixing in mass %. Table 1 shows the results.
  • Example 11 Using the polyvinyl alcohol composition described in Example 1, it was extruded from a round-hole nozzle at 260° C. by a melt blower to obtain a filament non-woven fabric having a basis weight of about 40 g/m 2 . Table 2 shows the results.
  • Example 12 and Example 13 A long-fiber nonwoven fabric was obtained in the same manner as in Example 11, except that the ratio of polyvinyl alcohol A and polyvinyl alcohol B was changed as shown in Table 2. Table 2 shows the results.
  • Example 14 A long-fiber nonwoven fabric was obtained in the same manner as in Example 11, except that the polyvinyl alcohol composition described in Example 10 was used. Table 2 shows the results.
  • Example 1 A polyvinyl alcohol fiber was obtained in the same manner as in Example 1 except that polyvinyl alcohol B used in Example 1 was not used and only polyvinyl alcohol A was used. Table 1 shows the results. The resulting fibers had a high melting point and could not be processed into nonwoven fabrics.
  • Example 2 A polyvinyl alcohol fiber was obtained in the same manner as in Example 1 except that polyvinyl alcohol A used in Example 1 was not used and only polyvinyl alcohol B was used. Table 1 shows the results. The strength of the obtained fiber was low and it was impossible to process it into a nonwoven fabric.
  • Example 3 instead of polyvinyl alcohol B used in Example 1, polyvinyl alcohol with a degree of saponification of 74 mol% and a degree of polymerization of 500 was used as polyvinyl alcohol B, and the ratio of polyvinyl alcohol A and polyvinyl alcohol B was changed as shown in Table 1.
  • a polyvinyl alcohol fiber was obtained in the same manner as in Example 1, except that the Table 1 shows the results. The resulting fiber had a high melting temperature in water.
  • MIBK methyl isobutyl ketone
  • Example 5 A polyvinyl alcohol fiber was obtained in the same manner as in Example 3, except that polyvinyl alcohol A having a degree of saponification of 98 mol % and a degree of polymerization of 500 was used instead of the polyvinyl alcohol A used in Example 1. Since the polyvinyl alcohol A was not ethylene-modified, the resulting fiber had a high melting point and was difficult to process into a nonwoven fabric. Table 1 shows the results.
  • Example 6 A long fiber nonwoven fabric was obtained in the same manner as in Example 11 except that polyvinyl alcohol B used in Example 1 was not used and only polyvinyl alcohol A was used. Table 2 shows the results.
  • Example 7 instead of polyvinyl alcohol B used in Example 1, polyvinyl alcohol having a degree of saponification of 74 mol% and a degree of polymerization of 500 was used as polyvinyl alcohol B, and the ratio of polyvinyl alcohol A and polyvinyl alcohol B was changed as shown in Table 2. A long-fiber nonwoven fabric was obtained in the same manner as in Example 11, except that the Table 2 shows the results.
  • the polyvinyl alcohol fibers of the present invention are excellent in water solubility and strength. In addition, it is excellent in secondary processability such as nonwoven fabric processability. Moreover, as is clear from Table 2, the polyvinyl alcohol fibers of the present invention are excellent in long-fiber nonwoven fabric by melt blowing or the like, and the resulting long-fiber nonwoven fabric is excellent in water solubility and mechanical properties. Therefore, the fiber structure at least partially containing the vinyl alcohol fiber of the present invention can be suitably used as a water-soluble fiber or a water-soluble nonwoven fabric.

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  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Nonwoven Fabrics (AREA)

Abstract

La présente invention aborde le problème de la fourniture d'une fibre d'alcool polyvinylique qui présente une excellente aptitude au façonnage secondaire et une excellente hydrosolubilité, en particulier, une hydrosolubilité à basses températures.　La présente invention se rapporte à une fibre d'alcool polyvinylique comprenant : un alcool polyvinylique A présentant un degré de saponification d'au moins 90 % en mole et un taux de modification d'éthylène de 4-15 % en mole ; et un alcool polyvinylique B présentant un degré de saponification qui satisfait à l'expression (1) suivante selon laquelle 0<αA−αB≤20. Dans l'expression (1), αA représente le degré de saponification de l'alcool polyvinylique A et αB représente le degré de saponification de l'alcool polyvinylique B.
PCT/JP2022/045689 2021-12-13 2022-12-12 Fibre d'alcool polyvinylique et procédé de production d'une telle fibre WO2023112895A1 (fr)

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CN202280082465.9A CN118401713A (zh) 2021-12-13 2022-12-12 聚乙烯醇纤维及其制造方法
JP2023567777A JPWO2023112895A1 (fr) 2021-12-13 2022-12-12

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4933945A (fr) * 1972-07-28 1974-03-28
JPS5090717A (fr) * 1973-12-24 1975-07-21
JP2000234214A (ja) 1998-12-16 2000-08-29 Kuraray Co Ltd 水溶性熱可塑性ポリビニルアルコール繊維およびその製造方法
JP2001248014A (ja) 2000-03-01 2001-09-14 Asahi Kasei Corp 異型断面再生セルロース繊維

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4933945A (fr) * 1972-07-28 1974-03-28
JPS5090717A (fr) * 1973-12-24 1975-07-21
JP2000234214A (ja) 1998-12-16 2000-08-29 Kuraray Co Ltd 水溶性熱可塑性ポリビニルアルコール繊維およびその製造方法
JP2001248014A (ja) 2000-03-01 2001-09-14 Asahi Kasei Corp 異型断面再生セルロース繊維

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