JP2002061027A - Splittable fiber and method for producing sheet comprising the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a splittable fiber having good processability without splitting in e.g. a nonwoven production process but easily splittable when only simply soaked in hot water to produce ultrafine fiber. SOLUTION: This splittable fiber comprises two components incompatible with each other and arranged alternately; wherein a small amount of a thermoplastic polyvinyl alcohol is dispersed in one of the two components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a splittable fiber suitable for a fiber sheet such as a nonwoven fabric and a fabric.
The splittable fiber can be easily split by a simple treatment such as immersion in hot water to obtain an ultrafine fiber. Further, in the production of a nonwoven fabric or the like, since there is substantially no division in a step before division such as a crimping step, a carding step, and a needle punching step, a nonwoven fabric or the like can be favorably produced. The present invention also relates to a method for producing a fiber sheet such as a nonwoven fabric from the splittable fibers.

[0002]

2. Description of the Related Art It is well known that the texture of a fiber sheet composed of long fibers and short fibers such as nonwoven fabrics and fabrics becomes softer as the constituting fibers become thinner. Many proposals have been made as a method for obtaining fine fibers. For example,
There is a method in which a sea-island composite fiber is formed from two or more polymers having different solubility in an organic solvent, an alkaline aqueous solution, or the like, and a sea component is dissolved and removed to obtain an ultrafine fiber.
However, in such a method, a solvent treatment step and a solvent recovery step are required, and there is a disadvantage that the process becomes complicated,
It is also disadvantageous in terms of cost.

[0003] As another method, a method has been proposed in which a splittable fiber made of a polymer having no affinity for each other, for example, polyester / polyamide, polyester / polyolefin, polyamide / polyolefin, etc. is formed into a fabric and then split. There is a problem that cannot be divided.

In order to complete the division, a method has been proposed in which a specific chemical treatment is applied to the dividable fibers to promote the division and obtain ultrafine fibers. For example, JP-A-56-15454
No. 6 discloses a method in which high-concentration benzyl alcohol is applied to splittable fibers and subjected to a steam treatment at a temperature of 65 to 100 ° C. However, this method not only splits the splitting fibers not enough as expected,
Cleaning of the drug attached to the fiber and recovery of the drug are required, and there is a disadvantage that the process becomes complicated.

[0005] When used as long fibers, a method of completely dividing the fiber by a simple method is desired, but such a method has not been proposed so far.

[0006] Similarly, polymers having no affinity for each other, such as polyester / polyamide, polyester /
Japanese Patent Application Laid-Open No. Sho 62-133164 proposes a method in which a splittable fiber composed of polyolefin, polyamide / polyolefin, or the like is formed into a nonwoven fabric and then divided into ultrafine fibers by mechanical impact such as a raising treatment and a high-pressure water flow treatment. ing. However, since the conjugate fiber obtained by such a method has poor affinity between polymers, there is a problem that division occurs when a web is formed by passing through a carding process, and productivity is significantly reduced.

Further, as another method, Japanese Patent Publication No. Sho 61-1
No. 9756 discloses that a polyalkylene glycol is blended into one component of a conjugate fiber, a high-pressure water stream is applied to a fiber product comprising the conjugate fiber to pulverize and remove the component containing the polyalkylene glycol, and Japanese Patent Application Laid-Open No. Hei 6-2221 discloses a method of fibrillation, which comprises two types of polyesters. By blending polyalkylene glycols with one of the polyesters, water coexists and swells to absorb the other component. Distortion occurs at the joint surface of
There has been proposed a method of easily dividing by mechanical shock. However, in any of the methods, the polyalkylene glycol is contained in a considerable amount and is finally divided. When the content of polyalkylene glycol increases, there is a new problem that spinnability decreases.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a splittable fiber which can be easily split by immersing it in hot water without any or no extract. Furthermore, in the steps of crimping, carding, needle punching and the like for producing nonwoven fabrics and the like, the process passability is good without substantial division, and a small amount of extract in the subsequent steps,
Another object of the present invention is to provide a splittable fiber which is easily split without giving out any extract. It is still another object of the present invention to provide a method for producing a fiber sheet having excellent texture, such as flexibility, fullness, surface feel, and appearance, from the splittable fiber.

[0009]

Means for Solving the Problems The inventors of the present invention have made intensive studies to achieve the above object, and as a result, as splittable fibers,
Potentially peelable combination of two components, at least one of which contains a small amount of thermoplastic polyvinyl alcohol, so that it can be easily immersed in hot water with little or no extractables. The present inventors have found that ultrafineness can be achieved, and that a thermoplastic polyvinyl alcohol having a specific structure has good process-passability such as spinnability, and the present invention has been achieved. In addition, by selecting a specific combination having an appropriate adhesiveness as a combination of two components that are potentially peelable, process passability such as card passability is good, and furthermore, only by immersing in hot water, It has been found that micronization can be easily achieved without any or little extract.

That is, the present invention provides a component (1) comprising the polymer (A), a polymer (B) incompatible with the polymer (A), and a component (2) comprising the thermoplastic polyvinyl alcohol.
Wherein the amount of the thermoplastic polyvinyl alcohol is 0.1 to 20% by weight of the component (2), and the component (1) and the component (2) are alternately arranged.

[0011] The present invention also relates to a method for producing a sheet from the above-mentioned splittable fibers. That is, the present invention is a method for producing a fiber sheet, comprising forming a nonwoven fabric from the splittable fibers, splitting the splittable fibers, and fuzzing the surface of the nonwoven fabric or forming a resin layer on the surface of the nonwoven fabric.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. First, FIG. 1 and FIG. 2 show schematic cross-sectional views of the splittable fiber of the present invention. FIG. 1 shows a case of a type in which multiple layers are stacked in parallel, and FIG. 2 shows a type in which multiple layers are stacked radially. In the figure, (1) is a component comprising a polymer (A), and (2) is a component comprising a polymer (B) incompatible with the polymer (A) and a thermoplastic polyvinyl alcohol.

The splittable fiber of the present invention comprises a component (1) comprising the polymer (A), a polymer (B) incompatible with the polymer (A) and a component (2) comprising a thermoplastic polyvinyl alcohol. Be composed. Considering the melt viscosity, the polymer (A) may be selected from polyesters, polyester copolymers, polyester block copolymers, polyamides, polyamide copolymers, polyamide block copolymers, vinyl polymers, and the like, from applications and demands. It can be arbitrarily selected according to the performance. Hereinafter, this polymer will be described more specifically.

As the polyester, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, polypentamethylene terephthalate, polyhexamethylene terephthalate, polyethylene naphthalate, polypropylene naphthalate, polybutylene naphthalate, polypentamethylene naphthalate, polypentamethylene naphthalate,
Part of the diol component and dicarboxylic acid component constituting the polyester, such as polyhexamethylene naphthalate, is further converted to 1,4-cyclohexanedimethanol, cyclohexanediol, bis (hydroxymethyl) tricyclo [5.2.1.0 ^{2 , 6} ] decane, decahydro-1,
Alicyclic diols such as 4: 5,8-dimethanonaphthalene-2,3-dimethanol; aromatic diols such as 1,4-bis (β-hydroxyethoxy) benzene, bisphenol A and bisphenol S; -Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3
-Propanediol, neopentyl glycol, 1,5
-Pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 2-methyl-
1,8-octanediol, 1,9-nonanediol,
Diol components such as aliphatic diols such as 1,10-decanediol, glycerin, trimethylolpropane,
Tri- or more functional polyol components such as butanetriol, hexanetriol, trimethylolbutane, trimethylolpentane, and pentaerythritol, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, terephthalic acid, and 2,6-naphthalenedicarboxylic acid , 1,5
Aromatic dicarboxylic acids such as -naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, isophthalic acid, sodium sulfoisophthalate, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, succinic acid, and glutaric acid And dicarboxylic acid components such as aliphatic dicarboxylic acids such as adipic acid, suberic acid, azelaic acid and sebacic acid; and polyesters substituted with a tri- or higher functional polycarboxylic acid component such as trimellitic acid. Examples of the polyester block copolymer include a block copolymer of the above polyester with an aliphatic polyester, an aliphatic polyether, an aliphatic polycarbonate and the like.

Examples of the polyamide include nylon-6, nylon-11, nylon-12, nylon-46, nylon-66, and nylon-96 (nonamethylenediamine and / or 2-methyl-1,8-octanediamine and adipic acid). Nylon 910 (nonamethylenediamine and / or 2-methyl-1,8-octanediamine and nylon composed of sebacic acid), nylon 912 (nonamethylenediamine and / or
And nylon-6 / 12 which is a copolymer of caprolactam and laurolactam, and the like. Examples of the polyamide block copolymer include a block copolymer in which the above-described polyamide and an aliphatic polyester, an aliphatic polyether, an aliphatic polycarbonate, or the like are bonded by an ester group, an amide group, or the like.

Examples of the vinyl polymer include polyolefins such as polyethylene and polypropylene; polystyrene polymers such as polystyrene and polystyrene block copolymers; ethylene-vinyl acetate copolymers; and saponified ethylene-vinyl acetate copolymers. And the like.

A polymer other than the polymer A may be added to the component (1), and the polymer (A) occupying the component (1)
Is 60% by weight or more, preferably 70% by weight or more, and more preferably 80% by weight or more. 60
When the amount is less than% by weight, the splitting properties of the fibers and the physical properties of the fibers are inferior.

As the polymer (B), the same polymer as the polymer (A) can be used, but it must be incompatible with the polymer (A). Examples of incompatible polymer (A) / polymer (B) combinations include polyester / polyamide, polyamide / polyester, polyester block copolymer / polyamide, polyamide / polyester block copolymer, and polyester / polyamide block copolymer. United, polyamide block copolymer / polyester, polyester / polyolefin, polyolefin /
Polyester, polyamide / polyolefin, polyolefin / polyamide, polyester / polystyrene-based polymer, polystyrene-based polymer / polyester, polyamide / polystyrene-based polymer, polyolefin / polystyrene-based polymer, polystyrene-based polymer / polyolefin, ethylene-vinyl acetate copolymer Coalescence / Polyester, Ethylene-vinyl acetate copolymer / Polyamide, Ethylene-vinyl acetate copolymer / Polystyrene-based polymer, Saponified ethylene-vinyl acetate copolymer / Polyester, Saponified ethylene-vinyl acetate copolymer / Polyamide, Ethylene vinyl acetate Copolymer / polystyrene-based polymer and the like.

The splittable fiber of the present invention is immersed in hot water to swell or dissolve the thermoplastic polyvinyl alcohol contained in the component (2), thereby forming an interface between the component (1) and the component (2). Distortion occurs and splits. Therefore, the polymer (B), which is the main component of the component (2), is preferably a polymer into which hot water permeates and thermoplastic polyvinyl alcohol easily swells or dissolves. Examples of such a polymer (B) include a polyamide, a polyamide block copolymer, and a saponified ethylene-vinyl acetate copolymer. As a result of studying the above viewpoints and the physical properties of fibers, etc., preferred combinations of the polymer (A) / polymer (B) include polyester / polyamide, polyester / polyamide block copolymer, and polyester / ethylene vinyl acetate copolymer. Combinations of coalesced saponified products are included.

When a polyamide or a polyamide block copolymer is used as the polymer (B), spinnability, especially continuous spinning operation is improved. It is preferable to make the concentration of the group or amino group 30 μeq / g or less. More preferably, it is 25 μeq / g or less. As a method for reducing the terminal group concentration, a known method can be used.

A polymer other than the polymer (B) and the thermoplastic polyvinyl alcohol may be added to the component (2). The content of the polymer (B) in the component (II) is 60% by weight. % Or more, preferably 70% by weight or more, more preferably 80% by weight or more. If the content is less than 60% by weight, the fiber splitting properties and fiber properties are poor, which is not preferable.

When the splittable fiber of the present invention is used for producing a nonwoven fabric, it is necessary to ensure the processability in the carding process. In the carding process for producing a nonwoven fabric or the like, when the fineness of the fiber to be spread is equal to or less than a specific value, the processability through the card decreases. Therefore, it is necessary that the splittable fiber does not substantially split in any of the steps from spinning to carding. Therefore, the adhesive force between the component (1) and the component (2) constituting the splittable fiber needs to be such that the splitting fiber does not split due to mechanical stress in each step of spinning to carding. Furthermore, in the steps after the carding step, the nonwoven fabric made of the splittable fiber is immersed in hot water, so that the thermoplastic polyvinyl alcohol contained in the component (2) swells or dissolves, so that the components (1) and ( It is required that the adhesive force is such that distortion occurs at the interface of 2) and the film is divided. Preferred combinations of the component (1) and the component (2) having a suitable adhesive strength include the above-mentioned preferred combination of the polymer (A) / polymer (B), polyester / polyamide, and polyester / polyamide. Examples of the polyester include block copolymers, and examples of the polyester include polyethylene terephthalate and polyester mainly composed of ethylene terephthalate units. The polyester mainly composed of ethylene terephthalate is a polyester containing 60% by weight or more of ethylene terephthalate units, more preferably 70% by weight.
The content is more preferably 80% by weight or more. The polyamide is a polyamide satisfying carbon number / amide group> 7, preferably carbon number / amide group> 8, and more preferably carbon number / amide group> 9. More specifically, nylon-11, nylon-12, nylon-6
10, nylon-612, nylon-910, nylon-912, nylon-6 / 12 and the like. Examples of the polyamide block copolymer include a block copolymer in which a polyamide satisfying the above-mentioned carbon number / amide group> 7 and an aliphatic polyester, an aliphatic polyether, an aliphatic polycarbonate or the like are bonded by an ester group, an amide group, or the like. Is mentioned.

Component (1) having moderate adhesive strength and component
As a preferable combination of (2), as described above, in addition to the method of selecting an appropriate combination of the polymer (A) / polymer (B), the component (1) is compatible with the polymer (B). The polymer (C) is contained in the range of 0.5 to 40% by weight, preferably 5 to 30% by weight, more preferably 10 to 30% by weight of the component (1), or the polymer (C) Coalescing (A)
0.5 to 40% by weight, preferably 5 to 30% by weight, more preferably 1 to 40% by weight of the component (2)
A method in which the content is contained in the range of 0 to 30% by weight is also possible.

The thermoplastic polyvinyl alcohol used in the present invention is obtained by saponifying a vinyl ester unit of a vinyl ester polymer. The saponification degree is 90-99.
Preferably, it is 99 mol%. More preferably 93
~ 99.98 mol%, more preferably 94 ~ 9.
9.97 mol%. If the saponification degree is less than 90 mol%, the thermal stability of the thermoplastic polyvinyl alcohol is poor, and the melt spinnability is lowered due to thermal decomposition or gelation, which is not preferable. On the other hand, polyvinyl alcohol having a degree of saponification of more than 99.99 mol% cannot be produced stably, and the melt spinnability also decreases.

In saponifying a vinyl ester polymer in a solvent such as methanol, methyl acetate, dimethyl sulfoxide, or dimethylformamide, an alkaline substance containing an alkali ion is used as a saponification catalyst. As the alkaline substance, sodium hydroxide, potassium hydroxide and the like are used. The polyvinyl alcohol obtained by saponification is washed with a washing liquid, but alkali metal ions such as sodium ions and potassium ions remain. The remaining alkali metal ion is 0.1% in terms of sodium ion with respect to 100 parts by weight of polyvinyl alcohol.
0003 to 1 part by mass, preferably 0.0003 to 0.8 part by mass, more preferably 0.0003 to 0.6 part by mass, and particularly preferably 0.0003 to 0.5 part by mass. When the content of the alkali metal ion is more than 1 part by mass, decomposition and gelation at the time of melt spinning are remarkable, and the melt spinnability is undesirably lowered. The content of the alkali metal ion can be determined by an atomic absorption method.

The vinyl compound monomer for forming the vinyl ester unit includes vinyl formate, vinyl acetate, vinyl propionate, vinyl valerate, vinyl caprate, vinyl laurate, vinyl stearate, vinyl benzoate, pivalin Examples thereof include vinyl acid and vinyl versatate, and among them, vinyl acetate is preferable.

The thermoplastic polyvinyl alcohol used in the present invention may be a homopolymer of polyvinyl alcohol or a modified polyvinyl alcohol into which copolymerized units have been introduced. In view of this, it is preferable to use modified polyvinyl alcohol into which copolymerized units have been introduced. Examples of the type of the comonomer include ethylene, propylene, 1-butene,
Α-olefins such as isobutene and 1-hexene, acrylic acid and its salts, acrylates such as methyl acrylate, ethyl acrylate, n-propyl acrylate and i-propyl acrylate, methacrylic acid and its salts, Methacrylic esters such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, acrylamide derivatives such as acrylamide, N-methylacrylamide, N-ethylacrylamide, methacrylamide, N-methylmethacrylamide , Methacrylamide derivatives such as N-ethyl methacrylamide, vinyl ethers such as methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether and n-butyl vinyl ether; Recall vinyl ether, 1,3
-Propanediol vinyl ether, hydroxy group-containing vinyl ethers such as 1,4-butanediol vinyl ether, allyl acetate, propyl allyl ether, butyl allyl ether, allyl ethers such as hexyl allyl ether, monomers having an oxyalkylene group, Vinylsilyls such as vinyltrimethoxysilane, isopropenyl acetate, 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, 7-octen-1-ol, 9-decene-1 -Ole, hydroxy-containing α-olefins such as 3-methyl-3-buten-1-ol, fumaric acid, maleic acid, itaconic acid, maleic anhydride, phthalic anhydride, trimellitic anhydride or itaconic anhydride Having a carboxyl group derived from etc .; Nsuruhon acid, allylsulfonic acid, methallyl sulfonic acid, 2-acrylamido-2
A monomer having a sulfonic acid group derived from methylpropanesulfonic acid or the like; vinyloxyethyltrimethylammonium chloride, vinyloxybutyltrimethylammonium chloride, vinyloxyethyldimethylamine, vinyloxymethyldiethylamine, N-acrylamidomethyltrimethylammonium chloride, Examples include monomers having a cationic group derived from N-acrylamidoethyltrimethylammonium chloride, N-acrylamidodimethylamine, allyltrimethylammonium chloride, methallyltrimethylammonium chloride, dimethylallylamine, allylethylamine and the like. The content of these monomers is usually 20 mol% or less.

Among these monomers, α-olefins such as ethylene, propylene, 1-butene, isobutene and 1-hexene, methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, Vinyl ethers such as i-propyl vinyl ether and n-butyl vinyl ether; hydroxy group-containing vinyl ethers such as ethylene glycol vinyl ether, 1,3-propanediol vinyl ether and 1,4-butanediol vinyl ether; allyl acetate, propyl allyl ether and butyl Allyl ether,
Allyl ethers such as hexyl allyl ether, monomers having an oxyalkylene group, 3-buten-1-ol, 4-penten-1-ol, 5-hexen-1-ol, 7-octen-1-ol, Monomers derived from hydroxy group-containing α-olefins such as 9-decene-1-ol and 3-methyl-3-buten-1-ol are preferred.

In particular, from the viewpoints of copolymerizability, melt spinnability and splitting properties of splittable fibers, ethylene, propylene, 1-butene and isobutene having 4 or less carbon atoms, α-olefins,
Methyl vinyl ether, ethyl vinyl ether, n-propyl vinyl ether, i-propyl vinyl ether, n
Vinyl ethers such as -butyl vinyl ether are more preferred. Units derived from α-olefins having 4 or less carbon atoms and / or vinyl ethers are preferably present in polyvinyl alcohol in an amount of 0.1 to 20 mol%, more preferably 1 to 20 mol%, and still more preferably. Is 4 to 15 mol%, particularly preferably 6 to 13 mol%. Furthermore, when the α-olefin is ethylene, it is particularly preferable to use a modified polyvinyl alcohol into which ethylene units have been introduced in an amount of 4 to 15 mol%, and more preferably 6 to 15 because the melt spinnability is particularly high.
Modified polyvinyl alcohol introduced at 13 mol%.

Examples of the method for producing the pre-saponified polymer of the thermoplastic polyvinyl alcohol used in the present invention include known methods such as bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization. Among them, a bulk polymerization method or a solution polymerization method in which polymerization is performed without a solvent or in a solvent such as an alcohol is usually employed. Examples of the alcohol used as a solvent during the solution polymerization include lower alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol. As the initiator used for the copolymerization, α, α′-azobisisobutyronitrile, 2,2′-azobis (2,
4-dimethyl-valeronitrile), benzoyl peroxide,
Known initiators such as an azo initiator such as n-propyl peroxycarbonate and a peroxide initiator are exemplified. The polymerization temperature is not particularly limited.
A range of 50 ° C. is appropriate.

In the present invention, the proportion of the thermoplastic polyvinyl alcohol in the component (2) is extremely important from the viewpoints of melt spinnability and splitting property of splittable fibers.
That is, the proportion of the thermoplastic polyvinyl alcohol in the component (2) needs to be in the range of 0.1 to 20% by weight. Preferably, it is in the range of 0.5 to 10% by weight, and more preferably in the range of 1 to 6% by weight.
If the content of the thermoplastic polyvinyl alcohol in the component (2) exceeds 20% by weight, the melt spinnability, especially continuous spinning operability will be remarkably deteriorated, and if the spinning temperature exceeds 250 ° C, it will be difficult to produce a substantial mass. Becomes If the proportion of the thermoplastic polyvinyl alcohol in the component (2) is less than 0.1% by weight, the splitting properties of the splittable fiber are inferior.

The weight ratio of component (1) to component (2) of the splittable fiber of the present invention is such that component (1) / component (2) is 90/1.
It is preferably in the range of 0 to 10/90. More preferably, 85/15 to 15/85, even more preferably 80
/ 20 to 20/80. If the ratio of the component (1) / the component (2) exceeds the above range, it is difficult to obtain a target cross-sectional fiber, which is not preferable. In the fiber of the present invention, the layer composed of the component (1) and the layer composed of the component (2) are alternately present, but depending on the case, even if another layer exists inside both layers. Alternatively, each layer may be partially bonded to a layer made of the same component.

It is desired that the splittable fiber of the present invention does not contain a heavy metal or the like, that is, it can be dyed with a disperse dye which is preferable from an environmental point of view. Fibers composed of a polymer having a low glass transition temperature are dyed with a disperse dye, but have poor color fastness. In the splittable fiber of the present invention, the polymer (A),
When the glass transition temperature of the polymer (B) is low, for example, about 5
When it is lower than 0 ° C., the polymer (E) having a glass transition temperature of 50 ° C. or higher, preferably 60 ° C. or higher, more preferably 70 ° C. or higher is added to the component (1) or the component (2).
And 3 to 40 parts by weight of each of the components (1) and (2).
%, Especially 5 to 30%, and particularly preferably 10 to 30%. Examples of the high molecular polymer (E) include polyesters, polyamides, polystyrenes, polymethacrylates, and the like having a glass transition temperature of 50 ° C. or higher. The component (1) and the component (2) constituting the splittable fiber of the present invention may contain a coloring agent such as a dye or a pigment, various stabilizers, and the like.

In the composite fiber comprising the components (1) and (2), it is necessary that one component is divided and arranged in multiple layers by the other component, and the other component is embedded in the one component. Those having a shape not formed are preferred.
Specific examples include those shown in FIGS. 1 and 2, and the splittable fibers having these cross-sectional shapes are preferable because they are easily split by hot water. In order to obtain fibers of each cross-sectional shape, a corresponding nozzle nozzle hole structure may be used. The splittable fiber of the present invention has a structure in which layers composed of the component (1) and layers composed of the component (2) are alternately laminated. Preferably 4 to 100 layers, more preferably 5 to 5 layers.
0 layer.

The fiber sheet of the present invention can be obtained by performing the following steps in combination. That is,
It is obtained by sequentially performing the following steps (a) to (d). (A) a step of producing a joined-type splittable conjugate fiber composed of the component (1) and the component (2), wherein at least one of the components is divided and arranged in multiple layers by the other component; A step of manufacturing a nonwoven fabric, (c) a step of separating and separating the fibers into a fiber bundle, and (2) forming a nap of the fiber bundle on at least one surface of the nonwoven fabric, or forming a resin layer on at least one surface of the nonwoven fabric. The following steps (e) to (g) may be added as necessary between steps (b) and (c) or between (c) and (2). The following step (h) may be added after the step (d). (E) a step of shrinking the nonwoven fabric, (f)
Temporarily fixing nonwoven fabric with water-soluble glue, etc.
Impregnating the polymer liquid, coagulating, and drying to give the polymer to the nonwoven fabric, (h) dyeing the obtained sheet,

Next, the process of the present invention will be described in detail. First, a spun yarn of splittable conjugate fiber used in the present invention is obtained by spinning. Then, the obtained spun yarn is stretched, and if necessary, subjected to processing steps such as crimping, heat setting, and cutting to obtain splittable fibers having a fineness of 2 to 15 dtex.

The splittable fibers are defibrated with a card and formed through a webber to form a random or cross-wrapped web. If necessary, other fibers may be mixed. The resulting fibrous web is laminated to the desired weight and thickness. Next, needle punching is performed by a known method to obtain a needle punched nonwoven fabric. The number of punches is usually 200 to 250
The range is 0 punches / cm ² .

It is necessary to peel and split the splittable fibers constituting the fiber entangled nonwoven fabric to make them ultrafine. Examples of the method of peeling and splitting include immersion in hot water or an alkaline aqueous solution, and high pressure water flow. A method of applying water while giving a mechanical impact can be cited.

Then, the fiber entangled nonwoven fabric is heated to 50 to 150 ° C.
, And more preferably, the fiber-entangled nonwoven fabric is heated in a hot water tank at 50 to 95 ° C to shrink the fiber-entangled nonwoven fabric. By shrinking,
The sense of fulfillment of the fiber sheet is significantly improved. The shrinkage is determined by the types and weight ratios of polyester and polyamide, spinning conditions, stretching conditions, etc. In order to improve the feeling of fulfillment and flexibility of the fiber sheet, the area shrinkage should be in the range of 10 to 60%. And more preferably 20 to 5
The range is 0%.

If necessary, a resin which can be dissolved and removed, for example, a water-soluble sizing agent such as a polyvinyl alcohol-based resin may be applied to the nonwoven fabric to temporarily fix the nonwoven fabric.

Further, the fiber sheet of the present invention may be provided with a polymer liquid in order to supplement the surface appearance and feel of the fiber sheet, such as a feeling of fulfillment, and mechanical properties. As the polymer liquid to be used, a polymer liquid obtained by dissolving a polyurethane polymer or an acrylic polymer in a solvent or dispersing in a non-solvent such as water is impregnated into a fiber-entangled nonwoven fabric and treated with a resin non-solvent. Then, wet coagulation, or heat treatment, dry coagulation, or heat treatment, hot water treatment, steam treatment, and heat-sensitive coagulation. The polymer used may be solidified so as to be uniformly applied to the entire nonwoven fabric, or may be migrated to the surface and applied with a gradient in the thickness direction. Impregnated with a polymer liquid,
The polymer after coagulation and drying may be adhered to the fiber, or may form a space between the polymer and the fiber. The amount of the polymer to be applied is as follows.
The amount of the polymer is 120 parts by weight or less, preferably 100 parts by weight or less, more preferably 80 parts by weight or less, based on 0 parts. If it exceeds 120 parts by weight, the flexibility of the obtained fiber sheet is impaired, and the fiber sheet becomes rubber-like, which is not preferable.

Next, at least one surface of the sheet made of the ultrafine fiber entangled nonwoven fabric and the resin used as required is subjected to a raising treatment to form a raised surface of the ultrafine fibers mainly composed of the ultrafine fibers, thereby forming a suede-like leather-like material. A sheet or a resin layer is laminated on at least one side to form a leather-like sheet with a silver surface. As a method for forming the fiber raised surface, a method of buffing using a sandpaper or the like is used after adjusting the thickness of the fibrous substrate to a desired thickness or before adjusting the thickness. If the thickness has not been adjusted, the thickness is adjusted to a desired thickness. Similarly, in the case of a leather-like sheet on which a resin layer is laminated, the thickness is adjusted. As the resin layer to be laminated on the surface, an elastic polymer layer represented by a polyurethane layer is suitably used, and the resin layer may be a non-porous layer or a porous layer, and may be a porous layer. A non-porous layer may be laminated on the above. As the thickness of the resin layer,
A range of 400 μm is common. If necessary, a coloring agent and various stabilizers may be added to the resin layer.
The surface of the nonwoven fabric can be melted to form a resin layer by heating the surface of the fiber sheet and pressing it against a smooth surface. Next, the obtained suede-like leather-like sheet or grain-like leather-like sheet is dyed as necessary. Dyeing is carried out with a dye mainly composed of a disperse dye or the like by a usual dyeing method. Further, the leather-like sheet can be subjected to finishing treatment such as kneading softening treatment and brushing as necessary to obtain a leather-like sheet.

The leather-like sheet obtained according to the present invention has extremely good color fastness and color development and excellent texture, and is used as a suede type or a type with silver. It is suitable for shoes, car seats, bags, various gloves and the like.

[0044]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, parts and% relate to weight unless otherwise specified. The glass transition temperature and the logarithmic viscosity of the polyamide in the present invention were measured by the following methods.

[Glass Transition Temperature] The glass transition temperature of the high molecular weight polymer (E) was measured using a differential scanning calorimeter (DSC) manufactured by Mettler (TA-3000) under a nitrogen gas stream as shown in Table 2 below. Steps 1 to 3 shown were sequentially performed, and the glass transition temperature was determined from the transition point at that time.

[0046]

[Table 1]

[Logarithmic viscosity of polyamide] Calculated from a value measured using a Ubbelohde type viscosity system in a constant temperature bath at 30 ° C. using concentrated sulfuric acid. The resins used in the following examples and comparative examples are shown in the following table.

[0048]

[Table 2]

Example 1 IPA-modified PET was used as the polymer (A), and this was used as the component (1). Nylon 12-based elastomer / modified PVA using nylon 12-based elastomer as polymer (B) and modified PVA as thermoplastic polyvinyl alcohol
A mixture having a weight ratio of A of 97/3 was used as the component (2). Nylon 12-based elastomer and modified PVA in a weight ratio of 97
/ 3 is pellet blended beforehand, and this and IP
The A-modified PET is melt-extruded with a separate extruder, weighed by a gear pump so that the weight ratio of component (1) / component (2) becomes 70/30, and then supplied into a spinning pack. C. and discharged at a speed of 500 m / min. A fiber having a cross section shown in FIG. 1 in which the component (1) and the component (2) were alternately arranged in 11 layers was obtained. In the cross section of FIG. 1, component (1) forms a five-layer portion and component (2) forms a six-layer portion. The continuous spinning for 30 hours was performed, but no breakage occurred. After spinning, it was stretched, mechanically crimped, and then cut to 51 mm to obtain a composite staple fiber having a single yarn fineness of 3.0 dtex.

The obtained composite staple fiber is a card,
A web was produced via a cross wrapper. No process trouble occurred in the web preparation, and good passability was exhibited. When the inside of this web was observed with a scanning electron microscope, almost no split fibers were seen. Next, needle punching was performed to obtain a fiber-entangled nonwoven fabric. Then, the fiber entangled nonwoven fabric was immersed in a bath containing hot water at 90 ° C. to shrink the nonwoven fabric. The shrinkage ratio [(length of nonwoven fabric after shrinkage / length of nonwoven fabric before shrinkage) × 100] is 24% in the vertical direction,
It was 25% in the horizontal direction. After drying the shrunk nonwoven fabric, 100 parts of the nonwoven fabric was mixed with an aqueous urethane emulsion (Bondick 131 manufactured by Dainippon Ink and Chemicals, Inc.).
The nonwoven fabric is impregnated with the aqueous urethane emulsion so that 10 parts of the solid content of 0) is added, dried with hot air at 130 ° C., and then pressed with a roller heated to 120 ° C. to smooth the surface, and the thickness is reduced. A fibrous substrate of about 1 mm was obtained. Subsequently, one surface of the fibrous substrate was buffed with sandpaper to adjust the thickness to 0.80 mm, and then the other surface was treated with an emery buffing machine to form an extremely fine nap surface, and further a circular jet dyeing machine. Was dyed brown using a disperse dye, and finished to obtain a leather-like sheet having a specific gravity of 0.52. This product was excellent in a feeling of fulfillment and flexibility, had a uniform nap, and was excellent in surface appearance. When the surface and the inside of the obtained artificial leather were observed with a scanning electron microscope, the fibers on the surface were completely split, and the fibers inside were also split by 90% or more.

Example 2 PET was used as the polymer (A), and this was used as the component (1). Nylon 12 was used as the polymer (B) and modified PVA was used as the thermoplastic polyvinyl alcohol.
A mixture in which the weight ratio of 2 / modified PVA was 95/5 was used as the component (2). Nylon 12 and modified PVA in a weight ratio of 9
Pellets are blended in advance so that the ratio becomes 5/5, and this and P
Each ET is melt-extruded by a separate extruder, and component (1)
After weighing each with a gear pump so that the weight ratio of / component (2) becomes 70/30, it is supplied into a spinning pack,
It was discharged at a die temperature of 290 ° C. and wound up at a speed of 500 m / min. A fiber having a cross section shown in FIG. 1 in which the component (1) and the component (2) were alternately arranged in 11 layers was obtained. In the cross section of FIG. 1, component (1) forms a five-layer portion and component (2) forms a six-layer portion. The continuous spinning for 30 hours was performed, but no breakage occurred. After spinning, the film is stretched and mechanically crimped.
mm to obtain a composite staple fiber having a single yarn fineness of 3.0 dtex.

The obtained composite staple fiber is a card,
A web was produced via a cross wrapper. No process trouble occurred in the web preparation, and good passability was exhibited. When the inside of this web was observed with a scanning electron microscope, almost no split fibers were seen. Next, needle punching was performed to obtain a fiber-entangled nonwoven fabric. This fiber-entangled nonwoven fabric was immersed in a bath containing hot water at 90 ° C. to shrink the nonwoven fabric. The shrinkage ratio [(length of nonwoven fabric after shrinkage / length of nonwoven fabric before shrinkage) × 100] was 18% in the vertical direction and 18% in the horizontal direction. After drying the contracted nonwoven fabric, the nonwoven fabric is impregnated with the aqueous urethane emulsion such that 13 parts of the solid content of the aqueous urethane emulsion (Bondick 1310 manufactured by Dainippon Ink and Chemicals, Inc.) is added to 100 parts of the nonwoven fabric. After drying with hot air at 130 ° C,
The surface was smoothed by pressing with a roller heated to 120 ° C. to obtain a fibrous substrate having a thickness of about 1 mm. Subsequently, one surface of the fibrous substrate was buffed with sandpaper to a thickness of 0.1 mm.
After adjusting the thickness to 80 mm, the other surface is treated with an emery buffing machine to form an extremely fine nap surface, and further dyed brown with a circular jet dyeing machine using a disperse dye, and finished with a specific gravity. A 0.46 leather-like sheet was obtained. This product was excellent in a feeling of fulfillment and flexibility, had a uniform nap, and was excellent in surface appearance. When the surface and the inside of the obtained artificial leather were observed with a scanning electron microscope, the fibers on the surface were completely split, and the fibers inside were also split by 90% or more.

Example 3 IPA-modified PET was used as the polymer (A), and this was used as the component (1). Nylon 6/1 as polymer (B)
2. Using modified PVA as thermoplastic polyvinyl alcohol, the weight ratio of nylon 6/12: modified PVA is 97:
The mixture of No. 3 was used as the component (2). Nylon 6/12 and modified PVA are pellet-blended in advance so that the weight ratio becomes 97/3, and this and IPA-modified PET are melt-extruded by separate extruders, respectively, and the weight ratio of component (1) / component (2) is obtained. Was measured by a gear pump so as to be 70/30, then supplied into a spinning pack, discharged at a die temperature of 270 ° C., and wound at a speed of 500 m / min. A fiber having a cross section shown in FIG. 1 in which the component (1) and the component (2) were alternately arranged in 11 layers was obtained. In the cross section of FIG. 1, component (1) forms a five-layer portion and component (2) forms a six-layer portion. The continuous spinning for 30 hours was performed, but no breakage occurred. After spinning, stretch,
Mechanical crimping was applied and then cut to 51 mm to obtain a composite staple fiber having a single yarn fineness of 3.0 dtex.

The obtained composite staple fiber is a card,
A web was produced via a cross wrapper. No process trouble occurred in the web preparation, and good passability was exhibited. When the inside of this web was observed with a scanning electron microscope, almost no split fibers were seen. Next, needle punching was performed to obtain a fiber-entangled nonwoven fabric. Next, this fiber-entangled nonwoven fabric was immersed in a bath containing hot water at 90 ° C. to shrink the nonwoven fabric. The shrinkage ratio ((length of nonwoven fabric after shrinkage / length of nonwoven fabric before shrinkage) × 100) was 22% in the vertical direction and 23% in the horizontal direction. After drying the shrunk nonwoven fabric,
Aqueous urethane emulsion (Bondick 1310 manufactured by Dainippon Ink and Chemicals, Inc.) for 100 parts of nonwoven fabric
A non-woven fabric is impregnated with an aqueous urethane emulsion so as to give 13 parts of solid content, dried with hot air at 130 ° C., and then pressed with a roller heated to 120 ° C. to smooth the surface to a thickness of about 1 mm. Was obtained. continue,
After buffing one surface of the fibrous substrate with sandpaper and adjusting the thickness to 0.80 mm, the other surface is treated with an emery buffing machine to form an extremely fine nap, and further dispersed with a circular jet dyeing machine. After dyeing brown using a dye,
After finishing, a leather-like sheet having a specific gravity of 0.51 was obtained. This product was excellent in a feeling of fulfillment and flexibility, had a uniform nap, and was excellent in surface appearance. When the surface and the inside of the obtained artificial leather were observed with a scanning electron microscope, the fibers were almost completely divided on both the surface and the inside.

Example 4 IPA-modified PET was used as the polymer (A), and this was used as the component (1). Nylon 1 as high polymer (B)
2, modified PVA as thermoplastic polyvinyl alcohol,
Further, as a polymer (D) having at least a part of the constitutional unit of the polymer (A) and a polymer (E) having a glass transition temperature of 50 ° C. or more, IPA-modified PET is used. Using nylon 12 / modified PVA
A mixture in which the weight ratio of / IPA-modified PET (the polymer (D) and the polymer (E)) was 78/3/19 was used as the component (2). Nylon 12, modified PVA, and IP
A-modified PET (polymer (E)) having a weight ratio of 76 /
Pellets were blended in advance so that the ratio became 3/19, and this and IPA-modified PET (polymer (A)) were melt-extruded with separate extruders, respectively, and the weight ratio of component (1) / component (2) was 70. / 30 and then fed into the spinning pack, and the die temperature is 270 ° C.
At a speed of 500 m / min. Ingredient (1)
And the component (2) were alternately arranged in 11 layers to obtain a fiber having a cross section shown in FIG. In the cross section of FIG. 1, the component (1) has five layers,
Component (2) forms a six-layer portion. The continuous spinning for 30 hours was performed, but no breakage occurred. After spinning, it was stretched, mechanically crimped, and then cut to 51 mm to obtain a composite staple fiber having a single yarn fineness of 3.0 dtex.

The obtained composite staple fiber is a card,
A web was produced via a cross wrapper. No process trouble occurred in the web preparation, and good passability was exhibited. When the inside of this web was observed with a scanning electron microscope, almost no split fibers were seen. Next, needle punching was performed to obtain a fiber-entangled nonwoven fabric. Next, this fiber-entangled nonwoven fabric was immersed in a bath containing hot water at 90 ° C. to shrink the nonwoven fabric. The shrinkage ratio [(length of nonwoven fabric after shrinkage / length of nonwoven fabric before shrinkage) × 100] was 16% in the vertical direction and 17% in the horizontal direction. After drying the shrunk nonwoven fabric,
Aqueous urethane emulsion (Bondick 1310 manufactured by Dainippon Ink and Chemicals, Inc.) for 100 parts of nonwoven fabric
A non-woven fabric is impregnated with an aqueous urethane emulsion so that 14 parts of solid content is added thereto, dried with hot air at 130 ° C., and then pressed with a roller heated to 120 ° C. to smooth the surface and to have a thickness of about 1 mm. Was obtained. continue,
After buffing one surface of the fibrous base material with sandpaper and adjusting the thickness to 0.80 mm, the other surface is treated with an emery buffing machine to form an extremely fine nap surface, and further a disperse dye is formed with a circular jet dyeing machine. After dyeing brown using, a leather-like sheet having a specific gravity of 0.44 was obtained. It was excellent in fullness and flexibility, and the nap was uniform and the surface appearance was excellent. When the surface and the inside of the obtained artificial leather were observed with a scanning electron microscope, the fibers on the surface were completely split, and the fibers inside were also split into 80% or more.

Example 5 An IPA-modified PET was used as the polymer (A) and a nylon 12-based elastomer was used as the polymer (C) having at least a part of the structural unit of the polymer (B).
A mixture in which the weight ratio of the nylon 12-based elastomer was 90/10 was used as the component (1). Nylon 12 elastomer was used as the polymer (B) and modified PVA was used as the thermoplastic polyvinyl alcohol. A mixture of nylon 12-based elastomer / modified PVA at a weight ratio of 95/5 was used as the component (2). The IPA-modified PET and the nylon 12-based elastomer are previously pellet-blended (component (1)) so that the weight ratio becomes 90/10, and the nylon 12-based elastomer and the modified PVA are separately prepared so that the weight ratio becomes 95/5. Pellet blend, component (1), component (2)
Are extruded in separate extruders, and the component (1) /
The components (2) were each weighed by a gear pump so that the weight ratio became 70/30, then supplied into a spinning pack, discharged at a die temperature of 270 ° C, and wound up at a speed of 500 m / min. A fiber having a cross section shown in FIG. 1 in which the component (1) and the component (2) were alternately arranged in 11 layers was obtained. In the cross section of FIG. 1, component (1) forms a five-layer portion and component (2) forms a six-layer portion. The continuous spinning for 30 hours was performed, but no breakage occurred. After spinning, the film is stretched and mechanically crimped.
mm to obtain a composite staple fiber having a single yarn fineness of 3.0 denier.

The obtained composite staple fiber is a card,
A web was produced via a cross wrapper. No process trouble occurred in the web preparation, and good passability was exhibited. When the inside of this web was observed with a scanning electron microscope, almost no split fibers were seen. Next, needle punching was performed to obtain a fiber-entangled nonwoven fabric. Next, this fiber-entangled nonwoven fabric was immersed in a bath containing hot water at 90 ° C. to shrink the nonwoven fabric. The shrinkage ratio ((length of nonwoven fabric after shrinkage / length of nonwoven fabric before shrinkage) × 100) was 25% in the vertical direction and 25% in the horizontal direction. After drying the shrunk nonwoven fabric,
The aqueous urethane emulsion is impregnated into the nonwoven fabric so that the solid content of the aqueous urethane emulsion (Bondick 1310 manufactured by Dainippon Ink and Chemicals, Inc.) is added to the nonwoven fabric, and dried with hot air at 130 ° C. 12
The surface was smoothed by pressing with a roller heated to 0 ° C. to obtain a fibrous substrate having a thickness of about 1 mm. Subsequently, one surface of the fibrous base was buffed with sandpaper to a thickness of 0.80.
After adjusting the thickness to mm, the other surface was treated with an emery buffing machine to form a very fine nap surface, further dyed brown using a disperse dye with a circular jet dyeing machine, finished, and finished with a specific gravity. A leather-like sheet of 0.54 was obtained. It was excellent in fullness and flexibility, and the nap was uniform and the surface appearance was excellent. When the surface and the inside of the obtained artificial leather were observed with a scanning electron microscope, the fibers on the surface were completely split, and the fibers inside were also split into 90% or more.

Example 6 IPA-modified PET was used as the polymer (A), and this was used as the component (1). Nylon 912 as the polymer (B),
Modified PVA was used as the thermoplastic polyvinyl alcohol, and a mixture having a weight ratio of nylon 912 / modified PVA of 95/5 was used as the component (2). Nylon 912 and modified PV
A is preliminarily pellet-blended (component (2)) so that the weight ratio becomes 95/5, and this and IPA-modified PET are melt-extruded with separate extruders, respectively, and the weight ratio of component (1) / component (2) is obtained. Was measured by a gear pump so as to be 70/30, then supplied into a spinning pack, discharged at a die temperature of 270 ° C., and wound at a speed of 500 m / min. A fiber having a cross section shown in FIG. 1 in which the component (1) and the component (2) were alternately arranged in 11 layers was obtained. In the cross section of FIG.
The layer part, component (2), forms a six-layer part. The continuous spinning for 30 hours was performed, but no breakage occurred. After spinning, it was stretched, mechanically crimped, and then cut to 51 mm to obtain a composite staple fiber having a single yarn fineness of 3.0 dtex.

The obtained composite staple fiber is a card,
A web was produced via a cross wrapper. No process trouble occurred in the web preparation, and good passability was exhibited. When the inside of this web was observed with a scanning electron microscope, almost no split fibers were seen. Next, needle punching was performed to obtain a fiber-entangled nonwoven fabric. Next, this fiber-entangled nonwoven fabric was immersed in a bath containing hot water at 90 ° C. to shrink the nonwoven fabric. The shrinkage ratio ((length of nonwoven fabric after shrinkage / length of nonwoven fabric before shrinkage) × 100) was 15% in the vertical direction and 15% in the horizontal direction. After drying the shrunk nonwoven fabric,
Aqueous urethane emulsion (Bondick 1310 manufactured by Dainippon Ink and Chemicals, Inc.) for 100 parts of nonwoven fabric
A non-woven fabric is impregnated with an aqueous urethane emulsion so that the solid content of 10 parts is added, dried with hot air at 130 ° C., and then pressed with a roller heated to 120 ° C. to smooth the surface, and the thickness is about 1 mm. Was obtained. continue,
After buffing one surface of the fibrous base material with sandpaper and adjusting the thickness to 0.80 mm, the other surface is treated with an emery buffing machine to form an extremely fine nap surface, and further a disperse dye is formed with a circular jet dyeing machine. After dyeing brown using, a leather-like sheet having a specific gravity of 0.42 was obtained. It was excellent in fullness and flexibility, and the nap was uniform and the surface appearance was excellent. Observation of the surface and the inside of the obtained artificial leather with a scanning electron microscope revealed that the fibers were completely split on both the surface and the inside.

Comparative Example 1 IPA-modified PET was used as the polymer (A), and this was used as the component (1). Nylon 12 was used as the polymer (B), and this was used as the component (2). IPA-modified PET (component (1)) and nylon 12 (component (2)) are each melt-extruded with separate extruders, and each gear pump is adjusted so that the weight ratio of component (1) / component (2) becomes 70/30. , And the mixture was fed into a spinning pack, discharged at a die temperature of 270 ° C, and wound up at a speed of 500 m / min.
FIG. 1 in which component (1) and component (2) are alternately arranged in 11 layers
Was obtained. In the cross section of FIG. 1, component (1) forms a five-layer portion and component (2) forms a six-layer portion. 30
A continuous spinning of time was carried out, but there was no breakage at all. After spinning, it was stretched, mechanically crimped, and then cut to 51 mm to obtain a composite staple fiber having a single yarn fineness of 3.0 dtex.

The obtained composite staple fiber is a card,
A web was produced via a cross wrapper. No process trouble occurred in the web preparation, and good passability was exhibited. When the inside of this web was observed with a scanning electron microscope, no split fibers were found. Next, needle punching was performed to obtain a fiber-entangled nonwoven fabric. Next, this fiber-entangled nonwoven fabric was immersed in a bath containing hot water at 90 ° C. to shrink the nonwoven fabric. The shrinkage ratio [(length of nonwoven fabric after shrinkage / length of nonwoven fabric before shrinkage) × 100] was 18% in the vertical direction and 19% in the horizontal direction. After drying the contracted nonwoven fabric, the nonwoven fabric is impregnated with the aqueous urethane emulsion such that 13 parts of the solid content of the aqueous urethane emulsion (Bondick 1310 manufactured by Dainippon Ink and Chemicals, Inc.) is added to 100 parts of the nonwoven fabric. After drying with hot air at 130 ° C,
The surface was smoothed by pressing with a roller heated to 120 ° C. to obtain a fibrous substrate having a thickness of about 1 mm. Subsequently, one surface of the fibrous substrate was buffed with sandpaper to a thickness of 0.1 mm.
After adjusting the thickness to 80 mm, the other surface is treated with an emery buffing machine to form an extremely fine nap surface, and further dyed brown with a circular jet dyeing machine using a disperse dye, and finished with a specific gravity. A leather-like sheet of 0.46 was obtained. This product was excellent in terms of fulfillment, but inferior in flexibility. The nap was partially non-uniform, had some color unevenness, was slightly inferior in appearance, and had a slightly rough touch on the surface. Further, when the surface and the inside of the obtained artificial leather were observed with a scanning electron microscope, the fibers on the surface were split by about 80%, but there were portions that were not split. The fibers inside were hardly split.

Comparative Example 2 PET was used as the polymer (A), and this was used as the component (1). Nylon 6 was used as the polymer (B), and this was used as the component (2). PET (component (1)), nylon 6
(Component (2)) is melt-extruded with separate extruders,
After weighing each with a gear pump so that the weight ratio of component (1) / component (2) becomes 70/30, the mixture is fed into a spinning pack, discharged at a die temperature of 290 ° C., and has a speed of 500 m / m.
Wound in minutes. A fiber having a cross section shown in FIG. 1 in which the component (1) and the component (2) were alternately arranged in 11 layers was obtained. In the cross section of FIG. 1, component (1) forms a five-layer portion and component (2) forms a six-layer portion. The continuous spinning for 30 hours was performed, but no breakage occurred. After spinning, it was stretched, mechanically crimped, and then cut to 51 mm to obtain a composite staple fiber having a single yarn fineness of 3.0 dtex. The obtained composite staple fiber was processed into a web through a card and a cross wrapper. In the carding process, the fibers wrapped violently and could only be processed for a few minutes. When the inside of the web was observed with a scanning electron microscope, most of the web was split. Judging that there was no passability in the card process, the following examination was suspended.

[0064]

The present invention relates to splittable fibers suitable for sheets such as nonwoven fabrics and fabrics. The fibers of the present invention can be easily split by a simple treatment such as immersion in hot water.
Furthermore, it passes well through the nonwoven fabric manufacturing process.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a splittable fiber of the type according to the present invention, which is multi-layered in parallel.

FIG. 2 is a schematic cross-sectional view of a radially multi-layer type splittable fiber of the present invention.

[Explanation of symbols]

1: Component consisting of polymer (A) 2: Component consisting of polymer (B) incompatible with polymer (A) and thermoplastic polyvinyl alcohol

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F055 AA02 AA21 AA27 BA06 EA04 EA05 EA09 EA13 EA14 EA24 EA34 FA15 GA29 HA04 4L041 AA07 BA04 BA05 BA11 BA35 BA49 BA59 BD11 BD15 CA06 CA12 CA22 CA44 CA55 DD01 DD06 DD14 EE DD 18 4L047 AA16 AA21 AA23 AA27 AA28 AB02 AB08 BA03 CA08 CC01 CC09 CC16 DA00

Claims (4)

[Claims] 1. A composition comprising a component (1) comprising a polymer (A), a polymer (B) incompatible with the polymer (A) and a component (2) comprising a thermoplastic polyvinyl alcohol. The amount of the plastic polyvinyl alcohol is 0.1% of the component (2).
1 to 20% by weight, and a splittable fiber in which component (1) and component (2) are alternately arranged. 2. The splittable fiber according to claim 1, wherein the thermoplastic polyvinyl alcohol is a modified thermoplastic polyvinyl alcohol containing 1 to 20 mol% of α-olefin units or vinyl ether units having 4 or less carbon atoms. 3. A polymer (D) containing 0.5 to 40% by weight of the polymer (C) having the structural unit of the polymer (B) in the component (1), or the polymer (D) having the structural unit of the polymer (A). ) Is contained in component (2) in an amount of 0.5 to 40% by weight.
The splittable fiber according to the above. 4. A nonwoven fabric is formed from the splittable fiber according to any one of claims 1 to 3, the splittable fiber is split, and the surface of the nonwoven fabric is fluffed or a resin layer is formed on the nonwoven fabric surface. A method for producing a fiber sheet, comprising: