JP2001131878A - Sheet-like material excellent in finishing property for napping, and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a sheet-like material suitable for providing a napped sheet such as a suede-like artificial leather excellent in density of fiber naps on the surface, hardly causing color difference in dying, and excellent in processability for raising naps. SOLUTION: This sheet-like material excellent in processability for raising the naps is obtained by bringing at least one surface of a fiber assembly composed of a conjugate fiber comprising a high-softening point polymer A and a low-softening point polymer B having different solvent solubilities and softening points, and capable of being formed into micro fibers, into contact with a face heated to a temperature not lower than the softening temperature of the low-softening point polymer B, not higher than the softening point of the high-softening point polymer A and not higher than the temperature of the softening point of the low-softening point polymer plus 70 deg.C, to provide a fibrous base material having a fused layer with 0.05-0.50 mm thickness on the surface, and subjecting the resultant fibrous base material to impregnation treatment with a high-molecular elastic polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-like material excellent in napping workability which is suitable for obtaining a napping sheet such as a suede-like artificial leather which is excellent in fiber napping density on the surface and has no coloring discoloration. It is about.

[0002]

2. Description of the Related Art A suede-like artificial leather made of ultrafine fibers such as polyester fibers and a polymer elastic polymer is produced by impregnating a fibrous base material composed of the ultrafine fibers with a polymer elastic polymer and then raising the fiber. Processing and then dyeing are common. However, in such a method, since the high-molecular elastic polymer tends to remain on the surface, there is a problem that surface heterogeneity tends to appear in a dyed product due to a difference in dyeability between the polymer and the ultrafine fiber. In particular, in the case of suede-like artificial leather in which the ultrafine fibers are polyester fibers and the polymer elastic polymer is a polyurethane elastomer, dyeing with a disperse dye is common, but dyeing with a disperse dye usually improves the color fastness. Since reduction washing is performed after dyeing for the purpose of dyeing, the disperse dye adsorbed in the polyurethane elastomer is reduced, and dye heterochromism tends to appear between the polyester fiber and the polyurethane elastomer. on the other hand,
When the ultrafine fibers are nylon fibers and the polymer elastic polymer is a polyurethane elastomer, it is common to dye the fibers and the polyurethane elastomer simultaneously with a gold-containing dye, but it is difficult to dye both in the same color. Because
As described above, the dye heterochromia tends to appear.

[0003] In order to solve the problem of surface discoloration of a napped sheet such as a suede-like artificial leather, a method of increasing the napped density of a conventionally napped sheet, the amount of a polymer impregnated in the surface layer of a fibrous base material, and the like. Various methods have been proposed, such as a method for reducing odor. For example, Japanese Patent Publication No. 47-44606 discloses a method of sizing a fibrous base material which is to be napped, and Japanese Patent Publication No. 53-35122 discloses a method of sizing treatment and then compressing and fixing with a heating roll. It is disclosed that the amount of the polymer elastic polymer impregnated in the portion to be the raised surface can be reduced by the above method.

[0004] However, in these methods, it is difficult to control the penetration depth of the sizing agent in the thickness direction of the fibrous base material. There is a problem that adhesion spots easily occur. Further, since a step of removing the used paste is required, there is a problem that the step becomes complicated and the cost increases.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art.
Even without sizing treatment, it is possible to obtain a nap sheet having an improved surface nap density and a reduced amount of impregnated high-molecular elastic polymer on the surface, and a nap sheet that does not exhibit surface heterochromism even when dyed. It is an object of the present invention to provide a sheet-like material excellent in napping workability and a method for producing the same.

[0006]

According to the study of the present inventors, the above-mentioned object is to provide a high softening point polymer component (A) and a low softening point polymer component (B) having different solvent solubility and softening point temperature. )
A sheet comprising a fibrous base material formed of a conjugate fiber capable of forming ultrafine fibers, and a high-molecular elastic polymer contained in voids of the fibrous base material; Has a thickness of 0.05 to 0.05 due to fusion of the low softening point polymer component (B) of the conjugate fiber.
It has been found that a 0.50 mm fusing layer can be present and the fusing layer can be achieved by a sheet substantially free of the high molecular elastic polymer.

[0007] Still another object is to form a composite fiber which can be converted into an ultrafine fiber comprising a high softening point polymer component (A) and a low softening point polymer component (B) having different solvent solubility and softening point temperature. The at least one surface of the fiber assembly is heated at a temperature equal to or higher than the softening point of the low softening point polymer component (B), equal to or lower than the softening point of the high softening point polymer component (A), and has a low softening point polymer component ( (B) contacting the surface heated to a temperature equal to or lower than the softening point of + 70 ° C. to form a fibrous base material having a fusion layer on the surface by fusing at least a part of the conjugate fibers of the surface layer of the contact surface; Next, it has been found that this can be achieved by a method for producing a sheet-like material by impregnating a non-fused layer portion of the fibrous base material with a polymer elastic polymer.

[0008]

Embodiments of the present invention will be described below in detail. The composite fibers capable of being converted into ultrafine fibers used for forming the fibrous base material of the present invention include a high softening point polymer component (A) and a low softening point polymer component having different solvent solubility and heat softening point temperature. (B) which can be converted into ultrafine fibers by subjecting the low-softening point polymer component (B) to ultrafine fiber treatment such as dissolution and removal (usually, a high softening point polymer component (A ) Is an ultrafine fiber), and may be any of composite fibers obtained by ordinary composite spinning of the above two types of polymers, mixed spun fibers spun after mixing two types, and the like. Here, the softening point temperature is JI
The softening point temperature difference between the high softening point polymer component (A) and the low softening point polymer component (B) is measured according to the SK6760 method. If the temperature difference is too small, the allowable range of conditions for producing a fibrous base material having a later-described fusion layer narrows. If the temperature difference is too large, the low-softening point polymer component (B) may be thermally decomposed when spinning the conjugate fiber. Therefore, the upper limit of the temperature difference is limited to the low-softening point polymer component. Is preferably not higher than 250 ° C. On the other hand, when the solvent solubility is the same, it is not preferable because the ultrafine fiber forming treatment described later cannot be performed.

As the high softening point polymer component (A) which is one component of the ultrafine fibers, for example, nylon 6, nylon 6
6, polyamides such as nylon 12 and polyesters such as polyethylene terephthalate and polybutylene terephthalate.

The low softening point polymer (B), which is the other component of the ultrafine fibers, includes the high softening point polymer component (A).
Any material having a lower softening point and a different solubility in a solvent can be used, and examples thereof include polyethylene, polypropylene, polystyrene, high molecular weight polyethylene glycol, and polyacrylate. Further, polyamide or polyester may be used.

[0011] Such a conjugate fiber is formed into a web by a card and a cross layer after being made into a short fiber, for example, and then subjected to needle punching to form a fiber aggregate such as an entangled nonwoven fabric. Subsequently, at least one surface of the obtained fiber assembly is, for example, at or above the softening point of the low softening point polymer component (B), at or below the softening point of the high softening point polymer component (A), and at a low softening point. The polymer component (B) is brought into contact with a surface heated to a temperature equal to or lower than the softening point of + 70 ° C., and the conjugate fiber of the surface layer of the contact surface is at least partially fused to form a low softening point polymer component (B). The thickness by thermal fusion is 0.05 to 0.50 mm, preferably 0.05 to 0.40 mm, and particularly preferably 0.1 to 0.5 mm.
The fibrous base material has a fusion layer of 0.05 to 0.20 mm on at least one surface. The fusion layer referred to here is
This refers to a state in which the low softening point polymers between the conjugate fibers are fused together to form a layer having substantially no voids. Since the fusion layer is in such a state, when the polymer elastic polymer solution is impregnated later, the solution does not substantially impregnate the fusion layer.

Here, when the temperature of the heating surface brought into contact with the surface of the fiber assembly is lower than the softening point of the low softening point polymer component (B), no fused layer is formed, while the low softening point weight is low. If the temperature is higher than the softening point of the coalesced component (B) + 70 ° C., the resulting fibrous base material will adhere to the heating surface, and if the temperature exceeds the softening point of the high softening point polymer component (A), Is not preferred because the mechanical properties of the resulting fibrous base material become insufficient. The preferred temperature range is the temperature of the softening point of the low softening point polymer component (B) + 10 ° C or higher, the temperature of the softening point of the low softening point polymer component (B) + 55 ° C or lower, more preferably the low softening point polymer component. The temperature is not lower than the softening point of (B) + 20 ° C. and not higher than the softening point of the low softening point polymer component (B) + 45 ° C.

The thickness of the fusion layer of the fibrous base material is 0.05 mm.
If the amount is less than the above, undesirably, the nap length of the finally obtained nap product becomes too short to develop dye heterochromism. On the other hand, if it exceeds 0.50 mm, the nap length of the finally obtained nap product becomes too long, and the appearance quality deteriorates, which is not preferable for artificial leather. The thickness of the fusion layer can be controlled by appropriately selecting the temperature of the contact heating surface, the contact time, the load pressure at the time of contact, and the like.

[0014] The sheet-like material of the present invention can be used, for example, in a void portion of a fibrous base material formed of a composite fiber which can be formed into ultrafine fibers and has a fusion layer on at least one surface produced as described above. It contains a high-molecular elastic polymer.

Preferred examples of the high molecular elastic polymer include polyurethane elastomer, polyurea elastomer, polyurethane urea elastomer, polyacrylate elastomer, acrylonitrile / butadiene elastomer, and styrene / butadiene elastomer. Among them, polyurethane elastomers such as polyurethane elastomer, polyurea elastomer, and polyurethane urea elastomer are preferable. These polyurethane elastomers have at least one selected from polyether glycols, polyester glycols, polycaprolactone glycols, polycarbonate glycols and the like having an average molecular weight of 500 to 4000.
Species of polymer glycols, organic diisocyanates such as 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, tolylene diisocyanate, dicyclohexyl methane diisocyanate, isophorone diisocyanate, and low molecular weight glycols, diamines Hydrazine, organic acid hydrazite, amino acid hydrazite and the like, and is obtained by reacting with at least one kind of chain extender. Note that an additive such as a coloring agent may be blended in the high-molecular elastic polymer.

The weight of the conjugate fiber of the high molecular elastic polymer in the fibrous base material portion excluding the fusion layer (therefore, the same as the weight of the conjugate fiber in the portion other than the fusion layer of the sheet material of the present invention) The content with respect to ()) is suitably in the range of 10 to 120% by weight, preferably 20 to 80% by weight.
When the content of the elastic polymer is less than 10% by weight, it is difficult to obtain a raised sheet having a leather-like texture, which tends to be pepper-like, and conversely 120% by weight.
In the case of exceeding, it becomes difficult to obtain a nap sheet having a leather-like feeling because of a rubber-like feeling.

Next, as a method for allowing the above-mentioned elastic polymer to be contained in the voids in the fibrous base material, for example, the elastic polymer is converted into an organic solvent solution or dispersion (including an aqueous emulsion). Then, the fibrous base material is impregnated, and then the high molecular elastic polymer is coagulated in the fibrous base material. As a specific method for coagulating the high molecular elastic polymer, any of a conventionally known wet coagulation method and dry coagulation method can be adopted. It is preferable that the solvent solution of the high-molecular elastic polymer is uniformly penetrated into the non-fusion layer.

The solvent used in the organic solvent solution of the high molecular weight elastic polymer used herein does not substantially dissolve the high softening point polymer component (A) and the low softening point polymer component (B). If present, optionally, for example, dimethylformamide, dimethylacetamide, dimethylsulfoxide, N
-Methylpyrrolidone, tetrahydrofuran, toluene,
Organic solvents such as methyl ethyl ketone can be exemplified. The preferred concentration range of the solution is 8 to 20% by weight, and the solution may contain optional additives such as a porosity adjuster and a colorant.

The above-described sheet-like material of the present invention is subjected to an ultrafine fiber treatment by a conventionally known method suitable for the type of the conjugate fiber capable of being used as an ultrafine fiber. For example, when the polymer forming the ultrafine fibers is the high softening point polymer component (A), the low softening point polymer (B) is dissolved, but the high softening point polymer component (A) is difficult to dissolve. The polymer is treated with a solvent to dissolve and remove the low-softening point polymer (B) to form ultrafine fibers. When the low softening point polymer (B) component is a polyolefin such as polyethylene, the solvent to be dissolved and removed is preferably benzene, toluene, xylene and the like.

The sheet thus obtained has a layer of ultrafine fibers substantially free of a high-molecular elastic polymer on the side of the fibrous base material having the fused layer, so that the suede having a high surface nap density is provided. It is extremely suitable as a base material for artificial leather.

Such a suede-like artificial leather base material has a high surface nap density by raising a microfiber layer containing no elastic polymer by a conventionally known method, and furthermore, even when dyed, the surface has a different coloration. It is possible to obtain an excellent nap sheet (suede-like artificial leather) that does not exhibit any odor.

[0022]

EXAMPLES The present invention will be described below more specifically with reference to examples.

Example 1 Polyethylene terephthalate having a softening point of 238 ° C. was used as the high softening point polymer component (A) as the island component of the composite fiber, and the softening point temperature was 85 ° C. as the low softening point polymer component (B). Low density polyethylene as the sea component of the composite fiber, and the island component thickness 0.17 dtex (0.15 dtex)
de), number of islands 19, composite spinning so that the blending weight ratio (high softening point polymer component (A): low softening point polymer component (B)) = 60:40, and a fineness of 5.3 dtex (4 .8d
e) A composite fiber having a fiber length of 51 mm was obtained. The obtained composite fiber was formed into a web by a card and a cross layer, and then subjected to needle punching to prepare an entangled fiber aggregate having a basis weight of 400 g / m ² .

After preheating this entangled fiber aggregate in a hot-air oven at 150 ° C., it was roll-pressed with a press roll so that the apparent density was 0.30 g / cm ³ and the thickness was 1.3 mm. Next, one of the press rolls is a heating roll at 120 ° C.
g / cm ³ ).
A fibrous base material having a polyethylene fused layer formed on one surface was formed. The thickness after pressing was 1.10 mm, the apparent density was 0.36 g / cm ³ , and the thickness of the fusion layer was 0.1 mm.
It was 108 mm. The thickness of the fusion layer is determined by an electron microscope (JSM-6100, manufactured by JEOL Datum Co., Ltd.).
A cross-sectional photograph of the fibrous base material was taken and measured (average value of n = 9).

The resulting fibrous base material was impregnated with a 15% by weight polyurethane elastomer dimethylformamide solution, and then immersed in a 10% by weight aqueous solution of dimethylformamide for coagulation. Subsequently, it was sufficiently washed in warm water at a temperature of 40 ° C. to obtain a sheet having a polymer-elastic polymer impregnated thereon. The weight ratio of the composite fiber to the polyurethane elastomer in the non-fused layer portion of the obtained polymer-elastic polymer impregnated sheet was 100: 30, and the cross section was measured by the electron microscope. Did not contain a polyurethane elastomer.

The step of dipping the obtained sheet in toluene at a temperature of 80 ° C. and then nipping was repeated to dissolve and remove the polyethylene, and subjected to ultrafine fiber treatment of the composite fiber. Thereafter, in a steam at a temperature of 110 ° C., the toluene contained in the sheet was removed, followed by drying in a hot air dryer at a temperature of 120 ° C. The average fineness of the obtained ultrafine fibers was 0.17 dtex (0.15 de). The surface of the obtained artificial leather substrate was covered with ultrafine fibers, and the surface of the impregnated polyurethane was not exposed.

After buffing the surface of the artificial leather substrate with 400 mesh sandpaper,
The obtained napped substrate was dyed with a disperse dye using a liquid jet dyeing machine, and then subjected to reduction washing treatment with hydrosulfite.

Since the obtained napping sheet does not have polyurethane exposed on its surface, it emits a vivid color without dyeing and heterochromism, and its surface is covered with a napping layer having a high napping density and has an excellent chalk mark property. It was suede-like artificial leather.

Example 2 Nylon 6 having a softening point of 180 ° C. was softened as a high softening point polymer component (A) as an island component of a conjugate fiber (mixed spun fiber) and a low softening point polymer component (B). A low-density polyethylene having a point temperature of 79 ° C. is used as the sea component of the conjugate fiber (mixed spun fiber), and the island component has a thickness of about 3.3 /
1000-1.1 / 100 dtex (3 / 1000-1
/ 100 de), about 600 islands, mixing weight ratio (high softening point polymer component (A): low softening point polymer component (B) = 5
The mixture is spun at a ratio of 0:50 and the fineness is 5.3 dtex.
(4.8 de), a mixed spun fiber having a fiber length of 51 mm was obtained. The obtained mixed spun fiber was formed into a web by a card and a cross layer, and then subjected to needle punching to prepare an entangled fiber aggregate having a basis weight of 400 g / m ² .

After preheating this entangled fiber aggregate in a hot air oven at 150 ° C., it was pressed with a press roll so that the apparent density was 0.30 g / cm ³ and the thickness was 1.3 mm. Next, a press roll, one of which is a heating roll at 110 ° C. (roll interval is 0.8 g / c in density at compression)
(adjusted to an interval of m ³ ) to form a fibrous base material having a polyethylene fused layer formed on one surface. The thickness after pressing is 1.10 mm, the apparent density is 0.36 g / cm ³ , and the thickness of the fusion layer is 0.095
mm.

The resulting fibrous base material was impregnated with a 15% by weight polyurethane elastomer dimethylformamide solution, and then immersed in a 10% by weight aqueous solution of dimethylformamide for coagulation. Subsequently, it was sufficiently washed in warm water at a temperature of 40 ° C. to obtain a sheet having a polymer-elastic polymer impregnated thereon. The weight ratio of the conjugate fiber to the polyurethane elastomer in the non-fused layer portion of the obtained polymer-elastic polymer impregnated sheet was 100: 40, and the cross section was measured by the electron microscope. Did not contain a polyurethane elastomer.

The process of dipping the obtained sheet in toluene at a temperature of 80 ° C. and then nipping was repeated to dissolve and remove the polyethylene, and subjected to ultrafine fiber treatment of the composite fiber. Thereafter, in a steam at a temperature of 110 ° C., the toluene contained in the sheet was removed, followed by drying in a hot air dryer at a temperature of 120 ° C. The average fineness of the obtained ultrafine fibers is 0.0056 dtex (0.005 de).
Met. The surface of the obtained artificial leather substrate was covered with ultrafine fibers, and the surface of the impregnated polyurethane was not exposed.

After buffing the surface of the artificial leather substrate with 400 mesh sandpaper,
The obtained napped substrate was dyed with a gold-containing dye using a jet dyeing machine. Since the obtained nap sheet does not have polyurethane exposed on the surface, it emits a vivid color with no dyeing discoloration, and the surface is covered with a nap layer having a high nap density and has an excellent suede tone with sharp chalk mark properties. It was artificial leather.

Comparative Example 1 The same entangled fiber nonwoven fabric as used in Example 1 was preheated in a hot air oven at 150 ° C., and then apparent density was 0.30 g / c by a press roll.
m ^3, and pressed so as to have a thickness of 1.3 mm. Then, unlike in Example 1, the entangled nonwoven fabric was impregnated with a 15% by weight polyurethane elastomer dimethylformamide solution without being pressed through a heating roll, and then immersed in a 10% by weight dimethylformamide aqueous solution for coagulation. I let it. Subsequently, it was sufficiently washed in warm water at a temperature of 40 ° C. to obtain a polymer-elastic polymer impregnated sheet having a weight ratio of the conjugate fiber to the polyurethane elastomer of 100: 40. The step of dipping the obtained sheet in toluene at a temperature of 80 ° C. and then nipping was repeated to dissolve and remove the polyethylene, and subjected to ultrafine fiber treatment of the composite fiber. Thereafter, in a steam at a temperature of 110 ° C., toluene contained in the sheet material is removed,
It dried in the hot air dryer of ° C. The average fineness of the obtained ultrafine fibers was 0.17 dtex (0.15 de). After buffing the surface of the obtained artificial leather substrate with a 400 mesh sandpaper, the obtained napped substrate is dyed with a disperse dye using a liquid jet dyeing machine, and then hydrosulfite. For reduction cleaning treatment Because the obtained raised hair sheet has exposed polyurethane on the surface,
Dyeing heterochromia was developed and it was unclear.

[Comparative Example 2]
1. Pressing through a heating roll at 80 ° C. instead of pressing through a heating roll at 80 ° C.
m, the apparent density was 0.33 g / cm ³ , and the procedure was the same as in Example 1 except that the fibrous base material had substantially no fused layer. Since the obtained napped sheet had the polyurethane exposed on the surface, it was unclear due to the development of dye heterochromism.

[Comparative Example 3]
Press processing through a heating roll at 160 ° C. which is equal to or higher than the softening point (85 ° C.) of the low softening point polymer component (B) + 70 ° C. Polyethylene, which is the point polymer component (B), adhered, and the surface of the resulting fibrous base material became severely uneven, so that subsequent operations could not be performed satisfactorily.

Comparative Example 4 150 ° C. in Example 1
Pressed after preheating in a hot air oven, using an entangled fiber nonwoven fabric having an apparent density of 0.30 g / cm ³ and a thickness of 1.3 mm, one of which is a heating roll at 120 ° C. through a press roll Without processing
A 15% by weight aqueous solution of polyvinyl alcohol (glue) was applied to the surface with a knife coater at a rate of 30 g / m ² and then dried. The obtained glue-coated nonwoven fabric was impregnated with a 15% by weight polyurethane elastomer dimethylformamide solution, and then immersed in a 10% by weight aqueous dimethylformamide solution to coagulate. Subsequently, it was sufficiently washed in warm water at a temperature of 40 ° C. to obtain a polymer-elastic polymer impregnated sheet having a weight ratio of the conjugate fiber to the polyurethane elastomer of 100: 40. The obtained sheet-like material was subjected to puffing treatment after removing polyethylene in the same manner as in Example 1, and then subjected to dyeing and reduction washing treatment to obtain a napped sheet. The obtained napped sheet had an improved degree of dye heterochromism as compared with that of Comparative Example 1, but had a poor degree of dye heterochromism and was unclear as compared with that of Example 1. .

[Comparative Example 5] In Example 1, the thickness was 1.20 mm and the apparent density was 0.33 g / cm. ^{3. The} thickness of the fused layer is 0.04m
m of fibrous base material was obtained. The obtained fibrous base material was prepared in Example 1.
The napped sheet was obtained in the same manner as described above, but the polyurethane was exposed on the surface, and thus it was still insufficient in terms of dyeing and discoloration.

[Comparative Example 6] A thickness of 1.00 mm and an apparent density of 0.40 g / cm were obtained in the same manner as in Example 1 except that the interval between the press rolls in the press treatment with the heating roll was reduced. ^{3. The} thickness of the fused layer is 0.06m
m of fibrous base material was obtained. The obtained fibrous base material was prepared in Example 1.
A nap sheet was obtained in the same manner as in Example 1, but the nap on the surface was too long, resulting in poor quality.

[0040]

According to the sheet-like material of the present invention, it is possible to easily obtain a nap sheet having a nap layer having a high nap density on the surface, and the surface of the nap sheet has a different dyeing property with the fiber. Since the amount of the molecular elastic polymer can be reduced, an excellent product (e.g., suede-like artificial leather) having no staining discoloration even when dyed is obtained. Further, it is possible to completely eliminate the problems such as the production cost and the sizing removal that the conventional sizing treatment method has.

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[Procedure amendment]

[Submission date] November 29, 1999 (1999.11.
29)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0039

[Correction method] Change

[Correction contents]

[Comparative Example 6] A thickness of 1.00 mm and an apparent density of 0.40 g / cm were obtained in the same manner as in Example 1 except that the interval between the press rolls in the press treatment with the heating roll was reduced. ^{3. The} thickness of the fused layer is 0.60m
m of fibrous base material was obtained. The obtained fibrous base material was prepared in Example 1.
A nap sheet was obtained in the same manner as in Example 1, but the nap on the surface was too long, resulting in poor quality.

Continued on the front page F term (reference) 4F055 AA02 BA06 CA18 DA07 DA09 EA04 EA12 EA14 EA15 EA29 EA30 EA34 EA35 FA15 GA02 HA04 HA22 4F100 AK01A AK01B AK06 AK42 JA25 AK51 AL09 BA02 DG06B DG16B08 EB18 EB18 EB18 ECB JK07B JL01 4L033 AB01 AC15 CA50 4L047 AA14 AA21 AA25 AA27 AB08 BA09 CC16 DA00

Claims (5)

[Claims] 1. A fibrous base formed from a composite fiber capable of forming ultrafine fibers comprising a high softening point polymer component (A) and a low softening point polymer component (B) having different solvent solubility and softening point temperature. And a high molecular elastic polymer contained in voids of the fibrous base material, wherein at least one surface of the sheet material has a low softening point polymer of the conjugate fiber. Thickness of 0.05 to 0.1 due to fusion of component (B).
A sheet-like material having excellent napping properties, characterized by having a 50 mm fusion layer, and the fusion layer does not substantially contain the high-molecular elastic polymer. 2. The content of the high-molecular-weight elastic polymer in the sheet-like material portion other than the fusion layer is 10 to 120 with respect to the weight of the conjugate fiber.
The sheet-like material having excellent napped processability according to claim 1, which is contained by weight. 3. The sheet-like sheet having excellent napped processability according to claim 1, wherein the difference in softening point between the high softening point polymer component (A) and the low softening point polymer component (B) is 70 ° C. or more. object. 4. A fiber assembly formed from ultrafine fibrable composite fibers comprising a high softening point polymer component (A) and a low softening point polymer component (B) having different solvent solubility and softening point temperature. The softening point of the low softening point polymer component (B) at a temperature not lower than the softening point temperature of the low softening point polymer component (B) and not higher than the softening point temperature of the high softening point polymer component (A). The fiber is brought into contact with a surface heated to a temperature not higher than the point temperature of + 70 ° C., and at least a part of the conjugate fiber of the surface layer of the contact surface is fused to form a fibrous base material having a fusion layer on the surface. A method for producing a sheet-like material having excellent napping properties, comprising impregnating a non-fused layer portion of a substrate with a high-molecular elastic polymer. 5. The sheet-like material according to claim 1, which is treated with a solvent that dissolves the low-softening point polymer component (B) but does not substantially dissolve the high-softening point polymer component (A) to make it ultrafine. A method for producing a raised sheet, in which a possible composite fiber is made into an ultrafine fiber, and then the surface of the sheet-like material on which the fused layer was present is raised.