JP3430852B2 - Method of manufacturing nap sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a napped sheet having excellent compactness, short napping property, smoothness and flexibility.

[0002]

2. Description of the Related Art In a napped sheet composed of ultrafine fibers and a polymer elastic material, a technique for shortening the napped length of the surface to densify it is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-126986. Slicing a sheet made of a polymer, coating the solution containing the solvent of the elastic polymer on the sliced surface, after solidification, a method of buffing the application surface is proposed, and JP-A-7-126985 discloses, A method has been proposed in which a microfiber sheet is impregnated with a polymer elastic material, and then a part of the polymer elastic material in the thickness direction is squeezed from the surface of the base material to be solidified and then buffing.

However, in these methods, it is difficult to control the degree of permeation of the solution in the thickness direction of the sheet and the squeeze amount when the sheet thickness changes, and although the denseness is improved, fluff length unevenness occurs due to the grinding amount. It is easy and the adhesive strength between the ultrafine fibers and the polymeric elastic body is increased, so that the nap length can be shortened, but there is a problem that the texture of the product is hardened.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a method for producing a napped sheet having compactness, short napping property, and flexibility.

[0005]

The present inventors have finally arrived at the present invention as a result of intensive studies to solve the above-mentioned problems. The gist of the present invention is as follows.

An object of the present invention is to impart a polymer elastic body to a fiber entangled body of composite fibers composed of at least two components which can be made into ultrafine fibers and have an average fiber diameter of ultrafine fibers of 0.1 to 7 μm,
After substantially solidifying the polymeric elastic body, it is immersed in a swelling agent for the polymeric elastic body, further compressed, and then the swelling agent is removed with an aqueous solvent, followed by an ultrafine treatment and at least one surface. It is achieved by applying a raising process.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below.

As the conjugate fiber used in the present invention, at least two-component polymers having mutually different properties are used,
It is a composite fiber formed by a composite spinning or a mixed spinning, and at least one component is dissolved and removed, or is separated and divided by a physical or chemical action, and an ultrafine composite fiber is used. The form of the composite fiber is not particularly limited.

Examples of the polymer forming the ultrafine fibers of such composite fibers include nylon 6, nylon 66,
Examples thereof include polyamides such as nylon 12 and copolymerized nylon, polyesters such as polyethylene terephthalate, copolymerized polyethylene terephthalate, polybutylene terephthalate, and copolymerized polybutylene terephthalate. Examples of the polymer that is removed by dissolution or peeled or divided by a physical or chemical action include the above-mentioned polyamides, polyesters, and polyolefins such as polyethylene, polystyrene and polypropylene. Among these, the combination may be performed in consideration of the cross-sectional formability, spinnability, drawability, etc. of the ultrafine fibers. Further, additives such as a stabilizer, a matting agent, an antistatic agent, and a flame retardant may be added to these polymers as needed, as long as the effects of the present invention are not impaired.

The average fiber diameter of the ultrafine fibers after the above composite fibers are dissolved and removed, or peeled and divided by a physical or chemical action is preferably 0.1 to 7 μm. If it is less than 0.1 μm, it is difficult to obtain color developability, and if it exceeds 7 μm, the texture and touch are deteriorated, which is not preferable.

In the combination of the above-mentioned polymers, considering the high entanglement property of the composite fiber in the needle punch, the adhesive property with the polymer elastic body, and the environmental property of the organic solvent used for the ultrathinning, etc. It is preferable that the removal component is made of an alkali-soluble polymer that is soluble in alkali and insoluble in the solvent of the elastic polymer.

Specific examples of the alkali-soluble polymer include, for example, a polymer comprising terephthalic acid and ethylene glycol as main constituents, 5-sodium sulfoisophthalic acid, and a copolymerized polyester containing isophthalic acid. .

In the dissolution of these polymers, acid treatment may be carried out in advance, or a suitable dissolution accelerating method utilizing microwaves may be used. Considering the deterioration of the polymer elastic body during the ultrafine treatment which will be described later, the alkali-soluble polymer retains the property of being soluble at a caustic soda solution concentration of 1% by weight, a treatment temperature of 90 ° C. and a treatment time of 20 to 30 minutes. Are particularly preferable. As an example of such a polymer, for example, a copolymerized polyester in which an alkali-soluble polymer contains 6 to 12 mol% 5-sodium sulfoisophthalic acid and / or 0 to 10 mol% isophthalic acid based on all acid components is used. However, the present invention is not limited to these, and it goes without saying that various kinds of binary, ternary and higher multi-component copolymerized polyesters can be used.

Next, in the present invention, a fiber entangled body of composite fibers is formed. As a forming means, the composite fibers are made into short fibers, and a web is prepared by a conventional method such as a card / cloth wrapper or a random webber. Then, it is formed by performing needle punching or water jet punching. The web can be formed directly from spinning such as melt blowing.

Before applying a polymer elastic material to these fiber entangled bodies, shrinkage heat treatment, heat press, wet press, etc. are used to increase the density of the fiber entangled bodies or to fix the form with a sizing agent such as polyvinyl alcohol. Combining the steps is preferable for improving product quality.

As the structure of the fiber entangled body, the above-mentioned three-dimensional entangled structure of the composite fibers is generally used. However, as the product thickness becomes thinner, its strength is low and it cannot be used depending on its development item. A case arises. As a preferred embodiment for solving this problem, a structure in which a fiber entangled body is entangled and integrated with a composite fiber web and a woven fabric and / or a knitted fabric is particularly preferable. In this structure formation, the above-mentioned composite fiber web is laminated on a woven fabric and / or a knitted fabric, and entangled and integrated by needle punching, water jet punching, or a combination thereof.

As a laminating method, a method of laminating a woven fabric and / or a knitted fabric on both sides or one side of a composite fiber web and performing an entanglement treatment, or a method of laminating on one side and entanglement treatment, and then further laminating a plurality of the entangled bodies A method of performing entanglement processing again and slicing in a later step is used.

The type of yarn constituting the woven or knitted material may be filament yarn, spun yarn, mixed spun yarn of filament and short fiber, and is not particularly limited. Also, as the type of woven or knitted fabric,
Use of warp knitting, weft knitting typified by tricot knitting, lace knitting and various knitting based on their knitting, plain weave, twill weaving, satin weaving and various weaving based on those weaving However, it is not particularly limited.

Depending on the yarn type, when the entanglement of the composite fiber and the woven or knitted fabric is strengthened by needle punching, the yarn may be easily cut, and means for preventing this is as follows.
It is preferable that these yarn types are strongly twisted yarns.

The number of twists of the strongly twisted yarn is preferably 500 T / m or more and 4500 T / m or less, more preferably 1500 T / m or more, and most preferably 2000 T / m or more. If it is less than 500 T / m, the single yarns that compose the yarn are not sufficiently squeezed, so that the yarn is easily caught by the needle, and the fiber becomes too hard even if the number of twists is too large. Because it becomes unfavorable from 4
It is more preferably 000 T / m or less.

It is preferable that the woven or knitted fabric uses the above-mentioned strongly twisted yarn at least in part, and it is particularly preferable that all the strongly twisted yarns are used because high tenacity is exhibited. Further, these strongly twisted yarns may be provided with a polyvinyl alcohol-based or acrylic-based sizing agent.

As the fibers constituting the woven or knitted material, polyesters, polyamides, polyethylene, polypropylene and copolymers thereof are used. Among them, polyesters, polyamides and copolymers thereof are preferably used alone or in combination.

In order to make the product texture softer, the fibers constituting the woven or knitted fabric should have the alkali-soluble polymer-removing component, the ultrafine fiber component as polyesters, polyamides, polyethylene, polypropylene, and their co-weights. It is preferable that the fiber is a thinnable composite fiber formed by coalescing. The cross-sectional shape of the composite fiber is not particularly limited. That is, when a woven fabric or knitted fabric composed of a composite fiber forming a napped fiber and a thinnable composite fiber containing such an alkali-soluble polymer as a removal component is entangled and integrated, the desalination treatment method described below is performed. When the hot water or hot water of caustic soda is used, the composite fibers of both are simultaneously ultrafine, which is particularly preferable for further enhancing the softening effect.

The average fiber diameter of the single yarn constituting the above woven or knitted fabric is preferably 1 μm to 30 μm, more preferably 2 μm to 15 μm, and the constituent yarn is 30 μm to 15 μm.
The range is 0 μm, more preferably 50 μm to 120 μm. If the single yarn is less than 1 μm, it is preferable for softening the product, but it becomes difficult to obtain strength, and if it exceeds 30 μm, the opposite tendency occurs. Further, if the constituent yarn is less than 30 μm, wrinkles are likely to occur during lamination with the web, and if it exceeds 150 μm, entanglement and integration with the web are insufficient and peeling easily occurs, which is not preferable.

In the present invention, a polymer elastic body is provided to the thus obtained fiber entangled body. Examples of the polymer elastic body used in the present invention include polyurethane elastomer, acrylonitrile-butadiene rubber, butadiene rubber, Examples include natural rubber, polyvinyl chloride, and polyamide. Among them, from the viewpoints of processability in the process of the present invention and the quality of the final product, polyurethane elastomer is preferable, and the average molecular weight is 500 to 300.
The polyester diol type, the polyether diol type, and the polycarbonate diol type of No. 0, which are used alone or in combination, are preferably used. Among them, polyether diol type and polycarbonate diol type, which have alkali resistance, are particularly preferably used.

These polymer elastic bodies are impregnated or coated on the fiber entangled body to remove the solvent of the elastic body and substantially solidify. Substantially solidifying means that the polymer elastic body is squeezed together with the solvent when the sheet is compressed to half the thickness and released even if a part of the solvent remains in the polymer elastic body. It refers to the state that it is not issued. Upon application of the polymeric elastic material, additives such as a colorant, an antioxidant, an antistatic agent, a dispersant, a softening agent, and a coagulation modifier may be added to the elastic material, if necessary.

The sheet comprising the fiber entangled body and the polymer elastic body thus obtained is subsequently dipped in a solution containing the swelling agent for the polymer elastic body and subjected to compression treatment.

As the swelling agent, a solvent having a good affinity with water, which is diluted with water, is preferable. The solution concentration at this time is a concentration at which the polymeric elastic body is swollen without being dissolved, and after the sheet is treated with this swelling agent, it is compressed to a thickness of 1/2 and released. It is preferable to have the effect of being 90% or less with respect to the thickness of.
Specific examples of such a solvent include dimethylformamide,
Examples of the swelling agent include dimethylacetamide and dimethylsulfoxide. Such a solvent can be obtained by appropriately diluting such a solvent with water. The concentration of the swelling agent varies depending on the polymer elastic material used and cannot be generally stated, but one guideline is 60
% Or more is preferable, and 80% or more is more preferable. 60%
If it is less than the above range, the thickness reduction rate of the sheet is low and the densification tends to be insufficient. The time for immersing the sheet in the swelling agent and the compression ratio may be appropriately adjusted in consideration of the type and amount of the polymeric elastomer.

The point of the present invention is to apply a swelling agent solution to a sheet with a gravure coater or a spray coater or transfer a swelling agent solution onto the surface of a release paper and transfer it to the sheet, then nipping the sheet and subjecting it to hot air drying treatment. Different from the above, the sheet itself is dipped in a swelling agent solution, compression nipped in a dipping bath or after rising, and then the swelling agent is removed with an aqueous solvent and then dried with hot air.

In the former method, only the polymer elastic material near the surface layer is dissolved or swelled, the swelling agent concentration is increased by hot air drying treatment, and the polymer elastic material is dissolved and penetrates into the interfiber voids of the fiber entangled body. , Dry film is formed, the adhesion between the fiber and the polymer elastic body is strengthened, and the texture is hardened, and the nap length and density are likely to change greatly even if the nap treatment is slightly shifted or the sheet thickness is changed. , There was a difficulty in its quality control.

However, according to the method of the present invention, since the polymeric elastic body of the whole sheet is swollen, the density in the thickness direction of the fiber entangled body is easily made uniform, and the swelling agent is removed and solidified in the aqueous solvent, so that the polymer is Since the elastic body does not easily penetrate into the inter-fiber voids, a wet film is formed, and then a part of the composite fiber, which will be described later, is ultrafine by solvent removal, physical and chemical action, and therefore adhesion between the ultrafine fiber bundle and the polymer elastic body. It is possible to largely eliminate the conventional defects.

After the above-mentioned processing, the composite fibers and / or the thinnable composite fibers for woven or knitting are subjected to ultrafine or raised treatment, and then ultrafine.

In this ultrafine treatment, any solvent may be used as long as it can dissolve and remove one component or peel off two components and does not substantially dissolve the elastic polymer. In a special case, it may act as a swelling agent for the elastic polymer, and in such a case, the composite fiber and the elastic polymer can be swelled and compressed simultaneously.

For example, in the case where the polymer composition of the conjugate fiber is polyamides / polyethylene, in the toluene solution, in the case of polyamides / polystyrene, in the trichloroethylene solution, the polyamides / alkali-soluble polymer, polyester / polyester In the case of alkali-soluble polymer,
It is dissolved and removed in hot water of caustic soda to make it ultra-fine, and then napped using a conventional method such as sandpaper, brush, and grindstone. Alternatively, the sheet in which the polymer elastic body is applied to the fiber entangled body is subjected to a nap treatment using a conventional method such as sandpaper, a brush, a grindstone, and the like.
It is dissolved and removed to make it ultrafine.

As the method of ultrafine processing, compression with mangle, circular, wins, vibro washer, etc. are used, and the processing is carried out in each solvent. The concentration, temperature, and processing time for setting the processing conditions are appropriately set in consideration of the solubility of the removed component and the sea component ratio of the composite fiber. When the elastic polymer is a polyurethane elastomer, it may be a polyester type or a polyester / polyether diol type when the alkali concentration is low, but a polyether type, polycarbonate type or These combined systems are particularly preferred.

When the fiber entangled body is entangled and integrated with a woven or knitted fabric, the entangled surface of the composite fiber is raised, but when the woven fabric or knitted fabric is near the surface layer, the woven fabric is woven. Alternatively, it may be lightly scraped so as not to damage the knitting.

As described above, the production method of the present invention eliminates the texture hardening which is a problem of the prior art due to the densification and shortening of the napped sheet, which is a problem of the prior art. It is possible to obtain a napped sheet with improved softness and smoothness.

[0038]

EXAMPLES The present invention will be described in detail below with reference to examples, but the scope of validity and rights of the present invention is limited thereby.
It is not constrained. Rather, it brings about the next application and development.

Example 1 Polyethylene terephthalate as the island component, polystyrene as the sea component, island / sea ratio = 55/45% by weight, 36 islands,
Composite fiber denier about 4d, cut length about 51mm, Ken number of about 12 peaks / in staple of the polymer mutual arrangement fiber was used, and this staple was made into a web with a card cross wrapper, and needle punched to have a basis weight of 570g / m ² felts were made and these felts were shrink treated and dried. This sheet was impregnated with a solution in which polyester-polyether polyurethane was dissolved in DMF / water = 92/8% by weight so as to have a solid content of about 30 parts per island fiber, and wet-coagulated. Then, it is dipped in a 90% by weight aqueous solution of dimethylformamide, compressed with a clearance of about half the thickness, immersed in water to remove the solvent, dried, and entangled with ultrafine fibers of polyethylene terephthalate having a fiber diameter of about 2.2 μm. A sheet having a polymer elastic body provided in the united body was obtained. This sheet was dipped in trichlorethylene, squeezed to remove sea, and then dried. The obtained sheet was sliced and the non-sliced surface was napped with 400 mesh sandpaper.

The thus-obtained sheet was a napped sheet which was dense and had short napped fibers, which was excellent in smoothness and flexibility and had a writing effect.

Example 2 Nylon 6 as the island component, 5.2 mol% of the total acid component units as a copolymer of 5-sodium sulfoisophthalate units as the sea component, island / sea ratio = 50/50% by weight,
36 islands, composite fiber denier about 4d, cut length about 51
mm, a staple of polymer mutual array fibers with a reduction factor of about 12 peaks / in. This staple is made into a web with a card cross wrapper, and needle punched to give a basis weight of 60.
Felts of 0 g / m ² were made, and these felts were contracted and dried. This sheet DMF: type polyester-polyether type polyurethane was impregnated as a solid content to about 30 parts per island fiber and wet-coagulated.

Next, it was immersed in a 90% by weight aqueous solution of dimethylformamide and compressed with a clearance of about half the thickness, then immersed in water to remove the solvent and dried. This sheet, caustic soda solution concentration 3% by weight,
Immersion and mangled squeezing were repeated at a temperature of 98 ° C. for 40 minutes, neutralized with acetic acid, washed with water and dried to give a polymer elastic body to an entangled body of nylon ultrafine fibers having a fiber diameter of about 2.4 μm. Got the sheet. Then, the sheet was sliced, and the non-sliced surface was raised with a 400 mesh sandpaper.

The thus obtained sheet was a napped sheet that was dense and had short napped fibers, and had excellent smoothness and flexibility and a writing effect.

Example 3 A sheet was used which was compressed in a 90% by weight aqueous solution of dimethylformamide in Example 2, immersed in water, and subjected to solvent removal.
The sheet was sliced, and the non-sliced surface was napped with 400 mesh sandpaper. Then, this sheet was repeatedly immersed and mangled for 40 minutes at a caustic soda solution concentration of 3% by weight at a temperature of 98 ° C., neutralized with acetic acid, washed with water and dried.

The sheet thus obtained had a napped fiber slightly longer than that of Example 2, but was a napped sheet having a writing effect excellent in compactness and smoothness.

Example 4 Polyethylene terephthalate as the island component, a polyester in which 8 mol% of 5-sodium sulfoisophthalic acid and 1 mol% of isophthalic acid were copolymerized with respect to the total acid component, and the island / ocean ratio was 50/50% by weight. %, 36 islands,
Composite fiber denier about 4d, cut length about 51mm, Ken number of about 12 peaks / in staple of polymer mutual array fiber was used, and this staple was made into a web with a card cross wrapper, and needle punched to have a basis weight of 600g / m ² felts were made and these felts were shrink treated and dried. DMF-based polyester-polyether-based polyurethane was added to this sheet as a solid content to about 30 fibers per island fiber.
It was impregnated so that it became a part and was wet-solidified.

Next, it was immersed in a 90% by weight aqueous solution of dimethylformamide and compressed with a clearance of about half the thickness, then immersed in water to remove the solvent and dried. This sheet is a caustic soda solution concentration 1% by weight,
Immersion and mangle compression are repeated for 20 minutes at a temperature of 90 ° C., neutralized with acetic acid, washed with water and dried to give a polymer elastic body to the entangled body of ultrafine fibers of polyethylene terephthalate with a fiber diameter of about 2.2 μm. The obtained sheet was obtained. Then, the sheet was sliced, and the non-sliced surface was raised with a 400 mesh sandpaper.

The thus-obtained sheet was a napped sheet which was dense and had short napped fibers and which was excellent in smoothness and flexibility and had a writing effect.

Example 5 A web using staples of the same polymer inter-array fiber as in Example 1 was made of polyethylene terephthalate 75D-7.
It was laminated on a plain fabric (weight per unit area: 70 g / m ² ) using a raw yarn false-twisted yarn of 2 f and a twist number of 200 T / m, and light needle punching was performed to prepare a felt with a weight per unit area of 580 g / m ² . After that,
The sheet was treated under the same conditions as in Example 1 to obtain a sheet in which polyurethane was added to a fiber entangled body in which an ultrafine fiber bundle of polyethylene terephthalate having a fiber diameter of about 2.2 μm and a woven fabric were entangled and integrated. Next, the sheet was sliced, and the sliced surface was raised with a 400 mesh sandpaper.

The thus-obtained sheet was a napped sheet which was dense and had short napped fibers, which had smoothness and lighting effect and improved strength.

Example 6 A web using staples of the same polymer inter-array fiber as in Example 4 was made of nylon 6 with 65D-94f and a twist number of 25.
A plain woven fabric using a strong twist yarn of 00 T / m (weight per unit area: 56 g / m ² ).
Between them and needle punching to make a fabric weight of 600 gm ²
Created a felt. This felt will be referred to as Example 4 hereinafter.
The sheet was treated under the same conditions as above to obtain a sheet in which polyurethane was added to the fiber entangled body in which the ultrafine fiber bundle of polyethylene terephthalate and the strongly twisted plain weave of nylon were entangled and integrated.
Next, the sheet was sliced, and the sliced surface was raised with a 400 mesh sandpaper.

The sheet thus obtained was a napped sheet which was dense and had short napped fibers, and which was excellent in smoothness, lighting effect and high strength.

Example 7 The staple of the polymer inter-array fiber used in Example 4 was used, and the staple was used as a web with a card cross-wrapper. The island component was polyethylene terephthalate and the sea component was 8 mol% based on the total acid component. 90D-18, which is a polyester obtained by copolymerizing 5-sodium sulfoisophthalic acid and 1 mol% of isophthalic acid with a polymer inter-array fiber having an island / sea ratio of 90/10% by weight and 36 islands.
f, laminated between flat woven fabrics using a strongly twisted yarn with a twist number of 2500 T / m, and needle punched to create a felt. This felt was then treated under the same conditions as in Example 4, and a fiber entangled body in which an ultrafine fiber bundle of polyethylene terephthalate having a fiber diameter of about 2.2 μm and a highly twisted flat woven fabric of polyethylene terephthalate were entangled and integrated. A sheet in which polyurethane was applied was obtained. Next, the sheet was sliced, and the sliced surface was raised with a 400 mesh sandpaper.

The thus obtained sheet was a napped sheet having extremely high flexibility, denseness, short nap length and excellent smoothness and a writing effect.

Example 8 Using the felt which had been contracted and dried in Example 2, the felt was impregnated with a polyether polyurethane having a molecular weight of 1500 at about 30 parts per island fiber and wet-coagulated. This sheet was then processed under the same conditions as in Example 2.

The sheet thus obtained has a soft touch,
The denseness, short napping property, and smoothness were similar to those in Example 2, but the napped sheet had improved abrasion resistance. Comparative Example 1 Using the sheet to which the polyurethane of Example 1 was applied, the sheet was immersed in a 90% by weight aqueous solution of dimethylformamide and compressed with a clearance of about half the thickness, and then the solvent was removed with a hot air drier. Next, deseaing treatment, slicing, and raising treatment were performed under the same conditions as in Example 1.

The thus-obtained sheet was a napped sheet having a shorter nap length than that of Example 1, but having a poor openability of the nap and having a feeling of roughness and an extremely hard texture.

Comparative Example 2 Using the sheet to which polyurethane was applied in Example 1, slicing and raising were performed in the same manner as in Example 1 without treatment with the dimethylformamide aqueous solution.

The sheet thus obtained was a napped sheet which had longer naps than Example 1 and was inferior in compactness and smoothness.

Comparative Example 3 Using the sheet to which polyurethane was applied in Example 6, slicing and raising were performed in the same manner as in Example 6 without treatment with an aqueous dimethylformamide solution.

The thus obtained sheet was a napped sheet which had longer napped fibers than Example 6 and was inferior in compactness and smoothness.

[0062]

EFFECTS OF THE INVENTION The production method of the present invention can eliminate the texture hardening due to the densification and short nap of the napped sheet, which are problems of the prior art, and can be further improved by the above preferred embodiment. It is possible to manufacture a napped sheet with improved softness and product strength.

Further, even if the thickness of the ultrafine fibers changes, by using the production method of the present invention, it is possible to adjust the fineness of the napped fibers, the napped length, the strength, the texture, etc., and the suede appearance of the product, In addition, a delicate and elegant nubuck quality can be obtained. Therefore, the product obtained by the production method of the present invention can be suitably used not only as clothing, but also as materials such as shoes, bags, hats, gloves, chairs and car seats.

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Claims (7)

(57) [Claims] 1. An ultrafine fiber having an average fiber diameter of 0.
A polymer elastic body is applied to a fiber entangled body of composite fibers composed of at least two components having a size of 1 to 7 μm, and the polymer elastic body is substantially solidified and then immersed in a swelling agent for the polymer elastic body. A method for producing a napped sheet, further comprising compressing, then removing the swelling agent with an aqueous solvent, and then subjecting it to an ultrafine treatment and a nap treatment on at least one side. 2. A napped sheet according to claim 1, wherein one component of the composite fiber is an alkali-soluble polymer that is soluble in alkali and insoluble in the solvent of the elastic polymer. Method. 3. The alkali-soluble polymer contains terephthalic acid and ethylene glycol as main constituent components, and contains 6 to 12 mol% of 5-sodium sulfoisophthalic acid and / or 0 to 10 mol% of isophthalic acid, based on all acid components. The method for producing a napped sheet according to claim 1 or 2, characterized in that the napped sheet comprises a copolyester contained therein. 4. The napped sheet according to any one of claims 1 to 3, wherein the fiber entangled body is a woven fabric and / or a knitted fabric and entangled and integrated composite fibers. Method. 5. The napped sheet according to claim 4, wherein at least a part of the constituent yarns of the woven or knitted fabric is composed of a strong twist yarn of 500 T / m or more and 4500 T / m or less. Method. 6. The method for producing a napped sheet according to claim 4 or 5, wherein the constituent yarn of the woven or knitted fabric is composed of a thinnable composite fiber containing an alkali-soluble polymer as a sea component. . 7. The method for producing a napped sheet according to claim 1, wherein the elastic polymer is made of ether type and / or polycarbonate type polyurethane.