JPS6017871B2 - Method for producing leather-like sheet material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a leather-like sheet material having an appearance and feel similar to natural leather.

Today, many types of artificial leather are emerging as substitutes for natural leather.

Among these artificial leathers, conventionally, the mainstream is artificial leather consisting of three layers: a nonwoven fabric layer containing porous polyurethane elastomer inside, a woven fabric layer containing porous polyurethane elastomer inside, and a porous coating layer. However, this three-layered artificial leather had a hard texture and lacked flexibility, and was far from natural leather. Today, instead of artificial leather having a three-layer structure, it consists of a base layer made of a nonwoven fabric having porous PoIJ urethane elastomer inside and a porous covering layer (so-called silver surface layer) of PoIJ urethane elastomer. Two-layer structures are becoming the mainstream of artificial leather. This two-layered artificial leather is considerably more supple and has a softer feel than the three-layered artificial leather. Furthermore, in this two-layer artificial leather, two or more types of polymers are mixed and spun or composite paper yarn is used as the fibers constituting the nonwoven fabric of the base layer, and at least one component is extracted and removed from the resulting fibers. When using the ultrafine fibers obtained by or porous fibers, it is possible to obtain artificial leather that is more supple and has a softer texture than when using ordinary natural fibers or single spun fibers. Today, artificial leather, which has been made more flexible through these improvements, can be used in a variety of products such as shoes, school bags, school bags, and sports equipment by providing finishing layers on the surface of the porous coating layer to meet various requirements. It is said that it can be processed into various products. However, these two-layer artificial leathers still have a stiff feel and poor drapability compared to natural leather, so they are not suitable for clothing or interior goods. If it were possible to produce artificial leather that has less anti-twill properties than two-layer artificial leather, in other words, is similar to natural leather and has no rubbery feel, it would be possible to use it for clothing and interior goods, and at the same time, it would be possible to Even more demand can be expected in the fields of shoes, bags, sporting goods, etc. that used artificial leather. As a result of repeated research aimed at obtaining artificial leather that has an appearance and feel much closer to natural leather than conventional artificial leather, the present inventors found that The inventors have discovered that the porous coating layer made of polyurethane elastomer gives artificial leather a rubbery feel, giving it an appearance and feel that is far removed from natural leather, leading to the present invention.

That is, the present invention consists of a nonwoven fabric formed by integrating ultrafine fibers and a porous polymer mainly composed of polyurethane elastomer, and the porous polymer in parentheses is present inside the nonwoven fabric. After coating the base layer (A) with an aqueous emulsion of a polymer mainly composed of polyurethane elastomer and drying it to form a non-porous filling layer (B), a polyurethane containing pigment is applied. A colored non-porous layer (C) is formed by coating and drying a solution of a polymer mainly composed of elastomer, and further contains fine particles for adjusting gloss.A polymer mainly composed of polyurethane elastomer. This is a method for producing a leather-like sheet material, which comprises applying and drying a solution to form a gloss-adjusting non-porous layer (D).

The leather-like sheet material obtained by the method of the present invention does not have a porous coating layer on the base layer. That is, to use the conventional expression of artificial leather, the leather-like sheet material obtained by the method of the present invention has a single layer structure, and a non-porous surface finishing layer is directly laminated on this single layer structure sheet material. This is what is being done. The leather-like sheet obtained by the present invention does not have a rubbery feel because the porous coating layer is omitted, and the appearance is extremely similar to natural leather due to the special surface finishing layer provided on the base layer. It becomes. In addition, the non-porous layer referred to in the present invention does not refer only to a film-like non-porous membrane layer with a uniform thickness, but also a non-porous film layer with a non-uniform thickness, and in some cases exists discontinuously in spots. It also includes a non-porous resin layer. Next, the present invention will be explained in detail.

First, the base layer (A) used in the method of the present invention is composed of a nonwoven fabric in which ultrafine fibers are integrated and a polymer mainly composed of porous polyurethane elastomer present inside the nonwoven fabric.

Ultra-fine fibers are made by combining two or more polymers that are incompatible and have different solubility into yarn, and then extracting and removing the sea components from the resulting sea-island fibers using a solvent. It is. Polymers used to obtain the sea-island structure fibers include, for example, polyethylene phthalate, 6-nylon, 6,6-nylon, and 6,10-nylon. Examples include spinnable polymers such as polyethylene, polypropylene, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride, and polystyrene. Which of these polymers is used as the island component polymer and which is used as the sea component polymer may be determined based on the requirements of the final product. Examples of combinations of island component polymers, sea component polymers, and solvents for extracting and removing the sea component polymers are as follows. Polyethylene terephthalate-nylon-penzyl alcohol-or calcium chloride-containing methanol 6-nylon-polyvinyl alcohol-water polyethylene terephthalate-polyethylene-
Toluene polypropylene-polystyrene trichlorene 6
-Nylon-Polyethylene Tricrene The sea-island structure fiber thus obtained is subjected to operations such as stretching, winding, and cutting as necessary, then formed into a web, and subjected to an entanglement process such as needle punching. to form a nonwoven fabric.

The sea-island structure fibers used for nonwoven fabrics usually have a weave of about 1.
It ranges from 0 denier to 20 denier, preferably from 1.5 denier to 15 denier. If the weave of the sea-island structure fibers is outside the above range, problems will arise in the process when the fibers are entangled to obtain a nonwoven fabric. In addition, the number of islands in each cross section of the fibers with the Umejima structure used for manufacturing the nonwoven fabric is preferably 100 or more, and the thickness of the island component is 0.1 denier or less, particularly 0.01 denier or less, 0. It is preferable that it is .0001 denier or more. If the thickness of the islands is larger than 0.1 denier, the suppleness of the resulting leather-like sheet product will be poor, and irregularities on the surface of the base layer will appear on the sheet surface even after the surface finishing layer is applied. It becomes difficult to obtain the appearance of leather. It has been widely known that composite spinning in which 10 to 30 island components having a thickness of 0.1 to 0.4 denier are present in one fiber can be used for the base of artificial leather.

However, when such composite grade yarn fibers are used in the artificial leather without a porous coating layer according to the present invention, since the degree of weaving is large, irregularities on the surface of the substrate appear on the surface of the artificial leather after surface finishing. It is difficult to obtain the artificial leather that the method aims for. In the method of the present invention, the basis weight of the nonwoven fabric serving as a substrate is preferably in the range of 100 to 1,500 polysaccharide based on the weight excluding sea components.

For the nonwoven fabric in which sea-island structure fibers are entangled, a method of temporarily fixing the fibers is adopted as necessary.

By temporarily fixing the fibers, it is possible to prevent inconveniences in the process such as the fibers coming apart during subsequent impregnation with a solution of a polymer mainly composed of polyurethane elastomer. As a specific method for temporarily fixing the fibers, if the sea component of the sea-island structure fiber is a heat-weldable polymer, a method of temporarily heat-welding it by heat treatment can be adopted. Alternatively, a method of temporary fixation using a glue such as starch, polyvinyl alcohol, or carboxymethyl cellulose can also be adopted.
These glues must be removed from the nonwoven fabric after it has been impregnated with a solution of a polyurethane elastomer-based polymer and solidified. It is preferable to use a water-soluble polymer as the adhesive because the adhesive can be removed simply by washing the nonwoven fabric with water, and the temporary fixation can be released. The nonwoven fabric thus obtained is then impregnated with a solution of a polymer based on polyurethane elastomer and wet coagulated.

The polyurethane elastomer used for impregnation is made by using one or more polymer diols of polyester diol, polyether diol, or polyester ether diol as a soft segment, and polymerizing this soft segment with an organic diisocyanate and a compound having two active hydrogen atoms. The polyurethane elastomer is preferably one in which the weight percentage (hereinafter referred to as N%) of the nitrogen atoms constituting the isocyanate group of the organic diisocyanate relative to the polyurethane elastomer is 2.5 to 7. preferable. If a polyurethane elastomer with an N% of less than 2.5 is used, solvent resistance, heat resistance, and heat fixability will decrease, and if a polyurethane elastomer with an N% of more than 7 is used, In this case, the sponge becomes hard and its bending resistance decreases. A solution of a polymer mainly composed of polyurethane elastomer used for impregnation is a solution containing polyurethane elastomer or a small amount of other polymers such as polyvinyl chloride, polyacrylic acid methiol, polyvinyl formal, etc. A composition prepared by mixing a polymer compatible with a polyurethane elastomer is dissolved in a solvent. The concentration of polymer in solution is preferably between 10 and 2% by weight. The solution may contain colorants such as pigments and dyes, coagulation regulators, various stabilizers, and other fillers. The amount of impregnation of this solution into the nonwoven fabric is preferably in the range of 20 to 150 days in terms of the polymer in the solution per 100 days of the nonwoven fabric from which sea components have been removed. If the impregnated amount in terms of the polymer is less than 20 ta, there will be a disadvantage that Empos cannot be fixed, and if the polymer is impregnated for more than 150 ta, the excess polymer solution will form a layer on the surface of the nonwoven fabric. As a result, a porous coating layer may be formed on the surface of the nonwoven fabric, and the nonwoven fabric may become rubbery, thereby defeating the purpose of the present invention. A nonwoven fabric impregnated with a solution of a polymer mainly composed of polyurethane elastomer is soaked in a coagulation bath containing a liquid that has an affinity for the solvent of the polymer but does not have an affinity for the polymer. As a result, a nonwoven fabric having a porous polymer mainly composed of polyurethane elastomer is formed.

Furthermore, in order to extract and remove the sea components of the sea-island structural fibers, the sea-island structural fibers are transformed into ultra-fine fibers by immersing the non-woven fabric in an extraction bath or by manipulating the non-woven fabric while sprinkling yuzu on the surface. This completes the base layer used in the method of the invention. The surface of the base layer is made of a polymer mainly composed of polyurethane elastomer with ultrafine fibers similar to the inside, but when wet coagulated, the surface is made of a polymer mainly composed of polyurethane elastomer. However, in such a case, the surface finish layer is more beautiful and easier to finish than in the case where the ultrafine fibers forming the ultrafine fibers are scattered and fluffy on the surface of the substrate. The leather-like sheet material obtained by the method of the present invention does not have a thick porous grain layer on the surface of the base layer unlike conventional artificial leather.
If a polymer solution for surface finishing is applied directly to the surface of such a substrate layer and dried, the unevenness of the substrate surface will affect the finished leather-like sheet, causing cracks and depressions to appear in the surface layer. , a good appearance cannot be obtained. In this experiment, by applying an aqueous dispersion of a polymer mainly composed of polyurethane elastomer to the surface of the base layer and drying it, the recesses on the surface of the base layer were filled with a polymer mainly composed of polyurethane elastomer. Such defects were removed by forming a so-called plugging layer, which is a layer for filling and flattening the substrate surface (in the present invention, this non-porous layer is referred to as the (B) layer). The polyurethane elastomer constituting the aqueous emulsion may use any of polyether glycol, polyester glycol, and polyether/ester glycol as the soft segment, but in particular polyether glycol It is preferable to use soft segments as they have a large packing effect.

Furthermore, the polyurethane elastomer used for this layer (B) preferably has an N% in the range of 3 to 6 from the viewpoint of texture and heat fixability. (B) When a solution of a polymer mainly composed of polyurethane elastomer or a solution of another polymer is applied and dried instead of an aqueous emulsion of a polymer mainly composed of polyurethane elastomer. In this case, almost no filling effect can be obtained. The filling effect can only be obtained by applying and drying an aqueous dispersion of a polymer mainly composed of polyurethane elastomer. The aqueous emulsion used in layer (B) may contain a small amount of resin other than polyurethane elastomer, such as acrylic or polyvinyl chloride. The optimum amount of the aqueous emulsion liquid to obtain the packing effect is 5
~60 evening/That range.

If it is less than 5 days, large cracks and pinholes will remain in the surface layer after packing, which will spoil the appearance.

If the amount is more than 60 minutes, the texture becomes hard and rubbery. More preferably, the amount of polyurethane elastomer used is as little as possible (
B) To form a layer, it is preferable to smooth the surface of the base layer by calendering it before applying the aqueous emulsion liquid. As a device for hanging this calendar,
The substrate is crimped onto the metal belt using a device such as that described in the publication, i.e., a calendering device having a smooth metal belt whose crimping part is heated but the peeling part is cooled. - Peeling and calendering the substrate facilitates the formation of a surface finishing layer later, and also reduces the amount of resin used as the (B) layer, resulting in a leather-like sheet product with a good texture. is a preferred additional step to obtain. (B) The aqueous emulsion of a polymer mainly composed of polyurethane elastomer used to form the layer preferably has a polymer concentration of 20 to 6% by weight.

If it is less than 20%, it will easily penetrate into the inside of the substrate and the target effect will be low.

Moreover, when it is 60% or more, a continuous film is likely to be formed and the physical properties are deteriorated. Methods for applying the aqueous dispersion include a gravure method, a spraying method, and the like, and among them, the gravure method is most preferred because it can reliably perform plugging. By drying the base coated with the aqueous emulsion, non-porous closed eyebrows (B) are completed. On the surface of the leather-like sheet material on which the packing layer (B) is laminated, a non-porous layer (C) is formed from a solution of a polymer mainly composed of polyurethane elastomer containing a pigment. are laminated.

This is to eliminate color unevenness caused by variations in the composition ratio of fibers and porous polyurethane in the base layer and variations in the thickness of the packing layer (B), and at the same time to give the leather-like sheet material a desired color. This layer (C) is essential for the leather-like sheet material of the present invention in which no porous coating layer is present on the surface of the base layer. The (C) layer is formed at a solid content of 0.5 to 50 m/m.
3 to 35q parts by weight of pigment per 0 parts by weight, preferably 20 parts by weight
~30 parts by weight.

If the solid content of the layer (C) is less than 0.5 mm, there will be a disadvantage that color spots will appear, and if it is more than 50 mm/〆, there will be a disadvantage that the texture will be hard. In addition, when the pigment content in the report (C) is less than 3 parts by weight, it is difficult to hide the color spots with a solid content of 50 parts by weight or less, and if it exceeds 30 parts by weight, ( The adhesive strength between layer C) and packing layer (B) may become weak, resulting in peeling. (C)
The polymer used in the layer is polyurethane elastomer alone or a mixture thereof with other polymers.

The polyurethane elastomer used in this layer may be polyether-based, polyester-based, or polyether-ester-based. Further, the N% of this polyurethane elastomer is preferably in the range of 3 to 6 from the viewpoint of incorporation and heat setting. Examples of polymers that can be used in combination with the polyurethane elastomer include acrylic resins and polyvinyl chloride resins. Layer (C) is formed by applying and drying a solution of a polymer mainly composed of polyurethane elastomer containing a pigment, but the concentration of the polymer in this polymer solution is 3 to 2. A range of % by weight is preferable from the viewpoint of coating operation. Examples of methods for applying the polymer solution onto the layer (B) to form the layer (C) include the gravure method and the spraying method. Among them, the gravure method easily forms a layer of uniform thickness. It is preferable because it can be formed. In addition to the pigment, this layer (C) may also contain dyes, softeners, various stabilizers, antistatic agents, and the like. As described above, by sequentially laminating the filling layer (B) and the surface finishing layer (C) on the base layer (A), an artificial leather having an appearance similar to that of natural leather can be obtained. C) By providing on the layer a non-porous layer (D) formed from a solution of a polymer mainly composed of polyurethane elastomer containing fine particles for matting, the surface gloss can be controlled. In particular, the artificial leather made of (A), (B), and (C), which can provide a leather-like sheet with a gloss that is suitable for various purposes, has a higher surface gloss than a conventional artificial leather with a porous coating layer. In this respect, the artificial leather of the present invention has a problem, but this problem can be solved by providing the layer (D).

(D) The type of fine particles added to the layer may be of any type as long as it has a matting effect, and in particular, among silica, calcium carbonate, titanium oxide, etc., particles with good dispersibility in the polyurethane elastomer solution, Alternatively, a powder of a hard resin such as polycarbonate, which is incompatible with the polymer constituting the layer (D), is used.

Further, these fine particles preferably have a particle size of 0.01 to 0.1 mound. Furthermore, the fine particles used in the (D) layer usually make the (D) layer white, when the (D) layer is formed.
Alternatively, a powder that is colored almost white is preferable. The amount of fine particles added is 3 parts per 10 parts by weight of the polymer mainly composed of polyurethane elastomer constituting layer (D).
A range of 0 to 6 parts by weight is preferred. (D) The thickness of the layer is
The optimum surface gloss differs depending on the application, such as clothing, interior decoration, sporting goods, etc., so it cannot be generalized, but it is usually preferable to have a thickness of 0.5 to 30 minutes after molding. Specifically, the thickness and fine particle concentration are such that when the leather-like sheet material provided with the (D) layer is viewed from above, the (C) layer is sufficiently visible on the surface through the cloudy (0) layer. . The polyurethane elastomer used in the layer (D) may be polyether-based, polyester-based, or polyether/ester-based, but
If you want to obtain artificial leather with a deeper color by dyeing the artificial leather obtained later, the polyurethane elastomer constituting layer (C) and/or layer (D) may be dyed.
It is preferable to use a polyurethane elastomer containing polyethylene glycol as at least a part of the soft segment component.

The polyurethane elastomer used in layer (D) preferably has an N% of 3 to 7 in terms of texture and heat fixability. (D) The polymer constituting the layer may be the above polyurethane elastomer alone or a mixture with other polymers, or a polymer that can be used in combination with the polyurethane elastomer. Examples of the combination include acrylic resin and vinyl chloride resin. (D)
The layer is formed by applying and drying a solution of a polymer mainly composed of polyurethane elastomer containing fine particles, and the concentration of the polymer in this polymer solution is 3 to 3.
A range of 6% by weight is preferred.

Although it is essential that the layer (D) contains fine particles for matting, it may also contain dyes, softeners, various stabilizers, antistatic agents, and the like. Examples of the method for applying the polymer solution onto the layer (C) to form the layer (D) include a gravure method and a spraying method. A preferred method for forming layer (D) is to first prepare a solution of a polymer mainly composed of polyurethane elastomer containing fine particles with a solid content of 0.5 to
This is a method in which it is coated on layer (C) in an amount of 30 coats/coat, dried, and then embossed. If the matting effect is insufficient with this method, add 0.5~
It is preferable to use a method of laminating the fine particle-containing layer having a thickness of 15 mm. In this case, the (D) layer is reapplied only to the ridges of the embossing, and the entire (D) layer has a non-uniform thickness. Obtained by the method of the present invention (
The artificial leather consisting of layers A), (B), (C), and (D) can be dyed, coated, calendered, etc., if necessary, and further provided with a surface finishing layer if necessary. Leather-like sheet products with an appearance and texture extremely similar to natural leather can be obtained, and these leather-like sheet products can be used not only in the fields of shoes and bags where conventional artificial leather has been used, but also in clothing and interior goods. It is also suitable for use in sports equipment.

The method of the present invention will be specifically explained below using Examples.

Parts and percentages used in the Examples and Comparative Examples are by weight unless otherwise specified. Example 1 6-nylon 10 anchor part and polyethylene 10 part were mixed into paper yarn, then stretched, crimped, and cut to produce 4 dr raw cotton in which 6-nylon had an average denier of 0.004 r and was an island component. created.

A web was made from this raw cotton using a random webber, and an intertwined nonwoven fabric with a rating of 100 coughs/filter was made by needle punching. Then soaked in polyvinyl alcohol aqueous solution,
After drying, it was further heat-treated at 135 qo to fuse the polyethylene, which is a sea component, to create a hard sheet. Thereafter, a 16% dimethylformamide solution of a polyurethane elastomer with a soft segment of polyethylene polypropylene adipate and N% of 4% was mixed into a coagulation chamber at 30°C consisting of 7 parts of water and 3 parts of dimethylformamide. It was soaked and wet coagulated. Subsequently, this sheet material was soaked in toluene to extract the polyethylene as a sea component, thereby obtaining a nonwoven fabric having a porous polyurethane elastomer inside the 6-nylon ultrafine fiber composite. The component ratio of nylon 6 and urethane elastomer was 55:47.

This sheet having a thickness of 2.2 mm was used as it was as the base layer (A). A 40% aqueous emulsion of polyether polyurethane (Vondic 1310) was placed on the substrate (A).
: manufactured by Dainippon Ink & Chemicals Co., Ltd.) was coated as a solid component using a gravure method and dried for 16 minutes to form a filling layer (B). On (B), a 14% solution of a polyurethane elastomer with an N% of 4.0 containing 200% yellow-brown pigment based on the polyurethane elastomer (solvent: ethyl cellosolve-isopropyl alcohol-toluene mixture) ) was coated using a gravure method and dried to form a colored layer (C) for 5 days. Further on top of this (D)
To form the layer, polyethylene glycol is soft segmented, and silica with an average particle diameter of 4 mm is added to the polyurethane elastomer with an N% of 5%. A 7% solution of a 30% mixed polyurethane elastomer (solvent: acetone-cyclohexanone-dimethylformamide mixture) was prepared, and this solution was applied onto a sheet using a gravure method to form a 3-layer (D) layer. . The resulting sheet had a suitable level of gloss. A pattern similar to natural leather was applied to this using a heated embossing roller. Furthermore, with a dye aqueous solution mixed with Ingaran Yello Station L, Ingaran Brown 20L, and Ingaran Ollip BGL, 85-95 pm
A leather-like sheet dyed brown was produced by dyeing for 1 hour. Furthermore, when the surface of the sheet was calendered, a leather-like sheet material having color development, gloss, and texture equivalent to natural leather was obtained. Example 2 In Example 1, polyethylene glycol was used as a soft segment in place of the colored layer (C) described above, and N% was 5%.
14% of polyurethane elastomer containing 200% yellow-brown pigment for easy-liang polyurethane.
A solution (solvent: ethyl cellosolve) was applied using a gravure method and dried to form a colored layer (C) for 5 days/time.

Next, on the surface of the sheet material on which the layer (C) was formed, a polyurethane material with an N% of 4.0, which contains 30% of silica with an average particle size of 4 m2 to the polyurethane elastomer, was applied to the surface of the sheet material on which the layer (C) was formed. A 6.8% solution of lastomer (solvent: cyclohexanone-tetrahydrofuran mixture) was mixed with solids for 2 nights/
〆Apply using the Labya method so that it is applied and dry it (D
) layer to obtain a leather-like sheet material with low gloss.
A pattern similar to natural leather was applied to this using a heated embossing roller. Further, the obtained sheet material was dyed with an aqueous dye solution containing Ingaran Yellow 2RL, Ingaran Brown 20L, and Ingaran Olive BRL for 85-9yo.
A leather-like sheet dyed brown was produced by dyeing for 1 hour. In order to impart gloss and smoothness to the obtained sheet,
Calendering was performed to obtain a leather-like sheet material that was extremely similar in texture and grain to natural leather. Example 3 In Example 1, a smooth metal belt whose temperature is controlled so that the temperature at the time of adhesion is 120 degrees Celsius and the temperature at the time of peeling is 100 degrees Celsius before forming the layer (B) is provided. The surface of the sheet (A) was heat-treated using a calendar device.

The surface was even smoother compared to the surface of Example 1. Thereafter, the filling layer (B), colored layer (C), and gloss adjustment layer (D) were finished in the same manner as in Example 1. The obtained sheet material was a leather-like sheet material having a smoother surface than that of Example 1. Example 4 The fibers of the base material of Example 1 were made into a 0.0.
A leather-like sheet was obtained in the same manner as in Example 1, except that the mixed yarn fiber was made of polyethylene terephthalate having a thickness of 0.002 mm as an island component.

The texture was a little harder than that of 6-nylon, but the appearance was extremely similar to natural leather.

Comparative Example 1 In the operation of Example 1, instead of using an aqueous emulsion liquid as the layer (B), a dimethylformamide solution of polyether polyurethane was used. In this case, the solution penetrated into the interior of the substrate (A), the texture became hard, and there was no packing effect to reduce unevenness and flatten the surface of the substrate. Furthermore, even if layer (C), which is the same as in Example 1, and layer (D), which is the same as in Example 2, are laminated, the surface smoothness is poor and the texture is hard, which is far from natural Tsujishikin. It was a sheet-like product. Comparative Example 2 A leather-like sheet material was produced by the same treatment as in Example 1 except that the layer (B) was not formed or omitted.

This leather-like sheet material had poor flatness and embossing properties, lacked the luxurious feel that natural leather has, and at first glance it was obvious that it was an imitation of artificial leather. Comparative Example 3 Leather was produced in the same manner as in Example 1, except that raw cotton was used, which was a multicore sheath fiber of 6-nylon and polyethylene (number of cores: 9), and the fibers of 6-nylon as the island component had a diameter of 0.3. A similar sheet was obtained.

This leather-like sheet material had surface fuzz that was not sufficiently suppressed and had a surface with many pinhole-like defects, and did not have the appearance and softness of natural leather. Comparative example
4 In the operation of Example 1, an acrylic emulsion liquid (dispersed soot: water) with a resin concentration of 40% was used instead of using a water-based polyurethane emulsion as the layer (B).

In this case as well, hardening of the texture was felt. Furthermore, Example 1
Even if the same layer (C) as in Example 2 and the layer (D) as in Example 2 were laminated, the sheet-like product was far different from natural leather, especially in terms of texture. Comparative Example 5 After impregnating the substrate with a dimethylformamide solution of polyurethane during the preparation of the substrate in the operation of Example 1, the surface was further coated with the following:
The same polyurethane solution was coated and wet-coagulated to obtain a substrate having a porous coating layer of about 70 mm thick on the substrate surface.

Thereafter, layers (B) and (C) were applied in the same manner as in Example 1 to obtain a leather-like sheet material. Although the appearance was very similar to natural leather, the texture was hard and it was not the artificial leather aimed at by the present invention, that is, a sheet product similar to natural leather in both texture and appearance. . Comparative Example 6 In Example 1, the layer (C) was not formed, but the surface of the sheet material on which the layer (B) was formed was coated with a polyurethane fester having an average particle diameter of 4 degrees for matting. 30% against
A 6.8% solution (solvent: cyclohexanone-tetrahydrofuran mixture) of a polyurethane elastomer containing 4.0 N% was applied as a solid component two times a day (D). A layer was formed, and a pattern similar to natural leather was applied thereto using a heated embossing roller to obtain a leather-like sheet material.

Claims (1)

[Scope of Claims] 1. A nonwoven fabric formed by entangling ultrafine fiber bundles and a porous polymer mainly composed of polyurethane elastomer, and the porous polymer is present inside the nonwoven fabric. After coating and drying a water-based emulsion liquid of a polymer mainly composed of polyurethane elastomer to form a non-porous packing layer (B) on the base layer (A), a polyurethane elastomer containing a pigment is applied. A colored non-porous layer (C) is formed by applying and drying a solution of a polymer mainly consisting of a polyurethane elastomer, and then a solution of a polymer mainly consisting of a polyurethane elastomer containing fine particles for gloss adjustment is applied and dried.
A method for producing a leather-like sheet product, which comprises drying to form a gloss-adjusting non-porous layer (D). 2. The manufacturing method according to claim 1, wherein the surface of the base layer is calendered prior to applying the aqueous emulsion liquid of a polymer mainly composed of polyurethane elastomer.