JP2020066821A - Sheet-like material and method for manufacturing the same - Google Patents

Abstract

To provide a sheet-like material excellent in durability of an uneven pattern while having a feeling of natural nubuck leather.SOLUTION: In a fiber structure that contains ultrafine fibers having an average single fiber diameter of 0.1 μm or more and 10 μm or less, a sheet-like material of the invention has a napped surface on at least one surface thereof and has a resin layer of a multilayer structure. According to a preferred embodiment of the invention, the total thickness of the resin layer is 0.001 mm or more and 0.400 mm or less. The change rate of an emboss height (R) is 0.40 or more and 0.90 or less, and a ratio of the tangent of the emboss (tan(α)/tan(α)) calculated from emboss angle (α, α) before and after an abrasion resistance test is 0.20 or more and 1.00 or less.SELECTED DRAWING: None

Description

  TECHNICAL FIELD The present invention relates to a sheet-like material which has the feel of natural nubuck leather and is excellent in the durability of an uneven pattern.

  The suede-like artificial leather composed of ultrafine fibers and a polymer elastic material has excellent properties that natural leather does not have in terms of durability and uniformity. Utilizing such characteristics, suede-like artificial leather is used in a wide range of applications such as furniture and interior materials for automobiles, and development of artificial leather having a quality other than suede-like is desired.

  Examples of the artificial leather having a quality other than suede tone include artificial leather such as silvered tone and nubuck tone. Unlike suede, natural nubuck leather is obtained by brushing the silver surface of leather. For this reason, it has a feature that it has a wet feel while having the surface of the leather with a denseness and flatness. However, none of the artificial leather and synthetic leather simulating the existing nubuck have achieved sufficient quality and texture.

  For nubuck-like artificial leather, for example, a method of exposing the napped fibers by chemically and / or mechanically dividing the napped surface with a resin solution applied to a leather-like sheet made of ultrafine fibers Has been proposed (see Patent Document 1).

  In addition, as for the silver-tone artificial leather, as a sheet having excellent gripping property, a leather sheet having a silver layer including a clothing layer, a modified hollow nanosilica particle and a surface layer made of a polymer elastic material is provided on the equipment (Patent Document 2). And a synthetic leather (see Patent Document 3) in which two polyurethane adhesive layers are laminated on the surface of a fiber base material has been proposed as a material having excellent abrasion resistance.

  On the other hand, for a silver-tone artificial leather having a concavo-convex pattern, a method has been proposed in which a napped sheet is coated with a polyurethane resin and then heated and pressed (see Patent Document 4).

Japanese Patent No. 3409554 Japanese Patent No. 5452477 Japanese Patent No. 3133957 Japanese Patent Application No. 2001-19245

  However, in the technique disclosed in Patent Document 1, the resin layer portion after division is largely damaged, and abrasion resistance thereafter is a problem. Also, in the technologies disclosed in Patent Documents 2 and 3, since no napped fiber is present on the surface, there is no lighting effect due to the short napped peculiar to nubuck leather, and the breathability is poor, and quality and comfort are issues. Is. Further, also in the technique disclosed in Patent Document 4, an artificial leather having a concave / convex pattern in which the resin portion is selectively recessed by performing hot pressing after drawing a pattern on the napped surface with resin can be obtained. However, in practice, since the abrasion progresses from the raised portion corresponding to the convex portion, the durability of the uneven pattern has not been sufficiently improved.

  Therefore, an object of the present invention is to provide a sheet-like material in which the tactile sensation of a nubuck leather and the durability of an uneven pattern are compatible with each other in view of the above-mentioned actual state of the art.

  As a result of intensive studies to achieve the above-mentioned object, the present inventors have applied two or more layers of resin on the napped surface and then applied an uneven pattern by hot pressing to give a texture of the uneven pattern and a nubuck tone. We have found that the reproduction of quality can be improved. Further, it was also found that this sheet-like material can remarkably improve the durability of the uneven pattern.

  The present invention has been completed based on these findings, and the present invention provides the following inventions.

  That is, the sheet-like product of the present invention has a napped surface formed by napping the ultrafine fibers on at least one surface of a fiber structure containing ultrafine fibers having an average single fiber diameter of 0.1 μm or more and 10.0 μm or less. A discontinuous resin layer is formed on the raised surface in the surface of the raised surface, and further has an uneven pattern, and the resin layer is composed of two or more layers. There is.

  According to a preferred embodiment of the sheet material of the present invention, the resin layer has a structure including three or more layers including an adhesive layer, an intermediate layer and a surface layer.

  According to a preferred embodiment of the sheet-shaped product of the present invention, the total thickness of the resin layer is 0.001 mm or more and 0.400 mm or less.

According to a preferred embodiment of the sheet-like material of the present invention, a pressing load of 12 kPa and a friction number of 50,000 are in accordance with “8.19.5 E method (Martindale method)” of JIS L1096: 2005 “Test method for woven and knitted fabrics”. in the wear test of the sheet material takes place at times conditions, the embossing height before and after the abrasion test _(R 1, _{R 2)} rate of change _(R 2 / _{R 1)} is 0.40 to 0.90 It is the following.

According to a preferred embodiment of the sheet-like material of the present invention, a pressing load of 12 kPa and a friction number of 50,000 are in accordance with “8.19.5 E method (Martindale method)” of JIS L1096: 2005 “Test method for woven and knitted fabrics”. In the abrasion resistance test of the sheet-like material performed under the condition of the number of times, the ratio of tangents of embossing calculated from the embossing angles (α ₁ , α ₂ ) before and after the abrasion resistance test (tan (α ₂ ) / tan (α ₁ )) is 0.20 or more and 1.00 or less.

  Further, in the method for producing a sheet-shaped material of the present invention, the step of imparting an uneven pattern is a step of hot pressing the surface of the sheet.

  According to the present invention, it is possible to obtain a sheet-like material having a texture similar to that of natural nubuck leather and having an uneven pattern and excellent durability. In particular, the sheet-like article of the present invention is excellent in durability of the uneven pattern because the napped surface is covered with a multilayer resin layer, and thus is widely suitable for furniture, chairs and vehicle interior materials, clothing and the like. Can be used for.

FIG. 1 is a schematic top view illustrating an embodiment of a raised surface of a sheet-like material according to the present invention. FIG. 2 is a conceptual cross-sectional view illustrating an example of the cross-section of the sheet-like material of the present invention. FIG. 3 is a conceptual cross-sectional view illustrating an example of a convex portion in the cross section of the sheet-like material of the present invention.

  In the sheet-like material of the present invention, at least one surface of a fiber structure comprising ultrafine fibers having an average single fiber diameter of 0.1 μm or more and 10 μm or less is a napped surface on which the above-mentioned ultrafine fibers are napped, and the napped hair of FIG. As shown in the conceptual top view illustrating one embodiment of the surface, the raised surface has a discontinuous resin layer and an uneven pattern in the surface of the raised surface, and the resin layer is 2 It is composed of more than one layer. The details will be described below.

[Ultra fine fiber]
It is important that the average single fiber diameter of the ultrafine fibers constituting the sheet-like fiber structure according to the present invention is 0.1 μm or more and 10.0 μm or less. By setting the average single fiber diameter of the ultrafine fibers to 0.1 μm or more, preferably 0.3 μm or more, more preferably 0.5 μm or more, the dispersibility of the fibers and the easiness of dispersal during nap treatment such as grinding with sandpaper. It is possible to obtain a sheet-shaped product having excellent properties. On the other hand, when the average single fiber diameter of the ultrafine fibers is 10.0 μm or less, preferably 7.0 μm or less, more preferably 5.0 μm or less, a sheet-like material having excellent flexibility can be obtained.

In the present invention, the average single fiber diameter of the ultrafine fibers is a value measured and calculated as follows.
(1) A sheet-like material is cut to expose a cross section in the thickness direction, which is an observation surface.
(2) A scanning electron microscope (SEM) photograph is taken of the cross section in the thickness direction.
(3) Randomly select 100 circular or elliptical ultrafine fibers close to a circle.
(4) The single fiber diameter of the selected ultrafine fibers is measured, and the number average value thereof is calculated.

  The ultrafine fibers constituting the fiber structure are in the form of a bundle (ultrafine fiber bundle) composed of a plurality of ultrafine fibers. By taking the form of an ultrafine fiber bundle, it is possible to improve physical strength such as tensile strength and tear strength when a sheet-like material is formed, and also develop wear resistance. As the form of the ultrafine fiber bundle, the ultrafine fibers may be separated from each other to some extent, or in some cases, they may be partially bonded, or may be in the form of agglomeration.

  In the present invention, examples of the polymer forming the ultrafine fibers include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and polylactic acid, polyamides such as 6-nylon and 66-nylon, acrylic, polyethylene, polypropylene, And melt-spinnable thermoplastic resins such as thermoplastic cellulose. Among them, polyester fibers made of polyester polymers such as polyethylene terephthalate, polybutylene terephthalate and polytrimethylene terephthalate are preferably used from the viewpoints of strength, dimensional stability, light resistance and dyeability. It is also possible to adopt a form in which at least two or more polymers selected from these polymers are combined.

  The polyester polymer used in the present invention is mainly composed of a structure obtained by copolymerizing a dicarboxylic acid or a derivative thereof and a diol or a derivative thereof. It means more than 50% by mass relative to the mass. The polyester polymer may contain other copolymerizable components capable of ester bond. Examples of the copolymerizable compound include dicarboxylic acids such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimer acid, sebacic acid and 5-isophthalic acid, ethylene glycol, butanediol, neopentyl glycol, cyclohexanedimethanol. , Diols such as polyethylene glycol and polypropylene glycol. If necessary, titanium dioxide as a matting agent, fine particles of silica or alumina as a lubricant, a hindered phenol derivative as an antioxidant, and a coloring pigment can be added.

  The polybutylene terephthalate-based polymer used in the present invention is mainly composed of a structure obtained by copolymerizing terephthalic acid or its derivative with 1,4-butanediol or its derivative.

  On the other hand, from the viewpoint of environment, fibers obtained from recycled raw materials or plant-derived raw materials can also be used. Further, the ultrafine fibers can be formed by mixing fibers of different materials.

  In addition, the polymer constituting the ultrafine fibers may be copolymerized with other components, and also organic particles, inorganic particles such as titanium oxide particles, lubricants, pigments, heat stabilizers, etc. according to the desired purpose. Further, additives such as an ultraviolet absorber, a conductive material, a heat storage material, a flame retardant, an antibacterial agent and an antistatic agent may be contained.

  As for the cross-sectional shape of the ultrafine fibers, in addition to the round cross-section, polygonal shapes such as oval, flat, and triangular shapes, and irregular cross-sections such as fan-shaped and cross-shaped shapes can be adopted.

[Fiber structure]
The fiber structure constituting the sheet-like material of the present invention is preferably a non-woven fabric, and may be any form of a mode in which a polymeric elastic body is impregnated in the non-woven fabric that is the fibrous structure, It can be used properly according to the cost and characteristics required for each application and purpose. As the non-woven fabric used in the present invention, general non-woven fabrics and long-fiber non-woven fabrics, needle punched non-woven fabrics and paper-made non-woven fabrics, spunbond non-woven fabrics, melt blown non-woven fabrics, electrospun non-woven fabrics, and all non-woven fabrics expressed in various categories. Can be applied. Here, non-woven fabrics are preferable in terms of a rich texture and fine napped quality, but artificial leather filled with a polymer elastic body in these structures is used for the durability of the sheet-like material and the surface resistance. It is more preferably used from the viewpoint of excellent abrasion resistance.

  When a short-fiber nonwoven fabric is used as the fiber structure, the fiber length of the ultrafine fibers is preferably 25 mm or more and 90 mm or less. By setting the fiber length of the ultrafine fibers to 90 mm or less, good quality and texture can be obtained, and by setting the fiber length to 25 mm or more, a sheet-like material having good wear resistance can be obtained.

  The polymer elastic material used in the present invention is a polymer compound having rubber elasticity that expands and contracts, and includes, for example, polyurethane, polyurethane, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR) and An acrylic resin etc. can be mentioned. Among them, a polymer elastic body containing polyurethane as a main component, specifically, a polymer elastic body containing 50% by mass or more of polyurethane is preferably used from the viewpoint of balancing the texture and the physical properties.

  Polyurethanes include organic solvent-based polyurethanes used in a state of being dissolved in an organic solvent and water-dispersed polyurethanes used in a state of being dispersed in water, and both can be used in the present invention.

  As the polyurethane used in the present invention, a polyurethane having a structure in which a polyol, a polyisocyanate and a chain extender are appropriately reacted can be used.

  As the polyol, for example, a polycarbonate diol, a polyester diol, a polyether diol, a silicone diol, a fluorine diol, or a copolymer obtained by combining these can be used. Among them, the polycarbonate-based diol and the polyester-based diol are preferably used from the viewpoint of light resistance. Further, from the viewpoint of hydrolysis resistance and heat resistance, a polycarbonate diol is preferably used.

  The polycarbonate diol can be produced by a transesterification reaction of an alkylene glycol and a carbonic acid ester, or a reaction of a phosgene or chloroformate and an alkylene glycol.

  Examples of the alkylene glycol include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol and 1,10-decanediol. Linear alkylene glycol, branched alkylene glycols such as neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5pentanediol, 2-methyl-1,8-octanediol, 1 Alicyclic diols such as 4-cyclohexanediol, aromatic diols such as bisphenol A, glycerin, trimethylolpropane, and pentaerythritol.

  In the present invention, either a polycarbonate diol obtained from a single alkylene glycol or a copolycarbonate diol obtained from two or more kinds of alkylene glycols can be used.

  Examples of polyisocyanates include hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, aliphatic polyisocyanates such as isophorone diisocyanate and xylylene diisocyanate, and aromatic polyisocyanates such as diphenylmethane diisocyanate and tolylene diisocyanate. Can be used in combination. Among them, when importance is attached to durability and heat resistance, aromatic polyisocyanates such as diphenylmethane diisocyanate are preferable, and when importance is attached to light resistance, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate and isophorone diisocyanate are included. Aliphatic polyisocyanates are preferably used.

  As the chain extender, for example, an amine chain extender such as ethylenediamine or methylenebisaniline, a diol chain extender such as ethylene glycol, or a polyamine obtained by reacting polyisocyanate with water may be used. it can.

  The elastic polymer used in the present invention may contain an elastomer resin such as polyester, polyamide, and polyolefin, an acrylic resin, an ethylene-vinyl acetate resin, etc. within a range that does not impair the performance and texture as a binder. it can.

  In addition, various additives such as pigments such as carbon black, flame retardants such as phosphorus-based, halogen-based and inorganic-based, antioxidants such as phenol-based, sulfur-based and phosphorus-based, and benzo are included in the elastic polymer. UV absorbers such as triazole type, benzophenone type, salicylate type, cyanoacrylate type and oxalic acid anilide type, light stabilizers such as hindered amine type and benzoate type, hydrolysis stabilizers such as polycarbodiimide, plasticizer, anti-electricity Inhibitors, surfactants, coagulation regulators, dyes and the like can be contained, and the content of the additives is appropriately adjusted in consideration of the type of the polymer elastic material to be used, the production method and the texture. be able to.

[Puffed surface]
In the sheet-shaped article of the present invention, at least one surface of the fiber structure has a napped surface formed by napped microfibers. By having a napped surface, excellent adhesion between the fiber structure body and the resin layer described below can be obtained, and the napped fibers exposed on the surface of the sheet-like material can provide a surface feel closer to natural leather. .

[Resin layer]
The sheet-like material of the present invention comprises a discontinuous resin layer formed on the raised surface within the raised surface. By forming the resin layer discontinuously in this way, in the portion without the non-resin layer, sufficient breathability of the leather-like sheet material is secured, and when the sheet material bends, In addition, the resin layer does not crack, and good quality and texture can be maintained.

  Further, in addition to the fact that the sheet-shaped article of the present invention is formed with a discontinuous resin layer, it is important that the resin layer is composed of a plurality of layers. More preferably, the resin layer is a structure having three or more layers including an adhesive layer, an intermediate layer and a surface layer. By having two or more resin layers, it is possible to obtain a leather-like cloth that is required to have higher durability and is excellent in abrasion resistance, such as an automobile seat or a sofa.

  Further, in the sheet-shaped article of the present invention, the total thickness of the resin layer, which is the total thickness of the layers constituting the resin layer, is preferably 0.001 mm or more and 0.400 mm or less. By setting the total thickness of the resin layer to 0.001 mm or more, more preferably 0.010 mm or more, it is possible to obtain a sheet-shaped material having excellent wear resistance and durability of uneven patterns. On the other hand, when the thickness is 0.400 mm or less, and more preferably 0.100 mm or less, the texture of the sheet-like material can be made flexible.

  At this time, the thickness of each layer constituting the resin layer can be set to about 0.250 mm at the maximum for the layer closest to the napped surface (adhesive layer if three or more layers), and 0.008 mm or more and 0.060 mm or less. Is preferred. On the other hand, the other layers can each have a maximum thickness of about 0.065 mm, preferably 0.001 mm or more and 0.020 mm or less.

In the present invention, as the total thickness of the resin layer and the thickness of each layer constituting the resin layer, the values measured and calculated as follows are adopted.
(1) The cross section obtained by cutting the sheet-like material in the thickness direction is used as an observation surface, and the resin layer is magnified at a magnification of 50 to 200 times by a scanning electron microscope (SEM). Observe.
(2) The total thickness of the resin layer and the thickness of each layer constituting the resin layer are measured from each photographed image by using image analysis software or the like.
(3) A number average value is calculated for each of 10 values obtained from each captured image.

[Sheet]
The sheet-like article of the present invention is a sheet-like article having a concavo-convex pattern in which a discontinuous resin layer is formed on the napped surface as described above, and the concavo-convex pattern is added to the resin layer.

Furthermore, the sheet-like material of the present invention is a sheet-like material having excellent wear resistance, and has a change rate (R ₂ / R ₁ ) of emboss heights (R ₁ , R ₂ ) before and after the wear resistance test described below. It is in the range of 0.40 or more and 0.90 or less, and the ratio of the tangent of embossing calculated from the embossing angles (α ₁ , α ₂ ) before and after the wear resistance test (tan (α ₂ ) / tan (α ₁ )). Is preferably 0.20 or more and 1.00 or less.

Here, in the present invention, the rate of change (R ₂ / R ₁ ) of the emboss height (R ₁ , R ₂ ) before and after the abrasion resistance test, the ratio of the tangent of emboss (tan (α ₂ ) / tan (α ₁ )) Will be described.

(I) Method for calculating embossing height (R), embossing angle (α), embossing tangent (tan (α)) In the present invention, embossing height (R), embossing angle (α), embossing tangent (tan). For (α)), the value measured and calculated as follows is adopted.
(1) A scanning electron microscope (SEM) is used to magnify the convex portion of the napped surface with a scanning electron microscope (SEM) at a cross section obtained by cutting the sheet-shaped material in the thickness direction, and the convex portion can be arbitrarily selected. Observe 10 spots.
(2) For each of these captured images, the highest position z ₁ and the lowest position z ₂ on the slope of the convex portion are determined as shown in the sectional conceptual diagram of the convex portion illustrated in FIG.
(3) Embossing height (R) is the height of a right-angled triangle formed by the intersection of a vertical line drawn from the position z ₁ and a line extending from the position z ₂ in parallel with the napped surface, and the parallel line and the hypotenuse of the right-angled triangle. The angle formed by is the embossing angle (α), and the tangent of this angle is tan (α). These are measured from each photographed image by using image analysis software or the like.
(4) For ten embossed heights (R), embossed angles (α), and tangents of embossed (tan (α)) obtained from each captured image, a number average value is obtained.

(Ii) Abrasion resistance test In the present invention, the abrasion resistance test of the sheet-like material is in accordance with JIS L1096: 2005 “Method for testing woven and knitted fabrics”, “8.19.5 E method (Martindale method)”. This means a wear resistance test for a sheet-like material under the conditions of a pressing load of 12 kPa and a friction number of 50,000 times.

(Iii) abrasion resistance test before and after the embossing height _(R 1, _{R 2)} rate of change _(R 2 _/ R 1), the ratio of embossed tangent _{(tan (α 2) / tan} (α 1))
In the present invention, the rate of change (R ₂ / R ₁ ) of the emboss height (R ₁ , R ₂ ) before and after the abrasion resistance test of the sheet-like material, the ratio of the tangent of emboss (tan (α ₂ ) / tan (α ₁ )) indicates the value calculated by the following procedure for each sheet-like material.
(1) The emboss height (denoted by R ₁ ), the emboss angle (denoted by α ₁ ), and the tangent of the emboss (denoted by tan (α ₁ )) calculated by the measuring method described in (i) are calculated. To do.
(2) Subsequently, the abrasion resistance test described in (ii) is performed.
(3) After the test of (2), the emboss height (R ₂ ), the emboss angle (α ₂ ), and the tangent (tan (α ₂ ) of the emboss calculated by the measuring method described in (i)). ) And)) respectively.
(4) The rate of change (R ₂ / R ₁ ) of the emboss height (R ₁ , R ₂ ) before and after the abrasion resistance test, and the ratio of the tangent of the emboss (tan (α ₂ ) / tan (α ₁ )), respectively. calculate.

[Method of manufacturing sheet material]
(1) Formation of Ultrafine Fiber Generating Fiber In the method for producing a sheet-like material according to the present invention, the ultrafine fibers constituting the sheet-like material are ultrafine fibers composed of two or more kinds of polymer substances having different solubility in a solvent. It is preferable to use expression fibers.

  As the ultrafine fiber-expressing fiber used in the present invention, a thermoplastic resin of two components having different solubilities in a solvent is used as a sea component and an island component, and the sea component is dissolved and removed by the solvent, and the island component is made into an ultrafine fiber. Examples include sea-island type composite fibers and release type composite fibers in which two-component thermoplastic resins are alternately arranged on the fiber surface in a radial or multi-layered manner, separated by solvent treatment and split, and split into ultrafine fibers. Among them, the sea-island type composite fiber can provide appropriate voids between the island components by removing the sea component, that is, between the ultrafine fibers in the ultrafine fiber bundle, so that the flexibility and texture of the fiber structure can be obtained. It is also preferably used from the viewpoint of improving

  As the sea-island type composite fiber, a sea-island type composite spinneret is used, and the polymer mutual array method in which the two components of the sea component and the island component are mutually arranged and spun, and the two components of the sea component and the island component are mixed. A mixed spinning method of spinning can be used, but sea-island type composite fibers of a polymer array method are preferably used because ultrafine fibers having a uniform fineness can be obtained.

  In the case of the sea-island type composite fiber, those listed as the above-mentioned “polymer for forming ultrafine fiber” are used as the island component. On the other hand, examples of the polymer used for the sea component include polyethylene, polypropylene, polystyrene, a copolyester obtained by copolymerizing sodium sulfoisophthalate and polyethylene glycol, polylactic acid, and PVA.

(2) Formation of Nonwoven Fabric Comprising Ultrafine Fiber Generating Fibers In the method for producing a sheet-like article according to the present invention, it is preferable to perform a step of forming a nonwoven fabric from ultrafine fiber generating fibers. More specifically, the ultrafine fiber-generating fiber is preferably crimped and then cut into a predetermined length to obtain a raw non-woven fabric. In the present invention, the ultrafine fiber generating fiber is not cut into a predetermined length, a long fiber non-woven fabric can also be used, but when the texture and quality are important, the short fiber non-woven fabric is cut into a predetermined length. Is the preferred embodiment. As described above, when the texture and the quality are important, the fiber length of the short fibers is preferably 25 mm or more and 90 mm or less in consideration of the wear resistance due to the entanglement.

  A known method can be used for crimping and cutting the ultrafine fiber-generating fiber. The obtained raw cotton is made into a fibrous web by a cross wrapper or the like, and the basis weight of the fibrous web can be appropriately set in consideration of the design of the final product, the dimensional change in the post-process, the characteristics of the processing machine, and the like.

  In the method for producing a sheet-like material of the present invention, a method such as needle punching or water jet punching can be used as a method for intertwining a nonwoven fabric made of ultrafine fiber-generating fibers. Among them, the entanglement treatment with the needle punch is the preferred embodiment from the viewpoint of the quality of the product.

(3) Formation of Precursor Sheet of Sheet-like Material The non-woven fabric made of the ultrafine fiber-generating fibers thus obtained is a step before applying the polymer elastic body in order to make the sheet-like material dense. In the above, it is a preferred embodiment to shrink the composition by dry heat or wet heat or both to further increase the density. This shrinking treatment may be carried out before or after expressing the ultrafine fibers from the ultrafine fiber generating fiber, but the characteristic of the sea component polymer of the ultrafine fiber generating fiber can be used for the shrinkage. In the above, it is a preferred embodiment that the shrinking treatment is performed before the generation of the ultrafine fibers.

  The range of the area shrinkage ratio of the laminated sheet in this shrinking step is preferably 15% or more and 35% or less. By setting the area shrinkage ratio to 15% or more, the effect of improving the quality due to the shrinkage can be preferably obtained. Further, by setting the area shrinkage ratio to 35% or less, preferably 30% or less, more preferably 25% or less, it becomes possible to efficiently shrink the polymer elastic body after it is applied.

(4) Expression of Ultrafine Fibers As the method for generating (expressing) ultrafine fibers employed in the method for producing a sheet-like material according to the present invention, one of the resins (polymers) forming the ultrafine fiber-generating fibers is a solvent. And a method of dissolving by. In particular, with respect to the ultrafine fiber-generating sea-island composite fiber in which the sea component is composed of a readily soluble polymer and the island component is composed of a sparingly soluble polymer, desalination treatment in which the sea component is dissolved is preferable.

  As the solvent for dissolving the sea component, when the sea component is polyethylene, polypropylene or polystyrene, an organic solvent such as toluene or trichlorethylene is used. When the sea component is copolyester or polylactic acid, an alkaline aqueous solution such as sodium hydroxide or hot water is used as the solvent.

  The expression of the ultrafine fibers (desalination treatment) can be carried out by immersing a fiber entangled body made of ultrafine fibers in a solvent and constricting the solution.

  Next, a treatment for imparting a polymeric elastic body is performed on the obtained fiber entangled body containing the ultrafine fibers. The sheet-shaped material of the present invention comprises a polymeric elastic body. By including the elastic polymer, it is possible to obtain a full-feeling touch, a leather-like appearance, and physical properties to endure actual use.

  It is possible to employ a method in which the treatment of expressing the ultrafine fibers from the ultrafine fiber-expressing fibers and the treatment of applying the polymer elastic body are performed first. When the treatment for expressing the ultrafine fibers is performed first, the polymer elastic body holds the ultrafine fibers, so that the ultrafine fibers do not fall off and can be used for a longer period of time. Further, when the polymeric elastic body is applied first, the polymeric elastic body has a structure in which the ultrafine fibers are not gripped, so that a sheet-like material having a good texture can be obtained. Which is to be performed first can be appropriately selected depending on the type of polyurethane used and the like.

  Further, in the case where the polymer elastic body is applied after the treatment for expressing the ultrafine fibers, it is a preferable embodiment to provide a step of applying the water-soluble resin between both steps. By providing this step of applying the water-soluble resin, the surface of the fiber is protected by the water-soluble resin, and the places where the fibers are directly bonded to the elastic polymer will be present intermittently rather than continuously. Can be moderately suppressed. As a result, it is possible to obtain a sheet-like material having a good hand-held feeling due to the polymeric elastic body.

  As such a water-soluble resin, polyvinyl alcohol, polyethylene glycol, saccharides, starch and the like can be used. Among them, polyvinyl alcohol having a saponification degree of 80% or more is preferably used.

  The application amount of the water-soluble resin is preferably 1% by mass or more and 30% by mass or less with respect to the mass of the fiber entangled body (nonwoven fabric) immediately before application. Good texture can be obtained by controlling the applied amount to be 1% by mass or more. Further, when the applied amount is 30% by mass or less, artificial leather having good workability and good physical properties such as abrasion resistance can be obtained. In addition, since the amount of the polymer elastic body that can be applied to the fiber entangled body (nonwoven fabric) is increased in the subsequent step, it is possible to increase the density of the sheet-like material and the touch feeling.

(5) Formation of Sheet-like Material In the method for producing a sheet-like material according to the present invention, a step of half-cutting the precursor sheet of the sheet-like material to which the polymeric elastic body is applied in the plane direction can be performed. By including the half-cutting step, the productivity of the sheet-like material can be improved. For example, as a method for laminating a woven or knitted material, when a method of sandwiching a non-woven fabric layer composed of ultrafine fiber-generating fibers between the woven and knitted material layers is used, half-cut the precursor sheet to make the inner surface a raised surface. Is a preferred embodiment as a method for achieving a fine quality.

  In the method for producing a sheet-shaped product according to the present invention, at least one surface has naps, so that the surface of the non-woven fabric can be buffed using sandpaper, a roll sander or the like. Particularly, by using sandpaper, uniform and dense naps can be formed. Furthermore, in order to form uniform naps on the surface of the sheet-like material, it is a preferable embodiment to reduce the grinding load.

  In the method for producing a sheet material according to the present invention, the fiber structure can be dyed. Dyeing is preferably performed with a high-temperature and high-pressure dyeing machine in order to use a disperse dye, a cationic dye or other reactive dyes, and to soften the texture of the sheet-like product to be dyed.

  Further, if necessary, a finishing treatment such as a softening agent such as silicone, an antistatic agent, a water repellent, a flame retardant and a lightproofing agent can be applied. But you can do it too. For flame retardant treatment, halogen-based flame retardants such as bromine and chlorine and non-halogen flame retardants such as phosphorus can be used. Even when applied by dipping after dyeing, back coating such as knife coating or rotary screen method can be used. It can also be done by giving.

  The method for forming the resin layer in the present invention is a method that can be applied discontinuously to the surface of the fiber entangled body (nonwoven fabric), for example, after applying by a screen method such as a flat screen or a rotary screen or a gravure coating method. A method of drying to form a resin layer, or after forming a discontinuous resin film on a supporting base material such as release paper, applying an adhesive on the surface of the resin film and applying it to the surface to be the base material. Examples of the method include a method of forming a resin layer by adhering together and peeling off the release paper.

  Furthermore, in order to make the resin layer into two layers, three layers, or more, the resin layer can be formed by repeating the above-described resin layer forming method a plurality of times. As for the method of forming the resin layer, the same method of forming the resin layer may be repeated, and two or more kinds of resins, forming conditions, and / or forming methods may be used in combination.

(6) Providing Concavo-convex Pattern The method for imparting a concavo-convex pattern to the napped surface in the present invention is to emboss the napped surface. For embossing, an uneven pattern can be efficiently provided by using an embossing roll heated to the highest softening point or higher among the softening points of the resin of each layer constituting the resin layer. Furthermore, since the sheet-shaped product of the present invention has a resin layer having a two-layer structure or more, the effect of transferring the uneven pattern to the napped surface by embossing is enhanced, and a stronger uneven pattern can be imparted.

  Next, the sheet-like material of the present invention and the method for producing the same will be described in more detail with reference to examples, but the present invention is not limited to these examples. The evaluation method and its measurement conditions used in the examples are as follows. However, in the measurement of each physical property, unless otherwise specified, the measurement was carried out based on the above method.

(1) Average Single Fiber Diameter, Total Thickness of Resin Layer As a scanning electron microscope (SEM), “VE-7800 type” manufactured by Keyence Corporation was used.

(2) embossing the height of the front and rear abrasion resistance test rate of change _{(R 1, R 2) (} R 2 / R 1), the ratio of embossed tangent _{(tan (α 2) / tan} (α 1))
As in (1), "VE-7800 type" manufactured by Keyence Corporation was used as a scanning electron microscope (SEM). Further, in the abrasion resistance test, as a abrasion resistance tester, James H. “Nu-Martindale” manufactured by Heal & Co was used.

(2) Surface texture evaluation of sheet:
It was evaluated by a sensory test of 10 subjects. 6 or more were judged to have a nubuck-like precise and wet texture (○), 3-5 were judged to be (△), and 2 or less were judged to be (x), respectively. Divided. ○ was passed. In this judgment, the one having a natural nubuck-like touch is judged to be high.

(3) Evaluation of surface nap feeling of the sheet-like material:
It was evaluated by a sensory test of 10 subjects. 6 or more were classified as having a suede-like napped feeling (◯), 3 to 5 were judged as (Δ), and 2 or less were judged as (x). ○ was passed. In this judgment, the one having a natural suede-like tactile sensation is highly judged.

(4) Evaluation of uneven surface pattern of sheet material:
It was evaluated by a sensory test of 10 subjects. 6 or more persons were judged to have an uneven pattern (O), 3 to 5 persons judged to be (Δ), and 2 persons or less judged to be (X). ○ was passed. In this determination, those having an uneven pattern are highly determined.

[Example 1]
(raw cotton)
Polyethylene terephthalate was used as the island component, polystyrene was used as the sea component, and a melt-spun fiber was stretched at an island / sea mass ratio of 80/20 using a sea-island composite spinneret having 16 islands, After crimping, the fiber was cut into a length of 51 mm to obtain a raw cotton of an ultrafine fiber expressing type fiber (sea-island type composite fiber) having an average single fiber diameter of 21 μm.

(Nonwoven fabric made of sea-island type composite fiber)
A laminated web was formed by using the raw cotton of the sea-island type composite fiber through a card and cross-wrapper process, and needle punching was performed at a punch number (density) of 100 / cm ² . Separately, using a multifilament (84 dtex, 72 filaments) having a twist number of 2500 T / m as a warp and a weft, a plain woven fabric having a weaving density of 97 warps / 2.54 cm and weft 76 warps / 2.54 was woven. The obtained plain woven fabric was laminated on and under the above laminated web. After that, needle punching was performed with a number of punches (density) of 2500 / m ² to obtain a nonwoven fabric composed of sea-island type composite fibers having a basis weight of 720 g / m ² and a thickness of 3.1 mm.

(Precursor sheet of sheet material)
After shrinking the above non-woven fabric with hot water at a temperature of 98 ° C., it was impregnated with a PVA (polyvinyl alcohol) aqueous solution to obtain a non-woven fabric having a PVA mass of 30 mass% with respect to the mass of the non-woven fabric. The non-woven fabric thus obtained was immersed in trichlorethylene to dissolve and remove the sea component, thereby obtaining a non-woven fabric made of ultrafine fibers (sea-free sheet). The non-woven fabric (sea-sealing sheet) made of ultrafine fibers thus obtained was immersed in a 12% polycarbonate DMF (dimethylformamide) solution of polycarbonate polyurethane, and then the polyurethane was coagulated in the aqueous solution. Then, PVA is immersed in hot water to be removed, and dried with hot air at a temperature of 110 ° C. for 10 minutes to obtain a precursor of a sheet-like material having a polyurethane mass of 27% by mass with respect to the mass of the ultrafine fibers composed of island components. I got a body sheet.

  Then, the above precursor sheet was half-cut in the thickness direction, and the half-cut surface was ground using 320 mesh sandpaper to form a napped surface. The precursor sheet thus obtained was dyed using a jet dyeing machine under a temperature condition of 130 ° C. and then dried using a drier to obtain a precursor sheet. The obtained precursor sheet had a sheet thickness of 0.80 mm and an average single fiber diameter of 4.4 μm.

(Sheet)
The rotary coating method was repeated 3 times on the napped surface of the precursor sheet to form three polyurethane resin layers whose surfaces were discontinuously coated, and then the softening point of the resin of each layer constituting the resin layer Then, it was pressed by an embossing roll heated to the highest softening point temperature to give an uneven pattern, and a sheet-like material having a total resin layer thickness of 0.060 mm was obtained. The surface of the obtained sheet-like material had irregularities and discontinuously arranged resin portions and napped portions, and had an uneven pattern. The sheet-like material thus obtained had a tactile feel of natural nubuck leather, a napped feel of suede leather, and an uneven pattern excellent in durability. The results are shown in Table 1.

[Example 2]
(raw cotton)
In the same manner as in Example 1, an ultrafine fiber-expressing fiber (sea-island composite fiber) raw cotton was obtained.

(Nonwoven fabric made of sea-island type composite fiber)
In the same manner as in Example 1, a nonwoven fabric made of sea-island type composite fiber was obtained.

(Precursor sheet of sheet material)
A precursor sheet was obtained in the same manner as in Example 1.

(Sheet)
The rotary coating method is repeated twice on the raised surface of the precursor sheet to form two polyurethane resin layers whose surfaces are discontinuously coated, and then the softening point of the resin of each layer constituting the resin layer Then, an embossing roll heated to the highest softening point temperature was pressed to give an uneven pattern, and a sheet-shaped product having a resin layer with a total thickness of 0.042 mm was obtained. The surface of the obtained sheet-like material had irregularities and discontinuously arranged resin portions and napped portions, and had an uneven pattern. The sheet-like material thus obtained had a tactile feel of natural nubuck leather, a napped feel of suede leather, and an uneven pattern excellent in durability.

[Example 3]
(raw cotton)
Polyethylene terephthalate is used as the island component, polystyrene is used as the sea component, and a melt-spun fiber is stretched at an island / sea mass ratio of 55/45 using a sea-island composite spinneret with 36 islands, After crimping, the fiber was cut into a length of 51 mm to obtain a raw cotton of an ultrafine fiber expressing type fiber (sea-island type composite fiber) having an average single fiber diameter of 18 μm.

(Nonwoven fabric made of sea-island type composite fiber)
A nonwoven fabric made of sea-island type composite fibers having a basis weight of 590 g / m ² and a thickness of 2.4 mm in the same manner as in Example 1 except that the raw material of the sea-island type composite fibers made of the sea-island type composite fibers was used. Got

(Precursor sheet of sheet material)
A precursor sheet was obtained in the same manner as in Example 1 except that the above nonwoven fabric was used, with a polyurethane mass of 20% relative to the mass of the ultrafine fibers composed of the island component. Then, the above precursor sheet was half-cut in the thickness direction, and the half-cut surface was ground using 320 mesh sandpaper to form a napped surface. The precursor sheet thus obtained was dyed under a temperature condition of 130 ° C. using a jet dyeing machine and then dried using a dryer to obtain a precursor sheet. The obtained precursor sheet had a sheet thickness of 0.60 mm and an average single fiber diameter of 3.1 μm.

(Sheet)
A sheet-like product having a total resin layer thickness of 0.060 mm was obtained in the same manner as in Level 1 except that the above precursor sheet was used. The surface of the obtained sheet-like material had irregularities and discontinuously arranged resin portions and napped portions, and had an uneven pattern. The sheet-like material thus obtained had a tactile feel of natural nubuck leather, a napped feel of suede leather, and an uneven pattern excellent in durability. The results are shown in Table 1. The results are shown in Table 1.

[Comparative Example 1]
(raw cotton)
In the same manner as in Example 1, an ultrafine fiber-expressing fiber (sea-island composite fiber) raw cotton was obtained.

(Nonwoven fabric made of sea-island type composite fiber)
In the same manner as in Example 1, a nonwoven fabric made of sea-island type composite fiber was obtained.

(Precursor sheet of sheet material)
A precursor sheet was obtained in the same manner as in Example 1.

(Sheet)
The fluffed surface of the precursor sheet is subjected to the rotary coating method once to form one layer of the polyurethane resin layer whose surface is discontinuously coated, and then pressed with an embossing roll heated to the softening point temperature of the resin. A concavo-convex pattern was provided to obtain a sheet-shaped product having a total resin layer thickness of 0.005 mm. Although the resin portion and the napped portion were arranged irregularly and discontinuously on the surface of the obtained sheet-like material, the touch feeling of the natural nubuck leather and the durability of the uneven pattern were poor. The results are shown in Table 1.

[Comparative Example 2]
(raw cotton)
An ultrafine fiber having an average single fiber diameter of 29 μm was produced in the same manner as in Example 1 except that the spinning speed was reduced from 1000 m / min to 500 m / min using a sea-island type composite spinneret having 4 islands. A raw cotton of a type fiber (sea-island type composite fiber) was obtained.

(Nonwoven fabric made of sea-island type composite fiber)
A nonwoven fabric made of sea-island type composite fiber having a basis weight of 710 g / m ² and a thickness of 3.5 mm was obtained in the same manner as in Example 1 except that the raw material of the sea-island type composite fiber was used.

(Precursor sheet of sheet material)
A precursor sheet was obtained in the same manner as in Example 1 except that the above non-woven fabric was used, with a polyurethane mass of 37% relative to the mass of the ultrafine fibers composed of the island component. Then, the above precursor sheet was half-cut in the thickness direction, and the half-cut surface was ground using 320 mesh sandpaper to form a napped surface. The precursor sheet thus obtained was dyed under a temperature condition of 130 ° C. using a jet dyeing machine and then dried using a dryer to obtain a precursor sheet. The obtained precursor sheet had a sheet thickness of 0.73 mm and an average single fiber diameter of 12.5 μm.

(Sheet)
A sheet-shaped product having a total resin layer thickness of 0.061 mm was obtained in the same manner as in Level 1 except that the above precursor sheet was used. The surface of the obtained sheet-like material had resin parts and napped parts arranged irregularly and discontinuously and had an uneven pattern, but was poor in touch and napped feeling. The results are shown in Table 1.

[Comparative Example 3]
(raw cotton)
In the same manner as in Example 1, an ultrafine fiber-expressing fiber (sea-island composite fiber) raw cotton was obtained.

(Nonwoven fabric made of sea-island type composite fiber)
In the same manner as in Example 1, a nonwoven fabric made of sea-island type composite fiber was obtained.

(Precursor sheet of sheet material)
A precursor sheet was obtained in the same manner as in Example 1.

(Sheet)
A rotary coating method was repeated 3 times on the napped surface of the precursor sheet to form three polyurethane resin layers whose surfaces were discontinuously coated, and the resin was pressed by an embossing roll without giving an uneven pattern. A sheet-like material having a total layer thickness of 0.061 mm was obtained. On the surface of the obtained sheet-like material, the resin portion and the napped portion were arranged irregularly and discontinuously, but there was no uneven pattern and the design was poor. The results are shown in Table 1.

[Comparative Example 4]
(raw cotton)
In the same manner as in Example 1, an ultrafine fiber-expressing fiber (sea-island composite fiber) raw cotton was obtained.

(Nonwoven fabric made of sea-island type composite fiber)
In the same manner as in Example 1, a nonwoven fabric made of sea-island type composite fiber was obtained.

(Precursor sheet of sheet material)
As in Level 1, except that the napped surface was not formed using sandpaper,
A precursor sheet having a sheet thickness of 0.73 mm and an average single fiber diameter of 4.4 μm was obtained.

(Sheet)
The rotary coating method is repeated three times on one side of any of the above precursor sheets to form three layers of polyurethane resin layers whose surfaces are discontinuously coated, and then the softening point of the resin of each layer constituting the resin layer is changed. Of these, an embossing roll heated to the highest softening point temperature was pressed to give an uneven pattern, and a sheet-shaped product having a resin layer with a total thickness of 0.060 mm was obtained. The surface of the obtained sheet-like material had an uneven pattern, but only the resin portion was arranged, and the surface feel and nap feeling were poor. The results are shown in Table 1.

1: Sheet-like object 2: Fiber structure 3: Convex part 4: Resin layer 5: Raised surface α: Embossing angle R: Embossing height z ₁ : Maximum position on slope of convex part z ₂ : Minimum on slope of convex part position

Claims (6)

  At least one surface of a fiber structure containing ultrafine fibers having an average single fiber diameter of 0.1 μm or more and 10.0 μm or less has a raised surface formed by raising the ultrafine fibers, and on the raised surface, A sheet-like material, which comprises a discontinuous resin layer formed within the nap surface and further has an uneven pattern, and the resin layer is composed of two or more layers.   The sheet-like article according to claim 1, wherein the resin layer has a structure including three or more layers including an adhesive layer, an intermediate layer, and a surface layer.   The sheet material according to claim 1 or 2, wherein the total thickness of the resin layer is 0.001 mm or more and 0.400 mm or less. Abrasion resistance of the above-mentioned sheet-like material performed under the conditions of a pressing load of 12 kPa and a friction number of 50,000 according to "8.19.5 E method (Martindale method)" of JIS L1096: 2005 "Test method for woven and knitted fabrics". in the test, the embossing height before and after the abrasion test _(R 1, _{R 2)} rate of change _(R 2 / _{R 1)} is 0.40 to 0.90, to any one of claims 1 to 3 The sheet material described. Abrasion resistance of the above-mentioned sheet-like material performed under the conditions of a pressing load of 12 kPa and a friction number of 50,000 according to "8.19.5 E method (Martindale method)" of JIS L1096: 2005 "Test method for woven and knitted fabrics". In the test, the ratio (tan (α ₂ ) / tan (α ₁ )) of tangents of embossing calculated from the embossing angles (α ₁ , α ₂ ) before and after the abrasion resistance test was 0.20 or more and 1.00 or less. The sheet-like material according to any one of claims 1 to 4.   The method for producing a sheet-like article according to any one of claims 1 to 5, wherein the step of imparting an uneven pattern is a step of hot pressing the surface of the sheet.