JP2020051003A - Grained artificial leather and method for producing the same - Google Patents

Abstract

To provide a grained artificial leather, in which a tip of an ultrafine fiber has a shape of a hammer head, thereby generating an excellent peeling strength between a resin layer and a base layer due to an anchor effect thereof, and to provide a method for producing the same.SOLUTION: There is provided a grained artificial leather comprising: a base layer composed of an ultrafine fiber having an average single fiber diameter of 0.1 μm or more and 10.0 μm or less and an elastic polymer; and a resin layer formed on the base layer. The base layer has a structure in which fiber bundles comprising the ultrafine fibers are mutually entangled. A raised fiber layer having raised fibers is formed on at least one face of the base layer coming into contact with the resin layer. In the raised fibers, 90% or more of the raised fibers have hammer-head-like tip shape, and a maximum diameter of the hammer-head-like tip shape to an average single filament diameter is 150% or more and 350% or less.SELECTED DRAWING: None

Description

  The present invention relates to artificial leather with silver having high peel strength between a resin layer and a base material layer, and a method for producing the same.

  So-called artificial leather with silver, which is formed by coating or laminating a resin such as polyurethane on a fibrous base material, has characteristics such as excellent flexibility and mechanical properties that are not found in natural leather, and , Bags, belts, school bags, etc. One of the problems of the artificial leather with silver is that the resin layer and the base layer are easily peeled off with use.

  In order to overcome the above problems, various studies have been made on a base material layer made of ultrafine fibers.

  For example, in Patent Document 1, a nonwoven fabric (A) mainly composed of an elastic fiber and a nonwoven fabric (B) mainly composed of an inelastic fiber are laminated so that the nonwoven fabric (A) becomes the surface, and the surface of the nonwoven fabric (A) is formed. The artificial leather with silver in which the elastic fiber of the above is mainly melted to form a silver surface layer has been proposed. By laminating two types of nonwoven fabrics, a certain peel strength can be exhibited without using an adhesive between the silver surface layer and the base sheet.

  Patent Literature 2 proposes artificial leather with silver in which latent crimp-expressing fibers are applied to ultrafine fibers. By using crimped ultrafine fibers, high peel strength can be exhibited by the anchor effect.

JP 2005-2481A JP 2018-3181 A

  However, the technique disclosed in Patent Document 1 reports that a high peel strength is exhibited by laminating the nonwoven fabric (A) and the nonwoven fabric (B), but the entanglement of the nonwoven fabric (A) and the nonwoven fabric (B) is reported. If the strength is weak, peeling is likely to occur at the interface between the nonwoven fabrics. In addition, when the nonwoven fabric (A) and the nonwoven fabric (B) are strongly entangled, there is a problem that the formation of the grain surface layer becomes insufficient, and the smoothness becomes weak.

  On the other hand, in the technique disclosed in Patent Document 2, it is necessary to apply a side-by-side type latent crimp-expressing fiber in order to crimp an ultrafine fiber, and a technique applicable to a wider range of fibers is required.

  Accordingly, an object of the present invention is to provide a silver-coated artificial leather having excellent peel strength between a resin layer and a base material layer, and a method for producing the same, in view of the above-mentioned state of the art.

  The present inventors have tried to make the tip of the microfiber into a hammerhead shape in order to impart an anchor effect to the microfiber in contact with the resin layer. However, it has been very difficult to make the tip shape of the ultrafine fiber having a small average single fiber diameter so as to achieve the above object. Therefore, after further intensive studies to achieve the above object, it was found that under specific grinding conditions, a tip shape effective for improving the adhesion between the base material layer and the resin layer can be obtained. The knowledge that the peel strength of artificial leather can be improved was obtained. Furthermore, it has been found that this artificial leather with silver can be applied to a wider range of fibers and can be developed for various uses.

  The present invention has been completed based on these findings, and according to the present invention, the following inventions are provided.

  The present invention relates to a silver comprising a base layer composed of an ultrafine fiber having an average single fiber diameter of 0.1 μm or more and 10.0 μm or less and an elastic polymer, and a resin layer formed on the base layer. In the artificial leather, the base layer has a structure in which fiber bundles made of the ultrafine fibers are entangled with each other, and at least a surface of the base layer which is in contact with the resin layer is napped. In the above-mentioned napping layer, 90% or more of the number of the naps has a hammer head-like tip shape, and the maximum diameter of the hammer head-like tip shape is It is 150% or more and 350% or less based on the average single fiber diameter.

According to a preferred embodiment of the artificial leather with silver of the present invention, the tip shape of the hammer head is 500 pieces / mm ² or more and 2000 pieces / mm ² or less.

  According to a preferred aspect of the artificial leather with silver of the present invention, the average single fiber diameter is an ultrafine fiber having a diameter of 3.5 μm or more and 8.0 μm or less.

  According to a preferred embodiment of the artificial leather with silver of the present invention, the ultrafine fibers are made of a polyester polymer.

Further, the present invention is a method for producing the artificial leather with silver as described above, wherein a base layer composed of the ultrafine fibers and the elastic polymer is formed, and a base layer forming step; A nap layer forming step of forming a nap layer by performing a dry buffing process; and a resin layer forming step of forming a resin layer on the surface of the nap layer. A nonwoven fabric forming step of forming a nonwoven fabric composed of the ultrafine fiber-expressing fibers; (2) an ultrafine fiber expressing step of expressing the ultrafine fibers from the ultrafine fiber-expressing fibers constituting the nonwoven fabric; and (3) elasticity of the nonwoven fabric. Applying an elastic body polymer, including an elastic polymer applying step, wherein in the napped layer forming step, the dry buffing process rotates a buff polishing means in a direction opposite to a traveling direction of the nonwoven fabric sheet, and a grinding load is reduced. 1000W / m or more 000W / m or less, and grinding amount is within a range of from 10 g / ^{m 2} or more 200 g / ^{m 2} or less.

  According to a preferred embodiment of the method for producing artificial leather with silver of the present invention, in the method for producing artificial leather with silver, the base layer forming step is (1) a nonwoven fabric forming step, (2) an ultrafine fiber expressing step, 3) It is performed in the order of the elastic polymer application step.

  ADVANTAGE OF THE INVENTION According to this invention, the artificial leather with silver excellent in peel strength between a base material layer and a resin layer can be obtained, without using a specific fiber or a resin layer. In particular, the silver-coated artificial leather of the present invention has a very elegant appearance as a skin material for seats, ceilings and interiors in vehicle interiors such as furniture, chairs and wall materials, automobiles, trains and aircrafts from the above-described features. Suitable for use as interior materials, shirts, jackets, casual shoes, sports shoes, uppers for shoes such as men's shoes and women's shoes, trims, bags, belts, wallets, etc., and clothing materials used for some of them Can be.

  The artificial leather with silver of the present invention has a base layer composed of an ultrafine fiber having an average single fiber diameter of 0.1 μm or more and 10.0 μm or less and an elastic polymer, and a resin layer formed on the base layer. Wherein the base layer has a structure in which the fiber bundles of the ultrafine fibers are entangled with each other, and is in contact with at least the resin layer of the base layer. The surface is formed with a nap layer having a nap. In the nap layer, 90% or more of the naps have a hammer head-like tip shape, and the hammer head-like tip shape. Is 150% or more and 350% or less with respect to the average single fiber diameter. Hereinafter, these will be described in detail according to the manufacturing method.

[Base layer forming step]
In the method for producing artificial leather with silver according to the present invention, first, a base layer forming step of forming a base layer composed of ultrafine fibers and an elastic polymer is performed. The substrate layer forming step includes: (1) forming a nonwoven fabric made of ultrafine fiber-expressing fibers; and forming a nonwoven fabric; and (2) expressing ultrafine fibers from the ultrafine fiber-forming fibers constituting the nonwoven fabric. A developing step, and (3) an elastic polymer applying step of applying an elastic polymer to the nonwoven fabric. The details will be described below.

(1) Nonwoven Fabric Forming Step First, ultrafine fiber-expressing fibers are spun to obtain the ultrafine fibers constituting the nonwoven fabric. Ultrafine fiber-expressing fibers generally include sea-island composite fibers, exfoliated splittable fibers, and the like. When sea-island composite fibers are used, thermoplastic polymer components having different solubilities in solvents and the like are converted into sea components and island components, and in a later step, the sea components are dissolved and removed with a solvent to make the island components ultrafine fibers. be able to. In the case of using split-split fibers, ultrafine fibers can be formed by splitting by splitting with a physical force such as a water jet or swelling of a solvent. Among them, when the sea-island type composite fiber is used, the diameter of the ultrafine fiber can be controlled uniformly, and the surface appearance of the artificial leather with silver can be made elegant. In addition, the sea-island type conjugate fiber can provide an appropriate space between the island components, that is, between the microfibers inside the fiber bundle by removing the sea component. Small ultrafine fibers can be efficiently expressed. From these viewpoints, it is important to use sea-island composite fibers as the ultrafine fiber-expressing fibers.

  For the production of sea-island composite fibers, a sea-island-type composite mouthpiece is used, and a polymer mutual array method in which two components, a sea component and an island component, are arranged and spun, or a mixture of two components, a sea component and an island component And a mixed spinning method of spinning. Of these, sea-island composite fibers of a polymer array type are preferable in that ultrafine fibers having a uniform fineness can be obtained.

  Examples of the island component of the sea-island composite fiber include polyesters such as polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate and polylactic acid, polyamides such as polyamide 6 and polyamide 66, acrylics, polyethylene, polypropylene, and thermoplastics. A melt-spinnable thermoplastic resin such as cellulose is exemplified. Among them, from the viewpoints of strength, dimensional stability, light fastness and dyeability, polyester fibers made of a polyester polymer such as polyethylene terephthalate, polybutylene terephthalate, and polytrimethylene terephthalate are preferably used. In addition, at least two or more kinds selected from these polymers may be combined. Further, from the viewpoint of environmental consideration, fibers obtained from recycled materials or plant-derived materials may be used. Further, the ultrafine fibers can be formed by mixing fibers of different materials. Further, the polymer constituting the ultrafine fibers may be copolymerized with other components, and may contain additives such as organic particles, inorganic particles, a flame retardant, and an antistatic agent.

  Here, the polyester-based polymer referred to in the present invention has a main component having a structure obtained by copolymerizing a dicarboxylic acid or a derivative thereof and a diol or a derivative thereof. Means more than 50% by weight based on the weight of The polyester-based polymer may include a copolymer component capable of forming another ester bond. Examples of the copolymerizable compound include diphthalic acids such as isophthalic acid, succinic acid, cyclohexanedicarboxylic acid, adipic acid, dimeric acid, sebacic acid and 5-isophthalic acid, ethylene glycol, butanediol, neopentyl glycol, and cyclohexanediene. Examples include diols such as methanol, polyethylene glycol and polypropylene glycol. If necessary, titanium dioxide as a matting agent, silica or alumina fine particles as a lubricant, a hindered phenol derivative as an antioxidant, and a coloring pigment may be added.

  The polyethylene terephthalate-based polymer referred to in the present invention has a main component of a structure obtained by copolymerizing terephthalic acid or a derivative thereof and ethylene glycol or a derivative thereof.

  Examples of the sea component of the sea-island composite fiber include polyethylene, polypropylene, polystyrene, copolymerized polyester obtained by copolymerizing sodium sulfoisophthalate, polyethylene glycol, and the like, polylactic acid, and polyvinyl alcohol.

  The mass ratio between the sea component and the island component is preferably in the range of sea component: island component = 5: 95 to 80:20. When the mass ratio of the sea component is 5% by mass or more (the mass ratio of the island component is 95% by mass or less), more preferably 10% by mass or more (the mass ratio of the island component is 90% by mass or less), Conversion can be performed sufficiently. On the other hand, when the mass ratio of the sea component is 80% by mass or less (the mass ratio of the island component is 20% by mass or more), more preferably 60% by mass or less (the mass ratio of the island component is 40% by mass or more), If the amount is not too large, it is possible to process with good productivity.

  The number of microfibers in the microfiber bundle generated by expressing microfibers from one sea-island type conjugate fiber is preferably 10 or more and 900 or less. When the number of the ultrafine fibers is 10 or more per bundle, the fineness of the ultrafine fibers is improved, and for example, mechanical properties such as abrasion tend to be improved. On the other hand, when the number is 900 or less, more preferably 400 or less, the spreadability at the time of raising is improved, and the fiber distribution on the raised surface can be made uniform.

  From the viewpoint of the density of the ultrafine fibers, the degree of fiber density in the ultrafine fiber bundle is preferably 30 (lines · μm) or more, and more preferably 50 (lines / μm) or more. On the other hand, the density of the fibers in the ultrafine fiber bundle is preferably 1000 (lines / μm) or less, and more preferably 700 (lines / μm) or less. The degree of fiber denseness is calculated by (number of fibers in ultrafine fiber bundle) × (diameter of single fiber), and serves as an index of the size of the bundle of ultrafine fibers. As described above, by setting the degree of fiber denseness in the ultrafine fiber bundle to 30 (lines · μm) or more and 1000 (lines · μm) or less, the processing operability when forming a fiber entangled body is good, and the density of the ultrafine fiber bundle is high. Becomes better.

  Next, the drawn ultrafine fiber-expressing fiber is preferably subjected to a crimping process and cut to a predetermined length to obtain a raw nonwoven fabric. An ordinary method can be used for crimping and cutting.

  The thus obtained raw nonwoven fabric is carded, passed through a thin sheet of cotton, and then laminated with a cross wrapper to obtain a laminated fiber web.

  The nonwoven fabric constituting the substrate layer of the artificial leather with silver of the present invention may be either a short fiber nonwoven fabric or a long fiber nonwoven fabric, but a short fiber nonwoven fabric is preferably used in terms of texture and quality.

  The fiber length of the short fibers in the short-fiber nonwoven fabric is preferably 25 mm or more and 90 mm or less. When the fiber length is at least 25 mm, more preferably at least 30 mm, a base layer of artificial leather with silver having excellent abrasion resistance due to entanglement can be obtained. Further, by setting the fiber length to 90 mm or less, more preferably 80 mm or less, it is possible to obtain a base layer of artificial leather with silver having excellent compression characteristics and surface quality of the artificial leather base layer.

  The short-fiber nonwoven fabric used in the artificial leather with silver of the present invention is obtained by forming a laminated web of short fibers using a card and a cross wrapper, and then performing a needle punch or a water jet punch, or a papermaking method. As a material to be obtained or a long-fiber nonwoven fabric, a material obtained from a spun bond method, a melt blow method, or the like can be appropriately adopted.

  Thereafter, in order to obtain a fiber entangled body, a method of entanglement of the laminated fiber web with a needle punch or a water jet punch, a spun bond method, a melt blow method, a paper making method, or the like can be adopted. Above all, in order to form the ultrafine fiber bundle as described above, a method in which a laminated fiber web made of ultrafine fiber-expressing fibers is entangled with a needle punch or a water jet punch is preferably used.

The apparent density of the fiber entangled body composed of the ultrafine fiber-generating fibers after the needle punching treatment or the water jet punching treatment is preferably 0.15 g / cm ³ or more and 0.40 g / cm ³ or less. When the apparent density is 0.15 g / cm ³ or more, a fiber entangled body having excellent morphological stability and dimensional stability can be obtained. On the other hand, by setting the apparent density to 0.40 g / cm ³ or less, more preferably 0.30 g / cm ³ or less, a sufficient space for providing the elastic polymer can be maintained between the fibers.

  From the viewpoint of densification, the fiber entangled body composed of the ultrafine fiber-expressing fibers thus obtained is preferably subjected to heat shrinkage treatment with dry heat or wet heat, or both, to further increase the density. It is. Further, the fiber entangled body can be compressed in the thickness direction by calendering or the like.

(2) Ultrafine fiber development step In the present invention, as a means for obtaining ultrafine fibers constituting the artificial leather with silver, it is a preferable embodiment to use ultrafine fiber-generating fibers. After the ultrafine fiber-generating fibers are entangled in advance to form a nonwoven fabric, the fibers are ultrafine, whereby a nonwoven fabric in which the ultrafine fibers are entangled can be obtained.

  The treatment for deriving the ultrafine fibers from the sea-island composite fibers which are the ultrafine fiber-expressing fibers (desealing treatment) can be performed by immersing the sea-island composite fibers in a solvent and squeezing the solution. As the solvent for dissolving the sea component, when the sea component is polyethylene, polypropylene or polystyrene, an organic solvent such as toluene or trichloroethylene can be used. When the sea component is a copolymerized polyester or polylactic acid, an alkaline aqueous solution such as sodium hydroxide or hot water can be used. For the treatment for expressing the ultrafine fibers, devices such as a continuous dyeing machine, a vibro washer type desealer, a liquid jet dyeing machine, a Wins dyeing machine and a Jigger dyeing machine can be used.

  The sea removal treatment for removing the sea component of the sea-island composite fiber can be performed before and / or after the application of the elastic polymer to the fiber entangled body composed of the ultrafine fibers. If the desealing treatment is performed before the elastic polymer is applied, the structure is such that the elastic polymer directly adheres to the ultrafine fibers, and the ultrafine fibers can be strongly gripped.

  In the present invention, it is important that the average single fiber diameter of the ultrafine fibers expressed from the ultrafine fiber-expressing fibers is 0.1 μm or more and 10 μm or less from the viewpoint of the flexibility of the artificial leather with silver and the quality of the nap. The average single fiber diameter is preferably 9 μm or less, more preferably 8 μm or less, since a smaller average fiber diameter has better surface quality and glossiness. On the other hand, it is preferably at least 0.5 μm, more preferably at least 3.5 μm, from the viewpoint of the coloring properties after dyeing, the dispersibility of the fibers during the raising treatment such as grinding with sandpaper or the like, and the ease of handling.

  The average single fiber diameter of the ultrafine fibers was determined by taking a scanning electron microscope (SEM) photograph of a cross section cut in the thickness direction of the artificial leather with silver, and randomly selecting 100 circular or nearly circular elliptical fibers. , The fiber diameter is measured, and the arithmetic average is calculated.

(3) Elastic Polymer Application Step Further, an elastic polymer can be contained in the fiber entangled body or in the fiber entangled body laminated and integrated with the reinforcing layer.

  When the base layer of the artificial leather with silver of the present invention contains 5% by mass or more, more preferably 15% by mass or more of the porous elastic polymer with respect to the mass of the ultrafine fibers of the fiber entangled body, It is possible to impart appropriate compression characteristics to the base material layer of the leather. On the other hand, the base layer of the artificial leather with silver of the present invention contains up to 60% by mass, more preferably up to 55% by mass, of the porous elastic polymer based on the mass of the ultrafine fibers of the fiber entangled body, so that the nap is raised. The fiber opening property in the process can be improved. Further, when the artificial leather with silver is dyed and used, there is no difference in the color tone between the fiber of the fiber entangled body after dyeing and the elastic polymer, and the surface quality is excellent. Furthermore, when fibers obtained from recycled materials or plant-derived materials are used, recycling, collection and disposal are facilitated.

  The above-mentioned elastic polymer includes pigments such as carbon black, dyes, fungicides and antioxidants, ultraviolet absorbers, light stabilizers such as light stabilizers, flame retardants, penetrants and lubricants, silica if necessary. Agents such as water and titanium oxide, water repellents, viscosity modifiers, surfactants such as antistatic agents, defoamers such as silicone, fillers such as cellulose, and coagulation regulators, and silica and titanium oxide. Inorganic particles and the like can be contained.

  Examples of the elastic polymer used in the present invention include polyurethane elastomer, polyurea, polyacrylic acid, ethylene / vinyl acetate elastomer and acrylonitrile / butadiene elastomer and styrene / butadiene elastomer, polyvinyl alcohol, and polyethylene glycol. From the viewpoint of compression characteristics, a polyurethane elastomer is preferably used. A plurality of polymer elastic bodies can be contained in the polymer elastic body.

  Examples of the polyurethane elastomer particularly preferably used in the present invention include polyurethane and polyurethane / polyurea elastomers.

  As the polyurethane-based elastomer used in the present invention, a solvent-based and / or water-dispersed polyurethane-based elastomer can be used.

  As the polyurethane elastomer used in the present invention, a polyurethane elastomer obtained by reacting a polymer diol, an organic diisocyanate, and a chain extender is preferably used.

  As the polymer diol, for example, a polycarbonate diol, a polyester diol, a polyether diol, a silicone diol, and a fluorine diol can be employed, and a copolymer obtained by combining these can also be used. Among them, from the viewpoint of hydrolysis resistance, it is a preferred embodiment to use a polycarbonate diol and / or a polyether diol.

  The above polycarbonate diol can be produced by a transesterification reaction between an alkylene glycol and a carbonic acid ester, or a reaction between 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 glycols and branched alkylene glycols such as neopentyl glycol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol and 2-methyl-1,8-octanediol And alicyclic diols such as 1,4-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 alkylene glycols can be employed.

  Examples of the polyester diol include polyester diols obtained by condensing various low molecular weight polyols with polybasic acids.

  Examples of the low molecular weight polyol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, and 2,2-dimethyl-1,3-propane. Diols, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,4-diol, and One or more selected from cyclohexane-1,4-dimethanol can be used.

  Further, adducts obtained by adding various alkylene oxides to bisphenol A can also be used.

  Examples of polybasic acids include, for example, succinic acid, maleic acid, adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, and hexahydroacid One or more kinds selected from isophthalic acid can be mentioned.

  Examples of the polyether diol used in the present invention include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and a copolymerized diol obtained by combining them.

  The number average molecular weight of the polymer diol is preferably in the range of 500 or more and 4000 or less when the molecular weight of the polyurethane elastomer is constant. By setting the number average molecular weight to preferably 500 or more, more preferably 1500 or more, the base layer of the artificial leather with silver can be prevented from becoming hard. Further, by setting the number average molecular weight to 4000 or less, more preferably 3000 or less, the strength as a polyurethane elastomer can be maintained.

  Examples of the organic diisocyanate used in the present invention include aliphatic diisocyanates such as hexamethylene diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and xylylene diisocyanate, and aromatic diisocyanates such as diphenylmethane diisocyanate and tolylene diisocyanate. And they can be used in combination.

  As the chain extender, preferably, an amine chain extender such as ethylenediamine or methylenebisaniline, and a diol chain extender such as ethylene glycol can be used. Further, a polyamine obtained by reacting a polyisocyanate with water can be used as a chain extender.

  The polyurethane used in the present invention may be used in combination with a crosslinking agent for the purpose of improving water resistance, abrasion resistance, hydrolysis resistance and the like. The cross-linking agent may be an external cross-linking agent added as a third component to the polyurethane-based elastomer, or an internal cross-linking agent that previously introduces a reaction point to be a cross-linked structure into the polyurethane molecular structure can also be used. It is preferable to use an internal cross-linking agent from the viewpoint that a cross-linking point can be formed more uniformly in the polyurethane molecular structure and a decrease in flexibility can be reduced.

  As the crosslinking agent, a compound having an isocyanate group, an oxazoline group, a carbodiimide group, an epoxy group, a melamine resin, a silanol group, or the like can be used.

[Napped layer forming step]
In the method for producing artificial leather with silver according to the present invention, a nap layer forming step is performed, in which the base layer obtained in the above step is subjected to dry buffing to form a nap layer. The details will be described below.

  The raising treatment for forming the nap of the ultrafine fibers on the surface of the substrate layer of the artificial leather with silver of the present invention can be performed by dry buffing using a buffing means such as sandpaper or a roll sander. Before the raising treatment, a lubricant such as a silicone emulsion may be applied to the surface of the base material layer.

  In the dry buffing used in the present invention, multi-stage buffing in which dry buffing is performed a plurality of times is preferably used because a uniform nap layer can be formed.

It is important that the base layer of the artificial leather with silver of the present invention has nap on at least one surface of the base layer. A buff polishing means such as a sandpaper or a roll sander is rotated in the direction opposite to the traveling direction of the sheet, and the grinding load is in the range of 1000 W / m or more and 4000 W / m or less, and the grinding amount is 10 g / m ² or more and 200 g / m ² or less. Buffing grinding is preferably performed within the range. By setting the grinding load to be 1000 W / m or more, more preferably 1400 W / m or more, the tip of the ultrafine fiber can be made into a hammerhead shape by the raising treatment. On the other hand, by setting the grinding load to 4000 W / m or less, more preferably 3800 W / m or less, breakage of the sheet due to overload can be prevented. By setting the amount of grinding to 10 g / m ² or more, more preferably 20 g / m ² or more, the napped layer can be formed sufficiently without exposing the base material layer on the surface. On the other hand, by setting the amount of grinding to 200 g / m ² or less, more preferably 180 g / m ² or more, it is possible to prevent fiber waste during grinding from adhering to the sheet.

In the present invention, the grinding load is the work (W ₂ ) required for dry buffing, and is obtained as follows.
(1) Electric power applied to rotation of the sandpaper when not in contact with the sheet: Work (W ₀ ) is measured.
(2) The electric power (W ₁ ) when the dry buffing is performed through the sheet is measured.
(3) Calculate the difference W ₂ = W ₁ −W ₀ before and after.
Here, in the case of multi-stage buffing, since the stage with the highest grinding load affects fiber fusion and the like, the value of the stage with the largest grinding load is set as the maximum grinding load.

  In the base layer of the artificial leather with silver of the present invention, it is preferable that the tip of the ultrafine fiber has a hammerhead shape. When the ultrafine fibers have a hammerhead-like tip shape, the anchoring effect can make the peel strength between the resin layer and the base material layer excellent. The napped layer in the present invention refers to a layer formed by napped ultrafine fibers in the base material layer.

  It is preferable that 90% or more of the total number of raised hairs is made of the raised hair having the hammer head shaped tip shape. Since the anchor effect becomes stronger when the ratio of the tip shape of the hammer head is large, it is preferably at least 91%, more preferably at least 93%.

  In the present invention, the ratio of the tip shape of the hammer head is defined as the hammer in any 10 squares (200 μm on each side) observed with the SEM using the raised side of the artificial leather with silver as an observation surface. The ratio of the head-shaped tip shape was calculated, and the average value of the whole was calculated. At this time, the tip shape of the hammer head is 150% or more with respect to the average single fiber diameter, the tip shape of the hammer head, and the number of the tips of the microfibers existing in the square as the denominator. Calculated.

  When the size of the tip shape of the hammer head is 150% or more, more preferably 160%, based on the average single fiber diameter, the adhesion between the base material layer and the resin layer can be improved by the anchor effect. . On the other hand, when the size of the tip shape of the hammer head is 350% or less, more preferably 340% or less with respect to the average single fiber, the tips of the ultrafine fibers do not come into contact with each other and maintain an appropriate distance. be able to.

  In the present invention, the size of the tip shape of the hammer head is defined as the observation surface with the raised side of the artificial leather with silver as the observation surface, and the size of the tip shape at any 50 positions is measured by observing with the SEM. , An arithmetic average value.

When the number of the hammer head-shaped tips is 500 / mm ² or more, more preferably 700 / mm ² or more, the adhesion between the base material layer and the resin layer can be improved by the anchor effect. On the other hand, the number of the hammerhead-like tip shape, 2000 / mm ² or less, more preferably it is 1800 / mm ² or less, does not impair the excellent surface quality of the substrate layer.

  In the present invention, the number of hammer-head-shaped tips refers to the number of squares (200 μm on each side) at any 10 places observed with the SEM using the raised side of the artificial leather with silver as an observation surface. And the value obtained by calculating the arithmetic average value.

  The shape of the hammer head at the tip is mostly spherical, but a polygonal shape represented by a trapezoidal shape is also a projection. For a polygonal projection, a portion having the maximum diameter (width) is measured as the size of the projection.

  The tip portion of the ultrafine fiber refers to a portion existing within 50 μm from the tip of the ultrafine fiber. It is assumed that the projections present on the inner side (the base material layer side) of 50 μm from the tip of the ultrafine fiber are not counted as the projections at the tip end as nodes or foreign substances.

  When observing the hammer head-like tip shape of the microfiber, the method of removing the resin layer described below may be any method that does not damage the hammer head-like tip shape at the time of removal, and the resin layer is extracted. Observation is preferable from the viewpoint of workability. In particular, as a method of extraction, an amide-based solvent such as DMF (N, N-dimethylformamide) or the like can be used because only the resin layer is dissolved, and the hammer head-shaped tip shape can be maintained without being dissolved by the solvent. A method of dissolving the resin layer using a sulfoxide-based solvent such as DMSO (dimethyl sulfoxide) and the like or a mixture of two or more thereof is more preferably used.

  In the artificial leather with silver of the present invention, a reinforcing layer can be included in the inner layer portion or the surface thereof for the purpose of improving the strength and the like. As the reinforcing layer, a woven fabric, a knitted fabric, a nonwoven fabric (including paper), a film-like material such as a plastic film or a metal thin film sheet, or the like can be employed. In the case of a woven or knitted fabric in which the reinforcing layer is composed of fibers, the average single fiber diameter of the fibers is preferably about 0.1 μm or more and about 20 μm or less from the viewpoint of the texture of artificial leather with silver.

  Examples of the types of fiber yarns constituting the woven or knitted fabric used in the present invention include filament yarns, spun yarns, innovative spun yarns, and mixed composite yarns of filament yarns and spun yarns. It is preferable to use a filament yarn because the surface is less exposed due to the fluff falling off. Further, filament yarns are roughly classified into monofilaments composed of one single fiber and multifilaments composed of a plurality of filaments, but the woven or knitted fabric used in the present invention does not impair the soft feel of the nonwoven fabric. Therefore, it is preferable to use a multifilament.

  The total fineness of the fiber yarns constituting the woven or knitted fabric is preferably 50 dtex or more and 150 dtex or less for reasons such as rigidity and basis weight.

By setting the basis weight of the woven or knitted fabric to 20 g / m ² or more, more preferably 30 g / m ² or more, when the woven or knitted fabric is inserted between the nonwoven fabric and the nonwoven fabric, or when the woven or knitted fabric is superimposed on the surface of the nonwoven fabric, wrinkles are formed. The layers can be evenly stacked without generation of any. On the other hand, by setting the basis weight of the woven or knitted fabric to 200 g / m ² or more, more preferably 150 g / m ² or more, the nonwoven fabric and the woven or knitted fabric can be easily entangled. The weight per unit area in the present invention refers to "8.3.2 Mass per unit area" in "8.3 Mass per unit area" in JIS L1096: 2010 "Test method for fabrics and knits" a) A method (JIS method) ”, two specimens of 200 mm x 200 mm were sampled per 1 m width of the sample, each mass (g) in a standard state was weighed, and the arithmetic average value was converted to one decimal place. In summary, it refers to a value represented by mass per 1 m ² (g / m ² ).

  As the basic structure of the woven fabric used in the present invention, twill or satin may be used, but a flat structure in which misalignment is unlikely to occur is preferably used.

When the apparent density of the sheet material of the present invention is 0.10 g / cm ³ or more, more preferably 0.20 g / cm ³ or more, the sheet material has good denseness and mechanical properties. On the other hand, the apparent density, 0.80 g / cm ³ or more, more preferably by a 0.70 g / cm ³ or more, it is possible to avoid the hardening of the texture.

[Resin layer forming step]
In the method for producing artificial leather with silver according to the present invention, a resin layer forming step of forming a resin layer on the surface of the napped layer is further performed. The details will be described below.

  According to the present invention, artificial leather with silver is formed by forming a resin layer such as an elastic polymer on at least one or both surfaces of the napped layer.

  Examples of a method for forming a coating layer or an undercoat layer for producing artificial leather with silver include a dry surface method and a direct coating method, and various conventionally known methods can be employed. For example, a method using an apparatus such as a reverse roll coater, a spray coater, a roll coater, a gravure coater, a kiss roll coater, a knife coater, and a comma coater can be used. The thickness of each layer can be set appropriately according to the application. The thickness is 10 μm or more, more preferably 50 μm or more, in order to prevent exposure of the base material layer. On the other hand, from the viewpoint of reducing the weight of the artificial leather with silver, the thickness is 1000 μm or less, more preferably 800 μm or less.

  Examples of the resin forming the resin layer include polyurethane, acrylic-based elastic, silicone-based elastic, diene-based elastic, nitrile-based elastic, fluorine-based elastic, polystyrene-based elastic, polyolefin-based elastic, and polyamide-based. Examples include resin liquids such as emulsions, suspensions, dispersions, and solutions of elastomers such as elastic bodies. These resins may be used alone or in combination of two or more. Among these resins, polyurethane is preferably used because of its excellent wear resistance and mechanical properties. The resin component may contain a colorant, an ultraviolet absorber, a surfactant, a flame retardant, an antioxidant, and the like, if necessary.

  The resin layer may be either a foam layer made of an elastic polymer or a dry layer, or a combination of both.

  The thickness of the artificial leather with silver is preferably 0.1 mm or more and 7 mm or less. When the thickness is 0.1 mm or more, preferably 0.3 mm or more, the artificial leather with silver has excellent shape stability and dimensional stability. On the other hand, by setting the thickness to 7 mm or less, more preferably 5 mm or less, the formability of the artificial leather with silver is excellent.

  The artificial leather with silver of the present invention contains, for example, a functional agent such as a dye, a pigment, a softener, a texture adjuster, an anti-pilling agent, an antibacterial agent, a deodorant, a water repellent, a lightfast agent, and a weathering agent. Can be done.

  Next, the present invention will be described more specifically with reference to examples. In addition, in the measurement of each physical property, those not particularly described are those measured based on the above-described method. However, the present invention is not limited to only these examples.

  Next, the evaluation method used in the examples and the measurement conditions will be described.

(1) Intrinsic viscosity of polymer (IV)
0.8 g of a sample polymer is dissolved in 10 mL of orthochlorophenol (hereinafter, abbreviated as OCP), and the relative viscosity η _r is determined by the following equation using an Ostwald viscometer at a temperature of 25 ° C., and the intrinsic viscosity ( IV) was calculated.
Η _r = η / η ₀ = (t × d) / (t ₀ × d ₀ )
-Intrinsic viscosity (IV) = 0.0242 η _r + 0.2634
(Where η is the viscosity of the polymer solution, η ₀ is the viscosity of the OCP, t is the fall time of the solution (seconds), d is the density of the solution (g / cm ³ ), and t ₀ is the fall time of the OCP (seconds) , _{d 0} is the density of OCP a (g / cm ^3), representing respectively.).

(2) Polymer melt flow rate (MFR)
ISO 1133: 2005 "Plastics-Determination of the melt mass-flow rate (MFR) and the melt volume-flow rate (MVR)" (G) was measured. The same measurement was repeated three times, and the arithmetic average value was defined as MFR (g / 10 minutes).

(3) Average single fiber diameter “VW-9000” manufactured by Keyence Corporation was used as a scanning electron microscope.

(4) Thickness of the sheet-like material Five points were measured at equal intervals in the sheet width direction under a load of 10 kPa using a thickness gauge (disc diameter of 9 mm or more) with a scale of 0.01 mm, and the average value was obtained.

(5) Peeling strength The peeling strength between the base material layer and the resin layer of the artificial leather with silver is defined in JIS K 6854-2: 1999 "Adhesive-Peeling adhesive strength test method-Part 2: 180 degree peeling". The measurement was carried out according to the measurement method described above.

  A crepe rubber plate made of polyurethane (length 150 mm, width 27 mm, thickness 5 mm) was used as a rigid adherend, and three pieces were cut out in a longitudinal direction and a lateral direction, respectively, as a flexible adherend. Artificial leather with silver having a length of 250 mm and a width of 25 mm was used. A test piece was prepared by bonding the artificial leather with silver and the rubber plate using a polyurethane two-liquid adhesive so that the adhesive force was sufficiently exhibited. The stress required when the test piece was peeled off at a speed of 50 mm / min and the peel length were measured to determine a stress-peel length curve. The average peel strength was determined from the obtained curve. The average peel strength of three pieces obtained in each of the vertical direction and the horizontal direction was calculated by averaging.

  In the present invention, a good level (target value) is a peel strength of 100 N / cm or more.

[Example 1]
(raw cotton)
Polyethylene terephthalate (PET) having an intrinsic viscosity (IV) of 0.718 as an island component, and a polystyrene (Vicat softening point of 100 ° C. and an MFR of 120 g / 10 minutes, measured according to JIS K7206 (1999) as a sea component) PSt) was drawn using a sea-island type compounding die having 24 islands at an island / sea mass ratio of 80/20, and the fiber was drawn by a roller plate method under ordinary conditions and crimped. Was cut into a length of 51 mm to obtain raw cotton of sea-island composite fibers having an average single fiber diameter of 26 μm.

(Nonwoven fabric made of ultrafine fibers)
Using the raw cotton of the sea-island type composite fiber, a laminated fiber web is formed through a card and a cross-wrapper process, and is needle-punched at a punch number of 600 / cm ² and then needle-punched at a punch number of 3000 / cm ^2. To obtain a substrate layer.

(Base material layer)
After shrinking the nonwoven fabric with hot water at a temperature of 98 ° C., the nonwoven fabric is impregnated with a 12% aqueous solution of PVA (polyvinyl alcohol), and dried with hot air at a temperature of 120 ° C. for 10 minutes to obtain a nonwoven fabric. A nonwoven fabric having a PVA mass of 30% by mass based on the mass was obtained. The nonwoven fabric thus obtained was immersed in trichlorethylene to dissolve and remove the sea component, thereby obtaining a nonwoven fabric (desealed sheet) made of ultrafine fibers. The nonwoven fabric (desealed sheet) made of the ultrafine fibers thus obtained is immersed in a DMF (N, N-dimethylformamide) solution of a polycarbonate polyurethane having a solid content adjusted to 12%, and then a DMF concentration of 30. % Of the polyurethane was coagulated in an aqueous solution. Thereafter, PVA and DMF were removed with hot water, and dried with hot air at a temperature of 110 ° C. for 10 minutes to obtain a base material layer having a polyurethane content of 27% by mass relative to the mass of the ultrafine fibers composed of island components. .

Thereafter, the base material layer was cut in half in the thickness direction, and the cut surfaces were all ground from the same direction using a 120-mesh sandpaper, and the cut surfaces were ground at 120 g / m ² to form a raised surface. At this time, the maximum grinding amount was 3500 W / m.

The base material layer thus obtained was dyed using a jet dyeing machine at a temperature of 110 ° C. and dried using a drier to obtain a base material for artificial leather with silver. The obtained artificial leather base material with silver had a sheet thickness of 1.0 mm and an average single fiber diameter of 4.5 μm. On the other hand, by SEM observation (× 1000) of the surface, the size of the tip shape of the hammer head is 10 μm, which is 220% of the average single fiber diameter, and the number of tip shapes is 1000 / mm ^2. And the ratio of the tip shape was 100%. Table 1 shows the results.

(Artificial leather with silver)
Polyether-based polyurethane is coated with a knife coater to a coating weight of 110 g / m ² on the surface of the above-mentioned artificial leather base material with silver, which has been subjected to the napped treatment, and is coated in an aqueous solution having a DMF concentration of 30%. Coagulated. Thereafter, a top layer (100 g / m ² ) made of polyether / polycarbonate-based polyurethane formed on release paper was adhered to the outermost layer with an adhesive to obtain artificial leather with silver.

  In the obtained artificial leather with silver, it was confirmed by SEM observation (500 times) of the cross section that the polyurethane was porous. The measured peel strength was 134 N / cm. Table 1 shows the results.

[Example 2]
(raw cotton)
Raw cotton of sea-island type composite fiber was obtained in the same manner as in Example 1 except that the island / sea mass ratio was changed to 85/15.

(Nonwoven fabric made of ultrafine fiber-expressing fiber)
In the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber-expressing fibers was obtained.

(Base material layer)
A substrate layer was obtained in the same manner as in Example 1 except that the grinding conditions were changed. The grinding conditions were such that the half-cut surfaces were all from the same direction using a 120-mesh sandpaper, the grinding amount of the half-cut surfaces was 115 g / m ² , and the maximum grinding amount was 2400 W / m.

The resulting sheet had a thickness of 0.8 mm and an average single fiber diameter of 5.8 μm. On the other hand, by SEM observation (× 1000) of the surface, the size of the tip of the hammer head is 16 μm, which is 270% of the average single fiber diameter, and the number of tips is 1100 / mm ^2. And the ratio of the tip shape was 100%. Table 1 shows the results.

(Artificial leather with silver)
In the same manner as in Example 1, an artificial leather with silver was obtained.

  The peel strength of the obtained artificial leather with silver was 141 N / cm. Table 1 shows the results.

[Example 3]
(raw cotton)
Raw cotton of sea-island type composite fiber was obtained in the same manner as in Example 1 except that the island / sea mass ratio was 55/45.

(Nonwoven fabric made of ultrafine fiber-expressing fiber)
In the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber-expressing fibers was obtained.

(Base material layer)
A substrate layer was obtained in the same manner as in Example 1 except that the grinding conditions were changed. Grinding conditions were such that the half-cut surfaces were all from the same direction using a 180-mesh sandpaper, and the grinding amount of the half-cut surface was 91 g / m ² , and the maximum grinding amount was 2700 W / m.

The obtained sheet had a thickness of 0.9 mm and an average single fiber diameter of 3.0 μm. On the other hand, by SEM observation (× 1000) of the surface, the size of the tip shape of the hammer head is 8.5 μm, which is 290% of the average single fiber diameter, and the number of tip shapes is 800 / a mm ^2, the ratio of the end form was 99%. Table 1 shows the results.

(Artificial leather with silver)
In the same manner as in Example 1, an artificial leather with silver was obtained.
The peel strength of the obtained artificial leather with silver was 130 N / cm. Table 1 shows the results.

[Example 4]
(raw cotton)
Nylon 6 having an MFR of 58.3 g / 10 min was used as an island component, and polystyrene (Co-PSt) obtained by copolymerizing 22 mol% of 2-ethylhexyl acrylate having a MFR of 300 g / 10 min as a sea component was used. Using a sea-island type composite die with 36 islands, melt-spun at an island / sea mass ratio of 30/70, stretched and crimped, then cut to 51 mm, and a single fiber fineness of 24 μm A raw cotton fiber was obtained.

(Nonwoven fabric made of ultrafine fibers)
In the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber-expressing fibers was obtained.

(Base material layer)
After shrinking the nonwoven fabric with hot water at a temperature of 98 ° C., the nonwoven fabric is impregnated with a 12% aqueous solution of PVA (polyvinyl alcohol), and dried with hot air at a temperature of 120 ° C. for 10 minutes to obtain a nonwoven fabric. A nonwoven fabric having a PVA mass of 30% by mass based on the mass was obtained. The nonwoven fabric thus obtained was immersed in trichlorethylene to dissolve and remove the sea component, thereby obtaining a nonwoven fabric (desealed sheet) made of ultrafine fibers. The nonwoven fabric (desealed sheet) made of the ultrafine fibers thus obtained is immersed in a DMF (N, N-dimethylformamide) solution of a polycarbonate polyurethane having a solid content adjusted to 12%, and then a DMF concentration of 30. % Of the polyurethane was coagulated in an aqueous solution. Thereafter, PVA and DMF were removed with hot water and dried with hot air at a temperature of 110 ° C. for 10 minutes to obtain a base material layer having a polyurethane content of 30% by mass based on the mass of the ultrafine fibers composed of island components. .

Thereafter, the base material layer was cut in half in the thickness direction, and the product surface was ground at 48 g / m ² using sandpaper of 180 mesh from the same direction in all directions to form a napped surface. At this time, the maximum grinding amount was 1400 W / m.

The resulting sheet had a thickness of 0.7 mm and an average single fiber diameter of 0.7 μm. On the other hand, according to SEM observation of the surface (× 1000), the size of the tip shape of the hammer head is 3.4 μm, which is 340% of the average single fiber diameter, and the number of tip shapes is 1,800 / a mm ^2, the ratio of the end form was 100%. Table 1 shows the results.

(Artificial leather with silver)
In the same manner as in Example 1, an artificial leather with silver was obtained.
The peel strength of the obtained artificial leather with silver was 128 N / cm. Table 1 shows the results.

[Example 5]
(raw cotton)
Raw cotton of sea-island type composite fiber was obtained in the same manner as in Example 1 except that the island / sea mass ratio was set to 90/10.

(Nonwoven fabric made of ultrafine fiber-expressing fiber)
In the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber-expressing fibers was obtained.

(Base material layer)
A substrate layer was obtained in the same manner as in Example 1 except that the grinding conditions were changed. The grinding conditions were such that the half-cut surfaces were all from the same direction using a 180-mesh sandpaper, the grinding amount of the half-cut surfaces was 90 g / m ² , and the maximum grinding amount was 1500 W / m.

The obtained sheet thickness was 0.9 mm, and the average single fiber diameter was 6.7 μm. On the other hand, according to SEM observation (× 1000) of the surface, the size of the tip of the hammer head is 12 μm, which is 180% of the average single fiber diameter, and the number of tips is 800 / mm ^2. And the ratio of the tip shape was 95%. Table 1 shows the results.

(Artificial leather with silver)
In the same manner as in Example 1, an artificial leather with silver was obtained.
The peeling strength of the obtained artificial leather with silver was 110 N / cm. Table 1 shows the results.

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

(Nonwoven fabric made of ultrafine fiber-expressing fiber)
In the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber-expressing fibers was obtained.

(Base material layer)
A substrate layer was obtained in the same manner as in Example 1 except that the grinding conditions were changed. The grinding conditions were such that all the half-cut surfaces were sanded from the same direction using a 320-mesh sandpaper, the grinding amount of the half-cut surface was 86 g / m ² , and the maximum grinding amount was 1400 W / m.

The obtained sheet had a thickness of 1.0 mm and an average single fiber diameter of 4.5 μm. On the other hand, according to SEM observation of the surface (× 1000), the size of the tip of the hammer head is 6.4 μm, which is 140% of the average single fiber diameter, and the number of tips is 700 / a mm ^2, the ratio of the end form was 45%. Table 1 shows the results.

(Artificial leather with silver)
In the same manner as in Example 1, an artificial leather with silver was obtained.

  The peel strength of the obtained artificial leather with silver was 86 N / cm. Table 1 shows the results.

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

(Nonwoven fabric made of ultrafine fiber-expressing fiber)
In the same manner as in Example 1, a nonwoven fabric made of ultrafine fiber-expressing fibers was obtained.

(Base material layer)
A substrate layer was obtained in the same manner as in Example 1 except that the grinding conditions were changed. The grinding conditions were such that the half-cut surfaces were all sanded from the same direction using sandpaper of 600 mesh, the grinding amount of the half-cut surfaces was 15 g / m ² , and the maximum grinding amount was 700 W / m.

The obtained sheet thickness was 1.1 mm, and the average single fiber diameter was 4.5 μm. On the other hand, according to SEM observation (× 1000) of the surface, the size of the tip of the hammer head is 4.6 μm, which is 100% of the average single fiber diameter, and the number of tips is 0 / a mm ^2, the ratio of the tip shape became 0%. Table 1 shows the results.

(Artificial leather with silver)
In the same manner as in Example 1, an artificial leather with silver was obtained.

  The peeling strength of the obtained artificial leather with silver was 54 N / cm. Table 1 shows the results.

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

(Nonwoven fabric made of ultrafine fiber-expressing fiber)
In the same manner as in Example 3, a nonwoven fabric made of ultrafine fiber-expressing fibers was obtained.

(Base material layer)
A substrate layer was obtained in the same manner as in Example 3 except that the grinding conditions were changed. The grinding conditions were such that the half-cut surfaces were all from the same direction using a 120-mesh sandpaper, and the amount of grinding of the half-cut surface was 70 g / m ² , and the maximum grinding amount was 1300 W / m.

The obtained sheet had a thickness of 1.0 mm and an average single fiber diameter of 3.0 μm. On the other hand, according to SEM observation (× 1000) of the surface, the size of the tip shape of the hammer head is 3.6 μm, which is 120% of the average single fiber diameter, and the number of tip shapes is 600 / a mm ^2, the ratio of the end form was 30%. Table 1 shows the results.

(Artificial leather with silver)
In the same manner as in Example 3, artificial leather with silver was obtained.

  The peel strength of the obtained artificial leather with silver was 82 N / cm. Table 1 shows the results.

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

(Nonwoven fabric made of ultrafine fibers)
In the same manner as in Example 4, a nonwoven fabric made of ultrafine fiber-expressing fibers was obtained.

(Base material layer)
A substrate layer was obtained in the same manner as in Example 4, except that the grinding conditions were changed. The grinding conditions were such that the half-cut surfaces were all from the same direction using a 180-mesh sandpaper, the grinding amount of the half-cut surfaces was 52 g / m ² , and the maximum grinding amount was 2100 W / m.

The resulting sheet had a thickness of 0.7 mm and an average single fiber diameter of 0.7 μm. On the other hand, by SEM observation of the surface (× 1000), the size of the tip of the hammer head is 3.1 μm, which is 440% of the average single fiber diameter, and the number of hammer heads is 4800 / a mm ^2, the proportion of the hammer head became 100%. Table 1 shows the results.

(Artificial leather with silver)
In the same manner as in Example 1, an artificial leather with silver was obtained.

  The peeling strength of the obtained artificial leather with silver was 90 N / cm. Table 1 shows the results.

  All the artificial leathers with silver of Examples had good peel strength between the base material layer and the resin layer due to the anchor effect. On the other hand, the artificial leather with silver of Comparative Examples 1 to 3 had poor peeling strength because the size of the tip shape of the hammer head was smaller than the average single fiber diameter and the ratio of the tip shape of the hammer head was smaller. I was In addition, the artificial leather with silver of Comparative Example 4 was inferior in peeling strength because the size of the tip of the hammer head was larger than the average single fiber diameter and the number of tips of the hammer head was also larger. .

Claims (6)

An artificial leather with silver comprising: a base layer made of an ultrafine fiber having an average single fiber diameter of 0.1 μm or more and 10.0 μm or less and an elastic polymer; and a resin layer formed on the base layer. hand,
The base material layer has a structure in which fiber bundles made of the ultrafine fibers are entangled with each other,
At least a surface of the base material layer in contact with the resin layer is formed with a nap layer having nap.
In the nap layer, 90% or more of the naps have a hammer head-like tip shape,
The artificial leather with silver, wherein the maximum diameter of the tip of the hammer head is 150% or more and 350% or less with respect to the average single fiber diameter. In the napped layer, said hammer napped with a head-like tip shape is 2000 / mm ² or less 500 / mm ² or more, a grain-artificial leather according to claim 1.   3. The artificial leather with silver according to claim 1, wherein the average single fiber diameter is 3.5 μm or more and 8.0 μm or less. 4.   The artificial leather with silver according to any one of claims 1 to 3, wherein the ultrafine fibers are made of a polyester polymer. Forming a base layer composed of the ultrafine fibers and the elastic polymer, a base layer forming step,
Performing a dry buffing process on the base material layer to form a napped layer, a napped layer forming step,
Forming a resin layer on the surface of the napped layer, a resin layer forming step,
It is a manufacturing method of the artificial leather with silver according to any one of claims 1 to 4,
The base layer forming step,
(1) a nonwoven fabric forming step of forming a nonwoven fabric composed of ultrafine fiber-expressing fibers;
(2) an ultrafine fiber expressing step of expressing an ultrafine fiber from the ultrafine fiber expressing fiber constituting the nonwoven fabric;
(3) an elastic polymer application step of applying an elastic polymer to the nonwoven fabric,
In the napped layer forming step, in the dry buffing, the buff polishing means is rotated in a direction opposite to a traveling direction of the nonwoven fabric sheet, and a grinding load is 1000 W / m or more and 4000 W / m or less, and a grinding amount is 10 g / m2. m performed at ² or more 200 g / ^{m 2} or less of the range, the production method of the grain-artificial leather.   6. The method for producing artificial leather with silver according to claim 5, wherein the base layer forming step is performed in the order of (1) a nonwoven fabric forming step, (2) an ultrafine fiber expressing step, and (3) an elastic polymer applying step. Production method of artificial leather with silver.