JP2016044362A - Artificial leather with soft feeling and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an artificial leather having flexibility and low repulsion similar to those of natural leather with a high-class feeling while maintaining mechanical properties.SOLUTION: An artificial leather comprises a fibrous base material in which a first polymeric elastomer is impregnated and imparted to a fiber entangled body composed of ultrafine filaments having an average fineness of 0.001 to 0.5 dtex such that a mass ratio of the ultrafine filaments to the polymeric elastomer (the ultrafine filaments/the polymeric elastomer) is 0/100 to 20/80 and the ultrafine filaments form fiber bundles. The fibrous base material is impregnated and imparted with 0.1 to 10 mass% of an acrylic resin and 0.1 to 10 mass% of a fat liquoring agent, and both the acrylic resin and the fat liquoring agent exist on the outside and inside of the fiber bundles.SELECTED DRAWING: None

Description

  The present invention relates to an artificial leather having both natural leather-like flexibility and a method for producing the same.

  Conventionally, a sheet in which a resin such as polyurethane elastomer is added to a fiber assembly such as a nonwoven fabric is similar to natural leather, and many proposals have been made to improve the performance as artificial leather. For example, as a flexible artificial leather, a sea-component multicomponent fiber from which sea components can be eluted, for example, a sea-island structure fiber made of polyethylene as a sea component is used as a non-woven fabric, and the sea-island structure fiber is used as a final product. In this process, sea components are removed to make ultrafine fibers, and artificial leather using them has been proposed. Patent Document 1 proposes a method for obtaining a flexible artificial leather with a feeling of rubber and resilience and a sense of fulfillment by converting the elastic polymer into microfibers that have a texture closer to that of the skin. ing. Patent Document 2 discloses a leather-like material in which a fibrous base material is treated with a treatment liquid containing a silicone resin using a mixture of dimethylpolysiloxane and amino-modified silicone and then impregnated and solidified with a polymer elastic body. A method for producing a sheet-like material is disclosed. In this method, low resilience is exhibited, but flexibility is insufficient.

Furthermore, as a technique for making the artificial leather have both flexibility and mechanical properties, Patent Document 3 discloses a cross section of the ultrafine fiber in a virtual cross section perpendicular to the thickness direction of the artificial leather substrate made of the ultrafine fiber and the polymer elastic body. An artificial leather has been proposed in which the average number density is 1000 pieces / mm ² or more and the area ratio of the polymer elastic body exposed on the surface is 20% or less on average. However, in this method, mechanical properties and flexibility of the skin tone are obtained, but the low resilience peculiar to natural leather has not been sufficiently reproduced.

  In recent years, artificial leather has been widely used as a substitute for natural leather in all fields such as shoes, clothing, gloves, bags, balls, interiors, etc., and these have higher quality, aesthetics, and comfortable use. It is requested. In particular, it is required to have a beautiful natural leather-like appearance, low rebound and flexibility of natural leather-like, and a high level of mechanical properties according to each application. The physical properties are often contradictory to the sensibility aspects such as excellent flexibility and low resilience, and it is difficult to achieve a balance between these, and any of the methods described above can solve such problems. It wasn't.

Japanese Patent Laid-Open No. 9-31862 JP 2004-324012 A JP 2014-005564 A

  As described above, in artificial leather, it has been very difficult to provide a natural leather-like low resilience and to impart flexibility while maintaining high mechanical properties. An object of the present invention is to solve such problems, that is, to provide an artificial leather having flexibility and low resilience similar to high-quality natural leather while maintaining mechanical properties. .

  The present inventors diligently studied means for improving flexibility and low resilience while maintaining mechanical properties. That is, according to the present invention, the first polymer elastic body has an ultrafine fiber / polymer elastic body mass ratio of 0/100 to a fiber entangled body made of ultrafine fibers having an average fineness of 0.001 to 0.5 dtex. 20/80 impregnated and impregnated and artificial leather comprising a fibrous base material in which the ultrafine fibers form a fiber bundle, and 0.1% relative to the fibrous base material. 10% by mass of acrylic resin and 0.1-10% by mass of a greasing agent are impregnated, and the acrylic resin and the greasing agent exist both outside and inside the fiber bundle. It is an artificial leather characterized by that. Giving a greasing agent lowers the frictional resistance between ultrafine fibers and provides a softening effect. In addition, it is different from the touch unique to silicone softeners commonly used in artificial leather. The slimy feeling is obtained. Moreover, since a silicone type softening agent increases the slip between fibers excessively, there exists a tendency which causes the fall of a mechanical physical property. By applying the acrylic resin, the elasticity of the acrylic resin is easily plastically deformed, so that the rubber elasticity of the first polymer elastic body applied to the fiber entangled body is suppressed, and there is little rebound, and the skin tone It is possible to achieve a texture. In particular, since the acrylic resin has entered not only the outside of the fiber bundle but also the inside, the acrylic resin can bind the fiber entanglement more strongly, and the rubber of the first polymer elastic body The effect of suppressing elasticity increases. In particular, when 60% or more of the total amount of the acrylic resin and the greasing agent is present in the fiber bundle, the effect of suppressing the softening effect and the resilience more effectively can be enhanced.

  Moreover, this invention can be suitably utilized as a suede-like artificial leather by performing a raising process on the surface. Similarly, by forming a silver surface with the second polymer elastic body on at least one surface of the artificial leather of the present invention, the artificial leather can be suitably used as a silver-tone artificial leather. These artificial leathers are soft and have a skin-like texture with little rebound.

  Further, according to another aspect of the present invention, the mass ratio of the ultrafine fiber / polymer elastic body is such that the first polymer elastic body has a fine fiber entangled body having an average fineness of 0.001 to 0.5 dtex. A first step of producing a fibrous base material of an artificial leather base material impregnated so as to be in the range of 0/100 to 20/80, and 0.1 to 10% by mass relative to the fibrous base material A second step of impregnating and imparting 0.1 to 10% by weight of a greasing agent, and mechanically disentangling at a temperature higher than the glass transition temperature (Tg) of the polymer constituting the ultrafine fiber. It is a manufacturing method of artificial leather comprising three steps in the order described. Rubber elasticity of the first polymer elastic body impregnated in the fiber entangled body with respect to the fibrous base material in the second step with respect to the fibrous base material obtained in the first step of the production method In addition to restraining, an acrylic resin that increases the retention of the stagnation effect in the subsequent mechanical stagnation process, and a greasing agent that enhances the softening effect are impregnated. Thereby, since acrylic resin and a greasing agent spread to the inner side of a fiber bundle and restrain a fiber, the effect which suppresses the said rubber elasticity increases. Subsequently, in the third step, a sufficient stagnation effect is expressed by mechanically degreasing the fiber temporarily fixed in the second step at a temperature higher than the Tg of the polymer constituting the ultrafine fiber, A flexible artificial leather with little rebound can be obtained.

  In the artificial leather of this embodiment, the first polymer elastic body is impregnated with a fiber entangled body made of ultrafine fibers having an average fineness of 0.001 to 0.5 dtex, and the ultrafine fibers / polymer elastic bodies An artificial leather comprising a fibrous base material having a mass ratio of 0/100 to 20/80 and in which the ultrafine fibers form a fiber bundle. 1-10% by mass acrylic resin and 0.1-10% by mass greasing agent are impregnated, and the acrylic resin and the greasing agent are present both outside and inside the fiber bundle. It is an artificial leather characterized by Hereinafter, an example of each process will be described in order.

  First, a method for producing a fibrous base material mainly composed of a fiber entanglement of ultrafine fibers having an average fineness of 0.001 to 0.5 dtex and a first polymer elastic body impregnated in the fiber entanglement is illustrated. The shape of the fiber constituting the fiber entangled body is not particularly limited, but from the viewpoint of improving the crease and surface quality of the artificial leather with silver tone, the sea-island type fiber obtained by using a method such as a mixed spinning method or a composite spinning method is used. It is preferable that it is an ultrafine fiber obtained by making such an ultrafine fiber generation type fiber ultrafine. Specifically, for example, melt spinning a microfiber-generating fiber such as a sea-island type fiber including a sea component made of a selectively removable resin and an island component made of a resin for forming a microfiber, A fiber web is produced.

  In addition, in this embodiment, although the case where a sea island type fiber is used as an ultra fine fiber generation type fiber is explained in detail, even if an ultra fine fiber generation type fiber other than a sea island type fiber is used, an ultra fine fiber generation type fiber is used. Alternatively, the fine fiber may be directly spun. In addition, as a specific example of the ultrafine fiber generating type fiber other than the sea-island type fiber, a plurality of ultrafine fibers are formed by lightly bonding immediately after spinning, and a plurality of ultrafine fibers are formed by unraveling by mechanical operation. Examples of such a separation-dividing fiber and a petal-type fiber in which a plurality of resins are alternately gathered in a petal shape in the melt spinning process are used, and any fiber that can form ultrafine fibers is used without particular limitation. .

  Specific examples of the resin for forming ultrafine fibers, which are island components of sea island type fibers, include, for example, polyethylene terephthalate (PET), isophthalic acid modified PET, sulfoisophthalic acid modified PET, polybutylene terephthalate, polyhexamethylene terephthalate. Aromatic polyester such as polylactic acid, polyethylene succinate, polybutylene succinate, polybutylene succinate adipate, polyhydroxybutyrate-polyhydroxyvalylate copolymer, etc .; polyamide 6, polyamide 66, polyamide 10 Polyamides such as polyamide 11, polyamide 12 and polyamide 6-12; polyolefins such as polypropylene, polyethylene, polybutene, polymethylpentene and chlorinated polyolefin; ethylene units Modified polyvinyl alcohol and modified polyvinyl alcohol containing 5 to 70 mol%; and polyurethane elastomer, polyamide elastomer, and a thermoplastic resin such as an elastomer such as polyester elastomer. These thermoplastic resins may be used alone or in combination of two or more. Among these, PET, isophthalic acid-modified PET, polylactic acid, polyamide 6, polyamide 12, polyamide 6-12, a copolymer of these polyamides, and polypropylene are excellent in productivity such as spinnability, and the obtained artificial leather It is preferable from the viewpoint of excellent mechanical properties.

  It should be noted that the resin for forming the ultrafine fiber is various additives within a range not impairing the object and effect of the present invention, specifically, for example, a catalyst, an anti-coloring agent, a heat-resistant agent, a flame retardant, a lubricant, Antifouling agent, fluorescent brightening agent, matting agent, coloring agent, gloss improver, antistatic agent, fragrance, deodorant, antibacterial agent, acaricide, inorganic fine particles etc. may be blended as required Good.

  The sea component of the sea-island fiber is a component that is selectively extracted and removed by a solvent or selectively decomposed and removed by hot water or a decomposing agent when the sea-island fiber is converted into a fiber bundle of ultrafine fibers. . Therefore, as the resin that forms the sea component, a resin that has higher extraction and removal properties by the solvent and decomposition and removal properties by hot water or a decomposing agent than the resin that forms the island components is selected. In addition, from the viewpoint of spinning stability of sea-island type fibers, the resin has a low affinity with the resin that forms the island component, and the melt viscosity and / or surface tension is lower than the resin that forms the island component under the spinning conditions. Is preferably used.

  Specific examples of the resin for forming the sea component of such sea-island fibers include, for example, polyethylene, polypropylene, polystyrene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, styrene-ethylene copolymer. , Styrene-acrylic copolymer, and polyvinyl alcohol resins such as water-soluble thermoplastic polyvinyl alcohol (water-soluble PVA). Among these, water-soluble PVA is particularly preferable because it can be produced without using an organic solvent.

  The saponification degree of the water-soluble PVA resin is 90 to 99.99 mol%, more preferably 93 to 99.98 mol%, particularly 94 to 99.97 mol%, particularly 96 to 99.96 mol%. % Is preferable. When the degree of saponification of the water-soluble PVA resin is within such a range, the water-soluble PVA resin is excellent in water solubility, excellent in thermal stability, excellent in melt spinnability, and excellent in biodegradability. Is obtained.

  As a method for forming a fiber web, a method of forming a long fiber web without cutting ultrafine fiber generating long fibers such as sea-island long fibers spun by a spunbond method or the like is preferably used.

  For example, sea-island long fibers are extruded from a spinneret for sea-component polymer and island-component polymer, melt-spun, and after the molten sea-island long fibers discharged from the base are cooled by a cooling device, an air jet nozzle, etc. By using a suction device of the above, it is pulled and refined by a high-speed air current at a speed corresponding to a take-up speed of 1000 to 6000 m / min so as to achieve a desired fineness, and is deposited on a collection surface such as a mobile net. To form an unstretched long fiber web. In addition, if necessary, the obtained long fiber web may be partially crimped, for example, by pressing to stabilize the form. Such a long fiber web manufacturing method is advantageous in production because it does not require a series of large-scale equipment such as a raw cotton supply device, a fiber opening device, and a card machine, which is essential in the conventional fiber web manufacturing method using short fibers. . In addition, since the long fiber web and the artificial leather obtained by using the same tend to have low fiber bulk and tend to have high fiber density, the conventional short fiber web and artificial manufactured using the same are used. Compared to leather, it excels in mechanical properties such as peel strength. In addition, by increasing the density of the long fibers, it is easy to reproduce a sense of fulfillment similar to natural leather.

  The spinning temperature (die temperature) in melt spinning is, for example, higher than the melting points of the sea component and island component resins, and the range of 180 to 350 ° C. is likely to cause a melting point peak and a sub-endothermic peak to exist. To preferred.

The average cross-sectional area of the sea-island long fibers is not particularly limited, but is preferably 30 to 800 μm ² . The average area ratio between the sea component and the island component in the cross section corresponding to the volume ratio between the sea component and the island component of the sea-island long fibers is not particularly limited, but is preferably 5/95 to 70/30. Moreover, although the fabric weight of the obtained long fiber web is not specifically limited, 10-1000 g / m < ² > is preferable.

A web entangled sheet, which is an entangled body of ultrafine fiber-generating fibers, is formed by stacking a plurality of the long fiber webs obtained as described above and performing an entanglement treatment. Specifically, after a plurality of long fiber webs are stacked in the thickness direction using a cross wrapper or the like, needle punching is performed under the condition that at least one barb penetrates from both outer sides simultaneously or alternately. The punching density is not particularly limited, but is preferably in the range of 500 to 5000 punches / cm ² from the viewpoint that the fibers can be sufficiently entangled while suppressing damage to the sea-island long fibers by the needle.

By such a process, the sea-island long fibers are entangled three-dimensionally, and the sea-island long fibers are present at an average density of, for example, 600 to 4000 / mm ² in a cross section parallel to the thickness direction. Thus, an entangled long fiber web in which sea-island type long fibers are gathered very densely is obtained. The basis weight of the entangled long fiber web is preferably 100 to 2000 g / m ² . The long fiber web may be provided with a silicone oil agent or a mineral oil oil agent such as a needle breakage preventing oil agent, an antistatic oil agent, or an entanglement improving oil agent at any stage from the production to the entanglement treatment. preferable.

  The entangled long fiber web is preferably subjected to a heat shrink treatment. By such heat shrinking treatment, the entangled state of the long fiber web is further densified, the shape retention is improved, and the fibers are prevented from coming off.

  Examples of the heat shrink treatment include heat shrink treatment with water vapor and treatment immersed in warm water at 70 to 150 ° C., and heat shrink treatment with water vapor is particularly preferable. The heat shrink treatment with water vapor is performed, for example, by adding moisture to the entangled long fiber web so that the sea component is 10 to 200% by mass, and then the relative humidity is 70% or more, and further 90% or more. It is preferable to heat-treat for 60 to 600 seconds in a heated steam atmosphere of 60 to 130 ° C. When the heat shrink treatment is performed under such conditions, the sea component resin plasticized with water vapor is compressed and deformed by the shrinkage force of the long fibers of the island component resin and becomes denser.

As a shrinkage rate of the entangled long fiber web by the heat shrink treatment, the following formula:
[(Area before shrinkage treatment−Area after shrinkage treatment) / Area before shrinkage treatment] × 100
Is preferably 35% or more, more preferably 35 to 90%, and particularly preferably 40 to 80%.

  And the 1st polymeric elastic body is impregnated and given to the web entanglement sheet which is the fiber entanglement body of the long fiber web obtained as mentioned above. Specifically, for example, the web entangled sheet is impregnated with a liquid containing the first polymer elastic body, and then the first polymer elastic body is solidified, whereby the web entangled sheet has the first The polymer elastic body is impregnated.

  As the first polymer elastic body, a polymer elastic body conventionally used for producing artificial leather can be used without any particular limitation. Specific examples thereof include a polyurethane resin, an acrylic resin, a polyamide resin such as a polyamide elastomer, a polyester resin such as a polyester elastomer, an elastic polystyrene resin, an elastic polyolefin resin, and the like. These may be used alone or in combination of two or more. Among these, polyurethane resins are particularly preferable because they are excellent in flexibility and fulfillment.

  As a specific example of the method for impregnating the web entangled sheet with the first polymer elastic body, for example, an emulsion containing the first polymer elastic body such as polyurethane emulsion or acrylic emulsion is added to the web entangled sheet. A method of solidifying by impregnation and then drying is preferable.

  In addition, when a web entangled sheet is impregnated with an emulsion containing a general polymer elastic body and dried, the emulsion of the inner layer moves to the surface layer of the web entangled sheet as the drying of the emulsion proceeds from the surface, and the surface layer There is a tendency that a so-called migration phenomenon occurs, in which polymer elastic bodies are ubiquitous. When migration occurs, the distribution of the elastic polymer becomes non-uniform in the thickness direction of the web entangled sheet. Generation | occurrence | production of such a migration is suppressed by using the emulsion of the polymeric elastic body which has heat-sensitive gelling property.

  When an emulsion containing a polymer elastic body has a heat-sensitive gelling property, a web entangled sheet is impregnated with the emulsion of a polymer elastic body having a heat-sensitive gelling property, and then hot air, steam, microwave, heat By treating with a water bath or the like, before the inner layer emulsion migrates to the surface layer of the web entangled sheet, the polymer elastic body is gelled or solidified by heat and fixed uniformly in the thickness direction.

  The emulsion of a polymer elastic body having heat-sensitive gelation properties is obtained by emulsifying a polymer elastic body using a nonionic surfactant having a low hydrophilic / lipophilic balance (HLB) as an emulsifier, or by heating a polymer elastic body with an emulsion. Is obtained by adding a heat-sensitive gelling agent that gels the emulsion. Specific examples of the heat-sensitive gelling agent include inorganic salts such as calcium chloride, polyethylene glycol type nonionic surfactant, polyvinyl methyl ether, polypropylene glycol, silicone polyether copolymer, polysiloxane and the like. These may be used alone or in combination of two or more.

  As described above, the web entangled sheet is impregnated with the first polymer elastic body by impregnating the web entangled sheet with an aqueous liquid such as an emulsion containing the first polymer elastic body and then drying. Can be granted. As a ratio of the first polymer elastic body impregnated in the web entangled sheet, the mass ratio of the solid content amount of the first polymer elastic body / the amount of ultrafine fibers formed is 0/100 to 20/80, Is preferably adjusted to a ratio of 5/95 to 15/85. If the ratio of the first polymer elastic body is too high, the resulting artificial leather with a silver tone will have a rubber or resin texture unique to polymer elastic bodies, resembling high-quality natural leather. It tends to be difficult to obtain a supple texture.

  As the liquid containing the first polymer elastic body, an aqueous liquid such as the above-described aqueous emulsion is preferable because it does not use an organic solvent and has a small environmental load. Examples of the aqueous liquid of the first polymer elastic body include an aqueous emulsion of the polymer elastic body, an aqueous suspension of the polymer elastic body, and an aqueous solution in which the polymer elastic body is dissolved in an aqueous medium. Can be mentioned.

  The drying condition of the aqueous liquid containing the first polymer elastic body is not particularly limited as long as the first polymer elastic body is dried and solidified and sufficiently cured. For example, in the case of an aqueous emulsion, there may be mentioned conditions such as drying at a temperature of about 100 to 160 ° C. for 1 to 20 minutes.

  And, by selectively removing the sea component of the sea-island long fibers contained in the web entangled sheet impregnated with the first polymer elastic body obtained as described above, ultrafine fibers are obtained. .

  As a method for selectively removing the sea component, the first method is to use a solvent or a decomposing agent that does not dissolve and decompose the resin that forms the island component but selectively dissolves or decomposes only the resin that forms the sea component. A method of treating a web entangled sheet impregnated with a polymer elastic body is exemplified. Specifically, for example, when the resin that forms the island component is a polyamide-based resin or a polyester-based resin, and the resin that forms the sea component is a water-soluble PVA resin, hot water of 85 to 100 ° C. is used as the solvent. . In addition, when the resin that forms the island component is a polyamide-based resin or a polyester-based resin, and the resin that forms the sea component is an easily alkali-degradable modified polyester, an alkaline decomposing agent such as an aqueous sodium hydroxide solution is used as the decomposing agent. Used. Among these, in particular, a water-soluble PVA resin is used as the resin for the sea component, and the water component is treated by treatment in hot water at 85 to 100 ° C. for 100 to 600 seconds until the removal rate of the sea component reaches 95% by mass or more. It is preferable to extract and remove the conductive PVA resin. In this way, by converting the sea-island long fibers into ultrafine fibers, ultrafine fibers existing in a fiber bundle are formed. In addition, when processing with warm water, since generation | occurrence | production of the volatile substance which generate | occur | produces when using an organic solvent in the case of an extraction process is suppressed, environmental impact is low and it is preferable also on occupational health.

  In the present invention, a sufficient effect can be obtained even if a fibrous base material not containing the first polymer elastic body is used. Such an intermediate sheet that does not contain the first polymer elastic body is preferably produced by a method in which shrinkage treatment and ultrafine processing are simultaneously performed. That is, after the web entangled sheet is immersed in hot water at 65 to 90 ° C. for 3 to 300 seconds, it is subsequently treated at 85 to 100 ° C., preferably 90 to 100 ° C. for 100 to 600 seconds. Can be mentioned. In the preceding stage, the sea component polymer is squeezed simultaneously with the shrinkage of the ultrafine fiber bundle-forming long fibers. Part of the compressed sea component polymer elutes from the fiber. Therefore, voids formed by the removal of the sea component polymer are further reduced, so that a more dense long fiber entangled body can be obtained.

Thus, with respect to the fiber entanglement of the fiber bundle of ultrafine fibers having an average fineness of 0.001 to 0.5 dtex, the first polymer elastic body has an ultrafine fiber / polymer elastic body mass ratio of 0/100 to A fibrous base material that is impregnated so as to be in the range of 20/80 and in which the ultrafine fibers form a fiber bundle is formed. The average fineness of the ultrafine fibers in the formed fibrous base material is 0.001 to 0.5 dtex, preferably 0.005 to 0.3 dtex, and more preferably 0.01 to 0.2 dtex. . When the average fineness of the ultrafine fibers is less than 0.001 dtex, the mechanical properties of the artificial leather obtained when the fiber strength is too low are lowered. On the other hand, if it exceeds 0.5 dtex, the fiber itself is bulky, so that the fiber density cannot be increased, and the sense of fullness of the resulting artificial leather is lowered. Moreover, as a fabric weight of the fiber entanglement body of the ultrafine fiber in the fibrous base material formed, it is preferable that it is about 140-3000 g / m < ² >. The thickness of the intermediate sheet is not particularly limited, but specifically, for example, it is preferably 0.5 to 4.0 mm, and more preferably 0.8 to 3.0 mm.

  The fibrous base material can be used as it is as the base material for artificial leather of the present invention. However, if necessary, slice treatment, contact buffing, emery buffing, etc. for thickness adjustment and surface smoothing can be performed. In addition to the buffing treatment used, itching softening treatment, reverse seal brushing treatment, antifouling treatment, hydrophilization treatment, lubricant treatment, softener treatment, antioxidant treatment, UV absorber treatment, fluorescent agent as necessary Finishing treatment such as treatment or flame retardant treatment may be performed.

  Moreover, when manufacturing the suede-like artificial leather in this invention, it is preferable to pass through the coloring process by dyeing etc. after the said slice process and buffing process. The dye to be used is not particularly limited, and is preferably selected appropriately according to the type of fiber. Examples thereof include disperse dyes, acid dyes, cationic dyes, sulfur dyes, metal-containing dyes, and selenium dyes. Also, the dyeing method is not particularly limited, and it is preferably selected appropriately from the high-pressure liquid dyeing method, the jigger dyeing method, the thermosol continuous dyeing method, the Wins dyeing method, and the like according to the types of fibers and dyes. The dyed intermediate sheet thus obtained can be suitably used as a fibrous base material in the suede-like artificial leather of the present invention.

  Next, an acrylic resin and a greasing agent application process will be described.

  In the present invention, the fibrous base material is impregnated with 0.1 to 10% by mass of an acrylic resin and 0.1 to 10% by mass of a greasing agent.

  Acrylic resins generally have spreadability. That is, particularly in a state heated to a temperature equal to or higher than Tg, the acrylic resin tends to be deformed so as to be plastically stretched by applying mechanical force from the outside. Due to this feature, the elastic rebound of the first polymer elastic body applied to the fiber entangled body is suppressed, and the softening effect by mechanical stagnation becomes relatively large. The amount of the acrylic resin applied is preferably in the range of 0.1 to 10% by mass, more preferably in the range of 0.5 to 8% by mass, and still more preferably in the range of 1 to 6%. If the amount of the acrylic resin is too small, the effect of suppressing the elastic rebound is weakened. On the other hand, if the amount is too large, the texture becomes hard.

  The acrylic resin is not particularly limited. For example, water-dispersible, emulsifiable, or water-soluble obtained by copolymerizing a soft monomer, a hard monomer, a crosslinkable monomer, and other monomers used as necessary. These polymers are mentioned.

  The soft monomer is a monomer component having a non-crosslinkable ethylenically unsaturated bond whose glass transition temperature (Tg) is less than −5 ° C., preferably −90 ° C. or more and less than −5 ° C. Specific examples of the soft monomer include, for example, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, isopropyl acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and (meth) acrylic. (Meth) acrylic acid derivatives such as lauryl acid, stearyl (meth) acrylate, cyclohexyl acrylate, benzyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and the like.

  The hard monomer is a monomer component having a non-crosslinkable ethylenically unsaturated bond whose Tg of the homopolymer exceeds 50 ° C, preferably exceeds 50 ° C and is 250 ° C or less. Specific examples of the hard monomer include, for example, methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, cyclohexyl methacrylate, (meth) acrylic acid, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and methacrylic acid 2 -(Meth) acrylic acid derivatives such as hydroxyethyl; aromatic vinyl compounds such as styrene, α-methylstyrene and p-methylstyrene; acrylamides such as (meth) acrylamide and diacetone (meth) acrylamide; maleic acid and fumar Acids, itaconic acids and their derivatives; heterocyclic vinyl compounds such as vinylpyrrolidone; vinyl compounds such as vinyl chloride, acrylonitrile, vinyl ether, vinyl ketone, vinylamide; ethylene, pro Typified by Ren α- olefins, and the like.

  The crosslinkable monomer is a monomer capable of forming a crosslinked structure by reacting with a monofunctional or polyfunctional ethylenically unsaturated monomer unit capable of forming a crosslinked structure or an ethylenically unsaturated monomer unit introduced into a polymer chain. is there. Specific examples of such a crosslinkable monomer include, for example, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and 1,4-butanediol di (meth) acrylate. 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dimethylol tricyclodecane di (meth) acrylate, glycerin di (meth) Di (meth) acrylates such as acrylate; Tri (meth) acrylates such as trimethylolpropane tri (meth) acrylate and pentaerythritol tri (meth) acrylate; Pentaerythritol tetra (meth) acrylate and the like Tora (meth) acrylates; polyfunctional aromatic vinyl compounds such as divinylbenzene and trivinylbenzene; (meth) acrylic unsaturated esters such as allyl (meth) acrylate and vinyl (meth) acrylate; 2-hydroxy-3 -The molecular weights of 2: 1 addition reaction product of phenoxypropyl acrylate and hexamethylene diisocyanate, 2: 1 addition reaction product of pentaerythritol triacrylate and hexamethylene diisocyanate, 2: 1 addition reaction product of glycerin dimethacrylate and tolylene diisocyanate, etc. 1,500 or less urethane acrylate; (meth) acrylic acid derivatives having a hydroxyl group such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; (meth) acrylamide, diacetone Acrylamides such as (meth) acrylamide and their derivatives; (meth) acrylic acid derivatives having an epoxy group such as glycidyl (meth) acrylate; carboxyl groups such as (meth) acrylic acid, maleic acid, fumaric acid, itaconic acid Vinyl compounds; vinyl compounds having an amide group such as vinyl amide, etc. may be mentioned.

  The various monomers described above may be used alone or in combination of two or more. In addition, these acrylic resins are preferably water-based emulsion types from the viewpoint of reducing environmental burden and ease of handling. Tg of such an acrylic resin is −60 to 20 ° C., preferably −40 to 0 ° C., more preferably −30 to −10 ° C. When Tg is lower than −60 ° C., since the acrylic resin does not have sufficient strength, the effect of suppressing the rubber elasticity of the first polymer elastic body applied to the fiber entangled body may be reduced. There is. On the other hand, when Tg is higher than 20 ° C., the acrylic resin becomes too hard, which may cause a texture effect.

  As the greasing agent impregnated in the present invention, a greasing agent generally used in a softening process of natural leather can be suitably used. By adding a greasing agent, it is possible to reduce the frictional resistance between the fibers and improve the slippage between the fibers, so that the flexibility of the artificial leather can be improved. Moreover, compared with the chemical softener represented by the silicone type softener generally used for the artificial leather conventionally, the softness | flexibility and slime feeling which are close to a skin can be given. Silicone softeners tend to increase the slip between fibers excessively, or tend to reduce mechanical properties. However, when a greasing agent is used as a softener, the decrease in mechanical properties is minimal. It is known that it can be limited to the limit. Specific examples of greasing agents include anionic greasing agents such as sulfated fatty acid esters and sulfonated esters, cationic greasing agents such as quaternary ammonium salts and aliphatic amines, and amphoteric greasing such as alkylbetaines and lecithins. Agents, nonionic greasing agents such as fatty acid monoglycerides and the like. These greasing agents may be used alone or in combination of two or more. In addition, for these greasing agents, it is particularly preferable to use a water-based emulsion type for the same reason as the acrylic resin.

  The application amount of the greasing agent is preferably in the range of 0.1 to 10% by mass, more preferably in the range of 1 to 6% by mass, based on the mass of the fibrous base material. If the amount of the greasing agent is too small, a sufficient softening effect cannot be obtained. On the other hand, if the amount is too large, stickiness due to the greasing agent and contamination may be caused.

  In the present invention, the acrylic resin and the greasing agent are added after the ultrafine fiber generating fiber is converted into the ultrafine fiber. Thereby, the acrylic resin and the greasing agent can penetrate into the fiber bundle, and the ultrafine fibers can be gripped more strongly. By doing so, the rubber entangled body is impregnated in advance, and the elasticity of the first polymer elastic body is suppressed by the extensibility of the acrylic resin, and the entire fiber entangled body is given flexibility with a greasing agent. be able to.

  In another aspect of the present invention, 60% or more of the total amount of the acrylic resin and the greasing agent impregnated in the artificial leather is preferably present in the fiber bundle. More preferably, it is 70% or more. The presence of more acrylic resin and greasing agent inside the fiber bundle makes it possible to more effectively exhibit low resilience and flexibility. In order to set the abundance ratio within the above range, the total adhesion amount of the acrylic resin and the greasing agent to be impregnated is preferably in the range of 2 to 14% by mass. By setting it as said range, a capillary phenomenon works and it becomes possible to make acrylic resin and a greasing agent distributed inside a fiber bundle into 60% or more. When the amount is less than 2% by mass, the acrylic resin and the greasing agent are thinly distributed over the whole and it is difficult to obtain a sufficient effect. Moreover, since it will fill the space | gap inside a fiber bundle when more than 14 mass%, it will result in that more acrylic resin and a greasing agent distribute to the exterior of a fiber bundle.

  The method for applying the acrylic resin and the greasing agent is not particularly limited, but a solution impregnation method is preferably used because of the simplicity of the process. Specifically, for example, a method in which a fibrous base material is impregnated with a mixed solution of an acrylic resin emulsion and a greasing agent emulsion and dried to be solidified is preferable. Although a drying temperature is not specifically limited, It is preferable to dry about 1 to 20 minutes in the range of 100-150 degreeC.

  Next, the stagnation process will be described. In this step, the fiber structure temporarily fixed by impregnation with the acrylic resin and the greasing agent is solved to impart flexibility. Although the processing method of a stagnation process is not specifically limited, In order to provide the softening effect by a stagnation process effectively, it is preferable that it is a heating type stagnation machine. Specifically, known stagnation processing such as a tumbler type squeezing machine and a cam fit processing machine can be suitably used.

  In the present invention, it is important to stagnate at a temperature equal to or higher than the glass transition temperature of the polymer constituting the ultrafine fiber. By heating above the above temperature, the entangled body of ultrafine fibers is softened by heat, and the stagnation effect can be further enhanced. After scouring, finishing of reverse seal brushing treatment, antifouling treatment, hydrophilic treatment, lubricant treatment, softener treatment, antioxidant treatment, UV absorber treatment, fluorescent agent treatment, flame retardant treatment, etc. Processing may be performed. The artificial leather thus obtained has little resilience and has a skin-like flexibility, and can be suitably used as a base material for a later-described suede-like artificial leather or silver-like artificial leather.

  When the artificial leather of the present invention is used as a suede-like artificial leather, an acrylic resin and a greasing agent are impregnated and imparted to the dyed intermediate sheet that has been previously brushed and dyed as described above, and then the stagnation process It is preferable to go through. After the kneading process, as described above, various finishing processes can be performed as necessary. The suede-like artificial leather thus obtained becomes an artificial leather having a combination of softness and a repelling feel.

  Subsequently, the manufacturing method of the silver-finished artificial leather of this invention is demonstrated. A silver surface layer is formed on at least one exposed surface of the artificial leather by a silver surface layer forming method such as a dry surface forming method or a direct coating method. In the dry surface-forming method, after forming a silver surface coating containing a second polymer elastic body on a support substrate such as a release paper, an adhesive is applied to the surface of the silver surface coating, It is a method of forming a silver layer by sticking to the exit surface, pressing and adhering if necessary, and peeling the release paper. The direct coating method is a method in which a silver resin layer is formed by directly applying a liquid resin or a resin liquid containing a second polymer elastic body to the exposed surface, followed by curing.

  As the second polymer elastic body, a polymer elastic body conventionally used for forming a silver surface layer, such as the same type of polymer elastic body as listed in the first polymer elastic body described above. Can be used without any particular limitation.

  Although the thickness of the silver surface layer to be formed is not particularly limited, for example, it is preferably about 50 μm to 300 μm from the viewpoint that the balance between mechanical properties and texture can be maintained. In addition, in the silver surface layer formed by the dry surface forming method, the thickness including the adhesive layer is defined as the thickness of the silver surface layer.

Similar to the suede-like artificial leather, the silver-tone artificial leather thus obtained has a combination of a softness and a texture with less rebound.

  Hereinafter, the present invention will be described more specifically with reference to examples. The scope of the present invention is not limited to these examples.

Water-soluble thermoplastic PVA resin is used as the sea component, PET with an isophthalic acid modification degree of 6 mol% is used as the island component, the number of islands per fiber is 25 islands, and the sea component / island component is 25/75 (mass) Ratio), a sea-island filament was discharged from the die at 260 ° C. Then, the ejector pressure was adjusted so that the spinning speed was 4000 m / min, and the sea-island long fibers having an average fineness of 2.5 dtex were collected on a net to obtain a long fiber web having a basis weight of 30 g / m ² .

And 6 sheets were piled up by carrying out cross wrapping of the obtained long fiber web, and the needle | hook breaking prevention oil agent was sprayed on this. Then, an intertwined long fiber web was obtained by needle punching with a 6 barb needle needle at a punch density of 2000 punch / cm ² .

  And the entangled long fiber web was heat-shrinked with water vapor. In the heat shrink treatment with water vapor, first, 30% by mass of water is given to the amount of sea components in the entangled long fiber web, and then a heated water vapor atmosphere with a relative humidity of 90% and a temperature of 110 ° C. Under heat treatment for 80 seconds. The area shrinkage rate at this time was 45%.

  Next, the web entangled sheet obtained by the heat shrink treatment was impregnated with anionic self-emulsifying aqueous polyurethane (100% modulus 3.0 MPa) and ammonium sulfate as a heat-sensitive gelling agent. The concentration of the aqueous polyurethane was adjusted so that the mass ratio of the solid content of the aqueous polyurethane / the amount of the island component was 12/88. In order to prevent migration, the aqueous polyurethane dispersion was subjected to gelation treatment in a water vapor atmosphere and then dried at 120 ° C. for 10 minutes.

Then, the web entangled sheet impregnated with aqueous polyurethane was immersed in hot water at 95 ° C. for 10 minutes to remove sea components to form ultrafine fibers, and then dried at a temperature of 120 ° C. for 10 minutes. Subsequently, the both surfaces were buffed with sandpaper of # 240 and # 320 to obtain a fibrous base material (hereinafter sometimes referred to as an intermediate sheet) 1 having a thickness of 0.8 mm and a basis weight of 450 g / m ² .

A portion of the obtained intermediate sheet 1 was passed through hot water at 80 ° C. for 20 minutes to allow it to adjust to the hot water and the dough was relaxed, and then a high pressure liquid dyeing machine (Hisaka Seisakusho Circular Dyeing Co., Ltd.). Machine) under the following conditions. In this manner, a dyed intermediate sheet 2 having a suede-like surface and having a basis weight of 495 g / m ² dyed beige with a disperse dye was obtained.

Dyeing condition dye solution:
Disperse Blue 73 (disperse dye) (Hokuriku Color Co., Ltd.) 4.35% o.d. w. f.
Disperse Red 167.1 (disperse dye) (Hokuriku Color Co., Ltd.) 2.01% o.d. w. f.
Disperse Yellow 163 (disperse dye) (Hokuriku Color Co., Ltd.) 5.48% o.d. w. f.
・ "AL" (leveling agent) (Nippon Kayaku Co., Ltd.) 2.0 g / dm ³
・ "New Buffer K" (pH adjusting agent) (manufactured by Mitsima Chemical Co., Ltd.) 1.8 g / dm ³
- "H867" (sequestering agent) (On the other hand the company fat Kogyo Co., Ltd.) 0.5g / dm ³
Dyeing temperature: 120 ° C
Dyeing time: 40 minutes Bath ratio: 1:20

The entangled long fiber web obtained after the needle punching obtained in the production process of the intermediate sheet 1 was processed by a technique of simultaneously performing shrinkage treatment and ultrathinning. That is, the long fiber web is immersed in hot water at 70 ° C. for 90 seconds to cause area shrinkage due to stress relaxation of the island component, and then immersed in hot water at 95 ° C. for 10 minutes to dissolve and remove the sea component. It was dried at a temperature of 120 ° C. for 10 minutes. Subsequently, the intermediate sheet 3 having a thickness of 0.8 mm and a weight per unit area of 480 g / m ² was obtained by buffing both sides with sandpaper of # 240 and # 320.

In the manufacturing process of the intermediate sheet 1, after impregnating and drying the first polymer elastic body, and before the extraction process, the amount of adhesion in terms of solid content of the acrylic resin and the greasing agent is the intermediate The chemical | medical solution which adjusted the density | concentration so that it might become 2.5 mass% and 3.0 mass% with respect to the mass of the body sheet | seat 1 was made to dry for 10 minutes at 120 degreeC. Thereafter, sea components were removed under the same conditions as in Example 1 to form ultrafine fibers, and then dried at a temperature of 120 ° C. for 10 minutes. Subsequently, the intermediate sheet 4 having a thickness of 0.8 mm and a basis weight of 490 g / m ² was obtained by buffing both surfaces with sandpaper of # 240 and # 320.

In the first polymer elastic body providing step of the production process of the intermediate sheet 1, the concentration of the aqueous polyurethane was adjusted so that the mass ratio of the solid content of the aqueous polyurethane / the amount of the island component was 25/75. The intermediate sheet 5 was processed in the same manner as the intermediate sheet 1 except that the thickness was 0.8 mm and the basis weight was 510 g / m ² .

[Example 1]
The intermediate sheet 1 has an acrylic resin (Casesol ARS-2 manufactured by Nikka Chemical Co., Ltd.) and a greasing agent (oil GR-50 manufactured by Toyoshima Chemical Co., Ltd.) in terms of solid content, respectively. A chemical solution whose concentration was adjusted to 2.5% by mass and 3.0% by mass with respect to the mass was impregnated and dried at 120 ° C. for 10 minutes. The obtained intermediate sheet 1 after impregnation is subjected to a rubbed treatment at a temperature of 100 ° C. for 30 minutes with a tumbler-type squeezing machine to obtain an intermediate sheet 1 after squeezing with a thickness of 0.8 mm and a basis weight of 476 g / m ^2. Next, a silver surface layer was formed by the following dry surface forming method.

First, on the release paper, an aqueous polyurethane liquid for silver surface coating having the following composition was applied at 100 g / m ² , and then dried at 90 ° C. for 1 minute and then at 120 ° C. for 2 minutes to obtain a thickness of 30 μm. An epidermal layer was formed.
(Aqueous polyurethane solution for silver surface coating)
Polycarbonate polyurethane (Hydran WLS-210 manufactured by DIC Corporation, solid content 35%): 100 parts by mass Carbodiimide crosslinking agent (Carbodilite manufactured by Nisshinbo Co., Ltd.): 4 parts by mass Thickener (DIC ( Hydran Assister T-10, manufactured by Co., Ltd.): 1.5 parts, brown pigment (Dilak Brown HS-8640, manufactured by DIC Corporation): 10 parts

Next, on the silver surface film formed on the release paper, an aqueous polyurethane liquid for adhesive layer having the composition shown below was applied at 150 g / m ² and then dried at 90 ° C. for 3 minutes to obtain a thickness. A 60 μm adhesive layer was formed.
(Aqueous polyurethane liquid for adhesive layer)
Polycarbonate polyurethane (Hydran WLA-412 manufactured by DIC Corporation, solid content 45%): 100 parts by mass Thickener (Hydran Assister T-5 manufactured by DIC Corporation): 1.5 parts by mass Modified polyisocyanate crosslinking agent (Hydran Assist C-5 manufactured by DIC Corporation): 10 parts by mass

  A roll having a clearance of 70% of the thickness of the artificial leather base material, placed in such a manner that the adhesive layer side of the silver surface layer on the release paper is placed in contact with the slice surface of the artificial leather base material. Crimped. And after drying at 100 degreeC for 2 minute (s) and further aging at 60 degreeC for 2 days, the silver-tone artificial leather was obtained by peeling a release paper. Then, toughness (tensile product) was evaluated as an index of mechanical properties of the obtained silver-tone artificial leather. Similarly, softness, flexibility, resilience, and surface touch were evaluated as evaluation items on the sensitivity side. Each evaluation method is shown below.

<Toughness>
In JIS L1096 8.12.1 “Tensile strength test”, a 2.5 cm × 16 cm test piece was obtained according to the measurement method described. The stress and elongation at the time of breaking were read from the stress-strain curve, and the breaking strength (N / cm) and the breaking elongation (%) were determined respectively. The toughness (N ·% / cm) was calculated from the product of these numerical values.

<Abundance ratio of acrylic resin and greasing agent in fiber bundle>
An enlarged photograph was taken with a scanning electron microscope of a cross section substantially parallel to the thickness direction of the artificial leather. The magnification at that time was adjusted between 100 times and 1000 times so that the inside of the fiber bundle could be sufficiently observed. Then, in a rectangular area of 0.2 mm × 0.2 mm selected uniformly, the mixture of the acrylic resin and the greasing agent existing inside the fiber bundle is colored with a fluorescent pen, and the portion is cut with a cutter. It cut out correctly and measured the mass. Then, the ratio of the area of the acrylic resin and the greasing agent existing inside the fiber bundle to the area of the whole artificial leather in the photograph is calculated from the mass ratio, and the average value of the 10 places is the acrylic existing inside the fiber bundle. The area ratio of the resin and the greasing agent was used. Next, the ratio of the theoretical area occupied by the acrylic resin and the greasing agent in the photograph was calculated by the following formula.

(Percentage of theoretical area occupied by acrylic resin and greasing agent%)
= {(A / G _A + K / G _K ) / (W / G _S )} × 100

However,
W: Weight of artificial leather (g / m ² )
(In the case of artificial leather with a silver tone, the weight obtained by subtracting the basis weight of the silver layer)
A: Acrylic resin theoretical adhesion amount (g / m ² )
K: Theoretical amount of greasing agent (g / m ² )
G _S : Specific gravity of artificial leather (g / cm ³ )
G _A : Specific gravity of acrylic resin (g / cm ³ )
G _K : specific gravity of greasing agent (g / cm ³ )
In addition, in the process of giving each to the intermediate | middle sheet | seat of an artificial leather with the theoretical adhesion amount of acrylic resin and a greasing agent, each solid content (mass%) of the acrylic resin in the process liquid and a greasing agent ) And their pickup rate (%) multiplied by the basis weight of the intermediate sheet.

The ratio of the area of the acrylic resin and the greasing agent existing inside the fiber bundle by the ratio of the theoretical area occupied by the obtained acrylic resin and the greasing agent. Leather softness measuring device ST- of UK MSA Engineering System Co., Ltd. Using 300, measurement was performed at an arbitrary five points for one sample, and the ratio of the acrylic resin and the greasing agent in the total amount of the acrylic resin and the greasing agent was calculated by dividing the five points. .

<Softness> The average value of points was defined as the softness value.

<Flexibility>
A test piece was prepared by cutting the artificial leather into a square 20 cm long by 20 cm wide. Then, five panelists selected from those skilled in the art of artificial leather touched the test piece and judged flexibility according to the following criteria.
A: Like high-quality cowhide leather, it was very supple and flexible.
B: There was a standard flexibility to the extent that it could be used as a leather material used for sundries and the like.
C: Wrinkles that were rounded when folded were inferior in flexibility.

<Rebound>
A test piece was prepared by cutting the artificial leather into a square 20 cm long by 20 cm wide. And after grasping strongly so that the cut-out test piece might be rounded in a random manner, the state of the sample after placing it gently on the desk and observing it was judged and judged according to the following criteria.
A: The shape held by the hand remained almost intact.
B: It spread on the desk, but the shape held by the hand remained slightly.
C: The test piece spread in a completely flat state.

<Surface touch>
A test piece was prepared by cutting the artificial leather into a square 20 cm long by 20 cm wide. Then, five panelists selected from those skilled in the art of artificial leather touched the test piece and judged flexibility according to the following criteria.
A: There was an appropriate slime feeling with a high-class skin tone, and it was a very preferable touch.
B1: Although there was a skin-like slimy feeling, a slight stickiness was felt on the hand after touching the test piece.
B2: Although there was a slight slimy feeling, it was a touch inferior to a high-grade skin.
C1: The test piece was sticky and could not be used as general artificial leather.
C2: There was no skin-like sliminess, and the touch was dry.

As a result of the above evaluation, the toughness of the resulting silver-tone artificial leather was 33218 N ·% / cm, and the softness was 3.4 mm. Furthermore, the flexibility, the resilience, and the surface touch were all determined as A. Moreover, the ratio which exists in the fiber bundle inside of the total amount of acrylic resin and a greasing agent was 72%. (Calculation method: Ratio of area of acrylic and greasing agent inside fiber bundle is 2.20%, divided by 3.05% and multiplied by 100)
The percentage of the theoretical area occupied by the acrylic resin and the greasing agent was obtained from the following calculation.
{(A / G _A + K / G _K ) / (W / G _S )} × 100 = 3.05%
W: 476 g / m ² , A: 11.3 g / m ² (= 450 g / m ² × 2.5%) (solid content: 2.5% = resin apparent concentration 7.5% × resin stock solution solid content 60 % × Pickup 55%), K: Fatty agent theoretical adhesion amount 13.5 g / m ² (= 450 g / m ² × 3.0%) (solid content adhesion amount 3.0% = resin apparent concentration 11% × resin stock solids 50% × pickup ^{_{55%), G S: 0.595g}} / cm 3, G a: 1.18g / cm 3, G K: 0.91g / cm 3, results are shown in table 1.

[Example 2]
Except having adjusted the density | concentration so that the solid content adhesion rate of acrylic resin might be 9 mass%, the silver-tone artificial leather was obtained by the process and conditions similar to Example 1, and evaluated similarly. The results are shown in Table 1.

[Example 3]
Except having adjusted the density | concentration so that the solid content adhesion rate of a greasing agent might be 9 mass%, the silver-tone artificial leather was obtained by the process and conditions similar to Example 1, and evaluated similarly. The results are shown in Table 1.

[Example 4]
The dyeing intermediate sheet 2 has an acrylic resin (Casesol ARS-2 manufactured by Nikka Chemical Co., Ltd.) and a greasing agent (Oil GR-50 manufactured by Toshima Chemical Co., Ltd.) in terms of solid content, respectively. A chemical solution whose concentration was adjusted to 2.5% by mass and 3.0% by mass with respect to the mass of 2 was impregnated and dried at 120 ° C. for 10 minutes. The obtained dyed intermediate sheet 2 after impregnation was subjected to a frying treatment for 30 minutes at a temperature of 100 ° C. with a tumbler type grinder. Next, the obtained dyed intermediate sheet 2 after squeezing was hair-set by reverse sealing treatment to obtain a suede-like artificial leather. The softness, flexibility, resilience, and surface touch of the obtained suede-like artificial leather were evaluated in the same manner as in Example 1. The results are shown in Table 1.

[Example 5]
Except that the intermediate sheet 3 was used instead of the intermediate sheet 1, it was processed in the same manner as in Example 1 to obtain a silver-tone artificial leather, which was similarly evaluated. The results are shown in Table 1.

[Comparative Example 1]
Except that the acrylic resin was excluded during the impregnation treatment, the same treatment as in Example 1 was performed to obtain a silver-finished artificial leather, which was similarly evaluated. The results are shown in Table 1.

[Comparative Example 2]
Except having adjusted the density | concentration of the impregnation liquid so that the solid content adhesion rate of acrylic resin might be set to 12.5% at the time of an impregnation process, it processed similarly to Example 1 and obtained the artificial leather with a silver tone, evaluated. The results are shown in Table 1.

[Comparative Example 3]
Except that the greasing agent was removed during the impregnation treatment, the same treatment as in Example 1 was performed to obtain a silver-coated artificial leather, which was similarly evaluated. The results are shown in Table 1.

[Comparative Example 4]
Except that the concentration of the impregnating solution was adjusted so that the solid content adhesion rate of the greasing agent was 12.5% during the impregnation treatment, the same treatment as in Example 1 was performed to obtain a silver-finished artificial leather. evaluated. The results are shown in Table 1.

[Comparative Example 5]
Except that the intermediate sheet 4 was used instead of the intermediate sheet 1, it was processed in the same manner as in Example 1 to obtain a silver-tone artificial leather, which was similarly evaluated. The results are shown in Table 1.

[Comparative Example 6]
Except that the intermediate sheet 5 was used instead of the intermediate sheet 1, it was processed in the same manner as in Example 1 to obtain a silver-tone artificial leather, which was similarly evaluated. The results are shown in Table 1.

[Comparative Example 7]
A silver-finished artificial leather was treated in the same manner as in Example 1 except that a silicone softener (Softlon DX-1 manufactured by Yoshimura Yuka Chemical) was used at an apparent concentration of 1% instead of a greasing agent during the impregnation treatment. And evaluated similarly. The results are shown in Table 1.

  The artificial leather of the present invention can be suitably used for the production of men's shoes, sports shoes, bags, belts, camera cases, school bags, and the like. In particular, the artificial leather with silver using the base material of the present invention is excellent in flexibility and has a supple texture like a skin, so it is suitable for applications such as gloves and clothing where importance is placed on the texture. Can be used.

Claims (5)

  The mass ratio of the first polymer elastic body to the ultrafine fiber / polymer elastic body is 0/100 to 20/80 with respect to the fiber entangled body made of ultrafine fibers having an average fineness of 0.001 to 0.5 dtex. It is an artificial leather made of a fibrous base material that is impregnated so that the ultrafine fiber forms a fiber bundle, and is 0.1 to 10% by mass relative to the fibrous base material An acrylic resin and 0.1 to 10% by mass of a greasing agent are impregnated, and the acrylic resin and the greasing agent exist both outside and inside the fiber bundle. Artificial leather.   2. The artificial leather according to claim 1, wherein 60% or more of the total amount of the acrylic resin and the greasing agent impregnated is present in the fiber bundle.   A silver-tone artificial leather in which a silver surface is formed on at least one surface of the artificial leather according to claim 1 or 2 by a second polymer elastic body.   A suede-like artificial leather in which at least one surface of the artificial leather according to claim 1 or 2 is raised. With respect to the fiber entanglement of ultrafine fibers having an average fineness of 0.001 to 0.5 dtex, the first polymer elastic body has an ultrafine fiber / polymer elastic body mass ratio in the range of 0/100 to 20/80. A first step of producing a fibrous base material of an artificial leather base material that has been impregnated and the ultrafine fibers form a fiber bundle;
A second step of impregnating the fibrous base material with 0.1 to 10% by mass of an acrylic resin and 0.1 to 10% by mass of a greasing agent;
And a third step of mechanically melting at a temperature higher than the glass transition temperature (Tg) of the polymer constituting the ultrafine fiber,
Are provided in the order described.