JP4048160B2 - Leather-like sheet and manufacturing method thereof - Google Patents

Description

  The present invention relates to a leather-like sheet and a method for producing the same. More specifically, the present invention is a soft leather-like sheet-like product that has a high-quality appearance but does not feel stretchy, and has a feeling of surface similar to natural leather and a leather-like sheet that has a small wrinkle appearance when folded. And a manufacturing method thereof.

  As an alternative to natural leather, artificial leather using fibers and polymer elastic bodies is widely used as a leather-like sheet. However, although these artificial leather-like sheets are superior in physical properties compared to natural leather, they are insufficient in appearance and texture.

  For example, as artificial leather with silver, artificial leather (for example, Patent Document 1) in which a porous polyurethane layer by a wet coagulation method is provided as a skin on a substrate composed of ultrafine fibers and a polymer elastic body, or normal solid polymer elasticity. There is artificial leather with the body applied as an epidermis by laminating or gravure.

  However, when a porous polyurethane layer by a wet coagulation method is used, the polyurethane does not sufficiently surround the fibers in the skin layer, and the problem that the function of suppressing the fiber fluff constituting the substrate in the polyurethane layer is weak, When a thick skin layer is used to suppress the fluff and improve physical properties such as adhesion, there is a problem that the surface becomes a rubber-like texture and the excavation is large.

In addition, when a normal solid polymer elastic body is directly applied on a substrate containing fibers using a lamination method or a gravure method, the polymer elastic body existing on the surface and the fibers are bonded, There is a problem that a high-density layer consisting of fiber and polymer elastic body is difficult to deform on the adhesive surface, and there is a problem that a feeling of tension is generated, which is an excellent texture that natural leather has, a very repulsive and dull feeling A sheet-like material having a soft texture could not be realized.
JP-A-8-41786

  The object of the present invention is a soft leather-like sheet that has a high-grade appearance that cannot be obtained by these conventional leather-like sheets, but has no surface tension, and has a surface that is similar to natural leather. It is to provide a leather-like sheet-like material having a feeling and a small wrinkle appearance at the time of bending, and a method for producing the same.

The leather-like sheet-like material of the present invention is a sheet-like material in which a skin layer is present on a substrate containing ultrafine fibers, and the ultrafine fibers constituting the substrate enter the skin layer in a fiber bundle state, and the skin layer Is characterized in that the polymer elastic body surrounds the outer periphery of the fiber bundle, but the polymer elastic body does not exist inside the fiber bundle. Further, the fine fiber occupies 20 to 80% of the void space of the polymer elastic body surrounding the outer periphery of the fiber bundle, and the apparent density of the skin layer is 0.6 g / cm ³ or more. Preferably there is.

  In addition, the method for producing a leather-like sheet according to the present invention comprises a polymer that surrounds the sea-island fibers without voids on a substrate containing ultra-fine fiber-forming sea-island fibers composed of two or more components having different solvent solubility. A skin layer made of an elastic material is formed, and then the sea component is removed using a solvent that dissolves the sea component of the sea-island fiber.

  Furthermore, the dissolution rate of the film using the polymer elastic body constituting the skin layer by the solvent that dissolves the sea component of the sea island fiber is 15% by weight or less, or the polymer elastic body constituting the skin layer is The area change rate after drying of the used film is preferably 5% or less. Moreover, it is preferable that a base | substrate contains a polymeric elastic body.

  According to the present invention, it is a leather-like sheet-like material having a surface feeling similar to natural leather and a small wrinkle appearance at the time of folding, and does not have a surface tension feeling while having such a high-grade appearance. A soft leather-like sheet and a method for producing the same are provided.

  The present invention relates to a leather-like sheet-like material with a silver tone in which a skin layer is present on a substrate containing ultrafine fibers.

  The ultrafine fiber in the present invention is an ultrafine fiber having a fineness of 0.2 dtex or less, preferably 0.1 dtex or less, particularly preferably 0.0001 to 0.05 dtex. Examples of such ultrafine fibers include polyester fibers such as polyethylene terephthalate and polybutylene terephthalate, and polyamide fibers such as nylon 6, nylon 66, and nylon 12. Furthermore, in the present invention, it is necessary that there are ultra-fine convergent fibers in which the ultra-fine fibers are assembled as a bundle. For example, as such an ultra-fine bundled fiber, at least one component of a multi-component fiber obtained by spinning as a sea-island type fiber by a composite spinning method, a mixed spinning method or the like from a polymer composition having two or more components different in solvent solubility is used. Examples thereof include fibers that have been removed to make them extremely fine. However, when the ultrafine fibers are in a bundle shape, the ultrafine fibers are preferably contained in 10 to 5000 fibers, more preferably 100 to 2000 fibers in one bundle.

  The substrate containing the ultrafine fibers of the present invention is not particularly limited as long as it is a sheet-like material containing the ultrafine fibers as described above, and all of the fibers may contain a portion of the ultrafine fibers instead of the ultrafine fibers. Such a substrate may be a woven or knitted fabric. However, in order to improve the feeling, the nonwoven fabric is mainly used, and the woven or knitted fabric is preferably included in part for reinforcement or not at all.

  Moreover, the base | substrate of this invention can be used also when the polymer elastic body is not included in parts other than the skin layer. However, in order to prevent the fibers from falling off and to increase the strength, the substrate of the present invention is preferably a sheet-like material in which fibers are filled with a polymer elastic body. In such a case, the polymer elastic body / fiber ratio is preferably 30 to 80%, and most preferably 40 to 60%.

  In this case, examples of the polymer elastic body filled in the substrate include polyurethane elastomers, polyurea elastomers, polyurethane / polyurea elastomers, polyacrylic resins, acrylonitrile / butadiene elastomers, styrene / butadiene elastomers. Polyurethane polymers such as elastomers, polyurea elastomers and polyurethane / polyurea elastomers are preferred.

  The polymer at this time may be the same as or different from the polymer elastic body of the skin layer described later, but is preferably different from the polymer elastic body of the skin layer, An elastic body is preferred. That is, the substrate may be substantially composed of only ultrafine fibers, but it is preferably composed of ultrafine fibers and a polymer elastic body. It is preferable that the body is a porous polyurethane formed by a wet coagulation method.

The 100% elongation modulus of the polymer elastic body used for the substrate is preferably 390 to 3000 N / cm ² . When the 100% elongation modulus is less than 390 N / cm ² , the obtained substrate is rich in flexibility, but the heat resistance, solvent resistance, etc. tend to decrease. Conversely, when it exceeds 3000 N / cm ² , the texture of the obtained substrate tends to be hard. As a method for adjusting the 100% elongation modulus of the polymer elastic body to a preferable range, for example, when a polyurethane elastomer is used, it can be easily performed by adjusting the content of organic diisocyanate and the amount of chain extender in the polymer.

  Further, the leather-like sheet of the present invention has a skin layer, the ultrafine fibers constituting the substrate enter the skin layer in a fiber bundle state, and the polymer elastic body constituting the skin layer is a fiber bundle. The outer circumference of the fiber bundle is surrounded, but the polymer elastic body does not exist inside the fiber bundle. Here, the outermost surface of the skin layer is preferably a suede tone or nubuck tone having napped hair, in addition to a silver tone. Here, the leather-like sheet-like material having a silver tone is one whose outermost surface is made of a polymer elastic body, and the leather-like sheet-like material having napping is a polymer elastic body that is close to the outermost surface of the skin layer. And ultrafine fibers exist, and the outermost surface of the sheet-like material has ultrafine fiber napping.

The leather-like sheet material of the present invention has a skin layer whose outermost surface is a polymer elastic body or ultrafine fiber, and the skin layer is mainly composed of a polymer elastic body. Examples of the polymer elastic body used for such a skin layer include polyurethane elastomers, polyurea elastomers, polyurethane / polyurea elastomers, polyacrylic acid resins, acrylonitrile / butadiene elastomers, styrene / butadiene elastomers, among others, polyurethane elastomers, Polyurethanes such as polyurea elastomers and polyurethane / polyurea elastomers are preferred. The 100% elongation modulus is preferably 390 to 1500 N / cm ² . When the 100% elongation modulus is less than 390 N / cm ² , the obtained leather-like sheet is rich in flexibility, but tends to decrease the wear resistance, heat resistance, solvent resistance, and the like. Conversely, when it exceeds 1500 N / cm ² , the texture of the obtained leather-like sheet tends to be hard, and properties such as bending resistance and low temperature hardness tend to be reduced.

  The polymer used for the skin layer preferably has high solvent resistance. As a more specific example, the weight reduction rate after being immersed in hot toluene at 80 ° C. for 3 minutes is 15% by weight or less, more preferably 10% by weight or less, most preferably 7 It is preferable that it is below wt%. Furthermore, it is preferable that the elastic polymer used for the skin layer has DMF solubility resistance in addition to toluene solubility resistance as solvent resistance. Examples of such a polymer elastic body include a crosslinked type, and examples thereof include a two-component type polyurethane. By having such DMF solubility resistance, it becomes possible to treat a wet polyurethane resin or the like dissolved in DMF at any stage for the purpose of reinforcing the base portion other than the skin layer.

  The leather-like sheet material of the present invention is composed of the base and the skin layer as described above. The most characteristic feature of the present invention is that the ultrafine fibers constituting the base are in a fiber bundle state in the skin layer. The polymer elastic body that intrudes in and forms the skin layer surrounds the outer periphery of the fiber bundle, but the polymer elastic body does not exist inside the fiber bundle. On the contrary, when the ultrafine fibers intruded into the skin layer in the form of ultrafine single fibers instead of fiber bundles, the ultrafine single fibers were densely present between the polymer elastic bodies and reinforced with the ultrafine single fibers. The polymer elastic body tends to be difficult to deform. In addition, the distance between the ultrafine fiber and the polymer elastic body is short, the degree of freedom of the fiber and the polymer elastic body is low, and there is a tendency to form a layer that is a hard structure. In contrast, when the ultrafine fibers are present in the fiber bundle, the polymer elastic body surrounds the fiber bundle, and the polymer elastic body does not exist inside the fiber bundle. The polymer elastic body which is large and is not reinforced with fibers exists in a relatively large lump, and the properties as an elastic body are strongly drawn out and easily deformed. In addition, the distance between the ultrafine fiber and the polymer elastic body is large, the degree of freedom of the fiber is large, and the structure becomes more flexible, and a flexible texture can be realized.

  In the present invention, since the polymer elastic body surrounds the fiber bundle, only the polymer elastic body is deformed and only a small stress is generated when the sheet-like material is small deformed. The deformation is transmitted to the fiber bundle surrounded by the elastic body, and a large stress is generated. In order to generate such a phenomenon, it is necessary that the fiber bundle is sufficiently surrounded by the polymer elastic body, and if possible, the cross section is preferably substantially circular. For example, when there is a crack in the polymer elastic body around the fiber bundle, or there is a part or direction in which stress to the fiber bundle is difficult to be transmitted in the space around the fiber bundle, Only the composite effect of fibers occurs, which is not preferable. Furthermore, it is preferable that the fine fiber occupies 20 to 80% of the void space of the polymer elastic body surrounding the fiber bundle, more preferably 30 to 70%, most preferably 40 to 60%. The occupied state is preferable. If the void space around the fiber bundle is too large, the stress to the fiber bundle is difficult to be transmitted and tends to have a low feeling of stretching, and conversely, if the void space is too small, it tends to be hard. In order for the polymer elastic body to take such a structure, the skin layer into which the ultrafine fiber bundle made of the polymer elastic body invades is a solid layer or an independent porous structure in which no voids are continuous. It is preferable to take

Moreover, it is preferable that the density of the skin layer of the leather-like sheet material of the present invention is 0.6 g / cm ³ or more. Further, it is preferably 0.8 g / cm ³ or more, most preferably 1.0 g / cm ³ or more. The upper limit depends on the density of the polymer, but is generally 1.4 g / cm ³ or less. When the density is too low, the polymer elastic body tends to be deformed more than necessary and tends to have a low feeling of stretching. Furthermore, the thickness of the skin layer is preferably 10 to 200 μm, more preferably 150 μm or less, and most preferably 20 to 100 μm. When the density and thickness are small, the surface physical properties tend to decrease, and when the density and thickness are large, the high-grade appearance such as the appearance of a small wrinkle at the time of bending tends to decrease. Moreover, it is preferable that the structural form is changing continuously along the thickness direction between the skin layer into which the fiber has penetrated and the inside of the base material.

  Further, when the outermost surface of the sheet-like material of the present invention has a silver tone, an adhesive layer in which the ultrafine fiber bundle penetrates as described above, and an ultrafine fiber bundle in the inside. It is preferably composed of two or more layers of the outer layer outside the adhesive layer into which no penetration has occurred. When there is an outer layer into which the fiber bundle does not penetrate, even if the entire skin layer is a thin layer, it is possible to prevent the occurrence of fluff of ultrafine fibers on the surface to be avoided in the case of a silver-tone surface. Since the adhesive layer into which the bundle penetrates exerts a strong anchor effect, the physical adhesive force can be improved.

  Furthermore, it is also preferable that the whole or a part of the skin layer is composed of a cross-linked type polymer. By using a crosslinking type, the surface strength and solvent resistance can be increased.

  Another method for producing a leather-like sheet according to the present invention is to enclose the sea-island fibers without voids on a substrate containing ultra-fine fiber-forming sea-island fibers composed of two or more components having different solvent solubility. In this method, a skin layer composed of the elastic polymer is formed, and then the sea component is removed using a solvent that dissolves the sea component of the sea-island fiber. At this time, the substrate is mainly composed of ultrafine fiber-forming sea-island fibers, but preferably contains a polymer elastic body when strength is required.

  By doing so, the ultrafine fibers constituting the substrate enter the polymer elastic body existing on the surface in a fiber bundle state, and the polymer elastic body constituting the skin layer surrounds the fiber bundle. In addition, a leather-like sheet-like product in which no polymer elastic body is present inside the fiber bundle can be produced. Such a sheet-like material is soft and has a low resilience.

  As the ultra-fine fiber-forming sea-island fiber composed of two or more components having different solvent solubility of the present invention, for example, specifically, a composite spinning method, mixing from a polymer composition having two or more components having different solvent solubility is used. This is a sea-island type fiber that is spun by a spinning method or the like. At this time, the fineness of the island component is 0.2 dtex or less, preferably 0.1 dtex or less, particularly preferably 0.0001 to 0.5 dtex.

  In addition, as a preferable combination of two or more polymer compositions having different solvent solubility, when polyester such as polyethylene terephthalate or polybutylene terephthalate is selected as an insoluble component, polyethylene, polypropylene, polystyrene as easily soluble components are selected. When a polyamide such as nylon 6, nylon 66, nylon 12 or the like is selected as the insoluble component, polyesters and polyolefins are preferably selected as the easily soluble component.

  The substrate including such ultrafine fiber-forming sea-island fibers used in the present invention is not particularly limited as long as it is in a sheet form, and may include fibers other than sea-island fibers or polymer elastic bodies. Also, any of various woven and knitted fabrics and non-woven fabrics may be used, but most preferably, a fibrous base material is impregnated and solidified with a polymer elastic body. The fibrous base material is also preferably based on a nonwoven fabric. For example, in order to make a fiber into a non-woven fabric, a known card, layer, needle locker, fluid entanglement device, or the like can be used, and a non-woven fabric that is densely and three-dimensionally entangled with a high density of entangled fibers can be obtained.

  Furthermore, the fibrous base material obtained here is not less than the softening temperature of the sea component constituting the sea island fiber and less than the softening temperature of the island component before impregnating and coating the polymer elastic body. It is preferable to adjust the thickness and the surface by pressing the sheet surface. Here, the thickness of the product finally obtained can be controlled by adjusting the thickness. Furthermore, the smoothness of the product surface can be controlled by adjusting the surface. Further, the degree of penetration of the elastic polymer solution can be adjusted by adjusting the heating and pressurizing conditions. When the prepared surface forms a film by fusion or the like, the polymer elastic body to be applied hardly penetrates, while the film cannot be formed by fusion or the like, and the outermost surface fiber density is low. Elastic body solutions penetrate well.

When the substrate containing the ultra-fine fiber-forming sea-island fibers is obtained by impregnating and solidifying the above-mentioned various fibrous base materials with a polymeric elastic body, the whole of the fibrous base material is made of an organic polymer elastic body. It is impregnated with a solvent solution or dispersion (including an aqueous emulsion) and coagulated by heat drying or wet coagulation. At this time, the concentration of the polymer elastic body liquid to be impregnated is preferably 5 to 25%. Further, the polymer elastic body to be impregnated is preferably porous, and most preferably a porous polymer elastic body having a density of 0.5 g / cm ³ or less as obtained by a known polyurethane wet coagulation method. Preferably there is.

  Next, in the production method of the present invention, it is necessary to form a skin layer or an impregnation layer made of a polymer elastic body that surrounds the sea-island fibers without voids on a substrate containing the sea-island fibers capable of forming ultrafine fibers. Independent pores such as bubbles may partially exist around the fiber, but it is basically preferable that the sea-island fiber and the polymer elastic body have no voids. When there is a void, the polymer elastic body cannot finally surround the outer periphery of the ultrafine fiber bundle. Furthermore, it is preferable that there is no gap between the fiber and the polymer elastic body, and no adhesion is made.

  As the method for forming the skin layer, any known method can be used, and a skin layer can be formed by laminating or coating a solution or dispersion comprising a polymer elastic body on a substrate.

  In order to obtain a leather-like sheet-like material with a silver tone, the most preferable method is a laminating method. Specifically, for example, a solution made of a polymer elastic body is cast on a release paper, and then dried to form a film. Then, a solution of a polymer elastic body to be an adhesive layer is re-applied, pasted onto a substrate before the solution is dried, and dried and bonded by heating. In this case, the skin layer is formed of two layers: an adhesive layer into which sea-island fibers have infiltrated and a film layer into which sea-island fibers have not infiltrated, and even when the skin layer is thin, the fluff of fibers is not on the surface. There is.

  Further, as a method for forming the skin layer, it is also preferable to apply a solution of a polymer elastic body on one surface of a substrate to form an impregnated layer and solidify the polymer elastic body. An impregnated layer is formed by coating a substrate with a solution or dispersion made of a polymer elastic body to form a skin layer. At this time, it is more preferable that the coagulation method of the polymer elastic body solution is a dry method. For example, it is preferable to apply an organic solvent solution or dispersion liquid (including an aqueous emulsion) of a polymer elastic body from one side of a fibrous base material, and sufficiently infiltrate the base material, and then solidify by heating and drying. Further, in order to adjust the impregnation depth, the number of times of application is not one time, but the amount of impregnation of the polymer elastic body in a portion closer to the surface layer by repeatedly applying and drying multiple times, for example, 2 to 5 times Can be increased and the texture can be improved.

  The solid component concentration of the polymer elastic body fluid applied at this time is preferably 5 to 50%. Further, it is more preferably 7 to 30%, and most preferably 10 to 20%. When the concentration is 5% or less, the viscosity of the polymer elastic body solution is too low to penetrate into the base material, and it is difficult to process uniformly because it cannot flow uniformly through the base material surface. On the other hand, as the concentration becomes higher, the viscosity of the polymer elastic body solution tends to increase, the balance of the degree of penetration into the base material tends to be lost, and it tends to be difficult to uniformly apply the polymer elastic body.

  Furthermore, in the coating method, the degree of penetration into the substrate can be adjusted by the viscosity of the polymer elastic body solution to be applied and the surface tension. In addition to adjusting the concentration of the elastic polymer, a general thickener can be used. Further, the surface tension of the polymer elastic body solution can be controlled by using various additives in the solution.

The polymer elastic body used for the skin layer of the present invention can be the same as the polymer elastic body preferably used for the impregnation of the whole substrate described above, but the 100% elongation modulus is 390 to 1500 N / cm ^2. It is preferable that When the 100% elongation modulus is small, the obtained leather-like sheet is rich in flexibility, but wear resistance, heat resistance, solvent resistance, etc. tend to decrease. The texture of the obtained leather-like sheet tends to be hard, and properties such as bending resistance and hardness at low temperatures tend to decrease.

  Moreover, it is preferable that this polymer elastic body is 15 weight% or less in weight reduction after being immersed in the solvent which melt | dissolves only the sea component of a fiber used at a next process. Further, it is preferably 10% by weight or less, and most preferably 7% by weight or less. The smaller the weight loss rate, the better the surface appearance after treatment. When the weight reduction rate is too large, a dissolution phenomenon occurs in the solvent that dissolves only the sea component of the fiber, and the surface appearance tends to be difficult to maintain.

  Furthermore, the high molecular weight polymer of the skin layer causes a swelling phenomenon with an area swelling rate of 2 to 160% in a solvent that dissolves only the sea component of the fiber, but by removing the solvent, the area change rate is 5% or less. Therefore, it is preferable to select and use an object that returns to its original shape. A polymer elastic body having a large area swelling ratio in a solvent that dissolves only the sea component of the fiber is one of the parts having a low molecular weight or a part that is soluble in the solvent in the solvent that dissolves only the sea component of the fiber. Part or most of the part is dissolved and the shape as a film cannot be maintained. Even if this is not the case, if the area swelling rate is large in a solvent that dissolves only the sea component of the fiber, the deformation at the time of swelling is large, and after the treatment, traces such as wrinkles remain randomly on the surface and the appearance is unstable. It tends to be a bad product.

  Here, when calculating | requiring a weight reduction | decrease rate or an area swelling rate, after making the film of 200 micrometers in thickness of a polymeric elastic body and immersing for 3 minutes in this solvent which melt | dissolves only the sea component of the fiber to process Measure with film. For example, when polyethylene is used as the sea component, the measurement is performed using toluene as the solvent. Moreover, the temperature at the time of processing may be used as the measurement temperature, for example, hot toluene at 80 ° C. is used.

  In the production method of the present invention, the sea component is then removed using a solvent that dissolves the sea component of the sea-island fiber. This solvent needs not to dissolve the island component of the ultrafine fiber, and may dissolve a small amount of the elastic polymer used in the substrate or the skin layer, but preferably it does not dissolve. By removing the sea component of the sea-island fiber in this way, a structure is formed in which the polymer elastic body is not joined to the ultrafine fiber of the island component in the skin layer. More specifically, for example, when nylon is used for the island component and polyethylene is used for the sea component, it is preferable to use toluene. It is also a preferable method to use a heated solvent in order to increase the extraction efficiency.

  At this time, it is preferable to shrink the base material portion from the original area while removing the sea component of the sea-island fiber. The degree of shrinkage can be adjusted by the density of the nonwoven fabric constituting the substrate, the modulus of the elastic polymer impregnated in the nonwoven fabric, and the amount of impregnation applied. If the density of the nonwoven fabric is low, the modulus of the polymer elastic body is low, and if the amount of impregnation is reduced, the shrinkage tends to increase. On the contrary, the density of the nonwoven fabric is high, and the modulus of the polymer elastic body is high. When the impregnation amount is increased, it tends to be difficult to shrink. Therefore, it is preferable to optimize these conditions and shrink the base material portion by 2 to 20% from the original area. More preferably, the shrinkage is in the range of 2 to 12%, and most preferably, the shrinkage is in the range of 2 to 7%.

  On the other hand, in the polymer elastic body forming the skin layer, a swelling phenomenon of 2 to 100% in the area swelling rate occurs in a solvent that dissolves only the sea component of the fiber, but the area change rate is reduced by removing the solvent. It is preferably 5% or less, more preferably 2% or less, and it is preferable to return to the original shape.

  And it is preferable that the value when the shrinkage rate of a skin layer is subtracted from the shrinkage rate of a base material is 1 to 25%. Furthermore, it is preferably 20% or less, most preferably 2 to 10%. Thus, when the shrinkage rate of the base material is larger than the shrinkage rate of the skin layer, the skin layer has a little feeling because the base material is shrinking relative to the original area of the skin, and the silver surface It is possible to obtain a soft sheet-like material that does not feel sticky. When the shrinkage of the base material with respect to the original area of the skin is small, the difference in area from the skin is small, and there is little feeling of the surface layer, and there is a tendency to feel the tension of the silver surface. On the other hand, if the shrinkage of the substrate relative to the original area of the skin is too large, the area difference from the skin is too large, and many wrinkles are generated from the surface layer, which tends to result in a surface with a poor appearance. .

  Furthermore, the obtained leather-like sheet-like product can be further trimmed by subjecting the polymer to a gravure treatment or an emboss treatment on the surface. Moreover, in the manufacturing method of this invention, it is also preferable to stagnate the base material obtained in this way. As a method of stagnation processing, for example, a sheet-like object is gripped by a clamp and one clamp is driven so that stagnation deformation is applied to the sheet, or a sheet-like object is placed between stays having two combined protrusions. For example, a method of carrying out kneading while pushing the protrusions into the threaded sheet.

  The leather-like sheet-like material of the present invention obtained in this way is an extremely stretch-resistant strength and low resilience, which is a characteristic of natural leather that cannot be possessed by conventional leather-like sheet materials. The product has a soft texture. Especially in the case of a leather-like sheet with a silver-tone tone made of a polymer elastic body, it has a high-grade appearance and is soft without the feeling of tension on the silver surface. Has a gavel appearance. The leather-like sheet-like material of the present invention is suitable for materials such as shoes, clothing, furniture, and gloves.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not restrict | limited by these. Unless otherwise specified in the examples, percentages (%) and ratios indicate weight% or weight ratios. The measured values in the examples are based on the following methods.

(1) Elongation modulus A test piece taken from a resin film (thickness: about 0.1 mm) was subjected to an elongation test at 100% / min with a constant speed elongation tester, and the load at the time of 100% elongation was read and N / cm ^2. Convert to units. The test piece conforms to JIS-K-6301-2 type dumbbell method.

(2) Skin layer density Obtained from the weight calculated from the thickness after coating on the release paper and drying, the polymer elastic solution concentration and the coating weight.

(3) Silver surface layer measurement average value Measured from a cross-sectional electron micrograph of the substrate.

(4) Thickness Measured with a spring-type dial gauge (load: 1.18 N / cm ² ).

(5) Weight A test piece cut to 10 cm × 10 cm is measured with a precision balance.

(6) 5% elongation stress (σ5) / 20% elongation stress (σ20) / tensile strength / elongation Test pieces taken from the leather-like sheet were subjected to an elongation test using a constant-speed elongation tester and 5% and 20% elongation. It is indicated by the load value at the time of breaking and breaking. The elongation at break is also measured. The test piece conforms to JIS-K-6550 5-2-1.

(7) Peeling strength A PVC sheet bonded with a plain woven fabric of the same size is bonded to the silver surface layer side of a test piece having a width of 2.5 cm and a length of 15 cm with a urethane adhesive. The test piece is marked with 5 sections at intervals of 2 cm, and a peel test is performed at a speed of 50 mm / min with a constant speed tensile tester. The peel strength at this time is recorded on a recorder, and the minimum value of each of the 5 sections at intervals of 2 cm is read, and the average value of the 5 points is converted per 1 cm width and displayed.

(8) Wear (number of times)
Using a Taber abrasion tester, measure the number of appearances up to grade 3 with a wear wheel CS10 load of 1 kg (9.8 N).

(9) Wear (weight loss)
Using a Taber abrasion tester, the weight change (mg) at the time of 100 wears is measured with a wear wheel # 280 load of 1 kg (9.8 N).

(10) Appearance / Crimp / Softness The “appearance”, “crimpiness”, and “softness” in the table are evaluated on a 10-to-10 scale. “5” is normal, and the larger the number, the better.

(11) Hip feeling In the table, “waist feeling” is 5 as normal, and the higher the number, the lower the waist, and the lower the number, the lower the waist.

(12) Bending softness (cantilever method)
A sample having a size of 2 cm × about 15 cm was used, and the measurement was performed according to the 45 ° cantilever method described in JIS L-1096 6.19.1. The unit was cm.

(13) Bending recovery rate The surface of the test piece having a width of 1 cm and a length of 9 cm is placed on the lower side and placed 1 cm beyond the end of the measuring table. Thereafter, the protruding portion is bent upward and a 9.8 N load is placed and left. The load is released exactly one hour after the load is applied, and the protractor measures how much the fold has recovered from the horizontal platform just 30 seconds after the load is released. The case where it is restored to horizontal (180 degrees) is 100%, and the case where it remains folded and does not change is 0%.

[Example 1]
Nylon-6 as an island component and low density polyethylene as a sea component were mixed and spun at 50/50 to obtain a sea-island type composite fiber having a fineness of 9.0 dtex. The obtained sea-island fiber was cut into a cut length of 51 mm to obtain raw cotton. This is made into a web using a card and a cross layer, needle punching is performed at 1000 pieces / cm ² , then heat-treated in a hot air chamber at 150 ° C., and pressed with a calender roll at 30 ° C. before the substrate cools down. A nonwoven fabric having a thickness of 370 g / m ² , a thickness of 1.4 mm, and an apparent density of 0.26 g / cm ³ was obtained.

Next, a dimethylformamide solution (solid content concentration) of Crisbon TF50P (polyurethane resin having a 100% elongation stress of 1080 N / cm ² , manufactured by Dainippon Ink & Chemicals, Inc., solid content concentration 30% by weight), which is a polymer elastic body. 15% impregnating solution (1)) was impregnated with 920 g / m ^{2 on} the nonwoven fabric obtained earlier, immersed in 12% DMF aqueous solution and wet coagulated, and then thoroughly washed in warm water at 40 ° C., It dried in a 135 degreeC hot air chamber, and obtained the base material which consists of a sea island fiber and a porous polymer elastic body.

On the other hand, Cu9430NL (polyurethane resin with a 100% elongation stress of 325 N / cm ² , manufactured by Dainichi Seika Kogyo Co., Ltd., solid content concentration of 30% by weight) as a polymer elastic body is a mixed solution of dimethylformamide and methyl ethyl ketone (mixing ratio: 4). : The solution for skin (1) diluted in 6) (solid content concentration 15%) was applied on release paper (AR-74M, thickness 0.25 mm, manufactured by Asahi Roll Co., Ltd.), coating amount, basis weight 250 g / m ² (wet), and a base material made of sea-island fibers and a porous polymer elastic body was laminated thereon, followed by drying at 100 ° C. for 30 seconds and then aging at 70 ° C. for 48 hours. The release paper was separated by cooling for a while to obtain a sheet having a skin layer made of a polymer elastic body on the surface.

At this time, the thickness of the film for the skin applied and dried on the release paper without being bonded to the substrate was 29 μm, and the density was 1.3 g / cm ³ . Moreover, after making this polymeric elastic body Cu9430NL film (thickness 200 micrometers) and immersing in 80 degreeC toluene for 3 minutes, the weight reduction | decrease rate is 5.5 weight%, The area swelling rate of the film at that time is It was 113.2%. Moreover, the area reduction rate after completely removing toluene from this film was 1.2%, and it was a polymer elastic body with little change in appearance even when treated in toluene at 80 ° C.

  Thereafter, dip and nip were repeated in toluene at 80 ° C. to dissolve and remove the polyethylene component which is the sea component of the sea-island fiber, and the sea-island fiber was made ultrafine. Subsequently, toluene contained in the base material was removed by azeotropic distillation in hot water at 90 ° C., and dried in a hot air chamber at 120 ° C. to obtain a sheet-like material composed of ultrafine fibers and a polymer elastic body. The area shrinkage rate of the base material in this sea component removal step was 4%.

Further, after applying a polyurethane resin having a 100% elongation stress of 350 N / cm ² to a surface having a skin layer made of a polymer elastic body of the obtained sheet-like material with a 200 mesh gravure roll, a softening agent is applied. The scumming process was performed.

  The obtained leather-like leather-like sheet-like material was soft and lumpy, and the surface of the silver layer was much more similar to high-quality natural leather, and the cramped feeling was also very good. . Further, the adhesion peeling performance on this surface was 29 N / cm, and a very good result was obtained. Furthermore, when the cross section of the surface was observed with a microscope, the ultrafine fibers constituting the substrate entered the skin layer in a fiber bundle state, and the polymer elastic body constituting the skin layer surrounded the outer periphery of the fiber bundle. However, no elastic polymer was present inside the fiber bundle. Further, in this skin layer, the ultrafine fibers and the polymer elastic body are substantially unbonded, and the space between the polymer elastic bodies surrounding the outer periphery of the fiber bundle is 50% by volume of the ultrafine fibers. % Accounted for. In addition, the structural form continuously changed along the thickness direction between the skin layer into which the fiber had invaded and the inside of the base material. The skin layer made of a polymer elastic body was a solid layer that was not made porous, and its thickness was an average of 34.8 μm.

[Example 2]
A base material composed of sea-island fibers and a polymer elastic body was prepared in the same manner as in Example 1.
On the other hand, the coating solution (1) (concentration 15%) of the polymer elastic body used in Example 1 was applied onto a release paper (AR-74M, thickness 0.25 mm, manufactured by Asahi Roll Co., Ltd.) It was applied at a basis weight of 100 g / m ² (wet) and first dried at 100 ° C. for 3 minutes. The film layer of the polymer elastic body obtained at this time had an average thickness of 11.5 μm and a density of 1.3 g / cm ³ .

Next, 20 parts of polymer elastic body Chrisbon TA265 (cross-linked polyurethane resin having a 100% elongation stress of 245 N / cm ² , manufactured by Dainippon Ink and Chemicals, Inc., solid content concentration 65% by weight), polymer elastic body Crisbon TA290 (Crosslinked polyurethane resin with 100% elongation stress of 245 N / cm ² , manufactured by Dainippon Ink & Chemicals, Inc., solid concentration 45% by weight), 80 parts, Coronate L (isocyanate-based crosslinking agent, manufactured by Nippon Polyurethane Co., Ltd.) ) 15 parts, 3 parts of Crisbon Axel T (crosslinking accelerator, manufactured by Dainippon Ink & Chemicals, Inc.) and 10 parts of dimethylformamide were prepared for a skin solution (2). On the film layer obtained above, the skin solution (2), which is a compounding solution for the adhesive layer, is applied in an application amount of 130 g / m ² (wet) per unit area. After the base materials to be bonded together, the substrate is dried at 100 ° C. for 30 seconds, then subjected to aging at 70 ° C. for 48 hours, then allowed to cool for 12 hours, the release paper is separated, and the surface is made of a polymer elastic body. A sheet-like material having a skin layer was obtained.

At this time, the thickness of the adhesive layer was 49 μm and the density was 1.0 g / cm ³ in the film for the skin applied and dried on the release paper without being bonded to the substrate. Also, a 200 μm thick film was prepared from a solution (2) for the skin consisting of the polymer elastic body Chrisbon TA265 and Crisbon TA290, the crosslinking agent Coronate L, and the crosslinking accelerator Chrisbon Axel T, and used in toluene at 80 ° C. After 3 minutes of immersion, the weight reduction rate was 2.6% by weight, and the area swelling rate of the film at that time was 96.0%. Moreover, the area change rate after completely removing toluene from this film is 0.8%, and it is a polymer elastic body with little change in appearance even when treated in toluene at 80 ° C. It could be confirmed.

  Thereafter, the obtained sheet-like material was repeatedly dipped and niped in toluene at 80 ° C. to dissolve and remove the polyethylene component, which is the sea component of the sea-island fiber, and to refine the sea-island fiber. Thereafter, toluene contained in the base material was removed by azeotropic distillation in warm water at 90 ° C., and dried in a hot air chamber at 120 ° C. to obtain a sheet-like material composed of ultrafine fibers and a polymer elastic body. At this time, the area shrinkage of the sheet was 3%.

  Furthermore, the polyurethane resin was apply | coated to the surface of the obtained sheet-like material with the gravure roll similarly to Example 1, the softening agent was provided, and the stagnation process was performed.

  The resulting silvered leather-like sheet-like product was soft and had a good surface tightness. The adhesion peeling performance on this surface was 27 N / cm, which was a very good result. Furthermore, when the cross section of the surface was observed with a microscope, the ultrafine fibers constituting the substrate entered the adhesive layer in the skin layer in a fiber bundle state, and the polymer elastic body constituting the adhesive layer was in the fiber bundle. Although the outer periphery was surrounded, the polymer elastic body did not exist in the inside of the fiber bundle, and the ultrafine fibers did not penetrate into the outer film layer of the adhesive layer. Furthermore, the ultrafine fibers and the polymer elastic body are substantially non-bonded, and in the skin layer, the space between the polymer elastic bodies surrounding the outer periphery of the fiber bundle is 50% by volume of the ultrafine fibers. Accounted for. In addition, the structural form continuously changed along the thickness direction between the skin layer into which the fiber had invaded and the inside of the base material. The skin layer made of a polymer elastic body was a solid layer that was not made porous, and its thickness was an average of 65.3 μm.

[Example 3]
A base material composed of sea-island fibers and a polymer elastic body was prepared in the same manner as in Example 1.
On the other hand, the coating solution (1) (concentration 15%) of the polymer elastic body used in Example 1 was applied onto a release paper (AR-74M, thickness 0.25 mm, manufactured by Asahi Roll Co., Ltd.) It was applied at a basis weight of 60 g / m ² (wet) and first dried at 100 ° C. for 3 minutes. The layer thickness of the polymer elastic body obtained at this time was 6.9 μm on average and the density was 1.3 g / cm ³ .

Next, on the obtained film, the skin solution (2), which is the compounding solution for the adhesive layer used in Example 2, was applied at a coating amount and a basis weight of 90 g / m ² (wet). And a substrate made of a polymer elastic body are bonded together, dried at 100 ° C. for 30 seconds, then subjected to aging at 70 ° C. for 48 hours, followed by cooling for 12 hours, separating the release paper, A sheet-like material having a layer of a polymer elastic body was obtained. At this time, the thickness of the adhesive layer was 34 μm and the density was 1.0 g / cm ³ in the film for the skin applied and dried on the release paper without being bonded to the substrate.

  Thereafter, the same processing as in Example 2 was performed to finish as a leather-like leather-like sheet. The area shrinkage of the sheet-like material in the polyethylene component removing step was 6%.

  The obtained leather-like leather-like sheet-like material was very soft, and a high-quality feeling was expressed in the surface silver surface layer, and the tight feeling was good. Moreover, the adhesive peeling performance on this surface was as good as 26 N / cm. Further, when the cross section of the surface was observed with a microscope, an ultrafine fiber bundle was present as in Example 2, and the ultrafine fiber and the polymer elastic body were substantially unbonded. Further, the skin layer made of a polymer elastic body was a solid layer that was not made porous, and its thickness was an average of 45.0 μm. In addition, the structural form continuously changed along the thickness direction between the skin layer into which the fiber had invaded and the inside of the base material.

[Example 4]
A base material composed of sea-island fibers and a polymer elastic body was prepared in the same manner as in Example 1.
On the other hand, as an aqueous dispersion (1) of a polymer elastic body, a water dispersion type polymer elastic body Hydran TMS-172 (aqueous self-emulsifying polyurethane resin, manufactured by Dainippon Ink & Chemicals, Inc., solid content concentration: 35 wt. %) / DISPERSE HG-950 (water dispersible black pigment, manufactured by Dainippon Ink & Chemicals, Inc.) / Water-repellent fine particles S-21 (methylated silica content: 12%, manufactured by Matsumoto Yushi Seiyaku Co., Ltd., solid content) Concentration 20% by weight) / Water-repellent fine particles C-10 (Methylated silica content 5.9%, manufactured by Matsumoto Yushi Seiyaku Co., Ltd., solid content 30%) / Hydran WL Assister T1 (urethane thickener, large Nippon Ink Chemical Co., Ltd.) / Hydran WL Assist C3 (isocyanate-based crosslinking agent, Dainippon Ink & Chemicals Co., Ltd.) = 100/5/30/20/4 (parts by weight) . This aqueous dispersion (1) was applied on a release paper (AR-144SM, thickness 0.25 mm, manufactured by Asahi Roll Co., Ltd.) with a coating thickness of 300 μm (wet), and first pre-dried at 70 ° C. for 3 minutes. It was. The water content in the film at this time was 60 wt%. Next, drying is carried out in three stages of 95 ° C. for 3 minutes and 120 ° C. for 10 minutes, and an independent porosity having a density of 0.59 g / cm ^{3 made} of a polymer elastic body having a thickness of 0.10 mm and a basis weight of 59 g / m ² A porous sheet was formed.

Next, as an aqueous dispersion (2) of a polymer elastic body, a water dispersion type polymer elastic body Hydran TMA-168 (aqueous polyurethane resin, manufactured by Dainippon Ink & Chemicals, Inc., solid content concentration: 45% by weight) / DISPERSE HG-950 (water dispersible black pigment, manufactured by Dainippon Ink & Chemicals, Inc.) / Hydran WL Assister T1 (urethane thickener, manufactured by Dainippon Ink & Chemicals, Inc.) / Hydran WL Assistor C3 ( Isocyanate-based crosslinking agent, manufactured by Dainippon Ink & Chemicals, Inc.) = 100/5/1/10 (part). This aqueous dispersion (2) was applied as an adhesive compounding liquid on the porous sheet obtained from the aqueous dispersion (1) so as to have a dry basis weight of 60 g / m ² at a coating thickness of 150 μm (wet). After coating, pre-dry at 70 ° C. for 2 minutes, and then stick to a substrate made of sea-island fibers and a polymer elastic body. Preheat it for 15 seconds by bringing the release paper side into contact with a thermal cylinder (surface temperature 130 ° C.). Thereafter, a hot nip was performed using the hot cylinder under the condition of a clearance of 1.0 mm, followed by curing at 120 ° C. for 2 minutes. Further, after aging at 50 ° C. for 24 hours, the release paper was separated to obtain a sheet-like material having a skin layer made of a polymer elastic body on the surface. At this time, the thickness of the adhesive layer was 46 μm and the density was 1.3 g / cm ³ in the film for the skin applied and dried on the release paper without being bonded to the substrate.

  Thereafter, the obtained sheet-like material was repeatedly dipped and niped in toluene at 80 ° C. to dissolve and remove the polyethylene component, which is the sea component of the sea-island fiber, and to refine the sea-island fiber. Thereafter, toluene contained in the base material was removed by azeotropic distillation in warm water at 90 ° C., and dried in a hot air chamber at 120 ° C. to obtain a sheet-like material composed of ultrafine fibers and a polymer elastic body. At this time, the area shrinkage of the sheet was 7%.

  Furthermore, the polyurethane resin was apply | coated to the surface of the obtained sheet-like material with the gravure roll similarly to Example 1, the softening agent was provided, and the stagnation process was performed.

  The obtained leather-like leather-like sheet-like material was soft and supple, and the surface of the silver surface layer had a good feeling of cramping. Moreover, the adhesive peeling performance on this surface was as good as 25 N / cm. Further, when the cross section of the surface was observed with a microscope, and further, when the cross section of the surface was observed with a microscope, an ultrafine fiber bundle was present in the same manner as in Example 2, and the ultrafine fiber and the polymer elastic body were substantially It was unbonded. In addition, the structural form continuously changed along the thickness direction between the skin layer into which the fiber had invaded and the inside of the base material. The polymer elastic film layer made of the water dispersion (1) into which the fiber bundle has not penetrated is made porous, but the polymer made from the water dispersion (2) into which the fiber bundle has penetrated. The elastic adhesive layer was not made porous, and the thickness of the entire skin layer was 154.5 μm on average.

[Comparative Example 1]
A nonwoven fabric composed of sea-island fibers and having a basis weight of about 370 g / m ² , a thickness of 1.4 mm, and an apparent density of 0.26 g / cm ³ was produced in the same manner as in Example 1.

Next, this non-woven fabric is used as a polymer elastic body to be impregnated with the base material, Crisbon TF50P / Chrisbon TF300TD (100% elongation stress of 2750 N / cm ² polyurethane resin, manufactured by Dainippon Ink & Chemicals, Inc., solid content concentration 30% by weight) = 6/4 dimethylformamide solution (solid content concentration 15%), squeeze the excess impregnating solution so that the weight of the impregnating solution is 920 g / m ² , and then continue as a polymer elastic body to become the skin layer TF50P / Crisbon TF700S (polyurethane resin with 100% elongation stress of 340 N / cm ² , manufactured by Dainippon Ink & Chemicals, Inc., solid content concentration 30% by weight) = 9/1 dimethylformamide solution (solid content concentration 20%) Was coated so as to have a basis weight of 300 g / m ² . Next, the sheet comprising the nonwoven fabric and the polymer elastic body is immersed in a 12% DMF aqueous solution and wet-coagulated, and then thoroughly washed in warm water at 40 ° C. and dried in a hot air chamber at 135 ° C. A sheet-like material having a skin layer made of a polymer elastic body on a substrate made of a fiber and a polymer elastic body was obtained. The polymer elastic bodies here were all porous having continuous porosity by wet coagulation.

Thereafter, dip and nip were repeated in toluene at 80 ° C. to dissolve and remove the polyethylene component which is the sea component of the sea-island fiber, and the sea-island fiber was made ultrafine. Subsequently, toluene contained in the base material was removed by azeotropic distillation in hot water at 90 ° C., and dried in a hot air chamber at 120 ° C. to obtain a sheet-like material composed of ultrafine fibers and a porous polymer elastic body. Further, after embossing the surface having the skin layer of the obtained sheet-like material to give a texture pattern, a polyurethane resin having a 100% elongation stress of 350 N / cm ² is finished and applied with a 200-mesh gravure roll, and then a softening agent. And scouring.

  The obtained silver-colored sheet-like product was soft but lacked in softness, and the feeling of cramping in the surface silver layer was not so good. On the other hand, the adhesive peeling performance on this surface was as good as 25 N / cm. Furthermore, when the cross section of the surface was observed with a microscope, the ultrathin fibers constituting the base had entered the skin layer in a fiber bundle state, but the polymer elastic body constituting the skin layer had a porous structure. The outer periphery of the fiber bundle could not be surrounded, and the adhesion between the fiber and the polymer elastic body was low. Moreover, the average thickness of the skin layer mainly composed of a polymer elastic body was 230.8 μm.

[Comparative Example 2]
Comparative Example 1 except that the coat weight of the dimethylformamide solution (solid content concentration 20%) of the polymer elastic body to be the skin layer of Comparative Example 1 was set to 150 g / m ² instead of 300 g / m ² In the same manner as in No. 1, a leather sheet was prepared.

  The obtained silver-colored sheet-like product was soft but lacked in softness, and the feeling of cramping in the surface silver layer was not so good. Further, the fibers of the nonwoven fabric layer jumped out from the surface in a fluffy shape, and the appearance was very bad. Further, the result of the adhesive peeling performance on this surface was as low as 20 N / cm. Further, when the cross section of the surface was observed with a microscope, the polymer elastic body constituting the skin layer had a continuous porous structure and could not surround the outer periphery of the fiber bundle, and the degree of adhesion between the fiber and the polymer elastic body was It was low. Moreover, the average thickness of the skin layer mainly composed of a polymer elastic body was 169.2 μm.

[Comparative Example 3]
A base material composed of sea-island fibers and a polymer elastic body was prepared in the same manner as in Example 1.
Next, the base material having no skin layer was repeatedly dip and niped in toluene at 80 ° C. to dissolve and remove the polyethylene component, which is the sea component of the sea-island fiber, and thereby refined the sea-island fiber. Thereafter, toluene contained in the base material is removed azeotropically in hot water at 90 ° C., dried in a hot air chamber at 120 ° C., and composed of ultrafine fibers having no polymer elastic layer on the surface and a polymer elastic material. A sheet material for a substrate was obtained.

On the other hand, the coating solution (1) (concentration 15%) of the polymer elastic body used in Example 1 was applied onto a release paper (AR-74M, thickness 0.25 mm, manufactured by Asahi Roll Co., Ltd.) The coating weight was 130 g / m ² (wet), and it was first dried at 100 ° C. for 3 minutes. The thickness of the layer of the polymer elastic body obtained at this time was 15.0 μm on average, and the density was 1.3 g / cm ³ .

Next, on the obtained film, the skin solution (2), which is the compounding solution for the adhesive layer used in Example 2, was applied at a coating amount and a basis weight of 100 g / m ² (wet). And a substrate sheet made of a polymer elastic material, and then dried at 100 ° C. for 30 seconds, then aged at 70 ° C. for 48 hours, then allowed to cool for 12 hours to separate the release paper Thus, a sheet-like material having a layer of a polymer elastic body on the surface was obtained. At this time, the thickness of the adhesive layer was 37.7 μm and the density was 1.0 g / cm ³ in the film for the skin applied and dried on the release paper without being bonded to the substrate.

Thereafter, a polyurethane resin having a 100% elongation stress of 350 N / cm ² was finished with a 200-mesh gravure roll on the surface of the obtained sheet-like material having a skin layer, and then a softening agent was applied to perform stagnation.

  The obtained leather-like leather-like sheet-like material obtained had a good feeling of cramping, but had a surface tension and became a hard material. Further, the result of the adhesion peeling performance on this surface was a little low, 18 N / cm. Furthermore, when the cross section of the surface was observed with a microscope, the ultrafine fibers present in the skin layer were partly bundled, but the polymer elastic body entered the ultrafine fiber bundle, and the fibers and the polymer The elastic body was joined. The elastic polymer constituting the skin layer had a non-porous structure, and the average thickness was 56.5 μm.

[Example 5]
Nylon-6 as an island component and low density polyethylene as a sea component were mixed and spun at 50/50 to obtain a sea-island type composite fiber having a fineness of 9.0 dtex. The obtained conjugate fiber was cut into a cut length of 51 mm to obtain raw cotton. This is made into a web using a card and a cross layer, needle punching is performed at 1000 pieces / cm ² , then heat-treated in a hot air chamber at 150 ° C., and pressed with a calender roll at 30 ° C. before the substrate cools down. A nonwoven fabric (sheet) was obtained which was formed from sea-island type composite fibers having an ultrafine fiber shape of 450 g / m ² , thickness 1.5 mm, and apparent density 0.30 g / cm ³ .

Next, Crisbon TF50P (polymer elastic body (1) having a 100% elongation stress of 1080 N / cm ² , polyurethane resin) used in Example 1 was mixed with dimethylformamide (hereinafter referred to as DMF) and methyl ethyl ketone (mixing ratio). Apply the impregnated skin solution (1) (concentration: 15%) diluted 4: 6) to the surface of the non-woven fabric obtained previously so that the basis weight of the solution is 150 g / m ² (wet). After sufficient impregnation, it was dried in a hot air chamber at 120 ° C. Further, the same impregnating type skin solution (3) was applied again to the previously applied surface so as to have a basis weight of 150 g / m ² (wet), and the impregnated layer was formed by thoroughly soaking in the sheet. And dried in a hot air chamber to obtain an impregnated base material in which only the surface side was impregnated with the polymer elastic body (1).

  It was confirmed by an electron micrograph that the polymer elastic body (1) impregnated and distributed at this time was distributed from the surface side to an average depth of 120 μm in a solid state. 8% of the substrate thickness. The weight loss rate of the used polymer elastic body (1) with respect to the organic solvent was 1.6% with respect to toluene (80 ° C., 3 minutes).

  Thereafter, the impregnated substrate was repeatedly dipped and niped in toluene at 80 ° C. to dissolve and remove the polyethylene component of the sea component, and the composite fiber was made ultrafine. Thereafter, toluene contained in the base material was removed by azeotropic distillation in hot water at 90 ° C., and dried in a hot air chamber at 120 ° C. to obtain a leather-like sheet material in which the fibers were made into ultrafine fibers.

Further, 20 g / m ^{2 of} DMF, which is a good solvent for the impregnated polyurethane resin, was applied to the surface of the obtained leather-like sheet impregnated with a resin with a 200 mesh gravure roll and dried, and the surface was coated with a particle size of # 320. A suede-like leather-like sheet having napped fibers was obtained by polishing the surface fibers and raising the surface fibers.

The suede-like leather-like sheet was dyed with a metal-containing dye and then finished by scouring. When the cross section of the obtained sheet-like material was observed with an electron micrograph, the structural forms of the skin layer and the unimpregnated layer formed from the polymer elastic body (1) and the ultrafine fiber bundle were continuously changed. It was also confirmed that the skin layer was distributed from the surface side to an average depth of 105 μm. The ratio of the fibers of the skin layer to the polymer elastic body was 29:71, and the fiber basis weight of the unimpregnated portion where no polyurethane resin was present was 207 g / m ² . In the skin layer, about 1000 ultrafine fibers having an average fineness of 0.005 dtex are present in a bundle of about 1000 fibers, and there is no polymer elastic body inside the fiber bundle, and the ultrafine fiber bundle is surrounded. In the void space of the polymer elastic body, the ultrafine fibers occupied 50% of the space volume.

  The obtained sheet-like material was difficult to extend in any direction, and the values of the bending resistance by the cantilever were 6.2 cm and the width was 6.3 cm, and the characteristics of the soft material in the bending direction were observed. The value of σ20 / σ5 was vertical 3.7, horizontal 4.8, and an excellent value for artificial leather, but the bending recovery rate was 5%, showing almost no repulsive force. The obtained leather-like sheet was a very soft and low-resilience material, and resembled high-grade and soft natural leather when held. Table 3 shows the physical properties.

[Example 6]
In the same manner as in Example 5, except that a sea-island type composite fiber of nylon-6 and low-density polyethylene was used, the basis weight was increased, and the needle punching was changed to 1400 pieces / cm ² , the basis weight was 570 g / m ^2. A nonwoven fabric (sheet) having a thickness of 2.3 mm and an apparent density of 0.25 g / cm ³ was obtained.

Next, using the same polymer elastic body (1) impregnated type skin solution (3) (concentration 15%) as in Example 5 except that the basis weight of the solution was changed to 340 g / m ² (wet). As in No. 5, it was applied to the surface of the non-woven fabric obtained earlier, sufficiently impregnated into the sheet, and then dried in a hot air chamber at 120 ° C. to obtain an impregnated base material impregnated with a polymer elastic body only on the surface side. It was. It was confirmed with an electron micrograph that the polymer elastic body (1) impregnated at this time was distributed in a solid form to an average depth of 150 μm from the surface side. It is 6.5% of the substrate thickness.

  Thereafter, the polyethylene component was dissolved and removed from the impregnated base material in the same manner as in Example 5 to obtain a leather-like sheet-like product with ultrafine fibers.

  Further, the surface of the obtained leather-like sheet was surface-treated in the same manner as in Example 5 to obtain a napped and dyed suede-like leather-like sheet. When the cross section of the obtained sheet-like material was observed with an electron micrograph, the structural forms of the skin layer and the unimpregnated layer formed from the polymer elastic body (1) and the ultrafine fiber bundle were continuously changed. Further, it was confirmed that the skin layer was distributed from the surface side to an average depth of 128 μm. In the skin layer, ultrafine fibers exist in a fiber bundle state, and there is no polymer elastic body inside the fiber bundle. In the void space of the polymer elastic body surrounding the ultrafine fiber bundle, The fiber occupied 50% of the space volume.

  The obtained sheet-like material was not easily stretched in any direction, both vertically and horizontally compared to its thickness, and when held, it was a very soft and low-resilience material similar to high-quality and soft natural leather. The physical properties are also shown in Table 3.

[Example 7]
In the same manner as in Example 5, except that a sea-island type composite fiber of nylon-6 and low-density polyethylene was used, the basis weight was increased, and needle punching was changed to 1400 pieces / cm ² , the basis weight was 870 g / m ^2. A nonwoven fabric (sheet) having a thickness of 2.8 mm and an apparent density of 0.31 g / cm ³ was obtained.

Next, the same polymer elastic body (1) impregnated type skin solution (3) (concentration: 15%) as in Example 5 was used, and the solution basis weight was first obtained to be 320 g / m ² (wet). After applying to the surface of the non-woven fabric and thoroughly soaking into the sheet, it is dried in a hot air chamber at 120 ° C., and then the same impregnation solution is applied to the surface opposite to the above so that the basis weight is 320 g / m ^2. After coating and soaking into the sheet, it is dried in a hot air chamber at 120 ° C. to obtain a double-side impregnated base material in which only the both surface sides of the base material other than the center part of the sheet are impregnated with the polymer elastic body (1). It was. It was confirmed by electron micrographs that the polymer elastic body (1) impregnated at this time was distributed to an average depth of 150 μm from both surfaces of the base material in a solid form. The impregnation depth is 4.5% on one side.

  Thereafter, the polyethylene component was dissolved and removed from the impregnated base material in the same manner as in Example 5 to obtain a sheet-like material with ultrafine fibers.

After that, both surfaces impregnated with a sheet-like polymeric elastic body were applied with 20 g / m ² of DMF with a 200 mesh gravure roll, dried, and then both surfaces were polished with abrasive paper of particle size # 320. After raising the surface fibers, slicing was performed at a half-thickness portion which is an unimpregnated portion of the polymer elastic body to obtain a leather-like sheet-like material having a suede appearance.

  Further, the obtained leather-like sheet was treated in the same manner as in Example 5 to obtain a napped and dyed suede-like leather-like sheet. When the cross section of the obtained sheet-like material was observed with an electron micrograph, the structural forms of the skin layer and the unimpregnated layer formed from the polymer elastic body (1) and the ultrafine fiber bundle were continuously changed. Further, it was confirmed that the skin layer was distributed from the surface side to an average depth of 125 μm. In the skin layer, ultrafine fibers exist in a fiber bundle state, and there is no polymer elastic body inside the fiber bundle. In the void space of the polymer elastic body surrounding the ultrafine fiber bundle, The fiber occupied 50% of the space volume.

  The obtained sheet-like material was not easily stretched in any direction diagonally and longitudinally compared to its thickness, and was easily deformed with low stress. However, there was a characteristic characteristic of soft natural leather that stopped growing when stretched a little. The physical properties are also shown in Table 3.

[Example 8]
The same processing as in Example 6 was performed to obtain a leather-like sheet material in which the fibers were extremely thinned.
Furthermore, instead of raising the surface of the obtained leather-like sheet-like material to make a suede tone, a polymer elastic layer was applied to the surface in order to obtain a silver tone.

That is, the skin solution (1) used in Example 1 (100% elongation stress of 325 N / cm ² polyurethane resin, solid content concentration 15% by weight) was released from release paper (AR-74M, thickness 0.25 mm, Asahi The coating weight was 130 g / m ² (wet) on a roll (manufactured by Roll Co., Ltd.) and first dried at 100 ° C. for 3 minutes. Next, on the obtained film, the skin solution (2), which is an adhesive compounding solution used in Example 2, was applied at a basis weight of 100 g / m ² (wet), and the leather-like sheet was applied thereon. After bonding the surfaces impregnated with the polymer elastic body (1) as a bonding surface, drying was performed at 100 ° C. for 30 seconds, and then aging was performed at 70 ° C. for 48 hours, followed by cooling for 12 hours. The release paper was separated to obtain a leather-like sheet-like material with a silver tone having a polymer elastic layer on the surface.

Further, a polyurethane resin having a 100% elongation stress of 350 N / cm ² was finished with a 200 mesh gravure roll on the surface of the sheet-like material having a skin layer, and then a softening agent was applied to stagnation.

When the cross section of the obtained leather-like sheet was observed with an electron micrograph, the impregnated layer in the skin layer where the polymer elastic body was present was distributed to an average depth of 128 μm from the lower side of the adhesive layer on the surface side. It was confirmed that The ratio of the fibers of the impregnated layer to the polymer elastic body was 27:73, and the fiber basis weight of the non-impregnated portion where no polymer elastic body was present was 266 g / m ² . In the impregnated layer, ultrafine fibers exist in a fiber bundle state, and no polymer elastic body exists inside the fiber bundle. In the void space of the polymer elastic body surrounding the ultrafine fiber bundle, The fiber occupied 50% of the space volume.

  Moreover, this leather-like sheet-like material had a good feeling of cramping and was a very soft and low-resilience material similar to high-quality and soft natural leather when held. The physical properties are also shown in Table 3.

Claims (15)

  A sheet-like material having a skin layer on a substrate containing ultrafine fibers, wherein the ultrafine fibers constituting the substrate penetrate into the skin layer in a fiber bundle state, and the polymer elastic body constituting the skin layer is the fiber. A leather-like sheet-like material characterized in that it surrounds the outer periphery of the bundle, but no polymer elastic body is present inside the fiber bundle.   The leather-like sheet material according to claim 1, wherein the fine fibers occupy 20 to 80% of the void space of the polymer elastic body surrounding the outer periphery of the fiber bundle. The leather-like sheet material according to claim 1 or 2, wherein the apparent density of the skin layer is 0.6 g / cm ³ or more.   The leather-like sheet material according to any one of claims 1 to 3, wherein the skin layer has a thickness of 10 to 200 µm.   The leather-like sheet material according to any one of claims 1 to 4, wherein the substrate comprises a polymer elastic body.   The leather-like sheet-like material according to any one of claims 1 to 5, wherein the skin layer has a structure of two or more layers, and at least one layer is a layer into which the ultrafine fiber bundle does not penetrate.   The leather-like sheet material according to any one of claims 1 to 6, wherein the polymer elastic body constituting the skin layer is a crosslinked type.   The leather-like sheet material according to any one of claims 1 to 7, wherein the skin layer is a solid layer or an independent porous layer.   On the substrate containing ultra-fine fiber-forming sea-island fibers composed of two or more components having different solvent solubility, a skin layer made of a polymer elastic body surrounding the sea-island fibers without voids is formed, and then the sea-island fiber sea A method for producing a leather-like sheet, wherein a sea component is removed using a solvent that dissolves the component.   The method for producing a leather-like sheet-like material according to claim 9, wherein the dissolution rate of the film using the polymer elastic body constituting the skin layer is 15% by weight or less by the solvent for dissolving the sea component of the sea-island fiber.   The leather-like sheet-like material according to claim 9 or 10, wherein the area change rate after drying of the film using the polymer elastic body constituting the skin layer by the solvent that dissolves the sea component of the sea-island fiber is 5% or less. Production method.   The method for producing a leather-like sheet according to any one of claims 9 to 11, wherein the substrate comprises a polymer elastic body. The leather-like sheet material according to any one of claims 9 to 12, wherein a skin layer is formed by a laminating method.   The method of forming a skin layer is a method in which a solution of a polymer elastic body is applied to one surface of a substrate to form an impregnated layer, and the polymer elastic body is solidified. A method for producing a leather-like sheet.   The method for producing a leather-like sheet material according to any one of claims 9 to 14, wherein a polymer elastic body is further provided on the surface of the sheet material.