Kuraray Co., Ltd.

Mikasa Corporation

Tetsuya Ashida

Hisao Yoneda

Koji Hirai

Shizuo Iwata

Kansai Hara

Kimio Nakayama

Michinori Fujisawa

Michihiro Ishiguro

Hisaichi Watanabe

Kazumasa Inoue

Shinya Kato

Yoshiki Nobuto

Yukio Maeda

Shinya Katoh

Yasutoshi Nomura

Norio Makiyama

Yoshiaki Yasuda

Taketoshi Saeki

Daisuke Tanaka

Shinichi Yoshimoto

Koki Ogata

Tuyosi Yamasaki

Kyoichi Fujimoto

Kozo Hayashi

Osamu Ogawara

Disclosed is a grain-finished leather-like sheet including: a fiber base material; and a polyurethane skin film stacked, as a surface layer, directly on the fiber base material or via another polyurethane layer, wherein the polyurethane skin film contains at least one of a diketopyrrolopyrrole-based red pigment and an α-type phthalocyanine-based blue pigment, the grain-finished leather-like sheet further includes a clear polyurethane film layer coating the polyurethane skin film, and the grain-finished leather-like sheet has a grade of color difference, determined using a Grey scale for assessing staining, of 4-5 or more, when 0.03 g of oleic acid is added dropwise to a surface of the clear polyurethane film layer, and thereafter a white cotton fabric is reciprocated 100 times on the surface, using a crockmeter.

Grain-finished leather-like sheet and evaluation method for grain-finished leather-like sheet

Disclosed is a grain-finished leather-like sheet including a polyurethane skin film containing a polyether-based polyurethane, wherein the polyurethane skin film contains a quinacridone-based red pigment, and is colored in a red color having an L* value of ≤80, an a* value of ≥20, and a b* value of ≤15 in an L*a*b* color system, and the number of cycles of a flexing endurance test at which cracking occurs in a surface of the polyurethane skin film is 100000 or more, when the flexing endurance test is performed on the grain-finished leather-like sheet under an environment of 20° C. using a flexometer after the grain-finished leather-like sheet has been irradiated with carbon arc at a black panel temperature of 63° C. for 100 hours with an irradiance of 500±50 W/m, using ultraviolet carbon arc lamp light compliant with JIS B 7751.

Grained leather-like sheet

Disclosed is a grain-finished leather-like sheet including: a fiber base material; a polyurethane intermediate layer stacked on the fiber base material; and a polyurethane skin film stacked directly on the polyurethane intermediate layer or via another polyurethane layer, wherein the polyurethane skin film contains a silicone-modified polyurethane, and the grain-finished leather-like sheet has an uneven surface whose skewness (Ssk), kurtosis (Sku), and maximum height (Sz) of surface roughness in accordance with ISO 25178 respectively satisfy &#x2212;0.4&#x2264;Ssk&#x2264;&#x2212;0.2, 3&#x2264;Sku&#x2264;4, 60 &#x3bc;m&#x2264;Sz&#x2264;150 &#x3bc;m.

Grain-finished leather-like sheet

Disclosed herein is a method for producing an elastically stretchable artificial leather, which includes the steps of forming microfiberizable fibers into a web, entangling the obtained web to produce an entangled nonwoven fabric, converting the microfiberizable fibers in the nonwoven fabric to microfine fibers thereby producing a substrate for artificial leather, producing an artificial leather from the obtained substrate for artificial leather, bringing the obtained artificial leather into close contact with an elastomer sheet stretched in a machine direction by 5 to 40%, shrinking the artificial leather in the machine direction simultaneously with the elastomer sheet by relaxing elongation of the elastomer sheet to obtain an artificial leather in shrunk state, heat treating the artificial leather in shrunk state, and then peeling the heat treated artificial leather off from the elastomer sheet.

Elastic artificial leather and production method therefor

A production method of an elastically stretchable artificial leather which includes a step of making microfiberizable fibers into a web; a step of entangling the obtained web to produce an entangled nonwoven fabric; a step of converting the microfiberizable fibers in the nonwoven fabric to microfine fibers, thereby producing a substrate for artificial leather; a step of producing an artificial leather by using the obtained substrate for artificial leather; and a step wherein the obtained artificial leather is brought into close contact with an elastomer sheet stretched in a machine direction by 5 to 40%; the artificial leather is allowed to shrink in the machine direction simultaneously with allowing the elastomer sheet to shrink in the machine direction by relaxing elongation of the elastomer sheet; the artificial leather is heat-treated in shrunk state; and then the artificial leather is peeled off from the elastomer sheet.

An object of the invention is to provide a leather-like sheet having excellent water absorbability (sweat absorbability, defined the same hereinafter), providing a natural leather-like touch, and suitably used as a ball covering or a non-slip covering, without lowering surface wear resistance. An aspect of the invention is directed to a leather-like sheet including a base material having an entangled fiber sheet; and a porous elastic resin layer laminated on a surface of the base material. The porous elastic resin layer has a concave-convex surface. The concave-convex surface of the porous elastic resin layer includes a projection having a top surface and a side surface, and a recess having a bottom surface contiguous to the side surface. The top surface of the projection has openings with a diameter from 10 to 500 nm at a density of 1,000 openings/mmor more.

Leather-like sheet and method of producing leather-like sheet

Provided are: a sheet-like ball material including a fibrous base material, and an elastic polymer cover layer that is laminated on a surface of the fibrous base material, in which continuous pebbles and discontinuous valleys are formed on a surface of the cover layer, the valleys discontinuously formed are formed at average intervals of 0.5 to 3 mm, the valley has a depth of 50 to 500 &#x3bc;m, a vertical projected area of each valley is 1 to 5 mm, and a total area of the vertical projected area of each valley accounts for 3 to 30% relative to a surface area of the elastic polymer cover layer; a ball used for volleyball or beach volleyball including the sheet-like ball material, which is excellent in the controllability for all types of ball plays such as tossing and serving in the smoothness of the attenuation degree in the ball speed of the ball during flight of the ball, and in the design, e.g., three-dimensional shape, which is not realized in a heretofore-existing ball, and also has a sufficient surface abrasion resistance; and a sheet-like ball material suitably used for such balls.

Sheet-like object for ball and ball

A grain-finished leather-like sheet having a fibrous substrate layer, a polyurethane non-porous layer and a polyurethane surface layer which are successively laminated in this order. The polyurethane surface layer contains a binder polyurethane and polyurethane fine particles having a particle size of 1 to 50 &#x3bc;m. The total thickness of the polyurethane non-porous layer and the polyurethane surface layer is 150 &#x3bc;m or more. The polyurethane surface layer contains the polyurethane fine particles in an amount of 10 to 40 parts by mass per 100 parts by mass of the binder polyurethane. The polyurethane fine particles are not exposed to the surface. The grain-finished leather-like sheet characterized by the above features has a smooth and luster surface, a good hand, and excellent scratch resistance, abrasion resistance and buckling wrinkle resistance. The sheet hardly damages or soils an object which is in contact with its surface by friction.

Grain leather-like sheet having excellent scratch resistance and abrasion resistance

Provided is an artificial leather sheet that comprises microfine fibers of an inelastic polymer having a mean fiber diameter of at most 5 &#x3bc;m and an elastic polymer, in which the major portion of the elastic polymer forms a fibrous structure of the entangled nonwoven fabric with the microfine fibers of inelastic polymer throughout the entire layer of the artificial leather sheet in the thickness direction thereof, and a part of the elastic polymer forms a porous layer integrated with the entangled nonwoven fabric structure on at least one face of the artificial leather sheet. The artificial leather sheet does not substantially undergo structure deformation even when repeatedly elongated and deformed. It has good elastic stretchability, and has a soft and dense feel, and its appearance is good not detracting from the drapability of the sheet.

Artificial leather sheets and method for producing them

Disclosed are thermoplastic polyurethanes obtainable by reacting (a) a polyester-polyol that satisfies all the following requirements (1) to (4):

Thermoplastic polyurethanes and molded articles comprising them

A laminate comprising a layer formed by melt molding a thermoplastic polyurethane and a fibrous base layer, a film or sheet melt molded from the thermoplastic polyurethane, and a thermoplastic polyurethane composition comprising the thermoplastic polyurethane and tin compound in an amount of 0.3 to 15 ppm (in terms of tin atom) based on the thermoplastic polyurethane; the thermoplastic polyurethane being a thermoplastic polyurethane obtained from a polymeric diol (a) having a number average molecular weight of 1,500 to 4,000, an organic diisocyanate (b) and a chain extender (c) and having an inherent viscosity of at least 0.9 dl/g and a retention of long-chain hard segments when heat melted of at least 80%, the polymeric diol (a) having a crystallization enthalpy (.DELTA.H) of not more than 70 J/g and having low molecular diol units comprising at least 30 mole % of 1,9-nonanediol units. These articles are excellent in resistance to abrasion melting and abrasion and resistance to bleed/whitening and also good in tensile strength and like mechanical properties, durability and cold resistance, as well as softness and flexibility, so that they can be used for leather-like products and other various purposes.

Laminate comprising a polyurethane layer

Disclosed are thermoplastic polyurethanes obtainable by reacting (a) a polyester-polyol that satisfies all the following requirements (1) to (4): (1) its ester group content (number of ester bonds/number of all carbon atoms) is from 0.08 to 0.17; (2) it has hydroxyl groups of from 2.01 to 2.08 per one molecule; (3) it has a number average molecular height of from 1000 to 7000; and (4) it has a crystallization enthalpy (.DELTA.H) of 70 J/g or less, (b) an organic diisocyanate and (c) a chain extender at a ratio that satisfies the following numerical formula (i):

A suede-like artificial leather which is composed of fiber bundles and an elastomeric polymer, has fibrous nap on its surface and is dyed, said fiber bundles being composed of fine fibers (A) having a finess of 0.02-0.2 denier and microfine fibers (B) having a fineness not more than 1/5 of the average fineness of said fine fibers (A) and also less than 0.02 denier, said fibers (A) and (B) being substantially uniformly dispersed in cross sections of the fiber bundles, the ratio between the strand numbers of fibers (A) to fibers (B) ranging from 1/2 to 2/3, said fiber bundles not substantially containing the elastomeric polymer in the interspaces among the individual fibers constituting each of the fiber bundles, and the ratio of the number of fibers (A) to that of fibers (B) in the nap-constituting fibers being at least 3/1, is provided. The artificial leather has good appearance and hand and excels in color-developing property and pilling resistance, and is useful for making cloths, shoes, pouches, gloves and the like.

Growing community of inventors

Okayama, Japan

Tetsuya Ashida