Kuraray Co., Ltd.

Sumitomo Electric Industries, Limited

Okayama University

Jiro Tanaka

Yoshiyuki Ando

Tsuyoshi Yamasaki

Kimio Nakayama

Michinori Fujisawa

Norio Makiyama

Yoshiki Nobuto

Mamoru Sugimoto

Nobuo Takaoka

Mitsuru Kato

Masato Warita

Kazuomi Suzuki

Yoshiaki Yasuda

Yoshihiro Tanba

Hirofumi Kikuchi

Rei Nagayama

Yoshiaki Wakimoto

Disclosed is a nubuck-finished leather-like sheet including a non-woven fabric that is an entangled body of ultrafine filaments, wherein the non-woven fabric includes a napped surface having napped fibers formed thereon, and the napped fibers are fixed to an acrylic resin on the napped surface while being laid down. Preferably, the acrylic resin is present so as to retain voids in the napped surface, while being made malleable.

Nubuck-leather-like sheet and manufacturing process therefor

An artificial leather including a base layer and a surface layer which is formed on one of surfaces of the base layer. The base layer includes bundles of microfine filaments and an elastic polymer. The surface layer includes the microfine filaments or includes the microfine filaments and the elastic polymer. The surface layer satisfies the relationship of X/Y&#x2265;1.5 wherein X is the number of cut ends of the microfine filaments which exist in a region from a surface to a 20 &#x3bc;m depth in a cross section of the artificial leather, Y is the number of cut ends of the microfine filaments which exist in a region from a surface to a 20 &#x3bc;m depth in a cross section perpendicular to the cross section for determining X, and X&#x3e;Y. The artificial leather having such surface layer exhibits a sufficient gloss without coating a pigment such as metallic powder.

Artificial leather, entangled web of filaments, and process for producing these

A substrate for artificial leather comprising a nonwoven fabric of bundles of microfine filaments. The substrate for artificial leather simultaneously satisfies the following requirements 1 to 4: (1) the bundle of microfine filaments comprises 8 to 70 microfine filaments having a cross-sectional shape of nearly circle; (2) the bundle of microfine filaments has a cross-sectional area of 170 to 700 &#x3bc;mand a flatness of 4.0 or less; (3) on a cross section parallel to a thickness direction of the nonwoven fabric body, cross sections of the microfine fiber bundles exist in a density of 1500 to 3000/mm; and (4) on a cross section parallel to a thickness direction of the nonwoven fabric body, gaps between the microfine fiber bundles have a size of 70 &#x3bc;m or less. By satisfying the requirements, the substrate for artificial leather combines high level of sensuous qualities and high level of physical properties which have been considered to be mutually exclusive.

Base material for artificial leather and process for producing the same

A medical resin composition is produced by mixing a powder of a polymer (A) comprising repeating units having an ester group and a liquid of a vinyl ester monomer (B) having 6 or more carbon atoms to increase a viscosity and, according to demand, further performing a polymerization reaction. The thus produced resin composition inhibits leaching of irritative substances, reduces any adverse effects on the human body by endocrine disruptors, etc. and can be prepared with high operational efficiency. The resin composition is suitably used as a dental resin composition such as a tissue conditioner, a functional impression material, a lining material, a denture base material or a mouth piece material.

Process for producing resin composition and process for producing molded article

A (semi)grain-finished leather-like sheet composed of an entangled nonwoven fabric of three-dimensionally entangled fiber bundles containing microfine long fibers and an elastic polymer contained in the entangled nonwoven fabric. When dividing the (semi)grain-finished leather-like sheet to five layers with equal thickness, i.e., surface layer, substrate layer, substrate layer, substrate layerand back layer in this order along the thickness direction, part of the microfine long fibers forming the surface layer and/or the back layer are fuse-bonded to each other and the microfine long fibers forming the intermediate layer are not fuse-bonded. With such a fuse-bonding state of the microfine long fibers, the (semi)grain-finished leather-like sheet combines a low compression resistance and a dense feel each comparable to natural leathers, has a sufficient practical strength, and are excellent in properties which are required according to its use.

Leather-like sheet bearing grain finish and process for producing the same

A method of producing a substrate suitable for artificial leathers. The substrate is composed of an entangled nonwoven fabric made of microfine fibers and a binder resin. At least one surface of the substrate is a densified layer which is made of the microfine fibers and which is substantially free from the binder resin. The binder resin is impregnated into a portion of the substrate other than the densified layer. The densified layer prevents the binder resin impregnated into the entangled nonwoven fabric from migrating into the surface of the entangled nonwoven fabric, thereby providing the substrate having the surface substantially free from the binder resin. The peeling strength between the substrate and a grain layer formed on the surface thereof is drastically improved because the surface of the substrate is substantially free from the binder resin.

Base material for artificial leather and grained artificial leather

It is an object of the present invention to provide a polishing pad that is resistant to scratching and also has excellent flattening performance. One aspect of the present invention is a polishing pad, comprising a fiber-entangled body formed from fiber bundles made up of ultrafine fibers in which the average cross sectional area is between 0.01 and 30 &#x3bc;m, and a macromolecular elastomer, wherein part of the macromolecular elastomer is present inside the fiber bundles, whereby the ultrafine fibers are bundled, the number of fiber bundles per unit of surface area present in a cross section in the thickness direction is at least 600 bundles per square millimeter, and the volumetric ratio of a portion excluding voids is between 55 and 95%.

Polishing pad, and method for manufacturing polishing pad

A leather-like sheet composed of a microfine-fiber entangled body made of bundles of microfine fibers and an elastic polymer impregnated therein. The bundles of microfine fibers are composed of microfine monofibers having an average cross-sectional area of 0.1 to 30 &#x3bc;mand have an average cross-sectional area of 40 to 400 &#x3bc;m. The bundles of microfine fibers exist in a density of 600 to 4000/mmon a cross section taken along the thickness direction of the microfine-fiber entangled body. The elastic polymer contains 30 to 100% by mass of a polymer of ethylenically unsaturated monomer. The polymer of ethylenically unsaturated monomer is composed of a soft component having a glass transition temperature (Tg) of less than &#x2212;5&#xb0; C., a crosslinkable component, and optionally a hard component having a glass transition temperature (Tg) of higher than 50&#xb0; C. and another component. The polymer of ethylenically unsaturated monomer is bonded to the microfine fibers in the bundles of microfine fibers. The leather-like sheet has a flexibility and hand such as dense feeling each resembling natural leathers and a high quality appearance. The leather-like sheet is highly stable in quality such as fastness and surface abrasion resistance and excellent in practical performance.

Leather-like sheet and method of manufacturing the same

A method of producing an entangled sheet of microfine long fibers using long fibers for forming microfine fibers. The method includes a step of forming a long-fiber web made of long fibers for forming microfine fibers, at least one component of the long fibers being a water-soluble, thermoplastic polyvinyl alcohol resin; a step of entangling the long-fiber web to form a long-fiber entangled sheet; a step of shrinking the long-fiber entangled sheet to form a long-fiber shrunk sheet; and a step of converting the long fibers for forming microfine fibers in the long-fiber shrunk sheet to microfine long fibers, thereby producing the entangled sheet of microfine long fibers. The step of entangling is conducted so as to allow the long-fiber entangled sheet to have an interlaminar peel strength of 2 kg/2.5 cm or more. The step of shrinking is conducted so as to shrink in an areal shrinkage of 35% or more.

Process for producing intertwined ultrafine filament sheet

A substrate for artificial leathers which is composed of a nonwoven fabric made of fiber bundles of microfine fibers having an average single fiber fineness of 0.5 dtex or less and an elastic polymer impregnated into the nonwoven fabric. The substrate for artificial leathers satisfies the following requirements 1 and 2: (1) the number of fiber bundles which are oriented to a thickness direction of the nonwoven fabric is 75 to 300 per 1 cm of width which is perpendicular to the thickness direction, when measured on a cross section parallel to the thickness direction; and (2) the number of cross sections of the fiber bundles which are oriented to the thickness direction is 30 to 800 per 1 mm, when measured on a cross section perpendicular to the thickness direction. The substrate for artificial leathers is suitable for the production of a grain-finished artificial leather which combines a non-repulsive softness and firm hand resembling natural sheep leathers and has fine buckling wrinkles, and a suede-finished or nubuck artificial leather having a surface touch with fine texture and a grace writing effect each being hitherto not obtained.

Base material for artificial leathers and method of producing the same

A substrate for artificial leathers, comprising a nonwoven fabric body made of microfine fiber bundles and an elastic polymer impregnated therein. The substrate for artificial leathers simultaneously satisfies the following requirements 1 to 4: (1) each of the microfine fiber bundles contains 6 to 150 bundled microfine long fibers in average; (2) a cross-sectional area of the microfine long fibers constituting the microfine fiber bundles is 27 &#x3bc;mor less, and 80% or more of the microfine long fibers has a cross-sectional area of from 0.9 to 25 &#x3bc;m; (3) an average cross-sectional area of the microfine fiber bundles is from 15 to 150 &#x3bc;m; and (4) on a cross section parallel to a thickness direction of the nonwoven fabric body, cross sections of the microfine fiber bundles exist in a density of from 1000 to 3000/mmin average. The raised artificial leathers and grain-finished artificial leathers made from the substrate for artificial leathers are excellent in the properties which are hitherto difficult to be combined.

Base for synthetic leather and synthetic leathers made by using the same

A spiral bevel gear having right and left tooth flanks having such a small pitch angle that either right or left ones are not seen in plan from the apex side of cone is molded by a powder molding device so as not to interfere with a die of the device when removed from the die. The die has teeth for molding and is rotatably supported. A fixed guide mechanism for guiding the die is provided. Guide portions of the guide mechanism have a predetermined lead so that the die is rotated guided by the guide portions when the molded article is punched out of the die. Thus, the teeth formed on the molded article reliably disengage from the teeth for molding. This makes it possible to reliably punch the molded article out of the die.

Powder molding device for forming spiral bevel gear

A spiral helical gear having right and left tooth flanks having such a small pitch angle that either right or left ones are not seen in plan from the apex side of cone is molded by a powder molding device so as not to interfere with a die of the device when removed from the die. The die has teeth for molding and is rotatably supported. A fixed guide mechanism for guiding the die is provided. Guide portions of the guide mechanism have a predetermined lead so that the die is rotated guided by the guide portions when the molded article is punched out of the die. Thus, the teeth formed on the molded article reliably disengage from the teeth for molding. This makes it possible to reliably punch the molded article out of the die.

Method for forming spiral bevel gear

A bevel gear in which the sizing can be easily effected without degrading the quality of the gear. In a sintered or forged gear having a toothed portion (1) formed on an axial end face thereof, a notched groove (4) is formed in and across an outer circumferential surface of the gear in an axial direction. The construction of the notched groove (4) is specified so that its quality is kept.

Growing community of inventors

Okayama, Japan

Jiro Tanaka