Patents Assigned to Nippon Zeon Co. Ltd.
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Patent number: 6054245Abstract: An object of the present invention is to provide an electrophotographic developer having a good fluidity, an excellent shelf stability, and a lesser reduction in image quality under various conditions.An electrophotographic one component nonmagnetic developer includes toner particles obtained by polymerizing a polymerizable monomer component, such as styrene, methacrylate, acrylate and the like, and outer-additives, such as silicon dioxide particles, on the toner particles. The developer has pH of 4 to 7 measured by a decoction method, and .sigma.2 of not more than 20 .mu.S/cm and .sigma.2-.sigma.1 of 0 to 10 .mu.S/cm, in which .sigma.1 is an electric conductivity of water, .sigma.2 is an electric conductivity measured by a decoction method.Type: GrantFiled: September 24, 1999Date of Patent: April 25, 2000Assignee: Nippon Zeon Co., Ltd.Inventors: Hidetoshi Azuma, Hiroshi Yamamoto
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Patent number: 6043308Abstract: Conductive rubber compositions comprising a vulcanizate of a rubber component (A), a rubber component (B) vulcanized by a mechanism different from that in the rubber component (A), and conductive particles, a production process thereof, conductive rubber members making use of such a conductive rubber composition, a production process of the conductive rubber members, conductive rubber-covered rolls, and image forming apparatus equipped with the conductive rubber-covered roll are provided.Type: GrantFiled: May 11, 1998Date of Patent: March 28, 2000Assignee: Nippon Zeon Co., Ltd.Inventors: Naoki Tanahashi, Kouichirou Maeda
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Patent number: 6037413Abstract: A polyester having a hydroxyl value of at least 30 mg KOH/g and a weight average molecular weight (Mw) of preferably from 1,000 to 500,000 and prepared by polycondensation of a polycarboxylic acid ingredient predominantly comprised of an aromatic dicarboxylic acid and a polyhydric alcohol ingredient predominantly comprised of a hindered alcohol. This polyester is suitable for modifying a resinous or rubbery polymer.Type: GrantFiled: December 16, 1998Date of Patent: March 14, 2000Assignee: Nippon Zeon Co, Ltd.Inventors: Shizuo Kitahara, Shinya Ikeda
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Patent number: 6033822Abstract: Disclosed herein are a polymerized toner of core-shell structure, comprising core particles composed of colored polymer particles having a volume average particle diameter (dv) of 0.5-20 .mu.m and a ratio (dv/dp) of the volume average particle diameter (dv) to a number average particle diameter (dp) of at most 1.7, and shell which is formed of a polymer layer having an average film thickness of 0.001-0.1 .mu.m and covers each of the core particles, and a production process thereof.Type: GrantFiled: July 27, 1999Date of Patent: March 7, 2000Assignee: Nippon Zeon Co., Ltd.Inventors: Jun Hasegawa, Tokudai Ogawa, Jun Sakai, Takahiro Takasaki, Noboru Yanagida
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Patent number: 6030255Abstract: An insulator for high frequency connectors which comprises a thermoplastic norbornene resin and has a voltage and standing wave ratio of 1.89 or less even in the high frequency band of 2-3 GHz, and a high frequency connector using the insulator.Type: GrantFiled: July 23, 1997Date of Patent: February 29, 2000Assignee: Nippon Zeon Co., Ltd.Inventors: Yuichiro Konishi, Hajime Tanisho, Yuji Koshima, Teiji Kohara
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Patent number: 6025106Abstract: An object of the present invention is to provide an electrophotographic developer having a good fluidity, an excellent shelf stability, and a lesser reduction in image quality under various conditions.An electrophotographic one component nonmagnetic developer includes toner particles obtained by polymerizing a polymerizable monomer component, such as styrene, methacrylate, acrylate and the like, and outer-additives, such as silicon dioxide particles, on the toner particles. The developer has pH of 4 to 7 measured by a decoction method, and .sigma.2 of not more than 20 .mu.S/cm and .sigma.2 - .sigma.1 of 0 to 10 .mu.S/cm, in which .sigma.1 is an electric conductivity of water, .sigma.2 is an electric conductivity measured by a decoction method.Type: GrantFiled: June 23, 1998Date of Patent: February 15, 2000Assignee: Nippon Zeon Co., Ltd.Inventors: Hidetoshi Azuma, Hiroshi Yamamoto
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Patent number: 6025098Abstract: The present invention is intended to provide a photosensitive rubber plate which is superior in transparency and strength balance and high in rate of washing with water after light exposure, and a photosensitive composition used for obtaining the rubber plate. The photosensitive composition contains 20-65 parts by weight of a block copolymer havingat least one polymer block A consisting of a polymer containing 95% by weight or more of an aromatic vinyl monomer unit andat least one polymer block B consisting of a conjugated diene polymer containing 20% by weight or more of a conjugated diene monomer unit and having a vinyl bond content in the conjugated diene monomer unit, of 15-70% by weight.35-80 parts by weight of a hydrophilic copolymer, the total amount of the block copolymer and the hydrophilic copolymer being 100 parts by weight,5-300 parts by weight of a photopolymerizable ethylenically unsaturated monomer, and0.1-10 parts by weight of a photopolymerization initiator.Type: GrantFiled: March 28, 1997Date of Patent: February 15, 2000Assignee: Nippon Zeon Co., LtdInventors: Fusayoshi Sakurai, Haruo Ueno
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Patent number: 6015850Abstract: Disclosed herein are a rubber composition comprising a diene rubber and silica, wherein (i) the silica is compounded in a proportion of 10-150 parts by weight per 100 parts by weight of the diene rubber, and (ii) a silicone oil having a polar group at its side chain or terminal is compounded in a proportion of 0.1-50 parts by weight per 100 parts by weight of the silica, and has excellent rebound resilience, tensile property, abrasion property and processability, and a preparation process thereof.Type: GrantFiled: September 17, 1997Date of Patent: January 18, 2000Assignee: Nippon Zeon Co., Ltd.Inventors: Masao Nakamura, Yukio Takagishi
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Patent number: 6013407Abstract: A positive resist composition is excellent in sensitivity, film loss after development, resolution, thermal-flow resistance, storage stability, exposure margin and focus margin and comprises in combination (A) an alkali-soluble phenol resin, (B) a quinonediazide sulfonate type photosensitive agent and (C) a phenolic compound, wherein the phenolic compound (C) is at least one phenolic compound selected from the group consisting of phenolic compounds (CX) having a structural unit represented by the following formula (I) and phenolic compounds (CD) having a structural unit represented by the following formula (II): ##STR1## wherein R.sup.1 to R.sup.3 are, independently of one another, a hydrogen atom, a hydroxyl group, a halogen atom, an alkyl group which may be substituted, a cycloalkyl group which may be substituted, an alkenyl group which may be substituted, an alkoxy group which may be substituted, or an aryl group which may be substituted, R.sup.4 to R.sup.Type: GrantFiled: July 8, 1997Date of Patent: January 11, 2000Assignee: Nippon Zeon Co., Ltd.Inventors: Shoji Kawata, Hiroshi Hayashi, Hirokazu Higashi, Takeyoshi Kato, Masahiro Nakamura
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Patent number: 6013737Abstract: A rubber composition comprising 100 parts by weight of a diene rubber ingredient containing an amino group-containing diene rubber, 10 to 120 parts by weight of silica, 0.1 to 15 parts by weight a vulcanizer and 0.1 to 15 parts by weight of a sulfenamide vulcanization accelerator.This rubber composition exhibits excellent heat build-up, tensile property and abrasion resistance, and is suitable for tires and others.Type: GrantFiled: March 5, 1998Date of Patent: January 11, 2000Assignee: Nippon Zeon Co., Ltd.Inventors: Yukio Takagishi, Masao Nakamura
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Patent number: 6010826Abstract: The invention provides a resist composition comprising a polymer (a) having groups cleavable by an acid and a compound (b) which can form an acid upon exposure to active rays, wherein the polymer (a) is a polymer having, as the groups cleavable by an acid, groups containing a substituted allyloxy group having at least two substituents, and a resist composition comprising a resin binder (A), a compound (B) which can form an acid upon exposure to active rays, and a compound (C) having a group cleavable by an acid, wherein the compound (C) having the group cleavable by an acid is a compound having a group containing a substituted allyloxy group having at least one substituent. The resist compositions have excellent sensitivity, resolution and heat resistance and can provide excellent pattern form.Type: GrantFiled: April 11, 1997Date of Patent: January 4, 2000Assignee: Nippon Zeon Co., Ltd.Inventors: Nobunori Abe, Shugo Matsuno, Hideyuki Tanaka, Tatsuya Sugimoto, Yasumasa Wada
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Patent number: 6005765Abstract: A conductive rubber film having a volume resistivity in the direction perpendicular to the film surface of 0.1-5 .OMEGA.cm is obtained by blending 100 parts by weight of a rubber component comprising rubber with an iodine value of 30 or less (e.g. hydrogenated acrylonitrile butadiene copolymer rubber) with 5 to 100 parts by weight of conductive carbon having a specific surface area of 20 to 2000 m.sup.2 /g, and forming the blend into a film of 0.01-0.2 mm thick by casting by the use of a solvent (e.g. methyl isobutyl ketone). The film is made into collectors and an electric double layer capacitor using an aqueous electrolyte is produced by using the collectors. This capacitor has a low internal resistance, namely, it can be obtained as a high-output capacitor.Type: GrantFiled: July 10, 1998Date of Patent: December 21, 1999Assignees: Nippon Zeon Co., Ltd., NEC CorporationInventors: Koichiro Maeda, Yukari Kibi
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Patent number: 6001488Abstract: A resin composition comprising an epoxy group-containing cycloolefin resin and a crosslinking agent is provided. More specifically, a resin composition comprising an epoxy group-containing thermoplastic norbornene resin obtained by introducing epoxy groups into a thermoplastic norbornene resin, and as the crosslinking agent, a curing agent for epoxy resins or a photoreactive substance is provided. The resin composition is suitable for use as an insulating material.Type: GrantFiled: June 29, 1998Date of Patent: December 14, 1999Assignees: Nippon Zeon Co., Ltd., Fujitsu LimitedInventors: Hideaki Kataoka, Eiko Yuda, Shigemitsu Kamiya, Masahide Yamamoto, Yoshikatsu Ishizuki, Yasuhiro Yoneda, Daisuke Mizutani, Kishio Yokouchi
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Patent number: 5998531Abstract: This invention provides a vulcanizable rubber composition for use as hot-water seals comprising 100 parts by weight of a rubber mixture composed of 90 to 50% by weight of a nitrile-containing highly saturated copolymer rubber obtained by hydrogenating the conjugated diene portions of an unsaturated nitrile-conjugated diene copolymer rubber or unsaturated nitrile-conjugated diene-ethylenically unsaturated monomer terpolymer rubber, and 10 to 50% by weight of an ethylene-.alpha.-olefin copolymer rubber; 0.1 to 30 parts by weight of an organic peroxide vulcanizing agent; and optionally 10 to 100 parts by weight of carbon black. Seals formed by vulcanizing this composition show a very low percent change in volume and elongation, and are not liable to the release of carbon black or the production of surface cracks, upon exposure to hot water containing bleaching powder.Type: GrantFiled: June 19, 1998Date of Patent: December 7, 1999Assignee: Nippon Zeon Co LtdInventors: Yoshiaki Aimura, Hiroko Ohnishi
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Patent number: 5972272Abstract: An unsaturated polyester resin composition for molding comprising (A) an unsaturated polyester resin, (B) a thickening agent containing powder of a thermoplastic resin as the effective component thereof in an amount of 20 to 120 parts by weight per 100 parts by weight of the unsaturated polyester resin, (C) a liquid polymerizable monomer in an amount of 30 to 120 parts by weight per 100 parts by weight of the unsaturated polyester resin, and (D) a curing agent; SMC and BMC prepared by adding (E) a reinforcing material to the composition; and a process for molding the SMC and the BMC at a low temperature under a low pressure. The unsaturated polyester resin composition of the present invention can be converted into SMC in a short time. The obtained SMC has an excellent storage stability, can be molded at a low temperature under a low pressure, and provides a molded product exhibiting low shrinkage, excellent surface smoothness, a large strength, and a large modulus.Type: GrantFiled: December 26, 1996Date of Patent: October 26, 1999Assignee: Nippon Zeon Co., Ltd.Inventors: Toshio Nagase, Takeo Kobayashi, Atsushi Tsukamoto
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Patent number: 5968705Abstract: An object of the present invention is to provide a process for producing stably a polymerized toner having excellent balance of shelf stability and fixability, and high resolution visible image formation. The process for producing a polymerized toner comprising a step of raising the temperature of an aqueous dispersion of monomer composition comprising a colorant, a polymerization initiator such as t-butyl peroxy-2-ethylhexanoate and a polymerizable monomer component such as styrene to a temperature lower than a target polymerization temperature by about 10 to about 40.degree. C., a step of raising the temperature of the dispersion at the rate of about 1 to about 20.degree. C. an hour to a temperature lower than the target polymerization temperature by about 5.degree. C., and a step of raising the temperature of the dispersion at the rate of about 3 to about 10.degree. C. an hour to the target polymerization temperature, whereby the polymerizable monomer component is polymerized.Type: GrantFiled: May 21, 1998Date of Patent: October 19, 1999Assignee: Nippon Zeon Co., Ltd.Inventors: Ikuo Yamada, Hiroshi Yamamoto
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Patent number: 5952144Abstract: A process for producing a toner for development of electrostatic latent images, which is composed of colored polymer particles and has a low fixing temperature, good permeability through OHP and excellent shelf stability, by subjecting a monomer composition containing at least a polymerizable monomer and a colorant to suspension polymerization in an aqueous dispersion medium containing a dispersing agent comprises at least two steps of:(1) the first step of subjecting a monomer composition for core component containing at least one monomer for core component, which is capable of forming a polymer having a glass transition temperature not higher than 80.degree. C.Type: GrantFiled: December 18, 1997Date of Patent: September 14, 1999Assignee: Nippon Zeon Co., Ltd.Inventors: Jun Hasegawa, Jun Sakai, Makoto Watanabe, Fumio Yamada, Tokudai Ogawa
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Patent number: 5912102Abstract: A positive resist composition comprising an alkali-soluble phenolic resin, a photosensitive agent composed of a quinonediazide sulfonate of a specific polyhydroxy compound, and an aromatic compound having at least one phenolic hydroxyl group.Type: GrantFiled: June 26, 1997Date of Patent: June 15, 1999Assignee: Nippon Zeon Co., Ltd.Inventors: Shoji Kawata, Motofumi Kashiwagi, Teturyo Kusunoki, Masahiro Nakamura
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Patent number: 5905129Abstract: A thermoplastic norbornene resin having a number-average molecular weight (Mn) of 12,000 or more in terms of polyisoprene value measured by gel permeation chromatography and excellent in low birefringence property and resistance to deterioration with greases and oils is obtained by ring-opening polymerizing a polycyclic norbornene monomer containing at least 70% by weight of a norbornene monomer represented by the following formula I (for example, 1,4-methano-1,4,4a,9a-tetrahydrofluorene): ##STR1## (wherein the lower 6-membered ring structure may have a double bond) and hydrogenating the polymer so that the hydrogenation rate of double bond in the main chain is at least 98% and the hydrogenation rate of the 6-membered ring structure is at least 90%.Type: GrantFiled: March 27, 1997Date of Patent: May 18, 1999Assignee: Nippon Zeon Co., Ltd.Inventors: Toshihide Murakami, Mitsushi Tada, Yasuo Tsunogae
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Patent number: 5902856Abstract: A diene rubber (iii) can be obtained by mixing in a solution state:a modified styrene-butadiene rubber (i) having a weight-average molecular weight of 150,000-500,000, obtained by reacting a diene polymer having a bound active metal in the molecule, with a modifier such as N-methyl-.epsilon.-caprolactam or the like, anda branched styrene-butadiene rubber (ii) having a weight-average molecular weight of 800,000 or more.This diene rubber (iii) and a rubber composition comprising the diene rubber (iii) and other diene rubber (iv) have superior processability when unvulcanized and give a vulcanized rubber having improved abrasion resistance, resiliency and low-temperature properties.Type: GrantFiled: May 22, 1997Date of Patent: May 11, 1999Assignee: Nippon Zeon Co., Ltd.Inventors: Fumitoshi Suzuki, Masao Nakamura, Manabu Tomisawa