Patents by Inventor Yoshitomo Nakata
Yoshitomo Nakata has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 10391205Abstract: To Provide is a polymer having high antithrombogenicity compared to a conventional polymer having a glycerol group and suitable as a medical device material. It is the polymer having a structural unit derived from a glycerol group-containing monomer, and a structural unit derived from an unsaturated monomer having a structure in which an organic group having a structure site having 4 or more carbon atoms continuously bound is bound to an ethylenically unsaturated group; and satisfying a glass-transition temperature of 10° C. or less and/or a glass-transition temperature of ?25° C. or less at a saturated water content.Type: GrantFiled: November 28, 2016Date of Patent: August 27, 2019Assignees: National University Corporation Yamagata University, Nippon Shokubai Co., Ltd.Inventors: Masaru Tanaka, Naoki Kobayashi, Yoshitomo Nakata, Asuka Sugawara
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Publication number: 20170157304Abstract: To Provide is a polymer having high antithrombogenicity compared to a conventional polymer having a glycerol group and suitable as a medical device material. It is the polymer having a structural unit derived from a glycerol group-containing monomer, and a structural unit derived from an unsaturated monomer having a structure in which an organic group having a structure site having 4 or more carbon atoms continuously bound is bound to an ethylenically unsaturated group; and satisfying a glass-transition temperature of 10° C. or less and/or a glass-transition temperature of ?25° C. or less at a saturated water content.Type: ApplicationFiled: November 28, 2016Publication date: June 8, 2017Inventors: Masaru TANAKA, Naoki KOBAYASHI, Yoshitomo NAKATA, Asuka SUGAWARA
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Patent number: 7851568Abstract: There is provided a vinylpyrrolidone-based copolymer having as essential components N-vinylpyrrolidone and hydroxyl group-containing (meth)acrylate, which gives a favorable crosslinked coating film, and a method for production by which the copolymer is easily obtained. A vinylpyrrolidone-based copolymer of the present invention contains a constitutional unit derived from N-vinylpyrrolidone and a constitutional unit derived from hydroxyl group-containing (meth)acrylate at a specific ratio, in which a K value according to Fikentscher is 12 or more, water insoluble matter is 0.5% by mass (on the basis of solid content) or less, and each content of iron, nickel, chromium, sodium and calcium is 500 ppb (on the basis of mass: the same hereinafter) or less, or electrical conductivity of a 10% by mass-aqueous solution of the vinylpyrrolidone-based copolymer is 35 ?S/cm or less.Type: GrantFiled: October 18, 2007Date of Patent: December 14, 2010Assignee: Nippon Shokubai Co., Ltd.Inventors: Daisuke Imai, Keiko Izumi, Yoshitomo Nakata
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Publication number: 20100168363Abstract: The low birefringent material of the present invention is, for example, an acrylic copolymer including a lactone ring structure which can provide a positive retardation and a structural unit which can provide a negative retardation, the acrylic copolymer satisfying following conditions that: (A) the copolymer has a glass transition temperature (Tg) of 100° C. or higher; (B) a film comprising the copolymer has a total light transmittance of 85% or higher; and (C) a retardation per 100 ?m of thickness in an in-plane direction of the film is 10 nm or lower, and a difference between a retardation per 100 ?m of thickness in an in-plane direction of the film after the film is drawn by 1.5 times and a retardation per 100 ?m of thickness in an in-plane direction of the film before the film is drawn is 20 nm or lower.Type: ApplicationFiled: August 2, 2006Publication date: July 1, 2010Inventors: Ken-ichi Ueda, Hiroko Izumi, Yoshitomo Nakata, Nobuhiro Maeda
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Publication number: 20100020396Abstract: Provided are: a polarizer protective film, which is allowed to express excellent UV-absorbing ability by using a UV-absorbing monomer as a raw material, has excellent heat resistance and excellent optical transparency, and has much less coloring and foaming; a polarizing plate with less defects in an outer appearance, using the polarizer protective film; and an image display apparatus of high quality, using the polarizing plate. The polarizer protective film of the present invention has a light transmittance at 380 nm in a thickness of 80 ?m of 30% or less, and is obtained by molding a forming material that contains a resin component containing as a main component a (meth)acrylic resin obtained by polymerizing a monomer composition containing a UV-absorbing monomer and a (meth)acrylic monomer by extrusion molding.Type: ApplicationFiled: September 27, 2007Publication date: January 28, 2010Applicants: NIPPON SHOKUBAI CO., LTD., NITTO DENKO CORPORATIONInventors: Hiroko Izumi, Yoshitomo Nakata, Ken-Ichi Ueda, Daisuke Hattori, Tadashi Kojima, Hiroyuki Takao, Tsutomu Hani
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Publication number: 20090124775Abstract: To provide a high concentration solution of a vinylpyrrolidone polymer having a low K value, which can be used in various applications such as medical applications and applications where coloring is problematic. A monomer component essentially containing N-vinylpyrrolidone, hydrogen peroxide, and ammonia are sequentially added to a copper catalyst-containing aqueous solvent and polymerized at 55 to 90° C., and the ammonia is used in an amount of 0.1 to 0.37% by weight based on the N-vinylpyrrolidone. As a result, a 40 to 60% by weight solution of a vinylpyrrolidone polymer having a K value of 60 or less, wherein the solution has: an N-vinylpyrrolidone content of 10 ppm or less relative to the vinylpyrrolidone polymer; an alkanol concentration of 100 ppm or less; and an ignition residue of 0.1% by weight or less, and a 50% by weight solution of the vinylpyrrolidone polymer has a hue (APHA) according to JIS-K3331 of 280 or less.Type: ApplicationFiled: November 4, 2005Publication date: May 14, 2009Applicant: NIPPON SHOKUBAI CO., LTD.Inventors: Takashi Miyai, Yoshitomo Nakata, Yasuhiro Matsuda, Mitsuru Nakajima
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Publication number: 20080247981Abstract: To provide a vinylpyrrolidone/vinyl acetate copolymer which is extremely reduced in thermal yellowing and is usable even at high temperatures and which can dissolve in water to give a transparent solution. The vinylpyrrolidone/vinyl acetate copolymer of the present invention has a residual vinylpyrrolidone content of 100 ppm or less relative to a solid content of the copolymer. A 5% by weight aqueous solution of the copolymer has an NTU value of 4.0 or less. A 50% aqueous solution of the copolymer has a Hazen color number (APHA) according to JIS-K3331 of 350 or less, the Hazen color number being measured by the following accelerated test.Type: ApplicationFiled: November 4, 2005Publication date: October 9, 2008Applicant: NIPPON SHOKUBAI CO., LTD.Inventors: Daisuke Imai, Keiko Izumi, Yoshitomo Nakata
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Publication number: 20080220235Abstract: To provide an amorphous thermoplastic resin and a film or sheet each having high transparency and high heat resistance and a UV-absorbing ability, which can be used in various optical materials which needs to have excellent optical characteristics and well-balanced mechanical strength, molding processability, and surface hardness. An amorphous thermoplastic resin including a UV-absorbing monomer unit and having a glass transition temperature of 120° C. or more, in which the amorphous thermoplastic resin has a light transmittance of 80% or more at 500 nm and a light transmittance of less than 30% at 380 nm.Type: ApplicationFiled: September 29, 2006Publication date: September 11, 2008Applicant: Nippon Shokubai Co LtdInventors: Hiroko Izumi, Yoshitomo Nakata, Kenichi Ueda
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Publication number: 20080154001Abstract: There is provided a vinylpyrrolidone-based copolymer having as essential components N-vinylpyrrolidone and hydroxyl group-containing (meth)acrylate, which gives a favorable crosslinked coating film, and a method for production by which the copolymer is easily obtained. A vinylpyrrolidone-based copolymer of the present invention contains a constitutional unit derived from N-vinylpyrrolidone and a constitutional unit derived from hydroxyl group-containing (meth)acrylate at a specific ratio, in which a K value according to Fikentscher is 12 or more, water insoluble matter is 0.5% by mass (on the basis of solid content) or less, and each content of iron, nickel, chromium, sodium and calcium is 500 ppb (on the basis of mass: the same hereinafter) or less, or electrical conductivity of a 10% by mass-aqueous solution of the vinylpyrrolidone-based copolymer is 35 ?S/cm or less.Type: ApplicationFiled: October 18, 2007Publication date: June 26, 2008Inventors: Daisuke Imai, Keiko Izumi, Yoshitomo Nakata
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Patent number: 7345103Abstract: It is an object of the present invention to provide a hydraulic composition which enables both of high fluidity and material separation reducing and can eliminate the delay of setting. The present invention is directed to a hydraulic composition comprising cement (A), a copolymer (B), a high-performance water reducing agent (C) and a powdery cement admixture (D), wherein the copolymer (B) comprises a repeating unit (I) represented by the following formula (1); (wherein R1 represents a hydrogen atom or a methyl group. n is an integer of 2 to 4.), and a repeating unit (II) represented by the following general formula (2); (wherein R2, R3 and R4 are same or different and each represents a hydrogen atom, a methyl group or a (CH2)pCOOM2 group, and may form a structure of an anhydride when the total number of COOM1 groups and COOM2 groups are 2.Type: GrantFiled: September 1, 2004Date of Patent: March 18, 2008Assignee: Nippon Shokubai Co., Ltd.Inventors: Yoshitomo Nakata, Norihiro Wakao, Takashi Tomita
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Patent number: 7214753Abstract: The present invention provides an innovative N-vinylamide polymer with decreased contents of impurities and suppressed coloration, a higher K-value, and preferably usable in a variety of fields such as cosmetic and pharmaceutical products, and to provide a production method of the polymer. An N-vinylamide polymer comprising an N-vinylamide monomer unit, wherein the N-vinylamide polymer has K-value of 60 or higher, a content of hydrolysis products of N-vinylamide monomer of 0.02% by weight or less, a content of ashes of 0.1% by weight or less, and hue of 10% aqueous solution of 10 or less measured according to JIS K0071.Type: GrantFiled: March 23, 2005Date of Patent: May 8, 2007Assignee: Nippon Shokubai Co., Ltd.Inventors: Yoshitomo Nakata, Norihiro Wakao
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Publication number: 20050215740Abstract: The present invention provides an innovative N-vinylamide polymer with decreased contents of impurities and suppressed coloration, a higher K-value, and preferably usable in a variety of fields such as cosmetic and pharmaceutical products, and to provide a production method of the polymer. An N-vinylamide polymer comprising an N-vinylamide monomer unit, wherein the N-vinylamide polymer has K-value of 60 or higher, a content of hydrolysis products of N-vinylamide monomer of 0.02% by weight or less, a content of ashes of 0.1% by weight or less, and hue of 10% aqueous solution of 10 or less measured according to JIS K0071.Type: ApplicationFiled: March 23, 2005Publication date: September 29, 2005Applicant: Nippon Shokubai Co., Ltd.Inventors: Yoshitomo Nakata, Norihiro Wakao
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Publication number: 20050045070Abstract: It is an object of the present invention to provide a hydraulic composition which enables both of high fluidity and material separation reducing and can eliminate the delay of setting. The present invention is directed to a hydraulic composition comprising cement (A), a copolymer (B), a high-performance water reducing agent (C) and a powdery cement admixture (D), wherein the copolymer (B) comprises a repeating unit (I) represented by the following formula (1); (wherein R1 represents a hydrogen atom or a methyl group. n is an integer of 2 to 4.), and a repeating unit (II) represented by the following general formula (2); (wherein R2, R3 and R4 are same or different and each represents a hydrogen atom, a methyl group or a (CH2)pCOOM2 group, and may form a structure of an anhydride when the total number of COOM1 groups and COOM2 groups are 2.Type: ApplicationFiled: September 1, 2004Publication date: March 3, 2005Applicant: Nippon Shokubai Co., Ltd.Inventors: Yoshitomo Nakata, Norihiro Wakao, Takashi Tomita
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Patent number: 6642333Abstract: The present invention provides a vinylpyrrolidone (co)polymer excellent in the color tone and the thermal yellowing resistance despite its low molecular weight. The vinylpyrrolidone (co)polymer, according to the present invention, is a vinylpyrrolidone (co)polymer which has a Hazen value of not more than 30 in the form of 5% aqueous solution and a K value of not more than 60 and is obtained by a process including the step of polymerizing a polymerizable monomer component with an azo compound initiator and/or an organic peroxide initiator, wherein the polymerizable monomer component includes N-vinylpyrrolidone, and wherein the azo compound initiator has a chemical structure as shown by —C(CH3)2—N═N—C(CH3)2—, and wherein the organic peroxide initiator is soluble in water or ethyl alcohol of 25° C. in an amount of not smaller than 3 weight %.Type: GrantFiled: March 24, 2003Date of Patent: November 4, 2003Assignees: Nippon Shokubai Co., Ltd., Dai-ichi Kogyo Seiyaku Co., Ltd.Inventor: Yoshitomo Nakata
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Publication number: 20030191260Abstract: The present invention provides a vinylpyrrolidone (co)polymer excellent in the color tone and the thermal yellowing resistance despite its low molecular weight. The vinylpyrrolidone (co)polymer, according to the present invention, is a vinylpyrrolidone (co)polymer which has a Hazen value of not more than 30 in the form of 5% aqueous solution and a K value of not more than 60 and is obtained by a process including the step of polymerizing a polymerizable monomer component with an azo compound initiator and/or an organic peroxide initiator, wherein the polymerizable monomer component includes N-vinylpyrrolidone, and wherein the azo compound initiator has a chemical structure as shown by —C(CH3)2—N═N—C(CH3)2—, and wherein the organic peroxide initiator is soluble in water or ethyl alcohol of 25° C. in an amount of not smaller than 3 weight %.Type: ApplicationFiled: March 24, 2003Publication date: October 9, 2003Inventor: Yoshitomo Nakata
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Patent number: 6498231Abstract: The present invention provides: a vinylpyrrolidone polymer which exhibits good heat resistance and storage stability; a composition containing the vinylpyrrolidone polymer; a stabilization process for the vinylpyrrolidone polymer, and a preservation process for a vinylpyrrolidone polymer by which: even when the vinylpyrrolidone polymer is preserved for a long time or at high temperature, the physical properties such as molecular weight (K value) of the vinylpyrrolidone polymer can be prevented from changing, therefore the vinylpyrrolidone polymer can stably be preserved. To enhance the heat resistance and the storage stability, a vinylpyrrolidone polymer is mixed with a certain amount of antioxidant, and the oxygen concentration is suppressed to not higher than 50,000 ppm in a gas phase that contacts with the vinylpyrrolidone polymer when preserving.Type: GrantFiled: December 3, 2001Date of Patent: December 24, 2002Assignee: Nippon Shokubai Co., Ltd.Inventors: Daijo Tomihisa, Toshiaki Kuriyama, Tomiyasu Ueta, Akio Naka, Hideyuki Nishibayashi, Yoshitomo Nakata
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Publication number: 20020156218Abstract: The present invention is to provide a curable resin composition comprising a new crosslinking system by which both hydrophilicity and water resistance properties are realized, and a product treated by said curable resin composition.Type: ApplicationFiled: January 17, 2002Publication date: October 24, 2002Applicant: NIPPON SHOKUBAI CO., LTD.Inventors: Yoshitomo Nakata, Akio Naka, Miwako Yonezawa
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Publication number: 20020058782Abstract: The present invention provides: a vinylpyrrolidone polymer which exhibits good heat resistance and storage stability; a composition containing the vinylpyrrolidone polymer; a stabilization process for the vinylpyrrolidone polymer, and a preservation process for a vinylpyrrolidone polymer by which: even when the vinylpyrrolidone polymer is preserved for a long time or at high temperature, the physical properties such as molecular weight (K value) of the vinylpyrrolidone polymer can be prevented from changing, therefore the vinylpyrrolidone polymer can stably be preserved. To enhance the heat resistance and the storage stability, a vinylpyrrolidone polymer is mixed with a certain amount of antioxidant, and the oxygen concentration is suppressed to not higher than 50,000 ppm in a gas phase that contacts with the vinylpyrrolidone polymer when preserving.Type: ApplicationFiled: December 3, 2001Publication date: May 16, 2002Inventors: Daijo Tomihisa, Toshiaki Kuriyama, Tomiyasu Ueta, Akio Naka, Hideyuki Nishibayashi, Yoshitomo Nakata
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Patent number: 6346600Abstract: The present invention provides: a vinylpyrrolidone polymer which exhibits good heat resistance and storage stability; a composition containing the vinylpyrrolidone polymer; a stabilization process for the vinylpyrrolidone polymer, and a preservation process for a vinylpyrrolidone polymer by which: even when the vinylpyrrolidone polymer is preserved for a long time or at high temperature, the physical properties such as molecular weight (K value) of the vinylpyrrolidone polymer can be prevented from changing, therefore the vinylpyrrolidone polymer can stably be preserved. To enhance the heat resistance and the storage stability, a vinylpyrrolidone polymer is mixed with a certain amount of antioxidant, and the oxygen concentration is suppressed to not higher than 50,000 ppm in a gas phase that contacts with the vinylpyrrolidone polymer when preserving.Type: GrantFiled: April 6, 2000Date of Patent: February 12, 2002Assignee: Nippon Shokubai Co., Ltd.Inventors: Daijo Tomihisa, Toshiaki Kuriyama, Tomiyasu Ueta, Akio Naka, Hideyuki Nishibayashi, Yoshitomo Nakata
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Patent number: 6100366Abstract: The present invention provides: a cyclic imino ether group containing polymer with an extremely reduced amount of residual cyclic imino ether group containing monomer; and a production process therefor. The cyclic imino ether group containing polymer is obtained by a process including the step of polymerizing a monomer component including a cyclic imino ether group containing monomer, and contains a cyclic imino ether group containing monomer unit in the ratio of not less than 0.1 mol %, wherein the amount of the cyclic imino ether group containing monomer remaining in the polymer is not more than 15 ppm.Type: GrantFiled: August 24, 1999Date of Patent: August 8, 2000Assignee: Nippon Shokubai Co., Ltd.Inventors: Yoshitomo Nakata, Kazumi Fujioka