Patents by Inventor Takashi Houkawa
Takashi Houkawa 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).
-
Patent number: 12030851Abstract: Provided is a phenol compound represented by general formula (I), shown below. In general formula (I), R1 and R2 each indicate, independently of each other, a hydrogen atom or an alkyl group.Type: GrantFiled: July 15, 2020Date of Patent: July 9, 2024Assignee: ZEON CORPORATIONInventors: Yosuke Harauchi, Takashi Houkawa
-
Publication number: 20220234986Abstract: Provided is a phenol compound represented by general formula (I), shown below. In general formula (I), R1 and R2 each indicate, independently of each other, a hydrogen atom or an alkyl group.Type: ApplicationFiled: July 15, 2020Publication date: July 28, 2022Applicant: ZEON CORPORATIONInventors: Yosuke HARAUCHI, Takashi HOUKAWA
-
Patent number: 11192976Abstract: The present invention provides: a copolymer (A) which is a copolymer obtained by copolymerizing one or plural cycloolefin monomers and one or plural acyclic olefin monomers, or a copolymer obtained by copolymerizing two or more cycloolefin monomers, wherein the glass transition temperature (Tg) of the copolymer is 100° C. or higher, the refractive index of the copolymer is 1.545 or higher, and the Abbe's number of the copolymer is 50 or larger, and at least one of the cycloolefin monomers is a deltacyclene.Type: GrantFiled: April 2, 2020Date of Patent: December 7, 2021Assignee: ZEON CORPORATIONInventors: Kensaku Fujii, Takashi Houkawa, Takuya Komatsubara, Yasuhiro Shimizu
-
Publication number: 20200231745Abstract: The present invention provides: a copolymer (A) which is a copolymer obtained by copolymerizing one or plural cycloolefin monomers and one or plural acyclic olefin monomers, or a copolymer obtained by copolymerizing two or more cycloolefin monomers, wherein the glass transition temperature (Tg) of the copolymer is 100° C. or higher, the refractive index of the copolymer is 1.545 or higher, and the Abbe's number of the copolymer is 50 or larger, and at least one of the cycloolefin monomers is a deltacyclene.Type: ApplicationFiled: April 2, 2020Publication date: July 23, 2020Applicant: ZEON CORPORATIONInventors: Kensaku FUJII, Takashi HOUKAWA, Takuya KOMATSUBARA, Yasuhiro SHIMIZU
-
Patent number: 10647811Abstract: The present invention provides: a copolymer (A) which is a copolymer obtained by copolymerizing one or plural cycloolefin monomers and one or plural acyclic olefin monomers, or by copolymerizing two or more cycloolefin monomers, wherein a glass transition temperature (Tg) is 100° C. or higher, a refractive index is 1.545 or higher, and an Abbe's number is 50 or larger; a polymer (B) selected from: a ring-opening homopolymer obtained by ring-opening polymerization of only a monomer represented by formula (I), a ring-opening copolymer obtained by ring-opening copolymerization of the monomer represented by formula (I) and a monomer capable of ring-opening copolymerization with the monomer represented by formula (I), a hydrogenated product of the ring-opening homopolymer and a hydrogenated product of the ring-opening copolymer; a forming material containing the copolymer (A) or the polymer (B); and a resin formed article obtained by forming the forming material.Type: GrantFiled: April 5, 2016Date of Patent: May 12, 2020Assignee: ZEON CORPORATIONInventors: Kensaku Fujii, Takashi Houkawa, Takuya Komatsubara, Yasuhiro Shimizu
-
Patent number: 10280253Abstract: The present invention is a hydrogenated cycloolefin ring-opening polymer comprising a repeating unit derived from tetracyclododecene, and a repeating unit derived from an additional norbornene-based monomer, the hydrogenated cycloolefin ring-opening polymer having a racemo diad ratio of 65% or more with respect to the repeating unit derived from tetracyclododecene, the hydrogenated cycloolefin ring-opening polymer having a weight average molecular weight (Mw) of 10,000 to 40,000, and a resin formed article obtained by forming the hydrogenated cycloolefin ring-opening polymer having a glass transition temperature of 140 to 165° C., a melt flow rate of 8 g/10 min or more as measured at a temperature of 280° C. under a load of 21.18 N, and a flexural strength of 60 MPa or more as measured by a flexural test at a test speed of 2 mm/min, and a resin formed article, and an optical member.Type: GrantFiled: September 24, 2015Date of Patent: May 7, 2019Assignee: Zeon CorporationInventors: Akira Furuko, Takashi Houkawa, Ayumi Sato, Kenji Umeda
-
Publication number: 20180188420Abstract: The invention is a resin composition comprising an alicyclic-structure-containing polymer, a hindered-phenol-based antioxidant and a hindered amine compound, wherein the hindered-phenol-based antioxidant is a compound having a group represented by the specific formula, the hindered amine compound is a compound having a group represented by the specific formula in its molecule, a content of the hindered-phenol-based antioxidant is 0.1 to 2.0 parts by weight based on 100 parts by weight of the alicyclic-structure-containing polymer, and a content of the hindered amine compound is more than 0 to 1.0 part by weight based on 100 parts by weight of the alicyclic-structure-containing polymer, and a resin formed article, and an optical member. One aspect of the invention provides a resin composition which is hardly burned during forming, has excellent long-term thermal yellowing resistance and also suppresses adhesion of foreign matters due to charge, a resin formed article, and an optical member.Type: ApplicationFiled: March 30, 2016Publication date: July 5, 2018Applicant: ZEON CORPORATIONInventors: Akira FURUKO, Ayumi SATO, Taichi SAWAGUCHI, Kensaku FUJII, Takashi HOUKAWA
-
Publication number: 20180086877Abstract: The present invention provides: a copolymer (A) which is a copolymer obtained by copolymerizing one or plural cycloolefin monomers and one or plural acyclic olefin monomers, or by copolymerizing two or more cycloolefin monomers, wherein a glass transition temperature (Tg) is 100° C. or higher, a refractive index is 1.545 or higher, and an Abbe's number is 50 or larger; a polymer (B) selected from: a ring-opening homopolymer obtained by ring-opening polymerization of only a monomer represented by formula (I), a ring-opening copolymer obtained by ring-opening copolymerization of the monomer represented by formula (I) and a monomer capable of ring-opening copolymerization with the monomer represented by formula (I), a hydrogenated product of the ring-opening homopolymer and a hydrogenated product of the ring-opening copolymer; a forming material containing the copolymer (A) or the polymer (B); and a resin formed article obtained by forming the forming material.Type: ApplicationFiled: April 5, 2016Publication date: March 29, 2018Applicant: ZEON CORPORATIONInventors: Kensaku FUJII, Takashi HOUKAWA, Takuya KOMATSUBARA, Yasuhiro SHIMIZU
-
Publication number: 20170306080Abstract: The present invention is a hydrogenated cycloolefin ring-opening polymer comprising a repeating unit derived from tetracyclododecene, and a repeating unit derived from an additional norbornene-based monomer, the hydrogenated cycloolefin ring-opening polymer having a racemo diad ratio of 65% or more with respect to the repeating unit derived from tetracyclododecene, the hydrogenated cycloolefin ring-opening polymer having a weight average molecular weight (Mw) of 10,000 to 40,000, and a resin formed article obtained by forming the hydrogenated cycloolefin ring-opening polymer having a glass transition temperature of 140 to 165° C., a melt flow rate of 8 g/10 min or more as measured at a temperature of 280° C. under a load of 21.18 N, and a flexural strength of 60 MPa or more as measured by a flexural test at a test speed of 2 mm/min, and a resin formed article, and an optical member.Type: ApplicationFiled: September 24, 2015Publication date: October 26, 2017Applicant: Zeon CorporationInventors: Akira FURUKO, Takashi HOUKAWA, Ayumi SATO, Kenji UMEDA
-
Patent number: 9459376Abstract: An optical polymer satisfying an expression: (?A??B)/?B×100<60, where, ?A is the melt viscosity of the optical polymer measured at a temperature of 290° C. and a shear rate of 200 (l/s), and ?B is the melt viscosity of the optical polymer measured at a temperature of 290° C. and a shear rate of 2000 (l/s).Type: GrantFiled: December 17, 2013Date of Patent: October 4, 2016Assignee: ZEON CORPORATIONInventors: Ayumi Sato, Yosuke Harauchi, Hiroya Nishioka, Takashi Houkawa, Kenji Umeda, Takuya Komatsubara
-
Publication number: 20150346386Abstract: An optical polymer satisfying an expression: (?A??B)/?B×100<60, where, ?A is the melt viscosity of the optical polymer measured at a temperature of 290° C. and a shear rate of 200 (l/s), and ?B is the melt viscosity of the optical polymer measured at a temperature of 290° C. and a shear rate of 2000 (l/s).Type: ApplicationFiled: December 17, 2013Publication date: December 3, 2015Inventors: Ayumi SATO, Yosuke HARAUCHI, Hiroya NISHIOKA, Takashi HOUKAWA, Kenji UMEDA, Takuya KOMATSUBARA
-
Patent number: 8053531Abstract: A hydrogenated crystalline norbornene ring-opening polymer is obtained by hydrogenating 80% or more of carbon-carbon double bonds of a ring-opening polymer that is obtained by ring-opening polymerization of norbornene monomers including 90 to 100 wt % of 2-norbornene and 0 to 10 wt % of a 2-norbornene derivative having a substituent which does not include an aliphatic carbon-carbon double bond in the presence of a branching agent, the hydrogenated crystalline norbornene ring-opening polymer having a melting point of 110 to 145° C. and a branching index of 0.3 to 0.98, and a molded article is obtained by molding the hydrogenated crystalline norbornene ring-opening polymer. The hydrogenated crystalline norbornene ring-opening polymer has excellent industrial productivity, and the molded article has excellent productivity and moisture resistance.Type: GrantFiled: February 27, 2009Date of Patent: November 8, 2011Assignee: Zeon CorporationInventors: Takeshi Hirata, Takashi Houkawa, Hiroaki Matsuda, Yosuke Naka
-
Publication number: 20110021731Abstract: A hydrogenated crystalline norbornene ring-opening polymer is obtained by hydrogenating 80% or more of carbon-carbon double bonds of a ring-opening polymer that is obtained by ring-opening polymerization of norbornene monomers including 90 to 100 wt % of 2-norbornene and 0 to 10 wt % of a 2-norbornene derivative having a substituent which does not include an aliphatic carbon-carbon double bond in the presence of a branching agent, the hydrogenated crystalline norbornene ring-opening polymer having a melting point of 110 to 145° C. and a branching index of 0.3 to 0.98, and a molded article is obtained by molding the hydrogenated crystalline norbornene ring-opening polymer. The hydrogenated crystalline norbornene ring-opening polymer has excellent industrial productivity, and the molded article has excellent productivity and moisture resistance.Type: ApplicationFiled: February 27, 2009Publication date: January 27, 2011Applicant: ZEON CORPORATIONInventors: Takeshi Hirata, Takashi Houkawa, Hiroaki Matsuda, Yosuke Naka