Patents by Inventor Takeshi Fujikawa

Takeshi Fujikawa 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).

  • Publication number: 20200115491
    Abstract: The present invention provides a curable composition excellent in curability and capable of forming, through light irradiation, a cured product excellent in light resistance, heat resistance, and transparency. The curable composition contains the following component (A), the following component (B), and the following component (C): the component (A): an alicyclic epoxy compound represented by the following formula (a): the component (B): a light resistance imparting agent having a maximum absorption wavelength in a region between 280 and 320 nm in an ultraviolet-visible light absorption spectrum from 250 to 400 nm; and the component (C): an optical cationic polymerization initiator: wherein R1 to R18 are the same as or different from one another and represent a hydrogen atom, a halogen atom, a hydrocarbon group that may contain an oxygen atom or a halogen atom, or an alkoxy group that may have a substituent; and X represents a single bond or a linking group.
    Type: Application
    Filed: December 16, 2019
    Publication date: April 16, 2020
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Kyohei ISHIDA
  • Patent number: 10604617
    Abstract: Provided is a curable composition capable of giving a lens that has excellent transfer accuracy from a mold and offers heat resistance and optical properties at excellent levels. The curable composition according to the present invention for lens formation contains a cycloaliphatic epoxide (A) represented by Formula (a), a cationic-polymerization initiator (B), and a polysiloxane (C) represented by Formula (c). The curable composition contains the polysiloxane (C) in an amount of 0.01% to 5% by weight based on the total amount of the curable composition. The curable composition according to the present invention for lens formation may further contain a siloxane compound (D) containing two or more epoxy groups per molecule.
    Type: Grant
    Filed: October 6, 2017
    Date of Patent: March 31, 2020
    Assignee: DAICEL CORPORATION
    Inventors: Takeshi Fujikawa, Takashi Kubo
  • Patent number: 10584200
    Abstract: The present invention provides a curable composition excellent in curability and capable of forming, through light irradiation, a cured product excellent in light resistance, heat resistance, and transparency. The curable composition contains the following component (A), the following component (B), and the following component (C): the component (A): an alicyclic epoxy compound represented by the following formula (a): the component (B): a light resistance imparting agent having a maximum absorption wavelength in a region between 280 and 320 nm in an ultraviolet-visible light absorption spectrum from 250 to 400 nm; and the component (C): an optical cationic polymerization initiator: wherein R1 to R18 are the same as or different from one another and represent a hydrogen atom, a halogen atom, a hydrocarbon group that may contain an oxygen atom or a halogen atom, or an alkoxy group that may have a substituent; and X represents a single bond or a linking group.
    Type: Grant
    Filed: July 14, 2016
    Date of Patent: March 10, 2020
    Assignee: DAICEL CORPORATION
    Inventors: Takeshi Fujikawa, Kyohei Ishida
  • Publication number: 20200039136
    Abstract: The present invention provides a method for producing a resin molded article through which air bubbles are not easily formed during imprint molding when a curable composition is applied to a mold having a pattern shaped section.
    Type: Application
    Filed: February 8, 2018
    Publication date: February 6, 2020
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Sadayuki FUKUI
  • Patent number: 10550219
    Abstract: The present invention provides a curable composition excellent in curability and capable of forming, through light irradiation, a cured product excellent in light resistance, heat resistance, and transparency. The curable composition contains the following component (A), the following component (B), and the following component (C): the component (A): an alicyclic epoxy compound represented by the following formula (a): the component (B): a light resistance imparting agent having a maximum absorption wavelength in a region between 280 and 320 nm in an ultraviolet-visible light absorption spectrum from 250 to 400 nm; and the component (C): an optical cationic polymerization initiator: wherein R1 to R18 are the same as or different from one another and represent a hydrogen atom, a halogen atom, a hydrocarbon group that may contain an oxygen atom or a halogen atom, or an alkoxy group that may have a substituent; and X represents a single bond or a linking group.
    Type: Grant
    Filed: July 14, 2016
    Date of Patent: February 4, 2020
    Assignee: DAICEL CORPORATION
    Inventors: Takeshi Fujikawa, Kyohei Ishida
  • Publication number: 20200031024
    Abstract: Provided is a silicone mold with which a curable composition containing an epoxy resin can be molded with good precision even if used repeatedly. The silicone mold according to an embodiment of the present invention is a silicone mold for use in molding a curable composition containing an epoxy resin, the silicone mold including a cured product of a silicone resin composition, wherein the cured product has a light transmittance at a wavelength of 400 nm of 80% or higher at a thickness of 1 mm, an elongation at break in accordance with JIS K 7161 of 250% or less, and a thermal linear expansion coefficient of 350 ppm/° C. or less at 20 to 40° C.
    Type: Application
    Filed: February 5, 2018
    Publication date: January 30, 2020
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Sadayuki FUKUI
  • Patent number: 10544918
    Abstract: Provided is a Fresnel lens which has excellent heat resistance and which can covert light even from a poor-quality semiconductor light sources into uniform, high-quality light and can disperse the resulting light without lowering the central illuminance. The Fresnel lens according to the present invention includes two or more sawtooth prisms in a surface thereof and is made of a cured product of a curable composition containing an epoxy compound (A). Of the sawtooth prisms, a sawtooth prism having a longest inclined side in a cross section has a roughened surface, where the cross section is given by cutting the Fresnel lens in a plane which passes through the center of the Fresnel lens and which is perpendicular to a reference plane of the Fresnel lens.
    Type: Grant
    Filed: October 7, 2015
    Date of Patent: January 28, 2020
    Assignee: DAICEL CORPORATION
    Inventors: Takeshi Fujikawa, Sadayuki Fukui
  • Patent number: 10465038
    Abstract: Provided is a curable composition capable of giving a lens that has excellent transfer accuracy from a mold and offers heat resistance and optical properties at excellent levels. The curable composition according to the present invention for lens formation contains a cycloaliphatic epoxide (A) represented by Formula (a), a cationic-polymerization initiator (B), and a polysiloxane (C) represented by Formula (c). The curable composition contains the polysiloxane (C) in an amount of 0.01% to 5% by weight based on the total amount of the curable composition. The curable composition according to the present invention for lens formation may further contain a siloxane compound (D) containing two or more epoxy groups per molecule.
    Type: Grant
    Filed: December 19, 2014
    Date of Patent: November 5, 2019
    Assignee: DAICEL CORPORATION
    Inventors: Takeshi Fujikawa, Takashi Kubo
  • Patent number: 10421834
    Abstract: Provided is a curable composition capable of giving a lens that has excellent transfer accuracy from a mold and offers heat resistance and optical properties at excellent levels. The curable composition according to the present invention for lens formation contains a cycloaliphatic epoxide (A) represented by Formula (a), a cationic-polymerization initiator (B), and a polysiloxane (C) represented by Formula (c). The curable composition contains the polysiloxane (C) in an amount of 0.01% to 5% by weight based on the total amount of the curable composition. The curable composition according to the present invention for lens formation may further contain a siloxane compound (D) containing two or more epoxy groups per molecule.
    Type: Grant
    Filed: December 19, 2014
    Date of Patent: September 24, 2019
    Assignee: DAICEL CORPORATION
    Inventors: Takeshi Fujikawa, Takashi Kubo
  • Patent number: 10351663
    Abstract: Provided is a curable composition which has excellent thin-film curability and which can form, via the application of light and/or heat, a cured product having heat resistance and thermal yellowing resistance at excellent levels. This curable composition contains cationically curable compounds and a cationic-polymerization initiator. The cationically curable compounds include an epoxy compound (A) in an amount of 10 to 90 weight percent of the total weight of the cationically curable compounds, and an oxetane compound (B) in an amount of 5 to 40 weight percent of the total weight of the cationically curable compounds. The cationic-polymerization initiator includes an onium borate salt (C). The onium borate salt (C) preferably has an anionic moiety selected from [(C6H5)B(C6F5)3]?, [(C6H5)B((CF3CF2)2C6H2F)3]?, and [(C6H5C6H4)B(C6F5)3]? and a cationic moiety selected from arylsulfonium ions.
    Type: Grant
    Filed: August 28, 2015
    Date of Patent: July 16, 2019
    Assignee: DAICEL CORPORATION
    Inventors: Takeshi Fujikawa, Takashi Kubo
  • Publication number: 20180237579
    Abstract: Provided is a curable composition which has excellent curability, less causes silicone molds to swell, and allows the silicone molds to have better durability and a longer service life in repeated use. The curable composition according to the present invention is a curable composition for production of an optical component by molding using silicone molds. The curable composition contains curable compounds and a cationic initiator. The curable compounds include (A) a cycloaliphatic epoxy compound and (B) an oxetane compound. The oxetane compound (B) is present in a content of 10 to 45 weight percent of the totality of all the curable compounds contained in the curable composition. Of the totality of all the curable compounds contained in the curable composition, 90 weight percent or more is a compound or compounds having a solubility parameter of 9.0 (cal/cm3)1/2 or more as determined at 25° C. by the Fedors' method.
    Type: Application
    Filed: August 3, 2016
    Publication date: August 23, 2018
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Sadayuki FUKUI
  • Publication number: 20180230260
    Abstract: The present invention provides a curable composition excellent in curability and capable of forming, through light irradiation, a cured product excellent in light resistance, heat resistance, and transparency. The curable composition contains the following component (A), the following component (B), and the following component (C): the component (A): an alicyclic epoxy compound represented by the following formula (a): the component (B): a light resistance imparting agent having a maximum absorption wavelength in a region between 280 and 320 nm in an ultraviolet-visible light absorption spectrum from 250 to 400 nm; and the component (C): an optical cationic polymerization initiator: wherein R1 to R18 are the same as or different from one another and represent a hydrogen atom, a halogen atom, a hydrocarbon group that may contain an oxygen atom or a halogen atom, or an alkoxy group that may have a substituent; and X represents a single bond or a linking group.
    Type: Application
    Filed: July 14, 2016
    Publication date: August 16, 2018
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Kyohei ISHIDA
  • Publication number: 20180215861
    Abstract: Provided is a curable composition which has chargeability into silicone molds and curability at excellent levels, less causes the silicone molds to swell, and allows the silicone molds to have better durability and a longer service life in repeated use. The curable composition according to the present invention contains curable compounds and a cationic initiator and is used for production of an optical component by molding using silicone molds. The curable compounds include (A) a cycloaliphatic epoxy compound in a content of 10 weight percent or more of the totality of all the curable compounds contained in the curable composition. Of the totality of all the curable compounds contained in the curable composition, 10 to 50 weight percent is a curable compound or compounds having a molecular weight of 400 or more.
    Type: Application
    Filed: August 3, 2016
    Publication date: August 2, 2018
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Sadayuki FUKUI
  • Publication number: 20180196167
    Abstract: Provided is a fine and highly heat-resistant optical component having a coating layer on part thereof. The optical component according to the present invention includes a cured product of a curable composition of an epoxy compound (A); and at least one coating layer having a thickness of 0.1 mm or less on part of the cured product. The optical component has a maximum thickness of 2 mm or less and a maximum width in a plan view of 10 mm or less. This optical component is produced through the steps 1, 2, and 3 as follows. In the step 1, the curable composition is charged into a mold having two or more optical-component concave patterns, and at least one of light and heat is applied to give a cured product having two or more optical-component forms. In the step 2, the cured product is separated to give separated articles. In the step 3, a coating layer or layers is formed on the separated articles.
    Type: Application
    Filed: August 3, 2016
    Publication date: July 12, 2018
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Sadayuki FUKUI
  • Publication number: 20180134838
    Abstract: Provided is a photocurable composition which less causes resin-induced swelling of molds, allows the molds to endure more satisfactorily, and has excellent economic efficiency. This photocurable composition includes components (A), (B), (C), and (D). The component (A) is present in a content of 10 to 50 weight percent of the totality of photocurable compounds contained in the photocurable composition. The component (A) is a cycloaliphatic epoxy compound represented by Formula (a). The component (B) is an oxetane compound having a solubility parameter of 9.5 (cal/cm3)1/2 or more as determined by the Fedors' method. The component (C) is a glycidyl ether epoxy compound having a molecular weight of 250 or more. The component (D) is a photoinitiator: wherein R1 to R18 are each, identically or differently, selected from hydrogen, halogen, a hydrocarbon group optionally containing oxygen or halogen, and optionally substituted alkoxy; and X is selected from a single bond and a linkage group.
    Type: Application
    Filed: May 24, 2016
    Publication date: May 17, 2018
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Kyohei ISHIDA
  • Publication number: 20180094098
    Abstract: Provided is a curable composition capable of giving a lens that has excellent transfer accuracy from a mold and offers heat resistance and optical properties at excellent levels. The curable composition according to the present invention for lens formation contains a cycloaliphatic epoxide (A) represented by Formula (a), a cationic-polymerization initiator (B), and a polysiloxane (C) represented by Formula (c). The curable composition contains the polysiloxane (C) in an amount of 0.01% to 5% by weight based on the total amount of the curable composition. The curable composition according to the present invention for lens formation may further contain a siloxane compound (D) containing two or more epoxy groups per molecule.
    Type: Application
    Filed: October 6, 2017
    Publication date: April 5, 2018
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Takashi KUBO
  • Publication number: 20170260323
    Abstract: Provided is a curable composition which has excellent thin-film curability and which can form, via the application of light and/or heat, a cured product having heat resistance and thermal yellowing resistance at excellent levels. This curable composition contains cationically curable compounds and a cationic-polymerization initiator. The cationically curable compounds include an epoxy compound (A) in an amount of 10 to 90 weight percent of the total weight of the cationically curable compounds, and an oxetane compound (B) in an amount of 5 to 40 weight percent of the total weight of the cationically curable compounds. The cationic-polymerization initiator includes an onium borate salt (C). The onium borate salt (C) preferably has an anionic moiety selected from [(C6H5)B(C6F5)3]?, [(C6H5)B((CF3CF2)2C6H2F)3]?, and [(C6H5C6H4)B(C6F5)3]? and a cationic moiety selected from arylsulfonium ions.
    Type: Application
    Filed: August 28, 2015
    Publication date: September 14, 2017
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Takashi KUBO
  • Publication number: 20170232695
    Abstract: Provided is a molded article that has such a shape as to offer a light condensing or light diffusing effect, has excellent mechanical strengths and heat resistance, and has a high thickness deviation ratio. This molded article includes a cured product of a curable composition containing an epoxy compound (A). The cured product has a flexural modulus of 2.5 GPa or more as measured in conformity with JIS K 7171:2008, except for performing measurement on a test specimen having a length of 20 mm, a width of 2.5 mm, and a thickness of 0.5 mm and at a span between specimen supports of 16 mm. The molded article has a thickness deviation ratio (thickest portion thickness to thinnest portion thickness ratio) of 5 or more and offers a light condensing or light diffusing effect. The molded article preferably has a thinnest portion thickness of 0.2 mm or less. The curable composition is preferably a photocurable composition.
    Type: Application
    Filed: August 4, 2015
    Publication date: August 17, 2017
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Sadayuki FUKUI
  • Publication number: 20170227190
    Abstract: Provided is a Fresnel lens which has excellent heat resistance and which can covert light even from a poor-quality semiconductor light sources into uniform, high-quality light and can disperse the resulting light without lowering the central illuminance. The Fresnel lens according to the present invention includes two or more sawtooth prisms in a surface thereof and is made of a cured product of a curable composition containing an epoxy compound (A). Of the sawtooth prisms, a sawtooth prism having a longest inclined side in a cross section has a roughened surface, where the cross section is given by cutting the Fresnel lens in a plane which passes through the center of the Fresnel lens and which is perpendicular to a reference plane of the Fresnel lens.
    Type: Application
    Filed: October 7, 2015
    Publication date: August 10, 2017
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Sadayuki FUKUI
  • Publication number: 20160334701
    Abstract: Provided is a photocurable composition that is used for nanoimprinting and can give, on a wafer, a uniform thin film that maintains a uniform thickness without causing uneven resin distribution even after being left stand for a certain time and still enables transfer of, and formation of, a fine pattern with good precision from a mold onto the thin film. The photocurable composition for nanoimprinting includes components (A), (B), (C), and (D) and includes the component (C) in a content of 1 to 30 weight percent based on the total amount (100 weight percent) of the photocurable composition. The component (A) is a cationically curable compound represented by Formula (1). The component (B) is a cationic photoinitiator. The component (C) is a hydroxy-containing solvent having a boiling point of 100° C. to 210° C. (at 760 mmHg). The component (D) is a solvent that is devoid of hydroxy, has a boiling point of 140° C. to 210° C. (at 760 mmHg), and has monomer solubility in terms of solubility parameter of 8.
    Type: Application
    Filed: January 6, 2015
    Publication date: November 17, 2016
    Applicant: DAICEL CORPORATION
    Inventors: Takeshi FUJIKAWA, Takuya YAMAMOTO