Patents by Inventor Hisayuki Kuwahara

Hisayuki Kuwahara 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: 20050038298
    Abstract: The process for producing an amino composition of the present invention by addition reaction of a polyamine with an alkenyl group-containing compound wherein said polyamine is reacted preliminarily with a strongly basic catalyst to produce a reaction mixture comprising a reaction intermediate and then an alkenyl group-containing compound is added to the reaction mixture to proceed the addition reaction provides an amino composition having stable properties.
    Type: Application
    Filed: August 5, 2004
    Publication date: February 17, 2005
    Inventors: Masatoshi Echigo, Hisayuki Kuwahara, Takeshi Koyama
  • Publication number: 20040210011
    Abstract: A modified polyoxyalkylene polyamine obtained by addition reaction of a polyoxyalkylene polyamine and an alkenyl group-containing compound has a low viscosity and it provides, when used as a curing agent for epoxy resin, an epoxy resin composition which can provide an epoxy resin cured product having excellent chemical resistance.
    Type: Application
    Filed: January 30, 2004
    Publication date: October 21, 2004
    Inventors: Masatoshi Echigo, Hisayuki Kuwahara, Takeshi Koyama
  • Publication number: 20040171770
    Abstract: The epoxy resin curing agent of the present invention comprises a polyamino compound obtainable by addition reaction of aliphatic diamine represented by the formula (1) and styrene and a curing accelerator comprising an organic compound having at least one carboxyl group and at least one hydroxyl group within the molecule, which can achieve a low viscosity without containing environmental harmful substances such as phenol and solvents. In addition, the epoxy resin composition using said epoxy resin curing agent shows an excellent curability at low temperature and it provides a cured coating film having excellent appearance.
    Type: Application
    Filed: February 9, 2004
    Publication date: September 2, 2004
    Inventors: Hisayuki Kuwahara, Masatoshi Echigo, Takeshi Koyama
  • Publication number: 20040171791
    Abstract: A modified chain aliphatic polyamine obtained by addition reaction of a chain aliphatic polyamine having a specific structure and an unsaturated hydrocarbon compound has a low viscosity and it provides, when used as a curing agent for epoxy resin, an epoxy resin composition which can provide an epoxy resin cured product having an excellent property. Further, a modified chain aliphatic polyamine composition obtained by addition reaction of a chain aliphatic polyamine having a specific structure and an unsaturated hydrocarbon compound followed by the removing step of unreacted chain aliphatic polyamine to reduce its amount less than 2% by weight provides, when used as a curing agent for epoxy resin, an epoxy resin composition which can provide an epoxy resin cured product having an excellent property.
    Type: Application
    Filed: December 19, 2003
    Publication date: September 2, 2004
    Inventors: Masatoshi Echigo, Hisayuki Kuwahara, Takeshi Koyama
  • Publication number: 20040106684
    Abstract: An object of the present invention is to provide a modified cyclic aliphatic polyamine having a low viscosity and a small content of unreacted polyamine which can provide, when it is used as a curing agent for epoxy resin, an epoxy resin composition having an improved workability without adding solvent or diluent and an excellent property of epoxy resin cure product. The above modified cyclic aliphatic polyamine is obtained by addition reaction of a cyclic aliphatic polyamine such as isophoronediamine and norbornanediamine and an alkenyl compound such as styrene. The modified cyclic aliphatic polyamine thus obtained is added in epoxy resin to be used as a curing agent for epoxy resin.
    Type: Application
    Filed: September 25, 2003
    Publication date: June 3, 2004
    Inventors: Takeshi Koyama, Tetsushi Ichikawa, Hisayuki Kuwahara, Masatoshi Echigo
  • Publication number: 20040044176
    Abstract: An object of the present invention is to provide an amino composition which provides, when used as a curing agent for epoxy resin, a long pot life and an excellent appearance of a coating film to an epoxy resin composition without deteriorating the reactivity of the composition. The amino composition is obtained by addition reaction of diamine such as metaxylylenediamine and 1,3-bis (aminomethyl) cyclohexane and styrene, wherein the content of the diamine is less than 15% by weight based upon the total weight of the amino composition and the content of 1-addition product of having one phenethyl group is 50 to 100% by weight based upon the total weight of amino compound(s) obtained by the addition reaction.
    Type: Application
    Filed: June 18, 2003
    Publication date: March 4, 2004
    Inventors: Tetsushi Ichikawa, Hisayuki Kuwahara, Masatoshi Echigo
  • Patent number: 5596040
    Abstract: A thermoplastic resin composition comprising:(a) about 20 to 80% by weight of polyphenylene ether resin comprising at least one structural unit in its backbone represented by the formula: ##STR1## wherein (b) about 0.01 to 10% by weight of a modified aromatic hydrocarbon-formaldehyde resin produced by modifying an aromatic hydrocarbon-formaldehyde resin which is obtained by reacting alkyl benzene with formaldehyde, using a modifying agent reactive with its methylol group, methylene ether group, or acetal group;(c) about 2 to 30% by weight of a rubber-like polymer; and(d) about 20 to 80% by weight of a polyamide resin; and a method for its preparation.
    Type: Grant
    Filed: October 4, 1995
    Date of Patent: January 21, 1997
    Assignee: Mitsubishi Gas Chemical Company, Inc.
    Inventors: Shinya Miya, Yuichi Kano, Hisayuki Kuwahara, Takeshige Kasuya, Yosio Fukaya