Patents by Inventor Tsuneichi Takeshita

Tsuneichi Takeshita 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: 5140072
    Abstract: The subject invention provides a cured non-foamed composition consisting of (i) polychloroprene and (ii) 2-25% by weight of the polymer composition of a copolymer of ethylene and at least one alpha-beta unsaturated carboxylic acid (or ionomer) or ester thereof and a process for making the same.
    Type: Grant
    Filed: November 2, 1990
    Date of Patent: August 18, 1992
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Tsuneichi Takeshita
  • Patent number: 4605705
    Abstract: A heat resistant sulfur-modified polychloroprene copolymer of 2-chloro-1,3-butadiene and 2,3-dichloro-1,3-butadiene characterized in that said polychloroprene has a Mooney viscosity ML 1+4' (100.degree. C.) of from about 25-75, contains from about 3-25% by weight of units derived from 2,3-dichloro-1,3-butadiene, and of the units derived from 2-chloro-1,3-butadiene, 92-96% by weight of said units have a 1,4-trans configuration, said polychloroprene copolymer being curable with 4 parts MgO and 5 parts ZnO per 100 parts of copolymer at about 160.degree. C. for 30 minutes to yield a vulcanizate having a tensile strength of at least 10 MPa.
    Type: Grant
    Filed: September 10, 1984
    Date of Patent: August 12, 1986
    Assignee: E. I. du Pont de Nemours and Company
    Inventor: Tsuneichi Takeshita
  • Patent number: 4154707
    Abstract: The viscosity of chloroprene polymers is stabilized by addition to the polymer of 0.1-5 weight % of an ester, amide, or amic acid derived from maleic acid or fumaric acid or a diacylethylene compound or from their halogenated derivatives. Stabilization of chloroprene polymers made in the absence of elemental sulfur allows them to be mixed under high temperature/high shear conditions, without undergoing substantial crosslinking for practical periods. Sulfur-modified chloroprene polymers are stabilized against viscosity increases during ambient temperature aging. Blends of either type of chloroprene polymers with hydrocarbon diene elastomers can be similarly stabilized.
    Type: Grant
    Filed: April 24, 1978
    Date of Patent: May 15, 1979
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Wolfgang Honsberg, Tsuneichi Takeshita
  • Patent number: 3963772
    Abstract: Liquid alkylene/acrylic telomers predominantly terminated with functional groups are prepared from acrylic and lower alkylene units by carrying out the polymerization in the presence of a Lewis acid halide and an organic halide.
    Type: Grant
    Filed: February 9, 1973
    Date of Patent: June 15, 1976
    Assignee: E. I. Du Pont de Nemours and Company
    Inventor: Tsuneichi Takeshita