Patents by Inventor Motoyuki Yamada

Motoyuki Yamada 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: 5523370
    Abstract: Provided is a poly(para-t-butoxycarbonyloxystyrene) having recurring units of the formula: ##STR1## which is prepared by anionic polymerization of para-t-butoxycarbonyloxystyrene. The polymer is of a controlled molecular weight and a narrow molecular weight distribution and has a high degree of resolution and development, meeting the requirements of resist materials. The method allows for simple preparation of such polymers.
    Type: Grant
    Filed: April 12, 1995
    Date of Patent: June 4, 1996
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Osamu Watanabe, Toru Nakanishi, Tomoyoshi Furihata, Motoyuki Yamada, Fujio Yagihashi
  • Patent number: 5412050
    Abstract: A polystyrene type monodispersion polymer having at least a monomer unit represented by the following general formula (I), and having a molecular weight which lies in the range 500-500,000 and manufacturing process thereof are disclosed; ##STR1## where R is a hydrogen atom or methyl group, and the R in the molecule may be identical or different.
    Type: Grant
    Filed: August 19, 1993
    Date of Patent: May 2, 1995
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Osamu Watanabe, Motoyuki Yamada, Fujio Yagihashi, Akira Yamamoto, Yoshinobu Isono
  • Patent number: 5356753
    Abstract: A positive resists material for high energy-sensitive positive resists which can be developed in aqueous alkali solution, said material comprising (A) a polyhydroxystyrene resin wherein some hydroxyl groups are substituted by t-butoxycarbonyloxy groups, (B) a solution blocking agent, and (C) an onium salt, and being characterized in that said solution blocking agent contains at least one t-butoxycarbonyloxy group per molecule, said onium salt is bis(p-t-butylphenyl) iodinium trifluormethylsulfonate represented by the following formula (1): ##STR1## and the weight proportions of (A), (B), (C) are given by the relations: 0.07.ltoreq.B-.ltoreq.0.40, 0.005.ltoreq.C.ltoreq.0.15, 0.55.ltoreq.A, A+B+C=1. As the resist has low absorption at the exposure wavelength of a KrF exima laser, a fine pattern having vertical walls is easily formed.
    Type: Grant
    Filed: November 12, 1992
    Date of Patent: October 18, 1994
    Assignees: Shin-Etsu Chemical Co., Ltd., Nippon Telegraph and Telephone Corp.
    Inventors: Motoyuki Yamada, Osamu Watanabe, Akinobu Tanaka, Hiroshi Ban, Yoshio Kawai
  • Patent number: 5314931
    Abstract: A resist based on a living polymer is provided. Living anionic polymerization of p-alkoxycarbonylstyrene monomers results in polymers having a molecular weight distribution (Mw/Mn) of from 1 to 1.4.
    Type: Grant
    Filed: May 28, 1992
    Date of Patent: May 24, 1994
    Assignee: Shin-Etsu Chemical Co., Limited
    Inventors: Motoyuki Yamada, Tomoyoshi Furihata, Osamu Watanabe, Fujio Yagihashi
  • Patent number: 5252691
    Abstract: A p-vinylphenoxydimethylphenylcalbyldimethylsilane homopolymer having a molecular weight dispersion narrow enough to ensure high resolution and high developability to resists containing said homopolymer as main component can be manufactured by anionic polymerization of a p-vinylphenoxydimethylphenylcalbyldimethylsilane monomer.
    Type: Grant
    Filed: January 13, 1992
    Date of Patent: October 12, 1993
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Osamu Watanabe, Motoyuki Yamada, Fujio Yagihashi, Minoru Takamizawa
  • Patent number: 5219681
    Abstract: A lithium cell having excellent discharging and recharging characteristics is proposed which is characteristic in the unique formulation of the polymeric solid electrolyte composition having a high ionic conductivity to fill the space between the anode and the cathode. The electrolyte composition comprises: (a) a block copolymer of styrene and 4-hydroxystyrene, of which the phenolic hydroxy groups in the 4-hydroxystyrene moiety are substituted by the grafting chains of poly(ethylene oxide) moiety having a specified chain length, (b) an ionic lithium salt and (c) a poly(ethylene oxide) in a specified weight proportion.
    Type: Grant
    Filed: October 10, 1991
    Date of Patent: June 15, 1993
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Motoyuki Yamada, Osamu Watanabe, Toru Nakanishi, Minoru Takamizawa
  • Patent number: 4981666
    Abstract: In place of the conventional silicon source materials used in the prior art method for the preparation of silicon carbide whiskers, the inventive method utilizes a hydrolysis product of a chlorosilane compound R.sub.a SiCl.sub.4-a or a chlorodisilane compound R.sub.b Si.sub.2 Cl.sub.6-b, in which R is a hydrogen atom or a monovalent hydrocarbon group, a is zero to 3 and b is 1 to 5, as the silicon source which is intimately mixed with a powder of carbon and the mixture is heated at 1400.degree. to 1700.degree. C. to give silicon carbide whiskers in a high conversion. Alternatively, the hydrolysis of the chloro(di)silane compound is performed in an aqueous medium in which a powder of carbon is dispersed in advance so that the hydrolysis product as formed is already a mixture with the carbon powder.
    Type: Grant
    Filed: November 17, 1986
    Date of Patent: January 1, 1991
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Motoyuki Yamada, Minoru Takamizawa, Akira Hayashida, Nobuaki Urasato, Hiromi Ohsaki
  • Patent number: 4975392
    Abstract: A method for manufacturing silicon carbide whisker which has a cross-sectional diameter of greater than about 1 .mu.m by mixing a source of silicon atom in the form of grains having a mean grain diameter of at least 50 .mu.m with a carbon atom source in the presence of an element or compound of the element, the element being yttrium, calcium, manganese, aluminum, indium, or rare earth elements in an amount from about 100 to 2,000 ppm and growing the silicon carbide whisker therefrom.
    Type: Grant
    Filed: November 20, 1989
    Date of Patent: December 4, 1990
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Motoyuki Yamada, Kazutoshi Numanami, Takahiro Iizuka, Akira Hayashida
  • Patent number: 4849196
    Abstract: The present invention provides a process for producing silicon carbide whiskers by reacting a starting mixture comprising starting silicon source material mainly composed of silicon and oxygen and carbonaceous material at a high temperature, wherein one or more of Fe, Co and Ni ingredients are contained in the starting mixture such that the total amount of the Fe, Co, Ni ingredients is from 25 to 2000 ppm based on the silicon ingredient in the starting silicon source material. Silicon carbide whiskers at high purity can be produced at high yield with less content of powdery silicon carbide.
    Type: Grant
    Filed: December 23, 1987
    Date of Patent: July 18, 1989
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Motoyuki Yamada, Akira Hayashida, Kazutoshi Numanami, Takahiro Iizuka
  • Patent number: 4432781
    Abstract: The invention provides a novel method for manufacturing fused quartz glass by the decomposition and oxidation of a vaporizable silicon compound such as silicon tetrachloride in a plasma flame according to which the quartz glass rod produced contains a controlled amount of hydroxy groups with high reproducibility. The principle of the inventive method consists in the admixture of gaseous hydrogen chloride into the gaseous reactant mixture or in the plasma-supporting gas as the source for the hydrogen atoms to be converted to the hydroxy groups in place of hydrogen gas or water vapor as the hydrogen source. Good proportionality is established between the concentration of the hydrogen chloride in the gaseous feed and the hydroxy content in the resultant fused quartz glass rod.
    Type: Grant
    Filed: February 26, 1982
    Date of Patent: February 21, 1984
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Haruo Okamoto, Motoyuki Yamada
  • Patent number: 4358306
    Abstract: The invention provides a method for molding a block of a fused quartz glass by the plastic deformation of a starting block with smaller dimensions at a high temperature. The molding procedure is carried out in a graphite mold under compression at a temperature of 1700.degree. C. or higher in an atmosphere of helium at a pressure in the range, preferably, from 50 to 500 Torr. The cooling schedule as specified is also of importance in order that the molded quartz glass block is freed from any strain or cracks.
    Type: Grant
    Filed: October 5, 1981
    Date of Patent: November 9, 1982
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Haruo Okamoto, Motoyuki Yamada