Patents by Inventor Kohtaro Nagasawa

Kohtaro Nagasawa 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: 4681833
    Abstract: A light-sensitive composition is described, containing: (A) a light-sensitive diazo compound, (B) a combination of Polymer (B-1) and Polymer (B-2), and (C) an epoxy resin. Polymer (B-1) is a polymer having the structural units of the general formulae (i), (ii) and (iii). Polymer (B-2) is a polymer having the structural units of the general formulae (iv), (v) and (vi). ##STR1## wherein R.sup.1 is a hydrogen atom or a methyl group, R.sup.2 is an unsubstituted or substituted benzyl group, a lower alkyl group, or a halogen-substituted lower alkyl group, R.sup.3 is a hydrogen atom, a lower alkyl group, or a halogen-substituted lower alkyl group, R.sup.4 is a tert- or iso-butyl group, and R.sup.5 is a lower alkyl group. This composition is a negative-type light-sensitive composition and is used to prepare a lithographic printing plate, for example. This printing plate is superior in lipophilic nature and also in mechanical properties such as abrasion resistance.
    Type: Grant
    Filed: March 7, 1985
    Date of Patent: July 21, 1987
    Assignee: Somar Corporation
    Inventors: Kohtaro Nagasawa, Kunio Morikubo
  • Patent number: 4349647
    Abstract: A resist material for micro-fabrication comprising a polymer in which the polymer backbone has thereon a moiety of the formula (I) ##STR1## wherein R represents a hydrogen atom, an alkyl group, an alkenyl group or an aryl group or an aralkyl group, the resist material being curable by electromagnetic radiation such as electron beams, X-rays or deep ultraviolet light with a wave length of less than about 3000A and being particularly suitable as a micro-fabrication resist material.
    Type: Grant
    Filed: February 5, 1981
    Date of Patent: September 14, 1982
    Assignee: Somar Manufacturing Co., Ltd.
    Inventors: Kohtaro Nagasawa, Hideo Ochi, Fujio Tanaka, Yumi Shibata
  • Patent number: 4299911
    Abstract: A resist material curable by irradiation with high energy radiation such as electron beams, X-rays, ion beams, neutron beams, .gamma.-rays or deep ultraviolet light but substantially non-curable by irradiation with light having a wavelength of about 300 nm or more, the resist material comprising, as a main component, a solvent-soluble polymer containing an ethylenically unsaturated double bond, the polymer being obtained by reacting (a) a polymer having a plurality of oxirane rings therein and (b) a monomer containing (i) at least one ethylenically unsaturated double bond and (ii) one functional group capable of opening the oxirane rings, and then opening the unreacted oxirane rings.
    Type: Grant
    Filed: August 9, 1978
    Date of Patent: November 10, 1981
    Assignee: Somar Manufacturing Co., Ltd.
    Inventors: Hideo Ochi, Yumi Shibata, Kohtaro Nagasawa
  • Patent number: 4284707
    Abstract: A photocurable composition comprising a first copolymer having a recurring unit of general formula (I): ##STR1## wherein Ar represents a substituted or unsubstituted phenyl group, R.sub.1 represents a lower alkyl group, and m.sub.1 and m.sub.2 are positive numbers with m.sub.1 being greater than or equal to m.sub.2 ;and a second copolymer having a recurring unit of general formula (II): ##STR2## wherein R.sub.2 represents a lower alkyl group, X represents a hydrogen atom or a methyl group, and R.sub.3 represents an isobutyl group, a t-butyl group or a --CH.sub.2 Ar group where Ar represents a substituted or unsubstituted phenyl group and when R.sub.3 is --CH.sub.2 Ar, R.sub.2 can also be t-butyl and isobutyl, and n.sub.1, n.sub.2 and n.sub.3 are positive numbers but n.sub.1 can be zero and (n.sub.1 +n.sub.2)/n.sub.3 equals to about 0.5 to 20; and containing suitable amounts of a cross-linking agent and a photoactivator.
    Type: Grant
    Filed: December 29, 1978
    Date of Patent: August 18, 1981
    Assignee: Somar Manufacturing Co., Ltd.
    Inventors: Kohtaro Nagasawa, Kunio Morikubo, Tsutomu Satoh
  • Patent number: 4273858
    Abstract: A resist material for micro-fabrication comprising a polymer in which the polymer backbone has thereon a moiety of the formula (I) ##STR1## wherein R represents a hydrogen atom, an alkyl group, an alkenyl group or an aryl group or an aralkyl group, the resist material being curable by electromagnetic radiation such as electron beams, X-rays or deep ultraviolet light with a wave length of less than about 3000A and being particularly suitable as a micro-fabrication resist material.
    Type: Grant
    Filed: July 19, 1978
    Date of Patent: June 16, 1981
    Assignee: Somar Manufacturing Co., Ltd.
    Inventors: Kohtaro Nagasawa, Hideo Ochi, Fujio Tanaka, Yumi Shibata
  • Patent number: 4205018
    Abstract: A resin composition is disclosed comprising, as essential ingredients, (I) a urethanized epoxy resin or a urethanized epoxy resin acrylate or methacrylate, (II) a ketone resin and (III) a cross-linkable or polymerizable compound containing at least two ethylenically unsaturated groups.
    Type: Grant
    Filed: November 3, 1978
    Date of Patent: May 27, 1980
    Assignee: Somar Manufacturing Co., Ltd.
    Inventors: Kohtaro Nagasawa, Osamu Ogitani, Ryuichi Fujii