Patents by Inventor Keizaburo Yamaguchi

Keizaburo Yamaguchi 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: 5260388
    Abstract: A heat-resistant and thermoplastic polyimide which has low dielectric characteristics and recurring structural units of the following formula ##STR1## wherein R is a tetravalent radical having from 2 to 27 carbon atoms and selected from the group consisting of an aliphatic radical, alicyclic radical, monoaromatic radical, condensed polyaromatic radical and noncondensed aromatic radical connected each other with a direct bond or a bridge member; aromatic diamines which are useful for the raw material monomers of the polyimide and have following formulas: ##STR2## and ##STR3## and a process for preparing the polyimide of the above formula by reacting these aromatic diamines with a tetracarboxylic dianhydride in the presence of an aromatic dicarboxylic anhydride or aromatic monoamine, and successively thermally or chemically imidizing the resultant polyamic acid.
    Type: Grant
    Filed: June 8, 1992
    Date of Patent: November 9, 1993
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Shoji Tamai, Wataru Yamashita, Yuichi Okawa, Yuko Ishihara, Keizaburo Yamaguchi, Akihiro Yamaguchi
  • Patent number: 5260403
    Abstract: A color-developing sheet for pressure-sensitive copying paper sheets is obtained using an aqueous suspension of a color-developing composition containing a multivalent metal salt of a salicylic acid resin obtained from a salicylic acid ester and a mixture of styrenes which include a styrene dimer, which aqueous suspension is obtained by finely wet-grinding the color-developing composition in the presence of at least one anionic, water-soluble, high-molecular weight substance selected from (a) polyvinyl alcohol derivatives containing at least one sulfonic acid group thereof and salts thereof and (b) polymers and copolymers containing as an essential component a styrenesulfonic acid salt.
    Type: Grant
    Filed: July 2, 1992
    Date of Patent: November 9, 1993
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Keizaburo Yamaguchi, Yoshimitsu Tanabe, Kiyoharu Hasegawa, Akihiro Yamaguchi
  • Patent number: 5231160
    Abstract: A novel aromatic diamine; a polyimide comprising 1,3-bis(3-aminobenzoyl)benzene or 4,4'-bis(3-aminobenzoyl)biphenyl as a diamine component and having recurring structural units represented by the formula (III): ##STR1## wherein R is a tetravalent radical selected from the group consisting of an aliphatic radical having from 2 to 27 carbon atoms, alicyclic radical, monoaromatic radical, condensed polyaromatic radical, and noncondensed aromatic radical connected each other with a direct bond or a bridge member, and X is a divalent radical of ##STR2## and a polyimide having a terminal aromatic group which is essentially unsubstituted or substituted with a radical having no reactivity with amines or dicarboxylic acid anhydrides or a composition comprising said polyimide.
    Type: Grant
    Filed: August 29, 1991
    Date of Patent: July 27, 1993
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Shoji Tamai, Keizaburo Yamaguchi, Yuko Ishihara, Saburo Kawashima, Hideaki Oikawa, Toshiyuki Kataoka, Akihiro Yamaguchi
  • Patent number: 5206438
    Abstract: Disclosed is an aromatic diamine compound represented by the formula (I) ##STR1## wherein R is H or CH.sub.3. Also disclosed is a bismaleimide compound represented by the formula (IV) ##STR2## wherein R is H or CH.sub.3, A resin forming composition comprising these compounds is also disclosed. The compounds are useful as raw materials for resins, and the resin forming composition and the resin can provide excellent heat resistance and impact resistance and low hygroscopicity.
    Type: Grant
    Filed: October 23, 1990
    Date of Patent: April 27, 1993
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Keizaburo Yamaguchi, Tatsuhiro Urakami, Yoshimitsu Tanabe, Midori Yamazaki, Shoji Tamai, Norimasa Yamaya, Masahiro Ohta, Akihiro Yamaguchi
  • Patent number: 5147948
    Abstract: A method for polymerizing vinyl chloride comprises polymerizing vinyl chloride in an aqueous medium or bulk-polymerizing vinyl chloride, wherein the inner wall of a polymerizer and parts of devices which come in contact with the monomer during the polymerization are coated, prior to the polymerization, with a reaction product having a molecular weight ranging from 500 to 100,000, obtained by condensing a polyhydric phenol and sulfur dichloride in the presence of a Lewis acid as a catalyst. The amount of the polymer adhered to the polymerizer during polymerization of vinyl chloride is substantially lowered and the adhered polymer can be easily washed away through simple water washing according to the foregoing method. Moreover, the method does not adversely affect the reaction time and the quality of the resulting product at all.
    Type: Grant
    Filed: December 21, 1990
    Date of Patent: September 15, 1992
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Seiichi Masuko, Ichisaburo Nakamura, Keiichi Fukuda, Yasuyuki Hatakeyama, Akihiro Yamaguchi, Keizaburo Yamaguchi
  • Patent number: 5145949
    Abstract: Disclosed herein is an aromatic amine resin formed of a mixture of aromatic amine compounds represented by the following general formula (a): ##STR1## wherein A means a phenylene, alkyl-substituted phenylene, diphenylene, diphenyl ether or naphthylenyl group, R.sup.1 denotes a halogen atom or a hydroxyl, C.sub.1-4 alkoxy or C.sub.1-5 alkyl group, l stands for 1 or 2, m is an integer of 0-3, when m is 2 or 3, R.sup.1 s may be the same or different and two of R.sup.1 s may join together into a 5- to 6-membered alicyclic moiety which may optionally contain one or more side chains, and n stands for an integer of 0-300.
    Type: Grant
    Filed: January 22, 1992
    Date of Patent: September 8, 1992
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Keizaburo Yamaguchi, Yoshimitsu Tanabe, Tatsuhiro Urakami, Akihiro Yamaguchi, Norimasa Yamaya, Masahiro Ohta
  • Patent number: 5106953
    Abstract: The invention relates to an aromatic amine resin comprising a mixture of aromatic amine compounds represented by the following general formula (a): ##STR1## wherein A represents a phenylene, alkyl-substituted phenylene, diphenylene, diphenyl ether or naphthylenyl group, R.sup.1 represents a halogen atom or a hydroxyl C.sub.1-4 alkoxy or C.sub.1-5 alkyl group, l is 1 or 2, m is 0, 1, 2 or 3, n is an integer from 0 to 300 and when m is 2 or 3, the R.sup.1 group may be same or different and may join to form a 5- or 6-membered alicyclic moiety which may optionally contain one or more side chains, and also relates to processes for producing the same and a thermosetting composition containing the same.
    Type: Grant
    Filed: April 19, 1990
    Date of Patent: April 21, 1992
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Keizaburo Yamaguchi, Yoshimitsu Tanabe, Tatsuhiro Urakami, Akihiro Yamaguchi, Norimasa Yamaya, Masahiro Ohta
  • Patent number: 5079331
    Abstract: Heat-resistant epoxy resin composition obtained by incorporation of 2-(4-hydroxyphenyl)-2-(4-maleimidophenyl)propane in a resin composition consisting esssentially of epoxy resin and an epoxy hardener is disclosed.
    Type: Grant
    Filed: May 23, 1990
    Date of Patent: January 7, 1992
    Assignee: Mitsui Toatsu Chemical, Inc.
    Inventors: Mikio Kitahara, Koichi Machida, Takayuki Kubo, Motoyuki Torikai, Koutarou Asahina, Yoshimitsu Tanabe, Keizaburo Yamaguchi, Akihiro Yamaguchi
  • Patent number: 5077436
    Abstract: Bis(3-nitrophenoxy) derivatives of aromatic or bridged aromatic hydrocarbons are derived from m-dinitrobenzene and dihydroxy derivatives of said hydrocarbons and certain substituted derivatives thereof by a condensation reaction in dipolar aprotic solvents in the presence of bases. The bis(3-nitrophenoxy) derivatives and derivatives obtained are successively reduced to afford bis-(3-aminophenoxy)derivatives. This is a new method for reacting the dihydroxy-derivatives with m-dinitrobenzene, and hence can prepare novel bis(3-aminophenoxy) derivatives such as 4,4'-bis(3-amino-phenoxy)biphenyl, 1-[4-(3-aminophenoxy)phenyl]-1,3,3-trimethyl-6-(3-aminophenoxy)indan, 6,6'-bis(3-aminophenoxy)3,3,3',3'-tetramethyl-1,1'spirobiindan, and methyl substituted 2,2'-bis[4-(3-aminophenoxy)phenyl]propane.
    Type: Grant
    Filed: February 21, 1986
    Date of Patent: December 31, 1991
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Yukihiro Yoshikawa, Keizaburo Yamaguchi, Kenichi Sugimoto, Yoshimitsu Tanabe, Akihiro Yamaguchi
  • Patent number: 5051494
    Abstract: The invention relates to an aromatic amine resin comprising a mixture of aromatic amine compounds represented by the following general formula (a): ##STR1## wherein A represents a phenylene, alkyl-substituted phenylene, diphenylene, diphenyl ether or naphthylenyl group, R.sup.1 represents a halogen atom or a hydroxyl C.sub.1-4 alkoxy or C.sub.1-5 alkyl group, l is 1 or 2, m is 0, 1, 2 or 3, n is an integer from 0 to 300 and when m is 2 or 3, the R.sup.1 group may be the same or different and may join to form a 5- or 6-membered alicyclic moiety which may optionally contain one or more side chains, and also relates to processes for producing the same and a thermosetting composition containing the same.
    Type: Grant
    Filed: April 19, 1990
    Date of Patent: September 24, 1991
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Keizaburo Yamaguchi, Yoshimitsu Tanabe, Tatshuiro Urakami, Akihiro Yamaguchi, Norimasa Yamaya, Masahiro Ohta
  • Patent number: 5028581
    Abstract: Odorless or absolutely ordorless multi-valent metal-modified salicylic acid. The former copolymers are obtained by condensing salicylic acid with a benzyl aldehyde, reacting the resultant resin with a styrene derivative and reacting the resin thus-obtained with a multivalent metal salt. The latter copolymers are obtained by adding water dropwise to the resultant multi-valvent metal-modified resin at a temperature above the boiling point of water to remove completely volatile matters.
    Type: Grant
    Filed: August 14, 1989
    Date of Patent: July 2, 1991
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Keizaburo Yamaguchi, Yoshimitsu Tanabe, Akihiro Yamaguchi
  • Patent number: 5023366
    Abstract: Disclosed herein are salicylic acid copolymers having a weight average molecular weight of 500-10,000 and obtained (a) by condensing salicylic acid (i) with a benzyl alcohol (ii) and/or benzyl ether (iii) or a benzyl halide (iv) in the presence of an acid catalyst or (b) by reacting a co-condensation resin of (i) and (ii) and/or (iii) with (iv) or (c) by reacting a co-condensation resin of (i) and (ii) and/or (iii) or (iv) with a styrene derivative in the presence of an acid catalyst; multivalent metal salts of the salicylic acid copolymers; color-developing agents comprising the multivalent metal salts; and color-developing sheets suited for pressure-sensitive copying paper and comprising the color-developing agents. Their production processes are also disclosed.
    Type: Grant
    Filed: October 23, 1987
    Date of Patent: June 11, 1991
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Keizaburo Yamaguchi, Yoshimitsu Tanabe, Makoto Asano, Akihiro Yamaguchi
  • Patent number: 5013848
    Abstract: A novel aromatic bismaleimide of the formula (I): ##STR1## wherein X is ##STR2## where R.sub.1 R.sub.2, R.sub.3 and R.sub.4 are a hydrogen atom or a methyl group. The bismaleimide is prepared by reacting an aromatic diamine having the formula (II): ##STR3## wherein X is the same as in the formula (I), with maleic anhydride and then conducting the ring-closing reaction of the resultant aromatic bismaleamic acid.
    Type: Grant
    Filed: July 22, 1987
    Date of Patent: May 7, 1991
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Yukihiro Yoshikawa, Midori Yamazaki, Keizaburo Yamaguchi, Kenichi Sugimoto, Yoshimitsu Tanabe, Akihiro Yamaguchi
  • Patent number: 4997874
    Abstract: An aqueous suspension of a multivalent-metal-modified salicylic acid resin, which is suitable for use in the production of color-developing sheets for pressure-sensitive recording paper sheets, contains a specific multivalent-metal-modified salicylic acid resin at the first-mentioned resin. Fine particles of the specific multivalent-metal-modified salicylic acid is dispersed in an aqueous solution of a dispersant composed of at least one compound selected from the group consisting of:(a) water-soluble anionic high-molecular compounds composed of polyvinyl alcohol derivatives containing sulfonic acid groups in their molecules, and salts thereof,(b) acrylamide-modified polyvinyl alcohols, and(c) water-soluble anionic high-molecular compounds composed of polymers or copolymers comprising particular styrenesulfonic acid derivatives as their essential components.The aqueous dispersion is prepared by finely grinding the specific multivalent-metal-modified salicylic acid in the aqueous solution of the dispersant.
    Type: Grant
    Filed: March 17, 1988
    Date of Patent: March 5, 1991
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Makoto Asano, Kiyoharu Hasegawa, Masatoshi Takagi, Akihiro Yamaguchi, Keizaburo Yamaguchi, Yoshimitsu Tanabe, Hiroyuki Akahori
  • Patent number: 4987261
    Abstract: The invention relates to diaminoindane derivatives represented by the following formula: ##STR1## wherein R.sub.1 and R.sub.2 are each selected from the group consisting of a hydrogen atom and a lower alkyl group having from 1 to 4 carbon atoms, and a process for preparing same.
    Type: Grant
    Filed: August 15, 1989
    Date of Patent: January 22, 1991
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Keizaburo Yamaguchi, Masayuki Ooe, Akihiro Yamaguchi
  • Patent number: 4966961
    Abstract: The present invention relates to polymaleimide compounds having the following chemical structure: ##STR1## wherein n represents an integer of from 0 to about 50 and to a process for preparing the same.
    Type: Grant
    Filed: May 15, 1989
    Date of Patent: October 30, 1990
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Yoshimitsu Tanabe, Keizaburo Yamaguchi, Tatsuhiro Urakami, Akihiro Yamaguchi
  • Patent number: 4957994
    Abstract: An opoxy resin is obtained by reacting an epihalohydrin with an imido-ring-containing diphenol represented by the following formula (I): ##STR1## wherein R represents an aliphatic group having at least two carbon atoms, an alicyclic group, a monocyclic aryl group, a fused polycyclic aromatic group, or a non-fused polycyclic aromatic group formed of aromatic groups coupled together directly or via a linking member and the two hydroxyl groups are each bonded to a meta position or the para position. In the epoxy resin, at least 50% of the hdroxyl groups of molecules of the diphenol have been opoxidized.
    Type: Grant
    Filed: August 15, 1989
    Date of Patent: September 18, 1990
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Tatsuhiro Urakami, Yoshimitsu Tanabe, Keizaburo Yamaguchi, Akihiro Yamaguchi
  • Patent number: 4952648
    Abstract: Disclosed herein are novel multivalent metal-modified salicyclic acid resins useful as color-developing agents for pressure-sensitive copying paper. They can each be produced by causing a salicyclic acid ester and a styrene derivative to undergo a Friedel-Crafts reaction in the presence of a strong acid catalyst, hydrolyzing the resulting salicylic acid ester resin, and then reacting the thus-obtained salicyclic acid resin with a multivalent metal salt.
    Type: Grant
    Filed: August 4, 1988
    Date of Patent: August 28, 1990
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Keizaburo Yamaguchi, Yoshimitsu Tanabe, Akihiro Yamaguchi
  • Patent number: 4937318
    Abstract: The invention relates to an aromatic amine resin comprising a mixture of aromatic amine compounds represented by the following general formula (a): ##STR1## wherein A represents a phenylene, alkyl-substituted phenylene, diphenylene, diphenyl ether or napthylenyl group, R.sup.1 represents a halogen atom or a hydroxyl C.sub.1-4 alkoxy or C.sub.1 -5 alkyl group, l is 1 or 2, m is 0, 1, 2 or 3, n is an integer from 0 to 300 and when m is 2 or 3, the R.sup.1 group may be same or different and may join to form a 5- to 6-membered alicyclic moiety which may optionally contain one or more side chains, and also relates to processes for producing the same and a thermosetting composition containing the same.
    Type: Grant
    Filed: October 7, 1988
    Date of Patent: June 26, 1990
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Keizaburo Yamaguchi, Yoshimitsu Tanabe, Tatsuhiro Urakami, Akihiro Yamaguchi, Norimasa Yamaya, Masahiro Ohta
  • Patent number: 4803258
    Abstract: Disclosed are thermoplastic aromatic polyetherpyridines composed of repeating structural units each containing one or more pyridine rings. These polymers are prepared by reacting a 2,6-dihalogenopyridine with one or two dihydroxy compounds or by reacting a bis(6-chloro-2-pyridyloxy) compound with a dihydroxy compound. The polymers thus obtained have an excellent combination of heat resistance, moldability and other properties, and hence are useful in a wide variety of applications.
    Type: Grant
    Filed: July 23, 1987
    Date of Patent: February 7, 1989
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Keizaburo Yamaguchi, Hideaki Oikawa, Kenichi Sugimoto, Masahiro Ohta, Akihiro Yamaguchi