Patents by Inventor Mizuo Ito

Mizuo Ito 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: 5744653
    Abstract: A method for preparing 1,3-dihydroxy-4,6-bis?.alpha.-methyl-.alpha.-.alpha.(4'-hydroxyphenyl)ethy l!benzene represented by the following formula (1): ##STR1## comprising the step of initiating a reaction of resorcin with 4-isopropenylphenol in a mixed solvent which comprises a non-polar solvent and a polar solvent in the presence of an acidic catalyst. The method can easily be handled, ensures a high yield, permits the reduction of impurity content and can provide highly pure 1,3-dihydroxy-4,6-bis?.alpha.-methyl-.alpha.-(4'-hydroxyphenyl)ethyl!benze ne. The resulting phenolic compound is useful as, for instance, a branching agent for polycarbonates, polyesters or the like; a raw material for radiant ray-sensitive components for use as resist materials; a raw material for epoxy resins; and a hardening agent for epoxy resins.
    Type: Grant
    Filed: August 19, 1996
    Date of Patent: April 28, 1998
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Mizuo Ito, Shigeru Iimuro
  • Patent number: 5399783
    Abstract: Crystals of 6,6'-dihydroxy-3,3,3',3'-tetramethyl -1,1'-spirobiindane (hereinafter referred to as SPI) are obtained by cooling a phenol solution containing 6,6'-dihydroxy-3,3,3',3'-tetramethyl-1,1'-spirobiindane when crystallization is started at a temperature higher than a transition temperature between SPI and an adduct of SPI with phenol. The crystals are washed with an organic solvent or contacted with water and further washed with an organic solvent. When crystallization is started at a temperature less than the transition temperature, adduct crystals of SPI with phenol are obtained from the phenol solution. Phenol is removed from the adduct crystals and the adduct crystals are contacted with water to obtain a hydrate and further the hydrate is washed with an organic solvent.
    Type: Grant
    Filed: April 11, 1994
    Date of Patent: March 21, 1995
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Mizuo Ito, Shigeru Iimuro
  • Patent number: 5304624
    Abstract: A method for preparing 1,1,2,2-tetrakis(4-hydroxy-3,5-dimethylphenyl)ethane (TKXE) comprising subjecting two molecules of bis(3,5-dimethyl-4-hydroxyphenyl) methane to dehydration-condensation under oxidizing conditions, an epoxy resin prepared by epoxidating TKXE obtained by the method and an epoxy resin composition comprising TKXE obtained by the method as a hardener and an epoxy resin as well as methods for preparing the resin and composition. The method makes it possible to prepare highly pure TKXE in the form of crystals. Moreover, the epoxy resin and the epoxy resin composition can provide hardened products excellent in physical properties such as heat resistance and mechanical strength.
    Type: Grant
    Filed: July 9, 1992
    Date of Patent: April 19, 1994
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Naru Koike, Shigeru Iimuro, Mizuo Ito
  • Patent number: 5157165
    Abstract: Herein provided are a method for preparing 1,1,2,2-tetrakis(4-hydroxy-3,5-dimethylphenyl)ethane (TKXE) comprising subjecting two molecules of bis(3,5-dimethyl-4-hydroxyphenyl) methane to dehydration-condensation under oxidizing conditions, an epoxy resin prepared by epoxidating TKXE obtained by the method and an epoxy resin composition comprising TKXE obtained by the method as a hardener and an epoxy resin as well as methods for preparing the resin and composition. The method makes it possible to prepare highly pure TKXE in the form of crystals. Moreover, the epoxy resin and the epoxy resin composition can provide hardened products excellent in physical properties such as heat resistance and mechanical strength.
    Type: Grant
    Filed: November 22, 1991
    Date of Patent: October 20, 1992
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Naru Koike, Shigeru Iimuro, Mizuo Ito
  • Patent number: 3933928
    Abstract: 2,6-DI-TERT.-BUTYL-4-CUMYL PHENOL IS PRODUCED BY REACTING P-CUMYL PHENOL WITH ISOBUTYLENE, AT A REACTION TEMPERATURE OF FROM 40.degree. TO 120.degree.C. in the presence of from 0.01 to 20% by weight of p-toluene sulfonic acid based on the weight of the p-cumyl phenol. Isobutylene is charged into the reaction system at a high rate and is always present in the reaction system during the reaction. A substantially 100% conversion of p-cumyl phenol is attained and the weight ratio of 2,6-di-tert.-butyl-4-cumyl phenol/2-tert.-butyl-4-cumyl phenol in the reaction product is greater than 10, while splitting off of the cumyl group at the para position is suppressed.
    Type: Grant
    Filed: August 21, 1974
    Date of Patent: January 20, 1976
    Assignee: Mitsui Toatsu Chemicals, Incorporated
    Inventors: Kunio Hanauye, Tsutomu Takase, Mitsuhiro Iwasa, Mizuo Ito