Patents by Inventor Tooru Nakaguchi

Tooru Nakaguchi 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: 6875896
    Abstract: A method for producing a high purity 1,1-bis(4-hydroxyphenyl)cyclohexane represented by the general formula (II), wherein R is a hydrogen atom or alkyl group, comprising the steps of: reacting cyclohexanone and a phenol represented by the general formula (I) in the presence of an acid catalyst; wherein R is the same as defined above, neutralizing the resultant reaction mixture with an alkali; primarily crystallizing and filtering a 1,1-bis(4-hydroxyphenyl)cyclohexane produced to obtain a primary crystallization filtrate; dissolving 100 parts by weight of the primary crystallization filtrate in a mixed solvent, which comprises 5 to 10 parts by weight of water and 100 to 200 parts by weight of a lower aliphatic ketone solvent, or 200 to 400 parts by weight of a lower aliphatic alcohol solvent; filtering the resulting solution through a zeta potential filter; and secondarily crystallizing and filtering the 1,1-bis(4-hydroxyphenyl)cyclohexane from the resulting filtrate in the presence of water.
    Type: Grant
    Filed: June 29, 2004
    Date of Patent: April 5, 2005
    Assignee: Honshu Chemical Industry Co., Ltd.
    Inventors: Kazuhiko Yao, Tooru Nakaguchi, Kenji Ekawa
  • Publication number: 20050004405
    Abstract: A method for producing a high purity 1,1-bis(4-hydroxyphenyl)cyclohexane represented by the general formula (II), wherein R is a hydrogen atom or alkyl group, comprising the steps of: reacting cyclohexanone and a phenol represented by the general formula (I) in the presence of an acid catalyst; wherein R is the same as defined above, neutralizing the resultant reaction mixture with an alkali; primarily crystallizing and filtering a 1,1-bis(4-hydroxyphenyl)cyclohexane produced to obtain a primary crystallization filtrate; dissolving 100 parts by weight of the primary crystallization filtrate in a mixed solvent, which comprises 5 to 10 parts by weight of water and 100 to 200 parts by weight of a lower aliphatic ketone solvent, or 200 to 400 parts by weight of a lower aliphatic alcohol solvent; filtering the resulting solution through a zeta potential filter; and secondarily crystallizing and filtering the 1,1-bis(4-hydroxyphenyl)cyclohexane from the resulting filtrate in the presence of water.
    Type: Application
    Filed: June 29, 2004
    Publication date: January 6, 2005
    Inventors: Kazuhiko Yao, Tooru Nakaguchi, Kenji Ekawa