Patents Assigned to C. Itoh & Co.
  • Process for purifying crude dibenzylidene sorbitol
    Patent number: 4131612
    Abstract: Purified dibenzylidene sorbitol is prepared by mixing crude dibenzylidene sorbitol containing monobenzylidene sorbitol and tribenzylidene sorbitol as by-product impurities with a lower aliphatic alcohol to dissolve the impurities, and separating and recovering the undissolved dibenzylidene sorbitol. This process affords dibenzylidene sorbitol having a purity of at least 98% from crude dibenzylidene sorbitol with a purity of about 95%.
    Type: Grant
    Filed: May 9, 1977
    Date of Patent: December 26, 1978
    Assignees: E. C. Chemical Ind. Co., Ltd., C. Itoh & Co.
    Inventor: Hiroshi Uchiyama