Patents Assigned to Showa Kagaku Kogyo Company, Ltd.
  • Patent number: 4371475
    Abstract: This invention relates to a novel 1,4-bis-styrylbenzene derivative, in particular, suitable for use as an optical brightening agent, which is represented by the following general formula, ##STR1## in which R and R.sub.1, which may be same or different, represent a member selected from the class consisting of hydrogen atom, halogen atoms, lower alkyl groups and lower alkoxy groups, A and A.sub.1, which may be same or different, represent a member of lower alkylene groups which may be substituted by a member selected from the class consisting of halogen atoms, hydroxyl group and lower alkyl groups and X and X.sub.1, which may be same or different, represent a member selected from the class consisting of --COOM groups and --SO.sub.3 M groups wherein M represents a member selected from the class consisting of hydrogen atom, alkali metals, alkaline earth metals, organic ammoniums and guanidiniums.
    Type: Grant
    Filed: August 21, 1978
    Date of Patent: February 1, 1983
    Assignee: Showa Kagaku Kogyo Company, Ltd.
    Inventors: Takao Yanagisawa, Meguru Tanaka