Patents by Inventor Sim Y. Leong

Sim Y. Leong 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).

  • Production of thermosetting phenol-formaldehyde resins
    Patent number: 4235989
    Abstract: Thermosetting water-immiscible phenol-formaldehyde resins in which a large proportion of the linkages between the benzene rings are benzyl ether linkages located ortho to the phenolic hydroxyl groups are produced by reaction of at least one mole of formaldehyde with 1 mole of phenol in an aqueous reaction medium in the presence of a metal carboxylate catalyst, such as, zinc acetate. Methods of control of the exothermic addition of formaldehyde to phenol are described.
    Type: Grant
    Filed: December 22, 1978
    Date of Patent: November 25, 1980
    Assignee: Cor Tech Research Ltd.
    Inventors: Sim Y. Leong, Pitchaiya Chandramouli, Ramesh C. Vasishth