Patents by Inventor R. Selvarajan

R. Selvarajan 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).

  • Branched/cross-linked cationic phenol-formaldehyde polymers useful in wastewater treatment
    Patent number: 4308149
    Abstract: Oily waste emulsions which cause low turbidity in industrial waste water effluents are successfully treated with cross-linked cationic polymeric compounds synthesized by reacting phenol, substituted phenol, formaldehyde and various low molecular weight polyamines having a preferred molecular weight of at least 1500 and not exceeding a molecular weight of about 30,000. The polyamines are derived from a base catalyzed polymerization of ammonia and ethylene dichloride or by the oligomerization of ethyleneimine.
    Type: Grant
    Filed: July 14, 1980
    Date of Patent: December 29, 1981
    Assignee: Nalco Chemical Company
    Inventor: R. Selvarajan