Patents by Inventor Shenghong Dai

Shenghong Dai 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).

  • Publication number: 20050049358
    Abstract: The present invention relates to a water dispersible polyisocyanate composition bearing urea comprising (a) an aliphatic polyisocyanate or a mixture of aliphatic polyisocyanates or a mixture of aliphatic polyisocyanates with other polyisocyanates; and (b) a reaction product of component (a) with component (c) a polyether amine or a mixture of a polyether amine and a polyether alcohol. The present invention also relates to a water dispersible polyisocyanate composition bearing urea and urea derivatives which is obtained by heating the above composition bearing urea for conducting a subsequent reaction, to increase the numbers of isocyanate functional groups contained in said composition, wherein the urea derivatives include biuret, triuret and tetrauret, and most of them are biuret.
    Type: Application
    Filed: December 1, 2003
    Publication date: March 3, 2005
    Inventors: Shenghong Dai, Chinghung Chen, Will Yang, Tsai-Lung Chen
  • Publication number: 20020010369
    Abstract: Residues from the distillation of a toluene diamine phosgenation mixture are hydrolyzed by mixing them with water and subjecting the mixture to a temperature of 200-350° C. The hydrolysis is performed in the presence of a sufficient amount of a base to maintain the pressure in the reactor to no more than a predetermined operating level. The product mixture is then extracted to recover TDA, which can be recycled. This provides an efficient process whereby nearly quantitative conversion of the residues to TDA can be achieved.
    Type: Application
    Filed: May 5, 2000
    Publication date: January 24, 2002
    Inventors: Shenghong Dai, Duane S. Treybig, Kathryn Hock, Van A. Kent
  • Patent number: 5525681
    Abstract: Polyurea polymers prepared from formulations including a polyisocyanate, a polyamine and a polyepoxide can have good heat stability and good physical properties in the substantial absence of uretidine diones and isocyanurates. The polymers can be prepared in one step of admixing and heating at greater than 150.degree. C. or in a two step process by first admixing the components at less than 130.degree. C. and then postcuring the product at greater than 150.degree. C. The polyurea polymer, after postcuring, can have substantially no residual epoxy or oxazolidinone groups. These polymers were particularly useful for applications which require the exposure of the polyurea polymers to both intermittent high temperatures and high humidity. The polyurea polymers of the present invention can withstand higher temperatures than conventional polyurea polymers without blistering.
    Type: Grant
    Filed: April 13, 1995
    Date of Patent: June 11, 1996
    Assignee: The Dow Chemical Company
    Inventors: Benny G. Barron, Shenghong Dai, James R. Porter