Patents by Inventor Kaoru Usami

Kaoru Usami 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).

  • Process for producing crosslinked urea-formaldehyde polymer particles
    Patent number: 4433133
    Abstract: Disclosed is a process for producing fine particles of crosslinked urea-formaldehyde polymer which comprises the steps of synthesizing a precondensate of urea and formaldehyde, allowing the precondensate to react by the addition of an aqueous solution of an acid catalyst, and then neutralizing the reaction mixture, characterized in that the filtrate obtained in the filtration step for separating the polymer particles is recycled to the reaction system at the step of synthesizing a precondensate of urea and formaldehyde and/or the step of allowing the precondensate to react by the addition of an aqueous solution of an acid catalyst and in that the precondensate is obtained by reaction 1 mole of urea with 1.4 to 1.9 moles of formaldehyde at a pH of 6 to 10 and a temperature of 10 to 95.degree. C.
    Type: Grant
    Filed: March 28, 1983
    Date of Patent: February 21, 1984
    Assignee: Mitsui Toatsu Chemicals, Inc.
    Inventors: Naoyuki Ifuku, Akio Kurokawa, Kenzo Seita, Kaoru Usami, Naoyuki Aikawa