The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 19, 1999
Filed:
Apr. 14, 1998
Takahiro Adachi, Osaka, JP;
Toshiaki Takata, Osaka, JP;
Mitsubishi Gas Chemical Company, Tokyo, JP;
Abstract
A process for producing a polycarbonate resin with high flowability having a viscosity average molecular weight (Mv) of 13,000 to 20,000 according to an interfacial polymerization method which comprises the steps of forming a reaction mixture while injecting phosgene into bisphenol, after the completion of injection of phosgene, adding a tetraammonium salt to the reaction mixture, then, conducting polycondensation reaction, after a viscosity average molecular weight (Mv) of a reaction mixture containing the resultant reaction products has reached to 3,000 or above and less than 6,000, adding a molecular weight modifier to the reaction mixture, further conducting polycondensation reaction, and thereby obtaining the polycarbonate resin.