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:
May. 24, 1994
Filed:
Dec. 23, 1992
Hiroshi Ohishi, Kawasaki, JP;
Shinji Inaba, Kawasaki, JP;
Masao Kimura, Kawasaki, JP;
Koichi Fujishiro, Kawasaki, JP;
Masanao Kawabe, Kawasaki, JP;
Takumi Tanaka, Uji, JP;
Keizo Kyuda, Uji, JP;
Souichiro Kishimoto, Uji, JP;
Takamasa Owaki, Uji, JP;
Akio Motoyama, Uji, JP;
Unitika Ltd., Amagasaki, JP;
Nippon Steel Corporation, Tokyo, JP;
Nippon Steel Chemical Co. Ltd., Tokyo, JP;
Abstract
A process is disclosed for preparing of aromatic polyester-polystyrene block copolymers which comprises subjecting preferentially styrene polymers (A) having terminal functional groups reactive with acid chloride groups and an excess of aromatic dicarboxylic acid dihalides (C) to condensation and then subjecting continuously the resultant mixture and aromatic dihydroxy compounds (B) to interfacial polymerization at the ratio (A)/[(B)+(C)] by weight of 5/95 to 80/20, without separating reaction products of styrene polymers (A) and aromatic dicarboxylic acid dihalides (C), and the block copolymers thus prepared contain a small amount of uncopolymerized styrene polymers, have long aromatic polyester segments, show low birefringence, good transparency, exceptionally low birefringence, low melt viscosity, and good mechanical strength, and are particularly useful as materials for optical instruments.