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:
Mar. 17, 2009
Filed:
Jan. 21, 2004
Hirohito Kawama, Fukushima, JP;
Mitsuhiro Matsuzaki, Fukushima, JP;
Michihisa Miyahara, Fukushima, JP;
Koichi Suzuki, Fukushima, JP;
Hiroyuki Sato, Fukushima, JP;
Hirohito Kawama, Fukushima, JP;
Mitsuhiro Matsuzaki, Fukushima, JP;
Michihisa Miyahara, Fukushima, JP;
Koichi Suzuki, Fukushima, JP;
Hiroyuki Sato, Fukushima, JP;
Kureha Corporation, Tokyo, JP;
Abstract
A dehydration step is conducted by heating a mixture containing an organic amide solvent and a sulfur source including an alkali metal hydrosulfide, and a part of an overall charged amount of an alkali metal hydroxide as needed. The mixture remaining within the system after the dehydration step is mixed with a dihalo-aromatic compound, the resultant mixture is heated to conduct a polymerization reaction, and the alkali metal hydroxide is added to the mixture for polymerization reaction continuously or in portions to control the pH of the mixture for polymerization reaction within a range of from 7 to 12.5 from the beginning to the end of the polymerization reaction. The poly(arylene sulfide) according to the present invention has a nitrogen content of at most 800 ppm.