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. 20, 2012
Filed:
Dec. 19, 2003
Hiroyuki Sato, Fukushima, JP;
Tatsuya Kawasaki, Tokyo, JP;
Yasushi Nakazawa, Fukushima, JP;
Kureha Corporation, Tokyo, JP;
Abstract
In a production process of a poly(arylene sulfide), a mixture containing an organic amide solvent, an alkali metal hydrosulfide and an alkali metal hydroxide in a proportion of 0.95 to 1.05 mol per mol of the alkali metal hydrosulfide is heated and dehydrated in a dehydration step. After the dehydration step, as needed, an alkali metal hydroxide and water are added to control the total number of moles of the alkali metal hydroxide, and the number of moles of water so as to amount to 1.00 to 1.09 per mol of a sulfur source including the alkali metal hydrosulfide existing in the system and to 0.5 to 2.0 per mol of the charged sulfur source, respectively. A polymerization step is conducted by a two-stage process.