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. 23, 1999
Filed:
Apr. 11, 1997
Applicant:
Inventors:
Kaoru Yamamoto, Shizuoka, JP;
Akira Nakai, Shizuoka, JP;
Assignee:
Polyplastics Co., Ltd., , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G / ;
U.S. Cl.
CPC ...
528410 ; 528417 ; 528418 ; 524718 ; 524720 ; 524726 ; 524741 ; 524773 ; 524779 ;
Abstract
To economically produce a polyacetal copolymer excellent in properties including thermal stability by copolymerizing trioxane as the main monomer through simple steps, a polyacetal copolymer is produced by copolymerizing trioxane as the main monomer using a nonvolatile protonic acid catalyst as a polymerization catalyst until the conversion reaches at least 60% (based on all monomers), and then vaporizing unreacted monomers to separate, remove, and recover the same from the polymerization system to thereby reduce the residual monomer content of the polymerization system to 5% by weight or lower.