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. 01, 2011
Filed:
Apr. 10, 2006
Satoshi Nagai, Yokkaichi, JP;
Akira Okamura, Yokkaichi, JP;
Daisuke Sunaga, Yokkaichi, JP;
Mitsubishi Gas Chemical Company, Inc., Tokyo, JP;
Abstract
The problem to be solved is to provide a process for producing a polyoxymethylene copolymer in a molding machine with a reduced generation of formaldehyde gas. In a process for continuously producing a polyoxymethylene copolymer comprising a step of melt-kneading a crude polyoxymethylene copolymer at a temperature not lower than the melting point thereof, devolatilizing under reduced pressure the formaldehyde gas generated as a decomposition product, subsequently mixing a formaldehyde scavenger containing a hydrazide compound (A) while keeping the copolymer in a molten state and immediately pelletizing the mixture, a dispersed solution obtained by slurry-dispersing said (A) in a diluent (B) having a melting point lower than temperature (Ta) which is the lower of the melting point and the decomposition temperature of (A), within a temperature range not lower than the melting point of (B) and lower than (Ta) is used as the formaldehyde scavenger.