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. 30, 2023
Filed:
Mar. 10, 2020
Polyplastics Co., Ltd., Tokyo, JP;
POLYPLASTICS CO., LTD., Tokyo, JP;
Abstract
A method for producing a polyacetal resin composition which allows for suppression of formaldehyde generation from a molded article to an extremely low level, and stable suppression of mold deposits during molding. The polyacetal resin composition contains: 100 parts by mass of a polyacetal polymer (A); 0.01 to 0.50 parts by mass of an aliphatic carboxylic acid hydrazide (B); 0.001 to 0.50 parts by mass of a hydantoin compound having two hydrazinocarbonylalkyl groups (C); and 0.001 to 0.30 parts by mass of an alkaline earth metal salt of aliphatic carboxylic acid (D), wherein the total amount of the components (B) and (C) with respect to 100 parts by mass of the polyacetal polymer (A) is 0.03 to 0.55 parts by mass, and the polyacetal polymer (A) is a polyacetal copolymer obtained by copolymerizing trioxane as a principal monomer (a) with a cyclic ether having at least one carbon-carbon bond as a comonomer (b) using a heteropolyacid represented by general formula (1) as a polymerization catalyst (c) to obtain a reaction product, and subsequently adding a carbonate of an alkali metal element or alkaline earth metal element (d) to the reaction product to deactivate the polymerization catalyst (c).