Mitsubishi Gas Chemical Company, Inc.

Thai Polyacetal Co., Ltd.

Yuuta Yamamoto

Daisuke Sunaga

Akira Ito

Takuya Okada

Yupin Pattamamongkolchai

Wandee Thuamthong

An oxymethylene-copolymer manufacturing method includes: polymerizing a polymerization raw material containing trioxane and a comonomer in the presence of an acid catalyst in a quantity that is 1.0×10moles to 5.0×10moles with respect to 1 mole of trioxane; adding a hydroxylamine compound represented by general formula (1) (in the formula, Rand Rare, independently of each other, a hydrogen atom or an organic group having 1-20 carbon atoms) to a reaction product obtained during the polymerizing of the polymerization raw material at 50-5000 times the quantity of the acid catalyst, in terms of the molar quantity, and mixing the hydroxylamine compound with the reaction product; and subjecting the mixture of the reaction product and the hydroxylamine compound, which is obtained during the adding of the hydroxylamine compound, to an additional melt-kneading.

Oxymethylene-copolymer manufacturing method

The present invention is to provide a process for producing an oxymethylene copolymer, in which deteriorate due to oxidation hardly occurs, an amount of formaldehyde generated from the product when stored for a long time under environment of high temperature and high humidity is reduced, and occurrence of mold deposit during molding is small. A process for producing an oxymethylene copolymer includes Step 1 of polymerizing polymer raw materials containing trioxane and a comonomer in the presence of a specific amount of an acid catalyst, Step 2 of adding a hydroxylamine compound represented by the following general formula (1): to a product obtained in the Step 1 in an amount of 1 to 20-fold mol based on an amount of the acid catalyst and mixing these, andStep 3 of further melting and kneading a mixture of the product and the hydroxylamine compound obtained in the Step 2.

Process for producing oxymethylene copolymer

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Mie, Japan

Yuuta Yamamoto