Abstract

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): Step 3 of further melting and kneading a mixture of the product and the hydroxylamine compound obtained in the Step 2.

IPC Classes  ?

• C08G 2/24 - Copolymerisation of aldehydes or ketones with acetals
• C08G 2/06 - Catalysts
• C08G 2/28 - Post-polymerisation treatments
• C08L 59/04 - Copolyoxymethylenes
• C08K 5/17 - AminesQuaternary ammonium compounds

Abstract

2 per 100 g of the polyacetal resin (A); as well as an article molded therefrom.

IPC Classes  ?

• C08L 59/04 - Copolyoxymethylenes
• C08K 3/22 - OxidesHydroxides of metals
• C08K 5/17 - AminesQuaternary ammonium compounds
• C08K 5/3435 - Piperidines
• C08L 77/00 - Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chainCompositions of derivatives of such polymers

Abstract

The present invention provides a method for producing an oxymethylene copolymer which is not susceptible to deterioration due to oxidation, and which is reduced in formaldehyde generation amount, especially in formaldehyde generation amount in cases where the oxymethylene copolymer is stored for a long period of time in a high temperature high humidity environment, while being suppressed in the occurrence of mold deposit during molding. Specifically disclosed is a method for producing an oxymethylene copolymer, which comprises: a step 1 wherein a polymerization starting material containing trioxane and a comonomer is reacted in the presence of a predetermined amount of an acid catalyst; a step 2 wherein a hydroxylamine compound represented by general formula (1) is added to and mixed with the product obtained in the step 1 in an amount of 1-20 times the molar amount of the acid catalyst; and a step 3 wherein the mixture of the product and the hydroxylamine compound obtained in the step 2 is subjected to melt-kneading. (In the formula, R1 and R2 are as defined in claims and the description.)

IPC Classes  ?

• C08G 2/28 - Post-polymerisation treatments
• C08K 5/17 - AminesQuaternary ammonium compounds
• C08L 59/00 - Compositions of polyacetalsCompositions of derivatives of polyacetals

Abstract

The present invention provides a polyacetal resin composition, and an article molded therefrom, said composition containing a polyacetal resin (A) and zinc oxide (B), wherein the amount of oxyalkylene structural units other than oxymethylene groups in the polyacetal resin (A) of the polyacetal resin composition is 0.1 mass% or higher; and the total surface area of the zinc oxide (B) in the polyacetal resin composition is 0.1-40 m2 per 100 g of the polyacetal resin (A).

IPC Classes  ?

• C08L 59/04 - Copolyoxymethylenes
• C08K 3/22 - OxidesHydroxides of metals
• C08K 5/17 - AminesQuaternary ammonium compounds
• C08L 77/00 - Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chainCompositions of derivatives of such polymers