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?10.sup.?8 moles to 5.0?10.sup.?6 moles with respect to 1 mole of trioxane; adding a hydroxylamine compound represented by general formula (1) (in the formula, R.sup.1 and R.sup.2 are, 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. ##STR00001##

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?10.sup.?8 moles to 5.0?10.sup.?6 moles with respect to 1 mole of trioxane; adding a hydroxylamine compound represented by general formula (1) (in the formula, R.sup.1 and R.sup.2 are, 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. ##STR00001##

Polyoxymethylene, where a ratio of a low molecular weight component having a molecular weight of 10,000 or less in a molecular weight distribution is 7.0% or less of the total, and the molecular weight distribution is obtained by measurement by gel permeation chromatography (GPC) using polymethyl methacrylate (PMMA) as a standard substance.

Polyoxymethylene, where a ratio of a low molecular weight component having a molecular weight of 10,000 or less in a molecular weight distribution is 7.0% or less of the total, and the molecular weight distribution is obtained by measurement by gel permeation chromatography (GPC) using polymethyl methacrylate (PMMA) as a standard substance.

Polyoxymethylene-polydimethysiloxane block copolymers are disclosed. In one embodiment, the siloxane monomer used to make the polymer is soluble in the polyoxymethylene monomers, namely trioxane. The polymer can be formed having relatively small particle sizes, such as less than about 350 microns, such as less than about 200 microns, which makes the polymer well suited for powder coating applications.

A method for producing an oxymethylene copolymer includes copolymerizing trioxane and a comonomer copolymerizable with the trioxane in a presence of a cationic polymerization catalyst and a polymerization controlling agent, wherein the polymerization controlling agent is a cyclic ether with a 4- or more-membered ring containing one oxygen atom.

A production method for a polyacetal copolymer that makes deactivation of a catalyst simple and efficient and that achieves a high polymerization yield and high quality using equipment that does not require a cleaning step and a process that involves a simple operation technique. The production method for a polyacetal copolymer uses trioxane as a main monomer and a cyclic ether and/or a cyclic formal having at least one carbon-carbon bond as a comonomer. In the production method, a predetermined heteropoly acid is used as a polymerization catalyst to perform copolymerization, a predetermined salt is added to the reaction product, melt kneading processing is performed, and the polymerization catalyst is deactivated.

A production method for a polyacetal copolymer that makes deactivation of a catalyst simple and efficient and that achieves a high polymerization yield and high quality using equipment that does not require a cleaning step and a process that involves a simple operation technique. The production method for a polyacetal copolymer uses trioxane as a main monomer and a cyclic ether and/or a cyclic formal having at least one carbon-carbon bond as a comonomer. In the production method, a predetermined heteropoly acid is used as a polymerization catalyst to perform copolymerization, a predetermined salt is added to the reaction product, melt kneading processing is performed, and the polymerization catalyst is deactivated.