It has been desired to develop a method for producing an oxymethylene polymer, by which an oxymethylene polymer having a high polymerization degree can be produced with high efficiency while suppressing increase in the amount of generation of an odor. Further, it has been desired to develop an oxymethylene polymer resin composition, wherein generation of an odor at the time of molding or after molded to obtain a molded body is suppressed. The present invention provides a method for producing an oxymethylene polymer, wherein the oxymethylene polymer is produced by polymerizing a cyclic oligomer of formaldehyde, and wherein a boron trifluoride compound and an aryl fluoride boron compound are used as polymerization catalysts. The present invention also provides an oxymethylene polymer resin composition containing an oxymethylene polymer and a derivative of an aryl fluoride boron compound.

It has been desired to develop a method for producing an oxymethylene polymer, by which an oxymethylene polymer having a high polymerization degree can be produced with high efficiency while suppressing increase in the amount of generation of an odor. Further, it has been desired to develop an oxymethylene polymer resin composition, wherein generation of an odor at the time of molding or after molded to obtain a molded body is suppressed. The present invention provides a method for producing an oxymethylene polymer, wherein the oxymethylene polymer is produced by polymerizing a cyclic oligomer of formaldehyde, and wherein a boron trifluoride compound and an aryl fluoride boron compound are used as polymerization catalysts. The present invention also provides an oxymethylene polymer resin composition containing an oxymethylene polymer and a derivative of an aryl fluoride boron compound.

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.

It has been desired to develop a method for producing an oxymethylene polymer, by which an oxymethylene polymer having a high polymerization degree can be produced with high efficiency while suppressing increase in the amount of generation of an odor. Further, it has been desired to develop an oxymethylene polymer resin composition, wherein generation of an odor at the time of molding or after molded to obtain a molded body is suppressed. The present invention provides a method for producing an oxymethylene polymer, wherein the oxymethylene polymer is produced by polymerizing a cyclic oligomer of formaldehyde, and wherein a boron trifluoride compound and an aryl fluoride boron compound are used as polymerization catalysts. The present invention also provides an oxymethylene polymer resin composition containing an oxymethylene polymer and a derivative of an aryl fluoride boron compound.

It has been desired to develop a method for producing an oxymethylene polymer, by which an oxymethylene polymer having a high polymerization degree can be produced with high efficiency while suppressing increase in the amount of generation of an odor. Further, it has been desired to develop an oxymethylene polymer resin composition, wherein generation of an odor at the time of molding or after molded to obtain a molded body is suppressed. The present invention provides a method for producing an oxymethylene polymer, wherein the oxymethylene polymer is produced by polymerizing a cyclic oligomer of formaldehyde, and wherein a boron trifluoride compound and an aryl fluoride boron compound are used as polymerization catalysts. The present invention also provides an oxymethylene polymer resin composition containing an oxymethylene polymer and a derivative of an aryl fluoride boron compound.

Poly-1,3-dioxepane, poly-1,3-dioxolane, polytetrahydrofurane or mixtures thereof are used in molding materials comprising polyoxymethylene or a copolymer containing a majority of oxymethylene units, for improving the flexural toughness of moldings formed from the molding materials.

Poly-1,3-dioxepane, poly-1,3-dioxolane, polytetrahydrofurane or mixtures thereof are used in molding materials comprising polyoxymethylene or a copolymer containing a majority of oxymethylene units, for improving the flexural toughness of moldings formed from the molding materials.

A method for producing an oxymethylene copolymer which gives molded articles that are inhibited from emitting formaldehyde and can be reduced in yellowness is provided. In producing an oxymethylene copolymer, an effective polymerization initiator amount is regulated to a value within a given range, the amount being calculated from the amount of perchloric acid or a derivative thereof contained in the polymerization initiator and the amount of triethanolamine contained in all the monomers comprising trioxane and comonomers, which are starting materials for the copolymer.

A method for producing an oxymethylene copolymer which gives molded articles that are inhibited from emitting formaldehyde and can be reduced in yellowness is provided. In producing an oxymethylene copolymer, an effective polymerization initiator amount is regulated to a value within a given range, the amount being calculated from the amount of perchloric acid or a derivative thereof contained in the polymerization initiator and the amount of triethanolamine contained in all the monomers comprising trioxane and comonomers, which are starting materials for the copolymer.