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.

Potentially degradable isohexide based compounds and their polymers, derived from renewable resources, are described. Degradable isohexide-based monomers and polymers obtained from renewable resources are also described. Finally, processes for synthesizing such degradable polymers via copolymerization of the isohexide-based monomers and long chain diols are disclosed.

Potentially degradable isohexide based compounds and their polymers, derived from renewable resources, are described. Degradable isohexide-based monomers and polymers obtained from renewable resources are also described. Finally, processes for synthesizing such degradable polymers via copolymerization of the isohexide-based monomers and long chain diols are disclosed.

The patent application relates to a process for preparing polyoxymethylene by polymerization of a reaction mixture (R.sub.G) which comprises at least one formaldehyde source and at least one initiator mixture (I.sub.G), wherein the initiator mixture (I.sub.G) comprises at least one polymerization initiator and at least one solvent of the general formula (I)
R.sup.1—O—[—R.sup.3—O—].sub.m—R.sup.2  (I), where m is 1, 2, 3 or 4; R.sup.1 and R.sup.2 are each, independently of one another, C.sub.3-C.sub.6-alkyl; R.sup.3 is C.sub.1-C.sub.5-alkylene.

The patent application relates to a process for preparing polyoxymethylene by polymerization of a reaction mixture (R.sub.G) which comprises at least one formaldehyde source and at least one initiator mixture (I.sub.G), wherein the initiator mixture (I.sub.G) comprises at least one polymerization initiator and at least one solvent of the general formula (I)
R.sup.1—O—[—R.sup.3—O—].sub.m—R.sup.2  (I), where m is 1, 2, 3 or 4; R.sup.1 and R.sup.2 are each, independently of one another, C.sub.3-C.sub.6-alkyl; R.sup.3 is C.sub.1-C.sub.5-alkylene.

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.

A method for producing an oxymethylene copolymer, in which a copolymer starting material containing a trioxane and a comonomer is subjected to a polymerization reaction in the presence of a polymerization initiator that contains an acidic compound (A), and where: the copolymer starting material contains a basic compound (B); an acidic compound (C) that is different from the acidic compound (A) is added into the copolymer starting material before performing the polymerization reaction, thereby causing a reaction between the basic compound (B) and the acidic compound (C) in advance; and the polymerization reaction is carried out by means of melt polymerization.

A photochromic polyurethane laminate wherein the photochromic polyurethane layer of the laminate has been crosslinked with an isocyanate-active prepolymer using a crosslinking agent. The crosslinking agent is formulated to have at least three functional groups that are reactive with functional groups of the polyurethane or of the isocyanate-active prepolymer. A method of making the photochromic polyurethane laminate includes steps of causing the crosslinking.