Polyplastics Co., Ltd.

Clariant Catalysts (japan) K.k.

Hiroaki Nakao

Hatsuhiko Harashina

Yoshihisa Tajima

Kuniaki Kawaguchi

Eiji Masuda

Xin Chen

Yutaka Kubota

A high-quality polyacetal produced by a process including supplying a raw material comprising trioxane, a comonomer capable of copolymerizing with trioxane and a non-volatile protonic acid to a reactor of a continuous stirring/mixing machine type; carrying out a polymerization reaction of the raw material to produce a reaction mixture; vaporizing an unreacted monomer to separate the unreacted monomer from the reaction mixture and supplying the unreacted monomer to the raw material supplying; collecting a polyacetal copolymer from the reaction mixture into a collection unit which is arranged downstream from a discharge port and is adjusted to have a gauge pressure of 0.2 kPa or more; and adding a basic compound to the collected polyacetal and then subjecting the resultant mixture to a melt-kneading treatment to deactivate the non-volatile protonic acid.

Method for producing polyacetal copolymer

A solid phosphoric acid catalyst which, when gas-phase synthesizing trioxane from formaldehyde, results in production of trioxane at a high yield and at a high selection rate by markedly suppressing side reactions, reduces the adhesion of organic matter to the catalyst surface, and achieves a stable and long-term catalyst reaction. This solid phosphoric acid catalyst contains silicon phosphate oxide (SPO) obtained by sintering at a temperature of at least 200&#xb0; C. a carrier material to which a phosphoric acid component has been added, and the total quantity of acid does not exceed 5 mmol per 1 g of solid phosphoric acid catalyst when calculated as acid quantity determined by NH-TPD measurement.

Solid phosphoric acid catalyst, and method for producing trioxane

The present invention provides a method of manufacturing a stabilized polyacetal resin, comprising the step of applying a heat treatment to a polyacetal resin having an unstable terminal group in the presence of an unstable terminal group decomposer selected from the following Group I, Group II and Group III, thereby decreasing the unstable terminal group:

Unstable terminal group decomposer, and stabilized polyacetal resin, manufacturing method, composition and molded article using the same

The invention is to provide a polymer, having a high affinity to water, is liquid in spite of being a polymer, simultaneously possesses also a thermal stability and is suitably used as a heating medium or a lubricant. It is the polyacetal (co)polymer, being liquid at room temperature, prepared by copolymerizing (A) 75 to 100 mol % of 1,3-dioxolane and (B) 25 to 0 mol % of trioxane and having the total amount of terminal groups of 15 to 300 mmol/kg and an amount of a hemiformal terminal group of 80 mmol/kg or less.

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Fuji, Japan

Hiroaki Nakao