Japan Atomic Energy Research Institute

Tokyo Optical Company, Ltd.

Koichiro Hayashi

Akihiko Ito

Isao Kaetsu

Hiroshi Okubo

Masamichi Kato

Masaru Yoshida

Yuji Maeda

Yoshiaki Nakase

Tadafumi Yamauchi

Tadashi Iwai

Akira Shimizu

A multi-step process of producing polyoxymethylenes by solid state polymerization of trioxane is disclosed. Trioxane is irradiated with ionizing radiation within a temperature range in which no polymerization of trioxane takes place. The irradiated trioxane is then polymerized by raising the temperature to a value at which polymerization of trioxane takes place, said temperature value being at least 15.degree. C above the first mentioned temperature. The polymerization is effected in the presence of an amount of alkyl acetal. The polymerized product thus obtained is then again irradiated, whereupon further polymerization of the irradiated product takes place. The resulting polyoxymethylenes are snow white and exhibit excellent thermal stability. They also have high molecular weights.

Multi-step radiation process of producing polyoxymethylenes

A novel thermosetting resin composition comprising at least one [(2,3-epoxypropoxy)alkyl]trialkoxysilane and at least one selected from polymers, prepolymers, copolymers and coprepolymers of epoxy-group-containing vinyl monomers, which may further contain at least one selected from polymers, prepolymers, copolymers and coprepolymers of vinyl monomers containing no epoxy group, is disclosed. This composition is cured by heating with addition of a ring-opening polymerization catalyst and remarkably improves surface hardness, abrasion resistance, weathering resistance, chemical resistances, heat resistances, etc. of acrylic resins and many other plastic materials without imparing the inherent transparency and other optical properties of these materials when it is applied on the surface of them and cured.

Thermosetting resin composition comprising an

Transparent resin composites comprising a substrate of a transparent plastic material coated with a cured film of at least one [(2,3-epoxypropoxy)alkyl]trialkoxysilane or of at least one [(2,3-epoxypropoxy)alkyl]trialkoxysilane and at least one transparent polymer compatible with said silane are provided. The resin composites have excellent abrasion resistance, surface hardness, heat resistance, chemical resistance, weathering resistance, etc. well retaining the transparency and other optical characteristics of the substrate resin. These resin composites can be used as transparent plastic panels, lenses, etc.

Transparent resin composite

Trioxane can advantageously be polymerized in the presence of a thiocyanate (an ester of thiocyanic acid), to obtain an oxymethylene polymer having thermal stability. The polymerization is further promoted by means of an ionizing radiation or an ultraviolet light.

Process for preparing thermally stabilized oxymethylene polymer from

Growing community of inventors

Suita, Japan

Koichiro Hayashi