Central Glass Company, Limited

Asahi Kasei Kogyo Kabushiki Kaisha

Taku Yamauchi

Kazuhiko Maeda

Toshio Koishi

Shinichi Teshima

Shigeki Katsuta

A polymer blend of 2-80 wt % of an acrylic or methacrylic ester base polymer and the balance of a ternary copolymer of vinylidene fluoride (VDF), hexafluoroacetone (HFA) and tetrafluoroethylene (TFE) is very high in transparency and serves as a thermoplastic resin useful for optical purposes. The first polymer of the blend can be selected from homopolymers and copolymers of C.sub.1 -C.sub.4 alkyl acrylates and methacrylates. The second polymer is preferably made up of 2-15 mol % of HFA, 5-60 mol % of TFE and the balance of VDF. The polymer blend has a relatively low index of refraction, which can be controlled by selecting the first and second polymers and/or by varying the blending ratio. The polymer blend is soluble in various organic solvents. Besides, the polymer blend serves as a thermochromic material that becomes opaque by heating and resumes transparency by cooling.

Polymer blend composition suitable as optical material

A cladding material for plastic optical fiber comprising a vinylidene fluoride-trifluoroethylene-hexafluoroacetone copolymer which comprises 3.5 to 6.5% by mole of hexafluoroacetone units, a molar ratio of vinylidene fluoride unit to trifluoroethylene unit of 3 to 6:1, and a melt index of 10 to 60 g/10 min, and a plastic optical fiber comprising said cladding material and a methyl methacrylate homopolymer or copolymer which comprises over 50% by weight of methyl methacrylate units as the core material.

Cladding material for plastic optical fiber and plastic optical fiber

The invention is an optical fiber having a core formed of either an inorganic glass or an organic polymer such as polymethyl methacrylate and a cladding layer formed of a ternary copolymer of vinylidene fluoride, hexafluoroacetone and either trifluoroethylene or tetrafluoroethylene. This cladding material is superior particularly in transparency and flexibility.

Growing community of inventors

Kamifukuoka, Japan

Taku Yamauchi