Toray Industries, Inc.

Shunichi Osada

Kenji Tsunashima

Tetsuya Tsunekawa

Wataru Gouda

Hirofumi Hosokawa

Nobutsugu Chigira

Katsutoshi Miyakawa

Hiroshi Yoshimura

Masatoshi Oyama

Hitomi Horiuchi

Chie Makiyama

Masaharu Toyama

An optical waveguide film is provided having a cross-sectional structure wherein claddings composed of a thermoplastic resin B and dispersions (cores) composed of a thermoplastic resin A extend in the machine direction of the film and are arrayed in the transverse direction of the film, the optical waveguide film comprising not less than 3 cores, diameters (We1, We2) of cores located at the both ends in the transverse direction of the film and diameter (Wc) of a core in the central portion in the transverse direction of the film satisfying the following Formulae (1) and (2), the optical waveguide film comprising a continuous cladding layer at at least one side thereof, the thicknesses of the cladding layers (Te1, Te2) at the both ends thereof in the transverse direction of the film and the thickness (Tc) of the cladding layer in the central portion in the transverse direction of the film satisfying the following Formulae (3) and (4):0.8&#x2266;We1/Wc&#x2266;1.2&#x2003;&#x2003;Formula (1)0.8&#x2266;We2/Wc&#x2266;1.2&#x2003;&#x2003;Formula (2)0.8&#x2266;Te1/Tc&#x2266;1.2&#x2003;&#x2003;Formula (3)0.8&#x2266;Te2/Tc&#x2266;1.2&#x2003;&#x2003;Formula (4).

Optical waveguide film

A multilayer film of which the optical properties hardly change due to heat and where detachment hardly occurs between layers is provided. The multilayer film has a structure where five or more layers made of thermoplastic resin A (layers A) and five or more layers made of thermoplastic resin B (layers B) having a basic skeleton that is the same as that of thermoplastic resin A are alternately layered on top of each other, and is wherein at least one reflection peak is provided and the difference between the reflectance of the reflection peak before heating and after heating for 30 minutes in an atmosphere of 150&#xb0; C. is no greater than 15%.

Multilayer film

An object of the invention is to provide a laminated film which hardly gives transmission loss based on reflection or scattering, is excellent in heat resistance and humidity resistance, and has an arbitrarily-controlled refractive index distribution. Accordingly, the invention is a laminated film comprising 5 or more laminated resin layers; the thickness of each of the resin layers being from 1 to 100 nm; and the film having a layer structure wherein the thicknesses of resin layers having the same composition A, out of the resin layers, increase or decrease from the side of a surface of the laminated film toward the side of the other surface opposite thereto.

Laminated film

Method and apparatus for producing thermoplastic resin film which allows a biaxially oriented polyester film to be formed at a high speed of 400 m/min or more. In the method, a molten thermoplastic resin film is brought into contact with a cooling medium, to be cooled and solidified, for producing a cast film. The method is characterized by keeping the surface temperature of the cooling medium in the region immediately before the melt reaching position at not lower than the glass transition temperature and not higher than the melting point of the thermoplastic resin. The apparatus is characterized by a cooling medium having a heater and a cooler to ensure that the surface temperature of the cooling medium in the region immediately before the melt reaching position is kept at the requisite temperature, and by a surface temperature of the cooling drum in the region immediately before the film leaving position being maintained lower than the glass transition temperature of the thermoplastic resin.

Method of producing thermoplastic resin films and apparatus for producing the same

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Shiga, Japan

Shunichi Osada