Nitto-denko Corporation

Hidenori Suzuki

Makoto Kai

Mitsuyoshi Shirai

Kenichi Shibata

Yasunori Yamamoto

Kunio Nagasaki

Yoshio Nakagawa

Eiichi Imoto

Masanori Uesugi

Yoshinori Yoshida

Yuka Oosawa

[Problem] To provide a composite film having light-curing property and weather resistance. [Means for solving] A composite film is one that comprises at least a urethane polymer, wherein both an initial b* value of the composite film measured by a spectrocolorimeter (value at an angle of 15 degrees) and a b* value after performing an accelerated weathering test for 120 hours (value at an angle of 15 degrees) are 4.0 or less, and a non-volatile component after heating the composite film at 130&#xb0; C. for two hours is 96% or more.

Composite film

To provide a composite film having low-temperature flexibility. The composite film including an acrylic polymer and a urethane polymer, in which the acrylic polymer includes an acryl component containing at least an acrylic acid-based monomer and a monofunctional acrylic monomer whose homopolymer has a glass transition temperature (Tg) of 273 K or more; the content of said acrylic acid-based monomer in said composite film is from 0.5 to 15 wt %; the glass transition temperature (Tg ac) of the acrylic polymer is 273 K or more; the glass transition temperature (Tg ur) of the urethane polymer is 273 K or less; and the glass transition temperature (Tg) of the composite film is 269 K or less.

To provide an adhesive sheet for protecting coating films which is excellent in the adhesion between a coating layer and a composite film, and has weather resistance. The adhesive sheet for protecting coating films is one comprising a base layer and an adhesive layer, and the base layer has a coating layer produced by using the fluoroethylene vinyl ether alternating copolymer having a specific structure on one surface of a composite film containing an acrylic polymer and a urethane polymer. It is preferable that the coating layer is cross-linked with a composite film and has cross-linked points.

Adhesive sheet for protecting coating film

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Ibaraki, Japan

Hidenori Suzuki