Nitto-denko Corporation

Souya Jo

Keiji Hayashi

Takeshi Nakano

Shogo Sasaki

Kenichi Kataoka

A reinforcing film comprises a pressure sensitive adhesive layer laminated and fixed on a principal surface of a film substrate. The pressure sensitive adhesive layer is formed of a photocurable composition containing a photocurable agent and a base polymer having a crosslinked structure. The gel fraction of the photocurable composition is preferably 60% or more. The shear storage elastic modulus at 25° C. of the pressure sensitive adhesive layer is preferably 1×10to 1.2×10Pa. The shear storage elastic modulus at 25° C. of the pressure sensitive adhesive layer after photocuring is preferably 1.5×10to 2×10Pa.

Reinforcing film

A reinforcing film comprises a pressure sensitive adhesive layer laminated and fixed on a principal surface of a film substrate. The pressure sensitive adhesive layer is formed of a photocurable composition containing a photocurable agent and a base polymer having a crosslinked structure. A frictional force of the pressure sensitive adhesive layer measured with a frictional force microscope at a frequency of 5 Hz is preferably 2 to 5 times a frictional force at a frequency of 0.1 Hz. After photocuring of the pressure sensitive adhesive layer, a frictional force of a photocured pressure sensitive adhesive layer measured with the frictional force microscope at a frequency of 5 Hz is preferably not less than 5 times a frictional force measured at a frequency of 0.1 Hz.

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Ibaraki, Japan

Souya Jo