Curable pressure sensitive adhesive composition, optical disk producing sheet, and optical disk

An optical disk comprising:

• an optical disk substrate having a concavo-convex pattern on a first surface;
• an information recording layer formed on the concavo-convex pattern of the first surface;
• and
• a curable pressure sensitive adhesive layer compression-bonded onto the surface of the information recording layer, the curable pressure sensitive adhesive layer formed using a curable pressure sensitive adhesive composition including a polymer-containing energy rays-curable component and fine particles having an average particle diameter of not more than 30 nm, wherein
• the solid content of the fine particles is from 5 to 60 wt,
• the curable pressure sensitive adhesive layer has a pre-curing storage elastic modulus of from 1×103 to 5×106 Pa, and has a post-curing storage elastic modulus of at least 1×108 Pa,
• the curable pressure sensitive adhesive layer acts as a stamper-receiving layer, and
• the polymer-containing energy rays-curable component comprises an acrylate copolymer having energy rays-curable pendant groups and a weight average molecular weight of 150,000 to 1,500,000.

A method for producing an optical disk producing sheet, comprising:

• preparing a curable pressure sensitive adhesive composition including a polymer-containing energy rays-curable component and fine particles having an average particle diameter of not more than 30 nm, the solid content of the fine particles being from 5 to 60 wt %;
• applying the curable pressure sensitive adhesive composition onto a release treatment-subjected surface of a release sheet;
• and
• drying the curable pressure sensitive adhesive composition to form a stamper-receiving layer, wherein
• the curable pressure sensitive adhesive layer has a pre-curing storage elastic modulus of from 1×103 to 5×106 Pa, and has a post-curing storage elastic modulus of at least 1×108 Pa, and
• the polymer-containing energy rays-curable component comprises an acrylate copolymer having energy rays-curable pendant groups and a weight average molecular weight of 150,000 to 1,500,000.