Surface-protecting film

A surface protective film, comprising:

• a polyolefin-based substrate layer and
• a pressure-sensitive adhesive layer,
• wherein:
• the pressure-sensitive adhesive layer comprises
• a styrene-based elastomer and
• an acrylic-based pressure-sensitive adhesive, and
• in the pressure-sensitive adhesive layer,
• the styrene-based elastomer is blended in an amount of not less than 60% by mass but not more than 90% by mass based on the total amount of the pressure-sensitive adhesive layer, and
• the acrylic-based pressure-sensitive adhesive is blended in an amount of not less than 10% by mass but not more than 40% by mass based on the total amount of the pressure-sensitive adhesive layer,
• the acrylic-based pressure-sensitive adhesive comprises, as a constituent, a polymer of a structure represented by formula (3),
• [C-D-C]n (3),
• wherein C represents a polymer block C,
• D represents a polymer block D, and
• n represents an integer of 1 to 3,
• the polymer block C is a polymer block composed of continuous methacrylic ester units, and
• the polymer block D is a polymer block composed of continuous acrylic ester units.

A surface protective film, comprising:

• a polyolefin-based substrate layer, and
• a pressure-sensitive adhesive layer,
• wherein:
• the pressure-sensitive adhesive layer, comprising:
• a styrene-based elastomer and
• an acrylic-based pressure-sensitive adhesive, and
• optionally a tackifier, and
• in the pressure-sensitive adhesive layer,
• the styrene-based elastomer is blended in an amount of not less than 50% by mass but not more than 90% by mass based on the total amount of the pressure-sensitive adhesive layer,
• the acrylic-based pressure-sensitive adhesive is blended in an amount of not less than 1% by mass but not more than 40% by mass based on the total amount of the pressure-sensitive adhesive layer, and
• the tackifier, if present, is blended in an amount of not more than 49% by mass based on the total amount of the pressure-sensitive adhesive layer,
• the acrylic-based pressure-sensitive adhesive comprises, as a constituent, a polymer of a structure represented by formula (3),
• [C-D-C]n (3),
• wherein C represents a polymer block C,
• D represents a polymer block D, and
• n represents an integer of 1 to 3,
• the polymer block C is a polymer block composed of continuous methacrylic ester units, and
• the polymer block D is a polymer block composed of continuous acrylic ester units.