Pressure-sensitive adhesive composition, laminate, and surface protection film

A pressure-sensitive adhesive composition, comprising a styrenic block copolymer (A1) and an acrylic block copolymer (B) and satisfying conditions (1) to (4) set forth below:

• (1) the melt viscosity (measured at a temperature of 230° C. and a shear rate of 121.6 (1/sec) in accordance with ISO 11443:1995) of the styrenic block copolymer (A1)<the melt viscosity (measured at a temperature of 230° C. and a shear rate of 121.6 (1/sec) in accordance with ISO 11443:1995) of the acrylic block copolymer (B);
• (2) the mass ratio [(A1):(B)] of the content of the styrenic block copolymer (A1) to the content of the acrylic block copolymer (B) in the pressure-sensitive adhesive composition is from 10:90 to 90:10;
• (3) the styrenic block copolymer (A1) is a hydrogenated product of a block copolymer (P1), including one or more polymer blocks (a11) containing a structural unit derived from an aromatic vinyl compound and one or more polymer blocks (a12) containing a structural unit derived from a conjugated diene;
• and
• (4) the acrylic block copolymer (B) includes one or more polymer blocks (b11) containing a structural unit derived from an acrylic acid ester and one or more polymer blocks (b12) containing a structural unit derived from a methacrylic acid ester, and has a number average molecular weight (Mn) of 60,000 or more and 300,000 or less.