Acrylic pressure-sensitive adhesive composition and pressure-sensitive adhesive products

A pressure-sensitive adhesive composition, comprising an acrylic block copolymer (I) in an amount of not less than 40% by mass based on the total amount of solid components of the pressure-sensitive adhesive composition, said acrylic block copolymer (I) having at least one polymer block (A) comprising methacrylic acid ester units and at least one polymer block (B) comprising acrylic acid ester units,

• wherein:
• the acrylic block copolymer (I) has a weight-average molecular weight (Mw) of 30,000 to 300,000 and a molecular weight distribution (Mw/Mn) of 1.0 to 1.5;
• the acrylic acid ester units are derived from an acrylic acid ester (1) represented by the general formula CH2═CH—COOR1 (1) and an acrylic acid ester (2) represented by the general formula CH2═CH—COOR2 (2);
• R1 is an organic group of 4 to 6 carbon atoms;
• R2 is an organic group of 7 to 12 carbon atoms;
• the mass ratio (1)/(2) of the acrylic acid ester (1) to the acrylic acid ester (2) is 65/35 to 20/80;
• and
• the tan δ value of dynamic viscoelasticity of the acrylic block copolymer (I), as measured at a frequency of 1 Hz, is 3.53×10−2 to 1×10−1 in the range of 50 to 100° C.