Silicone-modified acrylic copolymer and adhesive thereof

A silicone-modified acrylic copolymer comprising:

• I. a structural unit of the formula ##STR57## wherein R.sup.1 is a hydrogen atom, a methyl group or an ethyl group, and R.sup.3 is an alkyl group with 1 to 13 carbon atoms or an aryl group with 6 to 14 carbon atoms,
• II. a structural unit of the formula ##STR58## or of the formula ##STR59## wherein R.sup.2 is a hydrogen atom, a methyl group or an ethyl group, each of R.sup.4 is an alkyl group with 1 to 6 carbon atoms or an aryl group with 6 to 14 carbon atoms which may be the same or different, each of R.sup.5 is a hydrogen atom, an alkyl group with 1 to 6 carbon atoms or an aryl group with 6 to 14 carbon atoms which may be the same or different, A is a divalent organic group with 2 to 20 carbon atoms which may have an ether bond or an ester bond in the main chain, and c and d are average recurring unit numbers, c being a number of 1 to 100 and d being a number of 0 to 100,
• and
• III. a structural unit of the formula ##STR60## wherein R.sup.6 is a hydrogen atom, a methyl group or an ethyl group, and R.sup.7 is an ethylenically unsaturated hydrocarbon group with 2 to 20 carbon atoms which may have an ether bond or an ester bond in the main chain,
• wherein the unit (I), the unit (II) and the unit (III) are contained at ratios in mole % of (I)=10 to 99.9, (II)=90 to 0.1, and (III)=0 to 89.9, and have weight average molecular weights of from 5,000 to 1,000,000.