Epoxy-functionalized siloxane resin copolymers as controlled release additives

An improved ultraviolet radiation-curable epoxyfunctionalized silicone controlled release composition, having a release of at least about 500 grams/2 inches, comprising:

• (A) an epoxyfunctional diorganopolysiloxane having the general formula
• R.sub.2 R.sup.1 SiO(RR.sup.1 SiO).sub.x (R.sub.2 SiO).sub.y SiR.sub.2 R.sup.1 (i)
• wherein R is individually a lower alkyl radical having from 1 to about 8 carbon atoms;
• R.sup.1 individually is a monovalent cycloaliphatic epoxy-functional organic radical having from 2 to about 20 carbon atoms;
• "x" is a number ranging from about 1 to about 50;
• and "y" is a number ranging from about 1 to about 1000;
• (B) a catalytic amount of a photocatalyst or a combination of photocatalysts;
• and
• (C) from about 20% to about 30% by weight based on (A) of a siloxane resin comprising monovalent R.sub.3.sup.2 SiO.sub.1/2 and R.sup.3 R.sub.2.sup.2 SiO.sub.1/2 units and tetravalent SiO.sub.4/2 units, the ratio of the monovalent units to tetravalent units being from about 0.6:1 to about 1.1:1;
• wherein R.sup.2 individually is a monovalent hydrocarbon radical of no more than 2 carbon atoms, R.sup.3 is a monovalent epoxy functional organic radical of from about 2 to about 20 carbon atoms;
• and the R.sup.3 R.sub.2.sup.2 SiO.sub.1/2 units comprising from about 1% to about 90% of the total number of monovalent units present;
• and
• (D) a hydrocarbon solvent in an amount sufficient to provide the composition With a solids content of about 20% by weight and a solvent content of about 80% by weight, the percentages being based on the total weight of components (A)-(D).