Patent ID: 8048611

Claim:
A polyorganosiloxane compound having the average compositional formula (1) which is modified such that some hydrogen atoms of silicon-bonded hydroxyl groups are substituted by acid labile groups of the general formula (2) and/or are crosslinked within the molecule or between molecules with a crosslinking group having a C—O—C linkage represented by the general formula (3), said polyorganosiloxane compound having a weight average molecular weight of 300 to 200,000 as measured by GPC versus polystyrene standards, R 1 a Si(OR 2 ) b (OH) c O (4−a−b−c)/2 (1) wherein R 1 is one or more groups selected from hydrogen and C 1 -C 18 organic groups, R 2 is one or more groups selected from straight or branched C 1 -C 6 alkyl groups, a, b and c are numbers in the range: 0.3≦a≦1.6, 0≦b≦0.3, and 0.001≦c≦2, wherein R 3 and R 4 are each independently hydrogen or a straight, branched or cyclic C 1 -C 6 alkyl group, R 5 is a straight, branched or cyclic C 1 -C 30 alkyl group, C 6 -C 20 aryl group or C 7 -C 20 aralkyl group, or R 3 and R 4 , R 3 and R 5 , or R 4 and R 5 may bond together to form a ring with the carbon atom or carbon and oxygen atoms to which they are attached, wherein ring-forming R 3 , R 4 or R 5 is a straight or branched C 1 -C 18 alkylene group, wherein R 6 , R 7 , R9 and R 10 are each independently hydrogen or a straight, branched or cyclic C 1 -C 6 alkyl group, or R 6 and R 7 , or R 9 and R 10 may bond together to form a ring with the carbon atom to which they are attached, wherein ring-forming R 6 , R 7 , R 9 or R 10 is a straight or branched C 1 -C 17 alkylene group, and R 8 is a divalent C 1 -C 6 hydrocarbon group which may contain an oxygen atom.