Patent ID: 6875821

Claim:
A process for the preparation of partially protected poly(hydroxystyrene)s characterized in that it is a process for producing Polymer (A) having a repeating unit represented by Formula (IA) wherein, R 1 is hydrogen or methyl, R 2 is alkyl having 1 to 6 carbons, R 3 is an acid-decomposable or -eliminable group and p is 0, 1 or 2, and R 2 may be the same or different when p is 2, and a repeating unit represented by Formula (IB) wherein, R 1 , R 2 and p are as defined above, and R 4 is hydrogen or a group derived from R 3 by decomposition with an acid at a molar ratio (IB/IA) of 98/2 to 30/70 in a molecule, and the process contains a step that Polymer (B) having a repeating unit represented by Formula (II) wherein, R 1 , R 2 , R 3 and p are as defined above in a molecule is reacted in an organic solvent with an acid which is diluted with a dilluent to 10% to 70% by weight added at a molar ratio of 0.0001 equivalents or more and less than 0.05 equivalents to the OR 3 group.