Patent ID: 7358027

Claim:
A copolymer prepared by copolymerization of: a first monomer having the structure of formula (I) wherein R 1 is H, F, CN, CH 3 , or C 1-6 fluoroalkyl, R 2a and R 2b are independently H or F, and R 3 is CN or COOR, wherein R is selected from the group consisting of H, C 1-12 alkyl and C 1-12 fluoroalkyl, or is selected so as to render R 3 acid-cleavable; and a second monomer having the structure of formula (II) wherein R 4 is H, C 1-12 alkyl, C 3-15 alicyclic, or fluorinated C 3-15 alicyclic, R 5 is C 1-12 alkyl, C 1-12 alkyl substituted with 1-12 fluorine atoms and 0-2 hydroxyl groups, or C 3-15 alicyclic, or R 4 and R 5 together form a five-, six-, or seven-membered ring, R 6 is H, C 1-12 alkyl, or C 1-12 fluoroalkyl, or R 4 and R 6 together form a five-, six-, or seven-membered ring, and R 7 is H, C 1-12 alkyl, or C 1-12 fluoroalkyl, or R 7 and R 5 together represent —X—(CR 8 R 9 ) n —, in which case R 4 and R 6 are H, X is O or CH 2 , n is 1 or 2, R 8 and R 9 are H, C 1-12 alkyl, or C 1-12 fluoroalkyl, or together form an oxo moiety (═O), with the proviso that when R 8 and R 9 together form ═O, n is 1, wherein: (1) any of R 1 , R 3 , R 4 , R 5 , R 6 , and R 7 may be further substituted with an inert, nonhydrogen substituent; (2) when R 5 is C 1-12 alkyl, at least one of R 4 , R 6 and R 7 is other than hydrogen; and (3) at least one of the first monomer and the second monomer contains one or more fluorine atoms.