| abstract |
Copolymers containing the units A, B, C, D and optionally E are used to prepare radiation sensitive compositions and lithographic printing plates. The copolymer contains about 25 to 55 mol% of unit A which has the formula (A). The copolymer contains about 0.5 to 25 mol% of unit B which has the formula (B) wherein R1 is selected from the group consisting of alkyl, aryl and aralkyl. The copolymer contains about 0.5 to 40 mol% of unit C which has the formula (C) wherein X is an aliphatic or aromatic spacer group, and Ac is an acidic group selected from the group consisting of -COOH, -SO¿3?H, -SO2NR?9R10 with R9 and R10¿ independently being selected from hydrogen and alkyl; and when X is phenylene, Ac can also be OH. The copolymer contains about 20 to 70 mol% of unit D which has the formula (D) wherein Ci is selected from the group consisting of Ci-1, Ci-2, Ci-3 and Ci-4 which are represented by the following formulae (Ci-1, Ci-2, Ci-3 and Ci-4) wherein: k, m and n are integers independently selected from 0 to 5, R?3, R4 and R7¿ are independently selected from the group consisting of alkyl, alkoxy, -COOR?8, -NR9R10¿, -NH-CO-CH¿3?, halogen, and cyano, R?8¿ is selected from hydrogen and alkyl, R?9 and R10¿ are independently selected from hydrogen and alkyl, R5 is selected from the group consisting of hydrogen, alkyl, aryl and aralkyl, R6 is selected from the group consisting of alkyl, aryl and aralkyl and Y is selected from the group consisting of alkylene, arylene and arylenealkylene. The copolymer contains about 0 to 50 mol% of unit E which has the formula (E) wherein R2 is selected from the group consisting if alkyl, aryl and aralkyl groups. |