Solvent resistant polymers with improved bakeability features

A radiation-sensitive composition comprising

• (a) at least one novolak;
• (b) at least one naphthoquinone diazide derivative;
• and
• (c) a copolymer comprising units A, B, and a unit C comprising a cyclic terminal urea group, wherein unit A is present in an amount of about 5 to about 50 mol % and has the formula
• 18
• wherein R1 is selected such that the homopolymer of A is alkali-soluble, unit B is present in an amount of about 20 to about 70 mol % and has the following formula
• 19
• wherein R1 is selected such that the homopolymer of B has a glass transition temperature greater than 100° C., preferably a glass transition temperature in the range from about 100 to about 380° C., and the unit C comprising a cyclic terminal urea group is present in an amount of about 10 to about 50 mol % and has the formula
• 20
• wherein X is a spacer group which is preferably selected from the group consisting of (a) a —CR2)m— chain, (b) a —[CH2—CH2—O]m— chain;
• and (c) a —[Si(R2)—O]m— unit, wherein m is an integer between 2 and 12, the spacer group is connected to one of the carbon ring atoms of the cyclic urea unit or to one of the nitrogen atoms of the cyclic urea unit, and n is an integer between 1 and 5;
• and
• Y is a group selected from the group consisting of:
• 21
• wherein each R in units A, B, and C, the —(CR2)m— chain, the —[Si(R2)—O]m— unit, and group Y is independently selected from hydrogen, aryl, (C1-C12) alkyl, and halogen.

A printing plate comprising

• (a) a substrate;
• and
• (b) a radiation-sensitive layer, wherein the radiation sensitive layer comprises a copolymer comprising units A, B, and a unit C comprising a cyclic terminal urea group, wherein unit A is present in an amount of about 5 to about 50 mol % and has the formula
• 23
• wherein R1 is selected such that the homopolymer of A is alkali-soluble, unit B is present in an amount of about 20 to about 70 mol % and has the following formula
• 24
• wherein R2 is selected such that the homopolymer of B has a glass transition temperature greater than 100° C., preferably a glass transition temperature in the range from about 100 to about 380° C., and the unit C comprising a cyclic terminal urea group is present in an amount of about 10 to about 50 mol % and has the formula
• 25
• wherein X is a spacer group which is preferably selected from the group consisting of (a) a —CR2)m— chain, (b) a —[CH2—CH2—O]m— chain;
• and (c) a —[Si(R2)—O]m— unit, wherein m is an integer between 2 and 12, the spacer group is connected to one of the carbon ring atoms of the cyclic urea unit or to one of the nitrogen atoms of the cyclic urea unit, and n is an integer between 1 and 5;
• and
• Y is a group selected from the group consisting of:
• 26
• wherein each R in units A, B, and C, the —(CR2)m— chain, the —[Si(R2)—O]m— unit, and group Y is independently selected from hydrogen, aryl, (C1-C12) alkyl, and halogen.

A method for producing a printing plate comprising:

• (a) providing a substrate;
• (b) preparing a solution of a radiation-sensitive composition in an organic solvent,
• wherein the radiation-sensitive composition comprises
• (i) at least one novolak;
• (ii) at least one naphthoquinone diazide derivative;
• and
• (iii) a copolymer comprising units A, B, and a unit C comprising a cyclic terminal urea group, wherein unit A is present in an amount of about 5 to about 50 mol % and has the formula
• 28
• wherein R1 is selected such that the homopolymer of A is alkali-soluble, unit B is present in an amount of about 20 to about 70 mol % and has the following formula
• 29
• wherein R2 is selected such that the homopolymer of B has a glass transition temperature greater than 100° C., preferably a glass transition temperature in the range from about 100 to about 380° C., and the unit C comprising a cyclic terminal urea group is present in an amount of about 10 to about 50 mol % and has the formula
• 30
• wherein X is a spacer group which is preferably selected from the group consisting of (a) a —(CR2)m— chain, (b) a —[CH2—CH2—O]m— chain;
• and (c) a —[Si(R2)—O]m— unit, wherein m is an integer between 2 and 12, the spacer group is connected to one of the carbon ring atoms of the cyclic urea unit or to one of the nitrogen atoms of the cyclic urea unit, and n is an integer between 1 and 5;
• and
• Y is a group selected from the group consisting of:
• 31
• wherein each R in units A, B, and C, the —(CR2)m— chain, the —[Si(R2)—O]m— unit, and group Y is independently selected from hydrogen, aryl, (C1-C12) alkyl, and halogen;
• (c) applying the solution prepared in step (b) to the substrate;
• and
• (d) drying the solution.