Photopolymerizable compositions having improved sidewall geometry and development latitude

A photopolymerizable element for producing a relief image having good sidewall geometry upon imagewise exposure and subsequent development, which comprises:

• (1) a support, and
• (2) a photopolymerizable composition consisting essentially of:
• (a) a polymeric binder having weight average molecular weight in the range of 20,000 to 160,000, the polymeric binder comprising a polymer having the formula:
• (A).sub.w (B).sub.x (C).sub.y (D).sub.z (E).sub.u
• where A is a substituted or unsubstituted C.sub.4 -C.sub.10 alkyl methacrylate, B is a substituted or unsubstituted C.sub.4 -C.sub.10 alkyl acrylate, C is selected from the group consisting of methyl methacrylate and ethyl methacrylate, D is selected from the group consisting of methacrylic acid and acrylic acid, and E is styrene;
• and where w, x, y, z, and u are weight percentages of comonomers in the polymeric binder, w is 5 to 40%, x is 5 to 40%, y is 10 to 70%, z is 15 to 30%, and u is 1 to 20%;
• (b) at least one ethylenically unsaturated monomer;
• and
• (c) at least one component selected from the group consisting of a photoinitiator or photoinitiator system;
• with the proviso that the photopolymerizable composition does not contain a basic compound used for the neutralization or partial neutralization of component (a).

A process for producing a relief image having good sidewall geometry upon imagewise exposure and subsequent development, which comprises:

• (1) preparing a photopolymerizable element comprising a support and a photopolymerizable composition consisting essentially of:
• (a) a polymeric binder having weight average molecular weight in the range of 20,000 to 160,000, the polymeric binder comprising a polymer having the formula:
• (A).sub.w (B).sub.x (C).sub.y (D).sub.z (E).sub.u
• where A is a substituted or unsubstituted C.sub.4-C.sub.10 alkyl methacrylate, B is a substituted or unsubstituted C.sub.4-C.sub.10 alkyl acrylate, C is selected from the group consisting of methyl methacrylate and ethyl methacrylate, D is selected from the group consisting of methacrylic acid and acrylic acid, and E is styrene;
• and where w, x, y, and z are weight percentages of comonomers in the polymeric binder, w is 5 to 40%, x is 5 to 40%, y is 10 to 70%, z is 15 to 30%, and u is 1 to 20%;
• (b) at least one ethylenically unsaturated monomer;
• and
• (c) at least one component selected from the group consisting of a photoinitiator or photoinitiator system;
• with the proviso that the photopolymerizable composition does not contain a basic compound used for the neutralization or partial neutralization of component (a);
• (2) imagewise exposing the photopolymerizable element to actinic radiation to afford an imagewise exposed photopolymerized element;
• and
• (3) developing the imagewise exposed photopolymerized element of step (2) to form a relief image having good sidewall geometry.