Elements and method which use photopolymerizable compositions based on salt-forming polymers and polyhydroxy polyethers

Claim 1

A photopolymerizable element which comprises a substrate coated with a layer of a photopolymerizable composition comprising 0 to 70% by weight of components which do not contribute to the photoactivity of the composition and 30 to 100% by weight of photoactive system components consisting essentially of (1) polymer having a number average molecular weight of at least 500, at least two-salt forming groups selected from the group consisting of carboxylic acid groups and amine groups per polymer molecule, and at least 0.025 equivalent of salt-forming group per 1000 grams of polymer; (2) addition-polymerizable, nongaseous, ethylenically unsaturated compound having at least one complementary salt-forming group selected from the group consisting of carboxylic acid groups and amine groups and being capable of forming a polymer by free-radical initiated, chain-propagating addition polymerization; the ratio of equivalents of complementary salt-forming groups in compound (2) to equivalents of salt-forming groups in polymer (1) being 1:2 to 50:1; (3) ethylenically unsaturated diester polyhydroxy polyether of the formula ##STR6## wherein R is H or CH 3 ; R 1 is H or an alkyl group of 1-4 carbon atoms; n is 1-15; p is 0 or 1; and when p is 1, R 2 is H or CH 3 and R 3 is H, CH 3 or C 2 H 5 ; the amount of polyether (3) being 10 to 75% by weight of the combined total of components (1), (2) and (3); and (4) 1 to 20% by weight, based on the total photopolymerizable composition, of a free-radical generating system, activatable by actinic radiation, which initiates polymerization of the unsaturated compounds; said layer having a thickness in the range from a coating weight of 1 mg/dm 2 to 5 mils in thickness.

Claim 12

A method of photoimaging which comprises imagewise exposing a photopolymerizable composition to actinic radiation containing wavelengths of 2000-8000 A through an image-bearing transparency and developing the image, said photopolymerizable composition comprising 0 to 70% by weight of components which do not contribute to the photoactivity of the composition and 30 to 100% by weight of photoactive system components consisting essentially of (1) polymer having a number average molecular weight of at least 500, at least two salt-forming groups selected from the group consisting of carboxylic acid groups and amine groups per polymer molecule, and at least 0.025 equivalent of salt-forming group per 1000 grams of polymer; (2) addition-polymerizable, nongaseous, ethylenically unsaturated compound having at least one complementary salt-forming group selected from the group consisting of carboxylic acid groups and amine groups and being capable of forming a polymer by free-radical initiated, chain-propagating addition polymerization; the ratio of equivalents of complementary salt-forming groups in compound (2) to equivalents of salt-forming groups in polymer (1) being 1:2 to 50:1; (3) ethylenically unsaturated diester polyhydroxy polyether of the formula ##STR7## wherein R is H or CH 3 ; R 1 is H or an alkyl group of 1-4 carbon atoms; n is 1-15; p is 0 or 1; and when p is 1, R 2 is H or CH 3 and R 3 is H, CH 3 or C 2 H 5 ; the amount of polyether (3) being 10 to 75% by weight of the combined total of components (1), (2) and (3); and (4) 1 to 20% by weight, based on the total photopolymerizable composition, of a free-radical generating system, activatable by actinic radiation, which initiates polymerization of the unsaturated compounds.

Claim 13

A method of photoimaging which comprises imagewise exposing a photopolymerizable composition to actinic radiation containing wavelengths of 2000-8000 A through an image-bearing transparency and developing the image, said photopolymerizable composition comprising 0 to 70% by weight of components which do not contribute to the photoactivity of the composition and 30 to 100% by weight of photoactive system components consisting essentially of (1) polymer having a number average molecular weight of at least 500, at least two salt-forming groups selected from the group consisting of carboxylic acid groups and amine groups per polymer molecule, and at least 0.025 equivalent of salt-forming group per 1000 grams of polymer; (2) addition-polymerizable, nongaseous, ethylenically unsaturated compound having at least one complementary salt-forming group selected from the group consisting of carboxylic acid groups and amine groups and being capable of forming a polymer by free-radical initiated, chain-propagating addition polymerization; the ratio of equivalents of complementary salt-forming groups in compound (2) to equivalents of salt-forming groups in polymer (1) being 1:2 to 50:1; (3) ethylenically unsaturated diester polyhydroxy polyether of the formula ##STR7## wherein R is H or CH 3 ; R 1 is H or an alkyl group of 1-4 carbon atoms; n is 1-15; p is 0 or 1; and when p is 1, R 2 is H or CH 3 and R 3 is H, CH 3 or C 2 H 5 ; the amount of polyether (3) being 10 to 75% by weight of the combined total of components (1), (2) and (3); and (4) 1 to 20% by weight, based on the total photopolymerizable composition, of a free-radical generating system, activatable by actinic radiation, which initiates polymerization of the unsaturated compounds.