Elements and method which use photopolymerizable compositions based on salt-forming polymers and polyhydroxy polyethers
AssigneeE. I. Du Pont de Nemours and Company
InventorWilliam J. Chambers
Life of this patent
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Abstract
Photopolymerizable compositions containing (1) a polymer having a plurality of salt-forming groups, (2) an ethylenically unsaturated compound having at least one complementary salt-forming group, (3) an ethylenically unsaturated diester polyhydroxy polyether of the formula ##STR1## where R is H or CH.sub.3 ; R.sup.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.sup.2 is H or CH.sub.3, and R.sup.3 is H, CH.sub.3 or C.sub.2 H.sub.5 ; and (4) a radiation-sensitive, free-radical generating system provide photopolymerizable elements which have outstanding photospeeds and are relatively insensitive to oxygen.
Claims13
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.sub.3 ;
- R.sup.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.sup.2 is H or CH.sub.3 and R.sup.3 is H, CH.sub.3 or C.sub.2 H.sub.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.sup.2 to 5 mils in thickness.
The photopolymerizable element of claim 15 in which R.sup.1 is H, p is 1, and R.sup.2 and R.sup.3 are CH.sub.3.
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.sub.3 ;
- R.sup.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.sup.2 is H or CH.sub.3 and R.sup.3 is H, CH.sub.3 or C.sub.2 H.sub.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.
Dependencies are inferred from the claim text.