Abstract: In an aqueous-developable dry-film photoresist containing a carboxyl-group containing film-forming polymeric binder, the improvement wherein the binder is obtained by polymerizing a mixture including: (a) a monomer of the formula H.sub.2 C.dbd.CRCOO[(C.sub.n H.sub.2n)X(C.sub.p H.sub.2p)].sub.m R', wherein R is hydrogen or methyl and R' is a saturated or unsaturated C.sub.5 -C.sub.12 bridged alkyl optionally substituted by at least one C.sub.1 -C.sub.4 alkyl or halogen, X is oxygen or sulfur, n is 2-4, p is 0-4, m is 0-2; and (b) at least one C.sub.3 -C.sub.15 .alpha.,.beta.-unsaturated carboxyl-containing monomer having 3-15 carbon atoms.

Abstract: A urethane polymer having free acidic groups on the backbone of the polymer and terminal (meth)acrylate groups is prepared by (1) reacting a mixture comprising an aliphatic diol and a diol having acidic functionality with an excess of an aliphatic, cycloaliphatic or aromatic diisocyanate in the presence of a catalyst to produce an isocyanate-terminated urethane polymer and (2) reacting the terminal isocyanate groups of the product of step (1) with a mono- or dihydroxy (meth)acrylate. The diol comprises greater than 50% of the reaction mixture, based on the total weight of reactants. The polymer can be used in photopolymerizable compositions for making low tack flexographic printing plates and photopolymer masters.

Abstract: It has been found that excellent quality photopolymer printing plates having resistance to alcohol-based inks can be prepared by (a) spreading a photopolymer composition comprising a chain extended, liquid, terminally olefinically unsaturated polymer; from about 1% to about 50% by weight based on the weight of the polymer of at least one ethylenically unsaturated monomer; from about 0.1% to about 10% by weight based on the weight of the polymer of photoinitiator; and from about 0.01% to about 2% by weight based on the weight of the polymer of a stabilizer on a support to form a photopolymer element, (b) exposing to actinic light selected areas of said photopolymer composition on said support until substantial cross-linking takes place in the exposed areas without significant cross-linking in the unexposed areas, and (c) removing the unexposed areas of photopolymer composition by washing the plate with an aqueous detergent solution.

Abstract: It has been found that excellent quality photopolymer printing plates having resistance to alcohol-based inks can be prepared from photopolymer compositions comprising a chain extended, liquid, terminally olefinically unsaturated polymer; from about 1% to about 50% by weight based on the weight of the polymer of at least one ethylenically unsaturated monomer; from about 0.1% to about 10% by weight based on the weight of the polymer of photoinitiator; and from about 0.01% to about 2% by weight based on the weight of the polymer of a stabilizer.

Abstract: Disclosed is the improvement in post-exposing relief printing plates prepared from photosensitive polymeric compositions which comprises immersing the relief printing plate in a dilute aqueous solution of a persulfate salt and a sufficient amount of a water-soluble carboxylic acid to provide a pH of about 1.5 to about 2.5 during exposure to actinic radiation.

Abstract: It has been found that excellent quality photopolymer printing plates having hardness, flexibility, resilience, abrasion resistance and resistance to alcohol-based inks can be prepared from photopolymer compositions comprising a liquid polymer containing at least two terminal olefin groups attached to the polymer through a combination of at least two ether, thioether, ester, keto or amide groups, from about 1 to about 50% by weight based on the polymer of at least one ethylenically unsaturated monomer, from about 0.1 to about 10% by weight of a photoinitiator and about 0.01 to about 2% of a stabilizer.

Abstract: It has been found that high quality relief printing plates can be made using a photosensitive composition comprising at least one unsaturated polyester, at least one ethylenically unsaturated, addition polymerizable monomer, at least one photosensitive initiator and a poly(hydroxylether) derived from a diphenol and an epihalohydrin, such as bisphenol A-epichlorohydrin resin. The poly(hydroxylether) increases the viscosity of the photosensitive resin such that the resin is less likely to flow during platemaking process, thereby avoiding undesirable blemishes on the finished plate.

Abstract: It has been found that excellent quality photopolymer printing plates having hardness, flexibility, resilience, abrasion resistance and resistance to alcohol-based inks can be prepared from photopolymer compositions comprising a liquid polymer containing at least two terminal olefin groups attached to the polymer through a combination of at least two ether, thioether, ester, keto or amide groups, from about 1 to about 50% by weight based on the polymer of at least one ethylenically unsaturated monomer, from about 0.1 to about 10% by weight of a photoinitiator and about 0.01 to about 2% of a stabilizer.