Abstract: This invention presents terpene-based solvents suitable for use in the processing of a wide variety of photopolymer printing plates. The solvents, which may be terpenes alone, terpenes mixed with organic non-solvents, or terpenes emulsified with water are effective in developing a wide variety of photopolymer printing plates and can produce images superior to those obtained with commercially available solvents currently used in such applications.

Abstract: The present invention relates to a flexible photopolymer printing plate composition comprising a homogenous blend of:(A) a high molecular weight butadiene-acrylonitrile copolymer having a number average molecular weight of about 30,000 to 125,000, an acrylonitrile content of 10 to 50% by weight, a carboxyl content of 2 to 15% by weight, and a Mooney viscosity (ML-4 at 100.degree. C.) of 45 or higher; and(B) a medium molecular weight butadiene-acrylonitrile copolymer having a number average molecular weight of about 15,000 to 40,000, an acrylonitrile content of 10 to 40% by weight, a carboxyl content of 1-15%, and a Mooney viscosity (ML-4 at 100.degree. C.) of from 15 to less than 45.

Abstract: A photosensitive elastomeric composition which comprises a high molecular weight elastomeric diene polymer having a number average molecular weight (Mn) of about 30,000 to 125,000, and a Mooney viscosity (ML-4 at 100.degree. C.) of 35 or higher; a low molecular weight diene polymer having a number average molecular weight of about 1,000 to 25,000; a photopolymerizable, ethylenically unsaturated cross-linking agent; and an addition polymerization initiator activatable by actinic radiation.

Abstract: A layered sheet construction suitable after processing for use as a relief printing plate is provided. The sheet is made of a photosensitive layer comprising an elastomeric polymer, between about 5 and 30 phr of an ethylenically unsaturated compound and between 0.1 and 5 phr of a photoinitiator activatable by actinic radiation; a base layer immediately adjacent to said photosensitive layer capable of supporting a relief image after processing; having the same or a different composition than said photosensitive layer. The sheet is bonded to an open or closed cell foam layer having a thickness between about 0.010 inch and 0.250 inch. Said foam has a recovery rate of at least 80%, a compression value between about 0.003 inch and 0.030 inch and a density of between about 2 to 50 lbs/ft.sup.3 and is bonded to a dimensionally stable supporting layer.

Abstract: A layered sheet construction suitable after processing for use as a relief printing plate is provided. The sheet is made of a photosensitive layer comprising an elastomeric polymer, between about 5 and 30 phr of an ethylencially unsaturated compound and between 0.1 and 5 phr of a photoinitiator activatable by actinic radiation; a base layer immediately adjacent to said photosensitive layer capable of supporting a relief image after processing; having the same or a different composition than said photosensitive layer. The sheet is bonded to an open or closed cell foam layer having a thickness between about 0.010 inch and 0.250 inch. Said foam has a recovery rate of at least 80%, a compression value between about 0.003 inch and 0.030 inch and a density of between about 2 to 50 lbs/ft.sup.3 and is bonded to a dimensionally stable supporting layer.

Abstract: A high molecular weight butadiene/acrylonitrile copolymer is used in a photosensitive composition containing the following:(A) 40 to 90% by weight of the total composition of a high molecular weight butadiene/acrylonitrile carboxylated copolymer having a number average molecular weight of 30,000 to 125,000, an acrylonitrile content of 10 to 50%, and a carboxyl content of 1% to 15% by weight.(B) 5 to 60% by weight of the total composition of a high molecular weight butadiene/acrylonitrile noncarboxylated copolymer having a number average molecular weight of 50,000 to 100,000, an acrylonitrile content of 10 to 30% so that the combination of the carboxylated and non carboxylated high molecular weight copolymers give a composition with a carboxyl content of 3 to 10%.(C) 2 to 40% by weight of the total composition of an addition photopolymerizable ethylenically unsaturated monomer and(D) 0.1 to 10% by weight of the total composition of a photoinitiator activatable by actinic radiation.

Abstract: A photopolymer elastomeric article designed to be used primarily in a flexographic printing system comprising: a polymer matrix made up of a mixture of syndiotactic 1,2-polybutadiene and cis-1,4-polyisoprene; a photoinitiator, which is a compound, which when irradiated, will initiate polymerization and/or crosslinking; and optionally, 0-3 phr of photopolymerizable, ethylenically unsaturated crosslinking agent, as typified by esters of acrylic or methacrylic acid.