| 摘要 |
973,955. Photopolymerisable elements. E. I. DU PONT DE NEMOURS & CO. Oct. 5,1962 [Oct. 16, 1961 ], No. 37842/62. Heading G2C. A photopolymerizable element comprises (I) a support, (II) a solid photopolymerizable stratum comprising a preformed polymer binding agent, a compatible non-gaseous addition-polymerisable olefinic monomer of molecular weight below 1500 and boiling point above 100‹C. and at least 0. 001% of a polymerization initiator activatable by activic radiation but thermally inactive at 85‹C. and (III) between (I) and (II) a layer of adhesive composition comprising (A) at least 66. 5 parts by weight of a polyester of (a) 0 to 100% mole hexahydroterephthalic acid, (b) 0 to 50% mole of adipic, pimelic, suberic, azelaic or sebacic acid (c) 0 to 50% mole of terephthalic on isophthalic acid and (d) a glycol having 2 to 10 carbon atoms and 0 to 4 ether oxygen atoms, (B) up to 33. 5 parts of an olefinic monomer, (C) 0 to 0. 67 parts of a thermal polymerization inhibitor and (D) 0. 5 to 5 parts of a polymerisation inhibitor activatable by actinic radiation and thermally inactive below 80‹C. The induction period in the most sensitive region of layer (II) is at least 10% greater than in the least sensitive region of layer (III) and the element is prepared by uniform exposure to activic radiation sufficient to polymerize the adhesive but not the layer (II). Extensive lists of suitable materials are given with references to earlier Specifications; the polyesters (A) and many of the other materials are as described in Specification 864,041 which relates to a similar element wherein the adhesive layer is thermally polymerized. A detailed example of the preparation of an element and the formation of a relief printing plate is supplemented by further examples wherein various of its specific features are varied. Specifications 741,294, 741,441, 741,470, 741,570, 771,481, 786,119, 807,948, 815,277, 825,795, 826,272, 834,337, 854,980, 883,558, 905,700, 935,627 and 945,807 also are referred to.
|
