Photopolymerizable element and process for preparing same

Claim 1

IN A PROCESS FOR PREPAING A PHOTOPOLYMERIZABLE ELEMENT COMPRISING A SUPPORT (I), A SOLID PHOTOPOLYMERIZABLE STRATUM (II) COMPRISING A PERFORMED COMPATIBLE MACROMOLECULAR POLYMER BINDING AGENT, A NON-GASEOUS, ADDITION-POLYMERIZABLE ETHYLENICALLY UNSATURATED COMPOUND CONTAINING AT LEAST ONE TERMINAL ETHYLENIC GROUP, HAVING A MOLECULAR WEIGHT OF LESS THAN 1500, A BOILING POINT ABOVE 100*C. AT NORMAL ATOMOSPHERIC PRESSURE AND BEING CAPABLE OF FORMING A HIGH POLYMER OF FREE-RADICAL INITIATED, CHAINPROPAGATING ADDITION POLYMERIZATION IN THE PRESENCE OF AN ADDITION POLYMERIZATION INITIATOR THEREFOR ACTIVATABLE BY ACTNIC RADIATION AND FROM 0.001 TO 10 PERCENT, BY WEIGHT OF THE STRATUM, OF SUCH AN INITIATOR, SAID INITIATOR BEING THERMALLY INACTIVE AT 85*C. AND BELOW, AND BETWEEN THE SUPPORT (I) AND THE PHOTOPOLYMERIZABLE STRATUM II AND IN SURFACE CONTACT WITH AT LEAST THE LATTER, A LAYER (III) OF AN ADHESIVE COMPOSITION COMPRISING (A) AT LEAST 66.5 PARTS BY WEIGHT OF A MACROMOLECULAR LINEAR POLYESTER COMPOSITION SELECTED FROM THE GROUP CONSISTING OF (I) A POLYESTER PREPARED BY REACTING (A) A COMPOUND TAKEN FROM THE GROUP CONSISTING OF HEXAHYDROTEREPHTHALIC ACID AND AN ESTER-FORMING DERIVATIVE OF HEXAHYDROTEREPHTHALIC ACID AND (B) A GLYCOL HAVING FROM 2 TO 10 CARBON ATOMS AND 0 TO 4 OXYGEN ATOMS IN ADDITION TO THE HYDROXYL GROUPS; (2) AT LEAST ONE COPOLYESTER PREPARED BY REACTING (A) AT LEAST ONE SATURATED ALIPHATIC COMPOUND TAKEN FROM THE GROUP CONSISTING OF ADIPIC, PIMELIC, SUBERIC, AZELAIC AND SEBACIC ACIDS AND AN ESTER-FORMING DERIVATIVE OF SAID ACIDS, THE TOTAL OF THE SAID COMPOUNDS BEING IN AN AMOUNT OF 50 MOLE PERCENT OF SAID COPOLYESTER, (B) AT LEAST ONE AROMATIC COMPOUND TAKEN FROM THE GROUP CONSISTING OF TEREPHTHALIC ACID, ISOPHTHALIC ACID AND AN ESTER-FORMING DERIVATIVE OF SAID ACIDS, THE TOTALOF THE SAID COMPOUNDS BEING IN AN AMOUNT OF 50 MOLE PERCENT OF SAID COPOLYESTER AND (C) A GLYCOL HAVING FROM 2 TO 10 CARBON ATOMS AND 0 TO 4 OXYGEN ATOMS IN ADDITION TO THE HYDROXYL GROUPS; AND (3) A COPOLYESTER PREPARED BY REACTING (A) A COMPOUND TAKEN FROM THE GROUP CONSISTING OF HEXAHYDROTEREPHTHALIC ACID AND AN ESTER-FORMING DERIVATIVE OF SAID ACID IN AN AMOUNT UP TO 100 MOLE PERCENT OF THE COPOLYESTER (B) A SATURATED ALIPHATIC COMPOUND TAKEN FROM THE GROUP CONSISTING OF ADIPIC, PIMELIC, SUBERIC, AZELAIC AND SEBACIC ACIDS AND AN ESTER-FORMING DERIVATIVE OF SAID ACIDS, IN AN AMOUNT UP TO 50 MOLE PERCENT OF THE COPOLYESTER (C) AN AROMATIC COMPOUND TAKEN FROM THE GROUP CONSISTING OF TEREPHTHALIC, ISOPHTHALIC ACIDS AND AN ESTER-FORMING DERIVATIVE OF SAID ACIDS, IN AN AMOUNT UP TO 50 MOLE PERCENT OF THE COPOLYESTER AND (D) A GLYCOL HAVING FROM 2 TO 10 CARBON ATOMS AND 0 TO 4 OXYGEN ATOMS IN ADDITION TO THE HYDROXYL GROUPS; (B) UP TO 33.5 PARTS BY WEIGHT OF AN ETHYLENICALLY UNSATURATED ADDITION POLYMERIZABLE COMPOUND, (C) 0 TO 0.67 PART BY WEIGHT OF A THERMAL POLYMETRIZATION INHIBITOR; AND (D) FROM 0.5 TO 5.0 PARTS BY WEIGHT OF AN ADDITION POLYMERIZATION PHOTOINITIATOR ESSENTIALLY THEMALLY INACTIVE BELOW ABOUT 80*C. AND ACTIVATABLE BY ACTINIC RADIATION, THE IMPROVEMENT CHARACTERIZED BY UNIFORMLY EXPOSING SAID ELEMENT, INCLUDING SAID ADHESIVE LAYER TO ACTINIC RADIATION IN AN AMOUNT SUFFICIENT TO PHOTOPOLYMERIZE THE ADHSIVE BUT IN AN AMOUNT INSUFFICIENT TO INITIATE PHOTOPOLYMERIZATION INSAID PHOTOPOLYMERIZABLE LAYER THE AMOUNT, REACTIVITY AND RADIATION SENSITIVITY OF SAID PHOTOINITIATOR (D) BEING SUCH THAT THE MOST SENSITIVE REGION OF STRATUM (II) EXHIBITS AN INDUCTION PERIOD OF AT LEAST 10 PERCENT GREATER THAN THE INDUCTION PERIOD IN THE LEAST SENSITIVE REGION OF ADHESIVE LAYER (III).