Method of improving print performance in flexographic printing plates
First Claim
1. A method of making a relief image printing element from a photosensitive printing blank, said photosensitive printing blank comprising a laser ablatable layer disposed on at least one photocurable layer, the method comprising the steps of:
- a) selectively laser ablating the laser ablatable layer to create an in situ mask and uncovering portions of the photocurable layer;
b) exposing the laser ablated printing blank to at least one source of actinic radiation through the in situ mask to selectively cross link and cure portions of the photocurable layer,wherein the diffusion of air into the at least one photocurable layer is limited during the exposing step by a method selected from at least one of;
i) laminating a barrier membrane to the in situ mask and any uncovered portions of the photocurable layer using pressure and/or heat before step (b); and
ii) coating the in situ mask and any uncovered portions of the photocurable layer with a layer of liquid prior to step (b);
wherein the oxygen diffusion coefficient of the barrier membrane and/or the layer of liquid is less than 6.9×
10−
9 m2/sec.
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Accused Products
Abstract
A method of making a relief image printing element from a photosensitive printing blank is provided. A photosensitive printing blank with a laser ablatable layer disposed on at least one photocurable layer is ablated with a laser to create an in situ mask. The printing blank is then exposed to at least one source of actinic radiation through the in situ mask to selectively cross link and cure portions of the photocurable layer. Diffusion of air into the at least one photocurable layer is limited during the exposing step and preferably at least one of the type, power and incident angle of illumination of the at least one source of actinic radiation is altered during the exposure step. The resulting relief image comprises a plurality of dots and a dot shape of the plurality of dots is produced that is highly resistant to print fluting for printing on corrugated board.
51 Citations
17 Claims
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1. A method of making a relief image printing element from a photosensitive printing blank, said photosensitive printing blank comprising a laser ablatable layer disposed on at least one photocurable layer, the method comprising the steps of:
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a) selectively laser ablating the laser ablatable layer to create an in situ mask and uncovering portions of the photocurable layer; b) exposing the laser ablated printing blank to at least one source of actinic radiation through the in situ mask to selectively cross link and cure portions of the photocurable layer, wherein the diffusion of air into the at least one photocurable layer is limited during the exposing step by a method selected from at least one of; i) laminating a barrier membrane to the in situ mask and any uncovered portions of the photocurable layer using pressure and/or heat before step (b); and ii) coating the in situ mask and any uncovered portions of the photocurable layer with a layer of liquid prior to step (b); wherein the oxygen diffusion coefficient of the barrier membrane and/or the layer of liquid is less than 6.9×
10−
9 m2/sec. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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Specification