Thermally sensitive imageable element
View Patent ↗The present invention provides an imageable element including a substrate, a first layer applied to the substrate and a second layer applied to the first layer. The first layer may contain polymeric material and a radiation absorbing compound. The second layer may contain a hydroxyl group-containing polymer that includes a heat-labile moiety.
1. A positive working imageable element comprising:
a substrate;
a first layer disposed on a portion of the substrate comprising a polymeric material; and
a second layer disposed on the first layer comprising a hydroxyl group-containing polymer that includes from 5 mol % to 50 mol % of the hydroxyl groups functionalized with a heat-labile moiety represented by the formula:
wherein R 1 is an alkyl group, an arylalkyl group, an aryl group, an alkenyl group or a silyl group, with the remaining hydroxyl groups being free of said heat-labile moieties.
2. The element of claim 1 , wherein the heat-labile moiety is represented by the formula R 1 —NH—C(O)—O- or R 1 —O—C(O)—O—.
3. The element of claim 1 , wherein the substrate comprises grained aluminum, anodized aluminum, or grained and anodized aluminum.
4. The element of claim 1 , wherein the first layer comprises a copolymer including units of N-phenylmaleimide, methacrylic acid or methacrylamide.
5. The element of claim 1 , wherein the first layer comprises a copolymer including units of N-phenylmaleimide, methacrylamide, acrylonitrile, and a moiety represented by the formula:
or units of both moieties;
and wherein R 4 is OH, COOH, or SO 2 NH 2 , and R 5 is hydrogen, halogen or a C 1 –C 12 alkyl group.
6. The element of claim 1 , wherein the first layer comprises a first copolymer including units of N-phenylmaleimide, methacrylamide and methacrylic acid, and a second copolymer including units of N-phenylmaleimide, methacrylamide, acrylonitrile and a moiety represented by the formula:
or units of both moieties,
and wherein R 4 is OH, COOH, or SO 2 NH 2 , and R 5 is hydrogen, halogen or a G 1 –C12 alkyl group.
7. The element of claim 1 , wherein the first layer comprises a resin having activated methylol or activated alkylated methylol groups.
8. The element of claim 7 , wherein the resin comprises a resole resin.
9. The element of claim 1 , wherein the first layer comprises a radiation absorbing compound.
10. The element of claim 9 , wherein the radiation absorbing compound is an infrared radiation absorbing material.
11. The element of claim 10 , wherein the infrared radiation absorbing compound is a dye or a pigment.
12. The element of claim 1 , wherein the second layer comprises a radiation absorbing compound.
13. The element of claim 1 , wherein the hydroxyl group-containing polymer is a phenolic resin or a copolymer or derivative thereof.
14. The element of claim 1 , wherein the hydroxyl group-containing polymer is a novolak resin.
15. The element of claim 1 , wherein the heat-labile moiety comprises a pendant group on the hydroxyl group-containing polymer.
16. The element of claim 1 , wherein R 1 comprises:
17. The element of claim 1 , wherein R 1 is C(CH 3 ) 3 .
18. The element of claim 1 , wherein the hydroxyl group-containing polymer comprises units of:
19. The element of claim 1 , wherein the hydroxyl group-containing polymer includes 10 mol % to 30 mol % of the hydroxyl groups being functionalized with the heat-labile moiety.
20. The element of claim 1 , wherein the imageable element comprises a printing plate precursor, an electronic part precursor or a mask precursor.
21. A method of forming a printing plate precursor comprising:
providing a substrate;
applying onto the substrate a first layer comprising a polymeric material and a radiation absorbing compound; and
applying onto the first layer a second layer that comprises a hydroxyl group-containing polymer that includes from 5 mol % to 50 mol % of the hydroxyl groups functionalized with a heat-labile moiety having the formula:
wherein R 1 is an alkyl group, an arylalkyl group, an aryl group, an alkenyl group or a silyl group with the remaining hydroxyl groups being free of said heat-labile moieties.
22. The method of claim 21 , further comprising:
imagewise exposing the precursor to radiation such that exposed portions of the second layer are more developable in an alkaline developer liquid than unexposed portions; and
developing the precursor to form an image.
23. A positive working imageable element comprising:
a substrate;
a first layer disposed on a portion of the substrate comprising a polymeric material and a radiation absorbing compound; and
a second layer disposed on the first layer that is substantially free of the radiation absorbing compound and comprising a hydroxyl group-containing polymer that includes from 5 mol% to 50 mol% of the hydroxyl groups functionalized with a heat-labile moiety represented by the formula:
wherein R 1 is an alkyl group, an arylalkyl group, an aryl group, an alkenyl group or a silyl group with the remaining hydroxyl groups being free of said heat-labile moieties.