Thermal image receiver elements prepared using aqueous formulations
View Patent ↗A thermal image receiver element dry image receiving layer has a T g of at least 25° C. as the outermost layer. The dry image receiving layer has a dry thickness of at least 0.5 μm and up to and including 5 μm. It comprises a polymer binder matrix that consists essentially of: (1) a water-dispersible acrylic polymer comprising chemically reacted or chemically non-reacted hydroxyl, phospho, phosphonate, sulfo, sulfonate, carboxy, or carboxylate groups, and (2) a water-dispersible polyester that has a T g of 30° C. or less. The water-dispersible acrylic polymer is present in an amount of at least 55 weight % of the total dry image receiving layer weight and at a dry ratio to the water-dispersible polyester of at least 1:1. The thermal image receiver element can be used to prepare thermal dye images after thermal transfer from a thermal donor element.
1. A thermal image receiver element comprising a support, and having on at least one side of the support:
a dry image receiving layer having a T g of at least 25° C., which dry image receiving layer is the outermost layer of the thermal image receiver element, has a dry thickness of at least 0.5 μm and up to and including 5 μm, and comprises a polymer binder matrix that consists essentially of:
(1) a water-dispersible acrylic polymer comprising chemically reacted or chemically non-reacted hydroxyl, phospho, phosphonate, sulfo, sulfonate, carboxy, or carboxylate groups, and
(2) a water-dispersible polyester that has a T g of 30° C. or less,
wherein the water-dispersible acrylic polymer is present in an amount of at least 55 weight % of the total dry image receiving layer weight and is present at a dry ratio to the water-dispersible polyester of at least 1:1.
2. The thermal image receiver element of claim 1 , wherein the water-dispersible acrylic polymer comprises chemically reacted or chemically non-reacted carboxy or carboxylate groups.
3. The thermal image receiver element of claim 1 , wherein the dry image receiving layer has a T g of at least 35° C. and up to and including 70° C.
4. The thermal image receiver element of claim 1 , wherein the water-dispersible polyester has a T g of at least −10° C. and up to and including 30° C.
5. The thermal image receiver element of claim 1 , wherein the water-dispersible acrylic polymer is present in an amount of at least 60 weight % and up to and including 80 weight % of the total dry image receiving layer weight, and the weight ratio of the water-dispersible acrylic polymer to the water-dispersible polyester in the polymer binder matrix is from 1:1 to and including 6:1.
6. The thermal image receiver element of claim 1 , wherein the water-dispersible acrylic polymer comprises recurring units derived from: (a) one or more ethylenically unsaturated polymerizable acrylates or methacrylates comprising acyclic alkyl ester, cycloalkyl ester, or aryl ester groups having at least 4 carbon atoms, (b) one or more carboxy-containing or sulfo-containing ethylenically unsaturated polymerizable acrylates or methacrylates, and (c) optionally styrene or a styrene derivative,
wherein the (a) recurring units represent at least 20 mol % and up to and including 99 mol % of the total recurring units, and the (b) recurring units represent at least 1 mol % and up to and including 10 mol %.
7. The thermal image receiver element of claim 1 , wherein the water-dispersible acrylic polymer is crosslinked through hydroxyl or carboxy groups to provide aminoester, urethane, amide, or urea groups.
8. The thermal image receiver element of claim 1 , wherein the support is a polymeric film or a resin-coated cellulosic paper base.
9. The thermal image receiver element of claim 1 , wherein the support is a microvoided polymeric film.
10. The thermal image receiver element of claim 1 , wherein the support comprises a cellulosic paper base or a synthetic paper base, and the support optionally comprises a conductive agent.
11. The thermal image receiver element of claim 1 that is a duplex thermal image receiver element comprising the same or different dry image receiving layer on both opposing sides of the support.
12. The thermal image receiver element of claim 1 , wherein the dry image receiver layer is disposed directly on one or both opposing sides of the support.
13. The thermal image receiver element of claim 1 , further comprising an intermediate layer between the support and the dry image receiving layer on one or both opposing sides of the support.
14. A thermal image receiver element comprising a support, and having one or both opposing sides of the support:
a dry image receiving layer having a T g of at least 35° C. and up to and including 60° C., which dry image receiving layer is the outermost layer of the thermal image receiver element, has a dry thickness of at least 1 μm and up to and including 3 μm, and comprises a polymer binder matrix that consists essentially of:
(1) a water-dispersible acrylic polymer comprising chemically reacted or chemically non-reacted carboxy or carboxylate groups,
wherein the water-dispersible acrylic polymer comprises recurring units derived from: (a) one or more ethylenically unsaturated polymerizable acrylates or methacrylates comprising acrylic alkyl ester, cycloalkyl ester, or aryl ester groups having at least 4 carbon atoms, (b) one or more carboxy-containing or carboxylate salt-containing ethylenically unsaturated polymerizable acrylates or methacrylates, and (c) optionally styrene or a styrene derivative,
wherein the (a) recurring units represent at least 20 mol % and up to and including 99 mol % of the total recurring units, and the (b) recurring units represent at least 1 mol % and up to and including 10 mol %, and
(2) a water-dispersible, film-forming polyester that has a T g of at least 0° C. and up to and including 20° C., which water-dispersible, film-forming polyester having water-dispersibility groups,
wherein the water-dispersible acrylic polymer is present in an amount of at least 60 weight % and up to and including 80 weight % of the total dry image receiving layer weight, and is present in the polymer binder matrix at a dry ratio to the water-dispersible polyester of at least 2:1 and up to and including 4:1.
15. An imaging assembly comprising the thermal image receiver element of claim 1 , in thermal association with a thermal donor element.
16. A method for making the thermal image receiver element of claim 1 , comprising:
applying an aqueous image receiving layer formulation to one or both opposing sides of a support, the aqueous image receiving layer formulation comprising a polymer binder composition consisting essentially of:
(1) a water-dispersible acrylic polymer comprising chemically reacted or chemically non-reacted hydroxyl, phospho, phosphonate, sulfo, sulfonate, carboxy, or carboxylate groups, and
(2) a water-dispersible polyester that has a T g of 30° C. or less,
wherein the water-dispersible acrylic polymer is present in an amount of at least 55 weight % of the resulting total dry image receiving layer weight, and is present in the polymeric binder matrix at a dry ratio to the water-dispersible polyester of at least 1:1 to and including 6:1, and
drying the aqueous image receiving layer formulation to form a dry image receiving layer on one or both opposing sides of the support.
17. The method of claim 16 , wherein the aqueous image receiving layer formulation further comprises a crosslinking agent for the water-dispersible acrylic polymer.
18. The method of claim 16 , wherein the aqueous image receiving layer formulation is heat treated at a temperature of at least 70° C.
19. The method of claim 16 , wherein the aqueous image receiving layer formulation is applied to the support and dried to provide the dry image receiving layer in a predetermined pattern.
20. The method of claim 16 , wherein the same aqueous image receiving layer formulation is applied to both opposing sides of the support.
21. A method for making a thermal image, comprising:
imagewise transferring a clear polymeric film, one or more dye images, or both a clear polymeric film and one or more dye images, from a thermal donor element to the image receiving layer of the dry thermal image receiving element of claim 1 .