Conductive thermal imaging receiving layer with receiver overcoat layer
This invention relates to a conductive thermal image receiver element that has an aqueous coatable dye-receiving layer and an aqueous coatable receiver overcoat layer. The receiver overcoat layer comprises a conductive polymeric material and a two or more dispersants. The dye-receiving layer comprises a water-dispersible release agent, a crosslinking agent, and a polymer binder matrix consisting essentially of a water-dispersible polyester and a water-dispersible acrylic polymer. This invention also relates to a method for making this thermal image receiver element as well as method for using it to provide a dye image by thermal transfer from a donor element.
1. A conductive thermal image receiver element comprising a support, and having on at least one side of the support:
an aqueous-coatable receiver overcoat layer and aqueous-coatable dye-receiving layer,
wherein the aqueous-coatable receiver overcoat layer comprises a conductive polymeric material, a first dispersant, and a second dispersant, and
wherein the aqueous-coatable dye-receiving layer comprises a water-dispersible release agent, a crosslinking agent, and a polymer binder matrix 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 Tg of 30° C. or less;
wherein the water-dispersible acrylic polymer is present in an amount of at least 55 weight % of the total aqueous coatable dye-receiving layer weight and is present at a dry ratio to the water-dispersible polyester of at least 1:1.
2. The conductive thermal image receiver element of claim 1 , wherein the first dispersant and the second dispersant are independently selected from the group consisting of (a) a random copolymer; (b) an acrylic block copolymer; and (c) an acrylic block terpolymer.
3. The conductive thermal image receiver element of claim 2 , wherein (a) the random copolymer, (b) the acrylic block copolymer, and (c) the acrylic block terpolymer all comprise a hydrophilic constituent and a hydrophobic constituent.
4. The conductive thermal image receiver element of claim 3 , wherein the hydrophobic constituent for each of (a) the random copolymer, (b) the acrylic block copolymer, and (c) the acrylic block terpolymer are independently selected from the group consisting of: an aliphatic monomer, an aromatic monomer, an alicyclic monomer, an aromatic heterocycle, an alicyclic heterocycle, and a polycyclic monomer.
5. The conductive thermal image receiver element of claim 2 , wherein (a) the random copolymer, (b) the acrylic block copolymer, and (c) the acrylic block terpolymer all have a weight average molecular ranging from 5,000 to 100,000.
6. The conductive thermal image receiver element of claim 2 , wherein the first dispersant is a random copolymer comprising benzyl methacrylate and methacrylic acid.
7. The conductive thermal image receiver element of claim 6 , wherein the first dispersant is present in an amount ranging from 1% to 4% by weight, based on the total dry weight of the receiver overcoat layer.
8. The conductive thermal image receiver element of claim 6 , wherein the second dispersant is an acrylic block copolymer.
9. The conductive thermal image receiver element of claim 8 , wherein the second dispersant is present in an amount ranging from 1% to 4% by weight, based on the total dry weight of the receiver overcoat layer.
10. The conductive thermal image receiver element of claim 6 , wherein the second dispersant is an acrylic block terpolymer.
11. The conductive thermal image receiver element of claim 10 , wherein the second dispersant is present in an amount ranging from 1% to 4% by weight, based on the total dry weight of the receiver overcoat layer.
12. The conductive thermal image receiver element of claim 1 , wherein the first dispersant and the second dispersant are cumulatively present in an amount ranging from 0.5 to 10% by weight based on the total dry weight of the receiver overcoat layer.
13. The conductive thermal image receiver element of claim 1 , wherein the receiver overcoat layer further comprises at least one surfactant.
14. The conductive thermal image receiver element of claim 13 , wherein the at least one surfactant comprises P-isonoylphenoxypoly(glycidol).
15. The conductive thermal image receiver element of claim 1 , wherein the conductive polymeric material is Poly(3,4-ethylendioxythiophene)-poly(styrenesulfonate).
16. The conductive thermal image receiver element of claim 1 , wherein the thickness of the receiver overcoat layer ranges from 0.1 μm to 0.62 μm.
17. The conductive thermal image receiver element of claim 1 , wherein either the first dispersant or the second dispersant is a random terpolymer of benzyl methacrylate, octadecyl methacrylate, and methacrylic acid in an amount ranging from 1% to 4% by weight, based on the total dry weight of the receiver overcoat layer.
18. A method for making the conductive thermal image receiver element of claim 1 , comprising:
(A) applying an aqueous coatable dye-receiving layer formulation to one or both opposing sides of a support or to another layer that resides on one or both sides of the support, the aqueous coatable dye-receiving layer formulation comprising a water-dispersible release agent, a crosslinking agent, and 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 Tg 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 9.2:1, or at least 4:1 to and including 20:1;
(B) drying the aqueous image receiving layer formulation to form a dry image receiving layer on one or both opposing sides of the support;
(C) applying a receiver overcoat layer to at least on one side of a support coated with an aqueous coatable dye-receiving layer, the receiver overcoat layer comprising a first dispersant, a second dispersant, and a conductive polymeric material; and
(D) drying the aqueous image receiving layer formulation to form a dry receiver overcoat layer on one or both opposing sides of the support.
19. The method of claim 18 , wherein the same aqueous coatable dye receiving layer formulation and the same receiver overcoat layer are applied to both opposing sides of the support.