Fusible inkjet recording element and related methods of coating and printing

1. An inkjet recording element comprising a support having thereon a porous fusible top layer comprising fusible polymeric particles and, in an amount of 1 to 20 percent by weight of solids, a thermoresponsive polymer having a lower critical solution temperature (LCST) below 20° C., wherein greater than 90 percent, by weight solids, of total polymeric binder in the layer, including at least the thermoresponsive polymer, consists of one or more hydrophobic polymers.

2. The element of claim 1 wherein the porous fusible layer comprises a hydrophobic polymer in addition to the thermoresponsive polymer.

3. The element of claim 2 wherein the hydrophobic polymer is a polyurethane, styrene-butadiene, or acrylic polymer.

4. The element of claim 1 , further comprising, under the porous fusible top layer, at least one porous ink-receiving layer.

5. The element of claim 1 wherein the particle-to-binder ratio of the fusible porous layer is between about 95:5 and 60:40.

6. The element of claim 1 wherein the thermoresponsive polymer is a polyacrylamide.

7. The element according to claim 1 , wherein the thermoresponsive polymer comprises an N-alkyl or N-alkylene (meth) acrylamide monomeric repeat unit.

8. The element of claim 7 wherein the thermoresponsive polymer is an acrylamide copolymer prepared from at least two different N-alkylacrylamide monomers wherein each alkyl group has from 2 to 6 carbon atoms.

9. The element according to claim 1 , wherein the thermoresponsive polymer is a homopolymer or copolymer of at least one monomer selected from the group consisting of N-t-butyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-cyclopropyl(meth)acrylamide, N,N-diethylacrylamide, N,N-dimethyl(meth)acrylamide, N-n-propyl(meth)acrylamide, N-methyl-N-n-propylacrylamide, N-methyl-N-isopropylacrylamide, N-(meth)acryloylpyrrolidine, N-(meth)acryloylpiperidine, N-tetrahydrofurfuryl(meth)acrylamide, N-methoxypropyl(meth)acrylamide, N-ethoxypropyl(meth)acrylamide, N-isopropoxypropyl(meth)acrylamide, N-ethoxyethyl(meth)acrylamide, N-(2,2-dimethoxyethyl)-N-methylacrylamide, N-methoxyethyl(meth)acrylamide and N-(meth)acryloylmorpholine.

10. The element according to claim 9 , wherein the thermoresponsive polymer is a homopolymer or copolymer of at least one monomer selected from the group consisting of N-t-butylacrylamide, N-isopropylacrylamide, N-n-propylacrylamide, N,N-diethylacrylamide and N-acryloylmorpholine.

11. The element of claim 4 wherein the at least one porous ink-receiving layer comprises from about 20% to about 100% of particles and from about 0% to about 80% of a polymeric binder.

12. The element of claim 11 wherein the particles of the porous ink-receiving layer are selected from the group consisting of silica, alumina, titanium dioxide, clay, calcium carbonate, barium sulfate, zinc oxide, and combinations thereof.

13. The element of claim 11 wherein the polymeric binder of the porous ink-receiving layer is selected from the group consisting of poly(vinyl alcohol), hydroxypropyl cellulose, hydroxypropyl methyl cellulose, a poly(alkylene oxide), poly(vinyl pyrrolidinone), poly(vinyl acetate), copolymers thereof, gelatin, and combinations thereof.

14. The element of claim 4 wherein the porous fusible top layer has a thickness of about 1 μm to about 25 μm and the ink-receiving layer has a thickness of about 2 μm to about 50 μm.

15. An inkjet recording element comprising a support having thereon in order from the support:

a) at least one porous ink-receiving layer; and

b) a porous fusible topmost layer comprising fusible polymeric particles and a thermoresponsive polymer that exhibits a lower critical solution temperature (LCST) below 20° C. in an amount of 1 to 20 percent by weight of solids, wherein greater than 90 percent, by weight solids, of total polymeric binder in the layer, including at least the thermoresponsive polymer, consists of one or more hydrophobic polymers.

16. The inkjet recording element of claim 15 wherein the porous fusible topmost layer is an ink-transporting layer and the porous ink-receiving layer is an image-receiving layer.

17. A method of making an inkjet element comprising:

(a) providing a coating composition comprising an aqueous dispersion of fusible polymer particles and a thermoresponsive polymer having a lower critical solution temperature (LCST) below 20° C. in an amount of 1 to 20 percent by weight of solids, wherein greater than 90 percent, by weight solids, of total polymeric binder in the coating composition, including at least the thermoresponsive polymer, consists of one or more hydrophobic polymers;

(b) applying the coating composition over a substrate, the substrate comprising a support and optionally one or more ink-receiving layers, wherein the coating composition is at a temperature of at least 5° C. below the LCST of the thermoresponsive polymer, to form a coated layer; and

(c) drying the coated layer above the LCST, at a temperature of at least 20° C., but below fusing temperature of the fusible polymeric particles.

18. The method of claim 17 wherein another coating composition for an ink-receiving layer is simultaneously coated with the coating composition.

19. The method of claim 17 wherein the thermoresponsive polymer is present in an amount sufficient to provide the coating composition with an increase in viscosity of at least 5 cP measured at 5 degrees below the LCST.

20. An inkjet printing method, comprising the steps of:

A. providing an inkjet printer that is responsive to digital data signals;

B. loading the printer with the inkjet recording element of claim 1 ;

C. loading the printer with an inkjet ink composition;

D. printing on the inkjet recording element using the inkjet ink composition in response to the digital data signals; and

E. fusing at least the porous fusible top layer such that the layer becomes non-porous.