Heat transfer materials and methods of making and using the same
View Patent ↗Method of making a heat transfer materials are generally provided, along with the materials and the methods of using the materials. A splittable layer can be formed to overlie a base sheet, and an image-receptive coating can be formed to overlie the splittable layer. The image-receptive coating can include thermoplastic microparticles, a thermoplastic binder, and a humectant. The thermoplastic microparticles can be styrene particles having an average particle size of from about 5 microns to about 80 microns and melt at temperatures between about 90° C. and about 115° C. A second thermoplastic microparticle can also be included in the image-receptive coating. Alternatively, a combination of thermoplastic polyester microparticles and thermoplastic polyamide microparticles can be included in the image-receptive coating. The heat transfer material can then be dried. The humectant is configured to draw moisture back into the heat transfer sheet after drying.
1. A method of making a heat transfer material, the method comprising:
forming a splittable layer overlying a base sheet;
forming an image-receptive coating overlying the splittable layer to form the heat transfer material, wherein the image-receptive coating comprises thermoplastic polystyrene microparticles, a thermoplastic binder, and a humectant, wherein the thermoplastic polystyrene microparticles have an average particle size of from about 5 microns to about 80 microns and melt at temperatures between about 90° C. and about 115° C.; and
drying the heat transfer material, wherein the humectant is configured to draw moisture back into the heat transfer sheet after drying.
2. The method as in claim 1 , wherein the thermoplastic polystyrene microparticles melt at temperatures between about 95° C. and about 105° C.
3. The method as in claim 1 , wherein the thermoplastic polystyrene microparticles have a substantially spherical shape.
4. The method as in claim 1 , wherein the thermoplastic polystyrene microparticles have an average particle size of from about 38 microns to about 42 microns.
5. The method as in claim 1 , wherein the thermoplastic polystyrene microparticles have an average particle size of from about 18 microns to about 22 microns.
6. The method as in claim 1 , wherein the image-receptive coating further comprises a plurality of second thermoplastic polymer microparticles having an average particle size of from about 2 microns to about 50 microns.
7. The method as in claim 6 , wherein the image-receptive coating comprises the thermoplastic polystyrene microparticles in an amount from about 10% to about 75% by weight based on the dry weight of the image-receptive coating, and wherein the image-receptive coating comprises the second thermoplastic polymer microparticles in an amount from about 10% to about 75% by weight based on the dry weight of the image-receptive coating.
8. The method as in claim 6 , wherein the second thermoplastic polymer microparticles comprise polyimide microparticles.
9. The method as in claim 1 , wherein the humectant comprises urea.
10. The method as in claim 1 , wherein the image-receptive coating is substantially free from a cross-linking agent.
11. The method as in claim 1 , wherein the splittable layer directly overlies the base sheet, and wherein the image-receptive coating directly overlies the splittable layer.
12. The method as in claim 1 , wherein the splittable layer is melt extruded directly onto the base sheet, wherein the splittable layer comprises a polymeric material that melts at temperatures between 80° C. and 130° C.
13. The method as in claim 1 , wherein the image-receptive coating further comprises a hydrophilic polymer.
14. The method as in claim 13 , wherein the hydrophilic polymer comprises polyethylene glycol.
15. The method as in claim 13 , wherein the hydrophilic polymer is present in the image-receptive coating from a positive amount to about 3% by weight based on the dry weight of the image-receptive coating.
16. A method of making a heat transfer material, the method comprising:
forming a splittable layer overlying a base sheet;
forming an image-receptive coating overlying the splittable layer to form the heat transfer material, wherein the image-receptive coating comprises thermoplastic polyester microparticles, a thermoplastic binder, and a humectant, wherein the thermoplastic polyester microparticles have an average particle size of from about 5 microns to about 80 microns and melt at temperatures between about 90° C. and about 115° C.; and drying the heat transfer material, wherein the humectant is configured to draw moisture back into the heat transfer sheet after drying.
17. The method of claim 16 , wherein the image-receptive coating further comprises thermoplastic polyamide microparticles, and wherein the thermoplastic polyamide microparticles have an average particle size of from about 2 microns to about 50 microns.