Patent ID: 6790493
Filing Date: 2004-09-14
Classification: B41M,C08G,C09D,Y10T

Abstract:
A thermal transfer medium comprising a flexible substrate and a single thermal transfer layer, said thermal transfer layer having a softening point below 200Â° C. obtained from an aqueous coating formulation comprising a combination of:a) an aqueous emulsion of at least one thermoplastic resin and/or wax coemulsified with at least one epoxy curing agent which initiates crosslinking with an epoxy resin and b) an aqueous dispersion of at least one epoxy resin, said aqueous coating formulation further comprising an aqueous liquid which does not solubilize epoxy curing agents, thermoplastic resins, waxes or the epoxy resins, said single thermal transfer layer comprising: a) at least one epoxy resin, b) at least one epoxy curing agent which initiates crosslinking with an epoxy resin, and c) at least one thermoplastic resin and/or wax, wherein the epoxy curing agent is dispersed within the at least one thermoplastic resin and/or wax and separated from said epoxy resins so as to not react without melt mixing, wherein said epoxy resins, epoxy curing agents, thermoplastic resins and waxes each have a softening point below 200Â° C. so as to melt mix at a temperature in the range of 50Â° C. to 250Â° C., wherein each of the epoxy resins, thermoplastic resins and waxes are solid at 20Â° C. and each of the epoxy curing agents are either solid at 20Â° C. or encapsulated in a thermoplastic resin or wax which is solid at 20Â°C.