Heat-transfer label assembly and method of using the same
View Patent ↗A heat-transfer label assembly and method of using the same. In one embodiment, the assembly is adapted for decorating glass articles and comprises a carrier, the carrier comprising a paper substrate overcoated with a layer of polyethylene. The polyethylene layer is overcoated with a skim coat of wax. One or more heat-transfer labels are printed onto the skim coat and are spaced apart from one another. Each label consists of one or more ink design layers, each ink design layer comprising a binder resin, a pigment, a cross-linking resin and a catalyst. The catalyst is capable of causing the cross-linking resin to cross-link the binder resin within 1-2 minutes after the label has been transferred to a glass article that has been preheated to a temperature of about 250° F.-325° F.
1. A heat-transfer label assembly suitable for use in labeling a glass container, said heat-transfer label assembly consisting of:
(a) a carrier, said carrier consisting of a paper substrate overcoated with a layer of polyethylene;
(b) a wax skim coat deposited onto said polyethylene layer of said carrier, said wax skim coat having a thickness of about 0.1-0.4 lbs, per 3000 square feet; and
(c) a heat-transfer label, said heat-transfer label being deposited directly onto said wax skim coat for transfer of said heat-transfer label from said carrier to an article under conditions of heat and pressure, said heat-transfer label consisting of one or more ink design layers, each of said ink design layers being thermosetting and consisting of a binder, a colorant and a cross-linking system, said binder consisting of a copolyester resin and a vinyl chloride/vinyl acetate resin, said cross-linking system consisting of (i) a cross-linking resin for cross-linking said binder, said cross-linking resin consisting of a melamine-formaldehyde resin and (ii) a heat-activatable catalyst for catalyzing said cross-linking within about 1-2 minutes after said ink design layer has been transferred to an article that has been pre-heated, prior to label transfer, to a temperature of about 250° F.-325° F., said heat-activatable catalyst consisting of an amine-blocked sulfonic acid catalyst.
2. The heat-transfer label assembly as claimed in claim 1 wherein said vinyl chloride/vinyl acetate resin constitutes up to about 25%, by weight, of said binder.
3. The heat-transfer label assembly as claimed in claim 1 wherein said copolyester resin has a high tensile strength and low elongation.
4. The heat-transfer label assembly as claimed in claim 1 wherein said colorant is a pigment, said pigment being present in an amount ranging from about 50% to about 200%, by weight, of the total of said binder and said cross-linking system.
5. The heat-transfer label assembly as claimed in claim 4 wherein said pigment is titanium dioxide.
6. The heat-transfer label assembly as claimed in claim 1 wherein said cross-linking resin is present in an amount constituting about 5%-10%, by weight, of said binder.
7. The heat-transfer label assembly as claimed in claim 1 wherein said cross-linking resin consists of a partially methylated melamine-formaldehyde resin.
8. A heat-transfer label assembly suitable for use in labeling a glass container, said heat-transfer label assembly consisting of:
(a) a carrier, said carrier consisting of a paper substrate overcoated with a layer of polyethylene;
(b) a wax skim coat deposited onto said polyethylene layer of said carrier, said wax skim coat having a thickness of about 0.1-0.4 lbs, per 3000 square feet; and
(c) a heat-transfer label, said heat-transfer label being deposited directly onto said wax skim coat for transfer of said heat-transfer label from said carrier to an article under conditions of heat and pressure, said heat-transfer label consisting of one or more ink design layers, each of said ink design layers being thermosetting and consisting of a binder, a colorant and a cross-linking system, said binder consisting of a first copolyester resin, a second copolyester resin, and a vinyl chloride/vinyl acetate resin, said cross-linking system consisting of (i) a cross-linking resin for cross-linking said binder, said cross-linking resin consisting of a melamine-formaldehyde resin and (ii) a heat-activatable catalyst for catalyzing said cross-linking within about 1-2 minutes after said ink design layer has been transferred to an article that has been pre-heated, prior to label transfer, to a temperature of about 250° F.-325° F., said heat-activatable catalyst consisting of an amine-blocked sulfonic acid catalyst, wherein said first copolyester resin constitutes about 47%, by weight, of said binder and has a tensile strength of 7000 psi and a 4% elongation, wherein said second copolyester resin constitutes about 47%, by weight, of said binder and has a tensile strength of 8000 psi and a 7% elongation, and wherein said vinyl chloride/vinyl acetate resin constitutes about 5%, by weight, of said binder and has a composition of approximately 90 percent vinyl chloride, 4 percent vinyl acetate, with a hydroxyl content of approximately 2.3 percent.