Plastic film for printing by dye diffusion thermal transfer printing
View Patent ↗The invention relates to a special layer construction and a special film of plastic for the production of such a layer construction which is suitable for printing by means of dye diffusion thermal transfer printing, a process for the production thereof and a security and/or valuable document comprising such a layer construction.
1. A layer construction comprising
at least one layer (A) comprising at least one thermoplastic and
at least one layer (B) comprising a polyester component comprising at least one poly- or copolycondensate of terephthalic acid or naphthalenedicarboxylic acid,
wherein the polyester component has radicals of cyclohexane-1,4-dimethanol in an amount of from 25 to 75 mol %, based on the radicals of the diol component(s) in all the poly- or copolyesters which the polyester component comprises, wherein the at least one layer (B) comprises a phosphite, wherein the phosphite is an ester of phosphonic acid with the general structure P(OR) 3 and wherein the phosphite comprises an oxetane group, wherein R represents aliphatic, aromatic and/or cycloaliphatic hydrocarbon radicals, wherein the hydrocarbon radicals R can optionally also comprise hetero atoms, and wherein the aromatic hydrocarbon radicals can have further substituents.
2. The layer construction according to claim 1 , wherein the polyester component has in total radicals of cyclohexane-1,4-dimethanol in an amount of from 30 to 75 mol %, based on the radicals of the diol component(s) in all the poly- or copolyesters which the polyester component comprises.
3. The layer construction according to claim 1 , wherein the polyester component comprises poly- or copolycondensate of terephthalic acid or naphthalenedicarboxylic acid comprising one or more cyclohexane-1,4-dimethanol units, which comprise as further radicals of one of several diol components those of ethylene glycol and/or butane-1,4-diol, optionally in a mixture with poly(cyclohexane-1,4-dimethanol) terephthalate and/or poly(cyclohexane-1,4-dimethanol) naphthalate.
4. The layer construction according to at least claim 1 , wherein layer (A) comprises at least one thermoplastic selected from the group consisting of polycarbonates or copolycarbonates based on diphenols, poly- or copolyacrylates and poly- or copolymethacrylates, poly- or copolymers with styrene, transparent thermoplastic polyurethanes, polyolefins, and poly- or copolycondensates of terephthalic acid or naphthalenedicarboxylic acid.
5. The layer construction according to claim 1 , wherein layer (A) is a white or translucent layer.
6. The layer construction according to claim 1 , wherein layer (A) is between two layers (B).
7. The layer construction according to claim 1 , wherein between layer (A) and the layer(s) (B) it has at least one further layer comprising at least one thermoplastic.
8. A process for the production of a layer construction according to claim 1 comprising boding the various films of plastic to one another by means of lamination or producing the layer construction by coextrusion.
9. A security and/or valuable document, wherein the document comprises a layer construction according to claim 1 .
10. The security and/or valuable document according to claim 9 , wherein the document is an identification document.
11. A method comprising printing the at least one of the layer(s) (B) of a layer construction according to claim 1 by means of dye diffusion thermal transfer printing.
12. A single- or multilayer film of plastic comprising at least one layer comprising a polyester component comprising at least one poly- or copolycondensate of terephthalic acid or naphthalenedicarboxylic acid, wherein the polyester component has radicals of cyclohexane-1,4-dimethanol in an amount of from 25 to 75 mol %, based on the radicals of the diol component(s) in all the poly- or copolyesters which the polyester component comprises, wherein the at least one layer (B) comprises a phosphite, wherein the phosphite is an ester of phosphonic acid with the general structure P(OR) 3 and wherein the phosphite comprises an oxetane group, wherein R represents aliphatic, aromatic and/or cycloaliphatic hydrocarbon radicals, wherein the hydrocarbon radicals R can optionally also comprise hetero atoms, and wherein the aromatic hydrocarbon radicals can have further substituents.
13. The film of plastic according to claim 12 , wherein the film has at least one further layer comprising at least one thermoplastic.
14. Film of plastic according to claim 12 , characterized in that it has at least one layer (A) comprising at least one thermoplastic and at least two layers (B) comprising a polyester component comprising at least one poly- or copolycondensate of terephthalic acid or naphthalenedicarboxylic acid, wherein the polyester component has radicals of cyclohexane-1,4-dimethanol in an amount of from 25 to 75 mol %, based on the radicals of the diol component(s) in all the poly- or copolyesters which the polyester component comprises, at least one layer (A) being between two layers (B).
15. The layer construction according to claim 1 , wherein the amount of phosphite is from 0.05 to 0.5 wt. %—based on the total weight of the polyester components of layer (B).