HEAT TRANSFERABLE MATERIAL FOR IMPROVED IMAGE STABILITY
A heat transferable material includes a light stabilizer that is an N-oxyl radical derived from a hindered amine and having the formula, wherein R 1 , R 2 , R 5 , and R 6 are each independently selected from a straight or branched C 1 -C 6 alkyl or alkene, and R 3 and R 4 are each independently selected from H, CH 2 CH 3 , CH 3 , OH, OR, COOH, or COOR, wherein R is a straight or branched C 1 -C 6 alkyl or alkene, and having a molecular weight of 600 or less, except that all of R 1 , R 2 , R 5 , and R 6 are not methyl when both R 3 and R 4 are hydrogen. The heat transferable material can be in one or more sections or patches on a thermal donor element to provide a protective overcoat material. The heat transferable material provides better image stability and improved iridescence when applied to a receiver.
1 . A heat transferable donor element comprising a polymeric support, the support having at least one portion thereof coated with a heat transferable material comprising a heat transferable polymeric binder and a light stabilizer that is an N-oxyl radical that is derived from a hindered amine, the N-oxyl radical having the following formula:
wherein R 1 , R 2 , R 5 , and R 6 are each independently selected from a straight or branched C 1 -C 6 alkyl or alkene, and R 3 and R 4 are each independently selected from H, CH 2 CH 3 , CH 3 , OH, OR, COOH, or COOR, wherein R is a straight or branched. C 1 -C 6 alkyl or alkene, and having a molecular weight of 600 or less, except that all of R 1 , R 2 , R 5 , and R 6 are not methyl when both R 3 and R 4 are hydrogen.
2 . The element of claim 1 comprising at least one protective overcoat patch.
3 . The element of claim 1 , wherein the heat transferable material further comprises a UV absorbing material in the amount of 20% by weight or less.
4 . The element of claim 1 , wherein the heat transferable material further comprises a plasticizer in the amount of 5% by weight or less.
5 . The element of claim 1 , wherein the heat transferable material further comprises at least one resin selected from Formula I, styrene/allyl alcohol copolymer, and the combination thereof, wherein Formula I is
wherein n is from 10-100.
6 . The element of claim 5 , wherein the heat transferable material comprises from about 40% to about 90% by weight of the resin of Formula I, and from about 2 to about 20% of a UV absorbing material.
7 . The element of claim 1 , wherein R 1 , R 2 , R 5 , and R 6 are independently H or CH 2 CH 3 .
8 . The element of claim 1 , wherein R 3 and R 4 are independently H, OH, CH 2 CH 3 , or CH 3 .
9 . A heat transferable overcoat material comprising a heat transferable polymeric binder and a light stabilizer that is an N-oxyl radical that is derived from a hindered amine, the N-oxyl radical having the following formula:
wherein R 1 , R 2 , R 5 , and R 6 are each independently selected from a straight or branched C 1 -C 6 alkyl or alkene, and R 3 and R 4 are each independently selected from H, CH 2 CH 3 , CH 3 , OH, OR, COOH, or COOR, wherein R is a straight or branched C 1 -C 6 alkyl or alkene, and having a molecular weight of 600 or less, except that all of R 1 , R 2 , R 5 , and R 6 are not methyl when both R 3 and R 4 are hydrogen.
10 . The overcoat material of claim 9 further comprising a UV absorbing material in the amount of 20% or less, or a plasticizer in the amount of 0 to 2%.
11 . The overcoat material of claim 9 further comprising at least one resin selected from Formula I, styrene/allyl alcohol copolymer, and the combination thereof, wherein Formula I is:
wherein n is from 10-100.
12 . The overcoat material of claim 11 wherein the heat transferable material comprises from about 40% to about 90% by weight of the resin of Formula I, and from about 2 to about 20% of a UV absorbing material.
13 . A donor element comprising a polymeric support and the heat transferable overcoat material of claim 9 .
14 . A method of coating a receiver element with a protective overcoat material, comprising:
contacting the donor element of claim 13 with a receiver element;
applying heat or pressure sufficient to transfer the protective overcoat material from the donor element to the receiver element.
15 . The method of claim 14 wherein the receiver element is selected from an inkjet receiver, a thermal receiver, an electrophotographic receiver, and a silver halide print.
16 . A thermal transfer assemblage comprising a receiver element in contact with at least a portion of a heat transferable donor element, wherein the donor element comprises a polymeric support at least one portion thereof coated with a heat transferable material comprising a heat transferable polymeric binder and a light stabilizer that is an N-oxyl radical derived from a hindered amine, the N-oxyl radical having the following formula:
wherein R 1 , R 2 , R 5 , and R 6 are each independently selected from a straight or branched C 1 -C 6 alkyl or alkene, and R 3 and R 4 are each independently selected from H, CH 2 CH 3 , CH 3 , OH, OR, COOH, or COOR, wherein R is a straight or branched C 1 -C 6 alkyl or alkene, and having a molecular weight of 600 or less, except that all of R 1 , R 2 , R 5 , and R 6 are not methyl when both R 3 and R 4 are hydrogen.
17 . The assemblage of claim 16 wherein the heat transferable material of the donor element further comprises at least one resin selected from Formula I, styrene/allyl alcohol copolymer, and the combination thereof, wherein Formula I is
wherein n is from 10-100.
18 . The assemblage of claim 17 wherein the heat transferable material of the donor element comprises from about 40% to about 90% by weight of the resin of Formula I, and from about 2 to about 20% of a UV absorbing material.
19 . The assemblage of claim 15 wherein the donor element comprises two or more patches of a heat transferable material, wherein at least one patch includes a dye and at least one patch includes a protective overcoat material.
20 . The assemblage of claim 15 wherein the receiver element is selected from an inkjet receiver, a thermal receiver, an electrophotographic receiver, and a silver halide print.