Radiation-curable thermal printing ink and ink ribbons and methods of making, using and printing using the same
A radiation-curable ink, a method of making the ink, a thermal transfer printer ribbon having a radiation-curable ink layer, and a thermal transfer printer with an actinic energy source are provided. A method of thermal transfer printing using an ink ribbon having radiation-curable components is also provided. The radiation curable components of the ink can be thermally dried and are cured after printing of an image on a receiving article.
1. A method of thermal transfer printing comprising:
providing a thermal transfer printer, an ink ribbon having an ink layer with radiation-curable components and a receiving article to be printed;
positioning between the print head of said printer and said receiving article said radiation-curable ink ribbon;
establishing contact between said ribbon and said print head;
elevating the temperature of selected portions of said ribbon to effect transfer of said ink layer to said receiving article; and
curing the radiation-curable components of said transferred ink layer, wherein the ink layer comprises about 1 to 90% by weight of at least one radiation-curable monomer or oligomer, about 1 to 15% by weight of a photoinitiator, and about 1 to 25% by weight of at least one coating additive, and wherein said ink layer can be thermally dried prior to printing and the radiation curable monomer or oligomer remains in the uncured state until after printing, at which time exposure of the monomer or oligomer to actinic radiation will result in a thermoset structure which will not flow when heated and is of enhanced durability.
2. The method of claim 1 , wherein the curing is by electron beam.
3. The method of claim 1 , wherein the curing is by UV light.
4. The method of claim 1 , wherein the curing is by visible light.
5. The method of claim 1 , wherein the photoinitiator is selected from the group consisting of 1-hydroxycyclohexyl phenyl ketone and 2-benzyl-2-N,N-dimethylamino-1-(4-morpholinophenyl)-1-butanone.
6. The method of claim 1 , the ink layer further comprising: about 1 to 20% by weight of a binder.
7. The method of claim 6 , wherein the binder is selected from the group consisting of homopolymers of styrene, derivatives or substituted products of homopolymers of styrene, methacrylic acid, esters of methacrylic acid, acrylic acid, esters of acrylic acid, dienes, vinyl polymers, polycarbonate resins, polyester resins, silicone resins, fluorine-containing resins. phenolic resins, terpene resins, petroleum resins, hydrogenated petroleum resins, alkyd resins, ketone resins, and cellulose derivatives.
8. The method of claim 1 , the ink further comprising about 1 to 40% by weight of a colorant.
9. A thermal transfer printer comprising a thermal transfer print head, a ribbon feeder which feeds a thermal transfer ribbon to the heating elements of the thermal transfer print head, and an actinic energy source,
said thermal transfer ribbon characterized as having an ink layer with radiation curable components, wherein said ink layer is thermally dried during formation of the ribbon and the radiation-curable components remain in the uncured state until after printing, at which time exposure of the monomer or oligomer to the actinic energy source will result in a thermoset structure which will not flow when heated and is of enhanced durability.
10. The thermal transfer printer of claim 9 , wherein the actinic energy source is internal.
11. The thermal transfer printer of claim 9 , wherein the actinic energy source is external.
12. The thermal transfer printer of claim 9 , wherein the ink layer comprises about 1 to 90% by weight of at least one radiation-curable monomer or oligomer, about 1 to 15% by weight of a photoinitiator, and about 1 to 25% by weight of at least one coating additive.