Curable overcoat for wax-based inks
View Patent ↗An ink jettable overprint composition includes at least one of a polymerizable monomer and/or a polymerizable oligomer; at least one photoinitiator; and at least one wax.
1. An ink jettable overprint composition, comprising:
at least one of a polymerizable monomer and/or a polymerizable oligomer;
at least one photoinitiator; and
from about 30.6 wt % to about 60 wt % of at least one wax selected from the group consisting of waxes functionalized with UV curable groups, crystalline polymeric waxes, and hydroxyl-terminated polyethylene waxes,
wherein the waxes functionalized with UV curable groups are selected from the group consisting of esterified carboxylic acid-terminated polyethylene waxes functionalized with UV curable groups and esterified hydroxyl-terminated polyethylene waxes functionalized with UV curable groups; and
the crystalline polymeric waxes are selected from the group consisting of aliphatic polar amide functionalized waxes, carboxylic acid-terminated polyethylene waxes, aliphatic waxes consisting of esters of hydroxylated unsaturated fatty acids, high acid waxes, and mixtures thereof.
2. The composition of claim 1 , wherein the overprint composition has a viscosity ranging from about 2 cP to about 20 cP at a temperature ranging from about 70° C. to about 110° C.
3. The composition of claim 1 , wherein the wax increases an affinity of the overprint composition with an underlying printed image.
4. The composition of claim 1 , wherein the overprint composition comprises at least one polymerizable monomer and at least one polymerizable oligomer.
5. The composition of claim 1 , wherein the overprint composition comprises:
from about 20 to about 95 wt % of a polymerizable monomer;
from about 0 to about 30 wt % polymerizable oligomer; and
from about 0.5 to about 15 wt % of photoinitiator.
6. The composition of claim 1 , wherein the overprint composition comprises:
from about 30 to about 90 wt % of a polymerizable monomer;
from about 0 to about 20 wt % polymerizable oligomer; and
from about 1 to about 15 wt % of photoinitiator.
7. The composition of claim 1 , further comprising a component that reduces a coefficient of friction of the overprint composition.
8. The composition of claim 1 , wherein the monomer is cationically curable.
9. The composition of claim 1 , wherein the monomer is radically curable.
10. The composition of claim 1 , further comprising an amine synergist.
11. The composition of claim 1 , wherein the photoinitiator is selected from the group consisting of triarylsulfonium salts, diaryliodonium salts, aryldiazonium salts, triarylselenonium salts, dialkylphenacylsulphonium salts, triarylsulphoxonium salts, aryloxydiarylsulphonoxonium salts, and dialkylphenacylsulphoxonium salts, wherein the salts are formed with ions selected from the group consisting of BF 4 − , PF 6 − , AsF 6 − , SbF 6 − .
12. The composition of claim 1 , wherein the photoinitiator is selected from the group consisting of hydroxycyclohexylphenyl ketones, trimethylbenzophenones, polymeric hydroxy ketones, trimethylbenzoylphenylphosphine oxides, and mixtures thereof.
13. The composition of claim 1 , wherein the photoinitiator is selected from the group consisting of 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 2-hydroxy-2-methyl- 1-phenyl-propan- 1-one, alpha-amino ketone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl) ketone, 2-isopropyl-9H-thioxanthen-9-one, and mixtures thereof.
14. The composition of claim 1 , wherein the polymerizable monomer is present and is selected from the group consisting of neopentyl glycol diacrylates, butanediol diacrylates, trimethyloipropane triacrylates, and glyceryl triacrylates.
15. A method of ink jet printing, comprising:
providing an ink jettable overprint composition according to claim 1 ;
ink jetting the overprint composition onto a substrate having an image thereon; and
exposing the image to a radiation source for sufficient time to at least substantially cure the radiation curable components of the overprint composition.
16. The method of claim 15 , wherein the image is wax-based.
17. The method of claim 15 , wherein the image is ink-based.
18. The method of claim 15 , wherein the radiation source is an ultraviolet light.
19. The method of claim 15 , wherein the ink jet is a thermal ink jet printer or a piezoelectric ink jet printer.
20. A toner-based or ink-based print, comprising a substrate with a toner-based or ink-based image thereon coated with the overprint composition of claim 1 , wherein, upon curing, the toner or ink on the print resists smearing upon overwriting.
21. A system for creating an image on a substrate, comprising:
an image generating component;
a substrate for receiving an image generated from the image generating component; and
an overprint composition configured for being ink jetted onto the generated image;
wherein the overprint composition comprises:
at least one of a polymerizable monomer and a polymerizable oligomer;
at least one photoinitiator; and
from about 30.6 wt % to about 60 wt % of at least one wax selected from the group consisting of waxes functionalized with UV curable groups, crystalline polymeric waxes, and hydroxyl-terminated polyethylene waxes,
wherein the waxes functionalized with UV curable groups are selected from the group consisting of esterified carboxylic acid-terminated polyethylene waxes functionalized with UV curable groups and esterified hydroxyl-terminated polyethylene waxes functionalized with UV curable groups; and
the crystalline polymeric waxes are selected from the group consisting of aliphatic polar amide functionalized waxes. carboxylic acid-terminated polyethylene waxes, aliphatic waxes consisting of esters of hydroxylated unsaturated fatty acids, high acid waxes, and mixtures thereof.