Digital printing inks
The acrylate monomers of the present invention, particularly o-phenyl phenoxyethyl acrylate, provide very fast curing, hard and solvent resistant digital printing inks, and yet are also still surprisingly flexible. These properties make for a technically superior alternative to the widely accepted very hard monomer isobornyl acrylate. O-phenyl phenoxyethylacrylate also has the additional benefit of being free from the strong odor associated with isobornyl acrylate.
1. A printing ink composition comprising a colorant and a monomer of polyethylene glycol o-phenyl phenyl ether acrylate of formula (A):
wherein, n is 1 - 3,
or a monomer of formula (I):
wherein:
R 1 is selected from the group consisting of hydrogen, methyl and a hydroxyl group;
R 2 is either a hydrogen or a methyl group;
y is 1 to 6; and
Z is selected from the group consisting of formula (II), (III) and (IV):
wherein:
X is selected from the group consisting of a direct bond, O, CH 2 , C(CH 3 ) 2 and C═O;
p is 0 or 1;
Q is CH 2 or C═O;
R 3 and R 4 are selected from the group consisting of H, phenyl, dimethyl benzyl, C 1 -C 8 alkyl group and C 1 -C 8 alkoxy group, or alternatively R 3 and R 4 are joined to form a fused ring with the benzene rings to which they are attached; and
R 5 is —C(O)OR 6 , wherein R 6 is phenyl or C 1 - C 8 alkyl.
2. The printing ink composition of claim 1 , wherein the monomer of formula (I) or formula (A) is o-phenyl phenoxyethyl acrylate:
3. The printing ink composition of claim 1 , wherein the printing ink is a digital printing ink.
4. A digital printing ink composition comprising:
(a) the monomer of formula (A) or the monomer of formula (I) according to claim 1 ;
(b) a photoinitiator; and
(c) a colorant,
wherein, total photoinitiator content is from 1-15% by weight based on total weight of the ink.
5. A digital printing ink composition comprising the monomer of formula (A) or the monomer of formula (I) according to claim 1 present in an amount between 0.1-75% by weight of total weight of the ink.
6. A digital printing ink composition comprising the monomer of formula (A) or the monomer of formula (I) according to claim 1 present in an amount between 1-40% by weight of total weight of the ink.
7. A digital printing ink composition comprising the monomer of formula (A) or the monomer of formula (I) according to claim 1 present in an amount between 1-30% by weight of total weight of the ink.
8. A digital printing ink composition according to claim 1 , wherein the ink is an aerosol jet ink.
9. A printed article comprising the printing ink composition of claim 1 .
10. A method of printing a printing ink composition comprising applying to a substrate the printing ink composition of claim 1 .