Ink for decoration of paper substrates for poster displays
OwnerAdam Joseph Howard Batting, Paul James Chittenden +1inventors
InventorsAdam Joseph Howard Batting, Paul James Chittenden, Nigel Gould
Life of this patent
Estimating the term…
Abstract
Inks are described for use in screen printing on paper or other substrates, especially for mounting as posters. The inks contain an oligomer or prepolymer, a water-soluble monomer, a photoinitiator and a pigment. The inks are preferably cured by ultra-violet irradiation. The cured print is well wetted by aqueous paste and does not curl away from a mounting surface.
Claims25
A radiation curable ink for multi-layer screen process printing of poster paper which is to be coated with an adhesive paste and mounted on to a billboard, the poster paper exhibiting reduced curl away from the billboard when the poster paper is mounted on to the billboard;
- the ink comprising:
- (i) at least one photopolymerisable oligomer or prepolymer;
- (ii) at least one ethylenically unsaturated, water-soluble monomer;
- (iii) a photoinitiator or a mixture of photoinitiators;
- (iv) a pigment or a mixture of pigments;
- and
- (v) 0-20% by weight of water.
The ink as claimed in any one of the preceding claims, wherein the photopolymerizable oligomer or prepolymer (i) is present in the ink at a percentage by weight of between 5 and 50%, preferably between 8 and 30%, and more preferably between 10 and 20%.
The ink as claimed in any one of the preceding claims, wherein the ethylenically unsaturated water-soluble monomer (ii) has a solubility in water between 50 g/litre and complete miscibility, preferably between 200 g/litre and complete miscibility and more preferably between 400 g/litre and complete miscibility.
The ink as claimed in any one of the preceding claims, wherein the ethylenically unsaturated water-soluble monomer (ii) is an ester of acrylic or methacrylic acid with polyethylene glycol or with a mono-, di-, tri- or tetra-hydric alcohol derived by ethoxylating with ethylene oxide a mono-, di-, tri- or tetra-hydric aliphatic alcohol of molecular weight less than 200.
The ink as claimed in any one of the preceding claims, wherein the ethylenically unsaturated water-soluble monomer (ii) is present in an amount between 3 and 40%, preferably between 8-30%, and more preferably between 10-20%.
The ink as claimed in any one of the preceding claims, further including an ethylenically unsaturated monomer that is insoluble in water.
The ink as claimed in any one of the preceding claims, wherein the photoinitiator (iii) is a type known as Norrish Type I and II, and is preferably capable of initiating the polymerization of the components (i) and (ii) when exposed to ultra-violet or visible light of wavelengths between 200 and 420 nanometres.
The ink as claimed in any one of the preceding claims, wherein the proportion by weight of photoinitiator is between 0.5 and 10%, preferably 1-5%.
The ink as claimed in any one of the preceding claims, wherein the pigment is pre-dispersed in a liquid medium.
The ink as claimed in any one of the preceding claims, wherein the proportion by weight of the pigment is between 0.5 and 40%, preferably 1.5-10%, more preferably 2.5-6%.
The ink as claimed in any one of the preceding claims, further including an inorganic filler, preferably selected from:
- china clay, talc or calcium carbonate.
The ink as claimed in any one of the preceeding claims, wherein the ink includes less than 15% of water, preferably less than 10% water, more preferably less than 7% of water, more preferably less than 5% water, even more preferably less than 3% water and most preferably less than 1% water.
Dependencies are inferred from the claim text.