UV curable low gloss additives for overprint varnish coating formulations and coatings therefrom
View Patent ↗The invention relates to UV curable, low gloss overprint varnish coating formulations and cured coatings prepared therefrom. The low gloss overprint varnish formulations contain a Michael addition resin, a polyamide powder and a reactive monomer.
1. A low gloss, UV curable overprint varnish composition, comprising the reaction product of;
A. a low gloss additive, comprising:
i. a liquid Michael addition resin, comprising the reaction product of Michael donor and a Michael acceptor, and
ii. a polyamide polymer powder, and
B. a reactive acrylate monomer,
wherein the overprint varnish composition has a lower gloss value as determined by ASTM 523-89 at 60° than an overprint varnish composition without the combination of the Michael addition resin and the polyamide powder.
2. The composition as claimed in claim 1 , further comprising a photoinitiator.
3. The composition as claimed in claim 1 , further comprising a synergist.
4. The composition as claimed in claim 1 , further comprising a finish enhancer.
5. The composition as claimed in claim 1 , further comprising a flow and leveling aid.
6. The composition as claimed in claim 1 , wherein the Michael donor is a β-diketone, a β-ketoester, a β-ketoanilide, a β-ketoamide or mixtures thereof.
7. The composition as claimed in claim 1 , wherein the Michael acceptor is an acrylate having at least two acrylate groups.
8. The composition as claimed in claim 1 , wherein the polyamide powder has an average particle size of from 5 microns to 12 microns.
9. The composition as claimed in claim 1 , wherein the Michael donor and/or Michael acceptor are modified to contain Type I α-cleavage or Type II H-abstraction photolabile moieties.
10. A low gloss, UV curable overprint varnish composition as claimed in claim 1 comprising;
A. a low gloss additive, comprising
i. from about 10 wt % to about 90 wt % of a liquid Michael addition resin,
ii. from about 3 wt % to about 9 wt % of a polyamide polymer powder,
B. from about 5 wt % to about 70 wt % of an acrylate,
C. up to about 3 wt % of a photoinitiator,
D. up to about 10 wt % of a synergist,
E. up to about 10 wt % of a finish enhancer, and
F. up to about 10 wt % of a flow and leveling aid.
11. A low gloss, overprint varnish coating comprising the reaction product of claim 1 .
12. An article having at least one low gloss coated surface, comprising;
A. a substrate, and
B. a low gloss coating on at least one surface of the article, comprising the UV cured reaction product of claim 1 .