Control of volatile carbonyl compound in compositions used in printing, printing methods and resulting printed structure
View Patent ↗Volatile organic compounds containing carbonyl groups can be released by lithographic printing materials including inks, fountain solutions and printed materials. Volatile organic compounds containing carbonyl groups can also have a serious negative impact on the taste or odor of staple materials such as foodstuffs. The volatile materials can be retained in the lithographic compositions and printed materials can be trapped in the printed materials using an improved reactive technology involving a chemically reactive trap for such volatile carbonyl containing compounds.
1. A fountain solution used in defining an image on a printing plate, the fountain solution comprising a source of a volatile carbonyl compound and:
(a) a major proportion of an aqueous medium;
(b) a water soluble polymer in an amount from about 0.01 to about 1 wt% of the solution;
(c) a pH modifying substance to maintain the pH tinge from about 2 to about 7;
(d) an effective amount of a surfactant to spread the fountain solution uniformly on a printing plate; and
(e) a reactive composition capable of reacting with the volatile organic carbonyl compound in the fountain solution to substantially reduce the release of the carbonyl compound from the fountain solution.
2. The solution of claim 1 wherein the water soluble polymer is a natural product polymer is present in an amount from about 0.05 to about 0.5 wt % of the solution.
3. The solution of claim 1 comprising about 1 to 40 wt % of the reactive composition.
4. The solution of claim 3 wherein the reactive composition comprises a hydrazide compound.
5. The solution of claim 4 wherein the hydrazide compound comprises an aromatic hydrazide.
6. The solution of claim 5 wherein the aromatic hydrazide comprises benzoic hydrazide.
7. The solution of claim 1 wherein the reactive composition comprises urea.
8. The solution of claim 1 wherein the reactive composition comprises a guanidine sulfate.
9. The solution of claim 1 wherein the reactive composition comprises an alkali metal bisulfite.
10. The solution of claim 1 wherein the volatile organic carbonyl compound comprises a C 5-9 aldehyde or mixture thereof.
11. The fountain solution of claim 1 wherein the polymeric substance comprises a natural gum.
12. The fountain solution of claim 11 wherein the natural gum comprises gum arabic.
13. A overcoat solution used as a finish coating in a printed structure, the solution comprising:
(a) a major proportion of an aqueous medium;
(b) a water soluble polymer in an amount from about 10 to about 80 wt % of the solution; and
(c) a reactive composition capable of reacting with the volatile organic carbonyl compound in the fountain solution to substantially reduce the release of the carbonyl compound from the fountain solution, ink, paperboard, claycoat or overcoat.
14. The solution of claim 13 wherein the water soluble polymer is present in an amount from about 10 to about 80 wt % of the solution.
15. The solution of claim 13 comprising about 0.01 to 3.0 wt % of the reactive composition.
16. The solution of claim 15 wherein the reactive composition comprises a hydrazide compound.
17. The solution of claim 16 wherein the hydrazide compound comprises an aromatic hydrazide.
18. The solution of claim 17 wherein the aromatic hydrazide comprises benzoic hydrazide.
19. The solution of claim 13 wherein the reactive composition comprises urea.
20. The solution of claim 13 wherein the reactive composition comprises a mixture of urea and an aromatic hydrazide.
21. The solution of claim 13 wherein tho reactive composition comprises an alkali metal bisulfite.
22. The solution of claim 13 wherein the volatile organic carbonyl compound comprises a C 5-9 aldehyde or mixtures thereof.
23. The solution of claim 13 wherein the polymeric substance comprises an acrylic copolymer.