Developer regenerators
View Patent ↗The present invention provides an aqueous regenerator for addition to an aqueous developer that contains an organic solvent, a dispersing agent and a weak base, and has a pH of between about 8 and less than about 13. The aqueous regenerator includes an organic solvent, dispersing agent, and an effective amount of a strong base such that the regenerator has a greater pH than the developer into which the regenerator is to be added.
1. A combination of an aqueous developer and an aqueous regenerator wherein the aqueous developer comprises an organic solvent, a dispersing agent, and a first base, and has a pH between about 8 and less than about 13, and wherein the aqueous regenerator comprises an organic solvent, a dispersing agent, and an effective amount of a second base such that the regenerator has a pH at least 0.5 higher than the pH of the developer and wherein the K b of the second base is greater than the K b of the first base.
2. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein said aqueous regenerator comprises an effective amount of the second base such that the regenerator has a pH of about 10 or greater.
3. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein said aqueous regenerator comprises an effective amount of the second base such that the regenerator has a pH of about 11 or greater.
4. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein said aqueous regenerator comprises an effective amount of the second base such that the regenerator has a pH of about 12 or greater.
5. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the aqueous regenerator has a greater conductivity than the developer.
6. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the aqueous regenerator organic solvent comprises an alcohol.
7. The combination of an aqueous developer and an aqueous regenerator of claim 6 wherein the organic solvent comprises benzyl alcohol, a phenoxyethanol, a phenoxypropanol, or combinations or derivatives thereof.
8. The combination of an aqueous developer and an aqueous regenerator of claim 7 wherein the organic solvent comprises esters of ethylene glycol or propylene glycol with acids containing alkyl groups of C 1-6 or ethers of ethylene glycol, diethylene glycol or propylene glycol containing alkyl groups of C 1-6 .
9. The regenerator of claim 1 wherein the organic solvent comprises 2-(2-ethoxyethoxy)ethanol.
10. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein said aqueous regenerator comprises between about 1 and about 12 weight percent organic solvent.
11. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein said aqueous regenerator comprises between about 3 and about 6 weight percent organic solvent.
12. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the second base has a K b of about 1 or greater.
13. The combination of an aqueous developer and an aqueous regenerator of claim 1 comprising between about 0.1 and about 5.0 weight percent of the second base.
14. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the second base comprises a hydroxide.
15. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the second base comprises a metal hydroxide.
16. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the second base comprises sodium, lithium or potassium hydroxide.
17. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the second base comprises one or more bases wherein the K b of the bases is greater than the K b of the first base.
18. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein said aqueous regenerator comprises a total of between about 4 and about 20 weight percent dispersing agent.
19. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein said aqueous regenerator comprises comprising a total of between about 7 and about 15 weight percent dispersing agent.
20. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein said aqueous regenerator comprises a plurality of dispersing agents.
21. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the aqueous regenerator dispersing agent comprises a surfactant.
22. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the aqueous regenerator dispersing agent comprises an anionic, cationic, nonionic, or amphoteric surfactant or a combination thereof.
23. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the aqueous regenerator dispersing agent comprises an organic sulfate or sulfonate.
24. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the aqueous regenerator dispersing agent comprises an alkali metal alkyl sulfate, an alkali metal alkylnaphthalenesulfonate, or an alkali metal alkylbenzene sulfonate.
25. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the aqueous regenerator dispersing agent comprises sodium octyl sulfate, sodium methylnaphthalenesulfonate, sodium xylene sulfonate, sodium toluene sulfonate, or a combination thereof.
26. The regenerator of claim 1 wherein the dispersing agent comprises polyvinyl alcohol or polyvinyl pyrrolidone.
27. The combination of an aqueous developer and an aqueous regenerator of claim 1 further comprising a weak base that has a K b of between about 1×10 −2 to about 1×10 −5 .
28. The combination of an aqueous developer and an aqueous regenerator of claim 27 comprising between about 0.1 and about 5 weight percent of the weak base.
29. The combination of an aqueous developer and an aqueous regenerator of claim 27 wherein the weak base comprises an amine.
30. The combination of an aqueous developer and an aqueous regenerator of claim 27 wherein the weak base comprises monoethanolamine, diethanolamine, triethanolamine or combinations or derivatives thereof.
31. The combination of an aqueous developer and an aqueous regenerator of claim 27 wherein the weak base comprises sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, trisodium phosphate, tripotassium phosphate or combinations or derivatives thereof.
32. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein said aqueous regenerator further comprises a thickener, a conditioner, a preservative, a chelating agent, an anti-foaming agent, or combinations thereof.
33. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the pH of the aqueous regenerator is at least 0.7 higher than the pH of the aqueous developer.
34. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the pH of the aqueous regenerator is at least 1.0 higher than the pH of the aqueous developer.
35. The combination of an aqueous developer and an aqueous regenerator of claim 1 wherein the first base has a K b of between about 1×10 −2 to about 1×10 −5 and the second base has a K b of about 1 or greater.