Toner processes
View Patent ↗A toner process comprising mixing a colorant dispersion with a latex, a wax dispersion, and a coagulant, and wherein the polymer latex selected possesses a weight average molecular weight of from about 20,000 to about 55,000, a number average molecular weight of from about 5,000 to about 18,000, an onset glass transition temperature Tg of from about 40° C. to about 80° C., and a particle size distribution PSD of from about 50 to about 500 nanometers.
1. A toner process comprising mixing a colorant dispersion with a latex, a wax dispersion, and a single coagulant to form a mixture, wherein the coagulant is a polymetal halide, and wherein the polymer latex selected possesses a weight average molecular weight of from about 20,000 to about 55,000, a number average molecular weight of from about 5,000 to about 18,000, an onset glass transition temperature Tg of from about 40° C. to about 80° C., and a particle size distribution PSD of from about 50 to about 500 nanometers;
heating the mixture at a first temperature which is below the glass transition temperature of the latex to bring about aggregation;
heating the mixture at a second temperature which is above the glass transition temperature of the latex to enable coalescence;
lowering the pH of the mixture from about 9 to from 5 to 6.5 by the addition of an acid, wherein the acid is nitric, sulphuric, hydrochloric, citric, or acetic acid; and
cooling the mixture to about room temperature.
2. A process in accordance with claim 1 wherein said weight average molecular weight is from about 25,000 to about 45,000.
3. A process in accordance with claim 1 wherein said weight average molecular weight is from about 28,000 to about 40,000.
4. A process in accordance with claim 3 wherein said number average molecular weight is from about 8,000 to about 13,000.
5. A process in accordance with claim 4 wherein said particle size distribution PSD is from about 190 to about 260 nanometers.
6. A process in accordance with claim 1 wherein said weight average molecular weight is from about 28,000 to about 37,000.
7. A process in accordance with claim 6 wherein said number average molecular weight is from about 9,000 to about 12,000.
8. A process in accordance with claim 6 wherein said particle size distribution PSD is from about 180 to about 300 nanometers.
9. A process in accordance with claim 1 wherein said number average molecular weight is from about 6,000 to about 15,000.
10. A process in accordance with claim 1 wherein said onset glass transition temperature Tg is from about 45° C. to about 70° C.
11. A process in accordance with claim 1 wherein said onset glass transition temperature Tg is from about 48 to about 60° C.
12. A process in accordance with claim 1 wherein said particle size distribution PSD is from about 70 to about 400 nanometers.
13. A process in accordance with claim 1 wherein said particle size distribution PSD is from about 100 to about 350 nanometers.
14. A process in accordance with claim 1 wherein said particle size distribution PSD is from about 150 to about 300 nanometers.
15. A process in accordance with claim 1 wherein said polymer latex selected possesses a weight average molecular weight of about 33,000, a number average molecular weight of about 11,000, an onset glass transition temperature Tg of about 51° C., and a particle size distribution PSD of about 230 nanometers.
16. A process in accordance with claim 1 wherein said first temperature is from about 40° C. to about 70° C.
17. A process in accordance with claim 1 wherein said second heating is at a temperature of from about 80° C. to about 95° C.
18. A process in accordance with claim 1 wherein said first temperature is from about 35° C. to about 50° C., and said second temperature is from about 70° C. to about 98° C.
19. A process in accordance with claim 1 wherein the toner possesses a minimum fix temperature (MFT) of about 100° C. to about 180° C.
20. A process in accordance with claim 1 wherein the toner hot offset temperature (HOT) is from about 195° C. to about 250° C.
21. A process in accordance with claim 1 wherein said polymetal halide coagulant is a polymetal chloride.
22. A process in accordance with claim 1 wherein said polymer is selected from the group comprised of poly(styrene-butadiene), poly(methylstyrene-butadiene), poly(methyl methacrylate-butadiene), poly(ethyl methacrylate-butadiene), poly(propyl methacrylate-butadiene), poly(butyl methacrylate-butadiene), poly(methyl acrylate-butadiene), poly(ethyl acrylate-butadiene), poly(propyl acrylate-butadiene), poly(butyl acrylate-butadiene), poly(styrene-isoprene), poly(methylstyrene-isoprene), poly(methyl methacrylate-isoprene), poly(ethyl methacrylate-isoprene), poly(propyl methacrylate-isoprene), poly(butyl methacrylate-isoprene), poly(methyl acrylate-isoprene), poly(ethyl acrylate-isoprene), poly(propyl acrylate-isoprene), poly(butyl acrylate-isoprene), poly(styrene-propyl acrylate), poly(styrene-butyl acrylate), poly(styrene-butadiene-acrylic acid), poly(styrene-butadiene-methacrylic acid), poly(styrene-butadiene-acrylonitrile-acrylic acid), poly(styrene-butyl acrylate-acrylic acid), poly(styrene-butyl acrylate-methacrylic acid), poly(styrene-butyl acrylate-acrylononitrile), poly(styrene-butyl acrylate-acrylononitrile-acrylic acid), poly(styrene-butadiene-β-carboxyethyl acrylate), poly(styrene-butadiene-acrylonitrile-β-carboxyethyl acrylate), poly(styrene-butyl acrylate-β-carboxyethyl acrylate), and poly(styrene-butyl acrylate-acrylononitrile-β-carboxyethyl acrylate).
23. A process in accordance with claim 1 wherein said polymetal halide coagulant is selected from the group consisting of a polyaluminum chloride, a polyaluminum sulfosilicate, and a polyaluminum sulfate.
24. A process in accordance with claim 1 wherein said wax is selected in an amount of from about 5 to about 20 weight percent.
25. A process in accordance with claim 1 wherein said colorant is a cyan, a magenta, a yellow, a black, or mixtures thereof.
26. A process in accordance with claim 1 wherein said colorant is a carbon black.
27. A process in accordance with claim 1 wherein said colorant is a pigment, or a dye.
28. A process in accordance with claim 1 wherein the first temperature is from about 45° C. to about 60° C., and wherein the second temperature is from about 80° C. to about 95° C., and wherein said coagulant is a polyaluminum halide.
29. A process in accordance with claim 1 wherein said latex polymer has a static yield stress of from about 0.05 to about 3 dynes per cm 2 , and a viscosity of from about 5 to about 35 centipoises.
30. A process in accordance with claim 29 wherein the toner product possesses a volume average particle size distribution index GSDv of equal to or less than about 1.27, a number average particle size distribution index GSDn of equal to or less than about 1.30, a low number average particle size index GSDn 50/16 of equal to or less than about 1.32, and a ratio of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDn of from about 0.93 to about 1.
31. A process in accordance with claim 30 wherein the viscosity of the polymer latex is at a shear rate of from about 0.1 s −1 to about 10 s −1 and wherein said viscosity is measured at a temperature of from about 23° C. to about 27° C.
32. A process in accordance with claim 1 wherein the latex polymer has a gel content of from about 0.5 to about 5 weight percent, a polymer melt flow index (MFI) of from about 20 to about 45 grams/10 minutes at from about 115° C. to about 145° C., a crosslinking molecular weight M c of from about 12,000 to about 200,000, and a crosslinking density M e of from about 1.2×10 −9 to about 2×10 −7 /Kmole.
33. A process comprising heating a mixture of a colorant dispersion with a latex, a wax dispersion, and a single coagulant, wherein the coagulant is a polymetal halide, and wherein the polymer latex selected possesses a weight average molecular weight of from about 20,000 to about 55,000, a number average molecular weight of from about 5,000 to about 20,000, and an onset glass transition temperature Tg of from about 40° C. to about 80° C.; wherein said heating comprises a first and second heating, wherein said second heating is above the temperature of said first heating, the first heating brings about aggregation, and the second heating enables coalescence;
lowering the pH of the mixture from about 9 to from 5 to 6.5 by the addition of an acid, wherein the acid is nitric, sulphuric, hydrochloric, citric, or acetic acid; and
cooling the mixture to about room temperature.
34. A process in accordance with claim 33 wherein said polymer possesses a static yield stress of from about 0.05 to about 3 dyne/cm 2 , a viscosity of from about 5 to about 35 centipoises (cps), and wherein the toner product possesses a volume average particle size distribution index GSDv of equal to or less than about 1.27, a number average particle size distribution index GSDn of equal to or less than about 1.30, a low number average particle size index GSDn 50/16 of equal to or less than about 1.32, and a ratio of the volume average particle size distribution index GSDv to a number average particle size distribution index GSDn of from about 0.93 to about 1.
35. A toner process comprising
mixing a colorant dispersion with a latex, a wax dispersion, and a polymetal halide coagulant to form a mixture, wherein the polymer latex selected possesses a weight average molecular weight of from about 20,000 to about 55,000, a number average molecular weight of from about 5,000 to about 18,000, an onset glass transition temperature Tg of from about 40° C. to about 80° C., and a particle size distribution PSD of from about 50 to about 500 nanometers, and wherein said polymer possesses a static yield stress of from about 0.05 to about 3 dynes/cm 2 , and a viscosity of from about 5 to about 35 centipoises (cps);
heating the mixture at a first temperature which is below the glass transition temperature of the latex to bring about aggregation;
heating the mixture at a second temperature which is above the glass transition temperature of the latex to enable coalescence;
lowering the pH of the mixture from about 9 to from 5 to 6.5 by the addition of an acid, wherein the acid is nitric, sulphuric, hydrochloric, citric, or acetic acid; and
cooling the mixture to about room temperature to obtain a toner product, wherein the toner product resulting possesses a volume average particle size distribution index GSDv of equal to or less than about 1.27, a number average particle size distribution index GSDn of equal to or less than about 1.30, a low number average particle size index GSDn 50/16 of equal to or less than about 1.32, and a ratio of the volume average particle size distribution index GSDv to the number average particle size distribution index GSDn of from about 0.93 to about 1.
36. A process in accordance with claim 35 wherein the toner resulting possesses a GSDv of about 1.19, a GSDn of about 1.22, a GSDn 50/16 of about 1.25, and a GSDv/GSDn ratio of about 0.975, and wherein there was selected as said coagulant a polyaluminum chloride.
37. A process in accordance with claim 35 wherein the toner resulting possesses a GSDv of about 1.20, a GSDn of about 1.23, a GSDn 50/16 of about 1.24, and a GSDv/GSDn ratio of about 0.976, and wherein there is selected as said coagulant a polyaluminum halide.