Toner processes

• US 5,853,944 A
• Filed: 01/13/1998
• Issued: 12/29/1998
• Est. Priority Date: 01/13/1998
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Sacripante, Guerino G., Mychajlowskij, Walter, Patel, Raj D., Foucher, Daniel A.
• Primary Examiner(s): Martin, Roland
• Application Number:
  US09/006,612
• Time in Patent Office: 350 Days
• Field of Search: 430/137
• US Class Current: 430/137.14
• CPC Class Codes: G03G 9/0804 whereby the components are brought together in a liquid dispersing medium
• CPC Class Codes: G03G 9/08755 Polyesters

Abstract

A process for the preparation of toner with a first aggregation of sulfonated polyester, and thereafter a second aggregation with a colorant dispersion and an alkali halide.

Claims

1. A process for the preparation of toner, which process comprises a first aggregation of submicron sulfonated polyester in the presence of an alkali halide, and thereafter a second aggregation with a colorant dispersion and an alkali halide.

9. A process in accordance with claim 1 wherein the first aggregation is accomplished by heating below about the sulfonated polyester glass transition temperature.

15. A process in accordance with claim 1 wherein there is obtained a colored toner with a narrow GSD in the range of from about 1.18 to about 1.28.

16. A process in accordance with claim 1 wherein the alkali halide is beryllium chloride, beryllium bromide, beryllium iodide, magnesium chloride, magnesium bromide, magnesium iodide, calcium chloride, calcium bromide, calcium iodide, strontium chloride, strontium bromide, strontium iodide, barium chloride, barium bromide, or barium iodide;

and the concentration thereof is optionally in the range of from about 0.1 to about 5 weight percent.

22. A process in accordance with claim 1 wherein the halide is chloride, bromide, iodide, or fluoride.

2. A process for the preparation of toner, which process comprises a (1) first aggregation of dispersed submicron sulfonated polyester particles and thereafter a (2) second aggregation thereof with a colorant dispersion and an alkali halide, and wherein the first aggregation is accomplished by the mixing and heating of said sulfonated polyester and a dicationic salt, or alkali halide, and wherein said submicron is from about 5 to about 80 nanometers.

3. A process in accordance with claim 2 wherein the colorant is a pigment.

4. A process in a accordance with claim 2 wherein the colorant is a pigment or a dye, and the alkali halide is magnesium chloride.

6. A process in accordance with claim 2 wherein the colorant is a cyan, black, magenta, yellow dispersion or mixtures thereof with from about 20 to about 60 weight percent solids of colorant.

7. A process in accordance with claim 2 wherein the sulfonated polyester is of the formula ##STR3## wherein Y is an alkali metal, X is a glycol, and n and m represent the number of segments.

8. A process in accordance with claim 7 wherein the glycol is neopentyl glycol, ethylene glycol, propylene glycol, butylene glycol, propanediol, diethylene glycol, or mixtures thereof.

10. A process in accordance with claim 2 wherein the first aggregation is accomplished by increasing the ionic strength of the sulfonated polyester by the addition of a monocationic salt.

11. A process in accordance with claim 10 wherein the salt is sodium chloride.

12. A process in accordance with claim 2 wherein the sulfonated polyester is a dispersion comprised of from about 5 to about 30 weight percent solids, and the colorant dispersion contains from about 20 to about 50 weight percent of colorant.

13. A process in accordance with claim 2 wherein the sulfonated polyester has a degree of sulfonation of from about 2.5 to about 20 mol percent.

14. A process in accordance with claim 2 wherein the sulfonated polyester has a degree of sulfonation of from about 5 to about 10 mol percent.

17. A process in accordance with claim 2 wherein the toner particle size is from about 3 to about 7 microns in volume average diameter.

18. A process in accordance with claim 2 wherein said toner is isolated, filtered, washed with water, and dried.

19. A process in accordance with claim 2 wherein there is added to the surface of the formed toner of sulfonated polyester and colorant, metal salts, metal salts of fatty acids, silicas, metal oxides, or mixtures thereof, each in an amount of from about 0.1 to about 10 weight percent of the obtained toner.

20. A process in accordance with claim 2 wherein the particle size of the dispersed sulfonated polyester is from about 5 to about 200 nanometers.

21. A process in accordance with claim 2 wherein the polyester is random sulfonated copolyester comprised of, on a mol percent basis of the polymer repeat unit, approximately 0.47 of terephthalate/0.03 of sodium sulfoisophthalate/0.475 of 1,2 propanediol/0.025 of diethylene glycol, and which polyester possesses an M_w of about 3,790, an M_n of about 2,560, and a Tg of about 54.6°

C.

26. A process in accordance with claim 2 wherein the alkali halide is magnesium chloride.

27. A process in accordance with claim 2 wherein there is further added a mono cationic salt.

28. A process in accordance with claim 27 wherein the mono cationic salt is sodium chloride.

29. A process in accordance with claim 2 wherein said submicron is from about 5 to about 80 nanometers, and said colorant in said dispersion is of a size of from about 50 to about 150 nanometers.

30. A process in accordance with claim 2 further including a third aggregation of the resulting mixture in the presence of an alkali halide.

5. A process for the preparation of toner, which process comprises a first aggregation of sulfonated polyester and thereafter a second aggregation with a colorant dispersion and an alkali halide, and wherein

(i) said sulfonated polyester is dispersed in water, which water is at a temperature of from about 40°

C. to about 95°

C., or between about 5°

C. to about 15°

C. above the polyester polymer glass transition, and which dispersing is accomplished by a high speed shearing polytron device operating at speeds of from about 100 to about 5,000 revolutions per minute thereby enabling the formation of submicron sized particles;

(ii) accomplishing an initial aggregation of the dispersed sulfonated polyester particles to larger submicron particles of from about 50 to about 200 nanometers by the addition of a solution containing a monocationic salt, a dicationic salt, or an electrolyte solution;

(iii) adding a colorant dispersion with from about 20 to about 50 weight percent of predispersed colorant in water with a mean colorant size in the range of from about 50 to about 150 nanometers, and which dispersion is further diluted with deionized water, and controlling the aggregation rate by the dropwise addition of said salt, or said electrolyte, and then heating near the aggregation temperature of from about 40°

C. to about 60°

C. until toner sized aggregates are obtained as monitored by both optical microscopy and Coulter Counter particle size measurements;

cooling; and

(iv) recovering said toner composition, or said toner particles;

(v) drying said toner particles; and

(vi) optionally adding to said dry toner particles, or toner of resin and colorant, wax, charge additives, and surface flow additives.

23. A process for the preparation of toner which comprises a (1) first aggregation of submicron resin particles in the presence of an alkali halide, and thereafter a (2) second aggregation thereof with a colorant and an alkali halide, and wherein the first aggregation is accomplished by the heating of said resin and said alkali halide.

24. A process in accordance with claim 23 wherein said micron is about 1 micron or less.

25. A process in accordance with claim 23 wherein said resins are sulfonated polyester particles of (1) are submicron in size, and wherein said submicron is from about 5 to about 80 nanometers, and heating involves a first heating to enable aggregation, and a second heating to enable coalescence of the toner aggregates formed.