Surfactant free toner processes

• US 5,916,725 A
• Filed: 01/13/1998
• Issued: 06/29/1999
• 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., Ong, Beng S., Mychajlowskij, Walter, Patel, Raj D., Foucher, Daniel A.
• Primary Examiner(s): GOODROW, JOHN L
• Application Number:
  US09/006,299
• Time in Patent Office: 532 Days
• Field of Search: 430/137, 523/334, 523/335
• 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 9/0819 characterised by the dimensions of the particles
• CPC Class Codes: G03G 9/08755 Polyesters

Abstract

A process for the preparation of toner comprising mixing an amine, an emulsion latex containing sulfonated polyester resin, and a colorant dispersion, heating the resulting mixture, and optionally cooling.

Claims

1. A process for the preparation of toner comprising mixing an amine, an emulsion latex containing sulfonated polyester resin, and a colorant dispersion, heating the resulting mixture, and optionally cooling.

2. A process in accordance with claim 1 wherein said latex contains water and suspended therein a sodio sulfonated polyester resin of from about 5 to about 500 nanometers in size diameter, wherein said colorant is stabilized by submicron sodio sulfonated polyester resin, and thereafter adding to the mixture an amine, and wherein cooling is accomplished.

3. A process in accordance with claim 2 wherein said (i) sodio sulfonated polyester resin is prepared by heating said resin in water at a temperature of from about 65°

C. to about 90°

C.;

(ii) thereafter adding said colorant dispersion, wherein the colorant dispersion is stabilized by said submicron sodio sulfonated polyester resin particles, to said latex mixture with shearing, followed by the addition of said amine and water until there results an increase in the latex viscosity of from about 2 centipoise to about 100 centipoise, cooling, and heating the resulting mixture at a temperature of from about 45°

C. to about 80°

C. thereby enabling continuous aggregation and coalescence of particles of resin and colorant, resulting in toner particles of from about 2 to about 20 microns in volume average diameter; and

(iii) quenching, or cooling the product mixture followed by filtration and drying.

4. A process in accordance with claim 3 the colorant dispersion contains a pigment, and wherein the pigment is stabilized by said submicron sodio sulfonated polyester resin, and which resin is in the size range of from about 50 to about 250 nanometers, and wherein said shearing in (ii) is completed by homogenizing at from about 1,000 revolutions per minute to about 10,000 revolutions per minute, at a temperature of from about 25°

C. to about 35°

C., and for a duration of from about 1 minute to about 120 minutes.

5. A process in accordance with claim 3 wherein the dispersion of (ii) is accomplished by microfluidization in a microfluidizer, or in nanojet for a duration of from about 1 minute to about 120 minutes.

6. A process in accordance with claim 3 wherein shearing or homogenization is accomplished by homogenizing at from about 1,000 revolutions per minute to about 10,000 revolutions per minute for a duration of from about 1 minute to about 120 minutes.

7. A process in accordance with claim 1 wherein the resin is (i) a polyester of poly(1,2-propylene-sodio 5-sulfoisophthalate), poly(neopentylene-sodio 5-sulfoisophthalate), poly(diethylene-sodio 5-sulfoisophthalate), copoly(1,2-propylene-sodio 5-sulfoisophthalate)-copoly-(1,2-propylene-terephthalatephthalate), copoly(1,2-propylene-diethylene sodio 5-sulfoisophthalate)-copoly-(1,2-propylene-diethylene-terephthalatephthalate), copoly(ethylene-neopentylene-sodio 5-sulfoisophthalate)-copoly-(ethylene-neopentylene-terephthalatephthalate), or copoly(propoxylated bisphenol A)-copoly-(propoxylated bisphenol A-sodio 5-sulfoisophthalate).

8. A process in accordance with claim 3 wherein the resin of (i) is a polyester of poly(1,2-propylene-sodio 5-sulfoisophthalate), poly(neopentylene-sodio 5-sulfoisophthalate), poly(diethylene-sodio 5-sulfoisophthalate), copoly(1,2-propylene-sodio 5-sulfoisophthalate)-copoly-(1,2-propylene-terephthalatephthalate), copoly(1,2-propylene-diethylene sodio 5-sulfoisophthalate)-copoly-(1,2-propylene-diethylene-terephthalatephthalate), copoly(ethylene-neopentylene-sodio 5-sulfoisophthalate)-copoly-(ethylene-neopentylene-terephthalatephthalate), or copoly(propoxylated bisphenol A)-copoly-(propoxylated bisphenol A-sodio 5-sulfoisophthalate).

9. A process in accordance with claim 2 wherein the colorant is carbon black, cyan, yellow, magenta, and mixtures thereof.

10. A process in accordance with claim 2 wherein the resin utilized is from about 0.01 to about 0.2 micron in volume average diameter, and the colorant particles are from about 0.01 to about 500 nanometers in volume average diameter.

11. A process in accordance with claim 2 wherein the toner particles isolated are from about 2 to about 15 microns in volume average diameter, and the geometric size distribution thereof is from about 1.15 to about 1.35.

12. A process in accordance with claim 2 wherein there is added to the surface of the formed toner 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 particles.

13. A process in accordance with claim 2 wherein the toner obtained after cooling is from about 3 to about 15 microns in volume average diameter, and the geometric size distribution thereof is from about 1.15 to about 1.30.

14. A process in accordance with claim 3 wherein resin Tg is from about 50°

C. to about 65°

C.

19. A process in accordance with claim 3 wherein in (ii) the colorant dispersion is generated with a microfluidizer at from about 75°

C. to about 85°

C. for a duration of from about 1 hour to about 3 hours, and wherein subsequent to (iv) the toner compositions or particles resulting are (v) cooled to about 25°

C., followed by washing and drying.

20. A process in accordance with claim 2 wherein the amine is present in an amount of about 1 to about 10 weight percent based on the total solids.

21. A process in accordance with claim 1 wherein the amine is triethylamine, tripropylamine, 2-methyl-1,5-pentanediamine, 1,4-diaminobutane, 1,8-diaminooctane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,3-diaminopropane, 1,2-diaminopropane, or 1,3-diamino-2-hydroxypropane.

22. A process in accordance with claim 2 wherein the amine is triethylamine, tripropylamine, 2-methyl-1,5-pentanediamine, 1,4-diaminobutane, 1,8-diaminooctane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,3-diaminopropane, 1,2-diaminopropane, or 1,3-diamino-2-hydroxypropane.

23. A process in accordance with claim 1 wherein the amine is an aliphatic amine.

24. A process in accordance with claim 1 wherein the amine is 2-methyl-1,5-pentanediamine.

25. A process in accordance with claim 3 wherein the amine is 2-methyl-1,5-pentanediamine.

26. A process in accordance with claim 1 wherein the amine is selected in an amount of from about 0.5 to about 5 weight percent.

27. A process in accordance with claim 1 wherein the amine is selected in an amount of from about 1 to about 3 weight percent.

15. A surfactant free process for the preparation of toner, and which process comprises providing, or generating an emulsion latex comprised of sodio sulfonated polyester resin particles of less than about 0.2 micron in size diameter by heating said resin in water at a temperature of from about 15°

C. to about 30°

C. above the resin glass transition temperature;

mixing with a colorant dispersion wherein the dispersion is comprised of colorant and submicron sodio sulfonated resin particles of a size less than about 0.2 micron and which resin particles are coated on the colorant;

followed by the addition of an amine of from about 1 to about 2 weight percent in water until a slight increase in viscosity of from about 2 centipoise to about 100 centipoise results;

heating the resulting mixture at a temperature of from about 45°

C. to about 80°

C. thereby enabling aggregation and coalescence of particles of resin and colorant in a continuous manner, resulting in toner particles of from about 2 to about 20 microns in volume average diameter, and thereafter cooling the product mixture, followed by washing and drying.

16. A process for the preparation of toner comprising mixing an emulsion latex comprised of sodio sulfonated polyester resin particles and a colorant dispersion, and wherein the colorant is of submicron size and is stabilized by submicron resin particles, followed by the addition of an amine;

and heating the resulting mixture thereby causing aggregation and coalescence.

17. A process in accordance with claim 16 wherein subsequent to coalescence the toner product mixture is cooled, followed by isolation, washing and drying.

18. A process in accordance with claim 16 wherein the toner product mixture is cooled to about 25°

C.

28. A surfactant free process for the preparation of toner, which process comprises admixing an amine, an emulsion latex containing a sulfonated polyester resin and a colorant dispersion, heating the resulting components, and optionally cooling.

29. A process in accordance with claim 28 wherein cooling is accomplished.

30. A process in accordance with claim 28 wherein the amine is an aliphatic amine.

31. A process in accordance with claim 28 wherein the amine is triethylamine, tripropylamine, 2-methyl-1,5-pentanediamine, 1,4-diaminobutane, 1,8-diaminooctane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,3-diaminopropane, 1,2-diaminopropane, or 1,3-diamino-2-hydroxypropane.

32. A process in accordance with claim 28 wherein the amine is 2-methyl-1,5-pentanediamine.