Toner processes

• US 5,840,462 A
• Filed: 01/13/1998
• Issued: 11/24/1998
• 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., Patel, Raj D., Kmiecik-Lawrynowicz, Grazyna E., Foucher, Daniel A.
• Primary Examiner(s): MARTIN, ROLAND E
• Application Number:
  US09/006,622
• Time in Patent Office: 315 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
• CPC Class Codes: G03G 9/09 Colouring agents for toner particles

Abstract

A process for the preparation of toner which involves

i) flushing a colorant into a sulfonated polyester resin;

ii) mixing an organic soluble dye with the colorant polyester resin of i);

iii) dispersing the resulting mixture into warm water thereby enabling the formation of submicron particles;

iv) allowing the resulting solution to cool below about, or about equal to the glass transition temperature of said sulfonated polyester resin;

v) adding an alkali halide solution and heating; and optionally

vi) recovering said toner, followed by washing and drying.

Claims

1. A process for the preparation of toner which comprises

i) flushing a pigment into a sulfonated polyester resin;

ii) mixing an organic soluble dye with the colorant polyester resin of i);

iii) dispersing the resulting mixture into warm water thereby enabling the formation of submicron particles;

iv) allowing the resulting solution to cool below about, or about equal to the glass transition temperature of said sulfonated polyester resin;

v) adding an alkali halide solution and heating; and

optionally

vi) recovering said toner, followed by washing and drying.

2. A process in accordance with claim 1 wherein

i) said sulfonated polyester resin has a sulfonation amount of from about 2.5 and about 20 mol percent based on the repeat unit of the polymer;

ii) said mixing is accomplished by melt mixing an organic soluble dye into the pigment polyester resin of i);

iii) wherein said water is at a temperature of from about 40°

C. to about 95°

C., and which dispersion is 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 stable submicron particles, and which particles are of a volume average diameter of from about 5 to about 150 nanometers;

iv) allowing the resulting solution to cool to from about 5 to about 10°

C. below the glass transition temperature of said sulfonated polyester resin;

v) adding an alkali halide solution, which solution contains from about 0.5 percent to about 5 percent by weight of water, followed by stirring and heating from about 25°

C. to a temperature below the sulfonated polyester resin Tg to induce aggregation of said submicron particles to obtain toner size particles of from about 1 to about 20 microns in volume average diameter;

or subsequently stirring and heating to a temperature below the resin Tg, followed by the addition of alkali metal halide until the desired toner size of from about 1 to about 20 microns in volume average diameter is achieved; and

vi) recovering said toner by filtration, followed by washing and drying, and thereafter optionally blending charge enhancing additives and flow additives.

5. A process in accordance with claim 1 wherein said sulfonated polyester resin is in a molten form and is heated prior to flushing the pigment into the sulfonated polyester resin to obtain a flushed pigmented sulfonated polyester resin.

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

9. A process in accordance with claim 1 wherein the alkali metal 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.

10. A process in accordance with claim 1 wherein said sulfonated polyester resin is heated at a temperature of from about 175°

to about 200°

C., and wherein the pigment to be flushed is added to said molten sulfonated polyester resin followed by vigorous stirring for a period of from about 10 minutes to about 120 minutes.

13. A process in accordance with claim 1 wherein the toner particle size is from 3 to about 7 microns, and wherein said toner is filtered, washed with water and dried.

14. A process in accordance with claim 1 wherein the colorant pigment is carbon black, magnetite, cyan, yellow, magenta, or mixtures thereof.

15. A process in accordance with claim 1 wherein the organic soluble dye is black, red, blue, yellow, or mixtures thereof.

16. A process in accordance with claim 1 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.

17. A process in accordance with claim 1 wherein said sulfonated pigmented polyester is added to hot water at a temperature of from about 40°

C. to about 95°

C. thereby resulting in a stable dispersion containing submicron sized particles; and

wherein the particle size of the dispersed sulfonated polyester is from about 5 to about 200 nanometers.

18. A process in accordance with claim 1 wherein the polyester is random sulfonated copolyester comprised of, on a mol percent basis of the polymer repeat unit, about 0.465 terephthalate/0.035 sodium sulfoisophthalate0.475 1,2-propanediol/0.025 diethylene glycol, and which polyester possesses an M_w of about 3,160, an M_n of about 1,500, and a Tg of about 55°

C.

19. A process in accordance with claim 1 wherein the pigment is carbon black, magnetite, cyan, yellow, magenta, or mixtures thereof, wherein the organic soluble dye is 2 to about 15 microns in volume average diameter.

3. A process for the preparation of toner comprised of

i) flushing a pigment and organic soluble dye into a sulfonated polyester resin, and which resin has a degree of sulfonation of from between about 2.5 and about 20 mol percent based on the repeat unit of the polymer;

ii) dispersing the resulting sulfonated pigment polyester resin into warm water, which water is at a temperature of from about 40°

C. to about 95°

C. 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 stable toner sized submicron particles, and which particles are of a volume average diameter of from about 5 to about 150 nanometers;

iii) allowing the resulting solution to cool to from about 5°

C. to about 10°

C. below the glass transition temperature of said pigment sulfonated polyester resin;

iv) adding an alkali halide solution, which solution contains from about 0.5 percent to about 5 percent by weight of water, followed by stirring and heating from about room temperature, about 25°

C., to a temperature below the resin Tg to induce aggregation of said submicron particles to obtain toner size particles of from about 2 to about 20 microns in volume average diameter;

or subsequently stirring and heating to a temperature below the resin Tg, followed by the addition of alkali metal halide until the desired toner size of from about 2 to about 20 microns in volume average diameter is achieved; and

optionally

v) recovering said toner, washing and drying said toner.

4. A process in accordance with claim 3 wherein for i) there is accomplished the simultaneous flushing of pigment and organic soluble dye, or sequential flushing of said pigment then subsequently said organic soluble dye into said sulfonated polyester resin;

wherein said water is at a temperature of from about 40°

C. to about 75°

C., and said dispersing is by a high speed shearing polytron device operating at speeds of from about 1,000 to about 3,000 revolutions per minute thereby enabling the formation of stable sized submicron particles, and which particles are of a volume average diameter of from about 50 to about 100 nanometers;

adding said alkali halide solution, and accomplishing said heating to induce aggregation of said submicron pigmented particles to obtain toner size particles of from about 3 to about 10 microns in volume average diameter; and

recovering, washing, and drying said toner.

6. A process in accordance with claim 3 wherein said sulfonated polyester resin is in a molten form and is heated prior to the simultaneous flushing of the pigment and organic soluble dye into the sulfonated polyester resin to obtain said flushed pigment sulfonated polyester resin.

7. A process in accordance with claim 6 wherein an organic soluble dye is extruded into said flushed pigment sulfonated polyester resin by heating said resin to above the resin Tg and introducing the organic soluble dye by an extrusion process.

11. A process in accordance with claim 3 wherein the pigment and the organic soluble dye to be flushed are added simultaneously to said molten sulfonated polyester resin followed by vigorous stirring for a period of from about 10 minutes to about 120 minutes.

12. A process in accordance with claim 11 wherein said pigment sulfonated polyester resin mixture resulting is cooled, followed by water decantation, and vacuum drying.

20. A process for the preparation of toner comprised of flushing a pigment into a polyester resin;

mixing the resulting polyester resin with an organic soluble dye, and thereafter dispersing the resulting dye-pigmented polyester resin into warm water;

cooling the resulting solution;

adding an alkali halide solution, followed by heating.

21. A process in accordance with claim 20 wherein subsequent to heating cooling is accomplished and said toner is isolated, washed, and dried;

and wherein said warm water is at a temperature of from about 40°

C. to about 95°

C. enabling the formation of submicron particles, and which particles are of a volume average diameter of from about 5 to about 150 nanometers;

said cooling is from about 5°

C. to about 10°

C. below the glass transition temperature of said polyester resin, and which polyester resin is a sulfonated polyester;

said alkali halide solution contains from about 0.5 percent to about 5 percent by weight of water;

subsequently stirring and then heating from room temperature to a temperature below the resin Tg to induce aggregation of said submicron pigmented particles to obtain toner size particles of from about 1 to about 20 microns in volume average diameter.