Toner processes

• US 5,863,698 A
• Filed: 04/13/1998
• Issued: 01/26/1999
• Est. Priority Date: 04/13/1998
• Status: Expired due to Term

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Smith, Paul F., Hu, Nan-Xing, Ong, Beng S., Patel, Raj D., Hopper, Michael A., Dutoff, Beverly C.
• Primary Examiner(s): MARTIN, ROLAND E
• Application Number:
  US09/058,733
• Time in Patent Office: 288 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 9/09741 cationic

Abstract

A process for the preparation of toner comprising mixing a colorant containing a surfactant and a latex emulsion, and wherein the latex emulsion contains resin and a nonionic hydrolyzable surfactant, and wherein said surfactant is of the Formulas (I) or (II), or optionally mixtures thereof ##STR1## wherein R¹ is a hydrophobic aliphatic, or hydrophobic aromatic group; R² is selected from the group consisting of hydrogen, alkyl, aryl, alkylaryl, and alkylarylalkyl; R³ is hydrogen or alkyl; A is a hydrophilic polymer chain, and m represents the number of A segments; heating below about the resin latex glass transition temperature, followed by the addition of an anionic stabilizer, thereafter heating above about the resin glass transition temperature, and adjusting the pH of the resulting mixture of resin and colorant particles suspended in an aqueous phase containing anionic surfactant, cationic surfactant and nonionic hydrolyzable surfactant, wherein said pH is increased from about 1.7 to about 2.5 to about 6 to about 12 by adding a base during the heating above about said resin glass transition temperature wherein coalescence is being accomplished.

Claims

1. A process for the preparation of toner comprising mixing a colorant containing a surfactant and a latex emulsion, and wherein the latex emulsion contains resin and a nonionic hydrolyzable surfactant, and wherein said surfactant is of the Formulas (I) or (II), or optionally mixtures thereof ##STR10## wherein R¹ is a hydrophobic aliphatic, or hydrophobic aromatic group;

R² is selected from the group consisting of hydrogen, alkyl, aryl, alkylaryl, and alkylarylalkyl;

R³ is hydrogen or alkyl;

A is a hydrophilic polymer chain, and m represents the number of A segments;

heating below about or about equal to the resin latex glass transition temperature, followed by the addition of an anionic stabilizer, thereafter heating above about or about equal to the resin glass transition temperature, and adjusting the pH of the resulting mixture of resin and colorant particles suspended in an aqueous phase containing anionic surfactant, cationic surfactant and nonionic hydrolyzable surfactant, wherein said pH is increased or about equal to about 6 to about 12 by adding a base during the heating above about said resin glass transition temperature wherein coalescence is being accomplished.

2. A process in accordance with claim 1 wherein heating below about the resin latex glass transition temperature forms loosely bound particles that are electrostatically held together and wherein heating above about the resin glass transition temperature coalesces the aggregates;

and subsequent to adjusting said pH the toner formed is isolated and dried.

3. A process in accordance with claim 1 herein the base is added during the second half of the coalescence about 2.5 to about 4.5 hours.

4. A process in accordance with claim 1 wherein said base is added about 8 to about 14 hours after the coalescence, or heating about above the latex resin glass transition temperature is initiated.

5. A process in accordance with claim 1 wherein the base is an alkali metal hydroxide.

6. A process in accordance with claim 1 wherein the base is sodium hydroxide, potassium hydroxide, or ammonium hydroxide.

7. A process in accordance with claim 1 wherein after the addition of base there results a pH of the reactor mixture of about 6 to about 12 increased from about 1.7 to about 2.5.

8. A process in accordance with claim 7 wherein there results a pH of about 7 to about 11.5.

9. A process in accordance with claim 1 wherein m is a number of from about 5 to about 60, or from about 10 to about 50, and wherein the weight average molecular weight of A is from about 100 to about 3,000.

10. A process in accordance with claim 1 wherein R¹ is methylphenyl, ethylphenyl, propylphenyl, butylphenyl, pentylphenyl, hexylphenyl, octylpenyl, or nonylphenyl;

R² is hydrogen, methyl, ethyl, methylphenyl, or propyl;

R³ is methyl, ethyl, propyl, or butyl; and

A is polyoxyalkylene glycol, polyethylene glycol, or polypropylene glycol.

11. A process in accordance with claim 1 wherein R¹ is an alkylaryl group, or an alkylaryl group with a substituent of fluorine, chlorine, or bromine, wherein alkyl contains from about 2 to about 30 carbon atoms;

R² alkyl contains from 1 to about 30 carbon atoms;

R³ alkyl contains from 1 to about 3 carbon atoms; and

wherein A is a hydrophilic poly(oxyalkylene glycol) selected from the group consisting of a branched, block or homopolymeric polyoxyalkylene glycol derived from alkylene oxides with from about 2 to about 4 carbon atoms.

12. A process in accordance with claim 1 wherein the latex resin is generated from the polymerization of monomers to provide a latex emulsion with submicron resin particles in the size range of from about 0.05 to about 0.3 micron in volume average diameter and wherein the latex contains an anionic surfactant, a water soluble initiator and a chain transfer agent.

13. A process in accordance with claim 1 wherein the colorant dispersion comprises submicron pigment particles in the size range of from about 0.05 to 0.3 microns in volume average diameter stabilized by a nonionic surfactant.

14. A process in accordance with claim 1 wherein said cleavable surfactant is selected in an amount of from about 0.05 to about 10 weight percent based on the amount of monomer selected to generate said resin latex.

15. A process in accordance with claim 2 wherein the aggregation temperature is from about 45 degrees Centigrade to about 55 degrees Centigrade, and wherein the coalescence or fusion temperature is from about 85 degrees Centigrade to about 95 degrees Centigrade.

16. A process in accordance with claim 1 wherein said colorant is a pigment, or a dye.

17. A process in accordance with claim 1 wherein the surfactant utilized in the colorant dispersion is a cationic surfactant, and an anionic surfactant is present in the latex mixture, wherein the heating below is accomplished at a temperature of about 15 degrees Centigrade to about 5 degrees Centigrade below the Tg of the latex resin for a duration of from about 0.5 hour to about 3 hours;

and wherein the heating above or coalescence of the components of aggregates for the formation of integral toner particles comprised of colorant, and resin is accomplished at a temperature of from about 85 degrees Centigrade to about 95 degrees Centigrade for a duration of from about 1 hour to about 5 hour, wherein the pH of the mixture of resin and colorant particles suspended in an aqueous phase is increased from about 2.2 to about 8.5 by the addition of said base.

18. A process in accordance with claim 1 wherein the latex resin, or polymer is selected from the group consisting of poly(styrene-alkyl acrylate), poly(styrene-1,3-diene), poly(styrene-alkyl methacrylate), poly(styrene-alkyl acrylate-acrylic acid), poly(styrene-1,3-diene-acrylic acid), poly(styrene-alkyl methacrylate-acrylic acid), poly(alkyl methacrylate-alkyl acrylate), poly(alkyl methacrylate-aryl acrylate), poly(aryl methacrylate-alkyl acrylate), poly(alkyl methacrylate-acrylic acid), poly(styrene-alkyl acrylate-acrylonitrile-acrylic acid), poly(styrene-1,3-diene-acrylonitrile-acrylic acid), and poly(alkyl acrylate-acrylonitrile-acrylic acid).

19. A process in accordance with claim 1 wherein the latex resin is selected from the group consisting 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), and 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), and poly(styrene-butyl acrylate-acrylononitrile-acrylic acid).

20. A process in accordance with claim 17 wherein the anionic surfactant is selected from the group consisting of sodium dodecyl sulfate, sodium dodecylbenzene sulfate and sodium dodecylnaphthalene sulfate.

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

22. A process in accordance with claim 1 wherein the toner particles isolated are from about 2 to about 10 microns in volume average diameter, and the particle size distribution thereof is from about 1.15 to about 1.26 of the total reaction mixture.

23. 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 particles.

24. A process in accordance with claim 1 wherein the hydrolyzable surfactant is selected from the group consisting of poly(ethylene glycol) methyl p-tert-octylphenyl phosphate, poly(ethylene glycol)-α

-methyl ether-ω

-methyl p-tert-octylphenyl phosphate, poly(ethylene glycol) methyl decylphenyl phosphate, poly(ethylene glycol)-α

-methyl ether-ω

-methyl dodecylphenyl phosphate, poly(ethyleneglycol) methyl dodecylphenyl phosphate, bis poly(ethylene glycol)-α

-methyl ether!-ω

-p-tert-octylphenyl phosphate, poly(ethylene glycol)-α

,ω

-methyl p-tert-octylphenyl phosphate, poly( ethylene glycol) ethyl p- tert-octylphenyl phosphate, poly(ethylene glycol)-α

-methyl ether-ω

-ethyl p-tert-octylphenyl phosphate, poly(ethylene glycol) phenyl p-tert-octylphenyl phosphate, poly(ethylene glycol)-α

-methyl ether-ω

-phenyl p-tert-octylphenyl phosphate, poly(ethylene glycol) tolyl p-tert-octylphenyl phosphate, poly(ethylene glycol)-α

-methyl ether-ω

-tolyl p-tert-octylphenyl phosphate, and poly(ethylene oxide-co-propylene oxide) methyl p-tert-octylphenyl phosphate, wherein the polymer chain contains from about 5 to about 50 repeating units or segments.

25. A process in accordance with claim 1 wherein said surfactant in the colorant containing a surfactant is an ionic surfactant.

26. A process in accordance with claim 1 wherein said surfactant in the colorant containing a surfactant is a cationic surfactant.

27. A process in accordance with claim 1 wherein said surfactant in the colorant containing a surfactant is comprised of a mixture of anionic, cationic, and nonionic surfactants.

28. A process for the preparation of toner comprising mixing a colorant containing a cationic surfactant and a latex emulsion, and wherein the latex emulsion contains resin and a nonionic hydrolyzable surfactant, and wherein said surfactant is of the Formulas (I) or (II), or optionally mixtures thereof ##STR11## wherein R¹ is a hydrophobic aliphatic, or hydrophobic aromatic group;

R² is selected from the group consisting of hydrogen, alkyl, aryl, alkylaryl, and alkylarylalkyl;

R³ is hydrogen or alkyl;

A is a hydrophilic polymer chain, and m represents the number of A segments;

heating below about or about equal to the resin latex glass transition temperature, followed by the addition of an anionic stabilizer, thereafter heating above about or about equal to the resin glass transition temperature, and adjusting the pH of the resulting mixture of resin and colorant particles suspended in an aqueous phase containing anionic surfactant, cationic surfactant and nonionic hydrolyzable surfactant, wherein said pH is increased or about equal to about 6 to about 12 by adding a base during the heating above about said resin glass transition temperature wherein coalescence is being accomplished.