CURABLE TONER COMPOSITIONS AND PROCESSES

• US 20080199797A1
• Filed: 02/16/2007
• Published: 08/21/2008
• Est. Priority Date: 02/16/2007
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: MCANENEY, T. Brian, ZWARTZ, Edward G., SACRIPANTE, Guerino G., PUDWELL, Jessica E.
• Granted Patent: US 8,039,187 B2
• Time in Patent Office: Days
• US Class Current: 430/104
• CPC Class Codes: G03G 9/0804 whereby the components are brought together in a liquid dispersing medium
• CPC Class Codes: G03G 9/0806 whereby chemical synthesis of at least one of the toner components takes place
• CPC Class Codes: G03G 9/08755 Polyesters
• CPC Class Codes: G03G 9/08793 Crosslinked polymers
• CPC Class Codes: G03G 9/08795 characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants
• CPC Class Codes: G03G 9/08797 characterised by their physical properties, e.g. viscosity, solubility, melting temperature, softening temperature, glass transition temperature
• CPC Class Codes: G03G 9/09733 Organic compounds G03G9/08782 takes precedence
• CPC Class Codes: G03G 9/09758 comprising a heterocyclic ring
• CPC Class Codes: G03G 9/09775 containing atoms other than carbon, hydrogen or oxygen G03G9/09741 - G03G9/09766 take precedence

Abstract

An emulsion aggregation toner composition includes toner particles including: an unsaturated polymeric resin, selected from amorphous resins, crystalline resins, and mixtures thereof; an optional colorant; an optional wax; an optional coagulant; and a photo initiator capable of initiating crosslinking of said unsaturated polymeric resin.

Claims

1. An emulsion aggregation toner composition comprising toner particles comprising:

an unsaturated polymeric resin, wherein the unsaturated polyester resin is selected from the group consisting of amorphous resins, crystalline resins, and mixtures thereof;

an optional colorant;

an optional wax;

an optional coagulant; and

a photo initiator capable of initiating crosslinking of said unsaturated polymeric resin.

2. The toner composition of claim 1, wherein the polymeric resin is a polyester resin.

3. The toner composition of claim 1, wherein the polymeric resin is an unsaturated amorphous polyester resin selected from the group consisting of copoly (butylene-terephthalate)-copoly( butulene-fumarate), copoly (butylene-terephthalate)-copoly(butylene-terephthalate)-copoly(butulene-fumarate), copoly (propylene-terephthalate)-copoly( propylene-fumarate), poly(propoxylated bisphenol-A-fumarate), poly( ethoxylated bisphenol-A fumarate), poly(propoxylated bisphenol-A co-itaconate), poly(ethoxylated bisphenol-A co-itaconate), poly(propoxylated bisphenol-fumarate), poly(propoxylated bisphenol-succinate), poly(propoxylated bisphenol-adipate), poly(propoxylated bisphenol-glutarate), sulfonated forms of the preceding resins, and mixtures thereof.

4. The toner composition of claim 1, wherein the polymeric resin is a crystalline polyester resin selected from the group consisting of poly(ethylene-adipate), poly(propylene-adipate), poly(butylene-adipate), poly(pentylene-adipate), poly(hexylene-adipate), poly(octylene-adipate), poly(ethylene-succinate), poly(propylene-succinate), poly(butylene-succinate), poly(pentylene-succinate), poly(hexylene-succinate), poly(octylene-succinate), poly(ethylene-sebacate), poly(propylene-sebacate), poly(butylene-sebacate), poly(pentylene-sebacate), poly(hexylene-sebacate), poly(octylene-sebacate), copoly(5sulfoisophthaloyl)-copoly(ethylene-adipate), copoly(5-sulfoisophthaloyl)-copoly(propylene-adipate), copoly(5-sulfoisophthaloyl)-copoly(butylene-adipate), copoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), copoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), copoly(ethylene-sebacate)-copoly(ethylene-fumarate), copoly(ethylene-dodecanoate)-copoly(ethylene-fumarate), copoly(nonylene-sebacate)-copoly(nonylene-fumarate), copoly(nonylene-dodecanoate)-copoly(nonylene-fumarate), copoly(decylene-sebacate)-copoly(decyylene-fumarate), copoly(decylene-dodecanoate)-copoly(decylene-fumarate), copyl(butylene-fumarate)-copoly(hexylene-fumarate), and mixtures thereof.

5. The toner composition of claim 1, wherein the polymeric resin is a sulfonated polyester resin.

6. The toner composition of claim 1, wherein the polymeric resin has an acid number of from about 0 to about 40 mg KOH/g.

7. The toner composition of claim 1, wherein the photo initiator is an ultraviolet photo initiator.

8. The toner composition of claim 1, wherein the photo initiator is selected from the group consisting of hydroxycyclohexylphenyl ketones, other ketones, benzoins, benzoin alkyl ethers, benzophenones, trimethylbenzoylphenylphosphine oxides, azo compounds, anthraquinones, substituted anthraquinones, other substituted or unsubstituted polynuclear quinines, acetophenones, thioxanthones, ketals, acylphosphines, and mixtures thereof.

9. The toner composition of claim 1, wherein the photo initiator is selected from the group consisting of alpha-amino ketone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl) ketone, 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, phenylbis(2,4,6-trimethylvbenzyoyl) phosphine oxide, alkyl substituted or halo substituted anthraquinones, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2-isopropyl-9H-thioxanthen-9-one, 2-Hydrox-4′

-hydroxyethoxy-2-methylpropiophenone, 1-hydroxycyclohexylphenyl ketone, ethyl-2,4,6-trimethylbenzoylphenylphosphinate, and mixtures thereof.

10. The toner composition of claim 1, comprising polymeric resin in an amount of from about 70 to about 95 wt % and photo initiator in an amount of from about 0.5 to about 15 wt %, each by weight of the toner particles on a dry weight basis and exclusive of any optional external additives.

11. The toner composition of claim 1, wherein the wax is present and is an alkylene wax present in an amount of about 5% to about 15% by weight based upon the total weight of the composition.

12. The toner composition of claim 11, wherein the wax is a polyethylene wax, a polypropylene wax, or mixtures thereof.

13. The toner composition of claim 1, wherein the colorant is present and comprises a pigment, a dye, or mixtures thereof, and is present in an amount of about 1% to about 25% by weight based upon the total weight of the composition.

14. The toner composition of claim 1, wherein the colorant is not present, and the toner composition is clear and colorless.

15. The toner composition of claim 1, wherein the coagulant is present in the toner particles, exclusive of any optional external additives, and on a dry weight basis, in an amount of from 0 to about 5% by weight of the toner particles.

16. The toner composition of claim 1, wherein the photo initiator is capable of initiating crosslinking of said unsaturated polymeric resin when exposed to ultraviolet light from a source having an output of from about 1 to about 100 Watts/cm² for a period of time of from about 0.01 to about 10 seconds.

18. A method of developing an image, comprising:

applying the toner composition of claim 1 to a substrate; and

fusing the toner composition to the substrate by exposing said toner composition to an irradiation source that initiates crosslinking of said unsaturated polymeric resin.

19. The method of claim 18, wherein said fusing comprises subjecting said toner composition to an irradiation source having an output of from about 1 to about 100 Watts/cm² for a period of time of from about 0.01 to about 10 seconds, and at a temperature of from about 100 to about 250°

C.

20. The method of claim 18, wherein said toner composition is a colorless toner composition and is applied over a colored toner composition that does not include a photo initiator, and said colored toner composition is fused in a separate step under at least one of heat and pressure.

21. The method of claim 18, wherein said toner composition is a colored toner composition and is applied in image-wise fashion to said substrate.

17. A emulsion aggregation process for preparing a toner, comprising:

(i) emulsifying an unsaturated polyester resin with optionally a photo-initiator, wherein the unsaturated polyester resin is selected from the group consisting of amorphous resins, crystalline resins, and mixtures thereof;

(ii) adding thereto a colorant dispersion, optionally a photoinitiator dispersion, optionally a wax dispersion, and surfactant;

(iii) adding thereto a coagulant to form a mixture, with homogenization of from about 2,000 to about 10,000 rpm, and optionally adjusting a pH of the mixture from about 7 to about 2.5, and thereby generating an aggregate mixture comprising aggregated composites of from about 1 to about 4 microns in diameter;

(iv) heating the aggregate mixture to a temperature of from about 30 to about 50°

C. to generate aggregate composites with a particle size of from about 3 to about 11 microns in diameter;

(v) adjusting the pH to about 6 to about 9 to freeze the toner composite particle size, and optionally adding a metal sequestering agent;

(vi) heating the aggregate composites to a temperature of from about 63 to about 90°

C., and optionally adjusting the pH to about 8 to about 5.5, to result in coalesced toner particles; and

(vii) optionally washing and drying the toner particles.