Curable toner compositions and processes
View Patent ↗An emulsion aggregation toner composition includes toner particles including: an unsaturated polymeric resin, such as amorphous resins, crystalline resins, and combinations thereof; an optional colorant; an optional wax; an optional coagulant; and a photoinitiator. By optimizing the particle size of the emulsion, the aggregant concentration utilized in the emulsion aggregation process, and the solids content of the emulsion, toners may be produced capable of generating images with non-contact fusing that have high gloss.
1. An emulsion aggregation toner for a non-contact fusing system, comprising a toner particle comprising a core particle and a shell thereon, wherein said core particle comprises a crystalline resin, an optional colorant and an optional wax and said shell comprises an unsaturated resin and a photoinitiator, wherein said toner particle is from about 2.5 μm to about 4.2 μm in diameter and comprises gloss from about 20 to about 100 gu.
2. The toner of claim 1 , wherein said toner comprises a gloss of from about 70 to about 90 gu.
3. The toner of claim 1 , wherein the photoinitiator is present in an amount of from about 1 percent to about 10 percent by weight of the toner particle.
4. The toner of claim 1 , wherein said core particle further comprises an amorphous resin.
5. The toner of claim 1 , wherein said crystalline resin comprises a number average molecular weight of from about 1,000 to about 50,000, a weight average molecular weight of from about 2,000 to about 100,000 or a molecular weight distribution (M w /M n ) of from about 2 to about 6.
6. The toner of claim 1 , wherein said crystalline resin comprises a compound of the formula:
wherein b is from about 5 to about 2000 and d is from about 5 to about 2000.
7. The toner of claim 1 , wherein said photoinitiator comprises a UV initiator.
8. The toner of claim 1 , wherein said photoinitiator is selected from the group consisting of hydroxycyclohexylphenyl ketones, ketones, benzoins, benzoin alkyl ethers, benzophenones, trimethylbenzoylphenylphosphine oxides, azo compounds, anthraquinones, substituted anthraquinones, substituted or unsubstituted polynuclear quinines, acetophenones, thioxanthones, ketals, acylphosphines and mixtures thereof.
9. The toner of claim 1 , wherein said photoinitiator is selected from the group consisting of α-amino ketone, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl) ketone, 2,4,6-trimethylbenzophenon, 4-methylbenzophenone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, an alkyl substituted or halo substituted anthraquinone, 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 of claim 1 , wherein said toner does not exhibit printed document offset at temperatures up to about 90° C.
11. The toner of claim 1 , wherein said toner exhibits printed improved abrasion resistance and scratch resistance as compared to a conventional, non-curable fused toner.
12. The toner of claim 1 , wherein said unsaturated resin is selected from the group consisting of poly(1,2-propylene fumarate), poly(1,2-propylene maleate), poly(1,2-propylene itaconate) and combinations thereof.
13. The toner of claim 1 , wherein said core comprises an unsaturated amorphous resin.
14. The toner of claim 1 , which fuses to a substrate when exposed to radiation comprising a wavelength of form about 750 to about 2500 nm.
15. The toner of claim 1 , comprising an aluminum ion content of from about 0.1 to about 1 parts per hundred.
16. The toner of claim 1 , wherein the shell resin is present in an amount of from about 20 percent to about 45 percent by weight of the toner particle.
17. The toner of claim 1 , which fuses to a substrate when exposed to radiation for about 30 milliseconds to about 3 seconds.
18. The toner of claim 1 , which fuses to a substrate when exposed to infrared radiation.
19. The toner of claim 1 , which fuses to a substrate when exposed to a temperature of from about 100° C. to about 250° C.
20. The toner of claim 1 , wherein said photoinitiator reacts when exposed to radiation of from about 200 to about 500 nm.
21. The toner of claim 1 , wherein the core particle comprises at least one polymeric resin comprising particles of a size of from about 80 nanometers to about 120 nanometers; and
wherein said toner particle is of a size of from about 3 microns to about 4 microns, said toner particle size achieved without the use of classifiers.