Toner compositions and processes
View Patent ↗Toners are provided which possess excellent blocking characteristics. The toners include cores including amorphous resins having low glass transition temperatures, amorphous resins having high glass transition temperatures, and crystalline resins, and shells including amorphous resins having high glass transition temperatures.
1. A toner comprising, particles comprising:
a core comprising from 8% to 15% by weight of the toner of at least one low molecular weight amorphous resin having a glass transition temperature of from 58.5° C. to 66° C., in combination with from 36% to 43% by weight of the toner of at least one high molecular weight amorphous resin having a glass transition temperature of from 53° C. to 58° C. and a weight average molecular weight greater than 45,000, at least one crystalline resin, an optional wax and an optional colorant; and
a shell comprising from 25% to 35% by weight of the toner of at least one amorphous resin having a glass transition temperature of from 58.5° C. to 66° C.
2. The toner according to claim 1 , wherein the at least one amorphous resin having a glass transition temperature of from 58.5° C. to 66° C. and the at least one amorphous resin having a glass transition temperature of from 53° C. to 58° C. comprise a polyester resin, and the at least one crystalline resin comprises a polyester resin.
3. The toner according to claim 1 , wherein the amorphous resin having, a glass transition temperature of from 58.5° C. to 66° C., the amorphous resin having a glass transition temperature of from 53° C. to 58° C., or both, comprise an amorphous polyester resin of the formula:
wherein R is a hydrogen or a methyl group, and m and n represent random units of the copolymer and m is from 2 to 10, and n is from 2 to 10.
4. The toner according to claim 1 , wherein the at least one crystalline resin comprises a crystalline polyester resin of the formula:
wherein b is from 5 to 2000 and d is from 5 to 2000.
5. The toner according to claim 1 , wherein the core comprises from 9% to 12% by weight of the toner of the at least one amorphous resin having a glass transition temperature of from 58.5° C. to 66° C. and from 37% to 41% by weight of the toner of the at least one amorphous resin having a glass transition temperature of from 53° C. to 58° C.
6. The toner according to claim 1 , wherein the shell comprises from 26% to 30% by weight of the toner of the at least one amorphous resin having a glass transition temperature of from 58.5° C. to 66° C.
7. The toner according to claim 1 , wherein the wax is selected from the group consisting of polyethylene wax, polypropylene wax, polybutene wax, sumacs wax, jojoba oil, beeswax, montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax, stearyl stearate, behenyl behenate, butyl stearate, propyl oleate, glyceride monostearate, glyceride distearate, pentaerythritol tetra behenate; diethyleneglycol monostearate, dipropyleneglycol distearate, and combinations thereof.
8. The toner according to claim 1 , wherein the wax is present in an amount of from 3 percent to 20 percent by weight of the toner.
9. The toner according to claim 1 , wherein particles comprising the toner are from 3 to 15 microns in size.
10. A toner comprising particles comprising:
a core comprising from 8% to 15% by weight of the toner of at least one low molecular weight amorphous resin having a glass transition temperature of from 58.5° C. to 66° C., in combination with from 36% to 43% by weight of the toner of at least one high molecular weight amorphous resin having a glass transition temperature of from 53° C. to 58° C. and a weight average molecular weight greater than 45,000, at least one crystalline resin, at least one wax selected from the group consisting of polyethylene, polypropylene, and polybutene, and combinations thereof, and an optional colorant; and
a shell comprising from 25% to 35% by weight of the toner of at least one amorphous resin having a glass transition temperature of from 58.5° C. to 66° C.
11. The toner according to claim 10 , wherein the amorphous resin having a glass transition temperature of from 58.5° C. to 66° C., the amorphous resin having a glass transition temperature of from 53° C. to 58° C., or both, comprise an amorphous polyester resin of the formula:
wherein R is a hydrogen or a methyl group, and m and n represent random units of the copolymer and m is from 2 to 10, and n is from 2 to 10.
12. The toner according to claim 10 , wherein the at least one crystalline resin comprises a crystalline polyester resin of the formula:
wherein b is from 5 to 2000 and d is from 5 to 2000.
13. The toner according to claim 10 , wherein the core comprises from 9% to 12% by weight of the toner of the at least one amorphous resin having a glass transition temperature of from 58.5° C. to 66° C. and from 37% to 41% by weight of the toner of the at least one amorphous resin having a glass transition temperature of from 53° C. to 58° C.
14. The toner according to claim 10 , wherein the shell comprises from 26% to 30% by weight of the toner of the at least one amorphous resin having a glass transition temperature of from 58.5° C. to 66° C.
15. The toner according to claim 10 , wherein the wax is present in an amount of from 3 percent to 20 percent by weight of the toner.
16. The toner according to claim 10 , wherein particles comprising the toner are from 3 to 15 microns in size.
17. A toner comprising:
a core comprising from 8% to 15% by weight of the toner of at least one low molecular weight amorphous polyester resin having a glass transition temperature of from 58.5° C. to 66° C., in combination with from 36% to 43% by weight of the toner of at least one high molecular weight amorphous resin having a glass transition temperature of from 53° C. to 58° C. and a weight average molecular weight greater than 45,000, at least one crystalline polyester resin, at least one wax selected from the group consisting of polyethylene, polypropylene, and polybutene, and combinations thereof, and an optional colorant; and
a shell comprising from 25% to 35% by weight of the toner of at least one amorphous polyester resin having a glass transition temperature of from 58.5° C. to 66° C.,
wherein the amorphous resin having a glass transition temperature of from 58.5° C. to 66° C., the amorphous resin having a glass transition temperature of from 53° C. to 58° C., or both, comprise an amorphous polyester resin of the formula:
wherein R is a hydrogen or a methyl group, and m and n represent random units of the copolymer and m is from 2 to 10, and n is from 2 to 10, and
wherein the at least one crystalline resin comprises a crystalline polyester resin of the formula:
wherein b is from 5 to 2000 and d is from 5 to 2000.
18. The toner according to claim 17 , wherein the core comprises from 9% to 12% by weight of the toner of the at least one amorphous resin having a glass transition temperature of from 58.5° C. to 66° C. and from 37% to 41% by weight of the toner of the at least one amorphous resin having a glass transition temperature of from 53° C. to 58° C., and wherein the shell comprises from 26% to 30% by weight of the toner of the at least one amorphous resin having a glass transition temperature of from 58.5° C. to 66° C..
19. The toner according to claim 17 , wherein the wax is present in an amount of from 3 percent to 20 percent by weight of the toner.
20. The toner according to claim 17 , wherein particles comprising the toner are from 3 to 15 microns in size.