Negative charge carrier resins with RH sensitivity
View Patent ↗The instant disclosure describes methacrylate coated carrier resins with hydrophobic substituents for charge control and improved RH sensitivity.
1. A toner carrier composition comprising:
a polymer coating resin consisting of a methacrylate monomer having a hydrophobic substituent and a secondary aminoacrylate monomer, wherein the highest occupied molecular orbital (HOMO) of the methacrylate-containing polymer has greater than about 25% of the electron density of those molecular orbitals located on the hydrophobic substituent and less than about 75% of the electron density of those molecular orbitals on the carbonyl group of the methacrylate moiety, and wherein said methacrylate monomer having a hydrophobic substituent is present from about 98% to 100% by weight of the polymer and said secondary aminoacrylate monomer is present (a) from about 0.5 to about 1%; or (b) from about 1 to about 1.5; or (c) from about 1.5 to about 2% by weight of the polymer,
further wherein the methacrylate monomer has the formula as set forth in formula (I):
wherein Ar comprises at least one aromatic group, and
the secondary amino acrylate monomer is selected from the group consisting of dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and diethylaminopropyl methacrylate; and
a carrier core particle, wherein the polymer coating resin adheres to a surface of the carrier core particle.
2. The Carrier composition of claim 1 , wherein the monomer exhibits increased delocalization of Fukui (−) function electron densities from the carbonyl group to the hydrophobic substituent as compared to methyl-containing, hexyl-containing or cyclohexyl-containing methacrylate polymers.
3. The carrier composition of claim 1 , wherein Ar is a benzyl group, a naphthyl group or a phenyl group.
4. The Carrier composition of claim 1 , wherein the methacrylate monomer has a carbon oxygen (C/O) ratio of 4.75 or more.
5. The carrier composition of claim 1 , wherein the secondary amino acrylate monomer is present at about 1% by weight of the polymer.
6. The carrier composition of claim 1 , wherein said methacrylate monomer has an improved charging RH ratio as compared to that of methylmethacrylate (MMA).
7. A developer comprising:
a carrier composition;
a toner;
and a toner surface additive;
wherein the carrier composition comprises a polymer coating resin consisting of a methacrylate monomer having a hydrophobic substituent and a secondary aminoacrylate monomer, wherein the highest occupied molecular orbital (HOMO) of the methacrylate-containing polymer has greater than about 25% of the electron density of those molecular orbitals located on the hydrophobic substituent and less than about 75% of the electron density of those molecular orbitals on the carbonyl group of the methacrylate moiety, and wherein said methacrylate monomer having a hydrophobic substituent is present from about 98% to 100% by weight of the polymer and said secondary aminoacrylate monomer is present (a) from about 0.5 to about 1%; or (b) from about 1 to about 1.5; or (c) from about 1.5 to about 2% by weight of the polymer,
further wherein the methacrylate monomer has the formula as set forth in formula (I):
wherein Ar comprises at least one aromatic group, and
the secondary amino acrylate monomer is selected from the group consisting of dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and diethylaminopropyl methacrylate; and
a carrier core particle, wherein the polymer coating resin adheres to a surface of the carrier core particle.
8. The developer of claim 7 , wherein said at least one methacrylate monomer comprises a carbon:oxygen (C/O) ratio of 4.75 or greater.
9. The developer of claim 7 , wherein said toner surface additive comprises a silica, a titania, an alumina or mixtures thereof.
10. The developer of claim 9 , wherein said silica comprises at least one silica.
11. The developer of claim 7 , wherein an energy gap for forward charge transfer of electrons for said at least one methacrylate monomer and a toner surface additive is at less than about 5.1 eV.
12. The developer of claim 7 , wherein said toner comprises an emulsion aggregation toner.
13. The developer of claim 7 , wherein Ar comprises a benzyl group or a phenyl group.
14. The developer of claim 7 , wherein the secondary amino acrylate monomer is present at about 1% by weight of the polymer.
15. The developer of claim 7 , wherein said at least one methacrylate monomer comprises an improved charging RH ratio as compared to that of methylmethacrylate (MMA).