Two-component dry electrostatic developer composition containing onium charge control agent

Claim 2

A dry, two-component electrostatic developer composition comprising: (a) toner particles comprising a polymeric binder, (b) an onium compound, as a charge-control agent, dispersed in the toner binder and having the formula: ##STR3## wherein: X is a phosphorous, arsenic or antimony atom; each of R 2 , R 3 and R 4 , which are the same or different, represents alkyl having from 1 to about 20 carbon atoms; aralkyl or alkaryl in which the alkyl group has 1 to about 20 carbon atoms and the aryl group has from about 6 to about 14 carbon atoms; or aryl having from about 6 to about 14 carbon atoms; R 1 represents a group as defined with respect to R 2 , R 3 and R 4 ; a hetero ring system when taken together with X and any one of R 2 , R 3 and R 4 ; or the group: ##STR4## wherein: R 5 is alkylene having from about 1 to about 20 carbon atoms; oxydialkylene having from about 1 to about 20 carbon atoms in each alkylene group or dialkylenearylene having from about 1 to about 20 carbon atoms in each alkylene group and from about 6 to about 14 atoms in the arylene group; and Y - is an anion, and (c) carrier particles surface-coated with a fluoropolymer.

Claim 3

The developer of claim 1 wherein each of R 2 , R 3 and R 4 is optionally substituted aryl, or optionally substituted 2- to 5-carbon alkyl.

Claim 4

The developer of claim 1 wherein the fluoropolymer coating on the carrier is a polymer selected from the group consisting of perfluoroalkoxy fluoropolymers, poly(tetrafluoroethylene), poly(vinylidene fluoride), poly(vinylidene fluoride-co-tetrafluoroethylene), polyvinyl fluoride, and poly(hexafluoropropylene-tetrafluoroethylene).

Claim 5

A developer as in claim 1 wherein the charge-control agent is selected from the group consisting of: 1 benzyltriphenylphosphonium chloride; 2 methyltriphenylphosphonium bromide; 3 tetrabutylphosphonium bromide; 4 dodecyltributylphosphonium bromide; 5 phthalimidomethyltributylphosphonium bromide; 6 octadecyltributylphosphonium bromide; 7 methyltriphenylphosphonium fluoroborate; 8 ethyltriphenylphosphonium fluoroborate; 9 methyltriphenylphosphonium hexafluorophosphate; 10 dodecyltributylphosphonium p-toluenesulfonate; 11 bis(4-carbomethoxyphenyl)methylphenylphosphonium p-toluenesulfonate; 12bis(4-hydroxypropyl)methylphenylphosphonium p-toluenesulfonate; 13 bis(4-acetoxyphenyl)methylphenylphosphonium p-toluenesulfonate; 14 tris(4-acetoxyphenyl)methylphosphonium p-toluenesulfonate; 15 methyltriphenylphosphonium p-toluenesulfonate; 16 dodecyltriphenylphosphonium p-toluenesulfonate; 17 methyltriphenylphosphonium benzenesulfonate; 18 ethyltriphenylphosphonium p-toluenesulfonate; 19 phenethyltriphenylphosphonium p-toluenesulfonate; 20 ethylene-bis(triphenylphosphonium p-toluenesulfonate); 21 methyltriphenylphosphonium tetraphenylborate; 22 tris(methoxyphenyl)methylphosphonium p-toluenesulfonate; 23 methyltritolylphosphonium p-toluenesulfonate; 24 tris(chlorophenyl)methylphosphonium p-toluenesulfonate; 25 tris(carbomethoxyphenyl)methylphosphonium p-toluenesulfonate; 26 benzyltriphenylphosphonium phosphomolybdate; 27 benzyltriphenylphosphonium silicotungstate; 28 methyltriphenylphosphonium phosphomolybdate; 29 benzyltriphenylphosphonium phosphotungstate; 30 methyl 4-carbomethoxyphenyldiphenylphosphonium p-toluenesulfonate; 31 methyl 4-acetoxyphenyldiphenylphosphonium p-toluenesulfonate; 32 methyl 3,5-biscarbomethoxyphenyldiphenylphosphonium p-toluenesulfonate; 33 (m+p)vinylbenzyltriphenylphosphonium p-toluenesulfonate; 34 methyltriphenylarsonium p-toluenesulfonate; and 35 methyltriphenylantimonium p-toluenesulfonate.

Claim 6

The developer of claim 2 wherein said charge-control agent is methyltriphenylphosphonium tetrafluoroborate, methyltriphenylphosphonium p-toluenesulfonate, or bis(p-carbomethoxypheny)phenylmethylphosphonium p-toluene sulfonate.

Claim 7

The developer of claim 1, 2, 3, 4 or 5 wherein the carrier comprises a magnetic material.

Claim 8

The developer of claim 6 wherein the magnetic material is a hard magnetic material having a coercivity of at least 100 gauss at magnetic saturation.

Claim 9

The developer of claim 6 wherein the concentration of the charge-control agent is from about 0.5 to about 5.0 parts by weight charge-control agent per 100 parts by weight toner resin.

Claim 10

The developer of claim 6 wherein the charge of the developer is from about 9 to about 35 microcoulombs per gram of toner in the developer.