Electrographic toner and developer composition containing quaternary ammonium salt charge control agent
AssigneeEastman Kodak Company
InventorThomas A. Jadwin
Life of this patent
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Abstract
The present invention relates to the use of low levels of quaternary ammonium salt surfactants as charge control agents for an electrostatic toner contained in dry electrographic developer compositions. Particularly useful such charge control agents are those which contain at least one amido group having 10 or more carbon atoms attached to the ammonium cation and an anion selected from a halide ion or an organosulfur-containing anion.
Claims10
A dry, particulate, electrostatic toner composition having a particle size from about 0.1 to about 100 microns and comprising
- (a) a polymeric binder having a softening temperature from about 40.degree. C. to about 200.degree. C. and
- (b) from about 0.01 to about 2 percent by weight of a quaternary ammonium salt surfactant of the formula:
- ##STR4## wherein:
- R.sup.1, R.sup.2, and R.sup.3 are the same or different lower alkyl groups;
- R.sup.6 is an alkyl group having 7 or more carbon atoms;
- R.sup.7 is a straight chain alkylene group having from 1 to about 8 carbon atoms;
- and
- X.sup..crclbar. is a halide ion or an organosulfur-containing anion of the formula R.sup.5 SO.sub.n wherein R.sup.5 is an aliphatic or aromatic group having up to about 10 carbon atoms and n is 3 or 4,
- the amount of said quaternary ammonium salt being effective to provide an electrostatic toner that is capable of maintaining a relatively high, stable net toner charge level under widely varying relative humidity conditions.
A dry, particulate electrostatic toner composition having a particle size from about 0.1 to about 30 microns and comprising
- (a) a polymeric binder,
- (b) a pigment or dyestuff in an amount sufficient to color the particles, and
- (c) from about 0.01 to about 2 percent by weight of said composition of a quaternary ammonium salt of the formula:
- ##STR5## wherein:
- R.sup.1, R.sup.2 and R.sup.3 are the same or different alkyl groups, each having from 1 to about 4 carbon atoms;
- R.sup.6 is an alkyl group having from about 7 to about 11 carbon atoms;
- R.sup.7 is a straight-chain alkylene group having from 1 to about 8 carbon atoms;
- and
- X.sup..crclbar. is a halide ion or an organosulfur-containing anion of the formula R.sup.5 SO.sub.n wherein R.sup.5 is an alkyl or aryl group having up to about 10 carbon atoms and n is 3 or 4.
Dependencies are inferred from the claim text.