Liquid electrophotographic toner with acid containing polyester resins
AssigneeMinnesota Mining and Manufacturing Company
InventorsSusan K. Jongewaard, Mohamed A. Elmasry, Kevin M. Kidnie
Life of this patent
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Abstract
Liquid toners for developing electrophotographic images contain dispersed toner particles which are based on a polymer with multi-characteristics. These particles comprise a thermoplastic resinous core with a Tg below room temperature, which is chemically anchored to an amphipathic copolymer steric stabilizer containing covalently attached groups of a coordinating compound which in turn are capable of forming covalent links with organo-metallic charge directing compounds and a thermoplastic ester resin that functions as a charge enhancing component for the toner. The toner particles so formed have advantageous properties of high charge/mass, and good charge and dispersion stability.
Claims30
A liquid toner for developing an electrostatic image comprising chelating copolymer particles dispersed in a non-polar carrier liquid, said chelating copolymer particles comprising a thermoplastic resinous core having a Tg of 25.degree. C. or less and is insoluble or substantially insoluble in said carrier liquid, and chemically anchored to said core a copolymeric steric stabilizer soluble in said carrier liquid and having covalently attached thereto moieties of a coordinating compound and at least one metal soap compound derived from metals which form strong coordinate bonds with said moieties, said stabilizer being chosen from the classes of block and graft copolymers, and a thermoplastic ester resin present in an amount equal to 5-95% by weight of said metal soap compound, said resin is an acid containing resin and has an acid number of between 1 and 200.
A liquid toner for use in developing an electrostatic image comprising an electrically insulating non-polar carrier liquid having dispersed therein toner particles comprising pigment particles having on their exterior surfaces polymer particles, said polymer particles having charge carrying coordination moieties attached to the surface of said polymer particles, and comprise a thermoplastic ester resin having an acid number of less than or equal to 200.
A liquid toner for developing an electrostatic image comprising a dispersion of pigment and chelating polymer particles in a non-polar carrier liquid, said chelating polymer particles comprising a thermoplastic resinous core having a Tg of 25.degree. C. or less which is insoluble in said carrier liquid, said carrier liquid having therein 0.01% by weight of said carrier liquid of a thermoplastic ester resin having an acid number of between 1 and 200.
A liquid toner for developing an electrostatic image comprising a dispersion of toner particles in a non-polar carrier liquid, said toner particles comprising pigment particles having thermoplastic chelating polymer particles on their surface, said thermoplastic chelating polymer particles comprising a thermoplastic resinous core having a Tg of less than 25.degree. C. and a copolymeric steric stabilizer adhered to its surface, said copolymeric steric stabilizer having moieties attached thereto, said moieties being selected from the group consisting of coordinating groups and metal soap groups that form coordinate bonds with said coordinating groups, said dispersion of toner particles in a non-polar carrier liquid also having present as at least 0.01% by weight of said carrier liquid a thermoplastic ester resin having an acid number of from 1 to 200.
Dependencies are inferred from the claim text.