Xerox Corporation

Arthur Helbrecht

Allan K Chen

T Hwee Ng

Raj D Patel

Richard P Veregin

Tie Hwee Ng

Francisco E Torres

Grazyna E Kmiecik-Lawrynowicz

George Liebermann

Emily Louise Moore

David R Kurceba

Maria N McDougall

Abdisamed Sheik-Qasim

Chieh-Min Cheng

Kimberly D Nosella

Michael A Hopper

Paul Joseph Gerroir

Enno Eric Agur

David J Sanders

Patricia Ann Burns

Rosa M Duque

Danielle C Boils-Boissier

Nam S Ro

A process for the preparation of a latex polymer consistent with E/A (emulsion/aggregation/coalescence) toner manufacture. The process utilizes a standard (universal) latex composition and involves chain-transfer agent partitioning, emulsion polymerization that provides a latex polymer with a wide range of molecular properties. In particular, the process customizes a wide range M (weight average molecular weight) latex, without substantially varying the M (number average molecular weight) and hence, without substantially varying Tg (glass transition temperature) such that good toner performance is maintained. In a preferred process, a latex polymer is prepared by mixing a seed particle latex, generated by aqueous emulsion polymerization of a first portion of a monomer emulsion, with a second portion of the monomer emulsion and at least one chain-transfer agent. The mixing is done in the presence of a free-radical initiator and heated, and wherein the monomer emulsion comprises a mixture of polymerization reagents of at least one monomer, at least one chain-transfer agent, at least one surfactant, and water. This process may be applied to core-shell polymerization as well. These latex polymers are ideally suited in the manufacture of toner and developer for electrophotographic imaging and printing.

Latex processes

A process for making silica-containing latex particles involves polymerizing monomer in an emulsion comprising the monomer, water, silica particles, and optionally at least one surfactant, by adding at least one free radical initiator to the emulsion to form the silica-containing latex particles. In a preferred method, semicontinuous polymerization employing a seed latex is used to form the latex resin. The process achieves a silica-containing latex in which the silica is chemically incorporated therein that is ideally suited for use in the manufacture of toner and developer for xerographic use.

Semicontinuous emulsion polymerization process for making silica-containing latex for toners

Polymerization processes

A process for the preparation of toner comprising mixing a colorant dispersion in water, which dispersion is comprised of a colorant and an ionic surfactant with a resin latex; heating the resulting flocculent mixture with stirring at a temperature of from about 25.degree. C. to about 1.degree. C. below the glass transition temperature (Tg) of the latex resin to effect formation of toner sized aggregates; heating the resulting aggregate suspension in the presence of additional anionic surfactant, and which heating is at a temperature of from about 10.degree. C. to about 55.degree. C. above the Tg of the resin; cooling; adding a base component to the resulting slurry; filtering; and thereafter drying said toner.

Toner processes

An in situ chemical process for the preparation of toner comprised of

Low shear toner aggregation processes

A process for the preparation of toner comprising: (i) preparing a pigment dispersion, which dispersion is comprised of a pigment, an ionic surfactant, and optionally a charge control agent; (ii) shearing said pigment dispersion with a latex or emulsion blend comprised of resin, a counterionic surfactant with a charge polarity of opposite sign to that of said ionic surfactant and a nonionic surfactant; (iii) heating the above sheared blend below about the glass transition temperature (Tg) of the resin to form electrostatically bound toner size aggregates with a narrow particle size distribution; (iv) heating said bound aggregates above about the Tg of the resin; and (v) thereafter washing the toner obtained, adding initiator, adding monomer, polymerizing by heating, and thereafter cooling, followed by an optional second washing.

Toner grafting processes

A process for the preparation of toner comprising:

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Arthur Helbrecht