EP0376202A2
Expired / Lapsed
EP
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Electrostatographic toners and method of making
Assignee: NexPress Solutions LLC
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Filing: 1989-12-22
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Granted: —
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Expires: 2009-12-22
Abstract
Abstract An electrophotographic dry toner having excellent properties with respect to charging, RH stability and fusing is made in a process in which the binder polymer is formed by suspension polymerizing a styrene-acrylic monomer mixture in the presence of a polyester-promoted colloidal silica suspending agent which is free of other hydrophilic polymers. The resulting polymer is melt blended with toner addenda such as a colorant and a charge control agent and the mixture is pulverized to form the toner composition.
Inventors
- 👤 Allan Roy C/O Eastman Kodak Company Amering
- 👤 Dennis Edward C/O Eastman Kodak Company Smith
- 👤 John Michael C/O Eastman Kodak Company Spence
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 09:35
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/0802; G03G9/0804; G03G9/0806; G03G9/081; G03G9/087; G03G9/08702; G03G9/08726; G03G9/08728; G03G9/08742; G03G9/08755; G03G9/08784; G03G9/08793; G03G9/097; G03G9/09708; G03G9/09716
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
190 words
A method of making a fusible styrene-acrylic copolymer electrostatographic toner, characterized in forming a suspension in an aqueous medium of droplets of a monomer composition comprising a styrene and an alkyl acrylate or methacrylate, the styrene content of the monomer composition being at least 60 weight percent, forming on the surfaces of the monomer droplets a complex of hydrophilic silica with a polyester of a lower alkylene dicarboxylic acid and an amino alkanol, the complex being less hydrophilic than the silica alone and sufficiently hydrophobic to be attracted to the monomer droplets, and said complex being substantially free of other hydrophilic polymers, subjecting the suspension to polymerization conditions in admixture with a free radical initiator which is soluble in the monomers and insoluble in water, recovering the polymerization product comprising polymer beads having said complex on their surfaces, melt blending the polymer beads with toner addenda, and cooling and pulverizing the melt blended product to obtain toner particles having said addenda and said complex or its components distributed within the toner particle and having no more than a small concentration of said complex or its components on the particle surfaces.
Claim 2
Independent Claim
190 words
A method of making a fusible styrene-acrylic copolymer electrostatographic toner, characterized in forming a suspension in an aqueous medium of droplets of a monomer composition comprising a styrene and an alkyl acrylate or methacrylate, the styrene content of the monomer composition being at least 60 weight percent, forming on the surfaces of the monomer droplets a complex of hydrophilic silica with a polyester of a lower alkylene dicarboxylic acid and an amino alkanol, the complex being less hydrophilic than the silica alone and sufficiently hydrophobic to be attracted to the monomer droplets, and said complex being substantially free of other hydrophilic polymers, subjecting the suspension to polymerization conditions in admixture with a free radical initiator which is soluble in the monomers and insoluble in water, recovering the polymerization product comprising polymer beads having said complex on their surfaces, melt blending the polymer beads with toner addenda, and cooling and pulverizing the melt blended product to obtain toner particles having said addenda and said complex or its components distributed within the toner particle and having no more than a small concentration of said complex or its components on the particle surfaces.
Claim 3
Dependent Claim
16 words
A method according to claim 1 wherein the complex consists only of silica and said polyester.
Claim 4
Dependent Claim
19 words
A method according to claim 1 wherein the toner addenda is a charge control agent soluble in said polyester.
Claim 5
Dependent Claim
22 words
A method according to claim 2 wherein the dicarboxylic acid is adipic acid and the amino alkanol is diethanolamine or methyl aminoethanol.
Claim 6
Dependent Claim
22 words
A method according to claim 2 wherein the monomer composition comprises at least 75 weight percent styrene and includes a crosslinking agent.
Claim 7
Dependent Claim
62 words
An electrostatographic toner powder comprising particles of a suspension polymerized copolymer of a styrene and an alkyl acrylate or methacrylate, the styrene content being at least 60 weight percent, having dispersed therein toner addenda and a suspending agent complex of hydrophilic silica with a polyester of a lower alkylene dicarboxylic acid and an aminoalkanol, said complex being substantially free of hydrophilic polymers.
Claim 8
Dependent Claim
62 words
An electrostatographic toner powder comprising particles of a suspension polymerized copolymer of a styrene and an alkyl acrylate or methacrylate, the styrene content being at least 60 weight percent, having dispersed therein toner addenda and a suspending agent complex of hydrophilic silica with a polyester of a lower alkylene dicarboxylic acid and an aminoalkanol, said complex being substantially free of hydrophilic polymers.
Claim 9
Dependent Claim
17 words
A toner powder according to claim 6 wherein the complex consists only of silica and said polyester.
Claim 10
Dependent Claim
23 words
A toner powder according to claim 6 wherein said dicarboxylic acid is adipic acid and the amino alkanol is diethanolamine or methyl aminoethanol.
Claim 11
Dependent Claim
25 words
A toner powder according to claim 6 wherein the styrene content of the copolymer is at least 75 weight percent and the copolymer is crosslinked.
Claim 12
Dependent Claim
25 words
An electrostatographic developer comprising a mixture of (a) magnetic carrier particles coated with a fluorocarbon polymer and (b) a toner powder according to claim 6.
References Cited (Backward Citations)
No citation records indexed.
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