US4894309A
Expired / Lapsed
US
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Processes for the preparation of crosslinked copolymers
Assignee: Xerox Corp
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Filing: 1988-09-19
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Granted: 1990-01-16
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Expires: 2008-09-19
Abstract
Abstract A free radical suspension polymerization process for obtaining crosslinked styrene butadiene ternary copolymers which comprises the polymerization of styrene monomers, butadiene monomers, and crosslinking components in the presence of a surfactant, a stabilizer, and a first and second initiator; and wherein the aforementioned components are present in an aqueous phase; heating the resulting aqueous mixture at a temperature of from about 50° C. to about 110° C.; thereafter heating the mixture at a temperature of from about 110° C. to about 150° C.; followed by cooling and isolating the desired product.
Inventors
- 👤 Michael K. Georges
- 👤 Lupu Alexandru
- 👤 William J. Dale
- 👤 Paul D. Szabo
- 👤 Robert A. Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 23:43
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/087; G03G9/08784; G03G9/08793; C; C08; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/08; G03G9/08702; G03G9/08737
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
117 words
A toner composition comprised of the resin particles of crosslinked styrene butadiene ternary copolymers prepared by a free radical suspension polymerization process which comprises the polymerization of styrene monomers, butadiene monomers, and crosslinked components in the presence of a surfactant, a stabilizer, and a first and second initiator; and wherein the aforementioned components are present in an aqueous phase; heating the resulting aqueous mixture at a temperature of from about 50° C. to about 110° C. thereafter heating the mixture at a temperature of from about 110° C. to about 150° C.; followed by cooling; and isolating the desired product, second toner resin particles, pigment particles, a low molecular weight wax component, and a charge enhancing additive.
Claim 2
Dependent Claim
117 words
A toner composition comprised of the resin particles of crosslinked styrene butadiene ternary copolymers prepared by a free radical suspension polymerization process which comprises the polymerization of styrene monomers, butadiene monomers, and crosslinked components in the presence of a surfactant, a stabilizer, and a first and second initiator; and wherein the aforementioned components are present in an aqueous phase; heating the resulting aqueous mixture at a temperature of from about 50° C. to about 110° C. thereafter heating the mixture at a temperature of from about 110° C. to about 150° C.; followed by cooling; and isolating the desired product, second toner resin particles, pigment particles, a low molecular weight wax component, and a charge enhancing additive.
Claim 3
Dependent Claim
34 words
A toner composition in accordance with claim 1 wherein the wax is selected from the group consisting of polyethylene and polypropylene with a weight average molecular weight of from about 1,000 to about 6,000.
Claim 4
Dependent Claim
25 words
A toner composition in accordance with claim 1 wherein the pigment particles are selected from the group consisting of carbon black, magnetite, and mixtures thereof.
Claim 5
Dependent Claim
35 words
A toner composition in accordance with claim 1 wherein the charge enhancing additive is selected from the group consisting of alkyl pyridinium halides, stearyl phenethyl dimethyl ammonium methyl tosylate, and distearyl dimethyl ammonium methyl sulfate.
Claim 6
Dependent Claim
22 words
A toner composition in accordance with claim 1 wherein there is selected as resin particles a crosslinked styrene butadiene divinylbenzene ternary copolymer.
Claim 7
Dependent Claim
60 words
A toner composition in accordance with claim 5 wherein the copolymer has a gel content of from about 0.1 percent, to about 80 percent, a number average molecular weight of from about 15,000 to about 100,000, a weight average molecular weight of from about 100,000 to about 3,000,000, and Mw to Mn ratio of from about 3 to about 50.
Claim 8
Dependent Claim
136 words
A process for preparing a toner composition which comprises: a. forming a crosslinked styrene butadiene ternary copolymer by admixing styrene monomers, butadiene monomers, and crosslinking components in the presence of a surfactant, a stabilizer, and first and second initiators in an aqueous phase, heating the resulting aqueous mixture at a temperature of from about 50° C. to about 110° C., thereafter heating the mixture at a temperature of from about 110° C. to about 150° C., cooling the mixture, and isolating the resulting crosslinked styrene butadiene ternary copolymer product; b. admixing the crosslinked styrene butadiene ternary copolymer with toner resin particles, pigment particles, a low molecular weight wax, and a charge enhancing additive; c. subjecting the resulting mixture to melt blending and mechanical attrition; and d. micronizing and classifying the resulting material to obtain toner particles.
Claim 9
Dependent Claim
136 words
A process for preparing a toner composition which comprises: a. forming a crosslinked styrene butadiene ternary copolymer by admixing styrene monomers, butadiene monomers, and crosslinking components in the presence of a surfactant, a stabilizer, and first and second initiators in an aqueous phase, heating the resulting aqueous mixture at a temperature of from about 50° C. to about 110° C., thereafter heating the mixture at a temperature of from about 110° C. to about 150° C., cooling the mixture, and isolating the resulting crosslinked styrene butadiene ternary copolymer product; b. admixing the crosslinked styrene butadiene ternary copolymer with toner resin particles, pigment particles, a low molecular weight wax, and a charge enhancing additive; c. subjecting the resulting mixture to melt blending and mechanical attrition; and d. micronizing and classifying the resulting material to obtain toner particles.
Claim 10
Dependent Claim
67 words
A process according to claim 7 wherein the crosslinked styrene butadiene ternary copolymer is prepared by heating the reaction mixture at from about 50° C. to about 110° C. for a period of from about 2 to about 5 hours, and subsequently heating the reaction mixture at from about 115° C. to about 150° C. for a period of from about 15 minutes to about 2 hours.
Claim 11
Dependent Claim
25 words
A process according to claim 7 wherein the ratio of styrene monomer to butadiene monomer is from about 80:20 to about 95:5 by weight, respectively.
Claim 12
Dependent Claim
22 words
A process according to claim 7 wherein the monomer to aqueous phase ratio is from about 45:55 to about 30:70 by weight.
Claim 13
Dependent Claim
50 words
A process according to claim 7 wherein the first initiator initiates the suspension free radical polymerization reaction and the second initiator reduces the amounts of residual monomers, resulting in a styrene content of less than 1,600 parts per million and a butadiene content of less than 10 parts per million.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |