US4388395A
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US
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Liquid developer for use in electrophotography
Assignee: Ricoh Co Ltd
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Filing: 1982-01-15
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Granted: 1983-06-14
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Expires: 2002-01-15
Abstract
Abstract A liquid developer for use in electrophotography is disclosed which is prepared by dispersing a toner consisting essentially of a pigment or dye and a resin in a carrier liquid having a high insulating property and a low dielectric constant, wherein said resin is a nonaqueous dispersed resin obtained by effecting, in a nonaqueous solvent comprising an aliphatic hydrocarbon, the steps of: (a) copolymerizing (1) a monomer A having the general formula I: ##STR1## [wherein R is H or --CH 3 , and A is --COOC n H 2n+1 or --OC n H 2n+1 (n is an integer of 6 to 20)] with (2) a polyfunctional monomer having two or more double bonds and (3) a monomer B having a glycidyl group or a vinyl monomer C having a carboxyl group, (b) esterifying the resulting copolymer with the monomer C when the monomer B was used in the step (a) and with the monomer B when the monomer C was used in the step (a) respectively, and (c) grafting the resulting esterified copolymer with a monomer D selected from the group consisting of compounds having the general formula II: ##STR2## [wherein R is the same as previously stated and Z is --COOC m H 2m+1 (m is an integer of 1 to 4), --OCOC m' H 2m'+1 (m' is an integer of 1 to 6), ##STR3## (m is the same as previously stated), --COOH, --COOC 2 H 4 OH or ##STR4## styrene, vinyl acetate, vinyltoluene, chlorostyrene, vinylpyrrolidone and vinylpyridine.
Inventors
- 👤 Kazuo Tsubuko
- 👤 Junichiro Hashimoto
- 👤 Shinichi Kuramoto
- 👤 Makoto Okawara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:51
CPC Classifications
C; C08; C08F; C08F265/00; C08F265/04; C08F290/00; C08F290/08; C08F290/12; G; G03; G03G; G03G9/00; G03G9/08; G03G9/12; G03G9/13; G03G9/133
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
281 words
A liquid developer for use in electrophotography which is prepared by dispersing a toner consisting essentially of a pigment or dye and a resin in a carrier liquid having a high insulating property and a low dielectric constant, wherein said resin is a nonaqueous dispersed resin obtained by effecting, in a nonaqueous solvent comprising an aliphatic hydrocarbon, the steps of: (a) copolymerizing (1) a monomer A having the general formula I: ##STR17## wherein R is --H or --CH 3 , A is --COOC n H 2n+1 or --OC n H 2n+1 , and n is an integer of 6 to 20, with (2) a polyfunctional second monomer having two or more double bonds and (3) a third monomer selected from the group consisting of a monomer B having a glycidyl group or a vinyl monomer C having a carboxyl group, (b) esterifying the resulting copolymer with a fourth monomer selected from the group consisting of said monomer B and said monomer C, such that said fourth monomer is said monomer C when said third monomer is monomer B and said fourth monomer is said monomer B when said third monomer is monomer C, and (c) grafting the resulting esterified copolymer with a monomer D selected from the group consisting of styrene, vinyl acetate, vinyltoluene, chlorostyrene, vinylpyrrolidone, vinylpyridine, and compounds having the general formula II: ##STR18## wherein R is the same as defined above and Z is --COOC m H 2m+1 , wherein m is an integer of 1 to 4, --OCOC m' H 2m'+1 , wherein m' is an integer of 1 to 6, ##STR19## wherein m is the same as defined above, --COOH, --COOC 2 H 4 OH or ##STR20##
Claim 2
Dependent Claim
281 words
A liquid developer for use in electrophotography which is prepared by dispersing a toner consisting essentially of a pigment or dye and a resin in a carrier liquid having a high insulating property and a low dielectric constant, wherein said resin is a nonaqueous dispersed resin obtained by effecting, in a nonaqueous solvent comprising an aliphatic hydrocarbon, the steps of: (a) copolymerizing (1) a monomer A having the general formula I: ##STR17## wherein R is --H or --CH 3 , A is --COOC n H 2n+1 or --OC n H 2n+1 , and n is an integer of 6 to 20, with (2) a polyfunctional second monomer having two or more double bonds and (3) a third monomer selected from the group consisting of a monomer B having a glycidyl group or a vinyl monomer C having a carboxyl group, (b) esterifying the resulting copolymer with a fourth monomer selected from the group consisting of said monomer B and said monomer C, such that said fourth monomer is said monomer C when said third monomer is monomer B and said fourth monomer is said monomer B when said third monomer is monomer C, and (c) grafting the resulting esterified copolymer with a monomer D selected from the group consisting of styrene, vinyl acetate, vinyltoluene, chlorostyrene, vinylpyrrolidone, vinylpyridine, and compounds having the general formula II: ##STR18## wherein R is the same as defined above and Z is --COOC m H 2m+1 , wherein m is an integer of 1 to 4, --OCOC m' H 2m'+1 , wherein m' is an integer of 1 to 6, ##STR19## wherein m is the same as defined above, --COOH, --COOC 2 H 4 OH or ##STR20##
Claim 3
Dependent Claim
129 words
A developer according to claim 1 wherein said polyfunctional second monomer is used in an amount of 0.0001 to 0.5 part by weight to 1 part by weight of said monomer A in the step (a), said third monomer is used in an amount of 0.001 to 0.5 part by weight to 1 part by weight of said monomer A in the step (a), said fourth monomer in the step (b) is used in an amount of 0.001 to 0.5 part by weight to 1 part by weight of said copolymer produced in step (a), and said monomer D is used in the step (c) in an amount of 0.01 to 1.0 part by weight to 1 part by weight of said esterified copolymer produced in the step (b).
Claim 4
Dependent Claim
144 words
A developer according to claim 1 wherein said polyfunctional second monomer is one member selected from the group consisting of polyfunctional acrylate or methacrylate compounds having the general formula III: ##STR21## wherein R 1 , which may be the same or different, is a hydrogen atom or a methyl group, and R 2 is a dihydric aliphatic hydrocarbon, alicyclic hydrocarbon or aromatic hydrocarbon radical; compounds having the general formula VI: ##STR22## wherein R 1 is the same as defined in the general formula III, and R 3 is a dihydric aliphatic radical excluding a substituted or non-substituted methylene group, an alicyclic radical or an aromatic hydrocarbon radical; and compounds having the general formula V: ##STR23## wherein R 1 is the same as defined in the general formula III, and R 4 is a dihydric aliphatic radical, an alicyclic radical or an aromatic hydrocarbon radical.
Claim 5
Dependent Claim
34 words
A developer according to claim 1 further comprising a wax-like substance selected from the group consisting of a wax having a softening point of 60° to 130° C. and a low molecular weight polyolefin.
Claim 6
Dependent Claim
28 words
A developer according to claim 1 wherein said carrier liquid has a resistance of at least 10 9 Ω cm and a dielectric constant not greater than 3.
Claim 7
Dependent Claim
24 words
A developer according to claim 1 or claim 3 wherein the specific gravity of said resin is in the range of 0.85 to 1.05.
Claim 8
Dependent Claim
26 words
A developer according to claim 1 wherein said toner is in the form of approximately uniform particles having diameters in the range of 0.2 to 1.0μ.
References Cited (Backward Citations)
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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) | 1986-06-13 | 1986-12-13 | 1987-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-06-13 | 1990-12-13 | 1991-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-06-13 | 1994-12-13 | 1995-06-14 | $7700.00 | Window Closed / Lapsed |