US4939059A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrophotographic developer for fixing roller process using polyester resin
Assignee: Kao Corp
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Filing: 1987-08-26
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Granted: 1990-07-03
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Expires: 2007-08-26
Abstract
Abstract An electrophotographic developer composition comprises a binder resin, which comprises a polyester as the major component, said polyester obtained by co-condensation polymerization of (i) a diol component represented by the general formula: ##STR1## wherein R is an ethylene or propylene group and x and y are each an integer of 1 or more, with the proviso that the average sum total of x and y is 2 to 7, with (ii) a dicarboxylic acid, an anhydride or a lower alkyl ester thereof and (iii) a polycarboxylic acid having at least three carboxyl groups or an anhydride or a lower alkyl ester thereof or a polyhydric alcohol having at least three hydroxyl groups and having an OHV/AV value of at least 1.2 wherein AV is an acid value of the polyester and OHV is a hydroxyl value thereof, and at least two charge controllers.
Inventors
- 👤 Kuniyasu Kawabe
- 👤 Masayoshi Nawa
- 👤 Norihiro Hayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:53
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; C; C08; C08G; C08G63/00; C08G63/66; C08G63/668; G03G9/087; G03G9/08742; G03G9/08755; Y; Y10; Y10S; Y10S430/00; Y10S430/001; Y10S430/105; Y10S525/00; Y10S525/934
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
175 words
In a method for electrophotography wherein a latent electrostatic image is developed and fixed by a fixing roller, the improvement using a developer composition which comprises a polyester as the major component, said polyester obtained by co-condensation polymerization of components (i) a diol represented by the formula: ##STR3## wherein R is an ethylene or propylene group and x and y are each an integer of 1 or more, with the proviso that the average sum total of x and y is 2 or 7, with (ii) a dicarboxylic acid, an anhydride or a lower alkyl ester thereof; and (iii) a polycarboxylic acid having at least three carboxyl groups, an anhydride or a lower alkyl ester thereof, or a polyhydric alcohol having at least three hydroxyl groups and having an OHV/AV value of at least 1.2 wherein AV is an acid value of said polyester and OHV is a hydroxyl value thereof, and at least two charge controllers, wherein at least one of which is positively chargeable and at least one of which is negatively chargeable.
Claim 2
Dependent Claim
175 words
In a method for electrophotography wherein a latent electrostatic image is developed and fixed by a fixing roller, the improvement using a developer composition which comprises a polyester as the major component, said polyester obtained by co-condensation polymerization of components (i) a diol represented by the formula: ##STR3## wherein R is an ethylene or propylene group and x and y are each an integer of 1 or more, with the proviso that the average sum total of x and y is 2 or 7, with (ii) a dicarboxylic acid, an anhydride or a lower alkyl ester thereof; and (iii) a polycarboxylic acid having at least three carboxyl groups, an anhydride or a lower alkyl ester thereof, or a polyhydric alcohol having at least three hydroxyl groups and having an OHV/AV value of at least 1.2 wherein AV is an acid value of said polyester and OHV is a hydroxyl value thereof, and at least two charge controllers, wherein at least one of which is positively chargeable and at least one of which is negatively chargeable.
Claim 3
Dependent Claim
20 words
The method according to claim 1 wherein said fixing roller process occurs at a temperature of less than 220° C.
Claim 4
Dependent Claim
29 words
The method according to claim 1, wherein said binder resin has a softening point of 106 to 160° C. and a glass transition temperature of 50 to 80° C.
Claim 5
Dependent Claim
27 words
The method according to claim 1, wherein the amount of said positively chargeable charge controller does not exceed one-half of that of said negatively chargeable charge controller.
Claim 6
Dependent Claim
28 words
The method according to claim 1 wherein component (iii) is present in an amount of from 5 to 60 molar % based on component (ii) or component (i).
Claim 7
Dependent Claim
26 words
The method according to claim 1 wherein said charge controllers are present in an amount of from 0.1 to 8.0% by weight of said binder resin.
Claim 8
Dependent Claim
26 words
The method according to claim 1 wherein said charge controllers are present in an amount of from 0.02 to 5.0% by weight of said binder resin.
Claim 9
Dependent Claim
40 words
The method according to claim 1 wherein the binder resin comprises up to 30% by weight based on the weight of the binder resin of a styrene resin or styrene-acrylic resin having a number-average molecular weight of 11,000 or less.
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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) | 1993-07-02 | 1994-01-01 | 1994-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-02 | 1998-01-01 | 1998-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-02 | 2002-01-01 | 2002-07-03 | $7700.00 | Window Closed / Lapsed |