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EP0259642A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Electrophotographic developer composition

Assignee: Kao Corp
•
Filing: 1987-08-13
•
Granted: —
•
Expires: 2007-08-13
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Abstract

Abstract An electrophotographic developer composition comprises a polyester obtained by co-condensation polymerization of (i) a diol component represented by the general formula: <CHEM> wherein R is an ethylene or propylene group and x and y are each an integer of 1 or above, with the proviso that the average sum total of x and y is 2 to 7, with (ii) a dicarboxylic acid or anhydride or a lower alkyl ester thereof and (iii) a polycarboxylic acid having at least three carboxyl groups or 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 as a major component of a binder resin and at least two charge controllers. r

Inventors

  • 👤 Kuniyasu Kawabe
  • 👤 Masayoshi Nawa
  • 👤 Norihiro Hayashi

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-09 07:05
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: 5
Claim 1
Independent Claim 138 words
An electrophotographic developer composition containing a polyester obtained by co-condensation polymerization of (i) a diol component represented by the general formula: wherein R is an ethylene or propylene group and x and y are each an integer of 1 or above, with the proviso that the average sum total of x and y is 2 to 7, with (ii) a dicarboxylic acid or anhydride or a lower alkyl ester thereof and (iii) a polycarboxylic acid having at least three carboxyl groups or 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 as a major component of a binder resin and at least two charge control­lers.
Claim 2
Dependent Claim 138 words
An electrophotographic developer composition containing a polyester obtained by co-condensation polymerization of (i) a diol component represented by the general formula: wherein R is an ethylene or propylene group and x and y are each an integer of 1 or above, with the proviso that the average sum total of x and y is 2 to 7, with (ii) a dicarboxylic acid or anhydride or a lower alkyl ester thereof and (iii) a polycarboxylic acid having at least three carboxyl groups or 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 as a major component of a binder resin and at least two charge control­lers.
Claim 3
Dependent Claim 31 words
An electrophotographic developer composition as set forth in 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 4
Dependent Claim 28 words
An electrophotographic developer composition as set forth in claim 1, wherein said charge control­lers comprise at least one positively chargeable one and at least one negatively chargeable one.
Claim 5
Dependent Claim 31 words
An electrophotographic developer composition as set forth in claim 3, wherein the amount of said positively chargeable charge controller does not ex­ceed one-half of that of said negatively chargeable charge controller.

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