EP0495476A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Developer composition for electrophotography
Assignee: Kao Corp
•
Filing: 1992-01-15
•
Granted: —
•
Expires: 2012-01-15
Abstract
Abstract A developer composition for electrophotography comprising a binding resin and a colorant, said binding resin comprising a specified nonlinear first polyester and a specified linear second polyester, the weight ratio of the first polyester to the second polyester being (80 : 20) to (20 : 80) is disclosed. The developer composition of the present invention is excellent in the hot offset resistance, low temperature fixation, smoothness and transparency of fixed face and blocking resistance.
Inventors
- 👤 Eizi c/o Wakayama Laboratory Morimoto
- 👤 Kuniyasu c/o Wakayama Laboratory Kawabe
- 👤 Tetuhiro c/o Wakayama Laboratory Semura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:55
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/087; G03G9/08742; G03G9/08755
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
237 words
A developer composition for electrophotography comprising a binding resin and a colorant, said binding resin comprising a first polyester and a second polyester, the weight ratio of the first polyester to the second polyester being (80 : 20) to (20 : 80), said first polyester being a nonlinear polyester comprising an acid component (A) originated from an aliphatic dicarboxylic acid and/or acid anhydride thereof in an amount of 50% and more by mole based on the entire acid component, and an acid component (B) originated from a compound selected from the group consisting of a tricarboxylic acid, a higher polycarboxylic acid, acid anhydride thereof and lower alkyl ester thereof in an amount of 0.05% by mole to 40% by mole exclusive based on the entire acid component and/or an alcohol component (A) originated from a triol and/or a higher polyol in an amount of 0.05% by mole to 40% by mole exclusive based on the entire alcohol component, and having a softening point, Tsp, in the range of from 100°C to 130°C exclusive, said second polyester being a linear polyester comprising an acid component (C) originated from an aliphatic dicarboxylic acid and/or acid anhydride thereof in an amount of 50% and more by mole based on the entire acid component, and having a softening point, Tsp, in the range of from 80°C to 110°C exclusive and lower than that of the first polyester by at least 10°C.
Claim 2
Dependent Claim
82 words
The developer composition for electrophotography according to claim 1, wherein the first polyester and the second polyester each comprises an alcohol component (B) originated from a compound represented by the following general formula (1) as a main component of the alcohol component originated from a diol. wherein R stands for an ethylene group or a propylene group and x and y are each an integer, provided that the average value of the sum of x and y values is 2 to 7.
Claim 3
Dependent Claim
27 words
The developer composition for electrophotography according to claim 1, wherein the glass transition temperature of the first polyester and the second polyester each is 40 to 80°C.
Claim 4
Dependent Claim
23 words
The developer composition for electrophotography according to claim 1, wherein the first polyester has 0 to 5% by weight of chloroform insoluble matter.
Claim 5
Dependent Claim
38 words
The developer composition for electrophotography according to claim 1, wherein the binding resin comprises 70 to 100 % by weight of the total amount of the first polyester and the second polyester based on the entire binding resin.
Claim 6
Dependent Claim
48 words
The developer composition for electrophotography according to claim 1, wherein the binding resin comprises 70 to 100 % by weight of the total amount of the first polyester and the second polyester and 30 to 0 % by weight of styrene-acrylic resin based on the entire binding resin.
Claim 7
Dependent Claim
20 words
The developer composition for electrophotography according to claim 1, wherein the developer composition further comprises a low molecular weight polyolefin.
Claim 8
Dependent Claim
19 words
The developer composition for electrophotography according to claim 1, wherein the developer composition further comprises a magnetic impalpable powder.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.