US4797342A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Processes for the preparation of liquid developers with low vapor pressure components
Assignee: Xerox Corp
•
Filing: 1987-11-23
•
Granted: 1989-01-10
•
Expires: 2007-11-23
Abstract
Abstract A process for the preparation of liquid developer compositions which comprises mixing a resin with a low vapor pressure oil at elevated temperatures permitting the resin to melt and enabling the formation of a resin oil mixture; thereafter adding to the oil resin mixture at elevated temperatures pigment particles, and stirring until the pigment has become dispersed in the resin; followed by attriting the mixture while cooling, for example, to ambient temperatures; thereafter filtering the aforementioned mixture, and dispersing the product in a low viscosity oil; and subsequently adding to the formed mixture a charge control additive.
Inventors
- 👤 Melvin D. Croucher
- 👤 Raymond W. Wong
- 👤 Stephan Drappel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:20
CPC Classifications
G; G03; G03G; G03G9/00; G03G9/08; G03G9/12; G03G9/135; G03G9/1355
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
79 words
A process for the preparation of liquid developer compositions which comprises admixing molten resin components in a vehicle component possessing a vapor pressure of from about 0.01 to about 0.1 millimeter of mercury; thereafter adding thereto pigment particles; subsequently cooling and attriting the aforementioned resulting mixture thereby enabling entrapment of the vehicle in the developer composition; thereafter filtering and dispersing the resulting particles in a low viscosity oil; and adding to the formed composition a charge control director component.
Claim 2
Dependent Claim
79 words
A process for the preparation of liquid developer compositions which comprises admixing molten resin components in a vehicle component possessing a vapor pressure of from about 0.01 to about 0.1 millimeter of mercury; thereafter adding thereto pigment particles; subsequently cooling and attriting the aforementioned resulting mixture thereby enabling entrapment of the vehicle in the developer composition; thereafter filtering and dispersing the resulting particles in a low viscosity oil; and adding to the formed composition a charge control director component.
Claim 3
Dependent Claim
100 words
A process for the preparation of liquid developer compositions which comprises mixing a resin with a low vapor pressure oil at elevated temperatures permitting the resin to melt and enabling the formation of a resin oil mixture; thereafter adding to the oil resin mixture at elevated temperatures pigment particles, and stirring until the pigment has become dispersed in the resin; cooling the mixture with attrition, thereby enabling entrapment of said oil in the developer composition; thereafter filtering the aforementioned mixture, and dispersing the product in a low viscosity oil; and subsequently adding to the formed mixture a charge control additive.
Claim 4
Dependent Claim
100 words
A process for the preparation of liquid developer compositions which comprises mixing a resin with a low vapor pressure oil at elevated temperatures permitting the resin to melt and enabling the formation of a resin oil mixture; thereafter adding to the oil resin mixture at elevated temperatures pigment particles, and stirring until the pigment has become dispersed in the resin; cooling the mixture with attrition, thereby enabling entrapment of said oil in the developer composition; thereafter filtering the aforementioned mixture, and dispersing the product in a low viscosity oil; and subsequently adding to the formed mixture a charge control additive.
Claim 5
Dependent Claim
23 words
A process in accordance with claim 2 wherein the mixing is accomplished at a temperature of from about 90° to about 110° C.
Claim 6
Dependent Claim
34 words
A process in accordance with claim 2 wherein the low vapor pressure oil is present in the mixture in an amount of from about 80 percent by weight to about 90 percent by weight.
Claim 7
Dependent Claim
25 words
A process in accordance with claim 2 wherein the vapor pressure of the oil selected is from about 0.01 to about 0.1 millimeter of mercury.
Claim 8
Dependent Claim
25 words
A process in accordace with claim 2 wherein the low vapor pressure oil is selected from the group consisting of Isopar V and Magiesol 60.
Claim 9
Dependent Claim
26 words
A process in accordance with claim 2 wherein the pigment particles are selected from the group consisting of carbon black, cyan, magenta, yellow, or mixtures thereof.
Claim 10
Dependent Claim
28 words
A process in accordance with claim 7 wherein the pigment is present in an amount of from about 3 percent by weight to about 25 percent by weight.
Claim 11
Dependent Claim
52 words
A process in accordance with claim 2 wherein subsequent to dispersion of the pigment in the resin particles the mixture is allowed to cool to room temperature over a period of from about 3 to about 5 hours enabling particles with an average diameter of from about 2 to about 3 microns.
Claim 12
Dependent Claim
26 words
A process in accordance with claim 2 wherein the charge director is present in an amount of from about 0.01 to about 2 percent by weight.
Claim 13
Dependent Claim
22 words
A process in accordance with claim 2 wherein the charge director is selected from the group consisting of polyisobutylene succinimide and lecithin.
Claim 14
Dependent Claim
24 words
A process in accordance with claim 2 wherein the developers possess an image transfer efficiency of from about 80 percent to about 99.8 percent.
Claim 15
Dependent Claim
30 words
A process in accordance with claim 2 wherein the charge control additive is present in an amount of from about 0.02 percent by weight to about 0.05 percent by weight.
Claim 16
Dependent Claim
30 words
A process in accordance with claim 2 wherein the charge director is selected from a group consisting of salts of cadmium, calcium, manganese, magnesium, and zinc salts of heptanoic acid.
Claim 17
Dependent Claim
27 words
A process in accordance with claim 2 wherein the charge director is selected from barium, aluminum, cobalt, manganese, zinc, cerium and zirconium salts of 2-ethyl hexanoic acid.
Claim 18
Dependent Claim
30 words
A process in accordance with claim 1 wherein the charge director is selected from the group consisting of the barium, aluminum, zinc, copper, lead and iron salts of stearic acid.
Claim 19
Dependent Claim
22 words
A process in accordance with claim 1 wherein the charge director is selected from the group consisting of polyisobutylene succinimide and lecithin.
Claim 20
Dependent Claim
18 words
A process in accordace with claim 1 wherein the low viscosity oil is Isopar G or Isopar L.
Claim 21
Dependent Claim
18 words
A process in accordance with claim 2 wherein the low viscosity oil is Isopar G or Isopar L.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-10 | 1992-07-11 | 1993-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-10 | 1996-07-11 | 1997-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-10 | 2000-07-11 | 2001-01-10 | $7700.00 | Window Closed / Lapsed |