Patent US3620828A successfully refreshed from Google Patents.
US3620828A
Expired / Lapsed
US
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Process for producing pigmented electroconductive coating compositions
Assignee: Calgon Corp
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Filing: 1970-04-15
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Granted: 1971-11-16
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Expires: 1990-04-15
Abstract
Abstract A method of rendering polycationic materials compatible with anionic pigments in coating compositions is disclosed. Pigmented polycationic electroconductive polymer coatings on paper stock are used in direct electrophotographic reproduction machines. Polycationic components and anionic pigments are rendered compatible if the Zeta potential of the pigment is neutralized by the addition of a dilute cationic compound, and the electroconductive polycationic polymer is thereafter added to the pigment dispersion with a high degree of agitation. By following this procedure, the pigment dispersion remains stable, and neither the coated paper nor the dispersion stratifies or develops agglomerates.
Inventors
- 👤 Fritz M K Werdouschegg
- 👤 Robert H Windhager
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:16
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/10; G03G5/105; G03G5/107
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
24 words
The process as claimed in claim 1 wherein the concentration of said pigment slurry is about 3 to about 70 percent solids by weight.
Claim 2
Dependent Claim
23 words
The process as claimed in claim 2 wherein the concentration of said pigment slurry is about 30 to about 70 percent by weight.
Claim 3
Dependent Claim
25 words
The process as claimed in claim 2 wherein the Zeta potential of the anionic pigments after the initial neutralization step is at least about zero.
Claim 4
Dependent Claim
22 words
The process as claimed in claim 4 wherein the Zeta potential of the neutralized pigment slurry has a positive value above zero.
Claim 5
Dependent Claim
30 words
The process as claimed in claim 1 wherein the concentration of the neutralizing polycationic polymer solution is in the range of about 0.1 percent to 15 percent solids by weight.
Claim 6
Dependent Claim
14 words
The process as claimed in claim 2 wherein the polycationic polymer is a poly(ethylene)aMine.
Claim 7
Dependent Claim
16 words
The process as claimed in claim 2 wherein the neutralizing polycationic polymer is a 3,5-piperidinium polymer.
Claim 8
Dependent Claim
112 words
A process for producing a pigmented electroconductive paper, said process comprising the steps of (a) neutralizing the Zeta potential of an anionic pigment slurry of about 3 to about 80 percent solids by the addition of a dilute solution of at least one polycationic polymer, wherein the concentration of said polycationic polymer in said solution is from about 0.1 to about 20 percent by weight; (b) thereafter adding an electroconductive 3,5-piperidinium polymer with high agitation to the neutralized pigment slurry to form a coating slurry; (c) applying the coating slurry to a paper base stock; and (d) drying the coated paper base stock, thereby producing coated paper suitable for electrophotographic copy use.
Claim 9
Dependent Claim
24 words
The process as claimed in claim 9 wherein the Zeta potential of the anionic pigments after the neutralization step is at least about zero.
Claim 10
Dependent Claim
23 words
The process as claimed in claim 10 wherein the Zeta potential of the anionic neutralized pigment slurry is a positive value about zero.
Claim 11
Dependent Claim
17 words
The process as claimed in claim 9 wherein the 3,5-piperidinium polymer is a diallyl quaternary ammonium homopolymer.
Claim 12
Dependent Claim
25 words
The process as claimed in claim 9 wherein the concentration of said neutralizing polycationic polymer is from about 0.1 to about 15 percent by weight.
Claim 13
Dependent Claim
23 words
The process as claimed in claim 9 wherein the concentration of said pigment slurry is about 30 to about 70 percent by weight.
Claim 14
Dependent Claim
75 words
The process as claimed in claim 9, including the additional step of adding at least one natural or synthetic coating binder to the coating slurry prior to the application thereof to the paper base stock, wherein the amount of said natural or synthetic coating binder is less than 50 percent by weight, based on the weight of total coating formulation in said coating slurry, whereby solvent and toner holdout of the electroconductive paper is improved.
Claim 15
Dependent Claim
41 words
The process as claimed in claim 9 wherein two coating slurries of different concentrations are prepared and applied to different sides of paper base stock, thereby producing electroconductive papers having different degrees of surface resistivity on different sides of the paper.
Claim 16
Dependent Claim
42 words
The process as claimed in claim 16 wherein a sensitized zinc oxide coating is applied to at least one side of the coated paper, thereby producing electrophotographic copy paper which may be used in either dry or liquid toner system copy machines.
Claim 17
Dependent Claim
25 words
The process as claimed in claim 9, wherein the concentration of said neutralizing polycationic polymer is from about 0.1 to about 10 percent by weight.
Claim 18
Dependent Claim
25 words
The process as claimed in claim 9, wherein the concentration of said neutralizing polycationic polymer is from about 0.5 to about 2.5 percent by weight.
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) | 1974-11-15 | 1975-05-17 | 1975-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-15 | 1979-05-17 | 1979-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-15 | 1983-05-17 | 1983-11-16 | $7700.00 | Window Closed / Lapsed |