US4127421A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for granulating lead chromate-containing pigments
Assignee: Hercules LLC
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Filing: 1977-08-22
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Granted: 1978-11-28
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Expires: 1997-08-22
Abstract
Abstract A process is described for the production of high yields of lead chromate-containing pigments in a nondusting granular form. The process involves agitating in aqueous medium designated amounts of a lead chromate-containing pigment, a friable, low molecular weight hydrocarbon-type resin softening at 50°-95° C. and a cationic surfactant at a temperature above the softening point of the resin and continuing agitation at a temperature within the range of about 5° to about 20° C. above the softening point of the resin until the pigment dispersion is granulated. The process provides yields of at least 70% of granules in the particle size range of about 0.1 to about 4 millimeters. The granules are particularly useful as colorants for air-drying enamel coating systems and plastics.
Inventors
- 👤 Richard M. Ferrill, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:24
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/20; C08J3/22; C08J3/226; C08K; C08K9/00; C08K9/04; C09; C09C; C09C1/00; C09C1/14; C09C1/20; C09C3/00; C09C3/04; C09C3/045; C01; C01P; C01P2004/00; C01P2004/30; C01P2004/32; C01P2004/50; C01P2004/60; C01P2006/00; C01P2006/20; C01P2006/60
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
159 words
A process for the production of high yields of nondusting, free-flowing granules of a lead chromate-containing pigment composition, which process comprises (a) forming an aqueous slurry of a lead chromate-containing pigment dispersed in a friable hydrocarbon resin having a Ring and Ball softening point within the range of 50° to 75° C. and a number average molecular weight range of 500 to 900 by agitating said pigment and resin in water in the presence of a cationic surfactant at a temperature above the softening point of the resin, said pigment and resin being present in a weight ratio from 7:1 to 1:1 and said resin and surfactant being present in a weight ratio of from about 2.5:1 to about 3.5:1, (b) continuing agitation of said slurry at a temperature within the range of from about 5° to about 20° C. above the softening point of said resin until the pigment dispersion is granulated and (c) recovering the resulting granules.
Claim 2
Dependent Claim
159 words
A process for the production of high yields of nondusting, free-flowing granules of a lead chromate-containing pigment composition, which process comprises (a) forming an aqueous slurry of a lead chromate-containing pigment dispersed in a friable hydrocarbon resin having a Ring and Ball softening point within the range of 50° to 75° C. and a number average molecular weight range of 500 to 900 by agitating said pigment and resin in water in the presence of a cationic surfactant at a temperature above the softening point of the resin, said pigment and resin being present in a weight ratio from 7:1 to 1:1 and said resin and surfactant being present in a weight ratio of from about 2.5:1 to about 3.5:1, (b) continuing agitation of said slurry at a temperature within the range of from about 5° to about 20° C. above the softening point of said resin until the pigment dispersion is granulated and (c) recovering the resulting granules.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein the friable resin is an aliphatic, cycloaliphatic or aromatic hydrocarbon resin.
Claim 4
Dependent Claim
20 words
The process of claim 2 wherein the hydrocarbon resin is an aromatic hydrocarbon resin derived from coal and petroleum sources.
Claim 5
Dependent Claim
10 words
The process of claim 3 wherein the resin is hydrogenated.
Claim 6
Dependent Claim
14 words
The process of claim 2 wherein the hydrocarbon resin is a terpene hydrocarbon resin.
Claim 7
Dependent Claim
11 words
The process of claim 2 wherein the hydrocarbon resin is polystyrene.
Claim 8
Dependent Claim
10 words
The process of claim 6 wherein the resin is hydrogenated.
Claim 9
Dependent Claim
18 words
The process of claim 2 wherein the hydrocarbon resin is a copolymer of vinyl toluene and α-methyl styrene.
Claim 10
Dependent Claim
25 words
The process of claim 8 wherein the aqueous slurry also contains from 0.1 to 20% by weight of the pigment of a resinous granulating agent.
Claim 11
Dependent Claim
33 words
The process of claim 9 wherein the granulating agent is a low molecular weight hydrocarbon resin having a softening point of about 5° to about 40° C. or a viscous liquid rosin ester.
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) | 1981-11-27 | 1982-05-29 | 1982-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-11-27 | 1986-05-29 | 1986-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-11-27 | 1990-05-29 | 1990-11-28 | $7700.00 | Window Closed / Lapsed |