Patent US5006574A successfully refreshed from Google Patents.
US5006574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cationcally dispersed slurries of calcined kaolin clay
Assignee: BASF Corp
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Filing: 1989-02-10
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Granted: 1991-04-09
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Expires: 2009-02-10
Abstract
Abstract A stable fluid acidic concentrated aqueous slurry of positively charged particles of a calcined kaolin clay pigment wherein the dispersant is a water-soluble organic cationic material, such as a quarternary ammonium polyelectrolyte.
Inventors
- 👤 Paul Sennett
- 👤 Steven A. Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:38
CPC Classifications
C; C09; C09D; C09D17/00; C09D17/004; C09C; C09C1/00; C09C1/40; C09C1/42; C01; C01P; C01P2004/00; C01P2004/51; C01P2004/60; C01P2006/00; C01P2006/22; C01P2006/40
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
114 words
A method for preparing a fluid stable aqueous slurry of particles of a calcined clay pigment suitable for use in coating or filling paper or as an extender pigment in paint which comprises providing dispersant-free particles of calcined kaolin clay and adding said particles to a solution of a water-soluble polymeric cationic dispersant in amount sufficient to impart a positive zeta potential to said particles of said pigment and to result in a pH in the range of about 3 to 4, said dispersant being selected from the group consisting of alkyl diallyl quarternary ammonium salts, quarternary ammonium cationic polyelectrolytes obtained by copolymerizing aliphatic secondary amines with epichlorohydrin and poly (quarternary ammonium) polyester salts.
Claim 2
Independent Claim
114 words
A method for preparing a fluid stable aqueous slurry of particles of a calcined clay pigment suitable for use in coating or filling paper or as an extender pigment in paint which comprises providing dispersant-free particles of calcined kaolin clay and adding said particles to a solution of a water-soluble polymeric cationic dispersant in amount sufficient to impart a positive zeta potential to said particles of said pigment and to result in a pH in the range of about 3 to 4, said dispersant being selected from the group consisting of alkyl diallyl quarternary ammonium salts, quarternary ammonium cationic polyelectrolytes obtained by copolymerizing aliphatic secondary amines with epichlorohydrin and poly (quarternary ammonium) polyester salts.
Claim 3
Dependent Claim
33 words
The method as claimed in claim 1 wherein said cationic dispersant is added in amount in the range of about 0.2 to 0.8 percent based on the dry weight of the calcined clay.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein the amount of dispersant is such that said slurry has minimum Brookfield viscosity of 90 mPa.s measured at 100 rpm.
Claim 5
Dependent Claim
26 words
The method of claim 1 including the additional step of spray drying said fluid slurry of calcined clay, thereby providing a dried predispersed calcined clay pigment.
Claim 6
Dependent Claim
7 words
The spray dried product of claim 4.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-04-08 | 1994-10-08 | 1995-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-08 | 1998-10-08 | 1999-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-08 | 2002-10-08 | 2003-04-09 | $7700.00 | Window Closed / Lapsed |