Compositions: coating or plastic – Materials or ingredients – Pigment – filler – or aggregate compositions – e.g. – stone,...
Patent
1996-03-29
1998-07-14
Marcheschi, Michael
Compositions: coating or plastic
Materials or ingredients
Pigment, filler, or aggregate compositions, e.g., stone,...
106486, 106416, 106DIG4, 501146, 501148, C04B 3302, C09C 142, C09C 308
Patent
active
057797854
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates generally to smectite clays, and more specifically relates to aqueous low viscosity smectite clay slurries of elevated solids content, and to a method for producing same which while suppressing swelling of the smectite in the high solids slurry, enables the normal viscosifying and other properties of a swelled smectite to be restored at the point of slurry use.
BACKGROUND OF THE INVENTION
Smectite clays are phyllosilicates of the 2:1 layered type. The smectite group includes inter alia the mineral sub-groups montmorillonite, beidellite, nontronite, saponite, hectorite and sauconite. Among the smectite clays to which the present invention is applicable are the naturally occurring Wyoming variety of swelling bentonite and similar clays, and hectorite, which is a swelling magnesium-lithium silicate. For use in the invention, these clays are preferably converted to the sodium form if they are not already in this form. This can be effected by a cation exchange reaction with a soluble sodium compound. These methods are well-known in the art.
Smectite-type clays prepared synthetically can also be used in the slurries of the invention. Representative of such clays are montmorillonite, bentonite, beidellite, hectorite, saponite and stevensite. Representative hydrothermal processes for preparing synthetic smectites are described in U.S. Pat. Nos. 3,252,757 to Granquist; 3,586,478 to Neumann; 3,666,407 to Orlemann; 3,671,190 to Neumann; 3,844,978 and 3,844,979 to Hickson; and 3,852,405 and 3,855,147 to Granquist.
Smectite clays are commercially important minerals. Appropriately processed, smectite clays are excellent viscosifiers, binders, film formers, fabric softeners and retention aid additives in paper making. These clays are platey-type materials having a micaceous structure. They are highly colloidal and readily swell in water to form viscous, thixotropic gels which renders the clays useful as viscosity builders in many industries and applications including, for example, in foundry molding compositions, as suspension aids in agricultural sprays, and for thickening cosmetics. The high surface area generated by swelling in water also makes these clays useful in fabric softening and in paper making applications. In the latter environment smectite clays are particularly useful as retention aids. In such use it is often of interest to intermix an aqueous slurry of the smectite clay with a cellulosic suspension, and thereafter drain the cellulosic suspension.
Most smectite clays are sold as fine powders. As with most minerals, however, these powders are difficult and expensive to handle. They also are subject to considerable "dusting", i.e. to evolution of dust during handling, so that they can in some cases cause environmental problems, and even health risks. To minimize these problems and to provide the user of the mineral with a product which is more ready for the user's application, many minerals are sold or shipped by the manufacturer or distributor as high solids aqueous slurries. Such high solids slurries can be easily stored, shipped, transferred, e.g. pumped and metered, with significantly less capital expenditure and many fewer problems than are associated with dry mineral powders.
In most applications, nevertheless, it is not economical or practical to ship smectite clays as aqueous slurries because of the large quantity of water normally required in such slurries. This problem arises because smectites are indeed good viscosifiers, whereby it has not generally been possible to produce high solids aqueous slurries by the usual methods. In general, only about 8%-10% solids slurries of good quality swelling smectite can be produced in water, and at solids contents greater than about 10%, the viscosities of the slurries can become so high that they cannot readily be pumped by conventional equipment and gelling upon standing becomes a problem.
Thus, there is a need for aqueous slurries containing substantially greater than 10% by weight of smectite clay, which h
REFERENCES:
patent: 3080256 (1963-03-01), Bundy
patent: 3252757 (1966-05-01), Granquist
patent: 3298849 (1967-01-01), Dohman et al.
patent: 3586478 (1971-06-01), Neumann
patent: 3594203 (1971-07-01), Sawyer et al.
patent: 3666407 (1972-05-01), Orlemann
patent: 3671190 (1972-06-01), Newuman
patent: 3844978 (1974-10-01), Hickson
patent: 3844979 (1974-10-01), Hickson
patent: 3852405 (1974-12-01), Granquist
patent: 3855147 (1974-12-01), Granquist
patent: 3892587 (1975-07-01), Abercrombie, Jr.
patent: 3961979 (1976-06-01), Abercrombie, Jr.
patent: 4017324 (1977-04-01), Eggers
patent: 4078941 (1978-03-01), Bundy
patent: 4118246 (1978-10-01), Horzepa et al.
patent: 4359339 (1982-11-01), Van Fisk et al.
patent: 4695402 (1987-09-01), Finlayson et al.
patent: 5015334 (1991-05-01), Derrick
patent: 5057467 (1991-10-01), Croft
patent: 5075033 (1991-12-01), Cody et al.
patent: 5223098 (1993-06-01), Cluyse et al.
patent: 5266538 (1993-11-01), Knudson et al.
patent: 5279664 (1994-01-01), Robinson et al.
patent: 5407480 (1995-04-01), Payton et al.
Canaris Nicholas
Miranda Jorge
Payton James
Marcheschi Michael
Vinings Industries Inc.
LandOfFree
Stabilized, high solids, low viscosity smectite slurries, and me does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Stabilized, high solids, low viscosity smectite slurries, and me, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Stabilized, high solids, low viscosity smectite slurries, and me will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1877791