US4738726A
Expired / Lapsed
US
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Treatment of clays with cationic polymers to prepare high bulking pigments
Assignee: BASF Catalysts LLC
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Filing: 1986-05-12
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Granted: 1988-04-19
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Expires: 2006-05-12
Abstract
Abstract A highly bulked kaolin pigment is prepared by mixing a small but effective amount of a water-soluble cationic polyelectrolyte flocculant with a kaolin clay pigment in the presence of water to prepare a bulked clay pigment product. Upon dewatering, the resultant polyelectrolyte treated clay product can be dispersed to form high solids clay-water slurries useful in making aqueous coating colors suitable for manufacturing coating lightweight publication papers or the pigment can be used as a filler for paper webs.
Inventors
- 👤 Richard J. Pratt
- 👤 Richard A. Slepetys
- 👤 Saad Nemeh
- 👤 Mitchell J. Willis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:03
CPC Classifications
C; C09; C09C; C09C3/00; D; D21; D21H; D21H19/00; D21H19/36; D21H19/44; D21H19/56; D21H19/58; C09C1/00; C09C1/40; C09C1/42; D21H19/38; D21H19/40; D21H19/62; C01; C01P; C01P2002/00; C01P2002/80; C01P2002/84; C01P2004/00; C01P2004/01; C01P2004/03; C01P2004/30; C01P2004/32; C01P2004/51; C01P2004/60; C01P2004/61; C01P2004/62; C01P2006/00; C01P2006/10; C01P2006/22; C01P2006/60; C01P2006/80; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31855; Y10T428/31931; Y10T428/31971; Y10T428/31975
Claims Analysis
Total Claims: 50
Claim 1
Independent Claim
99 words
A novel opacifying pigment composition consisting essentially of particles of hydrous kaolin clay flocculated with a minor amount of a cationic polyelectrolyte flocculant, said particles of clay having a particle size distribution such that less than 35% by weight are finer than 0.3 micrometers prior to being flocculated, said pigment having a G.E. brightness of at least 85%, and scattering values at 457 nm and 577 nm higher than that of said clay in the absence of said polyelectrolyte, said pigment being capable of being formed into a 62% solids fluid slurry having useable low and high shear viscosity.
Claim 2
Dependent Claim
99 words
A novel opacifying pigment composition consisting essentially of particles of hydrous kaolin clay flocculated with a minor amount of a cationic polyelectrolyte flocculant, said particles of clay having a particle size distribution such that less than 35% by weight are finer than 0.3 micrometers prior to being flocculated, said pigment having a G.E. brightness of at least 85%, and scattering values at 457 nm and 577 nm higher than that of said clay in the absence of said polyelectrolyte, said pigment being capable of being formed into a 62% solids fluid slurry having useable low and high shear viscosity.
Claim 3
Dependent Claim
43 words
The pigment of claim 1 wherein the Hercules endpoint viscosity of a 62% solids slurry at 16×10 5 dyne-cm is 500 rpm or higher as measured using the "A" bob and the Brookfield viscosity is below 1000 cp when measured at 20 rpm.
Claim 4
Dependent Claim
45 words
The pigment of claim 1 wherein said 62% solids slurry has a Hercules end point viscosity of 800 rpm or higher and said hydrous clay has a particle size distribution such that less than 25% by weight is finer than 0.3 micrometers before being flocculated.
Claim 5
Dependent Claim
22 words
The pigment of claim 3 wherein said 62% solids slurry has a Brookfield viscosity below 500 cp when measured at 20 rpm.
Claim 6
Dependent Claim
20 words
The pigment of claim 1 which also contains a small amount, less than 0.2% by weight, of a deflocculating agent.
Claim 7
Dependent Claim
14 words
The pigment of claim 1 wherein said polyelectrolyte is a quaternary ammonium polymer salt.
Claim 8
Dependent Claim
14 words
The pigment of claim 1 wherein said polyelectrolyte is a diallyl ammonium polymer salt.
Claim 9
Dependent Claim
28 words
The pigment of claims 1 or 4 wherein said polyelectrolyte is a dimethyl diallyl ammonium polymer salt having a molecular weight between 1×10 4 to 1×10 6 .
Claim 10
Dependent Claim
25 words
The pigment of claims 1 or 4 wherein said polyelectrolyte is a dimethyl diallyl ammonium salt polymer having a molecular weight between 50,000 and 250,000.
Claim 11
Dependent Claim
13 words
The pigment of claims 1 or 4 wherein said polyelectrolyte is a polyamine.
Claim 12
Independent Claim
99 words
A method for preparing a bulking pigment suitable for use in coating or filling paper which comprises preparing a fluid aqueous suspension of particles of kaolin clay, adding thereto a water-soluble cationic polyelectrolyte flocculant and at least partially dewatering said suspension to recover the resulting bulked clay, the amount of said cationic polyelectrolyte being sufficient to substantially thicken and flocculate said fluid suspension and result in a clay pigment having improved opacification but being limited such that said bulked clay is capable of being formed into a 62% solids fluid aqueous slurry having useable low and high shear viscosity.
Claim 13
Independent Claim
99 words
A method for preparing a bulking pigment suitable for use in coating or filling paper which comprises preparing a fluid aqueous suspension of particles of kaolin clay, adding thereto a water-soluble cationic polyelectrolyte flocculant and at least partially dewatering said suspension to recover the resulting bulked clay, the amount of said cationic polyelectrolyte being sufficient to substantially thicken and flocculate said fluid suspension and result in a clay pigment having improved opacification but being limited such that said bulked clay is capable of being formed into a 62% solids fluid aqueous slurry having useable low and high shear viscosity.
Claim 14
Dependent Claim
43 words
The method of claim 11 wherein said 62% solids aqueous slurry has a Brookfield viscosity below 1000 cp when measured at 20 rpm and a Hercules endpoint viscosity at 16×10 5 dyne-cm of 500 rpm or higher as measured using the "A" bob.
Claim 15
Dependent Claim
14 words
The method of claim 11 wherein said polyelectrolyte is a quaternary ammonium polymer salt.
Claim 16
Dependent Claim
14 words
The method of claim 11 wherein said polyelectrolyte is a diallyl ammonium polymer salt.
Claim 17
Dependent Claim
19 words
The method of claim 14 wherein said polyelectrolyte has a molecular weight in the range between 50,000 and 250,000.
Claim 18
Dependent Claim
20 words
The method of claim 11 wherein said polyelectrolyte is polydimethyldiallyl ammonium chloride having a molecular weight between 50,000 and 250,000.
Claim 19
Dependent Claim
11 words
The method of claim 11 wherein said polyelectrolyte is a polyamine.
Claim 20
Dependent Claim
21 words
The method of claim 11 wherein either said polyelectrolyte or said fluid aqueous suspension is hot when said polyelectrolyte is added.
Claim 21
Dependent Claim
27 words
The method of claim 11 wherein said polyelectrolyte is added in amount in the range of about 0.03% to 0.15% based on the weight of said clay.
Claim 22
Dependent Claim
62 words
The method of claim 11 including the steps of acidifying the resulting flocculated clay suspension, bleaching the clay in said suspension with a hydrosulfite salt, filtering said acidified suspension to recover bulked clay, washing the filtered clay and adding a deflocculant in amount of less than 0.2% by weight to the recovered bulked clay to provide a fluid suspension of bulked clay.
Claim 23
Dependent Claim
14 words
The method of claim 20 wherein said filtered clay is washed with hot water.
Claim 24
Dependent Claim
30 words
The method of claim 21 wherein said fluid suspension of bulked clay has a clay solids content in the range of 60% to 65% and is shipped in said form.
Claim 25
Dependent Claim
48 words
The method of claim 20 wherein said fluid suspension of bulked clay has a solids content in the range of 55 to 60% and said suspension is spray dried to provide a pigment capable of being dispersed in water at a clay solids content of 62% or higher.
Claim 26
Dependent Claim
21 words
The method of claim 20 wherein said fluid suspension of bulked clay is spray dried without permitting said suspension to age.
Claim 27
Dependent Claim
13 words
The method of claim 20 wherein said polyelectrolyte is a quaternary ammonium salt.
Claim 28
Dependent Claim
14 words
The method of claim 20 wherein said polyelectrolyte is a diallyl ammonium polymer salt.
Claim 29
Dependent Claim
44 words
The method of claim 20 wherein said polyelectrolyte is a diallyl ammonium polymer salt wherein the ammonium group is either partially substituted with an alkyl group having 1 to 18 carbon atoms or totally substituted with alkyl groups having 1 to 18 carbon atoms.
Claim 30
Dependent Claim
13 words
The method of claim 20 wherein the said polyelectrolyte is polydimethyldiallyl ammonium chloride.
Claim 31
Dependent Claim
19 words
The method of claim 28 wherein said polyelectrolyte has a molecular weight in the range between 50,000 and 250,000.
Claim 32
Dependent Claim
66 words
The method of claim 20 wherein said polyelectrolyte is added to the clay suspension at a concentration in the range of about 0.03% to about 0.15% by weight based on the dry weight of the clay and the clay being treated contains less than 35% by weight of particles finer than 0.3 micrometers and from 80% to 95% by weight of particles finer than 2 micrometers.
Claim 33
Dependent Claim
33 words
The method of claim 30 wherein said clay contains 20% or less by weight of particles finer than 0.3 micrometers and from 85% to 90% by weight of particles finer than 2 micrometers.
Claim 34
Dependent Claim
11 words
The method of claim 20 wherein said polyelectrolyte is a polyamine.
Claim 35
Dependent Claim
28 words
The method of claim 20 wherein the clay suspension to which said polyelectrolyte is added is in the form of a deflocculated suspension before said polyelectrolyte is added.
Claim 36
Independent Claim
219 words
A method for preparing a bulked clay pigment capable of being dispersed in water to form a high solids clay-water suspension having high shear and low shear viscosity suitable for use in coating printing paper which comprises preparing a deflocculated aqueous suspension of kaolin clay the particles of which are no more than 20% by weight finer than 0.3 micrometers, the weight median particle size is about 0.5 to 0.6 micrometers and from 80% to 95% by weight is finer than 2 micrometers, adding thereto about 0.06 to 0.1% by weight of a water-soluble cationic polyelectrolyte, thereby thickening and flocculating said suspension, acidifying said suspension and to pH between about 2.5-4.0 and adding sodium hydrosulfite to the acidified suspension to bleach said clay, filtering the suspension to recover the resulting bulked bleached clay product, washing the filter cake with hot water to remove salts and adding a small amount of a deflocculating agent, less than 0.3% based on the dry clay weight, to the resulting filter cake of bulked clay product to form a fluid deflocculated slurry, the amounts of said polyelectrolyte and said deflocculating agent being such that said pigment can be formed into a 62% aqueous slurry having a Hercules end point viscosity of 800 rpm or higher at 16×10 5 dyne-cm as measured at 20 rpm.
Claim 37
Independent Claim
219 words
A method for preparing a bulked clay pigment capable of being dispersed in water to form a high solids clay-water suspension having high shear and low shear viscosity suitable for use in coating printing paper which comprises preparing a deflocculated aqueous suspension of kaolin clay the particles of which are no more than 20% by weight finer than 0.3 micrometers, the weight median particle size is about 0.5 to 0.6 micrometers and from 80% to 95% by weight is finer than 2 micrometers, adding thereto about 0.06 to 0.1% by weight of a water-soluble cationic polyelectrolyte, thereby thickening and flocculating said suspension, acidifying said suspension and to pH between about 2.5-4.0 and adding sodium hydrosulfite to the acidified suspension to bleach said clay, filtering the suspension to recover the resulting bulked bleached clay product, washing the filter cake with hot water to remove salts and adding a small amount of a deflocculating agent, less than 0.3% based on the dry clay weight, to the resulting filter cake of bulked clay product to form a fluid deflocculated slurry, the amounts of said polyelectrolyte and said deflocculating agent being such that said pigment can be formed into a 62% aqueous slurry having a Hercules end point viscosity of 800 rpm or higher at 16×10 5 dyne-cm as measured at 20 rpm.
Claim 38
Dependent Claim
22 words
The method of claim 34 wherein said polyelectrolyte is polydimethyl diallyl ammonium chloride and sodium polyacrylate is used as the deflocculating agent.
Claim 39
Dependent Claim
21 words
The method of claim 34 wherein said fluid slurry of bulked clay is spray dried and recovered as a dry pigment.
Claim 40
Dependent Claim
16 words
The method of claim 34 wherein said fluid slurry is recovered and supplied in that form.
Claim 41
Dependent Claim
15 words
A bulked clay pigment prepared by the method of claim 11, 34, 36 or 37.
Claim 42
Dependent Claim
76 words
A coating color composition suitable for coating paper webs comprising a deflocculated suspension in water of kaolin clay and an adhesive for the clay, the clay, prior to being formulated into said coating color composition, having been treated with a small but effective amount of water soluble cationic polyelectrolyte flocculant to prepare a bulked product, and then deflocculated with a minimal amount of deflocculating agent to form a fluid slurry of 60% clay solids or higher.
Claim 43
Dependent Claim
76 words
A coating color composition suitable for coating paper webs comprising a deflocculated suspension in water of kaolin clay and an adhesive for the clay, the clay, prior to being formulated into said coating color composition, having been treated with a small but effective amount of water soluble cationic polyelectrolyte flocculant to prepare a bulked product, and then deflocculated with a minimal amount of deflocculating agent to form a fluid slurry of 60% clay solids or higher.
Claim 44
Dependent Claim
45 words
The coating color of claim 39 wherein said polyelectrolyte is a diallyl ammonium polymer salt wherein the ammonium group is either partially substituted with an alkyl group having 1 to 18 carbon atoms or totally substituted with alkyl groups having 1 to 18 carbon atoms.
Claim 45
Dependent Claim
23 words
The composition of claim 39 wherein said polyelectrolyte is polydimethyldiallyl ammonium chloride having a molecular weight in the range between 50,000 and 250,000.
Claim 46
Dependent Claim
57 words
The composition of claim 35 wherein the clay is treated with about 0.03 to about 0.15% of the polyelectrolyte based on the dry weight of the clay and the clay being treated contains less than 25% by weight of particles finer than 0.3 micrometers and from 80% to 95% by weight of particles finer than 2 micrometers.
Claim 47
Dependent Claim
72 words
The composition of claim 39 wherein the clay is treated with less than 0.1% by weight of the polyelectrolyte based on the dry weight of the clay and the clay being treated contains less than 20% by weight of particles finer than 0.3 micrometers, from 85% to 90% by weight of particles finer than 2 micrometers and has a weight median particle size in the range of about 0.5 to 0.6 micrometers.
Claim 48
Dependent Claim
18 words
The composition of claim 39 wherein the adhesive is a mixture of a styrene-butadiene copolymer and a starch.
Claim 49
Dependent Claim
10 words
A paper web coated with the composition of claim 39.
Claim 50
Dependent Claim
16 words
A paper web coated with the composition of claim 39 and printed by gravure or offset.
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) | 1991-04-19 | 1991-10-19 | 1992-04-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-19 | 1995-10-19 | 1996-04-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-19 | 1999-10-19 | 2000-04-19 | $7700.00 | Window Closed / Lapsed |