Clay slurries and use thereof in pulp and papermaking applications
View Patent ↗The invention relates to a stable aqueous slurry composition comprising clay or clay-like material, hydrophobically associative polymer, and optionally a surfactant; and a method of inhibiting the deposition of organic contaminants in pulp and papermaking applications.
1. A stable, low viscosity, high solids_aqueous slurry composition comprising
a) at least one clay or clay-like material selected from the group consisting of talc, pyrophyllite, kaolinite, bentonite, montmorillonite, attapulgite, sepiolite, wollastonite and mixtures thereof,
b) at least one nonionic hydrophobically associative polymer selected from the group consisting of hydrophobically modified cellulose ether, hydrophobically modified poly[ethylene glycol], hydrophobically modified ethoxylated urethane, hydrophobically modified poly(acetal-polyethers), and mixtures thereof, and
c) at least one nonionic surfactant;
wherein said clay or clay like material is present in the slurry in an amount of from 20 to 65% by weight, and
wherein said aqueous slurry has a viscosity of less than 4000 centipoise, and
wherein the ratio of nonionic hydrophobically associative polymer to clay or clay-like material is 0.1 to 10.0 parts by weight nonionic hydrophobically associative polymer per 100 parts clay or clay-like material.
2. The composition according to claim 1 , wherein said clay or clay-like material is talc.
3. The composition according to claim 2 , wherein the talc has a mean particle size in the range of 0.5 micron to 20 microns.
4. The composition according to claim 1 , wherein said hydrophobically modified cellulose ether is selected from the group consisting of hydrophobically modified carboxymethyl cellulose (HMCMC), hydrophobically modified hydroxyethyl cellulose (HMHEC), hydrophobically modified hydroxypropyl cellulose (HMHPC), hydrophobically modified ethylhydroxyethyl cellulose (HMEHEC), hydrophobically modified carboxymethylhydroxyethyl cellulose (HMCMHEC), hydrophobically modified hydroxypropylhydroxyethyl cellulose (HMHPHEC), hydrophobically modified methyl cellulose (HMMC), hydrophobically modified methylhydroxypropyl cellulose (HMMHPC), hydrophobically modified methylhydroxyethyl cellulose (HMMHEC), and hydrophobically modified carboxymethylmethyl cellulose (HMCMMC).
5. The composition according to claim 4 , wherein the hydrophobically modified cellulose ether is hydrophobically modified hydroxyethyl cellulose (HMHEC).
6. The composition according to claim 5 , wherein the hydrophobically modified hydroxyethyl cellulose (HMHEC) has hydrophobes between 8 and 20 carbon atoms in length.
7. The composition according to claim 4 , wherein the hydrophobically modified hydroxyethyl cellulose (HMHEC) prior to hydrophobic modification has a degree of polymerization of about 75 to 1800.
8. The composition according to claim 4 , wherein the hydrophobically modified poly[ethylene glycol] comprises the formula:
(R 1 —) x —O—[—CH 2 —CH 2 —O—] n —(R 2 ) y —Z
wherein R 1 and R 2 are a hydrophobic moiety, or blocks of hydrophobic moieties of x and y repeat units, covalently bonded to poly[ethylene glycol]; n is 2 to 1200; x is 1 to 10; y is 0-10; Z is only present when y=0 and is hydrogen; the sum of x and y is greater than or equal to 2.
9. The composition according to claim 1 , wherein the surfactant is selected from the group consisting of alkyl polysaccharides, alkyl amine ethoxylates, amine oxides, poly(oxyethylene-oxypropylene) block copolymers, acetylenic diols, castor oil ethoxylates, fatty alcohol ethoxylates, fatty acid ethoxylates, alkylphenol ethoxylates, ethoxylated alkanolamides, ethylene glycol esters, fatty acid alkanolamides, sorbitan ester ethoxylates, and tall oil fatty acid ethoxylates.
10. The composition according to claim 1 , wherein the surfactant is nonionic and comprises a fatty alcohol ethoxylate.
11. The composition according to claim 10 , wherein the fatty alcohol ethoxylate has a Hydrophilic/lipophilic Balance (HLB) in range of 6 to 18.
12. The composition according to claim 1 , wherein the quantity of the surfactant in the slurry composition is in the range of between 0.1 part and 20 parts by weight per 100 parts of clay or clay-like material.
13. A method for inhibiting the deposition of organic contaminants in pulp and papermaking systems comprising the step of adding an slurry to the pulp or applying the aqueous slurry to the surface of the papermaking machinery wherein the aqueous slurry comprises
a) at least one clay or clay-like material selected from the group consisting of talc, pyrophyllite, kaolinite, bentonite, montmorillonite, attapulgite, sepiolite, wollastonite and mixtures thereof,
b) at least one nonionic hydrophobically associative polymer selected from the group consisting of hydrophobically modified cellulose ether, hydrophobically modified poly[ethylene glycol], hydrophobically modified ethoxylated urethane, hydrophobically modified poly(acetal-polyethers), and mixtures thereof, and c) at least one surfactant;
wherein said clay or clay-like material is present in the slurry in an amount of from 20 to 65% by weight,
wherein the ratio of nonionic hydrophobically associative polymer to clay or clay-like material is 0.1 to 10.0 parts by weight nonionic hydrophobically associative polymer per 100 parts clay or clay-like material; and
wherein the aqueous slurry has a viscosity of less than 4000 centipoise and is added in an amount of from about 0.1 ppm to about 20,000 ppm per ton of dry pulp.
14. The method according to claim 13 , wherein said clay or clay like material is talc.
15. The method according to claim 14 , wherein the talc has a mean particle size in the range of 0.5 micron to 20 microns.
16. The method according to claim 13 , wherein said hydrophobically modified cellulose ether is selected from the group consisting of hydrophobically modified carboxymethyl cellulose (HMCMC), hydrophobically modified hydroxyethyl cellulose (HMHPC), hydrophobically modified hydroxypropyl cellulose (HMHPC), hydrophobically modified ethylhydroxyethyl cellulose (HMEHEC), hydrophobically modified carboxymethylhydroxyethyl cellulose (HMCMHEC), hydrophobically modified hydroxypropylhydroxyethyl cellulose (HMHPHEC), hydrophobically modified methyl cellulose (HMMC), hydrophobically modified methylhydroxypropyl cellulose (HMMHPC), hydrophobically modified methylhydroxyethyl cellulose (HMMHEC), and hydrophobically modified carboxymethylmethyl cellulose (HMCMMC).
17. The method according to claim 16 , wherein the hydrophobically modified cellulose ether is hydrophobically modified hydroxyethyl cellulose (HMHEC).
18. The method according to claim 16 , wherein the hydrophobically modified cellulose (HMHEC) prior to hydrophobic modification has a degree of polymerization of about 75 to 1800.
19. The method according to claim 13 , wherein the surfactant is selected from the group consisting of alkyl polysaccharides, alkyl amine ethoxylates, amine oxides, poly(oxyethylene-oxypropylene) block copolymers, acetylenic diols, castor oil ethoxylates, fatty alcohol ethoxylates, fatty acid ethoxylates, alkylphenol ethoxylates, ethoxylated alkanolamides, ethylene glycol esters, fatty acid alkanolamides, sorbitan ester ethoxylates, and tall oil fatty acid ethoxylates and combinations thereof.
20. The method according to claim 13 , wherein the quantity of the surfactant in the slurry is in the range of between 0.1 part and 20 parts by weight per 100 parts of clay mineral.