US4319013A
Expired / Lapsed
US
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Powdered cationic polyelectrolytes, based on acrylamide and quaternized or salified dimethyl-aminoethyl acrylate, process for producing them
Assignee: SNF SA
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Filing: 1978-05-12
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Granted: 1982-03-09
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Expires: 1998-05-12
Abstract
Abstract Cationic polyelectrolytes in water-soluble powder form, applicable to the flocculation of municipal sludge comprise copolymers of acrylamide and of quaternized or salified dimethylamino-ethyl acrylate, containing in molar proportions 10 to 50% of cationic units distributed regularly along the copolymer chains. They have an intrinsic viscosity higher than 6 and a measured cationicity higher than 90% of the theoretical cationicity.
Inventors
- 👤 Jean Cabestany
- 👤 Claude Trouve
- 👤 Dominique Depernet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:14
CPC Classifications
C; C08; C08F; C08F220/00; C08F220/02; C08F220/10; C08F220/34; C02; C02F; C02F1/00; C02F1/52; C02F1/54; C08F220/52; C08F220/54; C08F220/56; Y; Y10; Y10S; Y10S524/00; Y10S524/922; Y10S526/00; Y10S526/909; Y10S526/923
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
91 words
Cationic polyelectrolyte in water-soluble powder form, applicable to the flocculation of municipal sludge, said polyelectrolyte comprising a mixture of copolymers of acrylamide and of a cationic monomer of quaternised or salified dimethyaminoethyl acrylate; said mixture of copolymers consisting essentially of copolymers each containing in molar proportions 10 to 50% of cationic units spaced regularly along its copolymer chain; said mixture of copolymers having an intrinsic viscosity higher than 6 dl/g measured at 30° C. in a molar solution of NaCl, and a measured cationicity higher than 90% of the theoretical cationicity.
Claim 2
Dependent Claim
91 words
Cationic polyelectrolyte in water-soluble powder form, applicable to the flocculation of municipal sludge, said polyelectrolyte comprising a mixture of copolymers of acrylamide and of a cationic monomer of quaternised or salified dimethyaminoethyl acrylate; said mixture of copolymers consisting essentially of copolymers each containing in molar proportions 10 to 50% of cationic units spaced regularly along its copolymer chain; said mixture of copolymers having an intrinsic viscosity higher than 6 dl/g measured at 30° C. in a molar solution of NaCl, and a measured cationicity higher than 90% of the theoretical cationicity.
Claim 3
Dependent Claim
27 words
Polyelectrolyte according to claim 1, in which the dimethylaminoethyl acrylate is quaternised by a quaternisation reactant selected from the group consisting of dimethyl sulfate and methyl chloride.
Claim 4
Dependent Claim
15 words
Polyelectrolyte according to claim 1, in which the dimethylaminoethyl acrylate is salified by hydrochloric acid.
Claim 5
Dependent Claim
92 words
Cationic polyelectrolyte in water-soluble powder form, applicable to the flocculation of municipal sludge, said polyelectrolyte comprising a mixture of emulsion polymerized copolymers of acrylamide and of a cationic monomer of quaternised or salified dimethyaminoethyl acrylate; said mixture of copolymers consisting essentially of copolymers each containing in molar proportions 10 to 50% of cationic units spaced regularly along its copolymer chain; said mixture of copolymers having an intrinsic viscosity higher than 6 dl/g measured at 30° C. in molar solution of NaCl, and a measured cationicity higher than 90% of the theoretical cationicity.
Claim 6
Dependent Claim
92 words
Cationic polyelectrolyte in water-soluble powder form, applicable to the flocculation of municipal sludge, said polyelectrolyte comprising a mixture of emulsion polymerized copolymers of acrylamide and of a cationic monomer of quaternised or salified dimethyaminoethyl acrylate; said mixture of copolymers consisting essentially of copolymers each containing in molar proportions 10 to 50% of cationic units spaced regularly along its copolymer chain; said mixture of copolymers having an intrinsic viscosity higher than 6 dl/g measured at 30° C. in molar solution of NaCl, and a measured cationicity higher than 90% of the theoretical cationicity.
Claim 7
Dependent Claim
113 words
Process for the manufacture of powder form cationic polyelectrolyte in water soluble powder form, applicable to the flocculation of municipal sludge, and comprising a copolymer of acrylamide and quaternised or salified dimethylaminoethyl acrylate, containing in molar proportions 10 to 50% of cationic units distributed regularly along the copolymer chain and having an intrinsic viscosity higher than 6 and a measured cationicity higher than 90% of the theoretical cationicity, said process comprising copolymerizing in an inverted water in oil emulsion acrylamide with quaternised or salified dimethylaminoethyl acrylate, at a pH between 3 and 6 in the presence of water emissible organic solvent and of an initiator, and dehydrating at a temperature below 80° C.
Claim 8
Dependent Claim
113 words
Process for the manufacture of powder form cationic polyelectrolyte in water soluble powder form, applicable to the flocculation of municipal sludge, and comprising a copolymer of acrylamide and quaternised or salified dimethylaminoethyl acrylate, containing in molar proportions 10 to 50% of cationic units distributed regularly along the copolymer chain and having an intrinsic viscosity higher than 6 and a measured cationicity higher than 90% of the theoretical cationicity, said process comprising copolymerizing in an inverted water in oil emulsion acrylamide with quaternised or salified dimethylaminoethyl acrylate, at a pH between 3 and 6 in the presence of water emissible organic solvent and of an initiator, and dehydrating at a temperature below 80° C.
Claim 9
Dependent Claim
17 words
Process according to claim 5 wherein said copolymerisation takes place at a pH between 4.5 and 6.
Claim 10
Dependent Claim
23 words
Process according to claim 5, wherein the oil phase is constituted by a hydrocarbon selected from alkanes and cycloalkanes containing 6-9 carbon atoms.
Claim 11
Dependent Claim
16 words
Process according to claim 7, in which said oil phase is constituted by heptane or cyclohexane.
Claim 12
Dependent Claim
44 words
Process according to claim 7, in which the dehydration is carried out by azeotropic distillation of the water to a water content of the copolymer not less than 10% and the drying is terminated on a fluidized bed at a temperature below 75° C.
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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) | 1985-03-08 | 1985-09-07 | 1986-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-03-08 | 1989-09-07 | 1990-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-03-08 | 1993-09-07 | 1994-03-09 | $7700.00 | Window Closed / Lapsed |