Patent US4740329A successfully refreshed from Google Patents.
US4740329A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dispersing agents for coal slurries
Assignee: WITTON CHEMICAL Co Ltd HAMPSTEAD AVE MILDENHALL ENGLAND IP28 7AS A CORP OF ENGLAND
•
Filing: 1987-04-14
•
Granted: 1988-04-26
•
Expires: 2007-04-14
Abstract
Abstract A slurry of coal particles in water includes as a dispersing agent a copolymer of acrylonitrile or methacrylonitrile with an acrylate or methacrylate compound wherein the copolymer has a molecular weight below 80,000 and comprises: (a) from 10 to 80% by weight of acrylonitrile or methacrylonitrile, and (b) 20 to 90% by weight of acrylic acid or methacrylic acid or an alkali metal, ammonium or amine salt thereof.
Inventors
- 👤 Eric Wrench
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 13:51
CPC Classifications
C; C10; C10L; C10L1/00; C10L1/32; C10L1/326; C09; C09K; C09K23/00; C09K23/16; Y; Y10; Y10S; Y10S516/00; Y10S516/01; Y10S516/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
75 words
A composition comprising a slurry of coal particles in water which composition additionally comprises as a dispersing agent a copolymer of acrylonitrile or methacrylonitrile with an acrylate or methacrylate compound wherein the copolymer has a molecular weight below 80,000 and comprises; (a) from 10 to 80% by weight of acrylonitrile or methacrylonitrile, and (b) from 20 to 90% by weight of acrylic acid of methacrylic acid or an alkali metal, ammonium or amine salt thereof.
Claim 2
Dependent Claim
75 words
A composition comprising a slurry of coal particles in water which composition additionally comprises as a dispersing agent a copolymer of acrylonitrile or methacrylonitrile with an acrylate or methacrylate compound wherein the copolymer has a molecular weight below 80,000 and comprises; (a) from 10 to 80% by weight of acrylonitrile or methacrylonitrile, and (b) from 20 to 90% by weight of acrylic acid of methacrylic acid or an alkali metal, ammonium or amine salt thereof.
Claim 3
Dependent Claim
73 words
A composition according to claim 1 wherein the copolymer comprises up to 5% by weight of additional co-monomer or co-monomers selected from as ester of acrylic or methacrylic acid with a monohydric alcohol, a half ester of acrylic or methacrylic acid with a dihydric alcohol, a sulphoalkyl ester or amide of acrylic or methacrylic acid, an ester of versatic acid or a half ester of an unsaturated dicarboxylic acid or vinyl sulphonic acid.
Claim 4
Dependent Claim
39 words
A composition according to claim 1 wherein the copolymer has a molecular weight of 600 to 8,000, is present in an amount of 0.1 to 5% by weight, and wherein the slurry comprises 60 to 80% of coal particles.
Claim 5
Independent Claim
75 words
A method of stabilising a slurry of up to 80% by weight of coal particles in water which comprises incorporating therein 0.1 to 5% by weight of a dispersing agent comprising a copolymer formed from (a) 10 to 80% by weight of acrylonitrile or methacrylonitrile and (b) from 20 to 90% by weight of acrylic acid or methacrylic acid or an alkali metal, ammonium or amine salt thereof and having a molecular weight below 80,000.
Claim 6
Independent Claim
75 words
A method of stabilising a slurry of up to 80% by weight of coal particles in water which comprises incorporating therein 0.1 to 5% by weight of a dispersing agent comprising a copolymer formed from (a) 10 to 80% by weight of acrylonitrile or methacrylonitrile and (b) from 20 to 90% by weight of acrylic acid or methacrylic acid or an alkali metal, ammonium or amine salt thereof and having a molecular weight below 80,000.
Claim 7
Dependent Claim
41 words
A method according to claim 4 wherein the polymer has a molecular weight of 600 to 8,000 and is added at a rate of 0.1 to 5% by weight to a slurry comprising 60 to 80% by weight of coal particles.
References Cited (Backward Citations)
US3019059A
Cited
US3524682A
Cited
US3956122A
Cited
US4004072A
Cited
US4081418A
Cited
US4217109A
Cited
EP0000500A2
Cited
EP0000501A1
Cited
EP0003617A1
Cited
EP0004044A1
Cited
EP0004045A1
Cited
EP0004046A1
Cited
US4242098A
Cited
US4314044A
Cited
US4330301A
Cited
US4370429A
Cited
US4358293A
Cited
EP0089766A1
Cited
EP0092353A1
Cited
EP0174509A2
Cited
GB2167434A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-26 | 1991-10-26 | 1992-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-26 | 1995-10-26 | 1996-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-26 | 1999-10-26 | 2000-04-26 | $7700.00 | Window Closed / Lapsed |