Patent EP0097495A1 successfully refreshed from Google Patents.
EP0097495A1
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EP
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Polymers of unsaturated acids
Assignee: Solvay Solutions UK Ltd
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Filing: 1983-06-16
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Granted: —
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Expires: 2003-06-16
Abstract
Abstract Water soluble polymers from acrylic acid optionally with other monomers have a narrow molecular weight distribution and are made by continuous loop polymerisation particular in the presence of sodium chlorate and sodium metabisulphite as redox initiator. The loop polymerisation gives more uniform product than batch operation and the narrow molecular weight distribution gives polyacrylates useful in water treatment, scale inhibition and as dispersants.
Inventors
- 👤 Michael Harry Haughton
- 👤 Clifford George Martin
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 16:58
CPC Classifications
C; C08; C08F; C08F20/00; C08F20/02; C08F20/04; C08F20/06; B; B01; B01J; B01J19/00; B01J19/24; B01J19/2415; B01J19/2435
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
128 words
A process for preparing a water soluble polymer characterised in that in a continuous process, a monomer component, which comprises at least 70 molar % of acrylic acid and optionally up to 30 molar % of a copolymerizable monomer, a free radical initiator and a free radical chain terminator are mixed with a recycled aqueous mixture comprising a water soluble polymer of said monomer component, and are reacted therein to form an aqueous reaction mixture, and a product portion of said reaction mixture is removed as a solution of water soluble polymer product leaving a remaining portion and said remaining portion is recycled as said recycled aqueous mixture for mixing again with said monomer component initiator and terminator, said aqueous reaction mixture and/or said remaining portion being cooled.
Claim 2
Dependent Claim
128 words
A process for preparing a water soluble polymer characterised in that in a continuous process, a monomer component, which comprises at least 70 molar % of acrylic acid and optionally up to 30 molar % of a copolymerizable monomer, a free radical initiator and a free radical chain terminator are mixed with a recycled aqueous mixture comprising a water soluble polymer of said monomer component, and are reacted therein to form an aqueous reaction mixture, and a product portion of said reaction mixture is removed as a solution of water soluble polymer product leaving a remaining portion and said remaining portion is recycled as said recycled aqueous mixture for mixing again with said monomer component initiator and terminator, said aqueous reaction mixture and/or said remaining portion being cooled.
Claim 3
Dependent Claim
34 words
A process according to claim 1 characterised in that the free radical initiator is the redox combination of a water soluble chlorate salt and a water soluble sulphur oxy compound derived from sulphurous acid.
Claim 4
Dependent Claim
17 words
A process according to claim 2 characterised in that the initiator is sodium chlorate and sodium metabisulphite.
Claim 5
Dependent Claim
19 words
A process according to any one of claims 1-3 characterised in that the chain terminator is a thiol compound.
Claim 6
Dependent Claim
14 words
A process according to claim 4 characterised in that the thiol compound is mercaptoethanol.
Claim 7
Dependent Claim
22 words
A process according to any one of claims 1-5 characterised in that said recycled aqueous mixture contains 35-65% by weight of polymer.
Claim 8
Dependent Claim
28 words
A process according to any one of claims 3-6 characterised in that the initiator is a chlorate salt and a metabisulphite salt in a molar ratio of 3-20:1.
Claim 9
Dependent Claim
25 words
A process according to any one of claims 3-7 characterised in that the total molar percentage of chlorate and metabisulphite to monomer component is 0.5-4%.
Claim 10
Dependent Claim
72 words
A process according to any one of claims 1-8 characterised in that the polymer is prepared in a loop apparatus comprising a loop pipe having in order of the direction of flow of liquid, (A) separate inlets for monomer, terminator and one or more initiators, (b) a mixer, (c) a pump, (d) a heat exchanger (e) an outlet for the product portion, said inlets being upstream of or integral with said mixer.
Claim 11
Dependent Claim
26 words
A process according to any one of claims 1-9 characterised in that at least 90% of polymerisation occurs within the average residence time in the loop.
Claim 12
Dependent Claim
27 words
A process according to any one of claims 1-10 characterised in that the polymerization is performed in the presence of a thiol free complexing agent for iron.
Claim 13
Dependent Claim
34 words
A process according to any one of claims 1-11 characterised in that the water soluble polymer product in the product portion is treated with base to form an at least partly neutralised salt thereof.
Claim 14
Dependent Claim
104 words
A process according to any one of claims 1-12 characterised in that in a continuous process aqueous sodium chlorate and sodium metabisulphite in molar amounts, whose sum is 0.5-4% (relative to the molar amount of monomer) and whose ratio is 3-10:1, and acrylic acid and mercaptoethanol are continuously passed into a recycled aqueous mixture comprising 35-65% recycled polyacrylic acid and reaction is performed at 80-100 0 C to form an aqueous reaction mixture, of which a product portion comprising polyacrylic polymer is removed, and the remaining portion recycled, the product portion being subsequently treated with further sodium metabisulphite and then at least partly neutralised.
Claim 15
Dependent Claim
86 words
A water soluble polymer having repeating units derived from a monomer component, which comprises at least 70 molar % of acrylic acid characterised in that, when in the form of an aqueous solution at pH 7.2 of 42% concentration of the sodium salt of the polymer then said salt has a weight average molecular weight Mw, and number average Molecular weight Mn, which are related according to the function Mw/Mn = ( a Mw)+b, where a is less than 7x10 -5 , and b is 1-1.8.
Claim 16
Dependent Claim
86 words
A water soluble polymer having repeating units derived from a monomer component, which comprises at least 70 molar % of acrylic acid characterised in that, when in the form of an aqueous solution at pH 7.2 of 42% concentration of the sodium salt of the polymer then said salt has a weight average molecular weight Mw, and number average Molecular weight Mn, which are related according to the function Mw/Mn = ( a Mw)+b, where a is less than 7x10 -5 , and b is 1-1.8.
Claim 17
Dependent Claim
18 words
A polymer according to claim 14 characterised in that is 10 5a is 1-3 and b is 1.4-1.7.
Claim 18
Dependent Claim
18 words
A polymer according to claim 14 or 15 characterised in that Mw is 1000-10,000 and Mw/Mn is 1.5-1.8.
Claim 19
Dependent Claim
32 words
An aqueous solution of a polymer characterised in that said polymer is in the form of an at least partly neutralised salt of a polymer according to any one of claims 14-16.
References Cited (Backward Citations)
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