US4539362A
Expired / Lapsed
US
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Polymerization process
Assignee: Imperial Chemical Industries Ltd
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Filing: 1983-05-16
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Granted: 1985-09-03
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Expires: 2003-05-16
Abstract
Abstract Sterically stabilized aqueous polymer dispersions free from charged species are made by emulsifying in water ethylenically unsaturated monomer(s), soluble in water to the extent of 0.08%-8% by weight but giving rise to a polymer which is insoluble, and polymerizing the monomer(s) in that state in the presence of (a) a non-ionizable azo initiator which is water-soluble and substantially monomer-insoluble and (b) a block or graft copolymer stabilizer of specified structure.
Inventors
- 👤 Stephen P. Davies
- 👤 Morice W. Thompson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:10
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/12; C08F2/16; C08F2/22; C08F2/24
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
212 words
A process for the preparation of a sterically stabilised aqueous polymer dispersion, in which at least one ethylenically unsaturated monomer, having a solubility in water in the range 0.08%-8% by weight but giving rise to a polymer which is insoluble in water, is emulsified in water and is subjected in that state to polymerisation in the presence of (a) a non-ionisable free-radical organic azo polymerisation initiator which is water-soluble and is substantially insoluble in the monomer or monomers, having a distribution ratio between water and pure styrene of at least 12 and (b) a precursor for the formation in situ of an amphipathic block or graft copolymer steric stabiliser for the polymer particles produced, the said precursor containing in the molecule a polymer chain derived from a polyethylene glycol, or a monomethyl ether thereof, of molecular weight in the range 2000-4000, and also containing in the molecule an unsaturated grouping with which the monomers can copolymerise, the azo initiator being present in an amount of from 0.1 mol % to 3.0 mol % of the amount of monomer being polymerised and the stabiliser precursor being present in an amount such as to provide, after copolymerization with the monomers, from 0.5% to 20% by weight of stabiliser based on the monomer being polymerised.
Claim 2
Dependent Claim
212 words
A process for the preparation of a sterically stabilised aqueous polymer dispersion, in which at least one ethylenically unsaturated monomer, having a solubility in water in the range 0.08%-8% by weight but giving rise to a polymer which is insoluble in water, is emulsified in water and is subjected in that state to polymerisation in the presence of (a) a non-ionisable free-radical organic azo polymerisation initiator which is water-soluble and is substantially insoluble in the monomer or monomers, having a distribution ratio between water and pure styrene of at least 12 and (b) a precursor for the formation in situ of an amphipathic block or graft copolymer steric stabiliser for the polymer particles produced, the said precursor containing in the molecule a polymer chain derived from a polyethylene glycol, or a monomethyl ether thereof, of molecular weight in the range 2000-4000, and also containing in the molecule an unsaturated grouping with which the monomers can copolymerise, the azo initiator being present in an amount of from 0.1 mol % to 3.0 mol % of the amount of monomer being polymerised and the stabiliser precursor being present in an amount such as to provide, after copolymerization with the monomers, from 0.5% to 20% by weight of stabiliser based on the monomer being polymerised.
Claim 3
Dependent Claim
18 words
A process as claimed in claim 1, wherein the initiator is the bis(diethanolamide) or bis(diisopropanolamide) of 4,4'-azobis(cyanopentanoic acid).
Claim 4
Dependent Claim
18 words
A process as claimed in claim 1, wherein the initiator is the bis-ester of 2,2'-azobis(2-methylpropanoic acid) with 2-ethoxyethanol.
Claim 5
Dependent Claim
19 words
A process as claimed in claim 1, wherein the initiator is the bis(1,2-dihydroxypropyl)ester or the bis(5,6-dihydroxyhexyl)ester of 2,2'-azobis(2-methylpropanoic acid).
Claim 6
Dependent Claim
22 words
A process as claimed in claim 1, wherein the emulsification of the monomer is assisted by the presence of a non-ionic surfactant.
Claim 7
Dependent Claim
19 words
A process as claimed in claim 1, wherein there is also present, during the polymerisation, a chain transfer agent.
Claim 8
Dependent Claim
24 words
A process as claimed in claim 1 in which the initiator is the bis-amide of 4,4'-azobis(cyanopentanoic acid) and -amino- -hydroxypoly(oxyethylene) of molecular weight 1600.
Claim 9
Dependent Claim
27 words
A process as claimed in claim 1 wherein the initiator is the bis-ester of the monomethyl ether of polyethylene glycol of molecular weight 2000 and 2,2'-azobis(2-methylpropanoic acid).
Claim 10
Dependent Claim
19 words
A process as claimed in claim 1 in which the initiator is the ester of 2,2'-azobis-(2-methylpropanoic acid) with 1-poly(ethyleneoxy)-glycerol.
References Cited (Backward Citations)
US3635867A
Cited
US4322328A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-02 | 1989-03-04 | 1989-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-02 | 1993-03-04 | 1993-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-02 | 1997-03-04 | 1997-09-03 | $7700.00 | Window Closed / Lapsed |