Patent US4082659A successfully refreshed from Google Patents.
US4082659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for concentrating latices
Assignee: Hoechst AG
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Filing: 1976-11-11
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Granted: 1978-04-04
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Expires: 1996-11-11
Abstract
Abstract The present invention is related to the process of concentrating K-polymer-latices by ultra filtration carried out by means of a semi-permeable membrane made of a synthetic polymer having a determined molecular weight, comprising that the membrane is pretreated with an emulsifier solution prior to ultra filtration. This operation substantially prevents the formation of solid matter deposits on the membrane.
Inventors
- 👤 Christoph Heinze
- 👤 Kasimir Ruchlak
- 👤 Holm Steude
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:51
CPC Classifications
C; C08; C08F; C08F6/00; C08F6/14; C08F6/20; B; B01; B01D; B01D61/00; B01D61/14; B01D61/145; B01D65/00; B01D65/08; B01D67/00; B01D67/0081; B01D67/0088; B01D2321/00; B01D2321/28
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
99 words
In a process for concentrating latices which are prepared by emulsion polymerization of vinyl chloride or of vinyl chloride and monomers copolymerizable with vinyl chloride by ultrafiltration by means of a semipermeable membrane of polyacrylonitrile, polymethylmethacrylate or polyamide having a partition cut at a molecular weight of from 10,000 to 50,000, the improvement which comprises the treatment of the membrane, prior to the ultrafiltration, with an aqueous solution having 0.5 to 70 weight % of one or more emulsifiers which are suitable for the emulsion polymerization of vinyl chloride or of vinyl chloride and monomers copolymerizable with vinyl chloride.
Claim 2
Dependent Claim
99 words
In a process for concentrating latices which are prepared by emulsion polymerization of vinyl chloride or of vinyl chloride and monomers copolymerizable with vinyl chloride by ultrafiltration by means of a semipermeable membrane of polyacrylonitrile, polymethylmethacrylate or polyamide having a partition cut at a molecular weight of from 10,000 to 50,000, the improvement which comprises the treatment of the membrane, prior to the ultrafiltration, with an aqueous solution having 0.5 to 70 weight % of one or more emulsifiers which are suitable for the emulsion polymerization of vinyl chloride or of vinyl chloride and monomers copolymerizable with vinyl chloride.
Claim 3
Dependent Claim
37 words
Process according to claim 1 which comprises the immersion of the membrane in an aqueous solution which contains from 1 to 10 weight % of emulsifier for a period of from half an hour to 48 hours.
Claim 4
Dependent Claim
42 words
Process according to claim 1 which comprises the use of an ammonium salt or an alkali metal salt of a sulfosuccinic acid diester as emulsifier, the alcohol component of which is a branched alkyl radical having from 8 to 12 carbon atoms.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |