US3923765A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for suspension polymerization of vinyl halides with low polymer deposition
Assignee: Wacker Chemie AG
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Filing: 1973-03-07
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Granted: 1975-12-02
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Expires: 1993-03-07
Abstract
Abstract An improvement in the suspension polymerization of a polymerizate containing at least 70 percent of polyvinyl halides with no polymer deposits by the steps of mixing (1) monomers selected from the group consisting of vinyl halides and mixtures of vinyl halides with up to 30 percent by weight of olefinically unsaturated compounds copolymerizable with vinyl halides, (2) an oil-soluble free-radical-forming polymerization catalyst, (3) suspension stabilizers including protective colloids, and (4) water, heating said mixture under agitation to polymerization temperatures and recovering said polymerizate, the improvement comprises conducting the polymerization in the presence of from 2 to 2,000 ppm, based on the water content, of water-soluble reducing agents, in a reactor whose inner surface has a mean peak-to-valley height of at most 10 Mu and where the flow velocity on said inner surface is at least 0.3 m/sec., whereby a polymerizate is recovered substantially without polymer deposits.
Inventors
- 👤 Ulrich Goetze
- 👤 Axel Wole
- 👤 Gottfried Nettesheim
- 👤 Thomas Balwe
- 👤 Johann Bauer
- 👤 Kurt Fendel
- 👤 Dieter Kurz
- 👤 Alex Sabel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 07:27
CPC Classifications
C; C08; C08F; C08F14/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
157 words
IN THE SUSPENSION POLYMERIZATION PROCESS FOR THE PRODUCTION OF POLYMERIZATES CONTAINING AT LEAST 70 PERCENT OF POLYVINYL HALIDES, WITH LOW POLYMER DEPOSITS, WHICH COMPRISES THE STEPS OF MIXING (1) MONOMERS SELECTED FROM THE GROUP CONSISTING OF VINYL HALIDES AND MIXTURES OF VINYL HALIDES WITH UP TO 30 PERCENT BY WEIGHT OF OLEFINICALLY UNSATURATED COMPOUNDS COPOLYMERIZABLE WITH VINYL HALIDES, (2) AN OIL-SOLUBLE FREERADICAL-FORMING POLYMERIZING CATALYST, (3) SUSPENSION STABILIZERS INCLUDING PROTECTIVE COLLOIDS, AND (4) WATER, HEATING SAID MIXTURE UNDER AGITATION TO A POLYMERIZATION TEMPERATURE OF BETWEEN 30*C AND 80*C AND RECOVERING SAID POLYMERIZATE, OF THE IMPROVEMENT WHICH CONSISTS OF CONDUCTING SAID POLYMERIZATION IN THE PRESENCE OF FROM 10 TO 300 PPM. BASED, ON THE WATER CONTENT, OF WATER-SOLUBLE REDUCING AGENTS, IN A REACTOR WHOSE INNER SURFACE HAS A MEAN PEAK-TO-VALLEY HEIGHT OF AT MOST 1 U AND WHERE THE FLOW VELOCITY ADJACENT SAID INNER SURFACE IS AT LEAST 0.3 M/SEC., WHEREBY A POLYMERIZATE IS RECOVERED SUBSTANTIALLY WITHOUT POLYMER DEPOSITS.
Claim 2
Dependent Claim
157 words
IN THE SUSPENSION POLYMERIZATION PROCESS FOR THE PRODUCTION OF POLYMERIZATES CONTAINING AT LEAST 70 PERCENT OF POLYVINYL HALIDES, WITH LOW POLYMER DEPOSITS, WHICH COMPRISES THE STEPS OF MIXING (1) MONOMERS SELECTED FROM THE GROUP CONSISTING OF VINYL HALIDES AND MIXTURES OF VINYL HALIDES WITH UP TO 30 PERCENT BY WEIGHT OF OLEFINICALLY UNSATURATED COMPOUNDS COPOLYMERIZABLE WITH VINYL HALIDES, (2) AN OIL-SOLUBLE FREERADICAL-FORMING POLYMERIZING CATALYST, (3) SUSPENSION STABILIZERS INCLUDING PROTECTIVE COLLOIDS, AND (4) WATER, HEATING SAID MIXTURE UNDER AGITATION TO A POLYMERIZATION TEMPERATURE OF BETWEEN 30*C AND 80*C AND RECOVERING SAID POLYMERIZATE, OF THE IMPROVEMENT WHICH CONSISTS OF CONDUCTING SAID POLYMERIZATION IN THE PRESENCE OF FROM 10 TO 300 PPM. BASED, ON THE WATER CONTENT, OF WATER-SOLUBLE REDUCING AGENTS, IN A REACTOR WHOSE INNER SURFACE HAS A MEAN PEAK-TO-VALLEY HEIGHT OF AT MOST 1 U AND WHERE THE FLOW VELOCITY ADJACENT SAID INNER SURFACE IS AT LEAST 0.3 M/SEC., WHEREBY A POLYMERIZATE IS RECOVERED SUBSTANTIALLY WITHOUT POLYMER DEPOSITS.
Claim 3
Dependent Claim
18 words
The process of claim 1 wherein said flow velocity adjacent said inner surface is at least 1 m/sec.
Claim 4
Dependent Claim
26 words
The process of claim 1 wherein said water with all water-soluble ingredients is charged first, then the said monomers and thereafter said polymerization catalyst are charged.
Claim 5
Dependent Claim
36 words
The process of claim 1 wherein said water-soluble reducing agent is selected from the group consisting of reducing oxygen acids of sulfur, reducing oxygen acids of phosphorus, reducing oxygen acids of nitrogen, and their water-soluble salts.
Claim 6
Dependent Claim
21 words
The process of claim 1 wherein said polymerization is effected at a pH which is optimum for said water-soluble reducing agents.
Claim 7
Dependent Claim
37 words
The process of claim 1 wherein said oil-soluble free-radical-forming polymerization catalyst is selected from the group consisting of Alpha -alkyl-substituted acyl peroxides, dialkylperoxy dicarbonates having from 6 to 22 carbon atoms in the alkyls, and mixtures thereof.
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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) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |