US4036794A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of expandable styrene polymers
Assignee: BASF SE
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Filing: 1976-10-08
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Granted: 1977-07-19
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Expires: 1996-10-08
Abstract
Abstract A process for the manufacture of expandable styrene polymers by suspension polymerization of the monomers in the presence of blowing agents and suspension stabilizers, the latter having been manufactured by polymerization of vinyl monomers in the presence of vinylpyrrolidone polymers. The expandable styrene polymers can be further processed to give foams.
Inventors
- 👤 Hans Georg Keppler
- 👤 Erhard Stahnecker
- 👤 Rolf Moeller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 12:54
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/16; C08J9/20; C08F; C08F271/00; C08F271/02; C08J2325/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
171 words
In a process for the manufacture of expandable polystyrene particles by suspension polymerization of styrene, with or without a minor amount of one or more other monomers, in the presence of a blowing agent and a suspension stabilizer, the blowing agent being added during or after the polymerization, wherein the suspension polymerization is carried out in the presence of a suspension stabilizer, the improvement wherein the suspension stabilizer has been manufactured by free radical polymerization, in the aqueous phase, of from 90 to 10 parts by weight of styrene, a substituted styrene, an ester of acrylic acid or methacrylic acid with an alcohol of 1 to 8 carbon atoms, a vinyl ester of a saturated monocarboxylic acid of 2 to 12 carbon atoms, a nitrile or amide of acrylic acid or methacrylic acid, vinyl chloride, butadiene or a mixture of two or more thereof, in the presence of from 10 to 90 parts by weight of polyvinylpyrrolidone or of a copolymer of vinylpyrrolidone in which polymerized units of the latter predominate.
Claim 2
Dependent Claim
171 words
In a process for the manufacture of expandable polystyrene particles by suspension polymerization of styrene, with or without a minor amount of one or more other monomers, in the presence of a blowing agent and a suspension stabilizer, the blowing agent being added during or after the polymerization, wherein the suspension polymerization is carried out in the presence of a suspension stabilizer, the improvement wherein the suspension stabilizer has been manufactured by free radical polymerization, in the aqueous phase, of from 90 to 10 parts by weight of styrene, a substituted styrene, an ester of acrylic acid or methacrylic acid with an alcohol of 1 to 8 carbon atoms, a vinyl ester of a saturated monocarboxylic acid of 2 to 12 carbon atoms, a nitrile or amide of acrylic acid or methacrylic acid, vinyl chloride, butadiene or a mixture of two or more thereof, in the presence of from 10 to 90 parts by weight of polyvinylpyrrolidone or of a copolymer of vinylpyrrolidone in which polymerized units of the latter predominate.
Claim 3
Dependent Claim
25 words
A process as claimed in claim 1, wherein the suspension stabilizer is manufactured with the aid of azoisobutyronitrile as initiator for the free radical polymerization.
Claim 4
Dependent Claim
20 words
A process as claimed in claim 1, wherein the suspension stabilizer is manufactured by free radical polymerization of tert.-butyl acrylate.
Claim 5
Dependent Claim
20 words
A process as claimed in claim 1, wherein the suspension stabilizer is manufactured by free radical polymerization of n-butyl acrylate.
Claim 6
Dependent Claim
19 words
A process as claimed in claim 1, wherein the suspension stabilizer is manufactured by free radical polymerization of styrene.
Claim 7
Dependent Claim
20 words
A process as claimed in claim 1, wherein the suspension stabilizer is manufactured in the presence of a crosslinking comonomer.
Claim 8
Dependent Claim
24 words
A process as claimed in claim 1, wherein the suspension stabilizer is manufactured by free radical polymerization in the presence of a surface-active compound.
Claim 9
Dependent Claim
42 words
A process as claimed in claim 1, wherein the suspension stabilizer is manufactured in the presence of from 50 to 75 parts by weight of polyvinylpyrrolidone or the vinyl pyrrolidone copolymer, from 25 to 50 parts by weight of monomer being polymerized.
Claim 10
Dependent Claim
23 words
A process as claimed in claim 1, wherein from 0.1 to 0.7 percent by weight, based on monomer(s), of suspension stabilizer is used.
References Cited (Backward Citations)
US2888410A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-07-18 | 1981-01-17 | 1981-07-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-18 | 1985-01-17 | 1985-07-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-18 | 1989-01-17 | 1989-07-19 | $7700.00 | Window Closed / Lapsed |