Patent US3839308A successfully refreshed from Google Patents.
US3839308A
Expired / Lapsed
US
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Styrene-methacrylic acid copolymers and their preparation
Assignee: Dart Industries Inc
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Filing: 1973-10-01
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Granted: 1974-10-01
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Expires: 1993-10-01
Abstract
Abstract A copolymer of styrene and methacrylic acid having from about 3 to about 15% by weight of methacrylic acid is produced at a polymerization temperature of between about 65* to 120*C. using short half life free radical initiators in a process which employs the continuous or incremental addition of methacrylic acid during at least the first part of the polymerization step. The copolymer produced has excellent tensile properties and a higher heat distortion temperature than the copolymers of styrene and methacrylic acid heretofore known.
Inventors
- 👤 F Carrock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 12:59
CPC Classifications
C; C08; C08F; C08F212/00; C08F212/02; C08F212/04; C08F212/06; C08F212/08
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
103 words
A PROCESS FOR THE PREPARATION OF A COPOLYMER OF FROM ABOUT 85 TO ABOUT 97 WT.% OF STYRENE AND FROM ABOUT 3 TO ABOUT 15 WT.% OF METHACRYLIC ACID WHICH COMPRISES REACTING IN A REACTION ZONE STYRENE AND METHACRYLIC ACID UNDER POLYMERIZATION CONDITIONS, AT A TEMPERATURE OF BETWEEN ABOUT 65* AND 120*C. IN THE PRESENCE OF FREE RADICAL POLYMERIZATION AND CATALYSTS, THE METHACRYLIC ACID BEING INTRODUCED INTO THE REA ACTION ZONE AFTER THE OTHER REACTANTS AND SUBSTANTIALLY CONTINUOUSLY THROUGHOUT THE POLYMERIZATION REACTION AR A RATE SUCH THAT SUBSTANTIALLY ALL OF SAID ACID IS ADDED BEFORE THE DEGREE OF POLYMERIZATION IS GREATER THAN 50%.
Claim 2
Dependent Claim
103 words
A PROCESS FOR THE PREPARATION OF A COPOLYMER OF FROM ABOUT 85 TO ABOUT 97 WT.% OF STYRENE AND FROM ABOUT 3 TO ABOUT 15 WT.% OF METHACRYLIC ACID WHICH COMPRISES REACTING IN A REACTION ZONE STYRENE AND METHACRYLIC ACID UNDER POLYMERIZATION CONDITIONS, AT A TEMPERATURE OF BETWEEN ABOUT 65* AND 120*C. IN THE PRESENCE OF FREE RADICAL POLYMERIZATION AND CATALYSTS, THE METHACRYLIC ACID BEING INTRODUCED INTO THE REA ACTION ZONE AFTER THE OTHER REACTANTS AND SUBSTANTIALLY CONTINUOUSLY THROUGHOUT THE POLYMERIZATION REACTION AR A RATE SUCH THAT SUBSTANTIALLY ALL OF SAID ACID IS ADDED BEFORE THE DEGREE OF POLYMERIZATION IS GREATER THAN 50%.
Claim 3
Dependent Claim
20 words
The process according to claim 1 in which the catalyst consists of both a high and a low temperature initiator.
Claim 4
Dependent Claim
16 words
The process according to claim 1 in which the styrene is suspended in water containing hydroxyethylcellulose.
Claim 5
Dependent Claim
22 words
The process of claim 1 wherein all of said acid is added before the degree of polymerization is greater than about 35%.
Claim 6
Dependent Claim
13 words
The process of claim 2 wherein the low temperature initiator is benzoyl peroxide.
Claim 7
Dependent Claim
20 words
The process of claim 2 wherein the high temperature initiator is either t-butyl peracetate, t-butyl perbenzoate or t-butylperoxy isopropyl carbonate.
Claim 8
Dependent Claim
30 words
A copolymer of from about 85 to about 97 wt.% of styrene and from about 3 to about 15 wt.% of methacrylic acid produced by the process of claim 1.
Claim 9
Dependent Claim
26 words
A copolymer according to claim 7 which consists essentially of from 92 to 95 wt.% of styrene and from 5 to 8 wt.% of methacrylic acid.
Claim 10
Dependent Claim
21 words
A copolymer according to claim 8 which consists essentially of about 92.5 wt.% of styrene and about 7.5 wt.% methacrylic acid.
Claim 11
Dependent Claim
17 words
The process according to claim 1 in which the styrene is suspended in water containing a dispersant.
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) | 1977-09-30 | 1978-04-01 | 1978-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-30 | 1982-04-01 | 1982-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-30 | 1986-04-01 | 1986-10-01 | $7700.00 | Window Closed / Lapsed |