Patent US4074036A successfully refreshed from Google Patents.
US4074036A
Expired / Lapsed
US
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Production of low molecular weight polyanhydrides
Assignee: PLASKON ELECTRONIC MATERIALS Inc A DE CORP
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Filing: 1976-11-05
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Granted: 1978-02-14
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Expires: 1996-11-05
Abstract
Abstract In a process for the production of a low molecular weight polyanhydride having a softening point within the range of about 111 DEG to 156 DEG C. by the mass polymerization reaction of a maleic monomer and at least one alkyl-substituted styrene at a temperature in the range of about 140 DEG to 200 DEG C., the improvement comprising employing an alkali metal bifluoride, preferably potassium bifluoride, as catalyst for the reaction.
Inventors
- 👤 Harold W. Tuller
- 👤 Ralph W. Nussbaum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:41
CPC Classifications
C; C08; C08F; C08F222/00; C08F222/04; C08F222/06; C08G; C08G59/00; C08G59/18; C08G59/40; C08G59/42; C08G59/4223
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
74 words
In a process for the production of a low molecular weight polyanhydride having a softening point within the range of 111° to 156° C., by the mass polymerization reaction of a maleic monomer and at least one vinyl monomer selected from the group consisting of styrene and alkyl-substituted styrenes at a temperature in the range of about 140° to 200° C., the improvement comprising employing an alkali metal bifluoride as catalyst for said reaction.
Claim 2
Dependent Claim
74 words
In a process for the production of a low molecular weight polyanhydride having a softening point within the range of 111° to 156° C., by the mass polymerization reaction of a maleic monomer and at least one vinyl monomer selected from the group consisting of styrene and alkyl-substituted styrenes at a temperature in the range of about 140° to 200° C., the improvement comprising employing an alkali metal bifluoride as catalyst for said reaction.
Claim 3
Dependent Claim
13 words
The process in accordance with claim 1 wherein said catalyst is potassium bifluoride.
Claim 4
Dependent Claim
24 words
The process in accordance with claim 2 wherein said potassium bifluoride is present in an amount of about 0.00005 to 1 percent by weight.
Claim 5
Dependent Claim
37 words
The process in accordance with claim 1 wherein said maleic monomer is selected from the group consisting of maleic acid, maleic anhydride, anhydrides which rearrange to maleic anhydrides and the halo-, aryl-, aralkyl-, or cycloalkylsubstituted derivatives thereof.
Claim 6
Dependent Claim
87 words
The process in accordance with claim 1 wherein said alkyl-substituted styrene is represented by the formula ##STR5## wherein R is hydrogen or alkyl of 1 to 4 carbon atoms with the proviso that where X 1 and X 2 are hydrogen, R is alkyl; X 1 and X 2 independently are hydrogen, halogen, alkoxy, alkyl and haloalkyl wherein the alkyl groups contain from 1 to 4 carbon atoms, acetyl, monocyclic aryl, aralkyl, or X 1 and X 2 together with the benzene nucleus form a fused ring.
Claim 7
Dependent Claim
30 words
The process in accordance with claim 1 wherein said vinyl monomer is a member selected from the group consisting of alpha-methyl styrene, vinyl toluene, tertiary butyl styrene and mixtures thereof.
Claim 8
Dependent Claim
14 words
The process in accordance with claim 6 wherein said maleic monomer is maleic anhydride.
Claim 9
Dependent Claim
28 words
The process in accordance with claim 7 wherein said maleic anhydride and said vinyl monomer are added to the reaction in a mol ratio of greater than 1:1.
Claim 10
Dependent Claim
32 words
The process of claim 8 wherein said vinyl monomer is alpha-methyl styrene and wherein said mol ratio of maleic anhydride to alpha-methyl styrene is in the range of about 1.1:1 to 2.5:1.
Claim 11
Dependent Claim
24 words
The process of claim 9 wherein said catalyst is potassium bifluoride which is present in an amount of about 0.00005 to 1 weight percent.
Claim 12
Dependent Claim
60 words
The process of claim 10 wherein at least a major portion of said maleic anhydride is heated to a temperature of about 160° to 200° C. in the presence of said catalyst, said alpha-methyl styrene is added to said maleic anhydride with agitation and said polymerization is continued until essentially all of the maleic anhydride and alpha-methyl styrene have polymerized.
Claim 13
Dependent Claim
20 words
The process of claim 11 wherein said potassium bifluoride is present in an amount of 0.0001 to 0.01 weight percent.
Claim 14
Dependent Claim
20 words
The process of claim 12 wherein said polyanhydride has a softening point in the range of 115° to 130° C.
Claim 15
Dependent Claim
24 words
The process of claim 1 wherein said polyanhydride has a number average molecular weight, as determined by vapor phase osmometry, of less than 1,000.
Claim 16
Dependent Claim
18 words
The process of claim 14 wherein said molecular weight is within the range of about 200 to 950.
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) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |