US4200720A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of low molecular weight anhydride interpolymers
Assignee: Dow Chemical Co
•
Filing: 1978-08-24
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Granted: 1980-04-29
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Expires: 1998-08-24
Abstract
Abstract Low molecular weight polymers of an unsaturated dicarboxylic anhydride monomer (e.g., maleic anhydride) and a copolymerizable monomer (e.g., styrene) are prepared by an improved process which comprises polymerizing the monomers in the presence of the hydroxide or a nucleophilic salt of a monovalent cation (e.g., a nucleophilic salt or the hydroxide of the ammonium cation, a quaternary ammonium compound, a protonated primary, secondary or tertiary amine, a sulfonium compound, a phosphonium compound or an alkali metal cation). By the practice of this process, low molecular weight polymers are conveniently and economically obtained without the use of high catalyst concentrations, high temperatures, conventional chain transfer agents, high boiling chain transfer solvents or combinations thereof.
Inventors
- 👤 Syamalarao Evani
- 👤 Russell J. Raymond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 00:38
CPC Classifications
C; C08; C08F; C08F222/00; C08F222/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
95 words
In a process for preparing a low molecular weight polymer comprising polymerizing at least one unsaturated dicarboxylic acid anhydride monomer with at least one copolymerizable monomer in an organic solvent in which the monomers and the polymer are soluble and in the presence of a free radical catalyst, the improvement which comprises polymerizing the monomers in the presence of the hydroxide or a nucleophilic salt of a monovalent cation selected from the group consisting of sulfonium cations, phosphonium cations, the ammonium cation, protonated primary, secondary or tertiary amines, quaternary ammonium cations and alkali metal cations.
Claim 2
Dependent Claim
95 words
In a process for preparing a low molecular weight polymer comprising polymerizing at least one unsaturated dicarboxylic acid anhydride monomer with at least one copolymerizable monomer in an organic solvent in which the monomers and the polymer are soluble and in the presence of a free radical catalyst, the improvement which comprises polymerizing the monomers in the presence of the hydroxide or a nucleophilic salt of a monovalent cation selected from the group consisting of sulfonium cations, phosphonium cations, the ammonium cation, protonated primary, secondary or tertiary amines, quaternary ammonium cations and alkali metal cations.
Claim 3
Dependent Claim
31 words
The improvement of claim 1 wherein the hydroxide or salt is employed in the amount of from about 50 to about 15,000 parts per million based on the total monomer weight.
Claim 4
Dependent Claim
31 words
The improvement of claim 1 wherein the hydroxide or salt is employed in the amount of from about 100 to about 5,000 parts per million based on the total monomer weight.
Claim 5
Dependent Claim
15 words
The improvement of claim 1 wherein the anhydride monomer comprises an α,β-monoethylenically unsaturated dicarboxylic anhydride.
Claim 6
Dependent Claim
12 words
The improvement of claim 1 wherein the anhydride monomer comprises maleic anhydride.
Claim 7
Dependent Claim
17 words
The improvement of claim 1 wherein the copolymerizable monomer comprises a monovinylidene monomer or an α-olefin monomer.
Claim 8
Dependent Claim
14 words
The improvement of claim 1 wherein the copolymerizable monomer comprises a monovinylidene aromatic monomer.
Claim 9
Dependent Claim
11 words
The improvement of claim 1 wherein the copolymerizable monomer comprises styrene.
Claim 10
Dependent Claim
22 words
The improvement of claim 1 wherein the mole ratio of anhydride monomer to copolymerizable monomer is from about 1:5 to about 1:1.
Claim 11
Dependent Claim
18 words
The improvement of claim 1 wherein the mole ratio of anhydride monomer to copolymerizable monomer is about 1:1.
Claim 12
Dependent Claim
18 words
The improvement of claim 1 wherein the organic solvent is a ketone, an ester or a cyclic ether.
Claim 13
Dependent Claim
26 words
The improvement of claim 1 wherein the organic solvent is acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl acetate, butyl acetate, dioxane or tetrahydrofuran.
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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) | 1983-04-29 | 1983-10-29 | 1984-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-29 | 1987-10-29 | 1988-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-29 | 1991-10-29 | 1992-04-29 | $7700.00 | Window Closed / Lapsed |