US3962196A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Technique for reducing polymer deposit during polymerization in aqueous dispersion
Assignee: VISTA POLYMERS Inc A DE CRP AND WHOLLY-OWNED SUBSIDIARY OF VISTA CHEMICAL Co
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Filing: 1974-10-29
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Granted: 1976-06-08
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Expires: 1994-10-29
Abstract
Abstract Polymer deposit or build-up on the interior surfaces of a polymerization vessel during polymerization of monoethylenically unsaturated monomers in aqueous dispersion may be inhibited by adding certain heterocyclic compounds to the dispersion prior to polymerization.
Inventors
- 👤 Dean R. Weimer
- 👤 Albert M. Durr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 02:38
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/12; C08F2/16
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
56 words
A method for inhibiting polymer build-up on the interior surfaces of a polymerization vessel during the polymerization of substantially water-insoluble monoethylenically unsaturated liquid monomer in aqueous dispersion comprising adding a polymer build-up inhibiting amount of a heterocyclic compound to the aqueous dispersion prior to polymerization, said heterocyclic compound being benzotriazole, tolyltriazole, 2(2'-hydroxy-5'-methylphenyl) benzotriazole, or mixtures thereof.
Claim 2
Independent Claim
56 words
A method for inhibiting polymer build-up on the interior surfaces of a polymerization vessel during the polymerization of substantially water-insoluble monoethylenically unsaturated liquid monomer in aqueous dispersion comprising adding a polymer build-up inhibiting amount of a heterocyclic compound to the aqueous dispersion prior to polymerization, said heterocyclic compound being benzotriazole, tolyltriazole, 2(2'-hydroxy-5'-methylphenyl) benzotriazole, or mixtures thereof.
Claim 3
Dependent Claim
65 words
A method according to claim 1 wherein an alkylated copolymer is employed in addition to the heterocyclic compound, said alkylated copolymer being prepared by simultaneously copolymerizing and alkylating (1) an N-vinyl pyrrolidone having the formula ##EQU3## wherein n is an integer of 1 to 3; R and R 1 are, independently, H, methyl, or ethyl; and (2) an alpha-olefin having at least 2 carbon atoms.
Claim 4
Dependent Claim
127 words
A method according to claim 1 wherein an alkali or alkaline earth metal salt of an amino carboxylic acid is employed in addition to the heterocyclic compound, said amino polycarboxylic acid being defined by (1) amino acids having the formula (R).sub.n N--A--COOH).sub.3-n wherein R is a --CH 2 CH 2 OH or --CH 2 CH 2 CH 2 OH group, A is an alkylene group of 1 to 3 carbon atoms and n is zero, 1 or 2; or (2) polyamino acids having the formula ##EQU4## wherein Z is an alkylene group of 1 to 4 carbon atoms; x is zero, 1, 2, 3 or 4; Y and Y' are, independently, hydrogen, --CH 2 COOH or C 1 -hydroxyalkyl; and Y" is hydrogen or --CH 2 COOH.
Claim 5
Dependent Claim
12 words
A method according to claim 1 wherein the heterocyclic compound is benzotriazole.
Claim 6
Dependent Claim
18 words
A method according to claim 3 wherein benzotriazole and the tetrasodium salt of ethylenediamine tetraacetic acid are employed.
Claim 7
Dependent Claim
67 words
A method according to claim 3 wherein in addition to the amino polycarboxylic acid and the heterocyclic compound, an alkylated copolymer prepared by simultaneously copolymerizing and alkylating (1) an N-vinyl pyrrolidone having the formula: ##EQU5## wherein n is an integer of from 1 to 3, R and R 1 are, independently, hydrogen, methyl, or ethyl, and (2) an alpha-olefin having at least 2 carbon atoms, is employed.
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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) | 1979-06-08 | 1979-12-08 | 1980-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-08 | 1983-12-08 | 1984-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-08 | 1987-12-08 | 1988-06-08 | $7700.00 | Window Closed / Lapsed |