Patent US4255470A successfully refreshed from Google Patents.
US4255470A
Expired / Lapsed
US
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Process for preventing polymer buildup in a polymerization reactor
Assignee: Geon Co
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Filing: 1977-07-15
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Granted: 1981-03-10
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Expires: 1997-07-15
Abstract
Abstract This invention relates to a process of coating the internal surface of a polymerization reactor in order to substantially eliminate the buildup of polymer on said surfaces during the polymerization process. There is applied to the surfaces a coating composition containing a straight chain or branched polyaromatic amine dissolved in an aqueous acid solution and thereafter the coated surfaces are flushed or rinsed with water without drying the same.
Inventors
- 👤 Louis Cohen
- 👤 James B. Haehn
- 👤 Donald E. Witenhafer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:21
CPC Classifications
C; C08; C08F; C08F2/00; C08F2/002; C08F2/004
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
80 words
A process for substantially eliminating the buildup of polymers on the internal surfaces of a polymerization reaction vessel which comprises applying to said surfaces a coating solution comprised of a polyaromatic amine having a molecular weight in the range of about 250 to about 1000 dissolved in an aqueous acid solution, said polyaromatic amine having the structure ##STR2## wherein R is H or NH 2 , x and y are 1 or 2, and n is from 0 to 5.
Claim 2
Dependent Claim
80 words
A process for substantially eliminating the buildup of polymers on the internal surfaces of a polymerization reaction vessel which comprises applying to said surfaces a coating solution comprised of a polyaromatic amine having a molecular weight in the range of about 250 to about 1000 dissolved in an aqueous acid solution, said polyaromatic amine having the structure ##STR2## wherein R is H or NH 2 , x and y are 1 or 2, and n is from 0 to 5.
Claim 3
Dependent Claim
23 words
A process as defined in claim 1 wherein the coating solution has a pH in the range of about 1.0 to about 5.0.
Claim 4
Dependent Claim
15 words
A process as defined in claim 1 wherein the acid solution is aqueous hydrochloric acid.
Claim 5
Dependent Claim
22 words
A process as defined in claim 2 wherein the polyaromatic amine has a molecular weight in the range of 300 to 600.
Claim 6
Dependent Claim
15 words
A process as defined in claim 1 wherein the polyaromatic amine is self-condensed m-phenylene diamine.
Claim 7
Dependent Claim
28 words
A process as defined in claim 1 wherein the concentration of acid in the aqueous solution is in the range of about 0.01% to about 20.0% by weight.
Claim 8
Dependent Claim
29 words
A process as defined in claim 1 wherein the concentration of polyaromatic amine in the coating solution is in the range of about 0.1% to about 20.0% by weight.
Claim 9
Dependent Claim
15 words
A process as defined in claim 1 wherein the acid solution is aqueous phosphoric acid.
Claim 10
Dependent Claim
17 words
A process as defined in claim 1 wherein said surfaces after being coated are rinsed with water.
Claim 11
Dependent Claim
30 words
A process as defined in claim 5 wherein the self-condensed m-phenylene diamine is dissolved in aqueous hydrochloric acid at a concentration of 1.5% by weight and a pH of 2.7.
References Cited (Backward Citations)
US4024330A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-09 | 1984-09-08 | 1985-03-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-09 | 1988-09-08 | 1989-03-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-09 | 1992-09-08 | 1993-03-10 | $7700.00 | Window Closed / Lapsed |