US3674651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymerization inhibition of acrylic acid
Assignee: Individual
•
Filing: 1970-06-10
•
Granted: 1972-07-04
•
Expires: 1990-06-10
Abstract
Abstract The inhibition of the polymerization of acrylic acid and a process for stabilizing the distillation of acrylic acid using a combination of a polymerization inhibitor, such as diphenylamine or its derivatives, and an oxygen-containing gas, or mixtures of polymerization inhibitors, such as diphenylamine or its derivatives, with benzoquinone and/or hydroquinone mono-methylether, and an oxygen-containing gas are disclosed.
Inventors
- 👤 Susumu Otsuki
- 👤 Kyoichi Hori
- 👤 Isao Miyanohara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:51
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/42; C07C51/487; C07C51/50; Y; Y10; Y10S; Y10S203/00; Y10S203/22
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
50 words
The process of claim 1, wherein the concentration of the member is from 50 to 5,000 ppm by weight to acrylic acid liquid, and the concentration of the gas is such that the concentration of the oxygen present ranges from 0.02 to 2 percent by volume to acrylic acid vapor.
Claim 2
Dependent Claim
39 words
A process for inhibiting the polymerization of acrylic acid which comprises treating said acid with the combination of (1) a mixture of at least one member selected from the group consisting of (a) a compound having the general formula:
Claim 3
Dependent Claim
51 words
The process of claim 3, wherein the concentratioN of the mixture is from 50 to 5,000 ppm by weight to the acrylic acid liquid and the concentration of the gas is such that the concentration of the oxygen present ranges from 0.02 to 2 percent by volume to acrylic acid vapor.
Claim 4
Dependent Claim
11 words
The process of claim 2, wherein said oxygen-containing gas is air.
Claim 5
Dependent Claim
11 words
The process of claim 4, wherein said oxygen-containing gas is air.
Claim 6
Dependent Claim
36 words
A process for stabilizing the distillation of acrylic acid which comprises treating said acid with the combination of (1) at least one member selected from the group consisting of (a) a compound having the general formula:
Claim 7
Dependent Claim
36 words
A process for stabilizing the distillation of acrylic acid which comprises treating said acid with (1) a mixture of at least one member selected from the group consisting of (a) a compound having the general formula:
Claim 8
Dependent Claim
92 words
In a process for the distilling of acrylic acid without polymerization comprising the steps of heating liquid acrylic acid at a top of the column temperature of from 39* to 95* C and a pressure of from 10 mm Hg to 150 mm Hg to form a vapor of acrylic acid, separating said vapor from said liquid, and condensing said vapor, the improvement which comprises distilling said acrylic acid in the presence of the combination of (1) a member selected from the group consisting of (a) a compound having the general formula:
Claim 9
Dependent Claim
12 words
The process of claim 1, wherein said alkyl groups are methyl groups.
Claim 10
Dependent Claim
26 words
The process of claim 1, wherein said compound of group (a) is selected from the group consisting of diphenylamine, N-methyl diphenyl amine, o-chlorophenyl-N-aniline, o-methylphenyl-N-aniline, diphenyl-paraphenylene diamine.
References Cited (Backward Citations)
US2388041A
Cited
US2399340A
Cited
US2863851A
Cited
US3239433A
Cited
US3366702A
Cited
US3433831A
Cited
US3527677A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-04 | 1976-01-03 | 1976-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-04 | 1980-01-03 | 1980-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-04 | 1984-01-03 | 1984-07-04 | $7700.00 | Window Closed / Lapsed |