US4061673A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of methacrylic acid
Assignee: Mitsubishi Chemical Corp
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Filing: 1976-07-30
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Granted: 1977-12-06
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Expires: 1996-07-30
Abstract
Abstract Methacrylic acid is manufactured by oxidative dehydrogenation of isobutyric acid in vapor phase in the presence of a supported catalyst containing a heteropolyacid and/or a reduced form of the heteropolyacid. A highly siliceous material having a high water absorbability is used as a carrier for the catalyst to improve the conversion rate and selectivity as well as the catalyst durability.
Inventors
- 👤 Takeru Onoda
- 👤 Masayuki Otake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:10
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/347; C07C51/377
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
87 words
In a process for the manufacture of methacrylic acid which comprises reacting oxygen and isobutyric acid in vapor phase in the presence of a supported catalyst containing a heteropolyacid having the general formula: H.sub.3+x Mo.sub.12-x-y W.sub.y V.sub.x PO.sub.40 wherein x and y are independently 0, 1, 2 or 3 and x + y < 5, and/or a reduced form of said heteropolyacid, the improvement wherein the carrier for said catalyst has a SiO 2 content of at least 70% and a water absorbability of at least 60%.
Claim 2
Dependent Claim
87 words
In a process for the manufacture of methacrylic acid which comprises reacting oxygen and isobutyric acid in vapor phase in the presence of a supported catalyst containing a heteropolyacid having the general formula: H.sub.3+x Mo.sub.12-x-y W.sub.y V.sub.x PO.sub.40 wherein x and y are independently 0, 1, 2 or 3 and x + y < 5, and/or a reduced form of said heteropolyacid, the improvement wherein the carrier for said catalyst has a SiO 2 content of at least 70% and a water absorbability of at least 60%.
Claim 3
Dependent Claim
20 words
The process according to claim 1, wherein said carrier is silica gel having a water absorbability of at least 60%.
Claim 4
Dependent Claim
20 words
The process according to claim 1, wherein said carrier is diatomaceous earth having a water absorbability of at least 60%.
Claim 5
Dependent Claim
18 words
The process of claim 1 wherein the molar ratio of oxygen to isobutyric acid is 0.1 to 10.
Claim 6
Dependent Claim
14 words
The process of claim 1 wherein the reaction temperature is 200 to 450° C.
Claim 7
Dependent Claim
16 words
The process of claim 1 wherein the reaction pressure is 0.5 to 30 kg/cm 2 .
References Cited (Backward Citations)
FR1338845A
Cited
GB1124797A
Cited
JPS49100027A
Cited
JPS504014A
Cited
JPS504016A
Cited
JPS504017A
Cited
US3948959A
Cited
US3917673A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-05 | 1981-06-06 | 1981-12-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-05 | 1985-06-06 | 1985-12-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-05 | 1989-06-06 | 1989-12-06 | $7700.00 | Window Closed / Lapsed |