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US4256914A
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Catalytic oxidation of methacrolein
Assignee: Ube Corp
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Filing: 1979-08-17
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Granted: 1981-03-17
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Expires: 1999-08-17
Abstract
Abstract Methacrolein is catalytically oxidized into methacrylic acid in the vapor phase at a temperature of 200 DEG to 450 DEG C. The catalyst used is comprised of molybdenum, phosphorus, potassium and/or cesium, vanadium, silver and/or tellurium, and oxygen, and represented by the formula: Mo12PaAbVcXdOe wherein A is K and/or Cs and X is Ag and/or Te, and a=0.5-5, b=0.1-4, c=0.05-3, d=0.001-2 and e is a positive number required by the valence states of the other elements present.
Inventors
- 👤 Sumio Umemura
- 👤 Kyoji Ohdan
- 👤 Fumihiko Sakai
- 👤 Kenichi Suzuki
- 👤 Toshihiko Hogami
- 👤 Masataka Fuginaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 11:43
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/25; C07C51/252
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
148 words
An improvement in the process for the preparation of methacrylic acid by catalytically oxidizing methacrolein in the vapor phase with molecular oxygen at a temperature of from 200° C. to 450° C., said improvement comprising using a catalyst consisting essentially of (A) molybdenum, (B) phosphorus, (C) potassium and/or cesium, (D) vanadium, (E) silver and/or tellurium and (F) oxygen and represented by the formula: Mo.sub.12 P.sub.a A.sub.b V.sub.c X.sub.d O.sub.e wherein Mo is molybdenum, P is phosphorus, A is at least one metal selected from potassium and cesium, V is vanadium, X is at least one metal selected from silver and tellurium, and O is oxygen, and the subscripts a through d are positive numbers falling within the following ranges: a=0.5 to 5, b=0.1 to 4, c=0.05 to 3 and d=0.001 to 2, and e is a positive number required by the valence states of the other elements present.
Claim 2
Dependent Claim
148 words
An improvement in the process for the preparation of methacrylic acid by catalytically oxidizing methacrolein in the vapor phase with molecular oxygen at a temperature of from 200° C. to 450° C., said improvement comprising using a catalyst consisting essentially of (A) molybdenum, (B) phosphorus, (C) potassium and/or cesium, (D) vanadium, (E) silver and/or tellurium and (F) oxygen and represented by the formula: Mo.sub.12 P.sub.a A.sub.b V.sub.c X.sub.d O.sub.e wherein Mo is molybdenum, P is phosphorus, A is at least one metal selected from potassium and cesium, V is vanadium, X is at least one metal selected from silver and tellurium, and O is oxygen, and the subscripts a through d are positive numbers falling within the following ranges: a=0.5 to 5, b=0.1 to 4, c=0.05 to 3 and d=0.001 to 2, and e is a positive number required by the valence states of the other elements present.
Claim 3
Dependent Claim
43 words
A process according to claim 1 wherein said catalyst is the calcined residue obtained by calcining at a temperature of from 300° to 550° C. a product formed by mixing the respective element-containing compounds in an aqueous medium and then drying the mixture.
Claim 4
Dependent Claim
41 words
A process according to claim 2 wherein said calcined residue is obtained by calcining said mixing and dried product at a temperature of from 350° to 450° C. for a period of from 2 to 24 hours in an air atmosphere.
Claim 5
Dependent Claim
47 words
A process according to claim 1 or 2 wherein the atomic ratios of the respective elements to molybdenum are such that the subscripts a through d are positive numbers falling within the following ranges: a=0.9 to 3, b=0.5 to 3 c=0.1 to 2 and d=0.01 to 1.
Claim 6
Dependent Claim
15 words
A process according to claim 1 or 2 wherein X in the formula is silver.
Claim 7
Dependent Claim
15 words
A process according to claim 1 or 2 wherein X in the formula is tellurium.
Claim 8
Dependent Claim
17 words
A process according to claim 1 or 2 wherein X in the formula is silver plus tellurium.
Claim 9
Dependent Claim
35 words
A process according to claim 1 or 2 wherein the catalytic oxidation of methacrolein is effected at a temperature of from 250° to 400° C. with a contact time of from 0.1 to 10 seconds.
Claim 10
Dependent Claim
35 words
A process according to claim 1 or 2 wherein the catalytic oxidation of methacrolein is effected at a temperature of from 300° to 340° C. with a contact time of from 0.5 to 5 seconds.
Claim 11
Dependent Claim
28 words
A process according to claim 1 or 2 wherein the amount of molecular oxygen is in the range of from 0.5 to 7 moles per mole of methacrolein.
Claim 12
Dependent Claim
30 words
A process according to claim 1 or 2 wherein the catalytic oxidation of methacrolein is effected in the presence of 1 to 30 moles of steam per mole of methacrolein.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |