US4075244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing methacrylic acid
Assignee: Nippon Shokubai Co Ltd
•
Filing: 1976-10-26
•
Granted: 1978-02-21
•
Expires: 1996-10-26
Abstract
Abstract A process for the preparation of methacrylic acid which comprises reacting methacrolein with molecular oxygen in the vapor phase in the presence of an oxidation catalyst composition having the following empirical formula Mo.sub.a P.sub.b V.sub.c L.sub.d M.sub.e O.sub.f wherein L is at least one element selected from the group consisting of Rb, Cs and K; M is at least one element selected from the group consisting of Sr, Zn, Cd, Nb, B, Pb, and W; and a, b, c, d, e and f each represent the number of atoms of each element; the atomic ratio of a:b:c:d:e is 12:0.1-8:0.1-8:0.1-8:0-6; and f is the number of oxygen atoms determined by the valence requirement of the other elements present.
Inventors
- 👤 Shinichi Akiyama
- 👤 Haruhisa Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:56
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/002; B01J27/00; B01J27/14; B01J27/186; B01J27/195; B01J27/198; B01J27/199; C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/25; C07C51/252; B01J2523/00
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
165 words
A process for the preparation of methacrylic acid which comprises reacting methacrolein with molecular oxygen in the vapor phase in the presence of an oxidation catalyst composition consisting essentially of a catalytic oxide of molybdenum (Mo), phosphorous (P), vanadium (V), at least one of rubidium (Rb), cesium (Cs), or potassium (K), and optionally at least one of strontium (Sr), zinc (Zn), cadmium (Cd), niobium (Nb), boron (B), lead (Pb) or tungsten (W), said catalyst composition having the following empirical formula: Mo.sub.a P.sub.b V.sub.c L.sub.d M.sub.e O.sub.f wherein L is at least one element selected from the group consisting of Rb, Cs and K; M is at least one element selected from the group consisting of Sr, Zn, Cd, Nb, B, Pb, and W; and a, b, c, d, e, and f each represent the number of atoms of each element; the atomic ratio of a:b:c:d:e is 12:0.1-8:0.1-8:0.1-8:0.6; and f is the number of oxygen atoms determined by the valence requirement of the other elements present.
Claim 2
Dependent Claim
165 words
A process for the preparation of methacrylic acid which comprises reacting methacrolein with molecular oxygen in the vapor phase in the presence of an oxidation catalyst composition consisting essentially of a catalytic oxide of molybdenum (Mo), phosphorous (P), vanadium (V), at least one of rubidium (Rb), cesium (Cs), or potassium (K), and optionally at least one of strontium (Sr), zinc (Zn), cadmium (Cd), niobium (Nb), boron (B), lead (Pb) or tungsten (W), said catalyst composition having the following empirical formula: Mo.sub.a P.sub.b V.sub.c L.sub.d M.sub.e O.sub.f wherein L is at least one element selected from the group consisting of Rb, Cs and K; M is at least one element selected from the group consisting of Sr, Zn, Cd, Nb, B, Pb, and W; and a, b, c, d, e, and f each represent the number of atoms of each element; the atomic ratio of a:b:c:d:e is 12:0.1-8:0.1-8:0.1-8:0.6; and f is the number of oxygen atoms determined by the valence requirement of the other elements present.
Claim 3
Dependent Claim
14 words
The process of claim 1, wherein the reaction temperature is 300° to 500° C.
Claim 4
Dependent Claim
14 words
The process of claim 1, wherein the source of the molecular oxygen is air.
Claim 5
Dependent Claim
16 words
The process of claim 1, wherein an inert diluent gas is introduced into the reaction zone.
Claim 6
Dependent Claim
20 words
The process of claim 1, wherein the catalyst is diluted with an inert diluent or supported on an inert carrier.
Claim 7
Dependent Claim
13 words
The process of claim 1, wherein the atomic ratio of a:b:c:d:e is 12:0.3-5:0.3-5:0.3-5:0-3.
Claim 8
Dependent Claim
9 words
The process of claim 1, wherein L is Rb.
Claim 9
Dependent Claim
9 words
The process of claim 1, wherein L is Cs.
Claim 10
Dependent Claim
9 words
The process of claim 1, wherein L is K.
Claim 11
Dependent Claim
13 words
The process of claim 1, wherein the atomic ratio of a:b:c:d:e is 12:0.3-5:0.3-5:0.3-5:0.05-3.
Claim 12
Dependent Claim
9 words
The process of claim 10 wherein M is Sr.
Claim 13
Dependent Claim
9 words
The process of claim 10 wherein M is Zn.
Claim 14
Dependent Claim
9 words
The process of claim 10 wherein M is Cd.
Claim 15
Dependent Claim
9 words
The process of claim 10 wherein M is Pb.
Claim 16
Dependent Claim
9 words
The process of claim 10 wherein M is Nb.
Claim 17
Dependent Claim
9 words
The process of claim 10 wherein M is B.
Claim 18
Dependent Claim
9 words
The process of claim 10 wherein M is W.
References Cited (Backward Citations)
US3865873A
Cited
US3795703A
Cited
US3925464A
Cited
US3857796A
Cited
US3875220A
Cited
US3976688A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-20 | 1981-08-22 | 1982-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-20 | 1985-08-22 | 1986-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-20 | 1989-08-22 | 1990-02-21 | $7700.00 | Window Closed / Lapsed |