Functionalized monolith catalyst and process for production...

Details Functionalized monolith catalyst and process for production... Functionalized monolith catalyst and process for production...

1999-12-27

2001-05-15

Vollano, Jean F. (Department: 1621)

Organic compounds -- part of the class 532-570 series

Organic compounds

Oxygen containing

C568S302000

Reexamination Certificate

active

06232504

ABSTRACT:

BACKGROUND OF THE INVENTION
Ketenes are highly reactive chemical intermediates of the general form RR′C═C═O. Ketenes find application as powerful acylating agents for a range of compounds. Alkyl ketene dimers (AKD) are produced from long chain (C
8
-C
32
) fatty acids for use as paper sizing agents.
While there exist a variety of routes to ketenes, these do not generally involve heterogeneous catalysis. Low molecular weight ketenes are produced by thermal pyrolysis of carboxylic acids or ketones at 600-800° C. (Encyclopedia of Polymer Science and Technology, Vol. 8, Interscience, New York, (1968), p. 45, Rice, F. O., Greenberg, J., Waters, C. E., Vollrath, R. E., J. Am. Chem. Soc. 56, 1760 (1934), Hurd, C. D. and Roe, A., J. Am. Chem. Soc. 61, 3355 (1939), Hurd, C. D. and Martin, K. E., J. Am. Chem. Soc. 51, 3614 (1929), Bamford, C. H. and Dewar, J. S., J. Chem. Soc., 2877 (1949) and Guenther, W. B. and Walters, W. D., J. Am. Chem. Soc. 81, 1310 (1959)). Higher molecular weight ketenes are produced by dehalogenation of &agr;-halo acyl halides or dehydrohalogenation of acyl halides with tertiary amines as disclosed in U.S. Pat. No. 2,383,863 issued to R. Heuter and U.S. Pat. No. 3,535,383 issued to E. S. Rothman. None of these routes enjoys the efficiency of a catalytic process. The dehalogenation-based processes are multi-step organic syntheses which utilize hazardous reagents, e.g., phosgene, and solvents, and yield undesirable byproducts. Thus efficiency, safety and waste minimization imperatives all favor the development of a one-step catalytic process.
Gun'ko and coworkers (Brei, V. V., Gunko, V. M., Khavryuchenko, V. D., Chuiko, A. A., Kinetics and Catalysis 31, 1019 (1991), Brei, V. V., Gun'ko, V. M. Dudnik, V. V., Chuiko, A. A., Langmuir, 8, (1992), and Gun'ko, V. M., Brei, V. V., Chuiko, A. A., Kinetics and Catalysis 32, 91 (1991)) observed the formation of ketene in temperature programmed desorption “TPD” experiments in which acetic acid and acetyl chloride were employed to synthesize acetoxysilyl groups on aerosils.
U.S. Pat. No. 3,366,689 issued to Maeda et al. describes a process for manufacturing ketenes by contact dehydration for aliphatic carboxylic acids having 3 to 6 carbon atoms with a silica catalyst having a specific surface area of less than 100 m
2
/g. and at a temperature of 400-900° C. The silica catalyst may be diatomaceous earth, pumice, acid clay, kaolin, aluminum silicate, magnesium silicate or silica-boric oxide.
U.S. Pat. No. 2,175,811 issued to Loder describes a process for preparation of ketene which comprises thermally decomposing lower aliphatic monocarboxylic acid esters in the vapor phase at 500-1000° C. in contact with a catalyst which can be silica gel supporting a promoter such as phosphoric acid or boron oxide.
U.S. Pat. No. 2,295,644 issued to Fallows et al. describes a process for manufacturing ketene and acetic anhydride by thermal dehydration of acetic acid vapors in the presence of a catalyst by passing the vapors at 500-1,000° C. over pumice with zinc oxide or cadmium oxide deposited on the surface.
U.S. Pat. No. 1,870,104 issued to Dreyfus describes a process for the manufacture of ketene, acetic acid or acetic anhydride or mixture thereof which comprises passing vapors of acetic acid and acetaldehyde at 500-600° C. over a catalyst selected from a group which includes pumice.
U.S. Pat. No. 2,108,829 issued to Sixt et al. describes a catalytic process for producing ketene which comprises subjecting acetic acid vapors containing acetic anhydride forming catalyst to heating at a temperature between 500-1000° C. under partial vacuum and immediately separating ketene from the other components. Solid catalysts, such as pea size “carborundum” coated with sodium metaphosphate, may be used (Example 1).
U.S. Pat. No. 5,475,144 issued to Watson et al., describes a catalyst and process for synthesis of ketenes from carboxylic acids. Some of the important features of this catalyst are surface areas of at least 100 m
2
/gram with a controlled population of hydroxyl groups on the surface. The selectivities disclosed were from 35 to 90% at conversions of 30 to 100%.
One of the difficulties with utilization of high surface area powder catalysts at high flow rates is the large pressure drop across the catalyst bed. We have invented a functionalized monolith catalyst which avoids this problem, and which produces higher product selectivities and yields than the catalysts disclosed in U.S. Pat. No. 5,475,144.
A BRIEF SUMMARY OF THE INVENTION
It is object of this invention to have a more efficient process for producing ketenes.
It is another object of this invention to operate at lower temperatures then described above.
It is another object of this invention to reduce the byproduct formation.
It is another object of this invention to have a process that can produce ketenes in a one-step catalytic process.
It is still a further object of this invention to have a safer process which also involves less waste formation than other processes such as (1) thermal pyrolysis of carboxylic acids or ketones, and (2) dehalogenation of &agr;-halo acyl halides, and (3) dehydrohalogenation of acyl halides with tertiary amines.
We have discovered three basic derivatization methods which give active and selective catalysts.
The ketenes manufactured according to the claimed process are useful in areas such as but not limited to, acylating agents for pharmaceutical and sizing agents (intermediates for alkyl ketene dimers and multimers).


REFERENCES:
patent: 3366689 (1968-01-01), Maeda et al.
patent: 3790620 (1974-02-01), Butler et al.
patent: 5475144 (1995-12-01), Watson et al.
CA:109:109951 abs of J Organomet Chem by Singh 338(2) by 255-60, 1988.*
CA:107:235774 abs of Can J Chem by Allen 65(8) pp 1719-23, 1987.

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