Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Mixing of two or more solid polymers; mixing of solid...
Patent
1990-10-02
1991-07-23
Lipman, Bernard
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Mixing of two or more solid polymers; mixing of solid...
5153338, C08F 806
Patent
active
050344714
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a process for producing active carbonyl compounds with long hydrocarbyl chains from polyolefins.
It is well known that polyolefins can be oxidised directly either by oxygen or by ozone to formcarbonyl compounds. Such processes are described for instance in GB-A-1172818 and EP-A-244616. In these reactions the oxidation results in the scission of the polyolefin chain at the point of the unsaturated linkage thereby
(a) reducing the length of the hydrocarbyl chain on the carbonyl compound and
(b) giving rise to a mixture of carbonyl compounds, at least one from either side of the unsaturated linkage in the polyolefin.
It is also known to epoxidise polyolefins followed by isomerisation to form carbonyl compounds. However, the products of such a process are usually ketones which are relatively inactive for subsequent reactions therewith due to the presence of bulky substituents on either side of the carbonyl group.
It has now been found that active carbonyl compounds predominating in aldehyde groups can be produced by the epoxidation route by choice of the appropriate polyolefin.
Accordingly, the present invention is a process for producing active carbonyl compounds predominating in aldehyde groups from polybutenes having at least 50% of the unsaturation in the terminal position, the process comprising
(a) epoxidising the polybutene in the liquid phase with a peroxygen compound or a compound capable of giving rise to a peroxygen compound under the reaction conditions and
(b) isomerising the epoxide formed from step(a) to the corresponding carbonyl compound.
The term "polybutenes" as used wherein is meant to embrace polyisobutenes because the latter are usually produced from feedstock e.g. butadiene raffinate which is a mixture of n-butenes and iso-butene.
By the term, "terminal position" as used herein is meant that at least 50% of the polybutene reactant used has the polymer chain terminating in a .dbd.CH.sub.2 group. Such a polybutene is also known as high vinylidene polybutene.
By the term "active carbonyl compounds" is meant carbonyl compounds in which the carbonyl function is readily accessible for further reactions such as e.g. amination.
Polybutenes having a high degree of terminal unsaturation are relatively novel compounds and methods of synthesising these have only recently been devised. For instance EP-A-145235 claims and describes such a process. The polybutenes used have a molecular weight in the range of 200-2000.
The epoxidation step is suitably carried out using a peroxygen compound e.g. m-chloroperbenzoic acid, mixture of hydrogen peroxide and sulphuric acid, or, tert-butyl peroxide in the presence of a molybdenum catalyst.
The epoxidation is suitably carried out using a solution of the polybutene in a solvent inert under the reaction conditions such as a chlorohydrocarbon e.g. dichloromethane or carbontetrachloride.
The epoxidation is preferably carried out in an atmosphere inert under the reaction conditions e.g. nitrogen.
The epoxidation reaction can be carried out in the presence of an acidic catalyst which may be organic or mineral acids. Thus, the acid catalyst may be organic or inorganic in nature and may include catalysts such as alumina, silica, aluminosilicates, zeolites, sulphuric acid and the like. Ideally, the epoxidation can be carried out using a hetrogeneous catalyst for ease of isolation of products. For instance, the catalyst may be impregnated upon or be part of a resin or support which can be formed into a column and the epoxidised polybutene passed through said column. Alumina is the preferred catalyst.
The epoxidation reaction is suitably carried out at ambient temperature and pressure, preferably at temperatures below 40.degree. C. It is generally not necessary to purify or isolate the epoxidation products unless the decomposition products from the peroxygen compounds used for epoxidation are undesirable and/or detrimental to the epoxide.
The epoxidised product from step (a) is isomerised to the corresponding carbonyl compound, preferably,
REFERENCES:
patent: 3382255 (1968-05-01), White
patent: 3515687 (1970-06-01), Listner
patent: 3842010 (1974-10-01), Pappas et al.
patent: 3949018 (1976-04-01), Agouri et al.
patent: 4309516 (1982-01-01), Schultz et al.
BP Chemicals Limited
Lipman Bernard
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