Procédé de vinylation catalytique et production des catalyseurs correspondants

摘要

The invention comprises mercuric salt forms of sulphonic cation exchange resins that have a monoreticular structure, and a specific surface area of at least 1 sq. meter per gram when measured by the B.E.T. method using nitrogen adsorption at - 195 DEG C. The resins are obtained by polymerizing a suitable monoethylenically unsaturated monomer, preferably a vinyl aromatic compound such as styrene, with a suitable polyethylenically unsaturable cross-linking monomer, preferably a compound with at least two non-conjugated groups, particularly polyvinyl aryl compounds such as divinyl benzene. Polymerization is conducted in the presence of a precipitant which is: (a) a solvent for the monomers, but, in the amount employed, is essentially a non-solvent for the polymer, and (b) is inert under the polymerization conditions. Suitable precipitants are C4-C10 alkanols, and certain saturated aliphatic hydrocarbons, such as heptane and iso-octane. Other suitable cross-linking monomers named are trivinyl benzene, and polyvinyl ethers of polyhydric alcohols; alternative mono-vinyl monomers are vinyl toluenes, vinyl xylenes, a - and b -alkyl styrenes, vinyl naphthalenes, and vinyl alkyl naphthalenes. If desired, the properties of the resin may be modified by copolymerizing with other mono-ethylenically unsaturated monomers, such as alkyl acrylates and methacrylates, acrylonitrile, or vinyl chloride or acetate. The technique employed is, advantageously, suspension polymerization, suitably in water, by conventional procedures. Preferred resins are those in which the sulphonic acid group is attached to aromatic nuclei, and sulphonation of the macro-reticular resin may be carried out with conc. H2SO4, oleum, or chlorosulphonic acid, at elevated temperatures. The mercuric salts are prepared by reacting the sulphonated resin with a mercuric salt, suitably of a C1-C8 carboxylic acid, or mercuric bromide, in a solvent which is water, a C1-C8 carboxylic acid, or a vinyl ester. The nature of the mercuric salt formed is governed by the reaction temperature and the solvent used: R is the polymeric matrix of the resin, (1 and (2) are conducted in acetic acid, (3) is conducted in water at 60 DEG C. (water at 25 DEG C. gives the same product as (1)) and (4) is carried out in vinyl acetate. Many examples are given for preparation of reticular resins, and sulphonation thereof, for mercurization of the sulphonated resins in all three classes of solvents given above, and for direct and indirect vinylation procedures using the resin catalysts so prepared.ALSO:Transvinylation reactions, of the type: wherein a carboxylic acid is vinylated by reaction with a vinyl carboxylate, or alternatively by direct vinylation with acetylene, are catalysed by a mercuric salt form of a sulphonic acid cation exchange resin having a macroreticular structure and a specific surface area of at least 1 sq. metre when measured by the B.E.T. method using nitrogen adsorption at - 195 DEG C. Vinyl esters used are vinyl acetate, propionate, butyrate, valerate, hexoate, or heptanoate. Carboxylic acids that are vinylated include saturated aliphatic acids, such as chloracetic, butyric, 2-ethylhexanoic, lauric, stearic, and mixed fatty acids from linseed oil, tung oil, soybean oil and safflower oil; also the unsaturated acids, acrylic, methacrylic, itaconic, 3-butanoic, 4-pentanoic, linoleic, and oleic acids; aromatic acids, such as benzoic, phthalic, iso-phthalic, terephthalic, and naphthoic acids; and dibasic aliphatic acids, such as adipic, succinic, and sebacic acids, and hydroxy acids, such as malic acid. The aforesaid carboxylic acids may be vinylated by reaction with acetylene, using the same catalyst. The reaction mixture preferably contains polymerization inhibitors to prevent polymerization of the vinyl reactant and product, such as hydroquinone, t.-butyl catechol, the methyl ether of hydroquinone, or copper salts. Examples are given for vinylation of the following acids using vinyl acetate: Benzoic, methacrylic, lauric, linseed oil fatty acids, 3-butenoic, 4-pentenoic, malic, adipic, and stearic acid; and for vinylation of benzoic acid with vinyl propionate; vinyl acetate, n-butyrate, and chloroacetate are prepared by reacting the corresponding acids with acetylene.