GB1196626A - The Polymerisation of Ethylenically Unsaturated Monomers - Google Patents

Abstract

1,196,626. Vinyl polymers. CHATILLON SOC. ANON. ITALIANA PER LE FIBRE TESSILI ARTIFICIALI S.p.A. 21 Aug., 1967 [24 Aug., 1966], No. 38489/67. Heading C3P. The polymerization of ethylenically unsaturated monomers is effected in the presence of ethylene-diamino tetraacetic acid, diethylene triamino pentaacetic acid, nitrile triacetic acid and/or one or more of their water-soluble salts in an aqueous medium having a pH of not more than 4 using a Redox catalyst system comprising chlorate ions as catalyst and reducing sulphoxy ions as activator and in the absence of molecular oxygen. The monomer is preferably acrylonitrile and is present in at least 80% by weight. Other monomers used in up to 20% by weight include aryl olefines, acrylic acid, substituted acrylic acid, their esters, nitriles, and amides, unsaturated ketones and monomers containing an acid function to improve the dyeability of the polymers with basic dyes. The nitrogen-containing organic additive may be present in less than 5% by weight of the initial monomer. As watersoluble salts of these additives that may be used are the di-, tri- and tetra-sodium and potassium salts, the mono- and bi-calcium and magnesium salts, the di-, tri- and tetra-ammonium salts and mixtures thereof. The chlorate ions may be present in from 0À1 to 2% by weight and may be supplied by the addition of a water-soluble ammonium, alkali, alkaline earth or heavy metal chlorate. The reducing sulphoxy ions (these are sulphur compounds in the form of ions or capable of forming ions in the polymerization medium in which the valency of sulphur is not more than 4) are formed by the addition of water-soluble sulphites, bi-sulphites and meta-bisulphites of ammonia, alkali, alkaline earth or heavy metals, or sulphur dioxide, or water-soluble dialkyl sulphites. The molar ratio of catalyst to activator is preferably less than 1 : 6. The polymerization may be conducted in a batchwise, semi-continuous or continuous way preferably at a temperature of 20-70‹ C. In the examples: (I) acrylonitrile, (II) 91% aorylonitrile, and (a) 9% methyl acrylate, or (b) 9% vinylacetate, and (III) 90À5% acrylonitrile, 9% vinyl acetate and 0À5% sodium p-methyl allyl ether are polymerized in the presence of ethylene diamino tetra-acetic acid, and (IV) acrylonitrile is polymerized in the presence of nitrile triacetic acid.