| 摘要 |
Stable aqueous dispersions of ethylene terpolymers are produced by polymerizing ethylene, e.g. 20-60%, in an aqueous medium at 50-500 Atm. and 50-100 DEG C. in the presence of a water soluble compound capable of forming free radicals, 10-60% of a polymerizable non-ionic compound containing at least one vinylidene group and 5-30% of an ethylenically unsaturated polymerizable acid or its salt, the ratio of ethylene to the non-ionic compound not being allowed to fall below 1:1 for ethylene. The non-ionic compound may be a vinyl ester of a C2- 5 aliphatic saturated monocarboxylic acid, vinyl or vinylidene chloride, an acrylic or methacrylic ester of a C1- 4 aliphatic saturated monohydric alcohol, acrylic or methacrylic amides or nitriles, styrene, a -methyl styrene, vinyl toluene, a -chlorostyrene, divinyl benzene. The acid or its salt may be a maleic or fumaric acid semi-ester which has been esterified with a C1- 18 aliphatic saturated monohydric alcohol vinyl or styrene sulphonic acid, the reaction product of an amide of acrylic or methacrylic acid with a C2- 18 aliphati saturated monoamino-monocarboxylic acid or an alkali or ammonium salt, sodium vinyl sulphonate, 3-methacryl-aminobenzene sulphonic acid-(N-benzene sulphonyl) amide or vinyl sulphonyl methyl-sulphonyl acetonitrile, compounds of formula: <FORM:0958465/C3/1> where R is H or CH3, X is NH or O, Y is a saturated alkyl or a radical containing a plurality of methylene groups and one or more hetero atoms, and Ac is COOH, SO3H or OSO3H, e.g. methacryl glycine, methacrylamino caproic acid, methacrylic esters of glycolic or lactic acids and the corresponding acrylic acid derivatives. The polymerization may be carried out at a pH 5.0-8.5 with the aqueous medium containing up to 20% tert.-butanol and in the presence of a redox system of a water soluble alkali metal persulphate and a water-soluble reducing agent e.g. sodium pyro- or bi-sulyphite, sodium formaldehyde sulphoxylate or triethanolamine. The free radical compounds may be potassium, sodium or ammonium peroxy-disulphates, perborates or hydrogen peroxide. The dispersions may be dried to form films or coagulated with mineral acids to isolate the polymers which may be pressed to form sheets. Specification 913,145 is referred to. |
