| 摘要 |
<p>The invention comprises thiodiglycol di-[b -(9-carbazolyl) propionate] and N-b -hydroxy-ethyl-carbazolthiodipropionate. The former is made by heating 2 mols of 9-carbazolyl propionic acid with 1 mol of thiodiethyleneglycol and the latter by heating 2 mols of 9-hydroxyethylcarbazole with 1 mol of b , b 1-thio-dipropionic acid. Preferably the reactions are effected in the presence of an acid catalyst and a solvent which permits of the removal of water as an azeotrope. The products are stabilizers for crystalline polyolefines made in the presence of stereospecific catalysts (see Division C3). Examples are provided of the preparation of both compounds.ALSO:Crystalline olefine polymers, made by the use of stereospecific catalysts, are stabilized against heat, light and ageing by the addition of thiodiglycol di-[b -(9-carbazolyl) propionate] or N-b -hydroxyethylcarbazol-thiodipropionate. Preferably 0.02 to 2% by weight, of stabilizer is used. Polypropylene is the preferred polyolefine. The stabilizers are especially useful when the polymers have been coloured with inorganic or organic pigments. Other stabilizers such as dialkylphenol sulphides, e.g. 4,41-thio-bis-6-tert, butylmetacresol, and aliphatic thiodiglycol esters, e.g. lauryl- and dodecyl-thiodiglycolate, may also be present. Examples are provided of the use of the stabilizers in spun yarn from polypropylene. The preparation of the stabilizers is described in Division C2.</p> |
