| CPC C08L 91/06 (2013.01) [C09D 11/12 (2013.01); C09D 191/06 (2013.01)] | 19 Claims |
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1. A process for producing rice bran wax oxidates (O) having an acid number of less than 40 mg KOH/g, comprising the steps of:
i) providing a rice bran wax (R) containing less than 5% by weight, based on the total weight of the rice bran wax (R), of polyesters formed from polyhydric alcohols and aliphatic carboxylic acids having 8 to 20 carbon atoms;
ii) providing a mixture (M) of chromium trioxide and sulfuric acid;
iii) performing an oxidation of the rice bran wax (R) by reacting the rice bran wax (R) with the mixture (M) while stirring and at a temperature of 80 to 150° C., in order to obtain a rice bran wax oxidate (O) in a reaction mixture;
iv) stopping the reaction and leaving the reaction mixture obtained in step iii) to stand until an organic phase has separated from an aqueous phase;
v) separating off the organic phase;
vi) optionally removing residues containing chromium compounds from the organic phase in order to obtain the rice bran wax oxidate (O) in purified form; and
vii) optionally repeating the sequence of steps ii) to vi) using the rice bran wax oxidate (O), optionally in purified form, rather than the rice bran wax (R),
wherein the oxidation in step iii) is effected over a period of 1 to 8 hours.
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