| abstract |
Abstract of the Disclosure The present invention relates to the use of water-soluble copolymers which consist, in random distribution, of radicals of the formula (I) to the extent of 5 to 60% by weight, of radicals of the formula II (II) to the extent of 2 to 40% by weight, and of radicals of the formula III (III) to the extent of 38 to 93% by weight, and derivatives thereof which are obtainable by partial hydrolysis, in which R1 and R2 are identical or differ-ent and denote hydrogen, methyl or ethyl or, where appropriate, together de-note trimethylene, Y denotes the radical -CO-NH-C(CH3)2-CH2- or a direct bond and X+ denotes a cation, as auxilaries in the deoiling of sand and rock masses containing mineral oil. The copolymers are partially new. The pre-sent invention also relates to the new copolymers and their preparation. |