Abstract: The present invention relates to environmentally friendly diesel fuel, containing natural, liquid triglycerides of natural or animal origin, such as rapeseed or soybean oil, and acetals of the formula (I) or (II) ##STR1## in which the substitutents have the meaning defined in the description. This diesel fuel is biodegradable and free of sulfur, nitrogen and aromatics.

Abstract: The invention relates to mixtures comprising acetals and oleophilic alcohols and/or oleophilic esters which are suitable for the preparation of inverted emulsion drilling muds and emulsion drilling muds. They completely or partly replace here the base oils, diesel oil, purified diesel oil, white oil, olefins and alkylbenzenes known to date.The invention furthermore relates to the use of the inverted emulsion drilling mud and emulsion drilling mud as claimed in claim 10.

Abstract: Acetals are used as a mineral oil substitute, oil component or base oil in invert-emulsion drilling muds, emulsion drilling muds, engine oils, gearbox oils, lubricating oils and also metal-working fluids, coolants, cooling lubricants and hydraulic fluids. As compared with conventional mineral oils, acetals show good biodegradability and are less toxic.

Abstract: The water-soluble copolymer comprises 5-90% by weight of groups of the formula ##STR1## in which R.sup.1 is hydrogen or methyl, R.sup.2 is C.sub.2 -C.sub.10 -alkylene, and Me is ammonium or an alkali metal, 5-90% by weight of groups of the formula--CH.dbd.CH--CH.sub.2 --N.sup.+ R.sup.3 R.sup.4 --CH.sub.2 --CH.dbd.CH-- X.sup.- IIin which X is a halogen, R.sup.3 and R.sup.4, independently of one another, are C.sub.1 -C.sub.6 -alkyl, 0-60% by weight of groups of the formula ##STR2## in which R.sup.5 and R.sup.6 together are a propylene group which with inclusion of the radical ##STR3## forms a pyrrolidone radical, and 0-30% by weight of groups of the formula--CHR.sup.7 --CHR.sup.8 -- IVin which R.sup.7 is hydrogen or methyl and R.sup.8 is CONH.sub.2, CON(CH.sub.3).sub.2, cyano, SO.sub.3 H, SO.sub.3 Me, C.sub.6 H.sub.4 SO.sub.3 H, C.sub.6 H.sub.4 SO.sub.3 Me, CH.sub.2 SO.sub.3 H, CH.sub.2 SO.sub.3 Me, COOH, COOMe, or carboxy-C.sub.1 -C.sub.

Abstract: Cement slurries for deep holes, with a content of copolymers which are composed of 5-95% by weight of groups of the formula ##STR1## in which R.sub.1 is hydrogen or methyl,R.sub.2 is C.sub.2 -C.sub.10 -alkylene andMe is ammonium, lithium, sodium or potassium, of 5-60% by weight of groups of the formula ##STR2## in which R.sub.3 is hydrogen, --CH.sub.3 or C.sub.2 H.sub.5 andR.sub.4 is --CH.sub.3 or C.sub.2 H.sub.5, orR.sub.3 and R.sub.4 together are a propylene group which, with incorporation of the radical ##STR3## forms a pyrrolidone radical, and of 0-90% by weight of groups of the formula ##STR4## in which R.sub.6 is hydrogen or methyl andR.sub.7 is carboxamido, carboxyl, cyano or carbomethoxy.These copolymers reduce the water loss of cement slurries which are required for deep holes.

Abstract: Outstandingly suitable drilling mud additives are water soluble copolymers consisting essentially of a random distribution of(a) 5 to 95% by weight of units of the formula ##STR1## (b) 5 to 95% by weight of units of the formula ##STR2## and (c) 0 to 80% by weight of units of the formula ##STR3## wherein R.sup.1 and R.sup.2 are the same or different and each is hydrogen methyl or ethyl; andX.sup..sym. is a cation.

Abstract: Outstandingly suitable drilling mud additives are water soluble copolymers consisting essentially of a random distribution of(a) 5 to 95% by weight of units of the formula ##STR1## (b) 5 to 95% by weight of units of the formula ##STR2## and (c) 0 to 80% by weight of units of the formula ##STR3## wherein R.sup.1 and R.sup.2 are the same or different and each is hydrogen, methyl or ethyl; and X.sup..sym. is a cation.