Water-soluble and biodegradable copolymers on a polyamide basis and use thereof

The invention relates to the use of copolymers on a polyamide basis, containing at least one graft lateral chain consisting of ethylenic unsaturated compounds, in construction chemistry, as well as with the prospecting, exploiting and completion of oil- and gas deposits and with deep bore holes. Preference is given to the use with compounds containing hydraulic binding agents, particularly as a water-retaining agent. The cementing of oil- and gas drillings is of particular importance. Typical representatives of the polyamide component are natural polyamides, like caseins, galantines, collagens and soy proteins. The copolymers used in the invention, having typically a molar mass of Mn > 20,000 g/mol, representatives being water-soluble and biodegradable are particularly preferred.