MIXTURE OF GRAFT COPOLYMERS Russian patent published in 2013 - IPC C08L51/00 C08L97/00 C08L89/00 C08L99/00 C08L87/00 C09K8/20 C09K8/42 

FIELD: chemistry.

SUBSTANCE: invention relates to a mixture of graft copolymers for use as an additive in chemical materials, as well as in development, exploitation and integration of underground deposits of oil and natural gas and in case of deep wells. The mixture of graft copolymers contains at components, at least one representative of brown coal, brown coal coke, lignite and a brown coal derivative, at least one representative of natural polyamides and different vinyl-containing compounds. The grafting base is selected from at least one representative of brown coal, brown coal coke, lignite and a brown coal derivative such as tannin and/or such a polyphenol derivative as lignosulphonate, or a polyamide component. Suitable polyamide components are natural polyamides, preferably caseins, gelatins and collagens, bone glues, blood albumins, soya proteins and products of splitting thereof, which are formed via oxidation, hydrolysis or depolymerisation, as well as mixtures thereof. The grafting component used is representatives of brown coal, brown coal coke, lignite, a brown coal derivative and natural polyamides, as well as vinyl-containing compounds in their O-, S-, P- and N-forms and styrenes, which can be in sulphonated form, or as a graft product. The graft product is obtained by grafting a vinyl-containing compound to at least one representative of natural polyamides or mixtures thereof, or grafting a vinyl-containing compound to at least one representative of brown coal, brown coal coke, lignite and a brown coal derivative. Graft copolymers with preferred molecular weight are used as a mixture, particularly in chemical construction materials and during development, exploitation and integration of underground deposits of oil and natural gas and in case of deep wells or as an additive for compositions containing hydraulic binding substances, as a water-retaining agent and/or liquefier.

EFFECT: graft copolymers have excellent resistance to salt and temperature and are also water-soluble and/or biodegradable.

17 cl, 2 tbl, 7 ex