Storage-stable urea preparations which are suitable as rheology control agents

Abstract

The invention relates to a urea preparation containing (A) 5 to 75 wt. % of one or more urea components which have a molecular weight of at least 350 g/mol and contain at least one urea group; (B) 15 to 95 wt. %, preferably 30 to 80 wt. %, of one or more organic solvents from the group of N alkyl amides that have a molecular weight of 155 to 700 g/mol, are free of urea groups, and have the following formula (I), in which (a) Ris an x-containing hydrocarbon group, where x=1 to 24 carbon atoms, Ris a y-containing organic group, where y=1 to 12 carbon atoms, and Ris a z-containing organic group, where z=1 to 12 carbon atoms, or (b) R, R, and Rare defined as in (a) but Rand Rare connected to each other by a chemical bond and together form a ring with 4 to 10 ring atoms while incorporating the group C(═O)N, and in the case of a ring with 4 or 5 ring atoms, Rcontains at least 6 carbon atoms and maximally 11 carbon atoms, or (c) R, R, and Rare defined as in (a) but Rand Rare connected to each other by a chemical bond and together form a ring with 4 to 10 ring atoms while incorporating the nitrogen atom of the general formula (I) with the proviso that for each of (a), (b), and (c), x+y+z≧8; (C) 0 to 35 wt. % of one or more organic solvents which differ from (B) and do not contain urea groups or ionic groups and which have maximally two heteroatoms selected from the group consisting of nitrogen and oxygen; and (D) 0 to 50 wt. % of a salt which differs from the urea component(s) (A), the solvent(s) (B), and the solvent(s) (C), wherein the sum of all of the stated weight percentages equals the total weight of the urea preparation. The invention further relates to the use of the urea preparation as a rheology additive for liquid compositions and to liquid media which contain the urea preparations.