Patent ID: 8747541

Claim:
A dispersion, obtained by a method comprising reacting a) in 50 to 75 parts by weight of water b) 25 to 50 parts by weight of silica particles having a BET surface area of 30 to 500 m 2 /g and c) an amount based on 100 to 300 μg/m 2 BET surface area of the silica particles from b) parts by weight of at least one aminofunctional, organosilicon compound, which is a quaternary, aminofunctional, organosilicon compound, obtained by reacting a reaction mixture comprising at least one haloalkylfunctional silane (A) with a tertiary amine (B) in the presence of water and at least partly removing a resulting hydrolysis alcohol from the reaction mixture, wherein the amount of component c) is determined based on the amount of component b) as follows: the amount of component b) in terms of grams is multiplied by its BET surface area to obtain a total BET surface area in terms of m 2 , and then the total BET surface area is multiplied by 100 to 300 μg/m 2 , wherein the haloalkylfunctional alkoxysilane (A): (i) is of formula (I) (R 1 O) 3-x-y (R 2 ) x Si[(R 3 ) n CH 2 Hal] 1+y (I), wherein the groups R 1 are identical or different and R 1 represents a hydrogen, a linear, branched or cyclic alkyl group having 1 to 8 C atoms, an aryl, arylalkyl, or acyl group, the groups R 2 are identical or different and R 2 represents a linear, branched or cyclic alkyl group having 1 to 8 C atoms, an aryl, arylalkyl, or acyl group, the groups R 3 are identical or different and R 3 represents a linear, branched or cyclic alkylene group having 1 to 18 C atoms, n is 0 or 1, Hal represents chlorine or bromine, and x is 0, 1, or 2, y is 0, 1, or 2, and (x+y) is 0, 1, or 2; or (ii) is a hydrolysis product or condensate of at least one alkoxysilane of formula (I); or (iii) is a mixture of at least one alkoxysilane of formula (I) and at least one selected from the group consisting of a hydrolysis product and a condensate of at least one alkoxysilane of formula (I), and wherein the tertiary amine (B) has a formula N(R 4 ) 3 (II), wherein the groups R 4 are identical or different and R 4 represents a group (R 1 O) 3-x-y (R 2 ) x Si[(R 3 ) n CH 2 —] 1+y , wherein R 1 , R 2 , R 3 , n, x, y and (x+y) likewise have the abovementioned meaning, or R 4 represents a linear, branched or cyclic alkyl group having 1 to 30 C atoms, which is optionally substituted, or optionally two groups R 4 in turn are linked to one another and forming a cyclic group with the nitrogen of the tertiary amine.