| 摘要 |
The invention relates to an electrorheological fluid essentially comprising an essentially non-conductive fluid with a solid phase comprising particles of a silicon-containing material with the exception of phyllosilicates, which material, on its surface, is modified by the reaction of its surface groups <IMAGE> with a suitable compound which may form groups of the general formula <IMAGE> in which R is a group of the formula <IMAGE> or <IMAGE> or <IMAGE> in which W is either Si or Ti, R1 is a straight-chain or branched C1-C4-alkyl, R2 is a group of the formula <IMAGE> in which x is an integer between 1 and 9; R' and R'' can be identical or different, and are selected from the group comprising hydrogen, C5-C20-alkyl, C5-C20-alkenyl and -(C2H4O)x-C6H5-C7-11-alkyl, x having the same meaning as above; Y' and Y'' can be identical or different and represent O, NH or NR, R''' being a group of the formula <IMAGE> in which R1 has the abovementioned meaning and in which y and z can be identical or different and are integers between 1 and 9, and in which n is an integer between 10 and 30; R3 represents a group of the formula CnH2n + 1-COO, in which n has the abovementioned meaning, R4 is a group of the formula <IMAGE> in which R5 represents aliphatic C7-20-alkyl or C7-20-alkenyl and B represents boron, characterised in that it has been obtained by suspending the finely dispersed particles of the silicon-containing base material in the fluid mentioned with stirring for from 0.5 to 24 hours at a temperature of from 60 to 300 DEG C, and by reacting them over this time with the modification compound in a manner known per se, and a process for the preparation thereof. |
