초록

is produced by spraying a silica under intensive mixing, optionally with water or dilute acid at first and then with a surface-modifying reagent or a mixture of several surface-modifying reagents, then mixing, tempering, and subsequently destructuring/compressing and grinding.

대표청구항 ▼

[ We claim:] [1.] A method of producing a surface modified, hydrophobic silanized silica powder with the following physicochemical properties:______________________________________ Specific surface m.sup.2 /g 80-400 area according to BET Average Primary particle size nm 7-40 area according to electr

[ We claim:] [1.] A method of producing a surface modified, hydrophobic silanized silica powder with the following physicochemical properties:______________________________________ Specific surface m.sup.2 /g 80-400 area according to BET Average Primary particle size nm 7-40 area according to electron microscope Tamped density g/l 50-300 according to DIN 1S0 787/11 pH value 3-10 Carbon content % 0.1-15 DBP number according to % <200 DIN 53601 ______________________________________consisting essentially of spraying pyrogenically produced silica powder in a mixing container under intensive mixing, with water or dilute acid at first and then with hexamethyldisilazanie, mixing for 15 to 30 minutes, and tempering at a temperature of 100 to 400.degree. C. for a period of 1 to 6 hours to produce a hydrophobic, silanized silica.