| abstract |
(57) [Abstract] [Purpose] Precipitated silicic acid, its production method and vulcanizable elastic rubber mixture containing it and vulcanized rubber [Constitution] The following physicochemical parameters: BET surface area 35-350 m 2 / g BET / CTAB surface area Ratio 0.8 to 1.1 Porosity PV 1.6 to 3.4 ml / g Silanol group density (V 2 = NaOH consumption) 6 to 20 ml Average aggregate size 250 to 1500 nm CTAB surface area 30 to 350 m 2 / g DBP the precipitated silicas having a number 150~300ml / 100g Hg- porosimeter V 2 / V 1 0.19~0.46 DBP / CTAB 1.2~3.9 by mineral acid and the temperature 60 alkali silicate The reaction was carried out under continuous stirring at 95 ° C, maintaining a pH value of 7.5 to 10.5, and the reaction was carried out with a solid concentration of 9 in the precipitation suspension. The process is carried out to 0 to 120 g / l, the pH value is adjusted to 5 or less, the precipitated silicic acid is filtered off, washed, dried and optionally ground or granulated. This precipitated silicic acid is used as a filler in vulcanizable elastic rubber mixtures and vulcanized rubbers. |