Abstract: The present invention relates to novel granular silicas for use as support material, especially as support for catalysts for fixed bed reactors, and to the production and use thereof.

Abstract: The present invention relates to novel granular silicas for use as support material, especially as support for catalysts for fixed bed reactors, and to the production and use thereof.

Abstract: A precipitated silica with the following physiochemical properties: BET surface area 35 m2/g to 350 m2/g BET/CTAB surface area ratio 0.8 to 1.1 Pore volume, PV 1.6 ml/g to 3.4 ml/g Silanol group density (V2 = NaOH 3 ml/(1.5 g) to 9.5 ml/(1.5 g) consumption) Average aggregate size 250 nm to 1500 nm CTAB surface area 30 m2/g to 350 m2/g DBP value 150 ml/100 g to 300 ml/100 g V2/V1 by Hg porosimetry 0.19 to 0.46 DBP/CTAB 1.2 to 3.5 is produced by reacting alkali silicate with mineral acids at temperatures of 60° C. to 95° C. while maintaining a pH of 7.5 to 10.5 and continuously stirring, continuing the reaction to a solids concentration in the precipitation suspension of 90 g/l to 120 g/l, adjusting the pH value to a value of less than or equal to 5, filtering out, washing, drying and optionally grinding or granulating the precipitated silica. The precipitated silica is used as a filler in vulcanizable rubber compounds and vulcanizates.

Abstract: Rubber compositions comprising a precipitated silica with the following physico-chemical properties: BET surface area ??35 to 350 m2/g BET/CTAB surface area ratio ?0.8 to 1.1 Pore volume, PV ?1.6 to 3.4 ml/g Silanol group density ??6 to 20 ml/(5 g) Average aggregate size ?250 to 1500 nm CTAB surface area ??30 to 350 m2/g DBP value ?150 to 300 ml/100 g V2/V1 by Hg porosimetry 0.19 to 0.46 DBP/CTAB ?1.2 to 3.5.

Abstract: A precipitated silica with the following physicochemical properties: BET surface area 35 m2/g to 350 m2/g BET/CTAB surface area ratio 0.8 to 1.1 Pore volume, PV 1.6 ml/g to 3.4 ml/g Silanol group density 3 ml/(1.5 g) to 9.5 ml/(1.5 g) (V2 = NaOH consumption) Average aggregate size 250 nm to 1500 nm CTAB surface area 30 m2/g to 350 m2/g DBP value 150 ml/100 g to 300 ml/100 g V2/V1 by Hg porosimetry 0.19 to 0.46 DBP/CTAB 1.2 to 3.5 is produced by reacting alkali silicate with mineral acids at temperatures of 60° C. to 95° C. while maintaining a pH of 7.5 to 10.5 and continuously stirring, continuing the reaction to a solids concentration in the precipitation suspension of 90 g/l to 120 g/l, adjusting the pH value to a value of less than or equal to 5, filtering out, washing, drying and optionally grinding or granulating the precipitated silica. The precipitated silica is used as a filler in vulcanizable rubber compounds and vulcanizates.

Abstract: A precipitated silica with the following physicochemical properties: BET surface area 35 m2/g to 350 m2/g BET/CTAB surface area ratio 0.8 to 1.1 Pore volume, PV 1.6 ml/g to 3.4 ml/g Silanol group density 3 ml/(1.5 g) to 9.5 ml/(1.5 g) (V2 = NaOH consumption) Average aggregate size 250 nm to 1500 nm CTAB surface area 30 m2/g to 350 m2/g DBP value 150 ml/100 g to 300 ml/100 g V2/V1 by Hg porosimetry 0.19 to 0.46 DBP/CTAB 1.2 to 3.5 is produced by reacting alkali silicate with mineral acids at temperatures of 60° C. to 95° C. while maintaining a pH of 7.5 to 10.5 and continuously stirring, continuing the reaction to a solids concentration in the precipitation suspension of 90 g/l to 120 g/l, adjusting the pH value to a value of less than or equal to 5, filtering out, washing, drying and optionally grinding or granulating the precipitated silica. The precipitated silica is used as a filler in vulcanizable rubber compounds and vulcanizates.

Abstract: Rubber compositions comprising a precipitated silica with the following physicochemical properties: 1 BET surface area   35 to 350 m2/g BET/CTAB surface area ratio  0.8 to 1.1 Pore volume, PV  1.6 to 3.4 ml/g Silanol group density (V2 =   6 to 20 ml NaOH consumption) Average aggregate size  250 to 1500 nm CTAB surface area   30 to 350 m2/g DBP value  150 to 300 ml/100 g V2/V1 by Hg porosimetry 0.19 to 0.46 DBP/CTAB  1.2 to 3.5.

Abstract: A precipitated silica which contains an active substance with a characteristic, delayed release of active substance is prepared by adding the active substance during preparation of the precipitated silica. The precipitated silica containing the active substance may be added to oral hygiene agents such as toothpastes, topical fluoride preparations, dental materials or medicinal chewing gums.

Abstract: A precipitated silica with the following physicochemical properties:______________________________________ BET surface area 35 to 350 m.sup.2 /g BET/CTAB surface area ratio 0.8 to 1.1 Pore volume, PV 1.6 to 3.4 ml/g Silanol group density (V2 = 6 to 20 ml NaOH consumption) Average aggregate size 250 to 1500 nm CTAB surface area 30 to 350 m.sup.2 /g DBP value 150 to 300 ml/100 g V.sub.2 /V.sub.1 by Hg porosimetry 0.19 to 0.46 DBP/CTAB 1.2 to 2.4. ______________________________________is produced by reacting alkali silicate with mineral acids at temperatures of 60 to 95.degree. C. while maintaining a pH of 7.5 to 10.5 and continuously stirring, continuing the reaction to a solids concentration in the precipitation suspension of 90 to 120 g/l, adjusting the pH value to a value of less than or equal to 5, filtering out, washing, drying and optionally grinding or granulating the precipitated silica. The precipitated silica is used as a filler in vulcanizable rubber compounds and vulcanizates.

Abstract: The description relates to vinyl alcohol copolymers which can be produced by the acid-catalysed acetalisation reaction of polyvinyl alcohols with a degree of saponification of 80-99.5 mol % and preferably between 88 and 99.5 mol % with natural substances or their derivatives containing carbonyl or presumptive carbonyl groups. The description also relates to water-soluble films containing such vinyl alcohol copolymers, the solubility of which can be adjusted to the desired solution temperature. Said water-soluble films are used as packaging materials and auxiliaries, e.g. in the form of sealing lacquers.

Abstract: Precipitated silica with a sodium sulphate content of 4 to 18 wt. %, particularly with the physical-chemical data:______________________________________ Sodium sulphate content: 4-14 wt. % BET surface area (DIN 66131): 100-190 m.sup.2 /g DBP absorption (anhydrous) 208-250 g/100 g (DIN 53601, ASTM D 2414): 3.0-6.5 wt. % (DIN ISO 787/II) Oversize with >63 .mu.m .ltoreq. 10.0 wt. % ALPINE air-jet sieve >150 .mu.m .ltoreq. 0.1 wt. % >250 .mu.m .ltoreq. 0.01 wt. % ______________________________________It is prepared by introducing hot water into a precipitation vessel, with stirring, adding water glass, then heating the mixture and maintaining the temperature throughout the remainder of the precipitation period. Water glass and sulphuric acid are added simultaneously during this process. The precipitated silica is then separated from the suspension and the filter cake containing sodium sulphate is dried in a spray drier and ground.

Abstract: A precipitated silica with the following physicochemical properties:______________________________________ BET surface area 35 to 350 m.sup.2 /g BET/CTAB surface area ratio 0.8 to 1.1 Pore volume, PV 1.6 to 3.4 ml/g Silanol group density (V2 = 6 to 20 ml NaOH consumption) Average aggregate size 250 to 1500 nm CTAB surface area 30 to 350 m.sup.2 /g DBP value 150 to 300 ml/100 g V.sub.2 /V.sub.1 by Hg porosimetry 0.19 to 0.46 DBP/CTAB 1.2 to 2.4. ______________________________________is produced by reacting alkali silicate with mineral acids at temperatures of 60.degree. to 95.degree. C. while maintaining a pH of 7.5 to 10.5 and continuously stirring, continuing the reaction to a solids concentration in the precipitation suspension of 90 to 120 g/l, adjusting the pH value to a value of less than or equal to 5, filtering out, washing, drying and optionally grinding or granulating the precipitated silica. The precipitated silica is used as a filler in vulcanizable rubber compounds and vulcanizates.

Abstract: Precipitated silica which has a BET surface area of 10-130 m.sup.2 /g, a CTAB surface area of 10-70 m.sup.2 /g , an average particle diameter of 5-20 .mu.m, a Cu abrasion value in a 10% glycerol dispersion of 4-50 mg and thickening behavior in a CMC solution (20% dispersion) of 300-3500 mPa.multidot.s, is produced by simultaneously adding alkali silicate (weight modulus SiO.sub.2 :alkali oxide=2.5-3.9:1) and a mineral acid to an initial amount of water which has been adjusted to a pH value of 7.0 to 9.9 or 10.0 to 10.7 by the addition of water glass, holding the pH value constant between 7.0 and 9.9 or 10.0 to 10.7 during addition, wherein the initial precipitation temperature is 50.degree.-90.degree. C. and an increase in viscosity occurs after at most 25% of the duration of precipitation, adjusting the pH value to .ltoreq.6, preferably 3.5, once a silica content of greater than 120 g/l or greater than 150 g/l, preferably .gtoreq.