Abstract: Essentially spherical precipitated silica beads, well adapted for the reinforcement of elastomeric matrices, have a mean particle size of at least 80 &mgr;m, a BET specific surface area ranging from 60 to 130 m2/g, a fill density in packed state ranging from 0.28 to 0.37, and a total pore volume ranging from 1.6 to 3.3 cm3/g.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a very good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 100 and 240 m2/g, a DOP oil uptake lower than 300 ml/100 g, a pore distribution such that the pore volume consisting of the pores whose diameter is between 175 and 275 Å represents less than 50% of the pore volume consisting of the pores of diameters which are smaller than or equal to 400 Å, a median diameter, after disintegration with ultrasound, smaller than 5 &mgr;m and an aluminum content of at least 0.35% by weight. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers.

Abstract: A mechanically strong, vulcanized elastomeric matrix having an effective amount of a reinforcing filler material homogeneously dispersed and distributed therethrough, the reinforcing filler material comprising finely divided precipitated silica particulates and the precipitated silica particulates deriving from a powder having a CTAB specific surface ranging from 100 to 140 m2/g, a median diameter &phgr;50, after ultrasonic disintegration, less than 2.8 &mgr;m, exhibiting an ultrasonic disintegration factor FD greater than 3 ml, having a BET specific surface ranging from 100 to 200 m2/g, having a mean particle size greater than 15 &mgr;m, a packing density in the tamped state of at least 0.17, and a DOP oil uptake ranging from 150 to 400 ml/100 g.

Abstract: The present invention relates to a rubber composition intended for the manufacture of road tires of improved resistance to rolling having a base of precipitated silica with a relatively high specific surface and special porosity properties.

Abstract: Silicas in the form of powder and substantially spherical beads or granules are characterized by a CTAB specific surface of 140 and 240 m2/g a high ultrasonic disaggregation factor, an average diameter, which is small after ultrasonic disaggregation, and optionally, a porous distribution, the porous volume formed by the pores with a diameter of 175 to 275 Å being less than 50% of the porous volume formed by the pores with diameters of 400 Å or less. The silicas may be used as reinforcing fillers for elastomers.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 90 and 250 m.sup.2 /g, a BET specific surface of between 90 and 250 m.sup.2 /g, a DOP oil uptake lower than 300 ml/100 g, a zinc content of between 1 and 5% by weight, and by the fact that the number N of stearic acid molecules consumed per nm.sup.2 of silica surface, when stearic acid is reacted with this silica in xylene for 2 hours at 120.degree. C., is at least 1. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers, especially for improving their rheological properties.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 90 and 250 m.sup.2 /g, a DOP oil uptake lower than 300 ml/100 g, a pore distribution such that the pore volume consisting of the pores whose diameter is between 175 and 275 .ANG. represents less than 50% of the pore volume consisting of the pores of diameters smaller than or equal to 400 .ANG., a zinc content of between 1 and 5% by weight and by the fact that the number N of molecules of stearic acid consumed per nm.sup.2 of silica surface, when stearic acid is reacted with the said silica in xylene for 2 hours at 120.degree. C., is at least 1.

Abstract: Essentially spherical precipitated silica beads, well adapted for the reinforcement of elastomeric matrices, have a mean particle size of at least 80 .mu.m, a BET specific surface area ranging from 60 to 130 m.sup.2 /g, a fill density in packed state ranging from 0.28 to 0.37, and a total pore volume ranging from 1.6 to 3.3 cm.sup.3 /g.

Abstract: Precipitated silica particulates suited for homogeneous incorporation, dispersion and distribution within vulcanized elastomeric matrices reinforced therewith can be formed as either a powder, substantially spherical beads, or granulates. The silica particulates have a CTAB specific surface ranging from 100 to 140 m.sup.2 /g, a median diameter .phi..sub.50, after ultrasonic disintegration, less than 2.8 .mu.m, an ultrasonic disintegration factor F.sub.D greater than 3 ml, a BET specific surface ranging from 100 to 200 m.sup.2 /g, a mean particle size greater than 15 .mu.m when formed as a powder, at least 80 .mu.m when formed a s substantially spherical beads, and at least 1 mm when formed as a granulate, a packing density in the tamped state of at least 0.17, and a DOP oil uptake ranging from 150 to 400 ml/100 g.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 90 and 250 m.sup.2 /g, a BET specific surface of between 90 and 250 m.sup.2 /g, a DOP oil uptake lower than 300 ml/100 g, a zinc content of between 1 and 5% by weight, and by the fact that the number N of stearic acid molecules consumed per nm.sup.2 of silica surface, when stearic acid is reacted with this silica in xylene for 2 hours at 120.degree. C., is at least 1. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers, especially for improving their rheological properties.

Abstract: The present invention relates to silicas, in particular precipitated silicas, which can be used in particular as abrasive agents in toothpaste compositions. The silicas according to the invention have, first of all, low specific surfaces. Their BET specific surface is between 20 and 75 m.sup.2 /g, preferably between 35 and 64 m.sup.2 /g. The invention also relates to a process for their preparation and to the toothpaste compositions containing them.

Abstract: Novel silicas in the form of powder and spherical beads or granules. The silicas are characterized by having a specific CTAB surface of 100-140 m.sup.2 /g, a small median diameter, following disaggregation by ultrasound means, and optionally, a porous distribution so that the porous volume occupied by the pores whose diameter is 175-275 .ANG. is less than 55% of the porous volume occupied by the pores having diameters of 400 .ANG. or less. The invention also concerns a method for the preparation of said silicas and their use as reinforcing fillers for elastomers.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a very good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 100 and 240 m.sup.2 /g, a DOP oil uptake lower than 300 ml/100 g, a pore distribution such that the pore volume consisting of the pores whose diameter is between 175 and 275 .ANG. represents less than 50% of the pore volume consisting of the pores of diameters which are smaller than or equal to 400 .ANG., a median diameter, after disintegration with ultrasound, smaller than 5 .mu.m and an aluminium content of at least 0.35% by weight. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 90 and 250 m.sup.2 /g, a DOP oil uptake lower than 300 ml/100 g, a pore distribution such that the pore volume consisting of the pores whose diameter is between 175 and 275 .ANG. represents less than 50% of the pore volume consisting of the pores of diameters smaller than or equal to 400 .ANG., a zinc content of between 1 and 5% by weight and by the fact that the number N of molecules of stearic acid consumed per nm.sup.2 of silica surface, when stearic acid is reacted with the said silica in xylene for 2 hours at 120.degree. C., is at least 1.

Abstract: The invention relates to a new process for the preparation of precipitated silica which has an excellent dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 140 and 200 m.sup.2 /g, a BET specific surface of between 140 and 200 m.sup.2 /g, a DOP oil uptake lower than 300 ml/100 g, a median diameter, after disintegration with ultrasound, smaller than 3 .mu.m, an ultrasonic disintegration factor higher than 10 ml and an aluminium content of at least 0.35% by weight. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers.

Abstract: Uniquely dispersible precipitated silica particulates, e.g., beads, powders and granulates/extrudates, very well suited for the reinforcement of elastomer/rubber matrices, e.g., tires for the automotive industry, have characteristic particle sizes, BET and CTAB specific surface areas, DOP oil absorption values, total pore volumes and pore size distributions, and reduced degree of attrition.

Abstract: Uniquely dispersible precipitated silica particulates, e.g., beads, powders and granulates/extrudates, very well suited for the reinforcement of elastomer/rubber matrices, e.g., tires for the automotive industry, have characteristic particle sizes, BET and CTAB specific surface areas, DOP oil absorption values, total pore volumes and pore size distributions, and reduced degree of attrition.

Abstract: Uniquely dispersible precipitated silica particulates, e.g., beads, powders and granulates/extrudates, very well suited for the reinforcement of elastomer/rubber matrices, e.g., tires for the automotive industry, have characteristic particle sizes, BET and CTAB specific surface areas, DOP oil absorption values, total pore volumes and pore size distributions, and reduced degree of attrition.

Abstract: Novel precipitated silica particulates having low water uptake and high BET and CTAB surfaces, well adapted as reinforcing fillers for, e.g., the silicones, are conveniently prepared by heat treating certain starting material precipitated silica particulates at a temperature of at least 700.degree. C., for at least one minute.

Abstract: Silica colloids having a spherical form, a mean diameter of between about 10 and 100 nm and a polydispersity index between about 1 and 4. A process for making silica colloids is also provided comprising a) forming a reaction medium by simultaneously adding an acidifying agent and an alkaline silicate solution to a reaction vessel, b) reacting the acidifying agent and alkaline silicate solution, and c) maintaining a constant volume of the reaction medium by drawing off the reaction medium.