Abstract: The invention relates to the use of a silica having a BET specific surface of at least 60 m2/g for increasing the rigidity of a thermoplastic polymeric material while maintaining i.e. improving its impact resistance. The silica used is of the type obtained according to a method involving the drying of a silica suspension obtained by reacting a silicate with an acidulant according to the following successive steps: (i) forming an aqueous starter having a pH between 2 and 5; (ii) simultaneously adding silicate and the acidulant while keeping the pH between 2 and 5; (iii) continuing with only the addition of silicate until a pH between 7 and 10 has been reached; (iv) simultaneously adding silicate and acidulant while keeping the pH of the reaction medium between 7 and 10, and; (v) continuing with only the addition of the acidulant until a pH value lower than 6 has been obtained. The invention also relates to the materials obtained within this scope.

Abstract: The invention concerns thermoplastic materials with improved mechanical properties, comprising a matrix and inclusions. The materials comprise at least two families of inclusions defined by their type, shape and dimensions and optionally by their concentration. The materials can in particular be used for making molded thermoplastic articles.

Abstract: The invention relates to the use of a silica having a BET specific surface of at least 60 m2/g for increasing the rigidity of a thermoplastic polymeric material while maintaining i.e. improving its impact resistance. The silica used is of the type obtained according to a method involving the drying of a silica suspension obtained by reacting a silicate with an acidulant according to the following successive steps: (i) forming an aqueous starter having a pH between 2 and 5; (ii) simultaneously adding silicate and the acidulant while keeping the pH between 2 and 5; (iii) continuing with only the addition of silicate until a pH between 7 and 10 has been reached; (iv) simultaneously adding silicate and acidulant while keeping the pH of the reaction medium between 7 and 10, and; (v) continuing with only the addition of the acidulant until a pH value lower than 6 has been obtained. The invention also relates to the materials obtained within this scope.

Abstract: The invention relates to a method for employing, in a thermoplastic polymer, a silica having a BET surface less than or equal to 130 m2/g for increasing the impact resistance of a material. The silica employed can be obtained by drying a silica aqueous dispersion produced from a reaction of a silicate and of an acidulant, comprising the following steps: forming a starter containing at least a portion of the total quantity of the silicate and an electrolyte; (B) adding an acidulant to the starter of step (A) until a pH value ranging from 7 to 8.5 is obtained, and; (C) if necessary, adding the remaining quantity of silicate to the reaction medium obtained from step (B), in conjunction with another portion of the acidulant. The invention also relates to the thermoplastic polymeric materials, particularly based on polyolefins that are obtained within this scope.

Abstract: The invention concerns thermoplastic materials with improved mechanical properties, comprising a matrix and inclusions. The materials comprise at least two families of inclusions defined by their type, shape and dimensions and optionally by their concentration. The materials can in particular be used for making molded thermoplastic articles.

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 m2/g, a BET specific surface of between 140 and 200 m2/g, a DOP oil uptake lower than 300 ml/100 g, a median diameter, after disintegration with ultrasound, smaller than 3 &mgr;m, an ultrasonic disintegration factor higher than 10 ml 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: The invention concerns thermoplastic materials with improved mechanical properties, comprising a matrix and inclusions. The materials comprise at least two families of inclusions defined by their type, shape and dimensions and optionally by their concentration. The materials can in particular be used for making molded thermoplastic articles.

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 m2/g, a BET specific surface of between 140 and 200 m2/g, a DOP oil uptake lower than 300 ml/100 g, a median diameter, after disintegration with ultrasound, smaller than 3 &mgr;m, an ultrasonic disintegration factor higher than 10 ml 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: Rubber composition intended for the manufacture of tire casings which have improved hysteretic properties and scorch safety, based on at least one elastomer and silica by way of reinforcing filler enclosing a reinforcing additive consisting of the mixture and/or the product of in situ reaction of at least one functionalized polyorganosiloxane compound containing, per molecule, at least one functional siloxy unit capable of bonding chemically and/or physically to the surface hydroxyl sites of the silica particles and at least one functionalized organosilane compound containing, per molecule, at least one functional group capable of bonding chemically and/or physically to the polyorganosiloxane and/or the hydroxyl sites of the silica particles and at least one other functional group capable of bonding chemically and/or physically to the polymer chains.

Abstract: The present invention relates to a process for preparing multifunctionalized polyorganosiloxanes (POSs) comprising alkoxyl functional siloxyl units and siloxyl units each having an SH functional group, which consists in introducing the SH functional group by the reaction of H2S on a precursor POS of formula: A—(RXSiO)a—(RYSiO)b—B where R is especially a C1-C6 alkyl radical, X is a C1-C15 alkoxyl radical, Y is a C2-C30 hydrocarbon group which includes an ethylenically unsaturated group from which the SH functionality derives, a is a number ranging from 1 to 150, b is a number ranging from 1 to 150, the number a+b ranging from 2 to 300 and A and B are terminal groups which are selected respectively, from, in particular, on the one hand (R)3SiO— radicals taken alone or as mixtures with (R)2XSiO— and/or R(X)2SiO— and/or (X)3SiO— radicals and on the other hand —Si(R)3 radicals taken alone or as mixtures with —SiX(R)2 and/or —Si(X)2R and/or —Si(

Abstract: The present invention relates to inorganic particles, with the exception of silica, comprising at least one functionalized polyorganosiloxane grafted over all or part of their surface, the said polyorganosiloxane being functionalized by: at least one alkoxy group, and at least one organic group chosen from alkyls, alkenyls, mercaptoalkyls, sulphoxides, epoxys, (meth)acryloyloxy groups, amino groups, hydroxyl groups, siloxy groups, ethers, ketones, esters, phosphorus-containing groups or polymer portions comprising vinylaromatic, ether, amide or sulphur repeat units. The invention also relates to the process for the preparation of these particles. It also relates to compositions comprising the said particles and at least one thermoplastic polymer, particularly polyolefins.

Abstract: Use of an effective amount of a specific combination of silicone compounds comprising the combination: of at least one functionalized polyorganosiloxane (abbreviated as POS) containing, per molecule, at least one functional siloxy unit (abbreviated as UN1) capable of binding chemically and/or physically with the hydroxylated surface sites of the silica particles, and of at least one functionalized organosilane (abbreviated as OS) containing, per molecule, at least one functional group (abbreviated as G1) capable of binding chemically and/or physically with the UN1 units and/or the hydroxylated sites of the silica particles and at least one other functional group (abbreviated as G2) capable of binding chemically and/or physically to the elastomer chains, as silica/elastomer coupling agent in the natural or synthetic elastomer compositions comprising a siliceous material as reinforcing filler intended for the manufacture of an article made of elastomer(s).

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: 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: Rubber composition intended for the manufacture of tire casings which have mproved hysteretic properties and scorch safety, based on at least one elastomer and silica by way of reinforcing filler enclosing a reinforcing additive consisting of the mixture and/or the product of in situ reaction of at least one functionalized polyorganosiloxane compound containing, per molecule, at least one functional siloxy unit capable of bonding chemically and/or physically to the surface hydroxyl sites of the silica particles and at least one functionalized organosilane compound containing, per molecule, at least one functional group capable of bonding chemically and/or physically to the polyorganosiloxane and/or the hydroxyl sites of the silica particles and at least one other functional group capable of bonding chemically and/or physically to the polymer chains.

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 compounds composed essentially of a linear, cyclic or branched polyorganosiloxane having, per molecule, at least 3 siloxy units, including at least one siloxy functional unit of formula: ##STR1## where R.sup.1 represents a C.sub.1 to C.sub.4 alkyl or phenyl radical, X contains an N,N'-di- and/or trisubstituted phenylenediamine functional group, bonded to the silicon via an Si-(hydrocarbon linking unit)-N and/or Si-(hydrocarbon linking unit)-C bond, and a is a number chosen from 0, 1 and 2. The present invention also relates to the use of such compounds as antiozonants for rubbers and in particular for rubber compositions for tires.

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.