Rhodia Operations

Compagnie Generale Des Etablissements Michelin

Emmanuelle Allain Najman

Laurent Guy

Pascaline Garbey

Sylvaine Neveu

Caroline Fayolle

Cédric Feral-Martin

Laure Bertry

Frédéric Colbeau-justin

Thomas Chaussee

Fabien Stocklouser

Angélique Pawlak

Stéphane Badaire

Pascaline Lauriol-garbey

Stéphanie Croyeau

A precipitated silica containing are least one element M selected from the group consisting of B, Al, Ga and mixtures thereof and characterized by the presence of specific acid sites on its surface and a process for its manufacture. Said precipitated silica is suitable for multiple applications, for instance as catalyst or catalyst support as well as reinforcing filler in polymeric compositions.

Precipitated silica and process for its manufacture

Precipitated silica having large median particle size for use as reinforcing filler in elastomeric compositions as well as its method of manufacture. In particular, a precipitated silica characterised by a CTAB surface area Sin the range from 70 to 350 m/g; an amount Wof at least one metal M selected from elements of groups 3, 4 and 5 of at least 0.1 mol %; and a median particle size d50, measured by centrifugal sedimentation, such that: |d50|≥183×|R|×|W|−0.67×|S|+233 (I) wherein |d50| represents the numerical value of median particle size d50 measured by centrifugal sedimentation and expressed in nm; |R|, the numerical value of the ionic radius of metal M expressed in nm; |S|, the numerical value of the CTAB surface area Sexpressed in m/g; and |W|, the numerical value of the percentage molar amount of the metal W.

A chemically modified precipitated silica characterised by the presence of alkyl moieties chemically bound to the silica and a process for its manufacture.

A precipitated silica having a broad particle size distribution and large median particle size as well as its method of manufacture is provided. The precipitated silica has a CTAB surface area Sin the range from 40 to 300 m/g, a difference between BET surface area Sand CTAB surface area Sof at least 35 m/g, a width of the particle size distribution Ld, measured by centrifugal sedimentation, of at least 1.5, an amount of aluminium Win the range from 0.5 to 7.0 wt %, and a median particle size d50, measured by centrifugal sedimentation, such that for a given value of CTAB surface area Sand amount of aluminium W, parameter A, defined by the following equation: A=|d50|+0.782×|S|−8.524×|W|.

A precipitated silica characterised by the presence of specific acid sites on its surface and a process for its manufacture.

A precipitated silica suitable for thermal insulation applications and a process for its manufacture.

A rubber composition is based on at least one elastomer, a reinforcing inorganic filler, an agent for coupling the elastomer to the reinforcing inorganic filler, and a crosslinking system. The reinforcing inorganic filler comprises at least one silica S having: a CTAB specific surface area Swithin a range extending from 40 to 300 m/g; a difference between the BET specific surface area Sand the CTAB specific surface area Sof greater than or equal to 35 m/g; an aluminium content Wwithin a range extending from 0.5 to 7.0% by weight relative to the weight of the silica S; a width of the aggregate size distribution Ld, measured by centrifugal sedimentation, of greater than or equal to 1.5; and a median aggregate diameter d50, measured by centrifugal sedimentation, such that for a given value of CTAB specific surface area Sand a given aluminium content W, a magnitude A is defined by the following equation (I): A=[d50]+0.782&#xd7;[S]&#x2212;8.524&#xd7;[W] (I), in which: [d50] is the numerical value of d50, expressed in nm; [S] is the numerical value of S, expressed in m/g; [W] is the numerical value of W, expressed in % by weight relative to the weight of the silica S; and said magnitude A satisfies the relationship (II): A&#x2265;253 (II). The compositions of the invention are of use in tyres or semi-finished articles for tyres.

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L'Hay les Roses, France

Emmanuelle Allain Najman