Method for preparing a masterbatch of natural rubber and silica
AssigneesCompagnie Generale Des Etablissements Michelin, Michelin Recherche et Technique S.A.
InventorsJulien Berriot, Benoit De Gaudemaris, Géraldine Laffargue
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Abstract
The invention relates to a method for preparing a silica/natural rubber masterbatch, comprising the following successive steps: doping the silica with an at least divalent metallic element; preparing at least one dispersion of the resulting doped silica in water; bringing a natural rubber field latex into contact with the aqueous doped-silica dispersion and mixing them together so as to obtain a coagulum; recovering the coagulum; and drying the recovered coagulum so as to obtain the masterbatch.
Claims9
A method for preparing a silica/natural rubber masterbatch, which can be achieved without adding any coagulant or any coupling agent, comprising in succession:
- doping a silica with an aluminum to form a doped-silica having a level of aluminum doping;
- preparing at least one dispersion of the doped silica in water to form an aqueous doped-silica dispersion;
- providing a natural rubber field latex;
- adjusting the pH of the aqueous doped-silica dispersion so that the pH of a formulation resulting from mixing the natural rubber field latex with the aqueous doped-silica dispersion is:
- between 3.5 and 6;
- or
- between 6 and 8 when the level of aluminum doping in percent by weight is ≧(1.75×pH−10.5);
- or
- greater than 8 when the level of aluminum doping ≧3.5% by weight;
- adjusting the volume of the aqueous doped-silica dispersion relative to the volume of the natural rubber field latex such that the combined volumes have the desired pH;
- bringing the volume of the natural rubber field latex into contact with the volume of the aqueous doped-silica dispersion and mixing them together to form the formulation and to obtain a coagulum;
- recovering the coagulum;
- and
- drying the recovered coagulum to obtain a silica/natural rubber masterbatch.
Dependencies are inferred from the claim text.