Silica pigments and elastomer-silica pigment masterbatches and production processes relating thereto

Abstract

Abstract Curbing of silica pigment losses and the promotion of uniformity of product in the preparation of an elastomer-silica pigment masterbatch are effected (a) by combining (1) an aqueously wet hydrated silica pigment precipitate which has a bound alkali content, which has been prepared by precipitation from an aqueous alkali metal silicate solution, and which has been continuously maintained in an aqueously wet state without drying therefrom after its precipitation, with (2) a quantity of oleophilic amine material, (3) combining the resulting treated silica pigment with an aqueous dispersion of the elastomer containing an anionic dispersing agent, with or without (4) carbon black and/or processing oil, and (5) with selected reactant-coagulant, and (b) recovering the resulting coagulum as a masterbatch, the steps prior to (b) having rendered the serum of the aqueous mixture essentially free of silica pigment. Prior to combination with the elastomer dispersion the amine treated alkaline silica pigment may be recovered as a useful dispersible alkaline silica pigment product, or the wet pigment may be treated with water soluble salt of aluminum, or zinc or the alkali earth metals and/or with water soluble mineral acid or organic acids, as well as with the said amine, and after such treatment the resulting pigment composition may be recovered as a useful dispersible silica pigment product, or the so treated wet silica pigment may be combined as in (3), (4) and (5) above, and be recovered as in (b) above in the form of a masterbatch.

Inventors

• 👤 Oliver W Burke Jr

Bibliographic Details