Showing papers on "Precipitated silica published in 1973"

Visually clear toothpaste containing a synthetic precipitated hydrated silica

Abstract: A visually clear toothpaste containing a particulate polishing agent, characterised in that the polishing agent is synthetic hydrated precipitated silica.

Precipitated silica reinforcing agents and rubber compositions containing same

Abstract: Improved reinforced rubber compositions are provided by dispersion into a vulcanizable rubber of dehydrated precipitated silicas in combination with polyethylenimine.

Stonework cleaning - using pastes of strong acids and abrasive powders

Abstract: Extremely dirty stone surfaces are cleaned using strong acids eg fluoric acid or one of the complexes such as nitrilo-tri-acetic acid, ethylene-diamino-tetra-acetic acid, 1,2-diamino-cyclohexane-tetra-acetic acid and di-ethylene-triamine penta-acetic acid or their mixts or the alkali polysulphates The conc of the acid is pref 5-15% and the pH is adjusted to pref 9-12 using alkali Pref 10-40% of an inorg powder with large surfaces, eg aerosil, precipitated silica, asbestos powder, perlite, kieselguhr, pref steeped in an org solvent to facilitate paint removal, eg ketones, chlorinated hydrocarbons, esters, dioxane, aniline or their mixt, is added Fluoric or hydrofluosilicic acid with organic powders, eg wood dust, cellulose, ground polyurethane foam, as well as pref 3-5% of a binding medium, eg dextrin, casein, gelatine, etc, may be used Fluoric or hydrofluosilicic acid with pref 6-15% bentonite or clay may also be used The substances made into a paste with 5% water soluble polyvinyl ether, 1-5% of an emulsifier, eg stearate, soap, etc, and 05% of a wetting agent pref sulphate and water The paste is coated onto the stones and after drying removed, mechanically, together with the adhering impurities