Polyol-silicate ester-exchange reaction product

Abstract

Abstract Protective coating compositions are prepared comprising aliphatic polyol-derived silicates and zinc dust as a filler. The compositions provide long-life protection for ferrous substrates against rusting in moist and salty atmospheres. The zinc filler and silicate components may be compounded in one package or as two packages to be mixed prior to application as a film. Compositions comprising zinc filler and the aliphatic polyol-derived silicates with solvents, and with or without other fillers or organic polymeric materials are especially useful as coatings. A range of aliphatic polyol to total alkyl-type or alkoxyalkyl-type silicate reacted in making the polyol-derived silicates is about 0.15 to 1.8 moles of reactive OH grouping supplied by the polyol per mole of ester-exchangeable group in the silicates, the larger ratios being especially useful for the silicate reactants having up to, for instance, an average of 5 or 6 SiO2 groups per molecule and decreasing progressively as the <IMAGE> CONTENT INCREASES. The preferred range of reactants provides about 0.35 to 1.5 moles of reactive OH grouping from the polyol per mole of ester-exchangeable groups of the silicate. The preferred silicate reactants have from 1 up to about 6 or 8 SiO groups per average molecule which corresponds to an extent of hydrolysis from 0% up to about 50%. Such hydrolysis may occur before or during the ester-exchange reaction which forms the aliphatic polyol-derived silicates of this invention. The polyol-derived silicates can also have other uses, e.g. as a binder for ceramic molding compositions using non-zinc fillers.

Inventors

• 👤 Gordon D. McLeod

Bibliographic Details