Tire curing bladder lubricant

Abstract

An aqueous lubricating composition for tire curing bladders containing polydimethylsiloxane, methyl hydrogen or methyl trimethoxy silane, a surfactant and optionally a metal salt of an organic acid.

What is claimed is: 
     
       1. A lubricant composition comprising an aqueous emulsion consisting essentially of: (i) about 20 to about 40 parts by weight polydimethylsiloxane characterized by having a viscosity in the range of about 12 million to about 28 million centistokes at 25° C.;   (ii) about .[.12 to about 20.]. .Iadd.35 to about 70 .Iaddend.parts by weight of at least one silane selected from (a) a methyl hydrogen silane, characterized by having a viscosity in the range of about 20 to about 40 centistokes at 25° C.,   (b) dimethyl hydrogen silane characterized by having a viscosity in the range of about 80 to about 120 centistokes at 25° C. and (c) methyl trimethoxy silane;   (iii) optionally, about 3 to about 12 parts by weight of a metal salt of an organic acid selected from at least one of zinc, magnesium, manganese and cobalt acetate, stearate, propionate and octoate;   (iv) about 10 to about 25 parts by weight surfactant for said polydimethylsiloxane and   (v) about 500 to about 1500 parts by weight water.   
     
     
       2. The lubricant composition of claim 1 where said polydimethylsiloxane is hydroxyl capped. 
     
     
       3. The compositionn of claim 2 where the silane is methyl hydrogen silane and/or dimethyl hydrogen silane. 
     
     
       4. The composition of claim 1 or 2 where said metal salt is zinc acetate and/or zinc stearate. 
     
     
       5. The lubricant composition of claim 2 where the silane is methyl hydrogen silane and/or dimethyl hydrogen silane and the metal salt is zinc acetate and/or zinc stearate.