Method of weatherproof caulking for the outer surfaces of iron and steel

Claim 1

A process for the weatherproof caulking of external metal surface base material containing iron comprising spraying thereon a thixotropic aqueous coating composition consisting essentially of: (a) 30 to 50 percent by weight of an aqueous dispersion binder of a copolymer formed by copolymerization of 35 to 65 percent by weight styrene, 10 to 64 percent by weight butadiene and 1 to 5 percent by weight of an unsaturated carboxylic acid having 3 to 30 carbon atoms; (b) b. 0.2 to 1.0 percent by weight of thickeners selected from the group consisting of acrylate-acrylic acid polymer dispersions, bentonite dispersions and mixtures thereof; (c) fibrous materials having a maximum length of 3 mm with at least 90 percent by weight thereof having a fiber length less than 0.5 mm selected from the group consisting of 16 to 30 percent by weight asbestos, 0.2 to 3 percent by weight polyamide fibers, 0.2 to 3 percent by weight polyester fibers or 0.2 to 3 percent by weight polyacryl nitrile fibers; (d) sufficient filler material and pigments that the total solids content of (a), (b), (c) and (d) is 55-70 percent; and drying said coating composition to a layer thickness of about 200 to 2,000 microns.