| 摘要 |
<p>1,240,409. Coating metal surfaces with polyvinyl fluoride. DYNAMIT NOBEL A.G. 31 Oct., 1969 [2 Nov., 1968], No. 53616/69. Heading B2E. Metallic surfaces are rendered suitable for the application of coatings of polyvinyl fluoride (PVF) by dipping, injecting, spraying or brushing a solution or suspension of a mixture of one or more basic metal oxides having a particle size of less than 25Á and PYF powder on a weight ratio of 1:3 to 1:8 onto the surface and stoving at 230-320‹C. The weight ratio of PVF powder and oxide to the solvent (many examples of which are specified) is preferably between 1:1 and 1:4. Suitable oxides are MgO, PbO, ZnO and alkaline earth metal oxides. Fillers and pigments may also be incorporated. After the primer layer has been stoved, one or more intermediate coatings may be applied e.g. by brushing with solutions or dispersions of PVF. The top coating may also be applied by brushing but preferably contains pigments and stabilisers in addition to PVF. The metal surface may be phosphatised or chromatised and specified substrates are aluminium, aluminium/ magnesium alloy or zinc plated, galvanised or untreated steel.</p> |
