Fluoro-resin coating compsn. with good adhesion - made of resin and pigment dispersed in surfactant, used as undercoat for moulding, esp. metal container

The compsn. contains a dispersion medium (I), consisting mainly of surfacant, with fluoro-resin particles (II) and pigment particles (III) dispersed in Ia. USE/ADVANTAGE - The compsn. is used as the undercoat of a system for coating mouldings (opt. with a finely roughened surface) overall or in a pattern, the top coat contg. (II) but no (III) or adhesive. It is useful for producing coatings or uniform colour or displays e.g. scales, patterns or lettering on metals, before or after moulding to containers. In an example, a finely etched Al alloy plate was given a 20 micron primer coat with a comspn. contg. 60 (wt)% PTFE, 3% polyamide-imide, 6% surfactant and 31% water (which was baked for 5 mins, at 420 deg. C. It was then screen printed with a compsn. contg. 26.25g PFA (TFE-perfluoro(alkylvinyl ether) copolymer) as 5 micron or coarser particles, 11.25 g PFE as 1 micron or finer particles, (A) 38.75, (B) 438.75 g nonionic surfactant and 11.25 g water and 12.5 g TiO2, which was baked for 10 mins, at 400 deg. C. The amt. of blurring of the edge of the letters was (A) none, (B) significant; flaking (A, B) none; and flow (A,B) no variation in film thickness