Primer coating composition for topcoats of fluorocarbon polymers containing a polyarylene sulfide resin, an aromatic polyether-sulfone resin or an aromatic polyether-ketone resin

Claim 1

A primer coating composition which comprises the following components, all amounts being based on the solids of said components: (a) a component comprising 20-100% by weight of a copolymer containing 0.5 to 11% by weight, based on the weight of the copolymer, of copolymerized units of a perfluoro(alkylvinyl) ether of the formula CF 2 ═CF--OR, wherein R is a perfluoroalkyl radical having 1 to 10 carbon atoms, 0 to 12% by weight, based on the weight of the copolymer, of copolymerized units of hexafluoropropylene or vinylidene fluoride or mixtures of these two monomers, essentially the remainder, to 100% of the weight of the copolymer, consisting essentially of copolymerized units of tetrafluoroethylene; 0 to 80% by weight of said component (a) comprising dispersed polytetrafluoroethylene particles having a mean particle size of 0.05 to 30 μm; (b) 10 to 250 parts by weight, per 100 parts by weight of said component (a), of a mixture comprising lithium hydroxide and finely divided SiO 2 which has been produced by thermal treatment, the LiOH:SiO 2 molar ratio ranging from about 1:0.5 to about 1:30; (c) 10 to 1000 parts by weight, per 100 parts by weight of said component (a), of a thermoplastic resin selected from the group consisting of: (c 1 ) a polyarylene sulfide resin, (c 2 ) an aromatic polyether-sulfone resin, (c 3 ) an aromatic polyether ketone resin, and mixtures thereof; and (d) water as a liquid carrier.