POLYMERIC COMPOSITION FOR USE AS A STOVING LACQUER

1361929 Hardenable compositions containing sulphonic acid ester curing catalysts BAYER AG 15 Feb 1972 [16 Feb 1971] 6960/72 Heading C3R A composition containing a polymer crosslinkable via methylol groups, which may be free or etherified or in carbamate ester form, contains as cross-linking catalyst an ester of a sulphonic acid which is a nitro-, halo-, carboxyl- or formyl-benzyl sulphonate or an optionally substituted trimethylene disulphonate; the sulphonate is used in amounts of 0À01-10 wt. per cent of the total composition. Suitable polymers include phenolic resins, urea-aldehyde and melamine-aldehyde resins, optionally mixed with nitrocellulose, alkyd resins or other polyesters, and polyacrylamides having methylol groups. Conventional fillers, dyes and pigments may be present, as may levelling agents. In Examples 1 and 2 lacquers are prepared containing rutile TiO 2 , an alkyd resin from phthalic anhydride, adipic acid, trimethylolpropane and a fatty acid, and a butylated MF resin in xylene/ butanol containing butyl glycollate and a silicone oil; to these are added as catalysts trimethylene di-benzenesulphonate or ditosylate, or p-nitrobenzyl p-toluenesulphonate.