SURFACE PROTECTIVE LAYER FOR TO ABRASSION EXPOSED CONSTRUCTIONAL PARTS,ESPECIALLY FOR TURBO-MACHINE BLADES AND METHOD OF MAKING

摘要

A protective coating for articles subjected to abrasion consists of the reaction prod. prepd. in absence of an accelerator, from (a) polyethylene glycol adipate and a polyester from glycerin, adipic acid with phthalic acid, and (b) an isocyanate resin from 3 moles toluylene diisocyanate and 1 mole trimethylolpropane. The coating is applied in several pref. 3 layers with total thickness 0.1-1 mm (0.1-0.5 mm) with the elasticity increasing towards the outer layer. The ratio OH: NCO is 1: 0.6-1.8. The coating is esp. used on blades for turbo-machines, formed of several layers of fibre-reinforced synthetic matrices. Abrasion-resistance is considerably better than with known polyurethane la cquers.