Continuous coating of leather - using UV cured solvent free coating compsn. of an unsaturated polyurethane and an unsaturated monomer

摘要

The leather, previously primed with one or more layers in the known way, is coated with a compsn. comprising (a) =1 polyurethane with ethylenic unsatn. in the chain, with a double bond index of 0.04-0.15 and (b) =1 polyethylenically unsatd. monomer and/or =1 monoethylenically unsatd. monomer, using a wt. ratio resin/monomer of 3-10. The coating is then cured by the action of ionising radiation, esp. UV radiation. The process allows leather to be coated continuously and very rapidly, without the necessity for drying or stoving. The coating compsns. contain no solvents which have to be driven off, which represents a saving in energy expenditure and avoids loss of material and the danger of atmospheric pollution.