IMPROVED COATING METHOD

摘要

The invention provides a method for the manufacture of a sheet product comprising a substrate having a coating of an adhesion promoter, which comprises applying to said substrate a solution or suspension of an adhesion promoter comprising a polymer bearing carboxylic acid, salt, amide and/or ester groups, said solution or suspension also comprising an indicator material which is colourless under the conditions of application of said solution or suspension to said substrate but which generates visible colouration upon the application of suitable chemical means. The method may be used as part of a quality control method for monitoring the application of a coating of an adhesion promoter to a substrate. The resulting sheets are novel.