. . "Poly(ethylenically unsaturated)alkanols of use in Step (1) of the preparation of the compounds of the invention are known and include, for example, the diacrylates and methacrylates of aliphatic triols such as glycerine, trimethylolmethane, 1,1,1-trimethylolpropane, 1,2,3-trimethylolpropane; the triacrylates and methacrylates of aliphatic tetrols such as pentaerythritol, 1,1,2,2-tetramethylolethan" . .