Abstract: Buffer-coated and overcoated optical glass fiber is disclosed in which the topcoat has the high strength and high tensile modulus combined with good elongation and water resistance associated with extruded jacket coatings, but which is applied by ordinary coating procedures and cured by exposure to ultraviolet radiation. The coating compositions which enable this to be achieved comprise 30% to about 80% of linear diacrylate-functional polyurethanes which are the linear polyurethane reaction product of polycarbonate diol with organic diisocyanate in molar proportions providing an average of at least about 2 urethane linkages per molecule, these linear polyurethanes being end-capped with acrylate groups, and these polyurethanes being used in combination with at least 15% of liquid monoethylenically unsaturated monomer having a glass transition temperature above about 55.degree. C.

Abstract: Radiation-curable coating compositions adapted for application to buffer-coated optical fibers are disclosed. These are intended to apply an adherent topcoat having greater toughness and greater hardness than the buffer coating. The new compositions comprise: (1) from 25% to 70% of diethylenic-terminated polyurethane, which may include urea linkages, the polyurethane being based on a diisocyanate having an average molecular weight of from 400 to 5000; (2) from 5% to 40% of a diethylenically unsaturated ester of a diglycidyl ether of a bisphenol, said ether having a molecular weight up to about 1000; and (3) from 5% to 30% of liquid radiation-curable monoethylenically unsaturated monomer having a T.sub.g above about 55.degree. C., especially N-vinyl pyrrolidone. Ultraviolet cures using acrylates as the ethylenic group are preferred.

Abstract: Photopolymerizable ethylenically unsaturated ester compositions useful as coating and printing ink vehicles, and especially pigmented coatings and inks, are stabilized to premature gelation by incorporating therein a small but effective amount of a stabilizing combination of a copper containing compound and a thiocarbamate compound.

Abstract: Pigmented photopolymerizable ethylenically unsaturated ester compositions used as coatings and printing inks are stabilized to premature gelation by incorporating therein a stabilizing amount of a thiocarbamate compound having the formula ##EQU1## OR A METAL CATION HAVING A VALENCE OF 1 TO 3 AND EACH OF R, R.sub.1, R.sub.2, and R.sub.3 (same or different) are hydrogen, aryl, saturated and unsaturated alkyl groups having 1 to 20 carbon atoms, aralkyl or alkaryl groups having 7 to 15 carbon atoms and amino, sulfo-and oxy-substituted alkyl and aryl groups, n is an integer of 1 to 3 and x is an integer from 0 to 1.