Matrices and sealants which are based on sulfur-containing polymers and which comprise a photoinitiator, curing and coating methods, and use of said matrices and sealants

A method for coating a substrate with a mixture B or with a curing sealant produced therefrom, wherein the mixture B and the sealant contain sulfur-based polymers,

• wherein the mixture B comprises an uncured mixture of
• a matrix A which is uncured and contains a mercapto-terminated polymer based on polythioether, polysulfide, copolymers thereof, and/or mixtures thereof, wherein the mercapto-terminated polymer has a mercaptan content, based on the reactive SH groups to the total weight of the polymer, in the range of 0.8 to 8 wt %, and
• a curing agent that contains isocyanate having an average functionality in the range of from 1.5 to 3.2;
• wherein the uncured matrix A, the curing agent or both further comprise at least one photoinitiator, which includes an α-aminoketone;
• wherein the at least one photoinitiator splits off at least one free radical per molecule based on tertiary amine on exposure to high-energy actinic radiation, and an active catalyst is formed from the amine by uptake of hydrogen and acts as a catalyst for curing the sealant;
• and
• wherein the matrix A and the sealant are free of (meth)acrylate-based compounds and polymers;
• the method comprising
• exposing mixture B to high-energy actinic radiation at a temperature in the range from −10 to +70° C.,
• where mixture B becomes a sealant when curing starts.