A process for the preparation of dual-cure hardeners, coating systems which contain these hardeners, and the use of these coating systems, as well as substrates coated with these coating agents. The dual-cure hardeners are prepared by reacting at least one diisocyanate or polyisocyanate A with the product B of the reaction of B1 acrylic acid, methacrylic acid and/or dimeric acrylic acid with B2 glycidyl methacrylate and/or glycidyl acrylate, wherein B contains less than 0.2 wt. % of epoxide groups.
1. A one-component or multi-component coating agent comprising
C1) one or more polyisocyanates having at least one ethylenic unsaturation and an isocyanate group content of 0.5-25 wt. %, and prepared by a process comprising reacting: a reaction mixture comprising at least one diisocyanate or polyisocyanate A with the product B of the reaction of B1 acrylic acid, methacrylic acid and/or dimeric acrylic acid and B2 glycidyl methacrylate and/or glycidyl acrylate, wherein B contains less than 0.2 wt. % of epoxide groups (calculated as M=42),
C2) one or more compounds which have at least one isocyanate-reactive group and optionally comprise one or more functional groups which under the influence of actinic radiation react with ethylenically unsaturated compounds, with polymerization,
C3) optionally further polyisocyanates, which optionally comprise one or more functional groups which under the influence of actinic radiation react with ethylenically unsaturated compounds, with polymerization,
C4) optionally compounds bearing functional groups which under the influence of actinic radiation react with ethylenically unsaturated compounds, with polymerization, which have neither isocyanate groups nor isocyanate-reactive groups,
C5) optionally catalysts,
C6) optionally auxiliary agents and additives, and
C7) optionally products of reactions between the components C1) to C6).
2. A method of coating a substrate comprising applying the coating agents according to claim 1 to at least a portion of the substrate.
3. Substrates coated with coating agents according to claim 1 .
4. Substrates according to claim 3 , wherein the substrates are automotive bodies or automotive construction parts.
5. A one-component or multi-component coating agent according to claim 1 , wherein the reaction of B1 with B2 is carried out at an equivalence ratio of acid to epoxide of 1.01 to 1.20.
6. Substrates coated with coating agents according to claim 5 .
7. Substrates according to claim 6 , wherein the substrates are automotive bodies or automotive construction pads.
8. A one-component or multi-component coating agent according to claim 1 , wherein the reaction of B1 with B2 is carried out, or the reaction product is post-treated, such that the reaction product has a maximum acid value of 10 mg/g KOH.
9. A one-component or multi-component coating agent according to claim 1 , wherein the reaction of B1 with B2 is carried out in the presence of a catalyst selected from the group consisting of phosphine, phosphonium, caesium, and potassium compounds.
10. Substrates coated with coating agents according to claim 8 .
11. Substrates according to claim 10 , wherein the substrates are automotive bodies or automotive construction pads.
12. Substrates coated with coating agents according to claim 9 .
13. Substrates according to claim 12 , wherein the substrates are automotive bodies or automotive construction pads.