Additive for laser-markable and laser-weldable polymer materials

1. A process for laser marking of an article, comprising exposing to laser radiation an article containing a pigment comprising a niobium-doped titanium dioxide laser absorbing additive in a polymer composition, the percentage molar proportion of niobium being 0.3 to 15% based on the molar mass of titanium, the polymer composition comprising polyethylene, polypropylene, a polyamide, a polyester, a polyester-ester, a polyether-ester, polyphenylene ether, polyacetal, polyurethane, polybutylene terephthalate, polymethyl methacrylate, polyvinyl acetal, polystyrene, acrylonitrile-butadiene-styrene, acrylonitrile-styrene-acrylate, polycarbonate, a polyether sulfone, a polyether ketone, or polymer blends or copolymers thereof, a melamine resin, an epoxy resin, a silicone resin or a polysiloxane, wherein the niobium-doped titanium dioxide is subjected to calcination under reducing conditions in an N 2 /H 2 atmosphere prior to use as a laser absorbing additive.

2. The process according to claim 1 , wherein the pigment consists of the niobium-doped titanium dioxide.

3. The process according to claim 1 , wherein the pigment comprises a substrate and a coating located thereon, and the niobium-doped titanium dioxide is present in the coating.

4. The process according to claim 3 , wherein the substrate is natural mica, synthetic mica, talc, sericite, titanium dioxide, titanium dioxide doped with Al, Si, Zr or Mn, alumina, silica, carbon, graphite, iron oxide, barium sulfate and/or a pearl pigment and has a coating which comprises niobium-doped titanium dioxide.

5. The process according to claim 1 , wherein the pigment has a particle size in the range of from 0.01 to 100 μm.

6. The process according to claim 1 , wherein the pigment is present in the polymer composition in a proportion in the range of from 0.001 to 20% by weight, based on the total weight of the polymer composition.

7. The process according to claim 1 , wherein the polymer composition comprises at least one polymer compound and the laser absorbing additive, and optionally solvents, fillers, additives and/or colorants.

8. The process according to claim 1 , wherein the polymer compound is a thermoset that is a polyurethane, a melamine resin, an epoxy resin or a polyester resin.

9. A polymer composition, comprising at least one polymer compound that is polyethylene, polypropylene, a polyamide, a polyester, a polyester-ester, a polyether-ester, polyphenylene ether, polyacetal, polyurethane, polybutylene terephthalate, polymethyl methacrylate, polyvinyl acetal, polystyrene, acrylonitrile-butadiene-styrene, acrylonitrile-styrene-acrylate, polycarbonate, a polyether sulfone, a polyether ketone, or polymer blends or copolymers thereof, a melamine resin, an epoxy resin, a silicone resin or a polysiloxane, and a laser absorbing additive, in a proportion of 0.001 to 20% by weight, based on the total weight of the polymer composition, where the laser absorbing additive is a pigment consisting of titanium dioxide which is doped with niobium and is subject to calcination under reducing conditions in an N 2 /H 2 atmosphere, prior to use as a laser absorbing additive, where the percentage molar proportion of niobium is 0.3 to 15%, based on the molar mass of titanium.

10. The polymer composition according to claim 9 , wherein the polymer compound is a thermoset that is a polyurethane, a melamine resin, an epoxy resin or a polyester resin.

11. A laser markable and/or laser-weldable article consisting of a corpus having a surface, wherein the corpus or at least a part of the surface thereof is composed of or comprises a polymer composition according to claim 9 .

12. The laser markable and/or laser weldable article according to claim 11 , wherein the corpus has a laser marking on the surface.