SOLVENT-CONTAINING COATING COMPOUND FOR STAIN AND VARNISH COATINGS

Abstract

A solvent-containing coating compound for varnish coatings, in particular for building varnishes or components thereof, containing or consisting of at least one oxidatively drying organic binder, selected from the group consisting of at least one oxidatively drying middle oil and/or long oil alkyd resin, in particular an oxidatively drying long oil alkyd resin, at least one primary drier based on iron, in particular comprising or consisting of at least one organic salt of iron and/or a coordination complex of iron, in particular a complex salt of iron, at least one first secondary drier, in particular comprising or consisting of at least one organic and/or inorganic salt or a compound of zirconium, magnesium, calcium, strontium, barium, zinc, lithium or aluminium, at least one solvent, and optionally, at least one conventional additive, wherein the coating compound is substantially free from amorphous silicon dioxide and SiO.sub.2-based compounds.

Claims

1. A solvent-containing coating compound for varnish coatings, in particular for building varnishes or components thereof, containing or consisting of at least one oxidatively drying organic binder, selected from the group consisting of at least one oxidatively drying middle oil and/or long oil alkyd resin, in particular an oxidatively drying long oil alkyd resin, at least one primary drier based on iron, in particular comprising or consisting of at least one organic salt of iron and/or a coordination complex of iron, in particular a complex salt of iron, at least one first secondary drier, in particular comprising or consisting of at least one organic and/or inorganic salt or a compound of zirconium, magnesium, calcium, strontium, barium, zinc, lithium or aluminium, at least one solvent, and optionally, at least one conventional additive, wherein the coating compound is substantially free from amorphous silicon dioxide and SiO.sub.2-based compounds.

2. The coating compound as claimed in claim 1, further comprising at least one second secondary drier comprising or consisting of at least one organic salt of calcium, zinc, zirconium and any mixture thereof, wherein the first and the second secondary drier are different.

3. The coating compound as claimed in claim 1, which is substantially free from cobalt and manganese compounds, in particular free from siccatives based on cobalt and manganese.

4. The coating compound as claimed in claim 1, characterized in that the oxidatively drying organic binder further comprises at least one oxidatively drying modified middle oil and/or long oil alkyd resin, in particular selected from the group consisting of siliconized alkyd resins, acrylated alkyd resins, isocyanate-modified alkyd resins and any mixtures thereof, in particular isocyanate-modified long oil alkyd resins.

5. The coating compound as claimed in claim 1, characterized in that the solvent comprises or consists of, in particular, aromatics-free aliphatic hydrocarbons, preferably selected from the group consisting of, in particular, dearomatized white spirit, n-paraffins, isoparaffins, cycloparaffins and any mixtures thereof, and preferably contains methoxypropoxypropanol as a co-solvent.

6. The coating compound as claimed in claim 1, characterized in that the additive is selected from the group consisting of defoaming agents, light stabilizers, radical scavengers, wetting agents, dispersing agents, surface additives, in particular silicone surface additives, for example polyether-modified polymethylakylsiloxane and/or silicone polyether copolymers and/or surface active polyacrylates, matting agents, in particular waxes, and any mixtures of these compounds.

7. The coating compound as claimed in claim 1, characterized in that the organic salt of the first and/or second secondary driers comprises neodecanoates, oleates, stearates, palmitates, octoates and/or naphthenates, in particular neodecanoates, particularly preferably zirconium neodeconoate and/or strontium neodecanoate.

8. The coating compound as claimed in claim 1, characterized in that the long oil fraction of the oxidatively drying long oil alkyd resins is based on linoleic acid, linolenic acid, oleic acid and palmitic acid, and/or in that the middle oil fraction of the oxidatively drying middle oil alkyd resins is based on linoleic acid, linolenic acid and/or oleic acid and optionally with the addition of palmitic acid, in particular linoleic acid, linolenic acid, oleic acid and palmitic acid.

9. The coating compound as claimed in claim 1, characterized in that the oxidatively drying long oil alkyd resins, determined in accordance with DIN 53241-1, have an iodine value of no greater than 120, in particular no greater than 100, preferably in the range of 20 to 120 or 20 to 100, preferably in the range of 40 to 80.

10. The coating compound as claimed in claim 1, characterized in that the fraction of the primary drier based on iron, with respect to its metallic fraction, is in the range of 0.0001 to 0.3 percent by weight, preferably in the range of 0.0001 to 0.1 percent by weight and particularly preferably in the range of 0.0001 to 0.05 percent by weight, respectively with respect to the total weight of the coating compound, the fraction of the at least one first secondary drier comprising or consisting of at least one organic salt of zirconium, magnesium, calcium, strontium, barium, zinc, lithium and/or aluminium, with respect to its metallic fraction, is in the range of 0.005 to 1.5 percent by weight, preferably in the range of 0.025 to 1.0 percent by weight and particularly preferably in the range of 0.05 to 0.8 percent by weight, respectively with respect to the total weight of oxidatively drying organic binder, and/or in that the fraction of the at least one second secondary drier comprising or consisting of at least one organic salt of calcium, lithium, zirconium and any mixture, with respect to its metallic fraction, is herein in the range of 0.005 to 1.5 percent by weight, preferably in the range of 0.01 to 3.0 percent by weight and particularly preferably in the range of 0.025 to 0.8 percent by weight, respectively with respect to the total weight of oxidatively drying organic binders, and/or in that the fraction of solvent is in the range of 1.0 to 40 percent by weight, preferably 2.0 to 35 percent by weight and particularly preferably in the range of 3.0 to 30 percent by weight, with respect to the total weight of the coating compound, wherein the proportions of the components forming the coating compound respectively always add up to 100% by weight.

11. The coating compound as claimed in claim 1, which contains less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.1% by weight of amorphous silicon dioxide and SiO.sub.2-based compounds and particularly preferably has no amorphous SiO.sub.2 and SiO.sub.2-based compounds which can be detected by XRD and/or EDX.

12. The coating compound as claimed in claim 1, with a pigment-volume concentration (PVC) according to EN ISO 4618-1 of 0 to 50%, more preferably 2 to 45%, particularly preferably 4 to 40%.

13. A coating on a substrate, in particular a cover coating, primer, primer-/topcoat-1-pot coating or transparent or semi-transparent final coating, obtained or obtainable by application of, and physical or chemical drying of, the coating compound in accordance with claim 1.

14. The coating as claimed in claim 13, characterized in that it has an average, in particular absolute, dry layer thickness, determined in accordance with DIN EN ISO 2808-2 (May 2017), which is not over 100 m, preferably not over 80 m and particularly preferably in the range of 5 to 60 m.

15. Use of a coating compound in accordance with one claim 1, for the production of stain and varnish coatings.

Description

EXEMPLARY EMBODIMENT 1

[0065] White varnish, satin finish: in accordance with the invention

TABLE-US-00001 Alkyd resin 24% by weight Thixotropic alkyd resin .sup.2% by weight Fillers 16% by weight Pigments/colorants 32% by weight Additives: wetting agents/dispersing agents, deaerators, defoaming agents, slip additives/free flow additives, anti-skinning agents, light stabilizers, radical scavengers, etc. 4.8% by weight Matting agent (PE-wax) 3.0% by weight Solvent 17.8% by weight Iron primary drier 0.0003% by weight (with respect to the metallic fraction) Zirconium siccative (auxiliary drier) 0.2% by weight Calcium siccative (through drier) 0.2% by weight

[0066] In Reference Example 1, in the formulation in accordance with the invention for the satin finish white varnish, the polyethylene wax matting agent was exchanged for amorphous silica.

[0067] Furthermore, an analogous coating compound contained a conventional cobalt primary drier in the usual quantity, instead of the iron primary drier as Reference Example 2.

[0068] The coating compounds (in accordance with the invention, Reference Example 1 and Reference Example 2) were applied with a 75 m doctor blade and tested with a Drying Recorder. The coating composition in accordance with the invention and the Reference Example 2 were sufficiently dry after approximately 3.5 hours. In contrast, Reference Example 1 was still not dry after 24 hours, and so the test was stopped.

EXEMPLARY EMBODIMENT 2

[0069] White Surface Stain: In Accordance with the Invention

TABLE-US-00002 Alkyd resin 34% by weight Thixotropic alkyd resin 12% by weight Pigments/colorants 8% by weight Additives: wetting / dispersing agents, deaerators, defoaming agent, slip additives/free flow additives, anti-skinning agents, light stabilizers, radical scavengers, etc. 3.6% by weight Matting agent 2.0% by weight Solvent 40% by weight Iron primary drier 0.0004% by weight (with respect to the metallic fraction) Zirconium siccative (auxiliary drier) 0.25% by weight.sup. Calcium siccative (through drier) 0.15% by weight.sup.

[0070] The coatings obtained from the coating compounds in accordance with the invention did not display any tendencies to discolouration. It is also of practical relevance to obtain film hardnesses with the coating compounds in accordance with the invention, as usually obtained when employing conventional cobalt-based primary driers. Furthermore, with the coating compounds in accordance with the invention, it is possible to obtain VOC values of below 500 g/L. As a matter of fact, for example, with the coating compounds in accordance with the invention for decorative applications, VOC values of less than 300 g/L were obtained. In order to determine the volatile organic compounds content (VOC content), DIN EN ISO standard 11890-1 (September 2007) may be employed.