DE202012100728U1 - Coating system for concrete surfaces of wind towers - Google Patents

Abstract

Coating system for coating a concrete surface, in particular concrete surfaces of towers for wind turbines, comprising a filler layer comprising a coating material containing a solvent-free 2K polyurea and a cover layer comprising a coating material containing a low-solvent 2K polyurea, the filler layer having a primer function and after the application is largely removed.

Description

The invention relates to a coating system consisting of a spatula applied over the entire area and deducted to zero and / or repelled and the order of a layer textured paint, the overall coating is already cured after a short time and thus water resistant.

Concrete wind towers are protected against external influences by protective layers for a long time.

The material-specific properties of the concrete require alkali-resistant and firmly adhering coatings. In particular, suitable polymers are selected as film formers and dyes. This results in different coating systems with different protective properties.

Coating systems for concrete wind towers consist of several protective layers with different functions. The protection system must comply with the specific atmospheric load at the wind turbine site and ensure the main functions of adhesion, high barrier to atmospheric exposure, long-term weather resistance with UV resistance and, consequently, long-term good decorative performance (gloss and color retention).

In addition to the very good weather resistance, the coating system must additionally be resistant to biological corrosion, which can occur, in particular, on the weather side.

Concrete wind towers may consist of individual concrete segments that are assembled on site or cast as a building on site. Depending on the concrete composition, the water content, the flux and the technology used to manufacture the concrete components, including the temperature control, blowholes and holes always form on the concrete surface during the hardening process. The resulting cavities must be closed for several reasons, such as accumulation of rainwater and / or condensation with subsequent erosion by heat / frost effect, mechanical surface load, and for decorative reasons.

First coatings on concrete surfaces must wet well and penetrate into the surfaces, achieve a high adhesion to concrete and have a high alkali resistance, so that long-term results in a high adhesive strength. The primary coatings must cure at a residual water content of up to 6 wt.% In the concrete and give a flawless coating. The bond strength of the first coating should allow full-scale concrete break-out in the event of tear tests to ensure long-term good adhesion and thus adhesion over the service life of the concrete wind power tower.

The one-coat application of the top coat, applied in structure, protects the concrete against atmospheric impact over the life of the wind tower by means of a weather- and UV-resistant coating and ensures the decorative properties such as color tone and gloss. The total layer thickness of the coating described according to the invention is max. 350 μm.

Usually multilayer coating systems are applied, in total high layer thicknesses up to 700 microns. Here, typical base coats are combined with top coats, partly in sandwich design with fabric / fleece of different materials. As a substrate and / or base coating while EP coatings are used, also in intermediate coatings, the low molecular weight EP resin content burdened the processor allergen health, protective measures and thus leads to work problems. This represents a significant deficiency of the current state of the art.

High labor costs and costs for the application of the currently common systems, consisting of multiple layers, with a total layer thickness up to 700 microns characterize the technical state of the systems for coating concrete wind towers.

So revealed the DE 102007014636 B4 a sandwich protection system for concrete surfaces of towers for wind turbines, consisting of a base layer of epoxy resin, an intermediate layer of glass fleece and a cover layer of polyurethane, characterized in that the sandwich protection system as a base coat of a solvent-free 2 component epoxy coating material with incorporated therein glass fleece or glass fabric to which is applied in the uncured, sticky state, a water-dilutable 2-component polyurethane coating material.

One shortcoming of current multi-layer systems is the required intermediate life to revision with the next following coating.

A lack of the currently state-of-the-art coating systems based on water-dilutable 2K-PUR top coats is their relatively slow drying and cross-linking, so that the late-achievable early water and frost resistance makes it possible to outsource the coated concrete parts only 24 hours after application all year round.

The coating system of the invention has compared to the usual coating systems a much faster curing and thereby achieves a much faster water resistance. The coating has a significantly higher surface hardness and thus achieves a higher mechanical strength. The coating has a very good adhesion to concrete and compared to previous coating systems a better UV and weather resistance, so that an overall improved long-term protection results.

The object of the invention is to formulate a coating system which, with minimum production costs, results in a higher-quality coating for concrete surfaces of wind towers than the current state of the art.

The object is also achieved by a coating system according to claim 1. Advantageous embodiments are specified in the dependent claims.

• – Beschichtung der Betonoberfläche mit einer Spachtelschicht, umfassend einen Beschichtungsstoff enthaltend einen lösungsmittelfreien 2K-Polyharnstoff, wobei die Spachtelschicht eine Grundierungsfunktion aufweist,
• – Abziehen und/oder Abstoßen der Spachtelschicht, wobei die Spachtelschicht weitestgehend entfernt wird,
• – Beschichtung der Betonoberfläche mit einer Deckschicht, wobei die Deckschicht einen Beschichtungsstoff aus einem lösungsmittelarmen 2K-Polyharnstoff umfasst.

The application of the coating system according to the invention is carried out on a concrete surface, in particular exposed to the weather concrete surfaces such as concrete surfaces of towers for wind turbines (wind towers), with the following steps:

• Coating the concrete surface with a trowel layer comprising a coating material containing a solvent-free 2K polyurea, the trowelling layer having a priming function,
• Peeling and / or repelling the filler layer, the filler layer being removed as far as possible,
• Coating the concrete surface with a topcoat, the topcoat comprising a low solvent 2K polyurea coating material.

Solvent-free in the context of the invention means that the coating material does not contain any solvent in the base materials nor are added during the production. A minimum solvent content (≤ 0.5% by weight) can result from impurities (GISCODE D 1).

Low solvent in the context of the invention means a solvent content below 20 wt.%. Solvents in the sense of the invention are solvents within the meaning of TRGS (Technical Rules for Hazardous Substances) 610 of the Federal Institute for Occupational Safety and Health (BAuA), according to which only volatile organic solvents having a boiling point of up to 200 ° C. are referred to as solvents Normal conditions (20 ° C and 101.3 kPa) are liquid and used to dissolve or dilute other substances without chemically altering them.

For the purposes of the present patent application, removal of the applied putty layer is understood to mean a removal of the putty layer as far as possible, with a remainder of the putty layer remaining in the layer thickness of preferably at least 5 μm, which performs the function of a primer, on the entire concrete surface. Thus, the removal and / or repulsion of the putty layer does not cause complete removal of the putty layer. The layer thickness of the putty layer remaining on the concrete surface depends inter alia on the nature and surface structure of the concrete surface.

The coating of the concrete surface with the cover layer can also be done in the "wet on wet" process.

Preferably, a polyaspartic acid ester is used as the polyurea.

The coating materials are preferably formulated with or without reactive diluents. The reactive diluent is preferably a blocked cycloaliphatic diamine.

Preferably, the cover layer is applied by rollers or spray applications, such as high pressure spraying, by airless, airmix spraying.

The coating system according to the invention for coating a concrete surface, in particular concrete surfaces of towers for wind turbines, comprises a filler layer comprising a coating material containing a solvent-free 2K polyurea and a cover layer comprising a coating material containing a low solvent 2K polyurea, wherein the filler layer Has priming function and as far as possible deducted and / or repelled after the application.

The coating material used as a putty is preferably made from a solvent-free 2K polyurea as a solvent-free 2K polyaspartic ester coating material.

For this purpose, the solvent-free 2-component polyaspartic acid ester coating material preferably contains a solvent-free, liquid polyaspartic acid ester and a polyisocyanate, preferably in a weight mixing ratio of 0.5: 1 to 10: 1.

The polyisocyanates used are preferably aromatic, cycloaliphatic and particularly preferably aliphatic polyisocyanates.

The 2K polyurea putty in mixture preferably has an intrinsic viscosity in the range from 200 dPa.s to 2000 dPa.s at 23 ° C., measured in the rotational viscometer VT 02-Plus from Thermo.

The low-solvent 2K-polyurea coating material used as topcoat is preferably designed as a low-solvent 2K-polyaspartic ester coating material.

The low-solvent 2K-polyaspartic acid ester coating material used as topcoat is preferably made from a solvent-free, liquid polyaspartic acid ester and an aliphatic and / or cycloaliphatic polyisocyanate, preferably in a weight mixing ratio of 0.5: 1 to 15: 1.

The polyaspartic acid ester is preferably selected from N, N '- (2-methyl-1,5-pentanediyl) bis-, 1,1,4,4'-tetraethyl ester, N, N' - (methylene-4,1-cyclohexanediyl) bis, 1,1'4,4'-tetraethyl ester and / or N, N '- [methylenebis (2-methyl-4,1-cyclohexanediyl)] bis, 1,1'4,4'-tetraethyl ester and mixtures from that.

In one embodiment of the invention, the low-solvent 2K-polyaspartic ester coating material used as topcoat comprises hexamethylene diisocyanate (HDI) and / or isophorone diisocyanate (IPDI) as aliphatic polyisocyanates and 1,4-cyclohexyl diisocyanate (CHDI) as cycloaliphatic polyisocyanate.

Preferably, the solvent-free 2K-polyaspartic acid ester coating material used as topcoat has a pigment volume concentration (PVK) in the range of 25% to 45%.

The solvent-poor 2K-polyaspartic ester coating material used as topcoat preferably has a solvent content in a range from 4% by weight to 20% by weight and a gloss level gloss of 10% to 35% at 60 °. This is achieved by a specific combination of selected functional fillers in combination with surface-active additives. Despite the high binder content of polyaspartic acid and polyisocyanate and the resulting low proportion of solvent in a range of 4 wt.% To 20 wt.% Matting in gloss level range of 10% to 35% in the 60 ° angle is achieved.

In one embodiment of the invention, the low-solvent 2K-polyaspartic acid coating material used as a topcoat has a pseudoplastic flow behavior in the range from 20 dPa.s to 500 dPa.s. This is achieved by a specific combination of selected functional fillers and rheology additives in combination with surface-active additives.

In a further embodiment of the invention, the cover layer has a layer thickness between 80 μm and 500 μm.

Advantageously, the spatula can be applied to residual moisture-containing concrete surfaces, wherein the hardening reaction of the spatula is catalyzed by the moisture of the concrete and the humidity at both interfaces, so that it is very reactive, hardens quickly and allows rapid reworking. In this case, the filler layer, despite low layer thickness as a result of peeling and / or repelling to "zero" and very fast curing, which leads to a dry coating, a very good penetration into the concrete surface and very good adhesion.

Advantageously, by using functional fillers in the scope of a PVK of 30% to 60%, the spatula can be used in conjunction with the surface tension-lowering additives to evenly fill a rheology of the filler compound with voids and holes up to a diameter of 70 mm. At the same time, the rheology of the spatula ensures easy processability over the period of time required in practice.

Advantageously, the low-solvent 2K-polyaspartic ester coating material used as topcoat enables wet film thicknesses up to 500 μm on vertical surfaces due to its rheological properties without the typical surface defects of PUR coatings.

Advantageously, the low-solvent, pseudoplastic 2K-Polyasparaginsäureester coating material used as a topcoat can be applied due to its rheological properties without additional energy supply by airless or Airmix spraying or by rolling, which results in a decorative high-quality, defect-free coatings.

Further advantageously, the low-solvent, pseudoplastic 2K-Polyasparaginsäureester coating material used as a topcoat due to its rheological properties has the application properties of a textured paint, which allows a structure formation during spraying as rolling.

Advantageously, the low-solvent, structurally viscous 2-component polyaspartic ester coating material used as topcoat completely hides surface irregularities of the concrete surface as a result of its application properties. In conjunction with the polyaspartic ester putty thus a decorative coating surface is achieved with minimal effort.

Advantageously, the overall coating consisting of filler and top coat, depending on the curing conditions, within 1 hour to 2 hours at 20 ° C after complete waterproofing, thus coated surfaces thus in any season and any weather conditions to the outside, exposed to the weather, can be outsourced.

In addition to the use of 2K-polyurea compounds as inventive solvent-free spatula and other liquid, non-solvent-containing polymers are applicable, which are applicable to alkaline surfaces. Thus, the use of a solvent-free filler based on a liquid epoxy resin is conceivable.

The coating system according to the invention is preferably composed of a solvent-free 2-component polyaspartic ester putty which closes voids, holes and other concrete surface irregularities and the subsequent, preferably single-layer, spray application of a polyaspartic ester structural paint.

In this case, an alkali-resistant coating is advantageously achieved on the concrete surface, which is produced "wet on wet" with high productivity and highest adhesion and highest achievable coating properties.

According to the invention, this is achieved by overcoating a spatula with polyaspartic ester-based primer function, once in a thick layer with a polyaspartic ester-based topcoat.

The single-layered 2-component polyaspartic acid ester topcoat, not including the filler layer which is largely removed from the concrete surface and / or repelled, is applied in a high layer thickness and results in a scarred structure which generally conceals surface irregularities. In this case, the 2K-Polyasparaginsäureester textured paint can be applied to the uncured 2K-Polyasparaginsäureester spatula, so that the manufacturing process compared to the currently used multi-layer systems is significantly shortened.

Compared with the previously used multilayer coating systems, with up to 5 layers, the number of layers is significantly reduced and thus the required labor costs.

The above-mentioned embodiments of the invention are suitable for solving the problems. Combinations of the disclosed embodiments are also suitable for the solution of the tasks.

The invention will be explained in more detail below with reference to some embodiments.

In a first embodiment, the topcoat has the following composition: TABLE 1 raw material Share (wt.%) In the range from to polyaspartic 22 30 Additive / wetting agent 2 1 Additive / deaerator 1 1 hydrogenated castor oil 2 1 Tinuvin 2 2 zeolites 2 2 Titanium dioxide 10 15 fillers 29 13 Talc, micronized 20 25 solvent 10 10 100 100

Hexamethylene diisocyanate having an NCO content of 10-25% is used as the polyisocyanate hardener and mixed with the polyaspartic ester composition according to Table 1 in a mixing ratio of 4: 1 to 7: 1 parts by weight. As a result, a coating composition according to the invention for the topcoat is obtained.

In another embodiment, the putty with primer function has the following composition: TABLE 2 raw material Share (wt.%) In the range from ... to polyaspartic 40 50 reactive 8th 7 zeolites 2 2 hydrogenated castor oil 3 3 Additive / wetting agent 1 1 Titanium dioxide 6 6 fillers 32 16 Talc, micronized 8th 15 100 100

Hexamethylene diisocyanate having an NCO content of 10-25% is used as the polyisocyanate hardener and mixed with the polyaspartic ester composition according to Table 2 in a mixing ratio of 4: 1 to 7: 1 parts by weight. Thereby, a filler composition according to the invention for the filler layer is obtained.

In a further embodiment, the above-described filler composition is first applied to the concrete surface of a wind turbine tower having voids and holes with a spatula. Subsequently, the filler layer is removed again with the spatula, wherein the voids and holes present in the concrete surface are substantially closed. It remains on the entire concrete surface a filler layer in different layer thickness, which takes over the function of a primer.

Thereafter, the application of the cover coating shown in the first embodiment takes place, which is applied by means of rollers. As a result, a completely coated concrete surface is obtained, which no longer has voids or holes and, moreover, exhibits a good structuring by means of the top coating, which is suitable for concealing irregularities in the concrete surface. Furthermore, the topcoat has a high barrier to atmospheric exposure and long term weathering resistance with UV resistance.

In one embodiment of the above-described embodiment, the top coat is applied by means of high-pressure spraying.

In a further embodiment of the above-described embodiment, the top coat is applied by airless spraying.

In a further embodiment of the above-described embodiment, the topcoat is applied by means of airmix spraying.

In a further embodiment of the above-described embodiments, the top coat is applied to the concrete surface not yet dried after the most extensive removal or repulsion of the filler layer by the wet-on-wet method.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007014636 B4 [0011]

Claims (14)

Coating system for coating a concrete surface, in particular concrete surfaces of towers for wind turbines, comprising a filler layer comprising a coating material containing a solventless 2K polyurea and a topcoat comprising a coating material containing a low solvent 2K polyurea, the surfacer layer having a primer function and after the application is largely removed. Coating system according to claim 1, characterized in that the coating material used as a filler is made of a solvent-free 2K polyaspartic acid ester. Coating system according to Claim 2, characterized in that the solvent-free 2-component polyaspartic ester coating material used as a filler contains a solvent-free, liquid polyaspartic acid ester and a polyisocyanate in a weight mixing ratio of 0.5: 1 to 10: 1. Coating system according to claim 3, characterized in that the polyisocyanate is selected from aromatic, cycloaliphatic and aliphatic polyisocyanates. Coating system according to one of claims 1 to 4, characterized in that the low-solvent 2K-polyurea coating material used as cover layer contains a low-solvent 2K-Polyasparaginsäureester coating material. Coating system according to one of claims 1 to 5, characterized in that the used as a topcoat low-solvent 2K-Polyasparaginsäureester coating material of a solvent-free, liquid polyaspartic acid ester and an aliphatic and / or cycloaliphatic polyisocyanate, in a weight mixing ratio of 0.5 to 1 to 15 to 1 is executed. Coating system according to one of claims 1 to 6, characterized in that the used as a topcoat low-solvent 2K-polyurea coating material, hexamethylene diisocyanate and / or isophorone diisocyanate as aliphatic polyisocyanates and / or 1,4-cyclohexyl diisocyanate as cycloaliphatic polyisocyanate. Coating system according to one of claims 1 to 7, characterized in that as polyaspartic acid ester N, N '- (2-methyl-1,5-pentanediyl) bis-, 1,1'4,4'-tetraethyl ester and / or N, N '- (methylene-4,1-cyclohexanediyl) bis, 1,1,4,4'-tetraethyl ester and / or N, N' - [methylenebis (2-methyl-4,1-cyclohexanediyl)] bis, 1 , 1'4,4'-tetraethyl ester is used. Coating system according to one of claims 1 to 8, characterized in that the used as a topcoat solvent-free 2K-Polyasparaginsäureester coating material, a pigment volume concentration in the range of 25% to 45%. Coating system according to one of Claims 1 to 9, characterized in that the 2K polyurea putty used as a putty layer has, in mixture, an intrinsic viscosity in the range from 200 dPa.s to 2000 dPa.s at 23 ° C. Coating system according to one of claims 1 to 10, characterized in that the low-solvent 2K-Polyasparaginsäureester coating material used as a topcoat a solvent content of 4 wt.% To 20 wt.% And a matting in the gloss level range of 10% to 35% at 60 ° angle having. Coating system according to one of claims 1 to 11, characterized in that the solvent-free 2K-Polyasparaginsäureester coating material used as a topcoat has a pseudoplastic flow behavior in the range of 20 dPa · s to 500 dPa · s. Coating system according to one of claims 1 to 12, characterized in that the cover layer has a layer thickness between 80 microns and 500 microns. Coating system according to one of claims 1 to 13, characterized in that the coating system after a drying time of up to 2 hours at 20 ° C is waterproof.