USE OF COATING COMPOSITIONS FOR WIND TURBINE BLADES

Abstract

The present invention relates to coating compositions for wind turbine blades. These compositions are particularly useful as finishes for wind turbine blades and for tip protection (LEP). The invention also relates to a wind turbine blade coated with a coating composition of the invention and to a method for applying the coating composition and to a method for repairing and / or replacing the existing coating layer on a wind turbine blade by applying a coating composition of the invention. The invention also relates to a parts kit comprising the base composition and the curing agent, used in the coating composition.The coating composition used for coating a wind turbine blade comprises a base composition comprising a polyetherespartic ester having formula (i) below, wherein each r represents a linear or branched c1-c10 alkyl residue, such as a linear or branched c1-c6 alkyl residue, such as, for example, a methyl, ethyl, propyl or butyl residue; and where x is a polyether. The coating composition further comprises a curing agent.

Description

"USE OF WIND TURBINE BLADE COATING COMPOSITIONS" FIELD OF THE INVENTION

[001] The present invention relates to coating compositions for wind turbine blades. The compositions are particularly used either as finishing compositions or as Tip Protection (LEP) compositions. The invention also relates to a wind turbine blade, such as the tip of a wind turbine blade coated with coating compositions of the invention, and to a method for applying the coating composition and to a method for repairing and / or replacing the existing coating layer on a wind turbine blade by applying a coating composition of the invention. The invention also relates to a parts kit comprising the base composition and the curing agent used in the coating compositions. HISTORY OF THE INVENTION

[002] In recent years, wind energy has become an important source of electricity production and contributes significantly to the reduction of CO2 emissions. Wind energy is the use of airflow through wind turbines to provide the mechanical energy to turn electric generators.

[003] Wind turbines typically have a three-bladed upwind rotor attached to a nacelle atop a tall tubular tower. Wind turbine blades, or wind turbine blades, are usually designed to last around 20 to 25 years. The blades are constantly exposed to the elements and are ideally designed to withstand temperature extremes, crosswinds, precipitation, and / or other environmental hazards with minimal failure. Coating failure due to erosion is frequently observed at the blade tip. Rain, hail, ice, UV, water absorption, and other weather conditions can all contribute to the damage. Petition 870250121402, dated 12 / 30 / 2025, pages 80 / 142 2 / 58 cause erosion of the blade tip. This affects the blade's aerodynamics and could cause serious damage.

[004] Common concepts for wind turbine blade tip protection include, for example, the application of an anti-erosion tape or the application of a suitable coating composition (see, for example, Herring, Dyer, Martin and Ward. Renewable and Sustainable Energy reviews 115 (2019) 109382). For both concepts, good adhesion to the blade and good resilience are of paramount importance. For coating compositions, the material properties also play a significant role in order to achieve the correct balance between, for example, robustness, hardness and elasticity of the coating. In addition, it is desirable that the coating compositions can be easily applied to the wind turbine blade.

[005] Various types of coating compositions are used in protective coatings for wind turbine blades to minimize erosion, including compositions formed from aliphatic polyaspartic esters and isocyanate curing agents. For example, WO 2015 / 136018 suggests the use of aliphatic polyaspartic esters in formulations for wind turbine blade coating, and WO 2015 / 049260 discloses coating compositions comprising an aliphatic polyaspartic ester and a polyisocyanate curing agent, and further comprising solid particles of an amino resin-based polymer. WO 2015 / 120941 discloses coating compositions comprising aliphatic polyaspartic esters and at least one polycarbonate diol in the paint base. SUMMARY OF THE INVENTION

[006] The present invention provides novel coating compositions for wind turbine blades. Within the scope of the invention are compositions of Petition 870250121402, dated 12 / 30 / 2025, pp. 81 / 142 3 / 58 coatings that are useful for Tip Protection (LEP) and compositions that are useful as finishing compositions for wind turbine blades.

[007] Consequently, in one embodiment, the present invention relates to the use of a coating composition comprising: a) a basic composition comprising polyetheraspartic ester having the formula (I) below: where each R represents a linear or branched C1-C10 alkyl residue, such as a linear or branched C1-C6 alkyl residue, such as, for example, a methyl, ethyl, propyl or butyl residue; and where X is a polyether; and b) a healing agent; for coating a wind turbine blade.

[008] In one embodiment, the invention relates to a wind turbine blade having, on at least part of its outer surface, a coating made of a coating composition as described above. DEFINITIONS

[009] In the context of the invention, the tip of a wind turbine blade indicates the part of the blade that cuts the wind first. The opposite edge may be designated the trailing edge. Petition 870250121402, dated 12 / 30 / 2025, pp. 82 / 142 4 / 58

[010] The term Tip Protection is typically abbreviated as LEP. In the present context, the terms Tip Protective Coating (composition) or LEP composition are used interchangeably and indicate a coating composition applied to at least part of a wind turbine blade, including at least the tip or at least part of the tip of a wind turbine blade, to provide protection against erosion caused by, for example, rain, hail, ice, UV, water absorption, and other weather conditions. One way to assess the effectiveness of a tip protective coating is the Rain Erosion Test (RET) described in the experimental section herein. Preferably, said LEP is applied on top of a finish, but it can also be applied under the finish, preferably on top of a primer layer.

[011] In the present context, the term finish refers to a coating layer applied to at least part of a wind turbine blade, preferably to the entire wind turbine blade. Preferably, said finishing coating composition (or finishing composition) is applied on top of a primer layer. Several primer compositions for wind turbine blades are known in the art.

[012] In the present context, the term outermost layer refers to the final coating system applied to the wind turbine blade, i.e., the outermost layer when the wind turbine blade is in operation. The outermost layer of the tip is typically a coating made of an LEP coating composition, while the outermost layer of other parts of the wind turbine blade typically refers to a coating made of a finishing composition.

[013] In terms of the complete coating composition, it typically consists of a base composition (in which the base component Petition 870250121402, dated 12 / 30 / 2025, pp. 83 / 142 5 / 58 is included) and a curing agent (in which the curing agent component is included). Typically, the coating composition also includes several other constituents, for example, filler materials and pigments, additives and solvents. It should be understood that when reference is made to the coating composition, the mixed composition, comprising both the base composition and the curing agent, is ready to be applied to the wind turbine blade.

[014] In the present context, a mixture of polyeteraspartic esters or a polyeteraspartic ester mixture indicates a mixture of at least two different polyeteraspartic esters.

[015] In the present context, a parts kit refers to a parts kit comprising two or more containers, wherein one container comprises the base composition and another container comprises the curing agent. The other constituents that may be present in the coating composition of the invention, as defined herein, for example, filler materials, pigments, solvents and additives, may be contained in both containers of the parts kit, typically in the container comprising said base composition. Alternatively, said other constituents may be contained in one or more additional containers.

[016] The term polyether indicates a polymer prepared by joining or polymerizing many molecules of simpler compounds (monomers) by establishing ether linkages between them. In the context of the present invention, the term polyether preferably indicates a polymer in which the repeating unit contains an alkyl residue of one or more carbon atoms linked by an oxygen atom, such as an alkyl residue of two to six carbon atoms linked by an oxygen atom, such as an alkyl residue of two carbon atoms linked by an oxygen atom. One or Petition 870250121402, dated 12 / 30 / 2025, pp. 84 / 142 6 / 58 more of said carbon atoms may be replaced by a small alkyl group such as, for example, methyl, ethyl or propyl; preferably methyl. DETAILED DESCRIPTION OF THE INVENTION

[017] The present invention relates to novel coating compositions for wind turbine blades, wherein the base composition comprises a polyetheraspartic ester having the formula (I) below: where each R represents a linear or branched C1-C10 alkyl residue, such as a linear or branched C1-C6 alkyl residue, such as, for example, a methyl, ethyl, propyl or butyl residue; and where X is a polyether. The coating composition also comprises a curing agent.

[018] Polyetheraspartic esters are distinguished from the more conventional aliphatic polyaspartic esters by the fact that X in an aliphatic polyaspartic ester is typically a straight or branched aliphatic alkyl and / or cycloalkyl residue rather than a polyether.

[019] In one embodiment, the invention relates to coating compositions comprising a mixture of polyetheraspartic esters wherein X is a polyether having a repeating unit of the structure: Petition 870250121402, dated 12 / 30 / 2025, pp. 85 / 142 7 / 58 where m is in the range of 2 to 35.

[020] The mixture of polyeteraspartic esters may comprise at least two different polyeteraspartic esters having a different number of repeating units in X. In one embodiment, a mixture is such that the average value of m is in the range of 2 to 10, such as 2 to 6, such as 2 to 4, such as 2.5 to 3.

[021] Polyetheraspartic esters can be prepared by reacting one or more polyether polyamines with a dialkylmaleate, such as, for example, a linear or branched C1-C10 dialkyl maleate, such as, for example, a linear or branched C1-C6 dialkyl maleate, such as, for example, diethyl maleate. Said polyetheraspartic esters can be prepared, for example, by employing the reagents in quantities such that there is at least one equivalent and, in some embodiments, approximately one equivalent of olefinic double bonds for each equivalent of primary amino groups. Examples of methods for the preparation of polyetheraspartic esters can be found in WO 2014 / 151307 and in Chen et al., RSC Advances (2018), 8:13474-13481.

[022] Suitable polyether polyamines, which can be reacted with dialkylmaleates in Michael addition reactions to produce polyetheraspartic esters for the coating compositions of the invention, include commercially available JEFFAMINE polyetheramines from Huntsman Corporation, The Woodlands, TX; for example, polyetheramines of the series Petition 870250121402, dated 12 / 30 / 2025, pp. 86 / 142 8 / 58 Jeffamine D, as well as, say, Jeffamine D-230. In one embodiment, a polyether polyamine mixture comprises a polyether polyamine mixture according to formula (II) below, wherein p is a number having an average value of at least 2, such as 2 to 35, or 2 to 8, or 2.5 to 6.1 (II) wherein the mixture comprises: (1) about 50 to 99% by weight, such as 50 to 90% by weight or, in some cases, 80 to 90% by weight, of polyether polyamines according to the formula wherein p has an average value of 2.5; and (2) about 1 to 50% by weight, such as 10 to 50% by weight or, in some cases, 10 to 20% by weight, of polyether polyamines according to the formula wherein p has an average value of 6.1.

[023] An example of a mixture of polyeteraspartic esters that is suitable for use in the present invention is Desmophen NH 2850 XP, from Covestro Deutschland AG, Leverkusen, Germany, which has an equivalent weight of about 295, a viscosity at 25°C of about 170-210 mPa.s, and an amine value between 170-210 mg KOH / g.

[024] The use of polyetheraspartic esters in coating compositions is known from WO 2014 / 151307, which discloses a coating composition with a resin comprising a polyetheraspartic ester in combination with an aliphatic polyaspartic ester made with Jeffamines. WO 2014 / 151307 specifically discloses a polyetheraspartic ester made with an aliphatic trifunctional polyamine polyether. WO 2014 / 151307 does not disclose or suggest the use of polyetheraspartic esters in coating compositions for wind turbine blades, nor does it Petition 870250121402, dated 12 / 30 / 2025, pp. 87 / 142 9 / 58 document WO 2014 / 151307 suggests the use of a difunctional polyeteraspartic ester.

[025] Polyetheraspartic ester mixtures have been further suggested for use in sealant compositions in document WO 2016 / 049104 where polyetheraspartic ester mixtures are used in combination with an aliphatic polyaspartic ester and / or polyether diol. The sealant compositions are intended for application in, for example, expansion joints, control joints and perimeter joints of substrates, such as concrete substrates.

[026] Polyeteraspartic ester mixtures have also been suggested, for example, for use in peelable automotive coatings (EP3495403) and for use in floor and countertop coatings in combination with an acrylate-containing compound (US 2018 / 0362801).

[027] In one aspect, the coating composition of the present invention comprising one or more polyetheraspartic esters is an LEP coating composition for wind turbine blades. Said LEP coating provides good protection against erosion as demonstrated by the Rain Erosion Test. The LEP composition is capable of providing protection under the particularly severe rain erosion conditions experienced by wind turbine blades.

[028] In another aspect, the coating composition of the present invention is for a finishing coating composition for wind turbine blades. Both the finishing composition and the LEP composition possess good mechanical and physical properties including a high degree of flexibility, which can, for example, be evaluated by tapered mandrel or tensile stress tests. Furthermore, both the finishing and the coating Petition 870250121402, dated 12 / 30 / 2025, pp. 88 / 142 10 / 58 LEP provides protection against rain erosion.

[029] The compositions of the invention can be applied using standard techniques such as brush and roller and can also be applied by spray application, such as by conventional air atomized spray application (finishing composition) or by airless spray application (both finishing and LEP compositions). The suitability for spray application is an advantage both in relation to the initial coating of a wind turbine blade and in relation to the repair and / or replacement or partial replacement of the existing coating layer on a wind turbine blade.

[030] The coating compositions of the invention may also comprise certain amounts of one or more aliphatic polyaspartic esters, which is an optional ingredient when the composition is for use as an LEP coating composition. Aliphatic polyaspartic esters are well known in the art. For a typical aliphatic polyaspartic ester X as illustrated in formula (I) is a straight or branched alkyl and / or cycloalkyl residue. Typical examples of aliphatic polyaspartic esters include substances sold under the trade names Desmophen NH 1220, Desmophen NH 1420, Desmophen NH 1423, Desmophen 1520 and Desmophen NH 1521 commercially available from Covestro Deutschland AG, Leverkusen, Germany.

[031] If the coating composition is for use as a finish, the composition comprises one or more aliphatic polyaspartic esters in addition to the polyetheraspartic ester blend. The blending ratio of polyetheraspartic ester to aliphatic polyaspartic esters is typically in the range of 40:60 to 60:40, such as in the range of 45:55 to 55:45, such as about 50:50. Petition 870250121402, dated 12 / 30 / 2025, pp. 89 / 142 11 / 58

[032] Preferably, if the coating composition is for use in Tip Protection and comprises one or more aliphatic polyaspartic esters, the mixing ratio of polyaspartic ester to aliphatic polyaspartic esters is in the range of 70:30 to 99:1, such as in the range of 80:20 to 99:1, such as in the range of 85:15 to 99:1, more preferably in the range of 90:10 to 99:1 as well as 95:5 to 99:1. In a preferred embodiment, the base composition comprises less than 20%, such as less than 15%, such as less than 10%, such as less than 5%, such as less than 1% of any aliphatic polyaspartic esters by weight of said base composition. In one embodiment, the said LEP composition is substantially free of any aliphatic polyaspartic esters. HEALING AGENT

[033] The coating composition of the invention further comprises a curing agent. In a preferred embodiment, said curing agent comprises one or more polyisocyanates. In the present context, polyisocyanate refers to any organic compound having two or more reactive isocyanate groups (-NCO) in a single molecule such as diisocyanates, triisocyanates, tetraisocyanates, etc., and mixtures thereof. Cyclic and / or linear polyisocyanate molecules can be usefully employed. The number of isocyanate groups per molecule is readily determinable by means of the isocyanate content and the weight-average molecular weight of the respective polyisocyanate. The isocyanate content can be determined, for example, according to DIN EN ISO 11909 by reacting the respective sample with excess dibutylamine and back-titrating the excess with hydrochloric acid against bromophenol blue.

[034] Examples of polyisocyanates according to the invention are compounds that are known per se, preferably aliphatic polyisocyanates. Petition 870250121402, dated 12 / 30 / 2025, pp. 90 / 142 12 / 58 with particular mention of diisocyanates and their dimers and trimers such as urethdiones and isocyanurates. Examples include derivatives of hexamethylene-1,6-diisocyanate (also called hexamethylene diisocyanate or HDI), octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, tetramethylhexane diisocyanate, isophorone diisocyanate (IPDI), 2-isocyanatopropylcyclohexyl isocyanate, dicyclohexylmethane 2,4'-diisocyanate, dicyclohexylmethane 4,4'-diisocyanate, 1,4- or 1,3-bis(isocyanate-methyl)cyclohexane, 1,4- or 1,3- or 1,2-diisocyanate-cyclohexane, and 2,4- or 2,6-diisocyanate-1-methyl-cyclohexane and mixtures thereof. The most preferred is hexamethylene diisocyanate (HDI).

[035] Similarly, reaction products or prepolymers of aliphatic polyisocyanates can be used.

[036] Particular mention is made of biurets, allophanates, urethdiones and isocyanurates of the indicated polyisocyanates. Preference is given here to the use of dimers and / or trimers of the indicated polyisocyanates, preferably hexamethylene diisocyanate. In particular, the urethdiones and isocyanurates of the polyisocyanates mentioned above that are known per se and also commercially available.

[037] Isocyanurates can be prepared from any of a very wide variety of isocyanates in the presence of particular catalysts, examples being sodium formate, potassium acetate, tertiary amines or triphenylphosphines. The isocyanurate ring system constitutes a trimer consisting of three isocyanate groups in each case; they are very stable, retaining their integrity even at high temperatures of more than 100°C, for example. Each of these three isocyanate groups originates from three different molecules of the respective isocyanate used; in other words, the structures Petition 870250121402, dated 12 / 30 / 2025, pp. 91 / 142 13 / 58 Trimeric molecules are formed. If polyisocyanates are used, examples being diisocyanates such as HDI, it is possible that an intermediate crosslinking occurs and therefore a plurality of isocyanurate rings can become linked to each other. It is also known that it is possible that linking diol moieties such as, for example, hexanediol, are added during the preparation of isocyanurates in order to modify their reactivity, for example, and so that, in this way, a plurality of isocyanurate ring systems become linked to each other. Similarly, urethdiones, which consist of two isocyanate groups, can be prepared by a similar catalytic reaction.

[038] In one embodiment, said curing agent comprises a prepolymer based on an aliphatic polyisocyanate, preferably hexamethylene diisocyanate. Prepolymers, in the context of the invention, are NCO-functional reaction products of isocyanates and polyols, such as polyethers or polyesters.

[039] An exemplary prepolymer is a polyisocyanate containing aliphatic polyester groups comprising repeating structural units -RC(=O)-OC-, where R is a divalent aliphatic radical. Preferred aliphatic polyester groups are polylactone groups, more particularly polycaprolactone groups. Polycaprolactones and their preparation, by reaction of a monoalcohol with epsiloncaprolactone, for example, are known. They can be introduced, for example, by common methods, by reaction of an isocyanate group with at least one of the hydroxyl groups they contain. As a result of the polyester groups present and the intermediate crosslinking where it occurs, polyisocyanates such as, for example, hexamethylene diisocyanate (HDI) isocyanurates containing aliphatic polyester groups have a lower isocyanate content than a pure HDI trimer. While the latter has an isocyanate content of about 25% (molecular weight 3xNCO = 126 g / mol; molecular weight Petition 870250121402, dated 12 / 30 / 2025, pp. 92 / 142 14 / 58 of the purely trimeric isocyanurate of HDl = 504.6 g / mol), the polyisocyanate containing aliphatic ester groups typically has an isocyanate content of 5-20%, such as 5-15%, preferably 6-14%, such as 6-11% or 8-14% or 10-12%, such as about 11%. A commercially available polyisocyanate prepolymer containing aliphatic polyester groups is Desmodur E 2863. Another exemplary HDI-based prepolymer is Desmodur XP 2599 containing ether groups. Both prepolymers mentioned above are available from Covestro Deutschland AG, Leverkusen, Germany.

[040] Preferred polyisocyanates are solvent-free and are substantially free of isocyanate monomer, i.e., contain less than 0.5% and more preferably less than 0.3% of isocyanate monomer as measured in accordance with DIN EN ISO 10 283.

[041] When polyisocyanates are used as curing agents, functionality is defined as the number of isocyanate groups present per molecule. For practical purposes, the number of isocyanate groups is given as an average due to the presence of various related types of polyisocyanate molecules within a commercial product. The expression average functionality refers to the functionality of a combination of two or more polyisocyanates. Average functionality is calculated as the total number of reactive (isocyanate groups) divided by the total number of polyisocyanate molecules.

[042] Typically, lower functionality yields less crosslinking, resulting in softer, more flexible products, and higher functionality yields more crosslinking, resulting in stiffer, harder products. In a preferred embodiment, the average functionality of the polyisocyanates used in the composition of the present invention is in the range of 2-4, as in the range of Petition 870250121402, dated 12 / 30 / 2025, pp. 93 / 142 15 / 58 3-4 or 2-3, just like in the 2-2.5 range.

[043] Examples of commercially available polyisocyanates that are useful within the present invention include Desmodur N 3900, Desmodur E 2863 XP, Desmodur N 3800, Desmodur XP 2860 and Desmodur XP 2599; all available from Covestro Deutschland AG, Leverkusen, Germany. In one embodiment, the curing agent according to the present invention comprises one or more polyisocyanates selected from the group consisting of Desmodur N 3900, Desmodur E 2863 XP, Desmodur N 3800, Desmodur XP 2860 and Desmodur XP 2599.

[044] The choice of one or more polyisocyanates to be comprised in the curing agent may be based on the desired properties of the coating composition, such as the preferred degree of viscosity of the coating composition and flexibility of the coating layer. The term one or more polyisocyanates indicates that a mixture of polyisocyanates may be used.

[045] For both the finish and the LEP composition of the present invention, the total number of isocyanate groups in the curing agent component to the number of amine groups in the base component will typically be in the range of 80:100 to 160:100, such as 90:100 to 125:100, such as 95:100 to 120:100, preferably in the range of 100:100 to 120:100, such as 100:100 to 110:100 or 105:100 to 110:100. Preferably, the number of isocyanate groups is in excess of the number of amino groups, preferably only in minimal excess in order to facilitate the complete reaction of the amine groups. PREPARATION OF THE COATING COMPOSITIONS OF THE INVENTION.

[046] Coating compositions can be prepared from Petition 870250121402, dated 12 / 30 / 2025, pp. 94 / 142 16 / 58 commercially available components. The base composition (including one or more polyeteraspartic esters and potentially one or more aliphatic polyaspartic esters) and the curing agent (including one or more polyisocyanates) may also typically comprise one or more other constituents, for example, fillers and pigments, solvents and additives (e.g., thickening agents, wetting agents, dispersing agents, anti-sag agents, anti-settling agents, anti-foaming agents and stabilizers).

[047] Examples of filler materials and pigments are calcium carbonate, dolomite, talc, mica, barium sulfate, kaolin, silica, titanium dioxide, red iron oxide, yellow iron oxide, black iron oxide, carbon black, phthalocyanine blue and phthalocyanine green. In the LEP coating composition the total amount of filler material(s) and pigment(s) is preferably between 5-30%, such as between 10-25% by weight of the coating composition while the finishing coating composition preferably contains about 20-40% such as about 25-30% of filler material(s) and pigment(s) by weight of the coating composition.

[048] Examples of additives are diluents, wetting agents, leveling agents and dispersants; antifoaming agents such as silicone oils; stabilizers such as light and heat stabilizers, for example, hindered amine light stabilizers (HALS); moisture stabilizers (water sequestrants) such as substituted isocyanates, substituted silanes, trialkyl esters of orthoformic acid and synthetic zeolites; oxidation stabilizers such as butylated hydroxyanisole and butylated hydroxytoluene; thickeners and antisettling agents such as Petition 870250121402, dated 12 / 30 / 2025, pp. 95 / 142 17 / 58 organo-modified clays (Bentone), polyamide waxes and polyethylene waxes.

[049] In addition, the base and / or curing agent may be supplemented with one or more solvents. Preferred examples of suitable solvents are organic solvents such as toluene, xylene and napta; ketones such as methyl ethyl ketone, methyl isobutyl ketone, diacetone alcohol and cyclohexanone; esters such as methoxypropyl acetate, n-butyl acetate and 2-ethoxyethyl acetate; and mixtures thereof. However, with respect to the claimed coating composition for use in LEP, a solvent may not even be necessary due to the low viscosity of the remaining constituents of the coating composition because of the combined properties of the polyetheraspartic esters and polyisocyanate curing agent. For example, the LEP coating composition of the invention can be prepared in solvent-free form and thus provide a good environmental profile. Therefore, in the LEP coating composition, preferably, one or more solvents are included (or not included) in an amount of less than 25% by weight, such as less than 15% by weight, such as less than 10% by weight, preferably less than 5%, such as less than 2.5% by weight of the coating composition.More preferably, when for use as an LEP coating composition, the composition is substantially free of any solvents, meaning that one or more organic solvents have not been explicitly added in order to, for example, adjust the viscosity of the composition. Substantially free of any solvents means that, if present, only small amounts of one or more organic solvents are present in the coating composition as a result of the use of, for example, typical coating additives, which may optionally be obtained commercially in solution in organic solvents. Petition 870250121402, dated 12 / 30 / 2025, pp. 96 / 142 18 / 58

[050] When the claimed coating composition is for use as a finish, said composition preferably contains one or more added solvents in addition to the solvents that may be included in the coating composition as a result of the use of, for example, coating additives, which may optionally be obtained commercially in solution in organic solvents. Preferably, an added solvent is present in an amount in the range of 10-30% by weight of the coating composition, such as in a range of 15-25%, such as about 20% of said coating composition.

[051] The coating composition can be prepared by suitable techniques that are commonly used within the field of coating production. The coating composition can be prepared by mixing two or more components, for example, two premixes, one of which comprises the base composition and the other the curing agent. Before mixing, one or both premixes may be preconditioned to meet specific temperature requirements. It should be understood that when reference is made to the coating composition, it is the mixed coating composition.

[052] The mixture of the base composition (comprising one or more polyeteraspartic esters) and the curing agent (comprising one or more polyisocyanates) allows a chemical reaction between the amino groups of the polyeteraspartic esters, and potential aliphatic polyaspartic esters when present, and the isocyanate groups of the polyisocyanates. The mixing ratio between the two components must therefore be carefully controlled in order to obtain a coating composition with the correct physical properties. The mixing ratio is defined as the volumetric or weight ratio between the Petition 870250121402, dated 12 / 30 / 2025, pp. 97 / 142 19 / 58 base composition and the curing agent. In the context of the present invention, the volumetric mixing ratio between the base composition and the curing agent is typically between 1:5 and 5:1, such as between 1:4 and 4:1, such as between 1:3 and 3:1, preferably between 1:2 and 2:1, such as between 1:1.5 and 1.5:1, such as approximately 1:1. APPLICATION OF THE COATING COMPOSITIONS OF THE INVENTION

[053] The application of the coating compositions can be done by standard application methods such as by brush or roller. In addition, the claimed coating composition can be applied to the wind turbine blade by spray application such as, for example, by conventional air atomized spray application (finish) or by airless spray application (both finish and LEP). In practical embodiments, the base composition and the curing agent are mixed in a single batch for normal spray application or as a continuous process when multi-component spray equipment is used.

[054] In order to facilitate easy application of the coating composition (e.g., by spray, brush or roller application techniques), the LEP composition typically has a viscosity in the range of 150-5000 mPa.s, such as 250-3000 mPa.s, preferably in the range of 500-2500 mPa.s, such as 500-2000 mPa.s; while the finishing composition typically has a viscosity in the range of 50-500 mPa.s, such as about 50-300 mPa.s, such as about 50-200 mPa.s. Typically, the LEP composition has a higher viscosity than the finishing composition.

[055] Preferably, the coating composition is applied in one or more layers and the total dry film thickness of the composition is Petition 870250121402, dated 12 / 30 / 2025, pp. 98 / 142 20 / 58 coating is between 50 and 1000 pm.

[056] Similarly, preferably, the outer surface of the wind turbine blade coated with the coating composition comprises at least a predominant part of the blade tip, but the entire surface of the wind turbine blade may be coated with the coating composition.

[057] In the context of the invention, the wind turbine blade to which the finishing coating composition is applied is typically pre-coated with one or more coating layers comprising a primer to which the finishing coating composition is applied. Preferably, the wind turbine blade to which the finishing coating composition is applied is pre-coated with at least one or more layers of a primer.

[058] In the context of the invention, the wind turbine blade to which the LEP coating composition is applied may be pre-coated with one or more coating layers comprising a primer and / or a finish to which the coating composition is applied. Preferably, the wind turbine blade to which the LEP coating composition is applied is pre-coated with at least one or more layers of a primer and / or a finish.

[059] In one embodiment, the invention relates to a wind turbine blade having on at least part of its outer surface one or more coating layers prepared from a finishing composition of the invention and thereon one or more layers of an LEP coating prepared from an LEP coating composition of the invention, wherein said LEP coating composition is applied to at least part of the tip of the wind turbine blade. Optionally, the wind turbine blade has been pre-coated with one or more coating layers comprising a primer.

[060] Therefore, the present invention also provides a method for Petition 870250121402, dated 12 / 30 / 2025, pp. 99 / 142 21 / 58 coating of a wind turbine blade, said method comprising applying a coating composition, as defined herein, to at least part of the surface of said wind turbine blade; and allowing the coating composition to cure.

[061] Since the use of the coating compositions according to the invention includes both use for finishes and use in Tip Protection, a further embodiment of the invention provides a method for coating a wind turbine blade comprising the steps, i) applying a coating composition according to the invention for use as a finish to at least part of the wind turbine blade and allowing the composition to cure; followed by ii) applying a coating composition according to the invention for use in Tip Protection at least to the tip of a wind turbine blade and allowing the composition to cure.

[062] In another embodiment, the invention provides a method for coating a wind turbine blade comprising the steps, i) applying a coating composition according to the invention for use in Tip Protection at least to the tip of a wind turbine blade and allowing the composition to cure, followed by ii) applying a coating composition according to the invention for use as a finish to at least a part of the wind turbine blade and allowing the composition to cure.

[063] The said wind turbine blade may be pre-coated with a primer before the application of the LEP finish and / or coating composition.

[064] After the coating composition is applied to the wind turbine blade, the coating composition is allowed to cure under controlled ambient temperature and humidity. The coating composition is preferably cured at a temperature not exceeding 70 °C, in particular at a temperature in the range of 0-45 °C, such as a temperature in the range of 15-35 °C. A Petition 870250121402, dated 12 / 30 / 2025, pages 100 / 142 22 / 58 The current temperature at which the coating composition can be cured is normally set at the lower limit by the temperature at which the coating composition is practically curable and at the upper limit by the temperature at which the integrity of the wind turbine blade and any underlying coatings will be compromised.

[065] The coating compositions of the present invention can also be used in a method for repairing a wind turbine blade. The method for repairing a wind turbine blade would comprise a step of applying the coating composition of the present application to at least a portion of the wind turbine blade. The coating may be applied to substantially all of the wind turbine blades, or only to a portion of the wind turbine blade, such as the tip of the wind turbine blade. In certain embodiments, one or more of the coating layers may be applied to at least a portion of the wind turbine blade. The wind turbine blade repaired in this manner may have a pre-existing coating or coating layers, some or all of which may be removed before application of the claimed coating composition. Alternatively, the claimed coating composition could be painted over the existing coating layer(s).Thus, the invention also relates to a method for repairing and / or replacing or partially replacing an existing coating layer on a wind turbine blade. In one embodiment, if the coating composition is painted over an existing coating layer(s), an adhesion promoter may be applied over the existing coating layer prior to application of the coating composition of the invention, to improve the adhesion of the coating composition. In another embodiment, no adhesion promoter is applied. Adhesion promoters and their uses are known in the art. Petition 870250121402, dated 12 / 30 / 2025, pp. 101 / 142 23 / 58

[066] The preferred characteristics of the claimed coating compositions (both finishing and LEP compositions) are – in addition to a high degree of flexibility – film cohesion (as a result of crosslinking density), UV resistance, gloss retention and adhesion to underlying coatings. Furthermore, preferably, the coating composition, in particular the LEP composition, provides a coating that provides good protection against erosion caused by adverse weather conditions. MODALITIES OF THE INVENTION

[067] Next, embodiments of the invention are disclosed. The first embodiment is designated E1, the second embodiment is designated E2, and so on.

[068] It should be understood that the various aspects, embodiments, implementations and features of the invention mentioned herein may be claimed separately or in any combination.

[069] E1. Use of a coating composition comprising: a) a basic composition comprising a polyeteraspartic ester having the formula (I) below: wherein each R represents a linear or branched C1-C10 alkyl residue, such as a linear or branched C1-C6 alkyl residue, preferably a methyl, ethyl, propyl or butyl residue; and where X is a Petition 870250121402, dated 12 / 30 / 2025, pp. 102 / 142 24 / 58 polyether; and b) a healing agent; for coating a wind turbine blade. [0 70] E2. Use according to embodiment 1, provided that said coating composition is not: a coating composition comprising: (a) an isocyanate-reactive component comprising: (a1) at least one polyaspartic ester and (a2) optionally a polyeteraspartic ester; (b) an isocyanate component comprising: (b1) at least one isocyanate prepolymer, the isocyanate prepolymer being a reaction product of components comprising at least one aliphatic isocyanate and at least one polyether polyol, the polyether polyol having a weight average molecular weight of 400 to 6000 and a structure of formula I: ho-rVr2l, where R1 has one or more of the following structures: II, III and IV, R2 is one or more of the following: hydrogen and an inert organic group to an isocyanate group, n is an integer from 6 to 100, the amount of the -R1n- structure is at least 40% by weight based on Petition 870250121402, dated 12 / 30 / 2025, pages 103 / 142 25 / 58 in weight of polyether polyol; and (b2) at least one isocyanate oligomer containing not less than two isocyanate groups, the weight ratio of the isocyanate prepolymer (bl) to the isocyanate oligomer (b2) being greater than 1:4 and less than 4:1; (c) a catalyst; and (d) optionally an additive; where the molar ratio of isocyanate groups to isocyanate-reactive groups in the coating composition is 1.5:1 to 4:1.

[071] E3. The use according to any of embodiments 1 to 2, wherein X is a polyether in which the repeating unit contains an alkyl residue of one or more carbon atoms linked by an oxygen atom, such as an alkyl residue of two to six carbon atoms linked by an oxygen atom, such as an alkyl residue of two carbon atoms linked by an oxygen atom; wherein one or more of said carbon atoms may be replaced by a small alkyl group such as, for example, methyl, ethyl or propyl.

[072] E4. The use according to any of the modalities 1 to 3, in which X has a repeating unit of the structure below: where m is in the range of 2 to 35, as well as in the range of 2 to 10, as well as in the range of 2 to 6, as well as in the range of 2 to 4. Petition 870250121402, dated 12 / 30 / 2025, pp. 104 / 142 26 / 58

[073] E5. The use according to any of embodiments 1 to 4, wherein said base composition comprises a mixture of polyeteraspartic esters having formula (I) comprising at least two polyeteraspartic esters wherein X has a repeating unit of the structure below: CH3em where the mixture is such that the average value of m is in the range of 2 to 35, such as in the range of 2 to 10, such as in the range of 2 to 6, such as in the range of 2 to 4, such as in the range of 2.5 to 3.

[074] E6. Use in accordance with any of the modalities 1 to 5, where each R in formula (I) represents an ethyl residue.

[075] E7. The use according to any of embodiments 1 to 4, wherein said polyetherespartic ester is the reaction product of a dialkylmaleate, preferably a linear or branched C1-C10 dialkyl maleate, such as a linear or branched C1-C6 dialkyl maleate, such as diethyl maleate; and of a polyether polyamine according to formula (II) below: (lI) where p is in the range of 2 to 35, as in the range of 2 to 10, as in the range of 2 to 6, as in the range of 2 to 4.

[076] E8. The use in accordance with any of embodiments 1 to 5, wherein the said basic composition comprises a mixture of esters Petition 870250121402, dated 12 / 30 / 2025, pp. 105 / 142 27 / 58 polyetheraspartic compounds comprising at least two polyetheraspartic esters which are each the reaction product of a dialkyl maleate, preferably a linear or branched C1-C10 dialkyl maleate, such as a linear or branched C1-C6 dialkyl maleate, such as diethyl maleate; and of at least two polyether polyamines according to formula (1I) below: (lI) where the average value of p is in the range of 2 to 35, as is in the range of 2 to 10, as is in the range of 2 to 6, as is in the range of 2 to 4, as is in the range of 2.5 to 3.

[077] E9. The use in accordance with any of embodiments 7 to 8, wherein said dialkylmaleate is diethylmaleate.

[078] E10. Use in accordance with any of embodiments 1 to 9, wherein said curing agent b) comprises one or more polyisocyanates.

[079] E11. Use in accordance with any of the embodiments 1 to 2, wherein said coating composition comprises: a) a basic composition comprising a polyeteraspartic ester having the formula below: where X has a repeating unit of the structure below: Petition 870250121402, dated 12 / 30 / 2025, pp. 106 / 142 28 / 58 where m is in the range of 2 to 35, as is the range of 2 to 10, as is the range of 2 to 6, as is the range of 2 to 4; b) a curing agent comprising one or more polyisocyanates.

[080] E12. Use in accordance with either of the modalities 1 or 11, wherein the said coating composition comprises: a) a base composition comprising a polyeteraspartic ester mixture having the formula below: where X has a repeating unit of the structure below: wherein the mixture is such that the average value of m is in the range of 2 to 35, such as in the range of 2 to 10, such as in the range of 2 to 6, such as in the range of 2 to 4, such as in the range of 2.5 to 3; and b) a curing agent comprising one or more polyisocyanates.

[081] E13. Use in accordance with any of the modalities 10 to Petition 870250121402, dated 12 / 30 / 2025, pp. 107 / 142 29 / 58 12, wherein one or more of said polyisocyanates is based on hexamethylene diisocyanate (HDI).

[082] E14. Use in accordance with any of embodiments 10 to 12, wherein one or more of said polyisocyanates is based on a hexamethylenediisocyanate (HDI) trimer.

[083] E15. Use according to any of embodiments 10 to 14, wherein said one or more polyisocyanates contain less than 0.5% isocyanate monomer, preferably less than 0.3% isocyanate monomer such as less than 0.1% isocyanate monomer; in accordance with DIN EN ISO 10 283.

[084] E16. Use in accordance with any of embodiments 10 to 15, wherein the average functionality of said one or more polyisocyanates is in the range of 2-4, such as in the range of 3-4 or 2-3, such as in the range of 2-2.5.

[085] E17. Use according to any of embodiments 10 to 16, wherein a) and b) are present in said coating composition in an amount such that the stoichiometric ratio of the number of isocyanate groups in the curing agent component to the number of amine groups in the base component is in the range of 80:100 to 160:100, such as 90:100 to 125:100, such as 95:100 to 120:100, preferably in the range of 100:100 to 120:100, such as 100:100 to 110:100 or 105:100 to 110:100; such as about 100:100.

[086] E18. Use in accordance with any of the modalities 1 to 17, in which the said coating composition further comprises: c) one or more additional components selected from filler materials, pigments, solvents and additives.

[087] E19. The use according to embodiment 18, in which the said one or more additional components comprise one or more components Petition 870250121402, dated 12 / 30 / 2025, pp. 108 / 142 30 / 58 selected from the group consisting of calcium carbonate, dolomite, talc, mica, barium sulfate, kaolin, silica, titanium dioxide, red iron oxide, yellow iron oxide, black iron oxide, carbon black, phthalocyanine blue and phthalocyanine green.

[088] E20. Use in accordance with any of embodiments 18 to 19, wherein the total quantity of filler material(s) and pigment(s) is between 5-30%, as well as between 10-25% by weight of the coating composition.

[089] E21. The use according to any of the embodiments 1 to 20, wherein said coating composition has a viscosity in the range of 150-5000 mPa.s, such as 250-3000 mPa.s, preferably in the range of 500-2500 mPa.s, such as 500-2000 mPa.s, such as about 1500 mPa.s.

[090] E22. Use in accordance with any of embodiments 1 to 21, wherein said coating composition is cured at a temperature below 90°C, such as below 70°C, such as at a temperature in the range of 0-45°C, such as in the range of 15-35°C.

[091] E23. The use according to any of the embodiments 1 to 22, wherein said base composition a) comprises less than 20%, such as less than 15%, such as less than 10%, such as less than 5%, such as less than 1% of any aliphatic polyaspartic esters by weight of said base composition.

[092] E24. The use according to any of embodiments 1 to 22, wherein said base composition a) optionally further comprises one or more aliphatic polyaspartic esters, wherein the mixing ratio of polyaspartic ester to aliphatic polyaspartic esters is in the range of 70:30 to 99:1, preferably in the range of 80:20 to 99:1, as well as in the range of 85:15 to 99:1, more preferably in the range of 90:10 to 99:1 as well as 95:5 to 99:1. Petition 870250121402, dated 12 / 30 / 2025, pp. 109 / 142 31 / 58

[093] E25. Use in accordance with any of embodiments 1 to 22, wherein said coating composition is substantially free of any aliphatic polyaspartic esters.

[094] E26. Use according to any of embodiments 1 to 22, wherein said base composition (a) optionally further comprises one or more aliphatic polyaspartic esters, wherein the mixing ratio of polyaspartic ester to aliphatic polyaspartic esters is in the range of 70:30 to 99:1, preferably in the range of 80:20 to 99:1, as well as in the range of 85:15 to 99:1, more preferably in the range of 90:10 to 99:1 as well as 95:5 to 99:1; or wherein said coating composition is substantially free of any aliphatic polyaspartic esters.

[095] E27. Use in accordance with any of embodiments 1 to 26, wherein said coating composition comprises one or more solvents, wherein the total amount of solvent constitutes less than 25% by weight, such as less than 15% by weight, such as less than 10% by weight, such as less than 5% by weight, such as less than 2.5% by weight of the coating composition.

[096] E28. Use in accordance with any of embodiments 1 to 26, wherein said coating composition is substantially free of any solvents.

[097] E29. Use according to any of embodiments 10 to 28, wherein said one or more polyisocyanates have an isocyanate content of 5-25%, such as 5-20%, such as 5-15%, preferably 6-14%, such as 6-11% or 8-14% or 10-12%; or such as about 6% or about 7% or about 8% or about 9% or about 10% or about 11%. Petition 870250121402, dated 12 / 30 / 2025, pp. 110 / 142 32 / 58

[098] E30. Use in accordance with any of embodiments 10 to 29, wherein said one or more polyisocyanates each contain aliphatic polyester groups.

[099] E31. Use in accordance with any of embodiments 1 to 19 and 29 to 30, wherein the total quantity of filler material(s) and pigment(s) is between 20-40%, as well as between 25-30% by weight of the coating composition.

[0100] E32. Use in accordance with any of embodiments 1 to 19 and 29 to 31, wherein said coating composition has a viscosity in the range of 50-1000 mPa.s, as well as in the range of 50-500 mPa.s.

[0101] E33. Use in accordance with any of embodiments 1 to 19 and 29 to 32, wherein said coating composition is cured at a temperature below 50°C, such as below 30°C, such as a temperature in the range of -10-30°C.

[0102] E34. The use according to any of embodiments 1 to 19 and 29 to 33, wherein said base composition a) further comprises one or more aliphatic polyaspartic esters, wherein the mixing ratio of polyaspartic ester to aliphatic polyaspartic esters is in the range of 40:60 to 60:40, as well as in the range of 45:55 to 55:45, as well as approximately 50:50.

[0103] E35. Use in accordance with any of embodiments 1 to 19 and 29 to 34, wherein said coating composition comprises one or more solvents, wherein the total amount of solvent constitutes an amount in the range of 10-30% by weight of the coating composition, such as in the range of 15-25% such as about 20% by weight of said coating composition.

[0104] E36. Use in accordance with any of the modalities 1 to 19 Petition 870250121402, dated 12 / 30 / 2025, pp. 111 / 142 33 / 58 and 29 to 35 wherein said curing agent further comprises a polyisocyanate, as defined in any of embodiments 13 to 16, and having an isocyanate content of between 20-26% w / w, such as between 15-30% w / w, such as between 22-24% w / w, such as about 23% w / w.

[0105] E37. The use in accordance with any of embodiments 1 to 30, wherein said composition is for use as a protective tip coating for said wind turbine blade.

[0106] E38. Use in accordance with any of embodiments 1 to 30, wherein said coating composition is applied at least to the tip of said wind turbine blade.

[0107] E39. Use in accordance with any of embodiments 1 to 30, wherein said coating composition is applied to the tip of said wind turbine blade.

[0108] E40. The use in accordance with any of embodiments 1 to 19 and 29 to 36; wherein said coating is for use as a finish for said wind turbine blade.

[0109] E41. A wind turbine blade having, on at least part of its outer surface, a coating prepared from a coating composition, as defined in any of embodiments 1 to 36.

[0110] E42. A wind turbine blade according to embodiment 41 having at least at the tip of said wind turbine blade a coating prepared from a coating composition, as defined in any of embodiments 1 to 36.

[0111] E43. A wind turbine blade according to any of the embodiments 41 to 42 having a coating on the tip of said wind turbine blade. Petition 870250121402, dated 12 / 30 / 2025, pp. 112 / 142 34 / 58 prepared from a coating composition, as defined in any of embodiments 1 to 30.

[0112] E44. A wind turbine blade according to any of the embodiments 41 to 43, wherein said coating constitutes the outermost coating layer.

[0113] E45. A wind turbine blade according to any of embodiments 43 to 44, wherein said coating is a protective tip coating.

[0114] E46. A wind turbine blade according to any of embodiments 43 to 45, wherein said coating is a protective end coating and wherein said coating has been applied on top of a finish or wherein said coating has been applied under a finish, preferably on top of a primer layer.

[0115] E47. The wind turbine blade according to the embodiment having a first coating layer which is a finish prepared from a coating composition, as defined in any of embodiments 1 to 19 and 29 to 36; and on top of said first coating layer having a second coating which is an LEP coating prepared from a coating composition, as defined in any of embodiments 1 to 30, applied over the first coating layer on at least part of the outer surface of said wind turbine blade such as on the tip of said wind turbine blade.

[0116] E48. A wind turbine blade according to embodiment 41 having a first coating layer which is an LEP coating prepared from a coating composition, as defined in any of the Petition 870250121402, dated 12 / 30 / 2025, pp. 113 / 142 35 / 58 embodiments 1 to 30, applied to at least part of the surface of said wind turbine blade such as on the tip of said wind turbine blade; and on top of said first coating layer having a second coating which is a finish prepared from a coating composition, as defined in any of embodiments 1 to 19 and 29 to 36, applied to the outer surface of said wind turbine blade and over the first coating layer of said wind turbine blade.

[0117] E49.A wind turbine blade according to any of the embodiments 41 to 44, wherein said wind turbine blade has a primer layer applied under the finish and / or protective tip coating layer.

[0118] E50. A parts kit comprising: i) a container comprising a) a base composition comprising a polyeteraspartic ester having the formula (I) below: (i) where each R represents a linear or branched C1-C10 alkyl residue, such as a linear or branched C1-C6 alkyl residue, preferably a methyl, ethyl, propyl or butyl residue; and where X is a polyether; and ii) a container comprising b) a curing agent.

[0119] E51. The kit according to modality 50, where X is a polyether Petition 870250121402, dated 12 / 30 / 2025, pp. 114 / 142 36 / 58 wherein the repeating unit contains an alkyl residue of one or more carbon atoms linked by an oxygen atom, such as an alkyl residue of two to six carbon atoms linked by an oxygen atom, such as an alkyl residue of two carbon atoms linked by an oxygen atom; wherein one or more of said carbon atoms may be replaced by a small alkyl group such as, for example, methyl, ethyl or propyl.

[0120] E52. The kit according to any of the modalities 50 to 51, where X has a repeating unit of the structure below: where m is in the range of 2 to 35, as well as in the range of 2 to 10, as well as in the range of 2 to 6, as well as in the range of 2 to 4.

[0121] E53. The kit according to any one of 50 to 52, wherein said base composition comprises a mixture of polyetherespartic esters having formula (1) comprising at least two polyetherespartic esters wherein X has a repeating unit of the structure below: - Jmem that the mixture is such that the average value of m is in the range of 2 to 35, as in the range of 2 to 10, as in the range of 2 to 6, as in the range of 2 to 4, as in the range of 2.5 to 3.

[0122] E54. The kit according to any of the modalities 50 to 53, Petition 870250121402, dated 12 / 30 / 2025, pp. 115 / 142 37 / 58 where each R in formula (I) represents an ethyl residue.

[0123] E55. The kit according to any one of embodiments 50 to 54, wherein said polyetherespartic ester is the reaction product of a dialkylmaleate, preferably a linear or branched C1-C6 dialkyl maleate, such as diethyl maleate; and of a polyether polyamine according to formula (1I) below: (lI) where p is in the range of 2 to 35, as in the range of 2 to 10, as in the range of 2 to 6, as in the range of 2 to 4.

[0124] E56. The kit according to any one of embodiments 50 to 54, wherein said base composition comprises a mixture of polyetheraspartic esters comprising at least two polyetheraspartic esters which are each the reaction product of a dialkylmaleate, preferably a linear or branched C1-C10 dialkyl maleate, such as a linear or branched C1-C6 dialkyl maleate, such as diethyl maleate; and of at least two polyether polyamines according to formula (II) below: (lI) where the average value of p is in the range of 2 to 35, such as in the range of 2 to 10, such as in the range of 2 to 6, such as in the range of 2 to 4, such as in the range of 2.5 to 3.

[0125] E57. The coating kit or composition according to Petition 870250121402, dated 12 / 30 / 2025, pp. 116 / 142 38 / 58 any of the embodiments 55 to 56, in which said dialkylmaleate is diethylmaleate.

[0126] E58. The kit according to any of the embodiments 50 to 57, wherein the said curing agent comprises one or more polyisocyanates.

[0127] E59. The kit according to modality 50, in which said kit comprises: i) a container comprising a) a basic composition comprising a polyeteraspartic ester having the formula below: where X has a repeating unit of the structure below: where m is in the range of 2 to 35, as in the range of 2 to 10, as in the range of 2 to 6, as in the range of 2 to 4; and ii) a container comprising b) a curing agent comprising one or more polyisocyanates.

[0128] E60. The kit according to any of the 50 or modalities Petition 870250121402, dated 12 / 30 / 2025, pp. 117 / 142 39 / 58 59, in which the said kit comprises: i) a container comprising a) a base composition comprising a polyetheraspartic ester mixture having the formula below: where X has a repeating unit of the structure below: wherein the mixture is such that the average value of m is in the range of 2 to 35, such as in the range of 2 to 10, such as in the range of 2 to 6, such as in the range of 2 to 4, such as in the range of 2.5 to 3; and ii) a container comprising b) a curing agent comprising one or more polyisocyanates.

[0129] E61. The kit according to any of embodiments 58 to 60, wherein one or more of said polyisocyanates is based on hexamethylenediisocyanate (HDI).

[0130] E62. The kit according to any of embodiments 58 to 61, wherein one or more of said polyisocyanates is based on a hexamethylenediisocyanate (HDI) trimer.

[0131] E63. The kit according to any of the modalities 55 to 62, Petition 870250121402, dated 12 / 30 / 2025, pages 118 / 142 40 / 58 wherein said one or more polyisocyanates contain less than 0.5% isocyanate monomer, preferably less than 0.3% isocyanate monomer, such as less than 0.1% isocyanate monomer; in accordance with DIN EN ISO 10 283.

[0132] E64. The kit according to any of the embodiments 58 to 63, in which the average functionality of said one or more polyisocyanates is in the range of 2-4, as well as in the range of 3-4 or 2-3, as well as in the range of 2-2.5.

[0133] E65. The kit according to any of embodiments 58 to 64, wherein said one or more polyisocyanates have an isocyanate content of 5-20%, such as 5-15%, preferably 6-14%, such as 6-11% or 8-14% or 10-12%; or such as about 6% or about 7% or about 8% or about 9% or about 10% or about 11%.

[0134] E66. The kit according to any of embodiments 58 to 65, wherein said one or more polyisocyanates each contain aliphatic polyester groups.

[0135] E67. The kit according to any of embodiments 50 to 67, wherein said base composition a) in container i) optionally further comprises one or more aliphatic polyaspartic esters, wherein the mixing ratio of polyaspartic ester to aliphatic polyaspartic esters is in the range of 70:30 to 99:1, such as in the range of 80:20 to 99:1, such as in the range of 85:15 to 99:1, more preferably in the range of 90:10 to 99:1 such as 95:5 to 99:1, or wherein said base composition a) in container i) is substantially free of any polyaspartic esters.

[0136] E68. The kit according to any of the embodiments 50 to 66, in which the said base composition in the container i) comprises less than 20%, Petition 870250121402, dated 12 / 30 / 2025, pp. 119 / 142 41 / 58 such as less than 15%, such as less than 10%, such as less than 5%, such as less than 1% of any aliphatic polyaspartic esters by weight of said base composition.

[0137] E69. The kit according to any of embodiments 50 to 67, wherein said base composition in the container i) comprises less than 20%, such as less than 15%, such as less than 10%, such as less than 5%, such as less than 1% of any acrylate-containing compound by weight of said base composition.

[0138] E70. The kit according to any of embodiments 50 to 69, wherein said base composition in the container i) comprises less than 20%, such as less than 15%, such as less than 10%, such as less than 5%, such as less than 1% of any silane-containing compounds by weight of the coating composition.

[0139] E71. The kit according to any of the modalities 50 to 70, where: the total amount of solvent in said base composition in the container i) constitutes less than 25% by weight, such as less than 15% by weight, such as less than 10% by weight, such as less than 5% by weight, such as less than 2.5% by weight of said base composition, or said base composition is substantially free of any solvents; and / or the total amount of solvent in said curing agent in the container i) constitutes less than 25% by weight, such as less than 15% by weight, such as less than 10% by weight, such as less than 5% by weight, such as less than 2.5% by weight of said curing agent, or said curing agent is substantially free of any solvents. Petition 870250121402, dated 12 / 30 / 2025, pp. 120 / 142 42 / 58

[0140] E72. The kit according to any of embodiments 50 to 66, wherein said base composition in container i) further comprises one or more aliphatic polyaspartic esters, wherein the mixing ratio of polyaspartic ester to aliphatic polyaspartic esters is in the range of 40:60 to 60:40, as well as in the range of 45:55 to 55:45, as well as approximately 50:50.

[0141] E73. The kit according to any of embodiments 50 to 72, wherein the said base composition a) in container i) and / or the said curing agent b) in container ii) further comprises one or more additional components selected from fillers, pigments, solvents and additives.

[0142] E74. The kit according to embodiment 73, wherein said one or more additional components comprise one or more components selected from the group consisting of calcium carbonate, dolomite, talc, mica, barium sulfate, kaolin, silica, titanium dioxide, red iron oxide, yellow iron oxide, black iron oxide, carbon black, phthalocyanine blue and phthalocyanine green.

[0143] E75. The kit according to any of the modalities 50 to 74, further comprising instructions for the use of said base composition and said curing agent.

[0144] E76. A method for coating a wind turbine blade comprising a step of applying a coating composition, as defined in any of embodiments 1 to 36, to at least a part of the wind turbine blade, such as to the tip of the wind turbine blade.

[0145] E77. The method according to embodiment 76, in which said wind turbine blade was pre-coated with a primer layer before the application of the coating composition, as defined in any of the embodiments Petition 870250121402, dated 12 / 30 / 2025, pp. 121 / 142 43 / 58 to 36.

[0146] E78. A method for coating a wind turbine blade comprising the steps: i) application of a coating composition, as defined in any of embodiments 1 to 19 and 29 to 36, to at least part of the wind turbine blade and allowing the composition to cure; followed by: ii) applying a coating composition, as defined in any of embodiments 1 to 30, to at least part of the wind turbine blade, such as at least the tip of a wind turbine blade, and allowing the composition to cure.

[0147] E79. A method for coating a wind turbine blade comprising the steps: (i) applying a coating composition, as defined in any of embodiments 1 to 30, to at least part of the wind turbine blade, such as at least the tip of a wind turbine blade, and allowing the composition to cure. ii) applying a coating composition, as defined in any of embodiments 1 to 19 and 29 to 36, to at least part of the wind turbine blade and allowing the composition to cure.

[0148] E80. The method according to any of the embodiments 78 to 79, wherein the said wind turbine blade was pre-coated with a primer layer before step i).

[0149] E81. A method for repairing a wind turbine blade comprising a step of applying the coating composition, as defined in any of embodiments 1-36, to at least a part of the wind turbine blade such as the tip of the wind turbine blade.

[0150] E82. A method for repairing and / or replacing or partially replacing an existing coating layer on a wind turbine blade. Petition 870250121402, dated 12 / 30 / 2025, pp. 122 / 142 44 / 58 comprising a step of applying the coating composition, as defined in any of embodiments 1 to 36, to at least a part of the wind turbine blade such as the tip of the wind turbine blade.

[0151] E83. The method according to any of the embodiments 81 to 82, in which the said wind turbine blade has one or more existing coating pre-layers; wherein said one or more existing coating layers are painted over said coating composition, or wherein said one or more existing coating pre-layers are at least partially removed before the application of said coating composition, or wherein said one or more existing coating pre-layers are completely removed before the application of said coating composition.

[0152] E84. The method according to any of the embodiments 81 to 83, wherein the said wind turbine blade has an existing pre-coating layer which is a Tip Protection coating layer; wherein said tip protection coating layer is painted over said coating composition, or wherein said tip protection coating layer is at least partially removed before application of said coating composition, or wherein said tip protection coating layer is completely removed before application of said coating composition.

[0153] E85. The method according to any of the modalities 74 Petition 870250121402, dated 12 / 30 / 2025, pp. 123 / 142 45 / 58 to 84, where the said coating composition is applied by brush or roller or by spray application, such as by airless spray application on the said wind turbine blade.

[0154] All references, including publications, patent applications and patents cited herein, are incorporated herein by reference in their entirety and in the same manner as if each reference were individually and specifically indicated as being incorporated by reference and were presented in their entirety herein (to the maximum extent permitted by law), independent of any separately provided incorporation of particular documents made elsewhere herein.

[0155] The use of the terms a and an and the / the referring similarly in the context of the invention description should be interpreted as covering both the singular and the plural, unless otherwise indicated herein or clearly contradicted by the context. For example, the phrase the composition should be understood as referring to several compositions of the invention or particular aspect described, unless otherwise indicated.

[0156] The description herein of any aspect or aspect of the invention using terms such as comprising, having, including or containing with reference to an element or elements is intended to provide support for a similar aspect or aspect of the invention that consists of, consists essentially of, or substantially comprises that particular element or elements, unless otherwise indicated or clearly contradicted by the context (for example, a composition described herein as comprising a particular element should also be understood as describing a composition that consists of that element, unless otherwise indicated or clearly contradicted by the context). Petition 870250121402, dated 12 / 30 / 2025, pp. 124 / 142 46 / 58

[0157] The use of any and all examples or exemplary language (including, for example, e.g., and such as) in this descriptive report is intended merely to better clarify the invention and does not represent a limitation on the scope of the invention unless otherwise indicated.

[0158] Titles and subtitles are used herein for convenience only and should not be construed as limiting the invention in any way. The use of any and all examples or exemplary language (including for example, e.g., and such as) in this descriptive report is intended merely to better clarify the invention and does not represent a limitation on the scope of the invention unless otherwise indicated. The citation and incorporation of patent documents herein are for convenience only and do not reflect any perspective on the validity, patentability and / or enforceability of such patent documents.

[0159] It should be understood that the various aspects, embodiments, implementations and features of the invention mentioned herein may be claimed separately or in any combination. EXPERIMENTAL

[0160] The invention will be illustrated by the following non-limiting examples. RAIN EROSION TEST

[0161] The Rain Erosion Test (RET) is widely accepted as the most suitable test for evaluating the anti-erosion properties of coatings on the tips of wind turbine blades. The idea is to simulate the erosive effect of collision with raindrops, dust particles, hail and the like by creating a controlled rain field in which the coated surface moves at high speed. Petition 870250121402, dated 12 / 30 / 2025, pp. 125 / 142 47 / 58

[0162] The Rain Erosion Test (RET) was performed using a rotating arm test rig that was designed for the purpose by R&D A / S. The test was performed in accordance with DNVGL-RP-0171 Recommended Practice, Rotor Blade Erosion Protection System Testing.

[0163] Erosion damage was reproduced on specimens mounted on an arm that rotates horizontally through an artificial rain field. Rain impacts the surface of the test specimen and causes erosion of the surface, which is protected by the coating being tested. The degree of erosion damage caused by the droplet impacts was inspected and documented. This was done by visual inspection and image documentation at defined intervals. Detailed image documentation allows investigation of initial damage at the end of the incubation period, as well as the progression of damage. The time required to cause erosion on the surface to a specified limit was the measure used to compare the performance of the protection systems relative to each other. There are two stages of erosion that are commonly used to specify the survival time of specimens: 1. End of Incubation Period: The incubation period is defined as the exposure time until the first damage is visually detectable on the outer surface of the test specimen. The incubation period depends on the speed of impact and, therefore, for rotating arm testing equipment, on the position on the specimen. 2. Rupture to the underlying substrate: Rupture is defined as the point in time when erosion breaks through the protective layer to the underlying substrate. The moment of rupture depends on the speed of impact and thus, Petition 870250121402, dated 12 / 30 / 2025, pages 126 / 142 48 / 58 for rotary arm testing equipment, it also depends on the location on the specimen.

[0164] U-shaped test specimens 45 cm long based on the geometry of the NACA 634-021 airfoil simulating the tip of a wind turbine blade (as described in Appendix A.1, DNVGL-RP0171), consisting of a composite substrate, were coated with 200-600 µm (dry film thickness) of the coating compositions to be tested. The coating compositions were cured under controlled laboratory conditions, typically 25°C and 50% RH, for at least 7 days to ensure complete curing of the binder system.

[0165] Three test specimens were then mounted on the horizontal rotor arms, with a radial position of 1 m to the center of the specimen. The rotor was rotated at a controlled radial speed resulting in a range of speeds of the test subject.

[0166] Tables 1a and 1b below indicate the test condition parameters specified and / or monitored during each test. TABLE 1A. RAINFALL EROSION TEST CONDITIONS FOR EXPERIMENTS IN TABLE 4A AND TABLE 5 Test Parameter Unit Nominal Condition Velocity (tip center - root) m / s 155 - 130 -105 Rainfall mm / h 29-33 Water Temperature °C 8 Water Quality pS <5 Test Chamber Temperature °C 8-10 Average Droplet Size, Diameter, d mm 2.2 TABLE 1B. RAINFALL EROSION TEST CONDITIONS FOR Petition 870250121402, dated 12 / 30 / 2025, pages 127 / 142 49 / 58 EXPERIMENTS IN TABLE 4B AND TABLE 6 Test Parameter Unit Nominal Condition Velocity (tip center - root) m / s 140 - 115 - 95 Rainfall mm / h 29-33 Water Temperature °C 8 Water Quality pS <5 Test Chamber Temperature °C 8-10 Average Droplet Size, Diameter, d mm 2.2 GENERAL PROCEDURE FOR THE PREPARATION OF COATING COMPOSITIONS

[0167] The components of each of the base composition a) and the curing agent b) were produced by mixing the ingredients indicated for each of a) and b) in a conventional manner known to a person skilled in the art.

[0168] Component a) was then subsequently mixed with Component b) before application.

[0169] The mixed coating composition was applied to composite test specimens, which were prepared for painting in advance, by brush application. The Examples below illustrate six coating compositions within the scope of the invention and a comparative coating composition in which polyether aspartic ester has been replaced by an aliphatic aspartic ester.

[0170] The LEP coating compositions in Table 4a and 5 were applied directly to the test specimens prepared for painting, while the LEP coating compositions in Table 4b were applied to test specimens prepared for painting that were coated with a finish. Petition 870250121402, dated 12 / 30 / 2025, pages 128 / 142 50 / 58

[0171] Tables 2 and 3 below indicate the identity of the aspartic ester and polyisocyanates used in the examples. TABLE 2: ASPARTIC ESTERS USED IN THE EXAMPLES (AVAILABLE FROM COVESTRO DEUTSCHLAND AG, LEVERKUSEN, GERMANY). Aspartic Acid Description Amine Value (mg KOH / g) Aliphatic Polyaspartic Ester 1: Desmophen NH 1420 Aminofunctional co-reagent for polyisocyanates 199 - 203 Aliphatic Polyaspartic Ester 2: Desmophen NH 1423 Aminofunctional co-reagent for polyisocyanates 202-208 Polyetheraspartic Ester: Desmophen NH 2850 XP Aminofunctional co-reagent for polyisocyanates 170 - 210 TABLE 3: POLYISOCYANATES USED IN THE EXAMPLES (AVAILABLE FROM COVESTRO DEUTSCHLAND AG, LEVERKUSEN, GERMANY).___________________________________________________ Composition Polyisocyanate Description Isocyanate content (%) Functionality (n) Viscosity (mPa*s) LEP Polyisocyanate 1 Desmodur E 2863 XP Polyester-modified polyisocyanate prepolymer based on hexamethylene-1,6-diisocyanate (HDI) 11.0 2.2 1350 LEP Polyisocyanate 2: Desmodur N 3800 Aliphatic polyisocyanate, HDI trimer flexibilizer. 11.0 3.8 6000 Petition 870250121402, dated 12 / 30 / 2025, pages 129 / 142 51 / 58 LEP Polyisocyanate 3: Desmodur XP 2860 Aliphatic polyisocyanate based on hexamethylene diisocyanate 20.0 2.5 500 LEP Polyisocyanate 4: Desmodur XP 2599 Aliphatic prepolymer containing ether groups and based on hexamethylene -1,6-diisocyanate (HDI) 6.0 4.0 2500 Polyisocyanate Finish 5: Desmodur XP 3900 Aliphatic polyisocyanate resin based on hexamethylene diisocyanate 23.5 3.2 730

[0172] Tables 4 and 5 indicate compositions and RET results for coating compositions of the invention and for comparative coating compositions with an aliphatic polyaspartic ester totally or partially replacing the polyetheraspartic ester.

[0173] The quantities of each component indicated in the coating compositions in tables 4 and 5 are given as weight percentages of each total coating composition.

[0174] The RET results are shown in Table 4a as follows: End of incubation period: Petition 870250121402, dated 12 / 30 / 2025, pages 130 / 142 52 / 58 > 30 min: * > 60 min: ** > 120 min: *** Breakthrough to the underlying substrate: > 30 min: + > 60 min: ++ > 120 min: +++ TABLE 4A: LEP COATING COMPOSITIONS RET RESULTS, COMPARATIVE EXAMPLE LEP Coating Model 1 Comparative LEP Coating Composition Component a) Aspart ester Aliphatic polyaspart ester 1 33.8 Polyether aspart ester 34.9 Additives: Wetting and dispersing agent 0.2 0.2 Thixotropic additive 1.8 1.9 Antifoaming agent 0.3 0.3 Light stabilizer 0.8 0.8 Pigments and fillers: Pigments 5.1 5.3 Fillers 8.7 8.1 Component b) Polyisocyanate: Polyisocyanate 1 48.2 49.7 Stoichiometric ratio of isocyanate groups in b) to amine groups in a) 107:100 107:100 Rain Erosion Test (RET) End of incubation period ** * Breakdown for the +++ ++ Petition 870250121402, dated 12 / 30 / 2025, pp. 131 / 142 53 / 58 underlying substrate TABLE 4B: LEP E COATING COMPOSITIONS RESULTS OF RET, EXAMPLES WITH INCREASING QUANTITIES OF ALIPHATIC POLYASPARTIC ESTER. Component Coating A Coating B Coating C Coating D Coating E Coating F Component a) Aspartic ester: Aliphatic polyaspartic ester 0.0 6.3 12.5 18.7 24.9 31.0 Polyether aspartic ester 31.7 24.4 18.2 12.1 6.0 0.0 Additives: Wetting and dispersing agents 0.1 0.1 0.1 0.1 0.1 0.1 Thixotropic additive 0.7 0.6 0.5 0.4 0.3 0.2 Antifoaming agent 0.3 0.3 0.3 0.3 0.3 0.3 Leveling agent 1.0 1.0 1.0 1.0 1.0 1.0 Light stabilizer 0.6 0.6 0.6 0.6 0.6 0.6 Pigments and fillers: Pigments 9.1 9.0 9.0 9.0 9.0 8.9 Fillers 11.9 13.6 13.8 14.0 14.1 14.3 Component b) Polyisocyanate: Polyisocyanate 1 44.6 44.1 44.0 43.8 43.7 43.6 Stoichiometric ratio of isocyanate groups in b) to amine groups in a) 111:100 109:100 107:100 105:100 103:100 101:100 Rain Erosion Test (RET) End of incubation period > 9h > 6h > 4h > 3h > 2h > 2h Breakdown to underlying substrate > 12h > 7h > 6h > 6h > 6h > 4h Petition 870250121402, dated 12 / 30 / 2025, pages 132 / 142 54 / 58 TABLE 5: LEP COATING COMPOSITIONS RESULTS OF RET, COATINGS MODEL OF THE INVENTION. Coating Model 2 Coating Model 3 Coating Model 4 Coating Model 5 Coating Model 6 Component a) Aspartic ester Polyether spartic ester 32.4 30.5 32.8 41.4 23.8 Additives: Wetting and dispersing agent 0.6 - 0.6 0.8 0.5 Thixotropic additive 2.2 2.2 2.2 2.8 1.6 Antifoaming agent 0.5 0.3 0.5 0.6 0.4 Light stabilizer 0.6 - 0.6 0.8 0.5 Pigments and fillers: Pigments 5.1 10.6 5.1 6.5 3.7 Fillers 12.9 12.3 11.3 14.3 8.2 Component b) Polyisocyanates Polyisocyanates 1 45.7 44.1 Polyisocyanates 2 46.7 Poly- 32.8 Petition 870250121402, dated 12 / 30 / 2025, pages 133 / 142 55 / 58 Isocyanate 3 Polyisocyanate 4 61.4 Stoichiometric ratio of isocyanate groups in b) to amine groups in a) 109:100 109:100 110:100 109:100 109:100 Rain Erosion Test (RET) End of incubation period *** *** ** * ** Breakthrough to the underlying substrate +++ +++ +++ + +++

[0175] The viscosities of the model LEP coating compositions are in the range of 800-2500 mPa.s. while the comparative LEP coating has a viscosity of about 5500 mPa.s. TABLE 6: COMPOSITION OF FINISHING COATING AND RESULTS OF RET, COATINGS MODEL OF THE INVENTION. Component a) Aspartic ester: Aliphatic polyaspartic ester 1 13.6 Polyetheraspartic ester 13.3 Additives: Leveling agent 0.4 Light stabilizer 0.5 Thixotropic agent 2.5 Smoothing agent 2.6 Wetting and dispersing agent 0.4 Solvents, pigments and fillers: Filler 16.5 Pigment 8.9 Solvent 23.0 Component b) Polyisocyanate Petition 870250121402, dated 12 / 30 / 2025, pages 134 / 142 56 / 58 Polyisocyanate 5 18.4 Stoichiometric ratio of isocyanate groups in b) to amine groups in a) 107:100 Rain Erosion Test (RET) End of incubation period > 2h Breakthrough to the underlying substrate > 3h

[0176] The formulation in Table 6 showed excellent properties for use as a finish on wind turbine blades. The finish provides a protective effect against rain erosion on its own, even without tip protection. In addition, the finish has very high abrasion resistance (60 mg, ASTM D4060, 23°C and 50% RH CS10, 1000 g, 1000 rotations), flexibility (< 8 mm φ cylindrical mandrel test at 23°C and 50% RH, ISO 1519), tensile strength (18% tensile strength at break) and resistance to accelerated weathering tests (ΔE < 1 after 3000 hours, ISO 16474-3, type 1A (UVA-340), method 1).

[0177] The finishing composition has a viscosity in the range of 80-150 mPa.s.

[0178] The characterization of various properties of coating compositions can be done, for example, by the following methods: VISCOSITY

[0179] The viscosity of the coating compositions was determined using a Cone and Plate viscometer according to ISO 2884-1:1999 using a Cone and Plate viscometer set at a temperature of 25°C and providing a viscosity measurement range of 0-5000 mPa.s. SOLIDS CONTENT

[0180] The solids content in coating compositions can be calculated according to ASTM D5201 or by determining the percentage volume of non-volatile matter, dry film density and spread rate of coating materials according to ISO 3233-1. Petition 870250121402, dated 12 / 30 / 2025, pages 135 / 142 57 / 58 CALCULATION OF VOLATILE ORGANIC COMPOUND CONTENT

[0181] The volatile organic compound (VOC) content of coating compositions can be calculated in accordance with ASTM D5201. CURVATURE TEST

[0182] A procedure in accordance with ISO 6860 or ISO 1519 may be followed. A wet film of 150-250 microns is applied to a polished and degreased steel panel 0.8 mm thick and, after curing, the coated metal panel is bent around a cylindrical mandrel and flexibility is assessed by observation of cracks. IMPACT

[0183] The impact can be tested according to ISO 6272-2, which specifies a method for evaluating the resistance of a dry film of paint, varnish or related product to cracking or peeling from a substrate when it is subjected to deformation caused by a dropped weight, lowered under standard conditions, acting on a small-area spherical indenter. TABER'S ABRASION

[0184] Taber abrasion is tested according to ASTM D 4060. A 1 kg weight is applied to the coated steel panel. A CS-10 abrasive wheel was used and 2 x 500 revolutions were used. The results are presented in terms of film loss in mg. DRYING TIME

[0185] Drying time can be evaluated using the Beck Koller method according to ISO 9117-4 which specifies a test for determining the times taken to reach various drying stages of organic coatings, using a mechanical time recorder. Petition 870250121402, dated 12 / 30 / 2025, pages 136 / 142 58 / 58 linear or circular drying. ARTIFICIAL WEATHERING

[0186] The resistance of coatings to UV degradation can be tested by artificial weathering according to ISO 16474-3, after Test Cycle 1. Test Cycle No. 1: 4 hours of UV light at 60°C with UVA340 lamps (UVA-340, 0.83 W / m2 irradiance at 340 nm) followed by 4 hours of condensation at 50°C for a total of 1000 to 3000 hours. GLASS TRANSITION TEMPERATURE

[0187] The glass transition temperature (Tg) of the binder and / or coating composition can be obtained by Differential Scanning Calorimetry (DSC) measurements and / or by DMA Glass Transition Temperature (Tg) of the cured paint films determined by Dynamic Mechanical Analyzer (DMA). TENSILE STRENGTH

[0188] The modulus of elasticity and other aspects of the tensile stress / strain relationship can be measured in accordance with ISO 527.

Claims

CLAIMS 1. Use of a coating composition CHARACTERIZED in that it comprises: a) a base composition comprising a polyetherespartic ester having the formula (I) below: (D wherein each R represents a linear or branched C1-C10 alkyl residue, such as a linear or branched C1-C6 alkyl residue, preferably a methyl, ethyl, propyl or butyl residue; and wherein X is a polyether; and b) a curing agent; c) one or more additional components selected from fillers and pigments; for coating wind turbine blades.

2. Use, according to claim 1, CHARACTERIZED in that said base composition a) optionally further comprises one or more aliphatic polyaspartic esters, wherein the mixing ratio of polyaspartic ester to aliphatic polyaspartic esters is in the range of 70:30 to 99:1, preferably in the range of 80:20 to 99:1, such as in the range of 85:15 to 99:1, more preferably in the range of 90:10 to 99:1 as well as 95:5 to 99:1; or Petition 870250121402, dated 12 / 30 / 2025, p. 71 / 142 2 / 3 wherein said coating composition is substantially free of any aliphatic polyaspartic esters.

3. Use, according to claim 1, CHARACTERIZED in that said base composition a) comprises less than 20%, such as less than 15%, such as less than 10%, such as less than 5%, such as less than 1% of any aliphatic polyaspartic esters by weight of said base composition.

4. Use, according to any one of claims 1 to 3, CHARACTERIZED in that X is a polyether in which the repeating unit contains an alkyl residue of one or more carbon atoms linked by an oxygen atom, such as an alkyl residue of between two and six carbon atoms linked by an oxygen atom, such as an alkyl residue of two carbon atoms linked by an oxygen atom; in which one or more of said carbon atoms may be substituted by a minor alkyl such as, for example, methyl, ethyl or propyl.

5. Use, according to any one of claims 1 to 4, CHARACTERIZED in that X has a repeating unit of the structure below: where m is in the range 2 to 35, such as in the range 2 to 10, such as in the range 2 to 6, such as in the range 2 to 4.

6. Use, according to any one of claims 1 to 5, CHARACTERIZED in that each R in formula (I) represents an ethyl residue.

7. Use, according to any of claims 1 to 6, Petition 870250121402, dated 12 / 30 / 2025, p. 72 / 142 3 / 3 CHARACTERIZED by the fact that said curing agent comprises one or more polyisocyanates.

8. Use, according to claim 7, CHARACTERIZED in that said one or more polyisocyanates in said coating composition have an isocyanate content of 5-20%, such as 5-15%, preferably 6-14%, such as 6-11% or 8-14% or 10-12%, such as about 11%, and / or in that the average functionality of said one or more polyisocyanates is in the range of 2-4, as well as in the range of 2-3, as well as in the range of 2-2.

5.

9. Use, according to claim 7 or 8, CHARACTERIZED in that said one or more polyisocyanates optionally each contain aliphatic polyester groups.

10. Use, according to any one of claims 1 to 9, CHARACTERIZED in that a) and b) are present in said coating composition in an amount such that the stoichiometric ratio of the number of isocyanate groups in the curing agent component to the number of amine groups in the base component is in the range of 80:100 to 160:100, such as 90:100 to 125:100, such as 95:100 to 120:100, preferably in the range of 100:100 to 120:100, such as 100:100 to 110:100 or 105:100 to 110:

100.

11. Use, according to any one of claims 1 to 10, CHARACTERIZED in that the total amount of filler(s) and pigment(s) is between 5-30%, such as between 10-25% by weight of the coating composition.

12. Use, according to any one of claims 1 to 11, CHARACTERIZED in that said use of the coating is for use as a protective tip coating of said wind turbine blade.