Waterborne high-solids epoxy coating composition

Abstract

A coating composition comprising components A and B, wherein component A comprises an epoxy-based binder, said epoxy-based binder comprising a solid epoxy-based binder, a liquid epoxy-based binder and less than 5 wt% water, relative to the total weight of component A. Component B comprises an amine-based curing agent and more than 5 wt% water relative to the total weight of component B. The compositions provide good corrosion protection.

Description

[0001] WATERBORNE HIGH-SOLIDS EPOXY COATING COMPOSITION TECHNICAL FIELD

[0002] The present invention lies in the field of epoxy coating compositions. It provides an epoxy coating composition comprising components A and B, wherein component A comprises an epoxy-based binder, said epoxy-based binder comprising a solid epoxy-based binder, a liquid epoxy-based binder and less than 5 wt% water, relative to the total weight of component A. Component B comprises an amine-based curing agent and more than 5 wt% water relative to the total weight of component B. The compositions provide good corrosion protection.

[0003] BACKGROUND

[0004] Epoxy coatings are used mainly as part of an anti-corrosive coating system on steel substrates due to outstanding corrosion and chemical resistance. Such coatings are designed to be used in aggressive corrosive environments like offshore platforms, windmill towers, steel chimneys, power stations, steel bridges, cranes etc. in costal, offshore, or industrial environments, but also tidal zone areas where saltwater resistance is required. Epoxy coating compositions are typically supplied as two-component products; a base component A normally comprising an epoxy-based binder and component B comprising a curing agent.

[0005] Epoxy coatings can be used as primers, i.e. first coating layer in a multiple coat system with subsequent layers of suitable generic types of coatings, or as an intermediate coat with subsequent suitable coats e.g. polyurethane or polyurea, or as a top-coat. However, epoxy paints can also be used as one-coat systems.

[0006] The content of Volatile Organic Compounds (VOC) is an important parameter for the epoxy coating. It is of interest to reduce the VOC of a coating system as low as possible for environmental reasons. Waterborne (WB) epoxy coating compositions offer a route to lower VOC; however they are generally regarded to have a lower performance than comparable solvent-borne and solvent-free epoxy primers. Waterborne epoxy coating compositions can pose difficulties in terms of pot-life; which is a measure of the time period in which coatings can be readily coated on a substrate.

[0007] Waterborne epoxy coatings can also be sensitive to curing conditions in which water evaporation is slow, e.g. high humidity and / or low temperature conditions. Slow curing - in turn - increases the risk of poor film formation.It is thus an object of the invention to provide new waterborne epoxy-based coating compositions which address at least some of the problems in the state of the art. The composition should offer good anticorrosive properties, and have the ability to cure and form films at low temperatures and high relative humidity. Furthermore, the composition should provide good pot life.

[0008] WO2023166212A1 provides a two-component coating composition comprising an aqueous epoxy-based binder in a first component and a curing agent and a silane in a second component (component B), wherein the second component comprises less than 5 wt% water.

[0009] SUMMARY

[0010] It has been found by the present inventor(s) that suitable pot life and good corrosion protection can be achieved for waterborne epoxy-based coating compositions. The present inventor(s) surprisingly found that waterborne coating compositions offer excellent anticorrosive properties, when the amine part is dispersed in the water phase, thereby reducing the total amount of water. Further, the epoxy part comprises a liquid epoxy which provides good compatibility with the waterborne amine part.

[0011] Therefore, a coating composition according to claim 1, the use of the coating composition, a coating system and a substrate are provided.

[0012] DETAILED DISCLOSURE

[0013] Definitions

[0014] As used herein, the term "waterborne composition" refers to a composition which comprises water as the continuous phase and main solvent in the ready-to-apply paint i.e. paint where all the necessary components are mixed together. Typically, water forms at least 65 wt% of the solvent contained in the formulation, preferably at least 75 wt% of the solvent is water. The term "binder" or "binder system" refers to the film forming components of the composition. The one or more epoxy-based binders of the coating composition are the main binders in the composition, i.e. they form at least 50 wt% of the binders present, preferably at least 60 wt%, such as at least 70 wt%.

[0015] When used herein, the term “hydrogen equivalents” is intended to cover only reactive hydrogen atoms linked to nitrogen.

[0016] The number of “hydrogen equivalents” in relation to the one or more curing agents is the sum of the contribution from each of the one or more curing agents. The contribution from each of the one or more curing agents to the hydrogen equivalents is defined as grams ofthe curing agent divided by the hydrogen equivalent weight of the curing agent, where the hydrogen equivalent weight of the curing agent is determined as: grams of the curing agent equivalent to 1 mole of active hydrogen. For adducts with epoxy resins the contribution of the reactants after adductation is used for the determination of the number of “hydrogen equivalents” in the epoxy-based binder system.

[0017] The number of “epoxy equivalents” in relation to the one or more epoxy resins is the sum of the contribution from each of the one or more epoxy resins. The contribution from each of the one or more epoxy resins to the epoxy equivalents is defined as grams of the epoxy resin divided by the epoxy equivalent weight of the epoxy resin, where the epoxy equivalent weight of the epoxy resin is determined as: grams of the epoxy resin equivalent to 1 mole of epoxy groups. It should be understood that if the epoxy-based binder system contains reactive acrylic modifiers then the number of “epoxy equivalents” is to be increased accordingly. E.g. if the epoxy-based binder system contains an acrylate oligomer comprising alpha, beta unsaturated carbonyl groups then the number of “alpha, beta unsaturated carbonyl group equivalents” are to be added to the epoxy equivalents of the one or more epoxy resins for the purpose of establishing the ratio between the hydrogen equivalents of the one or more curing agents and the epoxy equivalents of the one or more epoxy resins. Preferably, the ratio between the hydrogen equivalents of the one or more curing agents and the epoxy equivalents of the one or more epoxy resins is in the range of 20:100 to 120:100. In organic chemistry, amine value is a measure of the nitrogen content of an organic molecule. Specifically, it is usually used to measure the amine content of amine functional compounds. It may be defined as the number of milligrams of potassium hydroxide (KOH) equivalent to one gram of epoxy hardener resin. The units are thus mg KOH / g.

[0018] The term "paint" refers to a composition comprising the coating composition as herein described and any other components e.g. solvent, fillers, pigments and / or other additives which is in a condition ready for use, e.g. for application by spraying, brush or roller. Thus, the coating composition may itself be a paint or the coating composition may be a concentrate to which solvent or other components are added to produce a paint.

[0019] As used herein the term filler refers to a compound which increases the volume or bulk of a coating composition. The fillers are substantially insoluble in the coating composition and are dispersed therein.

[0020] The term "volatile organic compound (VOC)" refers to a compound having a boiling point of 250 °C or less.The term “modified” in respect of a polyamine or an epoxy component is typically used to mean “hydrophilic modified”; i.e. containing hydrophilic functional groups such as polyoxyethylene groups. Similarly, if a polyamine or epoxy component is “unmodified” it means that it does not contain hydrophilic functional groups such as polyoxyethylene groups.

[0021] Corrosive environments are rated according to ISO 12944 on a scale from C2 to C5 with C2 being mildly corrosive and C5 being an aggressively corrosive environment.

[0022] The epoxy coating compositions disclosed herein are designed to cure at ambient temperatures (i.e. typically the temperature at the location at which the coating composition is applied, e.g. in paint shops or outdoor where the temperature will depend on the general climate at the geographical location), e.g. at temperatures of 0-50 °C (either in cold or in very hot regions of the world), such as 5-30 °C, in particular about 15-25 °C, such as around 20°C. In other words, the coating composition disclosed herein is of the non-thermosetting type.

[0023] An epoxy coating composition is provided, which comprises components A and B. The epoxy coating composition may be in the form of a “kit-of-parts” in which components A and B are stored separately. As the coating composition is an epoxy coating composition, it is curable. Curing takes place between the active epoxy functional groups of component A, and the amine-based curing agents of component B.

[0024] The epoxy coating composition suitably has a total volume solids (VS) of at least 70%, preferably at least 75%, determined according to the methods set out herein.

[0025] The relative content of components A and B in the epoxy coating composition is suitably 1.5:1 - 3:1 V / V. The coating composition suitably has a total volume solids (VS) above 75%, thereby reducing the solvent content of the composition.

[0026] To further improve corrosion resistance, component A and / or component B may comprise zinc particles, such as zinc dust or zinc powder.

[0027] Component A

[0028] Component A of the coating composition comprises one or more epoxy-based binders. The epoxy-based binder(s) are one of the most important constituents of the primer composition, in particular with respect to the anticorrosive properties. In particular, component A comprises 15-40 wt%, preferably 15-30 wt%, relative to the total dry weight of component A of one or more epoxy-based binder(s). These weight percentages refer to the total amount of epoxy-based binder(s) in component A (i.e. liquid and solid).The one or more epoxy-based binder(s) comprise a solid epoxy-based binder and a liquid epoxy-based binder. Suitably, the one or more epoxy-based binder(s) consist of a solid epoxy-based binder and a liquid epoxy-based binder.

[0029] The content of solid epoxy-based binder in component A is between 3 and 10 % by dry weight, preferably between 5.5 and 8 % by weight, more preferably between 5.8 and 7.6 % by weight.

[0030] Suitable solid epoxy-based binders include:

[0031] - Solid epoxy resin Uapoly330, being a self-emulsifying epoxy from Aqua Union, China. - Solid epoxy resin WE3163A being a bisphenol A from Harz Performance Materials, China. - Solid epoxy resin RSS4656 being a dispersible solid epoxy resin solution in Propylene glycol mono methyl ether (PM) from Westlake, USA.

[0032] - Solid epoxy resin XQ83031 being a self-emulsifying bisphenol A epoxy resin from Olin, Germany.

[0033] The liquid epoxy-based binder is selected from the group consisting of: a bisphenol A epoxy resin, a bisphenol F epoxy resin, and a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin.

[0034] Suitably, the liquid epoxy-based binder is a hydrophilic-modified liquid epoxy-based binder, preferably selected from the group consisting of a hydrophilic-modified bisphenol A epoxy resin, a hydrophilic-modified bisphenol F epoxy resin, and a mixture of a hydrophilic-modified bisphenol A epoxy resin and a hydrophilic-modified bisphenol F epoxy resin.

[0035] The viscosity of the liquid epoxy-based binder is suitably 50-16000 mPa s. as determined by ISO 2555 at 25 + / - 0.5 degrees C

[0036] The content of liquid epoxy-based binder in component A is suitably between 14 and 22 % by dry weight, preferably 15-20% by dry weight.

[0037] Suitable liquid epoxy-based binders include:

[0038] - Liquid epoxy HDE3267 being a hydrophilic modified bisphenol A epoxy resin from Handai, China.

[0039] - Liquid epoxy Banco5120 being a modified bisphenol A epoxy resin from Aqua Union, China.- Liquid epoxy WE3107 being a modified bisphenol A I bisphenol F epoxy resin from Harz Performance Materials, China.

[0040] - Liquid epoxy EP257 being a modified epoxy resin bisphenol A I bisphenol F with modifier from Westlake, USA.

[0041] - Liquid epoxy EP147W being a liquid bisphenol A I bisphenol F epoxy resin and containing crosslinking emulsifiers from Allnex, USA.

[0042] - Liquid epoxy D.E.R. 354 being an unmodified bisphenol F epoxy resin from Olin, Germany. - Liquid epoxy RSE2633 being an unmodified bisphenol A I bisphenol F epoxy resin from Westlake, USA.

[0043] - Liquid epoxy EP816 being an unmodified bisphenol A epoxy resin, containing Glycidyl Neodecanoate as reactive thinner from Westlake, USA.

[0044] - Liquid epoxy KEM-1065M being an unmodified bisphenol A I bisphenol F epoxy resin. from Kukdo, Korea.

[0045] The one or more epoxy-based binder(s) comprise a solid epoxy-based binder.

[0046] Suitably, component A may further comprise (a3) a reactive epoxy diluent. Reactive diluents from the classes of functional glycidyl ethers or esters of aliphatic, cycloaliphatic or aromatic compounds can be included in order to reduce viscosity and for improved application and physical properties. The reactive diluent is preferably present in an amount of 0.1-30 % by dry weight, more preferably 0.5-10 % by weight, even more preferably 1-5 % by dry weight of the coating composition. Examples of suitable commercially available reactive epoxy diluents include:

[0047] Polypox R24, ex Ulf Prummer, Germany, aliphatic monofunctional diglycidylether Araldite DY-L / BD, ex Huntsmann Advanced Materials, Germany, polyoxypropylene-triglycidylether

[0048] Grilonit RV 1812, ex EMS-Primid, Switzerland, hexandiol-diglycidylether

[0049] Epodil 757, ex Air products Pic, USA, cyclohexane-dimethanoldiglycidylether

[0050] Epilox P 13-20, ex Leuna, Germany, Hexanediol diglycedylether.

[0051] Suitably, the liquid epoxy-based binder or the solid epoxy-based binder has an epoxy equivalent weight (EEW) of 150-1200 g / eq., preferably 150-880 g / eq. More suitably, all epoxy-based binder(s) in component A have EEW within these ranges.

[0052] Epoxy equivalent weight can be determined by methods commonly known in the art, such as titration. For example, according to ISO 3001 and ASTM D1652.The coating composition (typically component A thereof) can comprise one or more epoxy accelerators. Examples of suitable commercially available epoxy accelerators are:

[0053] Ancamine K 54, ex Air Products Pic, United Kingdom, tris-(dimethylamino methyl) phenol TL 0712, ex Vantico Ltd., Germany, phenol free Mannich base

[0054] Hiescat HI-K54, ex Keum Jung, Korea, Tris-(dimethylaminomethyl)phenol.

[0055] Component A comprises less than 5 wt% water, relative to the total weight of component A. Suitably, component A comprises less than 2 wt% water, preferably less than 1 wt% water, relative to the total weight of component A. Most preferably, component A is water-free. The coating compositions of the invention can provide good corrosion resistance and pot life, despite reducing or eliminating water in component A.

[0056] Component B

[0057] Component B comprises (b1) an amine-based curing agent, suitable for curing the one or more epoxy-based binder(s) in component A. Suitable selection of the amine-based curing agent for the above-mentioned epoxy-based binder(s) in component A allows good corrosion resistance and acceptable pot-life.

[0058] The amine-based curing agent (b1) comprises b1a) a polyetheramine, and bib) a first polyamine adduct having an amine value above 200 mg KOH / g.

[0059] The polyetheramine is therefore present in the amine-based curing agent, together with another component being a first polyamine adduct with a specified amine value.

[0060] Polyetheramines are characterized by repeating oxypropylene units in the backbone, plus one or more amine functionalities, such as aminated polyalkoxyethers (e.g. those sold commercially as “Jeffamines”). For instance, JEFFAMINE T-403 is a trifunctional primary amine having an average molecular weight of approximately 440. Its amine groups are located on secondary carbon atoms at the ends of aliphatic polyether chains. JEFFAMINE T-403 has high hydrophilicity and low viscosity. Other suitable polyetheramines for use in the present invention are Anquamine 401 (from Evonik, USA), ZT-143 and ZD-123 (from Shandong Zhengda, China) and D230 (from Huntsman, USA).

[0061] The first polyamine adduct may be modified or unmodified. Suitably, the first polyamine adduct is a modified polyamine adduct. In one aspect, the first polyamine adduct is an aliphatic amine adduct. The first polyamine adduct may be, or may further comprise, a polyamide adduct.

[0062] Suitably, the first polyamine adduct comprises an aliphatic or cyclic amine moiety. The amine-based curing agent may further comprise a second polyamine adduct. The secondpolyamine adduct suitably comprises a cyclic amine moiety. The second polyamine adduct suitably has an amine value below 200 mg KOH / g.

[0063] The amine-based curing agent b1) is water compatible. The curing agent is completely water-soluble, water-miscible or able to be emulsified, in a weight ratio up to 1:6 (amine: water).

[0064] Preferably, the curing agent is a polyamine comprising at least two amino groups. To obtain a crosslinked network the curing agent ideally contains at least three "reactive" hydrogen atoms. 'Reactive" hydrogen atom refers to the hydrogen atom that is transferred from the nucleophile to the oxygen atom of the epoxide during the ring opening reaction. Curing active amine groups cannot therefore be tertiary. Tertiary amine containing compounds may however be added to the composition as curing accelerators. The curing agent typically contains at least two curing reactive functional groups.

[0065] The amine part of the first or second polyamine adduct suitably includes a primary amine such as ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), and other higher polyethylene polyamines; aliphatic primary diamines like 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,5-diamino-2-methylpentane, 1,6-hexanediamine; primary diamines comprising a cyclic structure, such as, 1,4-diaminocyclohexane, isophoronediamine (I PDA), 1,3- bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3- 10 bis(aminomethyl)benzene (MXDA) and 1,4-bis(aminomethyl)benzene.

[0066] Suitable (first or second) polyamine adducts for use in the present invention include:

[0067] Beckopox VEH 2106w / 80WA (from Allnex, USA), ERSC2294, EPIKURE ™8530, EPIKURE 8545-W-52 (from Westlake, USA), Sunmide WH900, Sunmide WH-1000, Anquamine® 469 (from Evonik, USA), ARADUR®37, ARADUR® 38-1 Cl (from Huntsman, USA), HDH-6545, HDH6806-WB (from Handai, China), and WH3903B, WH3908B (from Harz, China).

[0068] The polyamine of the aliphatic polyamine adduct or of the polyamine adduct suitably comprises a cyclic amine moiety. Suitable cyclic amine moieties are m-xylylenediamine (MXDA) or isophorone diamine (IPDA).

[0069] The amine-based curing agent (b1) may further comprise a polyamide adduct. Suitable polyamide adducts include:

[0070] Ancamide 2839 (from Evonik, USA).The polyetheramine suitably has an active hydrogen equivalent weight (AHEW) of 50-150 g / eq, preferably 60-100 g / eq.

[0071] The polyamine adduct suitably has an AHEW of 80-350 g / eq, preferably 100-250 g / eq. The aliphatic polyamine adduct suitably has an AHEW of 100-190 g / eq, preferably 150-185 g / eq.

[0072] The first polyamine adduct suitably has an amine value above 200 mg KOH / g, more preferably the amine value is 200-350 mg KOH / g. The viscosity of the aliphatic polyamine adduct or the polyamine adduct is suitably 1000-50000 mPa s. measured according to ISO 2555, at a temperature of 25 + / - 0.5 °C.

[0073] Component B comprises (b2) more than 5 wt% water, such as 20-60 wt% water, relative to the total weight of component B.

[0074] Specific coating compositions are as follows:

[0075] A coating composition, wherein component A comprises:

[0076] a1) 15 to 40 dry wt%, preferably 15-25 dry wt%, relative to the total weight of component A of one or more epoxy-based binder(s), said epoxy-based binder(s) comprising a solid epoxy-based binder, and a liquid epoxy-based binder being a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin, wherein the content of solid epoxy-based binder in component A is between 3 and 10% by dry weight, preferably between 5.8 and 7.6 % by dry weight,

[0077] a2) less than 5 wt% water, relative to the total weight of component A;

[0078] and wherein component B comprises

[0079] b1) an amine-based curing agent, a comprising

[0080] b1a) a polyetheramine, and bib) a first polyamine adduct having an amine value above 200 mg KOH / g; and

[0081] b2) more than 5 wt% water, such as 20-60 wt% water, relative to the total weight of component B.

[0082] Fillers and pigments

[0083] The coating composition optionally comprises fillers and colour pigments.

[0084] The fillers comprise organic and inorganic fillers, the inorganic fillers may be naturally occurring, i.e. mined or of synthetic origin i.e. precipitated, and may or may not be surface treated.Non-limiting examples of fillers that can be used in the coating composition according to the present invention are nepheline syenite, talcum, plastorite, chlorites, chrysolite, mica, pyrophyllite, feldspars, bentones, kaolins, mica / muscovite, clays, wollastonite, quartz, christobalite, glass flakes, glass fibers, fumed silica, calcium silicate, pumice, diatomaceous earth, calcium carbonate, magnesium carbonate, calcium sulfate, dolomite, barium sulfate, iron oxide, micaceous iron oxide, zinc oxide, aluminium oxide, aluminium hydroxide, aluminium flakes, zinc flakes, and solid silicone resins, which are generally condensed branched polysiloxanes. Some fillers such as fumed silica and clays may have a thickening effect on the coating composition. Inorganic core-shell particles containing an organic compound(s) such as a dye, resin and / or an organic liquid may also be used.

[0085] The pigment(s) may be inorganic pigments, organic pigments or a mixture thereof. The pigments may be surface treated.

[0086] Representative examples of pigments include black iron oxide, red iron oxide, yellow iron oxide, titanium dioxide, zinc oxide, carbon black, graphite, red molybdate, yellow molybdate, zinc sulfide, antimony oxide, sodium aluminium sulfosilicates, quinacridones, phthalocyanine blue, phthalocyanine green, indanthrone blue, cobalt aluminium oxide, carbazoledioxazine, isoindoline orange, bis-acetoaceto-tolidiole, benzimidazolone, quinaphthalone yellow, isoindoline yellow, tetrachloroisoindolinone, and quinophthalone yellow, metallic flake materials (e.g. aluminium flakes). Preferred pigments are black iron oxide, red iron oxide, yellow iron oxide and titanium dioxide. In one preferred embodiment the titanium dioxide is surface treated with a silicone compound, a zirconium compound, an aluminium compound or a zinc compound.

[0087] Pigments and fillers may be added to the paint composition in the form of a powder or as a slurry or concentrate.

[0088] The amount of the at least one filler or pigment, including anticorrosive pigments, is preferably in the range 1-60 % by dry weight, preferably in the range 10-55 % by dry weight, more preferably 30-55 % by dry weight, based on the total weight of the coating composition.

[0089] Additives

[0090] The coating composition of the present invention optionally comprises one or more additives. Examples of additives that may be present in the coating composition of the invention include: rheology modifiers such as thixotropic agents, thickening agents and antisettling agents, dispersing agents, wetting agents, coalescing additives, surfactants, surface active additives such as surface tension reduction additives, defoamers, plasticizers, flashrust inhibitors, in can corrosion inhibitors and biocides. Suitable additives are not necessarily limited to additives developed and sold for use in paint. Additives developed and sold for use in for instance adhesives, building materials, plastics / resins, drilling fluids, paper coatings and pigment concentrates may be used if compatible with the coating composition. As the efficiency of any additive used in waterborne coating compositions may, to a great extent, be influenced by the other raw materials and additives contained therein, it is important that suitable types and concentrations of additives are determined by testing. In many cases it may be necessary and / or useful to add several different additives of any given type, i.e. two or more defoamers or two or more rheology modifiers, to achieve the desired properties / efficiency.

[0091] Biocides may be used to for instance prevent the in-can growth of bacteria and fungi. The type of biocide is not specifically limited and any suitable biocide can be used.

[0092] Surface-active additives may be added to for instance adjust the surface tension of the coating composition.

[0093] A rheology modifier may be employed to adjust the rheological profile of the paint as to prevent settling and floating issues, thus extending the shelf-life of the paint, as well as to adjust flow and to improve sag resistance, workability, application properties and the stabilization of pigment and extender particles.

[0094] Wetting and dispersing agents may be added to the paint composition to for instance facilitate dispersion and wetting of the pigment and filler particles, thus making it easier to break up agglomerates during production, preventing re-flocculation and settling in wet paint as well as formation of Benard cells in curing paint, reducing the paints viscosity and increasing its colour strength and colour stability.

[0095] Solvents

[0096] The coating composition of the present invention is a waterborne composition, i.e. one comprising water as the main solvent.

[0097] The coating compositions typically comprise no more than 30 wt% water, relative to the total weight of the composition as a whole. Preferably, the compositions comprise 5 to 30 wt% water, more preferably 5 to 25 wt%, even more preferably 5 to 20 wt% relative to the total weight of the composition as a whole.

[0098] Organic solvents are typically also present in the composition, either in component A, component B or in both component A and B. Organic solvents are typically added to a waterborne coating composition to improve freeze-thaw stability and open time, to reduce surface tension and viscosity, and to facilitate film formation. The type of solvent is notspecifically limited and any suitable solvent can be used. Suitable solvents may be, but are not limited to, aromatic hydrocarbons, ketones, esters, alcohols, glycol ethers, ethers and polyethers.

[0099] Examples of solvents that may be suitable for use in the composition include toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, methyl isoamyl ketone, ethyl acetate, butyl acetate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (Texanol (TM)), ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tertbutanol, diacetone alcohol, benzyl alcohol, propylene glycol monomethyl ether, propylene glycol propyl ether, propylene glycol n-butyl ether, dipropylene glycol methyl ether, dipropylene glycol n-butyl ether, propylene glycol phenyl ether, tripropylene glycol n-butyl ether, ethylene glycol propyl ether and ethylene glycol butyl ether.

[0100] Of the above-mentioned solvents, solvents capable of aiding the film formation of a waterborne coating composition are especially preferred. Such solvents are often called coalescing agents or film-forming agents.

[0101] In this waterborne coating composition, the waterborne epoxy system may be described as being composed of a hybrid of low molecular weight liquid epoxy resin and high molecular weight self-emulsifier solid epoxy and a waterborne epoxy curing agent. In this waterborne epoxy system, the curing agent has the dual function of crosslinking agent and emulsifier. The curing agent is based on polyamine, which connects the non-polar groups in the polyamine molecular chain segment to make it amphiphilic (hydrophilic and lipophilic) which can be better dissolved or dispersed in water and has a good emulsification effect on epoxy resin and improves the compatibility with the epoxy resin.

[0102] For a waterborne epoxy coating composition to form a continuous coating film, the epoxy resin-based binder dispersion particles or emulsion droplets must coalesce and flow together with the amine-based curing agent. Coalescing additives or coalescing agents aid this process during drying of the coating film.

[0103] Examples of suitable coalescing agents may be 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (Texanol (TM)), benzyl alcohol, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, propylene glycol phenyl ether, tripropylene glycol n-butyl ether, and diacetone alcohol. An example of a preferred solvent is benzyl alcohol. Benzyl alcohol may be present alone or in combination with glycol ethers such as, propylene glycol n-butyl ether and dipropylene glycol n-butyl ether.

[0104] The composition may comprise 0-15 % by weight organic solvents, preferably 0.5-10 % by weight, most preferred 0.5-3 % by weight.Specific embodiments of the invention

[0105] In one embodiment the epoxy coating composition comprises:

[0106] 15-20 % by weight of a liquid epoxy-based binder

[0107] 5-10 % by weight of a solid epoxy-based binder

[0108] 2-5 % of a polyetheramine

[0109] 1-3 % by weight of a polyamine having an amine value above 200 mg KOH / g 3-6 % by weight of a polyamine having an amine value below 200 mg KOH / g 45-65 % by weight of pigments and fillers

[0110] 5-10 % by weight of water.

[0111] In another embodiment the epoxy coating composition comprises:

[0112] 15-20 % by weight of a liquid epoxy-based binder

[0113] 5-10 % by weight of a solid epoxy-based binder

[0114] 2-5 % of a polyetheramine

[0115] 1-3 % by weight of a polyamide having an amine value above 200 mg KOH / g 3-6 % by weight of a polyamine having an amine value below 200 mg KOH / g 45-65 % by weight of pigments and fillers

[0116] 5-10 % by weight of water.

[0117] In another embodiment the epoxy coating composition comprises:

[0118] 15-20 % by weight of a liquid epoxy-based binder having an EEW of 150-300 g / eq 5-10 % by weight of a solid epoxy-based binder

[0119] 2-5 % of a polyetheramine

[0120] 1-3 % by weight of a polyamine having an amine value above 200 mg KOH / g 3-6 % by weight of a polyamine having an amine value below 200 mg KOH / g 45-65 % by weight of pigments and fillers

[0121] 5-10 % by weight of water.

[0122] In yet another embodiment the epoxy coating composition comprises:

[0123] 15-20 % by weight of a liquid epoxy-based binder

[0124] 5-10 % by weight of a solid epoxy-based binder

[0125] 2-5 % of a polyetheramine

[0126] 1-3 % by weight of a polyamine having an amine value between 200-350 mg KOH / g, preferably 220-350 mg KOH / g

[0127] 3-6 % by weight of a polyamine having an amine value below 200 mg KOH / g 45-65 % by weight of pigments and fillers

[0128] 5-10 % by weight of water.Applications

[0129] The composition as described herein may be prepared in a suitable concentration for use, e.g. in spray painting. In this case, the composition is itself a paint. Alternatively, the composition may be a concentrate for preparation of paint. In this case, further solvent and optionally other components are added to the composition described herein to form paint. Preferred solvents are as hereinbefore described in relation to the composition.

[0130] After mixing, and optionally after addition of solvent, the coating composition or paint is preferably filled into a container. Suitable containers include cans, drums and tanks.

[0131] The coating composition may be supplied as a one-pack, as a two-pack or as a three-pack. Preferably the composition is supplied as a two-pack.

[0132] The coating composition and paint of the invention preferably has a solids content of 60-90 % by weight and still more preferably 80-90 % by weight. In terms of solids by volume percent solids (VS%), the coating composition and paint of the invention preferably has a solids content of 60-90 %, more preferably 70-80 %.

[0133] Preferably the coating composition and paint of the invention has a content of volatile organic compounds (VOC) of less than 120 g / L, more preferably less than 100 g / L. Even more preferably, the VOC content is in the range of 35-55 g / L. VOC content can be calculated or measured (US EPA method 24 or ISO 11890-1).

[0134] The ratio of the sum of epoxy equivalents of the reactive components of Component A to the sum of active hydrogen equivalents of component B of the present invention is preferably in the range of 100:40 to 100:120, more preferably 100:50 to 100:80, even more preferably 100:60 to 100:70.

[0135] It is preferable that the two components of the coating composition are formulated such that an even mixing ratio by volume is achieved. By even mixing ratio it is understood that the mixing ratio A: B is such that A is an integer, (e.g. 4:1, 3:1, 2:1). A preferred range for the mixing ratio A: B is from 1.5:1 to 3:1 v / v.

[0136] The coating composition of the present invention may be applied to any suitable surface, such as metal substrates such as carbon steel, galvanized steel, stainless steel or aluminum. Furthermore, the coating composition may be applied to metal substrates with a non-optimal surface treatment such as rusted substrates, ultra-high-pressure water-jetted substrates, substrates containing old paint residues of paint as well as precoated substrates. The composition may also be applied to concrete substrates.The coating composition according to the present invention may be applied in one or two or more layers.

[0137] The use of a coating composition as set out herein in a coating method is therefore provided, said coating method comprising the steps of:

[0138] - applying the coating composition as defined herein to a surface,

[0139] - allowing the coating composition to cure to provide a cured coating composition, - optionally, applying one of more additional coating compositions to the cured coating composition.

[0140] A coating system is provided, comprising a layer being an epoxy coating layer made by applying and curing the coating composition as described herein, and one or more additional coating layers.

[0141] Also provided is a substrate coated with an epoxy coating layer made by applying and curing the coating composition as described herein.

[0142] Preferably the coating composition as hereinbefore defined is the first coating layer of the system, i.e. is applied directly to the substrate. Optionally the substrate may be pre-treated with a shop primer and / or a zinc rich primer before applying the coating composition of the present invention.

[0143] The additional coating compositions may form a "topcoat" layer which, as defined herein, refers to a layer which forms the outermost layer of a multilayer paint system. The components of the topcoat layer may be selected as appropriate depending on the application of the coating system. For example, where the coating system is intended for external use, a suitable topcoat layer which provides protection from the outdoor environment, such as UV light and / or moisture, can be selected. The topcoat layer may also refer to a coat that is intended for underwater use to prevent the growth of marine organisms. Such coatings are termed antifouling coatings. If an antifouling coating is to be applied to the primer layer, a tiecoat layer between the primer and antifouling layer might be necessary.

[0144] The coating composition may be cured at ambient and elevated temperatures (e.g. 18 to 40 °C), or even at lower temperatures, such as 0 to 18 °C.

[0145] The coating composition of the present invention can be cured at a relative humidity of below 90%, more preferred below 85%.The dry film thickness of each of the coating layers of the coating composition of the present invention is preferably 75-550 pm, more preferably 100-450 pm, most preferably 150-360 pm.

[0146] The wet film thickness of the coating composition of the invention is preferably 75 to 1000 pm, more preferably 100 to 800 pm, most preferably 125 to 600 pm.

[0147] Thus, the invention may further be considered to relate to a coating composition as hereinbefore defined, wherein said composition has a wet film thickness in the range 75 to 1000 pm, and can be cured at a temperature of 5 to 40 °C and a relative humidity below 90%, preferably below 85%. Sufficient ventilation is always necessary when curing waterborne paints, this is especially true when curing at a high relative humidity.

[0148] The invention also relates to substrates coated with a cured coating formed from a coating composition as hereinbefore defined as well as a process for applying a coating composition to a substrate comprising applying, e.g. by spraying, a coating composition as defined herein to a substrate and allowing the coating composition to cure.

[0149] The substrate is typically any surface that should be protected by an anticorrosive coating, especially for high to extreme corrosivity for atmospheric corrosivity. For example, the surface of a marine structure, preferably a marine structure which is submerged when in use. The surface may be permanently or intermittently underwater (e.g. through tide movement, different cargo loading or swell). Typical marine structures include vessels (including but not limited to boats, yachts, motorboats, motor launches, ocean liners, tugboats, tankers, container ships and other cargo ships, submarines, and naval vessels of all types), pipes, shore and off-shore machinery, constructions and objects of all types such as piers, pilings, bridge substructures, water-power installations and structures, underwater oil well structures, nets and other aquatic culture installations, nuclear, coal and gas fired installations, tower and buoys, etc. The surface of the substrate may be the "native" surface (e.g. the steel surface).

[0150] Application of the coating composition and paint can be accomplished by any convenient means, e.g. via painting (e.g. with brush or roller) or more preferably spraying the coating onto the article. Typically, the surface will need to be separated from the seawater to allow coating. After the coating is applied, it is preferably dried and cured.

[0151] EXAMPLE 1

[0152]

[0153] The paint may be prepared by any suitable technique that is commonly used within the field of paint production. Thus, the various constituents may be mixed together using a high-speed disperser, a ball mill, a pearl mill, a three-roll mill etc. The paints according to the invention may be filtered using bag filters, patron filters, wire gap filters, wedge wire filters, metal edge filters, EGLM turnoclean filters (ex. Cuno), DELTA strain filters (ex. Cuno), and Jenag Strainer filters (ex. Jenag), by vibration filtration, or by pressure filtration.

[0154] The paint composition to be used in the method of the invention is prepared by mixing two or more components e.g. two pre-mixtures, one pre-mixture comprising the one or more epoxy resins, component A, and one pre-mixture comprising the one or more curing agents, component B.

[0155] Component A is prepared by mixing the one or more epoxy resins in a vessel together with any further base parts, such as reactive diluents, any solvents, pigments, fillers, additives, epoxy accelerators and rheological agents, and stirred until the fineness meets the requirement. Any fillers and pigments are dispersed into the base part by high-speed dissolver.

[0156] Component B is prepared by adding the amine parts to a vessel and mixing until uniform appearance.

[0157] Just before the application, component 2 was added to component 1 and the paint composition was mixed to a homogenous mixture

[0158] It should be understood that when reference is made to the paint composition, it is the mixed paint composition ready to be applied. All amounts stated as % by weight of the paint should be understood as % by weight of the mixed paint composition ready to be applied.

[0159] Furthermore, all amounts stated as % by solids volume of the paint should be understood as % by solids volume of the mixed paint composition ready to be applied.

[0160] Kit-of-parts

[0161] The present invention also provides a kit-of-parts, suitable for use in the method described herein. The kit-of-parts comprises at least a first container and a second container.

[0162] In one aspect, the first container comprises component A, while a second container comprises component B.

[0163] With the kits set out above, curing agents and epoxy-containing components can be kept separate until use.

[0164]

[0165] Cold rolled mild steel panels of 150x75x4 mm and 150x75x6 mm are abrasive blasted to Sa 21 (ISO 8501-1), with a surface profile equivalent to Medium (G) (ISO 8503-1). All panels are 1.5 mm in thickness. The test paints are applied by airless spray to a DFT of 200 pm.Neutral salt spray test according to ISO 9227 / ASTM B117

[0166] This method is performed in order to assess the corrosion resistance of metallic materials with permanent or temporary corrosion protection.

[0167] The neutral salt spray test applies to organic coatings on metallic materials.

[0168] The operation conditions of the salt spray test are constant spray with 5% NaCI solution at 35°C. A scribe is prepared according to ISO 17872, cut down to the substrate.

[0169] At the selected inspection intervals during and after completion of exposure, blistering and rust are evaluated on both panel and around the scribe (in mm from centre), according to ISO 4628-2 and ISO 4628-3. Cracking is evaluated according to ISO 4628-4. Flaking according to ISO 4628-5. After completion of the exposure, adhesion is further evaluated according to ISO 4624 (pull-off test). Delamination and corrosion at score is evaluated according to ISO 4628-8, at scribe the paint film is removed, and the width of the rusting is measured at nine points, where from the M-max and M-avg values are calculated. The test is passed if the corrosion creep is less than or equal to 1.5 mm.

[0170] Determination of volume solids (%)

[0171] Volume solids % (VS %) was determined according to ISO 3233-1 with the modification that drying was carried out at 23 °C and 50 % relative humidity for 7 days.

[0172] Ten test items (i.e. ten-fold repetition) were prepared.

[0173] The volume solids (VS) figure expresses in percentage the ratio:

[0174] (Dry film thickness measured after 7 days) I (Wet film thickness measured immediately after application) x 100%.

[0175] Volume solids are usually slightly higher than the theoretical value (referred to as “solids volume”), which is found by a calculation based on the paint composition taking specific gravity and solid content of each individual raw material into consideration. Volume solids take into account that small amounts of solvents are usually retained, and that air may be entrapped in the dry paint film either in the form of vacuoles or as interstices. Volume solids are in general in better agreement with practical measurements of dry film thickness than the theoretical value.

[0176] Determination of PVC (%)

[0177] The pigment volume concentration (PVC) were calculated as the ratio of pigment volume and total paint volume according to the formula PVC = (Vpigment / (VPigment + Vender). The pigment volume includes all pigments and fillers.Determination of VOC (g / L)

[0178] The theoretical volatile organic compound (VOC) contents of the compositions were calculated.

[0179] Determination of viscosity

[0180] The viscosity was determined using a Cone & Plate (C&P) viscometer, and measured in accordance with ISO 2884-1 and ASTM D4287.

[0181] Viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress expressed in mPa s or Poise (1 mPa s = 1 cP) and measured at 25°C 177°F.

[0182] A cone and plate instrument comprises an electric motor that drives, at a constant rotational speed, a cone whose vertex touches a rigid temperature-controlled plate. In use, the liquid just fills the narrow gap between the plate and the cone.

[0183] Determination of drying time (hours)

[0184] The drying time was determined using a Beck Koller drying time recorder (BK) and measured according to ASTM D5895-20, stage III (BKIII), which is the point (in hours) when the needle stops tearing or cutting the film, leaving a visible track on the film surface.

[0185] Determination of adhesion

[0186] The adhesion before and after exposure was determined by a pneumatic adhesion tester in accordance with ISO 4624. The coating surface and the dolly (20 mm 0) were lightly sanded and the epoxy adhesive was applied. The adhesive was left to cure for min 24 hrs. The sample was drilled around the dolly down to the bare metal prior to testing.

[0187] Adhesion is evaluated after 1 week of reconditioning at standard atmosphere 23±2°C and 50±5 % RH. 3 dollies were glued on each panel.

[0188] Continuous condensation test

[0189] The continuous condensation test (Blister Box Test) was performed in order to evaluate the water resistance of a coating system using controlled condensation in accordance with ISO 6270.

[0190] The panel surface with the coating system was exposed to 38+2° C, saturated water vapour, at an angle of 15° / 60° to the horizontal. The reverse side of the panel was exposed to room temperature. At the selected inspection intervals during and after completion of exposure, blistering and rust were evaluated according to ISO 4628-2 and ISO 4628-3. Cracking was evaluated according to ISO 4628-4. The test is passed if no visible blistering, rust or cracking was observed.Cyclic ageing test (C5-VH)

[0191] The anticorrosive performance was tested in accordance with ISO12944-6-2018. The fully cured coating system was scribed horizontal down to the bare metal. The scratch line is 2 mm wide, 50 mm long, minimum 12.5 mm from each edge of the panel and minimum 25 mm from the short edge of the panel.

[0192] The panels were exposed to the following cycle:

[0193] - 72 hrs of accelerated weathering test (QLIV-A) (according to ISO 16474-3:2003)

[0194] - 72 hrs of Neutral Salt Spray Test (SST-A) (according to ISO 9227) and

[0195] - 24 hrs of exposure to low temperature (-20±2°C)

[0196] The cycle is continued for 2688 hours for C5 very high (C5-VH).

[0197] After completion of exposure blistering was evaluated according to ISO 4628-2, Rusting according to ISO 4628-3, cracking according to ISO 4628-4 and flaking according to ISO 4628-5. Delamination and corrosion creep at the score was evaluated according to ISO 4628-8. At the scribe the paint film was removed and the panel was rinsed with fresh tap water. The width of the corrosion creep was measured at nine points, where from the Mavgvalues are calculated. The corrosion zone can normally be observed visually as a difference in colour compared to the uncorroded substrate. The test is passed if the corrosion creep is less than or equal to 3.0 mm.

[0198] After completion of the exposure, adhesion was evaluated according to ISO 4624 (pull-off test / adhesion test).

[0199] Other embodiments and many of the intended advantages of embodiments will be readily appreciated, as they become better understood by reference to the detailed description. Table of the raw materials used

[0200]

[0201]

[0202]

[0203]

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[0205]

[0206] 1) Supplier information2) Sim 3267 is a bisphenol A resin, which is produced by mixing YD-128 (KLIKDO, Korea), NC-513 (Cardolite, USA), adhesion promoter a-187 (Momentive, USA) and Solvent TPnB (Tripropylene glycol n-butyl ether) (DOW, USA).

[0207] Table 1 - Formulation of water-based epoxy-based primer

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[0211]

[0212] Table 1 shows that the curing agent needs a combination of a polyetheramine and polyamine adduct having an amine value above 200 mg KOH / g. If one or more polyamine adducts having an amine value above 200 mg KOH / g is used alone, it may reach acceptable drying time and pot life, but at the compromise of a poor anticorrosive performance.Table 2 - Formulation of epoxy-based primer

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[0216]

[0217] Table 2 demonstrates that a solid epoxy and a polyetheramine is necessary for the compositions comprising a bisphenol F type liquid epoxy and a polyamine adduct having an amine value above 200 mg KOH / g to either reach an acceptable drying time or acceptable pot life. Compositions within these acceptance limits were further tested for A / C performance and also passes the C5-H test.Table 3 - Formulation of epoxy-based primer

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[0221]

[0222] Table 3 demonstrates that a mixture of bisphenol A and bisphenol F liquid epoxy resin reaches an acceptable drying time and acceptable pot life, and further passes the A / C performance test. When the amine has an amine value below 200 mg KOH / g, it increases the drying time.

[0223] Table 4 - Formulation of epoxy-based primer

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[0227]

[0228] Table 4 Shows that the inventive examples comprising a modified bisphenol A resin and a solid epoxy resin requires a curing agent of a combination of a polyetheramine and a polyamine adduct having an amine value above 200 Mg KOH / g.Table 5 - Formulation of epoxy-based primer

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[0232]

[0233] Table 5 demonstrates that a composition comprising a modified bisphenol A passes the A / C performance test and has acceptable drying time and pot life, when it also comprises a solid epoxy resin, and the curing amine package comprises a polyetheramine and a polyamine adduct having an amine value above 200 mg KOH / g. When the amine value is below 200 mg KOH / g, the pot life decreases.

[0234] Table 6 - Formulation of epoxy-based primer

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[0238]

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[0240] Table 6 demonstrates that a composition comprising a modified bisphenol A passes the A / C performance test and has acceptable drying time and pot life, when it also comprises a solid epoxy resin, and the curing amine package comprises a polyetheramine and a polyamine adduct having an amine value above 200 mg KOH / g. When the amine value is below 200 mg KOH / g, or no solid epoxy is present, the pot life decreases, the film becomes soft or the A / C performance fails.

Claims

CLAIMS1. An epoxy coating composition comprising components A and B,wherein component A comprises:a1) 15 to 40 % by dry weight relative to the total dry weight of component A of one or more epoxy-based binder(s), said epoxy-based binder(s) comprising a solid epoxybased binder and a liquid epoxy-based binder, wherein the liquid epoxy-based binder is selected from the group consisting of a bisphenol A epoxy resin, a bisphenol F epoxy resin, and a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin; and,a2) less than 5 % by weight water, relative to the total weight of component A; and wherein component B comprisesb1) an amine-based curing agent, comprisingb1a) a polyetheramine, and bib) a first polyamine adduct having an amine value above 200 mg KOH / g, andb2) more than 5 % by weight water, relative to the total weight of component B.

2. The coating composition according to claim 1, wherein component B comprises b2) 20-60 % by weight water, relative to the total weight of component B.

3. The coating composition according to claim 1 or claim 2, having a total volume solids (VS) of at least 70%, preferably at least 75%.

4. The coating composition according to any one of the preceding claims, wherein the liquid epoxy-based binder is a hydrophilic-modified liquid epoxy-based binder, preferably selected from the group consisting of a hydrophilic-modified bisphenol A epoxy resin, a hydrophilic-modified bisphenol F epoxy resin, and a mixture of a hydrophilic-modified bisphenol A epoxy resin and a hydrophilic-modified bisphenol F epoxy resin.

5. The coating composition according to any one of the preceding claims, wherein component A further comprises a3) a reactive epoxy diluent.

6. The coating composition according to any one of the preceding claims, wherein the liquid epoxy-based binder or the solid epoxy-based binder has an epoxy equivalent weight (EEW) of 150-1200 g / eq., preferably 150-880 g / eq.

7. The coating composition according to any one of the preceding claims, wherein the viscosity of the liquid epoxy-based binder is 50-16000 mPa s.

8. The coating composition according to any one of the preceding claims, wherein component A comprises less than 2 wt% water, preferably less than 1 wt% water, relative to the total weight of component A and more preferably wherein component A is water-free.

9. The coating composition according to any one of the preceding claims, wherein the amine-based curing agent (b1) further comprises a second polyamine adduct having an amine value below 200 mg KOH / g.

10. The coating composition according to any one of the preceding claims, wherein the first polyamine adduct is a modified polyamine adduct.

11. The coating composition according to any one of the preceding claims, wherein the first polyamine adduct is an aliphatic polyamine adduct.

12. The coating composition according to any one of the preceding claims, wherein the first polyamine adduct is, or further comprises, a polyamide adduct.

13. The coating composition according to any one of the preceding claims, wherein the first polyamine adduct comprises a cyclic amine moiety.

14. The coating composition according to claim 13, wherein the cyclic amine moiety is m-xylylenediamine (MXDA) or isophorone diamine (IPDA).

15. The coating composition according to any one of the preceding claims, wherein the polyetheramine has an active hydrogen equivalent weight (AHEW) of 50-150 g / eq, preferably 60-100 g / eq.

16. The coating composition according to any one of the preceding claims, wherein the first polyamine adduct is an aliphatic polyamine adduct having an amine value above 200 mg KOH / g, preferably above 220 mg KOH / g.

17. The coating composition according to any one of the preceding claims, wherein the viscosity of the first polyamine adduct is 1000-50000 mPa s.

18. The coating composition according to any one of the preceding claims, wherein the content of liquid epoxy-based binder in component A is between 14 and 22 % by dry weight, preferably 15-20% by dry weight.

19. The coating composition according to any one of the preceding claims, wherein the content of solid epoxy-based binder in component A is between 3 and10 % by weight, preferably between 5.5 and 8 % by weight, more preferably between 5.8 and 7.6 % by weight.

20. The coating composition according to any one of the preceding claims, wherein component A comprises:a1) 15 to 40 dry wt%, preferably 15 to 25 dry wt%, relative to the total weight of component A of one or more epoxy-based binder(s), said epoxy-based binder(s) comprising a solid epoxy-based binder, and a liquid epoxy-based binder being a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin, wherein the content of solid epoxy-based binder in component A is between 3 and 10% by dry weight, preferably between 5.8 and 7.6 % by dry weight,a2) less than 5 wt% water, relative to the total weight of component A;and wherein component B comprisesb1) an amine-based curing agent, comprisingb1a) a polyetheramine, and bib) a first polyamine adduct having an amine value above 200 mg KOH / g; andb2) more than 5 wt% water, such as 20-60 wt% water, relative to the total weight of component B.

21. The coating composition according to any one of the preceding claims, having a total volume solids (VS) above 75%.

22. The coating composition according to any one of the preceding claims, wherein component A and / or component B comprises zinc particles.

23. The use of a coating composition according to any one of claims 1-22 in a coating method, said coating method comprising the steps of:- applying the coating composition according to any one of claims 1-22 to a surface, - allowing the coating composition to cure to provide a cured coating composition, - optionally, applying one of more additional coating compositions to the cured coating composition.

24. A coating system comprising a layer being an epoxy coating layer made by applying and curing the coating composition according to any one of claims 1-22, and one or more additional coating layers.

25. A substrate coated with an epoxy coating layer made by applying and curing the coating composition according to any one of claims 1-22.

26. A kit-of-parts comprising at least a first container and a second container, wherein the first container comprises component A as defined in any one of claims 1-22 and the second container comprises component B as defined in any one of claims 1-22.

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