Conductive epoxy coating

Abstract

The present invention relates to a combination of single-walled carbon nanotubes (SWCNT) and at least one ionic liquid (IL) for the preparation of electrically conductive epoxy coatings useful in the preparation of dissipative coating systems wherein the amount of single-walled carbon nanotubes (SWCNT) is in the range of 0.0025%-0.0075%, based on the total weight of the electrically conductive epoxy coating, and wherein the ionic liquid (IL) is at least one ionic liquid (IL). And the amount of the at least one ionic liquid (IL) is in the range of 2.75%-4.5%. The produced dissipative coating system can be applied as a thin coating and has a ground resistance of less than 107 ohms. The cured coating has an aesthetic appearance and also has good or even improved mechanical properties.

Description

Technical Field

[0001] The invention relates to a conductive epoxy coating, a method for preparing a dissipative coating using the conductive epoxy coating, a dissipative coating system, and use of the epoxy coating for forming a dissipative layer. Prior art

[0002] Many industrial sectors today place stringent demands on optimum environmental conditions. Particularly in this regard, protection against uncontrolled electrostatic charging and discharging is of paramount importance.

[0003] Electrostatic charging and discharging occurs as a result of contact, friction or separation of two materials. In the process, one material becomes positively charged and the other negatively charged. In the case of floor coatings, this charge is generated by foot traffic or wheeled traffic, for example using rubber soles or rubber wheels. Charging can also occur by blowing air over an insulating surface, such as paint or coatings.

[0004] Therefore, in sensitive areas, floors and walls with low ground resistance are required, which dissipate the electrostatic charge immediately and in a controlled manner.

[0005] Coating systems are known which have ESD protection (ESD = “electrostatic discharge”), ie which have protection against electrostatic discharge. Dissipative systems based on epoxy resins or polyurethanes are usually used.

[0006] The grounding resistance and the system resistance can be determined according to DIN EN 61340-4-1. For example, a dissipative coating or sealing coating according to DIN EN 61340 series can be determined if its grounding resistance is less than 10 9 ohms, it is considered dissipative or static dissipative. Coatings with a larger resistance to ground are not dissipative. However, in order to have an adequate safety margin, especially for very low absolute humidity conditions, less than 5*10 7 A ground resistance of ohms is desired.

[0007] Ground planes made of synthetic resins are generally not conductive or dissipative. However, there are several options for implementing ESD properties.

[0008] Firstly, in order to obtain electrical conductivity, solid conductive particles such as carbon black or metals may be added to the synthetic resin composition. These conductive particles are usually very expensive and have an inherent color, which inevitably reduces the color selection and thus the decorative appeal of the product. These substances therefore have the disadvantage of being opaque and therefore always lead to a darkening of the material to which they are added. Their use is therefore limited to dark to black ground surfaces.

[0009] Another option is to use organic salts that are soluble in the synthetic resin matrix and provide sufficient conductivity. However, these options reduce the mechanical and chemical resistance of the coating system.

[0010] Another option is to use ionic liquids which are soluble in the synthetic resin matrix, but whose resistance is strongly dependent on humidity. At very low absolute humidity, they do not exhibit sufficient conductivity and their performance does not meet the standards of the DIN EN61340 series. In addition, since it does not participate in the chemical reactions in the coating, it can have a negative impact on the mechanical and chemical properties of the coating.

[0011] The use of carbon fibers is also an option, and carbon fibers can be formulated with ionic liquids in dissipative coatings. In general, the longer the length of the carbon fibers, the lower the resistance that can be achieved. However, in the case of long carbon fibers, for example with 3 mm, if the coating thickness is reduced to less than 1 mm, these carbon fibers may protrude significantly from the surface of the coating, like grass growing on the ground. Therefore, it is a challenge to use carbon fibers to develop thinly coated conductive grounds that have an aesthetic appearance while maintaining sufficient conductivity.

[0012] In addition, the addition of carbon fiber results in "conductive spots" in the epoxy matrix. However, the epoxy remains an insulator between these conductive spots. The portions of the charge that cannot be reached by the carbon fiber are often referred to as "blind spots," a significant drawback that carbon fiber cannot overcome. Coating systems constructed with carbon fiber typically have a traveling voltage greater than 100V. SUMMARY OF THE INVENTION

[0014] The object of the present invention is therefore to provide a composition for preparing a dissipative coating system, more particularly a floor coating system, which can exhibit a sufficient safety margin, having a relative humidity of less than 5*10 measured according to DIN EN 61340-4-1. 7 Ohm, preferably less than 10 7 Ohm, more preferably less than 5*10 6 Ohm or even less than 10 6 The ohmic resistance, especially to ground (including surface or volume resistance), produces a cured coating having an aesthetic appearance and good or even improved mechanical properties.

[0015] In particular, the composition of the invention is suitable for producing thin dissipative floor coatings having a smooth and glossy surface. Furthermore, the composition of the invention may have a low VOC (volatile organic compound) content.

[0016] In a first aspect, the present invention therefore relates to the use of single-walled carbon nanotubes (SWCNTs) in combination with at least one ionic liquid (IL) for preparing a conductive epoxy coating,

[0017] Wherein, based on the total weight of the conductive epoxy coating,

[0018] The amount of single-walled carbon nanotubes (SWCNT) is in the range of 0.0025% to 0.0075%, preferably 0.0035% to 0.0065%, and

[0019] The amount of at least one ionic liquid (IL) is in the range of 2.75% to 4.5%, preferably 3.4% to 4.0%.

[0020] It has surprisingly been found that the addition of a specific amount of at least one ionic liquid (IL) and single-walled carbon nanotubes (SWCNT) increases the conductivity of the coating or sealant obtainable by the epoxy composition of the invention, thereby allowing the current to be transmitted from the surface through the coating / sealant to the conductive varnish and / or to be transmitted through the coating down to the ground point in the absence of a conductive varnish. Dissipative coatings or sealants are obtained. With the aid of the ionic liquid, the single-walled carbon nanotubes can be uniformly dispersed in these coatings, thus making the resin a uniform conductor, which can largely eliminate the blind spots of the coating that usually occur in the case of the addition of carbon fibers. Such coatings and sealants exhibit a sufficient safety margin, with a resistance preferably less than 10 7 Ohm or even less than 10 7 Ohm, for example, 10 4 -10 6 ohm.

[0021] In a second aspect, the present invention relates to a conductive epoxy coating composition comprising:

[0022] - at least one epoxy resin,

[0023] - at least one curing agent for epoxy resins,

[0024] -0.0025%-0.0075% single-walled carbon nanotubes (SWCNTs), and

[0025] - 2.75% to 4.5% of at least one ionic liquid (IL),

[0026] Based on the total weight of the conductive epoxy coating composition.

[0027] Preferred embodiments of the composition are reproduced in the dependent claims.

[0028] Specific embodiments of the invention

[0029] Compound names beginning with "(poly)" denote substances that formally contain two or more of the functional groups that appear in their names per molecule. The compounds may be monomeric, oligomeric or polymeric. Polyamines, for example, are compounds having two or more amino groups. Polyepoxides are compounds having two or more epoxy groups.

[0030] The difference between a coating and a seal coat lies primarily in the amount of the composition of the invention applied. A seal coat is a coating for which a relatively small amount of material is applied, to give a coating thickness of up to about 500 μm. Even greater coating thicknesses are often referred to as coatings, although the transition from seal coat to coating is not clearly defined.

[0031] A “primary amino group” refers to an amino group that is bonded to a single organic group and carries two hydrogen atoms; a “secondary amino group” refers to an amino group that is bonded to two organic groups and carries one hydrogen atom, the two organic groups together may also be part of a ring; and a “tertiary amino group” refers to an amino group that is bonded to three organic groups, two or three of which may also be part of one or more rings, and does not carry any hydrogen atoms.

[0032] "Amine hydrogen" refers to the hydrogen atoms of primary and secondary amino groups.

[0033] "Amine hydrogen equivalent" refers to the mass of an amine or amine-containing composition that contains one molar equivalent of amine hydrogen.

[0034] "Thinner" refers to a substance that is soluble in the epoxy resin and reduces its viscosity, and that is not chemically incorporated into the epoxy resin polymer during the curing process.

[0035] "Molecular weight" refers to the molar mass of a molecule (g / mol). "Average molecular weight" refers to the number average Mn of a polydisperse mixture of oligomeric or polymeric molecules, which is usually determined by gel permeation chromatography (GPC) using polystyrene standards.

[0036] "Pot life" refers to the duration of workability of the epoxy coating composition, ie, the maximum possible time span between mixing the components and applying the mixed composition wherein the composition is sufficiently free-flowing and capable of wetting the substrate surface.

[0037] The "open time" of an adhesive refers to the maximum time span between application of the adhesive and joining of the parts to be bonded that is possible for a cohesive bond to form.

[0038] "Room temperature" refers to a temperature of 23°C.

[0039] A composition is said to be "storage stable" if it can be stored in a suitable container at room temperature for extended periods of time, generally at least 3 months to 6 months and longer, without its application properties being altered by storage to an extent relevant to its use.

[0040] A "diluent" is a substance that is soluble in the epoxy resin and reduces its viscosity, but that does not chemically bond into the epoxy resin polymer during cure.

[0041] “Carbon nanotubes” are carbon tubes with a diameter in the nanometer range, in particular in the range from 1 nm to 50 nm, and with a wall made of one or more layers of graphene (ie carbon with carbon atoms arranged in a ring).

[0042] Carbon nanotubes are industrially manufactured and commercially available in a variety of qualities. They are electrically conductive. Single-walled carbon nanotubes (so-called "SWCNTs") are particularly suitable for the present invention. They all consist of carbon atoms, and their geometric structure can be considered to be a curled-up monolayer of graphene. They are preferably used as dispersions in liquid carrier materials, particularly in liquids that are highly compatible with epoxy coating compositions (particularly alkyl glycidyl ethers, fatty acid esters or ethoxylated alcohols). Compared to single-walled carbon nanotubes, multi-walled carbon tubes have been found to be less suitable for the present invention.

[0043] Preference is given to dispersions with 10% by weight of single-walled carbon nanotubes, in particular in alkyl glycidyl ethers, in particular C12-C14 alkyl glycidyl ethers, such as are also used as reactive diluents for epoxy resins. Such dispersions are commercially available, for example as Matrix 301 (from OCSIAL).

[0044] The inventors have found that the specific amount of single-walled carbon nanotubes required by weight can achieve a good balance of sufficient electrical conductivity and satisfactory mechanical properties. Single-walled carbon nanotubes exceeding 0.0075% may no longer contribute significantly to electrical conductivity, but lead to a significant reduction in leveling properties. Less than 0.0025% will not result in sufficiently low electrical resistance, for example, less than 10 7 ohms, or may even result in higher than 10 9 Ohms of resistance.

[0045] The combination of the present invention further comprises 2.75% to 4.5%, preferably 3.4% to 4.0%, of at least one ionic liquid (IL), based on the total weight of the conductive epoxy coating to which the combination is added.

[0046] Preferred ionic liquids (ILs) useful in the present invention are selected from ethoxylated alkyl amides, stearyl glycerol, fatty acid esters, cationic polyacrylates, esters or ethers of polyols and sodium alkyl sulfonates, quaternary ammonium compounds, alkyl phosphates, sodium dicyanamide and liquid salts, preferably quaternary ammonium compounds, sodium dicyanamide and liquid salts, most preferably quaternary ammonium compounds or liquid salts.

[0047] In the case where the ionic liquid (IL) is a liquid salt composed of a cation and an anion, the liquid salt preferably contains at least one cation selected from imidazolium, pyridinium, pyrrolidinium, phosphonium, ammonium and sulfonium, more preferably imidazolium and ammonium.

[0048] The ionic liquid (IL) preferably contains an anion selected from halogen, carboxylate, sulfate, sulfonate, thiocyanate, aluminate, borate, phosphate, phosphinate, amide, antimonate, imide and methide. Most preferably, the anion is dicyanamide or sulfate.

[0049] Preferably the ionic liquid is water soluble.

[0050] A preferred specific example of the ionic liquid is tetraalkylammonium alkyl sulfate, such as tetraalkylammonium ethyl sulfate, which is available under the trade name Deuteron LE 100LV. Alkyl as used herein may refer to a C1-C20 alkyl group, such as a C6-C12 alkyl group.

[0051] It was found that adding less than 2.75% of ionic liquid (IL) to the epoxy coating composition may not result in sufficiently low resistance, while more than 4.5% may deteriorate the leveling and mechanical properties of the resulting coating.

[0052] Advantageously, the electrostatically conductive material used in the present invention consists essentially of a combination of single-walled carbon nanotubes (SWCNT) and at least one ionic liquid (IL), which means that at least 85%, preferably at least 90%, more preferably at least 95%, or most preferably at least 99%, or 100% of the total weight of the electrostatically conductive material added to the epoxy coating composition consists of the specific combination as described above. Other electrostatically conductive materials or conductive fillers such as conductive mica, metal powder, metal oxide, carbon black, carbon fiber or composite conductive powder constitute the remainder.

[0053] The epoxy coating composition of the present invention contains a curing agent for the epoxy resin. The curing agent preferably comprises at least one amine.

[0054] Preferred amines as curing agents are aliphatic, cycloaliphatic or araliphatic polyamines having at least 2, in particular at least 3 or 4, amine hydrogens, such as, in particular, 2,2-dimethylpropane-1,3-diamine, pentane-1,3-diamine (DAMP), pentane-1,5-diamine, 1,5-diamino-2-methylpentane (MPMD), 2-butyl-2-ethylpentane-1,5-diamine (C11 neodiamine), hexane-1,6-diamine, 2,5-dimethylhexane-1,6-diamine, 2,2(4),4-trimethylhexane-1,6-diamine (TMD), heptane-1,7-diamine, octane-1,8-diamine, nonane-1,9-diamine, decane-1,10-diamine, undecane-1,11-diamine, dodecane-1,12-diamine, 1,2-diamine, 1,3-diamine, 1,5-diamino-2-methylpentane (MPMD), 2-butyl-2-ethylpentane-1,5-diamine (C11 neodiamine), 2-, 1,3- or 1,4-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, bis(4-amino-3-ethylcyclohexyl)methane, bis(4-amino-3,5-dimethylcyclohexyl)methane, bis(4-amino-3-ethyl-5-methylcyclohexyl)methane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (isophoronediamine or IPDA), 2(4)-methyl-1,3-diaminocyclohexane, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane (NBDA), 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0 2,6 ] decane, 1,4-diamino-2,2,6-trimethylcyclohexane (TMCDA), menthane-1,8-diamine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 1,3-bis(aminomethyl)benzene (MXDA), 1,4-bis(aminomethyl)benzene, bis(2-aminoethyl)ether, 3,6-dioxaoctane-1,8-diamine, 4,7-dioxadecane-1,10-diamine , 4,7-dioxadecane-2,9-diamine, 4,9-dioxadodecane-1,12-diamine, 5,8-dioxadodecane-3,10-diamine, 4,7,10-trioxatridecane-1,13-diamine or higher oligomers of these diamines, bis(3-aminopropyl)polytetrahydrofuran or other polytetrahydrofuran diamines, cycloaliphatic diamines containing ether groups from the propoxylation and subsequent amination of 1,4-dimethylolcyclohexane, in particular RFD-270 (from Huntsman), or polyoxyalkylene diamines or triamines, especially D-230, D-400, D-2000, EDR-104, EDR-148, EDR-176, T-403, T-3000, T-5000 (both from Huntsman), or from BASF or Nitroi l, 2-aminoethylpiperazine, 3-dimethylaminopropylamine (DMAPA), 3-(3-(dimethylamino)propylamino)propylamine (DMAPAPA), bis(6-aminohexyl)amine (BHMT), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA) or higher homologues of linear polyethyleneamine, dipropylenetriamine (DPTA), N-(2-aminoethyl)propane-1,3-diamine (N3 amine), N,N'-bis(3-aminopropyl)ethylenediamine (N4 amine), N,N'-bis(3-aminopropyl)-1,4-diaminobutane, N5-(3-aminopropyl)-2-methylpentane-1,5-diamine, N3-(3-aminopentyl)pentane-1,3-diamine, N5-(3-aminopropyl)-2-methylpentane-1,5-diamine N,N'-bis(3-amino-1-ethylpropyl)-2-methylpentane-1,5-diamine, N-benzyldiethylenetriamine, N-benzyltriethylenetetramine, N,N'-dibenzyltriethylenetetramine, N"-benzyl-N,N'-bis(3-aminopropyl)ethylenediamine, N",N"'-dibenzyl-N,N'-bis(3-aminopropyl)ethylenediamine 1,2-diamine, N-benzylpropane-1,2-diamine, N,N'-dibenzylpropane-1,2-diamine, N-benzyl-1,3-bis(aminomethyl)benzene, N,N'-dibenzyl-1,3-bis(aminomethyl)benzene, N-(2-ethylhexyl)-1,3-bis(aminomethyl)benzene, N,N'-bis(2-ethylhexyl)-1,3-bis(aminomethyl)benzene, styrenated MXDA (can be used as 240 from Mitsubishi Gas Chemical); adducts of the abovementioned or other polyamines with epoxides or epoxy resins, especially with diepoxides or monoepoxides, or reaction products of polyamidoamines, especially mono- or polycarboxylic acids or their esters or anhydrides, especially dimer fatty acids, with a stoichiometric excess of aliphatic, cycloaliphatic or aromatic polyamines, especially polyalkyleneamines, such as DETA or TETA, or Mannich bases, especially phenalkamines (i.e. reaction products of phenols, especially cardanol, with aldehydes, especially formaldehyde and polyamines).

[0055] The curing agent preferably comprises at least one amine selected from the group consisting of TMD, 1,2-, 1,3- or 1,4-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, IPDA, 2(4)-methyl-1,3-diaminocyclohexane, MXDA, an amine with an average molecular weight of M n Polyoxypropylene diamines, DMAPAPA, BHMT, DETA, TETA, TEPA, PEHA, DPTA, N3 amines, N4 amines, adducts of these or other polyamines with mono- or diepoxides and Mannich bases in the range of 200 to 500 g / mol.

[0056] The curing agent may optionally comprise at least one diluent.

[0057] Particularly suitable are xylene, 2-methoxyethanol, dimethoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-isopropoxyethanol, 2-butoxyethanol, 2-phenoxyethanol, 2-benzyloxyethanol, benzyl alcohol, ethylene glycol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol diphenyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-butyl ether, propylene glycol butyl ether, propylene glycol phenyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol di-n-butyl ether, diphenylmethane, diisopropylnaphthalene, mineral oil fractions, for example grades (from Exxon), alkylphenols such as tert-butylphenol, nonylphenol, dodecylphenol, cardanol (from cashew nut shell liquid, containing 3-(8,11,14-pentadecatrienyl)phenol as its main component), styrenated phenols, bisphenols, aromatic hydrocarbon resins, especially those containing phenolic groups, alkoxylated phenols, especially ethoxylated or propoxylated phenol, especially 2-phenoxyethanol, adipates, sebacates, phthalates, benzoates, organic phosphates or sulfonates or sulfonamides.

[0058] Preferred diluents have a boiling point greater than 200°C.

[0059] The diluent is preferably selected from benzyl alcohol, styrenated phenol, ethoxylated phenol, aromatic hydrocarbon resins containing phenol groups, in particular LS 500, LX 200, LA 300 or LA 700 grades (from Rütgers), diisopropylnaphthalene and cardanol.

[0060] Benzyl alcohol is particularly preferred.

[0061] The curing agent optionally comprises at least one accelerator.

[0062] Suitable accelerators are substances which accelerate the reaction between amino and epoxy groups, in particular acids or compounds which can be hydrolyzed to acids, in particular organic carboxylic acids such as acetic acid, benzoic acid, salicylic acid, 2-nitrobenzoic acid, lactic acid, organic sulfonic acids such as methanesulfonic acid, p-toluenesulfonic acid or 4-dodecylbenzenesulfonic acid, sulfonic esters, other organic or inorganic acids such as, in particular, phosphoric acid, or mixtures of the aforementioned acids and esters; nitrates, in particular for example calcium nitrate; tertiary amines, in particular for example 1,4-diazabicyclo[2.2.2]octane, benzyldimethylamine, α-methylbenzyldimethylamine, triethanolamine, dimethylaminopropylamine; imidazoles, for example, in particular N-methylimidazole, N-vinylimidazole or 1,2-dimethylimidazole; salts of these tertiary amines; quaternary ammonium salts, such as, in particular, benzyltrimethylammonium chloride; amidines, such as, in particular, 1,8-diazabicyclo[5.4.0]undec-7-ene; guanidines, such as, in particular, 1,1,3,3-tetramethylguanidine; phenols, in particular bisphenols, phenol-formaldehyde resins or Mannich bases, such as, in particular, 2-(dimethylaminomethyl)phenol, 2,4,6-tris(dimethylaminomethyl)phenol or polymers of phenol, formaldehyde and N,N-dimethylpropane-1,3-diamine, phosphites, in particular diphenyl or triphenylphosphites, or compounds containing mercapto groups.

[0063] Preferred accelerators are acids, nitrates, tertiary amines or Mannich bases.

[0064] The epoxy coating composition of the present invention is based on an epoxy resin which constitutes the coating binder.

[0065] Suitable epoxy resins are obtainable in a known manner, in particular from the oxidation of olefins or from the reaction of epichlorohydrin with polyols, polyphenols or amines.

[0066] Suitable epoxy resins are especially aromatic epoxy resins, especially the glycidyl ethers of:

[0067] - Bisphenol A, bisphenol F or bisphenol A / F, where A stands for acetone and F stands for formaldehyde, are used as reactants for the preparation of these bisphenols. In the case of bisphenol F, positional isomers may also be present, in particular those derived from 2,4'- or 2,2'-hydroxyphenylmethane.

[0068] – dihydroxybenzene derivatives, such as resorcinol, hydroquinone or catechol;

[0069] – Other bisphenols or polyphenols, such as bis(4-hydroxy-3-methylphenyl)methane, 2,2-bis(4-hydroxy-3-methylphenyl)propane (bisphenol C), bis(3,5-dimethyl-4-hydroxyphenyl)methane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane (bisphenol B), 3,3-bis(4-hydroxyphenyl)pentane, 3,4-bis(4-hydroxyphenyl)hexane, 4,4-bis(4-hydroxyphenyl)heptane, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 2,4-bis(3,5-dimethyl-4-hydroxyphenyl)-2-methyl butane, 1,1-bis(4-hydroxyphenyl)cyclohexane (bisphenol Z), 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC), 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene (bisphenol P), 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene (bisphenol M), 4,4'-dihydroxybiphenyl (DOD), 4,4'-dihydroxybenzophenone, bis(2-hydroxynaphthalen-1-yl)methane, bis(4-hydroxynaphthalen-1-yl)methane, 1,5-dihydroxynaphthalene, tris(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)ether or bis(4-hydroxyphenyl)sulfone;

[0070] – novolacs, in particular condensation products of phenol or cresol with formaldehyde or paraformaldehyde or acetaldehyde or crotonaldehyde or isobutyraldehyde or 2-ethylhexanal or benzaldehyde or furfural;

[0071] – Aromatic amines, such as aniline, toluidine, 4-aminophenol, 4,4'-methylenediphenyldiamine, 4,4'-methylenediphenyldi(N-methyl)amine, 4,4'-[1,4-phenylenebis(1-methylethylidene)]dianiline (dianiline P) or 4,4'-[1,3-phenylenebis(1-methylethylidene)]dianiline (dianiline M).

[0072] Other suitable epoxy resins are aliphatic or cycloaliphatic polyepoxides, in particular

[0073] - saturated or unsaturated, branched or unbranched, cyclic or open-chain, difunctional, trifunctional or tetrafunctional, C2 to C 30 Alcohols, in particular ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, octanediol, polypropylene glycol, dimethylolcyclohexane, neopentyl glycol, dibromoneopentyl glycol, castor oil, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol or glycerol, or glycidyl ethers of alkoxylated glycerol or alkoxylated trimethylolpropane;

[0074] - hydrogenated bisphenol A, F or A / F liquid resins, or glycidyl products of hydrogenated bisphenol A, F or A / F;

[0075] - N-glycidyl derivatives of amides or heterocyclic nitrogen bases, such as triglycidyl cyanurate or triglycidyl isocyanurate, or the reaction products of epichlorohydrin with hydantoin.

[0076] Epoxy resins from the oxidation of olefins, such as, in particular, vinylcyclohexene, dicyclopentadiene, cyclohexadiene, cyclododecadiene, cyclododecatriene, isoprene, 1,5-hexadiene, butadiene, polybutadiene or divinylbenzene.

[0077] The epoxy resin is preferably a liquid resin or a mixture containing two or more liquid epoxy resins.

[0078] "Liquid epoxy resin" refers to commercial polyepoxides with a glass transition temperature below 25°C.

[0079] Epoxy resins are especially room temperature liquid aromatic diepoxides with an epoxy equivalent weight of 110-200 g / mol, preferably 150-200 g / mol, especially bisphenol-based resins, especially bisphenol A diglycidyl ether and / or bisphenol F diglycidyl ether, which are commercially available from, for example, Ol in, Huntsman or Momentive. These liquid resins have a low viscosity for epoxy resins and enable rapid curing and high hardness. They may contain a certain proportion of solid bisphenol A resins or novolac glycidyl ethers.

[0080] The resin component may contain a reactive diluent.

[0081] Preferred reactive diluents are reactive diluents containing epoxy groups, in particular butanediol diglycidyl ether, hexanediol diglycidyl ether, trimethylolpropane di- or triglycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, guaiacol glycidyl ether, 4-methoxyphenyl glycidyl ether, p-n-butylphenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, 4-nonylphenyl glycidyl ether, 4-dodecylphenyl glycidyl ether, cardanol glycidyl ether, benzyl glycidyl ether, allyl glycidyl ether, butyl glycidyl ether, hexyl glycidyl ether, 2-ethylhexyl glycidyl ether or glycidyl ethers of natural alcohols, for example, in particular C8-C 10 - or C 12 -C 14 - or C 13 -C 15 -Alkyl glycidyl ether.

[0082] The epoxy coating composition preferably contains at least one other ingredient selected from the group consisting of diluents, accelerators and fillers.

[0083] Suitable accelerators are those already mentioned, in particular salicylic acid, calcium nitrate or 2,4,6-tris(dimethylaminomethyl)phenol or a combination thereof. Most preferred is a combination of calcium nitrate and 2,4,6-tris(dimethylaminomethyl)phenol. This achieves particularly rapid curing, especially at low temperatures, and particularly high hardness.

[0084] Suitable diluents are those already mentioned, in particular those having a boiling point of greater than 200°C.

[0085] The diluent is preferably selected from benzyl alcohol, styrenated phenol, ethoxylated phenol, aromatic hydrocarbon resins containing phenol groups, in particular LS 500, LX 200, LA 300 or LA 700 grades (from Rütgers), diisopropylnaphthalene and cardanol.

[0086] Benzyl alcohol is particularly preferred.

[0087] The epoxy coating composition preferably contains only a small amount of diluent, preferably less than 25 wt%, more preferably less than 15 wt%, and especially less than 10 wt% of diluent. This enables low-emission or zero-emission epoxy resin products.

[0088] Suitable fillers are, in particular, ground or precipitated calcium carbonate, optionally coated with fatty acids, in particular stearates, barite (settled stone), talc, quartz powder, quartz sand, silicon carbide, ankerite, dolomite, wollastonite, kaolin, mica (potassium aluminum silicate), molecular sieves, aluminum oxide, aluminum hydroxide, magnesium hydroxide, silicon dioxide, cement, gypsum, fly ash, carbon black, graphite, metal powders such as aluminum, copper, iron, zinc, silver or steel, PVC powder or hollow beads.

[0089] Calcium carbonate, quartz powder and quartz sand are preferred.

[0090] The epoxy coating composition optionally contains other auxiliaries and additives, in particular the following:

[0091] - reactive diluents, in particular those already mentioned above, or epoxidized soybean oil or linseed oil, compounds containing acetoacetate groups, in particular acetoacetylated polyols, butyrolactones, carbonates, aldehydes, isocyanates or silicones having reactive groups;

[0092] – Solvents

[0093] - other amines, in particular monoamines, such as, in particular, benzylamine or furfurylamine, or aromatic polyamines, such as, in particular, 4,4′-, 2,4′- and / or 2,2′-diaminodiphenylmethane, 2,4- and / or 2,6-toluenediamine, 3,5-dimethylthio-2,4- and / or 3,5-dimethylthio-2,6-toluenediamine, 3,5-diethyl-2,4- and / or 3,5-diethyl-2,6-toluenediamine;

[0094] - compounds containing mercapto groups, in particular liquid mercaptan-terminated polysulfide polymers, mercaptan-terminated polyoxyalkylene ethers, mercaptan-terminated polyoxyalkylene derivatives, polyesters of thiocarboxylic acids, 2,4,6-trimercapto-1,3,5-triazine, triethylene glycol dithiol or ethanedithiol;

[0095] - polymers, in particular polyamides, polysulfides, polyvinyl formal (PVF), polyvinyl butyral (PVB), polyurethanes (PUR), polymers having carboxyl groups, polyamides, butadiene-acrylonitrile copolymers, styrene-acrylonitrile copolymers, butadiene-styrene copolymers, homopolymers or copolymers of unsaturated monomers, in particular selected from the group comprising ethylene, propylene, butylene, isobutylene, isoprene, vinyl acetate or alkyl (meth)acrylates, in particular chlorosulfonated polyethylene or fluorinated polymers or sulfonamide-modified melamine;

[0096] - fibres, in particular glass fibres, carbon fibres, metal fibres, ceramic fibres or polymer fibres such as polyamide fibres or polyethylene fibres;

[0097] - pigments, in particular titanium dioxide, iron oxide or chromium(III) oxide;

[0098] – rheology modifiers, in particular thickeners or anti-settling agents;

[0099] – adhesion improvers, especially organoalkoxysilanes;

[0100] - flame retardants, in particular the aluminum hydroxide or magnesium hydroxide fillers already mentioned, antimony trioxide, antimony pentoxide, boric acid (B(OH)3), zinc borate, zinc phosphate, melamine borate, melamine cyanurate, ammonium polyphosphate, melamine phosphate, melamine pyrophosphate, polybrominated diphenyl oxide or diphenyl ether, phosphates such as in particular diphenylcresyl phosphate, resorcinol bis(diphenyl phosphate), resorcinol diphosphate oligomers, tetraphenylresorcinol diphosphite, ethylenediamine diphosphate, bisphenol A bis(diphenyl phosphate), tris(chloroethyl)phosphate, tris(chloropropyl)phosphate, tris(dichloroisopropyl)phosphate, tris[3-bromo-2,2-bis(bromomethyl)propyl]phosphate, tetrabromobisphenol A, bis(2,3-dibromopropyl ether) of bisphenol A, brominated epoxy resin, ethylenebis(tetrabromophthalimide), ethylenebis(dibromonorbornanedicarboximide), 1,2-bis(tribromophenoxy)ethane, tris(2,3-dibromopropyl)isocyanurate, tribromophenol, hexabromocyclododecane, bis(hexachlorocyclopenta)cyclooctane, or chlorinated paraffin; or

[0101] - Additives, in particular dispersed paraffins, film-forming aids, wetting agents, leveling agents, defoamers, deaerators, stabilizers against oxidation, heat, light or UV radiation, dispersants or biocides.

[0102] The epoxy coating composition preferably comprises further auxiliaries and additives, in particular pigments, wetting agents, leveling agents, dispersants and / or defoamers.

[0103] In a preferred embodiment, the epoxy coating composition contains a polymer dispersant having acidic groups, especially a polymer phosphate-based dispersant, which may be a solution of a polymer phosphate having an acid value of about 50 mg KOH / g.

[0104] The amount of dispersant can be adjusted to significantly improve the flowability of the epoxy coating of the present invention. The preferred amount of dispersant, especially a polymer phosphate ester dispersant, can be in the range of 0.095% to 0.15%, based on the total weight of the conductive epoxy coating. An amount greater than 0.15% may result in significant sedimentation, while an amount less than 0.095% may result in insufficient flowability.

[0105] In the epoxy coating composition, the ratio of the number of groups reactive to epoxy groups relative to the number of epoxy groups is preferably 0.5-1.5, particularly 0.7-1.2. In an exemplary embodiment of the epoxy coating composition of the present invention, the amount of the epoxy resin may be at least 18 wt%, preferably 23 wt%, and for example less than 60 wt% or 50 wt%, based on the total weight of the epoxy coating composition.

[0106] The resin component and the curing agent component of the epoxy coating composition are stored in separate containers. The other ingredients of the epoxy coating composition can be present as a component of the resin component or the curing agent component; the other ingredients reactive with epoxy groups are preferably components of the curing agent component. The other ingredients can also be present as special other components.

[0107] Suitable containers for storing the resin component or the curing agent component are in particular buckets, pails, bags, barrels, cans, boxes or tubes. The components are storable, which means that they can be stored for several months to a year or more before use without their respective properties changing to an extent relevant to their use. In order to use the epoxy resin composition, the components are mixed with each other shortly before or during application. The mixing ratio between the resin component and the curing agent component is preferably selected so that the groups reactive toward epoxy groups in the curing agent component have a suitable ratio to the epoxy groups in the resin component, as described above. In parts by weight, the mixing ratio between the resin component and the curing agent component is generally 1:10-10:1.

[0108] The components are mixed by suitable methods; the mixing can be carried out continuously or batchwise. If mixing is not carried out immediately before application, it must be ensured that not too much time elapses between mixing of the components and application and that application takes place within the pot life. Mixing is carried out in particular at ambient temperature, which is generally in the range of about 5-40° C., preferably about 10-35° C.

[0109] As mentioned above, curing by chemical reaction begins with the mixing of the two components. Curing is usually carried out at a temperature of 0-150°C. It is preferably carried out at ambient temperature and usually lasts from a few days to a few weeks. The duration depends on factors including temperature, the reactivity of the ingredients and their stoichiometric ratio, and the presence of accelerators.

[0110] When freshly mixed, epoxy coatings have a low viscosity. Use a cone and plate viscometer at 20°C for 10 s -1 The viscosity measured after mixing the components for 5 minutes at a shear rate of 100-1500 Å is preferably in the range from 100 to 4000 mPas, preferably in the range from 200 to 3000 mPas, in particular in the range from 300 to 2000 mPas.

[0111] The epoxy coating composition is applied to at least one substrate, the following substrates being particularly suitable:

[0112] – concrete, mortar, cement screed, fiber cement, brick, tile, plaster or natural rock such as granite or marble;

[0113] – Repair or levelling compounds based on PCC (polymer modified cement mortar) or ECC (epoxy modified cement mortar);

[0114] – metals or alloys such as aluminium, iron, steel, copper, other non-ferrous metals, including metals or alloys with surface finishing such as zinc or chromium plating;

[0115] – bitumen or asphalt;

[0116] – leather, textiles, paper, wood, wood-based materials bonded with resins (e.g. phenolic resins, melamine resins or epoxy resins), resin-textile composites or other so-called polymer composites;

[0117] – plastics, such as rigid and flexible PVC, polycarbonate, polystyrene, polyester, polyamide, PMMA, ABS, SAN, epoxy resins, phenolic resins, PUR, POM, TPO, PE, PP, EPM or EPDM, in each case untreated or surface-treated, for example by plasma, corona or flame treatment;

[0118] – Fiber-reinforced plastics, such as carbon fiber reinforced plastic (CFRP), glass fiber reinforced plastic (GFRP) and sheet molding compound (SMC);

[0119] – coated or painted substrates, in particular painted tiles, coated concrete, powder-coated metals or alloys or painted metal sheets;

[0120] - coatings, paints or varnishes, especially coated floors which are topcoated with another floor covering.

[0121] If desired, the substrate can be pretreated before application, in particular by physical and / or chemical cleaning methods or by application of activators or primers.

[0122] During the pot life, the freshly mixed epoxy resin coating is applied to the substrate in a layer thickness of about 0.1 to about 5 mm at ambient temperature. It is applied in particular by pouring it onto the substrate to be coated and then spreading it evenly using, for example, a scraper or a squeegee. The application can also be carried out with a brush or a roller. During the curing process, a uniform, flat, glossy, non-tacky film of high hardness and robustness is generally formed, which has good adhesion to various substrates.

[0123] Another object of the present invention is a cured conductive epoxy coating obtained from the mixed epoxy coating composition.

[0124] After curing, the epoxy coating has an electrical conductivity in a range suitable for use as part of an electrostatic conductive floor coating system.

[0125] In particular, after curing with a layer thickness of 0.3 mm to 3 mm, the epoxy coating has a strength of >10 4 Ohm and <106 The resistance to ground is in the range of ohms.

[0126] The epoxy coating according to the invention is preferably used as part of a static dissipative floor coating system. Such floor coating systems are installed in particular in production halls or in rooms where uncontrolled electrostatic discharges are a problem. These are in particular rooms where electronic components are manufactured, stored or used, or where highly sensitive measuring systems are used, or where flammable liquids or explosives are handled or stored, in particular air-conditioned rooms with particularly low humidity and particles in the air environment, such as so-called clean rooms, radioactive facilities or operating halls.

[0127] Therefore, another object of the present invention is a method for preparing a dissipative coating system, preferably a topcoat system, the coating system comprising a dissipative coating or a dissipative sealing coating, the dissipative coating or the dissipative sealing coating comprising the conductive epoxy coating composition as described above, the method comprising:

[0128] a) applying the epoxy coating composition to a substrate,

[0129] b) optionally smoothing or degassing the applied coating, and

[0130] c) Drying the applied coating to obtain said dissipative coating or sealing coating.

[0131] Therefore, another object of the present invention is a static dissipative floor coating system comprising, from bottom to top:

[0132] (i) at least one substrate,

[0133] (ii) optionally at least one epoxy resin primer,

[0134] (iii) at least one conductive system connected to earth,

[0135] (iv) at least one conductive epoxy coating as described above,

[0136] (v) optionally at least one dispersed filler, and

[0137] (vi) Optionally at least one seal coating.

[0138] The static dissipative floor coating system preferably has a static dissipative floor coating system having ... 3 Ohm, preferably greater than 10 4 Ohm and <5*10 6 Ohm, preferably less than 10 6 Total ground resistance in ohms range.

[0139] Particularly suitable as substrate (i) is concrete, which has optionally been pretreated by grinding, sandblasting or shot blasting, or mortar, cement flooring, fiber cement, bricks, tiles, plaster, natural stone such as granite or marble, asphalt or repair or leveling compounds based on PCC (polymer modified cement mortar) or ECC (epoxy modified cement mortar). Concrete, mortar or cement flooring is preferred.

[0140] The substrate is preferably coated with at least one epoxy resin primer (ii). This preferably has a low viscosity and is substantially free of fillers. It is used in particular to strengthen the substrate, close any pores and ensure good adhesion between the substrate and the other layers. The primer is usually spread over the substrate with a brush, roller or scraper. It is applied in one or more layers, usually at a rate of 0.2 to 0.5 kg / m 2 Commercially available products suitable for this purpose are, for example, -150, -151, -160 or -161 (all from Sika).

[0141] The grounded conductive system (iii) is located on an optionally primed and optionally leveled substrate. For grounding, holes are preferably drilled in the ground and metal protruding screws are fastened therein. A network of copper wires or copper tapes is preferably laid over the screws, which are in contact with the screws. For example, in commercially available A detailed description of the equipment and installation for this can be found in Leitset (from Sika). Depending on the distance of the copper wire or copper tape from the grounding screw and the type of coating (iv), a so-called conductive film is additionally applied to the device, which ensures electrical conduction between the copper wire or copper tape. Suitable as conductive film are highly conductive epoxy resin coatings such as -220W Conductive (from Sika).

[0142] Preferably, the conductive system comprises at least one grounded copper wire or grounded copper tape and optionally at least one 4 The resistance of a conductive film in ohms.

[0143] Then, at least one conductive epoxy coating (iv) containing single-walled carbon nanotubes and ionic liquid as described above is applied to the conductive system as described above and cured thereon. The epoxy coating (iv) can be transparent or colored. It is applied to the conductive system in one or more layers, in particular with a layer thickness of 0.1 to 5 mm, preferably 0.2 to 3 mm. Preferably, the coating is applied at a rate of 0.2 to 3 kg / m 2 , preferably 0.3 to 2.5 kg / m 2 The amount is applied in one layer only.

[0144] The conductive epoxy coating can be filled with dispersed fillers (v) during the pot life, wherein in particular quartz powder and / or quartz sand are suitable as fillers.

[0145] Then, at least one sealing coating (vi) is applied on the conductive epoxy coating, optionally with fillers dispersed therein. The sealing coating is applied in an amount of, in particular, 0.1 to 1 kg / m 2 , preferably 0.2-0.7kg / m 2 .

[0146] In a preferred embodiment of the floor coating system, the conductive epoxy coating (iv) can be pigmented and have a layer thickness of 0.1 to 5 mm, in particular 0.2 to 3 mm. In this case, the floor coating system preferably does not contain excess scattered filler remaining on the upper surface filler and has no sealing coating. Therefore, the pigmented epoxy resin coating (iv) preferably forms the top layer of the floor coating system. It is particularly important that this surface is well ventilated and therefore particularly smooth to obtain a highly aesthetic appearance.

[0147] In this embodiment, the pigmented conductive epoxy coating (iv) is preferably applied directly to the at least one grounded copper wire or the at least one grounded copper tape without a conductive film in between.

[0148] The following examples illustrate the present invention but are not intended to limit the scope of the invention in any way. Example

[0149] 1. The main commercial products used are as follows:

[0150]

[0151]

[0152] 2. Preparation of coating composition:

[0153] A portion of the epoxy resin specified in Table 1 by weight was placed in an insulating dispersion cylinder and cooled with water while the rotation speed was maintained at 800-1200 rpm. Then the SWCNTs specified in Table 1 were added. The mixture was maintained at 60°C and dispersed for 30 minutes. The reactive diluent specified in Table 1 was added and dispersed for 30 minutes at a rotation speed reduced to 500-700 rpm. Then a slurry was prepared.

[0154] The remaining epoxy resin was placed in an insulating dispersion cylinder and maintained at a temperature below 60°C. The other ingredients were added in batches at 500-700 rpm according to the amounts specified in Table 1 and mixed uniformly. Then, the slurry prepared as above was added and dispersed for 30 minutes. After color adjustment and filtration, component A was obtained.

[0155] The epoxy resin and diluent in the weight specified in Table 1 are placed in a reaction kettle under stirring and heated to 60°C. Subsequently, the amine component is added. The mixture is kept stirred at 60°C. When the amine value meets the requirements, the temperature is lowered to below 40°C to obtain component B.

[0156] Finally, the two components were mixed for at least 3 minutes in the ratio specified in Table 1 until homogeneous. A portion of the sample was taken and supplied to the work surface for testing the performance of anti-settling and waterproofing after at least 7 days.

[0157] 3. Resistance measurement method:

[0158] 3.1 Resistance:

[0159] The surface and volume resistivity are measured according to DIN EN 61340-4-1:2015 Electrostatics – Part 4-1: Standard test methods for specific applications – Electrical resistance of floor coverings and installation floors.

[0160] 3.2 Leveling performance: The leveling performance is measured as fluidity in the flow test according to GB / T 22374-2018, and the results are evaluated as follows:

[0161] Good: >160mm; Acceptable: 140-160mm; Poor: <140mm; Very Poor: <100mm

[0162] 3.3 Mechanical properties: Shore D is measured according to GB / T 22374-2018.

[0163] 3.4 Precipitation of component A: The prepared component A was placed in an oscillator at 45°C for a certain period of time (75 rpm, 7 days), and then the precipitation and stratification of the material were observed. The upper layer is liquid and the lower layer is precipitation. If the material becomes uniform and usable after stirring, it is considered to be a soft precipitation; if it cannot become uniform and is therefore unusable after stirring, it is considered to be a hard precipitation.

[0164]

Claims

1. Use of a combination of single-walled carbon nanotubes (SWCNT) and at least one ionic liquid (IL) for preparing a conductive epoxy coating, in, Based on the total weight of the conductive epoxy coating, The amount of single-walled carbon nanotubes (SWCNT) is in the range of 0.0025% to 0.0075%, preferably 0.0035% to 0.0065%, and The amount of at least one ionic liquid (IL) is in the range of 2.75% to 4.5%, preferably 3.4% to 4.0%.

2. The use according to claim 1, characterized in that The ionic liquid is selected from ethoxylated alkylamides, glycerol stearate, fatty acid esters, cationic polyacrylates, esters or ethers of polyols and sodium alkyl sulfonates, quaternary ammonium compounds, alkyl phosphates, sodium dicyanamide and liquid salts, preferably quaternary ammonium compounds, sodium dicyanamide and liquid salts, most preferably quaternary ammonium compounds or liquid salts.

3. The use according to claim 1 or 2, characterized in that The ionic liquid is a tetraalkylammonium alkyl sulfate, such as tetraalkylammonium ethyl sulfate.

4. The use according to any one of the preceding claims, characterized in that At least 85%, preferably at least 90%, more preferably at least 95% or most preferably at least 99% or 100% of the total weight of the electrostatically conductive material added to the epoxy coating consists of the combination of single-walled carbon nanotubes (SWCNTs) and at least one ionic liquid (IL).

5. The use according to any one of the preceding claims, characterized in that A dispersant of a polymer having acidic groups, particularly a dispersant based on polymer phosphate esters, is added to the conductive epoxy coating.

6. The use according to claim 5, characterized in that The amount of the dispersant is in the range of 0.095% to 0.15% based on the total weight of the conductive epoxy coating.

7. A conductive epoxy coating composition comprising - at least one epoxy resin, - at least one curing agent for epoxy resins, -0.0025%-0.0075% single-walled carbon nanotubes (SWCNTs), and - 2.75% to 4.5% of at least one ionic liquid (IL), Based on the total weight of the conductive epoxy coating composition.

8. A conductive epoxy coating composition characterized in that It also comprises dispersants of polymers having acidic groups, especially dispersants based on polymeric phosphates.

9. A conductive epoxy coating composition, characterized in that: The amount of the dispersant is in the range of 0.095% to 0.15% based on the total weight of the conductive epoxy coating.

10. A conductive epoxy coating composition, characterized in that: At least 85%, preferably at least 90%, more preferably at least 95% or most preferably at least 99% or 100% of the total weight of the conductive electrostatic material added in the epoxy coating composition consists of the combination of single-walled carbon nanotubes (SWCNTs) and at least one ionic liquid (IL).

11. A method for preparing a dissipative coating system, preferably a surface coating system, comprising a dissipative coating or a dissipative sealing coating, wherein the dissipative coating or the dissipative sealing coating comprises the conductive epoxy coating composition according to claim 7, the method comprising: a) applying the epoxy coating composition to a substrate, b) optionally smoothing or degassing the applied coating, and c) Drying the applied coating to obtain a dissipative coating or a sealing coating.

12. A dissipative coating system, more particularly a floor coating system, comprising a dissipative coating or a dissipative sealing coating, wherein the dissipative coating or the sealing coating is formed from the conductive epoxy coating composition according to claim 7.

13. The dissipative coating system of claim 12, obtained by the method of claim 11.

14. The dissipative coating system of claim 12 or 13, wherein the ground resistance of the dissipative coating or the sealing coating is less than 5*10 7 Ohm, preferably less than 5*10 6 Ohm or even less than 10 6 Ohms, determined according to DIN EN 61340-4-1.

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