Conductive epoxy coatings and static dissipative flooring

Abstract

The present invention relates to the use of a combination of carbon nanotubes and at least one amine of the formula (I) for producing an electrically conductive epoxy resin coating, and to an electrostatically dissipative flooring system comprising the electrically conductive epoxy resin coating. The invention enables the production of an easily processable, robust, electrostatically dissipative epoxy resin flooring system with a largely constant electrical resistance, particularly high aesthetics, good degassing, and a homogeneous surface.

Description

Technical Field

[0001] The present invention relates to conductive epoxy resin coatings and their use in static dissipative flooring. Background Art

[0002] Static dissipative flooring, also known as ESD (electrostatic dissipative) flooring, is known. It dissipates static electricity generated in a room, such as by walking or driving, through shoes and the flooring to the ground. This prevents spontaneous electrostatic discharge, which can cause defects or malfunctions in the production or operation of sensitive products or equipment.

[0003] Static-dissipative flooring must have a sufficiently low electrical resistance relative to the ground to reliably dissipate electrical charges, but at a level that does not pose a health risk to people in the event of contact with the current. Several standards exist for such flooring, describing test methods for both electrostatic and electrical behavior. For example, DIN EN 61340-4-1 describes a test method for determining the electrical resistance of floor coverings and flooring installations, while DIN EN 61440-4-5 evaluates electrostatic safety in terms of electrical resistance and assesses the chargeability of combinations of people, shoes, and floor coverings.

[0004] Epoxy resin-based floors are particularly strong in terms of mechanical stress and resistance to many substances. Therefore, they are particularly suitable for demanding industrial production spaces. Epoxy resin-based static dissipative floor systems must meet a series of properties. They need to establish reliable adhesion on different substrates and be installed at the lowest possible cost. The static charge absorbed by the floor needs to be reliably dissipated downwards. For this purpose, a so-called conductive system with grounding copper tape or copper wire is laid under the coating. The epoxy resin coating should be easy to install and compatible with the conductive system located below, and after curing should have an aesthetically pleasing, uniform surface with high hardness and low brittleness. For this purpose, the epoxy resin coating needs to have low viscosity, good leveling and good degassing as well as a long open time at ambient temperature, but still cure as quickly as possible without forming hardening defects such as residual stickiness, spots or turbidity. In order to obtain high slip resistance, sand can be spread on the surface and covered with a sealant. After curing, the coated floor should have a hardness of about 10 5 to 10 8 The resistance is in the ohm range and is durable.

[0005] Flooring made of synthetic resins (such as epoxy resins) is an insulator. There are various possibilities for achieving electrical conductivity. It is known to use ionic liquids or organic salts soluble in the synthetic resin matrix to provide conductivity. However, this slows curing, severely reduces the mechanical and chemical durability of the flooring, and the electrical resistance is highly dependent on the surrounding air humidity. Furthermore, conductive solid particles can be added. Suitable materials for this are, for example, metals, which have a strong inherent color and, due to their high specific gravity, settle to the bottom of the container during storage of the still-liquid composition, making homogeneous mixing and distribution in the coating difficult. This results in uneven electrical resistance and areas of excessively low electrical conductivity. It is also known to add conductive carbon black or graphite. While this achieves reliable electrical conductivity, the intense black color of these substances only results in very dark to black coatings, which is generally undesirable for industrial flooring. Fine fibers made of carbon, so-called carbon fibers, are also known. However, these are also difficult to incorporate homogeneously and tend to aggregate, which remains visible after curing and results in an unsightly surface with uneven electrical resistance. More recently, so-called carbon nanotubes (CNTs) have also been found to be useful as conductive fillers. These are carbon nanotubes whose walls consist of individual graphite layers (so-called graphene). Even with very small amounts of carbon nanotubes, good electrical conductivity and uniform resistance can be achieved over large areas, essentially independently of the humidity. However, due to their high surface area, they have a significant thickening effect. This results in poor leveling during application and makes degassing difficult by escaping trapped air in the form of rising bubbles that burst at the surface. Consequently, conductive coatings based on carbon nanotubes require more care and time during application and, after curing, exhibit a less-than-flat surface due to incomplete degassing.

[0006] For example, in EP 1,437,182 an epoxy resin-based static dissipative flooring is described, in which carbon fibers are used as conductive fillers.

[0007] Amines of the formula (I) as epoxy resin curing agents are described, for example, in EP 3,180,383 or EP 3,344,677. SUMMARY OF THE INVENTION

[0009] The object of the present invention is therefore to provide an electrically conductive epoxy resin coating which has an electrical resistance which is essentially independent of the air humidity, which exhibits good leveling and good degassing even when processed without or with only small amounts of non-binding diluents, which cures rapidly and ultimately has a uniform, aesthetically pleasing surface, and which is suitable as a component of a static dissipative flooring system.

[0010] Surprisingly, this object is achieved by using a combination of carbon nanotubes as described below and at least one amine of formula (I). Although epoxy resin coatings containing carbon nanotubes have reliable electrical conductivity and an electrical resistance that is essentially independent of air humidity, the ultrafine carbon nanotubes make leveling and degassing significantly more difficult. In the case of filled pigmented coatings, degassing is particularly difficult, so that even after the still liquid coating is treated with a licker-in roller or a licker-in shoe, a slightly uneven surface with unbroken fine bubbles is still formed. The combination with the amine of formula (I) surprisingly achieves significantly improved leveling and significantly improved degassing, thereby making processing easier and forming an attractive, particularly uniform surface. The use according to the invention makes it possible to produce pigmented coatings with high color intensity, as well as clear coatings, in which the amine of formula (I) surprisingly achieves particularly high transparency. The cured coatings obtained by the use according to the invention have an attractive, uniform surface, high hardness and extremely low brittleness, high resistance to mechanical and chemical stresses, and a conductivity that is uniformly distributed over the surface and is essentially independent of air humidity. The use according to the invention also makes it possible, in particular, to produce electrically conductive coatings which, after curing, have particularly low emissions of organic substances and are suitable for use in hospitals or clean rooms.

[0011] The epoxy resin coatings obtained by the use according to the invention enable the creation of static-dissipative flooring systems that are easy and simple to install, result in particularly low emissions, and meet the highest aesthetic requirements. They enable the creation of flooring systems with a colored, particularly uniform surface, as well as flooring systems with a non-slip, transparently sealed, sand-sprinkled surface. Detailed Description of the Invention

[0013] The present invention provides the use of a combination of carbon nanotubes and at least one amine of the formula (I) for producing conductive epoxy resin coatings.

[0014] Z-NH-A-NH-CH2-Y (I)

[0015] in

[0016] A represents a divalent C2 to C12 radical optionally containing one or more nitrogen atoms or ether groups. 15 alkylene, cycloalkylene or aralkylene, and

[0017] Z represents H or ---CH2-Y, and

[0018] Y represents H or C1 to C 12 an alkyl group, a cycloalkyl group, an aralkyl group or an aryl group,

[0019] The amines of formula (I) contain at least 8 carbon atoms in total.

[0020] “Carbon nanotubes” are carbon tubes having a diameter in the nanometer range, in particular in the range from 1 to 50 nm, and whose walls consist of one or more layers of graphene (ie carbon with carbon atoms arranged in rings).

[0021] "Storage stable" means that the composition can be stored in a suitable container at room temperature for an extended period of time, typically at least 3 months to 6 months and longer, without its application properties or use properties changing during storage to an extent relevant to its use.

[0022] "Diluent" means a substance that is soluble in the epoxy resin and reduces its viscosity, which substance does not chemically bond to the epoxy resin polymer upon curing.

[0023] "Liquid epoxy resin" refers to commercial polyepoxides having a glass transition temperature below 25°C.

[0024] "Molecular weight" refers to the molar mass of a molecule (in grams per mole). "Average molecular weight" refers to the number average molecular weight of a polydisperse mixture of oligomeric or polymeric molecules. n The average molecular weights were determined by gel permeation chromatography (GPC) relative to polystyrene standards.

[0025] "Pot life" means the time interval, starting from mixing of the components of an epoxy resin composition, during which the composition can be processed without losses.

[0026] "Gel time" means the time interval from the mixing of the components of the epoxy resin composition to its gelation.

[0027] A “primary amino group” refers to an amino group that is bound to only one organic group and carries two hydrogen atoms; a “secondary amino group” refers to an amino group that is bound to two organic groups (which together may also form part of a ring) and carries one hydrogen atom; and a “tertiary amino group” refers to an amino group that is bound to three organic groups (two or three of which may also form part of one or more rings) and carries no hydrogen atoms.

[0028] "Amine hydrogen" refers to the hydrogen atoms of primary and secondary amino groups.

[0029] "Aliphatic" means that the amine hydrogen of an amino group is bonded to an aliphatic carbon atom.

[0030] "Amine hydrogen equivalent" means the mass of an amine or amine-containing composition that contains one molar equivalent of amine hydrogen.

[0031] Substance names beginning with "poly", such as polyamine or polyepoxide, indicate substances that formally contain two or more of the functional groups appearing in their names per molecule.

[0032] "Room temperature" means a temperature of 23°C.

[0033] Unless otherwise indicated, weight percent (abbreviated as wt%) represents the mass content of an ingredient in a composition or molecule based on the entire composition or based on the entire molecule. The terms "mass" and "weight" are used synonymously herein.

[0034] All industry standards or specifications mentioned herein refer to the versions in effect at the time the application was first filed.

[0035] Carbon nanotubes are produced industrially and sold commercially in various qualities. They have interesting properties for various applications. In particular, they are electrically conductive.

[0036] Suitable carbon nanotubes are in particular single-walled carbon nanotubes (so-called “single-wall carbon nanotubes”).

[0037] They are preferably used in the form of a dispersion in a liquid carrier material, in particular a liquid which is well compatible with the epoxy resin composition, in particular an alkyl glycidyl ether, a fatty acid ester or an ethoxylated alcohol.

[0038] It is preferred that alkyl glycidyl ethers (especially C 12 to C 14 A dispersion of carbon nanotubes having 10% by weight in an alkyl glycidyl ether (e.g., such as those also used as reactive diluents for epoxy resins) is prepared. Matrix 207 (from OCSiAl) is commercially available.

[0039] Even very small amounts by weight of carbon nanotubes achieve good electrical conductivity, but they significantly increase viscosity and leveling properties and darken the coating to a certain extent.

[0040] Preferably, an amount of carbon nanotubes is used such that the epoxy resin coating is light enough in color to be used as a tinted, light-colored paint or as a clear sealant.

[0041] An amount in the range of 0.001% by weight to 0.1% by weight, based on the entire epoxy resin coating, is preferred.

[0042] Amounts in the range of 0.001% by weight to 0.05% by weight, based on the entire epoxy resin coating, are particularly preferred.

[0043] Therefore, the amount of a dispersion containing 10% by weight of carbon nanotubes used, based on the entire epoxy resin coating, is preferably in the range of 0.01% to 1% by weight, particularly in the range of 0.01% to 0.5% by weight. Within this range, the desired conductivity can be achieved without excessive darkening.

[0044] The content of pigmented coating material is preferably in the range from 0.01% to 0.1% by weight, in particular from 0.01% to 0.05% by weight.

[0045] The content of the clear coating material is preferably in the range of 0.001% by weight to 0.01% by weight, in particular 0.001% by weight to 0.005% by weight.

[0046] In the amines of formula (I), A is preferably selected from the group consisting of 1,2-ethylene, 1,2-propylene, 1,3-propylene, 1,4-butylene, 1,3-butylene, 2-methyl-1,2-propylene, 1,3-pentylene, 1,5-pentylene, 2,2-dimethyl-1,3-propylene, 1,6-hexylene, 2-methyl-1,5-pentylene, 1,7-heptylene, 1,8-octylene, 2,5-dimethyl-1,6-hexylene, 1,9-nonylene, 2,2(4),4-trimethyl-1,6-hexylene, 1,10-decylene, 1,11-undecylene, 2-butyl-2-ethyl-1,5-pentylene, 1,12-dodecylene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, (1,5,5-trimethylcyclohex-1-yl)methane-1,3, 4(2)-methyl-1,3-cyclohexylene, 1,3-cyclohexylene-bis(methylene), 1,4-cyclohexylene-bis(methylene), 1,3-phenylene-bis(methylene), 1,4-phenylene-bis(methylene), 3-oxa-1,5-pentylene, 3,6-dioxa-1,8-octylene, 4,7-dioxa-1,10-decylene, 3-aza-1,5-pentylene, 3,6-diaza-1,8-octylene, 4,7-diaza-1,11-decylene and 3-aza-1,6-hexylene.

[0047] A preferably contains no nitrogen atoms and no ether groups.

[0048] A preferably represents a C2 to C8 alkylene group, in particular 1,2-ethylene, 1,2-propylene, 1,3-propylene, 1,4-butylene, 1,3-butylene, 1,5-pentylene, 1,6-hexylene, 2-methyl-1,5-pentylene, 1,7-heptylene or 1,8-octylene. Amines of formula (I) can achieve particularly good leveling properties.

[0049] Particularly preferably, A represents 1,2-ethylene. Such amines of the formula (I) enable particularly good leveling, particularly good degassing and particularly rapid curing.

[0050] Z is preferably H.

[0051] In the amines of formula (I), Y is preferably selected from the group consisting of H, methyl, ethyl, propyl, isopropyl, butyl, pentyl, heptyl, hept-2-yl, phenyl, naphthyl and cyclohexyl.

[0052] Particularly preferably, Y represents phenyl or cyclohexyl, in particular phenyl. Such amines of the formula (I) enable particularly rapid curing and particularly aesthetic surfaces with high gloss.

[0053] Most preferred are amines of formula (I) in which A represents 1,2-ethylene, Z represents H and Y represents phenyl.

[0054] This amine of formula (I) is N-benzyl-1,2-ethylenediamine, which enables epoxy resin coatings containing carbon nanotubes to have particularly good leveling and a particularly homogeneous, well-degassing surface, as well as very particularly rapid curing.

[0055] The amines of formula (I) in which Z represents H may contain a certain proportion of dialkylated amines, i.e., the corresponding amines in which Z represents ---CH2-Y. They preferably contain up to 30% by weight, particularly preferably up to 20% by weight, and in particular up to 15% by weight of dialkylated amines. Most preferably, the amines of formula (I) in which Z represents H are used in a purity of at least 95% by weight.

[0056] The amines of the formula (I) are preferably prepared by partial alkylation of at least one amine of the formula H2N-A-NH2 with at least one alkylating agent.

[0057] The alkylation is preferably a reductive alkylation, wherein an aldehyde and hydrogen are used as alkylating agents.

[0058] Preferably, the reductive alkylation is carried out in the presence of a suitable catalyst. Preferred catalysts are palladium supported on carbon (Pd / C), platinum supported on carbon (Pt / C), Adams catalyst or Raney nickel, in particular palladium supported on carbon or Raney nickel.

[0059] When molecular hydrogen is used, the reductive alkylation is preferably carried out in a pressure apparatus at a hydrogen pressure of 5 to 150 bar, in particular 10 to 100 bar. It can be carried out as a batch process or preferably as a continuous process.

[0060] The reductive alkylation is preferably carried out at a temperature in the range of 40 to 120°C, in particular 60 to 100°C.

[0061] In the case of small, volatile amines (e.g., in particular, 1,2-ethylenediamine), these are preferably used in a stoichiometric excess relative to the aldehyde, and after the alkylation, the unreacted amine is partially or completely removed from the reaction mixture, in particular by distillation or stripping. If necessary, the reaction mixture can then be further purified, in particular by distillation to separate partially or completely the monoalkylated amine of formula (I) obtained in which Z represents H from the dialkylated amine in which Z represents ---CH2-Y.

[0062] The amine of formula (I) may be in free form or in the form of an adduct with at least one epoxy resin, in particular at least one aromatic diepoxide having an epoxy equivalent weight in the range of 110 to 200 g / mol, preferably 150 to 200 g / mmol, in particular bisphenol A diglycidyl ether and / or bisphenol F diglycidyl ether. The adduct is in particular prepared with an excess of amine, such that at least 1.3 mol of amine of formula (I) are used per epoxy group.

[0063] Preferably, the amount of amine of formula (I) used is such that at least 5%, preferably at least 10%, of all amine hydrogens present in the epoxy resin coating are derived from the amine of formula (I). In particular, 5% to 70%, preferably 5% to 50%, of all amine hydrogens present are derived from the amine of formula (I). This also includes the amine hydrogens derived from the adducted amine of formula (I).

[0064] Another subject of the present invention is a conductive epoxy resin coating obtained by said use, comprising

[0065] - at least one liquid epoxy resin,

[0066] - at least one amine of formula (I),

[0067] - carbon nanotubes, and

[0068] - at least one further ingredient selected from other amines, accelerators, fillers, diluents, surface active additives and stabilizers.

[0069] Suitable liquid epoxy resins are in particular aromatic epoxy resins, in particular the glycidyl ethers of:

[0070] Bisphenol A, bisphenol F or bisphenol A / F, where A is acetone and F is formaldehyde, serves as a reactant for the preparation of the bisphenols. In the case of bisphenol F, positional isomers, in particular derived from 2,4′- or 2,2′-hydroxyphenylmethane, may also be present.

[0071] - dihydroxybenzene derivatives such as resorcinol, hydroquinone or catechol;

[0072] - other bisphenols or polyphenols, for example 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-hydroxynaphth-1-yl)methane, bis(4-hydroxynaphth-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;

[0073] - novolacs, in particular condensation products of phenol or cresol with formaldehyde;

[0074] Aromatic amines, for example aniline, p-toluidine, 4-aminophenol, 4,4′-methylenediphenyldiamine, 4,4′-methylenediphenyldi-(N-methyl)amine, 4,4′-[1,4-phenylene-bis(1-methylethylidene)]diphenylamine (diphenylamine P) or 4,4′-[1,3-phenylene-bis(1-methylethylidene)]diphenylamine (diphenylamine M).

[0075] Other suitable epoxy resins are aliphatic or cycloaliphatic polyepoxides, in particular

[0076] - saturated or unsaturated, branched or unbranched, cyclic or open-chain, difunctional, trifunctional or tetrafunctional C2- to C 30 - glycidyl ethers of 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 alkoxylated glycerol or alkoxylated trimethylolpropane;

[0077] - hydrogenated bisphenol A, F or A / F liquid resins, or glycidylation products of hydrogenated bisphenol A, F or A / F;

[0078] - N-glycidyl derivatives of amides or heterocyclic nitrogenous bases, for example triglycidyl cyanurate or triglycidyl isocyanurate, or the reaction products of epichlorohydrin and hydantoin.

[0079] Particularly preferred are aromatic diepoxides that are liquid at room temperature and have an epoxy equivalent weight in the range of 110 to 200 g / mol, preferably 150 to 200 g / mol, in particular bisphenol A diglycidyl ether and / or bisphenol F diglycidyl ether, such as those commercially available from Olin, Huntsman or Momentive. These liquid resins enable rapid curing and high hardness.

[0080] Along with the liquid epoxy resin, the coating may contain a certain proportion of solid bisphenol A resin or novolac-glycidyl ether or reactive diluent.

[0081] Suitable reactive diluents are, 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- to C 10 - or C 12 - to C 14 - or C 13 - to C 15 -alkyl glycidyl ether.

[0082] The epoxy resin coating preferably contains the aforementioned amines of the formula (I) and the aforementioned carbon nanotubes in the aforementioned amounts.

[0083] Besides at least one amine of the formula (I), the epoxy resin coating preferably comprises at least one further amine, in particular at least one further amine having at least four aliphatic amine hydrogens.

[0084] Suitable amines having at least four aliphatic amine hydrogens are in particular 2,2-dimethyl-1,3-propylenediamine, 1,3-pentanediamine (DAMP), 1,5-pentanediamine, 1,5-diamino-2-methylpentane (MPMD), 2-butyl-2-ethyl-1,5-pentanediamine (C11-neodiamine), 1,6-hexanediamine, 2,5-dimethyl-1,6-hexanediamine, 2,2(4),4-trimethyl-1,6-hexanediamine (TMD), 1,7-heptanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (TMD), A), 1,2-diaminocyclohexane, 1,3-diaminohexane, 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, 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), 1,8-menthane 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- diamines, 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, polyoxyalkylene diamines or triamines, in particular polyoxypropylene diamine or polyoxypropylene triamine, for example D-230, D-400 or T-403 (all from Huntsman), diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TEPA), pentaethylenehexamine (PEHA), dipropylenetriamine (DPTA), N-(2-aminoethyl)-1,3-propanediamine (N3-amine), N,N'-bis(3-aminopropyl)ethylenediamine (N4-amine), N,N'-bis(3-aminopropyl)-1,4-diaminobutane Alkane, N5-(3-aminopropyl)-2-methyl-1,5-pentanediamine, N3-(3-aminopentyl)-1,3-pentanediamine, N5-(3-amino-1-ethylpropyl)-2-methyl-1,5-pentanediamine, N,N'-bis(3-amino-1-ethylpropyl)-2-methyl-1,5-pentanediamine, 3-(2-aminoethyl)aminopropylamine, bis(hexamethylene)triamine (BHMT), and adducts of these amines with epoxy resins.

[0085] The other amines are preferably selected from TMD, IPDA, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, 2(4)-methyl-1,3-diaminocyclohexane, MXDA, average molecular weight M n Polyoxypropylene diamine, average molecular weight M in the range of 200 to 500 g / mol n Polyoxypropylenetriamines in the range of 300 to 500 g / mol, BHMT, DETA, TETA, TEPA, PEHA, DPTA, N3-amine, N4-amine, adducts of IPDA, MXDA, DETA, TETA or TEPA with epoxy resins, and mixtures of two or more of the aforementioned amines.

[0086] Particularly preferred are TMD, IPDA, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, MXDA, average molecular weight M n Polyoxypropylene diamines in the range of 200 to 500 g / mol, adducts of IPDA and / or MXDA with aromatic diepoxides or mixtures of two or more of said amines.

[0087] Other suitable amines are N-aminoethylpiperazine, 3-dimethylaminopropylamine (DMAPA), 3-(3-(dimethylamino)propylamino)propylamine (DMAPAPA), monoamines, polyamidoamines, in particular reaction products of mono- or polycarboxylic acids or their esters or anhydrides (in particular dimerized fatty acids) with polyamines used in a stoichiometric excess (in particular DETA or TETA), Mannich bases, in particular phenalkamines, i.e. reaction products of phenols (in particular cardanol) with aldehydes (in particular formaldehyde), and polyamines, or aromatic polyamines, such as in particular 4,4′-, 2,4′- and / or 2,2′-diaminodiphenylmethane, 2,4(6)-toluenediamine, 3,5-dimethylthio-2,4(6)-toluenediamine or 3,5-diethyl-2,4(6)-toluenediamine.

[0088] Preferably, 5% to 50% of all amine hydrogens present in the epoxy resin coating are derived from amines of formula (I), and at least one other amine having at least four aliphatic amine hydrogens is present.

[0089] Such other amines having at least four aliphatic amine hydrogens are preferably selected from TMD, IPDA, 1,3-bis(aminomethyl)cyclohexane, MXDA and amines having an average molecular weight of M n Polyoxypropylene diamine in the range of 200 to 500 g / mol. Combinations of two or more of the aforementioned other amines are also preferred.

[0090] Suitable accelerators are, 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 acid esters, other organic or inorganic acids such as, in particular, phosphoric acid, or mixtures of the aforementioned acids and esters; nitrates such as, in particular, calcium nitrate; tertiary amines such as, in particular, 1,4-diazabicyclo[2.2.2]octane, benzyldimethylamine, α-methylbenzyldimethylamine, triethanolamine, dimethylaminopropylamine, imidazoles such as, in particular, N-methylimidazole, N-ethylenedimethylamine, imidazole or 1,2-dimethylimidazole, salts of the aforementioned tertiary amines, quaternary ammonium salts, such as, in particular, benzyltrimethylammonium chloride, amidines, such as, in particular, 1,8-diazabicyclo[5.4.0]-7-undecene, guanidines, such as, in particular, 1,1,3,3-tetramethylguanidine, phenols, in particular, bisphenols, phenol 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-dimethyl-1,3-propylenediamine, phosphites, such as, in particular, di- or triphenylphosphite, or compounds having mercapto groups.

[0091] Preference is given to acids, nitrates, tertiary amines or Mannich bases, in particular salicylic acid, calcium nitrate or 2,4,6-tris(dimethylaminomethyl)phenol, or combinations of these accelerators.

[0092] Suitable fillers are, in particular, ground calcium carbonate or precipitated calcium carbonate, optionally coated with fatty acids, in particular stearates, barite (settled stone), talc, quartz powder, quartz sand, silicon carbide, mica iron ore, dolomite, wollastonite, kaolin, mica (potassium-aluminum-silicate), molecular sieves, aluminum oxide, zinc oxide, aluminum-doped zinc oxide, aluminum hydroxide, magnesium hydroxide, silicon dioxide, cement, gypsum, fly ash, carbon black, graphite, metal powders, for example aluminum, copper, iron, zinc, silver or steel, PVC powder or hollow spheres.

[0093] Fillers used in pigmented epoxy resin coatings are preferably calcium carbonate, talc, quartz powder, quartz sand, dolomite, wollastonite, or kaolin, particularly calcium carbonate, quartz powder, quartz sand, or a combination thereof. Due to their relatively low specific gravity, such fillers hardly settle during application and curing, resulting in a substantially homogeneous cured coating with particularly uniform conductivity.

[0094] The filler used in the transparent epoxy resin coating is preferably zinc oxide, in particular aluminum-doped zinc oxide, particularly in relatively low amounts, particularly in the range of 0.5 to 5 wt. %, preferably 1 to 3 wt. %, based on the total epoxy resin coating. This amount of zinc oxide brightens and compensates for the slightly darker hue of the small amount of carbon nanotubes and provides good electrical conductivity, thereby achieving high transparency without substantially darkening or lightening the substrate. This transparent epoxy resin coating is also suitable as a transparent sealant for various static-dissipative floor coverings. In particular, it is suitable as a transparent sealant for surfaces coated with conductive quartz sand, where the sand and the underlying coating are easily visible through the transparent sealant. Such surfaces are particularly non-slip and meet high aesthetic requirements.

[0095] The transparent epoxy resin coating preferably contains less than 0.1% by weight of fillers or pigments other than carbon nanotubes and zinc oxide, and in particular contains no such fillers or pigments.

[0096] Suitable diluents are, in particular, 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, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, diphenylmethane, diisopropylnaphthalene, petroleum fractions, for example -type (from Exxon), alkylphenols such as tert-butylphenol, nonylphenol, dodecylphenol, cardanol (from cashew nut shell liquid, containing 3-(8,11-pentadecadienyl)phenol), styrenated phenols, bisphenols, aromatic hydrocarbon resins, especially those containing phenolic groups, alkoxylated phenols, especially ethoxylated or propoxylated phenols, especially 2-phenoxyethanol, adipates, sebacates, phthalates, benzoates, organic phosphates or sulfonates or sulfonamides.

[0097] The diluent preferably has a boiling point greater than 200°C.

[0098] Particularly preferred is benzyl alcohol.

[0099] The epoxy resin coating preferably contains a particularly low content (in particular less than 1% by weight) of diluents having a boiling point below 200° C.

[0100] The epoxy resin coating preferably contains a relatively small amount (especially less than 20% by weight, preferably less than 15% by weight) of a diluent having a boiling point above 200°C.

[0101] Suitable surface additives are, in particular, defoamers, deaerators, wetting agents, dispersants, leveling agents or dispersing waxes. The epoxy resin coating preferably comprises a combination of these additives.

[0102] Suitable stabilizers are, in particular, stabilizers against UV rays or heat.

[0103] Epoxy resin coatings optionally contain further auxiliaries and additives, in particular:

[0104] - pigments, in particular titanium dioxide, iron oxide or chromium(III) oxide,

[0105] - compounds containing mercapto groups, in particular thiol-terminated polysulfide polymers, thiol-terminated polyoxyalkylene ethers, thiol-terminated polyoxyalkylene derivatives, polyesters of thiocarboxylic acids, 2,4,6-trimercapto-1,3,5-triazine, triethylene glycol dithiol or ethanedithiol in liquid form,

[0106] - other reactive diluents, in particular epoxidized soybean oil or linseed oil, compounds having acetoacetate groups, in particular acetoacetated polyols, butyrolactone, carbonates, aldehydes, isocyanates or silicones having reactive groups,

[0107] polymers, in particular polyamides, polysulfides, polyvinyl formal (PVF), polyvinyl butyral (PVB), polyurethanes (PUR), polymers containing carboxyl groups, polyamides, butadiene-acrylonitrile copolymers, styrene-acrylonitrile copolymers, butadiene-styrene copolymers, homopolymers or copolymers of unsaturated monomers, such as in particular ethylene, propylene, butylene, isobutylene, isoprene, vinyl acetate or alkyl (meth)acrylates, or chlorosulfonated polyethylene, fluoropolymers or sulfonamide-modified melamine,

[0108] - rheology modifiers, especially anti-settling agents,

[0109] - adhesion promoters, in particular organoalkoxysilanes,

[0110] flame retardants, in particular polybrominated diphenyl oxides or diphenyl ethers, 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, tetrabromo-bisphenol-A, bis(2,3-dibromopropyl ether) of bisphenol A, brominated epoxy resin, ethylene-bis(tetrabromophthalimide), ethylene-bis(dibromonorbornanedicarboximide), 1,2-bis-(tribromophenoxy)ethane, tris(2,3-dibromopropyl)isocyanurate, tribromophenol, hexabromocyclododecane, bis(hexachlorocyclopentadienyl)cyclooctane, or chlorinated paraffins,

[0111] - other conductive substances, in particular doped mineral fillers, metal powders, carbon fibers, carbon black, graphite or ionic liquids, or

[0112] - other additives, in particular film-forming aids or biocides.

[0113] The epoxy resin coating preferably comprises at least two components which are stored in separate containers and are mixed with one another only immediately before application.

[0114] The resin component comprises at least a liquid epoxy resin and optionally other compounds containing epoxy groups.

[0115] The curing agent component comprises an amine of formula (I) and optionally further compounds reactive toward epoxy groups.

[0116] Other components, in particular carbon nanotubes, can be present as components of the resin component and / or the curing agent component. The carbon nanotubes dispersed in the epoxy group-containing liquid are preferably a component of the resin component.

[0117] The epoxy resin coating preferably comprises

[0118] a resin component comprising at least one liquid epoxy resin, carbon nanotubes, at least one defoamer, optionally pigments and fillers and optionally at least one diluent, in particular benzyl alcohol, and

[0119] a curing agent component comprising at least one amine of formula (I), optionally further amines, optionally at least one diluent, in particular benzyl alcohol, and optionally at least one accelerator.

[0120] Epoxy resin coatings are preferably not water-based and contain only small amounts of water, preferably less than 5% by weight, in particular less than 1% by weight of water. Such coatings are particularly resistant to moisture.

[0121] However, epoxy resin coatings may also contain a relatively high content of water. In particular, the resin component or the curing agent component or both may be water-based.

[0122] The epoxy resin coating particularly preferably comprises, based on the entire coating,

[0123] - 0.001 to 0.05% by weight of carbon nanotubes,

[0124] - less than 1% by weight of diluents having a boiling point below 200°C, and

[0125] - less than 5% by weight of water.

[0126] Such coatings are easy to apply, cause virtually no emissions, and enable floor coatings to be achieved that have a particularly high resistance to moisture and good electrical conductivity.

[0127] In a preferred embodiment, the epoxy resin coating is pigmented and contains 20% to 70% by weight, in particular 30% to 60% by weight, of calcium carbonate, quartz powder, quartz sand or a combination thereof, based on the entire coating.

[0128] Such coatings enable particularly durable floor coatings with decorative colors, in which the fillers hardly settle during application and curing and thus cause few unevenness in the coating.

[0129] In another preferred embodiment, the epoxy resin coating is transparent and comprises, based on the total coating,

[0130] - 0.001 to 0.01% by weight of carbon nanotubes,

[0131] - 1 to 3% by weight of zinc oxide, in particular aluminum-doped zinc oxide; and

[0132] In particular, less than 0.1% by weight of fillers or pigments other than carbon nanotubes and zinc oxide.

[0133] Such coatings enable a high degree of transparency, wherein, in particular in combination with electrically conductive decorative quartz sand, particular aesthetic effects can be achieved.

[0134] In epoxy resin coatings, the ratio of the number of groups reactive toward epoxy groups to the number of epoxy groups is preferably in the range from 0.5 to 1.5, in particular from 0.7 to 1.2.

[0135] The resin component and the curing agent component of the epoxy resin composition are stored in containers separated from each other. Suitable containers for storing resin component or curing agent component are particularly buckets, bottles, barrels, bags or cans. Component is storable, that is, it can be stored for several months to one year and longer before use, and can not change its individual properties to the extent relevant to its use. In order to use epoxy resin coating, the components are mixed with each other immediately before application or during application. The mixing ratio between the resin component and the curing agent component is preferably selected so that the group reactive to the epoxy group of the curing agent component and the epoxy group of the resin component exist in a suitable ratio, as described above. In parts by weight, the mixing ratio between the resin component and the curing agent component is usually in the range of 1:10 to 20:1, preferably 1:1 to 10:1.

[0136] The components are mixed by any suitable method; this can be done continuously or batchwise. If mixing is not done immediately prior to application, care must be taken that no significant time elapses between mixing and application and that application is carried out within the pot life. Mixing is preferably carried out at ambient temperature, typically between about 5 and 40°C, preferably between about 10 and 35°C.

[0137] By mixing the two components, curing begins via a chemical reaction. Primary and secondary amino groups and optionally other groups reactive toward epoxy groups react with the epoxy groups via their ring opening (addition reaction). The primary result of these reactions is polymerization and thus curing of the epoxy resin coating.

[0138] Curing is preferably carried out at ambient temperature and generally lasts from a few hours to a few days. The duration depends mainly on the temperature, the reactivity of the ingredients and their stoichiometric ratios, and the presence of accelerators.

[0139] Epoxy resin coatings have low viscosity in the freshly mixed state. The viscosity at 20° C. 5 minutes after mixing the components is preferably in the range of 100 to 4000 mPa·s, preferably 200 to 3000 mPa·s, in particular 300 to 2000 mPa·s, as measured by a cone-plate viscometer in 10 s. -1 Measured at shear rate.

[0140] An epoxy resin coating is applied to at least one substrate, the following being particularly suitable:

[0141] - concrete, mortar, cement flooring, fiber cement, bricks, tiles, plaster, natural stone such as granite or marble, or sand, in particular conductive quartz sand;

[0142] - Repair or leveling materials based on PCC (polymer-modified cement mortar) or ECC (epoxy-modified cement mortar);

[0143] - metals or alloys, such as aluminium, iron, steel, copper, other non-ferrous metals, including metals or alloys with surface treatments, such as zinc-plated or chromium-plated metals;

[0144] - tar or bitumen;

[0145] - plastics, such as hard and soft PVC, polycarbonate, polystyrene, polyester, polyamide, PMMA, ABS, SAN, epoxy resins, phenolic resins, PUR, POM, TPO, PE, PP, EPM or EPDM, each untreated or surface-treated, for example, by means of plasma, corona or flame;

[0146] - fiber-reinforced plastics, such as carbon fiber-reinforced plastics (CFK), glass fiber-reinforced plastics (GFK) and sheet molding compounds (SMC);

[0147] - coated or painted substrates, in particular painted tiles, coated concrete, powder-coated metals or alloys;

[0148] - paints, coatings or lacquers, in particular coated floor coverings covered by other floor coverings.

[0149] If necessary, the substrate can be pretreated before application, in particular by physical and / or chemical cleaning methods or by applying an activator or primer.

[0150] Freshly mixed epoxy resin coatings are typically applied to substrates in a flat manner during their pot life at ambient temperature in a layer thickness of about 0.1 to about 5 mm. Application is typically performed by pouring the coating onto the substrate to be coated and then evenly distributing the coating, for example, using a scraper or squeegee. Application with a brush or roller is also possible. During curing, a homogeneous, uniform, glossy, non-tacky, pigmented or transparent film with high hardness and durability is typically formed, which has good adhesion to various substrates.

[0151] Another subject matter of the present invention is a cured electrically conductive epoxy resin coating obtained from the mixed epoxy resin coating.

[0152] The conductivity range of epoxy coatings after curing makes them suitable as part of static dissipative flooring systems.

[0153] In particular, the resistance to ground measured in accordance with DIN EN 61340-4-1 at a layer thickness in the range of 0.3 to 3 mm after curing of the epoxy resin coating is >5·10 4 Ohm and <10 9 ohm range.

[0154] If the cured epoxy resin coating is transparent, its absorption at 665 nm, determined by UV-Vis spectroscopy at a layer thickness of 0.5 mm on glass, is preferably at most 0.7, preferably at most 0.6, in particular at most 0.5. Such coatings are also particularly suitable as transparent sealants for static-dissipative floors, in particular also for floors sprinkled with conductive quartz sand, where the color and structure of the sand remain readily visible and a highly aesthetic surface is achieved.

[0155] The epoxy resin coatings of the present invention are preferably used as components of static-dissipative flooring systems. Such flooring systems are particularly installed in production halls or spaces where uncontrolled electrostatic discharges can be a problem. This applies in particular to rooms where electronic components are produced, stored, or used, or where highly sensitive measuring systems are operated, or where flammable liquids or explosives are processed or stored, and especially in climatic rooms with particularly low humidity and low atmospheric particle counts, such as so-called clean rooms, radiology facilities, or operating theatres.

[0156] Another subject of the present invention is therefore an electrostatic dissipative floor system comprising from bottom to top

[0157] (i) at least one substrate,

[0158] (ii) optionally at least one epoxy resin primer,

[0159] (iii) at least one earthed conductive system,

[0160] (iv) at least one layer of conductive epoxy coating as described above,

[0161] (v) optionally at least one spread filler, and

[0162] (vi) Optionally at least one sealant.

[0163] The static dissipative floor system preferably has an overall static dissipative flooring system having a static dissipative flooring system of >5.10 m 4 Ohm and <10 9 Resistance to ground in the ohm range.

[0164] Suitable substrates (i) include, in particular, concrete, optionally 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 materials based on PCC (polymer-modified cement mortar) or ECC (epoxy-modified cement mortar). Preference is given to concrete, mortar or cement flooring.

[0165] The substrate is preferably coated with at least one epoxy resin primer (ii). The primer (ii) preferably has a low viscosity and is substantially filler-free. 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 applied to the substrate with a brush, roller or rubber scraper. It is applied in one or more layers, usually in an amount of 0.2 to 0.5 kg / m 2 Commercially available products suitable for this are, for example, -150, -151, -160 or -161 (all from Sika).

[0166] If the substrate is uneven, the surface can be smoothed with a sand-filled epoxy resin composition after the primer is applied.

[0167] On the optionally primed and optionally smoothed substrate, a grounded conductive system (iii) is laid. For grounding, holes are preferably drilled in the floor and protruding metal screws are fixed therein. A mesh of copper wire or copper tape is preferably placed on the screws, which is in contact with the screws, for example, via provided metal washers. Detailed descriptions of the equipment and installation for this are provided, for example, in the commercially available 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 provided on the device, which ensures electrical conductivity between the copper wire or copper tape. Suitable conductive films are in particular highly conductive epoxy resin coatings, such as -220W Conductive (from Sika).

[0168] The conductive system preferably comprises at least one grounding copper wire or grounding copper tape and optionally at least one conductive wire in contact with it and having a resistance of <10 4 Ohmic conductive film.

[0169] Subsequently, at least one conductive epoxy resin coating (iv) comprising carbon nanotubes and at least one amine of formula (I) is applied to the conductive system and cured as described above. As described above, the epoxy resin coating (iv) can be transparent or pigmented. It is applied to the conductive system in one or more layers, in particular in a layer thickness range of 0.1 to 5 mm, preferably 0.2 to 3 mm. It is preferably applied at a rate of 0.2 to 3 kg / m 2 , preferably 0.3 to 2.5 kg / m 2 Amounts within the ranges should be applied in a single layer only.

[0170] The conductive epoxy coating can be filled with a filler (v) which is spread during the pot life, wherein suitable fillers are in particular quartz powder and / or quartz sand. The filler can be sized so that it largely sinks into the coating and reinforces the epoxy coating, or excess filler can be sanded off, resulting in a roughened, ground surface after curing and removal of excess sand.

[0171] To produce the ground rough surface, at least one electrically conductive quartz sand is preferably used.

[0172] Suitable conductive quartz sand is in particular quartz sand coated with a conductive synthetic resin, which in particular has a particle size in the range of 0.1 to 1.3 mm. This quartz sand can be used, for example, in the form of Conduct 2.0 (from Dorfner) is commercially available.

[0173] At least one sealant (vi) is then optionally applied to the conductive epoxy resin coating, which is optionally sprinkled with fillers. Particularly suitable for this are transparent conductive epoxy resin coatings, which contain, in particular, carbon nanotubes and at least one amine of formula (I), and preferably also zinc oxide, in particular aluminum-doped zinc oxide.

[0174] Especially at 0.1 to 1 kg / m 2 , preferably 0.2 to 0.7 kg / m 2 Apply sealant within the specified range.

[0175] In a preferred embodiment of the flooring system, the conductive epoxy resin coating (iv) is pigmented and has a layer thickness in the range of 0.1 to 5 mm, in particular 0.2 to 3 mm. In this case, the flooring system preferably contains no filler or sealant that has been applied excessively and remains on the surface. The pigmented epoxy resin coating (iv) therefore preferably forms the top layer of the flooring system. It is particularly important that this surface is well-ventilated and therefore particularly uniform in order to meet high aesthetic requirements.

[0176] In this embodiment, the conductivity of the epoxy resin coating (iv) is reliable and good, so that the so-called conductive film can be omitted in the ground conductive system (iii), e.g. - 220W Conductive (from Sika). This means that the entire operation including the waiting time for the conductive film to cure is omitted, which is particularly advantageous.

[0177] In said embodiment, the pigmented conductive epoxy coating (iv) is preferably applied directly to the at least one grounding copper wire or the at least one grounding copper tape without a conductive film therebetween.

[0178] In another preferred embodiment of the present invention, an excess of conductive quartz sand is spread over the conductive epoxy resin coating (iv) and covered with a transparent sealant. The epoxy resin coating (iv) is preferably present in a layer thickness in the range of 0.3 to 1 mm. It is preferably transparent and preferably contains zinc oxide, in particular aluminum-doped zinc oxide. The transparent sealant is also preferably a conductive epoxy resin coating and preferably contains carbon nanotubes and at least one zinc oxide.

[0179] The floor system according to the invention is preferably part of a building or a building space. In particular, the floor system is present wherever uncontrolled electrical discharges could cause damage. This applies in particular to spaces where electronic components are produced, stored, or used, or where highly sensitive measuring systems are operated, or where flammable liquids or explosives are processed or stored, and in particular to climatic rooms with particularly low humidity and a low atmospheric particle count, such as so-called clean rooms, radiology facilities, or operating theatres. Example

[0180] Examples are described below which explain the invention in more detail. The invention is of course not limited to the examples described.

[0181] "AHEW" stands for amine hydrogen equivalent weight.

[0182] "EEW" stands for epoxide equivalent weight.

[0183] "Standard climate" ("NK") means a temperature of 23±1° C. and a relative humidity of 50±5%.

[0184] If not stated otherwise, the chemicals used were from Sigma-Aldrich Chemie GmbH.

[0185] Substances and abbreviations used:

[0186] CNT dispersion 10%: 10 wt% single-walled carbon nanotube dispersion in alkyl glycidyl ether, EEW 266 g / mol ( Matrix Beta 207, from OCSiAl)

[0187] GY 250: Bisphenol A diglycidyl ether, EEW 187 g / mol (from Huntsman)

[0188] DY-P: tert-Butylphenyl glycidyl ether, EEW 225 g / mol (from Huntsman)

[0189] DY-H: Hexanediol diglycidyl ether, EEW 147 g / mol (from Huntsman)

[0190] chalk 10GU (from Omya)

[0191] Al-doped ZnO Aluminum-doped zinc oxide (ZnO-23K, from Itochu)

[0192] B-EDA N-benzylethane-1,2-diamine, AHEW 50.1 g / eq, was prepared as follows

[0193] IPDA 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, AHEW 42.6g / eq( IPD (from Evonik)

[0194] MXDA 1,3-bis(aminomethyl)benzene, AHEW 34 g / equivalent (from Mitsubishi Gas Chemical)

[0195] TMD 2,2(4),4-trimethylhexamethylenediamine, AHEW 39.6g / eq( TMD, from Evonik)

[0196] D-230 polyoxypropylene diamine, average molecular weight 230g / mol, AHEW 60g / mol ( D-230, from Huntsman

[0197] Adduct A1 IPDA, MXDA and The adduct of GY 250 in benzyl alcohol, AHEW 231 g / eq, was prepared as follows:

[0198] Adduct B1 B-EDA and The adduct of GY 250, AHEW 116.3 g / eq, was prepared as follows

[0199] K54 2,4,6-Tris(dimethylaminomethyl)phenol (from Air Products)

[0200] -150: Two-component epoxy resin primer (from Sika)

[0201] -151: Two-component epoxy resin primer (from Sika)

[0202] -220W two-component, water-based, highly conductive, black epoxy paint

[0203] Conductive:

[0204] Conductive quartz sand: Conductive quartz sand coated with synthetic resin, 0.3 to 0.8 mm ( Conduct 2.0 (from Dorfner)

[0205] N-Benzyl-1,2-ethylenediamine (B-EDA):

[0206] 180.3 g (3 mol) of 1,2-ethylenediamine was initially mixed with a solution of 106.0 g (1 mol) of benzaldehyde in 1200 ml of isopropanol at room temperature and stirred for 2 hours. The mixture was then hydrogenated in a continuously operating hydrogenation apparatus with a Pd / C fixed-bed catalyst at 80°C, 80 bar of hydrogen pressure, and a flow rate of 5 ml / min. The hydrogenated solution was concentrated on a rotary evaporator at 65°C to remove unreacted 1,2-ethylenediamine, water, and isopropanol. The resulting reaction mixture was purified by vacuum distillation at 80°C. This yielded a colorless liquid with an N-benzyl-1,2-ethylenediamine content of >97%, as determined by GC.

[0207] Adduct A1:

[0208] 57.3 g IPDA, 42.5 g MXDA and 318.8 g benzyl alcohol were heated to 80°C and 81.3 g GY 250, the temperature of the reaction mixture was maintained between 70 and 90° C. A clear, pale yellow liquid was obtained with a viscosity of 45 mPa·s at 20° C.

[0209] Adduct B1:

[0210] Heat 55.0 g of N-benzyl-1,2-ethylenediamine (B-EDA) to 80°C and slowly add 45.0 g of GY 250, the temperature of the reaction mixture was maintained between 70 and 90° C. A clear, pale yellow liquid was obtained with a viscosity of 262 Pa·s at 20° C.

[0211] The viscosity of the adduct was determined as described in Example 1.

[0212] Preparation of conductive epoxy coating:

[0213] Examples 1 to 3 (light grey pigmented coatings):

[0214] For these examples the resin components were prepared as follows: TM DAC150, FlackTek Inc.) Mix the following ingredients and store in the absence of moisture:

[0215] 125.9 parts by weight GY 250,

[0216] 25.2 parts by weight DY-P,

[0217] 11.5 parts by weight DY-H,

[0218] 0.27 parts by weight of CNT dispersion 10%,

[0219] 231.0 parts by weight of chalk,

[0220] 12.7 parts by weight of benzyl alcohol,

[0221] 5.6 parts by weight of additives / defoaming agents,

[0222] 45.8 parts by weight of light grey pigment paste.

[0223] For each example, the ingredients of the curing agent component specified in Table 1 were mixed in the specified amounts (parts by weight) by means of a centrifugal mixer and stored while excluding moisture.

[0224] The two components were then processed into a homogeneous liquid with the aid of a centrifugal mixer and immediately tested as follows:

[0225] After 5 minutes of mixing the resin component and the curing agent component, the viscosity was measured by a cone-plate viscometer at 10s -1 The viscosity was measured at a shear rate of 1000 nm and a temperature of 20°C.

[0226] The gel time is determined by moving a freshly mixed amount of about 3 g with a spatula at regular intervals under standard conditions until the mass gels.

[0227] The Shore D hardness was determined on two cylindrical specimens (20 mm diameter, 5 mm thickness), one stored in a standard climate and one at 8° C. and 80% relative humidity, according to DIN 53505. The hardness was measured after 1, 2 and 7 days.

[0228] Use 0.3kg / m 2 -150 Prime the cardboard, store it in standard climate for 24 hours, then apply 0.1kg / m 2 of -220W Conductive and the panels were stored for a further 24 hours in a standard climate. 1.3 kg / m 2 Various epoxy resin coatings were spread with a spatula and then re-rolled with a licker-in roller to deaerate while still liquid. Leveling and deaeration were observed. Leveling was considered "excellent" when the liquid coating quickly leveled out after a few strokes with the spatula and flowed perfectly into corners. Leveling was considered "acceptable" when the liquid coating required significantly more strokes with the spatula to reach corners and then leveled out slowly. Deaeration was considered "good" or "excellent" when finely dispersed air bubbles combined to form larger bubbles during licker-in rolling, which reliably collapsed at the surface, and when few or no additional bubbles rose after licker-in rolling. Deaeration was considered "incomplete" when, even after licker-in rolling, additional finely dispersed air bubbles rose and remained on the surface of the cured, highly viscous, and ultimately gelled coating, resulting in a slightly turbulent, not completely uniform surface.

[0229] After a curing period of 7 days, the appearance was evaluated on the coated cardboard. "Beautiful" means a glossy, non-tacky surface without streaks or haze. "Uniform" means a smooth surface without bumps or pits.

[0230] The electrical resistance to ground was measured at 8 points on the coated cardboard from Example 1 after curing for 7 days in standard climate in accordance with DIN EN 61340-4-1.

[0231] The results are listed in Table 1.

[0232] Examples indicated by "(Ref.)" are comparative examples.

[0233]

[0234] Table 1: Composition and properties of Examples 1 to 3.

[0235] "nb" means "not determined"

[0236] Examples 4 and 5 (clear coating or sealant):

[0237] For these examples, the resin component was prepared by mixing the following ingredients with the aid of a centrifugal mixer and storing them while excluding moisture:

[0238] 185.6 parts by weight GY 250,

[0239] 0.04 parts by weight of CNT dispersion 10%,

[0240] 4.2 parts by weight of Al-doped ZnO,

[0241] 4.8 parts by weight of additives / defoaming agents,

[0242] 15.4 parts by weight of benzyl alcohol.

[0243] For each example, the ingredients of the curing agent component specified in Table 2 were mixed in the specified amounts (parts by weight) by a centrifugal mixer and stored while excluding moisture.

[0244] The two components were then processed into a homogeneous liquid by a centrifugal mixer and tested as follows: Viscosity, gel time and Shore D were tested as described in Example 1.

[0245] Use 0.3kg / m 2 of -150 Prime the cardboard, store it in standard climate for 24 hours, then apply 0.1kg / m 2 of -220W Conductive and the panels were stored for a further 24 hours in a standard climate. 0.5 kg / m 2 The individual examples were spread with a spatula and re-rolled with a nylon roller while still liquid. Leveling and degassing were evaluated as described in Example 1.

[0246] To assess transparency, a film with a layer thickness of 500 μm was applied to a glass plate and stored in a standard climate for 7 days. The glass plate was then placed on a printed newspaper, and the visibility of the newspaper's lettering through the coated glass plate was assessed. Transparency was considered "high" when the lettering was clearly visible. Transparency was considered "medium" when the lettering was easily visible but not sharp.

[0247] As a measure of transparency, the absorbance was further determined by UV-Vis spectroscopy. For this purpose, the absorbance at 665 nm (red) was determined in a UV-Vis instrument (Cary 60 from Agilent Technologies) on glass plates coated for transparency assessment.

[0248] Appearance and electrical resistance were determined on the coated cardboard as described in Example 1.

[0249] The results are listed in Table 2.

[0250] Examples indicated by "(Ref.)" are comparative examples.

[0251]

[0252] Table 2: Composition and properties of Examples 4 and 5.

[0253] Preparation of static dissipative flooring system:

[0254] Example 6:

[0255] In indoor areas with an area of 55m 2 The static dissipative floor system was installed on the polished concrete floor. During the installation period, the air temperature was 25℃ to 30℃ and the air humidity was 35% to 40%.

[0256] First, at 0.4kg / m 2 Roll a layer of -151 as a primer and allowed to cure for 24 hours.

[0257] Then, according to the instructions, Leitset's grounding points and copper tape are installed on the floor thus prepared.

[0258] Then, apply 2.0 kg / m 2 The conductive epoxy coating of Example 1 was distributed using a rubber squeegee and then rolled using a licker-in roller. The epoxy coating exhibited excellent leveling and excellent degassing. The resulting gray-colored surface was uniform, hard, glossy, non-sticky, and free of streaks or turbidity.

[0259] The earth resistance of the completed floor system is measured at 30 points according to DIN EN 61340-4-1. The measurement value ranges are listed in Table 3.

[0260] Example 7:

[0261] In indoor areas with an area of 55m 2 The static dissipative floor system was installed on the polished concrete floor. During installation, the base temperature was 14°C to 17°C, the air temperature was 13°C to 19°C, and the air humidity was 49% to 66%.

[0262] First, at 0.4kg / m 2 Roll a layer of -151 as a primer and allowed to cure for 24 hours.

[0263] Then, according to the instructions, Leitset's grounding points and copper tape are installed on the floor thus prepared, followed by -220W Conductive coating, which is 0.1kg / m 2The amount is wound in the form of a conductive film.

[0264] After 24 hours of curing time, apply 0.5 kg / m 2 The transparent conductive epoxy resin coating of Example 4. For this purpose, the material was poured out, spread with a rubber scraper and rolled again with a roller. Within 30 minutes after application, 3 kg / m 2 Conductive quartz sand was sprinkled over the layer in excess. After a curing time of 24 hours, the excess sand was removed with a brush and vacuum cleaner.

[0265] The polished surface was then transparently sealed with the conductive epoxy resin coating of Example 4, wherein a rubber scraper was used at a speed of 0.4 kg / m 2 The amount is distributed and then rolled using a structural roller.

[0266] The sealant spreads well on the sanded surface and after re-rolling shows a uniform surface free from streaks, bubbles, pits or other unevenness. After curing the floor system has a highly aesthetic, uniform, light grey shiny, hard, non-stick, transparent surface through which the color of the sand is easily visible.

[0267] The earth resistance of the completed floor system is measured at 30 points according to DIN EN 61340-4-1. The measurement value ranges are listed in Table 3.

[0268]

[0269]

[0270] Table 3: Configuration and resistance of Examples 6 and 7.

Claims

1. Use of a combination of carbon nanotubes and at least one amine of formula (I) for preparing conductive epoxy resin coatings, Z-NH-A-NH-CH2-Y (I) in A represents a divalent C2 to C12 radical optionally containing one or more nitrogen atoms or ether groups. 15 alkylene, cycloalkylene or aralkylene, and Z represents H or ---CH2-Y, and Y represents H or C1 to C 12 an alkyl group, a cycloalkyl group, an aralkyl group or an aryl group, The amines of formula (I) contain at least 8 carbon atoms in total.

2. The use according to claim 1, characterized in that The carbon nanotubes are present in an amount ranging from 0.001 wt % to 0.1 wt % based on the entire epoxy resin coating.

3. The use according to claim 1, characterized in that The carbon nanotubes are present in an amount ranging from 0.001 wt % to 0.05 wt % based on the entire epoxy resin coating.

4. The method according to claim 1, wherein the method comprises: A represents 1,2-ethylene, Z represents H and Y represents phenyl.

5. The use according to any one of claims 1 to 3, characterized in that The amine of formula (I) is used in such an amount that at least 5% of all amine hydrogens present in the epoxy resin coating are derived from the amine of formula (I).

6. A conductive epoxy resin coating obtained by the use according to any one of claims 1 to 5, comprising - at least one liquid epoxy resin, - at least one amine of formula (I), - carbon nanotubes, and - at least one further ingredient selected from other amines, accelerators, fillers, diluents, surface active additives and stabilizers.

7. The epoxy resin coating according to claim 6, characterized in that From 5% to 50% of all amine hydrogens present are derived from amines of formula (I), and at least one other amine having at least four aliphatic amine hydrogens is present.

8. The epoxy resin coating according to claim 6, characterized in that: Based on the entire coating material, it contains less than 5% by weight of water.

9. The epoxy resin coating according to any one of claims 6 to 8, characterized in that Based on the entire coating meter, it contains - 0.001 to 0.05% by weight of carbon nanotubes, - less than 1% by weight of diluents having a boiling point below 200°C, and - less than 5% by weight of water.

10. The epoxy resin coating according to any one of claims 6 to 8, characterized in that It is pigmented and contains 20 to 70% by weight of calcium carbonate, quartz powder, quartz sand or a combination thereof, based on the total coating material.

11. The epoxy resin coating according to any one of claims 6 to 8, characterized in that: It is transparent and contains - 0.001 to 0.01% by weight of carbon nanotubes, and - 1 to 3% by weight of zinc oxide.

12. The epoxy resin coating according to claim 11, characterized in that: The zinc oxide is aluminum-doped zinc oxide.

13. The epoxy resin coating according to claim 11, characterized in that: The coating material further comprises less than 0.1% by weight of fillers or pigments other than carbon nanotubes and zinc oxide, based on the entire coating material.

14. A cured conductive epoxy resin coating obtained from the mixed epoxy resin coating according to any one of claims 6 to 13.

15. Static dissipative floor system, which includes from bottom to top (i) at least one substrate, (ii) optionally at least one epoxy resin primer, (iii) at least one earthed conductive system, (iv) at least one layer of the conductive epoxy resin coating according to claim 14, (v) optionally at least one spread filler, and (vi) Optionally at least one sealant.

16. The floor system according to claim 15, characterized in that The earth resistance determined according to DIN EN 61340-4-1 is >5 . 10 4 Ohm and <10 9 ohm range.

17. The floor system according to claim 15, wherein The conductive system comprises at least one grounding copper wire or grounding copper tape and optionally at least one conductive wire in contact with the grounding copper tape and having a resistance of <10 4 Ohmic conductive film.

18. The floor system according to any one of claims 15 to 17, characterized in that The conductive epoxy resin coating is pigmented and has a layer thickness in the range of 0.1 to 5 mm.

19. The floor system according to any one of claims 15 to 17, characterized in that The conductive epoxy resin coating is pigmented and has a layer thickness in the range of 0.2 to 3 mm.

20. The flooring system according to claim 18, wherein The conductive epoxy paint is applied directly to at least one grounding copper wire or at least one grounding copper tape without a conductive film therebetween.

21. The floor system according to any one of claims 15 to 17, characterized in that The conductive epoxy paint is sprinkled with excess conductive quartz sand and covered with a transparent sealant.

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