How to detect leaks in liquid coatings

Abstract

A method for detecting leaks in an impermeable liquid coating is described, comprising the steps of: a) applying a reactive composition in liquid form onto a conductive layer ECL disposed on a support substrate SuS, and curing the applied composition to provide an impermeable membrane M on the conductive layer ECL; b) applying a voltage between a conductive detector CD on the impermeable membrane M and the conductive layer ECL, causing a current to flow between the conductive layer ECL and the conductive detector CD through a leak location located in the impermeable membrane M; and c) detecting the leak by sensing the current between the conductive layer ECL and the conductive detector CD.

Description

[Technical Field]

[0001] The present invention relates to a method for detecting leaks in impermeable liquid coating membranes, preferably in roofs, using a voltage to generate a current through a defect detectable by a sensor on the membrane. [Background technology]

[0002] Failure to detect, locate, and repair membrane defects as soon as possible during and after installation can lead to premature failure. Problems include design flaws, poor installation of the membrane system, and subsequent damage by artisans involved. Green roofs, insulation layers, wear layers, or roof designs that incorporate waterproofing membranes under the upper slab greatly exacerbate the problem of leak location. Early detection of waterproofing membrane leaks is crucial during construction and for effective roof maintenance. Leaks in traditional roof assemblies allow moisture to accumulate under the membrane on underlying components such as protective boards and insulation. Water accumulation in the insulation compromises the thermal properties of the insulation. Water accumulation in building materials can cause corrosion and other damage that is very costly to repair.

[0003] Low-voltage conductance testing is often used to detect and locate leaks in waterproofing membranes. The basic technique of conductance leak location is to establish an electrical potential between the electrical insulating film and the underlying roof substrate. A controlled surface coating of water creates a conductive path horizontally across the membrane to a breach in the membrane. At the breach, the test device detects the electrical path created by the leaked water to the underlying conductive substrate.

[0004] Low-voltage electrical methods for detecting and locating breaches are effective but require a controlled surface coating of water to form a conductive path horizontally across the membrane. This method has the drawback of relying on water, requiring uniform water distribution, potentially damaging areas underneath due to leaking applied water, and not being able to detect leaks around uneven surfaces.

[0005] Furthermore, they require a conductive surface directly underneath and in intimate contact with the membrane. Conventional membrane assemblies are made from thermoplastic materials such as PVC or polyolefins. These membranes are adhesively bonded or mechanically fastened to non-conductive materials, such as plywood substrates or protective boards, which interfere with conductivity testing. U.S. Patent Application Publication No. 2014361796A1 discloses a method for addressing the interference problem by using low voltages to detect leaks in such thermoplastic membranes on roofs. It teaches attaching the membrane to the roof support substrate with an adhesive layer containing a conductive material on a conductive primer. This has the disadvantage of requiring an additional step of applying an adhesive layer, which may be susceptible to damage, on top of the applied conductive primer. Summary of the Invention [Problem to be solved by the invention]

[0006] To provide a method for detecting leaks in a waterproof membrane that does not rely on the application of water for detection purposes and does not require application on a conductive adhesive layer. [Means for solving the problem]

[0007] According to one aspect of the present invention, there is provided a method for detecting leaks in a liquid-applied impermeable membrane, comprising the steps of: a) applying a reactive composition in liquid form onto a conductive layer ECL disposed on a supporting substrate SuS, and curing the applied composition to provide an impermeable film M on the conductive layer ECL; b) applying a voltage between the conductive detector CD and the conductive layer ECL on the impermeable membrane M, so that a current flows between the conductive layer ECL and the conductive detector CD through a leak point located in the impermeable membrane M; c) detecting leakage by sensing a current between the conductive layer ECL and the conductivity detector CD; A method is provided that includes:

[0008] According to another aspect of the present invention, · at least one liquid epoxy resin LER; at least one amine curing agent AH; 4.50 to 9.00 wt. % of carbon fibers CF having a length of 40 to 200 μm, based on the total weight of the epoxy resin composition; An epoxy resin composition is provided which contains:

[0009] Preferred embodiments of the composition are set forth in the dependent claims.The invention is generally described below. DETAILED DESCRIPTION OF THE INVENTION

[0010] In step b), a voltage is applied between the conductive detector CD and the conductive layer ECL on the impermeable membrane M, and a current flows between the conductive layer ECL and the conductive detector CD through the leak point located in the impermeable membrane M.

[0011] Preferably, the voltage is applied by using a voltage higher than 600V, preferably higher than 2 kV, more preferably a voltage between 5 and 10 kV.

[0012] Therefore, in step b), an electric current is preferably caused to flow between the conductive layer ECL and the conductivity detector CD through the air at the leak point located in the impermeable membrane M, preferably by means of an electric arc.

[0013] Preferably, the conductivity detector CD is a handheld device. Preferably, in step c), the conductivity detector CD detects the current CD using an electrode brush, preferably an electrode brush with conductive metal bristles. It is further preferred that in step c), the current is detected on a dry, impermeable membrane M. A suitable conductivity detector CD is Buckley's Dry Roof Pro2 flat roof electronic leak detector unit from Buckleys (UVRAL) Ltd.

[0014] Preferably, the detection of the leak is performed by sensing the current between the conductive layer ECL and the conductive detector CD using a conductor provided on the impermeable membrane M, the conductor being connected to an electrical potential and including a sensor within the detector device for detecting the current formed through the impermeable membrane M due to the leak.

[0015] In step a), a water-impermeable membrane M is provided on the conductive layer ECL, which is located on the supporting substrate SuS, by applying a reactive composition in liquid form.

[0016] As used herein, the term "water-impermeable liquid coating" preferably refers to a material that is applied in liquid form as a layer onto a substrate and that hardens to form a resilient film that waterproofs the substrate.

[0017] As used herein, the term "polyurethane polymer" includes all polymers prepared by the so-called diisocyanate polyaddition process, including isocyanate-functional polyurethane polymers obtained by reacting polyisocyanates with polyols, also called prepolymers, which are themselves polyisocyanates.

[0018] The reactive composition is preferably a material that is applied in liquid form as a layer onto a substrate and cures to form an elastic film that waterproofs the substrate.

[0019] The reactive composition preferably has a water content of less than 10 wt. %, preferably less than 5 wt. %, more preferably less than 3 wt. %, based on the total weight of the composition.

[0020] Preferably, the reactive composition is selected from the list consisting of reactive one-component polyurethane compositions, reactive two-component polyurethane compositions, and reactive two-component polyurea compositions, preferably reactive one-component polyurethane compositions.

[0021] Preferably, the reactive one-component polyurethane composition comprises: at least one isocyanate-functional polyurethane polymer; at least one latent hardener; Contains:

[0022] The isocyanate-functional polymer is preferably a liquid at room temperature.

[0023] Preferred are isocyanate-functional polymers having low viscosities, preferably less than 50 Pa·s, more preferably less than 30 Pa·s, especially less than 20 Pa·s, as measured by a cone-plate viscometer with a cone diameter of 25 mm, a cone angle of 1° with a cone-plate distance of 0.05 mm, and a shear rate of 10 s at 20°C.

[0024] The isocyanate-functional polymer preferably has an NCO content of 1 to 8% by weight, preferably 1.5 to 6% by weight.

[0025] The isocyanate-functional polymer preferably has an average molecular weight M of 1,000 to 15,000 g / mol, preferably 1,500 to 12,000 g / mol. n It has.

[0026] The isocyanate-functional polymer is preferably obtained from the reaction of an aliphatic isocyanate, preferably isophorone diisocyanate, with at least one polyol.

[0027] Preferably, the reaction is carried out at an NCO / OH molar ratio of at least 3 / 1, preferably in the range of from 3 / 1 to 10 / 1, more preferably from 3 / 1 to 8 / 1.

[0028] The reaction of the isocyanate with the polyol is preferably carried out in the absence of moisture at a temperature in the range of 20 to 160°C, preferably 40 to 140°C, optionally in the presence of a suitable catalyst.

[0029] The polyol is preferably selected from the group consisting of polyether polyols, polyester polyols, polycarbonate polyols, and polyacrylate polyols.

[0030] Polyether polyols are preferred, preferably polyether polyols having repeating units selected from 1,2-ethyleneoxy, 1,2-propyleneoxy, 1,3-propyleneoxy, 1,2-butyleneoxy, and 1,4-butyleneoxy. 1,2-propyleneoxy units, optionally combined with multiple 1,2-ethyleneoxy units at the chain ends, are particularly preferred. 1,4-butyleneoxy units are even more preferred.

[0031] Polyether polyols having an unsaturation content of less than 0.02 mEq / g, preferably less than 0.01 mEq / g, are preferred.

[0032] Preferred are polyoxypropylene diols or triols having an OH number in the range of 10 to 250 mg KOH / g, preferably 20 to 125 mg KOH / g, optionally end-capped with ethylene oxide.

[0033] The polyol preferably has an average OH functionality in the range of 1.7 to 3.

[0034] Average molecular weight M in the range of 450 to 12,000 g / mol, preferably 1,000 to 6,000 g / mol, optionally end-capped with ethylene oxide. n Particularly preferred is a polyoxypropylene diol having the formula:

[0035] and an average molecular weight M of 3,000 to 8,000 g / mol, which may be optionally end-capped with ethylene oxide. n Particularly preferred are polyoxypropylene triols initiated with trimethylolpropane or glycerin, having the formula:

[0036] Furthermore, the OH value is in the range of 50 to 180 mg KOH / g, and the average molecular weight M n Poly(oxy-1,4-butylene)diol having a molecular weight of 650 to 2,000 g / mol is particularly preferred.

[0037] Preferred latent curing agents are blocked amines having a blocked hydrolytically activatable amino group and either at least one other blocked hydrolytically activatable amino group or at least one reactive group R selected from the group consisting of a hydroxyl group, a mercapto group, and a secondary amino group.

[0038] The blocked amino groups of the blocked amines which can be activated by hydrolysis are in particular selected from the group consisting of enamino, oxazolidino, ketimino and aldimino groups. Such blocked amines are known substances in polyurethane chemistry and are used as so-called latent hardeners in compositions containing isocyanate groups.

[0039] As used herein, the term "oxazolidino group" refers to both a tetrahydrooxazole group (a five-membered ring) and a tetrahydrooxazine group (a six-membered ring).

[0040] Preferably, the blocked amino group activatable by hydrolysis of the blocked amine is an aldimino group.

[0041] Blocked amines can be obtained in particular from the condensation reaction of primary or secondary amines with ketones or aldehydes. Particularly suitable ketones are acetone, methyl ethyl ketone, methyl propyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, methyl pentyl ketone, methyl isopentyl ketone, diethyl ketone, dipropyl ketone, diisopropyl ketone, dibutyl ketone, diisobutyl ketone, cyclopentanone, cyclohexanone, and acetophenone. Particularly suitable as aldehydes are formaldehyde, acetaldehyde, propanal, 2-methylpropanal, butanal, 2-methylbutanal, 2-ethylbutanal, pentanal, 2-methylpentanal, 3-methylpentanal, 4-methylpentanal, 2,3-dimethylpentanal, hexanal, 2-ethylhexanal, heptanal, octanal, nonanal, decanal, undecanal, 2-methylundecanal, dodecanal, methoxyacetaldehyde, cyclopropanecarboxaldehyde, cyclopentanecarboxaldehyde, cyclohexanecarboxaldehyde, diphenylacetaldehyde, benzaldehyde, and substituted benzaldehydes.

[0042] Blocked amines having at least one oxazolidino group can be obtained by condensation reaction of at least one hydroxyamine, in which the hydroxyl group and the primary amino group are separated by an optionally substituted ethylene or trimethylene radical, with at least one ketone or aldehyde, in particular formaldehyde or one of the above-mentioned enolizable ketones or aldehydes. Aldehydes, in particular 2-methylpropanal, are particularly suitable. Particularly suitable hydroxyamines are diethanolamine and diisopropanolamine, which give hydroxyoxazolidines, from which polyoxazolidines can be easily prepared, for example, by reaction with polyisocyanates or polyesters.

[0043] Blocked amines having at least one ketimino or aldimino group can be obtained in particular from the condensation reaction of the aforementioned amines having at least one primary amino group with at least one ketone or aldehyde: if a ketone is used to block the primary amino group, a ketimino group is formed, whereas if an aldehyde is used, an aldimino group is formed.

[0044] Most preferably, the latent curing agent is a blocked amine having at least one aldimino group.

[0045] Preferably, the blocked amine is present in an amount such that the ratio of the total number of aldimine groups to the total number of isocyanate groups is in the range of 0.3-1, preferably 0.4-1, more preferably 0.5-1.

[0046] Preferably, the reactive one-component polyurethane composition further contains a filler. Suitable fillers are precipitated or ground calcium carbonate (chalk), optionally surface-coated with fatty acids such as stearates, barium sulfate (baryte), slate, silicates (quartz), magnesiosilicates (talc) or aluminosilicates (clay, kaolin), dolomite, mica, glass bubbles, silicic acid, in particular highly dispersed silicic acid obtained from a pyrolysis process (fumed silica), carbon black, microspheres, pigments, in particular titanium dioxide or iron oxide, or flame-retardant fillers such as aluminum hydroxide, in particular aluminum trihydroxide (ATH), magnesium dihydroxide, antimony trioxide, antimony pentoxide, boric acid, zinc borate, zinc phosphate, melamine borate, melamine cyanurate, ethylenediamine phosphate, ammonium polyphosphate, dimelamine orthophosphate, dimelamine pyrophosphate, hexabromocyclododecane, decabromodiphenyl oxide, and tris(bromoneopentyl)phosphate.

[0047] Preferred fillers are chalk, barite, fumed silica, and / or ATH.

[0048] Preferably, the reactive one-component polyurethane composition further comprises a plasticizer. Suitable plasticizers are phthalates, in particular diisononyl phthalate (DINP) or diisodecyl phthalate (DIDP), hydrogenated phthalates, in particular hydrogenated DINP (which is diisononyl-1,2-cyclohexanedicarboxylate (DINCH)), terephthalates, in particular bis(2-ethylhexyl) terephthalate or diisononyl terephthalate, hydrogenated terephthalates, in particular bis(2-ethylhexyl)-1,4-cyclohexanedicarboxylate, trimellitates, adipates, in particular dioctyl adipate (DOA), azelates, sebacates, citrates, benzoates, glycol ethers, glycol esters, organic sulfonates or phosphates, in particular cresyl diphenyl phosphate (DPK), polybutene, polyisobutene, or plasticizers derived from natural fats and oils, such as epoxidized soybean oil or linseed oil.

[0049] Preferably, the reactive one-component polyurethane composition further comprises a catalyst. Suitable catalysts for accelerating the hydrolysis of the latent curing agent, preferably the aldimine, are acid catalysts, especially carboxylic or sulfonic acids, preferably aromatic carboxylic acids such as benzoic acid or salicylic acid.

[0050] Suitable catalysts are catalysts for promoting the reaction of isocyanate groups, in particular metal catalysts, preferably dialkyltin complexes, in particular dibutyltin or dioctyltin carboxylates, or acetoacetonates, such as dibutyltin dilaurate (DBTDL), dibutyltin di(acetoacetate) (DBT(acac)2), or dioctyltin dilaurate (DOTDL), or amine catalysts, preferably tertiary amino ethers, in particular 2,2'-dimorpholinodiethyl ether (DMDEE).

[0051] Preferably, the reactive one-component polyurethane composition further comprises an additive selected from the group consisting of an ultraviolet stabilizer, a wetting agent, a flow improver, a leveling agent, an antifoaming agent, a degassing agent, and a biocide.

[0052] Preferred reactive one-component polyurethane compositions are an isocyanate-functional polymer in an amount ranging from 15 to 80% by weight, in particular from 20 to 50% by weight, relative to the total composition; a latent hardener, preferably an aldimine, in an amount ranging from 0.5 to 25% by weight, preferably from 1 to 20% by weight, relative to the total composition; plasticizer in an amount ranging from 0 to 40% by weight, preferably from 10 to 30% by weight, relative to the total composition; fillers in an amount ranging from 0 to 80% by weight, preferably from 20 to 60% by weight, relative to the total composition; Preferably, the filler comprises at least one flame retardant component, more preferably aluminum trihydroxide (ATH).

[0053] The composition preferably contains a small amount of a volatile organic solvent having a boiling point at atmospheric pressure of less than 200° C. Preferably, it contains 200 g or less, more preferably 150 g or less of such a volatile organic solvent per liter of total composition. Such a composition is particularly suitable as a coating for waterproofing buildings.

[0054] The reactive one-component polyurethane composition is preferably formulated as a single packaged composition prepared by mixing all ingredients under conditions that exclude moisture to obtain a macroscopically homogeneous fluid or paste, and is stored at ambient temperature in a moisture-proof container. Suitable moisture-proof containers are preferably made of metal or plastic, optionally coated. They are preferably buckets, barrels, hobos, bags, sausages, cartridges, cans, bottles, or tubes.

[0055] The curing process begins when the reactive one-component polyurethane composition is applied and comes into contact with moisture, particularly atmospheric moisture. Upon curing, the isocyanate groups react with the hydrolyzable latent groups, preferably hydrolyzable aldimine groups, of the latent curing agent under the influence of moisture. Furthermore, the isocyanate groups react with each other under the influence of moisture. As a result of these reactions, the composition cures to form an elastomeric material.

[0056] The reactive one-component polyurethane composition is preferably applied under ambient conditions, preferably in the temperature range of -10 to 50°C, more preferably -5 to 45°C, especially 0 to 40°C.

[0057] Curing of the composition also preferably occurs at ambient conditions.

[0058] The reactive one-component polyurethane composition preferably has sufficient open time to allow accurate positioning and application to large surfaces, and a rapid cure process, whereby the composition quickly becomes tack-free and exhibits a rapid increase in mechanical strength and elasticity.

[0059] "Open time" is the time during which an applied composition can be processed or reprocessed without adverse effects. It ends when the viscosity of the composition increases too much due to curing, or at the latest when a skin forms on the surface. The time until a skin forms on the surface is called the "skin formation time" or "skinning time."

[0060] In step a), a water-impermeable membrane M obtained from a reactive composition in liquid form is applied onto the conductive layer ECL.

[0061] Preferably, the conductive layer ECL is 10 9 Less than Ω, preferably 10 6 Less than Ω, most preferably 10 4 Ω~10 3 It has a ground resistance of Ω.

[0062] Preferably, the conductive layer ECL has a layer thickness in the range of 20 to 5000 μm, preferably 150 to 1000 μm, more preferably 250 to 500 μm.

[0063] Preferably, the conductive layer ECL is applied to the support substrate SuS by spraying, brushing, or pouring. To form a uniform layer, the conductive layer ECL can then be optionally spread to the desired layer thickness before curing using a suitable tool, preferably a squeegee, toothed trowel, spatula, roller, brush, drawdown bar, or the like.

[0064] The conductive layer ECL is arranged on the support substrate SuS either in direct contact with it or via one or more additional material layers, preferably layers of hardened synthetic resin.

[0065] Preferably, the conductive layer ECL does not have adhesive properties, and preferably it cannot function as an adhesive to bond the impermeable membrane M to the support substrate SuS.

[0066] Preferably, the conductive layer ECL is a synthetic resin layer, preferably a synthetic resin layer selected from the list consisting of epoxy resin, polyurethane, polyurea, polymethacrylate, polyacrylate, cement hybrid systems, and polymer modified cement mixtures (PCC).

[0067] Preferably, the conductive layer ECL is an epoxy resin layer, preferably an epoxy resin layer obtained from a two-component epoxy composition, more preferably from a two-component epoxy composition described below.

[0068] Preferably, the conductive layer ECL comprises one or more conductive additives, preferably selected from the group consisting of carbon fibers, carbon black, graphite, silicon carbide, metal oxides, metals, such as iron, ammonium salts, heavy metal-containing or metal-containing fillers, in particular antimony-containing and tin-containing fillers based on titanium dioxide or mica, ionic liquids, ionic and nonionic surfactants, melamine sulfonates, and polycarboxylate ethers, preferably carbon fibers.

[0069] It is particularly preferred that the conductive layer ECL is an epoxy resin layer obtained from a two-component epoxy composition containing carbon fibers. Although any suitable conductive layer ECL described above can be used in the method of the present invention, the inventors have developed a composition that is particularly suitable for the conductive layer ECL.

[0070] Therefore, another aspect of the present invention is · at least one liquid epoxy resin LER; at least one amine curing agent AH; 4.50 to 9.00 wt % of carbon fibers CF having a length of 40 to 200 μm, preferably 50 to 150 μm, more preferably 60 to 120 μm, based on the total weight of the epoxy resin composition; The epoxy resin composition contains:

[0071] Preferred one-component epoxy resins LER are in particular aromatic epoxy resins, in particular the glycidyl ethers of: Bisphenol A, bisphenol F, or bisphenol A / F, where A stands for acetone and F for formaldehyde, serve as reactants for the preparation of these bisphenols. In the case of bisphenol F, positional isomers may also exist, especially those derived from 2,4'- or 2,2'-hydroxyphenylmethane; Dihydroxybenzene derivatives such as resorcinol, hydroquinone, or catechol; 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-methylbutane, 1,1-bis(4-hydroxyphenyl)-2-methylbutane, 2,4-bis(3,5-dimethyl-4-hydroxyphenyl)-2-methylbutane, 1,1-bis(4-hydroxyphenyl)-2-methylbutane, 2,2 ... (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'-dihydroxydiphenyl (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; · condensation products of phenol and formaldehyde obtained under acidic conditions, such as phenol novolac or cresol novolac (also called bisphenol F novolac); Aromatic amines, such as aniline, toluidine, 4-aminophenol, 4,4'-methylenediphenyldiamine, 4,4'-methylenediphenyldi(N-methyl)amine, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline (bisaniline P), or 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline (bisaniline M).

[0072] Preferred liquid epoxy resins are those based on bisphenols, particularly bisphenol A diglycidyl ether and / or bisphenol F diglycidyl ether, such as those commercially available from Dow, Huntsman, or Momentive. These liquid resins have low viscosity for epoxy resins and excellent coating properties when cured. They may contain a percentage of solid bisphenol A resin or novolac glycidyl ether.

[0073] Preferred amine curing agents AH are selected from the list consisting of: Aliphatic, cycloaliphatic, or arylaliphatic primary diamines or triamines, in particular isophoronediamine (IPD) and m-xylylenediamine (MXDA), Ether group-containing aliphatic primary diamines or triamines, secondary amino group-containing polyamines, preferably 2-piperazin-1-ylethylamine, and Adducts of these amines with epoxides or epoxy resins, especially with diepoxides or monoepoxides.

[0074] More preferably, the amine curing agent AH consists of a mixture of the above list.

[0075] Most preferably, the amine curing agent AH is Aliphatic, cycloaliphatic, or arylaliphatic primary diamines or triamines, in particular isophoronediamine (IPD) and m-xylylenediamine (MXDA), a polyamine containing secondary amino groups, preferably 2-piperazin-1-ylethylamine, It consists of a mixture of

[0076] The carbon fibers CF have a length of 40 to 200 μm, preferably 50 to 150 μm, and more preferably 60 to 120 μm. Fibers longer than 200 μm have the disadvantage of tending to stand upright and protrude in the vertical direction of the applied and cured epoxy resin composition. The length of the carbon fibers can be determined, for example, by microscopic observation.

[0077] Preferably, the carbon fibers CF have a diameter of 2 to 12 μm, preferably 3 to 10 μm, more preferably 4 to 7 μm.The length and diameter of the carbon fibers can be determined, for example, by observation under a microscope.

[0078] It is further preferred if the carbon fibers CF have an electrical resistivity of less than 5 mΩ*cm, preferably less than 3 mΩ*cm, more preferably less than 2 mΩ*cm.

[0079] The carbon fiber CF is present in an amount of 4.50 to 9.00 wt. % based on the total weight of the epoxy resin composition. As can be seen from a comparison of Ex. 1 and Ex. 2 with Ref. 5 to Ref. 7 in Table 1, amounts less than 4.50 wt. % result in insufficient conductivity. A comparison of Ex. 1 and Ex. 2 with Ref. 8 suggests that amounts greater than 9.00 wt. % result in an excessively high viscosity, which is detrimental to the mixing of the epoxy resin composition.

[0080] The amount of carbon fiber CF is preferably 5.00 to 8.00 wt%, 5.25 to 7.00 wt%, or 5.25 to 6.00 wt%, based on the total weight of the epoxy resin composition. As can be seen from a comparison of Ex.1 and Ex.2 in Table 1, these ranges are preferred for excellent conductivity combined with low viscosity. Furthermore, it was found that the adhesion of an impermeable liquid film applied directly onto a cured composition based on Ex.1 exhibited excellent adhesion, similar to that of a cured composition based on Ref.1, which does not contain carbon fiber.

[0081] Furthermore, comparing Ex. 1 and Ex. 2 with Ref. 2 and Ref. 3 shows that compositions containing carbon black either do not exhibit sufficient conductivity or are too viscous.

[0082] Preferably, the epoxy resin composition is a two-component composition consisting of a first component containing at least one liquid epoxy resin LER and a second component containing at least one amine curing agent AH. Preferably, the carbon fiber CF is present in the first component. Preferably, the two components are stored in separate containers.

[0083] Preferably, the epoxy resin composition has a water content of less than 5 wt. %, preferably less than 3 wt. %, based on the total weight of the composition.

[0084] Preferably, the epoxy resin composition has a viscosity of less than 15,000 cP, preferably less than 12,500 cP, more preferably less than 10,000 cP, two minutes after mixing all of the components, using a Brookfield DV1 viscometer equipped with an HB-04 spindle at 23°C and 100 rpm.

[0085] The supporting substrate SuS is preferably part of a waterproofing system.

[0086] The support substrate SuS is preferably a part of a building, such as a balcony, a terrace, a roof, in particular a flat or slightly sloping roof, a roof garden, an interior floor of a building, preferably a roof, in particular a flat roof.

[0087] The support substrate SuS is preferably made of a material selected from the list consisting of: Metals and alloys, such as aluminium, copper, iron, steel, non-ferrous metals (including surface-finished metals and alloys such as galvanised and chrome-plated metals); ·asphalt; ·Bitumen; Concrete, lightweight concrete, mortar, cement, fiber cement, brick, adobe, tile, slate, gypsum, gypsum panels, or natural stone, such as granite or marble; · Repair or leveling compounds based on PCC (polymer modified cement) or ECC (epoxy modified cement); Wood, plywood, paper, cardboard, wood-based materials bonded with organic resins, resin-fabric composites or so-called polymer composites; Insulating foams, especially EPS, XPS, PUR, PIR, rock wool, mineral wool or foam glass.

[0088] More preferably, the support substrate SuS is selected from the list consisting of metals, alloys, asphalt, bitumen, concrete, gypsum, wood and plywood.

[0089] The reactive composition is preferably applied by spraying or pouring onto a flat or slightly inclined surface, and can then be optionally spread to the desired layer thickness using a suitable tool, preferably a squeegee, toothed trowel, spatula, roller, brush, or drawdown bar, to form a uniform coating.

[0090] Preferably, the reactive composition is applied in a layer thickness ranging from 0.5 to 3.5 mm, preferably from 1.0 to 2.5 mm.

[0091] If the support substrate SuS is part of a waterproofing system, the reactive composition is preferably applied by pouring it onto the conductive layer ECL located on the support substrate SuS and then spreading it evenly to the desired layer thickness.

[0092] A preferred waterproofing system uses a fiber-reinforced mesh. The fiber-reinforced mesh is preferably processed into a first layer of reactive composition while the composition is still liquid, preferably by completely incorporating it into the liquid layer with a roller or brush. After the reactive composition with the incorporated fiber-reinforced mesh has cured, a subsequent layer of reactive composition is preferably applied and the reactive composition is allowed to cure.

[0093] The fiber reinforced mesh is preferably a nonwoven polyester fiber mesh, more preferably a nonwoven glass fiber mesh. [Example]

[0094] The following examples illustrate the invention without limiting it.

[0095] [Table 1]

[0096] The Part A compositions of the inventive compositions Ex.1 and Ex.2 and the reference compositions Ref.1 through Ref.8 were prepared by adding a conductive material (carbon black powder or carbon fiber) to the A component of the Sikalastic® EP Primer / Sealer product in weight percent (wt%) based on the total weight of the resulting composition after the addition of the conductive material. For the carbon black powder, three samples were prepared: 5 wt%, 10 wt%, and 15 wt% carbon black powder based on the total weight of the resulting composition. For the carbon fiber samples, six samples were prepared: 2 wt%, 4 wt%, 6 wt%, 8 wt%, 10 wt%, and 15 wt% carbon black based on the total weight of the resulting composition. Each composition was then mixed at 700 rpm for 30 minutes using a Cowles-type blade. The compositions containing 10 wt%, 15 wt%, and 15 wt% carbon black, based on the total weight of the resulting composition, were too viscous to mix. These Part A compositions were not further evaluated.

[0097] After mixing, the remaining Part A composition was evaluated for homogeneity and its viscosity was measured at 23°C using a Brookfield DV1 viscometer (HB-04 spindle, 100 rpm). Each measurement was recorded. The results of the viscosity measurements for the Part A composition are shown in Table 1 ("Viscosity").

[0098] The above-described Part A composition was then mixed with Part B (Part B) of Sikalastic® EP Primer / Sealer in a mix ratio such that the weight ratio of Part A (pure Part A of Sikalastic® EP Primer / Sealer) to Part B (Part A:Part B) without the conductive material added was 3:1. The compositions were mixed by hand for two minutes to achieve a uniform mixture. Each sample was applied to a paper substrate using a 1 / 8-inch notched squeegee, followed by rolling with a 3 / 8-inch paint roller to smooth out the squeegee notch. Each sample was allowed to fully cure for 24 hours. Furthermore, the viscosity of Composition Ex. 1 was measured two minutes after the aforementioned hand mixing and found to be 3500 cP.

[0099] Conductivity was tested using a Buckleys Dry Roof Pro2 flat roof electronic leak detector unit. A ground wire was secured to one corner of the applied, fully cured composition. The unit was set to output 7.56 kV from the electrode. Conductivity was measured by sweeping the electrode (a 150 mm long stainless steel drum brush) across the entire coating. The unit was set to detect a current of 200 μA or greater, accompanied by an audible alarm. Each sample was inspected across the entire surface area of ​​the applied composition to ensure uniform conductivity. The results are shown in Table 1 ("Conductivity").

[0100] After confirming electrical conductivity, a liquid reactive composition (Sikalastic®-641) was applied using a ½-inch nap roller to a thickness of approximately 1.25 mm directly onto the fully cured compositions of Ex. 1 and Ex. 2 described above. A chopped strand glass fiber mat, Sika Reemat Premium, was applied to the wet coating, rolled to embed the reinforcement, and then allowed to cure for 24 hours. After 24 hours of curing, a second coat of Sikalastic-641 was applied to the reinforcement to a thickness of approximately 0.75 mm (total system thickness of approximately 2.00 mm). The system was then allowed to cure for 72 hours.

[0101] The system was then tested for electrical conductivity to ensure the integrity of the film. As before, a ground wire was secured to one exposed corner of the fully cured (conductive) composition, and the electrode was swept across the entire surface of the cured Sikalastic-641 film. No electrical conductivity was observed, indicating the absence of gaps in the Sikalastic-641 film. Damage to the Sikalastic-641 film was simulated by making a 2-inch razor cut and by piercing a thumbtack through the system down to the primer layer. The system was then tested for electrical conductivity with a Buckleys leak detector unit. A signal was observed in both simulated damage conditions and not in other parts of the system.

[0102] Compositions Ref. 1 and Ex. 1 were also evaluated for the strength / quality of adhesion of a Sikalastic 641 film coated onto the cured compositions. Compositions Ref. 1 and Ex. 1 were applied to standard concrete blocks and allowed to cure for 24 hours. For conductivity testing, a Sikalastic 641 film was applied on top as described above and allowed to fully cure for two weeks. Adhesion was evaluated for both Compositions Ref. 1 and Ex. 1 using an Elcometer 510 automatic peel adhesion gauge in accordance with ASTM D7234-21. No significant differences in adhesion values ​​were observed, suggesting that the addition of carbon fiber did not adversely affect adhesion. The results are shown in Table 1 ("Adhesion").

[0103]

Table 2

Claims

1. A method for detecting leakage of an impermeable liquid coating, a) A step of applying a reactive composition in liquid form onto a conductive layer ECL placed on a support substrate SuS, and curing the applied composition to provide an impermeable film M on the conductive layer ECL; b) A step of applying a voltage between the conductive detector CD located on the impermeable film M and the conductive layer ECL so that current flows between the conductive layer ECL and the conductive detector CD through a leak located within the impermeable film M; c) A step of detecting leakage by sensing the current between the conductive layer ECL and the conductive detector CD; A method that includes this.

2. The method according to claim 1, wherein in step b), the potential is generated using a voltage higher than 600V, preferably higher than 2kV, more preferably 5 to 10kV.

3. The method according to claim 1 or 2, wherein the reactive composition is preferably selected from a list consisting of a reactive one-component polyurethane composition, a reactive two-component polyurethane composition, and a reactive two-component polyurea composition, and is preferably selected from a reactive one-component polyurethane composition.

4. The method according to claim 1 or 2, wherein the reactive composition has a water content of less than 10% by weight, preferably less than 5% by weight, and more preferably less than 3% by weight, based on the total weight of the composition.

5. The method according to claim 1 or 2, wherein in step b), an electric arc is preferably used to cause a current to flow between the conductive layer ECL and the conductive detector CD through the air at the leak location located within the impermeable film M.

6. The method according to claim 1 or 2, wherein in step c), the current is detected by the conductivity detector CD, which is equipped with an electrode brush, preferably an electrode brush having conductive metal bristles.

7. The method according to claim 1 or 2, wherein the impermeable film M is provided in direct contact with the conductive layer ECL on the support substrate SuS.

8. The method according to claim 1 or 2, wherein the conductive layer ECL is a synthetic resin layer, preferably selected from the list consisting of epoxy resin, polyurethane, polyurea, polymethacrylate, polyacrylate, cement hybrid system, and polymer-modified cement mixture (PCC), preferably from epoxy resin.

9. The method according to claim 1 or 2, wherein the conductive layer ECL comprises one or more conductive additives, preferably selected from the group consisting of carbon fiber, carbon black, graphite, silicon carbide, metal oxides, metals, such as iron, ammonium salts, heavy metal-containing or metal-containing fillers, particularly antimony-containing and tin-containing fillers based on titanium dioxide or mica, ionic liquids, ionic and nonionic surfactants, melamine sulfonates, and polycarboxylate ethers, preferably carbon fiber.

10. The conductive layer ECL is 10 ９ Less than Ω, preferably 10 ６ Less than Ω, most preferably 10 ４ Ω~10 ３ The method according to claim 1 or 2, having a grounding resistance of Ω.

11. The method according to claim 1 or 2, wherein the conductive layer ECL has a layer thickness in the range of 20 to 5000 μm, preferably 150 to 1000 μm, and more preferably 250 to 500 μm.

12. The method according to claim 1 or 2, wherein the reactive composition is applied in a layer thickness of 0.5 to 3.5 mm, preferably 1.0 to 2.5 mm.

13. The method according to claim 1 or 2, wherein the support base material SuS is a roof.

14. - with at least one type of liquid epoxy resin LER; - with at least one amine curing agent AH; - A carbon fiber CF having a length of 40 to 200 μm, preferably 50 to 150 μm, more preferably 60 to 120 μm, in an amount of 4.50 to 9.00% by weight based on the total weight of the epoxy resin composition; An epoxy resin composition containing the following:

15. The epoxy resin composition according to claim 14, wherein the carbon fiber CF has a diameter of 2 to 12 μm, preferably 3 to 10 μm, and more preferably 4 to 7 μm.

16. The epoxy resin composition according to claim 14 or 15, wherein the carbon fiber CF has an electrical resistivity of less than 5 mΩ*cm, preferably less than 3 mΩ*cm, and more preferably less than 2 mΩ*cm.

17. The epoxy resin composition according to claim 14 or 15, wherein the composition has a viscosity of less than 15,000 cP, preferably less than 12,500 cP, and more preferably less than 10,000 cP, when measured using a Brookfield DV1 viscometer equipped with an HB-04 spindle at 23°C and 100 rpm, two minutes after mixing all components.

18. The epoxy resin composition according to claim 14 or 15, wherein the amount of carbon fiber CF is 5.00 to 8.00% by weight, preferably 5.25 to 7.00% by weight, and more preferably 5.25 to 6.00% by weight, based on the total weight of the epoxy resin composition.

Images