Liquid coating film with improved interlayer adhesion

Abstract

The present invention provides a method for coating a surface, comprising the steps of: (a) applying a first layer of a moisture-curable composition to a surface; (b) optionally curing the applied moisture-curable composition to form a dry first layer; (c) applying a second layer of moisture-curable composition to the optionally dried first layer; Here, the moisture-curable composition is - 20 to 50% by weight, preferably 25 to 45% by weight, based on the total weight of the composition, of at least one organic polymer that is liquid at room temperature and contains reactive silane groups; and - 10 to 30% by weight, preferably 15 to 25% by weight, based on the total weight of the composition, of at least one polyether PE having 2 to 6 ether oxygen atoms and containing no hydroxy groups; and - at least one curing catalyst for reactive silane groups This method results in a multilayer coating with particularly high interlayer adhesion.

Description

[Technical Field]

[0001] The present invention relates to a reactive polymer composition that can be applied in liquid form, and its application as a liquid coating film for sealing structures against water penetration. [Background technology]

[0002] Liquid-applicable reactive polymer compositions, used as crack-crosslinking coatings to seal structures against water infiltration, are well-known and have been in use for a considerable period. They are also called liquid-coated films or "LAMs." Compared to prefabricated sealing films, they are particularly easy to apply to geometrically complex surfaces, offer improved protection from lateral movement due to full adhesion to the substrate, and enable seamless laying. Compared to non-reactive liquid coating systems such as polymer solutions, aqueous polymer dispersions, and bitumen-based products, they are characterized by high strength and elasticity even under low-temperature conditions, do not easily attract dirt, and provide long-term sealing even under standing water. To provide reliable protection of structures from water penetration, the crack-crosslinking properties of the cured liquid-coated film over a wide temperature range are highly influential and important. Therefore, the cured material needs to have high elasticity, high strength without excessively high modulus, and good tear resistance.

[0003] Known reactive liquid-coated polymer films are typically isocyanate-containing polyurethanes, commercially available as one-component moisture-curing or two-component systems. While they possess good mechanical properties and resistance, they also have technical drawbacks. During the curing stage, for example, they are affected by humidity and temperature. In combinations involving damp substrates, especially with high temperatures, or under direct water attack, CO2 can be generated, resulting in bubble formation and foaming of the coating, impairing its sealing function and resistance. Under warm conditions, they exhibit a short pot life or working life, while under cold conditions, they cure very slowly or remain soft and sticky for extended periods. Furthermore, they are under regulatory pressure due to the high EHS risk of isocyanate monomers and often high solvent concentrations, which cause unpleasant odors and VOC emissions; for this reason, alternatives are actively sought.

[0004] As an isocyanate-free alternative to liquid-coated polyurethane films, silane-functionalized polymer-based alternatives are described, for example, in European Patent No. 1987108 or U.S. Patent Application Publication No. 2009 / 0226740. However, these products have undesirably high viscosity or contain very high levels of low molecular weight silane to reduce viscosity, resulting in the violent release of low molecular weight alcohols and significant shrinkage during curing. Furthermore, they cure slowly and develop strength only in very limited ways, meaning they cannot be used without reinforcement with nonwoven fabrics, cloths, or glass fiber scrims.

[0005] Both U.S. Patent Application Publication No. 2020 / 0354584 and U.S. Patent Application Publication No. 2017 / 0292050 describe compositions based on silane-functionalized polymers that further contain polyetherdiamines, thereby resulting in compositions with relatively low viscosity and interesting mechanical and tackiness. However, in order to achieve a viscosity low enough for use as a liquid coating film, it is necessary to add plasticizers or other diluents.

[0006] For example, a low-viscosity polymer composition based on a combination of a silane-functionalized polymer and a silane-functionalized, hydrophobic reactive diluent is known, as described in European Patent No. 2 561 024. While such systems provide the necessary low viscosity along with excellent water-repellent properties by incorporating a hydrophobic organosilane as a reactive diluent, they suffer from poor interlayer adhesion when applying layers of liquid coating films. This problem is frequently encountered with liquid coating films based on silane-functionalized polymers. In many applications, to obtain a water-repellent coating, especially when coating over large areas or when coating cannot be completed in a single day, it is necessary to apply layers of this composition. However, these liquid coating films often fail to develop proper adhesion to unused compositions applied as a second layer on top, particularly once completely dried. This results in reduced interlayer adhesion between different layers applied in individual process steps, leading to a decrease in the performance of the multilayer coating under mechanical or environmental influences. Thus, reduced interlayer adhesion can result in a non-watertight seal. [Overview of the Initiative] [Means for solving the problem]

[0007] The object of the present invention is to provide a method for coating or sealing the surface of a structure using a liquid-applicable reactive polymer composition that does not contain isocyanate groups, the composition having low odor, low toxicity, low methanol emission, long shelf life, and low viscosity, making it easy to apply by hand. The composition cures rapidly and without decomposition at ambient temperature, and exhibits excellent interlayer adhesion when applied in layers, even after the base layer has dried for several days or more.

[0008] It has been surprisingly found that this objective can be achieved by a method using the composition described in claim 1. The composition has low odor, low toxicity, and low viscosity. It rapidly cures at room temperature, forming a high-quality, macroscopically homogeneous, non-stick material with good mechanical properties and high resistance to water, heat, and ultraviolet light. These properties allow the liquid composition to be easily applied and function as a multilayer encapsulation film, which rapidly cures in both humid and cool environments, forming a high-quality polymer film with an attractive surface and long weather resistance.

[0009] What is particularly surprising here is that even when the base layer is allowed to dry for several days or more before applying the top layer, the liquid coating can be applied in layers, and these layers exhibit unprecedented interlayer adhesion.

[0010] Further aspects of the present invention are the subject of further independent claims. Particularly preferred embodiments of the present invention are the subject of dependent claims. [Modes for carrying out the invention]

[0011] The present invention relates to a method for coating a surface, comprising the following steps: (a) Applying a first layer of moisture-curing composition to the surface, (b) Optionally, the applied moisture-curable composition is cured to form a dry first layer. (c) Applying the second layer of the moisture-curing composition to the first layer which has been optionally dried. Here, this moisture-curing composition, - At least one organic polymer which is liquid at room temperature and contains a reactive silane group, in an amount of 20 to 50% by weight, preferably 25 to 45% by weight, based on the total weight of the composition; and - At least one polyether PE having 2 to 6 ether oxygen atoms and containing no hydroxyl group, in an amount of 10 to 30% by weight, preferably 15 to 25% by weight, based on the total weight of the composition; and - At least one curing catalyst for the reactive silane group A method is provided which comprises the above components.

[0012] In this specification, the term "alkoxysilane group" or simply "silane group" refers to a silyl group bonded to an organic radical and having 1 to 3, particularly 2 or 3, hydrolyzable alkoxy radicals on the silicon atom.

[0013] Correspondingly, the term "organosilane" or simply "silane" refers to an organic compound containing at least one silane group.

[0014] "Aminosilane", "mercaptosilane", "hydroxysilane" and "isocyanatosilane" each refer to an organosilane having one or more amino groups, mercapto groups, hydroxy groups or isocyanate groups on the organic radical in addition to the silane group.

[0015] The term "polyether containing a silane group" includes polymers which may also contain urethane groups, urea groups or thiourethane groups in addition to the polymer and polyether units containing the silane group. Such silane group-containing polyethers are sometimes referred to as "silane group-containing polyurethanes".

[0016] Substance names starting with "poly", such as polyamine or polyisocyanate, formally refer to substances containing two or more of the functional groups of that name per molecule.

[0017] "Aliphatic polyamine" is a polyamine in which its amino group is bonded to an aliphatic or alicyclic or arylaliphatic radical.

[0018] "Primary amino group" refers to an amino group that is bonded to a single organic radical and has two hydrogen atoms, and thus "primary aminosilane" refers to an organosilane having a primary amino group in a non-hydrolyzable organic residue bonded to a silicon atom.

[0019] "Molecular weight" refers to the molar mass (g / mol) of a molecule. "Average molecular weight" is the number average Mn of a polydisperse mixture of oligomer or polymer molecules, which is customarily determined by gel permeation chromatography (GPC) relative to polystyrene as a standard.

[0020] "Viscosity" refers to the dynamic viscosity or shear viscosity defined by the ratio of shear stress to shear rate (velocity gradient), and is determined as described in the examples.

[0021] A substance or composition is said to have "storage stability" or "storability" when it can be stored at room temperature in a suitable container for a long time, usually at least 3 months to a maximum of 6 months or more, without undergoing changes in its application or use properties to such an extent as to be involved in its use as a result of storage.

[0022] The abbreviation "VOC" represents "volatile organic compound", i.e., a volatile organic substance having a vapor pressure of at least 0.01 kPa at 293.14 K.

[0023] "Solvent" is a liquid that dissolves a polymer containing a silane group and / or a liquid epoxy resin, and is a VOC and does not contain a group that reacts with a silane group or an epoxide group.

[0024] In the formulas of this specification, the dashed lines represent the bonds between the substituents and the corresponding molecular radicals in each case.

[0025] "Room temperature" refers to a temperature of 23 °C.

[0026] The composition is liquid at room temperature and contains at least one polymer containing a silane group.

[0027] This is preferably an organic polymer containing a silane group, more specifically a polyolefin, poly(meth)acrylate, or polyether, or a mixture thereof, each of which supports one or preferably one or more silane groups. The silane groups may be pendanted from the chain or at the end.

[0028] Specifically, the polymer containing silane groups is a polyether containing silane groups. This polyether preferably consists mostly of oxyalkylene units, and more specifically, 1,2-oxypropylene units.

[0029] A polymer containing silane groups and being liquid at room temperature preferably has an average of 1.3 to 4, particularly 1.5 to 3, and more preferably 1.7 to 2.8 silane groups per molecule. The silane groups are preferably terminal.

[0030] Preferred silane groups are trimethoxysilane, dimethoxymethylsilane, or triethoxysilane.

[0031] The polymer, which contains a silane group and is liquid at room temperature, preferably has an average molecular weight determined by GPC relative to a polystyrene standard in the range of 1,000 to 20,000 g / mol, specifically 2,000 to 15,000 g / mol.

[0032] A polymer containing a silane group is preferably of formula (II) [ka] [In the formula, p represents a value of 0, 1, or 2, preferably 0 or 1, more specifically 0. R 4 It is a monovalent hydrocarbyl radical having 1 to 5 carbon atoms, either linear or branched. R 5is a linear or branched monovalent hydrocarbyl radical having from 1 to 8 carbon atoms, especially methyl or ethyl, R 6 is a linear or branched divalent hydrocarbyl radical having from 1 to 12 carbon atoms, optionally having a cyclic moiety and / or an aromatic moiety, and optionally having one or more heteroatoms, especially one or more nitrogen atoms, X is selected from -O-, -S-, -N(R 7 ), -N(R 7 )-CO-, -O-CO-N(R 7 )-, -N(R 7 )-CO-O-, -N(R 7 )-CO-N(R 7 ), -N(R 7 )-CO-O-CH(CH3)-CO-N(R 7 ), -N(R 7 )-CO-O-CH(R 8 )-CH2-CH2-CO-N(R 7 )- and [[ID=3C]]-N(R 7 )-CO-O-CH(CH3)-CH2-O-CO-N(R 7 ), is a divalent radical selected from (where R<00C0017>is a hydrogen atom or a linear or branched hydrocarbyl radical having from 1 to 20 carbon atoms, optionally containing a cyclic moiety, and optionally containing an alkoxysilyl group or an ether or carboxylic acid ester group, and R 8 is an unbranched alkyl radical having from 1 to 6 carbon atoms, more particularly methyl.)] includes the terminal groups of

[0033] R 4 is preferably methyl, or ethyl, or isopropyl.

[0034] R 4 It is more preferable that the group is methyl. Polymers of this type containing a silane group are particularly reactive.

[0035] Furthermore, R 4 It is more preferable that the group is ethyl. This type of polymer containing a silane group has particularly excellent storage stability and is toxicologically advantageous.

[0036] R 5 It is preferable that it be methyl.

[0037] Preferably, R 6 is 1,3-propylene or 1,4-butylene, where butylene may be substituted with one or two methyl groups.

[0038] R 6 It is more preferable that it be 1,3-propylene.

[0039] The process for preparing silane group-containing polyethers is known to those skilled in the art.

[0040] In one process, a silane group-containing polyether can be obtained by the reaction (hydrosilylation) of an allyl group-containing polyether with a hydrosilane, or, optionally, by chain extension using a diisocyanate.

[0041] In an alternative process, silane-containing polyethers can be obtained by copolymerization of alkylene oxide and epoxysilane, or optionally by chain extension using diisocyanates.

[0042] In a further process, silane-containing polyethers can be obtained by chain extension using diisocyanates, optionally, from the reaction of polyether polyols with isocyanatosilanes.

[0043] In further processes, silane-containing polyethers can be obtained from the reaction of isocyanate-containing polyethers, particularly NCO-terminated urethane polyethers resulting from the reaction of a polyether polyol with a superstoichiometric amount of polyisocyanate, with aminosilane, hydroxysilane, or mercaptosilane. Silane-containing polyethers from this process are particularly preferred. This process allows for the use of many commercially available and inexpensive starting materials, thereby enabling the acquisition of different polymer properties such as high stretchability, high strength, low glass transition temperature, or high hydrolysis resistance.

[0044] Preferred silane-containing polyethers can be obtained from the reaction of an NCO-terminated urethane polyether with an aminosilane or hydroxysilane. Suitable NCO-terminated urethane polyethers for this process can be obtained from the reaction of a polyether polyol, particularly a polyoxyalkylenediol or polyoxyalkylentriol, preferably a polyoxypropylenediol or polyoxypropylenetriol, with a stoichiometric amount of polyisocyanate, particularly a diisocyanate.

[0045] Preferably, the reaction between the polyisocyanate and the polyether polyol is carried out at a temperature of 50°C to 160°C while removing moisture, and the polyisocyanate is added by metering in the presence of a suitable catalyst, with the isocyanate groups present in stoichiometric excess relative to the hydroxyl groups of the polyol. More specifically, the excess polyisocyanate is selected such that, after the reaction of all hydroxyl groups, a content of free isocyanate groups remains in the resulting urethane polyether in the range of 0.1% to 10% by weight, preferably 0.2% to 5% by weight, and more preferably 0.3% to 3% by weight, based on the total polymer.

[0046] Preferred diisocyanates are selected from the group consisting of hexamethylene 1,6-diisocyanate (HDI), 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (=isophorone diisocyanate or IPDI), torylene 2,4-diisocyanate, 2,6-diisocyanate and any desired mixture thereof (TDI), and any desired mixture thereof of diphenylmethane 4,4'-, 2,4'- and 2,2'-diisocyanates and their isomers (MDI). IPDI or TDI are particularly preferred. IPDI is most preferred. In this method, a silane group-containing polyether with particularly good weather resistance is obtained.

[0047] Polyoxyalkylenediols or polyoxyalkylentriols having a degree of unsaturation lower than 0.02 meq / g, particularly lower than 0.01 meq / g, and an average molecular weight in the range of 400 to 20,000 g / mol, particularly 1,000 to 15,000 g / mol, are especially suitable as polyether polyols.

[0048] In addition to polyether polyols, other polyols, particularly polyacrylate polyols or polyester polyols, and low molecular weight diols or triols can also be used in various proportions.

[0049] Aminosilanes suitable for reaction with NCO-terminated urethane polyethers are primary or secondary aminosilanes. Adducts formed from 3-aminopropyltrimethoxysilane, 3-aminopropyldimethoxymethylsilane, 4-aminobutyltrimethoxysilane, 4-amino-3-methylbutyltrimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, N-butyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, primary aminosilanes such as 3-aminopropyltrimethoxysilane, 3-aminopropyldimethoxymethylsilane, or N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, and Michael acceptors such as acrylonitrile, (meth)acrylic esters, (meth)acrylamide, maleic acid or fumaric acid diesters, citraconic acid diesters, or itaconic acid diesters, particularly dimethyl or diethyl N-(3-trimethoxysilylpropyl)aminosuccinate are preferred. Analogues of the above-mentioned aminosilanes having an ethoxy group or isopropoxy group instead of a methoxy group on the silicon atom are also suitable.

[0050] Hydroxysilanes suitable for reaction with NCO-terminated urethane polyethers can be obtained, in particular, by adding aminosilanes to lactones, cyclic carbonates, or lactides.

[0051] Preferred hydroxysilanes of this type are N-(3-triethoxysilylpropyl)-2-hydroxypropanamide, N-(3-trimethoxysilylpropyl)-2-hydroxypropanamide, N-(3-triethoxysilylpropyl)-4-hydroxypentanamide, N-(3-triethoxysilylpropyl)-4-hydroxyoctanamide, N-(3-triethoxysilylpropyl)-5-hydroxydecanamide, or N-(3-triethoxysilylpropyl)-2-hydroxypropylcarbamate.

[0052] Even more suitable hydroxysilanes can be obtained by adding an aminosilane to an epoxide, or by adding an amine to an epoxysilane.

[0053] Preferred hydroxysilanes of this type are 2-morpholino-4(5)-(2-trimethoxysilylethyl)cyclohexane-1-ol, 2-morpholino-4(5)-(2-triethoxysilyl-ethyl)cyclohexane-1-ol, or 1-morpholino-3-(3-(triethoxysilyl)propoxy)propane-2-ol.

[0054] Even more suitable silane group-containing polyethers are commercially available products, particularly the following: MS Polymer (trademark) (from Kaneka Corporation; particularly products S203H, S303H, S227, S810, MA903 and S943); MS Polymer (trademark) or Silyl (trademark) (from Kaneka Corporation; particularly products SAT010, SAT030, SAT200, SAX350, SAX400, SAX725, MAX450, MAX951); Excestar (registered trademark) (from Asahi Glass Co., Ltd.; particularly products S2410, S2420, S3430, S3630); SPUR+* (from Momentive Performance Materials; particularly products 1010LM, 1015LM, 1050MM); Vorasi (trademark) (from Dow Chemical Co.; particularly products 602 and 604); Desmoseal (registered trademark) (from Covestro; particularly S These include XP2458, S XP2636, S XP2749, S XP2774 and S XP2821 products), TEGOPAC® (from Evonik Industries AG; especially Seal100, Bond150, and Bond250 products), Polyvest® (from Evonik; especially EP ST-M and EP ST-E products), Polymer ST (from Hanse Chemie AG / Evonik Industries AG, especially products 47, 48, 61, 61LV, 77, 80, and 81); Geniosil® STP (from Wacker Chemie AG; especially products E10, E15, E30, and E35 products), or Arufon (from Toagosei Co., Ltd., especially products US-6100 or US-6170).

[0055] Particularly preferred silane group-containing polymers are silane group-containing polyethers that also contain urethane groups and / or urea groups in addition to silane groups. These are usually produced as a result of the reaction of isocyanate groups with hydroxyl groups or primary or secondary amino acids. This type of silane group-containing polymer allows for particularly rapid curing and particularly good properties.

[0056] The amount of silane group-containing polymer in the composition is preferably in the range of 10 to 80% by weight, more preferably in the range of 15 to 70% by weight, and more particularly in the range of 15 to 60% by weight.

[0057] The composition preferably further comprises at least one aminosilane, epoxysilane, or mercaptosilane.

[0058] Suitable epoxysilanes are particularly 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, or 3-glycidoxypropyltriethoxysilane.

[0059] Suitable mercaptosilanes are particularly 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyldimethoxymethylsilane, or 3-mercaptopropyltriethoxysilane.

[0060] It is particularly preferable that the composition contains at least one aminosilane. The aminosilane not only acts as a silane-functional crosslinking agent for the efficient curing of silane-functional polymers, but also acts as an adhesion promoter via its amino-functional group, and more importantly, acts as a curing catalyst for the crosslinking reaction by its alkaline amino group.

[0061] Preferred aminosilanes are selected from the group consisting of 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, 3-amino-2-methylpropyltrimethoxysilane, 4-aminobutyltrimethoxysilane, 4-amino-3,3-dimethylbutyltrimethoxysilane, 3-aminopropyldimethoxymethylsilane, N-(2-aminoethyl)-3-aminopropyldimethoxymethylsilane, and N-(2-aminoethyl)-N'-[3-(trimethoxysilyl)propyl]ethylenediamine, and their analogues having an ethoxy group instead of a methoxy group on silicon.

[0062] Of these, particularly preferred are 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, or N-(2-aminoethyl)-3-aminopropyltriethoxysilane.

[0063] The composition preferably contains at least one aminosilane in an amount ranging from 0.1% to 1% by weight, and particularly in the range of 0.2% to 0.99% by weight.

[0064] Preferably, the composition further comprises at least one additional desiccant, also called a moisture-scavenging agent. The desiccant improves storage stability by capturing free water or adsorbed water in the container, for example, from the filler.

[0065] Particularly suitable desiccants are tetraethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, organosilanes having a functional group at the α-position relative to the silane group, especially N-(methyldimethoxysilylmethyl)-O-methylcarbamate or (methacryloylmethyl)silane, methoxymethylsilane, orthoformic acid esters, and calcium oxide or molecular sieves.

[0066] The composition is particularly preferably vinyltrimethoxysilane or vinyltriethoxysilane. In this specification, vinyltrimethoxysilane is preferred when the silane group-containing polymer has a methoxysilane group, while vinyltriethoxysilane is preferred when the silane group-containing polymer has an ethoxysilane group.

[0067] In the case of a two-component composition, it is preferable that the desiccant, more specifically vinyltrimethoxysilane or triethoxysilane, is the same component as the silane group-containing polymer.

[0068] Suitable catalysts for curing silane-functionalized polymers are substances that accelerate the crosslinking of silane-containing polymers. Metal catalysts and / or nitrogen-containing compounds are particularly suitable for this purpose.

[0069] Suitable metal catalysts are titanium, zirconium, aluminum, or tin compounds, particularly organotin compounds, organotitanates, organozirconates, or organoaluminates, specifically those having alkoxy groups, aminoalkoxy groups, sulfonic acid groups, carboxyl groups, 1,3-diketonate groups, 1,3-ketoesterate groups, dialkylphosphate groups, or dialkylpyrophosphate groups.

[0070] Particularly preferred organotin compounds are dialkyltin oxides, dialkyltin dichlorides, dialkyltin dicarboxylates, or dialkyltin diketonates, especially dibutyltin oxides, dibutyltin dichlorides, dibutyltin dicarboxylates, dibutyltin dilaurates, dibutyltin diacetylacetonates, dioctylin oxides, dioctylin dichlorides, dioctyltin diacetates, dioctyltin dilaurates, or dioctyltin diacetylacetonates, as well as alkyltin thioesters.

[0071] Particularly preferred organotitanates are bis(ethylacetoacetate)diisobutoxytitanium(IV), bis(ethylacetoacetate)diisopropoxytitanium(IV), bis(acetylacetonate)diisopropoxytitanium(IV), bis(acetylacetonate)diisobutoxy-titanium(IV), tris(oxyethyl)amine-isopropoxy-titanium(IV), bis[tris(oxyethyl)amine]diisopropoxytitanium(IV), bis(2-ethylhexane-1,3-dioxy)titanium(IV), tris[2-((2-aminoethyl)amino)ethoxy]ethoxytitanium(IV), bis(neopentyl(diallyl)oxy)-diethoxytitanium(IV), titanium(IV) tetrabutoxide, tetra(2-ethylhexyloxy)titanium, tetra(isopropoxy)titanium, or polybutyl titanate. Commercially available products such as Tyzor® AA, GBA, GBO, AA-75, AA-65, AA-105, DC, BEAT, BTP, TE, TnBT, KTM, TOT, TPT or IBAY (all from Dorf Ketal); Tytan PBT, TET, X85, TAA, ET, S2, S4 or S6 (all from Borica Company Ltd.); and Ken-React® KR® TTS, 7, 9QS, 12, 26S, 33DS, 38S, 39DS, 44, 134S, 138S, 133DS, 158FS or LICA® 44 (all from Kenrich Petrochemicals) are particularly preferred.

[0072] Particularly suitable organozirconates are the commercially available products Ken-React®NZ®38J, KZ®TPPJ, KZ®TPP, NZ®01, 09, 12, 38, 44, or 97 (all from Kenrich Petrochemicals) or Snapcure®3020, 3030, or 1020 (all from Johnson Matthey & Brandenberger).

[0073] A particularly suitable organoaluminate is the commercially available product K-Kat5218 (from King Industries).

[0074] Particularly suitable nitrogen-containing compounds as catalysts include amines, specifically N-ethyldiisopropylamine, N,N,N',N'-tetramethylalkylenediamine, polyoxyalkylene amine, 1,4-diazabicyclo[2.2.2]octane, etc.; amidines, specifically 1,8-diazabicyclo[5.4.0]undeca-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), 6-dibutylamino-1,8-diazabicyclo[5.4.0]undeca-7-ene, etc.; guanidines, specifically , tetramethylguanidine, 2-guanidinobenzimidazole, acetylacetoneguanidine, 1,3-di-o-tolylguanidine, 2-tert-butyl-1,1,3,3-tetramethylguanidine, etc., or carbodiimidenes and amines, specifically polyetheramines or reaction products such as the above-mentioned aminosilanes; or imidazoles, specifically N-(3-trimethoxysilylpropyl)-4,5-dihydroimidazole or N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole, etc.

[0075] Various catalyst combinations for crosslinking silane group-containing polymers, more specifically combinations of at least one metal catalyst and at least one nitrogen-containing compound, are also particularly preferred.

[0076] Organotin compounds, organotitanates, amines, amidines, guanidines, or imidazoles are preferred.

[0077] In a particularly preferred embodiment, the curing catalyst is a combination of a primary aminosilane and a metal complex, the metal complex being specifically a tin complex. Preferably, the composition contains 0.5 to 1.0% by weight of the primary aminosilane and 0.01 to 0.1% by weight of the metal complex. The amounts of each allow for efficient curing while still enabling a beneficial low toxicity assessment of the composition.

[0078] The composition used in the method according to the present invention further comprises, based on the total weight of the composition, 10 to 30% by weight, preferably 15 to 25% by weight, and most preferably 17 to 23% by weight, of at least one polyether PE having 2 to 6 ether oxygen atoms and not containing a hydroxyl group. Instead of a hydroxyl group, the polyether PE contains an alkoxy-terminated group, preferably a methoxy, ethoxy, butoxy, or propoxy-terminated group, most preferably a methoxy-terminated group. The polyether PE does not contain a silane group, an amino group, or any other functional group having heteroatoms other than ether oxygen.

[0079] In a preferred embodiment, the polyether PE contains 4 to 12 carbon atoms, preferably 6 to 12 carbon atoms, and the ether oxygen atoms are crosslinked by 1 or 2 carbon atoms. The crosslinking units may be branched. However, branched carbon atoms are not counted as crosslinks; only carbon atoms directly bonded to the ether oxygen atoms are counted.

[0080] Preferably, the polyether PE is an aliphatic polyether.

[0081] Glycol ethers that do not contain any free hydroxyl groups, specifically ethylene glycol ether, propylene glycol ether, and acetal, are suitable as polyethers (PE). This means that all of the previously existing hydroxyl groups have been converted to ether groups.

[0082] Suitable glycol ethers for polyether PE include, for example, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol diphenyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-butyl ether, diethylene glycol propyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol di-n-butyl ether, dipropylene glycol dipropyl ether, and 2,5,7,10-tetraoxaundecane.

[0083] Most preferably, the polyether PE is selected from dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, dipropylene glycol dipropyl ether, and 2,5,7,10-tetraoxaundecane.

[0084] The composition according to the present invention may contain a plasticizer, but it is preferable that the amount of plasticizer is 30% by weight or less based on the total composition. Polyether PE is not considered to fall under this definition of a plasticizer. Preferably, the composition used in the method according to the present invention contains less than 20% by weight, and more preferably less than 10% by weight, of the plasticizer based on the total composition.

[0085] Suitable plasticizers include carboxylic acid esters, such as phthalates, particularly diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), or di(2-propylheptyl) phthalate (DPHP); hydrogenated phthalates, particularly hydrogenated diisononyl phthalate (DINCH); terephthalates, particularly dioctyl terephthalate; melitate esters; adipate esters, particularly dioctyl adipate (DOA); azelaic acid esters; sebacate esters, etc.; polyols, particularly polyoxyalkene polyols or polyester polyols; benzoic acid esters; glycol ethers; glycol esters; organic phosphoric acid esters; phosphonic acid or sulfonic acid esters; polybutenes; polyisobutenes; or natural oils or oil-derived plasticizers, particularly epoxidized soybean oil or linseed oil. DINP, DIDP, or DOA are preferred.

[0086] The most preferred plasticizers, if used in all cases, are flame-retardant plasticizers, particularly organophosphate esters, specifically triethyl phosphate, tricresyl phosphate, triphenyl phosphate, diphenylcresil phosphate, isodecyldiphenyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tris(2-ethylhexyl) phosphate, tris(chloroisopropyl) phosphate, tris(chloropropyl) phosphate, isopropylated triphenyl phosphate, mono-, bis- or tris(isopropylphenyl) phosphates of varying degrees of isopropylation, resorcinol bis(diphenyl phosphate) or bisphenol A bis(diphenyl phosphate). Diphenylcresil phosphate is preferred.

[0087] More preferred components of the composition are specifically the following excipients and adjuvants: - Adhesion promoters and / or crosslinking agents, particularly (meth)crirosilane, anhydridosilane, carbamatosilane, alkylsilane or iminosilane, or oligomeric forms of these silanes, or adducts of primary aminosilanes having epoxysilane or (meth)acrylosilane or anhydridosilane; - Solvents, diluents or extenders, for example, especially xylene, 2-methoxyethanol, dimethoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-isopropoxyethanol, 2-butoxyethanol, 2-phenoxyethanol, 2-benzyloxyethanol, benzyl alcohol, ethylene glycol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, propylene glycol butyl ether, propylene glycol phenyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, N-methylpyrrolidone, diphenylmethane, diisopropyl alcohol Mineral oil fractions such as ropylnaphthalene, Solvesso® products (from Exxon), alkylphenols, such as tert-butylphenol, nonylphenol, dodecylphenol, or cardanol (derived from cashew nut shell oil, containing 3-(8,11,14-pentadeca-trienyl)phenol as a main component), styrene-phenols, bisphenols, aromatic hydrocarbon resins, especially those containing phenol groups, alkoxylated phenols, especially ethoxylated or propoxylated phenols, especially 2-phenoxyethanol, adipates, sebacates, phthalates, benzoates, organophosphates, or sulfonic acids or sulfonamides; - Inorganic or organic fillers, in particular heavy or precipitated calcium carbonate coated optionally with fatty acids, especially stearate; brightite, talc, quartz powder, silica sand, iron mica, dolomite, wollastonite, kaolin, mica (potassium aluminum silicate), molecular sieves, aluminum oxide, aluminum hydroxide, magnesium hydroxide, silica, cement, gypsum, fly ash, carbon black, graphite, metal powders such as aluminum, copper, iron, zinc, silver, and steel, PVC powder, or hollow spheres; - Fibers, especially polymer fibers such as glass fibers, carbon fibers, metal fibers, ceramic fibers, polyamide fibers, or polyethylene fibers, or natural fibers such as wool, cellulose, hemp, or sisal; - Inorganic or organic pigments, especially titanium dioxide, chromium oxide, or iron oxide; - dye - Rheological modifiers, especially thickeners, particularly layered silicates such as bentonite, derivatives of cinnamon oil such as hydrogenated cinnamon oil, polyamides, polyurethanes, urea compounds, polyvinyl chloride, fumed silica; - Natural resins, fats, or oils, such as rosin, shellac, linseed oil, cantaloupe oil, or soybean oil; - Homopolymers of particularly unsaturated monomers from the group including nonreactive polymers, particularly ethylene, propylene, butylene, isobutylene, isoprene, vinyl acetate or alkyl (meth)acrylate, particularly polyethylene (PE), polypropylene (PP), polyisobutylene, ethylene-vinyl acetate copolymer (EVA) or atactic poly-α-olefin (APAO). or copolymer; - Flame retardants, particularly aluminum hydroxide or magnesium hydroxide, boron compounds, antimony trioxide, phosphorous acid, or the flame retardant plasticizers described above; or - Additives, particularly wetting agents, flow regulators, defoaming agents, deaeration agents, oxidation stabilizers, heat stabilizers, light stabilizers or UV stabilizers, or biocides.

[0088] If certain components are stored together, especially with silane group-containing polymers, it may be useful to dry them chemically or physically before mixing them into the composition.

[0089] Preferably, the moisture-curable composition according to the present invention contains less than 5% by weight of aliphatic or aromatic alkylalkoxysilane, specifically alkyltrialkoxysilane and / or alkyldialkoxysilane, based on the total composition. Specifically, if used in whole, alkyltrialkoxysilanes such as octyltrialkoxysilane and phenyltrialkoxysilane should be used in an amount of less than 5% by weight, preferably less than 2% by weight. Such compounds result in low viscosity and rapid curing, but adversely affect good interlayer adhesion when the top layer is applied to a substrate that has dried for more than two days. Furthermore, an excess amount of organosilane having two or three methoxy groups results in an increase in the level of methanol byproducts released into the environment during the curing of the composition.

[0090] Preferably, the moisture-curable composition further comprises 10% to 50% by weight, particularly 20% to 40% by weight, of at least one filler selected from chalk, aluminum hydroxide, and titanium dioxide, or mixtures thereof.

[0091] In particular, mixtures of chalk, aluminum hydroxide, and titanium dioxide provide a beneficial range of additional properties, including not only mechanical improvements but also enhanced flame retardancy and light resistance, without making the composition excessively expensive.

[0092] The composition preferably further comprises at least one additional component selected from moisture scavengers, UV absorbers and stabilizers, pigments, and rheological modifiers. In preferred embodiments, all of these additives are included in the composition. Such compositions are particularly stable against the effects of outdoor ultraviolet radiation, particularly storage stable, and particularly convenient for application as liquid coating films.

[0093] For use as a sealing film, the composition is preferably produced and used in the form of a one-component composition. The composition is stored in a moisture-tight container. Suitable containers include drums, bulk containers, hobocks, pails, pouches, canisters, or bottles. Since the composition is storage stable, it can be stored in the container for several months to more than a year before application without significantly altering its properties to a degree relevant to its use.

[0094] Chemical curing begins after the composition is applied. Silane groups undergo hydrolysis, accompanied by the release of alcohol, to form silanol groups (Si-OH groups), which then undergo a condensation reaction to form siloxane groups (Si-O-Si groups). As a result of these reactions, and possibly further reactions, the composition hardens to yield a crosslinked polymer. If water that hydrolyzes the silane groups is not yet present on the substrate, or is already present on the substrate or on the newly applied composition, it may originate from the air (atmospheric humidity), naturally originate from the substrate, or the composition may come into contact with, for example, a water-containing component through coating, spraying, or mixing.

[0095] Curing typically occurs at ambient temperature and usually takes several hours or several days until the curing is largely complete under typical conditions.

[0096] The above-mentioned moisture-curing composition can be coated with the surface according to the present invention using the following steps: (a) Applying a first layer of moisture-curing composition to the surface, (b) Optionally, cure the applied moisture-curable composition to form a dry first layer. (c) Apply the second layer of the moisture-curing composition to the first layer which has been optionally dried.

[0097] Therefore, the method for coating the surface is a multilayer coating process in which at least two layers of moisture-curable composition are applied.

[0098] Before applying the overlapping second layer, and before performing step (c), but after step (a), the first layer can be cured and dried for at least 48 hours, preferably at least 72 hours. A few days after step (a), the composition layer applied in step (a) can be completely dried, and step (c) can be performed without significantly losing interlayer adhesion.

[0099] However, this method is also effective in so-called wet-on-wet application, where the first layer is not yet dry.

[0100] Nevertheless, one significant advantage of the method according to the present invention is that the composition can form strong interlayer adhesion even when the first layer is partially or completely dry. This allows users of this method to have a more flexible and consumer-friendly approach to their coating processes, without the risk of poor interlayer adhesion that can result from long waiting times between applications of many coating compositions currently available.

[0101] Compositions coated by the method according to the present invention exhibit an interlayer adhesion strength of at least 15 N / mm, preferably at least 20 N / mm, and particularly at least 25 N / mm, based on peel adhesion using a topcoat time of 7 days under a climate of preferably 20°C and 50% relative humidity.

[0102] During application, the newly mixed composition, which is still liquid, is applied as a coating or sealing film to a horizontal or slightly inclined surface, usually by pouring it onto a substrate and then spreading it two-dimensionally until the desired layer thickness is reached, for example, using a brush, roller, slider, notched trowel, or spatula.

[0103] The newly mixed composition preferably has a viscosity in the range of 0.05 to 8.0 Pa·s, preferably 0.05 to 6.5 Pa·s, particularly 0.05 to 5.0 Pa·s, and most preferably 0.05 to 4.0 Pa·s at 20°C. Therefore, the composition can function well as a sealing film for liquid coating. It is preferably self-leveling, meaning that after being processed by a brush, roller, notched trowel, spiked roller, etc., it levels itself to give a uniform surface.

[0104] In a single operation, a layer thickness of typically 0.5 to 3 mm, and especially in the range of 0.75 to 2.5 mm, is applied.

[0105] The method using the composition defined above can be applied to various substrates and, upon curing, results in a sealing film in the form of an elastic coating that protects the substrate from water penetration.

[0106] The composition or sealing film is applied to one or more layers. One or more finishing coats may be applied to the layer system. A seal may be applied as the top or final layer.

[0107] This "seal" is a transparent or colored high-grade coating applied as a thin top layer to the coating. The seal protects and strengthens the surface of the coating, filling any remaining pores. The thickness of the seal (in its dry state) is typically in the range of 0.03 to 0.3 mm.

[0108] The seal provides additional protection from UV rays, oxidation, or microbial growth, offers opportunities for aesthetic design, protects the coating from mechanical damage, prevents soiling, and / or facilitates cleaning.

[0109] The liquid coating composition or sealing film can be used, using the method according to the present invention, for sealing roofs, particularly flat roofs or gently sloping roof areas, roof terraces or roof gardens, or otherwise planting containers, balconies, patios, plazas or building foundations, or for sealing water inside buildings, such as under tiles or ceramic slabs in wet cells, kitchens, industrial halls or manufacturing spaces. It can also be used for purposes such as repairing leaks in roof membranes.

[0110] The liquid coating composition or sealing film is preferably used on roofs, more specifically on flat roofs or gently sloping roofs. It can be used for sealing new roofs or for repair purposes. The sealing film is also particularly suitable for detailed work on roofs where sealing is performed, such as angled shapes, pipe penetrations, or built-in structures, such as solar power systems, energy lighting systems, or air conditioning systems.

[0111] The composition or sealing film is preferred for use in roof sealing systems including the following: - Optionally, a primer and / or base coat and / or a repair compound or leveling compound, - At least one layer of the described composition, with a thickness of 0.5 to 3 mm, combined with a mechanical reinforcing material of any choice. - Optional finish coat and / or seal coat.

[0112] Suitable mechanical reinforcements include, in particular, reinforcing fabrics, more specifically plastic mesh or fibers, or fleece mats, more specifically woven polyester fleece mats or fleece mats or chopped strand glass fiber mats made from nonwoven polyester fibers or nonwoven glass fibers.

[0113] When mechanical reinforcement is used in the form of a reinforcing fabric or mat, it is preferably laid on top of a newly applied first layer of the composition and incorporated into the composition while wet, for example, by a roller or brush. After the composition incorporating the mechanical reinforcement has cured, further layers of the composition and / or finish coats and / or seals may be applied thereon.

[0114] When using fibers, the fibers may be mixed into the liquid composition before application, or the fibers may be scattered while the applied composition is still liquid.

[0115] A further aspect of the present invention is a moisture-curable composition used in the method described above.

[0116] Yet another aspect of the present invention is a cured multilayer composition obtained by the method described above.

[0117] A suitable substrate to which the composition or sealing film can be applied is, specifically, - Concrete, lightweight concrete, mortar, brick, persimmon wood, tiles, slate, gypsum, anhydrite, or natural stone such as granite or marble; - Repair or leveling compounds based on PCC (polymer-modified cement mortar) or ECC (epoxy resin-modified cement mortar); - Metals and alloys with surface finishes, such as galvanized or chromium-plated metals, as well as metals and alloys such as aluminum, copper, iron, steel, and non-ferrous metals; - Asphalt or bitumen; - Plastics such as PVC, ABS, PC, PA, polyester, PMMA, SAN, epoxy resin, phenolic resin, polyurethane, POM, polyethylene, and polyolefins such as polypropylene, EPM, or EPDM, each either untreated or surface-treated by plasma, corona, or flame; especially PVC, polyolefin, or EPDM films; - Insulating foam materials, especially those made from EPS, XPS, polyurethane, PIR, rock wool, glass wool, or foamed glass; - Coating substrates such as colored tiles, coated concrete, or powder-coated metal That is the case.

[0118] If necessary, the substrate may be pre-treated before applying the composition or sealing film. Examples of such pre-treatment include physical and / or chemical cleaning methods, such as polishing, sandblasting, shot blasting, brushing, suction or blowing, spraying with high-pressure or ultra-high-pressure water, and / or treatment with cleaning agents or solvents, and / or application of adhesion promoters, adhesion promoters, or primers.

[0119] By applying the composition or sealing film according to the method of the present invention and curing it, an article sealed or coated with the composition is obtained. The article is more specifically a large structure, and more specifically a large structure in building construction or civil engineering.

[0120] The described method is characterized by advantageous properties. The composition or encapsulation film applied in liquid form is stable for storage in the form of a one-component or multi-component composition. The composition or encapsulation film cures rapidly and reliably under ambient conditions to form an elastic material with suitable strength, elasticity, and tear resistance, and an elastic modulus that is not excessively high. Since the composition or encapsulation film is low-toxicity, no special protective measures are required for safe use. [Examples]

[0121] The following are examples illustrating the present invention in detail. It will be understood that the present invention is not limited to these described examples.

[0122] "Standard climate conditions" refer to a temperature of 23±1°C and a relative humidity of 50±5%. "SCC" stands for "Standard Climate Conditions".

[0123] Silane group-containing polymer used: STP Polymer-1: In a moisture-free environment, 1000 g of Acclaim® 12200 polyol (from Covestro; low monool polyoxypropylene diol, OH value 11.0 mg KOH / g, water content approximately 0.02 wt%), 62.5 g of isophorone diisocyanate (Vestanat® IPDI from Evonik Industries), 131 g of triethylene glycol bis(2-ethylhexanoate) (TEG-EH from Eastman), and 0.3 g of Coscat 83 (from Vertellus) were heated to 90°C with continuous stirring, and allowed to stand at this temperature until the free isocyanate group content, determined by titration, reached 1.32 wt%. Subsequently, 144.9 g of diethyl N-(3-trimethoxysilylpropyl)aminosuccinate was mixed in, and the mixture was stirred at 90°C until no free isocyanates could be detected by FT-IR spectroscopy. The silane-functionalized polymer was cooled to room temperature and stored in a moisture-free environment. The polymer was liquid at room temperature and had a viscosity of 3.5 Pa·s at 20°C.

[0124] STP Polymer-1 contains 11% by weight of a plasticizer (triethylene glycol bis(2-ethylhexanoate)).

[0125] Further substances used: OCTMO Octyltrimethoxysilane; Dynasylan® OCTMO (Evonik) DMM Dipropylene Glycol Dimethyl Ether; PROGLYDE (trademark) DMM (Dow) PGDA (Propylene Glycol Diacetate); DOWANOL (Trademark) PGDA (Dow) DPM Dipropylene Glycol Monomethyl Ether; DOWANOL (Trademark) DPM (Dow) DPnP Dipropylene Glycol Monopropyl Ether; DOWANOL (Trademark) DPnP (Dow) TOU 2,5,7,10-tetraoxaundecane; tetraoxaundecane SOLVAGREEN (registered trademark) (Carl Roth) PC Propylene Carbonate; Propylene Carbonate (Sigma Aldrich) TEG-EH Triethylene glycol bis(2-ethylhexanoate); Eastman (trademark) TEG-EH (Eastman) VTMO Vinyltrimethoxysilane; Geniosil® XL 10 (Wacker); (Moisture scavenging agent) UV-A UV absorber (organic) UV-S UV stabilizer (Hindered Amine Light Stabilizer) Titanium dioxide (TiO2) (white pigment) Pigment: Black pigment ATH Aluminum trihydroxyoxide Al(OH)3 (filler) CaCO3 calcium carbonate (chalk) (filler) SiO2 exothermic silica (reinforcement material / rheological modifier) AMMO 3-aminopropyltrimethoxysilane; Dynasylan® AMMO (Evonik) (catalyst) DBTDL Dibutyltin dilaurate (catalyst) D-400 is a polyetherdiamine based on polypropylene glycol with a primary amino group at the terminus (average molecular weight 430 g / mol). Jeffamine® D-400 (Huntsman) D-230 is a polyetherdiamine based on polypropylene glycol with a primary amino group at the terminus (average molecular weight 230 g / mol); Jeffamine® D-230 (Huntsman)

[0126] Manufacturing of sealing films: For each sealing film, the raw materials specified in Tables 1 and 2 were mixed in the indicated amount (parts by weight) into a homogeneous liquid using a centrifugal mixer (SpeedMixer® DAC150, FlackTek Inc.) or a high-speed stirrer, and stored while removing moisture.

[0127] The following test protocol was applied: After 24 hours of mixing, the viscosity of each composition was determined at 20°C using a constant temperature Rheotec RC30 cone-plate viscometer (cone diameter 25 mm, cone angle 1°, distance from cone tip to plate 0.05 mm, shear rate 10 rpm) or Rotothinner® (according to the principles outlined in BS3900-A7).

[0128] Under SCC conditions, the composition was applied to a moistened first layer, followed by a first reinforcing layer and then a second layer, and complete curing was sought. Films that were fully cured after 24 hours were given a "pass" rating, while sample films that did not fully cure were given a "fail" rating.

[0129] To measure the time it takes for the composition to lose its tackiness, or the non-tackiness time abbreviated as "TFT," a small amount of the composition, mixed at room temperature, was applied to cardboard in a layer thickness of approximately 3 mm. Under standard conditions, the LDPE pipette was used to gently touch the surface of the composition for the first time, and the time elapsed until no residue remained in the pipette was determined.

[0130] To determine the interlayer adhesion strength, the composition was applied to a first reinforcing layer and a wet-on-wet second layer. The samples were left to cure and condition for a number of hours / days corresponding to the topcoat time to be tested. Once the desired conditioning period was reached, the first reinforcing layer was applied directly onto the conditioned sample (with bond fracture), followed by the wet-on-wet second layer. The combined samples were left to cure and condition for 7 days from the time of topcoat application. The samples were cut to a width of 50 mm and a minimum length of 120 mm. The tests were conducted according to the principles outlined in ISO 8510-2:2006 Adhesives—Peel tests of flexible bonded rigid specimen assemblies—Part 2: 180° peel).

[0131] The results are reported in Table 3. Examples I-1 to I-4 are compositions according to the present invention, while Examples R-1 to R-8 are control compositions not according to the present invention.

[0132] [Table 1]

[0133] [Table 2]

[0134] [Table 3]

[0135] Table 3 shows that control samples R-2, R-3, R-4, and R-5 did not show sufficient complete curing in the test layer after 24 hours.

[0136] The viscosity was excellent in Examples R-1, I-2, I-3, and I-4, and the viscosity was sufficient in Example I-1. Examples R-2, R-3, R-4, R-5, R-6, R-7, and R-8 all showed viscosities that were too high for their ideal applications as liquid coating films.

[0137] After 3 days, R-1 no longer provided satisfactory interlayer adhesion. It was impossible to adequately evaluate the interlayer adhesion in Examples R-7 and R-8. In both cases, particularly in R-8, after 24 hours, there was a strong formation of a fatty liquid layer on the surface of the first coating layer, likely due to surface migration of polyetherdiamine, which made further analysis of interlayer adhesion impossible.

[0138] Of this series of tests, only the examples according to the present invention showed good or excellent interlayer adhesion even after 7 days, along with complete curing and a viscosity low enough to be used as a liquid coating film. This disclosure includes the following embodiments of the invention: <Aspect 1> A method for coating a surface, comprising the following steps: (a) Applying a first layer of moisture-curing composition to the surface, (b) Optionally, the applied moisture-curing composition is cured to form a dry first layer. (c) Applying the second layer of the moisture-curing composition to the first layer which has been optionally dried. Here, the moisture-curing composition is - At least one organic polymer that is liquid at room temperature and contains reactive silane groups, in an amount of 20 to 50% by weight, preferably 25 to 45% by weight, based on the total weight of the composition; and - 10 to 30% by weight, preferably 15 to 25% by weight, of the total weight of the composition, of at least one polyether PE having 2 to 6 ether oxygen atoms and not containing hydroxyl groups; and - At least one curing catalyst for reactive silane groups including, method. <Aspect 2> The method according to embodiment 1, characterized in that the silane group-containing polymer is a polyether containing a silane group. <Aspect 3> The method according to embodiment 2, characterized in that the polyether containing the silane group contains a urethane group and / or a urea group in addition to the silane group. <Aspect 4> The method according to any one of embodiments 1 to 3, characterized in that, before applying the second layer and before performing step (c), and after step (a), the first layer is cured and dried for a drying time of at least 48 hours, preferably at least 72 hours, to obtain a dried first layer. <Aspect 5> The method according to any one of embodiments 1 to 4, characterized in that the moisture-curable composition preferably further comprises 10% to 50% by weight of at least one filler selected from chalk, aluminum hydroxide, and titanium dioxide. <Aspect 6> The method according to any one of embodiments 1 to 5, characterized in that the polyether PE contains 4 to 12 carbon atoms, and the ether oxygen atoms are crosslinked by 1 or 2 carbon atoms. <Aspect 7> The method according to embodiment 6, characterized in that the polyether PE is selected from dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, dipropylene glycol dipropyl ether, and 2,5,7,10-tetraoxaundecane. <Aspect 8> The method according to any one of embodiments 1 to 7, characterized in that the moisture-curing composition contains less than 5% by weight of an aliphatic or aromatic alkylalkoxysilane based on the total composition. <Pattern 9> The method according to any one of embodiments 1 to 8, characterized in that the curing catalyst is a combination of a primary aminosilane and a metal complex, and the metal complex is particularly a tin complex. <Aspect 10> The method according to embodiment 9, characterized in that the composition comprises 0.5 to 1.0% by weight of the primary aminosilane and 0.01 to 0.1% by weight of the metal complex. <Aspect 11> The method according to any one of embodiments 1 to 10, characterized in that the composition further comprises at least one further component selected from a moisture scavenger, an ultraviolet absorber and stabilizer, a pigment, and a rheological modifier. <Aspect 12> The method according to any one of embodiments 1 to 11, characterized in that the surface to be coated is the roof of a building. <Aspect 13> A moisture-curing composition used in the method described in any one of embodiments 1 to 12. <Aspect 14> A cured multilayer coating obtained by the method described in any one of embodiments 1 to 12. <Aspect 15> Roof sealing system including the following: - Optionally, a primer and / or base coat and / or repair or leveling compound, - At least two layers of the composition according to any one of embodiments 1 to 11, each having a thickness of 0.5 to 3 mm, optionally combined with a mechanical reinforcing material. - Optionally, a top coat and / or seal coat.

Claims

1. A method for coating a surface, comprising the following steps: (a) Applying a first layer of moisture-curing composition to the surface, (b) Optionally, the applied moisture-curable composition is cured to form a dry first layer. (c) Applying the second layer of the moisture-curable composition to the first layer which has been optionally dried. Here, the moisture-curing composition is - At least one organic polymer that is liquid at room temperature and contains reactive silane groups, in an amount of 20 to 50% by weight based on the total weight of the composition; and - 10 to 30% by weight of the total weight of the composition, at least one polyether PE having 2 to 6 ether oxygen atoms and not containing hydroxyl groups; and - At least one curing catalyst for reactive silane groups Includes, The polyether PE is selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, ethylene glycol diphenyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol di-n-butyl ether, diethylene glycol propyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol di-n-butyl ether, dipropylene glycol dipropyl ether, and 2,5,7,10-tetraoxaundecane. method.

2. The method according to claim 1, characterized in that the silane group-containing polymer is a polyether containing silane groups.

3. The method according to claim 2, characterized in that the polyether containing the silane group contains a urethane group and / or a urea group in addition to the silane group.

4. The method according to any one of claims 1 to 3, characterized in that, before applying the second layer and before performing step (c), and after step (a), the first layer is cured and dried for a drying time of at least 48 hours to obtain a first layer.

5. The method according to any one of claims 1 to 4, characterized in that the moisture-curing composition further comprises 10% to 50% by weight of at least one filler.

6. The method according to any one of claims 1 to 5, characterized in that the polyether PE is selected from dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, dipropylene glycol dipropyl ether, and 2,5,7,10-tetraoxaundecane.

7. The method according to any one of claims 1 to 6, characterized in that the moisture-curing composition contains less than 5% by weight of an aliphatic or aromatic alkylalkoxysilane based on the total composition.

8. The method according to any one of claims 1 to 7, characterized in that the curing catalyst is a combination of a primary aminosilane and a metal complex, and the metal complex is particularly a tin complex.

9. The method according to claim 8, characterized in that the composition comprises 0.5 to 1.0% by weight of the primary aminosilane and 0.01 to 0.1% by weight of the metal complex.

10. The method according to any one of claims 1 to 9, characterized in that the composition further comprises at least one further component selected from a moisture scavenger, an ultraviolet absorber and stabilizer, a pigment, and a rheological modifier.

11. The method according to any one of claims 1 to 10, characterized in that the surface to be coated is the roof of a building.

12. A moisture-curing composition used in the method according to any one of claims 1 to 11.

13. A cured multilayer coating obtained by the method according to any one of claims 1 to 11.

14. Roof sealing system including the following: - Optionally, a primer and / or base coat and / or repair or leveling compound, - At least two layers of the composition according to any one of claims 1 to 10, each having a thickness of 0.5 to 3 mm, optionally combined with a mechanical reinforcing material. - Optionally, a top coat and / or seal coat.

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