Polyurethane composition suitable as construction waterproofing and having extended pot life

Abstract

The present invention relates to a polyurethane composition comprising a first component A and a second component B. The first component A comprises a polyol mixture P containing - at least one polyol P1 having an average molecular weight of 800 to 30,000 g / mol, the polyol P1 being a polyhydroxy-functional fat and / or a polyhydroxy-functional oil, or a polyol obtained by chemical modification of natural fats and / or natural oils; and - preferably at least one polyol P2 selected from the group consisting of polyester polyols and polyether polyols; and the second component B comprises at least one aliphatic polyisocyanate I. The polyurethane composition contains additionally fillers F, an acid SA with a pKa value of ≤ 4.9, a tin catalyst K and a compound T that comprises at least one thiol group, the molar ratio of all thiol groups of the at least one compound T to all metal atoms of the at least one tin catalyst K (T / K) being between 2.75:1 and 10:1. The polyurethane composition is suitable for roof coatings and irrespective of the curing conditions has a long pot life and short curing times.

Description

[0001] POLYURETHANE COMPOSITION SUITABLE AS STRUCTURAL WATERPROOFING WITH EXTENDED POT LIFE

[0002] Technical area

[0003] The invention relates to the field of polyurethane compositions and their use, in particular as building waterproofing.

[0004] State of the art

[0005] Two-component polymethyl methacrylate compositions have long been used as roof coatings. They have the advantage of curing quickly after mixing, allowing for faster walkability. They also meet the requirements for a durable, weather- and water-resistant roof coating. However, such systems have the disadvantage of high VOC emissions.

[0006] Ideally, building waterproofing and roof coatings, in particular, should exhibit both a long pot life and a short curing time, regardless of the curing conditions. An open time of 15–45 minutes and a curing time of 60–220 minutes would be desirable under curing conditions across the entire temperature range of 5°C to 21°C, especially at 90% relative humidity.

[0007] When using two-component polyurethane compositions for structural waterproofing, it would therefore be desirable to be able to combine a sufficiently long pot life for application to the substrate with subsequent rapid curing and rapid recoatability / walkability. However, this is hardly achievable with today's two-component polyurethane compositions. Either the pot life is too short for compositions that cure and build strength quickly, or the curing and strength build-up are slow when applying compositions with a long pot life.In other technical fields, two-component polyurethane compositions have been developed that have a long pot life, even adjustable within certain limits, allowing the processing of larger components or manufactured parts. They also cure very quickly after application and exhibit strength and elasticity comparable to structural bonds within hours to a few days. One such two-component polyurethane composition in the field of structural bonding is disclosed in WO 2019 / 002538 A1. This publication teaches special catalyst systems comprising a metal catalyst and thiol-containing compounds that allow an adjustable pot life and subsequent rapid curing of the composition.

[0008] WO 2022043383 A1 is in the field of floor coatings and discloses a two-component polyurethane composition containing a metal catalyst and thiol group-containing compounds, in which the pot life and the curing of the composition can be adapted to the curing conditions.

[0009] In the field of the paint industry, EP 0454219 discloses polyurethane compositions based on polyacrylic polyols, aliphatic polyisocyanates, a dibutyltin dilaurate catalyst complexed with trimethylolpropane tris(3-mercaptopropionate) and a high proportion of organic solvents.

[0010] US 2019 / 0106527 A1 discloses coatings for vehicles comprising a polyol, preferably polyester polyols or polyacrylate polyols, a polyisocyanate, a catalyst, a tertiary acid, optionally a complexing agent containing at least one -SH group, and a high proportion of organic solvents. It would therefore be desirable to provide polyurethane compositions for roof coatings that exhibit both a long pot life and a short curing time, regardless of the curing conditions. A pot life of 15–45 minutes and a curing time of 60–220 minutes under curing conditions across the entire temperature range from 5°C to 21°C, particularly at 90% relative humidity, would be desirable.

[0011] Description of the invention

[0012] The object of the present invention is therefore to provide a polyurethane composition for roof coatings which has both a long pot life and a short curing time, regardless of the curing conditions.

[0013] Surprisingly, this object is achieved with the polyurethane composition according to the invention according to claim 1. Further aspects of the invention are the subject of further independent claims. Particularly preferred embodiments of the invention are the subject of the dependent claims.

[0014] Ways to implement the invention

[0015] The present invention relates to a polyurethane composition comprising a first component A and a second component B, wherein

[0016] - the first component A

[0017] - a polyol mixture P containing

[0018] - at least one polyol P1 having an average molecular weight of 800 to 30,000 g / mol, preferably 850 to 20,000 g / mol, more preferably 900 to 10,000 g / mol, wherein the polyol P1 is: a polyhydroxy-functional fat and / or a polyhydroxy-functional oil, or a polyol obtained by chemical modification of natural fats and / or natural oils; and - preferably at least one polyol P2 selected from the group consisting of polyester polyols and polyether polyols; and

[0019] - the second component B

[0020] - at least one aliphatic polyisocyanate I; wherein the polyurethane composition additionally comprises 5 wt.% to 70 wt.%, preferably 20 wt.% to 50 wt.%, of at least one filler F, based on the total weight of the polyurethane composition, and wherein the polyurethane composition additionally comprises 0.7 - 2.9 mM, based on 100 g of the polyurethane composition, of at least one acid SA with a pK a-value of < 4.9, and at least one tin catalyst K for the reaction of hydroxyl groups and isocyanate groups, which can form thio complexes, and at least one compound T which has at least one thiol group, and the molar ratio of all thiol groups of the at least one compound T to all metal atoms of the at least one tin catalyst K (T / K) is from 2.75:1 to 10:1 and the molar ratio of all NCO groups of the polyurethane composition to all metal atoms of the at least one tin catalyst K (NCO / K) is preferably from 20 to 200.

[0021] In this document, the prefix “poly” in substance names such as “polyol”, “polyisocyanate”, “polyether” or “polyamine” indicates that the respective substance formally contains more than one of the functional groups mentioned in its name per molecule.

[0022] In this document, the term "polymer" encompasses, on the one hand, a collective of chemically uniform macromolecules that differ in terms of degree of polymerization, molecular weight, and chain length, produced by a polyreaction (polymerization, polyaddition, polycondensation). On the other hand, the term also encompasses derivatives of such a collective of macromolecules from polyreactions, i.e., compounds obtained by reactions, such as additions or substitutions, of functional groups on given macromolecules, and which may be chemically uniform or chemically heterogeneous. The term also encompasses so-called prepolymers, i.e., reactive oligomeric pre-adducts whose functional groups are involved in the construction of macromolecules.

[0023] In this document, "molecular weight" refers to the molar mass (in grams per mole) of a molecule or a molecular residue. "Mean molecular weight" is the number average M n a polydisperse mixture of oligomeric or polymeric molecules or molecular residues, which is usually determined by gel permeation chromatography (GPC) against polystyrene as a standard.

[0024] Percentages by weight, abbreviated to wt%, refer to the mass fraction of a component of a composition relative to the total composition, unless otherwise stated. The terms "mass" and "weight" are used synonymously in this document.

[0025] A “primary hydroxyl group” is an OH group that is bonded to a C atom with two hydrogens.

[0026] In this document, “pot life” is defined as the time within which the polyurethane composition can be processed after mixing the components before the viscosity has become too high for further processing due to the progression of the crosslinking reaction.

[0027] In this document, “curing time” is defined as the time required to ensure sufficient hardness of the polyurethane composition, particularly with regard to its reworkability / walkability.

[0028] In this document, the term “strength” refers to the strength of the cured composition, whereby strength means in particular the tensile strength and the modulus of elasticity (E-modulus), in particular in the strain range 0.05 to 0.25% or in the range 0.5 to 5.0%.

[0029] In this document, “room temperature” is defined as 23 °C.

[0030] A substance or composition is described as “storage-stable” or “storable” if it can be stored at room temperature in a suitable container for a prolonged period of time, typically at least 3 months up to 6 months or more, without its application or use properties, in particular viscosity and crosslinking rate, changing as a result of storage to an extent relevant to its use.

[0031] All industry standards and norms mentioned in this document refer to the versions valid at the time of filing the initial application. The "average OH functionality" represents the number of OH groups per polymer molecule, averaged across all polymer molecules. For example, if 50% of all polymer molecules contain two hydroxyl groups and the other 50% contain three, the average OH functionality is 2.5. The average OH functionality can be determined, in particular, by calculation from the hydroxyl number and the molecular weight M determined by GPC. n be determined.

[0032] The polyurethane composition according to the invention comprises a first component A and a second component B, which are mixed only during the application of the polyurethane composition and are stored beforehand in separate packaging.

[0033] The first component A contains a polyol mixture P.

[0034] The proportion of the polyol mixture P is preferably 5 wt.% to 90 wt.%, preferably 10 wt.% to 80 wt.%, 20 wt.% to 70 wt.%, 30 wt.% to 60 wt.%, in particular 40 wt.% to 50 wt.%, based on component A.

[0035] It may further be advantageous if the proportion of the polyol mixture P is 5 wt.% to 70 wt.%, preferably 10 wt.% to 60 wt.%, 15 wt.% to 50 wt.%, 20 wt.% to 45 wt.%, in particular 30 wt.% to 40 wt.%, based on the total weight of the polyurethane composition. The polyol mixture P contains at least one polyol P1 with an average molecular weight of 800 to 30,000 g / mol, preferably 850 to 20,000 g / mol, more preferably 900 to 10,000 g / mol, where the polyol P1 is a polyhydroxy-functional fat and / or a polyhydroxy-functional oil, or a polyol obtained by chemical modification of natural fats and / or natural oils.

[0036] Examples of chemically modified natural fats and / or oils are polyols obtained from epoxy polyesters or epoxy polyethers, for example, by epoxidation of unsaturated oils, followed by ring opening with carboxylic acids or alcohols, polyols obtained by hydroformylation and hydrogenation of unsaturated oils, or polyols obtained from natural fats and / or oils by degradation processes such as alcoholysis or ozonolysis and subsequent chemical linking of the resulting degradation products or derivatives thereof, for example, by transesterification or dimerization. Also suitable are polyols obtained by polyoxyalkylation of natural oils such as castor oil, which are available, for example, under the trade name Lupranol Balance® from Elastogran GmbH.Suitable degradation products of natural fats and / or oils are in particular fatty acids and fatty alcohols and fatty acid esters, in particular the methyl esters (FAME), which can be derivatized to hydroxy fatty acid esters, for example by hydroformylation and hydrogenation.

[0037] The above-mentioned polyols P1 usually have a relatively high average molecular weight between 800 and 30,000 g / mol, preferably between 850 and 20,000 g / mol, more preferably between 900 and 10,000 g / mol and preferably an average OH functionality in the range of 1.6 to 3. Preferably, the polyol P1 is castor oil or a chemical modification thereof, in particular a chemical modification of castor oil, particularly preferably a reaction product of castor oil with ketone resins.

[0038] The polyol P1 is particularly preferably a polyol with an OH number of 110 to 200 mg KOH / g. An OH number of 140 to 190 mg, in particular 140 to 170 mg, and particularly preferably 150 to 170 mg KOH / g is preferred.

[0039] Particularly preferred are reaction products of castor oil with cyclohexanone-based ketone resins, in particular those sold, for example, by Nuplex Resins GmbH, Germany, under the names Setathane® 1150, Setathane® 1155 and Setathane® 1160.

[0040] In this document, the term "castor oil" is preferably understood to mean castor oil as described in the online Römpp Chemie Lexikon (Thöme Verlag), accessed on 23.12.2016.

[0041] In this document, the term "ketone resin" is preferably understood to mean ketone resin as described in the Online Römpp Chemie Lexikon, Thieme Verlag, accessed on 23.12.2016.

[0042] The polyol mixture P preferably contains at least one polyol P2 selected from the group consisting of polyester polyols and polyether polyols.

[0043] In all embodiments, the polyol P2 preferably has an average molecular weight in the range from 400 to 6,000 g / mol, in particular 450 to 5,500 g / mol, particularly preferably 500 to 5,000 g / mol, 750 to 3,000 g / mol, most preferably 0 to 2,000 g / mol.

[0044] In all embodiments, the polyol P2 preferably has an average OH functionality in the range from 2 to 4, in particular 2 to 3.5, particularly preferably 2 to 3. In all embodiments, the polyol P2 preferably has an OH number in the range from 20 to 600 mg KOH / g, 50 to 600 mg KOH / g, 100 to 600 mg KOH / g, in particular 200 to 600 mg KOH / g, 300 to 600 mg KOH / g, particularly preferably 350 to 600 mg KOH / g.

[0045] Polyether polyols, also called polyoxyalkylene polyols or oligoetherols, are particularly suitable as polymer P2 which are polymerization products of ethylene oxide, 1,2-propylene oxide, 1,2- or 2,3-butylene oxide, oxetane, or mixtures thereof, optionally polymerized with the aid of a starter molecule having two or more active hydrogen atoms such as, for example, water, ammonia or compounds having several OH or NH groups such as, for example, 1,2-ethanediol, 1,2- and 1,3-propanediol, neopentyl glycol, diethylene glycol, triethylene glycol, the isomeric dipropylene glycols and tripropylene glycols, the isomeric butanediols, pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 1,3- and 1 ,4-Cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol, aniline, and mixtures of the above-mentioned compounds.Both polyoxyalkylene polyols with a low degree of unsaturation (measured according to ASTM D-2849-69 and expressed in milliequivalent unsaturation per gram of polyol (mEq / g)), produced for example using so-called double metal cyanide complex catalysts (DMC catalysts), and polyoxyalkylene polyols with a higher degree of unsaturation, produced for example using anionic catalysts such as NaOH, KOH, CsOH or alkali metal alcoholates, can be used.

[0046] Polyoxyethylene polyols and polyoxypropylene polyols, in particular polyoxyethylene diols, polyoxypropylene diols, polyoxyethylene triols and polyoxypropylene triols, are particularly suitable as polyol P2.

[0047] Particularly suitable as polyol P2 are polyoxyalkylenediols or polyoxyalkylenetriols with a degree of unsaturation lower than 0.02 mEq / g and with a molecular weight in the range of 1,000 to 15,000 g / mol, as well as polyoxyethylenediols, polyoxyethylenetriols, polyoxypropylenediols and polyoxypropylenetriols with a molecular weight of 400 to 15,000 g / mol.

[0048] Also particularly suitable as polyol P2 are so-called ethylene oxide-terminated (EO-endcapped, ethylene oxide-endcapped) polyoxypropylene polyols. The latter are special polyoxypropylene polyoxyethylene polyols obtained, for example, by further alkoxylating pure polyoxypropylene polyols, especially polyoxypropylene diols and triols, with ethylene oxide after completion of the polypropoxylation reaction, thus giving them primary hydroxyl groups. Polyoxypropylene polyoxyethylene diols and polyoxypropylene polyoxyethylene triols are preferred in this case. Suitable polyether-based polymers P2 are available, for example, under the trade names Acclaim® and Desmophen® from Covestro, in particular Acclaim® 4200, Desmophen® 5034, Desmophen® 1381 BT and Desmophen® 28HS98, under the trade name Voranol® from Dow, in particular Voranol® EP 1900 and Voranol® CP 4755, and under the trade name Dianol® from Arkema, in particular Dianol® 3130 HP.

[0049] Particularly suitable polyester polyols are polyesters which carry at least two hydroxyl groups and are produced by known processes, in particular the polycondensation of hydroxycarboxylic acids or the polycondensation of aliphatic and / or aromatic polycarboxylic acids with di- or polyhydric alcohols.

[0050] Particularly suitable are polyester polyols which are produced from di- to trihydric alcohols such as, for example, 1,2-ethanediol, diethylene glycol, 1,2-propanediol, dipropylene glycol, or mixtures of the aforementioned alcohols with organic dicarboxylic acids or their anhydrides or esters such as, for example, succinic acid, glutaric acid, adipic acid, trimethyladipic acid, maleic acid, fumaric acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, dimethyl terephthalate, hexahydrophthalic acid, trimellitic acid and trimellitic anhydride or mixtures of the aforementioned acids, as well as polyester polyols from lactones such as, for example, £-caprolactone.Particularly suitable are hydrophilic polyesterdiols, in particular those made from adipic acid, phthalic acid, isophthalic acid and terephthalic acid as dicarboxylic acid or from lactones such as £-caprolactone and from ethylene glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol and 1,4-cyclohexanedimethanol as dihydric alcohol.

[0051] Suitable polyester polyols include those available under the trade name Kuraray® from Kuraray, in particular Kuraray® F-510, and those available under the trade name K-Flex® from King Industries, in particular K-Flex® 188.

[0052] Particularly suitable polyols P2 are polyether polyols, in particular selected from the list consisting of polyoxyethylene polyol, polyoxypropylene polyol and polyoxypropylene polyoxyethylene polyol, preferably polyoxyethylene diol, polyoxypropylene diol, polyoxyethylene triol, polyoxypropylene triol, polyoxypropylene polyoxyethylene diol and polyoxypropylene polyoxyethylene triol, most preferably polyoxypropylene triol.

[0053] Most preferably, the polyol P2 is a polyether polyol, in particular a polyether polyol with an average OH functionality of at least 2.5 and preferably with propylene glycol repeat units in the polymer backbone.

[0054] Preferably, the weight ratio of polyol P1 to polyol P2 ((P1) / (P2)) is from 3 to 10, preferably 5 to 9, most preferably 6 to 8. A ratio of less than 3 leads to lower elongation values, a ratio of more than 10 leads to lower mechanical properties and toughness.

[0055] Preferably, the total amount of the sum of the polyol P1 and the polyol P2 is more than 75 wt. %, preferably more than 80 wt. %, more than 90 wt. %, more than 95 wt. %, in particular more than 98 wt. %, of the polyol mixture P. Preferably, the polyol mixture P has more than 80 wt. %, more than 90 wt. %, in particular more than 95 wt. %, of the total amount of the NCO-reactive groups of the polyurethane composition.

[0056] The second component B comprises at least one aliphatic polyisocyanate I

[0057] An "aliphatic isocyanate" is an isocyanate whose isocyanate groups are directly bonded to an aliphatic carbon atom. Accordingly, such isocyanate groups are referred to as "aliphatic isocyanate groups."

[0058] Suitable aliphatic polyisocyanates I are in particular monomeric di- or triisocyanates, as well as oligomers, polymers and derivatives of monomeric di- or triisocyanates, and any mixtures thereof.

[0059] Preferred aliphatic monomeric polyisocyanates are aliphatic or cycloaliphatic diisocyanates, in particular HDI, TMDI, cyclohexane-1,3- or -1,4-diisocyanate, IPDI, H12MDI, 1,3- or 1,4-bis-(isocyanatomethyl)cyclohexane and XDI.

[0060] A particularly preferred monomeric polyisocyanate is HDI, IPDI, or H12MDI. Most preferred is HDI or IPDI, especially HDI.

[0061] Suitable oligomers, polymers, and derivatives of the above-mentioned monomeric di- and triisocyanates are, in particular, derived from HDI or IPDI, especially HDI. Commercially available types, such as Desmodur® N 75, Desmodur® N 3600, and Desmodur® N 3900 (all from Covestro), are particularly suitable. They preferably have an NCO content of 16 to 24% by weight, preferably 20 to 24% by weight.

[0062] Particularly preferred aliphatic polyisocyanates are oligomers, polymers, and derivatives derived from HDI or IPDI, especially HDI. They preferably have an NCO content of 16 to 24% by weight, preferably 20 to 24% by weight.

[0063] It is further advantageous if the sum of the NCO groups which do not originate from the aliphatic polyisocyanate I is <20%, in particular <10%, particularly preferably <5%, most preferably <1%, based on the sum of all NCO groups of the polyurethane composition.

[0064] The proportion of the aliphatic polyisocyanate I is preferably > 90 wt.%, in particular > 95 wt.%, particularly preferably > 99 wt.%, based on the total weight of the second component.

[0065] Preferably, the polyurethane composition has a proportion of aromatic polyisocyanates of less than 5 wt.%, less than 2 wt.%, less than 1 wt.%, less than 0.5 wt.%, less than 0.1 wt.%, based on the total weight of the polyurethane composition.

[0066] Aromatic polyisocyanates have the disadvantage that they significantly shorten the pot life and the cured polyurethane compositions tend to yellow.

[0067] Preferably, the polyurethane composition has a proportion of polyaspartic acid esters of less than 15% by weight, less than 10% by weight, less than 5% by weight, less than 2% by weight, less than 1% by weight, less than 0.5% by weight, less than 0.1% by weight, based on the total weight of the polyurethane composition.

[0068] Polyaspartic acid esters have the disadvantage that the curing reaction is too fast, especially at high humidity.

[0069] Preferably, the weight ratio of component (A): component (B) is 5:1 to 2:1, more preferably 4:1 to 3:1.

[0070] Preferably, the molar ratio between free NCO groups and NCO-reactive groups, preferably OH groups, in the composition according to the invention before mixing is between 0.8 - 1.2, preferably 0.9 - 1.1, in particular 0.95 - 1.05.

[0071] The polyurethane composition additionally contains 5 wt.% to 70 wt.% of at least one filler F, based on the total weight of the polyurethane composition. The filler F can be present in the first component A or in the second component B; in particular, it is present in the first component A.

[0072] Preferably, these are fillers selected from the list consisting of ground or precipitated calcium carbonates, which are optionally coated with fatty acids, in particular stearates, barytes (heavy spars), quartz flours, quartz sands, titanium dioxide, dolomites, wollastonites, kaolins, calcined kaolins, layered silicates such as mica or talc, zeolites, aluminum hydroxides, magnesium hydroxides, silicas including highly dispersed silicas from pyrolysis processes, cements, gypsum, fly ashes, industrially produced carbon black, graphite, metal powders, for example of aluminum, copper, iron, silver or steel, PVC powders and hollow spheres.

[0073] The polyurethane composition preferably contains at least one filler F selected from the group consisting of aluminum hydroxides, titanium dioxide, calcium carbonate, carbon black, quartz sands, kaolin, barite, talc, quartz flour, dolomite, wollastonite, kaolin, calcined kaolin and mica.

[0074] Particularly preferred fillers F are fillers selected from the list consisting of aluminum hydroxides, titanium dioxide, ground calcium carbonates, calcined kaolins, quartz sands and baryte.

[0075] It may be advantageous to use a mixture of different fillers. Combinations of aluminum hydroxide and titanium dioxide are most preferred. The particle size of the fillers F is preferably 0.1 to 50 pm, more preferably 1 to 30 pm.

[0076] Preferably, the proportion of fillers F is 10 - 55 wt.%, 15 - 50 wt.%, 20 - 50 wt.%, 25 - 45 wt.%, in particular 30 - 40 wt.%, based on the total weight of the polyurethane composition.

[0077] The polyurethane composition additionally contains at least one tin catalyst K for the reaction of hydroxyl groups and isocyanate groups, which can form thio complexes.

[0078] The tin catalyst K is preferably an organotin compound, in particular an organotin(IV) compound.

[0079] In particular, it is a tin catalyst K selected from the list consisting of dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dibutyltin diacetylacetonate, dimethyltin dilaurate, dioctyltin diacetate, dioctyltin dilaurate, dioctyltin diacetylacetonate, dioctyltin dineodecanoate, bis[(2-ethyl-1-oxohexyl)oxy]dioctylstannane, bis(neodecanoyloxy)dioctylstannane, bis(dodecylthio)dioctylstannane and bis(dodecylthio)dimethylstannane.

[0080] In particular, these are dibutyltin dilaurate, dioctyltin diacetylacetonate, dioctyltin dineodecanoate or bis(dodecylthio)dioctylstannane, particularly preferably dioctyltin dineodecanoate.

[0081] It may be advantageous if the tin catalyst K is only present in the first component A.

[0082] Particularly preferably, the tin catalyst K is contained in part in a third component C, which is not the first component A or the second component B. Preferably, 20 wt.% - 70 wt.%, in particular 30 wt.% - 60 wt.%, particularly preferably 40 wt.% - 50 wt.% of the tin catalyst K, based on the total amount of tin catalyst K in the polyurethane composition, is present in the third component C. This has the advantage of achieving better storage stability.

[0083] The amount of tin catalyst K, based on the total polyurethane composition, is preferably in the range from 0.8 to 1.5 wt.%, preferably 0.9 to 1.4 wt.%, particularly preferably 1.0 to 1.3 wt.%, based on the total polyurethane composition.

[0084] The polyurethane composition preferably has a proportion of less than 0.5 wt. %, less than 0.1 wt. %, less than 0.05 wt. %, less than 0.01 wt. %, less than 0.001 wt. %, based on the total weight of the polyurethane composition, of catalysts for the reaction of hydroxyl groups and isocyanate groups, which are not the aforementioned tin catalysts K. In particular, these are metal catalysts, in particular bismuth, zinc or zirconium compounds, which includes complexes and salts of these metals, preferably complex compounds of bismuth (III) or zirconium (IV), in particular with ligands selected from alkoxides, carboxylates, 1,3-diketonates, oxinate, 1,3-ketoesterates and 1,3-ketoamidates, or compounds containing tertiary amino groups, such as in particular 2,2'-dimorpholinodiethyl ether (DMDEE).

[0085] The polyurethane composition additionally contains at least one compound T containing at least one thiol group. A thiol group is understood here to be an -SH group bonded to an organic radical, for example, an aliphatic, cycloaliphatic, or aromatic carbon radical.

[0086] Preferred compounds are those having 1 to 6, in particular 2 to 4, most preferably 2 or 3, thiol groups. Suitable compounds T containing one thiol group are, for example, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercapto-1,2-propanediol, 2-mercaptotoluimidazole, or 2-mercaptobenzothiazole.

[0087] Suitable compounds T having more than one thiol group are preferably selected from the list consisting of ethylene glycol di(3-mercaptopropionate), ethylene glycol dimercaptoacetate, dipentaerythritol hexa(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), 2,3-dimercapto-1,3,4-thiadiazole, pentaerythritol tetrakis(3-mercaptopropionate) and 3,6-dioxa-1,8-octandedithiol.

[0088] Preferably, the compound T is selected from the group consisting of ethylene glycol di(3-mercaptopropionate), ethylene glycol dimercaptoacetate and dipentaerythritol hexa(3-mercaptopropionate), most preferably ethylene glycol di(3-mercaptopropionate).

[0089] The amount of compound T, based on the total polyurethane composition, is preferably in the range from 0.50 to 1.00 wt.%, preferably 0.60 to 0.90 wt.%, in particular 0.70 to 0.80 wt.%, based on the total polyurethane composition.

[0090] Preferably, the compound T is contained only in a third component C. The third component C is preferably the aforementioned component C, preferably containing the aforementioned tin catalyst K. This has the advantage that better storage stability is achieved.

[0091] Most preferably, the entire compound T and 20 wt.% - 70 wt.%, in particular 30 wt.% - 60 wt.%, particularly preferably 40 wt.% - 50 wt.% of the tin catalyst K, based on the total amount of tin catalyst K in the polyurethane composition, are contained in the third component C. The molar ratio of all thiol groups of the at least one compound T to all metal atoms of the at least one tin catalyst K (T / K) is from 2.75:1 to 10:1.

[0092] Preferably, the molar ratio (T / K) is 3:1 to 7.5:1, in particular 3.5:1 to 5:1, most preferably 3.5:1 to 4:1.

[0093] A molar ratio (T / K) of less than 2.75 leads to an excessively short pot life, particularly at temperatures of 21 °C and 90% RH. This can be seen, for example, in Table 2 when comparing Ex.1-3 with Ref.1 to Ref.4. The aforementioned preferred molar ratios (T / K) are advantageous in that they allow a particularly good ratio of particularly preferred pot life and particularly preferred curing time to be achieved. This can be seen, for example, in Table 2 when comparing Ex.2 with Ex.1 and Ex.3. A molar ratio of greater than 10:1 is disadvantageous in that it results in polyurethane compositions which, particularly when cured at 5 °C and 90% relative humidity, have curing times of more than 4 hours and tend to produce sticky surfaces for a long time.

[0094] The molar ratio of all NCO groups of the polyurethane composition to all metal atoms of the at least one tin catalyst K (NCO / K) is preferably from 20 to 200.

[0095] In particular, the molar ratio (NCO / K) is 50 to 125, preferably 60 to 100, most preferably 65 to 85.

[0096] The aforementioned preferred molar ratios (NCO / K) are advantageous in that they allow a particularly good ratio of particularly preferred pot life and particularly preferred curing time to be achieved. This can be seen, for example, in Table 2 when comparing Ex.2 with Ex.1 and Ex.3. The polyurethane composition comprises 0.7–2.9 mM, based on 100 g of the polyurethane composition, of at least one acid SA with a pKa value of <4.9. The at least one acid SA can be used as free acids or in blocked form; free acids are preferably used.

[0097] It is advantageous if the at least one acid SA has a pKa value of <3, preferably a pKa value of <1, in particular a pKa value of <0. A pKa value of <4.9 results in a sufficiently long pot life combined with a sufficiently short curing time. This can be seen, for example, in Table 3 when comparing Ex.2 with Ref.8 to Ref.11.

[0098] The proportion of the at least one acid SA is preferably 0.8–2.0 mM, preferably 0.9–1.5 mM, particularly preferably 0.9–1.25 mM, based on 100 g of the polyurethane composition. This has the advantage that a particularly good ratio of particularly preferred pot life and particularly preferred curing time can be achieved. This can be seen, for example, in Table 3 when comparing Ex.2 with Ref.5 to Ref.7.

[0099] The at least one acid SA with a pKa value of < 4.9 is preferably mono- or polybasic, in particular monobasic, organic or inorganic, preferably organic acids, particularly preferably organic sulfonic acids.

[0100] Preferred inorganic acids are selected from the group consisting of sulfuric acid, pyrophosphoric acid, sulfurous acid, tetrafluoroboric acid, trichloroacetic acid, dichloroacetic acid, oxalic acid, nitroacetic acid.

[0101] Particularly preferably, the at least one acid SA is selected from the group consisting of methanesulfonic acid, para-toluenesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, cyclododecanesulfonic acid, and camphorsulfonic acid, most preferably benzenesulfonic acid. The polyurethane composition preferably has a proportion of organic solvents, in particular organic solvents with a boiling point at 23°C of less than 200°C, of ​​less than 10 wt.%, less than 7.5 wt.%, preferably less than 5 wt.%, based on the total weight of the polyurethane composition.

[0102] The organic solvents mentioned are in particular organic solvents selected from the list consisting of acetone, methyl ethyl ketone, methyl n-propyl ketone, diisobutyl ketone, methyl isobutyl ketone, methyl n-amyl ketone, methyl isoamyl ketone, acetylacetone, mesityl oxide, cyclohexanone, methylcyclohexanone, ethyl acetate, propyl acetate, butyl acetate, n-butyl propionate, diethyl malonate, 1-methoxy-2-propyl acetate, ethyl 3-ethoxypropionate, diisopropyl ether, diethyl ether, dibutyl ether, diethylene glycol diethyl ether, ethylene glycol diethyl ether, ethylene glycol monopropyl ether, ethylene glycol mono-2-ethylhexyl ether, acetals such as in particular methylal, ethylal, propylal, butylal, 2-ethylhexylal, dioxolane, glycerol-formal or 2,5,7, 10-Tetraoxaundecane (TOU), toluene, xylene, heptane, getane, naphtha, white spirit, petroleum ether or gasoline, methylene chloride, propylene carbonate, butyrolactone, N-methylpyrrolidone and N-ethylpyrrolidone.

[0103] Furthermore, it may be advantageous if the polyurethane composition has a proportion of the aforementioned plasticizers of less than 5 wt.%, less than 2 wt.%, less than 1 wt.%, less than 0.5 wt.%, less than 0.1 wt.%, based on the total weight of the polyurethane composition.

[0104] Such plasticizers are in particular selected from the list consisting of carboxylic acid esters such as phthalates, in particular diisononyl phthalate (DINP), diisodecyl phthalate (DIDP) or di(2-propylheptyl)phthalate (DPHP), hydrogenated phthalates, in particular hydrogenated diisononyl phthalate or diisononylcyclohexane-1,2-dicarboxylate (DINCH), terephthalates, in particular dioctyl terephthalate, trimellitates, adipates, in particular dioctyl adipate, azelates, sebacates, benzoates, glycol ethers, glycol esters, organic phosphoric or sulfonic acid esters, polybutenes and polyisobutenes.

[0105] The composition may contain other additives commonly used in polyurethane compositions. In particular, the following auxiliaries and additives may be present:

[0106] - inorganic or organic pigments, in particular chromium oxides or iron oxides;

[0107] - fibers;

[0108] - adhesion promoter;

[0109] - Rheology modifiers;

[0110] - flame retardant substances;

[0111] - Additives, in particular wetting agents, flow control agents, defoamers, deaerators, stabilizers against oxidation, heat, light or UV radiation or biocides; or other substances commonly used in such compositions.

[0112] The polyurethane composition preferably contains less than 0.5 wt.%, in particular less than 0.1 wt.%, less than 0.01 wt.%, particularly preferably less than 0.001 wt.%, based on the total composition, of a tertiary acid of the formula RR'R"CCOOH, wherein each R, R' and R" group is independently an alkyl, alkenyl, aryl or aralkyl group containing at least one carbon atom, with the proviso that two or three of the R, R' and R" groups can be joined to form a ring structure, and wherein the R, R' and / or R" groups can be substituted and wherein the total number of carbon atoms in the R, R' and R" groups is in the range of 3 to 40.

[0113] A preferred polyurethane composition comprises a first component A and a second component B, wherein

[0114] - the first component A

[0115] - a polyol mixture P comprising - at least one polyol P1 having an average molecular weight of 800 to 30,000 g / mol, preferably 850 to 20,000 g / mol, more preferably 900 to 10,000 g / mol, wherein the polyol P1 is castor oil or a chemical modification thereof, in particular a chemical modification of castor oil, particularly preferably a reaction product of castor oil with ketone resins, preferably a polyol having an OH number of 110 to 200 mg KOH / g, 140 to 190 mg KOH / g, in particular 140 to 170 mg KOH / g, particularly preferably 150 to 170 mg KOH / g; and

[0116] - preferably at least one polyol P2 selected from the group consisting of polyester polyols and polyether polyols, preferably polyether polyols, particularly preferably polyoxyethylene polyols, polyoxypropylene polyols and polyoxypropylene polyoxyethylene polyols, in particular polyols having an average molecular weight in the range from 400 to 6,000 g / mol, in particular 450 to 5,500 g / mol, particularly preferably 500 to 5,000 g / mol, 750 to 3,000 g / mol, most preferably 1,000 to 2,000 g / mol, preferably polyols having an average OH functionality in the range from 2 to 4, in particular 2 to 3.5, particularly preferably 2 to 3;

[0117] -wherein preferably the weight ratio of the polyol P1 to the polyol P2 ((P1) / (P2)) is from 3 to 10, preferably 5 to 9, most preferably 6 to 8; and

[0118] - the second component B

[0119] - comprises at least one aliphatic polyisocyanate I, in particular oligomers, polymers and derivatives derived from HDI or IPDI, in particular HDI, in particular having an NCO content of 16 to 24% by weight, preferably 20 to 24% by weight.

[0120] The preferred polyurethane composition further comprises:

[0121] -5 wt.% to 70 wt.%, 10 - 55 wt.%, 15 - 50 wt.%, 20 - 50 wt.%, 25 - 45 wt.%, in particular 30 - 40 wt.%, of at least one filler F, based on the total weight of the polyurethane composition, in particular selected from the group consisting of aluminum hydroxides, titanium dioxide, ground calcium carbonates, calcined kaolins, quartz sands and baryte; and

[0122] - at least one tin catalyst K for the reaction of hydroxyl groups and isocyanate groups, which can form thiocomplexes, in particular an organotin compound, in particular an organotin(IV) compound; and

[0123] - at least one compound T which has at least one thiol group, in particular 2 to 4, most preferably 2 or 3 thiol groups, in particular selected from the list consisting of ethylene glycol di(3-mercaptopropionate), ethylene glycol dimercaptoacetate, dipentaerythritol hexa(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), 2,3-dimercapto-1,3,4-thiadiazole, pentaerythritol tetrakis(3-mercaptopropionate) and 3,6-dioxa-1,8-octandithiol; and

[0124] - the molar ratio of all thiol groups of the at least one compound T to all metal atoms of the at least one tin catalyst K (T / K) is from 2.75:1 to 10:1, in particular from 3:1 to 7.5:1, in particular from 3.5:1 to 5:1, most preferably from 3.5:1 to 4:1; and

[0125] - the molar ratio of all NCO groups of the polyurethane composition to all metal atoms of the at least one tin catalyst K (NCO / K) is preferably from 20 to 200, 50 to 125, preferably from 60 to 100, most preferably from 65 to 85.

[0126] Preferably, the molar ratio between free NCO groups and NCO-reactive groups, preferably OH groups, in the preferred composition prior to mixing is between 0.8 - 1.2, preferably 0.9 - 1.1, in particular 0.95 - 1.05. Preferably, the preferred polyurethane composition has a proportion of organic solvents, in particular organic solvents with a boiling point at 23°C of less than 200°C, of ​​less than 10 wt.%, less than 7.5 wt.%, less than 5 wt.%.

[0127] Preferably, in the preferred polyurethane composition, the total amount of the sum of the polyol P1 and the polyol P2 is more than 75 wt.%, preferably more than 80 wt.%, more than 90 wt.%, more than 95 wt.%, in particular more than 98 wt.%, of the polyol mixture P.

[0128] Preferably, the polyol mixture P comprises more than 80 wt.%, in particular more than 90 wt.%, more than 95 wt.%, of the total amount of NCO-reactive groups of the preferred polyurethane composition.

[0129] Preferably, in the preferred polyurethane composition, the proportion of the aliphatic polyisocyanate I is > 90 wt.%, in particular > 95 wt.%, particularly preferably > 99 wt.%, based on the total weight of the second component.

[0130] Particularly preferably, in the preferred polyurethane composition, the compound T is contained only in a third component C, which is not the first component A or the second component B, preferably additionally 20 wt.% - 70 wt.% of the tin catalyst K, based on the total amount of tin catalyst K in the polyurethane composition, is contained in the third component C.

[0131] The two components A and B are produced separately and preferably in the absence of moisture. Each component is typically stored in its own container. The other constituents of the polyurethane composition can be present as part of the first or second component, with other constituents reactive towards isocyanate groups preferably being part of the first component. A suitable container for storing the respective component is, in particular, a drum, a hobbock, a bag, a bucket, a can, a cartridge or a tube. Both components are storage-stable, which means that they can be stored for several months up to a year or longer before use without their respective properties changing to an extent relevant to their use.

[0132] The two components are stored separately before mixing the composition and are only mixed together during or immediately before use. They are preferably contained in a package consisting of two separate compartments.

[0133] In a further aspect, the invention comprises a package containing the polyurethane composition according to the invention, consisting of a package with at least two, in particular at least three, preferably three or four, most preferably three, separate chambers, each containing the first component A, or the second component B, or preferably the above-mentioned third component C, of ​​the polyurethane composition.

[0134] Particularly preferred is a package consisting of a package consisting of the above-described first component A, the second component B, and the third component C.

[0135] The third component C contains in particular the above-mentioned compound T. Preferably, the compound T is contained only in the third component C and preferably 20 wt.% - 70 wt.% of the tin catalyst K, based on the total amount of tin catalyst K in the polyurethane composition, is additionally contained in the third component C.

[0136] Mixing is typically done using a hand mixer. During mixing, care must be taken to ensure that the first component, A, and the second component, B, are mixed as homogeneously as possible. If the two components are incompletely mixed, local deviations from the optimal mixing ratio will occur, which can result in a deterioration in the mechanical properties.

[0137] When the first component, A, comes into contact with the second component, B, curing begins through a chemical reaction. The hydroxyl groups and any other isocyanate-reactive substances present react with the isocyanate groups. Excess isocyanate groups react primarily with moisture. As a result of these reactions, the polyurethane composition cures into a solid material. This process is also known as crosslinking.

[0138] A further subject of the invention is therefore also a cured polyurethane composition obtained from the curing of the polyurethane composition as described in the present document.

[0139] The invention thus also relates to a process for producing a building waterproofing, in particular a roof waterproofing, using the polyurethane composition according to the invention, the process comprising: a) mixing the first component (A) and the second component (B), as well as the at least one filler F, the at least one tin catalyst K and the at least one compound T; b) applying the mixed material to a substrate, c) optionally smoothing the applied mixed material and d) curing the applied mixed material to obtain a building waterproofing, in particular a roof waterproofing.

[0140] The first component (A), second component (B), filler F, tin catalyst K, and compound T described in step a) are preferably the embodiments identified above as preferred. Particularly preferably, a mixture of the polyurethane composition according to the invention, in particular a polyurethane composition identified above as particularly preferred, is formed in step a).

[0141] Preferably, steps a) - d) are carried out in this chronological sequence.

[0142] It is further advantageous if steps a) - d) are carried out in a temperature range of 5°C to 21°C, preferably 5°C to 15°C, in particular 5°C to 10°C, particularly preferably 4°C to 8°C. Preferably, in step a), a package as described above, consisting of a package consisting of the above-described first component A, the second component B, and optionally the third component C, is used.

[0143] In a preferred embodiment, the method is used to produce a balcony seal or a roof seal on multi-story buildings, in particular on buildings with more than 10 stories.

[0144] Preferred substrates to which the polyurethane composition can be applied are selected from the list consisting of concrete, brick, stone, asphalt, bitumen and metal, especially concrete.

[0145] The substrate is preferably a treated substrate, preferably pretreated with a polyurethane primer or an epoxy resin primer. This primer preferably has a thickness of 0.1 - 1 mm, in particular 0.3 - 0.7 mm.

[0146] The polyurethane composition can be applied by any conventional method, in particular coating, pouring, casting, or filling. The resulting structural waterproofing, in particular balcony waterproofing or roof waterproofing, preferably has a thickness of 0.1-10 mm, 0.5-10 mm, in particular 1-8 mm, 1.5-6 mm, 1.5-4 mm, and particularly preferably 1.5-3 mm. The application temperature for the polyurethane composition is preferably 5°C to 21°C, preferably 5°C to 15°C, in particular 5°C to 10°C, and particularly preferably 4°C to 8°C.

[0147] The invention also relates to the floor covering, preferably a building waterproofing system, in particular a balcony waterproofing system, or a roof waterproofing system, in particular roof waterproofing systems on multi-story buildings, particularly preferably on buildings with more than 10 stories, which is obtainable by the process according to the invention. The invention also relates to the use of the polyurethane composition as a building waterproofing system, in particular a balcony waterproofing system or roof waterproofing system.

[0148] The invention further relates to the use of the polyurethane composition according to the invention for producing the building seals described above, in particular balcony seals or roof seals.

[0149] Preferably, the polyurethane composition has the following properties over the entire temperature range (at 90% relative humidity) from 5 °C to 21 °C:

[0150] -Pot life, in particular measured as described in the experimental part: 15 min - 45 min, in particular 15 - 32 min, in particular 16 -25 min;

[0151] -Curing time, in particular measured as described in the experimental part: 60 min - 220 min, in particular 60 min - 205. Examples

[0152] Substances used:

[0153] Table 1: Substances used. Preparation of polyurethane compositions and measurement methods.

[0154] For each composition, the ingredients listed in Tables 2 and 3 were processed in the specified amounts (in parts by weight (wt%)) of the first component A using a vacuum dissolver under exclusion of moisture to form a homogeneous mixture and stored. The ingredients of the second component B, or component C, listed in the tables, were also processed and stored. The molar ratio between free NCO groups and NCO-reactive groups was 1.05 (NCO / OH). Examples Ex.1 - Ex.3 are compositions according to the invention, while Examples Ref.1 - Ref.11 are comparative examples.

[0155] To determine the pot life (TW), the reaction curve was determined at 5 °C, 10 °C, and 21 °C, in each case at 90% relative humidity (RH). Components A, B, and C were tempered at the temperature and relative humidity specified in Tables 2 and 3. The components were mixed according to their mixing ratio using a Speed ​​Mixer™ DAC 150.1 FVZKPG for 60 seconds at 2000 rpm. Time measurement begins at the start of mixing, and temperature measurement is performed using a Pt-100 resistance thermometer placed centrally in the mixed composition.

[0156] After mixing the three components, the crosslinking reaction begins. This is indicated by an increase in viscosity and a rise in temperature. Pot life is the time until the critical temperature is reached or a significant change in the temperature rise occurs. To determine reactivity, the rate at which a sample reaches its maximum temperature Tmax is measured. The temperature profile allows a comparative assessment of reactive resin compositions with regard to their reactivity.

[0157] The maximum temperature reached (Tmax) and the time required to reach T=50°C can be read from the temperature curve. The pot life is determined graphically from the recorded temperature-time diagram. The measured values ​​are determined as the perpendiculars of the tangent intersection points of the first change in gradient of the temperature-time curve to the time axis. The position of the intersection point on the time axis determines the pot life in minutes. To determine the curing time (CT), a 1 mm thick film of the mixed composition was poured onto a hard surface, and the time until tack-free was determined using an Erichsen "Drying Time Tester Model 415" in accordance with DIN 53 150 and DIN EN ISO 1517. The curing time of the cast film was determined periodically over time by applying a 2 kg load perpendicularly to a filter paper placed on the surface of the coating.The curing time was determined as the time during which the paper did not adhere to the coating when subsequently subjected to a load of 2 kg and no visible signs of change were present on the coated surface, in accordance with test standard DIN 53 150 (dryness level 4).

[0158]

[0159] Table 2

[0160]

[0161] Table 3

Claims

Patent claims 1 . A polyurethane composition comprising a first component A and a second component B, wherein - the first component A - a polyol mixture P containing - at least one polyol P1 having an average molecular weight of 800 to 30,000 g / mol, preferably 850 to 20,000 g / mol, more preferably 900 to 10,000 g / mol, wherein the polyol P1 is: a polyhydroxy-functional fat and / or a polyhydroxy-functional oil, or a polyol obtained by chemical modification of natural fats and / or natural oils; and - preferably at least one polyol P2 selected from the group consisting of polyester polyols and polyether polyols; and - the second component B - at least one aliphatic polyisocyanate I; wherein the polyurethane composition additionally comprises 5 wt.% to 70 wt.%, preferably 20 wt.% to 50 wt.%, of at least one filler F, based on the total weight of the polyurethane composition, and wherein the polyurethane composition additionally comprises 0.7 - 2.9 mM, based on 100 g of the polyurethane composition, of at least one acid SA with a pK a -value of < 4.9, and at least one tin catalyst K for the reaction of hydroxyl groups and isocyanate groups, which can form thio complexes, and at least one compound T which has at least one thiol group, and the molar ratio of all thiol groups of the at least one compound T to all metal atoms of the at least one tin catalyst K (T / K) is from 2.75:1 to 10:1 and the molar ratio of all NCO groups of the polyurethane composition to all metal atoms of the at least one tin catalyst K (NCO / K) is preferably from 20 to 200. Polyurethane composition according to claim 1, characterized in that the polyol P1 is castor oil or a chemical modification thereof, in particular a chemical modification of castor oil, particularly preferably a reaction product of castor oil with ketone resins. Polyurethane composition according to one of the preceding claims, characterized in that the polyol P2 is a polyether polyol, in particular selected from the list consisting of polyoxyethylene polyol, polyoxypropylene polyol and polyoxypropylene polyoxyethylene polyol, preferably polyoxyethylenediol, polyoxypropylenediol, polyoxyethylenetriol, polyoxypropylenetriol, polyoxypropylene polyoxyethylenediol and polyoxypropylene polyoxyethylenetriol, most preferably polyoxypropylenetriol.Polyurethane composition according to one of the preceding claims, characterized in that the at least one acid SA has a pKa value of < 3, preferably a pKa value of < 1, in particular a pKa value of < 0. Polyurethane composition according to one of the preceding claims, characterized in that the proportion of the at least one acid SA is 0.8 - 2.0 mM, preferably 0.9 - 1.5 mM, particularly preferably 0.9 - 1.25 mM, based on 100 g of the polyurethane composition. Polyurethane composition according to one of the preceding claims, characterized in that the at least one acid SA with a pKa value of < 5 is an organic acid, preferably an organic sulfonic acid, particularly preferably. selected from the group consisting of methanesulfonic acid, para-toluenesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, cyclododecanesulfonic acid and camphorsulfonic acid, most preferably benzenesulfonic acid.

7. Polyurethane composition according to one of the preceding claims, characterized in that the polyol mixture P has more than 80 wt. %, more than 90 wt. %, in particular more than 95 wt. %, of the total amount of NCO-reactive groups of the polyurethane composition.

8. Polyurethane composition according to one of the preceding claims, characterized in that the tin catalyst K is an organotin compound, in particular an organotin(IV) compound.

9. Polyurethane composition according to one of the preceding claims, characterized in that the compound T is contained only in a third component C, which is not the first component A or the second component B, preferably 20 wt.% - 70 wt.% of the tin catalyst K, based on the total amount of tin catalyst K in the polyurethane composition, is additionally contained in the third component C.

10. Polyurethane composition according to one of the preceding claims, characterized in that the molar ratio (T / K) is 3:1 to 7.5:1, in particular 3.5:1 to 5:1, most preferably 3.5:1 to 4:

1.

11. Polyurethane composition according to one of the preceding claims, characterized in that the molar ratio (NCO / K) is 50 to 125, preferably 60 to 100, most preferably 65 to 85. A package comprising a packaging containing the polyurethane composition according to claims 1-11 with at least two, in particular at least three, preferably three or four, most preferably three, separate chambers, each containing a first component A or a second component B, as described for the polyurethane composition according to claims 1-11, or preferably a third component C, as described for the polyurethane composition according to claim 9.A method for producing a structural waterproofing, in particular a balcony waterproofing or roof waterproofing, using a polyurethane composition according to claims 1-11, wherein the method comprises: a) mixing the first component (A) and the second component (B), as well as the at least one filler F, the at least one tin catalyst K, and the at least one compound T; b) applying the mixed material to a substrate, c) optionally smoothing the applied mixed material, and d) curing the applied mixed material to obtain a structural waterproofing, in particular a balcony waterproofing or roof waterproofing. Method according to claim 13, characterized in that steps a) - d) are carried out in a temperature range of 5°C to 21°C, preferably 5°C to 15°C, in particular 5°C to 10°C, particularly preferably 4°C to 8°C.Process according to claim 13 or 14, characterized in that in step a) a package according to claim 12, in particular with a third component C, is used. Use of a polyurethane composition according to any one of claims 1-11 as building waterproofing, in particular balcony waterproofing or roof waterproofing.

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