Roof sealing and use of a liquid-applied reactive roof sealant for creating a roof seal

Description

SUBJECT OF THE INVENTION

[0001] The invention relates to a roof seal and the use of a liquid-applied reactive roof sealant for the production of a roof seal. STATE OF THE ART

[0002] Roof waterproofing protects building roofs from weather conditions such as rain, snow, hail, and UV radiation. This places very high demands on the roofs in terms of elasticity, UV stability, crack bridging ability, impact resistance, watertightness, and resistance to pressurized water.

[0003] Common roof waterproofing systems include bituminous-based roofing felt and plastic-based roof waterproofing such as EPDM (i.e., plastics based on ethylene, propylene, and diene monomers), PUR (i.e., polyurethane systems), or PMMA (i.e., plastics based on methyl methacrylate or polyaspartic systems).

[0004] The current state of the art for sealing flat roofs is described in DIN EN 18531, the flat roof guideline and ETAG 005.

[0005] In the following, ETAG 005 is always cited in the version revised in March 2004. DIN EN 18531 is always cited in the version revised in July 2017. The Flat Roof Guideline is cited in the version revised in May 2019.

[0006] Flat roofs are typically sealed using bituminous or polymeric coating materials. A distinction is made between sheet materials in the form of films or sheets, such as bitumen sheets, plastic sheets, or TPO films (i.e., thermoplastic polyolefin films), and liquid-applied materials, which can be further subdivided into physically drying 1K materials and chemically curing polymers, for example, with atmospheric moisture or other added components.

[0007] With sheet materials, there is a risk of mechanical damage during transport and handling on the construction site. Sheet materials are also generally difficult for installers to handle, due to both the weight of the rolls and the limited flexibility of the sheets. Additionally, the need to weld or glue the individual sheets presents an inherent problem, which can lead to weak points in the waterproofing. The aforementioned poor handling characteristics also make it difficult to create details and connections with sheet materials. Furthermore, the application of bitumen sheets poses an increased risk of fire and burns, as welding them requires the use of gas torches, which can place a significant physical strain on installers, especially in summer temperatures and direct sunlight.

[0008] The application of liquid plastics, hereinafter referred to as FLKs, is particularly labor-intensive due to the need for multiple application steps, each with long drying times. FLKs require several steps to achieve the required layer thickness, significantly increasing the effort required to seal a structure. Furthermore, FLKs are highly sensitive to moisture in their uncured state. Contact with water almost always leads to defects that must be repaired later. In addition, FLKs typically have poor health compatibility or even harmful properties, which can lead to sensitization among applicators. Besides the inhalation exposure of applicators, FLKs often also have an extremely unpleasant odor, which can be perceived as a nuisance by both residents and applicators.

[0009] In contrast, single-component bituminous emulsions, bituminous dispersions, polymer emulsions and polymer dispersions exhibit slow physical drying, which is particularly disadvantageous at low temperatures and / or high humidity and on substrates that are not very absorbent or absorbent.

[0010] WO 2012 / 038099 A1 discloses a use of coating compositions based on one or more mineral binders, one or more polymers, one or more fillers, and optionally one or more additives for the production of roof coatings, wherein the coating compositions contain at least 50 wt.%, preferably 55–90 wt.% polymers, based on the dry weight of the polymers and the mineral binders, i.e., they can contain 1 to 9 times as much polymer solids as binder based on the dry weight. A disadvantage of the building material system is that it is not flexible and crack-bridging at low temperatures down to -20°C or even -30°C; this is due, among other things, to an insufficiently low Tg of the polymers used. The examples show single-component systems, i.e.,Dry formulations based on vinyl acetate-ethylene copolymer or vinyl acetate-ethylene vinyl ester terpolymer, to which water is added to produce the coating agent. The Vinnapas used in the examples has a solids content of 100 wt.%.

[0011] DE 20 2005 015 351 U1 discloses a building material system with one or more components, comprising as a first component a crushed rubber and as a second component a polymer dispersion with self-crosslinking properties, as well as cements and fillers. The polymer content is approximately 1.58 times that of the mineral binders. A disadvantage of the building material system is that it is not flexible and crack-bridging at low temperatures down to -20°C or even -30°C.

[0012] WO 2017 / 190766 A1, which forms the basis of the preamble of claim 1, discloses a two-component reactive building material comprising a calcium sulfate, an ettringite former, an activator, and a polymer-based binder, wherein the polymer content in the examples given therein is approximately 1.15 times that of the mineral binder. In example V10, the binder system consists of Belith CS 10, CEM I 52.5 R, and calcium sulfate hemihydrate. The polymer used, Acronal 5011, has a glass transition temperature of -8°C.

[0013] WO 2016 / 142339 A1 discloses compositions for sealing slurries, with one example on pages 15 / 16 disclosing a cementitious powder component consisting of 35 parts binder and 460 parts Acronal 5442, resulting in a ratio of 6.73 wt.% solids content of polymers to wt.% mineral binders. Acronal 5442 has a glass transition temperature of -15°C.

[0014] WO 2015 / 199984 A1 shows another reactive building material with a calcium sulfate, an ettringite formator and a polymer-based binder, wherein the proportion of polymers used in the examples given therein is 1.45 times the proportion of mineral binders. TASK OF INVENTION

[0015] In contrast, the present invention aims to create a waterproof, flexible, fast-curing and age-resistant roof sealant.

[0016] The aim is to reduce the disadvantages described above and at the same time combine the advantages of the individual systems in the form of a novel roof sealing system.

[0017] The roof waterproofing should be characterized by the ease of processing of its individual components, and above all, but not exclusively, by simple application without the need for torches, additional adhesives, or welding agents, as well as by application in as few steps as possible. Furthermore, the roof waterproofing should exhibit excellent properties for the creation of details and connections.

[0018] Furthermore, the roof waterproofing and the processing of its components should pose the lowest possible health risk to the installer and the environment, as well as enable the most environmentally friendly disposal possible. Additionally, the roof waterproofing should be characterized by high moisture tolerance in its uncured state, early rain resistance, and a fast drying time that is less dependent on weather conditions compared to systems that primarily dry physically.

[0019] In addition, the roof waterproofing should allow for individual surface design through pigmentation of the waterproofing and design by sprinkling in various fillers. REVELATION OF THE INVENTION

[0020] The invention is defined by the subject matter of independent claims 1 and 9.

[0021] According to a first aspect of the invention, the use of a liquid-applied reactive roof waterproofing agent for the production of a roof waterproofing is proposed, wherein the liquid-applied reactive roof waterproofing agent comprises a liquid component and a powder component, wherein the powder component comprises a mineral binder system capable of forming an ettringite phase, consisting of several mineral binders, and thus has the ability to rapidly bind water, and wherein the liquid component comprises one or more aqueous polymer dispersions.

[0022] The reactive roof sealant is designed to contain at least 2 times, preferably at least 2.5 times, and in particular at least 3 times as much wt.% polymer solids as wt.% mineral binders. The wt.% refers to the weight of the entire liquid reactive roof sealant to be applied.

[0023] In addition, it is provided that the proportion of PU polymer in the liquid component is a maximum of 30%, preferably less than 20%, and more preferably less than 15% of the solid content of polymers, based on the total mass of the polymers.

[0024] In addition, it is provided that at least 80 wt.%, preferably at least 90 wt.%, and in particular 100 wt.% of the polymers used, based on the total mass of the polymers, have a glass transition temperature Tg of less than -20 °C, preferably less than -30 °C.

[0025] The liquid-applied reactive roof sealant is suitable as a roof sealant for sealing roof surfaces, but also for covering, in particular and not exclusively, detail and connection areas, balconies, terraces and walkways.

[0026] Surprisingly, it has been found that with these proportions and properties of the binders (systems), excellent roof sealing properties can be reliably achieved. The result is a waterproof, flexible, fast-curing, age-resistant, and UV-stable roof seal.

[0027] The addition of the mineral binder system, which is capable of forming an ettringite phase, advantageously allows for a significant acceleration of the curing of the reactive roof waterproofing compound, essentially independent of weather conditions. This occurs through the rapid binding of water contained in the polymer dispersion within the ettringite phase.

[0028] With a polymer content of less than 2 times the wt% polymers as wt% mineral binders, based on the total weight of the reactive roof waterproofing compound, the mineral binder system predominantly determines the curing reaction, resulting in an overly rigid, three-dimensional cement matrix with polymer particles, and the required flexibility and crack-bridging properties of a roof waterproofing system cannot be achieved.

[0029] According to the invention, the liquid-applied reactive roof sealant contains at most 5 times the wt.% polymers as wt.% mineral binders. With a higher polymer content, the polymer would dominate the drying process, resulting in a polymer matrix with cement islands lacking a cohesive cement structure; see also [reference to be added]. Fig. 3 It has generally been observed that with a higher polymer content, the curing process is no longer significantly accelerated by the mineral binder system and the formation of an ettringite phase, resulting in a high dependence of the curing process on weather conditions, similar to that of purely physically drying, single-component polymer sealing systems. A curing or drying process that is too slow or more dependent on weather conditions, as well as a delayed development of rain resistance due to weather conditions, renders the product unsuitable as a roof sealant according to the invention.

[0030] It has been shown that a proportion of preferably at least 5% PU polymer in the solid polymer content has a positive effect on elasticity at particularly low temperatures of -30 °C and below, comparable to the incorporation of reinforcement, e.g., reinforcement with polyester fleece (110 g / m²). Additionally, it has been shown that incorporating more than 30% PU polymer in the solid polymer content leads to negative effects, such as coagulation of polymer particles, which impair the formation of a continuous sealing layer. Long drying times and partial to complete inhibition of the cement reaction were observed in tests. Above 20% and 15%, a lower quality of curing behavior is observed.Furthermore, it has been shown that the introduction of at least 1% PU polymer, based on the solid content of polymers, has a significant influence on the internal tension of the polymer film.

[0031] In contrast to a polyurethane-based thickener, which can be used to control the rheological properties of the liquid component and thus of the liquid-applied reactive roof sealant, the use of a PU polymer dispersion employed in the invention does not result in any relevant increase or change in the rheological properties, in particular the viscosity of the resulting liquid component and thus of the liquid-applied reactive roof sealant. The PU polymer described here, as a PU polymer dispersion, forms the described polymer film with one or more other polymers used.

[0032] According to the invention, the liquid-applied reactive roof sealant is a two-component (2K) system. The mineral binders are contained in the powder component, while the one or more aqueous polymer dispersions are contained in the liquid component. The two components can be supplied separately or in any container, provided they are stored separately, for example, in buckets, foil bags, or the like. The two-component reactive roof sealant is characterized by its particularly easy application, without the use of torches, additional adhesives, or welding agents, and allows for application in just a few steps.

[0033] Furthermore, the two-component reactive roof sealant is characterized by rapid drying even under cool or damp conditions, which is based on a chemical reaction between components of the liquid component and components of the powder component and, among other things, on the formation of an ettringite phase, which in particular reduces the risk of mechanical damage to the coating during drying.

[0034] One advantage of using polymer dispersions is that the organic polymer particles are stabilized in an aqueous medium using emulsifiers.

[0035] A polymer dispersion is a colloidally stable dispersion of polymer particles in an aqueous phase. The solids content (wt%) of the polymer dispersion describes the mass of the polymer dispersed in the aqueous phase.

[0036] Unlike polymer dispersions, polymer powders are the (usually spray-)dried form of these aqueous polymer dispersions. To produce a stable powder, drying aids, such as protective colloids, and antiblocking agents, such as precipitated or pyrogenic silica, kaolin (aluminum silicate), bentonite, talc, clays, fluorspar, calcium carbonate, magnesium carbonate, barium sulfate, and others, are generally used. Antiblocking agents improve the powder's flowability and prevent clumping during storage. Protective colloids are used as drying aids to prevent the polymer particles from sticking together and to control the powder's particle size. The advantage of polymer powders lies in the fact that the polymer is premixed with other powders, such as mineral binders or mineral aggregates, and only needs to be redispersed with water immediately before use, resulting in lower transportation and storage costs.Furthermore, polymer powders do not require preservatives. However, a major disadvantage of polymer powders is the reduced water resistance of the final products compared to aqueous polymer dispersions, for example, due to the necessary addition of protective colloids such as polyvinyl alcohol. Additionally, the content of pure polymer is reduced by the additives required for drying. Therefore, the performance of the original dispersion is not regained in the redispersed state of polymer powders.

[0037] The polymer dispersions preferably have a minimum film-forming temperature (MFT) of 0°C. If the MFT is below room temperature, the dispersion can form a closed, flexible film through drying. This polymer film provides the desired flexibility and crack-bridging ability in mineral two-component systems. According to DIN 53787:02-74, the MFT is defined as the lowest temperature at which a thin layer of a polymer dispersion still dries to form a continuous film. The MFT of the polymer dispersions is determined as described in the aforementioned standard.

[0038] According to the invention, the following proportions of polymer are contained in the liquid component: % by weight preferred wt.% polymer 30 - 70 50 - 60

[0039] Here, the specification refers to the solids content of the polymer in the polymer dispersion. The solids content of polymers in the polymer dispersion is therefore between 30% and 70%, preferably between 50% and 60%, based on the weight of the liquid component.

[0040] Advantageously, the polymer composition in the liquid component contains up to 30 wt.% of a PU polymer. Particularly preferred are PU polymer contents of 5–10 wt.% in the polymer composition of the liquid component. Here, wt.% refers to the proportion of PU polymer in the total mass of polymer.

[0041] The following water components are particularly preferred in the liquid component: % by weight preferred wt.% Water 30 - 80 40 - 50

[0042] The percentage by weight refers to the proportion of water in the liquid component. This includes all water contained in the liquid component.

[0043] The following components are particularly preferred as a mineral binder system in the powder component: % by weight preferred wt.% Mineral binder system 10 - 30 15 - 20

[0044] The percentage by weight refers here to the proportion of the mass of the mineral binders, which together form the mineral binder system, compared to the mass of the powder component.

[0045] The following filler components are particularly preferred in the powder component: % by weight preferred wt.% Fillers 70 - 90 80 - 85

[0046] The wt.% figure refers here to the proportion of the mass of the fillers present in the powder component compared to the mass of the powder component.

[0047] For example, the powder component may contain the following composition: % by weight preferred wt.% aluminate cement 5 - 25 10 - 15 Portland cement 2 - 12 3-6 Calcium sulfate carrier 2 - 8 3-6 TiO2 0 - 4 0-2 filler 55 - 80 58 - 70

[0048] Suitable mineral binder systems consist in particular of a mixture of cements and calcium sulfate carriers, which, as a mixture, are especially characterized by their ability to form an ettringite phase. Particularly suitable mineral binders include Portland cement, calcium aluminate cement (hereinafter referred to as aluminate cement), calcium sulfoaluminate cement, lime, and gypsum.

[0049] Suitable polymers exhibit a glass transition temperature Tg of less than -20 °C, and preferably less than -30 °C, as measured by DSC. Using polymers with excessively high Tg results in inability to achieve the required flexibility at low temperatures (-20 °C and below), as the polymer film behaves like glass below the Tg of the constituent polymers and thus fractures under stress. The glass transition temperature Tg of the polymer sample is determined by differential scanning calorimetry (DSC, DIN EN ISO 11357-2:2014-07 "Plastics - Differential scanning calorimetry (DSC) - Part 2: Determination of glass transition temperature and height of glass transition (ISO 11357-2:2013), German version EN ISO 11357-2:2014"). In this method, the sample is heated in 10 °C increments per minute from -90 °C to 20 °C, and its heat capacity is determined. A transition point of heat capacity below and above the glass transition is determined.

[0050] A polymer is a chemical compound consisting of chain or branched molecules (macromolecules) made up of identical or similar units called monomers. A polymer can be a natural or synthetic macromolecule composed of repeating units of a smaller molecule, monomers.

[0051] Preferably, at least one of the polymers is based on one or more monomers from the group comprising (meth)acrylates, acrylonitrile, isocyanate, polyols, or a combination thereof, for example, pure acrylate, polyurethane, or styrene acrylate. Surprisingly, it has been found that polymers based on these monomers reliably achieve the roof sealing properties described above.

[0052] Examples of (meth)acrylates are methacrylic acid esters and acylic acid esters of branched and unbranched alcohols with 1 to 15 carbon atoms. Suitable methacrylic acid esters include, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, i-propyl methacrylate, n-butyl methacrylate, i-butyl methacrylate, t-butyl methacrylate, and neopentyl methacrylate. Suitable acrylic acid esters include, for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, i-propyl acrylate, n-butyl acrylate, i-butyl acrylate, t-butyl acrylate, and 2-ethylhexyl acrylate.

[0053] Alternatively or additionally, at least one of the polymers can be conditioned natural latex. Natural rubber from latex is a polymer of the monomer isoprene (2-methyl-1,3-butadiene) and has a uniform structure with cis-1,4 linkages. Therefore, at least one of the polymers can contain the conditioned natural latex as the sole polymer. Alternatively, at least one of the polymers can contain the conditioned natural latex, which, as a prepolymer, is further cross-linked or polymerized with other monomers and / or substances. The conditioning of the natural latex can be achieved, for example, with ammonia or potassium hydroxide. A partially prevulcanized conditioned natural material is preferred. The properties described above for roof sealing can also be reliably achieved using conditioned natural latex.

[0054] In the case of conditioned natural latex, the liquid-applied reactive building material contains at least 2 times, and preferably at least 2.5 times, as much wt.% conditioned natural latex as wt.% mineral binders. Surprisingly, it has been found that the properties described above for roof sealing can be reliably achieved with these proportions.

[0055] If the liquid-applied reactive building material contains at least 2 times the wt.% conditioned natural latex as wt.% mineral binders, then it is sufficiently flexible and crack-bridging down to -20°C. If the liquid-applied reactive building material contains at least 2.5 times the wt.% conditioned natural latex as wt.% mineral binders, then it is sufficiently flexible and crack-bridging down to -30°C.

[0056] The liquid-applied reactive building material contains at most 5 times as much wt.% conditioned natural latex as wt.% mineral binders.

[0057] Preferably, at least one polymer is a homopolymer such as polystyrene, poly(meth)acrylate or (meth)acrylate polymer consisting of a monomer unit, polybutadiene or polyacrylonitrile.Alternatively, it is preferred that at least one polymer be a copolymer such as acrylonitrile-butadiene copolymer, acrylonitrile copolymer, butadiene copolymer, acrylonitrile-acrylate copolymer, acrylonitrile-methacrylate copolymer, acrylonitrile-butadiene acrylate copolymer, acrylate-butadiene copolymer, acrylonitrile-butadiene methacrylate copolymer, methacrylate-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, acrylonitrile-styrene acrylate copolymer, acrylate-styrene copolymer, acrylonitrile-styrene methacrylate copolymer, methacrylate-styrene copolymer, acrylonitrile-styrene-butadiene acrylate copolymer, acrylate-styrene-butadiene copolymer, acrylonitrile-styrene-butadiene methacrylate copolymer. The copolymer is a methacrylate-styrene-butadiene copolymer, or preferably an acrylate copolymer, methacrylate copolymer, or polyurethane. The copolymer can also be a (meth)acrylate copolymer containing more than one monomer unit.

[0058] In one embodiment, the aqueous polymer dispersion contains two or more polymers. Preferably, these are an acrylate polymer and polyurethane, or an acrylate polymer and conditioned natural latex.

[0059] In one embodiment, the aqueous polymer dispersion contains at least one copolymer. Preferably, this is an acrylate copolymer.

[0060] In one embodiment, the liquid-applied reactive material contains a calcitic filler, and the aqueous polymer dispersion contains conditioned natural latex. The chemical interaction between the conditioned natural latex and the Ca²⁺ ions proves advantageous in this case.

[0061] In an advantageous embodiment, the liquid-applied reactive building material contains one or more UV-stabilizing and IR-reflecting pigments.

[0062] Other pigments, especially color pigments, may be included to allow for individual customization of the roof surface by pigmenting the roof waterproofing.

[0063] Furthermore, the liquid-applied reactive roof sealant preferably contains one or more fillers, in particular mixtures of one or more silicate and / or calcitic fillers, as well as one or more lightweight silicate-based fillers. For the purposes of this disclosure, lightweight fillers are defined as fillers with a bulk density of less than 500 g / l. Examples of lightweight fillers include glass microspheres or silicon dioxide. Examples of silicate fillers are quartz sand and quartz flour, while examples of calcitic fillers are limestone flour, calcium carbonate, dolomite, and chalk, preferably limestone flour.

[0064] Alternatively or additionally, the fillers can contain recycled materials. Examples of recycled materials are rubber granules or plastic granules. For example, rubber granules are used that are produced from waste rubber such as material from rubber seals, rubber hoses, rubber linings, hard rubber, soft rubber, used tires, rubber grips, or the like. The rubber granules are preferably based on vulcanized natural rubber and / or vulcanized synthetic rubber, more preferably on unsaturated rubber with styrene and butadiene units.

[0065] Furthermore, the liquid-applied reactive building material preferably contains one or more additives, in particular additives from the group comprising thickeners such as polyurethane thickeners, acrylate thickeners, defoamers, wetting agents, accelerators, retarders, dispersants, crosslinkers, preservatives and flame retardants.

[0066] Examples of thickeners include polysaccharides such as cellulose ethers, modified cellulose, modified cellulose ethers, starch ethers, guar gum, xanthan gum, polycarboxylic acids such as polyacrylic acid and its partial esters, polyvinyl alcohols, hydrophobically modified polyvinyl alcohols, acetalized polyvinyl alcohols, bentonite, casein, associative thickeners, polyurethane thickeners, and acrylate thickeners. Other examples of thickeners are layered silicates. Examples of layered silicates include mica, talc, serpentine, and clay minerals such as vermiculite, especially muscovite, bentonite, and kaolinite.

[0067] Defoamers can be silicone-based, for example silicone oil-based, but also vegetable oil-based and mineral oil-based.

[0068] Wetting agents or dispersing agents can be anionic, cationic and / or non-ionic detergents.

[0069] Examples of accelerators are alkali or alkaline earth salts of inorganic acids such as alkaline carbonates like sodium carbonate, lithium carbonate or aluminates like tricalcium aluminate.

[0070] Retarders can be a combination of several inorganic and / or organic substances such as phosphates, lignosulfonates, sugars (derivatives) such as sucrose, glucose, fructose, saccharides, sorbitol, pentaerythritol, hydroxycarboxylic acids such as citric acid, tartaric acid, gluconic acid or dicarboxylic acids such as oxalic acid, succinic acid or their salts.

[0071] Examples of crosslinking agents include metal oxides and metal salts, semimetal oxides, boric acid or its salts, or dialdehydes such as glutaraldehyde, but also metals such as zirconium.

[0072] Examples of fire retardants include expanded graphite or aluminum hydroxide.

[0073] Other fillers that can be used include fibers, both organic and inorganic, such as basalt, glass fibers, polypropylene fibers, carbon fibers and polyester fibers.

[0074] For example, the liquid component may contain the following additives: % by weight preferred wt.% Thickener 0 - 1 0,14 - 0,4 Defoamer 0 - 1 0,2 - 0,7

[0075] According to another aspect of the invention, a roof sealant is produced by mixing a liquid component and a powder component, wherein the powder component comprises a mineral binder system capable of forming ettringite and thus having the ability to quickly bind water, consisting of several mineral binders, and the liquid component comprises one or more aqueous polymer dispersions, one of which, an aqueous polyurethane polymer dispersion, may hereinafter always be referred to as a PU dispersion.

[0076] The roof waterproofing is designed to contain at least 2 times, preferably at least 2.5 times, and in particular at least 3 times, a weight percentage of polymers as weight percentage of mineral binders, and at most 5 times a weight percentage of polymers as weight percentage of mineral binders, based on the total weight of the reactive roof waterproofing compound, with the PU dispersion comprising at most 30% of the polymers as weight. At least 80% by weight of the polymers used in the reactive roof waterproofing compound has a glass transition temperature Tg of less than -20 °C, preferably less than -30 °C.

[0077] Advantageously, the roof waterproofing is designed in a hardened state at temperatures up to at least TL3, preferably TL4, according to ETAG 005, Part 1, in the revision of March 2004, flexible with a classification W3 after carrying out a procedure specified in EOTA TR-008 and crack-bridging for cracks up to at least 1.5 mm after carrying out a procedure specified in EOTA TR-013.

[0078] The roof waterproofing should therefore be designed to be flexible and crack-bridging down to at least -20°C, preferably down to -30°C. The temperatures, performance classes, and references to the EOTA Technical Reports are defined in ETAG 005, Part 1.

[0079] If the roof waterproofing contains at least 2 times the weight percentage of polymers as of the weight percentage of mineral binders, based on the total weight of the reactive roof waterproofing compound, then it is sufficiently flexible and crack-bridging down to -20°C in its cured state. If the roof waterproofing contains at least 2.5 times the weight percentage of polymers as of the weight percentage of mineral binders, based on the total weight of the reactive roof waterproofing compound, then it is sufficiently flexible down to -25°C and sufficiently crack-bridging down to -20°C. If the roof waterproofing contains at least 3 times the weight percentage of polymers as of the weight percentage of mineral binders, based on the total weight of the reactive roof waterproofing compound, then it is sufficiently flexible and crack-bridging down to -30°C.

[0080] The roof waterproofing is superior to all previously known, comparable roof waterproofing systems in terms of its crack-bridging properties and is characterized by outstanding adhesion to various substrates, such as mineral, metallic, wooden and plastic-based substrates, and offers a permanently durable roof waterproofing or sealing of substrates even at low temperatures in winter.

[0081] Advantageously, the roof waterproofing is designed in a hardened state, preferably at temperatures up to at least TL3, preferably TL4, according to ETAG 005, Part 1, in the revision of March 2004, impact resistant with a classification P4 after carrying out a procedure specified in EOTA TR-006 (dynamic impression).

[0082] The roof seal is therefore advantageously designed to be impact-resistant down to at least -20°C, preferably down to -30°C, and is thus ideally suited as a permanently durable roof seal or sealing of substrates even at low temperatures in winter.

[0083] In particular, the roof waterproofing, in its cured state, is preferably impact-resistant at temperatures up to at least TH4 according to ETAG 005, Part 1, as revised in March 2004, with a classification of P4 after performing a procedure specified in EOTA TR-007 (static impression). The liquid-applied reactive roof waterproofing compound is therefore preferably also statically penetration-resistant up to at least 90°C. Advantageously, the roof waterproofing thus provides a permanently durable seal or waterproofing of substrates, even at high temperatures in summer and under direct sunlight.

[0084] In particular, the roof waterproofing, preferably in a cured state at temperatures up to at least TL3, preferably TL4, according to ETAG 005, Part 1, is flexible after a test based on the cold bending behavior test according to DIN 52123:2014-06, wherein in the test based on the cold bending behavior test according to DIN 52123:2014-06 samples of the roof waterproofing with layer thicknesses between 1.9 mm and 2.3 mm in the cured state after 24 hours of storage are bent over a cylinder with a diameter of 4 cm and visually examined for the formation of cracks > 0.1 mm.

[0085] Further preferred is the roof waterproofing in the cured state at temperatures down to at least -10°C according to ETAG 005, Part 1 and Part 8, revision March 2004, UV-resistant according to category "M" or "S" with a classification W3 after carrying out a procedure specified in EOTA TR-010.

[0086] In particular, the roof waterproofing, in its cured state, is designed such that, when tested for tensile properties according to DIN EN ISO 527-1:2019-12 "Plastics - Determination of tensile properties", it exhibits a tensile stress greater than 0.5 N / mm², preferably greater than 1 N / mm², and particularly preferably greater than 1.5 N / mm², as well as a tensile elongation at maximum stress greater than 20%, preferably greater than 30%, and particularly preferably greater than 40%. By using more than 1 wt% PU polymer, based on the total mass of the polymers, the measured tensile stress can be increased to greater than 1.5 N / mm².

[0087] A process for creating a roof seal includes the following steps: Mixing the above-described liquid reactive building material and applying the building material to a surface of the structure, such as a flat roof, a balcony, a detail and connection area, a terrace or a covered walkway.

[0088] In preferred embodiments, the roof sealant is applied to the surface of the roof with a layer thickness of 1 to 5 mm, preferably 2 to 3 mm.

[0089] In one embodiment, the liquid-applied reactive roof sealant is applied with a reinforcing nonwoven fabric, a woven fabric, a woven mat, or with at least one reinforcing material, particularly fibers. The nonwoven fabric comprises fibers such as glass fibers and / or basalt fibers and / or organic fibers such as polypropylene fibers, polyethylene fibers, or polyester fibers. For example, the nonwoven fabric is designed as a polyester fiber nonwoven or a stainless steel fiber nonwoven, preferably as a polyester fiber nonwoven. The reinforcing material preferably comprises glass fibers and / or plastic fibers such as polyvinyl alcohol fibers, polyester fibers, polypropylene fibers, polyamide fibers, polyethylene fibers, and / or aramid fibers. FIGURES

[0090] Figures 1-3 They show schematic diagrams to illustrate the reaction mechanism of the reactive roof waterproofing. Figures 1 - 3The schematic diagrams show reaction products that are formed when two-component reactive roof sealing agents with different compositions of polymers and mineral binders are mixed.

[0091] Figure 1 This shows the result of an optimal reaction according to the invention. The cement reaction, represented by star-shaped structures, for example ettringite needles, is permeated by the polymer film, shown as irregular lines. In this reaction, the polymer film formation occurred simultaneously with the formation of the mineral binder matrix. This results in a waterproof, flexible, fast-curing, age-resistant, and UV-stable roof sealant.

[0092] In Figure 2The result shown is a reaction not according to the invention. Here, the mineral binder system determined the reaction. Initially, in this example, the formation of the cement hydrate phases occurred without incorporation of the polymer matrix. Too late a formation of the polymer film leads to the formation of a rigid, three-dimensional cementitious binder matrix with globally filmed polymer particles within it, from which a flexible reactive roof waterproofing membrane cannot develop.

[0093] In Figure 3Figure 1 shows another result of a reaction not according to the invention. Here, the polymer content determined the reaction. Primarily, physical drying took place. If the polymer forms a film too early, a polymer matrix with few ettringite needles or cement islands is formed within it. The result is a flexible product with low tensile strength, low water resistance, and slow curing, which, depending on the degree of development of the cementitious binder matrix, is unsuitable as a roof sealant, for example, due to excessive water absorption by the sealing film. EXAMPLES

[0094] P1 P2 P3 P4 P5 P6 Powder compound [%] aluminate cement mineral binder system 11,38 13,62 17,04 22,8 27,36 34,2 Portland cement 2,84 3,41 4,26 5,7 6,84 8,55 Calcium sulfate hemihydrate 3,79 4,54 5,68 7,6 9,12 11,4 filler Fillers 64,99 61,43 56,02 46,9 39,68 28,85 lightweight filler 16 16 16 16 16 16 Additive Additive 1 1 1 1 1 1 sum 100,00 100,00 100,00 100,00 100,00 100,00 Liquid composition [%] Acrylate polymer Polymer dispersion(s) 54 54 54 54 54 54 PU polymer 0 0 0 0 0 0 Water 45,5 45,5 45,5 45,5 45,5 45,5 Defoamer Additive 0,2 0,2 0,2 0,2 0,2 0,2 Thickener 0,3 0,3 0,3 0,3 0,3 0,3 sum 100,00 100,00 100,00 100,00 100,00 100,00 Mixing ratio PK : FK 1 1 1 1 1 1 Polymers [wt%] Each figure refers to the total mass of the liquid reactive roof sealant to be applied. 27 27 27 27 27 27 mineral binders [wt.%] 9,01 10,79 13,49 18,05 21,66 27,08 Ratio wt.% polymers to wt.% mineral binders 3,00 2,50 2,00 1,50 1,25 1,00 Reinforcing fleece No No No No No No Proportion of PU polymer to total polymer mass 0,0% 0,0% 0,0% 0,0% 0,0% 0,0% Highest measured Tg according to DSC of the polymers used [°C] -35 -35 -35 -35 -35 -35 Low temperature elasticity minimum temp. [°C] -30 -25 -25 -25 -20 -20 Crack bridging (1.5 mm) minimum temp. [°C] -35 -30 -25 -20 -5 -5 P7 P 8 P9 P10 P 11 P12 Powder compound [%] aluminate cement mineral binder system 11,38 13,62 17,04 22,8 27,36 34,2 Portland cement 2,84 3,41 4,26 5,7 6,84 8,55 Calcium sulfate hemihydrate 3,79 4,54 5,68 7,6 9,12 11,4 filler Fillers 64,99 61,43 56,02 46,9 39,68 28,85 lightweight filler 16 16 16 16 16 16 Additive Additive 1 1 1 1 1 1 sum 100,00 100,00 100,00 100,00 100,00 100,00 Liquid composition [%] Acrylate polymer Polymer dispersion(s) 54 54 54 54 54 54 PU polymer 0 0 0 0 0 0 Water 45,5 45,5 45,5 45,5 45,5 45,5 Defoamer Additive 0,2 0,2 0,2 0,2 0,2 0,2 Thickener 0,3 0,3 0,3 0,3 0,3 0,3 sum 100,00 100,00 100,00 100,00 100,00 100,00 Mixing ratio PK : FK 1 1 1 1 1 1 Polymers [wt%] Each figure refers to the total mass of the liquid reactive roof sealant to be applied. 27 27 27 27 27 27 mineral binders [wt.%] 9,01 10,79 13,49 18,05 21,66 27,08 Ratio wt.% polymers to wt.% mineral binders 3,00 2,50 2,00 1,50 1,25 1,00 Reinforcing fleece Yes Yes Yes Yes Yes Yes Proportion of PU polymer to total polymer mass 0,0% 0,0% 0,0% 0,0% 0,0% 0,0% Highest measured Tg according to DSC of the polymers used [°C] -35 -35 -35 -35 -35 -35 Low temperature elasticity minimum temp. [°C] -35 -30 -30 -25 -25 -25 Crack bridging (1.5 mm) minimum temp. [°C] nb nb nb nb nb nb P 13 P 14 P 15 P 16 P 17 P 18 Powder compound [%] aluminate cement mineral binder system 11,38 13,62 17,04 22,8 27,36 34,2 Portland cement 2,84 3,41 4,26 5,7 6,84 8,55 Calcium sulfate hemihydrate 3,79 4,54 5,68 7,6 9,12 11,4 filler Fillers 64,99 61,43 56,02 46,9 39,68 28,85 lightweight filler 16 16 16 16 16 16 Additive Additive 1 1 1 1 1 1 sum 100,00 100,00 100,00 100,00 100,00 100,00 Liquid composition [%] Acrylate polymer Polymer dispersion(s) 53,46 53,46 53,46 53,46 53,46 53,46 PU polymer 0,54 0,54 0,54 0,54 0,54 0,54 Water 45,5 45,5 45,5 45,5 45,5 45,5 Defoamer Additive 0,2 0,2 0,2 0,2 0,2 0,2 Thickener 0,3 0,3 0,3 0,3 0,3 0,3 sum 100,00 100,00 100,00 100,00 100,00 100,00 Mixing ratio PK : FK 1 1 1 1 1 1 Polymers [wt%] Each figure refers to the total mass of the liquid reactive roof sealant to be applied. 27 27 27 27 27 27 mineral binders [wt.%] 9,01 10,79 13,49 18,05 21,66 27,08 Ratio wt.% polymers to wt.% mineral binders 3,00 2,50 2,00 1,50 1,25 1,00 Reinforcing fleece No No No No No No Proportion of PU polymer to total polymer mass 1% 1% 1% 1% 1% 1% Highest measured Tg according to DSC of the polymers used [°C] -35 -35 -35 -35 -35 -35 Low temperature elasticity minimum temp. [°C] -30 -25 -25 -25 -20 -20 Crack bridging (1.5 mm) minimum temp. [°C] -35 -30 -20 -20 -5 -5 P 19 P 20 P 21 P 22 P 23 P 24 Powder compound [%] aluminate cement mineral binder system 11,38 13,62 17,04 22,8 27,36 34,2 Portland cement 2,84 3,41 4,26 5,7 6,84 8,55 Calcium sulfate hemihydrate 3,79 4,54 5,68 7,6 9,12 11,4 filler Fillers 64,99 61,43 56,02 46,9 39,68 28,85 lightweight filler 16 16 16 16 16 16 Additive Additive 1 1 1 1 1 1 sum 100,00 100,00 100,00 100,00 100,00 100,00 Liquid composition [%] Acrylate polymer Polymer dispersion(s) 52,92 52,92 52,92 52,92 52,92 52,92 PU polymer 1,08 1,08 1,08 1,08 1,08 1,08 Water 45,5 45,5 45,5 45,5 45,5 45,5 Defoamer Additive 0,2 0,2 0,2 0,2 0,2 0,2 Thickener 0,3 0,3 0,3 0,3 0,3 0,3 sum 100,00 100,00 100,00 100,00 100,00 100,00 Mixing ratio PK : FK 1 1 1 1 1 1 Polymers [wt%] Each figure refers to the total mass of the liquid reactive roof sealant to be applied. 27 27 27 27 27 27 mineral binders [wt.%] 9,01 10,79 13,49 18,05 21,66 27,08 Ratio wt.% polymers to wt.% mineral binders 3,00 2,50 2,00 1,50 1,25 1,00 Reinforcing fleece No No No No No No Proportion of PU polymer to total polymer mass 2% 2% 2% 2% 2% 2% Highest measured Tg according to DSC of the polymers used [°C] -35 -35 -35 -35 -35 -35 Low temperature elasticity minimum temp. [°C] -30 -25 -25 -25 -20 -20 Crack bridging (1.5 mm) minimum temp. [°C] -35 -30 -25 -20 -5 -5 P 25 P 26 P 27 P 28 P 29 P 30 Powder compound [%] aluminate cement mineral binder system 11,38 13,62 17,04 22,8 27,36 34,2 Portland cement 2,84 3,41 4,26 5,7 6,84 8,55 Calcium sulfate hemihydrate 3,79 4,54 5,68 7,6 9,12 11,4 filler Fillers 64,99 61,43 56,02 46,9 39,68 28,85 lightweight filler 16 16 16 16 16 16 Additive Additive 1 1 1 1 1 1 sum 100,00 100,00 100,00 100,00 100,00 100,00 Liquid composition [%] Acrylate polymer Polymer dispersion(s) 51,3 51,3 51,3 51,3 51,3 51,3 PU polymer 2,7 2,7 2,7 2,7 2,7 2,7 Water 45,5 45,5 45,5 45,5 45,5 45,5 Defoamer Additive 0,2 0,2 0,2 0,2 0,2 0,2 Thickener 0,3 0,3 0,3 0,3 0,3 0,3 sum 100,00 100,00 100,00 100,00 100,00 100,00 Mixing ratio PK : FK 1 1 1 1 1 1 Polymers [wt%] Each figure refers to the total mass of the liquid reactive roof sealant to be applied. 27 27 27 27 27 27 mineral binders [wt.%] 9,01 10,79 13,49 18,05 21,66 27,08 Ratio wt.% polymers to wt.% mineral binders 3,00 2,50 2,00 1,50 1,25 1,00 Reinforcing fleece No No No No No No Proportion of PU polymer to total polymer mass 5% 5% 5% 5% 5% 5% Highest measured Tg according to DSC of the polymers used [°C] -35 -35 -35 -35 -35 -35 Low temperature elasticity minimum temp. [°C] -35 -30 -25 -25 -20 -20 Crack bridging (1.5 mm) minimum temp. [°C] -35 -35 -30 -20 -5 -5 P31 P32 P33 P34 P35 Powder compound [%] aluminate cement mineral binder system 11,38 13,62 17,04 22,8 27,36 Portland cement 2,84 3,41 4,26 5,7 6,84 Calcium sulfate hemihydrate 3,79 4,54 5,68 7,6 9,12 filler Fillers 64,99 61,43 56,02 46,9 39,68 lightweight filler 16 16 16 16 16 Additive Additive 1 1 1 1 1 sum 100,00 100,00 100,00 100,00 100,00 Liquid composition [%] Acrylate polymer Polymer dispersion(s) 48,17 48,17 48,17 48,17 48,17 PU polymer 0 0 0 0 0 Natural rubber polymer 5,83 5,83 5,83 5,83 5,83 Water 45,5 45,5 45,5 45,5 45,5 Defoamer Additive 0,2 0,2 0,2 0,2 0,2 Thickener 0,3 0,3 0,3 0,3 0,3 sum 100,00 100,00 100,00 100,00 100,00 Mixing ratio PK : FK 1 1 1 1 1 Polymers [wt%] Each figure refers to the total mass of the liquid reactive roof sealant to be applied. 27 27 27 27 27 mineral binders [wt.%] 9,01 10,79 13,49 18,05 21,66 Ratio wt.% polymers to wt.% mineral binders 3,00 2,50 2,00 1,50 1,25 Reinforcing fleece No No No No No Proportion of PU polymer to total polymer mass 0,0% 0,0% 0,0% 0,0% 0,0% Highest measured Tg according to DSC of the polymers used [°C] -35 -35 -35 -35 -35 Low temperature elasticity minimum temp. [°C] -35 -30 -20 -5 -5 Crack bridging (1.5 mm) minimum temp. [°C] -35 -35 -35 -30 -20 P36 P37 P38 P39 P40 Powder compound [%] aluminate cement mineral binder system 11,38 11,38 11,38 11,38 11,38 Portland cement 2,84 2,84 2,84 2,84 2,84 Calcium sulfate hemihydrate 3,79 3,79 3,79 3,79 3,79 filler Fillers 64,99 64,99 64,99 64,99 64,99 lightweight filler 16 16 16 16 16 Additive Additive 1 1 1 1 1 sum 100,00 100,00 100,00 100,00 100,00 Liquid composition [%] Acrylate polymer Polymer dispersion(s) 45,9 37,8 Acrylate polymer 2 53,46 Styrene acrylate polymer 53,46 Acrylate polymer 3 53,46 PU polymer 0,54 0,54 0,54 2,7 5,4 Natural rubber polymer 0 0 0 5,4 10,8 Water 45,5 45,5 45,5 45,5 45,5 Defoamer Additive 0,2 0,2 0,2 0,2 0,2 Thickener 0,3 0,3 0,3 0,3 0,3 sum 100,00 100,00 100,00 100,00 100,00 Mixing ratio PK : FK 1 1 1 1 1 Polymers [wt%] Each figure refers to the total mass of the liquid reactive roof sealant to be applied. 27 27 27 27 27 mineral binders [wt.%] 9,01 9,01 9,01 9,01 9,01 Ratio wt.% polymers to wt.% mineral binders 3,00 3,00 3,00 3,00 3,00 Reinforcing fleece No No No No No Proportion of PU polymer to total polymer mass 1% 1% 1% 5% 10% Highest measured Tg according to DSC of the polymers used [°C] -55 -30 -27 -35 -35 Low temperature elasticity minimum temp. [°C] -35 -25 -20 -35 -35 Crack bridging (1.5 mm) minimum temp. [°C] -35 -20 -20 -35 -35 P41 P42 P43 P44 Powder compound [%] aluminate cement mineral binder system 11,38 11,38 11,38 11,38 Portland cement 2,84 2,84 2,84 2,84 Calcium sulfate hemihydrate 3,79 3,79 3,79 3,79 filler Fillers 64,99 64,99 64,99 64,99 lightweight filler 16 16 16 16 Additive Additive 1 1 1 1 sum 100,00 100,00 100,00 100,00 Liquid composition [%] Acrylate polymer Polymer dispersion(s) 48,6 45,9 43,2 37,8 Acrylate polymer 2 Styrene acrylate polymer Acrylate polymer 3 PU polymer 5,4 8,1 10,8 16,2 Natural rubber polymer 0 0 0 0 Water 45,5 45,5 45,5 45,5 Defoamer Additive 0,2 0,2 0,2 0,2 Thickener 0,3 0,3 0,3 0,3 sum 100,00 100,00 100,00 100,00 Mixing ratio PK : FK 1 1 1 1 Polymers [wt%] Each figure refers to the total mass of the liquid reactive roof sealant to be applied. 27 27 27 27 mineral binders [wt.%] 9,01 9,01 9,01 9,01 Ratio wt.% polymers to wt.% mineral binders 3,00 3,00 3,00 3,00 Reinforcing fleece No No No No Proportion of PU polymer to total polymer mass 10% 15% 20% 30% Highest measured Tg according to DSC of the polymers used [°C] --35 -35 -35 -35 Low temperature elasticity minimum temp. [°C] -35 -35 -35 -35 Crack bridging (1.5 mm) minimum temp. [°C] -35 -35 -35 -35 Preparation of the samples

[0095] Six compositions of liquid-applied reactive roof waterproofing membranes were produced by mixing a liquid component containing an acrylate polymer with a powder component. The polymer-to-mineral binder ratio was varied by successively decreasing the filler content and increasing the mineral binder content, resulting in the ratios of polymer to mineral binder by weight listed in Table 1 for P1–P6. The percentage by weight refers to the respective ratio relative to the total mass of the liquid-applied reactive roof waterproofing membrane.

[0096] For each of these six compositions, a further sample mixture was produced, into which a nonwoven fabric was embedded. The samples are designated P7–P12. During the embedding of the nonwoven fabric, care was taken to ensure that it was fully embedded and free of bubbles in the liquid-applied reactive building material.

[0097] Six compositions of liquid-applied reactive roof waterproofing membranes were produced by mixing a liquid component with a powder component, with compositions derived from P1 to P6. The proportion of PU polymer, based on the mass of the liquid component, was 1%, 2%, and 5%, and based on the total mass of the polymers, 1.9%, 3.7%, and 9.4%. A corresponding acrylate polymer was substituted by the PU polymer. The samples are designated P13 to P30.

[0098] Furthermore, five compositions of liquid-applied reactive roof waterproofing membranes were produced by mixing a liquid component with a powder component, with compositions derived from P1 to P5, whereby a portion of the acrylate polymer was replaced by conditioned natural latex. These samples are designated P31 to P35.

[0099] Samples P36 - P40 differ from the previous samples by a changed composition of the polymer dispersion.

[0100] In sample P36, an acrylate polymer with a Tg = -55°C (acrylate polymer 2) was used. In sample P37, a styrene acrylate polymer with a Tg = -30°C (styrene acrylate polymer) was used. In sample P38, an acrylate polymer with a Tg = -27°C (acrylate polymer 3) was used.

[0101] In samples P39 and P40, the polymer dispersions are mixtures of acrylate polymer, PU polymer and natural rubber polymer, especially with varying PU content.

[0102] In samples P41 - P44, the proportion of PU polymer in the polymer mixture used is successively increased from 10 - 30%.

[0103] As a comparative example, a composition of a commercially available sealing product (Ref 1) was used, which is composed according to DE 20 2005 015 351 U1 and has, among other things, a polymer content of 1.58 times the proportion of mineral binders.

[0104] As a further comparative example (Ref 2), a composition of the applicant available under the trade name MB TX 2K was used, which has a polymer content of less than 1.5 times the content of mineral binders, namely 1.25 times.

[0105] Finally, as a further comparative example (Ref 3), a composition of the applicant available under the trade name MB 2K+ was used, which has a polymer content of less than 2 times the content of mineral binders, namely 1.65 times.

[0106] Furthermore, two mixtures analogous to Examples 1, 2, and 3 from WO 2012 / 038099 A1 were prepared (Ref 4, Ref 5, and Ref 6). Examples Ref 4, Ref 5, and Ref 6 were prepared according to the method described therein. Ref 10 had a polymer content 2.5 times that of the mineral binder. Ref 11 had a polymer content 1.8 times that of the mineral binder. Ref 12 had a polymer content 1.5 times that of the mineral binder.

[0107] In all examples and comparison examples, the mixing of the components was carried out in such a way that the mixture was lump-free and knot-free at the end of the mixing process.

[0108] All of the layer thicknesses examined were between 1.9 mm and 2.3 mm. Sample no. composition Polymer / min binder ratio Ref 1 Standard product 1,25 Ref 2 MB TX 2K 1,25 Ref 3 MB 2K+ 1,65 Ref 4 Example 1 from WO 2012 / 038099 A1 2,5 Ref 5 Example 2 from WO 2012 / 038099 A1 1,8 Ref 6 Example 3 from WO 2012 / 038099 A1 1,5 Crack bridging test

[0109] The reactive roof waterproofing compound of samples P1–P44 and Ref 1–Ref 6 was applied to two mortar prisms (16 x 4 x 4 cm³) rigidly connected over a square base, hereinafter referred to as concrete prisms. The minimum dry film thickness was applied to one of the resulting rectangular double surfaces with a central joint (32 x 4 cm²) in such a way that the joint was covered and the concrete prisms were connected exclusively by the reactive roof waterproofing compound after it had cured. The reactive roof waterproofing compounds were allowed to cure for 28 days at 20°C and 50% relative humidity.

[0110] The conditioning period of 28 days was chosen based on internal tests and experience, as well as the established testing principles PG-MDS / FPD (as of November 2016) for reactive waterproofing systems in the plinth area. These principles have been established as state of the art for many years and thus reflect a high degree of long-term reliability of the material properties.

[0111] The reactive roof sealing compound was then applied in the outlined test setup (see below). Figure 4The specimens were placed in a cooling station and cooled to -30°C. After one hour of conditioning at -30°C, the crack between the concrete prisms was widened to 0.5 mm, and the test setup was stored at -30°C for one hour. Then, the crack between the concrete prisms was widened to 1 mm, and the test setup was stored at -30°C for one hour. Afterward, the crack between the concrete prisms was widened to 1.5 mm, and the test setup was stored at -30°C for at least one hour. The specimens were evaluated by visually inspecting the reactive roof waterproofing compound for failure as a sealant above the widened crack between the concrete prisms; that is, it was checked whether the reactive roof waterproofing compound itself showed cracks. Cracks larger than 100 µm could be reliably identified.

[0112] The results after the 28-day conditioning are Figure 5 depicted.

[0113] For samples P1 and P2, crack bridging up to 1.5 mm was achieved at temperatures down to -30°C. For sample P1, crack bridging up to 1.5 mm was also achieved at temperatures down to -35°C. For sample P3, crack bridging up to 1.5 mm was achieved at temperatures down to -25°C. For sample P4, crack bridging up to 1.5 mm was achieved at temperatures down to -20°C.

[0114] For samples P5 and P6, crack bridging up to 1.5 mm could not be achieved at temperatures below -5°C.

[0115] For samples P13 and P14, P19 and P20, P25, P26 and P27, P31 to P34, as well as P36, P39 and P40, crack bridging up to 1.5 mm was achieved at temperatures down to -30 °C. For samples P13, P19, P25 and P26, as well as P31 to P33, as well as P36, P39 and P40, crack bridging up to 1.5 mm was also achieved at temperatures down to -35 °C. For sample P21, crack bridging up to 1.5 mm was achieved at temperatures down to -25 °C.

[0116] For samples P15, P16, P22, P28, P35, P37 and P38, crack bridging up to 1.5 mm was achieved for temperatures down to -20°C.

[0117] For samples P41 - P44, crack bridging up to 1.5 mm was achieved for temperatures down to -35°C.

[0118] In comparison, no crack bridging up to 1.5 mm could be achieved for the reference samples Ref 1, Ref 2, Ref 3, Ref 4, Ref 5 and Ref 6 at temperatures below -15°C.

[0119] In summary, it was observed that the described properties of the reactive roof waterproofing compound have a corresponding influence on crack bridging. Independent of other properties, crack bridging deteriorated with a decreasing ratio of wt% polymer to wt% mineral binder. Furthermore, it was found that only those samples containing exclusively polymers with a measured Tg of less than -20 °C met the requirement for crack bridging at low temperatures. For example, the reference samples Ref 1 - Ref 6 do not exhibit a sufficiently low measured Tg of the polymers and could not achieve crack bridging of 1.5 mm at temperatures below -20 °C.

[0120] Furthermore, it was shown that a proportion of 5% PU polymer and more, based on the total mass of the polymers, resulted in an improvement in the crack-bridging properties for sample P27 compared to the corresponding samples P15 and P21 with the same binder to polymer ratio. Testing of low-temperature flexibility

[0121] The flexibility test is carried out in accordance with the test of cold bending behavior according to DIN 52123, version 08 / 1985.

[0122] The reactive roof waterproofing compound of samples P1–P44 and Ref 1–Ref 6 was furthermore cooled in five-degree increments from -10°C to -35°C and bent over a 4 cm diameter cylinder after each 24-hour storage period. The specimens were assessed by visually inspecting the reactive roof waterproofing compound for crack formation. Cracks larger than 100 µm were reliably identified.

[0123] The results for the 28-day conditioning are in Figure 6 depicted.

[0124] Samples P1, P7, P8, P9, P13, P19, P25, P26, P31, P32, P36, P39, and P40 passed the test at least down to -30 °C. Samples P2, P3, P4, P10, P11, P12, P14, P15, P16, P20, P21, P22, P27, P28, and P37 showed no cracks down to -25 °C. Samples P5, P6, P17, P18, P23, P24, P29, P30, P33, P35, and P38 showed no cracks down to -20 °C.

[0125] Reference sample Ref 5 showed no cracks down to -15°C. Reference samples Ref 1, Ref 2, Ref 3, Ref 4 and Ref 6 showed cracks at temperatures above -15°C.

[0126] It was shown that the properties of the liquid-applied reactive building material according to the invention, with regard to low-temperature flexibility, could be achieved without reinforcement or embedding of nonwoven fabric, fibers, or woven fabric. Lower temperatures could be achieved by embedding nonwoven fabric or by using polyurethane (PU), as demonstrated by samples P7, P25, P31, P39, P40, P41, P42, P43, and P44. For low-temperature flexibility, it was also shown that both the ratio of wt.% polymer to wt.% mineral binders (wt.% refers here to the total mass of the reactive roof waterproofing compound) and the Tg of the polymers used play a crucial role. Testing of the tensile properties

[0127] Tensile test specimens type 1B, according to DIN EN ISO 527-2, were prepared from the reactive waterproofing compound for the investigation of tensile properties according to DIN EN ISO 527-1:2019-12 "Plastics - Determination of tensile properties" for samples P1 and P13. For this purpose, the liquid reactive roof waterproofing compound was applied to a glass plate (30 x 60 cm) coated with Teflon film in a layer thickness of 2.4 mm. After 28 days of conditioning under standard conditions, the test specimens were prepared from the resulting films. The tensile properties were tested on a Zwickiline DO731920 according to standard specifications. The results are presented in Figure 7 depicted.

[0128] It was found that sample P13 (2.2 N / mm²) achieved a tensile stress over 70% higher than sample P1 (1.24 N / mm²), while the elongation at maximum stress decreased by approximately 13% from 49.4% (P1) to 42.8% (P13). Consequently, even a small proportion of PU polymer in the total polymer content of the reactive roof waterproofing compound significantly increases the system's internal stress with a negligible reduction in elongation at maximum stress. Experience has shown that optimizing reactive waterproofing systems with respect to maximum stress and elongation at maximum stress leads to improved crack bridging capabilities. Therefore, it seems logical that the explicit addition of PU polymer results in an improvement of the reactive roof waterproofing. Testing according to ETAG 005

[0129] Further reactive roof waterproofing systems according to P1 and P13 were produced and subjected to testing in accordance with ETAG 005, the DIN 18531 based on it and the German flat roof guideline according to the performance classes in ETAG 005.

[0130] The test parameters included in particular the crack bridging capacity, the adhesion to various substrates and the aging behavior under heat, hot water and UV aging, as well as in all cases ensuring the watertightness of the seal, so that the penetration of water into the substrates covered with the roof seal is prevented and the substrates are thus protected from water damage.

[0131] The reactive roof waterproofing systems according to P1 and P13 each passed the test with a classification of W3 after carrying out the procedure specified in EOTA TR-008.

[0132] They proved to be crack-bridging for cracks up to at least 1.5 mm after carrying out the procedure specified in EOTA TR-013.

[0133] Furthermore, a BROOF T1 classification according to DIN EN 13501-5:2016-12 was successfully carried out. Visualization of the reaction process

[0134] In the Figures 8 - 13 The results of microscopic and spectroscopic measurements on a reactive seal according to P1 are presented.

[0135] After mixing the liquid and powder components in the middle, the sample was broken in half at various times. The fracture edge was then examined using cryo-SEM (scanning electron microscope) and energy-dispersive X-ray spectroscopy (EDX). Figures 8-10 These figures refer to a time point 75 minutes after mixing. Figures 11 - 13 refer to a time point 285 minutes after mixing.

[0136] In Figure 8Circle number "1" shows an inorganic phase with a planar, angular structure, representing incompletely converted hemihydrate. Circle number "2" shows a foam-like phase, representing the aggregation of polymer spheres. At this stage, the planar and foam-like structures are still separated.

[0137] Figure 9 shows the energy-dispersive X-ray spectroscopic analysis (EDX) of area "1" in Figure 8The spectrogram shows essentially six peaks. Two of these peaks are attributable to the element platinum, which was applied for the cryo-SEM image. The other peaks correspond to the elements carbon, oxygen, sulfur, and calcium. With the exception of carbon (originating from the organic phase), these elements are essentially attributable to the sulfate carrier of the mineral binding system. The absence of aluminum indicates that it cannot be ettringite. The planar structure in image "1" is therefore likely unreacted hemihydrate.

[0138] Figure 10 shows the energy-dispersive X-ray spectroscopic analysis of area "2" in Figure 8The spectrogram shows essentially four peaks. Two of these peaks are attributable to platinum, which was applied for the cryo-SEM imaging. The other peaks correspond to the elements carbon and oxygen. These elements are associated with the acrylate polymer, which forms cohesive, initially foam-like, later film-like cross-linked structures.

[0139] In Figure 11 and 12 The sample is shown at a later stage of hardening. The ettringite that has now formed is visible in Figure 11 in the form of cluster-shaped, star-like structures, each composed of hexagonal needles. The ettringite is completely embedded in the polymer matrix. Figure 12 shows more clearly the hexagonal cross-section of an ettringite needle resulting from the hexagonal crystal system, which pierces the polymer matrix.

[0140] Figure 13shows the energy-dispersive X-ray spectroscopic analysis of area "3" in Figure 11 The spectrogram essentially shows 7 peaks here. In addition to those in Figure 9 Among the existing peaks, the K-alpha line of aluminum can be seen here at 1.49 keV. The presence of aluminum indicates that the reaction product is ettringite. Measurement of the curing speed

[0141] The IP-8 Ultrasonic Multiplexer Tester V6 device from Ultratest was used to measure the curing speed.

[0142] Figure 14 The chart shows ultrasound measurements taken on samples P1, P25, P41, P42, P43, and P44. The PU content varies among these samples. P1 contains no PU, P25 contains 5% PU, P41 contains 10% PU, P42 contains 15% PU, P43 contains 20% PU, and P44 contains 30% PU.

[0143] In this experiment, the samples were mixed and immediately placed into a measuring container measuring 2 cm wide, 6 cm long, and 5 cm high, without any air inclusions. An ultrasonic transmitter sent pulses from the center of the side of the container at 1-minute intervals across the hardening sample. These pulses were detected by an ultrasonic receiver opposite the transmitter. The speed of the ultrasonic signal was measured in each instance.

[0144] The experimental setup allows conclusions to be drawn about the curing rate. In uncured, still liquid samples, an ultrasound signal propagates only slowly. Only as curing begins does the transmission speed of the ultrasound signal increase.

[0145] While an increase in transit speed was observed after approximately 110 minutes for P1 and P25, with P25 showing a comparatively slower increase, this was only the case for P41 and P42 after approximately 300 minutes. Furthermore, the increase in transit speed for P41 and P42 was even slower compared to P1 and P25. For P43 and P44, the increase was only observed after approximately 450 minutes. For P44, the increase in transit speed was almost imperceptible.

[0146] The results indicated that increasing the PU content in the polymer composition leads to both a delay and a slowing of the curing process.

[0147] As a result, samples with more than 20% PU content are no longer suitable for reactive roof waterproofing in practice due to their late onset and slow curing. In contrast, samples with less than 20%, preferably less than 15% PU content, cure begins sufficiently early, so that the advantages of using PU described above outweigh the disadvantages.

[0148] The invention is not limited to the embodiments described herein and includes a multitude of further alternatives which are within the skill and knowledge of the person in the field, provided that they fall within the scope of protection of independent claims 1 and 9.

Claims

1. Use of a reactive liquid applied roof waterproofing product for producing a roofing membrane, the reactive liquid applied roof waterproofing product having a liquid component and a powder component, the powder component comprising a mineral binder system consisting of a plurality of mineral binders capable of forming an ettringite phase in combination and the liquid component comprising one or more aqueous polymer dispersions, the reactive liquid applied roof waterproofing product comprising, in the liquid component, 30-70 percent by weight, preferably 50-60 percent by weight of a polymer, where the specification refers to the solids content of polymers in the polymer dispersion and the specification of percent by weight refers to the weight of the liquid component, a proportion of a PU polymer being at most 30% of the solids content of polymers, based on the total mass of the polymers, characterized in that the reactive waterproofing product contains at least 2 times, preferably at least 2.5 times, in particular at least 3 times as much percent by weight solids content of polymers as percent by weight mineral binder, and at most 5 times as much percent by weight solids content of polymers as percent by weight mineral binder, where the specification of percent by weight refers to the weight of the reactive liquid applied waterproofing product, and that at least 80 wt.-% of the polymers used, based on the total mass of the polymers, has a glass transition temperature Tg of less than -20 °C, preferably less than -30 °C, the glass transition temperature Tg of a polymer sample being determined by means of differential scanning calorimetry (DSC, DIN EN ISO 11357-2:2014-07 "Kunststoffe Dynamische Differenz Thermoanalyse (DSC) - Teil 2: Bestimmung der Glasübergangstemperatur und der Glasübergangsstufenhöhe (ISO 11357-2:2013), Deutsche Fassung EN ISO 11357-2:2014").

2. Use according to claim 1, characterized in that at least 90% by weight, preferably 100% by weight of the polymers used, based on the total mass of the polymers, have a glass transition temperature Tg of less than -20 °C, preferably less than -30 °C.

3. Use according to any one of the preceding claims, characterized in that the proportion of the PU polymer is at most 20%, preferably at most 15% of the solids content of polymers, based on the total mass of the polymers.

4. Use according to any one of the preceding claims, characterized in that the reactive liquid applied building material contains, in the powder component, 10-30 percent by weight, preferably 15-20 percent by weight mineral binder, where the specification of percent by weight refers to the weight of the reactive liquid applied waterproofing product.

5. Use according to any one of the preceding claims, characterized in that at least one of the polymers is based on one or more monomers of the group comprising (meth)acrylates, acrylonitrile, isocyanate, polyols, or a combination thereof, or contains conditioned natural latex.

6. Use according to any one of the preceding claims, characterized in that at least one of the polymers is based on pure acrylate, conditioned natural latex or polyurethane.

7. Use according to any one of the preceding claims, characterized in that the aqueous polymer dispersion contains two or more polymers, preferably (meth)acrylate polymer and polyurethane or (meth)acrylate polymer and conditioned natural latex.

8. Use according to any one of the preceding claims, characterized in that the polymer dispersions have a minimum film forming temperature according to DIN 53787:02-74 of 0 °C.

9. Roofing membrane, prepared by mixing a liquid component and a powder component, the powder component comprising a mineral binder system consisting of a plurality of mineral binders capable of forming an ettringite phase in combination and the liquid component comprising one or more aqueous polymer dispersions, a proportion of a PU polymer being at most 30% of the solids content of polymers, based on the total mass of the polymers, characterized in that the roofing membrane contains at least 2 times, preferably at least 2.5 times, in particular at least 3 times as much percent by weight solids content of polymers as percent by weight mineral binder, and at most 5 times as much percent by weight solids content of polymers as percent by weight mineral binder, where the specification of percent by weight refers to the weight of the reactive waterproofing product, and that at least 80 wt.-% of the polymers used, based on the total mass of the polymers, have a glass transition temperature Tg of less than -20 °C, preferably less than - 30 °C, the glass transition temperature Tg of a polymer sample being determined by means of differential scanning calorimetry (DSC, DIN EN ISO 11357-2:2014-07 "Kunststoffe Dynamische Differenz Thermoanalyse (DSC) - Teil 2: Bestimmung der Glasübergangstemperatur und der Glasübergangsstufenhöhe (ISO 11357-2:2013), Deutsche Fassung EN ISO 11357-2:2014"), the roofing membrane in a cured state at temperatures up to at least TL3, preferably TL4, according to ETAG 005, Part 1, being flexible with a classification W3 after performing a process specified in EOTA TR-008 and crack bridging for cracks up to at least 1.5 mm after performing a process specified in EOTA TR-013.

10. Roofing membrane according to claim 9, characterized in that the roofing membrane in a cured state at temperatures up to at least TL3, preferably TL4, according to ETAG 005, Part 1, is designed to be shock-resistant with a classification P4 after performing a process specified in EOTA TR-006.

11. Roofing membrane according to any one of claims 9 or 10, characterized in that the roofing membrane in a cured state at temperatures up to at least TH4 according to ETAG 005, Part 1, is designed to be shock-resistant with a classification P4 after performing a process specified in EOTA TR-007.

12. Roofing membrane according to any one of claims 9 to 11, characterized in that the roofing membrane in a cured state at temperatures up to at least TL3, preferably TL4, is flexible after a test based on cold bending behaviour according to DIN 52123 as explained in the description.