Kit for preparing a waterproof coating, method for producing a substrate coated with a kit, and use of a kit.

Description

48 Kit for preparing a waterproof coating, method for producing a substrate coated with a KIT, AND USE OF A KIT

[001] The invention relates to a waterproof coating comprising an aluminum and calcium sulfate mineral embedded in a polymeric matrix. State of the art

[002] In construction applications, concrete and other surfaces are frequently protected with waterproof coatings. For example, waterproof coatings may be applied to tunnel or mine walls to prevent water infiltration and concrete deterioration. The coatings must prevent the passage of liquid water, but not water vapor. Typically, large surfaces are coated, which are often not easily accessible and irregularly shaped. For convenience and high dispensing rate, coating compositions may be applied to the substrate by spraying. In this case, the coating composition must have a consistency such that it can be conveniently processed, pumped, and sprayed. Furthermore, the sprayed composition must adhere properly to the substrate, even if it has inclined and / or protruding surfaces, without significant dripping or creep.It is also desirable that the coating composition can be dried and consolidated within a short period of time after application. Furthermore, the waterproof coating should be uniform and have good mechanical properties.

[003] In the art, such waterproof coatings for construction applications are frequently prepared from mixtures of cementitious powders and organic polymers. Typically, the coating compositions in the art are prepared by adding water or a liquid component to a mixture of cementitious powder, thereby obtaining the Petition 870250088032, dated 09 / 29 / 2025, page 67 / 114 / 48 liquid coating composition, which is sprayed onto the substrate immediately after mixing.

[004] WO 01 / 28955 A1 describes cementitious compositions and methods for applying coatings to rock surfaces. First, a powder component is provided from cementitious constituents such as calcium aluminate, lime and calcium sulfate. The cement powder is mixed with a polymer emulsion, fed into a mixer and applied to the substrate.

[005] WO 98 / 58886 A2 describes a coating composition for construction applications, which is prepared from a dry mixture of cementitious components and a liquid component comprising a polymeric emulsion binder. The components are mixed in a tank and can be sprayed onto a substrate.

[006] WO 2005 / 070849 A1 refers to cementitious coating compositions comprising polymers. The inventors note that the methods of WO 01 / 28955 A1 and WO 98 / 58886 would require a relatively long drying and curing time. To reduce the consolidation time, a modified composition is proposed comprising calcium oxide as an aqueous binder component. The coating composition is prepared from a powder mixture of the cementitious components, which is mixed with a polymer emulsion.

[007] WO 00 / 05487 A1 describes a waterproof coating composition, which is especially suitable for protruding substrates, such as tunnel walls. The composition comprises cementitious and polymer emulsion components, and is sprayable onto the substrate wall.

[008] WO 2022 / 247993 A1 describes the use of a reactive liquid-applied material to produce a covering membrane, in which the reactive liquid-applied material has a liquid component and a Petition 870250088032, dated 09 / 29 / 2025, page 68 / 114 / 48 powder component, wherein the powder component comprises a mineral binder system consisting of a plurality of binders capable of forming an ettringite phase when combined. The liquid component comprises one or more polymeric dispersions. The powder component comprises cements, such as calcium aluminate cement, Ordinary Portland Cement (OPC), calcium sulfoaluminate cement and a calcium sulfate source.

[009] WO 2021 / 003519 A1 describes a composition for waterproof building substrates, the composition comprising a cementitious mixture, which includes calcium sulfoaluminate cement and at least one other cementitious material. Additionally, latex is included in the composition in a ratio with the cementitious mixture of at least 1.2:1. A method for forming a waterproof membrane on a building substrate and methods for applying the composition to a surface are also described.

[0010] A commercial product for preparing waterproof linings for tunnel excavation is available under the registered trademark MasterRoc MSL 345® (Master Builders Solutions, DE). The product is a cementitious powder mixture comprising mineral particles and ethylene vinyl acetate copolymer. On the construction site, a liquid lining composition is prepared by mixing the dry powder with water, for example in a static mixer. The lining composition is sprayed onto a concrete surface and dried, thus obtaining a waterproof membrane. During consolidation, the cementitious components can react with water to form ettringite. To complete the construction, the membrane is overlaid with a second layer of sprayed concrete, thus producing a compositional shell lining. The composite is distinguished by its high stability and effective water barrier properties. Petition 870250088032, dated 09 / 29 / 2025, page 69 / 114 / 48

[0011] However, the respective waterproof coating compositions that are known in the art can still be improved. The known systems have disadvantages, which can make them inconvenient for the user to apply a homogeneous coating in a convenient and efficient manner at a construction site.

[0012] It is a basic problem of known systems that a powder mixture of solid cementitious components must be processed on the construction site. In practice, the user prepares the liquid coating composition by adding water to the cementitious powder mixture. This step is considered necessary because the liquid coating composition is not stable and cannot be stored. Typically, the agglutination and solidification of the cementitious composition, by chemical reaction, begins as soon as water is added to the dry component. On the other hand, a considerable period of time is required for homogeneous mixing, and possibly also to control and adjust the properties of the composition before spraying. However, when the coating composition is prepared and homogenized, the agglutination reaction progresses, and the viscosity of the coating composition changes.Clumps and sticky pieces can form and accumulate, which can clog the spray nozzle, mixer, or tubes of the processing devices. This can lead to various problems, such as non-ideal spraying, insufficient adhesion to the substrate, poor uniformity, or cracking of the waterproof coating. Overall, the preparation and application of the coating composition is difficult to control, processing must be carried out within a short period of time, and non-homogeneous coatings may be obtained.

[0013] Furthermore, it is a problem that handling cementitious powder mixtures, which comprise very fine particles, causes severe dust formation. This is inconvenient for the user and can lead to safety problems. Cementitious components and additives, such as calcium oxide, Petition 870250088032, dated 09 / 29 / 2025, page 70 / 114 / 48 are irritants. Polymer dispersion powders can form explosive dusts and aerosols. Dust formation can especially lead to problems in indoor applications, for example tunnels or mines.

[0014] It is an additional problem that when the coating composition is prepared by the user at the construction site, the amount of water added to a powder mixture can be difficult to adjust. However, if too much water is added to the dry component, the composition may be conveniently mixed and sprayed, but it tends to flow or drip from the substrate, while the drying and consolidation time would be unduly prolonged. If an insufficient amount of water is added, mixing, pumping, and spraying becomes difficult, and the homogeneity of the coating may be low, so that spraying and uniform distribution over the substrate may be impaired. The ideal amount of water added depends on the temperature and conditions, and can be difficult to adjust. Consolidation can be sustained by coagulation of the composition, and the coagulation time increases with the amount of water added.However, it is difficult for the user on a construction site to take such environmental factors into account and balance the properties of the coating composition. Overall, it is difficult for the user to find an ideal balance between the time needed to mix and adjust the coating composition, and rapid spraying onto the substrate.

[0015] It would be desirable to provide a coating composition for construction applications that overcomes the problems mentioned above. Specifically, it would be desirable to provide a coating composition for construction applications that could be conveniently prepared, handled and applied, and that could produce uniform waterproof coatings having consistent and ideal properties. Underlying problem of the invention

[0016] The underlying problem of the present invention is to provide Petition 870250088032, dated 09 / 29 / 2025, page 71 / 114 / 48 waterproof coatings, methods for coating substrates and coated substrates that overcome the problems mentioned above. It is a specific problem to provide coating compositions to prepare waterproof coatings that can be conveniently produced, handled and applied by the user. At the same time, the waterproof coating must perform well, especially with respect to mechanical properties. The coating must be uniform and provide efficient water protection to the substrate.

[0017] It is an additional problem to provide a coating composition that can be stored and transported without impairing performance. It must be easy for the user to provide a homogeneous coating composition within a short time, which can provide uniform coatings, especially when applied by spraying with conventional devices.

[0018] It is an additional problem to provide a monitoring system by which it can be conveniently checked whether the coating composition is applied uniformly to the substrate. Description of the invention

[0019] Surprisingly, it has been found that the underlying problem of the invention is overcome by the kits, methods, coated substrates, structures and uses of the claims. Additional embodiments of the invention are outlined throughout the description.

[0020] The object of the invention is a kit for preparing a waterproof coating comprising an aluminum and calcium sulfate mineral embedded in a polymeric matrix, wherein the kit comprises a first container containing an aqueous suspension (A) comprising - a source of aluminum (III) and - an organic polymer, Petition 870250088032, dated 09 / 29 / 2025, page 72 / 114 / 48 in which suspension (A) has a pH of 5 to 9, and a second container containing an aqueous suspension (B) comprising - a source of calcium (II) and - a sulfate source, provided that there is a molar excess of calcium (II) for sulfate in suspension (B), wherein suspension (B) has a pH > 9.

[0021] As used herein, a “kit” (parts kit) is a combination of individual components interacting functionally. The components comprise the first container with the aqueous suspension (A) and the second container with the aqueous suspension (B). The kit is used to prepare a coating composition by mixing the suspension (A) with the suspension (B). The coating composition is applied to a substrate to prepare the waterproof coating.

[0022] The kit may comprise additional components, such as an instruction manual, tools or devices for preparing and applying the coating composition and / or waterproof coating, or additional containers or compositions. Typically, the first container and the second container are in spatial proximity, for example in a combined package, or as components of a system with connections to transfer the suspensions to a device for further applications such as mixing and / or spraying. The coating composition and / or suspensions (A) and (B) may comprise additional components and may be modified before coating onto a substrate.

[0023] A container is a receptacle for storing and handling suspensions (A) or (B). Preferably, the container may be closed, such that leakage of the suspension is prevented. Preferably, the container has an opening for filling and removing the suspension. The container may have a Petition 870250088032, dated 09 / 29 / 2025, page 73 / 114 / 48 standard form, such as a barrel or can, made of a suitable material, such as plastic.

[0024] Suspensions (A) and (B) are in liquid form, in which solid particles are suspended in the aqueous phase. However, components of the suspension may be completely or partially dissolved. The coating composition, which is obtained by mixing suspensions (A) and (B), is also an aqueous suspension. Preferably, the coating composition is applied to the substrate by spraying. The waterproof coating is obtained when the coating composition on the substrate has consolidated. During consolidation, the coating composition is dried. The waterproof coating blocks the passage of water in liquid form but is permeable to water vapor. The coating can prevent the passage of liquid water from the environment to the substrate, and from the substrate to the environment.

[0025] The solid waterproof coating is obtained when the coated composition is consolidated. The waterproof coating is also referred to as a “membrane” because it is typically relatively thin. The waterproof coating comprises an aluminum and calcium sulfate mineral. A mineral is an inorganic material having a crystalline structure. The aluminum and calcium sulfate mineral is not yet a component of suspension (A) or (B). Instead, it is formed after mixing suspensions (A) and (B) by the chemical reaction of the precursor components. Consequently, the mineral is formed during and after the application of the coating composition and becomes dispersed in the waterproof coating. Suspensions (A) and (B) comprise compounds that are capable of forming the aluminum and calcium sulfate mineral after mixing. Specifically, suspension (A) comprises the aluminum (III) source and suspension (B) comprises the calcium (II) source and the sulfate source.The term "source" refers to a compound that provides a constituent of... Petition 870250088032, dated 09 / 29 / 2025, page 74 / 114 / 48 aluminum and calcium sulfate mineral in a form that can participate in the crystallization reaction after mixing the suspensions.

[0026] The waterproof coating comprises aluminum calcium sulfate mineral in a polymeric matrix, preferably the aluminum calcium sulfate mineral is embedded in the polymeric matrix. The organic polymer that forms the polymeric matrix is ​​a component of the suspension (A). The polymeric matrix is ​​a continuous phase of the waterproof coating. The mineral can be dispersed throughout the matrix in the form of small particles or a continuous phase, depending on the amount of mineral and processing conditions.

[0027] According to the invention, the aluminum and calcium sulfate mineral is formed simply after mixing the suspensions (A) and (B). It is not required to initiate or sustain the reaction by additional means, such as additional additives, for example catalysts, or specific reaction conditions, such as high temperature or radiation. Surprisingly, it has been found that a coating composition, which is obtained simply by mixing the suspensions (A) and (B) with the components and pH values ​​as referred to above, can form an impermeable coating providing all the required characteristics.

[0028] Suspension (A) comprises a source of aluminum (III). The aluminum (III) source is an aluminum compound, which is capable of forming the mineral aluminum calcium sulfate when suspension (A) is combined with suspension (B). In principle, the aluminum (III) source can be an aluminum (III) salt, hydroxide, or complex.

[0029] In a preferred embodiment, the preferably consolidated waterproof coating comprises - 25 to 95% organic polymer - 5 to 75% of aluminum and calcium sulfate minerals, all of which are present in the waterproof coating. Petition 870250088032, dated 09 / 29 / 2025, page 75 / 114 / 48 preferably consolidated are % by weight, and the total is 100%, based on all solid components of the coating.

[0030] In a preferred embodiment, the invention is a kit for preparing a waterproof coating comprising an aluminum and calcium sulfate mineral embedded in a polymeric matrix, the waterproof coating preferably being consolidated comprising - 25 to 95% organic polymer - 5 to 75% of aluminum and calcium sulfate minerals, wherein all quantities in the preferably consolidated waterproof coating are % by weight, and the total is 100%, based on all solid components of the coating, wherein the kit comprises a first container containing an aqueous suspension (A) comprising - a source of aluminum (III) and - an organic polymer, in which suspension (A) has a pH of 5 to 9, and a second container containing an aqueous suspension (B) comprising - a source of calcium (II) and - a source of sulfate, on the condition that there is a molar excess of calcium (II) to sulfate in suspension (B), wherein suspension (B) has a pH > 9.

[0031] In a preferred embodiment, the aluminum (III) source comprises aluminum (III) hydroxide. Preferably, the aluminum (III) source is aluminum (III) hydroxide. Preferably, the aluminum (III) hydroxide is amorphous. It has been found that aluminum (III) hydroxide, especially in amorphous form, can provide a homogeneous and stable suspension with Petition 870250088032, dated 09 / 29 / 2025, page 76 / 114 / 48 organic polymers. Furthermore, it was verified that in the coating of suspensions (A) and (B), aluminum hydroxide (III), especially when amorphous, can produce the mineral aluminum and calcium sulfate in a homogeneous distribution in a polymeric matrix.

[0032] The pH of suspension (A) is in the range of 5 to 9, preferably between 5.5 and 8.5, more preferably between 6 and 8, and most preferably around 7. By adjusting the pH accordingly, the aluminum (III) source, especially aluminum (III) hydroxide, can be provided in suspension (A) in a stable state and uniform distribution. The pH of suspension (B) is > 9, preferably > 10; preferably between 9 and 13, and most preferably between 11 and 13. It has been verified that suspension (B) can be stable and uniform at such pH. Furthermore, when the pH is adjusted accordingly in suspensions (A) and (B), and suspensions (A) and (B) are combined, the aluminum (III) source, especially aluminum (III) hydroxide, can effectively react with the desired mineral in the coating composition, thus forming a homogeneous and effective waterproof coating.Immediately after mixing suspensions (A) and (B), the pH of the coating composition is preferably > 8 or > 9, for example, between 11 and 12.5. In a preferred embodiment, suspensions (A) and (B) and the coating composition reach their respective pH values ​​simply when prepared from their components, such that no pH adjustment by adding more acid or base is required.

[0033] It is also possible to adjust the pH in suspensions (A) and (B) by adding acids or bases. The acid for pH adjustment can preferably be chosen from the group of mineral acids and the base for pH adjustment can preferably be chosen from the group of alkaline (earthy) hydroxides.

[0034] The pH of aqueous suspensions (A) and (B) is preferably measured at a temperature of 20°C using the SevenGo pH meter, equipped Petition 870250088032, dated 09 / 29 / 2025, p. 77 / 114 / 48 with pH-Sensor InLab® 413 / IP67.

[0035] Preferably the following buffer solutions were used for pH meter calibration: InLab® NIST / DIN Buffer Solution pH 1.679 (Mettler Toledo) InLab® NIST / DIN Buffer Solution pH 4.006 (Mettler Toledo) InLab® Technical Buffer Solution pH 7.00 (METTLER TOLEDO) InLab® NIST / DIN Buffer Solution pH 10.012 (Mettler Toledo).

[0036] In additional embodiments, other sources of aluminum (III) may be used, such as aluminum sulfate or sodium aluminate.

[0037] Due to the strongly acidic pH of aqueous aluminum sulfate, it becomes necessary to adjust the pH with an alkaline chemical, such as an alkaline (earth) hydroxide. On the other hand, due to the strongly alkaline pH of aqueous sodium aluminate, it becomes necessary to adjust the pH with an acidic chemical, such as a mineral acid.

[0038] Suspension (B) comprises a calcium (II) source and a sulfate source, which provide the calcium (II) and sulfate in the coating composition for the formation of the calcium aluminum sulfate mineral. In this respect, it is preferred that the calcium (II) source and the sulfate source are different compounds, at least in part. Thus, suspension (B) does not only comprise calcium sulfate (II) as the sole source of calcium (II) and sulfate. This is particularly to obtain a molar excess of calcium to sulfate in suspension (B). Preferably, there is a significant molar excess of Ca compared to sulfate in suspension (B), which is preferably at least two times. Petition 870250088032, dated 09 / 29 / 2025, page 78 / 114 / 48

[0039] Preferably the molar ratio of Ca (II) to sulfate is from 1.5 / 1 to 5 / 1, more preferably from 1.5 / 1 to 4:1, most preferably from 2 / 1 to 4 / 1.

[0040] The calcium source is preferably an inorganic calcium salt or compound, such as calcium hydroxide, oxide, carbonate, chloride, or nitrate. Preferably, the calcium source is dissolved in the suspension at least in part. In a preferred embodiment, the calcium source (II) comprises calcium hydroxide and / or calcium oxide, more preferably the calcium source (II) is calcium hydroxide and / or calcium oxide. It has been found that efficient and homogeneous formation of the aluminum and calcium sulfate mineral can be achieved when the calcium source (II) is selected accordingly. In this respect, it would be advantageous if calcium oxide or hydroxide could provide a relatively high pH to activate the aluminum source (III), especially aluminum hydroxide, for mineral formation. Calcium hydroxide is especially preferred because it can be conveniently handled and dispersed in powder form or in water in the preparation of the suspension (B).

[0041] Conversely, it is less preferred to use other calcium salts, such as chloride or nitrate, as the calcium (II) source. The reason is that the anions can cause undesirable effects on the coating, for example due to leaching.

[0042] In a preferred embodiment, the sulfate source comprises calcium sulfate, preferably hydrated calcium sulfate, preferably dihydrated calcium sulfate. More preferably, the sulfate source is calcium sulfate, preferably hydrated calcium sulfate, preferably dihydrated calcium sulfate. Generally, it may be advantageous to provide the sulfate in the form of a calcium salt, because calcium can contribute to the formation of the calcium aluminum sulfate mineral. Hydrated calcium sulfate, and especially dihydrated calcium sulfate, can be Petition 870250088032, dated 09 / 29 / 2025, page 79 / 114 / 48 especially advantageous, because the reaction towards the aluminum and calcium sulfate mineral can be especially efficient. In this respect, the most efficient source of sulfate has been found to be calcium sulfate dihydrate (gypsum). When calcium sulfate is not (completely) hydrated, it has been found that hydration to gypsum occurs, which can lead to an undesirable change in the viscosity of the suspension (B). Preferably, an additional source of calcium is used in the suspension (B) along with the calcium sulfate in order to increase the molar ratio of calcium to sulfate. Preferably the additional source of calcium is calcium hydroxide and / or calcium oxide.

[0043] By mixing suspensions (A) and (B), the reaction to the aluminum and calcium sulfate mineral is initiated. In principle, several types of aluminum and calcium sulfate minerals can be formed in the coating. Depending on the type and quantities of compounds in the suspensions and coating composition, the mineral may comprise additional cations and / or anions, which are different from calcium, aluminum, and sulfate. However, it is highly preferred to adjust the suspensions, components, and quantities such that the mineral consists of calcium, aluminum, and sulfate ions, and optionally O (oxide), OH (hydroxide), and H2O.

[0044] Preferably, the main portion of the total mineral in the waterproof coating is aluminum calcium sulfate mineral, for example more than 50%, more than 80% or more than 95% by weight. When the waterproof coating is consolidated, it cannot be excluded that a certain portion of other minerals will also be formed. For example, limited quantities of gypsum and / or portlandite and / or calcium carbonate may also be present in the waterproof coating. Practically, it is difficult to completely avoid the formation of other minerals, which would result, for example, from an excess of reagents or competing side reactions. However, for an efficient waterproof coating, it is not required that all minerals in the coating be aluminum sulfate minerals. Petition 870250088032, dated 09 / 29 / 2025, page 80 / 114 / 48 calcium.

[0045] In a preferred embodiment, the aluminum calcium sulfate mineral is or comprises ettringite. Preferably, more than 50%, more than 80%, or more than 90% by weight of the aluminum calcium sulfate mineral is ettringite. Ettringite is a hydrated mineral having the formula Ca6Ah(SO4)3(OH)i226H2O. According to the invention, it has been found that the waterproof coating can have particularly favorable properties when the mineral is ettringite. By adjusting the components and quantities such that ettringite is formed, the reaction can be efficient and provide a stable and uniform coating. In building materials, ettringite is a frequently occurring hydration phase that can be formed from different chemical compositions containing soluble calcium, aluminum, sulfate, and water under alkaline conditions when the pH is about or >10.

[0046] Preferably, the amount of calcium, aluminum, and sulfate in suspensions (A) and (B) and in the coating composition is adjusted approximately to the stoichiometry for ettringite formation. Several reaction pathways are known in the art for ettringite formation. Under suboptimal conditions, a lower amount of ettringite is formed or other crystalline phases may be generated. For example, in the hydration of aluminum oxide and calcium-gypsum mixtures, such as Ca3Al2O6, Ca12Al14O33, and CaSO4^2H2O, the reaction products may be ettringite, Ca6Al(SO4)3(OH)^26H2O, or Ca4Al2O6(SO4)-14H2O, or the hydrated aluminum and calcium oxide, CaAl:O-J9I FO. Ettringite may especially be formed if sufficient CaSO4^2H2O is present. Ettringite can be converted to monosulfate if all the CaSO4^2H2O is consumed in the ettringite synthesis. Calcium aluminate hydrates can form if an insufficient amount of sulfate is present.These reactions and products were described in Christensen et al., 2004, J. Solid State Chem.,. Petition 870250088032, dated 09 / 29 / 2025, page 81 / 114 / 48 177, 6, 1944-1951.

[0047] According to the invention, it has been found that by mixing suspensions (A) and (B), a liquid composition can be obtained that provides efficient ettringite formation. For ettringite formation, it is especially preferred to use amorphous aluminum hydroxide in suspension (A) and calcium hydroxide and calcium sulfate dihydrate in suspension (B). It has been found that efficient ettringite formation is especially favored by a combination of these source materials.

[0048] In a preferred embodiment, suspensions (A) and (B) do not comprise compounds, and especially sources of calcium, aluminum, and sulfate, that can be hydrated under standard conditions in the presence of water. Instead, it is preferred that the components of suspensions (A) and (B), and especially the sources of calcium, aluminum, and sulfate, be completely hydrated. The use of water-consuming components, such as cements, for example ordinary Portland cement, calcium aluminate cement, calcium sulfoaluminate cement, and any combined versions, but also compounds such as calcium oxide, anhydrite calcium sulfate, or calcium sulfate hemihydrate, would be problematic for the formation of the waterproof coating. If unhydrated components of suspension (A) or (B) were to become hydrated over time, the viscosity would change.This would have the effect of making handling and processing difficult or impossible, for example when the coating composition is mixed and sprayed onto the substrate.

[0049] The suspension (A) comprises an organic polymer that forms the polymeric matrix of the waterproof coating. Preferably, the organic polymer is a synthetic polymer. The organic polymer may be a polymeric latex or a soluble polymer. Preferably, the polymer is in the form of a polymeric latex. It has been found that a stable coating, in which the mineral particles are distributed, can be prepared from Petition 870250088032, dated 09 / 29 / 2025, page 82 / 114 / 48 polymeric latex. The latex may be provided within the suspension (A) in the form of a dispersion or powder. Preferably, the suspension (A) comprises additives to keep the latex particles uniformly distributed, such as colloids or emulsifiers.

[0050] The polymer must be capable of forming a polymeric matrix in the coating, in which the mineral particles are dispersed. After application of the coating composition, the polymeric matrix is ​​formed upon drying. Preferably, the organic polymer forms a film upon drying. The film formation of an organic polymer depends on its film-forming temperature. According to the invention, the coating is preferably consolidated at room temperature. Thus, the organic polymer must be capable of film formation at 22°C and / or 10°C and / or 0°C; which are typical room temperatures in construction applications. Preferably, the glass transition temperature of the polymer is low, for example < 0°C, preferably < -10°C. Such a relatively low Tg can be advantageous for the stability of the waterproof coating, because the coating is flexible at room temperature and can provide a stable assembly with adjacent layers.

[0051] Preferably, the polymer is selected from ethylene-vinyl acetate copolymers, acrylic polymers, styrene-butadiene (SBR), polyurethane or copolymers of these polymers.

[0052] In a preferred embodiment, the organic polymer is an ethylene-vinyl acetate (EVA) copolymer. Ethylene-vinyl acetate (EVA) copolymers are copolymers of ethylene and vinyl acetate, which may optionally comprise additional monomeric units. It is especially preferred that the polymer be a copolymer of the ethylene-vinyl acetate dispersion, more preferably a latex dispersion. According to the invention, it has been found that ethylene-vinyl acetate copolymer can impart advantageous properties to the waterproof coating, Petition 870250088032, dated 09 / 29 / 2025, page 83 / 114 / 48 such as high uniformity, low liquid permeability to water and high adhesion strength to the substrate. Additionally, ethylene-vinyl acetate copolymers can have low film formation temperature and glass transition temperature, and have good water vapor permeability. Furthermore, ethylene-vinyl acetate copolymers can stabilize aluminum hydroxide in suspension (A).

[0053] Without being bound by theory, it appears that the use of ethylene-vinyl acetate copolymer is advantageous because it can promote rapid coagulation of the coating composition after mixing suspensions (A) and (B). Through coagulation, the viscosity of the coating composition can be significantly increased within a short time, for example within a few seconds. This is desirable for fixing the coating composition to the substrate in the spraying process, but also for accelerated consolidation and formation of a stable and uniform membrane.

[0054] Preferably, the ethylene vinyl acetate copolymer is based on at least 90%, more preferably at least 95%, of ethylene and vinyl acetate monomeric units, based on the total number of monomeric units. In a specific embodiment, the EVA is based solely on ethylene and vinyl acetate monomers. In a preferred embodiment, the EVA comprises other additional monomeric units, typically in small amounts of less than 10% or less than 5%, to modify properties such as solubility or elasticity. Preferably, the ethylene-vinyl acetate copolymer comprises acrylic monomeric units, such as acrylate (acrylic ester), for example methyl methacrylate or vinyl versicolor. Suitable ethylene-vinyl acetate copolymers are commercially available, for example under the trademarks Vinnapas or Etonis of Wacker, DE. Petition 870250088032, dated 09 / 29 / 2025, page 84 / 114 / 48

[0055] Preferably, the organic polymer is provided in the form of a powder dispersion. Preferably, the powder dispersion comprises additives, for example protective colloids, usually polyvinyl alcohol or an anti-caking agent, which may be advantageous for processing the coating composition or in the coating itself.

[0056] In another embodiment, the organic polymer is an acrylic polymer, preferably in the form of a latex. However, it has been found that coagulation and consolidation of the coating, and thus convenient processing, may be less efficient when compared to EVA polymers. Suitable acrylic polymers are commercially available, for example under the trademark Acronal (BASF, DE).

[0057] In a preferred embodiment, the suspension (A) comprises at least one additive selected from the group consisting of a biocide, filler, emulsifier, plasticizer, protective colloid and colorant. In a preferred embodiment, the suspension (B) comprises at least one additive selected from the group consisting of a gelling agent, stabilizer, plasticizer, filler and colorant.

[0058] Biocides can be added, especially to the suspension (A), to prevent deterioration by microorganisms. Liquid polymer dispersions are often supplied with suitable biocides from the manufacturer.

[0059] Plasticizers can be added to modify the physical properties of suspensions and coating compositions. For example, the plasticizer can adjust the viscosity, thereby improving the processing of the suspension and coating composition. The plasticizer can also keep the suspension stable during storage for extended periods of time. Preferably, the plasticizer, especially for suspension (B), is selected from polycarboxylate ether, acrylic polymer, copolymers thereof, or a polycondensate selected from Petition 870250088032, dated 09 / 29 / 2025, page 85 / 114 / 48 ketone-formaldehyde condensate, melamine-formaldehyde sulfonate condensate, polyaryl ether or lignin sulfonate. Preferably, the amount of plasticizer is less than 2% by weight, or less than 1% by weight, of the suspension.

[0060] A dye can be added to visually control the preparation and application of the coating composition and coating uniformity. For example, a uniform color may indicate homogeneous application of the coating composition onto the substrate, while regions with insufficient coating have deviant coloration. In a continuous process, the user can also visually monitor whether the coating composition is uniformly provided from suspensions (A) and (B). Conventional dyes that are stable at alkaline pH can be used, such as red iron oxide, carbon black, black iron oxide, chromium(III) oxide green, or fluorescein. The inventive use of a colored suspension is advantageous compared to conventional coating systems based on a dry powder mixture because it is often problematic to dissolve and homogenize solid dyes within the short time frame for mixing with water and application.

[0061] Emulsifiers or protective colloids may be included in the suspension (A) to stabilize the organic polymer, especially in latex dispersions. Emulsifiers to stabilize polymer particles, typically surfactants, or colloidal protectives, are often provided by the manufacturer along with the polymer dispersion or lyophilized powder.

[0062] Preferably, a stabilizer is added to the suspension (B) to prevent segregation effects. Stabilizers are typically high molecular weight organic polymers such as gums, cellulose or starch ethers, acrylamide copolymers or derivatives thereof. Preferably, the stabilizer is cellulose ether. It has been found that such a stabilizer can improve the stability of the suspension (B) and facilitate the Petition 870250088032, dated 09 / 29 / 2025, page 86 / 114 / 48 processing. Preferably, the amount of stabilizer is less than 2% by weight, or less than 1% by weight, of the suspension.

[0063] If desired, the suspension (A) and / or (B) may comprise a filler to modify the properties of the waterproof coating, for example a particulate filler such as sand, dolomite or limestone, or fibers such as microfibers. For example, a filler may be included for cost reasons, but also to modify the properties. For example, fibers may be added to reinforce and stabilize the coating.

[0064] In a preferred embodiment, the suspension (B) comprises a gelling agent. Preferably, the gelling agent is a borate compound, such as boric acid, or a borate salt, such as calcium, sodium, or potassium borate. Preferably, the borate compound is boric acid. A gelling agent can be advantageous because it can initiate and / or sustain the coagulation of the organic polymer after mixing suspensions (A) and (B). Consequently, the viscosity of the composition can be rapidly increased after mixing suspensions (A) and (B), typically during a period of a few seconds to 1 or 2 minutes. In this way, the adhesion of the coating composition to the substrate can be improved, and undesirable effects such as runoff are avoided. Additionally, coagulation can lead to more effective consolidation.

[0065] Typically, coagulation occurs when the organic polymer is mixed with the gelling agent. It is assumed that coagulation is mediated by the formation of a complex of the organic polymer and borate compounds. For this reason, the gelling agent is part of the suspension (B), separate from the organic polymer in the suspension (A). The desired coagulation time can be adapted for a specific system, for example by adjusting the amount of borate compound. It has been found that the coagulation effect can be especially strong for boric acid. Petition 870250088032, dated 09 / 29 / 2025, page 87 / 114 / 48 Preferably, the suspension (A) comprises a film-forming organic polymer, more preferably EVA, especially as a polymer dispersion. It has been found that coagulation of the coating composition was particularly rapid and pronounced when such polymers were combined with a gelling agent, especially a borate compound.

[0066] The use of boric acid as a gelling agent can be especially advantageous in combination with an alkaline calcium salt in the suspension (B), especially calcium hydroxide. Consequently, it has been found that a finely dispersed calcium borate (hexahydroborite) can be precipitated in the suspension (B), which can provide an effective coagulation effect upon contact with the polymer when mixing suspensions (A) and (B). It is also possible to add a calcium borate mineral (colemanite) to the suspension (B), but this may result in additional crystal growth in suspension, which may lead to an undesirable change in properties during storage. However, such a mineral borate source may be applicable if the suspension (B) is not stored for a long period of time.

[0067] The amount of water in suspensions (A) and (B) is adjusted so that the components can be homogeneously suspended, and so that the viscosities are appropriate for mixing and further processing. Preferably, the water content of each suspension is between 20% and 80% by weight, more preferably between 35% and 60% by weight. Specifically, the amount of water is adjusted so that the suspensions and the coating composition can be conveniently poured and pumped with the mixing and spraying device. However, the amount of water should be kept as low as possible so that the coating solution can adhere to the substrate and can dry quickly after coating. Petition 870250088032, dated 09 / 29 / 2025, p. 88 / 114 / 48

[0068] Preferably, suspensions (A) and (B) have similar viscosities. Similar viscosities can be advantageous for efficient mixing and processing of the suspensions in a mixing and spraying device. Preferably, the difference between the dynamic viscosities of suspensions (A) and (B) is less than 20%, as determined with a Brookfield viscometer or rheometer at a rotation speed of 100 rpm (e.g., as recorded after 1 min of spindle rotation on the sample or until the viscosity becomes constant; before measuring the viscosity, the sample is sufficiently agitated). For example, viscosities can be determined according to DIN EN ISO 2884-2, part 2.

[0069] Surprisingly, it has been found that suspensions (A) and (B) can be stable for long periods of time. Preferably, they can be stored at room temperature (22°C) for at least 7 days, more preferably at least 30 days. For example, the suspension is considered stable during storage if the viscosity does not change by more than 20%, more preferably by no more than 10% and / or if no phase separation or phase change occurs (such as sedimentation, solidification or growth of large crystals) and / or if no chemical reaction occurs in the suspension.

[0070] The object of the invention is also a method for producing a substrate coated with the inventive kit, comprising the steps of (a) preparing a coating composition by mixing suspension (A) and suspension (B), (b) coating the substrate with the coating composition obtained in step (a), and (c) consolidating the coating obtained in accordance with step (b).

[0071] In step (a), suspensions (A) and (B) are mixed to obtain the coating composition. In a preferred embodiment, the coating is prepared directly from the mixture without modification. Petition 870250088032, dated 09 / 29 / 2025, p. 89 / 114 / 48 intermediate. However, it is also possible to modify the mixture of suspensions (A) and (B), for example by adding water to adjust the viscosity or by adding additional components. In general, suspensions (A) and (B) and the coating composition can be flowable or paste-like. However, for better handling and processing, it is preferred that they be flowable.

[0072] In step (a), the suspensions are mixed in a continuous or batch process; preferably a continuous process. Preferably, in step (B) the substrate is also coated in a continuous process. Mixing is continuous if the suspensions are fed continuously into the mixing device, preferably at a constant flow rate. Preferably, solutions (A) and (B) are pumped into the mixing device (e.g., static mixer) directly from the kit containers. Preferably, a constant flow of the suspensions is set, such that the coating composition thus formed can be applied continuously to the substrate. Typically, the coating is applied to a defined region of the substrate, for example by moving the spray nozzle over the substrate, such that approximately the same amount of the coating composition adheres to the entire region.The continuous process ends when the desired quantity of the coating composition has been prepared and / or applied to the substrate. Preferably, the continuous mixing and coating, preferably by spraying, are carried out with the same device.

[0073] The mixing ratio of suspensions (A) and (B) is adjusted as required, such that the coating composition can be mixed and conveniently coated. Furthermore, the mixing ratio is adjusted such that the components are present in the coating composition in quantities for the effective formation of mineral and matrix. Preferably, suspension (A) is used in an excess relative to suspension (B) that is at least Petition 870250088032, dated 09 / 29 / 2025, p. 90 / 114 / 48 less two or three times (by volume). In a preferred embodiment, in step (a) the mixing ratio of suspension (A) to suspension (B) is in the range of 3:1 to 10:1 (by volume). Such an excess of suspension (A) can be advantageous because a high amount of organic polymer can be included, such that an efficient waterproof coating can be formed. Suspension (B), even in a lower quantity, can impart a relatively high pH to the coating composition, which can be advantageous for the formation of the aluminum and calcium sulfate mineral, especially ettringite.

[0074] Preferably the molar ratio of Ca (II) in suspension (B) to Al (III) in suspension (A) is from 1:1 to 5:1, more preferably from 1.5:1 to 3:1.

[0075] In step (a), the suspensions are mixed until a homogeneous coating composition is obtained. Especially when a gelling agent is present, the coating composition must be coated onto the substrate before a significant amount of coagulation occurs. Typically, it is advantageous to apply the coating composition quickly, for example within less than 30 s, or less than 5 s, or even less than 2 s after combining suspensions (A) and (B).

[0076] In step (b), the substrate is coated with the coating composition. In principle, the coating composition can be applied to any substrate for which a waterproof coating is desired. However, the inventive coating is especially advantageous when applied to inorganic substrates, particularly cementitious surfaces. The waterproof coating is preferably for a construction application, such as a wall, for example of a tunnel or mine; or construction, bridge, port or similar. Preferably, the substrate is inclined or vertical, or preferably even projecting. Because the coating composition can adhere strongly, it has been found that even substrates Petition 870250088032, dated 09 / 29 / 2025, p. 91 / 114 / 48 Protruding surfaces can be uniformly and conveniently coated with the inventive coating composition without undesirable effects such as runoff. This is especially advantageous if the substrate is not easily or conveniently accessible, such as the upper wall or ceiling of a tunnel. Because of its adhesiveness, the coating composition can be conveniently sprayed from a certain distance, so that the use of lifting platforms or ladders can be reduced or even avoided.

[0077] In step (b), the substrate can be coated by methods known in the art. For example, the coating composition can be applied to the substrate by spraying, extrusion or with appropriate hand tools, such as a trowel, brush or spatula. Typically, the coating composition is applied in such a way that a continuous and uniform layer is obtained. Preferably, a single device is used for mixing in step (a) and coating the composition in step (b).

[0078] In a preferred embodiment, in step (b) the substrate is coated by spraying. This is advantageous because the coating composition can adhere to a substrate even soon after mixing the suspensions (A) and (B), without unwanted flow or dripping. Consequently, a uniform waterproof membrane can be obtained even on protruding or irregular substrates. Furthermore, spraying is advantageous if the substrates are not easily accessible. In this respect, the distance between the spray nozzle and the substrate can be several meters. The user does not need direct access to the substrate, which makes the coating process more efficient in tunnels or similar structures.

[0079] Nevertheless, it may be advantageous to apply the coating with a tool, for example to irregularly shaped substrate regions such as edges or cavities, or when coating only small substrates, for example during restoration.

[0080] In step (c), the coating is consolidated. In this regard, the Petition 870250088032, dated 09 / 29 / 2025, p. 92 / 114 / 48 Consolidation is the change of the coating from a liquid to a solid state, in which the coated composition becomes the waterproof coating. Coating consolidation can be active or passive. Passive consolidation is preferred. Consequently, the coated substrate is simply left as is after the coating has been applied. Passive consolidation can be advantageous for reasons of efficiency and cost, especially for large-scale construction applications such as tunnel walls. It has been found that the waterproof coating can achieve good mechanical properties within a few days after coating. In another embodiment, consolidation can be actively sustained, for example by applying heat or ventilation. This can be advantageous if rapid consolidation is required.

[0081] During consolidation in step (c), the coating composition is dried and the coating compositions undergo physical and / or chemical changes. The organic polymer forms the polymer matrix, which can be especially stable when a film is formed from a film-forming polymer, and when the composition is subjected to coagulation. At the same time, the aluminum calcium sulfate mineral is formed in a crystallization reaction. Since these reactions and changes occur in parallel, a uniform layer can be formed in which the components are in intimate contact with each other.

[0082] In a preferred embodiment, mixing in step (a) and coating in step (b) are performed with a device comprising (i.) a static mixer for mixing the suspensions, (ii.) a nozzle for spraying the mixture, (iii.) means for continuously feeding the suspensions (A) and (B) into the static mixer, (iv.) means for continuously feeding the mixture from the static mixer to the nozzle, Petition 870250088032, dated 09 / 29 / 2025, page 93 / 114 / 48 (v.) optionally means to adjust the temperature of the suspensions and / or the mixture.

[0083] The device is capable of mixing suspensions (A) and (B) and spraying the resulting coating composition onto the substrate after mixing. Typically, the device comprises pumps for feeding the suspensions into the static mixer and / or from the static mixer into the nozzle. Preferably, the device comprises means for regulating the temperature of the static mixer and / or spraying means, especially for heating the coating composition during processing. Additionally, suspensions (A) and (B) can be heated to a desired temperature before feeding into the static mixer, for example by heating the kit containers. It may be advantageous to heat suspensions (A) and (B) and / or the coating composition during mixing and spraying. By heating, the viscosity of suspensions (A) and (B) can be reduced. This makes handling and processing more convenient and can accelerate coagulation.Additionally, by spraying the heated composition, adhesion and consolidation can be maintained even when the substrate or ambient temperature is lower, as the composition cools during coating. Overall, temperature control can be advantageous for optimal mixing and spraying, as well as adhesion and consolidation on the substrate, depending on external conditions. Preferably, spraying through the nozzle is airless. In a specific embodiment, an additional air supply line or water container may be present to dilute the mixture and adjust viscosity and / or for immediate flushing of the mixer and piping after the coating process is interrupted. Preferably, the nozzle is located at the outlet of the connection means to the mixer, such as a hose or tube. With a flexible hose, the user can conveniently distribute the composition over the surface. The respective mixing and spraying devices are commercially available. Petition 870250088032, dated 09 / 29 / 2025, pp. 94 / 114 / 48 available, for example from Sulzer, DE or Graco, DE.

[0084] Preferably, the substrate is selected from the group consisting of an inorganic material, an organic material, and an inorganic / organic composite material. Preferably, the substrate is concrete, mortar, glass, stone or rocks, metal, or plastic (e.g., PVC).

[0085] In a preferred embodiment, the substrate is an inorganic material, preferably a cementitious material. Preferably, the cementitious material is concrete. A cementitious material is a cement or a material obtained from or based on cement. A cement is a binder, a chemical substance used in construction that fixes, hardens, and adheres to other materials to bind them together. Typically, the cement comprises fillers such as sand or gravel. Cement mixed with fine aggregate produces mortar for masonry, or with sand and gravel, it produces concrete.

[0086] Shotcrete (sprayed concrete) is especially preferred. The combination of the inventive waterproof coating with shotcrete is particularly advantageous because the shotcrete and the inventive coating composition can be sprayed successively in an aligned workflow. Furthermore, the adhesion strength of the waterproof coating to the shotcrete has been found to be particularly high.

[0087] According to the invention, the coating composition has been found to be highly suitable for providing a stable waterproof coating on inorganic substrates, especially concrete. Without being bound by theory, adhesion would be sustained by the growth of aluminum calcium sulfate mineral crystals on the crystalline cores in the concrete substrate and / or by physical entanglement between the emerging aluminum sulfate mineral crystals of the coating and the surface crystals of the mineral substrate. The final adhesion strength of the inventive coating to a substrate was surprisingly high on both Petition 870250088032, dated 09 / 29 / 2025, page 95 / 114 / 48 rough substrate surfaces, for example shotcrete with aggregate size up to 12 mm, and smooth surfaces, for example, precast concrete elements. In view of the specific and novel process, in which the mineral and polymer matrix are formed in situ on the substrate, the structure of the waterproof coating on the concrete substrate is different from comparable coatings in the art, which are obtained from cementitious powders. Such conventional coatings may have lower adhesion strength because the coating's fixation to the substrate is weaker.

[0088] In a preferred embodiment, an additional (secondary) layer is applied over the surface of the waterproof coating of the invention. The additional layer is preferably an additional coating, which is provided in liquid or paste form, and which is consolidated after application over the waterproof coating. Preferably, the additional coating is applied over the solid waterproof coating after it has consolidated. Preferably, the additional coating is selected from the group consisting of an inorganic material, an organic material, and an inorganic / organic composite. Preferably, the additional coating is a cementitious material, especially cement, and more preferably shotcrete. According to the invention, it has been found that a highly stable composite can be obtained when an additional cementitious coating is provided over the inventive waterproof coating.Surprisingly, the so-called "double bond strength" can be especially high between the substrate, particularly a cementitious substrate, the waterproof coating, especially when comprising ettringite, and an additional cementitious coating. In this respect, the cement in the additional layer, during consolidation, can establish a strong bond to the aluminum and calcium sulfate mineral and / or to the functional groups of the polymer of the inventive coating. Thus, the waterproof coating... Petition 870250088032, dated 09 / 29 / 2025, page 96 / 114 / 48 may be especially advantageous when used as an internal waterproof layer between two cementitious layers, particularly in construction applications.

[0089] In a preferred embodiment, an additional (secondary) waterproof coating of the invention is applied over the surface of a composite of the substrate and the first waterproof coating. For example, this may be advantageous if the first coating is not yet sufficiently uniform or has defects, for example because the substrate has an irregular surface, or in order to improve strength and stability. In this way, more than two, for example three or four, inventive coatings can also be applied over a substrate, one on top of the other.

[0090] In a preferred embodiment, the first waterproof coating and at least one additional (secondary) waterproof coating, both provided according to the invention, are structurally distinct. Preferably, the first coating and at least the second coating have different colors. This can be advantageous for visually monitoring the process and uniformity of the waterproof membrane coating. Generally, it is important that the waterproof coating be uniform. Otherwise, water may leak into regions that are not adequately coated. In practice, the coating composition may be applied unevenly to a surface that is irregular or not easily accessible. In this case, a second inventive coating can be applied to correct the defects.When coating compositions have distinct colors, such as white and red, or red and blue, it can be conveniently monitored whether the first coating is uniformly covered with the second coating. For example, if a second white coating is applied over a first red coating, it can be examined to see if there are areas where the second coating is uneven. Petition 870250088032, dated 09 / 29 / 2025, page 97 / 114 / 48 coating was not applied uniformly, and thus are even more or less red. By selecting and combining appropriate colors, the user can conveniently monitor the performance and uniformity of the coating, and overall obtain an efficient and uniform waterproof coating. Notably, such colored coating compositions can be conveniently prepared and applied using only the inventive kit, because it is based on liquid suspensions. In contrast, it is difficult to use coloring in conventional solid powder-based systems, because conventional dyes often do not disperse quickly. Therefore, it is advantageous that the invention kit based on suspensions (A) and (B) can be adapted for coloring and used for monitoring.

[0091] The object of the invention is also a coated substrate, which is obtainable by the inventive method. The substrate is covered by the impermeable coating, which comprises an aluminum and calcium sulfate mineral embedded in a polymeric matrix. Surprisingly, it has been found that the coated substrate of the invention can have a unique structure and properties. Without being bound by theory, it is assumed that the in situ generation of aluminum and calcium sulfate mineral crystals in an emergent polymeric matrix, which is obtained from liquid polymer dispersion, confers a unique structure to the composite. It has been surprisingly found that the mechanical properties of the coated substrate can be superior compared to a comparative coating comprising ettringite particles from a cementitious powder mixture.In the inventive coating process, crystals can grow directly onto the substrate, which can lead to high bond strength, especially on a cementitious substrate. Furthermore, the in situ growth of mineral crystals can provide intimate dispersion within the polymer matrix. Overall, the coated substrate can be structurally distinct and advantageous compared to conventional composites of the prior art. Petition 870250088032, dated 09 / 29 / 2025, pp. 98 / 114 / 48

[0092] In one embodiment, the substrate is coated only with the waterproof coating, which thus forms the outer surface of the composite.

[0093] Preferably, the consolidated waterproof coating comprises - 25 to 95%, preferably 60 to 95%, of organic polymer, preferably ethylene vinyl acetate copolymer - 5 to 75%, preferably 10 to 40%, of aluminum and calcium sulfate minerals, preferably ettringite, - 0 to 3%, preferably 0.1 to 3%, of boron compound, and - 0 to 30% of additives.

[0094] where all quantities are % by weight, and the total is 100%, based on all solid components of the coating. Furthermore, the wet or even dry coating may comprise water, for example up to 10% by weight, or even up to 20% by weight, based on 100% of the total weight of the coating. The water content of the consolidated coating depends not only on the initial composition of the suspensions (A) and (B), but also on the ambient humidity. The coating may absorb water and become wet, but even the dry coating may comprise water that is internally bound.

[0095] Typically, the waterproof coating is a thin layer. Preferably, the thickness and / or average thickness is in the range of 0.5 to 20 mm, preferably 1 to 10 mm, more preferably 2 to 6 mm. It has been found that such a thin coating can have high mechanical strength and provide good waterproofing performance. A thin layer is advantageous for cost reasons, especially for large-scale applications.

[0096] However, the coating thickness is determined by the roughness of the substrate surface. The rougher the substrate, the thicker the coating must be. Applying the coating over Petition 870250088032, dated 09 / 29 / 2025, page 99 / 114 / 48 very rough substrate surfaces (>5 to 6 mm roughness) is possible, but would lead to considerably increased consumption of the inventive coating composition. In such cases, it may be advantageous from an economic perspective to apply an additional cementitious smoothing layer over the substrate, followed by the application of a relatively thin coating composition over the hardened smoothing layer.

[0097] The object of the invention is also a structure, comprising the coated substrate of the invention and at least one additional (secondary) layer, which is applied over the surface of the coated substrate. In this respect, the term “structure” refers to the composite comprising the at least two layers over the substrate. The structure can be formed by providing the inventive coating over a substrate, thereby obtaining the waterproof coating, followed by providing an additional layer over the surface of the coated substrate. Preferably, the additional layer is applied over the consolidated waterproof coating. As mentioned above, the additional layer can be at least one additional inventive coating, or it can be a different layer, such as a cementitious layer. The inventive structure is particularly advantageous with the cementitious layer because the adhesion strength can be very high.

[0098] The structure may consist of the coated substrate and the additional layer, or it may comprise two or more additional layers. In a preferred embodiment, the structure is or comprises an inventive waterproofing layer between a cementitious substrate and the cementitious top layer. In another preferred embodiment, the structure comprises two or more inventive waterproofing layers one on top of the other, on the same substrate. In yet another preferred embodiment, the structure comprises the substrate, two or more inventive waterproofing layers on the substrate, and an additional layer. Petition 870250088032, dated 09 / 29 / 2025, pp. 100 / 114 / 48 different on top, such as a cementitious layer. Consequently, a specific composite with customized properties can be provided, in view of the specific conditions and requirements with respect to the substrate material, stability, impermeability and the like.

[0099] The object of the invention is also a coating composition, which is obtainable by mixing suspension (A) and suspension (B) of the inventive kit. After mixing and during processing, the coating composition is liquid and can be coated onto the substrate. Preferably, it is a flowable liquid or paste. In the coating composition, the aluminum and calcium mineral has not yet been formed in significant quantities, for example less than 20% or less than 10%, based on the amount of mineral formed after coating and consolidation.

[00100] The objective of the invention is also the use of a kit of the invention for coating, covering, sealing, waterproofing, stabilizing, reinforcing and / or repairing a substrate. In applications, a waterproof coating is applied to the substrate as referred to above. For example, the coating can make the substrate waterproof. The coating can be used to cover the substrate, for example to protect it against the environment and / or mechanical stress. The coating can be used to stabilize the substrate, for example protecting it from deterioration and degradation.

[00101] The coating can also be used to cover another waterproof coating that has been previously applied, especially over a cementitious substrate. In this respect, the underlying waterproof coating, over which the inventive coating is applied, may be an inventive coating, but it may also be a different, conventional coating, such as a waterproof membrane or plastic sheet. For example, the inventive coating can be applied over another waterproof coating to repair, seal, stabilize or reinforce the Petition 870250088032, dated 09 / 29 / 2025, pp. 101 / 114 / 48 same. Generally, such waterproof coatings in construction applications have a limited lifespan. They can deteriorate, be damaged, and have defects. In such cases, the inventive waterproof coating can be used to improve the properties of an underlying waterproofing layer.

[00102] The inventive coated substrate, or structure, is especially for use in construction applications and / or for covering walls, particularly for a tunnel, mine or construction.

[00103] The invention also relates to a liquid suspension (A), comprising 70% ethylene vinyl acetate copolymer latex, 10% amorphous aluminum hydroxide, 15% filler, 2% biocide, 20% additional additives, and water making up the remainder, wherein the suspension has a pH of 5 to 9, wherein all quantities are % by weight, based on the total weight of the suspension (A).

[00104] The invention also relates to a liquid suspension (B), comprising 40% calcium hydroxide and 40% calcium sulfate dihydrate, 0.1 to 3% of a borate compound, 5% of stabilizer and / or plasticizer, 20% of additional additives, and water making up the remainder, wherein the suspension has a pH > 9, wherein all quantities are % by weight, based on the total weight of the suspension (B).

[00105] The kit, method, coated substrate, structure and inventive uses Petition 870250088032, dated 09 / 29 / 2025, pp. 102 / 114 / 48, resolves the underlying problem of the invention. A waterproof coating is provided, which can be conveniently handled and applied by the user, if desired in a continuous process. At the same time, the waterproof coating has excellent performance, especially with respect to mechanical properties. It can be uniformly applied to a substrate by spraying. The kit and suspensions can be stored and transported without impairing use and performance. The coating composition can be prepared quickly without significant dust formation during processing and application. By coloring the suspensions (A) and / or (B), a visual quality control of the coating procedure can be incorporated. The coating composition can be conveniently mixed and sprayed with conventional 2K devices and systems. Examples Testing methods

[00106] The following test methods were used to analyze the properties of the coated substrates.

[00107] The tensile failure at rupture and stress failure at rupture of the coatings were measured according to DIN 53504:2009-10. As specimens of the membrane samples, “dog bones” S2 were used, which were cut from the membrane sheets after applying them onto PET sheet (Hostaphan®, Mitsubishi Chemicals, DE), usually with a 3 to 6 mm thickness of fresh coating layer) and consolidation of the membranes under the required conditions for the required duration. The measurements were performed using the Inspekt Retrofit 1445® 10 kN universal testing machine.

[00108] The Shore A hardness of the membranes was measured according to DIN 53505, ISO 868. As specimens, the “dog bones” S2 membrane samples were used, which were cut from the membrane sheets after applying them to a PET sheet (Hostaphan®, Mitsubishi Chemicals, Petition 870250088032, dated 09 / 29 / 2025, pages 103 / 114 / 48 (DE), and consolidation under the required conditions for the required duration (usually with a fresh membrane layer thickness of 3 to 6 mm). Measurements were performed using the Shore A Durometer 3100 (Zwick, DE) and the PCE-DX-A handheld Shore A durometer (PCE Group, DE).

[00109] The unique bond strength of the membranes to the concrete was measured according to EN1542 or ASTM 1583 / C 1583M by the stripping method. For the strength measurements, fully cured precast concrete slabs with a smooth, flat surface and a size of 40 x 40 cm were coated with a membrane (usually with a fresh membrane layer thickness of 3 to 6 mm) and pre-stored under the required conditions for the required duration. After the membrane had consolidated, 50 mm diameter round steel seals were bonded to the 50 mm diameter round membrane specimens, which were cut from an applied membrane layer, and stripping measurements were performed using the HZP-12 D1® testing machine (Walter+Bai, DE) and the F20D EASY M2000® mobile testing machine (Baustoff-Prüfsistemae Wennigsen, DE).

[00110] The double bond strength of membranes to concrete was measured for “sandwich” specimens, prepared by coating fully cured precast concrete slabs with a smooth, flat surface of 40 x 40 cm2 with a membrane layer, consolidating the membrane under defined conditions for a defined time, followed by molding a second layer of concrete over the membrane layer and further consolidating the entire sandwich element under defined conditions for defined times. Prismatic “sandwich” specimens with a square cross-section of 60 x 60 mm or cylindrical sandwich specimens (cores) with round cross-sections of 50 mm diameter were cut / drilled, seals bonded to each side of the concrete, and strength measurements were made by the pull-out method as in the case of single bond measurement. Petition 870250088032, dated 09 / 29 / 2025, pages 104 / 114 / 48 Example 1: Preparation of suspensions (A) and (B)

[00111] Suspensions (A) and (B) were prepared and used to produce coatings on the substrates. The compositions are summarized in Table 1 below. The procedure for preparing the suspensions is described below. Suspension (A)

[00112] Amorphous aluminum hydroxide is added to water and mixed with a mechanical stirrer until the suspension is homogeneous. The polymer dispersion powder is added in portions to the aluminum hydroxide suspension and homogenized. If a liquid polymer dispersion is used, the aluminum hydroxide can be added directly to the liquid dispersion. Optionally, a biocide is added at the end of the mixing process. A white, viscous, but very flowable, pumpable suspension is obtained, which has a pH of about 7 to 8. Suspension (B)

[00113] If boric acid is added, crystalline boric acid is dissolved in water using a mechanical stirrer or, if available boric acid solution is used instead. The stabilizer is optionally added and mixed until homogeneous. Subsequently, calcium hydroxide, optionally calcium carbonate and calcium sulfate dihydrate are added and stirred until the mixture is completely homogeneous and free of lumps. Additional additives, such as a defoamer, plasticizer and / or pigment, may be added and mixed until homogeneous. A viscous, yet highly flowable and pumpable suspension, optionally colored, is obtained, which has a pH of about 12 to 13. Table 1: Compositions A to J for suspensions (A) and (B) Suspension (A) Suspension (B) EVA1 (1) EVA2 (2) H2O Amorphous Al(OH)3 Ca(OH)2 CaCO3 CaSO4 •2H2O stabilizer (3) H2O boric acid (4) [g] [g] [g] [g] [g] [g] [g] [g] [g] [g] A 82 0 50 7.26 2.97 3.63 7.51 0 10.5 3 Petition 870250088032, dated 09 / 29 / 2025, pp. 105 / 114 / 48 B 82 0 50 7.26 6.6 0 7.51 0 10.5 3 C 82 0 50 7.26 2.97 3.63 7.51 0 10.5 0 D 82 0 50 7.26 6.6 0 7.51 0 10.5 0 E 0 132 0 7.26 2.97 3.63 7.51 0 10.5 3 F 0 132 0 7.26 6.6 0 7.51 0 10.5 3 G 82 0 50 6.6 6 0 6.83 0.02 5.5 15 H 82 0 50 6.6 2.7 6.83 0.02 5.5 15 J 82 0 50 6.6 6 0 6.83 0.02 5.5 15 (1) EVA1: vinyl acetate-ethylene copolymer (2) EVA2: acrylic acid ester-ethylene-vinyl ester copolymer (3) synthetic, water-soluble, high molecular weight polymer (cellulose-based) (4) 1.54% boric acid solution in water Example 2: Methods for preparing coating compositions

[00114] The coating compositions were prepared in batch and continuous methods from suspensions (A) and (B) according to example 1. Conventional devices were used that can be fed with a single-component system (1K systems) or a two-component system (2K systems, with mixing media). a) Batch method

[00115] If the coagulation time of the mixture of suspensions (A) and (B) is long enough, the batch mixture can be used. Suspension (B) is added to suspension (A) in a suitable container (beaker, bucket, drum) and homogenized with a mechanical stirrer. As soon as a homogeneous mixture is obtained, the mixed material is applied. b) Continuous method

[00116] For continuous preparation of the coating composition, a two-component setup with a static mixer can be used, consisting of two separate supply units A and B. For example, the device could be 2K pumps with an appropriate A:B feed volume ratio or a 2K extrusion / spray gun with a 2K cartridge system at a suitable A:B volume ratio, such as the MixCoat® 2K spray cartridge gun (Sulzer, DE), and a static mixer, where A & B are continuously mixed during pumping. A continuous method is generally advantageous for large-scale application and for fast coating of compositions having a short time. Petition 870250088032, dated 09 / 29 / 2025, pp. 106 / 114 / 48 of short coagulation. Example 3: General methods for coating substrates

[00117] The substrates were coated by various methods with the coating compositions prepared according to Example 1. In all cases, the coatings were applied to the substrate and allowed to stand under standard conditions for defined periods of time, as indicated in the following examples. No additional means for drying or consolidation were applied, such as heating or radiation. a) Hand coating

[00118] If the coagulation time of the coating composition is long enough, the surface of the desired substrate can be coated by pouring the coating composition onto a substrate, or by brushing, painting or sweeping the coating composition with suitable tools (trowel, brush, etc.) before the coating composition coagulates. b) Coating with a one-component device

[00119] Alternatively, if the coagulation time is long enough, the coating composition prepared in a batch can be pumped by a suitable 1K pump for liquids and extruded or sprayed onto a substrate surface using an appropriate nozzle. c) Coating with a two-component device

[00120] For large-scale application, or if the coagulation time of the coating composition is short, airless spraying with 2K pumps such as XP50® (Graco, DE), or 2K cartridge guns such as MixCoat® Spray (Sulzer, DE) equipped with a static mixer and spray nozzle can be applied. Example 4: Manual coating of batch coating composition

[00121] The coating compositions were prepared from Petition 870250088032, dated 09 / 29 / 2025, p. 107 / 114 / 48 suspensions (A) and (B) according to formulations A to F of example 1 (table 1). The coating composition was prepared by the batch method a) of example 2. The substrate was coated by the manual coating method a) of example 3.

[00122] The substrate surfaces were placed horizontally so that even if coagulation was not rapid enough, the freshly applied coating composition would not flow down under gravity from the surface. The coated surfaces were PET sheets for the preparation of “dog bone” specimens and precast concrete slabs with a smooth, flat surface of 40 x 40 cm. The thickness of the fresh membrane layer, in all cases, was 3 mm. The membrane specimens were stored after preparation at +20°C and 65% relative humidity for 28 days, and the mechanical testing of the membrane specimens was performed after 1, 3, 7, 14, and 28 days according to the test procedures. The average of three specimens was determined, with the exception of two specimens, for Shore A hardness. The results are listed in Table 2 below. Table 2: Mechanical properties of coated substrates # Failure under tension [%] (ε Fmax) Failure under stress (Fmax. N / mm2) 1 day 3 days 7 days 14 days 28 days 1 day 3 days 7 days 14 days 28 days A 423 291 243 136 121 0.72 1.72 2.41 3.39 3.51 B 330 199 133 71 43 1.05 1.64 2.10 3.00 3.55 C 241 180 140 109 110 0.74 1.81 2.90 2.97 3.24 D 228 87 55 45 48 1.12 1.78 2.68 2.84 2.94 E 36 115 67 48 23 0.58 2.26 3.55 4.04 3.12 F 38 88 22 22 15 0.86 2.38 5.45 4.94 4.61 # Shore A 3 s Adhesion strength [N / mm2] 1 day 3 days 7 days 14 days 28 days 1 day 3 days 7 days 14 days 28 days A 32.8 48.8 59.4 73.7 80.1 0.12 0.66 1.19 2.30 2.21 B 42.2 62.6 71.7 83.6 82.3 0.18 0.55 1.41 2.18 - C 24.1 57.0 71.9 74.5 78.3 0.15 1.22 2.01 3.16 3.27 0.56 1.21 1.93 2.32 F 58.1 78.1 85.7 92.4 90.0 0.30 0.34 0.96 1.62 1.88

[00123] The results demonstrate that in all cases complete preparation and consolidation of the membranes were achieved. Petition 870250088032, dated 09 / 29 / 2025, pages 108 / 114 / 48

[00124] With the EVA2 polymer dispersion, much less elastic (significantly lower tensile failure values) and harder (higher Shore A hardness values) membranes could be obtained (compositions E, F) compared with membranes with EVA1 polymer (compositions A to D).

[00125] The results for coating compositions C and D show that even without boric acid preparation, membranes with sufficient final mechanical properties are possible (compared to compositions A and B which contain borate). However, applying coating compositions C and D to vertical surfaces would be difficult because the coagulation of the coating composition is low, so these compositions would flow down the vertically placed substrate before proper consolidation. Example 5: Preparation and continuous application of the coating composition

[00126] Coating compositions were prepared from suspensions (A) and (B) according to formulations G and H of example 1 (table 1). The coating composition was prepared by continuous method b) of example 2. The substrate was coated with a 2K spray device according to method c) of example 3. Continuous mixing of suspensions (A) and (B) at a volume ratio of 4:1 and surface coating were performed with the 2K MixCoat® cartridge gun with static mixer (Sulzer, DE). The coated surfaces were PET sheets for the preparation of “dog bone” specimens and 40 x 40 cm smooth flat precast concrete slabs. The thickness of the freshly applied membrane layer was approximately 3 mm.

[00127] Suspensions (B) of formulations G and H contain a stabilizer to improve stability in long-term storage of suspensions against sedimentation. Coating compositions G and H contain more boric acid than coating compositions A to F. Petition 870250088032, dated 09 / 29 / 2025, pp. 109 / 114 / 48 Therefore, they have a significantly shorter clotting time.

[00128] The membrane specimens obtained were stored at 20°C and 65% relative humidity for 28 days, and the mechanical testing of the membrane layers was performed after 1, 3, 7, 14, and 28 days according to the test procedures. The results are listed in Table 3. The results demonstrate that membranes G and H have very good mechanical properties. Table 3: Mechanical properties of coated substrates # Failure under tension [%] (ε Fmax) Failure under stress (Fmax. N / mm2) Shore A 3 s Adhesion resistance [N / mm2] 1 day 7 days 13 days 28 days 1 day 7 days 13 days 28 days 1 day 7 days 13 days 28 days 1 day 7 days 28 days G 409 202 169 102 0.74 2.68 3.55 3.49 40.4 71.9 75.7 78.4 0.18 1.24 1.94 H 639 314 246 171 1.02 3.27 3.63 4.77 39.4 56.5 71.5 71.4 0.11 1.05 2.31 Example 6: Comparison of the inventive membrane with a conventional membrane.

[00129] A coating composition was prepared from suspensions (A) and (B) according to formulation J of example 1 (table 1). The coating composition was prepared by continuous method b) of example 2. The substrate was coated with a 2K spray device according to method c) of example 3. Suspensions (A) and (B) were mixed in a 4:1 volume ratio and sprayed with the 2K MixCoat Spray cartridge gun with static mixer (Sulzer, DE) onto a PET sheet for the preparation of dog bone specimens and concrete slabs with a smooth, uniform surface for the preparation of specimens for single and double adhesion measurements, with a fresh membrane layer thickness of approximately 3 mm.

[00130] For comparison, a membrane was prepared from a commercial powder product for waterproof coatings for tunnel concrete surfaces (MasterRoc MSL 345®, Master Builders Solutions, DE). Like the inventive membrane J, the comparative membrane is based on ettringite and ethylene vinyl acetate copolymer. However, the Petition 870250088032, dated 09 / 29 / 2025, pp. 110 / 114 / 48 The coating composition for the comparative membrane is prepared by suspending MasterRoc MSL 345® powder, comprising mineral and polymer particles, in water. The coating composition was prepared according to the manufacturer's instructions by mixing the dry powder with a stirrer at a water / powder ratio of 0.5. The coating composition was manually applied to the same surfaces with the same layer thickness of approximately 3 mm.

[00131] After 7 days, the membranes were consolidated, and the second layer of concrete was applied over the surface of the membrane layers. After that, cylindrical specimens for testing the double bond strength were prepared as described above. Double bond strength measurements were performed 7, 14, and 28 days after the application of the second layer of concrete. The specimens were stored at +20°C and 65% relative humidity (RH) before each measurement. The results are shown in Table 4. Table 4: Mechanical properties of coated substrates for the inventive membrane J and the comparative membrane M. # Failure under tension [%] (ε Fmax) Failure under stress (Fmax. N / mm2) Shore A 3 s 3 days 7 days 14 days 28 days 3 days 7 days 14 days 28 days 3 days 7 days 14 days 28 days J 414 269 160 140 1.73 1.90 2.53 3.14 58.4 64.7 73.9 75 M 356 166 128 106 2.88 4.16 4.27 4.45 47.4 73.8 74.1 76 # Adhesion strength [N / mm2] Double adhesion strength [N / mm2] 3 days 7 days 14 days 28 days 7 days 14 days 28 days J 0.34 1.29 1.79 2.40 1.85 2.21 2.99 M 0.11 1.11 1.69 2.36 0.88 1.29 1.90

[00132] As observed in Table 4, both membranes achieve the target mechanical properties after 28 days, which are defined as follows in the MasterRoc MSL 345® technical documentation (membranes dried after 28 days, 20°C): Failure stress at rupture: 1.5 to 3.5 MPa (wet layer thickness of 3 to 6 mm) Failure rate at rupture: >100% (wet film thickness of 3 to 6 mm) Petition 870250088032, dated 09 / 29 / 2025, pages 111 / 114 / 48 Concrete bond strength (65% RH): 1.2 ± 0.2 MPa (wet film thickness of 3 to 6 mm) Shore hardness (65% RHy): approximately 80 ± 5 (wet film thickness of 3 to 6 mm)

[00133] Furthermore, the new 2K membrane is superior to the comparative membrane with respect to elasticity (tensile failure), single bond strength to concrete, and especially double bond strength. The Shore A hardness values ​​for both membranes are similar. Although the stress failure of the inventive membrane is lower, the target value > 1.5 MPa is already reached after 3 days, and thus the performance is very good. The results suggest that the inventive membrane has a unique structure that confers advantageous properties to the product. The new structure would result from the combined effect of in situ formation of ettringite crystals in the polymer dispersion and intimate adhesion of the composition and polymer to the substrate.

[00134] Another relevant difference of the new application process of the inventive membrane is that a dust-free mixing and spraying process can be carried out, in contrast to the powder-based comparative material and procedure. This provides a substantial environmental, health and safety benefit for the user during application. Example 7: Influence of ambient humidity on the double adhesion strength of the inventive membrane and the comparative membrane.

[00135] An inventive membrane of an inventive composition was prepared and sprayed using a 2K Sulzer MixCoat® Spray cartridge gun with a static mixer and a volume ratio A:B of 4:1 onto PET sheet and concrete slabs with a uniform smooth surface (fresh membrane layer thickness of 3 mm). For comparison, a membrane was prepared from the commercial product MasterRoc MSL 345® (water / powder ratio 0.5 w / w) with a stirrer and manually applied to the same surfaces with the Petition 870250088032, dated 09 / 29 / 2025, pp. 112 / 114 / 48 same thickness of fresh membrane layer of 3 mm. After 7 days of consolidation of both membranes, a second 5 cm thick layer of concrete was molded over both membrane layers. The concrete / membrane / concrete sandwich elements were stored for a further 35 and 56 days under various conditions. The cores of the second concrete layer were drilled and the double bond measurement was performed. In each case, the average of 5 specimens was determined. The results are summarized in Table 5: Table 5: Double bond strength [MPa] of membranes under various conditions Conditions 35 days 56 days inventive 20°C, 65% RH nd 2.81 comparative 20°C, 65% RH nd 2.41 inventive 20°C, 65% RH, last 7 days stored in water 1.86 2.08 comparative 20°C, 65% RH, last 7 days stored in water 1.05 1.38

[00136] The results demonstrate that under all conditions tested, the double bond strength values ​​for the inventive membrane are significantly higher than for the comparative membrane. In terms of double bond strength, the inventive membrane is less sensitive to humid conditions than the comparative membrane. The results suggest that the inventive membrane has a specific structure, which would result from the in situ formation of ettringite crystals in the polymeric matrix and confers advantageous properties to the membrane.

[00137] Another relevant difference in the application process of the new inventive membrane is that a dust-free mixing and spraying process can be carried out, in contrast to the powder-based comparative material and procedure. This provides a substantial environmental, health and safety benefit for the user during application. Example 8: Performance of the new 2K membrane applied by machine

[00138] In further experiments, an inventive membrane was prepared by mixing and spraying the inventive coating composition with an XP50 2K airless spray machine (Graco, DE) Petition 870250088032, dated 09 / 29 / 2025, pp. 113 / 114 / 48 equipped with the XHD549 nozzle at approximately 35 to 40°C of both suspensions (preheated in the spraying machine) on PET sheets, for the preparation of "dog bone" specimens for Shore A measurements, tensile failure and failure of the membranes themselves, as well as on concrete slabs with a smooth, uniform surface of 40 x 40 cm. The "sandwich" specimens for double bond strength measurements were prepared by molding the second layer of concrete over a membrane layer at the membrane age of 7 days, subsequently consolidating the sandwich element for 7 days, and then cutting the "sandwich" prisms with a square cross-section of 60 x 60 mm. The environmental conditions during pulverization and storage of the specimens were 20°C / 65% relative humidity.

[00139] The results demonstrate that the new inventive membrane, when sprayed with the 2K device, achieved the target performance values ​​for the comparator product MasterRoc 345® (Master Builders Solutions, DE) even earlier than 28 days of age, as defined above in Example 6. Specifically, the target values ​​for Shore A hardness of at least approximately 80 were achieved after as little as 14 days. The target values ​​with respect to stress failure (single adhesion strength) of at least 1.5 N / mm² were achieved as early as 3 days. The target values ​​for stress failure at rupture >100% were exceeded at all time points, including day 1. The results confirm that the membrane's performance is excellent and superior to the comparator membrane based on ettringite and EVA. The inventive kit can be used with standard 2K devices in the technical field. Petition 870250088032, dated 09 / 29 / 2025, p. 114 / 114

Claims

1 / 4 CLAIMS 1. Kit for preparing a waterproof coating comprising an aluminum and calcium sulfate mineral embedded in a polymeric matrix, characterized in that the kit comprises a first container containing an aqueous suspension (A) comprising - an aluminum (III) source and - an organic polymer, wherein the suspension (A) has a pH of 5 to 9, and a second container containing an aqueous suspension (B) comprising - a calcium (II) source and - a sulfate source, on the condition that there is a molar excess of calcium (II) to sulfate in the suspension (B), wherein the suspension (B) has a pH > 9.

2. Kit according to claim 1, characterized in that it is for preparing a waterproof coating comprising an aluminum and calcium sulfate mineral embedded in a polymeric matrix, wherein the waterproof coating comprises - 25 to 95% organic polymer - 5 to 75% aluminum and calcium sulfate minerals, wherein all quantities in the waterproof coating are % by weight, and the total is 100%, based on all solid components of the coating.

3. Kit according to claim 1 or 2, characterized in that the aluminum (III) source comprises aluminum hydroxide (III).

4. Kit according to any of the preceding claims, characterized in that the calcium (II) source comprises calcium hydroxide and / or calcium oxide. Petition 870250088032, dated 09 / 29 / 2025, page 61 / 114 2 / 4 5. Kit according to any of the preceding claims, characterized in that the sulfate source comprises a hydrated calcium sulfate, preferably dihydrated calcium sulfate.

6. Kit according to any of the preceding claims, characterized in that the aluminum calcium sulfate mineral is ettringite.

7. Kit according to any of the preceding claims, characterized in that the organic polymer is an ethylene-vinyl acetate copolymer.

8. Kit according to any of the preceding claims, characterized in that the suspension (A) comprises at least one additive selected from the group consisting of biocide, filler, emulsifier, plasticizer, protective colloid and dye.

9. Kit according to any of the preceding claims, characterized in that the suspension (B) comprises at least one additive selected from the group consisting of a gelling agent, stabilizer, plasticizer and colorant.

10. Kit according to claim 9, characterized in that the gelling agent is a borate compound, preferably boric acid.

11. Method for producing a coated substrate with a kit as defined in any of the preceding claims, characterized in that it comprises the steps of (a) preparing a coating composition by mixing suspensions (A) and (B), (b) coating the substrate with the coating composition obtained in step (a), and (c) consolidating the coating.

12. Method according to claim 11, characterized Petition 870250088032, dated 09 / 29 / 2025, page 62 / 114 3 / 4 by the fact that in step (a) the suspensions are mixed in a continuous process.

13. Method according to claim 11 or 12, characterized in that in step (a) the mixing ratio of suspension (A) to suspension (B) is in the range of 3:1 to 10:1 (by volume).

14. Method according to any one of claims 11 to 13, characterized in that in step (b) the substrate is coated by spraying.

15. Method according to any one of claims 11 to 14, characterized in that the mixing in step (a) and the coating in step (b) are carried out with a device comprising (i.) a static mixer for mixing the suspensions, (ii.) a nozzle for spraying the mixture, (iii.) means for continuously feeding the suspensions (A) and (B) into the static mixer, (iv.) means for continuously feeding the mixture from the static mixer to the nozzle, (v.) optionally means for adjusting the temperature of the suspensions and / or the mixture.

16. Method according to any one of claims 11 to 15, characterized in that the substrate is an inorganic material, preferably a cementitious material.

17. A method according to any one of claims 11 to 16, characterized in that at least one additional layer is applied to the surface of the substrate thus coated.

18. Method according to claim 17, characterized in that the additional layer is a second coating applied in a method comprising steps (a) to (c), wherein preferably the first coating and the additional coating have different colors. Petition 870250088032, dated 09 / 29 / 2025, p. 63 / 114 4 / 4 19. Use of a kit as defined in any of claims 1 to 10, characterized by being for coating, covering, sealing, waterproofing, stabilizing and / or repairing a substrate. Petition 870250088032, dated 09 / 29 / 2025, p. 64 / 114