NZ742596A - Contact layer with mineral binder component - Google Patents

Abstract

The invention is directed to a contact layer used in waterproofing and roofing applications. The contact layer comprises a mineral binder component B, thermoplastic polymer component P, and a surfactant component S. The invention is also directed to a method for producing the contact layer, to a method for binding two substrates to each other, to a method for waterproofing a substrate, to a waterproofed structure, to a method for sealing a substrate against water penetration, to a sealed construction for sealing a substrate against water penetration and to a use of the contact layer as a waterproofing membrane. hod for binding two substrates to each other, to a method for waterproofing a substrate, to a waterproofed structure, to a method for sealing a substrate against water penetration, to a sealed construction for sealing a substrate against water penetration and to a use of the contact layer as a waterproofing membrane.

Description

Contact layer with mineral binder component Technical field The invention relates to contact layers for use in the construction industry, for e for basements, g and tunneling applications to protect concrete structures against water penetration.

Background of the invention Waterproofing membranes are commonly used in the construction industry for sealing bases, underground surfaces or buildings against water penetration.

State-of-the-art waterproofing membranes are multilayer systems comprising a polymer-based barrier layer as the principal layer to provide watertightness.

Typical rs used in barrier layers include thermoplastics such as plasticized nylchloride ) and thermoplastic polyolefins (TPO) or elastomers such as ethylene-propylene diene monomer (EPDM) and crosslinked chlorosulfonated hylene (CSPE). One of the drawbacks of polymer-based barrier layers is their poor bonding properties; they typically show low bonding strength to adhesives that are ly used in the construction industry, such as epoxy adhesives, polyurethane adhesives, and cementitious compositions. Therefore, a contact layer, for example, a fleece backing, is typically used to provide sufficient bonding of the r-based r layer and the ure to be waterproofed.

One of the main challenges related to the multilayer waterproofing membranes is to ensure watertightness after infiltration in case of leak in the barrier layer.

Watertightness after infiltration means in general that the sealing construction should be able to prevent the rated water from penetrating to the space between the membrane and the waterproofed surface. A leak in the barrier W0 2017/108844 2016/082004 layer can be a result of inward growing tree roots, material failure or tensile or shear forces directed to the membrane. If the ightness after ration is lost, water is able to flow laterally underneath the membrane and to invade the interior of the building structure. In such cases the exact location of the leak in the barrier layer is also difficult to .

US879386282 describes a waterproofing membrane comprising a barrier layer, a composite layer arranged on one side of the barrier layer and a network of sealant between the barrier layer and the composite layer. The network of sealant is said to limit the size of area affected by penetrating water in case of water leakage in the barrier layer. In waterproofing applications the membrane is applied on a subsurface in such way that the barrier layer is directed against a concrete base and the composite layer is facing the concrete casted against the membrane. During the hardening process, the composite layer is ated by the liquid concrete forming a good bond with the hardened concrete.

U82015/0231863A1 discloses a waterproofing membrane including a barrier layer and a functional layer including a thermoplastic polymer that changes consistency under nce of highly alkaline media and an adhesive. Once the functional layer gets into contact with liquid concrete, the thermoplastic polymer dissolves and allows the adhesive to bond to the cast concrete. The functional layer may additionally se other thermoplastic polymers, fillers or concrete tuents. The construction of the onal layer is said to enable working with membranes in adverse weather conditions without diminishing the adhesive capacity of the membrane.

One antage of of—the—art multilayer waterproofing membranes is related to the use of ves, which increases the complexity of the ne build-up and consequently the production costs of such membranes. The adhesive has to provide good binding to the low surface energy polymers in the barrier layers, form a strong bond to the contact layer and to fresh concrete and have a good resistance to varying temperature W0 2017/108844 ranges, UV irradiation and ion. ves fulfilling all the requirements, if ble at all, are expensive and thus se the production cost of such membranes by a icant amount.

Another disadvantage of state-of—the-art multilayer waterproofing membranes is related to the use of fleece backings as contact layer to provide sufficient bonding between the ne and the substrate to be waterproofed. In roofing and roofing ations the adjacent membrane sheets have to be homogenouslyjoined to each other in a reliable way to ensure watertightness of the sealing uction. Membranes having a fleece backing cannot be joined by heat welding but instead the edges of the membranes have to be bonded together either with an adhesive or with a sealing tape adhered on top of the seam and/or under the seam. The use of an adhesive or a sealing tape to join adjacent membrane sheets complicates the installation process and increases application costs.

Summary of the invention The objective of the present invention is to provide a contact layer, which can be bonded to a thermoplastic layer without the use of adhesives.

Another objective is to provide a contact layer, which fully and permanently bonds to concrete and other cementitious compositions after hardening without the use of adhesives.

Still another objective of the present invention is to provide a contact layer, which has a good heat welding properties.

According to the invention, the aforementioned objectives are achieved with the contact layer according to claim 1.

W0 2017/108844 The main concept of the invention is that the contact layer comprises a mineral binder component, a thermoplastic polymer component and a surfactant component.

The combination of the mineral binder component, the thermoplastic polymer component and the surfactant component enables the contact layer to be bonded with thermoplastic layers and to cementitious compositions after hardening. It has been found by the ors of the present invention that the presence of the surfactant component in the contact layer significantly increases the strength of adhesion by which the t layer is bonded to cementitious compositions.

Without being bound by any theory it is believed that the ce of tants in the contact layer eases the “waterflow” through the percolated binder cavities in the polymer matrix, which s partial hydration of the binder particles in the contact layer and formation adhesion through hardening of the mineral binder component.

One of the advantages of the present invention is that the contact layer can be bonded to plastic layers and to cementitious compositions without the use of adhesives. This s the use of waterproofing and roofing nes, which have simple up and which can thus be ed with lower costs compared to state—of—the-art membranes.

Another advantage of the present invention is that the contact layer has good heat welding properties, which means that adjacent contact layers or thermoplastic membranes comprising a contact layer can be homogeneously joined by heat welding instead of using an adhesive or sealing tape to bond overlapping membrane sheets.

In another aspect of the present invention there is ed a method for producing a contact layer, a method for binding to substrates together, a method for waterproofing a substrate, a waterproofed construction, a method W0 2017/108844 for sealing a substrate, a sealedd arrangement and to use of the contact layer as a waterproofing membrane.

Detailed description of the invention The term “polymer” designates collective of chemically uniform macromolecules produced by a polyreaction (polymerization, polyaddition, polycondensation) where the macromolecules differ with respect to their degree of polymerization, molecular weight and chain length. The term also comprises derivatives of said collective of macromolecules resulting from polyreactions, that is, compounds which are obtained by reactions such as, for example, additions or substitutions, of functional groups in predetermined macromolecules and which may be ally uniform or chemically non- uniform.

The term “polymer component” designates polymer compositions comprising one or more polymers.

The term ng point” ates the maximum of the curve determined according to ISO 11357 standard by means of dynamic differential calorimetry (DSC). At the melting point the material undergoes transition from the solid to the liquid state. The ement can be performed with a Mettler Toledo 822e device at a g rate of 2 degrees centigrade/min. The melting point values can be determined from the measured DSC curve with the help of the DSC software.

The term “surfactant” designates e tension lowering substances.

Surfactants are usually organic nds containing both hobic and hydrophilic groups. Based on the charge of the hydrophilic group the surfactants are classified to anionic, cationic, amphoteric, non-ionic surfactants.

W0 2017/108844 By calcium carbonate as l filler is understood in the present document calcitic fillers produced from chalk, limestone or marble by grinding and/or precipitation.

The term “sand” designates mineral clastic sediments (clastic rocks) which are loose conglomerates (loose sediments) of round or angular small grains, which were detached from the al grain structure during the ical and chemical degradation and transported to their deposition point, said sediments having an Si02 t of greater than 50 wt.-%, in particular greater than 75 wt.-%, particularly preferably greater than 85 wt.-%.

The term “mineral binder” designates a binder, which in the presence of water reacts in a hydration reaction under formation of solid hydrates or hydrate phases. In particular, the term “mineral binder” refers to non-hydrated l binders, i.e. mineral binders, which have not been mixed with water and reacted in a hydration reaction.

The term "hydraulic binder" designates substances that harden as a result of chemical reactions with water (“hydration reactions”) and produce hydrates that are not water-soluble. In particular, the hydration reactions of the lic binder take essentially place independently of the water content. This means that hydraulic binders can harden and retain their strength even when exposed to water, for example unden/vater or under high humidity conditions. Examples of hydraulic binders include cement, cement r and hydraulic lime. In contrast, “non-hydraulic binders” such as air-slaked lime (non-hydraulic lime) and gypsum, are at least partially water soluble and must be kept dry in order to retain their th.

The term "gypsum" designates any known form of gypsum, in ular m e dehydrate, calcium sulfate hydrate, calcium sulfate [3- hemihydrate, or calcium sulfate anhydrite or mixtures thereof.

W0 2017/108844 The term "latent hydraulic binders” designates particular type II concrete additives with latent hydraulic character according to DIN EN 206-1 :2000.

These als are calcium aluminosilicates that are not able to harden directly or harden too slowly when mixed with water. The hardening process is accelerated in the presence of alkaline activators, which break the chemical bonds in the binder’s amorphous (or glassy) phase and promote the dissolution of ionic species and the formation of calcium aluminosilicate hydrate phases.

Examples of latent hydraulic binders include granulated blast furnace slag.

The term “pozzolanic binders" designates in particular type II concrete ves with pozzolanic character ing to DIN EN 000. These materials are siliceous or aluminosilicate compounds that react with water and m hydroxide to form calcium silicate hydrate or calcium aluminosilicate hydrate . Pozzolanic binders e natural pozzolans such as trass and artificial ans such as fly ash and silica fume.

The term t” designates ground hydraulic binders, which apart from the hydraulic binders as the main constituents, usually contain small quantities of m sulfate (gypsum and/or hemihydrate and/or anhydrite), and optionally secondary constituents and/or cement additives such as grinding aids. The main constituents are contained in quantities of more than 5% by weight. The main constituents can be Portland cement clinker, also referred to as clinker or cement clinker, slag sand, natural or artificial pozzolans, fly ash, for example, siliceous or calcareous fly ash, burnt shale, limestone and/or silica fume. As secondary tuents, the cements can contain up to 5% by weight of finely divided inorganic, mineral nces, which originate from clinker production.

The term “cementitious composition” designates concrete, shotcrete, grout, mortar, paste or a combination thereof. The terms ", "mortar", "concrete", “shotcrete”, and “grout” are well-known terms in the state-of-the—art. Pastes are mixtures comprising a hydratable cement binder, usually Portland cement, masonry cement, or mortar cement. Mortars are pastes additionally including fine aggregate, for example sand. te are mortars additionally including W0 08844 2016/082004 coarse aggregate, for example d gravel or stone. Shotcrete is concrete (or sometimes mortar) conveyed through a hose and pneumatically projected at high velocity onto a surface. Grout is a particularly flowable form of concrete used to fill gaps. The cementitious compositions can be formed by mixing required amounts of certain ents, for example, a hydratable cement, water, and fine and/or coarse aggregate, to produce the particular cementitious composition.

The term “fresh cementitious composition” or “liquid itious composition” designate cementitious compositions before hardening, particularly before setting.

The present invention relates in a first aspect of the ion to a contact layer comprising a mineral binder component B, a thermoplastic polymer component P, and a tant component S, wherein the amount of the mineral binder component B is 10.0 - 90.0 wt.-%, preferably 20.0 - 85.0 wt.-%, more ably 25.0 - 80.0 wt.—%, most preferably 30 — 75 wt.-%, based on the total weight of the contact layer.

The contact layer is typically a sheet-like element having top and bottom surfaces (first and second surfaces of the contact layer) defined by peripheral edges.

The thermoplastic polymer component P may have a Young’s modulus measured ing to ISO 527—3 standard at a temperature of 23 °C of not more than 1000 MPa, more preferably not more than 750 MPa, even more preferably not more than 500 MPa, most preferably not more than 450 MPa. In particular, the thermoplastic component P may have a Young’s modulus measured according to ISO 527—3 standard at a temperature of 23 °C in the range from 50 to 1000 MPa, preferably from 50 to 750 MPa, more preferably from 100 to 750 MPa, most preferably from 100 to 700 MPa. Contact layers containing a plastic polymer component P having a Young’s modulus at W0 2017/108844 the above mentioned ranges were found to provide good concrete adhesion strengths. ably, the thermoplastic polymer component P has a Young’s s measured according to ISO 527-3 standard at a temperature of 23 °C of less than 100 MPa, more preferably less than 50 MPa, even more preferably less than 50 MPa, most preferably less than 10 MPa. Contact layers with the thermoplastic polymer component P having Young’s modulus at the above mentioned ranges were found to have particularly good concrete adhesion th.

The glass transition temperature (T9) of the thermoplastic polymer component P is ably below the temperatures ing during the use of the contact layer. It is therefore preferred that the T9 of the thermoplastic polymer component P is below 0 °C, more preferably below -15 °C, most preferably below -30 °C.

The term “glass transition temperature” refers to the temperature measured with DSC according to ISO 11357 standard above which temperature a polymer component becomes soft and pliable, and below which it s hard and glassy. The measurements can be performed with a Mettler Toledo 822e device at a heating rate of 2 degrees centigrade /min. The T9 values can be determined from the ed DSC curve with the help of the DSC software.

The mineral binder component B is preferably dispersed throughout, preferably uniformly, the thermoplastic polymer component P in the contact layer to ensure that the properties of the contact layer do not change considerably along the length of the layer.

The mineral binder component B is preferably present in the contact layer as a discontinuous particle based phase, which is sed in a continuous phase of the thermoplastic r component P.

W0 2017/108844 Preferably, the contact layer has concrete adhesion th of at least 5 N/50 mm, more preferably of at least 10 N/50 mm, even more preferably of at least N/50 mm, most preferably of at least 20 N/50 mm. In particular, the contact layer has concrete adhesion strength of at least 30 N/50 mm, preferably of at least 35 N/50 mm, more preferably of at least 40 N/50 mm, even more preferably of at least 45 N/50 mm, most preferably of at least 50 N/50 mm.

Preferably, the contact layer has te adhesion strength in the range of 5— 400 N/50 mm, more preferably of 10-350 N/50 mm, even more preferably of -300 N/50 mm, most ably of 20-250 N/50 mm.

The term “concrete adhesion th of a contact layer” refers to the average peel resistance [N/mm] per unit width of the contact layer upon peeling the contact layer from a surface of a concrete specimen, which has been casted on the surface of the contact layer and hardened for 28 days under standard here (air temperature 23°C, ve air humidity 50%).

In the context of the present invention, the concrete adhesion strength of a contact layer is determined using the measurement method described below.

Method for determining the concrete adhesion strength of a contact layer For the determination of the concrete adhesion strength, the contact layer is bonded to a polyethylene—based barrier layer WT 1210 HE available form Sika to obtain a test ne, which can be used in measuring the average peel resistance from a hardened concrete specimen. The thickness of the barrier layer is approximately 0.5 mm. The barrier layer can be bonded to the t layer by welding or by adhesion with any adhesive suitable for the purpose, such as Sikadur—31 CF available from Sika.

W0 2017/108844 2016/082004 For the measurement of the average peel resistance, a concrete test specimen having a sample of the test membrane adhered on its e is first prepared.

A sample membrane with a ion of 200 mm (length) X 50 mm (width) is first cut from the test membrane. One edge of the sample membrane on the side of the t layer is covered with an adhesive tape having a length of 50 mm and a width coinciding with the width of the sample membrane to prevent the adhesion to the hardened concrete. The adhesive tapes are used to provide easier installation of the concrete test specimens to the peel resistance testing apparatus. The sample membrane is placed into a formwork having a dimension of 200 mm (length) x 50 mm (width) x 30 mm (height) with the contact layer of the sample membrane facing upwards and the barrier layer against the bottom of the rk.

For the preparation of the concrete specimen, a fresh concrete formulation is prepared by mixing 46.3 wt.-% of sand having a particle size of 0 — 1 mm, 7.1 wt.-% of ll—15 (from KFN) concrete additive (limestone filler), 32.1 wt.-% of CEM | 42.5 N cement (preferably Holcim Normo 4), 14.3 wt.-% of water and 0.2 wt.-% of Viscocrete® PC2 solution (from Sika) in a cement mixer for five minutes. The dry components of the concrete formulation are mixed and homogenized for two s in a tumbling mixer before ng with the liquid components.

The formwork containing the sample membrane is subsequently filled with the fresh te formulation and vibrated for two minutes to release the entrapped air. After hardening for one day the concrete specimen is stripped from the formwork and stored under standard atmosphere (air temperature 23°C, relative air humidity 50%) for 28 days before measuring the average peel resistance.

The average peel resistance upon peeling the sample membrane from the surface of the concrete en is measured using a Zwick Roell AllroundLine Z010 material testing apparatus equipped with a Zwick Roell 90°- W0 2017/108844 2016/082004 peeling device or using a similar g apparatus fulfilling the requirements of the DIN EN 1372 standard.

In the peel resistance measurement, the te specimen is clamped with the upper grip of the material testing apparatus for a length of 10 mm at the end of the concrete specimen comprising the taped section of the sample membrane. Following, the sample membrane is peeled off from the surface of the concrete specimen at a peeling angle of 90 ° and at a constant cross beam speed of 100 1 1O mm/min. During the peel resistance measurement the distance of the rolls is preferably approximately 570 mm. The peeling of the sample membrane is continued until a length of approximately 140 mm of the sample membrane is peeled off from the surface of the concrete specimen.

The average peel resistance is calculated as average peel force per unit width of the ne [N/ 50 mm] during peeling over a length of approximately 70 mm thus excluding the first and last quarter of the total peeling length from the calculation.

Preferably, the l binder component B comprises at least one mineral binder selected from the group ting of hydraulic, non-hydraulic, latent hydraulic, pozzolanic s, and mixtures thereof. The mineral binder component B can further comprise inert substances such as sand, calcium carbonate, crystalline silicas, talc, ts, and mixtures thereof.

The mineral component B preferably comprises a hydraulic binder, in particular cement or cement clinker. The l binder component B can further comprise latent hydraulic and/or pozzolanic binders, preferably slag and/or fly ash. In one embodiment, the mineral binder component B contains 5.0-50.0 wt.—%, preferably 5.0-40.0 wt.-%, more preferably 5.0-30.0 wt.-% of latent hydraulic and/or pozzolanic binders, preferably slag and/or fly ash and at least 35.0 wt.-%, more ably at least 65.0 wt.-% of hydraulic binder, preferably cement or cement clinker.

W0 2017/108844 Preferably, the mineral binder component B is a hydraulic binder, preferably cement.

The cement can be any conventional cement, for example, one in accordance with the five main cement types according to DIN EN 197—1: namely, Portland cement (CEM I), Portland composite s (CEM ll), blast-furnace cement (CEM lll), pozzolan cement (CEM IV) and composite cement (CEM V). These main cement types are subdivided, ing on the amount added, into an additional 27 cement types, which are known to the person skilled in the art and listed in DIN EN 197-1. Naturally, all other cements that are produced according to r standard are also suitable, for e, according to ASTM standard or Indian standard. To the extent that nce is made here to cement types according to DIN standard, this naturally also relates to the corresponding cement compositions which are produced according to another cement standard.

The mineral binder component B is preferably in the form of finely divided particles, in order to obtain a contact layer with uniform surface properties. The term “finely d particles" refers to particles, whose median particle size d50 does not exceed 500 pm. The term median particle size d50 refers to a particle size below which 50 % of all particles by volume are smaller than the d50 value.

The term “particle size” refers to the area-equivalent spherical diameter of a particle. The particle size distribution can be measured by laser diffraction according to the method as described in rd ISO 13320:2009. For determination of the particle size distribution, the particles are ded in water (wet dispersion method). A Mastersizer 2000 device (trademark of Malvern Instruments Ltd, GB) can be used in measuring particle size distribution.

Preferably the median particle size d50 of the mineral binder component B is 1.0 — 300.0 pm, more preferably 1.5 — 250.0 um, even more preferably 2.0 — 200.0 um, most preferably 2.0 — 150.0 pm.

W0 2017/108844 Preferably, less than 40 wt-%, more preferably less than 30 wt.-%, even more preferably less than 20-wt.—%, most preferably less than 10 wt.—% of the les of the mineral binder ent B have a particle size of less than 5 pm and preferably less than 40 wt.—%, more preferably less than 30 wt.—%, even more preferably less than 20-wt.-%, most ably less than 10 wt.-% of the particles of the l binder component B have a particle size of above 100 um.

Preferably, the overall particle size of the mineral binder component B (of at least 98 percent of the particles) is below 250 pm, more preferably below 200 um, even more preferably below 100 um.

Preferably, the surfactant component S ses at least one surfactant selected from the group consisting of anionic, cationic, amphoteric, non-ionic surfactants, and polymeric surfactants and mixtures thereof.

Examples of anionic surfactants include surfactants ning carboxylate, sulfate, phosphate or sulfonate groups, such as amino acid derivatives; fatty alcohol ether es; fatty alcohol sulfates; soaps; henol ethoxylates; fatty alcohol ethoxylates; alkanesulfonates; olefinsulfonates; and alkyl phosphates.

Examples of cationic surfactants include quaternary ammonium or phosphonium compounds, such as, for example, tetraalkylammonium salts; N,N-dialkylimidazoline compounds; dimethyldistearylammonium compounds, N-alkylpyridine compounds; and um des.

Amphoteric (zwitterionic) surfactants have both cationic and anionic centers attached to the same molecule. Examples of amphoteric surfactants include amphoteric electrolytes such as aminocarboxylic acis and betaines.

W0 2017/108844 Examples of non-ionic surfactants include ethoxylates, such as, for example, ethoxylated adducts of alcohols, such as polyoxyalkylene polyols; amines; fatty acids; fatty acid amides; alkylphenols; ethanolamides; fatty ; polysiloxanes; fatty acid esters; alkyl or alkylphenyl polyglycol ethers, such as, for e, fatty alcohol polyglycol ethers; alkylglycosides; sugar esters; sorbitan esters; polysorbates or trialkylamine oxides; esters and amides of poly(meth)acrylic acids with polyalkylene glycols or aminopolyalkylene glycols, which at most may be tacked at one end with alkyl groups.

Polymeric surfactants can be d into two groups of products. The first group includes comb or rake polymers where there is an organic polymeric chain with hobic groups at regular intervals along the chain and hydrophilic groups at random or regular intervals along that chain. The second group of polymeric surfactants includes block co-polymers where there are blocks of hydrophobic groups (B) and blocks of hydrophilic groups (A) usually in A-B-A configuration. Certain ric surfactants such as ethylene oxide- propylene oxide co-polymer surfactants can also be classified as non—ionic surfactants.

Preferably, the at least one surfactant is selected from the group consisting of glycerol monostearates, polycarboxylate ethers, polyether—modified polysiloxanes, kylene oxide siloxanes, hydroxyethyl amines, erucamides, stearyl stearamides, alkali metal alkanesulfonates, alkyl aryl sulfonates, and mixtures thereof.

Examples of suitable commercially available glycerol earates include Dimodan HP (from Danisco). es of suitable polycarboxylate ethers include polycarboxylate ether- based lasticizers (PCEs), which are composed by a methoxy- polyethylene glycol copolymer (side chain) d with rylic acid mer (main chain). Suitable commercially available polycarboxylate ether— W0 2017/108844 based superplasticizers include Viscocrete® Polymer PC-2, Viscocrete® Polymer RMC-2, and Cemerol® R-750 MC (from Sika).

Examples of suitable polyether-modified polysiloxanes include polyetherpolysiloxane copolymers. le commercially available polyether- modified polysiloxanes include Tegostab B8870 (from Evonik).

Examples of suitable commercially available polyalkylene oxide nes include Niax L-1500 (from Momentive). es of suitable hydroxyethyl amines include bis(2-hydroxyethyl) amines, which are commercially ble as Armostat 300 (from Akzo Nobel).

Examples of suitable commercially available erucamides and stearyl stearamides include Kemamide E180 and Kemamide 8180 (from PMC Biogenix). es of suitable alkali metal alkanesulfonates include sodium alkanesulfonates, which are commercially available as Armostat 3002 (from Akzo Nobel) and Loxiol 93P (from Emery emicals).

Examples of le commercially available alkylarylsulfonates include ZetaSphere 2300, 3100 and 3700 (from Airproducts).

Increasing the amount of the surfactant component S in the contact layer increases the amount of hydrated cement grains in the contact layer, which enables er bonding of the contact layer with cementitious compositions.

The surfactants, however, also have a tendency to migrate from the contact layer into the layer of cementitious composition applied on contact layer. In case the amount of surfactants is increased above a certain limit, the hydration of cement grains is inhibited in the cementitious composition. As a result, the contact layer is very weakly if at all bonded to the cementitious composition.

W0 2017/108844 Preferably, the amount of the surfactant component S is at least 0.1 wt.—%, in particular 0.1 — 15.0 wt.-%, preferably 0.5 — 15.0 wt.-%, more preferably 0.5 — .0 wt.-%, most preferably 0.5 — 5.0 wt.-%, based on the total weight of the contact layer. ably, the surfactant component S comprises at least one surfactant, preferably selected from the group consisting of glycerol monostearates, polycarboxylate ethers, polyether—modified polysiloxanes, polyalkylene oxide siloxanes, hydroxyethyl amines, erucamides, stearyl stearamides, alkali metal sulfonates, and alkyl aryl sulfonates, and the amount of the surfactant component S is 0.1 — 15.0 wt.-%, in particular 0.5 —15.0 wt.-%, preferably 1.0 — 10.0 wt.-%, more preferably 1.0 — 5.0 wt.-%, most preferably 1.5 — 5.0 wt.-%, based on the total weight of the contact layer.

Preferably, the surfactant component S comprises at least two surfactants. It has been found that the concrete adhesion strength of the contact layer is further improved if the contact layer comprises at least two surfactants selected from the group ting of anionic, cationic, amphoteric, non-ionic surfactants, and polymeric surfactants and mixtures thereof.

Preferably, the at least two surfactants are selected from a group consisting of glycerol earates, polycarboxylate ethers, her—modified polysiloxanes, polyalkylene oxide nes, yethyl amines, erucamides, stearyl stearamides, alkali metal sulfonates, alkyl aryl sulfonates, and mixtures thereof.

Preferably, the surfactant component S comprises at least two surfactants, preferably selected from a group consisting of ol monostearates, polycarboxylate ethers, polyether—modified polysiloxanes, polyalkylene oxide siloxanes, hydroxyethyl , erucamides, stearyl stearamides, alkali metal sulfonates, and alkyl aryl sulfonates, and the amount of the surfactant component S is 1.0—15.0 wt.-%, more preferably 2.0-10.0 wt.-%, most preferably 3.0-5.0, based on the total weight of the contact layer.

W0 2017/108844 Increasing the amount of the thermoplastic r component P in the contact layer increases the strength of adhesion by which a contact layer is bonded to thermoplastic layers. However, increasing the amount of the thermoplastic r component P above a n limit tends decrease the te adhesion strength of the contact layer. Preferably, the amount of the thermoplastic polymer component P is 20.0 — 90.0 wt.-%, based on the total weight of the contact layer.

In particular, the amount of the thermoplastic r ent P is preferably 20.0 — 85.0 wt.-%, more preferably 30.0 - 80.0 wt.-%, even more preferably 35.0 - 75.0 wt.-%, most preferably 40.0 - 70.0 wt.-%, based on the total weight of the contact layer.

Any kind of thermoplastic polymer component is in principle suitable to be used in the contact layer. Preferably, the thermoplastic polymer component P comprises at least one polymer selected from the group consisting of ethylene — vinyl acetate copolymers (EVA), ethylene — acrylic ester copolymers, ne — in co-polymers, ethylene — propylene co-polymers, polypropylene (PP), polyethylene (PE), polyvinylchloride (PVC), polyethylene terephthalate (PET), polystyrene (PS), polyamides (PA), chlorosulfonated polyethylene , ethylene propylene diene rubber (EPDM), polyisobutylene (PIB), and mixtures thereof.

Preferably the thermoplastic polymer component P comprises at least one polymer selected from the group consisting of low-density hylene, linear low-density polyethylene, high-density polyethylene, ethylene — vinyl acetate copolymer, ethylene — acrylic ester mers, ethylene — d-olefin copolymers , and ethylene — propylene co-polymers.

The properties of the contact layer were found especially suitable when the thermoplastic polymer component P comprises at least one ethylene-vinyl acetate copolymer having a content of a structural unit derived from vinyl W0 2017/108844 acetate (hereinafter ed to as “vinyl acetate unit”) of at least 7.0 wt.-%, more preferably at least 20.0 wt.-%, even more preferably at least 30.0 wt.-%, most preferably at least 35.0 wt.-%.

Preferably, the at least one ethylene-vinyl e mer has a content of vinyl acetate unit in the range from 7.0 wt.-% to 90.0 wt.-%, more preferably from 7.0 to 80.0 wt.—%, most preferably from 7.0 to 70.0 wt.-%.

Preferably, the amount of the at least one ethylene—vinyl acetate co-polymer is at least 5.0 wt.-%, more preferably at least 10.0 wt.-%, most preferably at least .0 wt.-%, based on the total weight of the thermoplastic polymer component P. In particular, the amount of the at least one ethylene-vinyl acetate co- polymer is in the range from 5.0 wt.-% to 90.0 wt.-%, preferably from 10.0 to 90.0 wt.-%, more preferably from 15.0 to 80 wt.-%, most preferably from 15.0 to 70.0 wt.-%.

The amount of the at least one ne-vinyl acetate co-polymer, preferably having a content of vinyl acetate unit of at least 7.0 wt.-%, more preferably at least 20.0 wt.-%, is preferably at least 30.0 wt.—%, more preferably at least 35.0 wt.-%, even more preferably at least 40.0 wt.-%, most ably at least 50.0 wt.-%, based on the total amount of the plastic polymer component P.

The contact layer can comprise, in addition to the mineral binder component B, the thermoplastic polymer component P, and the surfactant component S additives such as UV- and heat stabilizers, plasticizers, foaming agents, dyes, colorants, pigments, matting , antistatic agents, impact ers, flame retardants, and processing aids such as lubricants, slip agents, antiblock agents, and denest aids.

Typically, the contact layer contains only small amounts of water before it is contacted with a fresh cementitious composition. Preferably, the amount of water in the contact layer is less than 5.0 wt.-%, preferably less than 3.0 wt.-%, even more preferably less than 1.5 wt.-%, based on the total weight of the W0 2017/108844 contact layer. In particular, the amount of water in the contact layer can be less than 2.0 wt.-%, preferably less than 1.0 wt.-%, even more preferably less than 0.5 wt.-%, based on the total weight of the contact layer.

The mineral binders in the contact layer should remain in substantially non- hydrated state at least until the contact layer is contacted with a composition containing water, such as fresh cementitious composition. Hydration of the mineral binder particles contained in the contact layer would decrease the flexibility and thus deteriorate the ng properties of the t layer. It would also affect vely the concrete adhesion th of the contact layer. It has been found that the mineral binders contained in the contact layer remain in substantially non-hydrated if the contact layer is stored for l weeks at normal room temperature and relative humidity of 50 %.

The contact layer may se not more than 10.0 wt.—%, preferably not more than 5.0 wt.-% of hydrated mineral binders, based on the total weight of the t layer. Preferably, the contact layer comprises not more than 3.0 wt.—%, more preferably not more than 1.5 wt.-%, even more ably not more than 1.0 wt.-%, even more preferably not more than 0.5 wt.—%, most preferably not more than 0.1 wt.-% of hydrated mineral binders, based on the total weight of the contact layer.

In order to produce a contact layer containing non-hydrated mineral binders, the mineral binder component B is preferably mixed with the thermoplastic polymer component P and the surfactant component S in dry form, i.e. without being mixed with water. Mixing the mineral binder with water would result in initiation of the hydration ons, which is not desired. The contact layer of the present invention is preferably obtained by melt-processing a composition ning the mineral binder component B, the thermoplastic polymer component P and the surfactant component S to a nized melt, which is then further processed into a shaped article. The homogenized melt can be, for example, extruded through a manifold or a flat die followed by cooling the extruded material between calender cooling rolls.

W0 2017/108844 2016/082004 The homogenized melt is preferably obtained by melt-processing a composition comprising the mineral binder component B, the thermoplastic r component P, and the surfactant component S at a temperature, which is above the melting point of point of the plastic polymer component P. Preferably, the homogenized melt is substantially free of water.

In particular, the amount of water in the homogenized melt is less than 5.0 wt.— %, preferably less than 2.5 wt.-%, more preferably less than 1.0 wt.-%, even more preferably less than 0.5 wt.—%, most preferably less than 0.1 wt.-%, based on the total weight of the homogenized melt.

The surface of the contact layer is preferably non-tacky at normal room temperature (25 °C). Whether a surface of a specimen is tacky or not can be determined by pressing the surface with the thumb at a pressure of about 5 kg for 1 second and then trying to lift the specimen by g the hand. In case the thumb does not remain adhered to the e and the specimen cannot be raised up, the surface is ered to be cky. In the context of membrane of the present invention, the “specimen” used in the tackiness test refers to a membrane having width of 10 cm and length of 20 cm.

There are no particular restrictions for the thickness of the t layer.

However, contact layers having a thickness of above 50 mm are not practical in waterproofing or roofing applications and contact layers with a thickness of below 50 um have been found to be ult to produce with the desired mechanical properties. In particular, the contact layer has a thickness of at least 0.1 mm, preferably of 0.1 — 75.0 mm, more preferably 0.1 — 25.0 mm, most preferably 0.1 — 10.0 mm. Preferably, the contact layer has a thickness of 0.1 — 50.0 mm, preferably 0.2 —10.0 mm, more preferably 0.3 — 5.0 mm, most preferably 0.4 — 2.0 mm. The thickness of the contact layer is measured according to EN 1849-2 standard.

It is preferable that the contact layer has a certain flexibility to allow it to be wound into rolls, typically during production, and then easily applied to a W0 2017/108844 e of a substrate. The inventors of the present invention, however, also have found that contact layers with certain flexibility have better concrete adhesion strength. Preferably, the contact layer has a shear modulus at a temperature of 30 °C according to EN ISO 6721-2:2008 of less than 600 MPa, more preferably less than 200 MPa, and most preferably less than 100 MPa.

The contact layer preferably has a mass per unit area of 100 — 10000 g/m2, more ably of 200 — 6000 g/m2, even more preferably of 300 — 3000 g/m2.

The mass per unit area is measured according to EN 1849-2.

The density of the contact layer is preferably 0.25-3.00 g/cm3, particularly 0.30- 2.75 g/cm3, more preferably 0.35-2.50 g/cm3, even more preferably 0.40-2.00 g/cm3, most ably 0.50-1.50 g/cm3. The density of the contact layer is measured by using the buoyancy method.

In order to improve the mechanical properties of the contact layer, it can be advantageous that the t layer is reinforced with a layer of fiber material bonded to one of its surfaces. The reinforcement layer can be in the form of a fiber mat, a fiber-woven fabric or a fibrous tissue. Particularly suitable materials for the rcement layer include glass fibers, polyester fibers or nylon fibers.

It may be ageous that the contact layer comprises a first and second reinforcement layers bonded to the first and second es of the contact layer, respectively.

The preferences given above for the mineral binder component B, the thermoplastic r component P, and to the surfactant component apply equally to all aspects of the invention.

In another aspect of the present ion, a method for producing a contact layer, as it was described above in , is provided. The method for producing a contact layer is not particularly limited and any conventional technology used for producing sheets and films from plastic materials can be used.

W0 2017/108844 The contact layer can be produced by extruding, calendering, compressing or casting a homogenized melt comprising the components of the t layer.

Preferably, the method for producing a contact layer comprises ing and/or calendering a homogenized melt comprising the components of the contact layer.

The homogenized melt can be obtained by melt—processing a composition comprising mineral binder component B, the thermoplastic polymer component P, and the surfactant ent S in an extruder or kneader. The melt- processing is preferably conducted at a temperature that is higher than the melting point of the plastic polymer component P, typically at least 20 °C higher, preferably at least 30 °C higher. Preferably, the amount of water in the homogenized melt is less than 1.0 wt.-%, preferably less than 0.5 wt.-%, most ably less than 0.1 wt.-%.

Preferably, the plastic polymer component P is rocessed in an extruder before the mineral binder component B is fed into the extruder through a side feeder. Some or all of the components of the composition can also be first mixed in a mixing device to obtain a dry blend, which is then melt- processed in extruder or kneader. The components of the composition can also be first mixed in a compounding extruder to obtain pellets or granulates, which are then fed into extruder or kneader.

Preferably, the contact layer is produced by an extrusion process. In the extrusion s, a homogenized melt comprising the mineral binder component B, the thermoplastic polymer component P, and the surfactant component S through a manifold or a flat, annular, slot or cast die, preferably through a manifold or a flat die, and quenching the extruded web of material between water cooled chill rolls. The thickness of the produced contact layer can be controlled by die lip ment and/or by adjusting the gap size between the chill rolls. Any conventional er apparatus used for producing W0 2017/108844 flat film sheet as described in stoff Verarbeitung” by Schwarz, Ebeling and Furth, 10th Edition 2005, Vogel rlag, paragraph 5.7.2 can be used in the extrusion process.

The optimal extrusion temperature depends on the composition of the contact layer and on the desired throughput of the ion process. The extrusion temperature is preferably 80 — 250 °C, more ably 100 — 240 °C, even more preferably 120 — 220 °C, most preferably 140 — 200 °C. The term “extrusion temperature” refers to the temperature of the molten material in the extruder die or manifold. Contact layers extruded at a temperature within the above bed temperature ranges were found to provide particularly good te adhesion strengths.

Preferably, the ion pressure is 20.0-350.0 bar, more preferably 30.0-240 bar, even more preferably 35.0—200 bar, most preferably 40.0—130.0 bar. The term sion pressure” refers to the pressure of the molten material inside the extruderjust before the material enters the extruder die or manifold.

The gap size between the cooling rolls can be wider than the thickness of the produced contact layer. For e, the gap size between the cooling rolls can be 10 %, 25 %, 50 %, or 75 % wider than the thickness of the produced contact layer.

The contact layer can also be produced by a calendering process. In the calendering process, a homogenized melt comprising the mineral binder component B, the thermoplastic polymer ent P, and the surfactant component S is passed between a series of calender rolls, in the course of which the homogenized melt is spread across the width of the rolls, stretched and finally cooled to the form of a film or sheet with defined ess. The homogenized melt can be fed with an extruder to the top of the calendering section and into the gap between the first and second rolls. Preferably, the calendering section comprises at least four calender rolls. Any conventional calendering apparatus used for producing films or sheets from thermoplastic W0 2017/108844 materials as described in “Kunststoff eitung” by Schwarz, Ebeling and Furth, 10th n 2005, Vogel Buchverlag, chapter 3 can be used in the calendering process.

The homogenized melt can comprise, in addition to the mineral binder component B, the thermoplastic polymer component P, and the tant component S l additives used in extrusion and calendering ses such as internal lubricants, slip agents, ock agents, denest aids, oxidative stabilizers, melt strength enhancers. The nized melt can also further comprise other additives such as UV- and heat stabilizers, plasticizers, foaming agents, dyes, nts, pigments, matting agents, antistatic , impact modifiers, and flame retardants.

According to one embodiment, the homogenized melt comprises, in addition to the mineral binder component B, the thermoplastic polymer component P and the surfactant component S at least one chemical or physical foaming agent and optionally at least one activator for the foaming agent. Examples of suitable chemical foaming agents include azodicarbonamide, azobisisobutyronitrile, benzenesulphonyl hydrazide, 4,4-oxybenzenesulphonyl semicarbazide, 4,4-oxybis(benzenesulphonyl hydrazide), diphenyl sulphone- sulphonyl hydrazide, p-toluenesulphonyl semicarbazide, sodium bicarbonate, ammonium carbonate, ammonium bicarbonate, potassium bicarbonate, diazoaminobenzene, diazoaminotoluene, hydrazodicarbonamide, diazoisobutyronitrile, barium azodicarboxylate and 5-hydroxytetrazole.

Preferably, the foaming agent is sodium bicarbonate.

It has also been found that subjecting the contact layer to a washing step before contacting it with a fresh cementitious composition has a positive effect on the concrete adhesion strength ally in case the amount of the surfactant component S in the contact layer is near the upper limit of the preferable range. Water can be used as a washing liquid in the washing step.

The method for producing a contact layer can r comprise subjecting the contact layer to a washing step.

W0 2017/108844 The method for producing a t layer can also comprise a post-treatment step such as brushing and/or sand blasting and/or plasma treatment, in particular air plasma treatment step, to optimize the surface properties of the produced contact layer. The final t is preferably stored in the form of rolls.

In another aspect of the present invention a method for binding two ates to each other is provided. The substrates can be any objects having a surface, which can be covered with a contact layer.

The method for binding two substrates to each other comprises steps of: a) applying a layer of first adhesive on the surface of a first substrate, b) covering the layer of the first adhesive with a contact layer according of the present invention such that a first e of the contact layer is brought in contact with the layer of the first adhesive, c) applying a layer of a second adhesive on the second opposite surface of the contact layer and ting the layer of the second adhesive with the surface of the second substrate or applying a layer of a second adhesive on a surface of the second substrate and contacting the layer of the second adhesive with the second opposite surface of the contact layer d) letting the layers of the first and second ves to harden.

The first and the second adhesives can be fresh cementitious compositions or tic resin compositions, such as epoxy based two-component adhesive or EVA-based adhesive, preferably fresh cementitious compositions.

Preferably, the first and second substrates consist of or comprise material selected from the group consisting of hardened cementitious compositions, wood, plywood, le board, gypsum board, metal, metal alloy, plastic, thermal insulation material, or a combination thereof.

W0 2017/108844 The substrates can consist of or comprise same material or different material.

Preferably, at least one of the ates consists of hardened concrete.

In another aspect of the present invention a method for waterproofing a substrate is provided. The substrate can be any structural or civil ering structure, which is to be sealed against moisture and water. The surface of the substrate can be orientated horizontally or not.

The method for waterproofing a substrate comprises steps of - applying a contact layer according to the present ion to a surface of a substrate such that a first surface of the contact layer is directed against the surface of the substrate, - casting a fresh cementitious composition on a second opposing surface of the contact layer, and - ing the fresh cementitious composition.

Preferably, the fresh cementitious ition is a fresh concrete ition.

The casted cementitious ition after ing can be part of a structure, in particular, an above-ground or underground structure, for example a building, garage, tunnel, landfill, water retention, pond, dike or an element for use in pre-fabricated uctions.

In another aspect of the present invention a waterproofed construction for waterproofing a ate against water penetration is provided. The waterproofed construction comprises a layer of concrete and a contact layer according to the present invention arranged between surface of a substrate and the layer of concrete such that the first surface of the contact layer is directed against the surface of the ate and the second surface of the contact layer is fully bonded to the surface of the layer of concrete.

The term "fully bonded" refers to two surfaces being adhesively joined over the full surface.

W0 2017/108844 The ate can be any structural or civil engineering structure, which is to be sealed against moisture and water, such as a ed concrete structure or a subsurface.

In another aspect of the present ion a method for sealing a substrate against water penetration is provided. The method for sealing a substrate against water penetration ses steps of - applying a layer of ve on the surface of the substrate, - covering the layer of the adhesive with a contact layer of the present invention such that one of the surfaces of the contact layer brought in contact with the layer of adhesive, and - hardening the layer of adhesive.

The adhesive can be a fresh cementitious composition or a synthetic resin based adhesive, such as epoxy based two-component adhesive or sed adhesive, preferably a fresh cementitious composition, particularly a fresh concrete or a fresh shotcrete composition.

The adhesive can be a fresh cementitious composition or a synthetic resin based adhesive such as epoxy based two-component adhesive or EVA-based adhesive, ably a fresh cementitious composition, particularly a fresh concrete or shotcrete composition.

According to one embodiment, the method for sealing a substrate t water penetration comprises steps of - applying a layer of adhesive on one of the surfaces of a contact layer of the t invention, - covering surface of the substrate with the contact layer such that the layer of adhesive is brought in contact with surface of the substrate, and - hardening the layer of adhesive.

W0 2017/108844 The ve can be a fresh cementitious composition or a synthetic resin based adhesive such as epoxy based two-component adhesive or EVA-based adhesive, preferably a fresh cementitious composition, particularly a fresh concrete or shotcrete composition.

In another aspect of the t ion a sealed construction for sealing a substrate against water penetration is provided. The sealed construction comprises a contact layer according to the present invention and a layer of adhesive ed between a surface of the substrate and the contact layer such that one of the surfaces of the contact layer is bonded to the surface of the substrate with the layer of adhesive.

The adhesive can be a fresh cementitious composition or a synthetic resin based adhesive such as epoxy based two-component ve or EVA-based adhesive, preferably a fresh cementitious composition, particularly a fresh concrete or shotcrete composition.

In another aspect of the present invention use of the contact layer ing to the t invention as a waterproofing membrane is provided.

W0 2017/108844 Examples The materials shown in Table 1 were used in the experiments.

Table 1. Materials used in the experiments E-Modulus Polymers [Mpfl EVA copolymer with 28 wt.- Elvax® 265A DuPont 19 % vinyl acetate EVA copolymer with 40 wt.- Levapreen® 400 Lanxess 4.5 % Vinyl acetate. ne-propylene copolymer with ca. 20 wt.- Hifax® CA 212 Basell % ethylene Ethylene-propylene copolymer with 16 wt.-% Vistamaxx® 6202 Exxon Mobil 10 ethylene CEM | /42,5 cement Normo‘3 4 LafargeHolcim_ Glycerol monostearate Dimodant3 HP —_ Polyether—modified Tegostab® B8870 Evonik_ polysnloxan.

Anionic compound. . LOXIOl. ® Emew emlcals_ Ionic nd Zetaspheree’ 3700 AirProducts _ Poly carboxylate ether Viscocrete‘" PC-2—_ EVA, ethylene vinyl acetate copolymer ° E-modulus measured ing to ISO 527-3 standard at a temperature of 23 °C W0 2017/108844 For the measurement of the average peel resistances, each contact layer was bonded to a thermoplastic barrier layer to obtain an example ne, which could be used in the peel resistance test.

Preparation of the test membranes For each example membrane (EX1-EX16), a contact layer (E) was first produced by hot-pressing from a homogenized melt comprising the components of the respective contact layer.

The homogeneous melt of the contact layer was obtained by melt- homogenizing a composition comprising the components of the contact layer on a two-roll mill (from h Engineering). The melt-homogenizing was ted at a temperature, which is approximately 30 °C above the melting temperature of the polymer component. Sheets with a ess of approximately 1mm were subsequently pressed from the homogeneous melt using a hot press. The temperature of the al during pressing was kept approximately 30°C above the melting temperature of the polymer component.

Finally, the example membranes were produced by laminating each contact layer onto a polyethylene-based barrier layer (WP 1210-06 —H ble from Sika) in a hot press.

The compositions and Young’s modulus measured at a temperature of 23 °C of the contact layers (E) for the example membranes EX1-EX16 are presented in Tables 2 and 3.

Preparation of the test concrete specimen Three sample membranes with a dimension of 159 mm (length) x 39 mm (width) were cut from each of the example membranes 16 produced as W0 2017/108844 described above. The sample membranes were placed into formworks having a dimension of 160 mm (length) x 45 mm (width) X 30 mm (height) with the contact layer facing s and the thermoplastic barrier layer against the bottom of the formwork.

One edge of each sample membrane on the side of the contact layer was covered with an adhesive tape having a length of 50 mm and width coinciding with the width of the membrane sample to prevent the adhesion to the hardened concrete. The adhesive tapes were used to provide easier lation of the test specimens to the peel resistance testing tus.

For the ation of concrete test specimens a batch of fresh concrete formulation was ed. The fresh concrete formulation was obtained by blending 46.3 wt.-% sand having a particle size of 0-1mm, 7.1 wt.-% Nekafill-15 (from KFN) (limestone filler), 32.1 wt.-% CEM I 42.5 N cement m Normo 4), 14.3 wt.-% water and 0.2 wt.-% rete® PC 2 solution. The dry components were mixed and homogenized for 2 minutes in a tumbling mixer.

After adding water and Viscocrete® solution the concrete mixture was homogenized for 5 minutes in a cement mixer.

The formworks containing the sample membranes were subsequently filled with the fresh te formulation and vibrated for 30 seconds to release the entrapped air. After hardening for one day the test concrete specimens were stripped from the formworks and stored at humid atmosphere (temperature 23°C, relative air humidity 100 %) before measuring the peel resistances.

Measurement of peel resistances The measurement for peel resistances of sample membranes from ed concrete specimen was conducted in accordance with the procedure laid out in the standard DIN EN 1372:2015-06. A peel resistance testing apparatus fulfilling the requirements of the DIN EN 1372:2015 standard was used for conducting the peel resistance measurements.

For the peel resistance measurements, a concrete specimen was clamped with the upper grip of the material testing tus for a length of 10 mm at the end of the concrete en sing the taped section of the sample membrane. Following, the sample membrane was peeled off from the surface of the concrete specimen at a peeling angle of 90 ° and at a constant cross beam speed of 100 mm/min. The peeling of the sample membrane was continued until the entire sample membrane was peeled off from the surface of the concrete specimen. The values for peel resistance were calculated as average peel force [N/ 50 mm] during peeling over a length of approximately 70 mm thus excluding the first and last quarter of the total peeling length from the calculation.

The e peel resistance values for example membranes EX1-EX16 presented in Tables 2 and 3 have been calculated as an average of measured values obtained with three sample membranes cut from the same e membrane. mocmbEmE “we“ Lou, $8928; ©9338 89:2 69:8 HHEHHHHHE IIIIIIII HH HHHHHHII HHHHHHHH llllllll IHHIIHIH 20368800 30.3 Ea 3o- .3; Emcanoo $.33 3:er $.31: $3 N v o: 35; on Eeoeza .N 9502 EEOQZH 18 052. 22358222. ggzgigm @593 $.92; Eagesgsgs E66: “capomtsw c8055 _o_xo._ @9835 9% 9:8 m5 N mm 8 wxméxm. 398289: Lou, $8928; 859mm,: 89:2 69:8 IIII 20368800 EEOQE Egg 032. 9% £8 WO 08844

Claims (5)

Claims 1.

1. A contact layer comprising a mineral binder component B, a 5 thermoplastic polymer component P and a surfactant component S, wherein the amount of the l binder component B is 10.0 — 90.0 wt.-%, preferably 20.0 — 85.0 wt.-%, more preferably 25.0 — 80.0 wt.-%, most preferably 30.0 — 75.0 wt.-%, based on the total weight of the contact layer.

2. The contact layer according to claim 1 comprising not more than 3.0 wt.- %, preferably not more than 1.5 wt.—%, more preferably not more than 1.0 wt.-%, most preferably less than 0.5 wt.-% of hydrated mineral binders, based on the total weight of the contact layer.

3. The contact layer ing to claim 1 or 2, wherein the contact layer has concrete a adhesion strength, determined by means of the method cited in the description, of at least 5 N150 mm, more preferably of at least 10 N/50 mm, even more preferably of at least 15 N/50 mm, most 20 preferably of at least 20 N/50 mm.

4. The contact layer ing to any of previous claims, wherein the mineral binder component B comprises at least one mineral binder selected from the group consisting of hydraulic binders, non-hydraulic 25 binders, latent hydraulic binders, and pozzolanic binders, and mixtures thereof.

5. The t layer ing to any of previous claims, wherein the surfactant component S comprises at least one tant selected from 30 the group consisting of c, cationic, non-ionic, amphoteric, and polymeric surfactants, and mixtures thereof. W0