Composition for liquid sealing system comprising a rubber and an anionic copolymer

Abstract

The present invention relates to a composition for sealing various substrates such as substrates made of cementitious material. It also relates to a sealing coating, in particular a watertight coating, formed from such a composition. It further relates to a method of sealing a substrate via the formation of such a coating.

Description

Title of the invention: Composition for a liquid sealing system comprising a rubber and an anionic copolymer

[0001] The present invention relates to a composition for sealing various substrates such as substrates made of cementitious material. It also relates to a kit comprising such a composition. It also relates to a sealing coating, in particular a watertight coating, formed from such a composition. It further relates to a method of sealing a substrate via the formation of such a coating.

[0002] The waterproofing of roofs, terraces, balconies, wet rooms, swimming pools, or facades is essential to ensure the durability of buildings.

[0003] To achieve this, numerous waterproofing systems have been developed. These include bituminous membranes and thermoplastic or vulcanized synthetic membranes which are assembled by welding, hot-poured asphalt coatings or even systems known in the art as "liquid waterproofing systems" (LWS).

[0004] These are made of polymer resin-based materials implemented in one or more layers by projection or by application with a roller, brush or squeegee. Different types of resins are used, in particular polyesters, acrylics, neoprene bitumens, or polyurethane resins. Very durable and easy to apply, these systems generally allow pedestrian traffic directly after drying, eliminating the need for heavy protection.

[0005] The invention aims to propose new sealing coatings which are as efficient, from the point of view of sealing, as the systems known to date, but which also exhibit rapid coagulation, good adhesion to the substrate, good flexibility and good resistance to aging. Summary of the invention

[0006] To this end, the present invention relates to a composition for a liquid sealing system comprising, in dispersion in an aqueous phase:

[0007] - PI particles of natural or synthetic rubber; and

[0008] - particles P2 of a copolymer comprising 0.001 to 15% by weight of units re reactive compounds containing an anionic group and having a Tg less than or equal to 35°C.

[0009] In certain embodiments, the copolymer of the particles P2 comprises:

[0010] - repeating units U1 chosen from styrene and a rigid (meth)acrylate;

[0011] - repeating units U2 chosen from butadiene, chloroprene, isoprene, acrylonitrile, and a flexible (meth)acrylate; and

[0012] - 0.001 to 15% by weight of repeating units containing an anionic group.

[0013] In some embodiments, the copolymer of the particles P2 is a co styrene-butadiene polymer comprising 0.001 to 15% by weight of repeating units containing an anionic group.

[0014] In certain embodiments, the copolymer of the particles P2 comprises:

[0015] - repeating units U1 chosen from a rigid (meth)acrylate;

[0016] - repeating units U2 chosen from acrylonitrile and a flexible (meth)acrylate; And

[0017] - 0.001 to 15% by weight of repeating units containing an anionic group.

[0018] In certain embodiments, the total weight content of units U1 and U2 is from 85 to 99.999%, preferably from 90 to 99.99%, or even from 93 to 99.95%, or even 95 to 99.9%, for example from 97 to 99.5%.

[0019] In certain embodiments, the mass ratio of unit U1 to unit U2 is from 0.1 to 10, preferably 0.1 to 5, more preferably from 0.2 to 2, or even from 0.2 to 0.5.

[0020] In some embodiments, the anionic group is a carboxylate group -COO, a phosphate group -O-PO(O)2, or a sulfonate group -S(O)2O, preferably a carboxylate group -COO.

[0021] In some embodiments, the repeating units containing an anionic group are selected from a salt of acrylic acid, methacrylic acid, itaconic acid, fumaric acid, 2-hydroxyethyl methacrylate phosphoric acid, and 2-acrylamido-2-methyl-propanesulfonic acid.

[0022] In some embodiments, the PI particles are natural rubber particles.

[0023] In certain embodiments, the copolymer of the particles P2 comprises from 0.01 to 10% by weight, preferably from 0.05 to 7% by weight, or even 0.1 to 5% by weight, or even from 0.5 to 3% by weight of repeating units containing an anionic group.

[0024] In certain embodiments, the weight content of the particles P2 is from 20 to 95%, preferably from 30 to 90%, or even from 40 to 80%, or even from 50 to 70%, relative to the total weight of particles PI and P2.

[0025] In certain embodiments, the total weight content of particles PI and P2 is from 10 to 60%, preferably from 15 to 50%, or even from 20 to 40%, or even from 25 to 35%, relative to the total weight of the composition.

[0026] In certain embodiments, the composition according to the invention further comprises anionic surfactants, preferably in a weight content of 0.001 to 1% relative to the total weight of particles PI and P2.

[0027] In certain embodiments, the composition according to the invention further comprises fillers, preferably in a weight content of 5 to 70% relative to the total weight of the composition.

[0028] The present invention also relates to a kit comprising:

[0029] - a composition as defined in the present application, and

[0030] - a coagulating composition.

[0031] The present invention also relates to a sealing coating formed from a composition as defined in the present application.

[0032] Another object of the present invention is a method of sealing a substrate, preferably a substrate made of cementitious material, comprising:

[0033] a) applying a sealing composition as defined in the present application to said substrate, to form a layer of sealing composition and

[0034] b) coagulating said layer of sealing composition, preferably by contacting said layer of sealing composition with a coagulating composition, to form a sealing coating.

[0035] Another object of the present invention is a method of sealing a substrate, preferably a substrate made of cementitious material, comprising:

[0036] a2) applying a coagulating composition to said substrate, to form a primer coat, and

[0037] b2) the application of a sealing composition as defined in the present application, on the primer layer, to form a waterproof coating.

[0038] Another object of the present invention is the use of a waterproofing coating as defined in the present application, as a waterproofing coating.

[0039] The inventors have in fact demonstrated that, surprisingly, the combination of an aqueous dispersion based on natural or synthetic rubber particles and an aqueous dispersion based on particles of a copolymer having a low - but not zero - content of anionic groups and a low glass transition temperature led to a stable composition making it possible to form a waterproof coating having one or more of the aforementioned advantages. It has also been shown that the formation of the coating could be significantly accelerated by bringing the composition into contact with a coagulating agent. DETAILED DESCRIPTION

[0040] The composition (or “sealing composition”) according to the invention is an aqueous dispersion suitable for sealing (in particular, against water) a substrate, in particular a substrate made of cementitious material.

[0041] The composition according to the invention comprises:

[0042] - “PI” particles, which are particles of natural or synthetic rubber, And

[0043] - “P2” particles, which are particles of a copolymer comprising 0.001 to 15% by weight of repeating units containing an anionic group and having a Tg less than or equal to 35°C.

[0044] It is understood that the particles PI and P2 of the composition are different.

[0045] Unless otherwise stated, the weight content of a given repeating unit in a polymer corresponds to the weight quantity of the corresponding monomer used to form said polymer expressed relative to the total weight quantity of the monomers used to form said polymer. For example, a polymer formed from 38% by weight of butadiene, 58% by weight of styrene and 4% by weight of acrylate (38% + 58% + 4% = 100%) has a weight content of acrylate repeating units of 4%.

[0046] Unless otherwise stated, the weight content of a constituent (e.g. PI particles, P2 particles, etc.) corresponds to the weight of the constituent relative to the total weight of the composition. The weight of the constituent corresponds to the weight of the constituent itself, and therefore, to its weight in dry extract when it is used in particular in diluted form in a dispersion or solution. PI particles

[0047] In some embodiments, the PI particles are natural rubber particles.

[0048] So-called "natural" rubber is a raw material well known to those skilled in the art. It can be obtained from the latex of various plants, in particular the rubber tree. Natural rubber comprises cis-1,4-polyisoprene as well as a membrane based on proteins and phospholipids. The natural rubber used in the present invention may be a proteinized natural rubber (i.e. "non-deproteinized", i.e. which retains said membrane based on proteins and phospholipids) or a low-proteinized natural rubber. Preferably, the natural rubber is a non-deproteinized natural rubber. In particular, the protein level in natural rubber, generally measured according to the ASTM D 5712-15 standard, may be at least 10 ppm by weight.

[0049] The natural rubber used in the present invention is generally in the form of an aqueous dispersion. The solids content by weight of such an aqueous dispersion is generally between 20% and 80%, for example between 30% and 75%, or even between 50% and 70%, relative to the total weight of the aqueous dispersion.

[0050] In some embodiments, the PI particles are synthetic rubber particles.

[0051] Synthetic rubber is advantageously:

[0052] - a homopolymer of butadiene, chloroprene or isoprene,

[0053] - a copolymer comprising at least 60% by weight, preferably at least 70% by weight, better still at least 80% by weight, or even at least 90% by weight of one or more repeating units chosen from a butadiene unit, a chloroprene unit, and an isoprene unit, or

[0054] - a mixture of these.

[0055] When it is such a copolymer, the synthetic rubber may further comprise repeating units such as styrene units or acrylonitrile units.

[0056] More particularly, the synthetic rubber may be a polychloroprene rubber, a polyisoprene rubber, a polybutadiene rubber, a styrene-butadiene rubber, an acrylonitrile-butadiene rubber or a mixture thereof.

[0057] Preferably, the synthetic rubber does not comprise repeating units containing an anionic chemical group (such as a carboxylate group COO , a phosphate group -O-PO(O )2 , or a sulfonate group -S(O)2O ).

[0058] In particular, the synthetic rubber is not a copolymer comprising 0.001 to 15% by weight of repeating units containing an anionic group and having a Tg of less than or equal to 35°C.

[0059] Preferably, the PI particles are natural rubber particles.

[0060] Advantageously, the rubber of the PI particles has a transition temperature vitreous (Tg) less than or equal to 35°C, or even less than or equal to 30°C, or even less than or equal to 20°C, for example less than or equal to 10°C. For example, the Tg of the rubber of the PI particles can be -70°C to 35°C, -60°C to 35°C, -50°C to 30°C, -50°C to 25°C, -50°C to 20°C, -50 to 10°C, -30°C to 30°C, -25°C to 25°C, or -15°C to 20°C.

[0061] The glass transition temperature can be measured by differential scanning calorimetry (DSC).

[0062] Advantageously, the rubber of the PI particles has a minimum film forming temperature (MFFT) less than or equal to 30°C, or even less than or equal to 20°C, or even less than or equal to 10°C, for example less than or equal to 0°C. The MFFT is determined according to the standards ASTM D 2354 and ISO 2115. The MFFT is given here for atmospheric pressure (i.e. 1 bar). P2 particles

[0063] The “P2” particles are particles of a copolymer comprising 0.001 to 15% by weight of repeating units containing an anionic group and having a Tg of less than or equal to 35°C.

[0064] The glass transition temperature (Tg) of the copolymer of the particles P2 is advantageously less than or equal to 30°C, or even less than 25°C.

[0065] For example, the Tg of the copolymer of the particles P2 may be from -70°C to 35°C, from - 60°C to 35°C, -50°C to 30°C, -50°C to 25°C, -50°C to 20°C, -50 to 10°C, -30°C to 30°C, -25°C to 25°C, or -15°C to 20°C.

[0066] Advantageously, the copolymer of the particles P2 has a minimum film formation temperature (MFFT) less than or equal to 30°C, or even less than or equal to 20°C, or even less than or equal to 10°C, for example less than or equal to 0°C. The MFFT is determined according to the standards ASTM D 2354 and ISO 2115. The MFFT is given here for atmospheric pressure (i.e. 1 bar).

[0067] Typically, the anionic group is a carboxylate group COO, a phosphate group -O-PO(O)2, or a sulfonate group -S(O)2O. Preferably, the anionic group is a carboxylate group COO.

[0068] It is understood that, in order to respect chemical neutrality, said anionic group is necessarily associated with one (or more) counter-ions, that is to say a cation, which may for example be a monovalent cation such as an alkali metal (eg sodium, potassium) or an ammonium, or a divalent cation such as an alkaline-earth metal (eg calcium, magnesium).

[0069] In other words:

[0070] - the carboxylate group can be written: -COO, M+ or -COO, 1 / 2M2+,

[0071] - the sulfonate group can be written: -S(O)2O , M+ or -S(O)2O , 1 / 2M2+,

[0072] - the phosphate group can be written: -O-PO(O )2, 2M+ or -O-PO(O )2, M2+,

[0073] where, in the above formulas:

[0074] M+ is a monovalent cation such as an alkali metal (eg sodium, potassium) or an ammonium,

[0075] M2+ is a divalent cation such as an alkaline earth metal (eg calcium, magnesium).

[0076] The repeating units containing an anionic group are advantageously chosen from a salt of acrylic acid, methacrylic acid, itaconic acid, fumaric acid, 2-hydroxyethyl methacrylate phosphoric acid, and 2-acrylamido-2-methyl-propanesulfonic acid.

[0077] Preferably, the repeating units containing an anionic group are salts of acrylic acid, typically sodium acrylate.

[0078] Advantageously, the weight content of repeating units containing an anionic group is from 0.01 to 10%, preferably 0.05 to 7%, or even from 0.1 to 5%, for example from 0.5 to 3%.

[0079] By “copolymer” is meant a polymer resulting from the polymerization of at least two different monomers, for example two or three different monomers.

[0080] By “terpolymer” is meant a copolymer resulting from the polymerization of three different monomers.

[0081] In some embodiments, the copolymer is a terpolymer.

[0082] The copolymer of the particles P2 may comprise (or even be made up of):

[0083] - repeating units U1 chosen from styrene and a rigid (meth)acrylate,

[0084] - repeating units U2 chosen from butadiene, chloroprene, isoprene, acrylonitrile, and a flexible (meth)acrylate, and

[0085] - 0.001 to 15% by weight (preferably 0.01 to 10% by weight, or even 0.05 to 7% by weight, or even from 0.1 to 5% by weight, for example from 0.5 to 3% by weight) of repeating units containing an anionic group.

[0086] In such a copolymer, the total weight content of units U1 and U2 is advantageously from 85 to 99.999% (preferably from 90 to 99.99%, or even from 93 to 99.95%, or even 95 to 99.9%, for example from 97 to 99.5%).

[0087] In such a copolymer, the mass ratio of the unit U1 to the unit U2 is advantageously from 0.1 to 10, preferably 0.1 to 5, better still from 0.2 to 2, or even from 0.2 to 0.5.

[0088] In the present application, the expression "(meth)acrylate" encompasses acrylate and methacrylate.

[0089] In the present application, the term "rigid (meth)acrylate" means a (meth)acrylate monomer whose homopolymer (having a weight-average molecular mass typically of 2000 to 500,000 g / mol, in particular approximately 100,000 g / mol, and a polydispersity index of 0.5 to 2.5, in particular approximately 1) has a glass transition temperature greater than or equal to 25°C, typically greater than 30°C, or even greater than 35°C or even greater than 50°C, or even greater than 100°C. Preferably, said rigid (meth)acrylate is isobornyl acrylate, methyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, or ethyl methacrylate.

[0090] Weight average molecular weight and polydispersity index are generally measured by light scattering.

[0091] In the present application, the term "soft (meth)acrylate" means a (meth)acrylate monomer whose homopolymer (having a weight-average molecular mass typically of 2000 to 500,000 g / mol, in particular approximately 100,000 g / mol, and a polydispersity index of 0.5 to 2.5, in particular approximately 1) has a glass transition temperature of less than 25°C, typically less than 20°C, or even less than 5°C. Preferably, said soft (meth)acrylate is butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate or butyl methacrylate.

[0092] Preferably, the copolymer of the particles P2 is a styrene-butadiene copolymer comprising 0.001 to 15% by weight (preferably, from 0.01 to 10% by weight, or even from 0.05 to 7% by weight, or even from 0.1 to 5% by weight, for example from 0.5 to 3% by weight) of repeating units containing an anionic group.

[0093] In such a copolymer, the total weight content of styrene and butadiene units is advantageously from 85 to 99.999% (preferably from 90 to 99.99%, or even from 93 to 99.95%, or even 95 to 99.9%, for example from 97 to 99.5%).

[0094] In such a copolymer, the mass ratio of the styrene unit to the butadiene unit is advantageously from 0.1 to 10, preferably 0.1 to 5, better still from 0.2 to 2, or even from 0.2 to 0.5.

[0095] The copolymer of the particles P2 may comprise (or even be made up of):

[0096] - repeating units U1 chosen from a rigid (meth)acrylate (preferably, isobornyl acrylate, methyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, or ethyl methacrylate);

[0097] - repeating units U2 chosen from acrylonitrile and a flexible (meth)acrylate (preferably from butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate or butyl methacrylate), and

[0098] - 0.001 to 15% by weight (preferably from 0.01 to 10% by weight, or even from 0.05 to 7% by weight, or even from 0.1 to 5% by weight, for example from 0.5 to 3% by weight) of repeating units containing an anionic group.

[0099] In such a copolymer, the total weight content of units U1 and U2 is advantageously from 85 to 99.999% (preferably from 90 to 99.99%, or even from 93 to 99.95%, or even 95 to 99.9%, for example from 97 to 99.5%).

[0100] In such a copolymer, the mass ratio of the unit U1 to the unit U2 is advantageously from 0.1 to 10, preferably 0.1 to 5, better still from 0.2 to 2, or even from 0.2 to 0.5.

[0101] In a preferred embodiment:

[0102] - PI particles are natural rubber particles and

[0103] - the particles P2 are particles of a styrene-butadiene copolymer comprising 0.001 to 15% by weight (preferably 0.01 to 10% by weight, more preferably 0.05 to 7% by weight, or even 0.1 to 5% by weight, or even 0.5 to 3% by weight) of repeating units containing an anionic group, preferably a coo group.

[0104] In such a copolymer, the total weight content of styrene and butadiene units is advantageously from 85 to 99.999% (preferably from 90 to 99.99%, or even from 93 to 99.95%, or even 95 to 99.9%, for example from 97 to 99.5%).

[0105] In such a copolymer, the mass ratio of the styrene unit to the butadiene unit is advantageously from 0.1 to 10, preferably 0.1 to 5, better still from 0.2 to 2, or even from 0.2 to 0.5.

[0106] In such a copolymer, the repeating units containing an anionic group are typically an acrylate salt.

[0107] In another preferred embodiment:

[0108] - PI particles are natural rubber particles and

[0109] - the particles P2 are particles of a copolymer comprising (or even, consisting of):

[0110] - repeating units U1 chosen from isocarboxylic acid acrylate, methacrylate methyl, isobutyl methacrylate, isobutyl methacrylate, and ethyl methacrylate;

[0111] - repeating units U2 chosen from butyl acrylate, acrylate of 2-ethylhexyl, ethyl acrylate and butyl methacrylate, and

[0112] - 0.001 to 15% by weight (preferably 0.01 to 10% by weight, more preferably 0.05 to 7% by weight, or even from 0.1 to 5% by weight, or even from 0.5 to 3% by weight) of repeating units containing an anionic group, preferably a COO group.

[0113] In such a copolymer, the total weight content of units U1 and U2 is advantageously from 85 to 99.999% (preferably from 90 to 99.99%, or even from 93 to 99.95%, or even 95 to 99.9%, for example from 97 to 99.5%).

[0114] In such a copolymer, the mass ratio of the unit U1 to the unit U2 is advantageously from 0.1 to 10, preferably 0.1 to 5, better still from 0.2 to 2, or even from 0.2 to 0.5.

[0115] In such a copolymer, the repeating units containing an anionic group are typically an acrylate salt.

[0116] In certain embodiments, the particles P2 are a mixture of:

[0117] - particles P2a of a first copolymer comprising 0.001 to 15% by weight of units repeating containing an anionic group and having a Tg less than or equal to 35°C, as defined above, and

[0118] - P2b particles of a second copolymer comprising 0.001 to 15% by weight of repeating units containing an anionic group and having a Tg less than or equal to 35°C, as defined above,

[0119] the first copolymer and the second copolymer being different from each other.

[0120] In a preferred embodiment, the particles P2 are a mixture of:

[0121] - particles P2a of a styrene-butadiene copolymer comprising 0.001 to 15% in weight (preferably 0.01 to 10% by weight, more preferably 0.05 to 7% by weight, or even 0.1 to 5% by weight, or even 0.5 to 3% by weight) of repeating units containing an anionic group, preferably a COO group; and

[0122] - P2b particles of a copolymer comprising (or even consisting of) units repeating units U1 selected from isobutyl acrylate, methyl methacrylate, isobutyl methacrylate, and ethyl methacrylate, repeating units U2 selected from butyl acrylate, 2-ethylhexyl acrylate, ethyl acrylate, and butyl methacrylate, and 0.001 to 15% by weight (preferably 0.01 to 10% by weight, more preferably 0.05 to 7% by weight, or even 0.1 to 5% by weight, or even 0.5 to 3% by weight) of repeating units containing a group anionic, preferably a COO group.

[0123] In the copolymer of the particles P2a, the total weight content of styrene and butadiene units is advantageously from 85 to 99.999% (preferably from 90 to 99.99%, or even from 93 to 99.95%, or even 95 to 99.9%, for example from 97 to 99.5%).

[0124] In the copolymer of the particles P2a, the mass ratio of the styrene unit to the butadiene unit is advantageously from 0.1 to 10, preferably 0.1 to 5, better still from 0.2 to 2, or even from 0.2 to 0.5. In the copolymer of the particles P2b, the total weight content of units U1 and U2 is advantageously from 85 to 99.999% (preferably from 90 to 99.99%, or even from 93 to 99.95%, or even 95 to 99.9%, for example from 97 to 99.5%).

[0125] In the copolymer of the particles P2b, the mass ratio of the unit U1 to the unit U2 is advantageously from 0.1 to 10, preferably 0.1 to 5, better still from 0.2 to 2, or even from 0.2 to 0.5.

[0126] In the copolymer of particles P2a and P2b, the repeating units containing an anionic group are typically an acrylate salt.

[0127] Advantageously, the weight content (in dry weight) of the particles P2a is from 5 to 99%, preferably from 20 to 95%, or even from 50 to 90%, relative to the total weight (dry) of particles P2a and P2b.

[0128] Advantageously, the weight content (in dry weight) of the particles P2 is from 20 to 95%, preferably from 30 to 90%, or even from 40 to 80%, or even from 50 to 70% relative to the total weight (dry) of particles PI and P2.

[0129] Advantageously, the total weight content of particles PI and P2 is from 10 to 60%, preferably from 15 to 50%, or even from 20 to 40%, or even from 25 to 35%, relative to the total weight of the composition.

[0130] In general, the particles PI and the particles P2 have, independently, a volume size distribution such that the d50 is between 50 and 800 nm, in particular between 80 and 500 nm, or even between 100 and 250 nm. The particle size distribution is in particular determined by dynamic light diffraction.

[0131] The composition according to the invention may further comprise:

[0132] - a cationic polyelectrolyte,

[0133] - an anionic polyelectrolyte,

[0134] - optionally a water-soluble polyphenol, and

[0135] - optionally a mineral salt chosen from alkali metal halides or alkaline earth.

[0136] When present, the amount of mineral salt selected from the group consisting of alkali or alkaline earth metal halides is typically between 40% and 95% by weight, preferably between 55% and 75% by weight, relative to the total dry weight of cationic polyelectrolyte, anionic polyelectrolyte and said mineral salt.

[0137] When present, the cationic and anionic polyelectrolytes together represent, by weight, from 0.01 to 10%, preferably from 0.1 to 5%, better still from 0.5 to 2%, relative to the total weight of the composition.

[0138] When present, the cationic and anionic polyelectrolytes are advantageously in similar amounts, "similar amounts" meaning here that these two types of polyelectrolytes of opposite charges are used in respective amounts such that the ratio of the number of positive charges of the cationic polyelectrolyte to the number of negative charges of the anionic polyelectrolyte is between 0.5 and 2.0, preferably between 0.6 and 1.8, more preferably between 0.7 and 1.6 and even more preferably between 0.8 and 1.4, or even between 0.9 and 1.2.

[0139] The polyelectrolytes may be strong or weak polyelectrolytes. A strong polyelectrolyte is a polymer whose net charge, positive or negative, is essentially independent of the pH of the composition. In particular, the zeta potential of a strong cationic polyelectrolyte is positive for any pH in the range from 1 to 14 and the zeta potential of a strong anionic polyelectrolyte is negative for any pH in the range from 1 to 14. The potential may be measured using a zeta potential analyzer (e.g., a “zetasizer” device) at a suitable concentration (generally greater than 0.01%, for example, 1% by weight of polyelectrolyte relative to the volume of solution analyzed) and generally at 20°C.

[0140] In the present application, an anionic polyelectrolyte is a polymer having, at pH 7, a negative net charge and a cationic polyelectrolyte is a polymer having, at pH 7, a positive net charge. This does not mean that an anionic polyelectrolyte comprises only negative charges and is free of positive charges. By analogy, cationic polyelectrolytes can carry both positive and negative charges as long as at pH 7 the overall net charge is positive.

[0141] Therefore, the definition of anionic polyelectrolytes encompasses zwitterionic polyelectrolytes having an isoelectric point (pI) < 7, preferably < 6, and the definition of cationic polyelectrolytes encompasses zwitterionic polyelectrolytes having an isoelectric point > 7, preferably > 8. The most well-known zwitterionic polyelectrolytes are proteins or polypeptides comprising both carboxylate (-COO-) side groups and amino (-NH2) side groups.

[0142] The cationic polyelectrolyte is preferably chosen from the group consisting of: - poly(diallyldimethylammonium chloride), - poly [(2-hydroxypropyl)dimethylammonium chloride], - polyamidoamine-epichlorohydrin (PAAE), - polyethyleneimine, - poly(acrylamide-co-diallyldimethylammonium chloride), - copolymer of hydroxyethylcellulose and poly(diallyldimethylammonium chloride) (Polyquaternium-4), - copolymer of acrylamide and dimethylaminoethyl methacrylate quaternized with dimethyl sulfate (Polyquaternium-5, CAS 26006-22-4), - copolymer of dimethylaminomethyl methacrylate and alkyl methacrylate, - chitosan, - poly(quaternized N,N-(dimethylamino)ethyl methacrylate), - guar hydroxypropyltrimonium chloride, - poly(N,N-dimethyl-3,5-dimethylene piperidinium chloride), - poly(vinylbenzyltrimethylammonium chloride), - poly[3-(methacryloylamino)propyl-trimethylammonium chloride], - poly([2-(methacryloloxy)ethyl]-trimethylammonium chloride), - polyvinylamine (PVA), - poly(N,N-dimethyl-3,5-dimethylene piperidinium chloride) (PDDPC), - poly(vinylbenzyltrimethylammonium chloride) (PVBTAC), - poly(allylamine chloride) (PAH), and - poly[3-(methacryloylamino)propyltrimethylammonium chloride] (PMAPTAC), - cationic dextran.

[0143] The anionic polyelectrolyte is preferably selected from the group consisting of poly(acrylic acid), poly(acrylic acid-co-acrylamido), poly(sodium 4-styrenesulfonate), lignosulfonate, sodium humate, alginate, poly(sodium 2-acrylamido-2-methyl-l-propanesulfonate), hyaluronic acid, dextran sulfate and poly(sodium vinylsulfonate).

[0144] Preferably, the anionic and cationic polyelectrolytes have a weight average molecular mass (determined by light scattering) of between 1,000 and 2,000,000, preferably between 50,000 and 700,000 Da, in particular between 100,000 and 400,000 Da.

[0145] The term polyphenol designates an organic compound comprising at least one polyhydroxylated aromatic ring, i.e. carrying at least two hydroxyl groups (-OH) on the same cyclic structure. A water-soluble polyphenol is a polyphenol having a solubility in distilled water at 20°C of at least 100 g / L. Preferably, at least a portion of the polyphenols used comprise at least two, preferably at least three and more preferably at least four polyhydroxylated aromatic rings. The polyhydroxylated aromatic rings are preferably chosen from the group consisting of catechol, pyrogallol and tetrahydroxylated or pentahydroxylated aromatic rings.

[0146] Preferably, the polyphenol is tannic acid (CAS No. 1401-55-4).

[0147] The mass ratio (based on dry extract weights) of the cationic polyelectrolyte to the water-soluble polyphenol(s) is advantageously between 10 and 1000, preferably between 50 and 200.

[0148] The polyphenol is advantageously used in combination with a water-soluble salt of a transition metal, in particular a salt of iron (Fe), zinc (Zn), cobalt (Co), copper (Cu) and vanadium (V). Halides, in particular chlorides and bromides, are preferred anions of the transition metal salts used, in combination with the polyphenols, to reinforce the polyelectrolyte complexes. The water-soluble transition metal salt is preferably present in a total amount of between 0.0001 and 0.01%, preferably between 0.001 and 0.005%, these percentages by weight being expressed relative to the total weight of the composition. When present, the weight ratio of the transition metal salt to the polyphenol(s) is typically between 0.1 and 0.2, preferably between 0.12 and 0.18.

[0149] In certain embodiments, the composition according to the invention does not comprise a cationic polyelectrolyte and anionic polyelectrolyte.

[0150] Advantageously, the composition according to the invention further comprises one or more anionic surfactants.

[0151] Anionic surfactants are in particular carboxylates or sulfonates. Carboxylates are for example salts of saturated or unsaturated fatty acids such as stearates, oleates and laurates, rosin salts such as for example potassium oleate. Sulfonates are for example alkyl sulfonates (in particular C6-C9 alkyl sulfonates), aryl sulfonates, alkyl aryl sulfonates or sulfonated esters such as for example sodium dodecyl sulfate (SDS).

[0152] The weight content of anionic surfactants is preferably from 0.001 to 10%, in particular from 0.01 to 5%, or even from 0.05 to 2%, or even from 0.05 to 1% (for example from 0.001 to 1%) relative to the total weight of particles PI and P2.

[0153] Preferably, the composition according to the invention does not comprise non-ionic surfactants or cationic surfactants.

[0154] The composition according to the invention may further comprise one or more fillers.

[0155] The fillers are typically of a mineral nature. The fillers are preferably selected from calcium carbonate, calcium stearate, clays, talc, dolomite, mica, silica sands, ground basalt, barium sulfate, kaolin, wollastonite and laponite, and mixtures of two or more of these compounds. The fillers generally have a particle size ranging from 0.5 to 500 pm, especially from 1 to 200 pm, as measured by laser granulometry.

[0156] The weight content of fillers is preferably from 5 to 70%, for example from 10 to 60%, in particular from 15 to 50%, or even from 20 to 50%, relative to the total weight of the composition.

[0157] The composition may further comprise one or more pigments.

[0158] The pigments are preferably chosen from inorganic pigments (for example titanium dioxide or iron oxide), organic pigments (for example carbon black), and mixtures thereof.

[0159] The weight content of pigments is preferably from 0.1 to 20%, in particular from 0.2 to 10%, or even from 0.3 to 2%, relative to the total weight of the composition.

[0160] The composition may further comprise one or more additives, in particular chosen from:

[0161] - anti-foaming agents (for example of the silicone, fluoro-silicone, oil type mineral, acrylic, vinyl polymers),

[0162] - pH buffers,

[0163] - thickening agents (for example, cellulose-based derivatives),

[0164] - anti-sagging agents,

[0165] - coalescing agents (for example of the glycol type such as propylene glycol or diethylene glycol, glycol ethers such as dipropylene glycol n-butyl ether or propylene glycol methyl ether acetate, alcohol esters such as 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, pyrrolidone such as N-methyl-2-pyrrolidone or N-butyl-2-pyrrolidone),

[0166] - rheological agents (for example of the polyurethane / polyurea, polyacrylic type, polyamide, based on castor oil, or based on clays or cellulose ether),

[0167] - dispersing agents (for example of the silicone, polyacrylate, polyether type),

[0168] - adhesion promoting agents (for example, silanes),

[0169] - bactericidal or algicidal agents (in particular of the isothiazolinone type such as example benzisothiazolinone or methylisothiazolinone, or halogenated type).

[0170] The total weight content of these additives is preferably between 0.1 and 10%, preferably between 0.2 and 5% relative to the total weight of the composition.

[0171] Dispersing agents are useful to help disperse fillers and pigments.

[0172] The water content by weight is preferably 10 to 70% by weight, especially 15 to 60% by weight, or even 20 to 50% relative to the total weight of the composition.

[0173] The composition according to the invention is typically formed by simple mixing of the components. It is advantageous for the pH of the composition according to the invention to be greater than or equal to 9. The particles PI and P2 are generally each added to the composition in the form of an aqueous dispersion. The dry extract content of such dispersions is generally between 20% and 80%, for example between 30% and 75%, or even between 50% and 70%, relative to the total weight of the aqueous dispersion.

[0174] The composition according to the invention is particularly suitable for sealing (in particular, against water) substrates, in particular substrates made of cementitious material.

[0175] In certain embodiments, the composition according to the invention is a com single-component position, that is to say that it does not require the addition of another composition before or after application to a substrate, in order to form a waterproofing coating. A waterproofing coating can in fact be formed by a coagulation step by simple drying after application of said composition to a substrate.

[0176] However, it has been observed that the formation of the coating can be considerably accelerated by using a second composition, which comprises an agent accelerating the coagulation of the P1 and P2 particles.

[0177] Thus, another object of the present invention is a kit comprising:

[0178] - a composition as defined in the present application, and

[0179] - a coagulating composition.

[0180] Typically, the composition according to the invention forms a first component of the kit and the coagulant composition forms a second component of the kit,

[0181] the first component and the second component being in separate compartments.

[0182] By “coagulant composition” is meant a composition comprising a coagulating agent.

[0183] By “coagulating agent” is meant a compound (or a mixture of compounds) capable of accelerating the coagulation of the particles of the sealing composition according to the invention, typically to form a coating (eg membrane).

[0184] The coagulating agent is advantageously a compound comprising a multivalent cation (preferably a divalent cation), such as a calcium, magnesium, manganese, cobalt, zinc, copper, aluminum, zirconium, iron, or ammonium cation. The coagulating agent is preferably a water-soluble salt comprising a multivalent cation.

[0185] Examples of coagulating agents include calcium chloride, calcium nitrate, magnesium sulfate, aluminum sulfate, or iron sulfate.

[0186] Preferably, the coagulating agent is a water-soluble salt comprising calcium.

[0187] The weight content of coagulating agent is advantageously from 0.005 to 50%, in par in particular from 0.01 to 40%, preferably from 1 to 30%, better still from 2 to 20%, or even from 5 to 15%, relative to the total weight of the coagulating composition.

[0188] The coagulant composition further advantageously comprises one or more surfactants, additives and / or fillers, such as those described above for the composition according to the invention.

[0189] In particular, the coagulant composition preferably comprises one or more anionic surfactants (for example a sulfonate surfactant, such as SDS), typically in a weight content of 0.02 to 1% (or even 0.05 to 0.5%) relative to the total weight of the coagulant composition.

[0190] The coagulant composition may further comprise organic polymer particles, such as particles of alkyd resin, styrene-acrylic resin, VAE resin (vinyl acetate ethylene), or a mixture thereof. The weight content of film-forming polymer particles in the coagulant composition is advantageously 1 to 40%, or even 5 to 20%, relative to the total weight of the coagulant composition.

[0191] The coagulant composition is typically an aqueous composition.

[0192] Another object of the present invention is a method of sealing a substrate, said method comprising:

[0193] a) applying a sealing composition as defined in the present application to said substrate, to form a layer of sealing composition and

[0194] b) coagulating said layer of sealing composition, preferably by contacting said layer of sealing composition with a coagulating composition, to form a sealing coating.

[0195] The application of said sealing composition can be done in particular by roller, brush or even by spraying. It can be done in several layers (for example, two layers).

[0196] The application of said coagulating composition, when used, can be done in particular by roller, brush or even by spraying.

[0197] When no coagulant composition is used, the method according to the invention typically comprises:

[0198] aO) applying a sealing composition as defined in the present application to said substrate, to form a layer of sealing composition, and

[0199] bO) coagulation of said layer of sealing composition by drying, to form a sealing coating.

[0200] Steps aO) and bO) may be repeated several times (for example twice) cyclically, so as to form a sealing coating in several layers.

[0201] When a coagulant composition is used, the sealing composition according to the invention may be brought into contact with the coagulant composition, simultaneously with and / or after its application to the substrate. In particular, in certain embodiments, the coagulant composition may be applied to the substrate before the sealing composition.

[0202] Thus, in a first embodiment, the method comprises:

[0203] al) applying a sealing composition as defined in the present application to said substrate, to form a layer of sealing composition, and

[0204] bl) applying a coagulating composition to the layer of sealing composition, preferably by spraying, to form a coating sealing.

[0205] Steps a1) and b1) may be repeated several times (for example twice) in a cyclic manner, so as to form a sealing coating in several layers.

[0206] In a second embodiment, the method comprises:

[0207] a2) applying a coagulating composition to said substrate, to form a primer coat, and

[0208] b2) applying a sealing composition to the primer layer, to form a waterproof coating.

[0209] Step b2) can be repeated several times, so as to form a sealing coating in several layers.

[0210] When step b2) is implemented several times (for example, twice), the method advantageously comprises:

[0211] a2) applying a first coagulating composition to said substrate, for form a primer layer,

[0212] b2) applying a sealing composition in several layers, on the primer coat, and

[0213] b2') the application of a second coagulating composition, preferably by spraying rization, to form a waterproof coating.

[0214] The substrate is advantageously made of cementitious material (for example concrete, mortar or coating), but it can also be made of stone (in particular limestone), brick, terracotta, sandstone, ceramic, wood, paper, textile, plastic, plaster or even bitumen. Preferably, the substrate is made of cementitious material.

[0215] The substrate may in particular be a roofing substrate such as a tile or a membrane, a balcony substrate, a terrace substrate, a wet room substrate, or even a facade substrate.

[0216] The sealing method according to the invention makes it possible to form a sealing coating (or sealing membrane) on said substrate.

[0217] The final (dry) coating may result from the application of several successive layers. Its dry thickness is preferably between 0.1 and 2.0 mm, in particular between 0.2 and 1.5 mm. The thickness of the coating is conventionally measured with a caliper or a digital microscope.

[0218] The present invention also relates to a sealing coating formed from a composition as defined in the present application, typically by implementing a sealing method as described in the present application.

[0219] It further relates to the use of such a sealing coating as a water-proofing coating.

[0220] It is understood that the different aspects, particular modes, and preferred modes described for the composition according to the invention apply to the kit according to the invention, to the method according to the invention, and to the waterproofing coating according to the invention.

[0221] In the present application, a range defined with the expression "between (X) and (Y)" includes the lower (X) and upper (Y) limits, and is equivalent to "from (X) to (Y)".

[0222] The following examples illustrate the present invention in a non-limiting manner. EXAMPLES

[0223] Compositions S1-S4 as described in Table 1 below were prepared by mixing, with stirring (2000-5000 rpm), the different ingredients. These were subjected to the tests described below. The results of the tests are described in Table 2.

[0224] A coagulant composition (CC) was also prepared by mixing, with stirring, the following ingredients for 30 minutes at room temperature:

[0225] - 10 g of calcium chloride,

[0226] - 33 g of calcium nitrate solution (30% solution by weight in water),

[0227] - 1 g of sodium dodecyl sulfate, and

[0228] - 100 g of water.

[0229] 1 - Hardening in less than 2 min. Compositions S1-S4 were each deposited on a surface of a concrete block (surface 15x25 cm). Then the coagulant composition CC was applied by spraying.

[0230] The hardening (i.e. solid coating, no longer liquid) is checked two minutes after the application of the coagulating composition.

[0231] 2 - Waterproofing. To demonstrate that the resins have properties watertightness, a watertightness test was implemented. A first layer of composition (S1-S4) was applied on one surface of a concrete block (area 15x25 cm), then the coagulant composition was applied by spraying. A second layer of composition was applied on the first layer and again, the coagulant composition CC was applied by spraying (the dry thickness of the final coating is about 0.5 mm). The composition was applied in total for both layers at a rate of about lkg / m2. The samples were dried at room temperature for 24 hours. Then, a 10 cm diameter stainless steel capsule containing 500 ml of water is placed on the waterproof membrane. The water is placed under a pressure of 1.5 bar for 24 hours. After this period, the metal capsule is removed and the concrete block is cut in the middle to check the water diffusion.Immediately after cutting the concrete, if no water is present inside the concrete block, it means that the product is waterproof.

[0232] 3 - Adhesion test. To measure the adhesion properties of the coating to a concrete block, a pull-out test was carried out. Two layers of composition (S1-S4) were applied to a surface of a concrete block (area 15x25 cm), in the same way as for the waterproofing test (the dry thickness of the final coating is approximately 0.5 mm). The composition was applied in total for both layers at a rate of approximately 1 kg / m2. The samples were dried at room temperature for 24 hours. Then, three metal cylinders (diameter 1 cm) were glued with a standard epoxy adhesive (Loctite, Hysol® 3425) to the coating. After 24 hours, a pull-off test was carried out using an automatic adhesion gauge (Elcometer 510) at a peel rate of 1 MPa / s. The adhesion is measured and the type of failure is recorded, whether it is a cohesive failure or an adhesive failure. 3 samples are tested per composition S1-S4. The mean and standard deviation are determined based on the three metal cylinders, and are shown in Table 2.

[0233] 4 - Crack bridging capacity and compatibility with tile adhesive of cement (Webercol flex®) were measured in accordance with European standard EN14891.

[0234] [Tables 1] Dry SBR / (dry SBR + dry NR) SI S2 S3 S4 0% 40% 60% 100% Water 7.9% 8.1% 8.15% 8.3% pH buffer (AMP 95) 0.12% 0.12% 0.12% 0.12% Thickening agent (cellulose derivative) 0.35% 0.36% 0.36% 0.37% Anti-foaming agent (silicone derivative) 0.48% 0.48% 0.49% 0.50% Dispersant (polyacrylate copolymer type) 0.27% 0.27% 0.28% 0.28% Anti-slump agent (urea derivative) 1.7% 1.8% 1.79% 1.8% BaSO4 22.1% 22.6% 22.8% 23.3% CaCO3 14.5% 14.9% 15.0% 15.3% Kaolin 0.79% 0.81% 0.8% 0.83% Pigment Red 0.63% 0.65% 0.7% 0.67% Natural Rubber Dispersion “NR” (60% solids) 51.2% 27.8% 18% 0.0% Styrene-Butadiene Dispersion “SBR” (50% solids)* 0.0% 22.2% 32% 48.5%

[0235] *SBR particles comprise 0.001-2% of units having a COO- group and have a Tg of -7°C

[0236] [Tables2] SI S2 S3 S4 Curing in less than 2 min Yes Yes Yes Yes Watertightness Yes Yes Yes Yes Adhesion to concrete (MPa) Average cohesive (C) or adhesive (A) failure 0.78 (A) 1.7 (A / C) 2.1 (C) 2.5 (C) Standard deviation 0.05 0.2 0.06 0.32 Crack-bridging capacity* Yes Yes Yes No Compatible with cement tile adhesive No Yes Yes Yes Remarks Homogeneous films Surface cracks

[0237] *in English: “crack bridging”

[0238] The results in Table 2 show that the combination of rubber particles with particles of an anionic copolymer having a low Tg makes it possible to form a waterproof coating, and having both improved adhesion and crack-bridging capacity, compared to compositions comprising only one of the two types of particles. By using a coagulant composition, here based on calcium ions, a very rapid hardening of the coating was observed.

Claims

Claims

1. Composition for a liquid sealing system comprising, in dispersion in an aqueous phase: - particles PI of natural or synthetic rubber, and - particles P2 of a copolymer comprising 0.001 to 15% by weight of repeating units containing an anionic group and having a glass transition temperature of less than or equal to 35°C.

2. Composition according to claim 1, characterized in that the copolymer of the particles P2 comprises: - repeating units U1 chosen from styrene and a rigid (meth)acrylate; - repeating units U2 chosen from butadiene, chloroprene, isoprene, acrylonitrile, and a flexible (meth)acrylate; and - 0.001 to 15% by weight of repeating units containing an anionic group.

3. Composition according to claim 1 or 2, characterized in that the copolymer of the particles P2 is a styrene-butadiene copolymer comprising 0.001 to 15% by weight of repeating units containing an anionic group.

4. Composition according to claim 1 or 2, characterized in that the copolymer of the particles P2 comprises: - repeating units U1 chosen from a rigid (meth)acrylate; - repeating units U2 chosen from acrylonitrile and a flexible (meth)acrylate; and - 0.001 to 15% by weight of repeating units containing an anionic group.

5. Composition according to any one of claims 2 to 4, characterized in that the total weight content of units U1 and U2 is from 85 to 99.999%, preferably from 90 to 99.99%, or even from 93 to 99.95%, or even 95 to 99.9%, for example from 97 to 99.5%.

6. Composition according to any one of claims 2 to 5, characterized in that the mass ratio of unit U1 to unit U2 is from 0.1 to 10, preferably 0.1 to 5, better still from 0.2 to 2, or even from 0.2 to H

7. V, J. Composition according to any one of claims 1 to 6, characterized in that the anionic group is a carboxylate group -COO, a phosphate group -O-PO(O)2, or a sulfonate group -S(O)2 0, preferably a carboxylate group -COO.

8. Composition according to any one of claims 1 to 7, characterized in that the repeating units containing an anionic group are chosen from a salt of acrylic acid, methacrylic acid, itaconic acid, fumaric acid, 2-hydroxyethyl methacrylate phosphoric acid, and 2-acrylamido-2-methyl-propanesulfonic acid.

9. Composition according to any one of claims 1 to 8, characterized in that the PI particles are natural rubber particles.

10. Composition according to any one of claims 1 to 9, characterized in that the copolymer of the particles P2 comprises from 0.01 to 10% by weight, preferably from 0.05 to 7% by weight, or even 0.1 to 5% by weight, or even from 0.5 to 3% by weight of repeating units containing an anionic group.

11. Composition according to any one of claims 1 to 10, characterized in that the weight content of the particles P2 is from 20 to 95%, preferably from 30 to 90%, or even from 40 to 80%, or even from 50 to 70%, relative to the total weight of particles PI and P2.

12. Composition according to any one of claims 1 to 11, characterized in that the total weight content of particles PI and P2 is 10 to 60%, preferably 15 to 50%, or even 20 to 40%, or even 25 to 35%, relative to the total weight of the composition.

13. Composition according to any one of claims 1 to 12, characterized in that it further comprises anionic surfactants, preferably in a weight content of 0.001 to 1% relative to the total weight of particles PI and P2.

14. Composition according to any one of claims 1 to 13, characterized in that it further comprises fillers, preferably in a weight content of 5 to 70% relative to the total weight of the composition.

15. Kit comprising: - a composition as defined in any one of claims 1 to 14, and - a coagulating composition.

16. A sealing coating formed from a composition as defined in any one of claims 1 to 14.

17. A method of sealing a substrate, preferably a substrate made of cementitious material, comprising: a) applying a sealing composition as defined in any one of claims 1 to 14 to said substrate, to form a layer of sealing composition, and b) coagulating said layer of sealing composition, preferably by contacting said layer of sealing composition with a coagulating composition, to form a sealing coating.

18. A method of sealing a substrate, preferably a substrate made of cementitious material, comprising: a2) applying a coagulating composition to said substrate, to form a primer layer, and b2) applying a sealing composition as defined in any one of claims 1 to 14, to the primer layer, to form a sealing coating.

19. Use of a sealing coating as defined in claim 16, as a waterproofing coating.