EP0917601B1 - Adherence primer for bituminous apron and/or surfacing for circulation in structural works or buildings - Google Patents

Description

The present invention relates to a primer for waterproofing and / or circulation coating based on bitumen and / or asphalt, which can be used on construction works or buildings.

It also relates to coatings sealing and / or circulation formed using a such primary, as well as a method for carrying out such coatings on surfaces of works of construction or buildings.

A waterproof coating is an element continuous which can be obtained in particular by application to hot bitumen-based sheets comprising possibly one or more reinforcements, assembled together by flame welded or bitumen bonded covers heat melted, forming a bituminous membrane; through pouring asphalt continuously forming one or more overlapping layers; or by combining the two previous techniques.

A traffic liner also constitutes a continuous element formed on a roadway or construction such as a bridge deck, by deposit of a asphalt or bituminous concrete (mixture based on sand or pebbles stuck with bitumen) spread in layer (s) uniform (s) or by pouring asphalt, possibly over a waterproof coating.

A road surface must have particularly good resistance to deformation under the effect of repeated passage of vehicles, their acceleration or braking, good resistance to shocks, etc ...

It is often necessary or recommended that sealing and / or circulation coatings adhere to their support.

For this purpose, when the support is metallic, for example galvanized sheet steel, lead, aluminum or zinc, or based on hydraulic binder, by example in concrete or mortar, a primer is spread in thin layer on the surface of the support before the coating.

The functions of this primary can be multiple, this being used in particular for hanging the coating on the support, for temporary protection of the support against bad weather (rain, dew, etc.) in awaiting the completion of the final coating (s), impregnation to a certain depth from the surface when the support is porous, and as a medium prevent blistering of the waterproofing coating and / or circulation especially when the support is permeable gases, especially steam.

The blistering phenomenon is generally caused by the vaporization of moisture always present in permeable substrates such as concrete or cement mortar, under the effect of heating. This- last may be due to the sun, the coating often remaining exposed to it before the wearing course is not deposited. Warming up can also be due to the subsequent application of bituminous coating (s), which is carried out hot.

This vaporization is indeed accompanied by a increased gas pressures inside the protected structure, the pressure applying in particular on the lower surface of the waterproof coating.

Due in particular to their very low gas permeability and their thermoplasticity, bituminous coatings can peel off locally if the primary is not performing well enough, thus forming blisters of various sizes according to their rigidity and the pressure.

The origin of the heating which can cause the blistering phenomenon is therefore multiple, and this risk can manifest at different times during the sealing of a structure.

The most commonly used primaries under bituminous coatings, whether they are coatings with based on bituminous sheets, based on poured asphalt or of mixed systems, are based on bitumen solubilized in solvents. Bitumen emulsions are also used and more rarely epoxy resins.

Bituminous primers, which are monocomponents, wet the supports on which they are applied due to their surface tension, but have a low affinity for polar supports such as concrete or metal due to their low polarity.

In addition, after drying, these primers have a low internal cohesion and are highly thermoplastic. As a result, they do not effectively avoid blistering phenomena.

Conversely, resin-based primers epoxies adhere well to polar supports such as concrete or metal, being themselves polar, and can therefore resist blistering. These primaries are also used especially for bridge decks intended for circulation.

However, these primaries are generally bicomponents and have little affinity for bituminous coatings which are not very polar. Therefore, it is often necessary to incorporate in surface of these resins, grains such as for example grains of sand, so that bituminous coatings can hang on "mechanically". This technique, in addition to its complexity, becomes problematic on the supports sloping or vertical.

Also, given the disadvantages and problems encountered with the primaries currently available, there remains a demand for primers for coatings bituminous to avoid the blistering phenomenon while ensuring satisfactory adhesion qualities of these bituminous coatings, in particular on substrates polar like concrete.

Accordingly, the present invention has for objective of providing a one-component adhesion primer, making it possible to avoid the blistering phenomenon mentioned above, whatever the origin and the time of warming up.

Another object of the invention is to provide such a primary having at the same time a good affinity both with respect to polar supports such as concrete and bituminous coatings, not very polar, and allowing to obtain a satisfactory adhesion of the coating bituminous on such supports.

Yet another objective is to provide a primer that can be implemented in particular for construction and traffic works such as bridge decks and meeting requirements road surfaces.

To this end, the present invention relates to a coating sealing and / or circulation for construction or building, characterized in that it comprises at least one layer of adhesion primer comprising at least one polymer or one urethane copolymer in solution or dispersion including the chain has at least one group during anion, applied to the construction work or building surface to be protected, said surface constituting a polar support, and at least one layer of bituminous coating deposited on said layer (s) of primary, said polymer or copolymer allowing both the adhesion of the primer with bituminous coating, and with said work surface of construction or building by substantially eliminating the risks of blistering.

The invention also relates to a method to seal and / or provide a coating of circulation of a construction or building structure, characterized in that at least one layer of a adhesion primer as defined above, on the surface intended to be sealed and / or provided with a traffic coating, said surface constituting a polar support then in that we deposit at least one bituminous coating layer on said at least one primer layer (s).

The inventors have highlighted, in a way quite surprising, that a primary based on such (co) polymer allowed satisfactory adhesion to the times of the primary itself on a polar support such as concrete or metal, and bituminous coating on said primary, avoiding blistering phenomena, the primary here playing a role of the "intermediate connection or attachment "between the polar support and the bituminous coating.

The urethane polymers or copolymers with pendant polar groupings are examples of (Co) polymers useful for the purposes of the invention.

They usually enter the composition of inks, parquet varnish, paints, lacquers and coatings for wood, metal, concrete, materials plastics, etc. They then have an aesthetic role, a role or serve to improve the cleaning of surfaces or to give some resistance to abrasion.

In addition, we already knew the use polyurethanes having acidic groups pendants, in dispersion, in the field of inks and we knew that acid groups could be used for cross-linking or adhesion coatings formed on the basis of these dispersions.

However, such polymers have never been used. used in adhesion primers for coating bituminous and their ability to eliminate the risks of blistering just like their role as "liaison intermediary or bonding "for bituminous coatings on polar supports had never been highlighted.

The adhesion primer according to this invention contains at least one polymer or copolymer in particular urethane, the chain of which has at least one grouping during polar, and able to form a film on a support formed by the surface of a structure construction or building intended to be protected.

This surface is generally based on material such as for example concrete, cement mortar and / or metals and constitutes a polar support.

According to the invention, the polar group during may consist of an anionic group such as carboxylic or sulfonic acid group.

These groups can be present in the polymer or copolymer used, in particular available in commercial, but polymers can also be used by external emulsification, using agents emulsification (surfactants).

However, according to the invention, the polymers or copolymers with internal emulsification.

Such (co) polyurethanes are known in the art. technical and can in particular be obtained by replacing the polyol constituent, or only a part thereof depending on the number of acid groups desired, by a monomer containing an acid group (carboxylic or sulfonic) while.

The anion centers are then generated before that the (co) polymer is in the form in particular of dispersion.

The number of polar groupings is chosen advantageously so that the primary presents good affinity with polar supports and that the polarity of the film is relatively weak in surface, once formed.

It advantageously corresponds to an acid number between 5 and 50.

The basic structure of the (co) polymer used is relatively unpolar. It is advantageously compatible and refines with bituminous coating.

According to the invention, by bituminous coating, one hears a coating made from sheets bituminous and / or from poured asphalt, or bituminous coatings conventionally used for the surface course, such as asphalt bituminous.

The polymer or copolymer used may consist advantageously in an aliphatic chain polyurethane polyester, an aromatic polyurethane with a polyether chain or into an acrylic polyurethane copolymer. The polyester chain aliphatic polyurethanes are particularly preferred.

The molecular weight of these polymers or copolymers is preferably greater than 1 million.

The primary according to the invention comprises at least a polymer or copolymer as defined above under form of solution or dispersion.

Brookfield viscosity of the solution or dispersion, measured at 25 ° C, is advantageously included between 20 and 500 mPa.s.

It can advantageously be a solution in a solvent other than water, especially in a solvent chosen from hydrocarbons, aromatic solvents, acetates or mixtures thereof.

The (co) polymer is dissolved, preferably at a rate of 25 to 50% of dry extract.

According to another embodiment of the invention, it is a dispersion in water, in a other non-solvent medium of the (co) polymer or in a mixture of these.

The primer of the present invention comprises preferably a dispersion of the (co) polymer in water, in especially for applications on concrete substrates.

Preferably, this includes between 25 and 50% of (co) polymer and has a pH located between about 7 and 10.

The polymer or copolymer is advantageously insensitive to water.

In addition, this (co) polymer must be substantially non-thermoplastic at processing temperatures bituminous coatings, especially below 150 ° C.

According to alternative embodiments of the invention, the primer can comprise a mixture of (co) polymers as defined above or a mixture at least one of said polymers with one or more others (co) polymers such as (co) polymers acrylic.

The primer according to the invention forms a thin film polar substantially impermeable to gases and in particular to water vapor, unlike bituminous primers known.

The primary according to the invention is intended to be used for the protection of supports, in particular in concrete, construction works or buildings. he can be implemented using coating techniques classics.

It eliminates the risks of blistering encountered with the primaries used so far, at level of the primary itself before receiving the coating bituminous like when making it as well only at the bituminous coating once in place.

• par rapport aux résines époxydes, d'être monocomposants et de ne pas nécessiter l'incorporation de sable en surface, opération délicate en surfaces voisines de l'horizontale et pratiquement irréalisable en surfaces fortement inclinées ou verticales,
• par rapport aux solutions bitumineuses, de contenir très peu ou pas de solvants et d'être non inflammables,
• par rapport à la fois aux solutions bitumineuses et aux émulsions bitumineuses, d'être pratiquement incolores et donc très peu salissantes pour l'environnement du chantier, et facilement colorables à l'aide notamment de colorants ou pigments qui se fixent de façon privilégiée dans le solvant (ou le liquide dispersant), ou dans le polymère.

It should also be noted that the primers according to the invention have other advantageous characteristics compared to those usually used, namely:

• compared to epoxy resins, to be single-component and not to require the incorporation of sand on the surface, delicate operation in surfaces close to the horizontal and practically impracticable in strongly inclined or vertical surfaces,
• compared to bituminous solutions, to contain very little or no solvents and to be non-flammable,
• compared to both bituminous solutions and bituminous emulsions, to be practically colorless and therefore not very dirty for the work site environment, and easily stainable using in particular dyes or pigments which are favorably fixed in the solvent (or dispersing liquid), or in the polymer.

The primary according to the invention is particularly well suited for the realization of bridge decks or certain wide tracks circulation because this adhesion primer can lead in particular to total adhesion of the bituminous coating support, which makes it possible to satisfy all the better resistance requirements of such road surfaces to deformation and horizontal forces, in particular braking.

It should be noted in this connection that, in the technique factual, it is common to put in place the layer of bearing so that it does not adhere to the support (this is especially the bus lanes), for avoid the blistering phenomenon.

On the contrary, the primary according to the invention is particularly advantageous due to the adhesion of the coating on the support which it provides, which may allow in particular to avoid training risks or to improve impact resistance.

To seal a building or a construction work, in particular an apron of bridge, and / or provide the latter with a coating of circulation, at least one layer of primer is deposited of adhesion as defined previously on the support the more often made of concrete, then we realize the bituminous coating in a conventional manner, according to a 'or several superimposed layers.

The coating formed on the support using primary according to the invention, can constitute a simple waterproofing coating for example when applied on a building surface, in particular a roof or a terrace, this covering then comprising a membrane bituminous and / or a layer of poured asphalt.

In the case of a traffic lane, the bituminous coating formed using the primer according to the invention may possibly be intended to receive a other coating, such as a wearing course, or in other cases it can be a wearing course waterproof (for a bridge deck for example).

The invention is described in more detail using examples given below by way of illustration and not limiting as well as tests highlighting the properties of the adhesion primers according to the invention in reference to the figure schematically representing a blistering test device.

EXAMPLES

• primaire A : solution bitumineuse connue à 50 % d'extrait sec dans un mélange toluène-xylène
• primaire B : dispersion dans l'eau de polyuréthanne aliphatique à 32 % d'extrait sec, selon l'invention
• primaire C : dispersion dans l'eau d'un copolymère acrylique uréthanne aliphatique à 35 % d'extrait sec, selon l'invention
• primaire D : dispersion dans l'eau d'un copolymère acrylique uréthane aromatique à 33 % d'extrait sec, selon l'invention
• primaire E : solution de polyuréthanne aromatique dans le xylène, à 40 % d'extrait sec et de viscosité Brookfield, mesurée à 25° C, de 75 mPa.s, selon l'invention.

The primaries listed below are used for their lack of sensitivity to water:

• Primary A: known bituminous solution with 50% dry extract in a toluene-xylene mixture
• primary B: dispersion in water of aliphatic polyurethane with 32% dry extract, according to the invention
• primary C: dispersion in water of an acrylic urethane copolymer aliphatic with 35% of dry extract, according to the invention
• primary D: dispersion in water of an aromatic urethane acrylic copolymer containing 33% of dry extract, according to the invention
• primary E: solution of aromatic polyurethane in xylene, at 40% dry extract and Brookfield viscosity, measured at 25 ° C., of 75 mPa.s, according to the invention.

TACKLING TEST

The test is carried out using the device 1 illustrated in the attached figure.

It consists of covering one side with a plate of fiber cement 2 with a layer of primer 3 to be tested then, after drying it, to weld a sheet bituminous waterproofing 4.

This plate is then secured, using clamps 5 for example, provided with a seal 6, a cup 7 containing water 8, like a lid, the uncoated side of the plate being in contact with air of the cup 7.

The whole is placed in a heated enclosure 10 and brought to temperatures increasing from 10 ° C to 10 ° C for consecutive 24 hour periods.

In the figure we see a sealing sheet having blistered.

The temperatures of appearance of the blistering of the bituminous sheet 4 on the surface of the plate of fiber cement 2. This allows a global comparison of the behavior of different primaries towards the risk of blistering. Indeed, the saturated vapor pressures at inside the cup 7, tending to peel off the sheet 4, are increasing with the rise in temperature. 'In in addition, during this test, one can also appreciate the thermal susceptibility of primaries related to their possibly thermoplastic character.

The results obtained are given in Table 1 below: 40 ° C 50 ° C 60 ° C 70 ° C 80 ° C 90 ° C without primary Nothing Generalized blistering Generalized blistering / / / Primary A Nothing Nothing Generalized blistering Generalized blistering / / Primary B Nothing Nothing Nothing Nothing Nothing Slight blistering Primary C Nothing Nothing Nothing Nothing Nothing Slight blistering Primary D Nothing Nothing Nothing Nothing Nothing Slight blistering Primary E Nothing Nothing Nothing Nothing Nothing Slight blistering

PERPENDICULAR TRACTION TEST

The test is performed by setting up a sealing layer welded or hot-cast on the surface of a cement concrete plate with interposition of the primer to be tested, after it has dried.

A metal chip is then glued to the covering which is notched up to the concrete around the pastille.

A pull is then exerted on the pellet to a speed of 3 mm / min and we note the effort R necessary to his wrenching and possibly comments on the detachment mode.

• le Tableau 2 correspond au comportement des primaires sous un asphalte sablé coulé à 230°C en une couche de 12 mm d'épaisseur ;
• le Tableau 3 correspond au comportement des primaires sous un asphalte coulé à 210°C en 10 mm d'épaisseur ;
• le Tableau 4 correspond au comportement des primaires sous une feuille bitumineuse ;
• le Tableau 5 correspond au comportement des primaires sous une feuille bitumineuse, le béton étant alors remplacé par une plaque de tôle galvanisée. Tableau 2 Tableau 3 Asphalte coulé à 230°C - Epaisseur 12 mm Asphalte coulé à 210°C - Epaisseur 10 mm sans primaire 3,2 bars 10 bars Nombreuses bulles dans l'asphalte Primaire A 7 bars Bulles dans l'asphalte Primaire B 4,9 bars 12 bars Absence de bulles dans l'asphalte Primaire C 6,0 bars 13 bars " Primaire D 4,1 bars > 15 bars " Feuille bitumineuse soudée à la flamme sur dallette béton Sans primaire 4,7 bars Primaire A 3,8 bars Primaire B 5,0 bars Primaire C 5,4 bars Primaire D 5,2 bars Feuille bitumineuse soudée à la flamme sur tôle Sans Primaire 1,6 bar Rupture dans la feuille Ne pèle pas Primaire A 1,6 bar Rupture dans le primaire Pêle Primaire B 1,8 bar Rupture dans la feuille Ne pêle pas Primaire C 2,7 bars Rupture plan métal/primaire Ne pêle pas Primaire D 1,2 bar Rupture plan métal/primaire Pêle

The results obtained are given in the following tables:

• Table 2 corresponds to the behavior of the primers under a sanded asphalt poured at 230 ° C in a layer 12 mm thick;
• Table 3 corresponds to the behavior of the primers under an asphalt poured at 210 ° C in 10 mm thickness;
• Table 4 corresponds to the behavior of the primaries under a bituminous sheet;
• Table 5 corresponds to the behavior of primers under a bituminous sheet, the concrete then being replaced by a galvanized sheet metal plate. Table 2 Table 3 Asphalt poured at 230 ° C - Thickness 12 mm Asphalt poured at 210 ° C - Thickness 10 mm without primary 3.2 bars 10 bars Many bubbles in the asphalt Primary A 7 bars Bubbles in the asphalt Primary B 4.9 bars 12 bars No bubbles in the asphalt Primary C 6.0 bars 13 bars " Primary D 4.1 bars > 15 bars " Bituminous sheet welded to the flame on a concrete slab Without primary 4.7 bars Primary A 3.8 bars Primary B 5.0 bars Primary C 5.4 bars Primary D 5.2 bars Bituminous sheet welded to the flame on sheet metal Without Primary 1.6 bar Break in sheet Don't peel Primary A 1.6 bar Primary failure Stove Primary B 1.8 bar Break in sheet Don't fish Primary C 2.7 bars Metal / primary plane failure Don't fish Primary D 1.2 bar Metal / primary plane failure Stove

It can be seen that the primaries according to the invention eliminate the risks of blistering without reducing adhesion, or even improving it.

Claims (17)

1. Sealing and/or traffic-bearing coating for construction or building, characterised in that it comprises at least one layer of adhesion primer comprising at least one dissolved or dispersed urethane polymer or copolymer the chain of which has at least one anionic pendant group, which is applied to the surface of the construction or building which is to be protected, said surface constituting a polar support, and at least one bituminous covering layer deposited on said layer or layers of primer, said polymer or copolymer allowing the primer to adhere both to the bituminous covering and to said surface of the construction or building while substantially eliminating the risks of blistering.
2. Adhesion coating according to claim 1, characterised in that the primer comprises an aliphatic polyurethane having a polyester chain.
3. Coating according to claim 1, characterised in that the primer comprises an aromatic polyurethane having a polyether chain.
4. Coating according to claim 1, characterised in that the primer comprises an acrylic polyurethane copolymer.
5. Coating according to any one of the preceding claims, characterised in that the polymer or copolymer has a molecular mass of more than 1 million.
6. Coating according to any one of the preceding claims, characterised in that the anionic pendant group is a carboxylic or sulphonic acid group.
7. Coating according to any one of the preceding claims, characterised in that the number of anionic pendant groups corresponds to an acid index of between 5 and 50.
8. Coating according to any one of the preceding claims, characterised in that the polymer or copolymer is in the form of a dispersion in water.
9. Coating according to any one of the preceding claims, characterised in that the content of (co)polymer(s) is between 25 and 50% of dry extract,
10. Coating according to any one of the preceding claims, characterised in that it is applied to a surface forming a roadway, notably a bridge deck, and in that the bituminous covering layer is a road surface or a sealing coating covered by a road surface.
11. Coating according to any one of claims 1 to 9, characterised in that it is applied to a surface of a building, notably a roof or a terrace, and in that the bituminous covering layer is a sealing coating comprising a bituminous membrane and/or a poured asphalt layer.
12. Coating according to any one of the preceding claims, characterised in that it is applied to a surface comprising concrete, cement mortar and/or metals.
13. Process for providing a seal and/or a traffic-bearing surface on a construction or building, characterised in that at least one layer of an adhesion primer comprising at least one dissolved or dispersed urethane polymer or copolymer, the chain of which has at least one anionic pendant group, is deposited on the surface which is to be sealed and/or surfaced for traffic; said surface constituting a polar support, then at least one bituminous covering layer is deposited on said layer or layers of primer.
14. Process according to claim 13, characterised in that a sealing coating and/or traffic surface is formed as defined in any one of claims 2 to 9.
15. Process according to either of claims 13 and 14, characterised in that it is applied to a surface forming a roadway, notably a bridge deck, and in that the bituminous covering layer is a road surface or a sealing layer covered with a road surface.
16. Process according to either of claims 13 and 14, characterised in that it is applied to a surface of a building, notably a roof or a terrace, and in that the bituminous covering layer is a sealing coating comprising a bituminous membrane and/or a poured asphalt layer.
17. Process according to any one of claims 13 to 16, characterised in that it is applied to a surface comprising concrete, cement mortar and/or metals.

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