EP1529801A1 - Multilayer polymer film, production thereof, method for protecting and cleaning of a surface using said film - Google Patents

Abstract

In a multilayer film (A) comprising a surface layer (L1) and sublayer(s) (L2), all formed from organic polymer(s) and free of complexing/chelating agents and mineral fillers, (L1) contains agent(s) (I) for promoting the removal of the layer by a rinsing liquid (B). Independent claims are included for methods for the preparation of (A), involving: (1) applying an aqueous emulsion of the polymer to a surface to form a film by coalescence (specifically at room temperature or the temperature of use of the surface), optionally drying and impregnating with (I); or (2) adding (I) to at least one of two or more separate portions of the polymer emulsion and applying the portions successively to the surface.

Description

The present invention relates to a film or multilayer polymeric film.

The invention also relates to the method of preparation, forming, such a polymer film.

The invention also relates to a surface coated with such a film, such film, and a substrate, comprising such a coated surface.

The invention finally relates to a process protection of a surface against contaminants or pollutants using said film and a method of cleaning, decontamination, surface using likewise said film.

The technical field of the invention can be defined in a general way, such as that of cleaning the treatment, decontamination, surfaces and / or the protection of these surfaces vis-à-vis contaminants, pollutants, whether they are chemical, radioactive, biological or bacteriological.

More specifically, the field of the invention is more particularly that of the protection, surfaces, especially surfaces of walls, facades, road signs, etc., against graffiti and other unwanted listings, and cleaning these surfaces to eliminate these graffiti and unwanted inscriptions.

The term graffiti designates general [1], all paintings, inscriptions, drawings or other forms of undesirable marks on a given surface. Graffiti is usually applied in the form of aerosol spray paints, or ink markers.

• Le nettoyage par abrasion, par exemple par sablage, ou par projection de craie, est une technique agressive est coûteuse, qui nécessite de longs temps de main d'oeuvre, dégage des particules nocives et endommage les surfaces.
• L'application d'une nouvelle couche de peinture n'élimine pas le graffiti, elle permet seulement de le dissimuler lorsqu'il est appliqué sur une surface peinte.
• Le nettoyage par solvants chimiques met en oeuvre des produits chimiques agressifs, génère de nombreux effluents polluants et dégrade les surfaces.
• Une dernière catégorie de procédés dans laquelle peut être classé le procédé de l'invention fait appel à la mise en oeuvre de revêtements protecteurs.

At present, there are essentially four methods for protecting a surface from graffiti or removing the graffiti from said surface:

• Abrasive cleaning, for example sand blasting or chalk blasting, is an aggressive technique that is expensive, requires long labor times, releases harmful particles and damages the surfaces.
• The application of a new coat of paint does not eliminate the graffiti, it only allows to hide it when it is applied on a painted surface.
• Cleaning with chemical solvents uses aggressive chemicals, generates many pollutants and degrades surfaces.
• A final category of processes in which the process of the invention can be classified involves the use of protective coatings.

Protective coatings avoid the penetration and hanging of graffiti by modification of the surface and effect properties fence.

There are two types of coatings protectors: temporary or sacrificial and permanent coatings.

The existing sacrificial coatings are base of waxes, natural or synthetic, based on acrylic or polysaccharide-based polymers [2-6]. However, the materials described in these documents have major disadvantages: as well waxes melt too easily to heat and water, chemical solvents are used for their elimination and finally, it is necessary to hand over a new coating layer after each graffiti.

Specifically, document [2] describes a method of protecting buildings against graffiti in which is covered with a thin film of paraffin, buildings likely to be soiled. Paraffin can be applied hot-melted or under the form of an aqueous emulsion. The dirty film is eliminated with great difficulty by means of brushes, scrapers, knives, or melting the paraffin, or by burning the film.

The major disadvantage of the process of this document is therefore to implement a film extremely difficult to remove.

Document [3] concerns a composition nonstick, especially to protect various substrates against graffiti, containing in an aqueous medium with less a synthetic wax derived from vegetable wax, associated with a nonionic emulsifier and / or a wax microcrystalline.

The soiled composition can be removed from support by brushing or using a stripper, especially in the case of very rough supports.

The composition of this document presents the disadvantages of not being sustainable and unable to to be used only once.

Document [4] describes a system of antigraffiti coating comprising an agent coating itself and a cleaning agent regenerating. The coating agent comprises a so-called base composition and so-called additive composition graffiti.

The base is a composition of the group comprising acrylic and hydroxylated resins and their isocyanate hardener; and copolymer resins acrylics in solution in aromatic solvents and ketone. The antigraffiti additive is a composition incorporating a polyethylene wax, an oil of silicone, a mixture of polyurethanes, a solution acrylic. The cleaning agent is a mixture of wax polyethylene and a polar synthetic oil.

The system of this document is of a high cost and is not sustainable.

Document [5] relates to a solution antigraffiti that is formed by combining an alcohol polyvinyl chloride with a solution or emulsion of acrylic resin, to form a mixed resin partially cross-linked polyvinyl alcohol / acrylic catalyzed by exposure to heat and / or light.

The properties of the solution are improved by adding a solution of a zinc complex containing zinc tetramine and / or a donor of aldehyde such as formaldehyde or glyoxal.

In extreme cases of degradation, the film protector can be considered a membrane sacrificial. It can be washed out with a solvent such as toluene alternately with a solution of caustic soda or ammonia and rinse at the water.

There are problems in this document high cost and toxicity.

• on prépare une solution contenant un polysaccharide qui comprend au moins deux polysaccharides différents, le premier de ces polysaccharides formant directement un film lorsqu'il précipite pour évaporation d'un solvant dans la solution, et le second polysaccharide forme un film au moins partiellement par formation d'un gel lorsqu'on le fait précipiter à partir d'une solution par évaporation d'un solvant qui s'y trouve, ou le second polysaccharide forme un film au moins partiellement par formation d'un gel lors d'une interaction avec ledit premier polysaccharide lors de la précipitation avec évaporation d'un solvant ; lesdits films sont susceptibles d'être redissouts ou gonflables et la solution contenant les polysaccharides comprend un tampon pour compenser les variations de pH ;
• on applique la solution sur une surface sujette à contamination ;
• on fait sécher la solution sur la surface pour former un film solide sur la surface au moins partiellement par formation d'un gel ;
• on expose la surface à une source de contamination potentielle ;
• on traite la surface revêtue par le film avec un liquide capable de redissoudre le film ou de faire gonfler le film ;
• on élimine la contamination non-voulue déposée sur la surface en éliminant totalement ou partiellement le film de ladite surface.

The document [6] describes a method for protecting a surface of the contaminants and for facilitating the removal of said contaminants from this surface, wherein:

• a solution containing a polysaccharide which comprises at least two different polysaccharides is prepared, the first of these polysaccharides directly forming a film when it precipitates for evaporation of a solvent in the solution, and the second polysaccharide forms a film at least partially by formation of a gel when it is precipitated from a solution by evaporation of a solvent therein, or the second polysaccharide forms a film at least partially by forming a gel during an interaction with said first polysaccharide during the precipitation with evaporation of a solvent; said films are capable of being redissolved or swellable and the solution containing the polysaccharides comprises a buffer to compensate for pH variations;
• the solution is applied to a surface subject to contamination;
• the solution is dried on the surface to form a solid film on the surface at least partially by gel formation;
• the surface is exposed to a potential source of contamination;
• the film-coated surface is treated with a liquid capable of redissolving the film or swelling the film;
• the unwanted contamination deposited on the surface is removed by totally or partially removing the film from said surface.

The process of this document presents the disadvantage of using solvents.

Permanent coatings currently proposed are mainly based on polyurethanes (PU), silicones and fluorinated compounds [1]. However, polyurethane is extremely sensitive to moisture and has a poor surface appearance. Silicones have a long life polymerization and are permeable to oils. The Fluorinated compounds are toxic and require chemical solvents.

There are also some products that have non-stick properties vis-à-vis paints and inks, but they have the disadvantage of being very expensive, about 15 Euros per m ² treated in terms of material cost, and moreover lose their effectiveness after 3 to 4 cleanings.

• on applique sur la surface à revêtir une première couche d'un revêtement d'apprêt et d'étanchéité qui contient un agrégat et un agent liant ;
• on applique à la surface exposée de ladite première couche une composition de revêtement qui contient un mélange aqueux d'un matériau à base de plâtre, d'un agent de liaison, d'une charge pour durcir la composition de revêtement, et un colorant soluble dans l'eau ;
• on effectue une texturation de la surface exposée de la deuxième couche pour former un relief sur celle-ci ;
• on réalise un durcissement de ladite seconde couche ;
• on applique sur la seconde couche durcie une couche de finition à base de cellulose contenant une matière colorante.

Thus, the document [7] relates to a method of treating a surface to form this coating thereon, the coating having a colored and textured surface on which the graffiti can not be easily applied. In this process:

• a first coat is coated on the surface to be coated with a primer and sealant coating which contains an aggregate and a binder;
• applying to the exposed surface of said first layer a coating composition which contains an aqueous mixture of a plaster-based material, a binding agent, a filler for curing the coating composition, and a soluble colorant in water ;
• texturing of the exposed surface of the second layer to form a relief thereon;
• curing said second layer;
• a cellulose-based topcoat containing a coloring material is applied to the second hardened layer.

The process of this document changes the appearance of the surface and coating composition can actually to be considered more or less like a painting.

Finally, document FR-A-2 822 835 describes a film, dispersible in emulsion in water comprising a polymer and containing at least one chelant or complexant that allows decontamination, cleaning, and / or the protection of various surfaces, in particular metal.

The "removable" film of this document, which is formed on the surface by applying an aqueous emulsion of latex, in the same way as a paint, allows when removing from the surface to drive with it the impurities present. This film can allow, when removed, a moderate surface roughness to lead with him inscriptions that would be there. However, although this removable polymer film is inexpensive, or about 2 Euros per m ² treated, in terms of material cost, it can be used only once, since it must be removed. This removal can be difficult on very rough surfaces such as plaster or raw cement, while on surfaces on which its adhesion is lower, such as road signs or glazing, it can be eventually removed by the taggers Before applying graffiti.

In addition, some components of its formulation like fillers, complexing agents and chelants are harmful and opaque or color the film, for example, while incurring an additional cost.

It has also been observed that residues organic or inorganic, usually in the form of particles, from the film, described in this document, were present on the surface where he had been applied, then removed. In addition, the same particles could cause a deterioration of the state of surface when applying the emulsion.

It appears that none of the techniques described in the documents of the prior art mentioned above is sufficiently effective to allow total removal of graffiti from surfaces, and whereas, in addition, the existing techniques are expensive in terms of manpower and reagent consumption chemicals, damage surfaces and generate effluents.

There is a need for a polymer film and a process for decontamination, cleaning and / or the protection of various surfaces and completely eliminate pollutants or contaminants from these surfaces.

In particular, there is a need for a polymer film that allows to completely remove the graffiti and all other inscriptions and unwanted markings of any surfaces such as walls, façades, road signs, etc., and / or to protect these surfaces against these inscriptions and graffiti with great efficiency. There is in other words a need for a movie polymer that allows cleaning or protection perfect of the surface on which it is applied, then from which he is removed, that is, who completely eliminates all pollutants, contaminants said surface: as for example pollutants, contaminants from graffiti, markings and registrations.

There is also a need for a movie polymer, while completely eliminating the contaminants, pollutants, from the surface, does not leave no residue, particles or other on the surface when applying the emulsion (or solution) the container.

There is also a need for a film that can be easily and completely eliminated at the end its use, and which allows separation and easy recovery of constituents and pollutant contaminants trapped. In other words, the film and the process must ensure excellent recovery and purification of valuable materials going with a low impact on the environment.

This film and the process implementing it must, moreover, be effective vis-à-vis all contaminants, especially of all contaminants which constitute markings, graffiti or other, whatever their form: solid particles, liquids and others, and their nature: radioactive, biological and others.

This film and this process must finally be of a low cost, easy to implement, safe and reliable, not very aggressive towards the treated surface and, if possible, keep the appearance of the surface visualization of an untreated surface.

• l'adhésion du revêtement doit être bonne avec la surface à traiter, et peu importante avec le graffiti ;
• l'aspect de surface du revêtement défini notamment par sa rugosité, sa couleur, sa transparence et sa brillance, doit pouvoir être adapté au support traité ;
• le revêtement doit être imperméable à l'air pour laisser respirer la surface et imperméable aux solvants des marqueurs et aux peintures qui constituent les graffitis, inscriptions et marquages non-souhaités ;
• le revêtement doit être chimiquement inerte ;
• les constituants du revêtement ne doivent présenter aucune toxicité ;
• le temps de stockage des constituants du revêtement avant utilisation et la durée de vie du revêtement doivent être satisfaisants, en particulier le revêtement doit pouvoir résister de façon prolongée à une exposition à des températures aussi bien élevées que basses, à l'humidité, aux rayons UV, et aux autres facteurs atmosphériques, ainsi qu'aux contraintes mécaniques ; enfin, le revêtement doit pouvoir subsister suffisamment longtemps pour pouvoir, par exemple permettre l'élimination répétée de plusieurs graffitis successivement appliqués sur la surface.

In the case of a coating intended more particularly to eliminate graffiti from surfaces and / or to protect these surfaces against graffiti, the criteria and requirements that must be met by such a coating are, inter alia, the following:

• the adhesion of the coating must be good with the surface to be treated, and not important with the graffiti;
• the surface appearance of the coating, defined in particular by its roughness, color, transparency and gloss, must be suitable for the treated substrate;
• the coating must be impervious to air to allow the surface to breathe and solvent-resistant markers and paints that constitute graffiti, inscriptions and unwanted markings;
• the coating must be chemically inert;
• the constituents of the coating must have no toxicity;
• the storage time of the constituents of the coating before use and the service life of the coating must be satisfactory, in particular the coating must be able to withstand prolonged exposure to both high and low temperatures, moisture, UV, and other atmospheric factors, as well as mechanical stresses; finally, the coating must be able to remain long enough to be able, for example to allow the repeated elimination of several graffiti successively applied on the surface.

• l'application du revêtement, film sur la surface à protéger, à traiter doit être réalisée par un procédé simple et par exemple au rouleau ou par pulvérisation ;
• le séchage du film, revêtement appliqué doit être rapide ;
• le revêtement doit pouvoir être utilisé dans de larges plages de conditions, par exemple de température, humidité, pH et ces plages d'utilisation doivent être parfaitement connues et définies ;
• le retrait du revêtement doit se faire de manière simple, mais spécifique, afin d'éviter toute élimination indésirable ;
• le procédé doit être d'un faible coût, rapide, ne pas détériorer les surfaces, et doit pouvoir être répété de nombreuses fois, afin de permettre l'élimination répétée de plusieurs graffitis successivement appliqués sur la surface.

In addition, a method of removing, for example graffiti, a surface and / or protection of said surface employing such a coating must also meet a certain number of criteria and requirements which are, inter alia, the following :

• the application of the coating, film on the surface to be protected, to be treated must be carried out by a simple method and for example by roller or by spraying;
• drying the film, applied coating should be fast;
• the coating must be able to be used in wide ranges of conditions, for example temperature, humidity, pH and these ranges of use must be perfectly known and defined;
• the removal of the coating must be simple, but specific, to avoid any undesirable elimination;
• the process must be of a low cost, fast, not to deteriorate the surfaces, and must be able to be repeated many times, in order to allow the repeated elimination of several graffiti successively applied on the surface.

The purpose of the present invention is to provide a polymer film and a cleaning process, decontamination, or protection of a surface that meets all needs, among other things mentioned above and which satisfies the requirements, criteria and conditions set out above for such film and such a method.

The purpose of the present invention is particular to provide a polymer film and a method cleaning or protecting a surface opposite graffiti, markings and unwanted inscriptions which meets, among other things, all the needs mentioned above, as part of this particular application, and which satisfies the requirements, criteria and conditions set out above for such a film and method.

The purpose of the present invention is still to provide a film and a process, which do not exhibit disadvantages, defects, limitations and disadvantages films and methods of the prior art and which solves the problems of the prior art.

This goal and others are achieved, according to the invention by a multilayer film comprising a surface layer and at least one another layer under said surface layer, each said surface layers and said other layers comprising at least one organic polymer and being free from complexing, chelating and optionally mineral fillers, and said layer surface material further comprising at least one agent likely to favor the elimination of said layer superficial by a rinsing liquid.

Advantageously, at least one of the others layers under said surface layer comprises in in addition to at least one agent likely to favor the elimination of said layer by a liquid of rinsing.

The multilayer film can advantageously alternately to understand a first layer comprising at least one agent likely to favor the elimination of said first layer by a liquid rinsing and a second layer not including agent likely to promote the elimination of said second layer with a rinsing liquid.

Advantageously, all the layers include at least one agent likely to favor their removal by a rinsing liquid.

Preferably, two successive layers each contain an agent, likely to favor the elimination of said layers by a liquid of rinsing, different.

Thus, the film according to the invention can alternately to understand a first layer comprising a first agent likely to favor the elimination said first layer with a rinsing liquid, and a second layer comprising a second agent different from the first agent and likely to favor the elimination of said second layer by a liquid rinsing.

Said agents differ, from preferably by at least one of the conditions in which they promote the elimination of the layer in which they are, by the liquid of rinsing.

Said conditions are chosen for example among the temperature, the pH, the composition of the liquid rinsing, and the pressure of the rinsing liquid, as only water.

Advantageously, the agent (s) likely to favor the elimination of a layer by a rinsing liquid are chosen from the agents likely to favor the dissolution of the in a rinsing liquid, and the agents susceptible to promote the emulsification of the layer in a cleaning liquid.

The film according to the invention can general be defined as a film likely to be dispersed in emulsion in water or likely to be dissolve in solution in water.

Agents likely to favor the dissolution of a layer are advantageously chosen among the surfactants, preferably from the nonionic surfactants, anionic and cationic; and other additives such as acids or bases.

Examples of nonionic surfactants are fatty acid esters, examples of anionic surfactants are the sulfonates and carboxylates, and surfactant examples cationic are alkylamines.

Advantageously, said surfactants and additives are selected from surfactants allowing the dissolution of the layer in which they are under the effect of an acidic washing liquid, and surfactants allowing the dissolution of the layer in which they are under the effect of a liquid basic wash.

Advantageously, the film comprises in alternating a layer comprising a first surfactant A and a layer comprising a second surfactant B which are likely to be dissolved under different wash.

Preferably, the first surfactant A is a surfactant that promotes, allows, the dissolution of the layer in which they are by a liquid of acid wash, and the second surfactant B is a surfactant that promotes the dissolution of the layer in which it is by a washing liquid basic, or vice versa.

Advantageously, the superficial layer is a thin layer generally of a thickness of 5 to 500 microns, preferably from 5 to 100 microns.

Generally, the total thickness of the film is from 5 μm to 2 mm, preferably from 50 to 500 μm.

Generally, layers other than superficial layer are 1 to 50, preferably from 1 to 20.

The polymer film according to the invention fundamentally distinguishes films of the prior art and in particular films described in the document FR-A-2,822,835.

Indeed, the film according to the invention possesses a particular structure, in the sense that it is a multilayer film, that is to say a film consisting of several layers, which includes a layer superficial and at least one other layer under said superficial layer. This is already a essential difference compared to art movies prior art which are monolayer films. In addition, the superficial layer of the film according to the invention is a particular layer that specifically contains at least one agent likely to favor the removal of said surface layer by a cleaning liquid.

The film according to the invention responds to the whole needs mentioned above, satisfies all the criteria, conditions and requirements listed in what precedes, and solves the problems of the prior art mentioned above.

The film according to the invention can be defined as a multilayer film with elimination, for example dissolution, superficial programmed by treatment of said surface layer and possibly one or several other layers using a liquid of rinsing, for example a rinsing solution, determined, given, which is generally adapted to the agent likely to promote the elimination, by example the dissolution, being in the said one or more layers.

When rinsing, washing, specific, the treated surface layer dissolves and causes the pollutants, contaminants, for example paint or the ink constituting the graffiti, markings, inscriptions, with it without damaging the coating inferior. The film can in this case be reused several times by again treating its surface by thin layers so that these contain each once one or more agents promoting elimination, dissolution, of the superficial layer, and this until consumption of the whole thickness of the film.

The film according to the invention can therefore be used several times, and it protects the surface on which it has been applied, in particular against registration cycles, then successive cleaning.

In the context of the preferred application of the film according to the invention, which is the fight against graffiti, markings and other inscriptions not desired, the film according to the invention has the advantage to be totally impervious to inks and paints, and other constituents of such graffiti, markings, and registrations.

In addition to the benefits and effects of specific structure multilayer and to nature specific to the surface layer of the film according to the invention, the polymer film according to the invention also distinguishes fundamentally from the movies of art prior art, and in particular films described in document FR-A-2 822 835, in that it is free of chelating agents, complexing agents, and possibly mineral charges.

Thanks to the absence of chelants, complexing agents and possibly mineral fillers in the films according to the invention, no organic residue or mineral, for example in the form of particles, from the film is left on the surface on which it is applied and then removed.

It has been highlighted, indeed, according to the invention that some components of the formulation described in document FR-A-2 822 835 were unnecessary or harmful, in particular in the case of antigraffiti treatment of surfaces and left residues on the surface after removal.

In addition, since the emulsion from which the film according to the invention is prepared, contains, neither complexing nor chelating nor preference, loads, it is not found in the emulsion from which the film is prepared, from particles that can cause when applied a deterioration of the state of the surface.

The absence of complexing, chelating, and possibly in the film according to the invention also entails a reduction in the cost of the formed film and simplifies the preparation of the formulation from which the film is prepared.

Finally, the absence of complexing, chelating and possibly fillers in the film according to the invention avoids coloring or opacification of the film, which is particularly advantageous in the preferred anti-graffiti application of the film according to the invention, in which it is desired to conserve the visual appearance of the treated surface.

In particular, it was noted that the absence of charges does not harm the overall properties of the film because it does not undergo mechanical stress high (indeed, the coat of the film is not obligatory, and in addition the mechanical properties of the film can be improved by the addition of others polymers such as PVA that avoid having recourse to charges), but on the other hand it allows to obtain, after removal of the film, surfaces of a perfect cleanliness, never achieved in the prior art and that has been demonstrated by spectrometric analysis infrared.

In addition to the essential effects and benefits to the specific multilayer structure, and to the absence complexing agents, chelating agents and possibly charges, the film according to the invention has all the advantageous properties already presented by the film of FR-A-2 822 835 and due to the fact that this film comprises a generally insoluble polymer, insoluble, in water.

The film, according to the invention, is, indeed, prepared from an aqueous emulsion of said polymer (or said polymers), and therefore the polymer can be easily recovered after the use of the emulsion and flocculation film, which is not possible with water-soluble polymers, of some of the films of the prior art.

The film according to the invention responds to the whole needs, requirements and criteria mentioned more high, for example: it allows with great efficiency and high reliability of trapping, as curative or preventive, contaminants, pollutants in a superficial, sacrificial layer on the surface treated, that is, it is not only the contamination lying on the surface that is trapped, but also the one immediately under this surface.

The film according to the invention allows a mastery the spread of the contaminant, retaining this one within it.

The mechanical properties, adhesion and cohesion of the film are excellent even in the absence possible loads, and ensure a very good performance on any surface, while allowing for elimination easy, especially by peeling.

The film is of a low cost. He can be prepared with products readily available in trade and by processes that are easy to implement for example by application of an emulsion simply by brush or spray of said emulsion on the surface.

The film is not aggressive towards the surface on which it is applied. It does not change in nothing the properties of it (it can even the improve, even after a long period, for example during prolonged storage.

It does not degrade the appearance of the surface. In additionally, in most cases, the film being colorless and transparent, it does not affect the visual appearance from the surface.

The film is prepared from non toxic to staff and low impact on the environment.

In addition, all the constituents of the film can be easily separated, recycled and / or destroyed, at low cost, after the use of the film.

The film according to the invention allows a cleaning perfect of the surface on which it is applied, then removed; he leaves no residue on this area.

Thus, it has been shown that no organic trace from film residues is detectable on the surface after removal of the film as confirmed by surface analysis after removal of the film by infrared spectrometry with a total reflection accessory. attenuated multi-reflections in the spectral range of 4,000 to 600 cm ^-1 .

The film according to the invention ensures a long-term protection against pollutants and external contaminants.

Advantageously, the film according to the invention is non-porous.

The polymer is generally chosen from polymers, likely to be in the form aqueous emulsions of latex type.

Preferably, this polymer likely to find in the form of an aqueous emulsion is chosen among the styrene-butadiene copolymers, the styrene-(meth) acrylic copolymers, for example styrene (meth) acrylate (see below definition of the term (meth) acrylic) and polymers (homopolymers and copolymers) (meth) acrylic.

By (meth) acrylic polymer is generally meant all copolymers and homopolymers capable of being prepared by polymerization of acrylic acid, methacrylic acid and esters thereof, such as acrylates and alkyl methacrylate ( C ₁ to C ₆ ), such as methyl or ethyl (meth) acrylate.

Advantageously, the film can understand several polymers likely to be under the form of aqueous emulsions, preferably selected from styrene-butadiene (SBR) and styrene-(meth) acrylic copolymers, for example styrene- (meth) acrylate, which, moreover, preferably have different glass transition temperatures (Tg).

Advantageously, it is possible to use a polymer such as a styrene-butadiene, said autodispersant.

The film may include, in addition, one or several other polymers that are polymers likely to be in aqueous solution (these polymers are generally in the minority) (and no longer emulsion), which are preferably selected from polyvinyl alcohol (PVA), and PVP (Polyvinylpyrrolidone).

Some of these polymers such as PVA improve the mechanical properties and to avoid the use of charges.

Preferably, in particular to facilitate the film preparation, all layers (superficial and others) of the film include the same polymers. This means that these layers do not differentiate only by the presence or absence of an agent in facilitating the elimination and / or by the nature of the agent.

a) - on forme une émulsion aqueuse dudit polymère organique ;

b) - on applique ladite émulsion comprenant le polymère organique sur la surface, moyennant quoi le film se forme par coalescence ;

c) - on imprègne la surface dudit film par au moins un agent susceptible de favoriser l'élimination d'une couche superficielle du film par un liquide de rinçage, de façon à former une couche superficielle du film contenant au moins un agent susceptible de favoriser l'élimination de ladite couche superficielle du film par un liquide de rinçage.

The invention also relates to a method of forming a multilayer film as described above comprising a surface layer, and another layer under said surface layer, said surface layer and said other layer comprising the same organic polymer and being free from complexing agents, chelating agents and optionally mineral fillers, in which the following successive steps are carried out:

a) - an aqueous emulsion of said organic polymer is formed;

b) - applying said emulsion comprising the organic polymer on the surface, whereby the film is formed by coalescence;

c) - the surface of said film is impregnated with at least one agent capable of promoting the removal of a surface layer of the film by a rinsing liquid, so as to form a surface layer of the film containing at least one agent capable of promoting the removal of said surface layer of the film by a rinsing liquid.

The film is formed, usually rapidly, in minutes, ie for example from 1 or 2 to 10 minutes, on the surface, by coalescence.

Advantageously, the formation of the film produced by coalescence at room temperature or temperature of use of the surface (temperature at which is the surface) without any drying of the surface, and / or parts comprising this surface.

Indeed, given the conditions generally used to implement the emulsion intended to form the film according to the invention, namely with low-skilled staff, and in order to reduce the complexity of the material used to form the film, being able to allow training without drying is an important advantage of film and process according to the invention.

According to the invention, the formation of the film can be performed at room temperature without any heating the parts to be covered and without use of hot air, even on vertical surfaces, this which is particularly advantageous.

The conditions of coalescence are advantageously chosen so as to avoid any porosity, whether open or closed, in the film final formed obtained.

However, under certain conditions of the method of the invention further comprises between steps b) and c), a step of drying the movie.

The formation and eventual drying of the film according to the invention without any drainage or no absorption of any of the liquids entering the composition of the emulsion.

In this process, the agent likely to promote the elimination of the superficial layer of film is selected from the agents likely to promote the dissolution of the superficial layer, such as surfactants.

a) on forme une émulsion aqueuse dudit polymère organique ;

b) on sépare ladite émulsion en une première et une seconde portions,

c) on ajoute à la première portion un premier agent susceptible de favoriser l'élimination d'une couche du polymère organique sous l'effet d'un liquide de rinçage,

d) éventuellement on ajoute à la seconde portion un second agent susceptible de favoriser l'élimination d'une couche du polymère organique sous l'effet d'un liquide de rinçage,

e) on applique successivement lesdites seconde et première portions de l'émulsion sur une surface, moyennant quoi on forme un film comprenant depuis sa surface, une couche comprenant un premier agent susceptible de favoriser son élimination par un liquide de lavage et une seconde couche comprenant un second agent susceptible de favoriser son élimination par un liquide de lavage ou ne comprenant pas ledit second agent,

f) on répète éventuellement l'étape e) par exemple de 1 à 40 fois, de préférence de 1 à 20 fois.

In a second embodiment, the invention relates to a method of forming a multilayer film, as described above, comprising a surface layer, and at least one other layer under said surface layer, said surface layer and said other layer. layer comprising the same organic polymer and being free of complexing agents, chelating agents, and optionally mineral fillers, in which the following successive steps are carried out:

a) an aqueous emulsion of said organic polymer is formed;

b) said emulsion is separated into a first and a second portion,

c) adding to the first portion a first agent capable of promoting the removal of a layer of the organic polymer under the effect of a rinsing liquid,

d) optionally adding to the second portion a second agent capable of promoting the removal of a layer of the organic polymer under the effect of a rinsing liquid,

e) said second and first portions of the emulsion are successively applied to a surface, whereby a film comprising, from its surface, a layer comprising a first agent capable of promoting its elimination by a washing liquid and a second layer comprising a second agent capable of promoting its elimination by a washing liquid or not including said second agent,

f) optionally repeating step e) for example from 1 to 40 times, preferably from 1 to 20 times.

After the application of the second and the first portions of the emulsion, the layers are formed under the conditions already described above, usually quickly, for example in a few minutes, for example in 1 or 2 to 10 minutes by simple coalescence.

In this second embodiment of method of forming the film according to the invention, preferably said first and second different agents by at least one of the conditions in which they promote elimination, for example dissolution, of the layer in which they are found, by the cleaning liquid.

Advantageously, said conditions are chosen from the temperature, the pH, the composition of the rinsing liquid, and the pressure of the liquid rinsing.

The first agent is for example a surfactant A and the second agent is for example a surfactant B.

Preferably, the surfactant A is a surfactant that promotes the dissolution of the layer in which it is under the effect of a liquid of aqueous washing, for example of a washing solution, aqueous acid, and the second surfactant B is a surfactant that promotes the dissolution of the layer in which it is under the effect of a liquid of aqueous washing, for example of a washing solution, basic aqueous, or vice versa.

As in the case of the first mode of performing the method of forming a film according to the invention, said formation occurs by coalescence at room temperature or temperature use of the surface.

However, a final drying step g) film can be provided.

• on forme un film, tel que décrit plus haut, sur ladite surface ;
• on laisse le film en contact avec ladite surface jusqu'à ce qu'il soit contaminé, pollué, notamment par des graffitis, ou autres inscriptions ou marquages non souhaités ;
• et on élimine la couche superficielle dudit film par rinçage avec un liquide, de préférence un liquide aqueux, tel qu'une solution aqueuse.

The invention also relates to a method for protecting, cleaning or decontaminating a surface in which the following successive steps are carried out:

• forming a film, as described above, on said surface;
• the film is left in contact with said surface until it is contaminated, polluted, in particular by graffiti, or other unwanted inscriptions or markings;
• and removing the surface layer of said film by rinsing with a liquid, preferably an aqueous liquid, such as an aqueous solution.

The surface on which the film is formed is basically a clean surface, free of pollutants or contaminants, the latter being generally from the outside world which is in contact with the surface layer.

a) on forme un film sur ladite surface par le procédé de formation d'un film dans sa première forme de réalisation,

b) on laisse le film en contact avec ladite surface jusqu'à ce qu'il soit contaminé, pollué, notamment par des graffitis, ou autres inscriptions ou marquages non souhaités,

c) on élimine la couche superficielle polluée, contaminée dudit film par rinçage avec un liquide de préférence un liquide aqueux tel qu'une solution aqueuse, et

d) on imprègne éventuellement la surface du film avec au moins un agent susceptible de favoriser l'élimination d'une couche superficielle du film, de façon à former une couche superficielle contenant au moins ledit agent,

e) on répète éventuellement les étapes c) et d) jusqu'à consommation du film.

In a first preferred embodiment of this method of protection, decontamination cleaning of a surface, the following successive steps are carried out:

a) forming a film on said surface by the film forming method in its first embodiment,

b) the film is left in contact with said surface until it is contaminated, polluted, in particular by graffiti, or other undesired markings or markings,

c) removing the polluted surface layer, contaminated with said film by rinsing with a liquid, preferably an aqueous liquid such as an aqueous solution, and

d) the film surface is optionally impregnated with at least one agent capable of promoting the removal of a surface layer of the film, so as to form a surface layer containing at least said agent,

e) optionally, steps c) and d) are repeated until the film is consumed.

a) on forme un film sur ladite surface par le procédé de formation d'un film dans sa seconde forme de réalisation,

b) on laisse le film en contact avec ladite surface jusqu'à ce qu'il soit contaminé, pollué, notamment par des graffitis, ou autres inscriptions ou marquages non souhaités,

c) on élimine la première couche, polluée, contaminée dudit film par rinçage avec un liquide,

d) on laisse le film en contact avec ladite surface jusqu'à ce qu'il soit contaminé, pollué,

e) on élimine la seconde couche, polluée, contaminée dudit film par rinçage avec un liquide de préférence un liquide aqueux, tel qu'une solution aqueuse,

f) on répète éventuellement les étapes b) à e) jusqu'à consommation du film.

In a second preferred embodiment of the method of protecting, cleaning or decontaminating a surface, the following successive steps are carried out:

a) forming a film on said surface by the film forming method in its second embodiment,

b) the film is left in contact with said surface until it is contaminated, polluted, in particular by graffiti, or other undesired markings or markings,

c) removing the first layer, polluted, contaminated with said film by rinsing with a liquid,

d) the film is left in contact with said surface until it is contaminated, polluted,

e) removing the second, polluted, contaminated layer of said film by rinsing with a liquid, preferably an aqueous liquid, such as an aqueous solution,

f) steps b) to e) are optionally repeated until the film is consumed.

Preferably, the first and second layers are removed under rinse conditions such as temperature, pH, liquid composition rinsing, different rinsing fluid pressure.

Advantageously, the first layer which contains a surfactant A is removed by washing with an aqueous liquid, for example an aqueous solution of washing, acid and the second layer that contains a surfactant B is removed by washing with a liquid aqueous solution, for example an aqueous washing solution, basic.

In the event of the elimination of the superficial layer of the film according to the invention dissolution of the film in an aqueous medium, we thus obtain an aqueous solution or emulsion containing the material organic, and contaminants or pollutants. The material organic is separated from the solution by flocculation, then filtration. It is then generally rejected or eliminated, for example, by incineration.

Contaminants or pollutants are separated by filtration.

The invention further relates to a surface covered by the film as defined above, and a substrate, in particular an optical part or component comprising such a surface.

The invention will now be described detailed manner in the description which follows, given illustrative and not limiting, in particular certain preferred embodiments of the invention.

In a first step, we start with formulate, by preparing an aqueous emulsion of one or several polymers, latex type.

By polymer is meant, in the present description, both homopolymers and copolymers prepared from several monomers.

Among the preferred polymers and copolymers, mention may be made of styrene copolymers with butadiene (SBR) or styrene with a compound (meth) acrylic such as a (meth) acrylate.

These copolymers may have different styrene, or even polymers (Meth) acrylic.

Recall again that (meth) acrylic polymer means all copolymers and homopolymers capable of being prepared by polymerization of acrylic acid, methacrylic acid and esters thereof such as acrylates and methacrylates. (C ₁ -C ₆ ) alkyl, such as methyl or ethyl (meth) acrylate.

Preferably, an emulsion is used commercially available latex, examples of such emulsions are emulsions available from the BAYER® Company, under the BAYSTAL® name.

These emulsions in particular have the advantage low cost, very low toxicity, and absence of organic solvent.

The emulsion may comprise only one polymer likely to be in the form aqueous emulsion, but it can also understand two or more of these polymers preferably selected among styrene-butadiene copolymers (SBR), and styrene (meth) acrylic for example styrene (meth) acrylate, having, for example, different glass transition (Tg) and / or different styrene, so as to achieve a compromise between the adhesion and cohesion of the film adapted to the surface to be treated.

Thus, a first polymer may have a Tg -30 ° C to -5 ° C and a second polymer Tg + 5 ° C at + 50 ° C.

As a mixture of polymers in emulsion, in dispersion, it will be possible, for example, to use a mixture of two or more selected latexes of preferably among styrene-butadiene and styrene latices (meth) acrylic, for example styrene- (meth) acrylate, preferably having transition temperatures different vitreous and / or styrene levels different.

It is best to use a latex free surfactants that can leave residues on the area. For example, a mixture of styrene-butadiene with a higher carboxylation rate (commercially available under the denominations BAYSTAL® S42 or S44), said self-dispersing, dispersible in emulsions free of surfactants and simply added thickener.

With this mixture, one can, possibly, add a solution of polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP) (polymers in solution) and / or optionally one or more other polymers in an aqueous dispersion, chosen for example from (meth) acrylic polymers, as defined upper.

According to the invention, the formulation is free of complexing agents, chelating and preferably it is free of charge when it is specifically desired that the prepared film is transparent. However, in some applications, it is possible that the emulsion, so-called "basic formulation" contains one or more several charges selected for example from ZnO, the mica, clays called "nanoclays". A formulation typical aqueous solution, preferably free of charge, contain, for example, 30 to 60% of water, SBR at a rate of 20 to 60% by weight and polymer acrylic at 1 to 20% by weight. The latter can to be advantageously replaced by alcohol polyvinyl in the same proportions.

For example, we can proceed to mixture of 2 SBRs with different styrene levels, namely BAYSTAL® S42 and S44, in aqueous emulsion (from 30 to 70% of water), in proportion 50/50, then possibly add between 1 and 10% of a mixture of acrylic polymers based on ethyl acrylate and of methacrylic acid (aqueous dispersion of from 20 to 70% by weight of polymer), then add further optionally a polymer in solution such as PVA.

A particularly preferred composition will include in mass: from 0 to 20% of PVA, for example 15%; from 0 to 50% of BAYSTAL® S42 for example 17.5%; from 0 to 50% of BAYSTAL® S44, for example 17.5%; and of 30 to 70% water for example 50%.

When using multiple latexes, prepares the emulsion, usually by simply mixing the various latices, preferably with stirring.

This basic aqueous emulsion formulation communicates to the films according to the invention all advantages listed above while the components taken separately have disadvantages their low mechanical resistance and their solubility which do not allow them to be used [5; 7].

The aqueous emulsion of the or polymer (s) on the surface to be cleaned, decontaminate or protect.

There is no limitation on the nature and the shape of the surface to be treated. This surface can be a metal surface, or an organic polymer, or glass, or stone, plaster, cement, stucco or other or a surface comprising several of these materials or still a painted or enamelled surface; the surface can be non-porous, non-absorbent, or porous, it can be smooth or rough.

Advantageously, the emulsion is formulated to allow the formation of a non-porous film on a non-porous support and the application of the emulsion must be possible on non absorbents such as metals, glass and others plastic supports.

It can also be the surface of the top layer of a monolayer coating or multilayer protection or decoration of a substrate such as a wall, a billboard or signaling or other.

Such a top layer is for example a layer of paint, varnish or the like.

The surface may be opaque or transparent, this is one of the advantages of the invention that allow treatment, surface protection transparent, such as portholes, windows, because the film formed according to the invention is generally transparent and colorless due in particular to the absence loads and therefore does not mask the surface. That is particularly advantageous on surfaces transparent.

According to the invention, the shape of the surface can be any, and one can treat, with a same efficiency, shape surfaces as well simple as complex.

The size of the surface can be any but the invention makes it possible to treat large or even very large areas, quickly, without modifying them, nor degrade them.

The invention having for main application the protection of surfaces against graffiti, unwanted inscriptions and markings whatever their nature and method of application: aerosol, buffer, etc ..., the surface can be part of including a wall or any other part of a building or building, or a billboard or signaling.

The emulsion can be applied on the surface by any known means, for example by spreading brush or roller or by projection / spray.

The film is formed (for example, in a from 1 to 30 minutes) by coalescence "in situ" from polymers on the surface.

The formation of the film is fast at the temperature of use of the equipment whose surface is part. As an example, this may be from 10 to 70 ° C, preferably from 5 to at 50 ° C.

The film can usually be subsequently dried, for example by evaporation, at a temperature of 5 to 50 ° C.

The film becomes generally transparent drying (when it does not contain any charges). From this actually, the surface retains the visual appearance of a surface not treated. The film, once formed, has a role protection agent against contamination external and a role of decontaminating agent, cleaner, said surface due to the removal of the surface rinsing after it has been polluted, contaminated, dirty.

The film according to the invention is applied to preventative title on a clean surface, as a protective agent with respect to the contamination or well it can even be applied as a curative for decontaminate, clean the surface.

Contaminants and / or external pollutants can be removed from the surface in the diaper superficial film in which they are, and vis-à-vis which the surface can be protected, are of various natures. This may include contaminants or chemical pollutants, such as Pb, Cd, and / or radioactive contaminants, such as cesium, or biological contaminants (for example, Bacteriological).

In particular, the repulsed contaminants by the film, according to the invention, and which are eliminated in the surface layer of said film are the contaminants and pollutants found in paints, inks and other marking products that are used to form graffiti, markings and other unwanted listings. Pollutants for example, pigments, binders, resins, polymers, plasticisers, solvents present in such inks and paints.

In a first embodiment, the emulsion, basic formulation can be applied directly on the surface, like a painting, where she will form a film while drying.

The surface of the film is treated after drying using a specific surfactant or other product facilitating its elimination, for example its dissolution. In this case, the thickness of the film, for example from 5 to 500 μm, in which the surfactant or other agent has penetrated becomes for example soluble in aqueous media under specific conditions, for example temperature and pH, and graffiti removal is done by washing, rinsing, with a washing fluid such as aqueous medium, for example an aqueous solution. The washing can be carried out under pressure and the fluid can be simply water possibly heated for example at 0 to 145 ° C, and possibly under pressure.

The washing, rinsing, causes the delivery solution or emulsion of the fraction of the treated film. The graffiti is then eliminated together with the said fraction of the dissolved film. The part of the film treated remains intact. It is then possible to treat again the surface of the remaining film for example to using the same surfactant or other component and repeat the operation until the total consumption of movie.

If the surface of the film is not treated by an additive facilitating its dissolution, then the totality film is removed by peeling like a skin and thus eliminates the graffiti that leaves with said skin.

In the case of dissolution of the film surface layer in an aqueous medium by example in aqueous solution, the material is separated organic by flocculation by introducing a flocculant BAYER® specific, then by floc filtration as well trained. The organic matter thus recovered can be destroyed by incineration.

Pollutant contaminants are, in turn, separated by filtration, usually in the form of insoluble granules.

In another embodiment, the basic formulation can be separated into two lots (or plus) which will be additive of two (or more) types different surfactants or other additives. By For example, two types of surfactants A and B can be used so that polymer films their respective contents are soluble in different washing conditions A and B, for example pH different, and / or different temperature, and / or overall chemical composition of the solution of different wash.

In this case, a multilayer film is developed alternating application of formulations A and B.

When the surface is dirty with graffiti, just wash the surface with a solution type A washers if a layer with the Formulation A is on the surface. Graffiti is eliminated at the same time as said layer while the Underlying layer of formulation B remains intact. When the formulation layer B is polluted, it just wash it off with a wash solution type B and so on until consumption complete multilayer film. The treatment of disposal effluents, dissolution is analogous to the one described in the first mode of production.

The film and the methods according to the invention find their application in any treatment preventative measures against contamination or pollution - whatever its nature and form - of all surfaces.

The method and the film according to the invention are essentially preventative, which means that the movie is applied to non-degraded surfaces for protect vis-à-vis inscriptions made later.

The invention will now be described in reference to the following example given for illustrative purposes and not limiting.

EXAMPLE

An aqueous emulsion (45 to 55% by weight) is prepared water body), free of charges, comprising a mixture equal parts (50/50) of two types of content SBRs styrene (BAYSTAL® S42 and S44). We add to this emulsion, with stirring, a mixture of acrylic polymers based on ethyl acrylate and of methacrylic acid in the form of a suspension from 28 to 32% by weight of water.

Once spread on a wall such as a wall or a road sign by a simple mode of application such as brush, roller or spray, the coating is dried in ambient air at a temperature between 5 ° C and 50 ° C and at a relative humidity of between 10 and 80%. The drying time varies according to the thickness: for 200 μm, it takes between 1h and 3h. Drying is easy to find because the coating becomes progressively transparent. A mixture of nonionic surfactants comprising 50% by weight of fatty acid ester and 50% by weight of alkyl ethoxylated phenol is applied by brush on the dry coating. By drying in the ambient air, it penetrates the extreme surface of the film.

Then, a graffiti, a black painting under aerosol form, is sprayed on the dry coating and allowed to air dry.

The sample went under hot water and a thin layer of polymer is naturally removed coaching with her the graffiti. The surface of coating is then milky (because wet) but is cleaned of all traces of graffiti. The coating Drying resumes its transparent appearance and is then ready for another graffiti-cleaning operation.

REFERENCES

[1] Saidi S., Guittard F., Geribaldi S., Polymers against graffiti. Chemical update 03/2001; 3-13.

[2] Pomero V. FR-A-2,686,615 of 27 January 1992.

[3] Salvoldelli C., WO-A-80 01072 of November 16, 1979.

[4] Turzan G., FR-A-2,630,353 of April 25, 1988.

[5] Hansen RP, US-A-4 169 088 of May 30, 1978.

[6] Swensson S., US-A-5,750,189 of September 10, 1996.

[7] Rawlins PR, US-A-4,428,994, July 15, 1981.

Claims (42)

Multilayer film comprising a layer superficial, and at least one other layer under said superficial layer, each of said layers superficial and other layers comprising at least minus one organic polymer, and being free of complexing agents, chelating agents and possibly minerals, and said surface layer comprising in addition to at least one agent likely to favor the removal of said surface layer by a cleaning liquid. Multilayer film according to Claim 1, wherein at least one of said other layers under said surface layer further comprises at least an agent likely to promote the elimination of said layer with a rinsing liquid. Multilayer film according to Claim 2, which alternately includes a first layer comprising at least one agent capable of favoring the elimination of said layer by a liquid of rinsing, and a second layer not including agent likely to promote the elimination of said second layer with a rinsing liquid. Multilayer film according to any one claims 1 and 2, wherein all the layers of the film include at least one agent likely to favor their elimination by a cleaning liquid. Multilayer film according to Claim 4, in which two successive layers contain each an agent, likely to favor the elimination of said layers by a liquid of rinsing, different. Multilayer film according to Claim 5, alternately comprising a first layer comprising a first agent likely to favor the elimination said first layer with a rinsing liquid, and a second layer comprising a second agent, different from the first, likely to favor the elimination of said second layer by a liquid rinsing. Multilayer film according to claim 5 or 6, wherein said different agents, differ by at least one of the conditions in which they favor the elimination of the layer in which they are found by the rinsing liquid. The film of claim 7 wherein said conditions are selected from the temperature, the pH, the composition of the rinsing liquid and the rinse aid pressure such as water. Film according to any of Claims 1 to 8, in which the agent or agents likely to favor the elimination of a layer by a rinsing liquid are chosen from the agents likely to favor the dissolution of the said layer in a rinsing liquid, and the agents likely to promote the emulsification of the layer in a rinsing liquid. Film according to claim 9, in which the agents likely to favor the dissolution of a layer are selected from the agents surfactants, preferably surfactants anionic and cationic nonionics; And the others additives such as acids and bases. Film according to claim 10, in wherein said surfactants are selected from surfactants allowing the dissolution of the layer in which they are under the effect of a liquid acid wash and surfactants allowing the dissolution of the layer in which they are under the effect of a basic washing liquid. Multilayer film according to any one claims 5 to 11, which comprises alternately a layer comprising a first surfactant A and a layer containing a second surfactant B, which are likely to be dissolved under different wash. Multilayer film according to claim 12, wherein the first surfactant A is a surfactant that promotes the dissolution of the layer in which it is by a washing liquid acid, and the second surfactant B is a surfactant which promotes the dissolution of the layer in which it is found by a basic washing liquid, or vice versa. Film according to any of preceding claims, wherein the thickness of the surface layer is 5 to 500 μm, preferably from 5 to 100 μm. Film according to any of preceding claims, wherein the thickness total film thickness is 5 μm to 2 mm, preferably 50 μm. at 500 μm. Film according to any of preceding claims wherein the layers other than the superficial layer are 1 at 50, preferably from 1 to 20. Film according to any one of the preceding claims, characterized in that it is non-porous. Film according to any of preceding claims, wherein the polymer is chosen from the polymers likely to be found in the form of aqueous emulsions of latex type. Film according to any of Claims 17 to 18, wherein the polymer is a autodisperse polymer. Film according to any of Claims 18 to 19, wherein the polymer is selected from styrene-butadiene copolymers, styrene-(meth) acrylic copolymers for example styrene- (meth) acrylate, and polymers (meth) acrylic. Film according to any of Claims 18 to 20, wherein each layer includes several polymers, likely to find in the form of aqueous emulsions, polymers furthermore preferably having different glass transition temperatures (Tg). Film according to any of Claims 18 to 21, wherein each layer further comprises one or more other polymers likely to be in aqueous solution, chosen preferably from polyvinyl alcohol (PVA), and the polyvinylpyrrolidone (PVP). Film according to any of preceding claims, in which all the layers include the same polymer (s). A method of forming a multilayer film according to claim 1 comprising a surface layer, and another layer under said surface layer, said surface layer and said other layer comprising the same organic polymer and being free of complexing agents, chelating agents and optionally mineral fillers in which the following successive steps are carried out: a) - an aqueous emulsion of said organic polymer is formed; b) - applying said emulsion comprising the organic polymer on the surface, whereby the film is formed by coalescence; c) - the surface of said film is impregnated with at least one agent capable of promoting the removal of a surface layer of the film by a rinsing liquid, so as to form a surface layer of the film containing at least one agent capable of promoting the removal of said surface layer of the film by a rinsing liquid. Process according to claim 24, in which formation of the film occurs by coalescence at room temperature or temperature of use of the surface. Process according to claim 24 between steps b) and c), a step of film drying. Process according to any one of 24 to 26 in which the agent to promote the elimination of the superficial layer of the film is chosen from the agents likely to promote the dissolution of the superficial layer such as surfactants. A method of forming a multilayer film according to claim 1 comprising a surface layer, and at least one other layer under said surface layer, said surface layer and said other layer comprising the same organic polymer and being free of complexing agents, chelating agents, and optionally of mineral fillers, in which the following successive steps are carried out: a) an aqueous emulsion of said organic polymer is formed; b) said emulsion is separated into a first and a second portion, c) adding to the first portion a first agent capable of promoting the removal of a layer of the organic polymer under the effect of a rinsing liquid, d) optionally adding to the second portion a second agent capable of promoting the removal of a layer of the organic polymer under the effect of a rinsing liquid, e) said second and second portions of the emulsion are successively applied to a surface, whereby a film comprising, from its surface, a layer comprising a first agent capable of promoting its elimination by a washing liquid and a second layer comprising a second agent capable of promoting its elimination by a washing liquid or not including said second agent, f) optionally repeating step e) for example from 1 to 40 times, preferably from 1 to 20 times. Method according to claim 28, in which said first and second agents differ by at least one of the conditions in which they favor the elimination for example the dissolution of the layer in which they are, for the cleaning liquid. Process according to claim 29, in which said conditions are selected from the temperature, pH, liquid composition of rinsing, and the pressure of the rinsing liquid. Process according to claim 29, in which the first agent is a surfactant A and the second agent is a surfactant B. Process according to claim 30, in which surfactant A is a surfactant which favors the dissolution of the layer in which he finds himself under the effect of a liquid for example a solution aqueous acid wash and the second surfactant B is a surfactant that promotes the dissolution of the layer in which it is under the effect of a liquid for example a basic aqueous wash solution, or vice versa. Method according to claim 28, in which formation of the film occurs by coalescence at room temperature or temperature of use of the surface. Process according to claim 28, further comprising a final step g) of drying the movie. Method for protecting, decontaminating or cleaning a surface in which the following successive steps are carried out: forming a film according to any one of claims 1 to 23 on said surface; the film is left in contact with said surface until it is contaminated, polluted, in particular by graffiti, or other unwanted inscriptions or markings; the polluted contaminated surface layer of said film is removed by rinsing with a liquid, preferably an aqueous liquid such as an aqueous solution. Method for protecting, decontaminating or cleaning a surface, in which the following successive steps are carried out: a) forming a film on said surface by the method according to any one of claims 24 to 27, b) the film is left in contact with said surface until it is contaminated, polluted, in particular by graffiti, or other undesired markings or markings, c) removing the polluted surface layer, contaminated with said film by rinsing with a liquid, preferably an aqueous liquid such as an aqueous solution, and d) the film surface is optionally impregnated with at least one agent capable of promoting the removal of a surface layer of the film, so as to form a surface layer containing at least said agent, e) optionally, steps c) and d) are repeated until the film is consumed. Method for protecting, decontaminating or cleaning a surface, in which the following successive steps are carried out: a) forming a film on said surface by the method according to any one of claims 28 to 34, b) the film is left in contact with said surface until it is contaminated, polluted, in particular by graffiti, or other undesired markings or markings, c) removing the first layer, polluted, contaminated with said film by rinsing with a liquid, d) the film is left in contact with said surface until it is contaminated, polluted, e) removing the second, polluted, contaminated layer of said film by rinsing with a liquid, preferably an aqueous liquid, such as an aqueous solution, f) steps b) to e) are optionally repeated until the film is consumed. Process according to claim 37, in which the first and second layers are eliminated in rinsing conditions such as temperature, pH, composition of the rinsing liquid, pressure of rinsing liquid, different. Process according to claim 38, in which the first layer which contains a surfactant A is removed by washing with an aqueous liquid, by example an aqueous washing solution, acid and the second layer that contains a surfactant B is removed by washing with an aqueous liquid, for example an aqueous washing solution, basic. Surface coated by the film according to one any of claims 1 to 23. Surface according to claim 40, selected from glass, polymer surfaces organic, stone, plaster, cement, plaster, metal; surfaces comprising more than one of these materials, or still the painted and / or enamelled surfaces. Substrate comprising a surface according to any of claims 40 to 41.