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

0001The present invention relates to a film or multilayer polymer film.

0002The invention also relates to the method of preparation, training, such a polymer film.

0003The invention also relates to a surface coated with such a film, such film, and a substrate, comprising such coated surface.

0004The invention relates finally to a process for protecting a vis-a-vis surface contaminants or pollutants using said film and a method of cleaning, decontamination, surface using likewise said film.

0005The technical field of the invention can be broadly defined, such as the cleaning of the treatment, decontamination, surface, and / or Protection vis-à-vis surfaces contaminants or pollutants, that the latter are chemical, radioactive, biological or bacteriological.

0006Specifically, the domain the invention is more particularly that of the protection, of surfaces, particularly surfaces of walls, facades, road signs, etc., against the graffiti and other undesirable inscriptions, and the cleaning of these surfaces to remove these graffiti and unwanted entries.

0007The graffiti refers so General [1], all the paintings, inscriptions, drawings or other forms of unwanted marks on a given surface. Graffiti is usually applied as paint in spray cans or ink markers.

0008At present, there are essentially four methods for protecting a surface vis-à-vis graffiti or eliminate them to said surface:<ul><li>Cleaning by abrasion, for example by sand blasting, or by projection of chalk, is a technique aggressive is costly, which requires long time labor liberates harmful particles and damage the surfaces.</li><li>The application of a new layer of Painting graffiti is not removed, it allows only to conceal when applied a painted surface.</li><li>Cleaning by chemical solvents sets implement aggressive chemicals, generates many pollutants and degrades surfaces effluents.</li><li>A final process category in which can be classified to the method of the invention calls for the implementation of coatings protectors.</li></ul>

0009Protective coatings avoid penetration and bonding of graffiti by modification of surface properties and by effect fence.

0010There are two types of coatings protectors: temporary coverings or sacrificial and permanent coatings.

0011Existing sacrificial coatings are base waxes, natural or synthetic based acrylic polymers or based on polysaccharides [2-6]. However, the materials described in these Documents have major drawbacks: waxes melt too easily heat and water, chemical solvents are used for their elimination and finally, it is necessary to deliver a new coating layer after each graffiti.

0012More specifically, the document [2] discloses a process of building protection against graffiti wherein a thin film is covered with paraffin, buildings likely to be contaminated. The wax can be applied hot melt or under the form of an aqueous emulsion. Soiled film is eliminated with great difficulty through brushes, scrapers, knives, or by melting paraffin, or burning the film.

0013The major disadvantage of the process of this document is thus to implement a film extremely difficult to remove.

0014Document [3] A composition nonstick, especially to protect various media against graffiti, containing aqueous medium least one synthetic wax derived from vegetable wax, associated with a non-ionic emulsifier and / or a wax microcrystalline.

0015Soiled composition may be removed from carrier by brushing or using an etchant, in particular in the case of very rough surfaces.

0016The composition of this document presents the disadvantages of not being sustainable and not be able be used only once.

0017Document [4] describes a system of graffiti coating comprising an agent of coating itself and a cleaning agent regenerating. The coating agent comprises a said base composition and a said additive composition graffiti.

0018The base is a group composition comprising acrylics and hydroxylated resins and their isocyanate hardener; and copolymer resins acrylic in solution in aromatic solvents and ketone. The graffiti additive is a composition incorporating a polyethylene wax, oil silicone, a polyurethane mixture, a solution acrylic. The cleaning agent is a mixture of wax polyethylene and a polar synthetic oil.

0019The system of this document is of a high cost and is not sustainable.

0020The paper [5] relates to a solution graffiti which is formed by combining an alcohol polyvinyl with a solution or emulsion of acrylic resin to form a mixed resin polyvinyl alcohol / acrylic partially cross-linked, catalysed by exposure to heat and / or light.

0021the solution properties are improved by adding a solution of a zinc complex tetramine containing zinc and / or a donor aldehyde such as formaldehyde or glyoxal.

0022In extreme cases of degradation, the film protector may be considered a membrane sacrificial. It can be removed by washing with a solvent such as toluene alternating with a caustic soda or ammonia solution and rinsing at the water.

0023We face in this document problems cost and high toxicity.

0024Document [6] discloses a method for protecting a surface contaminants and to facilitate removing said contaminants from said surface, in which :<ul><li>a solution containing a preparing polysaccharide that comprises at least two different polysaccharides, the first of these polysaccharides directly forming a film when precipitates for evaporating a solvent in the solution, and the second polysaccharide forms a film least partially by forming a gel when the precipitated from a solution by evaporation of a solvent therein, or the second polysaccharide forms a film at least partially by formation of a gel upon interaction with said during the first polysaccharide precipitation evaporation of a solvent; said films are may be redissolved or inflatable and solution containing the polysaccharide comprises a buffer to compensate for pH changes;</li><li>the solution is applied on a surface subject to contamination;</li><li>the solution is dried on the surface to form a solid film on the surface at least partially by formation of a gel;</li><li>the surface is exposed to a source of potential contamination;</li><li>on traite la surface revêtue par le film with a liquid capable of redissolving the film or swelling the film;</li><li>non-desired contamination is eliminated deposited on the surface by removing totally or partially the film from said surface.</li></ul>

0025The process of this document presents the disadvantage of implementing solvents.

0026The permanent coatings currently proposed are mainly based on polyurethanes (PU), silicones and fluoro compounds [1]. However, polyurethane is extremely sensitive to moisture and has a poor surface appearance. Silicones exhibit long duration of polymerization and are permeable to oils. The Fluorine compounds are toxic and require chemical solvents.

0027There are also some products possess anti-adhesion properties vis-à-vis paints and inks, but they have the disadvantage of being very expensive, about 15 Euros per m² treated in terms of material cost, and Besides losing their effectiveness after 3-4 cleanings.

0028Thus, document [7] relates to a method of treating a surface to form said coating on thereof, the coating having a colored surface and textured on which graffiti can not be easily applied. In this process:<ul><li>is applied to the surface to be coated a first layer of a primer coating and sealing which contains an aggregate and an agent binder;</li><li>is applied to the exposed surface of said a first layer coating composition contains an aqueous mixture of a material based on plaster, a binding agent, a filler to harden the coating composition, and a soluble dye in water ;</li><li>performing a texturing of the surface the exposed second layer to form a relief on thereof;</li><li>there is provided a hardening said second layer;</li><li>is applied to the second cured layer a cellulose-based topcoat containing a coloring material.</li></ul>

0029The method of this document changes the appearance of the surface and the coating composition can in fact be considered more or less like a painting.

0030Finally, FR-A-2822835 describes a film, dispersible as an emulsion in water comprising polymer and containing at least one chelating or complexing allowing decontamination, cleaning, and / or protection of various surfaces, including metal.

0031The film "removable" in this document, which form on the surface by applying an emulsion is aqueous latex, in the same way as paint, allows during removal of the lead area with it the impurities. This film can allow, upon removal of a surface moderate roughness lead him registrations who would find it. However, although this film removable polymer is inexpensive, about 2 Euros per m² Treaty, in terms of material cost, it is used only once since it must be took of. This withdrawal can be difficult on very rough surfaces such as plaster or cement gross, while the surfaces on which its membership is lower, as the road signs or glazing, it may be optionally removed by the "taggers" before applying graffiti.

0032In addition, some of its components formulation as fillers, complexing and chelators are harmful and opacify or color the film, for example, while the extra cost.

0033It has also been found that the residues organiques ou minéraux, généralement sous la forme de particles from the film described in this document, were present on the surface where it was applied and then removed. In addition, the same particles could cause degradation of the state of surface upon the application of the emulsion.

0034It appears that none of the techniques described in the documents of the prior art mentioned above is effective enough to allow total removal of graffiti from surfaces, and that, in addition, the existing techniques are expensive in terms of labor and reagent consumption chemicals, damage the surfaces and generate effluents.

0035There is a need for a polymeric film and a method for the decontamination, cleaning and / or protection of various surfaces and allow to completely eliminate pollutants contaminants from these surfaces.

0036In particular, a need exists for a polymer film that allows completely remove graffiti and all other registrations and unwanted markings from all surfaces such as walls, facades, road signs, etc., and / or allows to protect these surfaces against these inscriptions and graffiti with high efficiency. There is in other words a need for a film polymer that allows for cleaning and protection perfect the surface on which it is applied, then which it is withdrawn, that is to say that completely eliminate all pollutants, contaminants said surface: such as pollutants, contaminants from graffiti and markings inscriptions.

0037There is also a need for a film polymer which, while completely eliminating the contaminants or pollutants, from the surface, leaves no residue, and other contaminants on the surface during application of the emulsion (or solution) the container.

0038There are further a need for a film that can be easily and completely removed after use, and which permits separation and an easy recovery of components and Pollutants trapped contaminants. In other words, the film and the method must ensure excellent recovery and purification of valuable materials coupled with low impact the environment.

0039The film and method employing it must, moreover, be effective vis-à-vis all contaminants, especially of all contaminants which are the markings, graffiti or other whatever their form: solid particles, and other liquids, and nature: chemical, radioactive, biological and others.

0040This film and this process should finally be a low cost, easy to implement, safe and reliable, low aggressive vis-a-vis of the treated surface and if possible, keep to the surface, appearance visual an untreated surface.

0041In the case of a coating for more especially to remove graffiti from surfaces and / or to protect these surfaces against graffiti, criteria and requirements that must be met by such a coating are, among others, the following: <ul><li>the adhesion of the coating must be good with the surface to be treated, and with the significant bit graffiti;</li><li>the surface appearance of the coating defined in particular by its roughness, color, transparency and brilliance, must be adapted to the support treaty ;</li><li>the coating must be impermeable to air breathe to let the surface impermeable solvents markers and paints that are graffiti, inscriptions and markings Non-desired;</li><li>the coating must be chemically inert;</li><li>the components of the coating should only present no toxicity;</li><li>the storage time of the components coating before use and life of the coating must be satisfactory, especially the coating must withstand prolonged to exposure to high temperatures as well that low, humidity, UV rays, and other atmospheric factors, as well as constraints mechanical; Finally, the coating must survive long enough to, by such as allowing repeated removal of several graffiti successively applied to the surface.</li></ul>

0042In addition, a process for removing, by graffiti example, a surface and / or protection of said surface using a such coating must also meet a number criteria and requirements that are, inter alia the following:<ul><li>the coating film on the surface to be protected, to be treated must be performed by a simple process and eg roller or spray;</li><li>drying the film coating applied must be fast;</li><li>the coating must be used within wide ranges of conditions, for example of temperature, humidity, pH and the beaches of Use must be fully known and defined;</li><li>removing the coating must be done so simple, but specific, to avoid to ute Junk removal;</li><li>the process should be a low cost, fast, does not damage the surfaces, and must be repeated many times in order to allow repeated several graffiti removal successively applied to the surface.</li></ul>

0043The object of the present invention is to providing a polymeric film and a cleaning process, decontamination, or protecting a surface which meets, inter alia to all needs mentioned above and meets the requirements, criteria and conditions set out above for such film such a method.

0044The object of the present invention is particular, to provide a polymeric film and a method cleaning or protection of a vis-a-vis area graffiti, markings and unwanted entries which satisfies, inter alia, 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 process.

0045The object of the present invention is to providing a film and a method, which do not disadvantages, defects, limitations and disadvantages films and processes of the prior art and which solves the problems of the prior art.

0046This aim 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 layer and said other layers including at least an organic polymer and being free of complexing, chelating and optionally mineral fillers, and said layer surface further comprising at least one agent may favor the elimination of the layer surface by a rinse liquid.

0047Advantageously, at least one of said other layers under the surface layer includes additionally at least one agent capable of promoting removing said layer by a liquid rinsing.

0048The multilayer film may advantageously understand alternately a first layer comprising at least one agent capable of promoting removing said first layer by a liquid rinsing and a second layer not comprising agent capable of promoting the elimination of said second layer by a rinsing liquid.

0049Advantageously, all the layers comprise at least one agent capable of promoting disposal by rinsing liquid.

0050Preferably, two layers each contain an agent capable of promoting the elimination of said layers by a liquid rinsing, different.

0051Thus, the film of the invention may understand alternately a first layer comprising a first agent capable of promoting the elimination said first layer by a rinsing liquid, and a second layer comprising a second agent different from the first agent and may favor removing said second layer by a liquid rinsing.

0052Said different agents differ from Preferably, at least one of the conditions in which they favor the elimination of the layer wherein they are, by the liquid rinsing.

0053Said conditions are selected such of temperature, pH, composition of the liquid rinsing and pressure rinsing liquid, such as water.

0054Advantageously, the or the agent (s) (s) capable of promoting the removal of a layer by a rinsing liquid are selected from agents likely to promote dissolution of the layer in a rinsing liquid, and agents capable promote the emulsification of the layer in a cleaning liquid.

0055The film of the invention may so generally be defined as a film capable of being dispersed as an emulsion in water or capable of being dissolved in solution in water.

0056The agents capable of promoting the dissolution of a layer are advantageously selected from surfactants, preferably from the nonionic, anionic and cationic; and other additives such as acids or bases.

0057Examples of nonionic surfactants are esters of fatty acids, examples of anionic surfactants are sulfonates and carboxylates, and examples of surfactants are cationic alkylamines.

0058Advantageously, said surfactants and additives are selected from surfactants allowing the dissolution of the layer in which they are under the influence of an acid washing liquid, and the surfactants which allow the dissolution of the layer in which they are under the influence of a liquid basic wash.

0059Advantageously, the film comprises alternating a layer comprising a first surfactant A and a layer comprising a second surfactant B may be dissolved under conditions different washing.

0060Preferably, the first surfactant A is a surfactant which promotes, allows the dissolution of the layer in which they are located by a liquid washing acid, and the second surfactant B is a surfactant which promotes dissolution of the layer in which it is located by a washing liquid basic, or vice versa.

0061Advantageously, the surface layer is a thin layer generally having a thickness of 5 to 500 .mu.m, preferably from 5 to 100 .mu.m.

0062Generally, the total thickness of the film is 5 .mu.m to 2 mm, preferably from 50 to 500 .mu.m.

0063Generally, the layers other than the surface layer are of from 1 to 50, preferably from 1 to 20.

0064The polymer film according to the invention fundamentally from the films of the prior art and in particular films disclosed in FR-A-2822835.

0065Indeed, the film of the invention has a particular structure in the sense that this is a multilayer film, that is to say a film comprising several layers, which comprises a layer surface and at least one other layer in said surface layer. This is already a essential difference from the film art prior which are monolayer films. In addition, the surface layer of the film of the invention is a particular layer that contains specifically at least one agent capable of promoting removing said surface layer by a cleaning liquid.

0066The film according to the invention meets all the listed requirements above, meets all criteria, conditions and requirements listed in the above, and solves the problems of the prior art mentioned above.

0067The film of the invention can be defined as a multilayer film removal, for example dissolution, programmed by superficial treatment said surface layer and optionally one or more other layers using a liquid rinsing, for example, a rinsing solution, determined, data, which is generally suitable for the agent capable of promoting the elimination by such dissolution, or being in the said layers.

0068During rinsing, washing, specific, the treated surface layer dissolves and drives the pollutants, contaminants, such as paint or ink constituting graffiti, markings, Registration with it without damaging the coating inferior. The film can in this case be reused repeatedly by treating its surface by new thin layers so that they each contain Once one or more agents promoting the removal, the dissolution of the surface layer, and until consumption of the entire thickness of the film.

0069The film according to the invention can therefore be used several times, and it protects the surface on which it has been applied, especially against several Registration cycles and successive cleaning.

0070In the context of the preferred application of film of the invention, which is the fight against graffiti, markings and other entries not desired, the film according to the invention has the advantage to be totally impervious to inks and paints, and other components of these graffiti markings, and inscriptions.

0071In addition to the advantages and effects of the specific multilayer structure and nature specific for the surface layer of the film according to the invention, the polymer film according to the invention also fundamentally different movies of art Anterior and in particular films described in FR-A-2822835, in that it is free from chelating agents, complexing agents, and optionally mineral fillers.

0072Thanks to the absence of chelating agents, of complexing and optionally mineral fillers in the films according to the invention, no organic residue or mineral, for example in particulate form, from the film is left on the surface on which it is applied and then removed.

0073It has been demonstrated, in fact, according to the invention that the components of the formulation film described in FR-A-2822835 were useless or harmful, especially in the case of graffiti treatment of surfaces and left residue on the surface after the removal.

0074In addition, the fact that the emulsion from which is prepared the film of the invention, not comprises, or complexing or chelating agents, or of Preferably, loads, it is not found in the emulsion from which the film is prepared from particles can cause when applied a degradation of the surface condition.

0075The absence of complexing agents, chelating agents, and optionally fillers in the film according to the invention also results in a decrease in the cost of film formed and simplifies the preparation of the formulation from which the film is prepared.

0076Finally, the absence of complexing agents, chelating and optionally fillers in the film according to the invention avoids the coloring or opacification film, which is particularly advantageous in anti-graffiti preferred application of the film according to the invention, in which you want to keep the visual appearance of the treated surface.

0077In particular, it was noted that the absence charges does not harm the overall film properties because it is not subjected to mechanical stresses high (indeed, the film coat is not binding, and further the mechanical properties of the film may be improved by addition of other polymers such as PVA thus avoid having use of fillers) but enables against to obtain, after removal of the film, the surfaces of a perfect cleanliness, never achieved in the prior art and which has been demonstrated by spectrometric analysis infrared.

0078In addition to the essential effects and benefits to the specific multilayer structure, and lack complexing agents, chelating agents and optionally loads, the film of the invention has all the advantageous properties already presented by the Film FR-A-2822835 and due to the fact that this film comprises a generally non-soluble polymer, insoluble in water.

0079The film, according to the invention is, in fact, prepared from an aqueous emulsion of said polymer (Or said polymers), and thus, the polymer may be easily recovered after use movie by re-emulsion and flocculation, which is not possible with polymers, water-soluble, of some of the films of the prior art.

0080The film according to the invention meets all needs, requirements and criteria mentioned above, for example: it allows with great efficiency and reliability of trap, as curative or preventive, contaminants, pollutants in a surface layer, sacrificial on the surface treated, that is to say that it is not only the contamination on the surface which is trapped, but also that occurring immediately under this surface.

0081The film according to the invention allows control of the release of the contaminant, retaining one in it.

0082The mechanical properties, adhesion and cohesion of the film are excellent, even in the absence possible charges, and provide very good performance on any surface, while allowing removal easy, in particular by peeling.

0083The film is a low cost. He can be prepared with readily available products Trade and easy procedures to be work, for example by application of an emulsion simply by brushing or spraying said emulsion on the surface.

0084The film is not aggressive vis-à-vis the surface on which it is applied. It does not in nothing the latter properties (it can even improvement), even after a long time, eg upon prolonged storage.

0085It does not degrade the appearance of the surface. In Furthermore, in most cases, the film being colorless and transparent, it does not affect the visual appearance of the surface.

0086The film is made from non compounds Toxic vis-à-vis staff, and low impact on the environment.

0087In addition, all the constituents of the film can easily be separated, recycled and / or destroyed, low cost, at the end of use of the film.

0088The film according to the invention allows cleaning perfect the surface on which it is applied, then removed; it leaves no residue on the area.

0089Thus, it was shown that no trace organic residues from the film is not detectable on the surface after removal of the film as it was confirmed by analysis of the surface after removal of Film by infrared spectrometry with accessory attenuated total reflection multi-reflections in the spectral range 4000 to 600 cm^-1.

0090The film of the invention provides long-term protection vis-a-vis pollutants and external contaminants whatsoever.

0091Advantageously, the film of the invention is non-porous.

0092The polymer is generally chosen from polymers may be in the form aqueous emulsions of latex.

0093Preferably, this polymer capable of find in the form of an aqueous emulsion is selected from styrene-butadiene copolymers styrene- (meth) acrylic styrene e.g. (Meth) acrylate (see below the definition of the term (Meth) acrylic acid) and polymers (homopolymers and copolymers) (meth) acrylic.

0094By (meth) acrylic is meant generally homopolymers and copolymers all may be prepared by polymerization of acrylic acid, methacrylic acid and esters thereof: as acrylate and methacrylate alkyl (C₁ -C₆) Such as (meth) acrylate methyl or ethyl.

0095Advantageously, the film may include more polymers may be in the form of aqueous emulsions, preferably selected from styrene-butadiene rubber (SBR) and styrene (meth) acrylic acid, for example styrene- (meth) acrylate, which have, in addition, preferably, the glass transition temperatures (Tg).

0096Advantageously, one can use a polymer such as a styrene-butadiene, said self-dispersing.

0097The film may further comprise one or more other polymers which are polymers likely to be in aqueous solution (such Minority polymers are in general) (no longer in emulsion), which are chosen from polyvinyl alcohol (PVA), and PVP (Polyvinylpyrrolidone).

0098Some of these polymers such as PVA possible to improve the mechanical properties and to avoid the use of fillers.

0099Preferably, in particular to facilitate the preparation of the film, all layers (surface and others) of the film are the same or polymers. This means that these layers are differ only by the presence or absence of an agent by facilitant l'élimination et/ou par la nature dudit agent.

0100The 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 another layer comprising the same organic polymer and being free of complexing agents, chelating agents and possibly fillers mineral, wherein the steps are carried out following successive:<sl><li>a) - an aqueous emulsion is formed of said organic polymer; </li><li>b) - applying said emulsion comprising the organic polymer on the surface, whereby the film is formed by coalescence;</li><li>c) - impregnating the surface of said film to least one agent capable of promoting the removal a surface layer of the film by a liquid rinsing, so as to form a surface layer of film containing at least one agent capable of promote the removal of said surface layer the film with a rinsing liquid.</li></sl>

0101The film is formed, usually quickly, a few minutes, namely for example 1 or 2-10 minutes on the surface, by coalescing.

0102Advantageously, the formation of the film produced by coalescence at room temperature or température d'utilisation de la surface (température à which is the surface) without drying the surface and / or parts comprising this surface.

0103Indeed, given the conditions generally used to implement the emulsion intended to form the film of the invention, namely with some qualified staff, and to reduce complexity of the material used to form the film, being able to afford an education without Drying is an important advantage of the film and the process according to the invention.

0104According to the invention, the film formation can be carried out at ambient temperature without any heating parts to cover and without use hot air, including on vertical surfaces, which is particularly advantageous.

0105coalescing conditions are advantageously chosen so as to avoid porosity, which is opened or closed in the film final got formed.

0106However, under certain conditions of employed, the method of the invention further comprises, between steps b) and c), a step of drying movie.

0107Training and optional drying of the film are made according to the invention without any drainage or no absorption of any liquid entering the composition of the emulsion.

0108In this method, the agent capable of promoting the removal of the surface layer of film is chosen from agents capable of promote dissolution of the surface layer, such as surfactants.

0109In a second embodiment, the invention relates to a method of forming a film multilayer, as described above, comprising a surface layer, and at least one other layer under said surface layer, said layer surface and said another layer comprising the same organic polymer and being free of complexing agents, chelating agents, and optionally mineral fillers, in which the successive steps are carried out following:<sl><li>a) an aqueous emulsion is formed of said organic polymer;</li><li>b) separating said emulsion into a first and second portions, </li><li>c) adding to the first portion a first agent capable of promoting the elimination of a the organic polymer layer under the effect of a liquid rinsing,</li><li>d) optionally adding to the second a second portion agent capable of promoting removing a layer of the organic polymer in the effect of a rinsing liquid,</li><li>e) successively applied said first and second portions of the emulsion on a surface, whereby a film is formed comprising since its surface a layer comprising a first agent capable of promoting its removal by a washing liquid and a second layer comprising a second agent capable of promoting its elimination by a washing liquid or not comprising said second agent,</li><li>f) optionally repeating step e) by example from 1 to 40 times, preferably 1 to 20 times.</li></sl>

0110After application of the second and first portions of the emulsion, the layers are formed under the conditions already described above, generally rapidly, for example in some minutes, for example 1 or 2 to 10 minutes by single coalescence.

0111In this second embodiment of the method of forming the film of the invention, of Preferably said first and second different agents by at least one of the conditions in which they help eliminate such dissolution, of the layer in which they are located, by the cleaning liquid.

0112Advantageously, said conditions are selected from temperature, pH, the composition of rinsing liquid, and the pressure of the liquid rinsing.

0113The first agent is e.g. surfactant A and the second agent is for example a surfactant B.

0114Preferably, the surfactant A is a surfactant which promotes dissolution of the layer wherein it is under the effect of a liquid aqueous washing, e.g., a wash solution, aqueous, acid and the second surfactant B is a surfactant which promotes dissolution of the layer wherein it is under the effect of a liquid aqueous washing, e.g., a wash solution, aqueous base, or vice versa.

0115As in the case of the first embodiment embodiment of the method for forming a film according the invention, the formation occurs by coalescence at room temperature or temperature use of the surface.

0116However, a final drying step g) film can be provided.

0117The invention further relates to a method of protection, cleaning or decontamination, a area in which the successive steps are carried out following:<ul><li>a film is formed, as described above, on said surface; </li><li>the film is allowed in contact with said surface until it is contaminated, polluted, especially by graffiti or other markings or unwanted markings;</li><li>and the surface layer is removed from said film with a rinsing liquid, preferably a aqueous liquid such as an aqueous solution.</li></ul>

0118The surface on which the film is formed is essentially a clean surface, free of pollutants or contaminants, the latter being usually from the outside environment which is in contact with the surface layer.

0119In a first preferred embodiment This method of protection, cleaning decontamination of a surface, the steps are carried out following successive:<sl><li>a) forming a film on said surface by the method of forming a film in its original form implementation,</li><li>b) allowing the film in contact with said surface until it is contaminated, polluted, especially by graffiti or other markings or unwanted markings,</li><li>c) the surface layer is removed polluted contaminated said film by rinsing with a preferably an aqueous liquid such as a liquid aqueous solution, and</li><li>d) optionally impregnates the surface of the Film with at least one agent capable of promoting removing a surface layer of the film, to form a surface layer containing at less said agent,</li><li>e) optionally repeating steps c) and d) until consumption of the film.</li></sl>

0120In a second preferred embodiment of the method for protecting, cleaning or decontamination a surface, the successive steps are performed following:<sl><li>a) forming a film on said surface by the method of forming a film in its second form of production,</li><li>b) allowing the film in contact with said surface until it is contaminated, polluted, especially by graffiti or other markings or unwanted markings,</li><li>c) removing the first layer, polluted, said film contaminated by rinsing with a liquid,</li><li>d) allowing the film in contact with said surface until it is contaminated, polluted,</li><li>e) removing the second layer, polluted, said film contaminated by rinsing with a liquid preferably an aqueous liquid, such as a solution aqueous,</li><li>f) optionally repeating steps b) to e) until consumption of the film.</li></sl>

0121Preferably, the first and second layers are removed in rinsing conditions such as temperature, pH, composition of the liquid rinsing, different rinsing liquid pressure.

0122Advantageously, the first layer contains a surfactant A is removed by washing with an aqueous liquid, for example an aqueous solution of washing acid and the second layer which contains a surfactant B is removed by washing with a liquid aqueous, eg an aqueous washing solution, basic.

0123In the case where it is carried out the elimination of superficial layer of the film according to the invention by dissolution of the film in an aqueous medium, thereby obtaining an aqueous solution or emulsion containing the material organic, and contaminants or pollutants. material organic is separated from the solution by flocculation, then filtration. It is then generally rejected or eliminated, for example by incineration.

0124The contaminants or pollutants are separated by filtration.

0125The invention further relates to a surface coated by the film as defined above, and substrate, in particular a workpiece or optical component comprising such a surface.

0126The invention will now be described in detail in the description which follows, given as illustrative and not exhaustive, in particular some preferred embodiments of the invention.

0127In a first step, one starts by formulate, by preparing an aqueous emulsion of one or several polymers, latex.

0128By polymer is meant, in this description, as well as homopolymers copolymers prepared from various monomers.

0129Among the preferred polymers and copolymers, there may be mentioned copolymers of styrene with butadiene rubber (SBR) or of styrene with a compound (Meth) acrylic acid such as (meth) acrylate.

0130These copolymers may have rates various styrene, or even polymers (Meth) acrylic.

0131Recall again that a polymer (Meth) acrylic means all copolymers homopolymers may be prepared by polymerisation of acrylic acid, the acid methacrylic acid and esters thereof such as acrylates and alkyl methacrylates (C₁ -C₆), Such as (meth) acrylate or ethyl.

0132Preferably, use of emulsion aqueous latex commercially available from Examples of such emulsions are the emulsions Bayer® available from the Company, under the BAYSTAL® name.

0133These emulsions particular advantage a low cost, very low toxicity, and a absence of organic solvent.

0134The emulsion may include only one polymer may be in the form aqueous emulsion, but can also include two or more of these polymers selected preferably from styrene-butadiene (SBR), and styrene (meth) acrylic styrene e.g. (Meth) acrylate having, for example, temperatures of glass transition temperature (Tg) and / or rate of various styrene, so as to obtain a compromise between adhesion and cohesion of the film adapted to the surface to be treated.

0135Thus, a first polymer may have a Tg of -30 ° C to -5 ° C and a second polymer Tg + 5 ° C to + 50 ° C.

0136As polymer blend in emulsion, dispersion, we can, for example, use a mixture of two or more than two selected from latex preferably from styrene-butadiene latex and styrene (Meth) acrylic acid, for example styrene- (meth) acrylate, having, preferably, transition temperatures different glass and / or styrene content different.

0137It is best to use a latex-free surfactants that can leave residues on area. Eg, you can use a mixture of styrene-butadiene 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.

0138To this mixture may, optionally, add a solution of polyvinyl alcohol (PVA) or polyvinylpyrrolidone (PVP) (Solution Polymers) and / or optionally one or more other polymers in aqueous dispersion, selected (s) for example, from polymers of (meth) acrylic acid, such as have been defined upper.

0139According to the invention, the formulation is free complexing agents, chelating and preferably it is free of filler when it is desired in particular that the film prepared to be transparent. However, in some applications, it is possible that the emulsion, formulation called "basic formulation" contains one or more fillers selected from, for example ZnO, mica, clays called "nanoclays". a formulation typical aqueous, preferably free of charge for example contain from 30 to 60% water, of additionée SBR with 20 to 60% by mass and polymer acrylic at 1 to 20% by mass. The latter can advantageously be replaced by alcohol polyvinyl in the same proportions.

0140Thus, it is possible for example to proceed mixture of 2 SBR having different styrene rate, namely BAYSTAL® S42 and S44, in aqueous emulsion (30 to 70% water) in a proportion of 50/50, then there optionally adding between 1 and 10% of a mixture of acrylic polymers based on ethyl acrylate and methacrylic acid (aqueous dispersion of 20 to 70% by weight of polymer), and then add optionally a polymer solution such as PVA.

0141A particularly preferred composition comprise by weight: 0 to 20% PVA, e.g. 15%; from 0 to 50% BAYSTAL® S42 for example 17.5%; from 0 to 50% BAYSTAL® S44, for example 17.5%; and of 30 to 70% of water for example 50%.

0142When several latex is used, preparing the emulsion, usually by simple mixing of various latex, preferably stirring.

0143This basic aqueous emulsion formulation communicate to the inventive films all benefits listed above as components taken separately have drawbacks related to their low strength and solubility which do not allow use of the [5; 7].

0144then applied aqueous emulsion or the polymer (s) on the surface to clean, decontaminate or protect.

0145There is no limitation on the nature and the shape of the surface to be treated. This surface may be a metal surface, or organic polymer, or glass or stone, plaster, cement, plaster or other or a surface comprising a plurality of these materials or yet a painted or enameled surface; the surface can be non-porous, non-absorbent, or porous, can be smooth or rough.

0146Advantageously, the emulsion is formulated to allow the formation of a nonporous film on a non-porous support and the application of the emulsion must be possible on non-carriers absorbents such as metals, glass and other plastic substrates.

0147It may be also of the surface of the top layer of a monolayer coating or multilayer protective or a decorative substrate such as a wall, a billboard or signaling or another.

0148Such top layer is e.g. a coat of paint, varnish or the like.

0149The surface may be opaque or transparent, this is one of the advantages of the invention to permit the processing, protection of surfaces transparent, such as portholes, windows, because the film formed according to the invention is generally transparent and colorless in particular due to the absence fillers and do not mask the surface. That is particularly advantageous on surfaces transparent.

0150According to the invention, the shape of the surface may be arbitrary, and can be treated with a same efficiency, as well as surfaces Simple and complex.

0151The size of the area may be any but the invention allows to treat large or even very large areas quickly, without modifying them, nor degrade.

0152The invention whose main application Protection vis-à-vis surfaces graffiti, unwanted inscriptions and markings whatever their nature and mode of application: aerosol, buffer, etc ..., the surface may be part in particular a wall or any other part of a building or structure, or a billboard or signaling.

0153The emulsion can be applied to the surface by any known means, for example, by spreading the brush or roller or by projection / spray.

0154The film is formed (e.g., over a period from 1 to 30 minutes) by coalescence "in situ" or the polymers on the surface.

0155Film formation is fast to operating temperature of the equipment surface is part. For example, this temperature can be 10 to 70 ° C, preferably from 5 at 50 ° C.

0156The film can usually then be dried, for example by evaporation, at a temperature of 5 to 50 ° C.

0157The film is generally transparent to drying (when it contains no fillers). this Indeed, the surface retains the visual appearance of a surface not treated. Said film, once formed, has a role protection agent vis-à-vis contamination and an external role of agent decontaminant, cleaner, said surface due to the elimination of the layer of surface rinsing after it has been polluted, contaminated, dirty.

0158The film according to the invention is applied to preventively on a clean surface, as agent vis-a-vis protection from contamination or it may even be applied for curative decontaminate, clean the surface.

0159The contaminants and / or external pollutants can be removed from the surface in the layer surface of the film in which they are located, and vis-a-vis the surface of which may be protected, are of various kinds. This may be particularly chemical contaminants or pollutants, such as Pb, Cd, and / or radioactive contaminants, such as cesium, or of biological contaminants (e.g., bacteriological).

0160In particular, contaminants repelled the film according to the invention, and which are removed in the surface layer of said film are the contaminants and pollutants which are found in paints, inks and other labeling products which are used to form graffiti, markings and other unwanted inscriptions. pollutants will therefore for example, pigments, binders, resins, polymers, plasticizers, solvents present in Such inks and paints.

0161In a first embodiment, the emulsion, base formulation can be applied directly on the surface, such as a painting, where it will form a film on drying.

0162The film surface is processed after drying using a specific surfactant or other product facilitating its removal, such dissolution. In this case, the film thickness, for example from 5 to 500 .mu.m, wherein the surfactant or other agent penetrated becomes soluble in aqueous media such under specific conditions, eg temperature and pH, and removal of the graffiti is by washing, rinsing, with a washing fluid such as an aqueous medium, eg an aqueous solution. The Washing can be carried out under pressure and the fluid may simply be water optionally heated for example from 0 to 145 ° C and optionally under pressure.

0163Washing, rinsing, led the restoration solution or emulsion of the portion of the film processed. The graffiti is then removed simultaneously with said fraction of the dissolved film. The film portion not treated remains intact. It is then possible to treat again the surface of the remaining film by example using the same surfactant or other component and repeat until total consumption movie.

0164If the film surface is not treated by an additive facilitating its dissolution, then all the film is peeled as a skin and eliminates graffiti which starts with said skin.

0165In the case where one proceeds to dissolution of the film surface layer in an aqueous medium by example in aqueous solution, separating the material organic flocculated by introducing a flocculating specific Bayer®, followed by filtration of the flocs and trained. The organic material can be recovered and destroyed by incineration.

0166Pollutants contaminants are, in turn, filtered, typically in the form of insoluble granules.

0167In another embodiment, the base formulation can be separated into two batches (or more) to be additivated to two (or more) kinds various surfactants or other additives. By example, two types of surfactants A and B may be used so that the polymer films respective containing the information are soluble in wash conditions different A and B, for example pH different and / or different temperature, and / or overall chemical composition of the solution different washing.

0168In this case, a multilayer film is drawn with alternately applying formulations A and B.

0169When the surface is soiled by graffiti, il suffit de laver la surface à l'aide d'une solution Type A washing if a layer having the A formulation is in surface. Graffiti is removed along with said layer while the underlying layer of formulation B remains intact. When formulation B layer is polluted, it enough to eliminate using a wash solution type B and so on until consumption complete the multilayer film. Treating Effluent disposal, dissolution is analogous to that described in the first embodiment production.

0170The film and the methods of the invention find application in any treatment preventive vis-à-vis contamination or pollution - whatever the nature and form - all surfaces.

0171The method and the film of the invention are essentially preventive, which means that the film is applied on non-degraded surfaces for protect vis-à-vis the entries made later.

0172The invention will now be described in reference to the following example given as an illustration and without limitation.

EXAMPLE

0173an aqueous emulsion is prepared (45 to 55% by mass of water), free of fillers, comprising a mixture equally (50/50) of two types of SBR contents various styrene (BAYSTAL® S42 and S44). is added to this emulsion, with stirring, a mixture of acrylic polymers based on ethyl acrylate and methacrylic acid in the form of a suspension from 28 to 32% by weight of water.

0174Once spread on a wall such as a wall or a road sign with a simple application such fashion that brush, roller or spray, the coating is dried in ambient air at a temperature between 5 ° C and 50 ° C and a relative humidity between 10 and 80%. The Drying time varies depending on the thickness to 200 microns, must be between 1 and 3 hours. Drying is easy mark because the coating gradually becomes transparent. A mixture of nonionic surfactants comprising 50% by weight of fatty acid ester and 50% by weight of alkyl phenol ethoxylate is brushed onto the dry coating. By drying in ambient air, it enters the outermost surface of the film.

0175Then a graffiti in black paint aerosol is sprayed on the dry coating and allowed to dry in ambient air.

0176The sample is passed under hot water and a thin layer of polymer naturally eliminates taking with it the graffiti. The surface of milky coating is then (for wet) but is cleaned of all traces of graffiti. The coating drying resumes its transparent appearance and then ready for another graffiti-cleaning operation.

REFERENCES

0177<sl><li><b>[1]</b> Saidi S., F. Guittard, Géribaldi S., Polymers against graffiti. topicality chemical 03/2001; 3-13.</li><li><b>[2]</b> Pomero V. FR-A-2,686,615 of January 27, 1992.</li><li><b>[3]</b> Salvoldelli C., WO-A-80 01072 of the November 16, 1979.</li><li><b>[4]</b> Turzan G., FR-A-2,630,353 of April 25, 1988.</li><li><b>[5]</b> Hansen RP, US Patent 4,169,088 of May 30, 1978.</li><li><b>[6]</b> S. Swensson, US Patent 5,750,189 of September 10, 1996.</li><li><b>[7]</b> Rawlins PR, US-A-4,428,994 of July 15, 1981.</li></sl>