MXPA98001924A - Improved coatings against graphite and method to remove graf - Google Patents

Abstract

A method for removing dirt and graphite marks from a previously formed barrier coating on an underlying surface is provided, wherein the method retains rather than sacrificing the barrier coating. The method includes applying a solvent system that includes at least one non-toxic organic solvent such as 1-methyl-2-pyrrolidinone to one area of the barrier coating. A method is also provided for improving the strength of a protective barrier coating for marking with graphite and other dirt over time, and thus facilitating any necessary cleaning of this barrier coating. The improvement in the case of wax coatings is achieved by including in the wax, at least one chemical protective agent selected from the group consisting of ultraviolet light absorbers in water / insoluble in water, free radical scavengers and peroxy radicals soluble in water. wax / insoluble in water, and wax-soluble wax-soluble / water-insoluble antioxidant. The improvement in the case of sodium silicate coatings is achieved by including in the coating material, an anionic or nonionic surfactant which improves the adhesion, cohesion and durability of the barrier coating, and which is compatible with the solutions and Aqueous silica emulsions

Description

IMPROVED COATINGS AGAINST GRAPHITE AND METHOD TO REMOVE GRAPHITE The present invention relates to improved coating materials against graphite and dirt for the protection of interior and exterior surfaces of buildings and other structures, and improved materials and methods for removing graphite and dirt from these coated and protected surfaces. In recent years there has been a growing interest in the costly damage caused by graphite. As noted by Black in U.S. Patent No. 5,387,434, (hereby incorporated by reference herein), it is particularly difficult to remove paint from graphite, permanent ink and other marking materials embedded in porous surfaces such like blocks of concrete, limestone and wood. An antecedent for the problem of graphite, and complications involve the removal of graphite from painted and unpainted surfaces, is provided by Black in the earlier patent as follows: In attempts to address the problem of graphite, much emphasis has been placed on cleaning techniques to be used in the treatment of surfaces to remove graphite. A common technique is to apply a paint remover coating, such as methylene chloride, benzene or toluene. After the coating settles for a while, it is removed by vigorous washing. This procedure can be repeated two to four times. Any graphite residue is then removed by sandblasting or sanding, which may require refinishing the surface to restore it to its previous appearance. Another technique to deal with graphite is to simply repaint the surface, which is disadvantageous because of the time and expense involved. The use of paint removers is disadvantageous and results in the release of harmful vapors, which harm both health and the environment. In addition, paint removers tend to soften and remove the underlying paint. Specialized cleaning compositions have been developed to remove graphite. Examples of these cleaning compositions are disclosed in U.S. Patent No. 5,024,780 to Leys. These cleaning compositions are designed for the removal of graphite and not as coatings against graphite. Guards against graphite for use as protective coatings have also been developed. These protectors have not been satisfactory for several reasons: they are not effective against all types and colors of graphite; These are expensive to manufacture; they are difficult to apply, usually require clean, oil-free and dry surfaces; they can not be applied to painted surfaces; and they are environmentally damaging, often having a high volatile organic content. To overcome the problems described above, Black described various protective coating compositions against graphite containing, mainly, either micro crystalline wax, sodium silicate, or combinations of wax and sodium silicate. The wax-containing compositions are water resistant and preferred for outdoor use, while the sodium silicate barriers slightly soluble in water are very useful for indoor use. Black also describes methods for applying these coatings and for the subsequent removal of graphite from protected surfaces. In summary, water-based coatings, substantially free of organic solvents, are applied and cleaning is achieved by using pressurized hot water to remove by washing the graphite together with a part of the protective coating. In the case of sodium silicate coatings, the silicate barrier tends to dissolve in hot water as the graphite is removed, while a wax barrier tends to soften and melt in the water, removing the applied graphite in this way. Protective coatings containing a mixture of microcrystalline wax and sodium silicate in varying proportions, or alternatively, a layer of wax applied on a layer of sodium silicate, were also formulated and successfully tested by Black. The paint graphite and permanent marker were again successfully removed by washing with hot water at a temperature between 120 and 190 ° C approximately, and applied with a pressure of at least 250 psi. Using this method, following several turns of application and removal of graphite, Black has found that the sacrificial silicate or wax protective coating must be reapplied to preserve the integrity of the graphite barrier. There is extensive literature on methods that are useful for producing, applying and removing temporary protective coatings such as the microcrystalline and silicate wax coatings used in the present invention. For example, Clapp, U.S. Patent No. 1, 787,338, discloses methods for producing wax dispersions in sodium silicate solutions, useful for waterproof surfaces. Berg, U.S. Patent No. 2,260,882, discloses a protective coating for interior wall surfaces, in which bentonite and vegetable gum are applied in water, and the resulting coating can then be removed by simple washing. Fisher, Patent of the US Pat. No. 3,102,038, describes a temporary protective coating for metal surfaces, in which a film consisting of sodium silicate particles in a binder is easily applied in a water solution, and subsequently removed by washing or steam cleaning. Hereth et al., U.S. Patent No. 4,315,957 discloses the use of an aqueous hydrocarbon wax emulsion to form a temporary waterproof protective coating for metallic and lacquered surfaces, in which a water-steam mixture is used. to remove the coating. Sejournant, U.S. Patent No. 4,349,586, describes the application of a protective coating and / or against graphite containing at least one wax, such as microcrystalline wax and silicone oil dissolved in an organic solvent. The graphite, along with the dry wax coating, are removed by means of a paint remover or pressurized hot water jet whose temperature exceeds the melting point of the wax. Kawataba, U.S. Patent No. 5,049,186, discloses a water-based, solvent-free wax emulsion containing an emulsifier and a dispersed phase including petroleum wax, an oxygen-containing wax, an ethylene / olefin, a fatty acid, and other constituents which may include antioxidants and ultraviolet absorbers. The coatings form environmentally resistant, waterproof protective barrier films that can be removed with hot water containing kerosene. Helmstetter, U.S. Patent No. 5,246,495, discloses a waterproof coating for cement surfaces, which includes sodium silicate, a surfactant, and an aqueous solution containing a polysiloxane. In the prior art there are very few teachings of the selective removal of graphite, paint, ink and the like, from a barrier protective surface consisting mainly of wax, sodium silicate or combinations thereof, without removing the same barrier. The reason for this lack of information is that the zero or silicate barrier is considered as a sacrificial material, and the dissolution or fusion of the underlying barrier is considered the easiest method to remove the graphite. In Leys, U.S. Patent No. 5,024,780, a cleaning composition for the removal of graphite containing 1-methyl-2-pyrrolidinone, propylene carbonate and thickening and dispersing agents is described. Leys proposes that the disclosed cleaning composition can remove the graphite without damaging an underlying coated surface in a protective manner. The applicant has obtained a sample of a commercial product known as "PGR" (manufactured by A.G.P. Systems, Inc., Windham, N.Y.), which is constituted in accordance with the Leys patent. This product has been tested for its stability to remove graphite from paint and ink, applied to the graphite wax and sodium silicate barriers described in Black, U.S. Patent No. 5,387,434. Although the PGR product removed the graphite, it also removed Black's graphite barrier. Similarly, Valasek, U.S. Patent No. 4,664,721, discloses a print screen cleaner containing 1-methyl-2-pyrrolidinone, an oxygenated solvent such as cyclohexanone, and a surfactant. This cleanser dissolved the waxes and, therefore, is not useful in the present invention. Similarly, Jackson et al., U.S. Patent No. 4,780,235, discloses a paint remover and Madsen, U.S. Patent No. 4,836,950 discloses a cleaner for printing inks containing 1-methyl-2-pyrrolidinone and a number of other constituents that are known to dissolve waxes. Because the compositions described in these patents dissolve the waxes, these compositions are not suitable to be useful in the present invention.

BRIEF DESCRIPTION OF THE INVENTION The present invention gives importance to methods for selectively removing graphite from graphite barrier coatings containing microcrystalline wax and sodium silicate, such as those of Black, U.S. Patent 5,387,434 without damaging the barriers by themselves. The invention also gives importance to the improved coating materials, which provide more durable and easily cleanable barriers that are not sacrificed during the graphite removal process. In a first aspect, the invention gives importance to a method for removing the marks of dirt and for graphite must a coating of barriers on an underlying surface, comprising the steps of applying an absorbent system to a barrier coating area wherein the The solvent system contains a functionally effective concentration of at least one substantially non-toxic organic solvent that softens and dissolves dirt and graphite marks without substantially dissolving the barrier coating, and removing the dirt and graphite marks by a mechanical means . By "graphite" is meant any undesired mark formed on a surface. This mark is made by painting, drawing or writing or by other means. Graphite is typically applied using paints, usually applied by spray cans, or markers. The paints are typically oil-based paints that include enamels, epoxies, lacquers and urethanes. The markers are typically color markers that have dyes pigmented with fast-drying solvents. See Black, United States Patent 5,387,434. Graphite can also be made by pencils, crayons, lipsticks, pens or any other similar marking device. By "dirt" is meant any of the marks made by these sources such as soot and smoke carried by the air, pollutants bearing in the rain, radioactive particles carried by the air, residues of grease, contact with human hands, contact with the soles of the shoes, contact with the tire rubber, or other similar sources. By "barrier coating" is meant a coating on an underlying surface formed from a coating material that protects the underlying surface from penetration by marking with graphite and staining. Preferably, the coating material used to form the barrier coating is substantially free of toxic organic solvents. More preferably, the coating material comprises water and at least one member selected from the group consisting of mineral waxes, synthetic waxes, and silicates, wherein said member is present in the coating material in an amount sufficient to form a coating of substantially adherent and continuous barrier against the penetration of the marks by graphite to said underlying surface. More preferably, the barrier coating is one of which is described by Black in U.S. Patent 5,387,434. The surfaces treated with said coating material to form the barrier coating can be selected from the group consisting of painted and unpainted surfaces, porous and non-porous surfaces, concrete, brick surfaces, stone surfaces, metal surfaces, surfaces of wood and plastic. By "solvent system" is meant a solvent or a mixture containing one or more solvents that dissolve and / or soften the graphite or dirt marks. Preferably, the solvent system contains a functionally effective concentration of at least one organic solvent. It is preferred that the solvent be substantially non-toxic. It is also preferred that the solvent system contains a dipolar aprotic organic solvent, as described below. The solvent system may also contain one or more diluents, and / or thickening agents, as described below. By "preserving rather than sacrificing the barrier coating", or "without substantially dissolving the barrier coating", it is implied that the solvent system does not significantly remove the barrier coating from the underlying surface. The point or limit of the removal can be determined by visual examination and / or determination by water repellency. Preferably, the coating material used to form the barrier coating (eg, mineral waxes, synthetic waxes, or silicates), is not soluble or is only slightly soluble in the solvent system. By "applying" it is meant to contact the surface having the barrier coating with the solvent system by means known to those in the art. These means of application include, but are not limited to, spraying, brush application or roller application. By "mechanical means" is meant the use of at least a slight amount of physical force in the removal of graphite or dirt. These mechanical means may include rubbing, brushing, cleaning with a cloth, the use of washing with a mixture of pressurized aqueous spray with high or low pressure at high, low or ambient temperature, cleaning by compressed air, or any other known means . The present invention is based on the recent application and surprising discovery that a dipolar aprotic organic solvent, 1-methyl-2-pyrrolidinone (hereinafter abbreviated MPD), and to some extent, 2-pyrrolidinone (abbreviated hereinafter PD) ), can selectively remove graphite, including oil-based paints and permanent marker inks from both the crystalline ceramic emulsion coatings and graphite barriers based on sodium silicate as described by Black, without Dissolve or remove any substantial amount of the barriers by themselves. The cleaned barrier coatings appear intact and without structural alteration, so that they can continue to provide the ratio against the graphite without the need to coat the underlying surface. While MPD is a known constituent of paint removal products for architectural surfaces, the observation of the selective removal of graphite from the wax and sodium silicate surfaces was particularly unexpected for several reasons. First, it was believed and established by Black in U.S. Patent 5,387,434"that the protective coating based on wax or sodium silicate chemically reacts with the graphite paint and alters its fixing properties." To remove the graphite, the surfaces Wash vigorously with hot, pressurized water, as described above. " The applicant tested the solubility of the individual components of microcrystalline wax and sodium silicate of the barriers in PMD and obtained the surprising result that the MPD did not even dissolve the barrier component. Therefore, these barrier components that were taught by Black to be chemically mixed with the graphite, were expected to protect the graphite against removal by MPD. However, in contrast to the insolubility of these barrier components in MPD reported above, the Applicant also observed that the graphite removal composition containing MPD from Leys, U.S. Patent 5,024,780, removed the same wax barriers and their times the barriers containing sodium silicate described by Black. These contradictory observations suggested that MPD may not be adequate to selectively remove the graphite from the barriers described by Black. Indeed, one or more components of these barriers applied from an aqueous emulsion medium could be attacked by the MPD despite the fact that the MPD did not dissolve the pure wax or the sodium silicate. In addition to being an effective cleaning agent for graphite and dirt, the organic solvent MPD is considered chemically non-reactive and stable, and environmentally "benevolent", being biodegradable, much less toxic than typical organic solvents, and substantially non-volatile (boiling point 396 ° F). This does not appear to be a skin-sensitive agent, but the eyes must be protected from contact irritation (see "pyrrolo" and derivatives of "pyrrolo"), by Hort and Anderson in the Encyclopedia of Chemical Technology, Third Edition, Volume 19, Pags. 510 to 520). Its use, or the use of an equivalently selective graphite solubilizing agent, pyrrolidinone, which retains the integrity of the graphite barrier is an important component of the present invention.

In addition, as used in the present invention, the "MPD", allows the removal at room temperature of the graphite from the graphite barriers described above using simple mechanical means such as cleaning with rag, or using washing with water at room temperature , whereas previously, water and / or pressurized hot steam was required for the cleaning procedure. Using the MPD-based cleaning system, the discovery that the graphite in practical terms can be separated and functionally removed from the protective barriers of wax and / or sodium silicate, allowing the applicant to re-evaluate these structures and barrier coating compositions. . That is, if the graphite can be removed selectively leaving the protective barrier intact, the barrier can now be considered a more permanent barrier instead of a sacrificial barrier that dissolves and / or melts with the hot water that follows the application of graphite. Accordingly, the Applicant has developed new barrier compositions for graphite to improve the resistance against graphite and the ease of cleaning of silicate and wax-based barriers based on the MPD-containing cleaning system described above. Thus, in a further aspect, the invention includes an improved method for surface treatment to increase the surface resistance over time to graphite and other dirt marks, and facilitating cleaning of surfaces, wherein The method comprises the steps of applying to the coating material a surface to form on it a barrier coating, wherein the coating material comprises water, and at least one constituent selected from the group consisting of mineral waxes and synthetic waxes, wherein the improvement comprises the inclusion within the coating material of an effective concentration of at least one wax protective chemical agent to select the group consisting of wax-soluble / water-insoluble ultraviolet light absorbers, free radical scavengers and peroxy radicals soluble in wax / insoluble in water, and wax-soluble / insoluble waxes antioxidants and n water. In a further aspect, the invention includes an improved method for treating the interior surfaces to increase the resistance to graphite and other dirt marks, and to facilitate the cleaning of the treated surfaces, wherein the method comprises the steps of applying a material of coating on a surface to form on it a barrier coating, wherein the coating material is substantially free of toxic organic solvents and comprises water and at least one constituent selected from the group consisting of sodium silicate, precipitated silica, and synthetic amorphous silica, the constituents being present in the coating material in an amount sufficient to form a substantially continuous and adherent barrier against the penetration of dirt and graphite to any underlying surface, where the graphite resistance and the ability to remove Graphite and / or dirt marks over time it is improved by including in said coating material, an effective practical concentration of at least one surfactant compatible with the aqueous silicate emulsions, the surfactant being selected from the group consisting of anionic and nonionic surfactants. In summary, (i) for sodium silicate coatings, the addition of improved aqueous emulsion surfactants, and (ii) for wax emulsion coatings, the addition of wax, the addition of wax protective agents (soluble waxed / insoluble in water in the wax phase of the emulsion (including ultraviolet absorbing agents, free radical sequestrants and hindered peroxy radical of amine, and antioxidants, improves resistance against graphite over time, and it facilitates the cleaning for a period of time of the graphite from these barrier coatings Other features and advantages of the invention will be apparent from the following description of the preferred embodiments, and from the claims.

BRIEF DESCRIPTION OF THE FIGURES Figure 1: A 15 micron sample coating of microcrystalline wax containing 1% by weight of Tinuvin 328 (plus HALS and AO as described above) was recorded against a reference coating (20 micron coating) of uncorrected monocrystalline wax). Figure 2: Same as Figure 1 except that the coating was 16 microns thick and contains 2% by weight of Tinuvin 328. Figure 3: Same as Figure 2, except that the coating is 18 microns thick and contains 2 % by weight of Tinuvin 1130. Analytical comments: Tinuvin 328 is developed at or near its theoretical optimum. With a molecular weight of 351 and a molar extension coefficient of approximately 16,000 at the wavelength of 350 nm, a 20 micron thick film containing 2% by weight of Tinuvin 328 should have an OD at 350 nm of 1.8 by the calculation of the Beer Law of OD = Elc Conversely by comparison, it is apparent that Tinuvin 1130 is probably inefficient ultraviolet light absorber due to a limited solubility in microcrystalline wax.

DESCRIPTION OF THE PREFERRED MODALITIES In accordance with the present invention, the Applicant has developed an improved method for removing dirt and graphite marks comprising paint and / or marking ink from a previously formed barrier coating on an underlying surface. . The barrier coating is formed from a coating material substantially free of its toxic organic solvents. The coating material includes water and at least one member selected from the group consisting of mineral waxes, synthetic waxes and silicates. The member is present in the coating material in an amount sufficient to form a substantially adherent barrier and continues against penetration by marking with graphite to the underlying surface. The improved cleaning method preserves rather than sacrificing the barrier coating, and involves the application of a solvent system to an area of the barrier coating to be cleaned containing the solvent system a functionally effective concentration of at least one organic solvent substantially non-toxic, which can soften or dissolve the graphite marking and / or dirt without substantially dissolving the barrier coating. Smoothed and / or dissolved graphite marks and dirt are removed by mechanical means. The solvent system can be applied to the area with graphite or dirt by spraying or applying with a brush or roller. The physical means to remove graphite and / or softened or dissolved dirt are selected from the group consisting of brushing, cloth cleaning, pressurized aqueous spray washing, and compressed air cleaning. Preferably, the organic solvent is selected from the group consisting of 1-methyl-2-pyrryloninone (abbreviated MPD) and 2-pyrrolidinone. Although the effective concentration of MPD can vary from 20% to 100% by weight, the preferred concentration of MPD. In the solvent system it is in the range of between about 40 and 60% by weight. The composition of the solvent containing 1-methyl-2-pyrrolidinone and / or 2-pyrryloninone also preferably includes a diluent such as propylene glycol or ethylene glycol and / or a co-solvent. The co-solvent can be replaced by a portion of, or all of the diluent, and serves to accelerate the removal of the graphite, for example, the natural terpene solvent, eg, limonene, can be used as a co-solvent. Depending on the requirements for the removal of the graphite, the limonene is typically added at a concentration ranging from 5% to 50% by weight / volume, and preferably a concentration ranging from 10% to 25% by weight / volume. In addition, the solvent system may include a thickening agent such as hydroxypropylcellulose, for example, Klucel® H, at a concentration ranging from 0.25% to 3% by weight, but preferably from a concentration ranging from 0.5% to 2% by weight. The solvent system also preferably includes a nonionic detergent such as octoxynol, for example Triton X-100 added to the system in a concentration ranging from about 1% to 2% by weight. For reference purposes, the method and composition are provided to constitute (i) the original wax and (ii) the original sodium silicate graphite barriers of Black, U.S. Patent 5,387,434. A preferred composition for constituting the barrier coating of Black wax, known as G PRO® coating. An aqueous wax emulsion concentrate known as PTGM 1303 concentrate from Hercules, Inc. (Paper Technology Division, Wilmington, DE) is purchased. This concentrate contains about 48% by weight solids, including about 43% by weight of petroleum hydrocarbon microcrystalline wax having a melting point of 165-170 ° F and about 5% by weight by a patented nonionic surfactant. To make 100 gallons (826 pounds) of original and preferred G PRO® wax coating material (density = 8.26 pounds / gallon), the following are combined: 274 pounds of PTGM concentrate 1303 (obtained from Hercules, Inc.) , 6 pounds of Natrosol 250 MBR thickener (hydroxyethylcellulose, CAS No. 9004-62-0, (obtained from Hercules Division, Inc., Wilmington, DE) .1 pound of preservative Troysan 174 2 ((hydroxymethyl) amino), ethanol, 97% content by weight (obtained from Troy Chemical Co., Newark, NJ) 545 pounds (68 gallons) of water diluent The percentages by weight for the constituents in this formulation of G PRO®, are about 14% wax, 1.7% surfactant, 17% aqueous carrier for wax, 0.7% thickener, 0.12% preservative, 66% water diluent, the scale of useful concentrations (% by weight) of this formulation of G PRO®, are approximately 5 to 30% wax, 0.5 to 3% surfactant, 0.25 to 2% of weigher, 0.05 to 2% by weight of preservative, with balance being aqueous. In the present invention, as explained below, the wax composition described above is modified by the addition of ultraviolet absorber, free radical scavengers and peroxy radical and antioxidant to the microcrystalline wax component of PTGM 1303. To constitute the coating of G PRO ®, based on original and typical sodium silicate designed for indoor use, as previously described by Black, the following are combined: 85% by volume of sodium silicate, Type O obtained from PQ Corp., Valley Forge, PA) , 15% by volume of water. Although an indoor G PRO coating composition contains about 85 vol% sodium silicate, the useful concentration ranges from about 10 to 95 vol%. Preferably, the sodium silicate has the following specifications: Weight ratio of SIO2: Na2O is 3.22: 1, density is 42.2 degrees Baume, pH is 11. 3 and viscosity is 400 centipoise. In the present invention, as explained below, the above composition is preferably modified by the addition of an anionic surfactant. A preferred anionic surfactant is known as Dowfax 1A manufactured by Dow Chemical Corp., or by Niaproof, or Dow Niaproof 089 anionic surfactant manufactured by Niacet Corp., and is used within a concentration range of about 0.1 to 3% by weight. weight (final concentration), and preferably within the range of 0.25 to 0.75% by weight.

This anionic surfactant is also chemically known as ethylhexyl sodium sulfate (sulfuric acid), mono (2-ethylhexyl) ester, CAS No. 126-92-1 and contains sodium chloride. The applicant proceeded to test the various components in the composition of Leys, U.S. Patent 5,024,780. In an initial experiment, propylene carbonate (2 drops on the sodium silicate and microcrystalline wax barrier coatings of Black, as described above, and in Example 1 and 4, respectively, of the United States patent was placed. 5,387,434 After two minutes, the liquid was removed with a paper towel.The propylene carbonate was found to completely remove the coating from the wax barrier, while the sodium silicate film was altered to a white coating. thus, propylene carbonate is an undesirable constituent with respect to the preservation of the structure of the barriers.Also, several of the dispersing agents named in the formulation of Leys (such as dipropylene glycol methyl ether) are known to dissolve waxes. of hydrocarbons and would be undesirable constituents in the present invention, in which the persistence of wax barriers is required. It is from MPD that they were found to be necessary and sufficient without propylene carbonate to remove graphite and clean Black's barriers without removing, damaging or otherwise altering them. Also in accordance with the present invention, the Applicant has developed an improved method for treating an interior or exterior surface to increase the resistance over time of this treated surface to the graphite and other dirt marks and to facilitate any necessary cleaning of said treated surface. . The method includes applying a coating material on the surface to form a dry barrier coating on it. The coating material is substantially of toxic organic solvents and includes water. The coating material and the dry barrier coating include at least one constituent selected from the group consisting of mineral waxes and synthetic waxes. The constituent is present in a coating material in an amount sufficient to form a substantially continuous and adherent barrier against the penetration of dirt and graphite to any underlying surface. The resistance to graphite and the ability to remove graphite and / or dirt marks over time is improved by the inclusion in the coating material, a practical and effective concentration of at least one chemical protective wax agent selected from the group that consists of wax-soluble / water-insoluble ultraviolet light absorbers, free-radical sequestrants and wax-soluble peroxy radical, insoluble in water, and wax-soluble / water-insoluble wax antioxidants. Similarly, the applicant has improved the silicate-based protective barrier coating. The silicate-based protective barrier coating is preferably used to protect an interior surface from the graphite and other dirt marks, and to facilitate any necessary cleaning of said surface. Preferably, the method includes applying a coating material to a surface to form a dry barrier coating thereon. In a further embodiment, the coating material is substantially free of toxic organic solvents and includes water, and the dry barrier coating includes at least one constituent selected from the group consisting of sodium silicate, precipitated silicic acid, and synthetic amorphous silica. . The constituent is present in the coating material in an amount sufficient to form a substantially continuous and adherent barrier against the penetration of dirt and graphite to any underlying surface. Graphite strength and the ability to remove graphite and / or dirt marks over time is improved by inclusion in the coating material, a practical and effective concentration of at least one surfactant compatible with the aqueous silicate emulsions, the surfactant being selected from the group consisting of anionic and nonionic surfactants. With respect to the state of the art, although there is a reference number describing the use of chemical additives to improve the stability and durability of wax products and wax coatings, very little information is available on the maintenance of resistance to the wax. graphite on a wax surface or a sodium silicate surface. Waxes are typically substances that are plastic solids at room temperature and liquids at moderately elevated temperatures. Many, but not all, waxes are insoluble in water and water repellent, including animal wax (eg, beeswax), vegetable wax (eg, carnauba wax), mineral wax (mainly petroleum hydrocarbon wax that includes the three groups of paraffin wax, microcrystalline wax and semi-microcrystalline wax), and synthetic wax including polyethylene waxes, Fisher-Tropsch waxes, chemically modified hydrocarbon waxes, and substituted amide waxes. The improvements in the present invention are more useful by the incorporation into the waxes of hydrocarbons and waxes of synthetically modified hydrocarbons of the microcrystalline and paraffin types. This wax, and in particular the microcrystalline varieties, are widely used in the manufacture of water resistant protective coatings, applied to the surface of objects, structures and tools used outside the doors, for example, automobiles, fiberglass boats, plastic and metal furniture, and part of wooden boxes. Considering the choice of wax in coatings, microcrystalline waxes tend to have better durability than paraffins recognizing their greater plasticity, flexibility and longer melting range (60 to 93 ° C - against 46 to 68 ° C). These properties are largely attributable to microcrystalline waxes that have higher carbon atoms per molecule (30 to 75 versus 20 to 36) and a higher average molecular weight (600 to 800 versus 350 to 420 Daltons) than paraffins. Despite these properties, these wax coatings have a limited functional life and must be periodically replaced. The mixed natural, synthetic and hydrocarbon waxes have been incorporated into many commercial products, and the state of the art provides examples of chemical shields incorporated in these products. For example, Yuma Japanese Patent No. 05093164 A2 930416 Heisei, discloses materials and entrainments of solids in which UV absorbers and hindered amines have been added to waxy crayon compositions to stabilize the color of the crayon. Stone, PCT International Application WO 9419414 A1 940901, discloses resistant skid coatings containing blends of polymers and a petroleum or synthetic wax, together with an ultraviolet light absorber or an antioxidant, among other additives. Other references in the literature teach the addition of ultraviolet light absorbers and light blocking or dispersing agents of waxes to protect the underlying surface from ultraviolet damage. Currently, several manufacturers of synthetic hydrocarbon waxes for automobiles have advised the addition of ultraviolet light blocking agents to a variety of emulsion wax coatings to protect the finish of the underlying automotive paint (and not the wax itself). discoloration or other damage induced by ultraviolet light. Applicants have developed a spectrophotometric test for ultraviolet protection that results from the addition of these UV blocking agents. The test involves applying the test coating material (as recommended by the manufacturers) to a transparent ultraviolet substrate to form a thin film coating of the product, and then obtain a UV absorption spectrum using a UV scanning spectrophotometer. The thickness of the film is determined by accurate measurements of the weight before and after applying the coating. By testing two commercial automotive wax coatings in this manner on polymethyl pentane thermoplastic UV transparent substrate materials, applicants have surprisingly discovered that when applied as recommended, the products provide very little blocking activity against UV light ( no more than 10% of the UV light between the wavelength of 300 and 400 nanometers is blocked). To make effective effective, a UV blocker in a coating must block at least 50% and preferably 90% of the incident ultraviolet light in the wavelength range of 325 to 350 nm as measured by a coating applied as described. recommended by the manufacturer. For the purpose of protecting the wax by itself in a wax coating against graphite the damage by UV light (instead of protecting an underlying surface), Black, in U.S. Patent 5,387,434 has suggested the addition of a ultraviolet blocker for the coating material. Black states, ("Ultraviolet radiation breaks the molecular bonds in the wax, thus making the wax less water-repellent.) To avoid such breakage by UV light, an appropriate UV blocker can be added." The applicant has tested recently the aromatic organic compound conjugate UV absorber named by Black as UV blockers (such as para-amino benzoic acid), some of which are known to block light 325-350 when mixed in aqueous emulsions of the oil type for care Surprisingly, these compounds worked inefficiently by absorbing UV light on the 325-350 scale when they were mixed in the aqueous wax emulsions (or part of their wax) named by Black in the United States patent ,387,434. The wax emulsions that were tested include the PTGM 1303 microcrystalline wax emulsion product manufactured by Hercules, Inc. (strial Specilty Paper Technology Division, Wilmington, DE). Applicants define the photochemical stability for a UV stabilizer in a coating, such as maintaining at least 80% of the original UV absorbance of the stabilizer during the one month period in the coating when exposed to the natural brightness of the light solar (5 South Florida), with the coating having an original optical density (including the UV stabilizer) of between 1.0 and 1.5 optical density units at a wavelength of 325 nm. For reference purposes, the PTGM 1303 product is described by Hercules, Inc., as a stable wax emulsion based on refined microcrystalline wax, and typically used as a ceramic br and as an antiblocking and releasing agent, and to improve slippage when applied to various substrates including paper, concrete forms. The PTGM 1303 as sold commercially does not contain UV stabilizers. The failure of UV absorbing agents (abbreviated UVA) to achieve significant UV absorption in protective coatings against microcrystalline wax graphite, and in automotive wax emulsions, has now been brightened by the applicants, the fact that the UV can be physically present but not futionally (not absorb UV light) in dry wax coatings. This is surprising because it is generally believed that "UVA", as long as they are compatible with the wax emulsion and can be mixed in the water phase or in the wax and then emulsified. "(Black US Patent 5,387, 4349) Consistent with this teaching, the Ciba-Geigy corporation, one of the largest UVA commercial suppliers (Ciba Additives, Ciba-Geigy Corp., Hawthore, NY) has published an instruction booklet entitled "Coatings Additives" dated in 1993. The UVA of the type of hydroxyphenyl benzotriazolo known as Tinuvin 1130 from Ciba-Geigy, is recommended for these emulsions in this brochure because as a liquid, it "can be easily emulsified in water, which makes it especially suitable for reducible coatings with water and latex. "The Tinuvin 1130 is also recommended in a detailed technical document by Ciba-Geigy entitled" Tinuvin 1130 Liquid Ultraviolet Light Absorber. "In this booklet of the product was established, "its unique structure allows it to be easily dispersed in floating coatings based on emulsion. Tinuvin 1130 migrates to the emulsion micelles and covers its exterior. This ensures molecular dispersivity and thus efficiency and optimum performance. "Despite these claims, applicants have now shown that Tinuvin 1130 is essentially non-functional in water-reduced microcrystalline wax coatings. Ciba Geigy's teaching on molecular dispersion may be relevant for UVA emulsification, but contrary to his suggestion, it is not sufficient for UVA performance.More precisely, Ciba-Geigy failed to teach the required molecular solubilization of UVA in the coating non-liquid residual, that is, wax, to achieve "performance", ie ultraviolet light absorption, despite the apparent emulsifying dispersion of various UVA including Tinuvin 1130 in petroleum hydrocarbon waxes of the aqueous emulsion type commercial, very few UVA that the applicant has tested from a variety of commercial sources are currently soluble in the residual phase of wax. As a result, absorption of ultraviolet light from negligible to poor in waxes occurs, and this leaves unprotected, as is the case with automotive commercial waxes containing Tinuvin 1130. Only the empirical spectrophotometric test of thin wax coatings (approximately 10 to 30 microns thick) prepared using different UVAs that are dispersed in hydrocarbon waxes and applied on transparent UV substrate surfaces can reveal that UVAs are functional. See example 7. Similarly, the saturation concentration of a UVA should be measured in a wax determined at the concentration of the UVA, before the incremental UV absorbance is not detectable. As explained above, Black in U.S. Patent 5,387,434 has attempted to protect the molecular structure of the wax and sustain water repellency by the addition of certain aromatic organic compounds. While Black has suggested the alternative use of optically opaque sunscreens such as sodium silicate to protect the waxes, the dark to white appearance of these sunscreens is undesirable in clearcoat applications. Applicants have also found that the addition of the slightly soluble sodium silicate to water to a wax film can undesirably reduce the long-term durability of the wax coating in exterior uses and destabilize the wax emulsion over time for storage. The applicant has formulated an emulsion of microcrystalline wax, in which the wax phase contains verifiably dissolved UVA agents, free radical scavengers and peroxy radical (such as hindered amines) and antioxidants to retard degradation by light and the air (oxygen). For the purposes of the present invention, the degradation of a hydrocarbon wax coating is patented because the coating becomes a less effective barrier against graphite through the erosion of the coating thickness, the brittleness of the wax and the breach. When the degradation of the wax is substantial, penetration and failure of the barrier with the application of graphite paint can occur. The loss of water repellency and yellowing of the wax can also be observed. One of the objects of the present invention is to provide a wax coating having an increased resistance to graphite paint over the time that external exposure to sunlight and other environmental elements follows. A secondary benefit of this improvement in wax as a barrier against graphite, is that the wax can also provide a degree of proportion to the underlying architectural surface against damage by environmental elements such as water and sun-related damage. With respect to the solids content in either the wax coating material or the silicate-based coating material, the weight percentage of the wax and / or silicate in the aqueous coating applied before material varies from about 5 to 50. %. Preferably, the percentage of the wax and / or silicate in this material coating varies from 10% to 20%. With a spreading rate of approximately 350 ft2 per gallon of coating, the resulting amount of the wax and / or silicate applied and deposited on the surface and contained within the barrier coating ranges from about 1 mg / cm2 to 3 mg / cm2. With respect to mineral wax coatings and / or coatings based on synthetic wax, to maintain the maximum resistance to penetration of graphite, and facilitate the removal of graphite over time, the protective material coating preferably includes at least 3 agents wax protective chemicals that include a wax-soluble / water-insoluble ultraviolet light absorber, a free-radical and peroxy radical-free wax insoluble / wax-insoluble sequestrant, and a wax-soluble / water-insoluble wax antioxidant. The free-radical radical peroxy radical-insoluble / water-insoluble peroxy sequestrant is preferably selected from the group consisting of amines and sterically hindered amino esters. The molecular structure of this scavenger preferably includes at least one piperidinyl moiety having at least 2 carbon atoms derived from alkyl and / or carbon atoms derived with alkyl-terminated side chains. The molecular structure of this scavenger also preferably includes at least one piperidinyl moiety wherein the nitrogen ring is derived with an alkyl or an alkyl-terminated side chain. A) Yes, the criteria of the above molecular structure are satisfied by at least two hindered amino and amino ether compounds known as Tinuvin 292 and Tinuvin 123 manufactured by the Ciba-Geigy Corporation (Additives, Division, Hawthore, N.Y.). The percentage by weight of the scavenger or scavengers of the free radical and peroxy radical in the dry barrier coating is preferably chosen to vary from about 0.5% and 4.0%. This scavenger is preferably selected from the group consisting of bis- (1, 2,2,6,6, -pentamethyl-4-piperidinyl) sebacate, CAS No. 41556-26-7 (Tinuvin 292, Ciba-Geigy) and bis- (2,2,6,6, -pentamethyl-4-piperidinyl) sebacate, CAS No. 52829.07-0 (Tinuvin 770, Ciba-Geigy). Alternatively, this scavenger is an aminoether derivative such as bis- (1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) cebacate, CAS No. 129757-67-1. The protective ultraviolet light absorber may be selected from the group consisting of derivatized benzotriazolo ultraviolet light absorbing molecules and derivatized benzophenone. The derivatized benzotriazole molecule is preferably selected from the group consisting of ultraviolet absorbing molecules of hydroxy-phenyl-benzotriazolo derivatized as manufactured by the Ciba-Geigy Corporation. The derivatized hydroxyphenyl portion of this hydroxy-phenylbenzotriazole molecule preferably includes at least two alkyl and / or two alkyl-terminated side chains (such as Tinuvin 328 and Tinuvin 384 from the Ciba Geigy Corporation), which provide solubility in the hydrocarbon waxes and allows the absorption of UV light and the energy transfer that occurs in this molecular environment (see, example 7). The wax-soluble / water-insoluble ultraviolet light absorber is selected from the group consisting of 2- (2H-benzotriazol-2-yl) -4,6-bis (1,1-dimethylpropyl) phenol, CAS No. 25973- 55-5 (Tinuvin 328, Ciba Geigy) and 2- (2-hydroxy-3-t-butyl-5- (2-octyloxycarbonyl) ethylphenyl) 2H-benzotriazolo, CAS No. 127519-17-9 (Tinuvin 384, Ciba Geigy ). The weight percentage of the ultraviolet light absorber in the dry barrier coating is chosen to vary from about 0.1% to 3.0%. Preferably, the weight percentage of the ultraviolet light absorber is between 1.0% and 2.0%. The antioxidant protective chemical agent can be selected from the group consisting of sterically hindered phenol antioxidant molecules. Sterically hindered phenol molecules preferably include at least one derivatized phenol moiety having at least 2 alkyl and / or two alkyl-terminated side chains that provide solubility to the hydrocarbon wax. It is more preferred that the derivatized phenol portion include 3 alkyl and / or 3 alkyl-terminated side chains that provide solubility to the hydrocarbon waxes. The weight percentage of the antioxidant in the dry barrier coating is chosen to vary between about 0.1% and 1.0%. Preferably, the weight percentage of the antioxidant is between 0.25% and 0.5%. The wax-soluble / water-insoluble wax antioxidant is preferably octadecyl-3,5-bis (1,1-dimethylethyl) -4-hydroxybenzene propanoate, CAS No. 2082-79-3 (Irganox 1076, Ciba-Geigy) . When the protective barrier coating includes a natural wax, it can be selected from the group consisting of microcrystalline waxes, semi-crystalline waxes, and paraffinic hydrocarbon waxes. The mineral wax is preferably a microcrystalline hydrocarbon wax. As indicated above, when the protective barrier coating includes a silicate, it may be selected from the group consisting of alkali metal silicates, for example, sodium silicate and potassium silicate, precipitated silicic acid, and synthetic amorphous silica. With the anionic surfactants, the surfactant is selected from the group consisting of alkyl ester sulfates and alkyl ether sulfates. With alkyl ester sulfates, the surface-active agent is preferably etylexyl sodium sulfate (sulfuric acid, mono (2-ethylexyl) ester) CAS No. 126-92-1. Preferably, the weight percentage of the anionic surfactant in the coating material ranges from about 0.25% to 0.75% by weight. The surfactant that is treated by the protective coating of the material is selected from the group consisting of painted and unpainted surfaces, porous and non-porous surfaces, concrete surfaces, brick surfaces, stone surfaces, metal surfaces, wood surfaces and plastic surfaces. The graphite marks that are protected against and which are removable from the protective coating of the material described in the present invention include the applied graphite using at least one marking medium selected from the group consisting of sprayed paint, permanent ink marker, pen, pencil, crayon and lipstick. The spray painting of the graphite may include a permanent paint based on oil selected from the group consisting of varnishes, epoxies, lacquers and urethanes. Where it is interested in dirt, this dirt can be derived from at least one source within the group consisting of ollin carried by the air, pollutants, carried in the rain, radioactive particles carried by the air, residues of fat, contact manual of the human, contact with the soles of the shoe and contact with the rubber tires. The present invention also gives importance to a case to minimize the year with graphite and facilitate the removal of paint or ink marks of graphite and dirt from a surface. The case includes an improved material suitable for forming a protective barrier coating on the surface, the coating material being substantially free of toxic organic solvents and including water. The coating material includes at least one member selected from the group consisting of mineral waxes, synthetic waxes and silicates, the member present in the coating material in an amount sufficient to form a substantially adherent barrier and continuous against penetration by the Graphite marks to an underlying surface. Where the improved coating material is used in forming wax-based barrier coatings, it includes a practical and effective concentration of at least one wax protective chemical selected from the group consisting of wax-soluble ultraviolet light absorbers. water-insoluble, free-radical and peroxy radical scavengers soluble in wax / insoluble in water, and wax insoluble in waxes / insoluble in water. Where an improved coating material is used in the formation of silicate-based barrier coatings, it comprises a practical and effective concentration of an anionic or nonionic surfactant which improves the adhesion, cohesion and durability of the protective barrier coating. The surfactant is compatible with aqueous silicate emulsions. The case also includes a solvent system for cleaning and maintenance, instead of sacrificing the protective barrier coating. The solvent system is applied to a protective barrier coating area to be cleaned and, the solvent system includes a functionally effective concentration of at least one non-toxic organic solvent with low volatility which can dissolve the graphite and / or dirt without substantially dissolving the protective barrier coating. In the case, it is preferred that the improved coating material for forming the wax-based barrier coatings include at least three chemical wax protective agents, including a water soluble / insoluble wax-soluble ultraviolet light absorber, an oxygen scavenger free radical and radical peroxy soluble in wax / insoluble in water and a wax antioxidant soluble in wax / insoluble in water. In the case, it is also preferred that the improved coating material to form silicate-based barrier coatings include an anionic surfactant selected from the group consisting of alkyl ester sulfates and alkyl ether sulfates. With respect to the choice of solvents within the composition of the kit, a preferred organic solvent is 1-methyl-2-pyrrolidinone. The following are non-limiting examples of the methods of the present invention.

EXAMPLE 1 An oil-based black enamel paint such as graphite is applied and allowed to dry on a wax coating of the prior art of Black (see example 4 of U.S. Patent 5,387,434). The wax coating has been applied to a clear glass substrate to facilitate visual observations. The MPD was diluted to several final concentrations (percent by volume) using propylene glycol to determine the minimum effective concentration of MPD required to remove the graphite. Two drops of each solution were applied to the paint and allowed to sit for 10 minutes at room temperature (20 ° C) before removal, paper towel. The results were as follows, with the * symbol denoting the rub action required to remove the indicated amount of paint: Percentage of MPD in propylene glycol 100 80 60 50 40 30 20 Removal limit all all all all all 5% * 0% * The observations and conclusions from this experiment were as follows: at least 30% by volume of MPD that may be present to allow rapid removal of the wax paint; propylene glycol seems to be a suitable diluent for MPD; the wax coating is not attacked by either the MPD propylene glycol; higher percentages of MPD tended to dissolve the paint faster while not damaging the wax coating; Any of the cleaning by rubbing or rinsing with water (with water at room temperature of low pressure) from a tube) removes the paint and takes care of the wax. As a result, the wax coatings previously described by Black in U.S. Patent 5,387,434 as sacrificed and removed with graphite by hot water under high pressure, do not need to be sacrificed when an appropriate cleaning agent is used which takes care of the barrier against graphite.

EXAMPLE 2 A commercial paint remover ("Piranha I"), produced by Fiberlock Technologies, Inc. (Cambridge, MA) is formulated to rapidly remove multiple coatings of lead-based paint. The Piranha paint remover contains 50 to 60% by volume of MPD, and approximately 40 to 50% by volume of various dicarboxylic acid derivatives including dimethyl glutarate, dimethyl adipate and dimethyl succinate. This was tested on the graphite in wax coatings of Example 1, using the same procedure. All of the graphite was removed without damaging the wax coating. Therefore, diluents other than propylene glycol (such as those in this example, as well as ethylene glycol) can be used with MPD and allow the removal of the graphite while taking care of the wax barrier against the graphite. In contrast to the propylene carbonate-containing compositions of Leys which damage, and remove the wax coatings, this Pirnaha product did not contain propylene carbonate.

EXAMPLE 3 As in Example 1, a black paint was applied to the coating to a coating against the sodium silicate graphite (prepared as described in the example 1 of U.S. Patent 5,387,434) and allowed to dry. Again the MPD was diluted to various final concentrations (percent by volume) using propylene glycol to determine the minimum effective concentration of the MPD required to remove the graphite.

Two drops of each solution were applied to the paint and allowed to sit for 10 minutes at room temperature of 20 C before removal by rubbing with a paper towel. And the results were as follows: Percentage of MPD in propylene licol 100 80 60 50 40 30 20 Limit of removal All all all all all all 0% The observations and conclusions from this experiment were as follows: at least 30% by volume of MPD must be present to allow the rapid removal of the silicate paint; propylene glycol seems to be a diluyen suitable for the MPD; the silicate coating most attacked by either the MPD, or the propylene glycol. The high percentages of MPD will not damage the silicate coating; Cleaning by rubbing with a paper towel or a cloth rag removed the paint and respected the sodium silicate.

EXAMPLE 4 A porous brick was treated with the aqueous emulsion coating of micro crystalline wax used in example 1, after the coating had dried it was dried with black paint graphite as in example 1. After you have dried the paint, The effectiveness of removing the paint using MPD diluted with either water or propylene glycol was tested. The MPD solutions were allowed a contact time of 10 minutes with the paint before being removed or with a paper towel. The limit of the removal of paint was judged immediately by rubbing with a paper towel. Percentage of MPD in water 100 50 40 30 Removal of Paint All 20% 10% 0% Percentage of MPD in propylene glycol 100 50 40 30 20 Paint Removal All 10% 0% 0% The observations and conclusions were as follows: the areas in which the paint was removed were examined visually and by water repellency due to the persistence of the microcrystalline wax coating. The results were positive in all cases, indicating that the MPD does not remove the wax coating, using either propylene glycol or water as a diluent. water and propylene glycol were not comparable as diluents or MPD enhancers in the removal of paint applied to wax barriers.

Although 50% by volume of MPD in propylene glycol was completely effective in the removal of all the paint, the same dilution of MPD in water was essentially ineffective (20% paint removal). Therefore, for the removal of the wax barrier paints, propylene glycol is preferred over water.

EXAMPLE 5 A porous brick was treated with a sodium silicate coating used in Example 3 as described in Example 1 of U.S. Patent 5,387,434. After the coating had dried, it was sprayed with a black paint graphite with Example 1 above. After the paint has dried the effectiveness of the paint removal remover using MPD diluted with water or propylene glycol was tested. The MPD solutions were allowed a contact time of 10 minutes with the paint before being removed with a paper towel, the limit of the paint removal was judged followed by cleaning by rubbing by a paper towel.

MPD percentage in water 100 50 40 30 Paint Removal All all 0% Percentage of MPD in propylene glycol 100 50 40 30 20 Paint Removal All 90% 0% 0% The observations and conclusions were as follows: the areas in which the paint was removed were examined visually by the persistence of the sodium silicate coating. The results were positive in all cases indicating that the MPD does not remove the sodium silicate using propylene glycol or water as a diluent. Water and propylene glycol were comparable as MPD diluents or enhancers by removing the paint applied to the sodium silicate barriers. 40% by volume of MPD in each diluent removed essentially all of the paint.

EXAMPLE 6 The compositions are described and their uses, whereby typical graphite (oil-based paint graphite and / or permanent-marking ink graphite) can be removed from Black's wax and / or sodium silicate barriers (described in US Pat. Nos. 5,387,4334 without removing these barriers.

Ingredient * Concentration range Preferred interval (by weight) (by weight) 1 - . 1-methyl-2-pyrrolidinone 20% -99 +% 40% -60% hydroxypropylcellulose (thickener, for example Klucel® H) 0.25% -3% 0.5% -2% propylene glycol (diluent) (optional use of cosolvent, eg limonene, as a part of the diluent) 80% -0% 58% -36% octoxynol (non-ionic detergent eg triton X-100) 0% - 2% 1% - 2% * MPD (1-methyl-2-pyrrolidinone), the active solvent for the graphite was obtained from GAF Corp. (Wayne, NJ). The selection of the thickening agent that is soluble in both MPD and the chosen diluent, serves to increase the amount of MPD that can be applied to a given area, and the length of time it will remain over the area that is cleaned before it slides. . Hydroxypropylcellulose in the form of a dry powder (Klucel® H) is soluble in this system and was obtained from the Aqualon Division of Hercules Inc. (Wilmington, DE). A diluent is selected, which can serve as a volume enhancer for the MPD, and which is preferably cheap and low in toxicity or non-toxic, so long as it does not inhibit the action of the MPD. Propylene glycol serves this purpose. Alternative diluents for MPD include other organic solvents of low volatility (low VOC solvents) such as glycol-derived solvents, for example, ethylene glycol which does not dissolve the sodium silicate waxes or the hydrocarbon waxes found in the barriers of Black graphite. A co-solvent for the graphite may also be included in the diluent component, provided that it is compatible and miscible with the MPD and the diluent. For example, co-solvent, limonene, CAS No. 5989-27-5, a terpene extracted from lemon and orange peel (obtained from Florida Chemical, Lakeland, FL), when mixed with MPD and a diluent such as propylene glycol, accelerates the removal of graphite. Limonene can be used as the total diluent if desired in combination with MPD for the removal of graphite from Black's sodium silicate barriers. However, with Black's microcrystalline wax barriers, pure limonene slowly dissolves the barrier. However, when used as a portion only of the diluent in combination with MPD, limonene is beneficial in accelerating the removal of graphite. For example, a combination of 50% by weight of MPD, 25% by weight of propylene glycol and 25% by weight of limonene, removes the graphite from Black's wax barriers more rapidly than a combination of 50% MPD and 50% by weight. % propylene glycol. No combination harms the wax barrier. A non-ionic detergent such as Triton X-100 which is soluble in the solvent system may be added to improve the surface wetting properties of the mixture. Although not required for the paint remover activity of this mixture, the detergent is particularly helpful when spreading and adhering the mixture over smooth and glossy surfaces. A composition for graphite removal including 50% by weight of MPD, 15% by weight of Klucel® H, 48% by weight of propylene glycol, was applied to the protected surfaces of wax and sodium silicate coated with graphite (black enamel) , oil paint graphite) from Black (U.S. Patent No. 5,387,434). After about 10 minutes, the paint and graphite residues of the treatment composition were removed by: (I) removing by washing with low pressure water from a garden tube, (II) washing with cold water at high pressure, or ( lll) wiping the material with a cloth. The length of time necessary to effect an adequate removal of the graphite varies with the ambient temperature, the number of coatings and the aging of the graphite, and its type of paint. The preferred method for removing the treated graphite depends on the underlying architectural surface sealed with the wax and / or sodium silicate coatings. If it is rough, such as the block of ashes or rough stone, energetic washing is preferred. If the surface is flat, such as metal, wood, plaster and the like, the low pressure washing method or the rag method can be used.

EXAMPLE 7 Representative compositions are described to establish the ultraviolet protection and oxidative stability in the wax coatings described in the present invention. A combination of a wax-soluble / water-insoluble UV absorber (ie, UVA), plus a hindered amine light stabilizer (i.e., a HALS agent) and an antioxidant (i.e., an AO) are incorporated into a aqueous wax emulsion (for example, in the G PRO® formulation described above) for effective protection against the external environment. The solubility of UVA, HALS, and AO, in the wax phase and not in water is critical to the effectiveness of these agents. The ratio of UVA to HALS varies from about 0.5: 1 to 2: 1, depending on the particular requirements of the protective coating. This combination of agents is important because they work synergistically to protect the wax coating as well as the underlying surface. UVA blocks incident UV light and thus protects both the coating and the underlying surface, while HALS (and AO) help to sequester free chemical radicals within the coating to prevent cracking, loss of repellency water, yellowing, and other degradation of the wax coating. The effectiveness of UVA is dependent on the agent that is chemically stable, as well as remaining soluble in the microcrystalline wax component of the G PRO® formulation and not in water, and its actual UV absorption spectrum in the final "cured" coating between the wavelengths of 300 and 400 nm. The UVA, a benzotriazolo known as Tinuvin 328 (Ciba-Geigy) has a strong and broad UV absorption spectrum in the dry coating of G PRO wax over the previous wavelength range. This UVA agent, commercially available as a dry powder, readily dissolves in a molten microcrystalline wax component of the G PRO® formulation. In contrast, a previously used UVA (Tinuvin 1130) is essentially insoluble in the same wax and provides negligible UV absorption in the cured coating (see below). In addition to UVA, Tinuvin 282 (Ciba-Geigy) as the HALS Agent, and Irganox (1076 (Ciba-Geigy) as the AO agent, are both easily dissolved in the molten wax component of the G PRO® formulation. for the G PRO® product it contains 2% Tinuvin 328, 2% Tinuvin 292 and 0.25 to 0.5% Irganox 1076. The following test system was used to quantify the absorption of ultraviolet light in the G PRO® wax coating: Coating mixture: A known amount of the microcrystalline wax (0.500 grams) was melted in a hot water bath at 100 ° C and combined with either 1% or 2% by weight of the UVA (Tinuvin 328 or Tinuvin 1130) plus 2% by weight of Tinuvin 292 and 0.25% by weight of Tinuvin 1076. Each mixture was vortex mixed before being applied to the substrate Substrate: Plastic sheets of polymethylpentene transparent to UV light (also known as TPX) of 5 thousandths of inches of thickness (which have been slightly worn using a thin steel filings pad to allow adhesion of the coating). Application Density: One gallon of G PRO® product containing 15% by weight of wax covers up to 350 square feet of surface area. 15% of approximately 3800 g / gallon = 570 grams of wax at 350 square feet per 929 cm2 / ft2 or 325,150 cm2 area. This application density is transformed to 1.75 mg of wax per cm2 and if the dry coating has a density of 0.9 gm / cm3, then a coating of 1.8 mg / cm2 has a thickness of about 20 microns or 0.0008 inches. A slight excess of the wax was applied to the substrate, using a preheated glass pipette, and the coating was allowed to cool and solidify. The coating was smoothed and polished in one direction using the surface and edge of a stainless steel spatula until a uniform thickness of wax was obtained. Weight and Thickness of the Coating: The plastic film substrate transparent to UV light was weighed on an analytical balance both before and after the application of the wax coating. The net weight of the coating divided by the measured area of the coating gives the application density of the coating. It was found that this number is between 1.3 and 1.8 mg per cm2 for the measured sample. The thickness of the coating was also measured by a micrometer at the point on the plastic film where the spectral light beam passed through the film. Spectral Scrutiny: A Hitachi scanning spectrophotometer, with a double beam, was used to generate the ultraviolet spectrum. Samples of the TPX plastic film that has been coated with the wax samples were placed in the sample beam, while samples that were similarly coated with the unmodified microcrystalline wax were placed in the reference beam of the instrument. The spectrophotometer was programmed to scrutinize or scan from 450 nm to 200 nm with a full scale defiection of any OD of 1.0 or 2.0. Three scrutinies or explorations are described herein and are presented as Figures 1, 2 and 3, respectively. All publications and patent applications cited in this specification are incorporated herein by reference as if each publication or individual patent application was specifically and individually indicated to be incorporated by reference. Although the above invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to those of ordinary skill in the art in light of the teachings of the present invention that certain changes and modifications may be made to it without departing from the spirit and scope of the appended claims.

Claims (34)

1. A method for removing dirt and graphite marks from a surface having a barrier coating formed of a coating material comprising at least one constituent selected from the group consisting of mineral waxes, synthetic waxes and silicates, retaining said method instead of sacrificing the barrier coating, comprising the steps of: applying a solvent system to an area of the barrier coating, the solvent system containing a functionally effective concentration of at least one organic solvent that can soften or dissolve the graphite marks and said dirt without substantially dissolving said constituent of the barrier coating, and removing the smoothed and / or dissolved graphite marks by at least one mechanical means.

2. The method according to claim 1, wherein the organic solvent is selected from the group consisting of 1-methyl-2-pyrrolidinone (MPD) and 2-pyrrolidinone.

3. The method according to claim 1, wherein said organic solvent is MPD, and its concentration in said solvent system ranges from 20% to 100% by weight.

4. The method according to claim 1, wherein said solvent system comprises MPD as said organic solvent, and at least one diluent and / or co-solvent in which the MPD is soluble.

5. The method according to claim 4, wherein said diluent and / or co-solvent are selected from the group consisting of propylene glycol, ethylene glycol and limonene.

6. The method according to claim 1, wherein said solvent system comprises a thickening agent.

7. The method according to claim 6, wherein said thickening agent is hydroxypropylcellulose.

8. The method according to claim 1, wherein said solvent system comprises a non-ionic detergent.

9. The method according to claim 8, wherein said non-ionic detergent is octoxynol.

10. An improved method for treating surfaces to increase the resistance over time of the surfaces for graphite and other dirt marks, and to facilitate the cleaning of said surfaces, the method comprising the steps of: applying a coating material to a surface for forming on it a barrier coating, wherein the coating material comprises water and at least one constituent selected from the group consisting of mineral waxes and synthetic waxes, wherein the improvement comprises including in said coating material an effective concentration of at least one chemical wax protective agent selected from the group consisting of wax-soluble / water-insoluble ultraviolet light absorbers, wax-free / water-insoluble peroxy radical-free radical sequestrants, and wax-soluble wax antioxidants / insoluble in water.

11. An improved method for treating interior surfaces to increase the resistance against graphite and dirt marks, and to facilitate the cleaning of said treated surfaces, comprising the steps of: applying a coating material to a surface to form a coating thereon; barrier, wherein the coating material comprises water and at least one constituent selected from the group consisting of sodium silicate, precipitated silica, and synthetic amorphous silica, wherein the improvement comprises including in said coating material at least one surfactant compatible with aqueous silicate emulsions, said surfactant being selected from the group consisting of anionic and nonionic surfactants.

The method according to claim 11, wherein the surfactant in said coating material is an anionic surfactant selected from the group consisting of alkyl ester sulfates and alkyl ether sulfates.

13. The method according to claim 12, wherein said surfactant is the anionic surfactant of alkyl ester sulfate, ethylhexyl sodium sulfate CAS No. 126-92-1 [sulfuric acid, mono (2-ethylhexyl) ester].

The method according to claim 10, wherein said dry barrier coating comprises at least three chemical wax protective agents including a water soluble / insoluble wax-soluble ultraviolet light absorber, a free radical scavenger and peroxy radical scavenger. soluble in wax / insoluble in water, and a wax-soluble / water-insoluble wax antioxidant.

The method according to claim 10, wherein said free radical and water soluble insoluble peroxy radical peroxy radical scavenger in said dry barrier coating is selected from the group consisting of sterically hindered amines and aminoethers.

The method according to claim 15, wherein the molecular structure of the sequestrant includes at least one piperidinyl moiety having at least two carbon atoms derived from alkyl and / or carbon atoms derived with alkyl-terminated side chains.

17. The method according to claim 15, wherein the molecular structure of the scavenger includes at least one piperidinyl moiety, wherein the nitrogen ring is derivatized with an alkyl or a side chain terminated with alkyl 18.

The method according to claim 15, wherein the radical free and peroxy radical scavenger is selected from the group consisting of bis- (1, 2,2,6,6-pentamethyl-4-piperidinyl) sebacate, CAS No. 41556-26-7 ( Tinuvin 292, Ciba Geigy), bis- (2,2,6,6-pentamethyl-r-piperidinyl) sebacate, CAS No. 52829-07-0 (Tinuvin 770, Ciba Geigy) and bis- (1-) sebacate. octyloxy-2,2,6,6-tetramethyl-4-piperdinyl), CAS No. 129757-67-1 (Tinuvin 123, Ciba-Geigy).

The method according to claim 10, wherein the water soluble / insoluble wax-soluble ultraviolet light absorber in said dry barrier coating is selected from the group consisting of derivatized benzotriazolo derivatized benzotriazole UV light molecules and derivatized benzophenone. .

The method according to claim 19, wherein said derivatized benzotriazolo UV light absorbing molecules are derivatized hydroxy-phenylbenzotriazole UV light absorbing molecules.

The method according to claim 20, wherein the derivatized hydroxy-phenyl portion of said hydroxy-phenylbenzotriazole molecules preferably include at least two alkyl and / or alkyl-terminated side chains that provide solubility to the hydrocarbon waxes.

22. The method according to claim 20, wherein the derivatized hydroxy-phenylbenzotriazole UV light absorbing molecules are selected from the group consisting of 2- (2H-benzotriazol-2-yl) -4,6-bis (1 , 1-dimethylpropyl) phenol, CAS No. 25973-55-5 (Tinuvin 328, Ciba-Geigy) and 2- [2-hydroxy-3-t-butyl-5- (2-octyloxycarbonyl) ethylphenyl] 2H-benzotriazolo , CAS No. 127519-17-9 (Tinuvin 384, Ciba-Geigy).

23. The method according to claim 10, wherein the wax-soluble / water-insoluble wax antioxidant in said coating material is a sterically hindered phenol molecule.

The method according to claim 23, wherein said sterically hindered phenol molecule includes at least one derivatized phenol moiety having at least two alkyl and / or two alkyl-terminated side chains that provide solubility to the hydrocarbon waxes.

25. The method according to claim 23, wherein the sterically hindered phenol molecule includes at least one derivatized phenol moiety having three alkyl and / or alkyl terminated side chains that provide solubility to the hydrocarbon waxes.

The method according to claim 23, wherein said wax-soluble / water-insoluble wax anti-oxidant is octadecyl 3,5-bis- (1,1 -dimethylethyl) -4-hydroxybenzene propanoate, CAS No. 2082-79-3 (Irganox 1076, Ciba-Geigy).

27. The method according to claim 10, wherein the mineral wax is selected from the group consisting of microcrystalline waxes, semimicrocrystalline waxes and paraffinic hydrocarbon waxes.

28. The method according to claim 10, wherein said mineral wax is a microcrystalline hydrocarbon wax.

29. A case for facilitating the removal of graphite marks from paint or ink and dirt from a surface, the case comprising an improved material of recurrence of claim 10 and a solvent system, wherein said solvent system can dissolve said graphite marks. and / or dirt without substantially dissolving said barrier protective coating.

The kit according to claim 29, wherein said improved coating material for forming wax-based barrier coatings comprises at least three chemical wax protecting agents that include a wax-soluble / water-insoluble ultraviolet light absorber., a radical-free and radical peroxy sequestrant soluble in wax / insoluble in water, and a wax-soluble / water-insoluble wax antioxidant.

31. A case for facilitating the removal of graphite marks from paint or ink and dirt from a surface, the case comprising an improved material of recurrence of claim 11 and a solvent system, wherein said solvent system can dissolve said graphite marks. and / or dirt without substantially dissolving said barrier protective coating.

32. The kit according to claim 31, wherein said improved coating material for forming silicate-based barrier coatings comprises an anionic surfactant selected from the group consisting of alkyl ester sulfates and alkyl ether sulfates.

33. The kit according to claim 29, wherein said organic solvent is 1-methyl-2-pyrrolidinone.

34. The kit according to claim 31, wherein said organic solvent is 1-methyl-2-pyrrolidinone.