FR3045661A1 - PRODUCT FOR THE REMOVAL OF ASBESTOS COATINGS AND ADHESIVES BASED ON BRAIS, TAR, BITUMES, VEGETABLE SOLVENT EMULSION IN AQUEOUS ALKALINE SOLUTION, PROCESS FOR PREPARATION AND USE - Google Patents

Abstract

The subject of the present invention is the composition and the preparation of a liquid product intended to facilitate the removal of coatings and adhesives based on pitches, tars, or bitumens, containing asbestos fibers, during the operation of maintenance or renovation of premises, buildings, apartment buildings or vehicles, vessels or rolling stock containing them. The product according to the invention is composed of a vegetable solvent having a low environmental impact and a low toxicity, emulsified in an alkaline aqueous solution, containing an alkaline salt and preferably a sodium silicate of molar formula nSiO 2, Na 2 O, n being included between 1 and 2. The present invention covers the composition of the product, its method of preparation, and its method of use.

Description

PRODUCT FOR REMOVING COATING AND BONDING GLUES BASED ON BRAIS, TAR, BITUMES, VEGETABLE SOLVENT EMULSION IN AQUEOUS ALKALINE SOLUTION, PROCESS FOR THE PREPARATION AND USE THEREOF

The subject of the present invention is the composition and the preparation of a liquid product in the form of an emulsion, intended to facilitate the removal of coatings and amine glues based on pitches, tars or bitumen, during operation deconstruction, maintenance or renovation, composed of: - a solvent of vegetable origin, liquid having an environmental impact and a low toxicity, added with one or more esters of glycerol, natural or modified, mono, di or triglycerides, solid at room temperature, and soluble in said solvent. this solvent being emulsified in an aqueous alkaline solution using a hydrophilic surfactant of HLB (hydrophilic / lipophilic balance) greater than 10, and preferably greater than 12, and compatible with the aqueous alkaline solution.

The present invention also relates to the process for preparing the composition, carried out by stirring at room temperature the mixture consisting of the solvent of vegetable origin, the aqueous alkaline solution and the compatible hydrophilic surfactant.

Deconstruction, maintenance or renovation operations shall mean operations involving premises, buildings, or collective dwellings or public transport vehicles, rolling stock or navigating whatever they may be.

By plant solvent is meant a terpenic hydrocarbon or a liquid mixture of terpenic hydrocarbons, obtained by extraction from plant materials such as coniferous resins, or citrus peel or any other plant product containing terpene hydrocarbons.

The terpenic hydrocarbons, thus nonaromatic, have solvent properties equivalent to those of aromatic hydrocarbons, without presenting environmental hazards or toxicity to living beings. In addition, they are renewable products because they come from plant materials.

Terpenic hydrocarbons are present in many plant products and can therefore be extracted for multiple uses, and especially for solvent uses according to the present invention.

Examples include d-limonene, which is a liquid hydrocarbon belonging to the family of terpenes. It is naturally produced by various plants, including citrus fruits and is the main constituent of oils extracted from the peels of these fruits.

Also terpene hydrocarbons derived from the resin of conifers and more particularly that of pine Landes can be used in the context of the invention.

Let's mention the essence of turpentine that comes directly from pine resins, and pine oil, which is a by-product of the terpineo separation operation! from the resin.

Liquid mixtures of terpene hydrocarbons such as alpha and beta-pinene, delta carene 3, limonene, carotene may also be suitable as a solvent in the context of the present invention.

By glycerol esters, natural or modified, mono, di or triglycerides, solid at room temperature, and soluble in said solvent, is meant monoglycerides, diglycerides, triglycerides of fatty acid having carbon chains between 10 and 22 carbon atoms, alone or in mixture.

The hydrophilic surfactants according to the invention have an HLB of greater than 10 and preferably greater than 12, and are chosen from nonionic surfactants such as alkylpolyglucosides (Glucopon® from Cognis BASF or Plantaren® from Henkel) and alkylpolypentosides. (Olean Appyclean®) ethoxylated or propoxylated terpene derivatives such as nopols (Rhodoclean® from Solvay Novecare), ethoxylated and / or propoxylated fatty alcohols, ethoxylated and / or propoxylated fatty acid esters, and in particular and preferably surfactants having a hydrophilic head classified in the family of sugars, or mixtures of these surfactants. Amphoteric surfactants based on betaine, known for their compatibility and their solubility in media at extreme pH are also likely to be used in the context of the invention, including Mirataine H2CHA® marketed by the firm Novecare Solvay.

Alkaline aqueous solution according to the invention means a solution of a mineral alkaline product, selected from alkaline phosphates, alkali carbonates or bicarbonates, alkali hydroxides, alkaline borates, alkali silicates of molar composition nSiO 2, Me 2 O, being between 0.5 and 3.5, the alkali borates, or mixtures thereof, Me being an alkali metal according to Mendeleev's classification.

In the context of the invention, use will preferably be made of an alkaline aqueous solution consisting of a solution of an alkali silicate having an SiO 2 / Me 2 O molar ratio of between 1 and 2, Me being preferably sodium, and a concentration of between 1% by weight and 50% by weight, and preferably between 10 and 40% by weight

The proportions of the constituents of the emulsion according to the invention are therefore between the following limits:

Solvent {terpene hydrocarbons) 20 to 55%

Mono, di or triglycerides of fatty acid 0.5 to 5%

Alkaline aqueous solution 30 to 79%

Hydrophilic surfactant (s) HLB> 10 1-15%

There are numerous prior patents describing emulsions or microemulsions of solvents in water, especially D-limonene.

The applicant's patent 2 986 535, issued in July 2015, describes a product consisting of a vegetable solvent emulsion containing additives modifying its rheological behavior in water, an emulsion obtained by means of a suitable surfactant, and intended for elimination of pitches and tar.

The product concerned by the present invention is notoriously different from the product described in this prior patent by the fact that the emulsion is produced in a solution of an alkaline mineral product, and preferably in an alkaline silicate solution, and is intended for the elimination of pitches and tars, but more particularly the elimination of asbestos pitches used as tile adhesive.

These disposal operations carried out by conventional mechanical means during the renovation and asbestos removal of social housing in particular, are difficult, long and painful for stakeholders and very expensive because they require to completely move the occupants of the buildings concerned , this for a significant duration. The use of a solvent emulsion product facilitates these operations, make them shorter and less painful and avoids having to move the occupants completely

Unexpectedly, the Applicant has found that the product according to the invention, thanks to the alkalinity imparted to the aqueous remulsion part, by the alkali silicate, still provided additional performance advantages over the re-emulsion claimed in the 2986 patent. 535.

These performance advantages are two-fold

Firstly, the Applicant has noticed that the speed of action of the emulsion made in an alkaline solution and more particularly alkali silicate was much greater on the asbestos glues and pitches than the emulsion made in water, which allows higher work rates, significantly shortening the waiting time required for the softening action.

Secondly, the Applicant has noticed that the alkali silicate present in the aqueous phase of rémulsion allowed to modify the asbestos fibers in situ in the asbestos glue, thanks to the property of the alkali silicates to bind strongly on the asbestos fibers, by the affinity due to an analogy of structural configuration between the alkaline silicate and the crystalline silicates constituting the asbestos.

In fact in another of its patents 2,956,046 issued in May 2014, the Applicant claims modification and amorphization of the asbestos by a treatment comprising an impregnation with an alkali silicate and a heat treatment.

The fact that the asbestos fibers present in the pitch-based tile adhesives are modified by the alkali silicate included in the emulsion according to the invention makes it possible to use the removal residue as an additional fuel without there being has a risk of emission of microscopic fine particles of asbestos fibers, very harmful, in the combustion gases. These particles are indeed coagulated as an aggregate by the alkali silicate contained in the aqueous phase of the emulsion, and rendered amorphous during the combustion of the residue due to the heat released by this combustion. The conditions of amorphization (asbestos fibers claimed in the patent 2 956 046 of the applicant are thus joined during the softening of the asbestos glue and during its combustion This allows to use the residue removal of glues or pitches asbestos as an additional fuel without risk to the environment.

Additional fuel is any product or mixture of products that can be burned and provide additional heating value in a combustion or incineration process.

Brais are residues from the distillation of petroleum tars, coal tar, wood or other organic matter. Tars are also waste products from the destructive distillation of organic matter. Likewise, coal tars are byproducts of the coking of coal at high temperatures.

These products have been and are still used in coating formulations to obtain insulating, waterproofing, anticorrosive effects for the surfaces to which they are applied or have been used as adhesive for PVC tiles. They have properties of interest for these areas of application, but they may have toxic or environmental hazards when they must be removed to allow for maintenance, renovation or deconstruction.

In addition, when their implementation is old, they very often contain low proportions of asbestos fibers The product according to the invention facilitates the operations of removal and disposal of these coatings, significantly reducing the risks related to to these renovation or maintenance operations.

The product according to the invention therefore consists of an emulsion in an aqueous alkaline solution of a solvent of plant origin presenting a minimum risk for the users and for the environment.

It is a direct emulsion that is to say that the organic phase immiscible with water, here referred to as "the solvent" is dispersed in the alkaline solution, which is therefore the continuous phase of the emulsion. In other words, the solvent is in some way encapsulated by the aqueous solution and is not in direct contact with the air or with the user.

On the other hand, when this emulsion is sprayed on the surface of pitch or tar to be removed, the hydrophobic-hydrophobic affinity solvent migrates towards the surface of the coating and participates in the softening of this coating, which facilitates their elimination. by scraping or any other means, mechanical, pneumatic, or hydraulic.

The presentation of a direct aqueous emulsion solvent thus has multiple advantages, and in the case of the present invention, does not reduce its effectiveness.

This is because the solvent is in the form of fine droplets dispersed in a continuous, protective medium, which is the aqueous phase. Thus, the fact that the water "coats" the solvent has the following positive consequences, such as limiting odor emission, limiting the emission of vapors, limiting direct contact with the skin or the mucous membranes. users, the deletion or in any case the strong limitation of the risks of flammability, and finally the dispersion of the mixture solvent and pitch or tar in the water of the emulsion after use and softening of the coating, which facilitates its elimination and also avoids contact between pitch or tar and the environment.

In addition, of course, and moreover, as already mentioned above, the product according to the invention is easily sprayed, acts rapidly on the glue or the impregnated pitch, and delivers a final residue that can be used as an additional fuel because the asbestos fibers it contains are inerted by the silicate present in the emulsion, according to the effects described in the previous patent No. 2 956 046 granted to the applicant, and therefore no longer present a danger of spreading the twist combustion

The present invention also claims the method of implementation of the product characterized in that it is sprayed or spread by any known means, including airless spray added, called "mono-fluid", the product on the coatings or glues asbestos based on pitches or tars, a sufficient time is left in contact to obtain a softening, then the whole residue is recovered by mechanical scraping, or by hydraulic means, preferably by a hydrogenation followed by suction with suitable equipment.

Spray without added air is to finely disperse the liquid through a nozzle by pressure on the product supply, without air being used to increase dispersion at the nozzle.

In particular, the terms "airless" or mono-fluid are used to characterize this type of spray, which has the advantage of not producing aeroosol and of avoiding the excessive dispersion of product in the ambient air, if one regulates suitably the air pressure in the product supply.

Finally, the use as additional fuel of the residue containing the coating or the adhesive and the solvent is also claimed by the present invention, this use being made possible by the fact that the product containing an alkaline silicate in solution, the asbestos fibers are encapsulated by the silicate and no longer present risks of flight or spread in the fumes during combustion, the asbestos fibers being rendered amorphous during combustion with the alkali silicate.

Example 1

Preparation of an aqueous alkaline emulsion according to the invention In a laboratory mixer that can be used for liquid-liquid mixtures, with a useful volume of 2 liters equipped with a vertical axis stirrer, is introduced successively

Pine oil 450 g

Glycerol monolaurate 10g

It is stirred for 2 minutes to dissolve the glycerol monolaurate in pine oil.

Then 80 g of an Emulson AG18 / C® reference surfactant from Lamberti, which is an ethoxylated fatty acid ester, are added.

Then we add

Permuted water 310 g and

Silicate solution of Rm SiO2 / Na2O = 2, concentration 45% in water 150 g

And we continue the agitation 3mn

1000 g is obtained a stable emulsion of white color, having a pH at 5% in water of 13.2, which corresponds to the product according to the invention.

Example 2

The dissolving power of two vegetable emulsion solvent formulations is compared on an asbestos glue composed of an old pitch, deposited on a cemented surface, updated after mechanical separation of PVC tiles.

The composition according to the invention described in Example 1 above is compared with a similar composition, but not containing sodium silicate in solution, which is replaced by deionized water in identical proportion.

We spread on a surface of 100 cm2 (10 x 10 cm) the two products side by side to visualize their effect and their speed of action, and let it act

After 45 minutes, by scraping, it is found that the glue is completely softened by the product according to the invention, while the product without silicate has not yet acted. It takes about 2 hours for the product without silicate to obtain a result equivalent to that obtained in 45 minutes by the product according to the invention.

Example 3

The residue obtained after softening the pitch glue binder by the emulsion product according to the invention is recovered by scraping and introduced into a platinum capsule. It is introduced into a cold muffle furnace, which is rapidly heated to 1000 ° C. At first, the water contained in the residue evaporates, then quickly the pitch and the vegetable solvent ignite. After complete combustion, a "heavy" mineral residue is obtained in the capsule, which is composed of the remainder of sodium silicate from the product according to the invention, which amalgamated and amorphized the asbestos fibers which were in the initial adhesive . The crystallographic examination of the mineral residue shows that the residual product is amalgamated, and amorphous, and is no longer asbestos.

Claims (8)

CLAIMS 1) Liquid product in the form of an emulsion, intended to facilitate the removal of coatings and asbestos glues based pitches, tars or bitumen, during deconstruction, maintenance or renovation, composed : a solvent of plant origin, liquid having an environmental impact and a low toxicity, added with one or more esters of glycerol, natural or modified, mono, di or triglycerides, solid at ambient temperature, and soluble ( s) in said solvent, said solvent being emulsified in an aqueous alkaline solution using a hydrophilic surfactant HLB (hydrophilic / lipophilic balance) greater than 10, and preferably greater than 12, and compatible with the aqueous alkaline solution . 2) A product according to claim 1, characterized in that the vegetable solvent is a liquid mixture of terpene hydrocarbons obtained by extraction from plant material such as conifer resins, or citrus peel or any other plant product containing terpene hydrocarbons. 3) Product according to claim 1, characterized in that the hydrophilic surfactant having an HLB of greater than 10 and preferably greater than 12, is chosen from nonionic surfactants such as alkylpolyglucosides, (Glucopon® from Cognis BASF or Plantaren® from Henkel) alkylpolypentosides, (Olean Appyclean®) ethoxylated or propoxylated terpene derivatives such as nopols (Rhodoclean® from Solvay Novecare), ethoxylated and / or propoxylated fatty alcohols, ethoxylated fatty acid esters and and / or propoxylates, and in particular and preferably surfactants with a hydrophilic head belonging to the family of sugars, or mixtures of these surfactants. 4) Product according to claim 1, characterized in that the aqueous alkaline solution is a solution of an inorganic alkaline product, selected from alkaline phosphates, alkali carbonates or bicarbonates, alkali hydroxides, alkaline borates, alkali silicates, molar composition nSiO 2, Me 2 O, n ranging from 0.5 to 3.5, or mixtures thereof, Me being an alkali metal according to the Mendeleyev classification. 5) The product according to claim 1 characterized in that the aqueous alkaline solution is a solution of an alkali silicate, having an SiO 2 / Me 2 O molar ratio of between 1 and 2, Me being sodium, and a concentration of between 1% by weight. weight and 50% by weight, and more particularly between 10 and 40% by weight 6) A product according to claim 1, characterized in that the proportions of the constituents of the emulsion are as follows: Solvent (terpene hydrocarbons) 20 to 55% Mono, di or triglycerides of fatty acid 0.5 to 5% Aqueous solution alkaline 30 to 79% Hydrophilic surfactant (s) HLB> 10 1 to 15% 7) A method of implementation of the product according to claims 1 to 6, characterized in that is sprayed or spread by any known means, including airless spraying added, the product on the plasters or asbestos glues based on tar or tar, a sufficient time is left in contact to obtain a softening, then the entire residue is recovered by mechanical scraping, or by a hydraulic means, preferably by a hydrogenation followed by suction with a suitable apparatus. 8) A process for preparing the product according to claims 1 to 6, carried out by stirring at room temperature of the mixture consisting of the solvent of vegetable origin, the aqueous alkaline solution and the compatible hydrophilic surfactant.