RU2738582C9 - Apparatus for detecting and removing metal inclusions on car paint coating surfaces - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to means for detecting and removing metal impregnations on car lacquer coating surfaces. Developed device can be used in the process of auto-detailing at the stage of surface cleaning of paint coating for improvement of adhesion of various protective polymer films, ceramic or oxide coatings. Agent for detection and removal of metal impregnations on surfaces of paint coating of vehicles contains components at the following ratio, wt%: sulfosalicylic acid 2-4, hydrogen peroxide 1-5, sodium laureth sulphate 5-15, citric acid 2-4, distilled water - the rest.

EFFECT: elimination of toxic sulfur-containing reaction by-products during detection and removal of metal impregnations on surface of vehicle lacquer coating, higher reactivity of the device without damaging paintwork surface of vehicles.

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Description

The technical field to which the invention relates

The invention relates to the field of chemistry, chemical synthesis, methods of obtaining means for detecting and removing metal inclusions on the surface of the paintwork of automobiles.

The developed tool for detecting and removing metal inclusions on the surface of car paintwork will find wide application in the field of auto detailing and will be used at the stage of cleaning the paintwork surface in order to improve the adhesion of various protective polymer films or ceramic (oxide) coatings.

A feature of the invention is the use of sodium laureth sulfate as a surfactant, hydrogen peroxide as an oxidizing agent, sulfosalicylic acid as an indicator, citric acid as a complexing agent, and water as a solvent in the composition of a means for detecting and removing metal inclusions on the surface of car paintwork. ...

State of the art

Currently, the field of auto detailing has received intensive development. Auto-detailing is a process of thorough treatment of a car inside and outside, including its cleaning, repair, restoration and protection of the car's paintwork.

Conventionally, the process of auto-detailing can be divided into three components: external, internal and engine detailing. Of particular importance is the exterior detailing, which consists in the repair, restoration and protection of car paintwork. As you know, the protection of car paint and varnish coatings includes the application of liquid or pasty compositions to the prepared surface, which, interacting with the top layer of the treated coating, form a thin protective film on it. In this connection, the stage of preparation of the surface of the paintwork is important. As you know, there is a line of drugs that provide a step-by-step cleaning of the surface from pollutants of various natures, including bitumen particles, metal inclusions and contamination in the form of sedimentary rocks (sand, dust, etc.).

As the analysis of analogues has shown, most of the means for cleaning the surface of the paintwork from metal inclusions contain sulfur-containing compounds, which, when interacting with pollution, are destroyed with the release of hydrogen sulfide. Hydrogen sulfide is a toxic gaseous compound with an unpleasant, pungent odor that irritates the mucous membrane of the respiratory tract.

Based on the foregoing, it is urgent to develop and optimize a method for obtaining a low-toxic, highly effective agent for the detection and removal of metal inclusions on the surface of car paintwork.

Since metal inclusions mainly consist of particles of iron and its oxides, hydroxides and oxohydroxides, compositions based on acids - orthophosphoric, tartaric, oxalic, citric, oxyethylidene diphosphonic and others are used to remove them from the surface of the paintwork, therefore, analogs of the developed means for detecting and removing metal inclusions on the surface of car paintwork are means for removing iron oxide compounds from various surfaces.

So known converter rust (see patent RU No. 2286999, publ. 10.11.2006), containing the following components in wt. %: orthophosphoric acid - 37.0-51.0; graphite - 24.0-34.0; lignosulfonates - 0.5-1.0; Concrepol B - 0.3-1.1; water - 18-27.

The rust converter is prepared as follows. Previously crushed in a mortar or in a laboratory mill and sifted through a sieve with a hole diameter of 0.125 mm graphite grade GSS-1 TU 21-25-166-75 is mixed in a beaker with orthophosphoric acid grade "h" GOST 6552-80. The resulting mixture is homogenized. Powdered technical lignosulfonates are poured into another glass.
TU-13-0281-036-15-90 and dissolve them in water GOST R51232-98. The resulting solution of lignosulfonates is poured into a glass with a mixture of graphite and orthophosphoric acid, after which the ingredients are thoroughly mixed. Concrepol B TU 9365-001-13802623-2003 is added to the resulting mixture, which is a water-polymer system in the form of a sol or gel of polymer N-vinylpyrrolidone. The components are thoroughly mixed until the finished product is completely homogenized with a syrupy consistency of black or black-gray color with a metallic sheen having a density of 1.58-1.60 g / cm ³ .

The disadvantage of this converter is the difficulty of observing the conditions for preparing the composition; components that strictly correspond to a certain quality marker are required. Also, this composition is not optimal for use in industrial conditions, since it takes a significant amount of time for visible results.

A rust converter similar in composition is represented by a patent (see patent RU No. 2158745, publ. 10.11.2000): orthophosphoric acid - 38-50; graphite - 25-33; lignosulfonates - 0.5-1.0; water is the rest.

The disadvantage of this converter is the complexity of its application, which occurs as follows: the rust converter is applied to the surface and mixed with the applied contaminants, forming a homogeneous oil-in-water emulsion due to the emulsifying component. The oil, previously sorbed by a layer of rust, goes into the converter, and the rust-converting component of the composition - orthophosphoric acid - freely interacts with rust, converting it into an inert product. Therefore, when, after drying, the coating is removed from the surface of the plates with a sharpened scalpel, rust is not detected under it. This process cannot be considered applicable in industry.

There is a rust converter and a method for its production (see patent RU No. 2693764, publ. 04.07.2019), which belongs to the paint and varnish industry and can be used to protect metal surfaces affected by rust. The rust converter contains components in the following ratio, wt. %: latex SKS-65 GP - 16-17.7; an aqueous solution of tannin - 7.7-9; oxalic acid - 1.9-2.4; water - the rest is up to 100%.

For preparation, latex is loaded into a mixing device at a mixer speed of 110 - 140 rpm and a temperature of 25 - 35 ° C. Gradually add the tannin solution to the latex with a minimum mixing time of 20 minutes. Add to the resulting mixture a solution of oxalic acid with a minimum mixing time of 8 minutes. EFFECT: improved adhesion properties and physical and mechanical properties of the protective film, reduced production time.

The main disadvantages of the known rust converter are high requirements for the technology of its production, namely:

1) firstly, the material of the walls of the reactor must be inert with respect to raw materials,

2) secondly, the mixing should be quite intense (with the formation of a "funnel"), but without foaming 110 - 140 rpm. This is necessary to introduce subsequent acidic components without destroying the latex base.

3) Prepared solutions of tannin and oxalic acid are introduced into the active mixing zone along the wall of the main reactor, and since they are prepared in containers located above the level of the main reactor, they move there by gravity. It is important to maintain a low volumetric rate of introduction of the second component (tannin solution) to prevent latex from degradation, while the minimum time for adding tannin solution to latex is 20 minutes, the feed volume is calculated in accordance with the working volume of the reactor and the required ratios of the components.

Known composition for processing a metal surface (see patent RU No. 2205895, publ. 10.06.2003), intended primarily for the formation of a protective non-metallic layer on the surface of cold-rolled steel before applying paint. The invention can be used in mechanical engineering and instrument making for processing car bodies, instruments and other blanks after stamping. The composition for processing a metal surface includes phosphoric acid, a reaction accelerator and water, and as a reaction accelerator contains acetone and, additionally, ammonium nitrate, urotropin and a surfactant in the following ratio of components, wt. %: orthophosphoric acid - 50, 0-60.0; ammonium nitrate - 1.5-2.0; acetone - 3.0-4.0; urotropin - 0.15-0.2; nonionic detergent - 0.01-0.05; water is the rest.

The disadvantage of this composition is the presence of an alkaline component - ammonium nitrate and an organic solvent - acetone, which can cause significant damage to the paintwork.

Also known is a method for preparing a rust converter (see international application PCT WO2016171641A1, publ. 27.10.2016), which includes the following components: tannic extract, oxalic acid, hydroxyethylidene diphosphonic acid-1, silver source - silver nitrate and water. The complete composition (in wt%) is as follows:

Tanning extract - 6.80-12.70

Oxalic acid - 3.80-7.72

Silver nitrate - 0.01-0.10

Oxyethylene diphosphonic acid-1 - 0.15-0.67

Water or water with alcohol is the rest.

All ingredients are mixed and then dissolved in a water or water-alcohol base.

The disadvantage of this tool is a long drying time (15 - 120 minutes or more), with a long drying time, drying and reapplication is necessary, this increases production costs.

There is another known method for converting and removing iron oxide from metal surfaces. (see international application PCT WO1999023283A1, publ. 14.05.1999). The composition of this tool includes the following components in wt. %:

Glycerin - 1%

Polyvinyl alcohol - 10%.

An aqueous solution is prepared from these components, which is subsequently applied to a metal surface. The composition needs time to dry, after which it can be removed in the form of solid deposits. According to the patent, iron oxide is removed along with the dried film.

The disadvantage of this method is the possible damage to the paint and varnish surface, a long drying time and the inconvenience of using it for cleaning metal.

There are also products from the following manufacturers on the market: neutral disc and body cleaner "M2" ( Leraton, St. Petersburg, Russia), CarPro cleaner " IronX LS" (manufactured by CarPro ltd. ), Iron cleaner " DeconPro " ( Chemical Guys , USA ), Iron Out ( Auto Finesse ), acid-free rust remover, Reactive Rust Remover ( Koch Chemie, Germany), IronX heavy deposits ( Ceramic Pro ltd. ), PH-neutral disc cleaner and bodywork " Ultra Ferrum " ( Ultra Technologies , Japan), ultra-cleaner of metal oxides " Krytex oxide Remover " with a color indicator ( KRYTEX ).

Analysis of these analogs showed that most of the means for cleaning and removing dirt from the surface of the car contain the following components:

1. Surfactants.

2. Indicator.

3. Complexing agent.

4. Solvent.

5. Others (dyes, flavors, etc.).

Compounds from the group of anionic and nonionic surfactants are used as surfactants: sodium laureth sulfate,berol 226, APG and others. The purpose of these components is to improve the contact of the means for removing metal inclusions and contaminants with the surface of the car's paintwork, as well as for dispersing and solubilizing contamination in the micelles of surfactants and then removing it from the surface of the car's paintwork.

Polybasic acids are used as complexing agents: citric, oxalic, oxyethylenediphosphonic, ethylenediaminetetraacetic and others. The use of which in products is necessary to remove metal cations by binding them with acid residues to form chelate complex compounds.

Water and polyhydric alcohols are used as solvents to form a certain consistency with certain rheological and physicochemical properties.

Indicators are used to determine the active acidity of the environment, to detect the presence of certain ions in pollution. The following compounds can be used as indicators for iron ions: potassium thiocyanide, potassium hexocyanoferrate, sulfosalicylic acid, phenol, and others.

Various colorants and fragrances can also be included in the composition of the product for removing metal inclusions on the surface of car paintwork.

The fundamental difference between the claimed invention and the prototype is the use of sodium laureth sulfate as a surface-active compound, citric acid as a complexing agent, sulfosalicylic acid as an indicator, and water as a solvent. Also, hydrogen peroxide is used to intensify the process of converting water-insoluble forms of iron ( Fe _metal , FeO, Fe ₂ O ₃ , FeO ⋅ Fe ₂ O ₃ , FeOH ₂ , FeOH ₃ , FeOOH ) into soluble forms .

Brief description of drawings and other materials

FIG. 1 shows a micrograph of a contaminated surface of a car paintwork.

FIG. 2 shows the EDS spectrum of the contaminated surface of the car paintwork.

FIG. 3 shows the elemental composition of the contaminated surface of the car paintwork.

FIG. 4 shows the EDS spectrum of a road dust sample.

FIG. 5 shows the elemental composition of road dust.

FIG. 6 shows photographs of the surface of the paintwork with the applied agent for detecting and removing metal inclusions on the surface of the paintwork of cars: a - after 0 seconds; b - after 5 seconds; c - after 10; d - after 25 seconds; d - 60 seconds.

FIG. 7 is a photomicrograph of a cleaned surface of a car paintwork.

FIG. 8 shows the EDS spectrum of the surface of a cleaned paintwork.

FIG. 9 shows the elemental composition of the cleaned surface of the car paintwork.

Disclosure of invention

The problem to be solved by the invention is to develop a new tool for detecting and removing metal inclusions on the surface of car paintwork, which will not contain volatile toxic sulfur-containing compounds, which is typical for analogues and prototype.

The technical result, which can be achieved with the help of the present invention, is reduced to the elimination of toxic sulfur-containing by-products of the reaction in the process of detecting and removing metal inclusions on the surface of the paintwork of cars by the developed tool, increasing the reactivity of the tool, without causing damage to the paintwork of cars.

Based on the studies carried out and the experimental data obtained, a tool has been developed for the detection and removal of metal inclusions on the surface of car paintwork using sodium laureth sulfate as a surfactant, hydrogen peroxide as an oxidizing agent, sulfosalicylic acid as an indicator, citric acid as a complexing agent. and water as a solvent. Means for detecting and removing metal inclusions on the surface of car paintwork contains components in the following ratio,% (wt.).

Sulfosalicylic acid 2 - 4;

Hydrogen peroxide 1 - 5;

Sodium laureth sulfate 5 - 15;

Citric acid 2 - 4;

Distilled water is the rest.

Method of obtaining a low-toxic agent for removing metal inclusions on the surface of car paintwork includes the following stages:

1) at the first stage sodium laureth sulfate and sulfosalicylic acid are dissolved in water;

2) then hydrogen peroxide is added to the reaction mass, and the whole system is stirred for 15 minutes;

2) then citric acid is introduced into the reaction mass;

4) then the reaction mixture is stirred for 20 minutes;

5) the resulting tool for the detection and removal of metal inclusions on the surface of the car paintwork is packaged.

The resulting tool for detecting and removing metal inclusions on the surface of car paintwork is a transparent solution, odorless, without foreign inclusions, the active acidity of the medium of which is equal to pH ≈ 7, which is stable during storage.

Implementation of the invention

Example 1.

Method of obtaining a means for detecting and removing metal inclusions on the surface of car paintwork includes several stages. In the first stage, 2 grams of sodium laureth sulfate and 1 gram of sulfosalicylic acid are dissolved in 100 ml of water and mixed. Then, 1 ml of 30% hydrogen peroxide is added dropwise to the reaction mass, and the whole system is stirred for 15 minutes. Next, 1 gram of citric acid is introduced into the reaction mass and the reaction mass is stirred for 20 minutes. With the following ratio of components,% (wt.):

Sulfosalicylic acid 0.01 - 2;

Hydrogen peroxide 0.01 - 1;

Sodium laureth sulfate 0.01 - 5;

Citric acid 0.01 - 2;

Distilled water is the rest.

Result: The resulting agent for detecting and removing metal inclusions on the surface of car paintwork is a transparent solution, odorless, without foreign inclusions, the active acidity of the medium of which is pH ≈ 7.5 - 7, is characterized by unsatisfactory wetting properties and poor interaction with the paintwork car.

Example 2.

Carried out analogously to example 1, but with the following ratios of components,% (wt.):

Sulfosalicylic acid 2 - 4;

Hydrogen peroxide 1 - 5;

Sodium laureth sulfate 5 - 15;

Citric acid 2 - 4;

Distilled water is the rest.

Result: The resulting agent for the detection and removal of metal inclusions on the surface of the paintwork of cars is a transparent solution, odorless, without foreign inclusions, the active acidity of the medium of which is equal to
pH ≈ 6 - 7.

Example 3.

Carried out analogously to example 1, but with the following ratios of components,% (wt.):

Sulfosalicylic acid 4 - 10;

Hydrogen peroxide 5 - 20;

Sodium laureth sulfate 15 - 20;

Citric acid 4 - 10;

Distilled water is the rest.

Result: The resulting agent for detecting and removing metal inclusions on the surface of car paintwork is a viscous gel-like agent that is not convenient for application and is difficult to wash off from the surface of car paintwork, has no smell, no foreign matter, the active acidity of the medium of which is pH ≈ 2 - 3, which is not permissible to preserve the integrity of the car's paintwork.

To study the effectiveness of the means for detecting and removing metal inclusions on the surface of the paintwork of cars, a sample was used, made according to
Example 2, which, in terms of its surface-active, optical, structural and mechanical properties, satisfies the technological and operational requirements for means for detecting and removing metal inclusions on the surface of a car paintwork.

Before testing prototypes of a low-toxic, highly effective agent for removing metal inclusions on the surface of car paintwork, a study of the microstructure of the surface of car paintwork was carried out in order to detect and identify contaminants. For this, microscopic examination of contaminated samples of car paintwork with a surface area of 1cm ² with an optical microscopeIM 7200MEIJI TECHNO... One of the obtained micrographs of the contaminated surface of the car paintwork is shown in FIG. one.

Analysis of the data obtained showed the presence of polydisperse particles of various sizes and irregular shapes on the surface of a car paintwork, having a monomodal size distribution, with an average surface area of about 25 μm ² .

In order to identify dirt particles and inclusions on the surface of the car's paintwork, an energy dispersive microanalysis was carried out using a scanning electron microscope MIRA-LMH with a system for determining the elemental composition AZtecEnergy Standart / X-max 20 (standard) from Tescan . Received
The EDS spectrum and the elemental composition of the contaminated surface of the car paintwork are shown in Fig. 2 and 3, respectively.

It was found that the particles of inclusions on the surface of the paintwork of cars are represented not only by metal materials, but also by mineral materials containing sedimentary rocks in the form of particles of sand, earth, clay and other things, which contain elements such as iron, potassium, magnesium, aluminum, sodium , silicon, chlorine, calcium. In order to confirm this fact, an energy dispersive microanalysis of road dust was carried out using a scanning electron microscope. For research, two dust samples were taken, which were dried and subjected to research on a scanning electron microscope MIRA-LMH with a system for determining the elemental composition of AZtecEnergy Standard / X-max 20 (standard) from Tescan , obtained, and the EDS spectrum and elemental composition of a sample of road dust are presented in FIG. 4 and 5, respectively.

As a result of energy dispersive microanalysis, the similarity of the compositions of contaminants on the surface of the paintwork of a car and road dust particles was established, and it can be concluded that most of the inclusions on the surface of the car are represented by both metal particles and road dust particles containing various mineral compounds.

Next, a test was carried out for a means for detecting and removing metal inclusions on the surface of car paintwork. For this, the paintwork of the car was treated with the obtained agent, the application was carried out with a spray gun. The experimental results are shown in FIG. 6. Analysis of the photographs obtained showed that the prototypes of the developed low-toxic high-performance agent actively reacted with metal impregnations after 5-10 seconds with the appearance of a bright-burgundy coloration caused by the formation of iron disulfosalicylate.

Complete removal of metal inclusions by prototypes of the developed low-toxic high-performance agent was confirmed using optical microscopy and energy dispersive microanalysis. The results are shown in FIG. 7 and 8.

As a result, it was found that when using the developed product, there is a complete removal of not only metal inclusions on the surface of car paintwork, but also mineral contaminants containing calcium, magnesium, silicon, sulfur, chlorine and other elements.

Claims (2)

A means for detecting and removing metal inclusions on the surface of car paintwork, including sodium laureth sulfate as a surfactant, sulfosalicylic acid as an indicator, citric acid as a complexing agent, distilled water as a solvent, characterized in that it contains hydrogen peroxide in as an oxidizing agent with the following ratio of components, wt%: sulfosalicylic acid 2-4 hydrogen peroxide 1-5 sodium laureth sulfate 5-15 lemon acid 2-4 distilled water rest

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