RU2571123C1 - Composition for removal of paint coatings - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: composition contains benzyl alcohol as main solvent, triethylcitrate or aromatic hydrocarbons as co-solvent, alkyl(hydroxyalkyl)cellulose as thickening agent, salts of monocarboxylic acids, or polyethyelenglycol ethers, or (polyethyelene)sorbitan esters as SAS and additionally carboxylic acids, selected from the group of stearic, palmitic, lauric, oleic or stearin, with the following component ratio, wt %: benzyl alcohol 11-98, SAS 0.2-50, alkyl(hydroxyalkyl)cellulose 0.01-20, carboxylic acids 0.02-10, triethylcitrate or aromatic hydrocarbons - the remaining part.

EFFECT: reduction of time for removal of pain coatings and composition consumption, increase of working temperature interval, elimination of abrasive action.

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Description

The invention relates to chemicals used to remove paint coatings.

Paint remover compounds are widely used in industry and the national economy.

Known composition for removing paint containing alkylene carbonate and alcohol. This composition may also contain a thickener, a surfactant and a corrosion inhibitor (US Patent No. 6,548,464 B1, C11D 3/44, 04/15/2003).

This composition is not effective enough, because Wash off the paint too slowly due to the presence of alkylene carbonate.

Also known is a composition for removing paint coatings, including methylene chloride, paraffin, ethoxylated alkyl phenols OP-7 or OP-10, a disintegrant (ammonia), a thickening agent (ethyl cellulose or methyl cellulose), an organic cosolvent (butanol, ethylene glycol and AML oil (RU7 patent No. 23) , С09В 9/04, C09D 9/00, published on December 10, 2007).

While methylene chloride-based formulations are very effective as paint removers (methylene chloride is a very volatile solvent and a known carcinogen), paint removers based on it are non-selective and will remove all layers of paint, including the lower layers and primer. In some cases, it is desirable that one or more coating layers be removed while leaving the primary layer intact. Application for cleaning graffiti is the very case when it is undesirable to remove all layers at once. Graffiti is often applied to painted surfaces, which, when cleaning, it is desirable to keep intact.

The closest composition for removing paint coatings (prototype) is a composition containing benzyl alcohol and water (co-solvent) as the main solvent; as a thickener, hydroxypropyl cellulose (hydroxyalkyl cellulose) or carboxymethyl cellulose or wheat starch, as a filler, glass microspheres, activated clay, or chalk, and surfactants (sodium dioctyl sulfosuccinate), in the following ratio of components, mass. %:

[US Pat. US 8361947, IPC С09В 9/04, 01/29/2013].

This composition is safe for the environment, but its disadvantages include:

- insufficiently high efficiency of the composition;

- the composition freezes when cooled to 0 ° C and is not suitable for operation at low temperatures;

- abrasive effect, damages glass and painted surfaces.

The problem to which the invention is directed, is to improve the known compositions for removing paint coatings.

The technical result that will be achieved by using the present invention is to increase the efficiency and selectivity when removing coatings from various surfaces, including painted ones, and to expand the range of operating temperatures and eliminate abrasive effects.

The technical result is achieved in that the composition for removing paint and varnish coatings, containing benzyl alcohol, co-solvent, surfactant and thickening agent - alkyl (hydroxyalkyl) cellulose as the main solvent, additionally contains carboxylic acids (stearic or palmitic, or lauric, or oleic acid, or stearin ); salts of monocarboxylic acids or polyethylene glycol esters or sorbitan esters (polyoxyethylene) are used as surfactants; and as a co-solvent use triethyl citrate or aromatic hydrocarbons, in the following ratio of components, mass. %:

Benzyl alcohol 11-98 Surfactant 0.2-50 Alkyl (hydroxyalkyl) cellulose 0.01-20 Carboxylic acids 0.02-10 Triethyl citrate or aromatic hydrocarbons rest

Salts of monocarboxylic acids can be used as surfactants, such as: sodium soap, ammonium soap or sodium (ammonium) stearate, sodium palmitate, sodium laurate; as polyethylene glycol esters, polyoxyethylene stearate, ethoxylated p-nonylphenol or ethoxylated p-octylphenol; Sorbitan esters (polyoxyethylene) include sorbitan monostearate, sorbitan tristearate, sorbitan monolaurate, sorbitan monopalmitate, sorbitan monooleate, sorbitan trioleate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan, polyoxyethylene sorbitan, polyoxyethylene sorbitan. As the alkyl (hydroxyalkyl) cellulose, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, methyl hydroxypropyl cellulose or hydroxyethyl ethyl cellulose are used.

As carboxylic acids, stearic or palmitic, or lauric, or oleic acid, or stearin is used.

As aromatic hydrocarbons use the aromatic fraction of oil, xylenes or toluene.

The invention consists in a qualitative and quantitative ratio of the ingredients of the composition.

Carboxylic acids used additionally in the composition act as a corrosion inhibitor due to the formation of an insoluble film on the metal surface.

The use of triethyl citrate or aromatic hydrocarbons as a co-solvent provides an optimal paint removal rate and the ability to work at temperatures below zero.

The use of monocarboxylic acid salts as a surfactant is necessary if it is necessary to introduce a surfactant and a thickener at the same time.

The use of polyethylene glycol esters as a surfactant is necessary to obtain a non-stratified homogeneous composition.

The use of sorbitan esters (polyoxyethylene) as surfactants ensures environmental friendliness and minimal toxicity of surfactants, and, as a result, low toxicity of the composition as a whole.

The ratio of the components is selected experimentally and is necessary and sufficient to achieve a technical result.

Thus, the claimed qualitative and quantitative composition has low toxicity, high efficiency in removing coatings, has a neutral pH (or slightly acidic, or slightly alkaline pH). Moreover, in the case of the use of triethyl citrate in the composition, it decomposes to non-toxic citric acid. Therefore, this composition containing triethyl citrate does not pollute the environment.

From an analysis of the scientific, technical and patent literature of the claimed combination of qualitative and quantitative composition of ingredients, leading to a significant increase in efficiency and selectivity when removing coatings from various surfaces, including painted, as well as expanding the range of operating temperatures and excluding abrasive action, it was not revealed that allows us to conclude that the claimed technical solution meets the criteria of "novelty" and "inventive step".

The invention is as follows.

In a reactor with a heating jacket and a reflux condenser, benzyl alcohol in an amount of 11-98 wt. %, 0.2-50 mass. % Surfactant, 0.01-20 mass. % alkyl (hydroxyalkyl) cellulose, 0.02-10 wt. % carboxylic acids and the rest is triethyl citrate or aromatic hydrocarbons. All are stirred for 3 hours at 85-92 ° C, then cooled to room temperature and incubated for 10-14 days to thicken.

Specific examples of paint removal compositions are shown in Table 1.

Graffiti removal using the compositions shown in Table 1 is performed as follows: the composition containing graffiti is uniformly applied with a roller, brush or trowel at a rate of about 60-100 g per square meter. m for smooth surfaces (glass, metal and stone) and about 100-200 g per square. m for multilayer old graffiti. After aging, rub it with a brush and remove it with a damp sponge or cloth in case of smooth surfaces and glass or with a stream of water under high pressure, if the surface is porous.

The removal efficiency is evaluated by the speed of removal of the coating from the surface of the sample - the removal time in seconds, at a temperature of 20 ° C.

There should be no signs of metal corrosion on the treated metal surface. The proposed composition determine the flow rate of washing per unit of the treated surface.

The proposed composition effectively destroys coatings based on the following film-forming agents: acrylates (acrylic spray paint, hereinafter AK), cellulose nitrate (for example, NTs-132), pentaphthalic resin (for example, PF-115 enamel), glyptal resin (for example, GF- 021) and others.

Table 2 shows comparative data on the effectiveness of the claimed composition and composition of the prototype.

As can be seen from Table 2, the proposed composition in comparison with the composition of the prototype can significantly reduce the removal time of various coatings and consumption of the composition, increase the range of operating temperatures (from -40 ° C and above), and also eliminate the abrasive effect.

The surfaces to be cleaned may contain the primary layers of various putties, such as polysulfides, polyurethane, epoxy resin, epoxy silane resin, fluorinated resin, silicone and so on, this invention can be used to remove paint from concrete, stone, tile, metal, glass, plastic, painted buildings and structures, furniture, cars, ships, trains, planes, military vehicles and so on.

In addition, the claimed composition does not contain abrasives and mineral fillers such as clay, bentonites, aluminum oxide, glass microspheres or sand, and is unable to scratch the glass or painted surface. In addition, it is worth noting that this composition reduces the adhesion between the outer layers of the paint and the primer or the inner layer of the paint in a short period of time, can be used both in liquid, in gel form or in the form of a paste, low volatility and does not contain carcinogenic components.

Claims (1)

A composition for removing paint coatings containing benzyl alcohol, co-solvent, surfactant and thickening agent as alkyl (hydroxyalkyl) cellulose as the main solvent, characterized in that the surfactant contains monocarboxylic acid salts or polyethylene glycol esters or sorbitan esters (polyoxyethylene), as a co-solvent contains triethyl citrate or aromatic hydrocarbons, additionally contains as carboxylic acids stearic, or palmitic, or lauric, or oleic acid, or stearin, in the following ratio of components, wt. %:
Benzyl alcohol 11-98 Surfactant 0.2-50 Alkyl (hydroxyalkyl) cellulose 0.01-20 Carboxylic acids 0.02-10 Triethyl citrate or aromatic hydrocarbons rest