CZ305526B6 - Cleaning mixture for removing coatings of water-based dispersions of acrylate polymers and method of removing thereof - Google Patents

Abstract

In the present invention, there is disclosed a cleaning mixture for removing coatings formed of water-based dispersions pf polymers, in particular that of acrylate polymers, which mixture comprises aqueous solution of surface-active substance with concentration in the range of 5 to 30 multiple of the critical micellar concentration and at least 10 percent by volume organic solvents, preferably 15 to 30 percent by volume, whereby the surface-active substance is non-ionogenic, such as a block polymer of the type poly(propylene glycol-block-ethylene glycol-block-propylene glycol), or ionogenic such as sodium laurylsulfate, wherein the mixture of the organic solvents comprises an aromatic hydrocarbon and/or a mixture of aromatic hydrocarbons and an organic acid ester and/or a mixture of organic acid esters. The invention also discloses a method of removing the above-indicated coatings, wherein the method is characterized by application of the above-described cleaning mixture to the coating to be removed and is left to act thereon for a period of 2 to 4 hours where the organic solvents cause swelling and erosion of the acrylate layer and aqueous solution of the surface-active substance promotes through solubilization and reduction of surface tension the removal of acrylate polymer from the surface, which is subsequently rinsed with water.

Description

A cleaning composition for removing coatings from aqueous dispersions of acrylate polymers and a process for removing them

Technical field

The present invention relates to a cleaning composition for removing coatings formed from aqueous dispersions of acrylate polymers and to a method for removing them.

BACKGROUND OF THE INVENTION

In the construction industry, for the impregnation of foundry molds and for the impregnation of paper and textiles, coatings of acrylate dispersions are used. Due to the nature and chemical composition of the coatings formed, these compositions are intended for professional use. Acrylate dispersions have very good adhesion to the surface, which in turn makes it difficult to remove them. The methods of removal used so far based on mechanical abrasion or the action of very aggressive chemical agents usually damage the material itself and are environmentally friendly.

SUMMARY OF THE INVENTION It is an object of the present invention to overcome these drawbacks and to propose a cleaning composition which is easy to manufacture from commercially available components and does not disturb the material to be treated or harm the environment.

SUMMARY OF THE INVENTION

The aforementioned drawbacks of the prior art are eliminated and the object of the present invention is to provide a cleaning composition for removing coatings formed from aqueous dispersions of acrylate polymers containing water and a surfactant according to the invention which comprises a mixture of an aqueous surfactant solution at from 5 to 30 times the critical micelle concentration and at least 10% by volume of the organic solvent or mixture of organic solvents, preferably 15 to 30% by volume;

According to the invention, it is preferred that the surfactant be non-ionic, in particular a block copolymer of the poly (propylene glycol-block-ethylene glycol-block-propylene glycol) type (Pluronic PI23).

A further preferred embodiment of the cleaning composition according to the invention is that the surfactant is ionic, in particular sodium lauryl sulfate.

The cleaning composition must contain an aromatic hydrocarbon or a mixture of aromatic hydrocarbons, an organic acid ester or a mixture of organic acid esters. It may then preferably contain alcohols.

It is preferred that the ratio of the aromatic hydrocarbon, especially toluene, to the ester of the organic acid, especially ethyl acetate, in the purification mixture is 2: 1 in volume by volume.

According to the invention, the method of removing coatings formed from aqueous dispersions of polymers, in particular acrylate polymers, is to apply the cleaning composition to the coating layer and allow it to act for 2 to 4 hours. The cleaning composition causes swelling and disruption of the acrylate layer, and an aqueous surfactant solution by solubilization and reducing surface tension helps to remove the acrylate polymer from the surface, which is subsequently rinsed with water.

- 1 GB 305526 B6

DETAILED DESCRIPTION OF THE INVENTION

Example 1

A 400 g / m ² aqueous dispersion of polymethyl methacrylate and alkaline polymethacrylate polymers was applied to the glass substrate. The surface was dried at 80 ° C to constant weight. The polymer coverage of the surface was 125 g / m ² . A washing composition containing 62% by volume of a mixture of organic solvents and 38% aqueous solution of a non-ionic surfactant poly (propylene glycol-block-ethylene glycol-block-propylene glycol) (Pluronic P123) at a concentration of 10 g / L was applied to the dried surface. The organic solvent mixture contained 62 vol% toluene, 15 vol% butyl acetate, 15 vol% ethyl acetate, 6 vol% 1-butanol and 2 vol% 2-ethoxyethyl acetate. The monitoring of the dependence of the degree of surface cleaning on the amount of the cleaning composition and the duration of its action showed that the use of 2.5 L / m ^{2 of} cleaning composition for 4 hours is sufficient for perfect surface cleaning.

Example 2

A 400 g / m ² aqueous dispersion of polymethyl methacrylate and alkaline polymethacrylate polymers was applied to the glass substrate. The surface was dried at 80 ° C to constant weight. The polymer coverage of the surface was 125 g / m ² . A cleaning composition containing 30% by volume of a mixture of organic solvents and 70% aqueous solution of a non-ionic poly (propylene glycol-block-ethylene glycol-block-propylene glycol) surfactant (Pluronic P123) at a concentration of 10 g / L was applied to the dried surface. The organic solvent mixture contained 62% by volume of toluene, 15% by volume of butyl acetate, 15% by volume of ethyl acetate, 6% by volume of 1-butanol and 2% by volume of 2-ethoxyethyl acetate. The monitoring of the dependence of the degree of surface cleaning on the amount of the cleaning composition and the duration of its action showed that the use of 2.5 L / m ^{2 of} cleaning composition for 4 hours is sufficient for perfect surface cleaning.

Example 3

200 g / m ^{2 of an} aqueous dispersion of polymethyl methacrylate and alkaline polymethacrylate polymers was applied to the marl material. The surface was dried at 80 ° C to constant weight. The polymer coverage was 62.5 g / m ² . A cleaning composition containing 62% by volume of a mixture of organic solvents and a 38% aqueous solution of a 10 g / L poly (propylene glycol-block-ethylene glycol-block-propylene glycol) non-ionic surfactant (Pluronic P123) was applied to the dried surface. The organic solvent mixture contained 62 vol% toluene, 15 vol% butyl acetate, 15 vol% ethyl acetate, 6 vol% 1-butanol and 2 vol% 2-ethoxyethyl acetate. The monitoring of the dependence of the degree of surface cleaning on the amount of the cleaning composition and the duration of its action showed that the use of 1.25 L / m ^{2 of} cleaning composition for 4 hours is sufficient for perfect surface cleaning.

Example 4

A 400 g / m ² aqueous dispersion of polymethyl methacrylate and alkaline polymethacrylate polymers was applied to the glass substrate. The surface was dried at 80 ° C to constant weight. The polymer coverage of the surface was 125 g / m ² . A cleaning composition containing 15% by volume of a mixture of organic solvents and an 85% aqueous solution of a 10 g / L non-ionic poly (propylene glycol-block-ethylene glycol-block-propylene glycol) surfactant was applied to the dried surface. The organic solvent mixture contained 67 vol% toluene, 33 vol% ethyl acetate. To completely clean the surface, it is sufficient to use 2.5 L / m ^{2 of} cleaning compound for 2 hours.

Claims (7)

PATENT CLAIMS A cleaning composition for removing coatings formed from aqueous dispersions of polymers, in particular acrylate polymers, containing water and a surfactant, characterized in that it comprises an aqueous surfactant solution at a concentration ranging from 5 to 30 times the critical micelle concentration and at least 10 % by volume of a mixture of organic solvents consisting of an aromatic hydrocarbon and / or a mixture of aromatic hydrocarbons and an organic acid ester and / or a mixture of organic acid esters. The cleaning composition according to claim 1, characterized in that the surfactant is a non-ionic, especially poly (propylene glycol-block-ethylene glycol-blockpropylene glycol) block copolymer. Cleaning composition according to claim 1, characterized in that the surfactant is ionic, in particular sodium lauryl sulphate. Cleaning composition according to claims 1 to 3, characterized in that the content of the organic solvent mixture is preferably 15 to 30% by volume of the resulting mixture. A cleaning composition according to claims 1-4, wherein the organic solvent mixture further comprises alcohols. Cleaning composition according to any one of claims 1 to 5, characterized in that the ratio of the aromatic hydrocarbon, in particular toluene, to the esters of the organic acid, in particular ethyl acetate, is preferably 2: 1 by volume. A method for removing coatings formed from aqueous dispersions of polymers, in particular acrylate polymers, characterized in that a cleaning composition according to claims 1 to 6 is applied to the coating and allowed to act for 2 to 4 hours when the organic solvents cause swelling and disruption of the acrylate layers and an aqueous surfactant solution by solubilizing and reducing surface tension helps to remove the acrylate polymer from the surface, which is then rinsed with water. End of document