RU2800456C2 - Composition (formulation) for antifungal treatment of swellable coatings - Google Patents

Abstract

FIELD: fungicidal compositions for paint and varnish industry.

SUBSTANCE: invention can be used to restore biocidal properties of silicone sealants, paints and varnishes. The composition for antifungal treatment of swellable coatings includes hexane from 15 to 25% by weight for dissolution and swelling of the treated coatings, ethyl alcohol from 40 to 60% for dissolution and introduction of a biocidal agent into the composition, alkyldimethylbenzylammonium chloride from 2 to 5% as a biocidal agent, thickening agent based on cellulose derivatives from 0.1 to 0.2%, neutralizing base from 0.1 to 0.15%, non-ionic surfactant neonol from 3.0 to 5.0%, water up to 100%.

EFFECT: provision of a composition for antifungal treatment of swelling coatings with an extended period of action.

1 cl, 1 dwg, 1 tbl

Description

The invention relates to the field of paint and varnish industry and can be used to restore the biocidal properties of silicone sealants and biocidal paints and varnishes. The composition of the tool includes, wt. %: hexane from 15 to 25%; ethyl alcohol from 40 to 60%; alkyldimethylbenzylammonium chloride 2 to 5%; cellulose derivative from 0.1 to 0.2%. The composition additionally contains a neutralizing base (triethanolamine) in an amount of 0.1 to 0.15% and a nonionic surfactant neonol in an amount of 3.0 to 5.0%, water up to 100%.

Currently, to impart fungicidal properties to coatings (paints, various putties and sealants), biocidal agents are introduced during their production.

The patent [1] describes a water-dispersed paint and varnish composition, including a water-borne film former, pigments, a thickener, an emulsifier, a biocidal additive, and water.

The disadvantage of this composition is the slight resistance of the coating to water, resulting in washable film.

When choosing known biocides for coatings, it is difficult to fulfill the main requirement - to ensure low toxicity. This problem is especially acute for antifouling paints used, for example, for application to the bottoms of ships, mooring equipment, etc., which usually use organic and inorganic compounds of copper, tin, zinc and lead. These coatings are highly toxic to fish and animals. Through food, they are able to enter the human body [2].

In addition, biocides are known to protect wood from wood-staining, destructive and mold fungi: pentachlor, sodium phenolate, sodium hydroxide, copper sulfate, arsenic, chromium, copper, zinc. Most of these biocides are also highly toxic compounds [3].

Known use in industry and construction of biocides based on high-molecular salts of polyhexamethyleneguanimide (PGMG). Preparations of PHMG salts meet many requirements for biocides for water-borne coatings. These preparations are effective against various microorganisms, have low toxicity for warm-blooded animals, are nonvolatile, dissolve well in water, are colorless and odorless, are stable during storage, and retain bactericidal properties in the coating [4].

However, when PHMG salts are introduced into coatings, the problem of their compatibility with various film formers and paint bases arises, since these salts dissolve only in water in lower alcohols, but do not dissolve in organic solvents used in coatings formulations, which leads to the impossibility of their use in solvent-borne coatings. .

Paints are known, in which polyguanidine bases are used as a biocidal additive in an organic-soluble varnish, which, unlike hydrophilic salts of polyguanidines, dissolve in one organic solvent - ethyl alcohol. To obtain a biocidal varnish, a solution of polyguanidine base in ethanol (biocidal additive) is mixed with a solution of a film-forming agent (chlorine-containing polymer) in an aromatic solvent. Thus, the paint and varnish composition [5] contains a PG base as a biocidal additive, contains a chlorine-containing polymer in nefras as a film-forming base and a crosslinking agent, and in the composition [6], in addition to the PG base and a chlorine-containing polymer, toluene is used as an aromatic solvent and additionally contains an active pigment and carboxylic acid.

The disadvantage of these compositions is the use of a mixture of two solvents, which adversely affects the stability of paints and varnishes and the quality of coatings, since each of the solvents is a precipitant for the second polymer.

PHMG is a moderately toxic substance (hazard class 3), exhibits general toxic and irritant effects, the severity of which directly depends on the level and duration of exposure. However, in scientific circles, there are still disputes about the toxicity of this drug, including its ability to cause toxic hepatitis.

In this regard, promising directions for the creation of bactericidal compositions are compositions based on quaternary ammonium compounds (QAC), for example, alkyldimethylbenzylammonium chloride, quaternary ammonium compound clathrate with urea, chlorhexidine gluconate, and other proven antiseptics.

It is known to use a mixture of biocides. So in the patent [7] biocidal paint includes a film-forming agent in the form of a paint and varnish material and a biocidal additive, where as a biocidal additive it contains an inorganic or organic salt of polyhexamethylene guanidine, or a base of polyhexamethylene guanidine, or a mixture of a salt or base of polyhexamethylene guanidine with dimethylalkylbenzylammonium chloride. In the patent [8], the coating composition includes the following components: TANEP-622 epoxy enamel, polyhexamethylene guanidine hydrochloride, and alkyldimethylbenzylammonium chloride. Patent [9] describes a composition for obtaining an antimicrobial coating, including nanosized particles of an inorganic substance, an active substance, a binder and a solvent, while the active substance contains a mixture of a quaternary ammonium compound and chlorhexidine.

Known application [10] to increase the time of manifestation of antimicrobial activity of products made of polyurethane with an antiseptic coating (probes, drains, catheters, etc.) compositions that can cause swelling of polyurethane tubular products. Chlorhexidine or its salts are used as a biocidal additive, and ethyl or methyl alcohol is used as a solvent capable of dissolving the biocidal additive and causing swelling of polyurethane tubular products.

Silicone sealants with antimicrobial additives are used to seal plumbing equipment. Over time, the concentration of antimicrobial additives as a result of washing out with water decreases and mold-affected zones are formed, which are located both on the surface and inside the material.

The treatment of areas affected by mold fungus with products based on quaternary ammonium salts (QAS), amines, aldehydes, gunaidins, alcohols, hydrogen peroxide and peracids does not stop the growth of mold fungi.

Currently, antifungal surface treatment (including the treatment of silicone sealants) is carried out by wiping or spraying. At the same time, mold fungi that are in contact with the agent used are destroyed. Molds in silicone sealant continue to grow. Therefore, the use of viscous formulations or repeated long-term processing does not lead to a positive effect.

Over time, the antiseptic silicone sealant applied to the joints, due to the washing out of antiseptic additives, begins to become covered with fungal colonies in the form of dark formations.

To implement the method of antifungal treatment of silicone sealants, which allows to increase the time of manifestation of the antimicrobial activity of products, it is necessary to include in the product: a disinfectant (active component), which is able to destroy fungal formations and exhibit properties that prevent the formation of new ones; solvent - to ensure the process of swelling (without destruction) of the material; film former or gel former - to increase the time of action of the composition on the sealant material.

The swelling of the silicone sealant will allow the disinfectant molecules to diffusely enter the material and, firstly, in addition to surface disinfection, destroy fungal formations inside the material, and secondly, part of the active component due to the swelling of the material will enter the surface layers and remain after the composition is removed and dried, providing prolongation of antiseptic properties over time. Using a thickened formulation will increase the exposure time.

To implement the proposed composition for antifungal treatment, alkyldimethylbenzylammonium chloride, which belongs to Quaternary ammonium compounds and has a wide spectrum of biocidal action: bactericidal, virucidal, fungicidal and sporicidal, was chosen as an active component. Alkyldimethylbenzylammonium chloride is available as 50% aqueous solutions and 80% solutions in isopropyl alcohol. The concentrations of alkyldimethylbenzylammonium chloride solutions for surface disinfection in bacterial infections are 0.1% and 0.3% in fungal infections [11]. When antisepticizing lumber, 1% solutions are used [12]. In terms of toxicity to humans and animals, alkyldimethylbenzylammonium chloride belongs to substances of the 3rd hazard class (moderately hazardous substances) according to GOST 12.1.007.

In order for a sufficient amount of biocide to penetrate deep into the material, the following conditions must be met:

- the solvent must dissolve the biocide;

- the solvent must cause the material to swell;

- the solubility of the material must be limited;

- after processing, the material must continue to perform its intended function.

During the experiments, solvents were determined in which silicone sealants swell. Chloroform, carbon tetrachloride, methylene chloride, acetonitrile, toluene, hexane can be used to dissolve the material. The most preferred solution for the material is the use of hexane. According to its toxicological characteristics, hexane belongs to substances of the 3rd hazard class (moderately hazardous substances) according to GOST 12.1.007.

To dissolve alkyldimethylbenzylammonium chloride in the composition, ethyl or isopropyl alcohol is used.

As a gelling agent, the composition may preferably contain a cellulose derivative, preferably ethylhydroxyethylcellulose, hydroxyethylcellulose, other polysaccharides, as well as synthetic polymers such as polyvinylpyrrolidones, polyethylene glycols, polyethylene oxides.

The composition of the composition, wt. %: hexane is preferably in the range from 5 to 95%, more preferably from 25 to 40%, most preferably from 15 to 25%; ethyl alcohol 5 to 70%, preferably 30 to 60%, most preferably 40 to 60%; alkyldimethylbenzylammonium chloride 0.5 to 30%, preferably 1.5 to 10%, most preferably 2 to 5%; cellulose derivative 0.1 to 5%, preferably 0.1 to 3%, most preferably 0.1 to 0.2%. The composition additionally contains a neutralizing base (triethanolamine) in an amount of 0.1 to 0.15% and a nonionic surfactant neonol in an amount of 3.0 to 5.0%, water up to 100%.

Receiving sequence:

a phase 1 is obtained wherein one cellulose derivative thickener is dispersed in a liquid mixture which contains an aqueous solution of aliphatic alcohol (40:60) in an amount necessary for dispersion. After dispersing the mixture, alkyldimethylbenzylammonium chloride was introduced;

get phase 2, which contains one or more aliphatic alcohols, aprotic solvent and nonionic surfactant; with stirring, phase 1 is introduced into phase 2;

if necessary, a neutralizing base is added to the resulting mixture (up to neutral pH values).

The stability of the alkyldimethylbenzylammonium chloride in the composition was tested by the method below.

1. Preparation of a 0.004 M solution of sodium dodecyl sulfate A 0.004 M solution of sodium dodecyl sulfate is prepared by dissolving 0.5777 g of sodium dodecyl sulfate in distilled water in a volumetric flask with a capacity of 500 cm ³ , bringing the volume to the mark with water.

2. Preparation of buffer solution with pH 11

In a volumetric flask with a capacity of 1000 cm ³ dissolve 100 g of sodium sulfate and 10 g of sodium carbonate in distilled water, bringing the volume to the mark with water.

3. Analysis

About 2 g of the product, taken to the fourth decimal place, is quantitatively transferred into a 250 cm ³ conical flask, 45 cm ^{3 of} distilled water, 0.5 cm ^{3 of} methylene blue solution, 5 cm ³ of buffer solution and 15 cm ³ of chloroform are added.

The resulting two-phase system, with the lower chloroform layer colored pink, is titrated with a solution of sodium dodecyl sulfate. After adding each portion of sodium dodecyl sulfate solution, stopper the flask and shake vigorously. A new portion of the titrating solution is added after phase separation. Titration is carried out until the pink color of the lower chloroform layer turns blue.

4. Processing of results

The mass fraction of alkyldimethylbenzylammonium chloride in the disinfectant solution (C, %) is determined by the formula:

where 0.00144 is the average mass of alkyldimethylbenzylammonium chloride, corresponding to 1 cm ³ solution of sodium dodecyl sulfate concentration exactly c (C ₁₂ H ₂₅ SO ₄ Na) = 0.004 mol / dm ³ , g;

V is the volume of the solution of sodium dodecyl sulfate concentration exactly c (C ₁₂ H ₂₅ SO ₄ Na)=0.004 mol/dm ³ used for titration, cm ³ ;

P is the multiplicity of dilution of the disinfectant solution, equal to 10;

m is the mass of the disinfectant solution taken for analysis, g.

The result of measurements of the mass fraction of alkyldimethylbenzylammonium chloride is taken as the arithmetic mean of two parallel determinations.

As a result of the tests, it was found that the concentration of alkyldimethylbenzylammonium chloride in the product did not change within two months.

The action of the proposed tool was studied as follows. The tests were carried out in natural conditions.

The surface with the applied sealant was divided into zones. The experiment (application) was started 6 months after the coating (sealant) was applied and was carried out for one year. Application of the product by wetting was carried out once a month. Before each experiment, the surfaces were washed with subsequent drying in natural conditions for 2 hours. The selected area was treated with the proposed tool (once a month). In the adjacent zone, a disinfectant was simultaneously treated, which was taken as a 2% solution of alkyldimethylbenzylammonium chloride. In parallel, a visual inspection was carried out and an assessment was made of the fouling of the surface of silicone sealants with mold fungi as a percentage of the total area. According to the results obtained, the safety of the samples was calculated, i.e. fungus-free surface.

The indicators of the safety of the surface of the samples after different times when treated with the proposed agent and disinfectant solution are presented in table 1.

It follows from Table 1 that the reliability of sample protection is much higher when treated with the proposed agent than with a disinfectant solution under equal conditions.

The proposed tool refers to promising drugs for the bioprotection of silicone sealants, when long-term action of the biocide is required.

Figure 1 shows the data of two zones after 12 months of observations.

It can be seen from the figure that the composition made on the basis of the proposed processing method leads to prolonged disinfection of the surface of the silicone sealant.

Literature

1. Pat. No. 2059673 C1, Russian Federation, MCP ⁷ C09D 5/02, C09D 5/14. Water-dispersion composition / Garabadzhiu A.V., Kostovskaya E.N., Molodyka A.V., Privalov V.A., Sokolov V.N., Udarov O.E., published on May 10, 1996

2. Roilkin A.I. Colonization processes and protection against biofouling. - St. Petersburg State University, 1998, p. 270.

3. Babkin O.E., Aristova L.I. Zh-l "Paints and varnishes", M., 1996, 12, p. 21.

4. Vointseva I.I., Skorokhodova O.N., Kazanno I.V., Valitsky P.M. Lacquer for biocidal coatings, Zh-l "Paints and varnishes", 3-12, 1999

5. Pat. No. 2254144 C1 Russian Federation, MCP ⁷ A61L 2/16, C09D 123/28. Interpolymer disinfectant / Vointseva I.I., Efimov K.M., published 06/20/2005

6. Pat. No. 2169163 C1, Russian Federation, MCP ⁷ C09D 123/28, C09D 5/14, C09D 123/34. Biocidal paint composition / Skorokhodova O.N., Vointseva I.I., Efimov K.M., published 06/20/2001

7. Pat. No. 2131897 C1, Russian Federation, MCP ⁷ C09D 5/14. Biocidal paint "Biokrapag" / Efimov K.M., published 06/20/1999

8. Pat. No. 2371460 C2, Russian Federation, MCP ⁷ C09D 5/14, C09D 163. Biocidal epoxy composition for coatings in contact with petroleum products / Shedroloseva G.V., Danilov V.R., Bakirova E.A., Varagina T. V., Bushuev V.V., published 27.10.2009

9. Pat. No. 2540478 C1, Russian Federation, MCP ⁷ A61L 2/16, A61L 101/46, B82 B1, Composition for obtaining an antimicrobial coating / Ivanov M.G., Bugaev D.P., Tkachenko N.A., Semenov A.P. ., published on February 10, 2015

10. Pat. No. 2296587 C2, Russian Federation, MCP ⁷ A61L 27/14, A61L 27/54, A61L 29/16, A61L 31/06, A61L 31/16. Method for manufacturing products from polyurethane with an antiseptic coating / Biber B.L., Gorshkov A.V., Sayan M.A., Ogray S.V., Khrapovsky I.G., published on April 10, 2007.

11. Instruction No. 01-02/18 on the use of the "Samarovka" agent for disinfection and pre-sterilization cleaning.

12. Instructions for the use of the preparation "Katamine AB" for antiseptic treatment of lumber.

Claims (1)

Composition for antifungal treatment of swelling coatings, comprising, wt. %: aprotic solvent hexane from 15 to 25% for sub-dissolution and swelling of treated coatings, proton-donor solvent ethyl alcohol from 40 to 60% for dissolution and introduction into the composition of a biocidal agent, alkyldimethylbenzylammonium chloride from 2 to 5% as a biocidal agent, thickening agent for based on cellulose derivatives from 0.1 to 0.2%, neutralizing base from 0.1 to 0.15%, nonionic surfactant neonol from 3.0 to 5.0%, water up to 100%.