RU2700876C2 - Biocidal powder composition - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to compositions for applying polymer powder coatings containing bactericidal and biocidal additives. Disclosed are compositions based on epoxy carboxyl-containing polyester resins, mixtures thereof and polyhexamethyleneguanidine hydrochloride as a biocidal ingredient. Biocidal powder coating composition consists of solid epoxy resin based on bisphenol A with an epoxy equivalent of 715–930 g/mol and/or a carboxyl-containing polyester with an acid number of 26–53 mg KOH/g, a hardener if necessary, a dispensing regulator, benzoin, a pigment and/or filler, and also contains a biocidal additive - polyhexamethylene guanidine hydrochloride together with dicyandiamide in the following ratio, wt. parts: epoxy diane resin 0–83.1, carboxyl-containing polyester 0–85.4, polyhexamethyleneguanidine hydrochloride 4.5–8, dicyandiamide 1.5–7.4, pigments 0–40, fillers 0–12, dispensing regulator 0.5–2.1, hardener if necessary 1.7–4.5, benzoin 0.2–0.7.

EFFECT: technical result is providing coatings of metal and non-metal surfaces of articles and structures in places susceptible to contamination, or mass accumulation of people.

1 cl, 2 tbl, 10 ex

Description

Antimicrobial coatings of powder compositions are an important tool in preventing the growth of bacteria and microbes in industrial and consumer products and products. Antibacterial coatings help fight disease and infection, as well as prevent the growth of bacteria and fungal infections. For this, the surface of premises, equipment, refrigerators, household goods and other products is covered with biocidal coatings. Compositions based on epoxy, polyester resins, mixtures thereof and polyhexamethylene guanidine hydrochloride as a biocidal ingredient are proposed. The invention allows to create a biocidal composition with a wide spectrum of action, showing both bactericidal and fungicidal properties with improved biocidal characteristics of the protective film.

To obtain powder compositions, solid epoxy, polyester resins or mixtures thereof are widely used as a binder.

According to patent No. 2478678 (POWDER COMPOSITION FOR COATINGS ON ITS BASIS), the invention relates to thermosetting powder compositions based on epoxy oligomer and can be used to produce coatings with enhanced barrier properties. The powder composition includes (parts by weight): epoxy resin - 96.7- 90.3, hardener dicyandiamide - 1.3-2.5, pouring agent - 0.6-0.9, aluminosilicate nanoparticles - 0.5- 5, anti-crater additive - 0.4-0.6, degassing agent - 0.5-0.7. As aluminosilicate nanoparticles the following are used: natural montmorillonite modified with a quaternary ammonium salt of the following structure, [(HT) ₂ N (CH ₃ ) ₂ ] ⁺ Cl ^- , where HT is dehydrogenated tall oil, or halloysite. The invention allows to create a thermoset powder composition for producing coatings with enhanced barrier properties with a high level of physico-mechanical properties

To give biocidal properties to paints and varnishes, it is recommended to use compounds of various chemical nature related to such classes of compounds as benzimidazoles and methyl urea derivatives (hazard class 3), phthalimides, carbamates, salicylimides, nitropropane diols (hazard class 2-3), acetamides (1-2 hazard class) and highly toxic compounds related to organotin and organochlorine compounds, derivatives of mercury, etc. (A.D. Yakovlev, S.A. Yakovlev Paint coatings for functional purposes. - St. Petersburg: Khimizdat, 2016, 272 s) .

According to the patent US 8063116 (Antimicrobial powder coatings) polymer particles are mixed with antimicrobial active agents based on metals and their salts (copper, silver, etc.).

In the patent US 6093407 (Anti-microbial powder coatings) it is proposed to obtain powders for coatings during the joint fusion of antimicrobial substances with thermoset or thermoplastic polymers based on epoxy, polyester, acrylate and / or polyurethane resins in an amount of from 0.1 to 10%. As antimicrobial agents are proposed: N- (trichloromethyl) -thiophthalimide, 2-bromo-2-nitropropane-1,3-diol, 3,5-dimethyltetrahydro-1,3,5-2H-thiazine-2-thione.

Despite the high effectiveness of these additives in relation to microorganisms, they are also characterized by high toxicity to humans, warm-blooded animals or aquatic organisms.

The domestic industry has mastered in solid form the low toxic (hazard class 3-4) class of biocides, the high molecular weight salts of polyguanidines (I.I. Vointseva, P.A. Gembitsky, Polyguanidines - disinfectants and multifunctional additives in composite materials. - M.: Publishing House “ LKM-press. ”- 2009. - 304 s), which were effective against a wide range of microorganisms: gram-positive and gram-negative bacteria, both aerobic and anaerobic microflora, viruses, dermatophytes, mold and yeast-like fungi as well as unwanted microflora and algae in the aquatic environment.

Based on polyguanidines, a number of paints and varnishes with biocidal properties have been created.

According to patent No. 2181737 (Bactericidal composition for coatings), the invention relates to the paint and varnish industry, namely bactericidal compositions used for protective coatings of various materials in air and water environments from biofouling. The composition consists of an organically soluble paint or varnish and a bactericidal component based on a derivative of polyhexamethylene guanidine. Moreover, as a bactericidal component, it contains polyhexamethylene guanidine derivatives of the general formula

where n = 30-60;

R - base, chloride, fluoride, phosphate, stearate, sorbate, carboxyl cellulose, isophthalate, acetate, oleate, folate, oxalate and dehydroacetate, in the following ratio, wt.

Derivatives of polyhexamethylene guanidine - 0.35-9.0

Organically soluble paint or varnish - 91-99.65

The technical result is the creation of a stable bactericidal composition with a wide range of biocidal properties.

According to patent No. 2189999 (WATER-DILUTABLE COMPOSITION FOR BACTERICIDAL COATINGS) it is proposed to obtain a bactericidal coating a water-borne composition based on, for example, water-based paints, liquid glass or slaked lime, contains a bactericidal component. A water-borne composition for bactericidal coatings of ceramics, concrete, brick, plaster and other materials in air is described, including a water-borne paint and a bactericidal component - derivatives of polyhexamethylene guanidine. Moreover, the water-borne composition contains, as a bactericidal component, polyhexamethylene guanidine derivatives of the general formula

where R is the base, chloride, phosphate; n - 2-60, in the following ratio of components, wt. hours:

derivatives of polyhexamethylene guanidine 0.5-9,

water-borne paint 91-99.5.

EFFECT: creation of a coating with stable bactericidal properties, which has a wide range of biocidal properties and is safe for humans.

According to patent No. 2282649 (BIOCIDE EPOXY COMPOSITION FOR COATINGS), the invention relates to the production of an organically soluble biocidal composition used for anticorrosive protection of internal surfaces of metal and reinforced concrete containers susceptible to electrochemical and microbiological corrosion, especially under the influence of molds and bacteria, which are specific for grain, flour, specific for bacteria as well as oil and petroleum products. The composition includes the following ratio of components, wt. h: 100 organically soluble epoxy enamels TANEP-5341 or TANEP-622, 1.5-3.0 polyhexamethylene guanidine hydrochloride as a bactericidal component and 1.5-3.0 hexahydro-1,3,5-tri- (hydroxyethyl) - triazine as a fungicide.

According to patent No. 2371460 (BIOCIDE EPOXY COMPOSITION FOR COATINGS CONTACTING WITH OIL PRODUCTS) for anticorrosive protection of the inner surface of pipelines and steel tanks intended for long-term storage of oil products and susceptible to microbiological corrosion, in particular, under the influence of sulfate recovery components, it is proposed to ratio, wt. hours:

epoxy enamel TANEP-622 one hundred polyhexamethylene guanidine hydrochloride 0.2-0.3 alkyldimethylbenzylammonium chloride 0.2-0.3.

Epoxy coating composition (Patent No. 2180907) is recommended as a means of protecting any surfaces from chemical, atmospheric and bio-corrosion damage. The composition contains an epoxy resin, polyethylene polyamine, a modifier, a plasticizer, a mixture of pigment with talc, polyhexamethylene guanidine hydrochloride and an organic solvent. As a modifier, the composition contains benzyl alcohol, a copolymer of vinyl chloride with vinyl acetate A-15, or KEP-1 organosilicon foam regulator.

According to patent No. 2131897, which is selected as a prototype, a paint is proposed comprising a film-forming in the form of an organosoluble paint and varnish material and a biocidal additive, characterized in that it contains an inorganic or organic salt of polyhexamethylene guanidine, or a base of polyhexamethylene guanidine, or a mixture of salt or base polyhexamethylene guanidine with dimethylalkylbenzylammonium chloride in a ratio of 1-10: 1 in the following ratio of components, wt. %:

Film-forming in the form of paint and varnish material - 93-97 Specified biocidal additive - 3-7

As a film-forming material for oil paints, linseed oil or drying oil is used in accordance with GOST 7931-76.

Also, film-forming resins for oil and alkyd-styrene paints use oil-styrene resins, alkyd-styrene resins (copolymers) (GOST 982573).

For water-based paints, aqueous dispersions of polymers are used as film-forming paints.

For silicate paints, liquid glass is used as a film-forming.

The paint is prepared as follows: the components of the paint that make up the colorful base and the biocidal additive are mixed, the prepared mixture is dispersed on the paint and varnish equipment.

It can be seen that, both in the analogues and the prototype, liquid paint and binder binders are used to obtain coatings, requiring special long-term conditions for drying the coating before using the product.

To eliminate this drawback, we are the first to propose using a pre-fused and powdered mixture of a solid polymer resin (for example, epoxy, polyester or a mixture thereof) with polyhexamethylene guanidine hydrochloride.

However, the difficulty of using low-toxic polyhexamethylene guanidine chloride lies in the fact that it significantly slows down the curing of epoxy and epoxy-polyester compositions by 2-3 times, which is unacceptable for their use in industrial conditions.

The technical problem is solved in that the proposed polymer thermosetting powder composition includes a solid epoxy resin based on bisphenol A with an epoxy equivalent of 715-930 g / mol, and / or a carboxyl-containing polyester with an acid number of 26-53 mg KOH / g, filling agent, hardener if necessary, a pigment and / or filler, characterized in that it contains a biocidal additive - polyhexamethylene guanidine hydrochloride together with dicyandiamide

in the following ratio, mass. hours:

Epoxy resin 0-83.1 Carboxyl-containing polyester 0-85.4 Polyhexamethylene guanidine hydrochloride 4,5-8 Dicyandiamide 1,5-7,4 Pigments 0-40 Fillers 0-12 Filling regulator 0.5-2.1 Hardener if necessary 1.7-4.5 Benzoin 0.2-0.7

To obtain a biocidal coating, the powder composition is made according to the technology traditional for thermosetting powder paints. All components are mixed in a ball mill or in a special mixer, the resulting mixture is fused in a twin-screw mixer at a temperature of 100-130 ° C and, after cooling, it is crushed to a particle size of less than 100 microns (after sieving on a vibrating screen).

Known components are used as pigments to impart opacity, color, and other properties to materials, for example, titanium dioxide, colored pigments.

Fillers (mineral) are used to improve the properties of filled polymers, for example, barium sulfate, calcium carbonate.

An acrylic copolymer, for example, Resiflow PV 88, is used as a filling regulator.

As hardeners of epoxy resins use

powder hardeners based on amide derivatives,

e.g. Araldit HT 2844,

Casamid 783.

The hardener for carboxyl-containing polyester resins is a hydroxyalkylamide crosslinker, for example, Primid ^® XL-552.

These powder compositions are applied by electrostatic spraying at a voltage of 50 kV to cleaned steel plates (steel grade St08ps GOST 16523-97) and the coatings are cured at a temperature of 180-185 ° C for 20-25 minutes. Examples of formulations are shown in Table 1

Table - 1. Composition of powder paints

Example one 2 3 four 5 6 7 8 9 10 Epoxy resin 50.7 83.1 - - 19.9 26.6 55.7 - 23.6 29.5 Polyester resin - - 50.7 85,4 29.9 61.9 - 56.0 35.5 68.8 Polyhexamethylene guanidine hydrochloride 4,5 8.0 8.0 6.0 8.3 5,0 - - - - Pigments 23 - 36,2 - 25.3 - 24.4 40 thirty - Fillers 12.1 - - - 8.4 - 14.2 - 10 - Filling regulator 2.1 1.3 0.7 1,0 0.5 0.9 2.9 0.8 0.6 1,0 Hardener 2.6 1.7 2.7 4,5 - - 2,8 3.0 - - Dicyandiamide 4,5 5.5 1,5 2.5 7.4 5,0 - - - - Benzoin 0.5 0.4 0.2 0.6 0.3 0.6 - 0.2 0.3 0.7

Physico-mechanical properties were evaluated by the impact strength of coatings on a UA1 device according to GOST 7465-73. The adhesive strength of the coatings was evaluated by the method of trellised notches in accordance with GOST 15140-78. The elasticity of the coatings was evaluated using the device "Ericksen press" according to GOST 29309-92. Examples of specific performance of the claimed composition are shown in table 1. Coatings based on the claimed composition (examples 1-6) have good physical and mechanical properties (Ericksen elasticity 7-7.5 mm, impact strength 50 cm, adhesion 1 point), comparable with the properties in examples 7-10 without biocidal additives.

The coatings obtained in this way have biocidal properties, which is confirmed by microbiological studies.

The bactericidal activity of the coatings was determined using Gram-negative bacteria Escherichia coli and Gram-positive bacteria Staphylococcus Aureus as test cultures. Bacteria were grown for 24 hours on beveled nutrient agar (SPA) supplemented with 1% glucose. Daily cultures were used to prepare a suspension of bacteria in sterile water. Suspensions of Escherichia coli and hay bacillus in a flask served as a control. Flasks with coating samples and bacterial suspensions were placed on a rotary shaker with a rotational speed of 220 rpm and kept for 1 and 4 days.

After 1 and 4 days, the concentration of living bacteria in suspensions was determined by the Koch method on a SPA medium. The Koch method is based on the mechanical distribution of bacterial suspensions over the surface of an agar medium in Petri dishes, followed by counting the grown bacterial colonies (Guide to Practical Activities in Microbiology, edited by N.S. Egorov. - 3rd ed., Revised and add. - M.: Publishing House of Moscow State University, 1995 .-- 224 p. S. 122). After growing for 3 days on Petri dishes, the number of colonies grown was counted. Data on the concentration of viable cells of E. coli and S. Aureus in suspensions were compared with the number of viable cells in the control samples.

Tests of the anti-mold action of the coatings were carried out on film samples according to the methods of GOST 9.050-75 according to method 2. The tests were carried out at a temperature of 29 ± 2 ° C and a relative humidity of more than 90% for 28 days.

The proposed biocide powder coatings are most preferable for use in industrial painting in places of mass congestion and prolonged stay of people, namely in institutions of cultural and domestic and medical purposes, in the food and trade industries, in transport, in everyday life, as well as in veterinary medicine and animal husbandry enterprises due to their high environmental, economic, energy efficiency and manufacturability.

Claims (2)

Biocidal powder coating composition consisting of a solid epoxy resin based on bisphenol A with an epoxy equivalent of 715-930 g / mol and / or a carboxyl-containing polyester with an acid number of 26-53 mg KOH / g, hardener, if necessary, a filling regulator, benzoin, pigment and / or filler, characterized in that it contains a biocidal additive - polyhexamethylene guanidine hydrochloride together with dicyandiamide in the following ratio, wt. hours: Epoxy resin 0-83.1 Carboxyl-containing polyester 0-85.4 Polyhexamethylene guanidine hydrochloride 4,5-8 Dicyandiamide 1,5-7,4 Pigments 0-40 Fillers 0-12 Filling regulator 0.5-2.1 Hardener if necessary 1.7-4.5 Benzoin 0.2-0.7