Bactericidal paints biokrapag ensures a long-term reliable protection
The Institute of Ecotechnologies has developed and produces special-purpose biocidal paints that form varnish and paint coatings with antimicrobial and fungicidal properties. The developed compoundings based on pentaphthalic and nitrocellulose enamels, water emulsion and oil paints with polyalkylene guanidine additives are registered under the common trademark Biokrapag?.
Their application allows preventing biocorrosion of engineering structures, and imparts long-term biocidal activity to the treated surfaces at child-care facilities, living quarters, medical institutions, as well as at food industry and agricultural facilities. The Biokrapag? paints are also licensed for application in penitentiary institutions (prisons, camps), which is especially important under the current difficult sanitary and epidemiological conditions.
Various bacteria, viruses, fungi, and other microorganisms living in great numbers in the environment are the source of biodestruction of materials and equipment. Provided favourable conditions, they can completely change the appearance and the physical and mechanical properties of materials in a very short time, if the latter are not sufficiently biostable.
The objects of such damage can be, e.g., such construction materials as wood, brick, building stone, concrete, metals, and polymers. The destructive changes of the surfaces caused by the vital activities of mould fungi, nitrifying and thionic bacteria are evidenced by the powder-like encrustation, surface pigmentation, swelling, peeling and flaking of the paint-work or plastering, their fracturing and destruction.
The basic requirements for the biocidal additives to the paint materials are following: high efficiency in small concentrations, wide range of biocidal activity, and low toxicity for humans and warm-blooded animals. Besides, such compounds should be colourless, non-volatile, stable in long-term storage, compatible with other ingredients of the paint composition, and economically efficient.
Unfortunately, many substances possessing fungicide activity lose it when admixed to paints and varnishes. Besides, the few types of biocides produced in Russia are based either on phenols, which have been recently prohibited, or environmentally hazardous organotin compounds.
Addition of PAGs in concentration sufficient for high biocidal activity does not change the technological properties of the paints and the exploitation characteristics of the painted surfaces.
Nowadays polyalkylene guanidines (PAGs) developed by the Institute of Ecotechnologies are the most perspective biocidal additives to paints and varnishes meeting the above-discussed requirements. These chemicals are the high-molecular analogues of the well-known low-molecular guanidine-containing chemical chlorhexidine. However, due to their polymeric structure, PAGs are more effective and less toxic, thus answering the demands to the biocidal additives for paints and varnishes.
PAGs have a wide range of biocidal activity; they are effective against various microorganisms, exhibit bactericidal, virucidal, fungicidal, pesticidal, insecticidal, and algaecidal action. According to their toxicity for warm-blooded organisms, these polymers are included into the III-IV class of moderate- or low-hazard compounds. PAGs are stable in long-term storage; do not loose their biocidal activity for at least 15 years (monitoring term); they are non-volatile, well soluble in water, have neither taste nor smell.
The Institute of Ecotechnologies has developed a series of biocidal paints called Biokrapag based on pentaphthalic and nitrocellulose enamels, water emulsion and oil paints with Phosphopag and Biopag additives. These paints have passed the necessary microbiological and climatic tests, and were proven effective in the full-scale field tests in medical and rehabilitation institutions, at food industry and agricultural facilities.
Tests have proved that addition of PAGs in biocide concentrations does not change the technological properties of the paints and service properties of the painted surfaces. On the other hand, PAGs admixed to paints and varnishes retain their biocidal properties.
Application of Biokrapag series paints ensures a 100% long-term (at lest one year) antimicrobial protection of surfaces.
Thus, according to the test data obtained by the A.N. Sysin Institute for human ecology and environmental hygiene, an almost complete deactivation of the colibacillus Escherichia coli and coliphag MS-2 on the treated surfaces is established within the period of 10-60 minutes.
Mould fungi Penicillium chrysogenum are deactivated within 30 minutes on the surfaces painted with pentaphthalic enamel or oil paint and within 24 hours – on those covered with water emulsion paint. Spores of Bacillus cereus are inactivated by 86% within 3 hours under the test conditions.
Application of the paints of the Biokrapag series in construction and maintenance indoors ensures a 100% long-term (at least 1 year) antimicrobial protection of surfaces, walls, ceiling, and equipment without any additional disinfection of the facilities. Painting workrooms and living quarters with biocidal paints allows to stabilise quickly their sanitary state, to limit infection propagation and contamination of the whole room with mould fungi, and to prevent mould penetration into the bulk of the supporting constructions.
Accelerated environmental tests of the paint and varnish coatings based on Biokrapag-2 (pentaphthalic enamel) have been performed by the Research Institute for paint and varnish coatings “Victoria”. The tests have shown that the guaranteed service term of the coatings preserving their biocidal activity outdoors is at least 4 years in moderate climate, and 2 years in tropical climate.
Analysis of the literature on this subject has shown that to date there are no competitive analogues of the biocide paints of the Biokrapag series.