RU2028652C1 - Biocidal preparation for protecting materials and articles of electronics from biodamages - Google Patents

Abstract

FIELD: electronics. SUBSTANCE: BIOCIDAL preparation has 0.001-0.01 wt.% of coniferous extract 1.0-6.0 wt. % of polyvinyl alcohol; 4.0-15.0 of 1,3,5-tri-(betta-hydroxyethyl)hexahydro= S=triazine, 15-33 wt.% of potassium dimethyldithiocarbamate and the remainder of water up to 100. EFFECT: enhanced efficiency pf protective properties and consequently prolonged service life of protected articles and materials of electronics. 5 tbl

Description

 The invention relates to compositions that can be used to protect against microbial damage to materials and electronic products.

 Many industrial materials and products during operation are subjected to the destructive action of microorganisms - mold fungi, yeast, bacteria, etc., widespread in nature. Microbial damage affects polymeric materials, plastics, rubbers, compounds, cotton and wool fabrics, products from natural and artificial leathers, paints and varnishes and insulation materials, products from metals and their alloys. This leads to a change in the appearance of the product or material, a violation of their most important performance characteristics.

 In connection with the expansion of the scope of application of various materials, the issue of ensuring their resistance to microorganisms becomes more and more relevant.

 It is known that microbial damage to industrial materials with a low moisture content in warm and humid air is caused mainly by mycelial (mold) fungi. To a lesser extent, bacteria and yeast. This also applies to electronic products that are affected mainly by mold fungi.

 Protection of electronic products is carried out by structural, sanitary-hygienic and chemical methods. Known drug (see US patent 3583914, class C 10 M 1/32, NKM 252-34.7, op. June 6, 1971) containing water, Na - salt of ethylenediaminetetraacetic acid, anionic surfactants, nonionic surfactants mixtures of diphenols, dithiocarbamate and thiodiaention. Possessing high antimicrobial activity, the given preparation turned out to be insufficiently effective in protecting materials and products of electronic equipment.

 In a. from. USSR N 751062 describes a method for producing antimicrobial films from an aqueous solution of PVA, boric acid, drugs, where the metal implant is a cathode, and the process is carried out by electrochemical deposition. In this composition, individual medicinal substances - furatsilin, chloramphenicol, monomendine - significantly exceed the control sample based on polyvinyl alcohol. Use in A.S. N 751062 medicinal substances are pure bactericides. This drug, which does not have fungicidal properties, cannot be used to protect electronic equipment from biodeterioration.

 In US Pat. USA N 4692494, CL 525/57 from 1981, a method for the publication of biostable packaging films for water-soluble bulk goods is proposed. The composition of this film includes PVA, polyacryl (hardener) and chlorine-containing substances are used as antimicrobial agents. The components used also do not have fungicidal properties, therefore they, as well as the method for producing biocidal films, cannot be implemented while protecting industrial materials (electronic equipment) from mold fungi.

 The aim of the invention is to increase the effectiveness of the protective properties of the drug, and therefore, the durability of the protected products, electronic equipment materials.

This goal is achieved in that the known biocidal preparation containing 1,3,5-tri (β-hydroxyethyl) hexahydro-S-triazine and sodium dimethyldithiocarbate additionally contains coniferous extract and polyvinyl alcohol (PVA) in the following ratio of components, wt.% : Coniferous extract 0.001-0.01
Polyvinyl alcohol 1.0-6.0
1,3,5-three (β-hydro-
xethyl) hexahydro-S- triazine 4.0-15.0
Dimethyldithiocarbomat sodium 16.0-35.0 Water Up to 100
Comparative analysis with the prototype allows us to conclude that the claimed composition of the drug differs from the known introduction of new components, namely polyvinyl alcohol and coniferous extract. Thus, the claimed technical solution meets the criterion of "novelty."

 The component 1,3,5-tri (β-hydroxyethyl) hexahydro-S-triazine (trade name "Vazin") is produced according to TU 6-09-4735-80 in the form of a 50% aqueous solution to stabilize cutting fluids, promotes the acquisition of the claimed drug bactericidal properties.

 Sodium dimethyldithiocarbomate is produced according to TU 8-14-540-83, also in the form of a 50% aqueous solution (trade name "Mn carbamate").

 Widely used in the vulcanization of rubber. This component plays an important role: it helps to impart high fungicidal properties to the claimed preparation.

 Polyvinyl alcohol (PVA) (GOST 10779-78) is widely used in the national economy.

 The properties of aqueous solutions of PVA to form polymer films allows us to develop bactericidal preparations used in medicine on their basis. In the developed biocide, an aqueous solution of PVA promotes the film formation of the drug when applied to a hard surface, as well as increasing the overall effectiveness of the proposed biocidal preparation. Eight grades of polyvinyl alcohol (PVA) are available. However, not all of them can be used in the composition of the biocidal preparation. It was found that the use of aqueous solutions of PVA for the formation of high-quality biocidal films at the protected object depends on the amount or mass fraction (%) of acetate groups. An insufficient or large number of them leads to a deterioration (for example, fragility) of the films of the biocidal preparation. An experimental technique showed that PVA grade 11/2 is most suitable as a component in creating a biocidal preparation. Amount of acetate groups (%) - this product contains the maximum available (1.1-2.0 premium, 0.5-4.0 first grade). An aqueous solution of polyvinyl alcohol grade 11/2 has optimal film-forming properties. In the inventive composition used a 10% aqueous solution of polyvinyl alcohol. A lower concentration of the PVA solution does not allow to obtain a stable polymer film and leads to dilution of the drug with water. The preparation of PVA solutions in concentrations above 10% is difficult, since the polymer phase is precipitated (precipitation). Coniferous extract (TU 10-04-16-3187) is a multicomponent mixture of substances with a characteristic odor. This is a homogeneous transparent liquid from light yellow to dark brown in color, the refractive index is 1,455-1,500, the acid number is not more than 6.0. In the composition of the biocidal preparation, coniferous extract plays the role of an antiseptic and deodorant and improves the toxicological properties of the composition.

 In accordance with the invention, samples of the preparation are prepared and tested, the composition of which is given in table 1.

 In the table. 2 gives their physico-chemical characteristics. It was shown that the samples of the drug are stable, readily soluble in water, have anti-corrosion properties, do not freeze at low temperatures, pH 12.1-12.5, form a thin polymer film with high biocidal properties on the surface of solid materials.

 A method of preparing a biocidal preparation.

First, prepare a 10% aqueous solution of polyvinyl alcohol. For this purpose, the standard apparatus of closed type, provided with a water jacket and a stirrer was charged with the calculated amount of polyvinyl alcohol (PVA), pour the required amount of distilled water (GOST 6709-72) at room temperature (25 ± 5 ° ^C) and left for 12 hours for swelling. The mixture was then heated with water PVA ^to 100 ° C (switching podogpeva water jacket), stirred continuously and "cook" PVA for 7 hours.

Next, PVA solution was cooled, filtered through nylon bolting cloth PATU RSFSR 62-10792-84-17 in another apparatus and is checked by viscosity viscometer VZ-4 (expiry time) (GOST 9070-75) at a temperature of 20 ^C. The viscosity should be equal to 20-40 s.

 A mixture of other components (1,3,5-tri (β-hydroxyethyl) hexahydro-S-triazine, sodium dimethyldithiocarbomate, coniferous extract), prepared in advance, is added to the PVA solution. The mixture is stirred until a uniform, clear liquid is obtained. At the same time, there is no sewage and air emissions.

 The proposed biocidal preparation can be used to protect against biodeterioration of various objects of electronic equipment, its components, parts, materials. In addition, the drug can be used in various sectors of the economy to protect objects with a solid surface from biodeterioration.

 The drug exhibits a high antimicrobial effect against almost all microflora, which affects electronic products and materials. Especially biocidal preparation is effective against mold fungi - active destroyers of industrial materials and products.

 The components of the drug are polyvinyl alcohol, 1,3,5-tri (β-hydroxyethyl) hexahydro-S-triazine, sodium dimethyldithiocarbomate, coniferous extract are produced in large quantities by the domestic industry.

 In the proposed biocidal preparation, all components used in the composition (coniferous extract, polyvinyl alcohol, triazine and sodium dimethyldithiocarbomatum) serve to increase the biocidal, especially fungicidal (antifungal) activity of the claimed preparation, because materials and electronic products are affected primarily by mold fungi. In addition, each of the components performs an additional very important function, including PVA film-forming. This is a significant difference between the proposed drug and other known compositions that contain PVA (e.g., A.S. USSR N 751062 and US Pat. No. 4,692,494), where the latter performs only one passive function - film-forming.

 It should be noted that any component taken into the composition by itself cannot be used as a means of protection against biodeterioration of electronic equipment. The same components in the proposed composition effectively protect it from fungal infections. A similar effect occurs due to the synergistic action of the components. Table 3 shows that the fungal infection of an unprotected electronic product (BK-3K N 64546004), estimated according to GOST 9.048.75, is 4 points (not mushroom resistance). A similar picture is observed when processing products with PVA, triazine, sodium dimethyldithiocarbonate (4 and 3 points).

 And only samples of the proposed composition completely prevent fungal infections of products. Confirmation of this are the data presented in table. 4 and 5. It was shown that the samples of the proposed composition in their antimicrobial activity significantly exceed the known biocides taken for comparison.

 An analysis of the known compositions of bactericidal preparations used to protect industrial materials and products, including electronic products, showed that the substances used in the claimed composition are known. However, their use (in combination with other components) does not provide the known antimicrobial agents with the necessary properties that they exhibit in the claimed solution, namely, increasing the effectiveness of the protective properties of the biocidal preparation and, as a result, increasing the durability of parts and materials during their processing with the claimed drug.

 Thus, the selected composition of the components of the biocidal preparation gives it new properties, which allows us to conclude that the proposed solution meets the criterion of "significant differences".

The proposed biocidal preparation has a high antimicrobial effect with respect to the entire microflora affecting industrial materials, namely aerobic and anaerobic bacteria, mold fungi. When determining the bactericidal activity of the drug against aerobic bacteria, the microbial test was:
Psendomonas aeruginosa,
Psendomonas oleovorans,
Escherichia coli,
Staphylococcus aurens,
Protens vulqasis,
Mycobacterium phlei; Anaerobic: Desulfovibrio desulfuricons.

When determining the fungicidal activity of the drug, the following types of molds served as test cultures:
Asperqillus niqer van Tieghem,
Asperqillus terrens Thom,
Aureabasidium pullulans (de Barry)
Arnaud,
Paccillomices varioti Bainier,
Penicillium ochro - chloron Biocorge,
Scopulariopsis previcaulis bainier,
Trichoderma viside Pers: ex Fr.

 Chaetomium globosum Kunze.

 Evaluation of the antimicrobial activity of the samples of the drug was carried out according to generally accepted methods.

 The essence of the methods is to place the drug in nutrient media (meat-peptone agar, wort-agar), pre-infected microorganisms, followed by exposure to conditions conducive to the growth and reproduction of these microorganisms. Antimicrobial concentrations of the samples are given in table.4.

 Given that the details and materials of electronic products are mainly affected by molds, their biostability of both untreated and treated with biocidal preparation was evaluated in relation to molds according to GOST 9.048.75 and 9.049.75. The essence of the methods used is to withstand products infected with mold spores under conditions optimal for their growth and development. To test samples of materials and electronic products used a mixture of molds (their name is indicated above).

To maximize the protection of electronic products and materials from fungal infections on their surface, it is necessary to create a biocidal film of the drug. To do this, with a brush or sprayer, the drug is applied to the surface of the product (at the rate of 20-40 g per 1 m ² ).

After drying and curing (at a temperature of 60-80 ^{° C} for 5-6 h) on the test article is formed biocidal polymer film of thickness 0.1-0.5 micrometers.

The strength of the biocidal film on the product was evaluated according to existing parameters:
exposure to elevated humidity (98%) and a temperature of 55 ^{° C} for 6 days;
exposure to low temperatures (-50, -60 ^о С);
exposure to elevated temperature (50 -60 ^C) for 6 hours;
cyclic exposure to temperatures (-60 ^o C); (60 ^{° C)} for 2 hours at each temperature, transfer time is not more than 3 min, number of cycles - 5;
impact test, in accordance with GOST 4765-73;
adhesion test by the method of trellised notches according to GOST 15140-78.

 Products coated with biocidal film are considered to have passed the climatic test if the film remains unchanged.

Withstand environmental testing products with film biocide mixture infect supports mold and placed in a weather chamber at 29 ± 2 ^{° C} and relative humidity greater than 90%. The test duration is up to 6 months or until the appearance of mushroom growth on the material (product) equal to 4-5 points (according to GOST 9.048-75 and 9.049-75).

 At the end of the test, samples from the chamber are removed and visually evaluated under illumination of 2000-3000 Lx, and if necessary, use a magnifier or optical microscope. A sample is considered biostable if the growth of mushrooms on it is estimated at 0 and 1 points according to the existing GOST.

 The study of the antimicrobial properties of the proposed drug is carried out in comparison with the known biocides used to protect industrial materials (products) from biodeterioration. The test results are shown in table.5.

 The biocidal preparation produced in Example 1, called "Mycocide", is safe to use. It does not have a general resorptive effect, does not irritate the skin and mucous membranes of the eyes, there is no sensitizing activity, it does not cumulate in the body.

 By the degree of exposure to the body, the biocidal preparation belongs to hazard class IV (low-hazard substances in accordance with GOST 12.007.-76).

The inventive biocidal preparation is a low-combustible liquid. This is an important difference from its known biocides, as well as the components that make up its composition. Since components of the formulation are flammable (flash point 205 ^{° C} PVA; triazine 137 ^{° C,} and after boiling flammable and sodium dimethyldithiocarbamate Study of the proposed preparation for the biocidal fire hazard revealed the following: the flash point in an open crucible, - absent (GOST 12.1.044-. 84, p. 44 TV device); the flash point in the closed crucible is absent (according to GOST 12.1.044-84, p. 4.3 The device according to GOST 1421-79); the ignition temperature is absent (according to GOST 12.1.044-84, p . 4.6 TV Device). It was only at 900 ^{° C} after boiling the preparation of Goran. These properties offer a biocidal product are extremely important when it is used in production and operation of electronic equipment.

Claims (1)

BIOCIDE PRODUCT FOR PROTECTING MATERIALS AND PRODUCTS OF ELECTRONIC EQUIPMENT FROM BIO DAMAGE, containing a carbamate derivative and water, characterized in that, in order to increase the effectiveness of its protective properties, it contains dimethyldithiocarbamate and additionally 1,3,5-tri- -Hydroxyethyl) -hexahydro-S-triazine, an aqueous solution of polyvinyl alcohol and coniferous extract with a refractive index of 1,455-1,500 and an acid number of not more than 6.0 in the following ratio, wt.%:
Coniferous extract - 0.001 - 0.01
Polyvinyl alcohol - 1.0 - 6.0
1,3,5-tri- (b-hydroxyethyl) -hexahydro-S-triazine - 4.0 - 15.0
Sodium Dimethyldithiocarbamate - 16.0 - 35.0
Water - Up to 100

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