RU2032531C1 - Compound for biological and fire protection of wood - Google Patents

Abstract

FIELD: biological and fire protection of wood. SUBSTANCE: compound for biological and fire protection of wood contains, mas.%: ammonium fluosilicate 80-90 and 50% aqueous solution of inhibiting substance 10-20. Inhibiting substance consists of carbamide and phosphoric acid at molar ratio of 2: 1. EFFECT: higher efficiency. 6 tbl

Description

 The invention relates to bio-fire retardant treatment of wood and wood materials, can be used in the woodworking industry, as well as in construction with the preventive effect of protecting dry wood.

Known compositions (1) for protecting wood from biodefeats based on sodium pentachlorophenolate and fluorine-containing compounds (ammonium silicofluoride or sodium fluoride). The main disadvantages of these compositions are:
high environmental hazard (preparations of the 1st hazard class);
weak ability to diffusion, washed out of antiseptic wood;
have insignificant flame retardant properties;
effective only for surface protection of wood from blueness and mold;
corrode metals;
have the smell of chlorinated phenols;
high alkalinity of the drug leads to a decrease in the mechanical strength of the surface zone of wood and the loss of presentation.

The closest in essence to the proposed composition is the antiseptic KFA (ammonium fluoride) (NH ₄ ) ₂ SiF ₆ (2). This drug has a good ability to protect wood from biodefeat, but has the disadvantages of:
emits gaseous hydrogen fluoride, polluting the environment and negatively affecting the human body;
corrodes metals;
it is well washed out of antiseptic wood;
has weak flame retardant properties;
It is a fine-dispersed powder, therefore, the sprayed fine particles enter the air. The consequence of this is an increase in the reaction surface of CFA, which accelerates its evaporation, oxidation, absorption, dissolution and physiological activity of powder particles in the human body, especially in the respiratory tract.

 The aim of the invention is to reduce the environmental hazard of the drug, improving the protective ability, technological and operational characteristics of the drug.

 This goal is achieved by the fact that the proposed composition for bio and fire retardant treatment of wood and wood based on ammonium silicofluoride additionally contains a 50% aqueous solution of an inhibitory substance consisting of urea and phosphoric acid in a molar ratio of 2: 1, in the following ratio of components wt. ammonium silicofluoride 80-90 inhibitory substance The rest.

PRI me R 1. The composition for protecting wood and wood materials from biodefeat contains the ingredients in the following ratio, wt. ammonium silicofluoride 80 inhibitory substance 20
PRI me R 2. The composition for protecting wood and wood materials from biodefeat contains the ingredients in the following ratio, wt. ammonium silicofluoride 85 inhibitory substance 15
PRI me R 3. The composition for protecting wood and wood materials from biodefeat contains the ingredients in the following ratio, wt. ammonium silicofluoride 90 inhibitory substance 10
Each of the proposed compositions in concentrations of 2, 4, 6% was tested to determine the biological activity against wood-staining, mold and wood-destroying fungi. The tests were carried out on wood infected with spores of wood-staining and mold fungi. For infection, spores of 8 species of fungi were used:
Pullularia pyllylans (De Bary) Berrkhout,
Phialophora fastigiata (Lag et Mei),
Alternaria huricola Oud,
Cladosporium herbarum link,
Ponicillium meleagrinum biourge,
Trichoderma harzianum Harz,
Chaotomium globosum Kunze,
Aspergillus niger V. Thieg.

For tests used samples of freshly sawn sapwood pine wood with a size of 5x15x180 mm and a humidity of 80%
Prototypes were treated by immersion in the impregnating solution and incubated for 50 days in a humid chamber at 20 ± 2 ^° C Humidity samples maintained constant. During the experiment, intermediate observations of the fouling of samples with mushrooms were carried out with an interval of 10 days from the moment of setting the experiment. The fouling area of the samples was expressed as a percentage of the area of the entire sample, and then the safety of the samples was determined.

 The results of mycological tests are given in table 1.

 Mycological tests of impregnated wood with respect to wood-destroying fungi were carried out using the “open ground” method. For testing we used air-conditioned: sapwood pine samples, 20x20x5 mm in size, impregnated with various compounds by the vacuum-atmospheric pressure method. The impregnated samples were weighed and placed in boxes with non-sterile forest soil. Infection was carried out by placing inoculant cubes with the culture of the wood-destroying fungus Serpula sclerotorum under the samples. The temperature and humidity during the tests were kept constant. Simultaneously with the impregnated samples, control (non-impregnated) samples were placed. After 16 weeks of testing, when the test samples were destroyed by 50-60%, the experiment was terminated, macromycological description of the samples was carried out, their conditioning and weighing were carried out. By the loss of mass (in to the initial), the state of the samples was evaluated. The results obtained are presented in table.2.

According to the results of mycological tests, we can conclude that the proposed composition has a higher protective effect, good penetration into wood compared to the prototype. The increase in the protective effect of the proposed drug for bio- and fire protection of wood is due to the introduction of an inhibitory substance containing urea and phosphoric acid in a molar ratio of 2: 1 and giving the drug a complex of directed action:
1. The drug takes on a granular appearance, which reduces its adverse effects on humans and the environment.

+ SiO₂+H₂SiF₆___→
Выделяющиеся в результате реакции аммиак и фтористый водород являются основными токсичными продуктами реакции, оказывающими подавляющие действия на грибы. Введение в предлагаемый состав препарата хорошо усвояемых грибами групп азота и фосфора, содержащихся в ингибирующем веществе, повышает токсичность препарата. Источниками азота являются ионы аммония HOH + NH₃ -> NH₄ ⁺ + OH^- и аминный азот, находящийся в составе NH₂-группы. Конечным продуктом жизнедеятельности грибов являются аммиак и мочевина, выделяющиеся во внешнюю среду и более не участвующие в процессах метаболизма. В период спороношения грибов, азот содержится в них в очень небольших количествах. Избыток в питании грибов азота приводит к созданию щелочной среды в клетках из-за накопления в них аммиака, за счет которого наступает отравление клетки и задерживается рост гриба. Выделяющийся фтористый водород обладает высокой реакционной способностью из-за сильно электроотрицательного фтора и образует водородные и координационные связи с химическими соединениями древесины, оказывая токсическое действие на ферменты грибов. Дереворазрушающие грибы оказывают прежде всего разрушающее действие на целлюлозу, вызывают деструктивную гниль и снижают прочность древесины. Под воздействием ферментов дереворазрушающего гриба происходит гидролиз целлюлозы до глюкозы, затем она реагирует с кислородом воздуха и в присутствии энзимов разлагается на углекислый газ и воду по реакциям:
C₆H₁₀O₅+ H₂O ____→ C₆H₁₂O₆
C₆H₁₂O₆+ 6O₂ ____→ 6CO₂+ 6H₂O
Ингибирующее вещество реагирует с глюкозой, предотвращает ее разложение и образование деструктивной гнили.2. Gives a high protective effect to the proposed drug by inhibiting the emission of hydrogen fluoride into the environment. The loss of hydrogen fluoride is reduced and its maximum amount is used to protect wood from biodefeat. The action of the proposed drug is not wood-staining, mold fungi and wood-destroying is as follows:
Ammonium silicofluoride in the presence of water is hydrolyzed to form ammonia, hydrogen fluoride, cremine dioxide and hydrofluoric acid by the reaction:
2 (NH ₄ ) ₂ SiF ₆ + 2H ₂ O ______ → 4NH

+ SiO ₂ + H ₂ SiF ₆ ___ →
Ammonia and hydrogen fluoride released as a result of the reaction are the main toxic reaction products that have inhibitory effects on fungi. The introduction into the proposed composition of the preparation of well-assimilated by mushrooms nitrogen and phosphorus groups contained in the inhibitory substance increases the toxicity of the drug. Sources of nitrogen are ammonium ions HOH + NH ₃ -> NH ₄ ⁺ + OH ^- and amine nitrogen, which is part of the NH ₂ group. The final product of the vital activity of fungi is ammonia and urea, which are released into the environment and are no longer involved in metabolic processes. During the sporulation period of mushrooms, nitrogen is contained in them in very small quantities. Excess nitrogen in the nutrition of mushrooms leads to the creation of an alkaline environment in the cells due to the accumulation of ammonia in them, due to which poisoning of the cell occurs and the growth of the fungus is delayed. The released hydrogen fluoride is highly reactive due to highly electronegative fluorine and forms hydrogen and coordination bonds with the chemical compounds of wood, exerting a toxic effect on fungal enzymes. Tree-destroying fungi primarily have a destructive effect on cellulose, cause destructive rot and reduce the strength of wood. Under the influence of the enzymes of the wood-destroying fungus, cellulose is hydrolyzed to glucose, then it reacts with atmospheric oxygen and, in the presence of enzymes, decomposes into carbon dioxide and water according to the reactions:
C ₆ H ₁₀ O ₅ + H ₂ O ____ → C ₆ H ₁₂ O ₆
C ₆ H ₁₂ O ₆ + 6O ₂ ____ → 6CO ₂ + 6H ₂ O
The inhibitory substance reacts with glucose, prevents its decomposition and the formation of destructive rot.

 As a result of the reaction, coordination bonds of hydrogen fluoride with an amino group are formed and partial liberation of hydrogen fluoride occurs.

 3. Reducing the emission of hydrogen fluoride from antiseptic wood improves the sanitary and hygienic characteristics of the drug. The test results by definition, allocated HF from antiseptics, are given in table. 3.

 Data on the partial binding of hydrogen fluoride by an inhibitory substance are confirmed by toxicological studies to determine acute toxicity when the drug is administered orally to laboratory animals. The results of toxicological tests are given in table.4.

 According to the results of sanitary-hygienic studies, we can conclude that the proposed drug is less toxic and safer from an environmental point of view.

 4. The introduction of an inhibitory substance into the formulation reduces the average rate and depth of corrosion penetration. When antiseptic lumber used equipment, usually made of carbon unalloyed steel. During the operation of the equipment due to the chemical and electrochemical interaction of steel with aqueous solutions of antiseptics, the metal goes into an oxidized state, which causes damage to the equipment and causes great economic damage. Underground corrosion is especially dangerous due to the nature of the destruction of pits and caverns of great depth. It should be borne in mind that the industrial areas of most woodworking enterprises are located on the shores of water bodies used for forest rafting, and are characterized by a high level and intensive groundwater migration. Therefore, the corrosive wear of the bath is a great danger to the environment.

 The results of determining the corrosiveness of aqueous antiseptic solutions after testing for 5 months are shown in table 5.

 5. Increases the fire retardant properties of wood and wood materials through the use of nitrogen-containing compounds in combination with phosphorus-containing. The synergism of the nitrogen-phosphorus system is as follows: urea forms a gas barrier of ammonia above the surface of the wood material, hindering the access of oxygen and inhibiting the oxidation of carbon in the gas phase, which creates a blowing effect. It interacts with phosphoric acid and, under normal conditions, excludes wood hydrolysis. At elevated temperatures, phosphoric acid is released and melts, covering the wood fibers with a protective film, protecting it from decay, after the cessation of flame burning.

Tests of the fire-retardant properties of wood impregnated with the proposed composition, was carried out by the method of "fire tube". The absorption of the proposed composition for wood impregnation by the method of "vacuum-atmospheric pressure" was 60 kg / m ³ .

 The test results are shown in table.6.

 According to the test results, we can conclude that the wood, impregnated with the proposed composition, has a pronounced fire resistance.

Claims (1)

 COMPOSITION FOR BIO- AND FIRE-PROTECTION OF WOOD and wood materials based on ammonium silicofluoride, characterized in that, in order to reduce environmental hazards, improve the protective ability of technological and operational characteristics, the composition additionally contains a 50% aqueous solution of an inhibitory substance consisting of urea and phosphoric acid in a molar ratio of 2 1, in the following ratio of components, wt. Ammonium silicofluoride 80 90
Inhibitory substance

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