IL34378A - Protection of organic materials by treatment with 2-chlorobenzimidazoles - Google Patents

Description

Protection 6 organic matqrialEs ¾y treatment with 2»c lorobGnaimifias5oles icrotoiocidal compositions containing chlororrderivativee of benzsimidazole The present invention concerns new microbiocidal compositions, in addition process for the control of microorganisms which damage or destroy organic material and articles of use, employing these compositions or the active ingredients or mixtures of ingredients contained therein, as well as the materials and articles protected by treatment with these active ingredients and agents. In particular, the invention concerns microbiocidal compositions for the control of microorganisms which damage and destroy cellulosic and cellulose-containing materials, as well as paints of all kinds.

For the protection of organic, materials , a number of micro-biocidally active substances are known, a large number of which do not completely meet the necessary requirements. Thus, for example, the use of phenols , in particular pentachlorophenol , or tri-alkyl tin oxides, in particular tributyl tin oxide, which are usually employed to control fungi which damage or destroy cellulosic or cellulose-containing material, is limited due to their properties such as, e.g. high vapor pressure, their unpleasant inherent smell, lack of light-fastness, etc. Although these active substances have a wide range of action, the duration of this action is unsatisfactory. Benzimidazole compounds which are substituted by one or more chlorine atoms in the benzene nucleus have previously been described as herbicidally and pestici-dally active agents 6 as agents for the control of insects which feed on keratin (cf. Swiss patent. No. 443,777).

Surprisingly, it has now been found that compositions containing as active ingredient a 2-chloro-benzimidazole compound or a mixture of such polychlorobenzimidazoles, are excellently suited for the control of microorganisms which destroy or damage organic materials and articles of use. The new compositions containing active substances and/or mixtures of active substances inhibit the growth of bacteria, fungi and yeasts, in particular however the growth of fungi and bacteria which destroy and damage cellu- losic and cellulose-containing materials and paints of all sorts. These polychlorobenziinidazoles have a broad range of action, are substantially stable against humidity and the influence of light, and have a very good affinity to the said materials and a long- lasting action. Due to these properties, as well as to their low vapor pressure combined with good light stability and their intrinsic odorlessness , the new agents are especially suited for providing a microbiocidal finish to paints of all types such as dyes tuffs on the most varied basis, lacquers, and varnishes , to wallpapers, to wood and wooden articles, and to textiles of all • kinds .

The microbiocidally active substances contained in the compo sitions according to the invention are preferably the following polychlorobenzimidazoles : 2,5, 6-trichloro-benzimidazole, 2,4,5, 6- tetrachloro-benzimidazole, 2 ,4 ,5 , 6 , 7-pentachlorobenzimidazole as well as mixtures of these polychlorobenzimidazoles, which preferably have the following composition: A. 4'..6% 2 ,5 , 6- trichloro -benzimidazole 29.7% 2,4,5 , 6- tetrachloro-benzimidazole 27.77a 2 , 4 , 5 , 6 , 7-pentachloro-benzimidazole Β. 61 . 87ο 2 , 4 , 5, 6 , 7-pentachloro-benzimidazole 3 3 . 8% 2 , 4,5, 6-tetrachloro-benzimidazole 4 . 47, 2,5, 6-trichloro-benzimidazole .

The production of these compounds is known from Swiss pat ent No. 44 3 , 7 7 7 (British patent No. 1 , 14 6,059). The production o the individual components as well as that of mixture A by chlori- nation 2-mercapto-benzimidazole in water is described. According to an improved process, the mixtures A and B are obtained by chlo rinating 2 , 5-dichlorobenzimidazole in the presence of ferric chloride in glacial acetic acid with the addition of a base.

While the process is being carried out, the addition of chlorine is interrupted several times and the acidity of the reaction mixture is reduced by the addition of a base such as sodium acetate. The chlorination practically ceases when the mixtures A and B are obtained. The two mixtures can be separated from one another by fractional distillation. The mixtures have good uniform melting points; their composition was determined by using a gas chromatogram.

Materials treated with the new agents have an excellent microbiocidal finish. Since the active ingredients are odorless, they are especially suitable for the treatment of materials which are in closed rooms, such as wood, paper, paints of all kinds, etc. Treated materials, such as paper, showed no discoloration after long exposure to light. Compared to tributyl tin oxide, the polyculorobenzimidazoles are practically non-volatile; after storage for 1 6 days at 90°C, tributyl tin oxide lost about 3.47o by weight; m contrast thereto, the polychlorobenzimidazole mixture A lost only 0. 47o by weight.

The compositions according to the invention are advantageously concentrates of the active substances which are either liquid (solutions, emulsifiable concentrates) or paste-like. The concentrates can be diluted to the necessary concentration shortly before use. Since the active substances are soluble in organic solvents, they are suitable for non-aqueous application. The poly-chlorobenzimidazoles form salts with alkali metal ions and can thus be applied from aqueous dispersions or solutions. The treatment of wood and wooden articles is thereby greatly simplified. · To determine the bactericidal and fungicidal action of the compounds of the polychloro-benzimidazoles employed according to the invention, the following tests were. carried out: 1. Range of Action' The solution of active substance is mixed with nutrient agar while still warm. The agar is then poured into plates and, after solidification, inoculated with the test germs.

The following microorganisms were used: A. Bacteria : Escherichia coli, Bacillus pumilus, Sarcina ureae, Bacillus subtilis, Sarcina lutea, Streptococcus faecalis, Staph, saproph. , Staph, aureus, Corynebact. diphtheroides 17, Brevibact. ammoniagenes , Salmonella pullorum, Proteus vulgaris HXL, Proteus vulgaris ox 19, Proteus mirabilis.

B. Fungi: la. Aspergillus niger , ■ PeniciLLium italieum, Fusariu oxy- sporum, Candida albicans, Stemphylium botryosum, Cellulose degraders : Chaetomium globosum, Trichoderma viride, Metarrhizium glutinosum, Stachybotrys atra, 2. yeasts: Saccharomyces cerevisiae, Torula utilis, Monilia ■ nigra, 3. Dermatophytes : Trichopyton gypseum, Ctenomyces Spec, , Keratinomyces ajelloi, Epidermophyton flossosum, 4.. Ubiquitous Saprophytes: Rhizop s nigricans, Paecilo- ' yces varioti, Penicillium citrinum, Aspergillus oryzae, Aspergillus clavatus, Aspergillus flavus , . Fungi imperfect! : Scopulariopsis brevicaulis , Alter- naria tenuis, Acrostalagmus cinnabarinus , 6. House rot: Coniophora cerebella, Poria vaporaria, Poria in- carnata, 7. Storage rot : Polystictus versicolor, Daedalea quericina, Lenzites abietina, Lentinus lepideus, 8. Parasites : Fomes annosus, 9. Wood stainers: Scopularia phycomyes, Pullularia pullulans.

In the following list there are given the nutrient media used for the various organisms, the incubation temperatures, and incubation time, as well as the concentration of the active substances used: Nutrient Incubation Concentra ion of Organisms medium temp. I timi active substance in ppm * A Bacteria Nutrient agar 37' 48 hrs 30-10-3-1 . la Nutrient agar 37° 48 hrs. 100-30-10-3 lb Maltose-agar 28° 5 days 100-30-10 + oats Wort-agar 28° 5 days 100-30-10 Sabouraud Dextrose-agar 28° 10 days 100-30-10 4. Sabouraud . Maltose-agar 28° 5 days 100-30-10 6.-9. Sabouraud Maltose-agar 28° 7 days 100-30-10 * ppm: parts of active substance per 10 parts of diluent Evaluation : The minimum growth- inhibiting concentration for the various microorganisms is determined.

In the following Table 1, the bacteriostatic action, and in Table 2, the fungistatic action of the polychlorobenzimidazoles on some of the previously listed microorganisms are given. (The numbers give the minimum growth-inhibiting concentrations in ppm.) The following were used as active substances: 1. 2 ,5 , 6- trichloro-benzimidazole 2. 2 , 4 , 5 , 6 , 7-pentachloro-benzimidazole 3. mixture A: 42.6% 2 , 5 , 6- trichloro-benzimidazole , 29.7% 2 ,4 , 5 , 6- tetrachloro-benzimidazole , and 27.77o 2 , 4 ,5 , 6 , 7-pentachloro-benzimidazole . 4. 2,4,5, 6- tetrachlorobenzimidazole . mixture B: 61.8% 2 ,4 , 5 , 6 , 7-pentachloro-benzimidazole , 33.8% 2 ,4 , 5 , 6- tetrachloro-benzimidazole , and .4.4% 2,5, 6- trichloro-benzimidazole.

Table I Bacteria Active Substances 1 2 3 4 5 Staphylococcus aureus SG 511 10 3 1 1 1 Escherichia coli NCTC 8196 30 300 10 10 30 Bacillus pumilus Fey 3 1 1 1 1 Sarcina ureae 10 1 1 1 1 Bacillus subr.ilia NCTC 6460 10 1 1 3 1 Table 2 Fungi- Active Substances 1 2 3 4 5 ' Keratinomyces ajelloi 10 10 10 10 10 ; Epidermophyton floccosum 10 10 10 10 10 Rhizopus nigricans 10 10 10 10 . 10 ' Paecilomyces varioti 10 >100 30 30 30 Penicillium citrinum 10 10 10 10 10 Memnoniella echinata 10 10 10 10 10 Aspergillus oryzae 30 >100 30 30 30.

Aspergillus clavatus 10 100 30 10 30 Aspergillus flavus 30 >100 30 30 30 Scopulariopsis brevicaulis 10 10 10 10 10 Alternaria tenuis 10 10" 10 - 10" 10 ' Acrostalagmus cinnabarinus 10 10 10 10 10 Wood Fungi Active Substances .1 .2 3 '4 5 Coniophora cerebella 10 10. 30 10 100 Poria vaporaria 10 10 10 10 10 Poria incarnata 10 10 10 10 10 Polystictus versicolor 30 - 10 30 — Daedalea quercina 30 100 100 30 10 Lenzites abitina 10 30 10 10 10 Lentinus lepideus 10 10 10 10 10 Fomes annosus 10 10 10 · 10 30 Pullularia pullulans 10 10 10 10 10 V 2. Inhibition Zone Test The active substances are applied onto circular paper samples from solutions containing varying amounts of the active substance from an exhaustion bath and on a padding mangle. As solvent, ethylene glycol monomethyl ether was used. As nutrien agar, so-called two-layer agar plates were used. These consist of a layer of Bacto-agar and a layer of agar suitable for the particular organisms being tested. This second plate is previously inocculated with the test germs. The circular paper samples which have been treated with the test substances are then laid on these plates and incubated for 24 hours at 37°C. Then the growth of the test organisms on and under the circles is evaluated.

The following test organisms were used: Bacteria : Staphylococcus aureus SG 511 (Nutrient agar ÷ potassium tellurite) Escherichia coli (Nutrient agar) Fungi : Aspergillus niger (Wort-agar) Candida albicans (Wort-agar) Range of Action Test In the table: means ineffective = growth corresponds to control ++ . means weak effect = 25-50%, of growth of the control +++ means fully effective = no growth. 3. Disinfection Test From an exhaustion bath (padding mangle) the active substances are applied from solutions containing varyitig amounts of the active substance onto circular paper samples. These test samples are then inocculated with suspensions (physiological saline solution having a 107, bouillon content) of the various test organisms. The paper circles are then incubated in a damp 3 chamber for 24 hours at 37°C and then washed out in 20 cm of physiological saline solution (contains polyoxyethylene sorbitol-mono-oleate to block the active substance) . Aliquot parts of this solution are taken and prepared in plates of appropriate nutrient medium. The plates thus prepared were then incubated for 24 hours at 37 °C. The test organisms named under 2. were used. Then the number of viable germs is determined in comparison with those of the control.

In the following table: · ,.. .- . means ineffective ·= growth. corresponds to control ++ means weak effect = 25-507» of growth of the control -H-+ means fully effective = no growth.

Bacteria Fungi Active Staph . aur . Esch. ( :oli Asp . ig # Cand . alb. Subs tance 0.05% 0.17o 0.05% 0.1% 0.05%. 0.1% 0.05% 0.1% 2 ,5 , 6- trichloro-benzimidazole ++ ++ I 1 1I 1I +++ 2,4,5,6-tetra-chlorobenzidazole ++ ++ +++ -HH- Mixture A (composition see under +++ ■I-Ή- +++ •H-+ +++ +++ ++ ÷++ 1.*) * Range of Action Test 4. Action on microorganisms which decompose urea A circular paper sample is placed in one of two powder flasks which are connected with each other. It is inocculated with a germ suspension consisting of liquid urea medium and urea-decomposing bacteria. 0.1 N hydrochloric acid is added to the other bottle . The bottles are then incubated on a rotating apparatus for 3 days at 28°C. Then the amount of ammonia resulting from · th e . decomposition of the urea is determined from the shift in pH. The following test organisms were used: Brevibacteriuiri' ammoniagenes Proteus OX 19.

The polychlorobenzimidazoles according to the invention inhibit, in concentrations of 0.05 and 0.1%, the growth of such bacteria. No change in the pH of the 0.1 N hydrochloric acid due t'o the absorption of ammonia could be determined.

. Moldy Spot Test Circular paper samples to which the active substances have been applied on a padding mangle are placed on a sterile Wort-Agar plate and inocculated with a germ suspension of the test organs ism. The circular samples are then incubated for 3 days at 28°C and 75-85% relative humidity. The growth on and under the test samples is then evaluated.

The following test organisms were used: Penicillium expansum Aspergillus niger Alternaria tenuis.

In the following table, the fungicidal effect at varying concentrations of active substance is shown: ineffective = growth corresponds to control ++ weak effect = 25-507o of growth of the control -H-+ fully effective = no growth...

* Range of Action Test 6 . Microbiocidal Activity in Paints X parts of active substance are first dissolved in 5 parts of a 1 : 1 mixture of dimethyl formamide and ethylene glycol mono-methyl ether and then homogeneously stirred with .( 90-x) parts of a commercial, polyvinyl acetate/ethylacrylate copolymer- type dispersion paint- and 5 parts of water to obtain a ready-for-use paint. Filter paper, e.g. Whatmann 3 MM filter paper, is painted therewith and dried for 3 days at room temperature. Then the test samples are aired for 8 days in a wind tunnel at 65 ° C and 80 - 907o relative humidity. The test samples are then cut and placed on innoculated agar plates. (Fungi: paint layer facing upward., bacteria : paint layer facing downward) .

- As active substance, the mixture A was used: 42 . 6% 2 , 5 , 6 - trichloro-benzimidazole , 2 9 . 7% 2 , 4 , 5 , - tetrachloro-benzimidazole , and 2 7 . 77o 2 , 4 , 5 , 6 , 7-pentachloro-benzimidaz.ole .

The following test organisms were used: Fungi : Pullularia pullulans Paecilomyces varioti Penicillium cyclopium Sabouraud- Aspergillus oryzae Maltose-Agar Chaetornium globosum Aspergillus niger Candida albicans Bacteria Staphylococcus aureus Escherichi coli Nutrient-Agar The plates are then incubated: Fungi: 7 days at 28°C and 70-807,, relative humidity; Bacteria: 24 hours at 37°C and 60% relative humidity.

In the following table the minimum concentrations of the active substances which inhibits the growth of the microorganisms before arid after airing are listed: In comparison therewith, tributyl tin oxide, even in a concentration of 6%, shows only a partial effect. - - 7. Protective Effect against Soft Rot Blocks of beech wood and pine sap wood (200 x 10 x 5 ran in size) were dried for 14 hours at 105°C and then weighed to determine their dry weight. The wood samples were then soaked for 24 hours at room temperature under normal pressure with a 2.5 and a 17„ acetone solution of the active substance and then stored for one week at room temperature under normal pressure. Afterwards, two-thirds of the length of the wood samples were buried in the earth, the remaining one- third being left above the surface. The beech samples were then left for 3 months and · the pine samples for 6 months in the earthwhich had a water content of 23 - 35%, a temperature of 28°C and 70-80% relative humidity. The samples of wood were then washed with a soft brush under running water and afterwards dried for 14 hours at 105 °C. They were then weighed. Compared with the weight found before the test, the wood samples had lost weight. The amount of weight lost shows to what extent the wood is protected by the active < substances against soft rot (micro-organisms which decompose cellulose and lignin) .

The losses in weight of the wood samples treated with active substances, expressed in per cent, can be seen from the following table: It can be seen from the values listed in the table that the mixture of chlorinated benzimidazole compounds provided a better protection of beech and pine wood against soft rot (fungi which decompose cellulose and lignin) than pentachlorophenol , which in a concentration of 2.5% was ineffective for pine after 6 months and for beech was only partially effective after 3 months.

Samples of various types of wood are dried for 16 to 20 hours at 105°C to determine their dry weight.' The samples are then soaked with the aid of a vacuum with solutions of the active substances in acetone in varying concentrations. By re-weighing, the amount of active substance absorbed is determined.

Then powder flasks are half-filled with quartz sand and 3 cm of a nutrient solution,' glucose, peptone dissolved in phosphate buffer, malz extract. A piece of wood suitable for the growth of the test fungi is inserted in the quartz sand, inoculated with fungi and preincubated for 3 weeks.

The pieces of wood which have been soaked with active substance are placed on the resultant evenly distributed surface growth, of fungi and kept for 2 months at 24°C. The growth of the fungi and the quality of the wood are then evaluated. Thereafter the samples are aired for 4 weeks in a wind tunnel at 65°C with fresh air; the growth of fungi is again evaluated.

The test organisms and types of wood used are the following Coniophora cerebella on pine (Pinus silvestris) Coriulus versicolor on beech (Fagus silvatica) Poria incarnata on linden (Tilia spec).

In the following table, the minimum growth- inhibiting concentrations are given: In order to determine the volatility of the compounds according to the invention the powdery mixture A was compared with liquid bis-tributyl- tinn -oxide, technical grade and with powdery triphenyl-tinn-hydroxide also technical grade.

The volatility of these substances is given by the loss of weight, which occurs whe 1 g of the substance is stored in the laboratory at about 20 to 25°C or in a drying oven at 90°C.

The follov7ing example describes the production' of poly chlorobenzimidazole mixtures, The temperatures are given in degrees centigrade.

Example 708 g of 2 , 5-dichlorobenzimidazole and 2.45 g of ferric chloride are slurried in 5800 ml of glacial acetic acid. The reaction mixture is heated to 40° , cooled and then 380 g of chlorine gas are intoduced into the mixture at 20° , then heated to 40 to 50°, and treated with 390 g of sodium acetate. After the exothermic reaction ceases , 380 g more of chlorine gas is introduced, and then heated again' to 45 to 50°. After cooling, 589 g of sodium acetate is added and 500 g more of chlorine gas is introduced. After standing for 1 hour, the mixture is poured onto 30 kg of ice and treated with 1500 ml of 30% aqueous sodium hydroxide solution, so that the mixture has a H-value of 4. The precipitated slurry is separated, brought to the boil in boiling methanol and filtered. The mixture A crystallizes from the filtrate and consists of 42.6% of 2 , 5 , 6- trichloro-benzimi-dazole, 29.7% 2 , 4 , , 6- tetrachloro-benzimidazole , and 27.7%, of 2 , 4 , 5 , 6 , 7-pentachloro-benzimidazole , having a melting point of 212 to 214° and a chlorine content of 54%. The filter residue is again brought to the boil in methanol and immediately filtered. The mixture B, consisting of 4.4% of 2 , 5 , 6- trichloro-benzimida-zole, 33.8%, of 2 , 4 , 5 , 6- tetrachloro-benzimidazole and 61.870 of 2 ,4 , 5 , 6 , 7-pentachloro-benzimidazole has a melting point of 280° with decomposition. The mixture has a chlorine content of 59.12%.

For the production of materials and in particular wood, the new compositions are applied in the form of solutions or emulsions. Wood and wooden objects are either impregnated, coated, soaked or sprayed with such liquid agents. The treatment can be applied externally or by impregnation of the wood b known technical processes.

To produce solutions , in particular organic solvents which are substantially odorless and non-volatile are used, such as mineral oil fractions , tar oils , high boiling aliphatic and aromatic hydrocarbons as well as their chlorinated derivatives. These are used alone or mixed together. To improve the penitra- tion, these solvents can contain low boiling aliphatic hydrocarbons and their derivatives as additives. Solvents having an insecticidal effect are preferred as solvents.

To produce emulsion concentrates, orga ic solvents, dispers ing agents and water are used. Examples of solvents are alcohols aromatic hydrocarbons as well as the solvents given above. The following substances can be used as dispersing agents: polyethylene glycol ethers of mono- and di-alkylphenols having 5-15 ethylene oxide radicals per molecule and 8-9 carbon atoms in the alkyl radical [e.g. the commercial products "Triton" (Rohm and Haas Co., Philadelphia) , "Tergitol" (Union Carbide Chemicals. Co., New York) and "Igepal" (General Aniline & Film Corp. , Antara Chemicals Div. , New York)], fatty alcohol polyethylene glycol ethers having 5-20 ethylene oxide radicals per molecule and 8 to 18 carbon atoms in the fatty alcohol moiety [e.g. the commercial products "Genapol" (Hoechst, Frankfurt a.M.) ], condensation products oi ' " (manufacturer: Wyandotte Chemical Corp., Industrial Chemical Div. Wyandotte, Mich.)], polyvinylpyrrolidones , urea/ formaldehyde ■ condensation products , condensation products from sulfonated naphthalene and sulfonated naphthalene derivatives with formaldehyde [e.g. the commercial product "Sellasol" (manufac urer: J.R. Geigy A.G., Basel) ],. condensation products of naphthalene or naphthalene sulfonic acids with phenol and formaldehyde [e.g. the ■ commercial products "Irgatan" (manufacturer: J.R. Geigy A.G.. , Basel)], furthermore , alkylaryl sulfoiiates , alkali metal and alkaline earth metal salts of dibutyl naphthalene sulfonic acid, fatty alcohol sulfates such as salts of sulfated hexadecanols , hepta-decanols , octadecanols , octadecenols , and salts of sulfated fatty alcohol polyglycol ethers [e.g. the commercial products "Eriopon" (manu acturer: J.R. Geigy A.G., Basel)], amino-fatty alcohol sulfates [e.g. the commercial products "Duponol" (manufacturer: Du Pont, Wilmington, Del.)], the sodium salt of oleoyl ethionate the sodium salt of oleoyl methyl- tauride [the commercial products "Arkopon" (manufacturer: Hoechst, Frankfurt a.M.)], ditertiary acetylene glycols [e.g. the commercial products "Surfynol" (manufacturer: Air Reduction Chemical Company, New York) ] , dialkyl di-lauryl ammonium chloride [the commercial product "Aliquat" (manufacturer: General Mills Inc., Kankakee, Illinois)].

In general, the solutions and emulsion concentrates contain the active substance in a concentration between 1 and 80%; preferably the content of active substance in the solutions used is between 4 and 1070. Such solutions can be used directly for the impregnation, spraying or painting of wood and wooden articles. For application, the emulsion concentrates are diluted with water to form emulsions having 1 - 1570 of active substance. Other biocidally active substances can be mixed with the agents described according to the invention. Thus, in addition to the polychlorobenzimidazoles , the new compositions may contain, e.g insecticides such as DDT active substance, other fungicides, bactericides, fungistatics and bacteriostatics, to widen the range of action. The agents may optionally also contain water repellents .

The following examples illustrate the production of a few typical embodiments of the compositions according to the in vention. Parts mean parts by weight.

Emulsion Concentrate The following substances are used to produce an 870 emulsi concentrate : 8 parts of Mixture A, consisting of 42.6%, of 2 , 5 , 6- trichloro-benzimidazole 29.77, of 2 ,4,5 , 6- tetrachloro-benzimi- dazole, and 27.7% of 2 , 4 , 5 , 6 , 7-pentachloro-benz- imidazole , 7 parts of DDT active substance (dichlorodiphenyl trichloroethane) , 80 parts of xylene, and parts of a mixture of emulsifying agents consis' ting of nonylphenol polyethylene glyco ether and calcium dodecylbenzene sulfonate.

The active substance is intimately mixed with DDT active substance and, with the addition of the mixture- of emulsifying agents, dissolved in xylene. An emulsion concentrate is obtained which can be diluted with water to any concentration desired.

When wood or wooden objects, particularly construction wood are painted, impregnated or sprayed with such aqueous emulsions, the treated material is protected against infestation by destructive microorganisms and insects.

Solution The following substances are used to produce a 47, solution: 4 parts of Mixture A, consisting of 42 . 67= of 2 , 5 , 6- trichloro-benzimidazole , 29 . 77o of 2 , 4 , 5 , 6- tetrachloro-benz imidazole, and 27 . 77» of 2 , 4 , 5 , 6 , 7-pentachloro-benz- imidazole, 3 parts of DDT active substance, 93 parts of solvent containing 9370 aromatic sub- . stances, boiling range 212- 273 ° , specific weight 0 . 930 .

The active substance and DDT active substance are dissolve The solution obtained can be used directly for the impregnation painting or spraying of wood, etc. and wooden articles, whereby the material obtains a microbiocidal and' insecticidal finish.

Claims (7)

34378/2 Claims f

1. Method for the protection of organic materials and commodities, preferably consisting of or containing cellulosej especially wood materials j against infestation by micoorganisms which damage or destroy such materials, characterized by treating the said materials and commodities with a 2-chloro-benzimidazole compound which is chlorinated at least twice in the benzene nucleus or with a mixture of such polychloro-benzitnidazoles or with compositions containing at least one of these substances as active component.

2. Method according to Claim 1, wherein the 2-chloro-benzimidazole compound is 2 , 5, 6-trichloro-benzimidazole.

3. Method according to Claim 1, wherein the 2-chloro-benzimidazole compound is 2 , 4, 5 , 6-tetrachloro-benzimidazole .

4. Method according to Claim 1, wherein the 2-chloro-benzimidazole compound is 2 , 4, 5 , 6 , 7-pentachloro-benzimidazole .

5. Method according to Claim 1, wherein the mixture of polychloro-benzimidazoles contains 2,5, 6-trichlorobenzimidazole. 2 , 4, 5 , 6-tetrachlorobenzimidazole and 2 , , 5 , 6 , 7-pentachloro-benzimidazole .

6. Method according to Claim 5, wherein the mixture of polychloro-benzimidazoles contains 4,4 - 42,6 % by weight 2, 5, 6-trichlorobenzimi.dazole, 29,7 - 33,8 % by weight 2 , 4, 5 , 6-tetrachlcrobenzimidazole and 27,7 - 61,8 70 by weight 2,4,5,6, 7-pentachlorobenzimidazole.

7. Organic materials and articles protected against