DE2728107A1 - Protecting wood from fungal attack - by treating with (N)-fluorotetrachloroethyl-(N)-phenyl-methanesulphonamide - Google Patents

Abstract

Process for protecting wood from fungal attack comprises applying a fungicidal amt. of N-(2-fluoro-1,1,2,2-tetrachloroethylthio)-N-phenyl-methanesulphon- amide (I) onto or into the wood. (I) is esp. useful for protecting timber (and also wood chips, e.g. for prodn. of mechanical pulp or chipboard) from wet and dry rot. It is active against fungi of the order Aphyllophorales and Agaricales, including the families Polyporaceae and Tricholomataceae.

Description

Wood protection against fungal attack

Considerable effort is being put into wood and wood products to protect against damaging biological attack, in particular against fungal attack. The present invention relates to protecting wood against fungal attack. In general the fungal attack on wood can be divided into the following four groups: Rot, mildew, discoloration of sapwood and mold growth. Usually fungi that attack wood are divided into four groups, depending on the type of damage caused, divided. Protecting wood against fungal attack is, as you would expect, essential for a large number of industries.

Mold is generally the development of surface fungus understood on wooden surfaces. Mold alone does not cause significant damage in the wood and can easily be removed by brushing or scratching. However can mold makes the wood more permeable to water, which promotes rot will.

Fungi, which cause discoloration of sapwood, attack this Sapwood from certain types of construction and timber, such as spruce and pine, at. Such fungi do not generally cause substantial physical damage of the wood, but they can stain and discolor up to a substantial one depth cause and affect the toughness and also the hardness of the wood. Rot and soft rot are the most damaging types of fungal attack. You attack the real one Wood structure and cause its destruction or weakening. Damage of this kind are mainly from fungi of the Basidiomycetes and Fungi Imperfecti groups, as also effected by Ascomycetes.

Protecting wood against fungal attack is particularly important with wood and wood products that are used outdoors, such as fence posts, telephone poles, Wood panels, shingles, signs, building elements for foundations and basements and others Construction and decorative materials used outdoors. It is also important to wood protect against rot and soft rot during storage.

Another important area of wood protection is protecting Wood chips, which are used for wood pulp and for the manufacture of other products, such as chipboard. Wood chips used in such procedures are usually stored outdoors and it is necessary to remove such wood chips to protect against fungal attack before they are used at the processing site.

The most common chemicals used to prevent fungal growth in wood are: a) tar products such as Creosot, b) polychlorinated phenols, especially pentachlorophenol and c) mercury compounds such as phenyl mercury acetate. The latter two Chemicals that are best for preventing rot and mildew rot, have toxicological properties that are disadvantageous for quantities and animals. Their use is therefore expected in general and as a fungicidal Wood preservatives in particular by the environmental protection agencies of various governments both in the USA and in is banned in other countries. It is therefore necessary to find other compounds that are suitable as fungicidal wood preservatives are.

For a fungicidal wood preservative to be commercially viable, it must a compound has additional important properties. In general Fungicides work by being consumed by the fungi they control will. Fungicides, which are used to protect grain, must be comparatively ephemeral, i.e. they should be persistent long enough to To protect grain against fungal attack, however, they should no longer be used after harvest remain in the plants, nor should substantial residues remain in the soil.

The other hand must have a compound that acts as a fungicidal wood preservative is used, their activity for long periods of time, preferably for years and not for weeks or months, sustaining the activity for a substantial period Part of this period must have the same relative height. The required Durability is particularly important in products such as telephone poles that are im generally have an average lifespan of 35 years or more should. Additionally, a fungicidal wood preservative should have adequate stability to light and heat, water should only give it a small amount be leachable, colorless and relatively free from harmful effects on wood as well as on the external condition of the processing of the wood devices used. Additionally, it would be beneficial to use a fungicidal wood preservative to find which is effective against at least two types of wood-damaging fungi is. For example, some compounds are only effective against Basidiomycetes species, while other compounds are only satisfactory against Fungi Imperfecti species can be used for wood protection. That is why it is often necessary to have a Mixture of at least two fungicidally active compounds to use.

The present invention relates to a method for protecting Wood against fungal attack, which is characterized by the fact that it has a fungicidal effect Amount of N- (2-fluoro-1,1,2,2-tetrachloroethylthio) -N-phenyl-methanesulfonamide applies the wood and / or introduces it into the wood.

In particular, the invention relates to a method for protecting Wood against rot or mildew rot, which is characterized by the fact that one effective amount of N- (2-fluoro-1,1,2,2-tetrachloroethylthio) -N-phenyl-methanesulfonamide applies to the wood and / or brings it into the wood.

In particular, the invention relates to a method of using the Above mentioned connection for the protection of wood against fungi of the order Aphyllophorales and Agaricales, still against the families Polyporaceae and Tricholomataceae.

It has been found that N- (2-fluoro-1,1,2,2-tetrachloroethylthio) -N-phenyl-methanesulfonamide of the formula is effective as a fungicidal wood preservative and meets the above conditions. In particular, it is effective against more than one species of fungus. These compounds have been described in GB Patent 1,242,266 as, inter alia, a satisfactory agricultural fungicide. However, as stated above, the fact that a fungicide is satisfactory for agricultural purposes does not necessarily mean that it is also suitable for wood preservation. Since a fungicide for agriculture must necessarily be short-lived, the fact that a compound can be used as a fungicide in agriculture indicates that such a compound cannot be an effective fungicidal wood preservative.

Working methods and results when testing for fungicidal activity The The following tests were done to determine the effects of this compound against wood Showing infesting fungi: The tests were carried out using the fungi Lenzites trabea (order: Aphyllophorales, family Polyporaceae), Lentinius lepideus (Order: Agaricales, family Tricholomataceae) and Poria placenta (order: Aphyllophorales, Family Polyporaceae). Sterilized strips of soft spruce sapwood (approx 5 cm x 3.5 cm) were infected with the fungi and at 26.70C and about 65 to 70% Moisture incubates until abundant growth appeared on the surface. Under Using an aseptic technique, the infected exit strip was placed on one Wire mesh stand in a sterilized 9.5 liter wide neck flask, the 50 until it contained 100 ml of distilled water.

1.8 cm large, soft spruce wood cubes were made by inserting the Cube in a Petri dish that contained the active ingredient in an acetone solution with vacuum impregnation of the compound to be tested using a bell jar. After 3 minutes the vacuum was released for one minute and the procedure three times repeated. The cubes soaked up about 75% of their weight in acetone. Hence became a solution of 0.133% was used to impregnate a cube with 0.1% active ingredient.

The impregnated cube was aseptically applied to the infected output strip and placed an untreated cube next to him. The screw cap was on the Wide-necked flask on, left a quarter turn open and the flask incubated for two weeks at 26.70C. After that, the cubes were placed on mushroom growth. observed. The results of these tests are shown in the following table: Tabel Concentration of the active ingredient% by weight untreated fungus 0.1% 0.05% 0.02% control Lenzites trabea 0 0 0 + Lentinius lepideus 0 0 0 + Poria placenta 0 0 0 + O = annihilation + = fungicidal growth, no destruction Thus prevented the compound N- (2-fluoro-1,1,2,2-tetrachloroethylthio) -N-phenylmethanesulfonamide at concentrations of 0.1 to 0.02% by weight, the growth of all three test mushrooms the treated cubes of spruce completely, whereas all three mushrooms are successful from sterile starting strips were transferred to the untreated cubes.

The compound N- (2-fluoro-1,1,2,2-tetrachloroethylthiop N-phenylmethanesulfonamide can be converted into preparations according to methods customary for combating fungal attack on wood are processed. For example, it can be incorporated into impregnating oils or aqueous solutions as they are used in the treatment of wood by techniques with or without pressure, Vacuum impregnation, etc. can be used.

The connection can also be carried out according to the standard methods customary in the art applied by brushing, spraying or dipping or also coatings, varnishes, Colors etc. are incorporated. The compound can be suitably used as a Solution, emulsion, mesh powder, grains can be prepared using the typical Diluents or carriers, together with such stabilizing and surface-active agents Means as they are commonly used in technology. Most preferred the connection with an inert carrier or diluent, such as an impregnating oil, prepared in such concentrations that are considered effective against fungal attack has found, e.g. in concentrations as given in the tests described above are.

Claims (8)

Patent claims 011 method for protecting wood against fungal attack, characterized in that a fungicidally effective amount of N- (2-fluoro-1,1,2,2-tetrachloroethylthio) -N-phenyl-methanesulfonamide applies to the wood and / or brings it into the wood. 2. The method according to claim 1, characterized in that mushrooms, which cause rot and / or mildew rot in wood. 3. The method according to claim 1, characterized in that one mushrooms of the Aphy1lophorales and / or Agaricales orders. 4. The method according to claim 3, characterized in that one mushrooms of the families Polyporaceae and / or Tricholomataceae. 5. The method according to claim 3, characterized in that one lenzites trabea, Lentinus lepideus and / or Poria placenta. 6. Wood preservatives containing a) a fungicidally effective amount of N- (2-fluoro-1,1,2,2-tetrachloroethylthio) -N-phenyl-methanesulfonamide and b) an inert one Carrier. 7. Wood preservative according to claim 6, characterized in that it contains component a) in an amount of about 0.0266 to about 0.133% by weight. 8. Wood material containing about 0.02 to about 0.1% N- (2-fluoro-1,1,2,2-tetrachloroethylthio) -N-phenyl-methanesulfonamide has been impregnated.