NO862995L - BIOCIDE TRIBUTYLTIN COMPOUNDS. - Google Patents

Description

Tributyltin compounds, e.g. tri-n-butyltin oxide and tri-n-butyltin esters of carboxylic acids have a high biocidal effect against fungi and bacteria. They are therefore widely used as active substances for biocide addition to many materials and as preservatives or disinfectants. The biocidal effect of the tributyltin compounds is not limited only to microorganisms, but also includes certain marine organisms. These compounds therefore prevent in anti-fouling paints a harmful growth of the underwater hull with weeds, mussels or algae.

An important area of application for triorganotin compounds is the protection of freshly cut or built wood before attack by highly damaging fungi. Due to their strong activity and their broad spectrum of action, tributyltin compounds are widely used as fungicides in wood preservatives.

In the case of the organotin compounds used so far

it is essentially tri-n-butyl tin oxide, or tri-n-butyltin esters of organic acids, such as tri-n-butyltin benzoate, -linoleate or -naphthenate. Solutions of these substances in organic solvents are usually used. However, with the help of emulsifiers, it is also possible to produce aqueous tributyltin preparations. The tributyltin compounds are already effective in very low concentrations.

Decisive for the activity of the various tributyltin compounds is usually the tin content. As this is lower in the case of tri-n-butyltin esters of long-chain carboxylic acids than in the case of tri-n-butyltin oxide, correspondingly higher amounts must be used when using such esters to achieve the same effect. A specific biocidal effect dependent on the nature of the carboxylic acid used has therefore not been known for tri-n-butyltin compounds.

The biocidal effect of wood preservatives can be expressed by the so-called limit value, whereby the lower limit indicates the concentration at which a fungal attack begins and the upper is the concentration at which no further attack occurs.

Thus, the limit value according to DIN 52 176 against a typical wood-destroying fungus (Coniophora puteana) for tri-n-butyl tin oxide is 0.34 - 0.70 kg/m 3 wood and for tri-n-butyl tin molate is correspondingly higher at 0.92 - 1 .3 kg/m 3.-'

Of great importance for the applicability of biocides as wood preservatives is their durability. The agents should give the thus treated wood the longest possible lasting protection against microbial attack. In principle, tributyltin compounds are fairly resistant substances with which wood preservatives can be produced with a good lasting effect. Under certain conditions, such as higher temperature or impact of special wood-containing substances, however, during the removal of butyl groups, they can be broken down into biologically less effective organotin compounds.

An important factor for the durability of wood preservatives is the thermal stability of the active ingredient. Biocide-treated wood that is exposed to the weather can be heated to over 70°C by solar radiation over a longer period of time.

It has now surprisingly been found that tri-n-butyltin compounds, which are obtained by reacting tri-n-butyltin oxide or tri-n-butyltin halides with divalent alcohols with an average hydroxyl number of approx. 200 and an average equivalent weight of approx. 280, which is obtained by hydration of dimeric fatty acids or by polymerization of unsaturated fatty alcohols, is distinguished by a very high thermal resistance in thus treated wood, which is considerably higher than the previously widely used compounds tri-n-butyl tin oxide (TBTO) or tri-n-butyl tin naphthenate respectively. -linoleate (TBTN, TBTL).

The object of the present invention is thus the aforementioned compounds, in particular the reaction products with the hydrogenation product of dimeric fatty acids or fatty acid esters, preferably the dimeric tall oil fatty acid or by polymerization of unsaturated fatty alcohols obtained dihydric alcohols, preferably with chain lengths of C^^ to C^g, as well as biocidal agents containing these compounds as active ingredients.

The object of the invention is further the use of these agents for combating fungi, algae, bacteria and underwater fouling organisms as well as in particular the use of the agent for wood protection for combating wood-damaging organisms.

The polyhydric alcohols used according to the invention are hydration products of dimeric fatty acids with a hydroxyl number of approx. 186 - 210 which are commonly known as dimer diols.

The term dimerized fatty acid generally refers to polymerized acids obtained from "fatty acids". The term "fatty acid" includes unsaturated, natural and synthetic monobasic, aliphatic acids of 12 to 22 carbon atoms, preferably 18 carbon atoms. These fatty acids can be polymerized by known methods (see DE-OS 14 43 938, DE-OS 14 43 968, DE-PS 21 18 702 and DE-PS 12 80 852).

Typical polymeric fatty acids available commercially have approximately the following composition:

The content of dimeric acids can be increased by commonly known distillation methods to up to 100% by weight.

The hydrogenation of the dimeric fatty acids to the corresponding alcohol takes place by known methods (DE-OS 17 68 313).

The polyhydric alcohols used according to the invention can optionally be produced by polymerization of unsaturated fatty alcohols in the presence of catalysts (DE-AS 12 07 371, DE-AS 11 98 348).

Preferred starting materials here are polyunsaturated fatty alcohols with 12-24 carbon atoms in the molecule as well as their mixtures with mono-olefinically unsaturated and saturated alcohols with corresponding chain length, such as e.g. allyl alcohol. Such mixtures, especially those with a high number of polyunsaturated C^g-alcohols, can be extracted in a known manner from highly unsaturated, drying or non-drying oils by reduction of the fatty acids contained therein such as e.g. linseed oil fatty acid, soybean oil fatty acid, tall oil fatty acid, cottonseed oil. The content of the starting material of polyunsaturated fatty alcohols must amount to at least 5% by weight, preferably more than 10% by weight. In such cases where the content of the starting material of unsaturated alcohols is relatively high, i.e. above 40 - 50%, an isomerization with the formation of conjugated double bonds (e.g. by heating in the presence of strong alkalis) can occur.

The polymerization is conveniently carried out under pressure i

an autoclave, and the reaction mixture is then worked up in the usual way by filtration and distillation. You get two-

or polyhydric alcohols which exist as yellow-coloured, clear liquids. They consist of 75 - 90% of dimeric diols and 25 - 10% of high molecular weight, preferably trimeric, trihydric alcohols, whereby, depending on the type of distillation, amounts of monomeric, monohydric alcohols may still be present.

The alcohols are offered as commercial products by different manufacturers under their different product names on the market.

The compounds according to the invention can be produced

in a manner known per se by reaction of essentially stoichiometric amounts of tri-n-butyl tin oxide and the corresponding alcohols, the reaction partners being heated in suitable solvents such as xylene or toluene, under reflux, and the reaction water is azeotropically distilled off. If tri-n-butyltin chloride is used as starting product, an analogous procedure is used, and the aqueous hydrochloric acid formed is removed azeotropically, or by addition of alkali hydroxides.

Due to their excellent biocidal properties and their high persistence, the compounds according to the invention thus provide materials equipped with a high biocidal duration effect.

They can therefore be used as an active ingredient in wood and textile preservatives, disinfectants or also for preserving paint, glue, sealants and drilling oils as well as anti-fouling active ingredients.

The agents according to the invention can be used in particular for wood protection as, in addition to the prevention of decay caused by wood-destroying fungi, protection is also achieved against wood-staining fungi and bacterial attack. Bacteria do not cause any degradation of wood, but can favor attacks by fungi.

The agents are used in the form of solutions, possibly with coloring and auxiliaries, in the wood by brushing, spraying, showering or immersion.

Furthermore, the agent according to the invention can be used for biocide treatment of textiles, plastics and building materials, as they are suitably used in the form of preparations such as solutions, emulsions, dispersions with or without a binder or with solid carriers or diluents and possibly with the addition of wetting, binding, emulsifying and dispersing aids.

The active ingredient concentration is generally in the range from 0.05 to 50% by weight and is determined by the requirements for use and the absorbency of the substrate.

For wood protection, solutions of the agent according to the invention are preferably used in the petrol fraction, possibly with the addition of penetration-promoting agents, binders or other solvents, in concentrations of 0.05 to 5% by weight and in amounts of 50 to 400 g of active ingredient solution per m 2 wooden surface by ironing, spraying and similar application.

A very effective wood protection is achieved when the agent according to the invention, dissolved in suitable substances, is introduced into the wood by special technical methods, e.g. the double-vacuum method, the vacuum method or the vacuum-pressure method, so that an introduction of 0.1 to 3.0 - preferably 0.3 to 1.0 - kg of active substance per m 3 wood, is achieved.

With the agents according to the invention, it is also possible by mixing suitable emulsifiers, e.g. non-ionic types, water-thinning preparations are produced which can also be used for wood protection, e.g. by applying, dipping, etc., with emulsions, which contain 0.5 to 3% by weight of active substance.

To protect wood preparations, the agents according to the invention can be added in the form of highly concentrated solutions, or formulations with emulsifiers; to-

the binder or adhesive in amounts of 0.1 to 2% by weight,

calculated for the active substance.

For the protection of textiles, e.g. cotton clothes, against microorganisms the agent can be applied from solutions, e.g.

in ethanol, xylene, ketones, with active substance concentrations of 0.05 to 3% by weight by means of spraying or dipping, as hydrophobizing agents can be added if necessary.

In order to increase the spectrum of active substances, to achieve particular effects against special microorganisms or insecticidal treatment, the agent according to the invention can be combined with other active substances, until this is e.g.

3-iodo-2-propynylbutyl carbamate,

copper naphthenate,

copper-8-oxyquinoline,

N-cyclohexyl-N-methoxy-2,5-dimethylfuran-3-carboxylic acid amide,

N,N-dimethyl-N'-phenyl-N<1->fluorodichloromethyl-thiosulfonyl-diamide,

N-trichloromethylthiophthalimide,

T-hexachlorocyclohexane,

permethrin,

suitable.

Manufacturing examples

Example 1

1 mol of dimer diol on a tall oil fatty acid basis (570 g) with an equivalent weight of 285 and a hydroxyl number of 197 is heated with 1 mol of TBTO (598 g) in 1,000 ml of xylene under reflux.

During approx. After 3 hours, the reaction water formed is azeotropically distilled off. After separation of the solvent, a yellowish, medium-viscous product with a tin content of 20.0% is obtained. The product (TBT-DD) is easily soluble in organic solvents such as alcohols, ketones, chlorinated hydrocarbons and petrol, but on the other hand is poorly soluble in water.

Example 2

540 g of a polyhydric alcohol (the dimerization product of a hydrogenated linseed oil fatty acid methyl ester with a hydroxyl number of 208 and an iodine number of 120) is heated with 1 mol of TBTO (598 g)

for about. 1,000 ml of xylene under reflux. During approx.

After 4 hours, the reaction water formed is azeotropically distilled off. After separation of the solvent, a yellow-coloured, microviscous product with a tin content of 20.7% is obtained. The product (TBT-DA) is easily soluble in petrol, alcohols, chlorinated hydrocarbons and ketones, but, on the other hand, is poorly soluble in water.

Formulation examples

Example 1

A colorless, low-binder wood protection primer consisting of

shows a good penetration ability and can be used very well as a wood protection primer for building wood.

Example 2

A colored wood protection glaze consisting of

Example 3

A water-thinning active ingredient combination consisting of

can be diluted with water in a wide range (1:5 to 1:50) and gives stable emulsions for applying, spraying or dipping e.g. freshly felled wood. In undiluted formulations, concentrations of 0.2 to 3% by weight are used for biocidal treatment of aqueous coating systems, e.g. acrylate-based dispersions.

Example 4

An active ingredient solution for biocide treatment of textiles, e.g. cotton canvas consisting of

can be applied to the materials to be treated either by spraying the solution or by dipping.

Examination of the durability of wood

The durability of biocidal wood preservatives can be determined by storage tests. Below, wooden blocks of pine wood in size 5.0 x 2.5 x 1.5 cm are soaked with solutions of the biocide to be tested, and after evaporation of the solvent they are stored for 4 weeks at 20°C and then for 2 weeks at 80°C.

The wooden blocks are then crushed and extracted for 24 hours with ethanol/HCl solution (0.3% HC1).

In the extracts, both the total tin and the tributyltin content are determined.

While the tri-n-butyltin compounds TBTO and TBTN show a decrease in the tributyltin content to 40 - 48% according to the load in the duration tests, the decrease in TBT-DD is resp. TBT-DA significantly lower. After the storage trial, more than 75% tributyltin compound is returned.

Biocidal effect

The tributyltin compounds according to the invention have a very strong biocidal effect against numerous bacteria and fungi.

To determine the biocidal effect, round paper filters with a diameter of 5.5 cm are soaked in graduated concentrations of the tributyltin compound in ethanol and, after drying, examined in the agar application test against fungi and bacteria. The size of the inhibition zone around the sample (in mm) serves as a measure of the biocidal effect.

Claims (6)

1. Tri-n-butyltin compounds obtained by reacting tri-n-butyltin oxide or tri-n-butyltin halides with dihydric alcohols with an average hydroxyl number of approx. 200 and an average equivalent weight of approx. 280, which is obtained by hydration of dimeric fatty acids or fatty acid esters or by polymerization of unsaturated fatty alcohols. 2. Tri-n-butyltin compound according to claim 1, characterized in that the dihydric alcohol is obtained by hydrogenating dimeric tall oil fatty acids. 3. Tri-n-butyltin compounds according to claim 1, characterized in that the dihydric alcohol is obtained by polymerization of unsaturated fatty alcohols. 4. Biocidal agent, characterized in that it contains as active ingredient one or more of the turnover products according to claims 1 to 3. 5. Use of the biocidal agent according to claim 4 for combating bacteria, fungi, algae and underwater growth organisms. 6. Use of biocidal agents according to claim 4 in wood protection for combating wood-damaging microorganisms.