NO840652L - BACTERICIDE AND FUNGICIDE EFFECTS - Google Patents

Abstract

1. Method for the treatment of wood against wood-colonizing fungi and bacteria, characterized in that a biocidal material is used which contains as active ingredients the components (a) trialkyltin compounds of the general formula R3 SnX where R represents propyl or butyl and X represents the acid group of an organic or inorganic acid or -OSnR3 , (b) methylenendithiocyanate in a weight ratio of 5:1 to 1:3 especially 5:2 to 1:1.

Description

The bactericidal and fungicidal effect of trialkyltin compounds is known. The optimum effect for this class of compounds generally occurs when the total number of carbons in the alkyl groups bound to tin is 9-12.

Shorter or longer groups impair the biocidal activity (Bokranz, Plum, Fortschritte der chemischen Forschung,

Vol. 16, Heft 3/4, p. 377). The trialkyltin compounds do indeed exhibit a relatively broad spectrum of action, in particular against brown rot fungi, but the action against various microorganisms, for example gram-negative bacteria and certain blue and mold fungi, is however relatively weak.

Methylenedithiocyanate shows good effects against basidiomycetes and certain blue and mold fungi, as well as against heat-loving fungal species. Against bacteria as well as certain moulds, blue- or molds such as Penicillium funiculosum, Aspergillus versicolor, Trichoderma viride, Chaetomium globosum, Pullularia pullulans and Cladosporum herbarum/ the effect is significantly lower.

Water-soluble formulations of the trialkyltin compounds, e.g. admixtures with emulsifiers do indeed show stable dilutions, but the spectrum of action for different conservation applications, e.g. freshly cut wood is not sufficient.

From the trialkyltin compounds with quaternary ammonium compounds, which likewise have a fungicidal effect, water-dilutable mixtures can be formulated which, admittedly, exhibit a somewhat wider spectrum of action than the trialkyltin compounds, but the dilutions are not stable. After a certain time, flocculation, deposition and phase separation take place.

Methylene dithiocyanate is offered commercially in a water-dissolvable formulation. The dilutions already show deposits and an early sedimentation after a few hours' delay. Furthermore, the spectrum of action of methyl dithiocyanate for certain applications, e.g. protection of freshly cut wood/not sufficient.

The aim of the present invention was to provide an agent for the treatment of wood against wood-colonizing fungi and bacteria which showed a good effect against a wide range of different microorganisms, whose undiluted formulation was storage and transport stable with an emulsifier, and which for use in the preservation of different materials can be tinned with water by a simple mixture.

The resulting aqueous dilutions should also not show any separation, deposition or flocculation after longer storage times.

It has now surprisingly been found that mixtures of trialkyltin compounds and methylenedithiocyanate meet this objective. They exhibit a synergistic biocidal effect,

i.e. the effect of such mixtures is greater than the individual components. The synergistic effect is shown on various microorganisms such as bacteria, molds and fungi, in particular Bacillus vulgaris, Trichoderma viride, Pullularia pullulans and Cladosporum herbarum.

From the new active substance mixtures, stable results can be produced with emulsifiers, which when diluted with water give stable, clear or opalescent preparations.

The invention thus relates to a means for treating wood against wood-colonizing fungi and bacteria, containing an active ingredient mixture from

a) trialkyltin compounds of general formula R^SnX^ in which

R denotes the propyl or butyl residue and X denotes the acid residue

of organic or inorganic acids or denotes -OSnR^,

b) methylene dithiocyanate.

Preferably, the active substances are used in a weight ratio of 5:1

to 1; 3, in particular 5:2 to 1:1.

A particularly preferred water-dilutable agent is obtained when the active substances, dissolved in a sufficient amount of a suitable solvent, also contain common emulsifiers in a weight ratio of 3:1 to 1:3, calculated for the active substance mixture.

The concentrates thus obtained are stable. Their aqueous dilutions, which are obtained by simple mixing with water, show no separation, deposits or flaking, even after longer storage.

Preferably used. the emulsifier a non-ionic emulsifier of the type alkylaryl polyglycol ether or carboxylic acid polyglycol ether•

Preferably, the new agent combined with an emulsifier contains 10 to 40% by weight of active ingredient, calculated on the total formulation.

Methylenedithiocyanate is suitably used in the commercially available form, i.e. dissolved in a suitable solvent, e.g. isopropanol, dimethylformamide.

As emulsifiers, those based on ethoxylated alkyl and/or aryl phenols, n-alkylbenzene sulphonates, carboxylic acid polyglycol esters can be used.

As organotin compounds, those of the general formula are used where X is only of minor importance for the biocidal effect (Bokranz, Plum, loe. eit.). Preferably, it is used as trialkyltin compounds:

tri-n-butyltin oxide

tri-n-butyltin naphthenate

tri-n-butyltin linoleate

tri-n-butyltin benzoate

tri-n-butyltin nabietate

tri-n-butyltin tallate

tri-n-butyltin dihexyl borate

tri-n-butyltin acetylsalicylate

tri-n-butyltin borate

tri-n-butyltin phosphate.

A number of further suitable triorganotin compounds are described, for example, in GB-PS 1 059 629, GB-PS 1 252 918. as well as in Ingham, Chemical Reviews, volume 60, 1960, p. 459 ff.

For specific areas of application, it may be appropriate to add an antifoam agent to the formulation, for example silicone antifoam in the order of 0.001-0.01% by weight, calculated on the formulation.

The new formulations with emulsifiers can be used in the form of aqueous dilutions to protect wood, e.g. for freshly cut wood which is easily attacked by bacteria and wood-fading fungi, and also for building wood which, through the synergistic effect of the new active substance combination, can be protected against wood-destroying and -fading fungi and also against bacterial attack. Bacteria usually do not cause any degradation of the wood, but can, however, favor an attack by fungi.

The application of the water-diluted new formulations to wood can be done by brushing, spraying or dipping, whereby the stability of the dilutions becomes particularly important.

For wood protection, the new formulations can be used

in combination with insecticides, such as e.g. carbamates, phosphoric acid esters, chlorinated hydrocarbons, pyrethroids.

Furthermore, the formulations diluted with water are suitable for biocidal treatment of various materials such as building materials, textiles, plastics, adhesives and leather.

The new formulations are also suitable for biocide treatment of aqueous coating systems, e.g. dispersions, as a drop preservative and for protection against attack on coating agents by bacteria and fungi, especially also against attack on water-based wood coating systems, e.g. alkyd resin dispersions of surface fungi.

When used, the active substance concentration in the dilutions is generally in the range from 0.1 to 5% for wood protection.

Example 1

Formulation containing 23% active ingredient

Weight ratio between tributyltin compounds and methylene dithiocyanate = 5:2

10 parts by weight of tri-n-butyltin linoleate

20 parts by weight 20% solution of methylenedithiocyanate in a mixture of dimethylformamide and isopropanol 30 parts by weight non-ionic emulsifier (Marlowet® ISM) The components were homogenized by stirring at room temperature and a clear mixture was obtained which diluted with tap water gave stable, clear to weak opal-like preparations.

Example 2

Formulation containing 15% active ingredient

Weight ratio between tributyltin compound and methylene dithiocyanate = 4:3

8 parts by weight of tri-n-butyltin naphthenate

30 parts by weight 20% solution of methylenedithiocyanate (see Example 1) 53 parts by weight non-ionic emulsifier (Marlowe EF) The components were homogenized by stirring at room temperature and a clear mixture was obtained which, diluted with tap water, gave stable, clear to slightly opal-like preparations .

Example 3

Formulation containing 28% active ingredient

Weight ratio between tributyltin compound and methylene dithiocyanate = 5:2

10 parts by weight of tri-n-butyltin dihexyl borate

20 parts by weight 20% solution of methylene dithiocyanate (see Example 1) 20 parts by weight non-ionic emulsifier (Marlowe^ SLS). The components were homogenized by stirring at room temperature and a clear mixture was obtained which, diluted with tap water, gave stable, clear to slightly opal-like preparations.

Exeirtpél 4

Formulation containing 20% active ingredient

Weight ratio between tributyltin compound and methylenedithiocyanate = 3:1

6 parts by weight of tri-n-butyltin acetylsalicylate

10 parts by weight of a 20% solution of methylenedithiocyanate (see Example 1) 25 parts by weight of non-ionic emulsifier (Marlowet® EF) The components were homogenized with stirring at room temperature and a clear mixture was obtained which, diluted with tap water, gave stable, clear to opal-like preparations .

Example 5

Formulation containing 25% active ingredient

Weight ratio between tributyltin compound and methylenedithiocyanate = 2:1

20 parts by weight of tri-n-butyltin naphthenate

50 parts by weight 20% solution of methylenedithiocyanate (see Example 1) 50 parts by weight non-ionic emulsifier (Marlowet® ISM) The components were homogenized by stirring at room temperature, and a clear mixture was obtained which, diluted with tap water, gave stable, clear to opal-like preparations.

Example 6

Formulation containing 25% active ingredient

Weight ratio between tributyltin compound and methylene dithiocyanate = 5:4

10 parts by weight of tri-n-butyltin oxide

50 parts by weight 20% solution of methylene dithiocyanate (see Example 1) 95 parts by weight non-ionic/anionic emulsifier

(Marlowet<®>OF A)

The components were homogenized by stirring at room temperature and a clear mixture was obtained which, diluted with tap water, gave stable, clear to opal-like preparations.

Example 7

Formulation containing 17% active ingredient

Weight ratio between tributyltin compound and methylene dithiocyanate = 1:1

6 parts by weight tri-n-butyltin linoleate

30 parts by weight 20% solution of methylene dithiocyanate (see Example 1) 34 parts by weight non-ionic emulsifier (Marlowet® EF).

Example 8

Formulation containing 16% active ingredient

Weight ratio between tripropyltin compound to methylene dithiocyanate = 5:3

5 parts by weight of tri-n-propyltin borate

15 parts by weight 20% solution of methylenedithiocyanate (see Example 1) 30 parts by weight ionogenic emulsifier (Marlowet^ EF) The components were homogenized by stirring at room temperature, and a clear mixture was obtained which, diluted with tap water, gave stable, clear to opal-like preparations.

Example 9

Solvent-based wood primer with fungicidal effect Weight ratio between tributyltin compound and methylene dithiocyanate = 3:1

1.5 parts by weight of tri-n-butyltin phosphate

2.5 parts by weight of a 20% solution of methylenedithiocyanate

(see Example 1)

10 parts by weight 60% alkyl resin solution in white

spirit

4.5 parts by weight of diethylene glycol monobutyl ether

81.5 parts by weight white spirit (boiling range 180-210°C) The components were homogenized at room temperature. A clear, ready-to-use solution was obtained.

For comparison of the effects, paper round filters (diameter 5.5 cm) were dipped in the following aqueous solutions, were dried in air and were then placed in Petri dishes with Plate-Count-Agar which had been inoculated with bacterial suspension, and were incubated for 2 days at +37°C. Then the size of the inhibition zone on the filter was determined:

Following the method described in table 1, the paper round filter, sprayed with spore suspension of the test fungi, was placed on biomalt agar and incubated for 3 weeks at +30°C. Then the zone of inhibition around the sample was determined:

Claims (4)

1. Means for treating wood against wood-colonizing fungi and bacteria, characterized in that it contains an active substance mixture of a) trialkyltin compounds of general formula R^ SnX, in which R denotes the propyl or butyl residue and X denotes the acid residue of organic or inorganic acids or -OSnR3 b) methylene dithiocyanate, in a weight ratio of 5:1 to 1:3, in particular 5:2 to 1:1. 2. Water-dilutable agent according to claim 1, characterized in that the active ingredient f is dissolved in a sufficient amount of a suitable solvent, and that it also contains common emulsifiers in a weight ratio of 3:1 to 1:3, calculated for the active ingredient mixture. 3. Means according to claim 2, characterized in that a non-ionic emulsifier of the type alkylaryl polyglycol ether or carboxylic acid polyglycol ester is used as emulsifier. 4. Means according to claims 1-3, characterized in that the content of active substance in the mixture constitutes 10-40% of the total formulation.