EP0944317A1

EP0944317A1 - Microbicidal mixtures

Info

Publication number: EP0944317A1
Application number: EP97954368A
Authority: EP
Inventors: Wolfgang Lindner; Jörg ROTHERMEL
Original assignee: Riedel de Haen AG
Current assignee: Honeywell Riedel de Haen AG
Priority date: 1996-12-10
Filing date: 1997-12-09
Publication date: 1999-09-29
Also published as: DE19651351A1; WO1998025464A1; AU5854998A; US6228382B1

Abstract

A mixture containing as active agent a) 0.01 - 99.99 wt. % of at least one 2-alkylisothiazolin-3-on or at least one derivative thereof, or a mixture of at least one 2-alkylisothiazolin-3-on and at least one derivative thereof and b) 0.01 - 99.99 wt. % of a further, microbicidally effective compound, whereby the sum of a) and b) comes to 100 wt. % of the active agent of the mixture. It is characterized in that the at least one 2-alkylisothiazolin-3-on, or the at least one derivative thereof, has an octanol -water distribution coefficient (logPOW) of 3 to 5.

Description

Microbicidal mixtures

Coated technical or natural materials exposed to the weather are quickly colonized by microorganisms (microbes) such as bacteria, mold, yeast, lichen or algae and are damaged by their metabolic products. For example, plasters, for example on insulating layers such as polystyrene panels (thermal insulation systems), on exterior facades or in damp rooms such as swimming pools, quickly turn green to black due to algae growth.

Biocides, for example substances which have a microbicidal action, i.e. Substances that largely prevent the growth of microorganisms or biostatics, such as microbistatic substances, i.e. Substances that only inhibit the growth of microorganisms, in order to increase their lifespan and in particular to enable a long-lasting high optical quality of the coatings.

Objects such as leather, paper such as cardboard, plastics and the like, insofar as they are exposed to weathering outdoors or are used or stored in damp rooms, are exposed to growth by microorganisms. Such fouling can not only impair the usage properties of the items listed, as a rule the visual impression suffers much more, which usually represents a loss of value for the owner of the item concerned.

Examples of microbicides for the microbicidal treatment of the abovementioned objects and coating compositions are tributyltin compounds, 2-n- Octylisothiazolinone, carbendazim, 2-thiocyanatomethylthiobenzothiazol, terbutryn or diuron are used.

However, it has been found that the substances hitherto used for microbicidal treatment do not guarantee long-term protection against fouling. Most of the microbicides known from the prior art are washed out of the article equipped with them under the influence of moisture. This leads to a continuous decrease in the microbicidal active ingredient in the object concerned, the protection against microbial attack thus becoming zero over a more or less short period (depending on the moisture level). Another associated disadvantageous aspect is the high discharge of the microbicides into the environment.

The microbicides which are frequently used in practice include the isothiazolin-3-ones substituted in the 2-position, in particular the 2-n-octylisothiazoline-3-one. It is used in a number of substances and objects that are exposed to microbes such as algae, lichen, fungi and the like, for example when used and stored outdoors or in damp rooms. An example of an application is facade paint.

In the patents US-A 3,523, 121, US-A 3,761,488 and US-A 4,243,403, the preparation and the microbicidal properties of 2-alkylisothiazolinones, including 2-n-octyl, 2-n-nonyl and 2 - n-Decylisothiazolin-3-one. In the publications, however, no statement is made about the washout behavior of the compounds or about their combination with other biocides, in particular microbicides. The Nerbindungen used so far as microbicides often have an incomplete spectrum of activity when used alone. For this reason, combinations of several microbicides are often used in practice in order to achieve the broadest and most comprehensive spectrum of activity.

Commercial products which, in addition to 2-n-octylisothiazolin-3-one, contain other fungicidal and algicidal active ingredients (eg MERGAL ^® S 89 paste and MERGAL ^® S 90 paste) are commercially available.

However, this has the disadvantage that, as a rule, the 2-n-octylisothiazolin-3-one is partially washed out of the object equipped with it when exposed to moisture (for example in outdoor applications), and the active ingredient combination is thus withdrawn. This creates a "gap" in microbicidal protection, and it can be colonized by appropriate microbes.

The task was therefore to provide microbicides which meet the following requirements:

a) the broadest possible spectrum of activity as a microbicide, the fungicidal action also being intended to extend to fungi which are particularly resistant to fungicides, such as, for example, fungi of the genus Alternaria, Mucor or Ulocladium or yeasts,

b) a slight tendency to wash out from the microbicidal objects and substances. In particular, the task was to provide a replacement for 2-n-octylisothiazolin-3-one in microbicidal mixtures, which shows a comparable microbicidal effect, but is less washed out.

Surprisingly, it has now been found that mixtures of 2-alkylisothiazolin-3-ones, which have an octanol / water partition coefficient (logP _ow ) of 3 to 5, and further microbicidal compounds in objects equipped therewith show long-lasting activity against microorganisms. Furthermore, the above-mentioned mixtures have a broad spectrum of activity against microorganisms and offer extensive protection against growth by yeast, fungi, algae and lichens.

Furthermore, it was surprisingly found that the 2-alkylisothiazolin-3-ones in a mixture with one or more algicides for incorporation into materials such as plastic, leather, paper, wood, a sealant or a coating agent, both on an aqueous basis and on a solvent basis, are suitable and have a long-lasting microbicidal action there.

Furthermore, it was surprisingly found that the known fungicidal activity of the 2-alkylisothiazolin-3-ones also extends to fungi which are very resistant to fungicides, such as, for example, Alternaria, Mucor or Ulocladium or also to yeasts, which are particularly useful in food processing plants, e.g. can grow on wall coatings that have been treated with conventional fungicides.

The invention therefore relates to a mixture comprising as active substance a) 0.01 to 99.99% by weight of at least one 2-alkylisothiazolin-3-one or at least one derivative thereof or a mixture of at least one 2-alkylisothiazolin-3-one and at least one derivative thereof and

b) 0.01 to 99.99% by weight of at least one further, microbicidally active compound,

the sum of a) and b) making up 100% by weight of the active substance of the mixture, characterized in that the at least one

2-alkylisothiazolin-3-one or the at least one derivative thereof has an octanol-water partition coefficient (logP _ow ) of 3 to 5.

For the purposes of the invention, “active substance” means those substances present in the mixture which have a microbicidal action.

For the purposes of the invention, “derivatives” are understood to mean compounds whose basic chemical structure (ie the part responsible for the basic, generic action of the compound) corresponds to that of the originally designated compound, but which is intended to improve, adapt or otherwise modify a biological one , chemical or physical properties have been chemically changed. For example, a derivative of a 2-alkylisothiazolin-3-one can be a 2-alkylisothiazolin-3-one substituted in the 4-position with a halogen. Further derivatives of 2-alkylisothiazolin-3-ones are mentioned in the patents US-A 3,523, 121, US-A 3,761, 488 and US-A 4,243,403.

The term "octanol-water partition coefficient" denotes the decimal logarithm of the partition coefficient between n-octanol and water. The mixture according to the invention preferably contains about 1 to about 99% by weight, more preferably about 2 to about 98% by weight, of at least one 2-alkylisothiazolin-3-one or at least one derivative thereof or a mixture of at least one 2-alkylisothiazoline -3-one and at least one derivative thereof (component a)).

The 2-alkylisothiazolin-3-ones which can be used for the purposes of the invention have an octanol / water partition coefficient (logP _ow ) of from about 3 to about 5. However, the logP _o can have any values lying between these limits, for example about 3.2, about 3.5, about 3.9, about 4, 1, about 4.5, about 4.7 or about 4.9.

The substances defined in this way include, for example, the compounds which are branched or straight-chain in the alkyl chain

2-n-nonyl,

2-n-decyl,

2-n-undecyl,

2- (2,5,5-trimethyl) hexyl-, 2- (3,5,5-trimethyl) hexyl-,

2- (2-methyl) octyl,

2- (8-methyl) -nonyl-,

2- (5,7-dimethyl) octyl,

2- (3,5,7-trimethyl) heptyl and 2- (2,8-dimethyl) nonyl isothiazolin-3-one.

2-n-Nonylisothiazolin-3-one and 2-n-decylisothiazolin-3-one are particularly preferred. Component a) can contain the above-mentioned compounds alone or as a mixture of two or more thereof. If necessary, component a) can also contain further 2-alkylisothiazolin-3-ones, such as, for example, 2-n-octylisothiazolin-3-one, 4,5-dichloro-2-octylisothiazolin-3-one or 2-n-dodecylisothiazolin- 3- on, which have a logP _o other than 3 to 5, included. However, the proportion of such 2-alkylisothiazolin-3-ones in component a) should be less than 50% by weight, preferably less than 40% by weight and particularly preferably less than 30% by weight, based on the total weight of the Active substance.

The addition of such further 2-alkylisothiazolin-3-ones, which have very good activity but are washed out relatively quickly, can be used, for example, to offer particularly good protection in the initial phase of an application.

The abovementioned 2-alkylisothiazolin-3-ones can be prepared, for example, as in US Pat. No. 4,243,403 (in particular as described there in column 3, lines 48 to 6, line 33 or in the examples).

In addition to component a), the mixtures according to the invention also contain a further microbicidally active, preferably algicidally active component b) which is different from component a).

As component b) in the mixtures according to the invention, for example, benzimidazol-2-ylmethyl carbamate, thiabendazole, 2-thiocyanatomethyl-thiobenzothiazole, iodopropargylbutylcarbamate, methylene-bis-thiocyanate, zinc pyrithione, silver salts, tebuconacholodoleol, propiconazole benzol, propicon Imazalil or mixtures of two or more of them are used. However, component b) preferably contains exclusively, or at least in addition to other microbicidally active compounds, such as, for example, those mentioned above, at least one triazine or a urea derivative or a mixture of two or more thereof.

It is particularly preferably a compound or a mixture of two or more compounds of the general formula I.

where R ¹ and R ^{2 are} alkyl or cycloalkyl groups having 1 to 12 carbon atoms, preferably ethyl, tert-butyl and / or cyclopropyl

or

a compound or a mixture of two or more compounds of the general formula II

(π) where R ¹ and R ² each independently represent linear or branched alkyl groups having 1 to 12 carbon atoms, preferably methyl, R ³ and R ⁴ each independently represent chlorine, bromine, alkyl, trifluoromethyl or O-aryl, where Aryl can optionally be substituted with alkyl groups with up to 24 C atoms or with alkoxy groups with up to 12 C atoms, and R ^{5 represents} hydrogen, chlorine, bromine, fluorine or a linear or branched alkyl radical with 1 to 12 C atoms ,

or a mixture of two or more of the above compounds of the general formulas (I) and (II).

Preferred component b) are commercially available triazine and / or urea derivatives such as, for example, ametryn, desmetryn, dimethametryn, dipropetryn, methoprotryn, prometryn, terbutryn, 2-methylthio-4-cyclopropylamino-6-t-butylamino-l, 3, 5-triazine (Mctt), chlorobromuron, chlorotoluron, diuron, difenoxuron, fluorometuron, isoproturon or neburon or mixtures of two or more thereof. The 2-methylt-hio-4-cyclopropylamino-6-t-butylamino-1,3,5-triazine (Mctt) is particularly preferred.

If component b) contains mixtures of triazine and / or urea derivatives and other microbicidally active compounds which do not belong to the triazine or urea derivatives or to the compounds of component a), component b) contains the triazine and / or urea derivatives preferably at least in a proportion of approximately 1% by weight, particularly preferably in a proportion of at least approximately 10% by weight, in each case based on the total weight of the active substance, the upper limit of the triazine and / or urea derivative content in particular for economic reasons is 90% by weight. The microbicidal mixtures preferably have components a) and b) in a proportion of approximately 20 to 80% by weight, the sum of a) and b) each making up 100% by weight of the active substance of the mixture.

As a rule, the weight ratio between component a) and component b) is about 1:10 to about 10: 1, a weight ratio of about 1: 5 to about 5: 1 being preferred.

The mixtures according to the invention are generally formulated with additives such as solvents, emulsifiers, stabilizers, antioxidants and the like, for example for easier delivery or to facilitate a specific form of use. Mixtures of this type which, in addition to the active substance, contain further compounds which are not microbicidally active in comparison with component a) and component b) at an identical use concentration are called "preservatives" in the context of the present text.

The invention thus also relates to preservatives containing 1 to 99% by weight of a mixture of components a) and b), as defined in the context of this text, and 1 to 99% by weight of at least one component from the group

i) formulation auxiliaries ii) solvents iii) surfactants (emulsifiers, dispersants) iv) protective colloids v) UV stabilizers vi) defoamers vii) fillers viii) pigments

is selected.

Formulation aids i) include, for example, thickeners.

The mixtures according to the invention can be dissolved both in organic, essentially polar or non-polar solvents (ii) or in mixtures of such solvents and made available for later use. Such preservatives are then generally used in the manufacture of plastics, in the manufacture of solvent-based coating compositions or in the microbicidal treatment of other materials which may be exposed to the weather, such as e.g. Leather, sealing compounds, wood, textiles and adhesives. As solvents (ii), for example, glycols such as ethylene glycol, propylene glycol, butylene glycol or glycol ethers such as di- or polyethylene glycol or the corresponding higher glycol ethers such as di- or polybutylene glycol can be used. The glycols and glycol ethers can be capped on one or on both OH end groups with an alkyl group, preferably a methyl group. It is also suitable to use less polar solvents such as tetrahydrofuran, dioxane, alkyl esters of low molecular weight carboxylic acids with short-chain monohydric alcohols such as ethyl acetate or aliphatic or aromatic solvents such as n-alkanes such as n-hexane, cycloalkanes such as cyclohexane and aromatics , such as toluene and xylene, the optimum solvent depending on the field of application, depending on the hydrophilicity of the substrate.

A preservative according to the invention contains, for example

(I) 2-10 parts by weight of 2-n-nonylisothiazolin-3-one, (II) 3 - 10 wt .-% 2-methylthio-4-cyclopropylamino-6-tert-butylamino-l, 3,5-triazine (Mctt) and

(III) 80-95% by weight butyl glycol.

The mixtures according to the invention can also be prepared as an aqueous dispersion or emulsion. For this purpose, the mixture according to the invention is mixed with a surfactant (emulsifier or dispersant) (iii) which, depending on the field of application, can be anionic, cationic or nonionic, or optionally with a mixture of two or more surfactants, optionally together with other additives W ^τ stirred ater. The order in which the individual components are added is irrelevant.

Suitable surfactants (iii) are the anionic surfactants customary for the preparation of dispersions, such as, for example, the alkali metal salts of fatty alcohol sulfates, such as sodium lauryl sulfate, or aromatic sulfonic acids such as, for example, the alkali metal salts of toluenesulfonic acids. It is also possible to use nonionic surfactants such as nonylphenol ethoxylates. Due to the known compatibility problems, cationic surfactants should be avoided when painting.

An overview of surfactants (dispersants / emulsifiers) which can be used in accordance with the invention can be found, for example, in Römpp Chemie Lexikon, 9th edition, pages 1156 to 1158, and in the standard works of organic or especially surfactant chemistry known to the person skilled in the art.

In addition, in order to obtain a dispersion which is particularly stable over the long term, customary protective colloids (iv) such as, for example, polyvinyl alcohol or polyvinylpyrrolidone can be added. The preservatives can contain, for example, commercially available products such as Tinuvin (Ciba-Geigy), Sanduvor (Sandoz) and Oxybenzone (2-hydroxy-4-methoxybenzophenone, HMB) (Riedel-de Haen) as UV stabilizers (v).

Defoamers (vi) for use in the preservatives according to the invention are, for example, commercially available products, such as Defoamer WO 150 (Worlee-Chemie), defoamer FN (Hoechst AG), AGITAN 280 (Nopco-Münzing) and NOPCO 8034 E (Nopco-Münzing) are suitable.

Suitable fillers (vii) or pigments (viii) for the preservatives according to the invention are, for example, commercially available products, such as China clay (aluminum silicates), kaolin, calcium carbonate (chalk, natural or precipitated), e.g. OMYACARB 130 (Omya), titanium dioxide, e.g. TIOX-YDE TR 92 (Tioxyde Group PLC), Lithopone (Sachtleben), cellulose derivatives, e.g. Tylose H 300 (Hoechst AG), xanthan derivatives, e.g. Kelzan S (Kelco), and modified layered silicates, e.g. Bentone (southern chemistry).

The preservatives prepared in this way contain the compounds of component a) depending on the desired application in an amount of about 1 to about 99% by weight, preferably in an amount of about 1 to about 50% by weight and particularly preferably in an amount of about 2.5 to about 25% by weight. Component b) is preferably in an amount of about 1 to about 99% by weight, preferably in an amount of about 1 to about 50% by weight and particularly preferably in an amount of about 2.5 to about 30% by weight. -% in front.

The mixtures according to the invention are notable for high activity and a broad spectrum of activity against algae such as, for example, Chlorella fusca and cyanobacteria such as, for example, Nostoc commune. Also particularly resistance Capable algae that are insensitive to the microbicides commonly used are detected by the mixtures according to the invention.

Accordingly, the present invention also relates to the use of a mixture according to the invention or a preservative which contains the mixture according to the invention, as defined above, for the microbicidal treatment of a plastic, leather, paper, wood, a sealant or a coating composition, preferably an aqueous coating means, such as a paint.

The invention further relates to materials or objects, such as e.g. a plastic, for example PVC, polyurethane, polyisobutylene, leather, paper, wood, a sealant or a coating agent, preferably an aqueous coating agent, for example a paint, in particular a paint for wood or a mineral substrate, such as e.g. Concrete or stone containing one of the mixtures according to the invention or one of the preservatives according to the invention as defined in the context of this text.

The articles or materials described above, preferably the coating compositions, generally contain from about 0.001 to about 5% by weight, preferably from about 0.005 to about 3% by weight, of the mixture defined above.

The term “coating agent” as used in the context of the present application refers both to coating agent as material for coatings, such as paints and plastering materials, and to the finished coatings themselves, such as paints on buildings and building plasters. Materials which contain one of the mixtures according to the invention or one of the preservatives according to the invention are also notable for high, long-lasting resistance to a large number of yeasts, such as, for example, Candida albicans, Torula utilis, Saccharomyces cerevisiae, molds, such as, for example, Cladosporum resinae, Fusarium spec , Mucor spec, Alternaria spec, Ulocladium spec, Penicillium funiculosum, Chaetomium globosum, Trichoderma viride, Sclerophoma pityophila and wood-fading and discoloring fungi such as, for example, Aureobasidium pullulans.

The mixtures and preservatives according to the invention are eminently suitable for use in the production of sealants or coating compositions based on solvents or water. Due to the advantageous properties with regard to the incorporation of the microbicidal active ingredient or the mixture of microbicidal active ingredients into the sealant or the coating composition, these can be formulated in such a way that the microbicides make no contribution to the emission of volatile organic carbon compounds (VOC). Surprisingly, the mixtures and preservatives according to the invention and used according to the invention do not significantly or not at all influence the mechanical properties of the seal or coating.

The use concentration of the mixtures or preservatives according to the invention in the objects equipped therewith, in particular in the sealants or coating compositions, is generally such that the concentration of microbicidal active ingredient is from about 0.001 to about 5% by weight, preferably from about 0.005 to about 3 % By weight and particularly preferably from about 0.05 to about 1% by weight, in each case based on the weight of the entire article, in particular based on the sealant or the coating agent. All coating agents customary in the coating industry are suitable as coating agents for the equipment according to the invention. In particular, these are polystyrene resins, vinyl ester resins, such as, for example, vinyl acetate resins, polybutadiene resins, acrylonitrile-butadiene-styrene copolymers, alkyd resins, polyacrylate resins, melamine-formaldehyde condensates.

Aqueous polymer dispersions, such as those based on acrylates, styrene acrylates, vinyl esters and their copolymers, serve, for example, as binders in paints and plasters. In addition to the binder, there are thus further functional components in the coating compositions. Pigments, fillers, auxiliaries such as film formers, defoamers, UV stabilizers and water repellents should be mentioned in particular. MOWILITH ^® DM 771 from Hoechst AG is an example of an advantageous coating agent which is excellently suitable for outdoor applications.

If appropriate, the preservative according to the invention can be formulated in such a way that it already contains one or more of the functional components provided in the coating composition. If necessary, this can be one or a mixture of several of the components listed in this text under i) to ix).

The production of the above Coating agent is carried out by stirring a mixture or preservative according to the invention with the corresponding coating agent which is to be treated with a microbicide.

The mixtures according to the invention can be introduced or applied in pure form or as a preservative, as stated above, into the article, preferably into the sealing compound or into the coating agent. The invention further relates to the use of at least one 2-alkylisothiazolin-3-one or at least one derivative thereof or a mixture of at least one 2-alkylisothiazolin-3-one and at least one derivative thereof, the at least one 2-alkylisothiazolin-3 -one or the at least one derivative thereof has an octanol-water partition coefficient (logP _ow ) of 3 to 5, for preventing the growth of photoorthotrophic microorganisms and for preventing the growth of fungi of the genus Alternaria, Mucor or Ulocladium and yeast , preferably each in a plastic, in leather, paper, wood, a sealant or a coating agent, preferably a coating agent.

The following examples serve to illustrate the invention. Unless otherwise stated, quantities such as percentages or parts are to be understood as percentages by weight or parts by weight and are based on the weight of the entire formulation.

EXAMPLES

example 1

The octanol / water distribution coefficient was determined using the HPLC method according to OECD Guideline 117 from the retention times on an RP-18 chromatography column. Biphthalic acid alkyl esters (Handbook of Environmental Fate and Exposure Data, Vol. 1, 1989) were used as comparison substances with a known octanol / water partition coefficient. Table 1: Determination of the Qctanol-Water Partition Coefficients (logP _ow )

Example 2: Determination of the relative leaching rate from facade paint

First 128 parts by weight (GT) of water were introduced. 11 pbw of 10% by weight Calgon N solution (sodium triphosphate) were then stirred into the water. Subsequently, 2 GT Tylose MHB 6000 (Hoechst AG), 3 GT Additol XW 330 (Hoechst AG), 4 GT Agitan 260 (Münzing-Chemie, Heilbronn), 226 GT titanium dioxide (e.g. Kronos 2065) , 375 GT ^® MOWILITH DM 771 (50%) (Fa. HOECHST) 84 Omyacarb 5 GT (Fa. Omya), 84 GT Micro Mica Wl, 38 GT Micro AT Tale 1, 20 parts china clay D was added and homogenized . In the mixture thus obtained 11 GT white spirit, 8 GT butyl diglycol acetate and 4 GT ^® Mergal K 9 N (Riedel de Haen) were stirred. The pH of the facade paint thus obtained was 8.8.

The preservatives listed in Table 2 were homogeneously dispersed into the facade paint thus obtained. Table 2

The color sample obtained in this way was in each case drawn onto a film at about 150 g / m ² on paper using a doctor blade. The paint sample thus prepared was then dried at a temperature of 30 ° C for 72 hours.

Test specimens with a diameter of 5.5 cm were punched out of the paint sample. To simulate leaching by rainwater, these test specimens coated with paint were washed in tap water (46.7 l / day / m ² paint). Specimens were removed after 24 hours and air dried for 72 hours.

To determine the microbicide concentration, one sample body was extracted in methanol. The methanol extracts were analyzed by HPLC.

HPLC conditions: column: RP-phenyl (Hypersil 5 μ)

Eluent: gradient water-acetonitrile

UV detector: 220 nm and 200 nm Since the substances listed in Table 3 were recorded as areas under the HPLC signal in each analysis, the leaching rates can be directly related to the known active ingredients OITZ and Mctt.

Table 3

After washing for 96 hours, the residual concentration of the known OITZ is only 0.7% of the Mctt concentration used at the same time. After a corresponding weathering period, the fungicide / algicide ratio is no longer suitable for extensive film preservation.

With the compounds NITZ and DITZ according to the invention, the leaching characteristics are much better matched. After 96 hours one is at 26% or 91.9% of the residual Mctt concentration. Even after leaching The fungicide / algicide ratio is therefore suitable for comprehensive film preservation.

Example 3: Determination of the long-term protection of a facade color against fungal growth

Analogously to Example 1, fungicides were stirred into samples of a facade paint according to Example 1, paint samples were prepared and watered. To test protection against fungal growth, the paint samples prepared in this way were sterilized under UV light and applied to fungal nutrient media in petri dishes which had previously been inoculated with a spore mixture of the Aspergillus niger and Penicilium funiculosum test fungi. The Petri dishes were then stored for 7 days at 29 ° C. in a warming cabinet at 80% relative humidity. The growth of the test fungi on the sample coats and the nutrient media was then assessed according to the following scheme:

OH test specimen not overgrown, inhibition zone on the nutrient medium

0 DUT not overgrown 1 DUT slightly overgrown, less than 10% of the surface

2 test specimen overgrown, 10 to 30% of the surface

3 DUT significantly overgrown, 30 to 60% of the surface

4 DUT heavily overgrown, over 60% of the surface

Table 4 - Fungal growth

Rating:

The paint finished with the comparative product OITZ is well protected against fungal growth without exposure to the weather. After 96 hours of soaking, however, this protection is completely lost. The comparative product Dodecyl-ITZ, on the other hand, is not sufficiently effective in color even when it is not weathered.

The active ingredients NITZ and DITZ according to the invention keep the paint surface largely free of fouling even after exposure to weathering. The fungicidal protection deteriorates only slightly when weathered.

Example 4: Determination of the long-term protection of a facade color against fouling with Ulocladium consortiale

The procedure was as described in Example 3. Table 5 - Long-term protection against Ulocladium consortiale

Example 5: Testing of algatic film preservation

0.025% DITZ and 0.025% finely ground Mctt were incorporated into a microbicide-free, commercially available facade filler based on an acrylic dispersion.

For comparison, a color sample of the same type was equipped with 0.025% Mctt and OITZ according to the prior art.

The color samples thus obtained were each coated at 300 g / m ² on round filter papers (No. 597 from Schleicher & Schüll, diameter 5.5 cm) and then dried at a temperature of 30 ° C. for 72 hours.

To simulate rainwater leaching, the test specimens coated with paint were soaked in tap water for 96 hours. The leaching water was changed every 24 hours. The growth resistance against algae was tested on solid Bold algae nutrient media. After double-sided sterilization under UV light, the dry test specimens were placed on the culture media in petri dishes. In each case 5 ml of a well-grown algae culture in Bold nutrient solution was inoculated onto the surface to be tested under sterile conditions, so that the color surface was pale green in color.

After a incubation period of 14 days at a temperature of 22 ° C, the degree of fouling with algae on the paint coats was assessed visually on a scale from 0 to 4:

0 paint not overgrown

1 coat slightly overgrown, under 10% of the surface 2 coat overgrown, 10 to 30% of the surface

3 coats overgrown, 30 to 60% of the surface

4 coat overgrown, over 60% of the surface

Table 6 - Testing of algistatic film preservation

Claims

PATENT CLAIMS

1. Mixture containing as active substance

a) 0.01 to 99.99% by weight of at least one 2-alkylisothiazolin-3-one or at least one derivative thereof or a mixture of at least one 2-alkylisothiazolin-3-one and at least one derivative thereof and

the sum of a) and b) 100% by weight of the active substance of

Mixture, characterized in that the at least one 2-alkylisothiazolin-3-one or the at least one derivative thereof has an octanol-water partition coefficient (logP _ow ) of 3 to 5.

2. Mixture according to claim 1, characterized in that it is as component b)

at least one compound of general formula I.

where R ¹ and R ^{2 are} alkyl or cycloalkyl groups having 1 to 12 carbon atoms, preferably ethyl, tert-butyl and / or cyclopropyl,

or

at least one compound of the general formula II

where R ¹ and R ² each independently represent linear or branched alkyl groups having 1 to 12 carbon atoms, preferably methyl, R ³ and R ⁴ each independently represent chlorine, bromine, alkyl, trifluoromethyl or O-aryl, where Aryl can optionally be substituted with alkyl groups with up to 24 C atoms or with alkoxy groups with up to 12 C atoms, and R ^{5 represents} hydrogen, chlorine, bromine, fluorine or a linear or branched alkyl radical with 1 to 12 C atoms ,

or contains a mixture of two or more of the above compounds of general formulas I and II.

3. Mixture according to claim 1 or 2, characterized in that it is as component a)

2-n-nonyl, 2-n-decyl, 2-n-undecyl, 2- (2, 5, 5-trimethyl) hexyl,

2- (3, 5, 5-trimethyl) hexyl,

2- (2-methyl) octyl,

2- (8-methyl) -nonyl-,

2- (5, 7-dimethyl) octyl,

2- (3,5,7-trimethyl) -heptyl- or

2- (2, 8-dimethyl) nonyl isothiazolin-3-one

or contains a mixture of two or more thereof.

4. Preservatives containing 1 to 99 wt .-%, a mixture according to any one of the preceding claims and 99 to 1 wt .-% of at least one component from the group

i) formulation auxiliaries ü) solvents iü) surfactants iv) protective colloids v) UV stabilizers vi) defoamers vii) fillers viii) pigments

is selected.

5. Preservative according to claim 4, characterized in that it

(I) 2-10% by weight of 2-n-nonylisothiazolin-3-one,

(II) 3 - 10 wt .-% 2-methylthio-4-cyclopropylamino-6-tert-butylamino-l, 3,5-triazine and (III) 80-95% by weight butyl glycol

contains.

Use of a mixture according to one of claims 1 to 3 or a preservative according to claim 4 or 5 for the microbicidal treatment of a plastic, leather, paper, wood, a sealant or a coating agent, preferably an aqueous coating agent.

7. Objects or materials, preferably a plastic, leather, paper, wood, a sealant or a coating agent, preferably an aqueous coating agent, containing a mixture according to one of claims 1 to 3 or a preservative according to claim 4 or 5.

8. Coating composition according to claim 7, characterized in that it contains 0.001 to 5% by weight, preferably 0.005 to 3% by weight, of a mixture according to one of claims 1 to 3 or a preservative according to claim 4 or 5.

9. Use of at least one 2-alkylisothiazolin-3-one or at least one derivative thereof or a mixture of at least one 2-alkylisothiazolin-3-one and at least one derivative thereof, the at least one 2-alkylisothiazolin-3-one or the at least one a derivative thereof has an octanol / water partition coefficient (logP _o ) of 3 to 5, for preventing the growth of photoautotrophic microorganisms and / or for preventing the growth of fungi of the genus Alternaria, Mucor or Ulocladium and yeast, preferably in each case in a plastic, in leather, paper, Wood, a sealant or a coating agent, preferably an aqueous coating agent.