Aqueous fungicidal composition and use thereof for combating harmful micro organisms

Abstract

The invention relates to aqueous fungicidal active substance compositions and to their use in the control of harmful microorganisms and in particular in the protection of cellulose-comprising materials, particularly wood, from infection by microorganisms, in particular those harmful fungi which can damage wood or cellulose. The active substance composition according to the invention comprises: a) at least one fungicidal organic active substance with a solubility in water of not more than 5 g/l at 25 C./1013 mbar, and b) a finely-divided polymer with an average particle size, determined by dynamic light scattering, of not more than 300 nm, in which the polymer particles comprise the active substance, the polymer being formed from ethylenically unsaturated monomers M comprising: at least 60% by weight, based on the total amount of the monomers M, of at least one neutral monoethylenically unsaturated monomer M1 with a solubility in water of not more than 30 g/l at 25 C., and up to 40% by weight, based on the total amount of the monomers M, of one or more ethylenically unsaturated monomers M2 other than the monomers M1.

Claims

1. A process for the protection of cellulose-comprising materials from infection by microorganisms comprising the treatment of the cellulose-comprising material with an aqueous active substance composition, said composition comprising (a) at least one fungicidal organic active substance with a solubility in water of less than 1 g/l at 25 C./1013 mbar, and (b) a finely-divided polymer with an average particle size, determined by dynamic light scattering, of 10 to 250 nm, in which the polymer particles comprise the active substance, the polymer having a glass transition temperature of at least 10 C. and being formed from ethylenically unsaturated monomers M consisting of: from 70 to 99.5% by weight, based on the total amount of the monomers M, of at least one neutral monoethylenically unsaturated monomer M1 with a solubility in water of not more than 30 g/l at 25 C., which is selected from styrene and esters of monoethylenically unsaturated mono- or dicarboxylic acids with C1-C10-alkanols or C5-C8-cycloalkanols, and from 0.50 to 30% by weight, based on the total amount of the monomers M, of at least one ethylenically unsaturated monomers M2, which is selected from: monoethylenically unsaturated monomers M2a exhibiting at least one acid group or at least one anionic group, the amount of monomers M2a being not more than 20% by weight, based on the total amount of the monomers M; monoethylenically unsaturated neutral monomers M2b exhibiting a solubility in water of at least 50 g/l at 25 C., the amount of monomers M2b being not more than 10% by weight, based on the total amount of the monomers M; and not more than 2% by weight, based on the total amount of the monomers M, of monomers having two or more nonconjugated ethylenically unsaturated double bonds, wherein the aqueous active substance composition is obtained by a process comprising radical aqueous emulsion polymerization of an oil-in-water emulsion of the monomers M, the monomer droplets of the oil-in-water emulsion to be polymerized comprising the fungicidal active substance in dissolved form.

2. The process according to claim 1, wherein the cellulose-comprising material is wood.

3. The process according to claim 1, wherein the monomers M1 are selected from styrene, C2-C10-alkyl acrylates and C1-C10-alkyl methacrylates.

4. The process according to claim 1, wherein the polymer exhibits a glass transition temperature TG of at least 30 C.

5. The process according to claim 1, wherein the aqueous active substance composition comprises at least one fungicidally active substance in an amount of 0.1 to 50% by weight, based on the weight of the monomers M used for the preparation of the polymer.

6. The process according to claim 5, wherein the fungicidally active substance is selected from the fungicides from the group of the conazoles, the group of the morpholines, the group of the strobilurins, the group of the thiazoles, the group of the sulfenamides and the group of the iodine compounds.

7. The process according to claim 1, where the polymer particles additionally comprise an insecticidally active substance.

8. The process according to claim 7, wherein the insecticidal active substance is selected from pyrethroids, arthropod growth regulators, chlorfenapyr and neonicotinoids.

9. The process according to claim 1, where the total amount of active substance is 0-5 to 50% by weight, based on the total amount of the monomers M.

10. The process according to claim 1, where the aqueous active substance composition has a content of volatile organic constituents of less than 1% by weight, based on the total weight of the composition.

11. The process according to claim 1, wherein the aqueous active substance composition has a solids content of 10 to 60% by weight.

Description

I. Preparation of the Active Substance Composition

Example 1a (Aqueous Polymer Dispersion with 3% by Weight of Active Substance, Dispersion D1)

(1) 300 g of deionized water and 13.6 g of a 33% by weight aqueous polystyrene dispersion (average particle size 30 nm) were introduced into a reaction vessel equipped with a stirrer, the vessel was flushed with nitrogen and was then heated to 75 C. Beginning simultaneously, feed 1 was added within 3 h and feed 2 was added within 3.15 h, with stirring and while maintaining the temperature. After the end of the addition of feed 2, the temperature was maintained for a further 30 min and then 3.0 g of a 25% by weight aqueous ammonia solution were added. Subsequently, for the purposes of chemical deodorization, feed 3 and feed 4 were added within 90 min while maintaining the temperature and then the reaction mixture was cooled down to ambient temperature. Feed 5 was then added in one portion and the reaction mixture was stirred for 10 min, then adjusted to a pH value of 7 to 7.5 with ammonia and then filtered through a mesh with a mesh size of 125 m.

(2) The dispersion obtained had a solids content of 38.7% by weight and a viscosity of 30 mPa.Math.s. The glass transition temperature of the polymer was +16 C. The average particle size, determined by means of light scattering, was 146 nm.

(3) Feed 1:

(4) 400.0 g of deionized water

(5) 25.7 g of a 28% by weight solution of an anionic emulsifier E1.sup.1)

(6) 21.0 g of a 28% by weight solution of a nonionic emulsifier E2.sup.2)

(7) 7.8 g of acrylic acid

(8) 292.0 g of styrene

(9) 237.0 g of n-butyl acrylate

(10) 60.0 g of ethyl acrylate

(11) 3.0 g of acrylamide

(12) 18.0 g of epoxiconazole

(13) Feed 2:

(14) 100 g of deionized water

(15) 2.4 g of sodium peroxodisulfate

(16) Feed 3:

(17) 22.0 g of deionized water

(18) 2.6 g of t-butyl hydroperoxide (70% by weight)

(19) Feed 4:

(20) 25.0 g of deionized water

(21) 1.7 g of sodium hydroxymethanesulfinate

(22) Feed 5:

(23) 37.0 g of deionized water

(24) 30.0 g of emulsifier solution E2

(25) 1) sodium lauryl sulfate

(26) 2) C.sub.16/C.sub.18 fatty alcohol ethoxylate with on average 18 ethylene oxide units per molecule

Example 1b (Aqueous Polymer Dispersion with 2% by Weight of Fungicidal Active Substance and 1% by Weight of Insecticidal Active Substance, Dispersion D2)

(27) The preparation was carried out analogously to the procedure of example 1a, feed 1 having the following composition:

(28) Feed 1:

(29) 400.0 g of deionized water

(30) 25.7 g of a 28% by weight solution of an anionic emulsifier E1.sup.1)

(31) 21.0 g of a 28% by weight solution of a nonionic emulsifier E2.sup.2)

(32) 7.8 g of acrylic acid

(33) 322.0 g of styrene

(34) 177.0 g of n-butyl acrylate

(35) 60.0 g of ethyl acrylate

(36) 30.0 g of acrylonitrile

(37) 3.0 g of acrylamide

(38) 12.0 g of epoxiconazole

(39) 6.0 g of chlorfenapyr

(40) The dispersion obtained had a solids content of 39% by weight and a viscosity of 45 mPa.Math.s. The glass transition temperature of the polymer was 31 C. The average particle size, determined by means of light scattering, was 151 nm.

Example 2 (Step Polymers with Different Active Substances, Dispersions D3 to D8)

(41) General Procedure:

(42) 183 g of water and 75.8 g of an aqueous polystyrene dispersion (33% by weight, average particle diameter 30 nm) were introduced into a reaction vessel, the vessel was flushed with nitrogen and was heated to 85 C. 25% by weight of a solution of 1.5 g of sodium peroxodisulfate in 21.4 g of water (feed 4) were added hereto while maintaining the temperature. After 10 min, beginning simultaneously, the addition of feed 1 and the addition of the remaining amount of feed 4 were commenced. Feed 1 was added within 90 min while maintaining the temperature, feed 4 within 255 min. After the end of the addition of feed 1, the temperature was maintained for 30 min, then feed 2 was added within 60 min, the temperature was maintained for a further 45 min and then feed 3 was added within 30 min while maintaining the temperature. After the end of the addition of feed 3, the temperature was maintained for a further 30 min and then the reaction mixture was cooled to ambient temperature.

(43) Feed 1:

(44) 220.1 g of water

(45) 220.8 g of styrene

(46) 1.6 g of allyl methacrylate

(47) 11.1 g of emulsifier solution E3

(48) x g of active substance (see table 1)

(49) Feed 2:

(50) 135.6 g of water

(51) 180.4 g of n-butyl acrylate

(52) 2.1 g of allyl methacrylate

(53) 7.2 g of emulsifier solution E3

(54) y g of active substance (see table 1)

(55) Feed 3:

(56) 92.5 g of water

(57) 19.7 g of styrene

(58) 75.5 g of methyl methacrylate

(59) 1.7 g of emulsifier solution E3

(60) z g of active substance (see table 1)

(61) Emulsifier solution E3: 45% by weight aqueous solution of a sodium salt of (C.sub.16-alkyl)-diphenyl ether sulfonic acid

(62) TABLE-US-00001 TABLE 1 Active Dispersion substance x [g] y [g] z [g] D3 Metconazole 26.4 14.4 12.0 D4 Cyproconazole 21.6 10.8 10.8 D5 Epoxiconazole 30.0 6.0 6.0 D6 Tebuconazole 15.0 18.0 D7 IPBC.sup.1) 21.0 4.2 6.0 D8 Epoxiconazole + 4.0 4.0 4.0 Chlorfenapyr 2.0 2.0 2.0

(63) 1) IPBC=3-iodo-2-propyl butylcarbamate.

(64) The dispersions obtained had a solids content of 45% by weight and a viscosity of 115 mPa.Math.s. The polymer showed 2 glass transition temperatures at 31 and +99 C. determined by means of DSC. The average particle size, determined by means of light scattering, was 95 to 105 nm.

Example 3 (Cationic Dispersions D9-D13 with Different Active Substances)

(65) General Preparation Procedure:

(66) 465 g of deionized water, 5% by weight of feed 1 and 10% by weight of feed 2 were heated to 80 C. After 10 min, the addition of the remaining amounts of feed 1 and feed 2 was commenced. The feed time was 3.5 h. After the end of the addition of the feeds, the mixture was maintained at 80 C. for a further 30 min and was cooled down to ambient temperature.

(67) Feed 1:

(68) 496.1 g of deionized water

(69) 7.6 g of sulfuric acid (50% by weight)

(70) 361.0 g of methyl methacrylate

(71) 19.0 g of dimethylaminoethyl methacrylate

(72) 57.0 g of emulsifier solution E4

(73) x g of active substance (see table 2)

(74) Feed 2:

(75) Solution of 1.5 g of 2,2-azobis(N,N-dimethylisobutyramidine) in 63.3 g of Deionized Water

(76) Emulsifier solution E4: 40% by weight aqueous solution of a cationic emulsifier obtained by successive ethoxylation of stearylamine with 4-5 mol of ethylene oxide and subsequent quatemization with dimethyl sulfate.

(77) TABLE-US-00002 TABLE 2 Active Dispersion substance x [g] D9 Metconazole 61.8 D10 Cyproconazole 42.9 D11 Epoxiconazole 0.4 D12 Tebuconazole 19.0 D13 IPBC 18.2

(78) The dispersion obtained had a solids content of 29.5% by weight and a viscosity of 100 mPa.Math.s. The polymer showed a glass transition temperature at 87 C. determined by means of DSC. The average particle size, determined by means of light scattering, was 157 to 175 nm.

Example 4 (Cationic Dispersions D14-D18 with Different Active Substances)

(79) General Preparation Procedure:

(80) 465 g of deionized water, feed 1 and 10% by weight of feed 2 were heated to 80 C. After 10 min, the addition of the remaining amount of feed 2 and of feed 3 was begun. The feed time of feed 2 and feed was 3.5 h. After the end of the addition of the feeds, the mixture was maintained at 80 C. for a further 30 min and was then cooled down to ambient temperature.

(81) Feed 1:

(82) 46.1 g of deionized water

(83) 38.0 g of styrene

(84) 7.6 g of 3-(N,N-dimethylamino)propylmethacrylamide

(85) 14.2 g of emulsifier solution E4 (see above)

(86) Feed 2:

(87) Solution of 1.5 g of 2,2-azobis(N,N-dimethylisobutyramidine) in 63.3 g of Deionized Water

(88) Feed 3:

(89) 450.1 g of deionized water

(90) 7.6 g of acrylic acid

(91) 270.0 g of methyl methacrylate

(92) 57.0 g of dimethylaminoethyl methacrylate

(93) 42.8 g of emulsifier solution E4 (see above)

(94) x g of active substance (see table 3)

(95) TABLE-US-00003 TABLE 3 Active Dispersion substance x [g] D14 Metconazole 61.8 D15 Cyproconazole 42.9 D16 Epoxiconazole 0.4 D17 Tebuconazole 19.0 D18 IPBC.sup.1) 18.2

(96) The dispersion obtained had a solids content of 29.8% by weight and a viscosity of 105 mPa.Math.s. The polymer showed a glass transition temperature at 110 C. determined by means of DSC. The average particle size, determined by means of light scattering, was 155 to 175 nm.

II. Application Investigation

(97) The limits of the effectiveness of the compositions according to the invention with regard to wood-destroying basidiomycetes were determined on wood test specimens of Pinus spp. (southern yellow pine) with the dimensions 40154 mm. The test method on comminuted wood test specimens, known as the Bravery test, is closely based on EN 113 and is used to determine the preventive effect of wood preservatives against wood-destroying fungi (see in this connection A. F. Bravery, Intern. Res. Group Wood Pres., Doc. No. IRG/WP/2113, 5S., Stockholm, 1978). The wood test specimens impregnated with the composition according to the invention were tested without or with the constraint of leaching according to EN 84. The investigation was carried out with 6 different active substance concentrations ranging from 0.4 to 4% by weight of active substance (with epoxiconazole) or 0.63 to 6.3% by weight of active substance (with tebuconazole) and each time 5 parallel test specimens per active substance concentration and test fungus. Coniophora puteana BAM Ebw. 15 and Poria placenta FPRL 280 were used as test fungi. The destruction of the wood caused by fungal infection was registered by the loss in weight of the test woods, which was determined after 6 weeks. If the loss in weight is less than 3% by weight, based on the starting dry weight of the test sample, the protection of the wood achieved by the preservative at a particular active substance concentration is regarded as satisfactory. The concentration limit of the effectiveness is given in two concentrations. The lower concentration gives the value at which the wood is no longer satisfactorily protected and the higher concentration corresponds to the minimum concentration with which complete protection is achieved.

(98) A dispersion with an active substance content of 5.52% by weight of epoxiconazole (based on the solids content, or 2.4% by weight, based on the dispersion), a solids content of 43.7% by weight and an average particle size of 107 nm, prepared according to the procedure in example 2, and a dispersion with an active substance content of 4.69% by weight of tebuconazole (based on the solids content, or 2.05% by weight, based on the dispersion), a solids content of 43.8% by weight and an average particle size of 98 nm, prepared according to the procedure in example 2, were tested.

(99) The limits of the effectiveness are represented in table 4. For comparison, the values determined for a solution of the active substance in acetone are given.

(100) TABLE-US-00004 TABLE 4 Limits of the effectiveness [kg/m.sup.3] Test fungus Without leaching With leaching (EN 84) Dispersion with epoxiconazole CP <0.066 <0.066 PP <0.066 <0.066 Solution of epoxiconazole CP <0.19 0.11-0.16 PP <0.19 0.11-0.18 Dispersion with tebuconazole CP <0.092 <0.089 PP 0.091-0.143 <0.092 Solution of tebuconazole CP <0.052 <0.054 PP 0.102-0.153 0.095-0.152

(101) In practice, the upper value after leaching in particular is decisive for the assessment of a wood preservative. The results represented in table 4 prove that the active substance compositions according to the invention show an effectiveness against wood-destroying fungi which is at least comparable to, in the case of epoxiconazole even better than, that of formulations in organic solvents.

(102) Wood test specimens which, for control purposes, were treated only with a dispersion free of active substance with otherwise an identical composition showed, under test conditions, serious damage to the wood substance by fungal infection which was only slightly less than with untreated wood test samples.