DD260486A1 - NEW NITRIFICATION-RESISTANT POLYMER-ACTIVE COMBINATIONS - Google Patents

Abstract

The invention relates to the use of new nitrification-inhibiting polymer-drug combinations. The object of the invention is to reduce by physical combination of synthetic or natural polymers with 3-methylpyrazole or 1-carbamoyl-3-methylpyrazole their volatility, water solubility and / or hydrolytic decomposition while maintaining the biological effect after application. The object is achieved according to the invention in that 3-methylpyrazole or 1-carbamoyl-3-methylpyrazole is molecularly dissolved, dispersed or sorbed in a solid polymer. It describes the criteria that must be met by the polymer to be used to fulfill the above tasks.

Description

Field of application of the invention

The invention relates to the use of novel nitrification-inhibiting polymer-drug combinations, which are composed of synthetic or natural polymers and low molecular weight nitrification inhibitors. The polymer protects the low molecular weight nitrification inhibitor during storage or during and shortly after administration before drug volatilization and / or hydrolytic decomposition and releases it in the soil so controlled that its biological activity is not limited.

The inventive agents can be used in agriculture and forestry before, simultaneously with or after the application of fertilizer in application rates of preferably 0.5 to 60 kg of active ingredient per hectare.

Ammonium nitrogen is subject in the soil in a relatively short time of the microwave conversion via the intermediate of the nitrite nitrogen to nitrate nitrogen.

This nitrification is significantly influenced by the temperature, the soil moisture, the pH and the biological activity of the soil or substrate.

Nitrate nitrogen, in contrast to ammonium nitrogen, is not sorbed by the sorption carriers clay and humus. The consequence of this is that nitrate nitrogen is subject to leaching during the winter half-year and during heavy precipitation or intensive irrigation even during the summer half-year, especially on light soils.

The leaching losses can average up to 20% of the fertilizer nitrogen per year.

The washed out nitrogen is not only lost for the nutrition of the crop plants, but it also comes to the enrichment of nitrate nitrogen in groundwater. In connection with drinking water supply, this can lead to damage to human and animal health.

In addition to the leaching losses occur annually significant gaseous nitrogen losses by denitrification of nitrate nitrogen.

Under tropical conditions, the losses of denitrification significantly influence the yield efficiency of nitrogen fertilization.

By inhibiting or regulating the nitrification, the utilization of the fertilizer nitrogen can be significantly improved and thus the economic benefits of nitrogen thinning can be increased.

Characteristic of the known technical solutions

It is known that various pyrazoles (substituted) z. For example, 3-methylpyrazole (3-MP) and 1-carbamoyl-3 (5) -methylpyrazole (CMP) inhibit the nitrification of ammonium nitrogen. (Japanese patents 47182 and 47183, DD-WP 131063 and 133088). When applied to the soil surface can occur in the 3-MP due to the high vapor pressure significant drug losses by volatilization, which lead to a reduction in the effectiveness.

With longer residence time on the Bodenoberfläghe these effect-reducing factors can also occur in the CMP by drug hydrolysis. It has therefore been proposed to protect the active ingredient from volatilization or hydrolysis by covalent polymer fixation (DD-WP 210025).

This method is, especially if all application criteria are to be met, associated with a high synthesis effort and therefore costly.

Object of the invention

The object of the invention is to reduce the disadvantages of the known solutions by physically combining synthetic or natural polymers with 3-methylpyrazole or 1-carbamoyl-3-methylpyrazole while maintaining a high biological activity.

Explanation of the essence of the invention

The object is achieved in that 3-methylpyrazole or i-carbamoyl-3-methylpyrazole are dissolved in a solid polymer matrix molecular, dispersed or sorbed. The purpose of the polymer is to protect 3-methylpyrazole from rapid volatilization and high water dissolution, and i-carbamoyl-3-methylpyrazole from rapid hydrolysis, and to provide the active ingredient after application, e.g. in the ground, release quickly. The release of active ingredient can take place both by diffusion of the active ingredient and by swelling or dissolution of the polymer matrix, possibly by both processes simultaneously.

It has now been found that the polymers to be used must meet certain criteria in order to meet the above requirements. So z. As polystyrene and polyvinyl chloride are not suitable because they sweat the 3-methylpyrazole during storage within a few days; In addition, diffusive drug release occurs so slowly that the biological effectiveness of these combinations is completely inadequate.

The latter can be observed with all hydrophobic polymers, for example: polyvinyl acetate, polyethylene, polypropylene, ethylene / vinyl acetate copolymers, cellulose ethers, etc.

On the other hand, only sufficiently hydrophilic polymers proved to be suitable for the stated purpose. For example: polyvinyl alcohol, various maleic anhydride copolymers, carboxymethyl cellulose, starch and urea-formaldehyde condensates. In addition to a sufficiently high hydrophilicity (i.e., solubility or swellability in water), the polymers suitable for the compositions of the invention must meet the following criteria:

1. Solubility of the active substance in the polymer C ₅ <2000 mg / cm ³

2. Diffusion rate of the active ingredient in the polymer> 0.3 mg / cm ² · h at a D> 1 · 10 ⁹ cm ² / sec.

3. Half-life (t ₅₀ ) of drug release in bidistilled water, pH = 5.6 1 min-60min, preferably <10 min.

By targeted variation of the base polymers, the release rate can be changed depending on the practical requirements (soil moisture, amount of precipitation, desired time of action, etc.). So it is possible, the hydrophilicity and thus the release rate of polyvinyl alcohol by

a) crosslinking with dicarboxylic acid dichlorides such. B. sebacic, adipic or oxalic acid dichloride or

b) to reduce over a residual acetate content of 1-70 mol%.

The same result is achieved in maleic anhydride copolymers by varying the comonomer or reactions to the half ester or diester and to the half-amide or imide with variation of the alkyl chain length. For natural polymers such. B. cellulose succeeds by introducing substituents, eg. To carboxymethyl cellulose, and change in the degree of substitution. Increasing the hydrophilicity is also known to be possible through the use of the salts of corresponding polymers (e.g., maleic anhydride copolymers or carboxymethyl cellulose) or addition of osmotically active agents (e.g., salts). The preparation of the compositions according to the invention is carried out according to the known methods for producing monolithic systems, for. B. by a) film formation from solution or melt and subsequent granulation, b) polymer precipitation in the presence of nitrogen, c) polymer crosslinking in the presence of the active ingredient, d) swelling of the polymer in a drug solution or by exchange of solvents and active ingredient. The active substance content of the polymer combination can be adjusted between 5 and 90%, advantageously between 10 and 30% by mass. The grain size of the combinations should be between 0.001 to 3 mm, preferably between 0.05 to 0.8 mm.

The advantages of the polymer combination according to the invention lie in the fact that they largely protect the active substance during storage from volatilization and hydrolysis, ensure rapid or easily variable release of active ingredient in the soil and can be produced cost-effectively by using processes known in polymer technology. In addition, waste polymers can be used as polymers and further formulation steps can be saved. Moreover, in the proposed production technologies, it is easily possible to use combinations of different polymers and / or different active ingredients, if they are compatible with one another.

The application of the new nitrification-inhibiting agents can be done with previously used methods and technologies. A particularly favorable procedure is to produce polymer films, films or plates and to granulate them immediately before use, whereby a substantial extension of the shelf life is achieved. The following examples illustrate the invention without limiting it.

embodiments

example 1

The compounds according to the invention of different active ingredient content are subjected to hydrolysis in bidistilled water at 30 ° C. and the concentration of 3-methylpyrazole in the hydrolysis medium is monitored over time. The half-life t ₅₀ of drug release, after which 50% of the active ingredient is released from the polymer combination, can be seen in Table 1.

Example 2 »

Planar polymer films of the compositions according to the invention are subjected to diffusion investigations in a self-built cell (chamber volume 5 cm ³ ). At 3O ⁰ C and intensive mixing of the solutions in the two separate measuring chambers through the polymer film layer thicknesses for the polymer is between 0.015 and 0,03cm and a 0.01 molar solution of active compound were used as the optimal experimental parameters. From the diffusion rate determined in the above measuring cell, the diffusion coefficient D and the solubility C _{s of} the 3-methylpyrazole in the polymer were determined according to the method proposed by PAUL and McPADDEN (J.Membr., 1) [1976]. The diffusion parameters and the corresponding half-lives of the 3-Methylpyrazolfreisetzung of the investigated polymers are summarized in Table 2. The polymers with poor diffusion parameters for the intended use (dQ / dt <0.3 mg / cm ² · h and D <1 x 10 ⁹ cm ² / sec), such as. As polyvinyl acetate or maleic acid monomethyl ester / styrene copolymers show a slow release behavior for 3-methylpyrazole (t ₅₀ > 60 min) and thus a poor biological activity.

Example 3

The compositions of the invention were added as urea-active ingredient mixture to a sandy loam soil and evenly

mixed.

The concentration is 4ppm (based on soil mass) with a nitrogen input of 20 mg N / 100g soil.

After humidifying the soil to 50% of the maximum water capacity was incubated at 2OX 14,28,42,56 and 70 days and then determined the formed nitrite and nitrate nitrogen.

The same urea addition to the bottom served as control as in the test variants.

The calculation of the inhibitory effect in percent is carried out

a- b a - ο

100 =% inhibition

a = nitrite and nitrate content of the control b = nitrite and nitrate content of the active substance samples c = nitrite and nitrate content of the soil used

 The results are summarized in Table 3

Example 4

To test the gaseous losses of active substance in an application to the soil surface, 30 g of a sand-rodeo were moistened to 50% of the water capacity and transferred to Conway dishes (0 = 28.3 cm ² ).

3 mg of 3-methylpyrazole or the inventive compositions (based on the Pyrazoi content) were dissolved in 0.5 ml of dist. Dissolved or suspended water and evenly distributed on the soil surface (amount of liquid equivalent to 1765 l / ha). For the sorption of the gas-phase-transferring active substance, the Conway dish was introduced with 4 ml of n / 1 OH ₂ SO 4 n. At the sampling dates after 3, 7, 11 and 14 days, the templates were made up to 25 ml with n / 1 OH ₂ SO ₄ and the UV spectrum was measured on the UV-Vis-Specord. After the quantitative analysis of the spectra, the results are displayed in% active ingredient volatilization (based on the applied amount).

Table 1: Physical polymer combinations of 3-methylpyrazole (3-MP) i-carbamoyl-3-methylpyrazole (CMP) and the release of the active ingredient

Comb. biol. active Wirkstoffgeh No. pyrazole Wt .-% 1 3-MP 10.9 2 3-MP 14.1 3 3-MP 13.0 4 3-MP 15.4 5 3-MP 13.3 6 3-MP 14.7 7 3-MP 15.0 8th 3-MP 22.4 9 3-MP 13.7 10 3-MP 20.3 11 3-MP 16.4 12 3-MP 13.0 13 3-MP 18.6 14 3-MP 20.3 15 3-MP 23.4 16 3-MP 75.3 17 3-MP 10.3 18 3-MP 9.8 19 3-MP 62.8 20 3-MP 23.4 21 3-MP 15.5

polymer

Half-life _{50 of} the drug release in bidest. Water at 3O ⁰ C

min

PVAL 55/00 grain size> 0.4 mm <5

PVAL55 / 00 grain size 0.1-0.4 mm <5

PVAL 55/00 Komg size <0.1 m m <5

PVAL 55/12 grain size> 0.4 mm 10

PVAL 55/12 grain size 0.1-0.4 mm <5

PVAL55 / 12 grain size <0.1 mm <5

P (VAL-co-VAC) 14 mol% VAC 5

P (VAL-co-VAC) 20 mol% VAC 20

P (VAL-co-VAC) 31 mol% VAC 35

P (VAL-CO-VAC) 40 mole% VAC-60

P (VAL-co-VAC) 48 mol% VAC 120

P (VAL-co-VAC) 74 mol% VAC 210

PVAC 240

1 part PVAC / 2 parts P (VAL-co-VAC) with 20 mol% VAC 30

1 part PVAC / 2 parts P (VAL-co-VAC) with 40 mol% VAC 90 PVAL crosslinked with 0.05 mol Sebacinsäuredichlorid,

swollen with water 10 PVAL crosslinked with 0.05 mol of sebacic acid dichloride,

swollen with methanol <5

Crosslinked PVAL with 0.05 mol of sebacyl chloride <5 PVAL crosslinked with 0.2 mol of sebacic acid dichloride,

crosslinked with water soaked 15 PVAL with 0.2 mol of sebacic acid dichloride,

pre-swollen with methanol <5

PVAL crosslinked with 0.2 mol of sebacic acid dichloride <5

Comb. biol. active Wirkstoffgeh. polymer styrene Half life t ₅₀ the No. pyrazole Wt .-% styrene Drug release in styrene dist. Water at 3O ⁰ C min 22 3-MP 63.6 styrene vinyl acetate 20 23 3-MP 28.5 PVAL crosslinked with 0.05 mol of adipic acid dichloride, propene pre-swelled with water propene <5 24 3-MP 11.3 propene <5 25 3-MP 30.2 PVAL crosslinked with 0.05 mol of adipic acid dichloride, isobutene Pre-swelled with methanol α-methylstyrene 20 26 3-MP 10.6 styrene PVAL crosslinked with 0.05 mol of adipic acid dichloride styrene <5 27 3-MP 8.2 PVAL crosslinked with 0.05 mol of oxalyl chloride, with styrene <5 28 3-MP 14.3 Water pre-swollen styrene <5 29 CMP 9.1 styrene <5 30 3-MP 13.8 PVAL crosslinked with 0.05 mol of oxalyl chloride, with styrene <5 31 CMP 7.9 Methanol pre-swollen styrene <5 32 3-MP + CuCl ₂ 13.7 styrene <5 33 3-MP + CuBr ₂ 16.0 PVAL crosslinked with 0.05 mol of oxalyl chloride styrene potato starch styrene 34 3-MP 15.0 potato starch styrene - 35 3-MP 21.8 corn starch styrene 60 36 CMP 29.6 corn starch styrene - 37 3-MP 20.0 potato starch Styrenkapseln - 38 3-MP 43.2 potato starch VAC capsules <5 39 3-MP 17.6 Propene capsules <5 40 CMP 34.9 styrene - 41 3-MP 20.0 vinyl acetate - 42 3-MP 31.4 propene 30 43 3-MP 15.0 isobutene 60 44 3-MP 16.9 60 45 CMP 31.6 Maleic acid derivative (MS) comonomer - 46 3-MP 30.3 MS-di-sodium salt 240 47 CMP 36.2 MSA - 48 3-MP 13.6 MSA - 49 3-MP 22.5 MSA + FeCI ₃ 1680 50 CMP 32.3 MSA - 51 3-MP 25.0 MSA - 52 3-MP 23.8 MSA - 53 3-MP 24.3 MSA + FeCI ₃ - 54 3-MP 16.1 MSA - 55 CMP 37.0 MSA - 56 3-MP 16.2 MS monomethylester - 57 CMP 76.2 MS monomethylester - 58 CMP 65.8 MS monoethyl - 59 CMP 65.2. MS monoethyl - 60 3-MP 27.5 MS-monopropyl - 61 3-MP 27.4 MS monobutyl <5 62 3-MP 32.6 MS monobutyl <5 63 3-MP 18.6 MS monohexyl - 64 3-MP 8.0 MS monoheptylester 10 65 3-MP 40.0 MS monooctyl 30 66 3-MP 80.0 MS-mono-cyclohexyl 30 67 3-MP 18.0 MS-mono-cyclohexyl 15 68 3-MP 44.0 MS-mo "nobenzylester 5. 69 3-MP 4.0 MSA 5 70 3-MP 16 MSA MSA <5 71 3-MP 12 MS-methyl-cyclohexyl ester MS monobutyl <5 72 3-MP 20 MS monohexyl MS monomethylester <5 73 3-MP 8th WofatitEP60 WofatitEP60 <5 WofatitEP60 cellulose acetate Spruce textile fabric Cell Spruce textile fabric Cell Urea formaldehyde condensate Urea-formaldehyde condensate Urea formaldehyde condensate Urea Formaidehyd- condensate

polymer dQ / dt D. 10 ⁹ -5- 260,486 PVAL 55/12 mg / cm ² h cm ² / S (d = 0.018cm) PVAL 55/01 0.92 84.0 C ₃ tso PVAL 55/02 0.72 23.5 mg / cm ³ H Table 2: Dependence of the diffusion parameters of 3-methylpyrazole on the polymer used PVAC 0.39 10.0. 150 <0.1 Ser. No. MSA / styrene 0.06 0.9 180 <0.1 gem. Tab. 1 MS monoethyl / styrene 0.50 2.0 .210 <0.1 4 MS-methyl-cyclohexyl ester / styrene 0.02 0.25 340 4 Cellulosedibenzylether 0.01 0.03 1000 1 0.03 280 4 13 450 20 35 6300 > 100 46 60

Table 3: Percent inhibition of nitrification by 3-methylpyrazole and the inventive compositions according to Table 1

Komb.Nr. gem. Tab.

% Inhibition after days incubation 28

42

3-methylpyrazole (known)

16 17 19 20 22: 23 24 25 26 27 34 35 37 41 43 45 50 57 58 59 67 68 70 72

89 76 46 26 CJL 87 83 61 8th 0 83 86 64 28 19 74 66 61 18 19 83 83 61 22 9 87 74 58 31 0 90 86 74 44 18 90 73 49 24 16 93 76 49 21 14 95 74 17 0 0 87 84 26 9 0 93 68 37 3 0 64 52 26 6 0 64 29 14 0 0 96 74 3 0 0 88 29 3 0 0 65 24 0 0 0 90 80 53 6 0 94 80 66 32 0 90 80 50 29 18 90 89 71 44 28 82 66 21 0 0 90 73 46 26 8th 93 73 43 21 16 90 86 74 56 31 90 86 71 56 28 88 63 3 0 0 76 34 30 0 0 85 31 0 0 0 90. 54 0 0 0 90 74 56 28 0

Table 4: Drug losses in percent after application to the soil surface

Komb.-Nr. gem. Tab.

% Drug losses after days 3

11

14

3-methylpyrazole 35 64 6566

5.7 3.6 6.9 6.8 5.1

11.0 6.6 6.5

10.3 7.2

15.5 9.5 9.8

14.8 9.4

18.4 12.2 11.5 17.7 11.2

Claims (8)

1. Novel nitrification-inhibiting polymer-drug combinations, characterized in that 3-methylpyrazole or i-carbamoyl-3-methylpyrazole are molecularly dissolved, dispersed or sorbed in a solid polymer matrix and the polymer protects the substituted pyrazole from volatilization and / or hydrolysis, and only after application by diffusion, degradation and / or swelling releases the biological effect of the substituted pyrazole. 2. New nitrification-inhibiting polymer-drug combinations according to claim 1, characterized in that they contain 5-90 wt .-%, preferably 10-30 wt .-% substituted pyrazole. 3. New nitrification-inhibiting polymer-drug combinations according to claim 1, characterized in that the polymer is a synthetic or natural polymer and the active ingredient is soluble therein to 2000 mg / cm ³ . 4. New nitrification-inhibiting polymer-active ingredient combinations according to claim 1, characterized in that the active ingredient in the polymer has a diffusion rate greater than 0.3 mg / cm ² · h at a diffusion coefficient greater than 1 10 ⁹ cm ² / sec. has. 5. New nitrification-inhibiting polymer-drug combinations according to claim 1, characterized in that the half-life of the drug release in bidistilled water at 30 ° C and pH = 5.6 to 60 min is preferably <10 min. 6. New nitrification-inhibiting polymer-drug combinations according to claim 1, characterized in that mixtures of polymers are used. 7. novel nitrification-inhibiting polymer-drug combinations according to claim 1, characterized in that mixtures of substituted pyrazoles and / or other Nitrifikationshemmern be used. 8. New nitrification-inhibiting polymer-drug combinations according to claim 1, characterized in that the particle sizes of the combinations 0.005 to 3 mm preferably 0.01-8mm. .