NL8002494A - PESTICIDES. - Google Patents

Description

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Pesticides

The invention relates to liquid recipes of phosphoric and thiophosphoric pesticides that are stable over time, in particular to liquid recipes of pesticides that can withstand both high and low temperatures.

The phosphoric and thiophosphoric pesticides have been known for some time, and brands will include Rogor * (brand of. Montedison SpA for 0,0-dimethyl S- (N-methyl-carbamoylmethyl) phosphonithionate), Cidial * (brand of Soc. Montejq dison for 0,0-dimethyl S- (α-ethoxycarbonylbenzyl) phosphorothithioate),

Malathion * (American Cyanamid brand for S - / - 1,2-di- (ethoxy-carbonyl) ethyl 7-phosphorothiol thionate '), Parathion (American Cyanamid Co. brand for 0.0-dimethyl 0-p-nitrophenyl phosphorothioate) and many others. Of these, Parathion, Malathion and many other liquids are, while Rogor * FAC (brand of Montedison S.p.A. for 0-0-diethyl S- (N-isopropylcarbamoylmethyl) phosphorothioioate) are solids.

The liquid solutions of these compounds are most suitable for their ease of handling and for the preparation of emulsifiable recipes and of concentrates used as such at very small volume.

However, these liquid solutions are difficult to prepare, with respect to physical stability at low and high temperatures, and with regard to chemical stability, which, if not taken into account, leads to a decrease in biological activity.

The pesticide phosphates or thiophosphates show either a low solubility in most common organic solvents, especially at low temperatures, or a 800 2 4 94

P

i 2 chemical stability insufficient to ensure activity.

To overcome this drawback, various solutions have been proposed, such as those described in US Patent 3 UUU 273, in which the thiophosphoric acid esters are mixed together with dialkyl phenols and this mixture is then diluted with aromatic hydrocarbons. This provides sufficient chemical stability and good resistance or fastness to low temperatures. However, the alkylphenols are expensive and difficult to treat, and sometimes impart a certain phytotoxicity to the recipes thus obtained.

On the other hand, it is also known that the phosphoric or thiophosphoric pesticides are often difficult to dissolve in many organic solvents, such as, for example, xylene, Sbellsol 1 £ A and Shellsol AB (a mixture of aromatic and aliphatic hydrocarbons from the Shell Company) while in solvents such as alcohols, glycols, ketones, dimethylformamide, dimethyl sulfoxide, often a decomposition of the active principle occurs.

Recipes of phosphoric acid or thiophosphoric acid pesticides have now been found, which are stable at both low and high temperatures and consist of solutions of: A) Phosphoric acid or thiophosphoric acid pesticides 0.05 - 90% B) One or more organic acids 99.5 - 10% to which are added one or more of the following diluents: 1) Aromatic solvents of the xylene type or aromatic-aliphatic solvents such as Shellsol A, AB (mixtures of dimethyl, ethyl, tetramethylbenzene) and the like, Solvesso 100- 150, 20 (mixtures of dimethyl, ethyl, tetramethylbenzene, 30 a trademark of the Esso Company).

2) Dimethylformamide, dimethyl sulfoxide, alcohols with C2-20 glycols.

3) Esters of the amyl acetate type, of the methyl benzoate type etc.

U) Ketones of the cyclohexane type, ethylamyl ketone, acetophenone.

35 5) Surfactants of the Setrolene 0 type registered 800 2 4 94 «3 trademark of the ROL-, Company, consisting of polyoxyethylate sorbitan oleate), Emulsion 10B (registered trademark of the ROL Company and consisting of alkylphenol polyoxyethylate), Emulsion 255 (registered trademark of the ROL-ΜΞ Company and 5 consisting of alkyl benzene sulfonate).

The A-type connections can be:

Rogor, Methylparathion (0,0-dimethyl Op-nitrophenyl-phosphorothioate) Monocrotophos Γ1-methyl 3 (methylamino) 3-oxo 1-propenylphosphate7, M 817 ^ · (idinphos, a Montedison brand for 0,0-diethyl 0- / " 1-methyl 10 3 (S, β-dichlorovinyl) 1,2,6-triazol-5-yl7thiophosphate), Pao,

Azinphos-methyl (0,0-dimethyl S - / - (i + -oxo 1,2,3-benzotriazin-3 ((H) -yl) -methyl-7-phosphedioate).

The B-type compounds (organic acids) can be: acetic acid, propionic acid, butyric acid, caprylic acid, oleic acid, phenylacetic acid, formic acid, caproic acid, stearic acid and generally all organic acids that are miscible with the pesticide phosphoric compounds. organic acid mixture.

Under such conditions, the stability at high and / or low temperatures and / or the solubility of the phosphoric or thiophosphoric pesticides increases significantly. As can be seen from Table A, the solubility of Rogor in various organic solvents is often not very high especially at low temperatures.

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Table A

Percent solubility of Rogor / “0,0-dimethyl S- (N-methylcarbamoylmethyl) phosphorothithioate 7 at 20 ° C and at 0 ° C.

k,. ,,, solvent temperature *

5 20 ° C 0 ° C

xylene 12% 3%

Shellsol AB 8 # 2% butyl alcohol 50% 10% amyl acetate 30% 8% 1q dimethylformamide 75% 50% diethyl oxalate 60% 35% cyclohexanone 60% 50%

When the solubility is found to be good (dimethylformamide, cyclohexanone), the chemical stability proves insufficient, especially at high temperature (ie above 50 ° C) for pesticide solutions.

In fact, the following Table B shows that the drop (calculated as a decrease in percent of active substance) is high in solvents in which Rogor is significantly soluble.

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Table B

Stability of Rogor in some solvents after 5 days at 60 ° C.

mixture: decrease in% 5 Rogor i + 0) 90 dimethylforamide 6θ)

Rogor 1 * 0) 90 dimethyl sulfoxide 6oj

Rogor 1 * 0) 30 10 butyl alcohol βθ}

Rogor 1 * 0) 70 propylene glycol 60)

Rogor 1 * 0) methylcellosolve éo) 50 15 Rogor 1 * 0) (63 cyclohexanone 60) 5

From Tables A and B it can be deduced that Rogor is sparingly soluble in the solvents in which it is stable, such as in the aromatic solvents, while in the solvents in which it is very soluble it is not stable. (Cyclohexanone is an exception, but it is very expensive).

With the mixtures according to the invention it is possible to avoid both decomposition or deterioration, as well as to increase the solubility of the pesticide solvents, in which it is generally sparingly soluble.

The invention will now be illustrated in a non-limiting manner with the following examples: 800 2 4 94 6 CÖ £ § a ï% μ ϋ 0) 10 - <3 ΙΑ Ο A Α Ο Ο Ο .at WW '". · Rad w • w ö & <ü o »

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Table Cbls recipe: decrease

5 days at 60 ° C

1) Techn. Rogor 95% 65% acetic acid 2k% k, 6%

Shell Sol AB 11% 2) 2) Techn. Rogor 95% 65% propionic acid 30% ^, 1

Shell Sol AB 5% («) 3) Techn, Rogor 95% 65% Phenol 30% 12.6

Shell Sol AB 5% (x) Traditional recipe ✓ - 800 24 94 8

Table D

Stability tests at different temperatures of

Rogor recipes with acetic acid (1, 2) compared to traditional Rogor recipes (3, * 0.

Drop in $ after: Mixture 5 days 1U days 1 month 1 month

at 60 ° C at 5 * + ° C at 50 ° C at 1 + 0 ° C

Tech. Rogor Uo acetic acid 10 2.0 $ 2.8 $ l + .7 $ 0.5 $ xylene 50

Tech. Rogor 1 + 0 acetic acid 10 xylene 1 + 0 2.1 $ 3.9 $ 6.8 $ 1 $

Setrolene 0 7 ^ emulsion 255 3

Tech. Rogor 1 + 0 xylene. 10 3.9 $ 6.6 $ 7.6 $ 3.1 $ cyclohexanone 50

Tech. Rogor 1 + 0 xylene 1 + 2 l +, 5 $ 6.3 $ 7.1 $ 2.9 $ phenol 18x: emulsion 255 = ROL-ΜΕ brand for alkyl benzene sulfonate.

80 0 2 4 94 9

Table E

Stability of some pesticidal compounds in acetic acid and xylene recipes after 5 days at 60 ° C.

mixture drop in% 5 Technical M 817¼ ^ 0 acetic acid 10 2.3% xylene 50

Tech. methyl parathion kO

acetic acid 10 0.8% 10 xylene 50

Monocrotophos Uo acetic acid 10 3.0% xylene 50

Example I

A solution of 0.5 g of Rogor, 0.1 g of acetic acid and 99.4 g of xylene is prepared by mixing the pesticide at room temperature with the acetic acid and then with xylene.

50 g of this solution, when kept at 0 ° C for ¼8 hours or for 5 days at 60 ° C, shows no

change while liquid-gas chromatographic analysis shows that no significant decomposition has taken place. Example II

A solution is prepared by mixing at room temperature and stirring with 72 g Rogor, 18 g acetic acid, 10 g Shell Sol AB (Shell Company brand) for a mixture of aromatic and aliphatic solvents consisting of dimethyl, ethyl, tetramethylbenzene ), 50 g of this mixture, when kept at 0 ° C for ¼8 hours or at 60 ° C for 5 days, shows no change and the liquid gas chromatographic analysis shows that no significant decomposition has taken place.

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Example III

A solution of 1 + 0 g Rogor, 10 g acetic acid, 50 g xylene is prepared at room temperature. This solution also exhibits the same stability as that described in the previous examples.

Examples IV-VIII

The same results are obtained with the following mixtures: Rogor 1 + 0 g, acetic acid 5 g, dimethylformamide 5 g, xylene 50 g, Rogor 1 + 0 g, acetic acid 5 g, cyclohexanone 25 g, xylene 10 30 g, Rogor 72 g, acetic acid 18 g, Setrolene (registered trademark of ROL-ΜΕ Company for the polyoxyethyl acrylate sorbitanate surfactant) 10 g; Rogor 1 + 0 g, acetic acid 10 g, xylene U0 g, mixture of nonylphenol polyoxyethylate and dodecyl benzene sulfonate 10 g; Rogor 1 + 0 g, acetic acid 5 g, dimethylformamide 15 5 g, xylene 1 + 0 g, Setrolene 10 g. The mixture of Examples III - VIII does not show any plant toxicity at doses of 0.05% and 0.1% with respect to cucumber, beet, vine, apple, cabbage, cotton.

EXAMPLE 9-20 A recipe is prepared by mixing together 1 + 0 g technical Rogor, 15 g propionic acid, 35 g xylene and 10 g Setrolene O (brand of ROL-ΜΕ for polyoxyethylate sorbitan oleate), while stirring. 50 g of this mixture are then left for 1 + 8 hours at 0 ° C and 50 g at 60 ° C for 5 days. In both 25 experiments, the liquid gas chromatographic analysis shows that no significant deterioration has taken place.

Example X.

A recipe is prepared by mixing together with stirring 1 + 0 g technical Rogor, 20 g phenylacetic acid, 25 g xylene 30 and 10 g Setrolene 0. 50 g of this mixture is kept at 0 ° C

for 1 + 8 hours, while holding 50 g at 60 ° C for 5 days. In both tests, the liquid gas chromatographic analysis shows that no significant deterioration has taken place.

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Example XI

Technically, the room temperature is mixed with 10 g acetic acid, 0 g xylene and 10 g Emulsion 10B. 50 g of this mixture is kept at 0 ° C for 8 hours and another 50 g at 60 ° C for 5 days. No separation could be observed after the tests, while the liquid-gas chromatographic analysis shows that no significant deterioration has taken place.

Example XII

10 g of technical methyl parathion are mixed at room temperature with 10 g of acetic acid, bo g of xylene and 10 g of emulsion 10B. 50 g of this mixture is held at 0 ° C for 1 + 8 hours, while 50 g is held at 60 ° C for 5 days. No separation could be observed after these tests, while the liquid-gas chromatographic analysis shows that no significant deterioration has taken place.

Example XII

Technical Monocrotophos is mixed with 10 g of acetic acid and 50 g of xylene. 50 g of this mixture is kept at 0 ° C for 20-8 hours and another 50 g at 60 ° C for 5 days. No change could be observed after these tests, while the liquid gas chromatographic analysis shows that no significant deterioration has taken place.

800 24 94

Claims (8)

Liquid preparations of phosphoric acid and thiophosphoric acid pesticides which are stable and resistant to low and high temperature, characterized in that said preparations consist of a mixture of - phosphoric acid or thiophosphoric acid pesticide 0.05-90 # - organic acid or mixture of organic acids 99 5-10 # to which mixtures one or more of the following solvents are added with stirring: a) Xylene-type aromatic solvents, or aromatic-aliphatic solvents such as Shellsol A, AB; or Solvesso 100, 150,200; h) dimethylformamide, dimethyl sulfoxide, alcohols with 1-6 carbon atoms, glycols with C-15 d-d, c) cyclohexanone-type ketones, ethylamyl ketone; d) esters of the amyl acetate type, methyl benzoate, etc., e) surfactants. Preparations according to claim. 1, characterized in that the organic acids are acetic acid, propionic acid, butyric acid, cp, pronic acid, caprylic acid, oleic acid, ricinoleic acid, stearic acid, formic acid and / or phenylacetic acid. Preparations according to claim 1, characterized in that the phosphoric or thiophosphoric pesticide is Rogor. Preparations according to claim 1, characterized in that the phosphoric or thiophosphoric pesticide is M 817 ^. Preparations according to claim 1, characterized in that the pesticide is methyl parathion. Preparations according to claim 1, characterized in that the pesticide is Monocrotophos. Preparations according to claim 1, characterized in that the pesticide is FAC. Preparations according to claim 1, characterized in that xylene is added to the mixture of phosphoric or thiophosphoric pesticide and organic acid. 800 24 94 V V Preparations according to claim 5, characterized in that a surfactant is added to the mixture of phosphoric or thiophosphoric pesticide, organic acid and xylene. 800 2 4 94