GB2029226A - Fenitrothion ULV formulations - Google Patents

Abstract

An ultra-low volume composition of Fenitrothion comprises 40 to 90% by weight of Fenitrothion and from 10 to 60% inclusive by weight of a component which is [1] an acetic ester solvent or an alicyclic or aliphatic ketone solvent, [2] a mixed solvent composed of A group solvent: a higher alkyl-substituted phenol or vegetable oil and B group solvent: a naphthene or paraffin hydrocarbon solvent having a viscosity of 5 cps or less at 25 DEG C in the A to B ratio of (50-95) to (5-50), [3] an aromatic hydrocarbon solvent having from 9 to 20 carbon atoms inclusive and [4] one or more of butyl cellosolve, ethyl carbitol and butyl carbitol. Such a composition can be effectively employed for knocking down of killing insects by spraying. F

Description

SPECIFICATION Fenitrothion concentrate for ulv spraying The present invention relates to a composition containing Fenitrothion [0,0 - dimethyl 0 - (3 methyl - 4- nitrophenyl) - phosphorothioate] and in particular to a composition containing Fenitrothion and 10 to 60% by weight of a solvent, which composition is useful for ultra-low volume spraying.

Ultra-low volume spraying is a technique for spraying high-concentration oil, without dilution, at a rate of about 300 to 600 mIll 0 are. Particularly for spraying into the air, this technique makes labour for loading chemicals very easy, decreases the number of machines and workers and saves fuels, thus elevating efficiency remarkably.

Further, the size of the particles of the sprayed oil is relatively small (about 100 microns), but the specific gravity of the particles is often larger than that of water and drifting is relatively little. In addition persistency is longer than with other compositions so that the effect of a given active ingredient is increased by spraying it in this manner.

Solvents used for ultra-low volume spraying should satisfy the following requirements: (1) High capacity to dissolve chemicals.

(2) Low viscosity (about 20 cps or less at 25 C).

(3) High flash point.

(4) Low toxicity.

(5) Cause no decomposition to chemicals.

(6) Cause no phytotoxicity.

(7) Low vapor pressure (Less volatile).

In Japan, ethyl cellosolve has been used as a solvent for ultra-low volume spraying of Fenitrothion.

But this solvent has the drawback that Fenitrothion is fairly unstable in it. We extensively studied solvent systems for the ultra-low volume spraying of Fenitrothion and found a solution to this problem by providing a composition for ultra-low volume spraying which includes Fenitrothion, which satisfies the abovementioned requirements, and in which the Fenitrothion has a satisfying stability.The composition comprises from 40 to 90 /O inclusive by weight of Fenitrothion, as hereinbefore defined, and from 10 to 60% inclusive by weight of a component which is one or more of [1] an acetic ester solvent or an alicyclic or aliphatic ketone solvent, [2] a mixed solvent composed of A group solvent: one or more higher alkyl substituted vegetable oil(s) and B group solvent: one or more naphthene or paraffin hydrocarbon solvent(s) having a viscos ity of 5 cps or less at 25"C in the A:B ratio of from 50:50 to 95:5 inclusive, [3] an aromatic hydrocarbon solvent having from 9 to 20 carbon atoms inclusive, and [4] one or more of ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether.

The solvents used in compositions embodying the present invention will be illustrated more specifically. Examples of the acetic ester solvents include benzyl acetate, butyl methoxyacetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate and the like. Examples of the aliphatic ketone solvents include cyclohexanone, 3-methylcyclohexanone, isobutyl heptyl ketone, acetophenone, isophorone and the like.

The A group solvent has a high capacity to dissolve Fenitrothion, but its viscosity is so high that it cannot be used also as a solvent for ultra-iow volume compositions.

In contrast, the B group solvent has a low viscosity, but its capacity to dissolve Fenitrothion is so low that it cannot be used alone as a solvent for ultra-low volume compositions. However, a mixed solvent comprising the A and B group solvents in the A:B ratio of from 50:50 to 95:5 inclusive are satisfactory in its capacity to dissolve Fenitrothion and is also in low viscosity.

Examples of the A group solvent include nonylphenol, linseed oil, cottonseed oil, soybean oil, corn oil, castor oil and the like.

Examples of the B group solvent include Diesel oil, kerosene, light oil, Shellsol 140, Shellsol 340 (Shell Oil), Solvent 140 (Allied Chemical), Ondina oil 17 (Shell Oil) and the like.

In preparing the ultra-low volume compositions of the present invention, the A and B group solvents may first be mixed, followed by dissolving Fenitrothion, or Fenitrothion may first be dissolved in the A group solvent, followed by adding the B group solvent.

Examples of the aromatic hydrocarbon solvents having 9 to 20 carbon atoms include dodecylbenzene, methyl naphthalene, trimethyl benzene, methylethylbenzene, dimethylethylbenzene, tet ramethyl benzene, higher alkyl-substituted benzene and the like.

Further, they include mixtures of these aromatic hydrocarbons for example Solvesso 100, Solvesso 150 (Esso Standard), Shellsol A, Shellsol AB (Shell Oil) Velsicol AR-60 (Versicol), Arotex 3470 (Texaco), Kawakasol, Cyclosol 63 (Shell Oil) and the like.

Alternatively ethylene glycol monobutyl ether (hereinafter called "butyl cellosolve", diethylene glycol monoethyl ether (hereinafter called "ethyl carbitol") and diethylene glycol monobutyl ether (hereinafter called "butyl carbitol") are particularly superior in terms of their high flash point and the stability of Fenitrothion therein.

The flash point and viscosity of these solvents and those of ethyl cellosolve, a control, is shown below.

Solvent Flash point Viscosity ( C) (25 C, cps) Ethyl cellosolve* 54 2.3 Butyl ceflosolve 0 74 1.8 Ethyl carbitol 96 5.0 Butyl carbitol 116 5.6 control Of course, the solvents which can be employed in compositions embodying the present invention are not limited to these examples.

The ultra-low volume compositions of the present invention can be prepared very simply by merely mixing the solvent and Fenitrothion in a predetermined proportion.

For example, 80% (weight'volume) compositions of the present invention can be prepared by adding the solvent to 800 q of Fenitrothion to qive a total volume of 1000 ml, followed by thorough stirring.

Further, even if one solvent of the composition is other than a mixed solvent composed of the A group solvent and the B group solvent, a naphthene or paraffin hydrocarbon (i.e. B group) solvent may still be added to that one solvent. The B group solvent may be any of Diesel oil, kerosene, light oil, Shellsol 140, Shellsol 340 (Shell Oil), Solvent 140 (Allied Chemical), Ondina oil 17 (Shell Oil) and the like.

Compositions embodying the present invention will be illustrated in more detail with reference to the following Examples.

Example 1 Ultra-low volume compositions of the present invention were prepared by mixing 2 parts by weight of Fenitrothion and 1 part by weight of a solvent.

One c.c. each of these composition was sealed in an ampouie and stored at 40"C and 60"C. The decomposition percentage was then examined.

Fenitrothiom content (%) Solvent Cyclo- Benzyl Ethyl t (Decomposition hexanone acetate cello solve percentage (S)) At the start 64.i 65.0 . 66.7 600C, 10 days 63.3 (2.2) 69.3 (1.1) 50.0 (25.0) 11o0c, 1 month 64.0 (1.1) 64.7 (0.5) 60.7 ( 9.0) 40 C, 2 months 63.8 (1.4) 611.5 (0.8) 53.0 (21.5) 40 C, 3 months 63.5 (1.9) 611.3 (1.1) 52.0 (22.0)

* Control The figures in parentheses are decomposition percentages.

Example 2 One hundred grams of Fenitrothion was placed in a measuring flask, and cyclohexanone was added thereto to give a total volume of 100 ml. This mixture was made into a homogeneous solution by thorough mixing and measured for viscosity and specific gravity to obtain the following results.

Temperature Viscosity ("c) (cps) 30 11.3 25 13.7 20 16.8 15 20.7 10 24.6 d3030 1.20

Example 3 One hundred grams of Fenitrothion was placed in a measuring flask, and benzyl acetate was added thereto to give a total volume of 100 ml. This mixture was made into a homogeneous solution by thorough mixing and measured for viscosity and specific gravity to obtain the following results.

Temperature Viscosity ( C) (cps) 30 10.5 25 12.8 20 15.9 15 19.6 10 21).1 d30 1.25 30 Example 4 One hundred grams of Fenitrothion was placed in a measuring flask, and ethyl cellosolve acetate was added thereto to give a total volume of 100 ml. This mixture was made into a homogeneous solution by thorough mixing and measured for viscosity and specific gravity to obtain the following results.

Temperature Viscosity ( C) (cps) 30 9.0 25 11.0 20 13.5 15 16.6 10 20.3 d30 1.23 -30 Example 5 A homogeneous solution was obtained in the same manner as in Example 3 except that the amount of Fenitrothion was changed to 50 g. This solution was measured for viscosity and specific gravity to obtain the following results.

Temperature Viscosity ( C) (cps) 30 4.0 25 4.5 20 5.1 15 5.7 10 6.3 d3030 1.14

Example 6 A homogeneous solution was obtained in the same manner as in Example 4 except that the amount of Fenitrothion was changed to 50 g. This solution was measured for viscosity and specific gravity to obtain the following results.

Temperature Viscosity ( C) (cps) 30 2.8 25 3.2 20 3.6 15 4.2 10 4.7 d3030 1.10 Example 7 A 1:1 mixed solvent of nonylphenol and Diesel oil A was added to 40 g of Fenitrothion to give a total volume of 100 ml. The ultra-low volume composition thus obtained was measured for viscosity to obtain the following results.

Temperature Viscosity ( C) (cps) 30 9.2 25 11.6 20 14.3 15 18.3 10 23.3 d3030 0.99 Example 8 An ultra-low volume composition of the present invention was obtained in the same manner as in Example 7 except that the amount of Fenitrothion was changed to 50 g. This composition was measured for viscosity to obtain the following results.

Temperature Viscosity ( C) (cps) 30 10.1 25 12.6 20 15.9 15 20.4 10 25.8 d3030 0.98

Example 9 A mixed solvent was prepared by mixing linseed oil and Diesel oil A in a ratio of 8 to 2. The mixed solvent was added to 40 g of Fenitrothion to give a total volume of 100 ml. The ultra-low volume composition thus obtained was measured for viscosity to obtain the following results.

Temperature Viscosity ( C) (cps) 30 18.6 25 22.5 20 27.4 15 34.4 10 41.7 d3030 1.00 Example 10 One millilitre of each of the ultra-low volume compositions prepared in Examples 7 and 9 was stored at 50 C and 40 C under an accelerated condition. The content of Fenitrothion in each composition was then measured.

Accelerated Content of Fenitrothion (%) condition Example 7 Example 9 Ethyl cellosolve* At the start 40.2 40.1 40.2 50"0, 10 days 40.0 (0.5) 40.1 ( - ) 38.9 (3.2) 20 days 39.5 (1.7) 39.9 (0.5) 37.8 (6.0) 30 days 39.1 (2.7) 39.7 (1.0) 36.0 (10.4) 40"0, 1 month 39.9 (0.7) 39.8 (0.7) 39.0 (3.0) 2 months 39.11 (2.0) 39.6 (1.2) 37.7 (6.2) 3 months 38.4 (11.5) 39.3 (2.0) 35.3 (11.7) Control The figures in parentheses are decomposition percentages.

Example 11 An ultra-low volume composition of the present invention was prepared as in Example 7, but using Light oil No. 1 in place of Diesel oil A.

Example 12 A mixed solvent was prepared by mixing nonylphenol and Solvent 140 in a ratio of 7 to 3. This mixed solvent was added to 100 g, 80 g, 50 g and 40 g each of Fenitrothion to give respective solutions each of a total volume of 100 ml. These solutions, designated as L-100, L-80, L-50 and L-40, respectively, were measured for viscosity to obtain the following results.

Tempera- Viscosity (cps) ture ( C) L-100 L-80 L-50 L-40 30 20.6 17.8 16.1 16.4 25 26.5 22.8 20.7 21.3 d3030 1.19 1.11 1.01 0.98 Example 13 Solvesso 150 and Velsicol AR-60 was added to respective 100 g portions of Fenitrothion to give a respective total volume of 100 ml, followed by thorough mixing. These solutions were measured for viscosity and specific gravity to obtain the following results.

Tempera- Viscosity (cps) ture ( C) Solvesso 150 Velsicol AR-60 40 6.8 9.1 30 9.8 13.3 20 14.3 21.4 10 23.0 37.0 d2525 1.23 1.25 Example 14 One millilitre of each of the test samples prepared in Example 13 was stored at 50 C and 60 C. The content of Fenitrothion was measured to obtain the following results.

Content or Fenitrothion (%) Accelerated condition Solvesso 150 Velsicol AR-60 solve At the start 102.4 102.7 102.5 600C, 10 days 101.4 101.5 81.3 600C, 20 days 100.11 100.0 75.8 50 C, 10 days 101.5 102.7 92.7 500C, 20 days # 101.0 102.0 83.4 control Example 15 An ultra-low volume composition of the present invention was prepared by mixing 66 g of Fenitrothion and 34 g of Solvesso 150.This solution was measured for change in Fenitrothion content during high-temperature, short-period accelerated storage to obtain the following results.

Content of Fenitrothion (%) Accelerated condition Ethyl Solvesso 150 cellosolve* At the start 62.1 62.7 1200C, 10 min 62.1 60.8 (3.0) 1200C, 20 min 61.3 (1.3) 58.4 (6.9) 100 C, 20 min 61.4 (1.1) 62.7 ( 0 ) 100 C, 40 min 61.3 (1.3) 61.1 (2.5) 80 C, 40 min 62.o ( 0 ) 62.2 (0.8)

* Control The figures in parentheses are decomposition percentages.

Example 16 A solution prepared by mixing Fenitrothion and Kawakasol in a weight ratio of 2 to 1 was stored at 40 C and 60 C to obtain the following results.

content or Fenitrothion (%) Accelerated condition Kawakasol Ethyl cellosolve* At the start 65.3 66.7 60 C, 10 days 64.7 (0.9) 50.0 (25.0) 40 C, 1 month 65.3 ( 0 ) 60.7 ( 9.0) 11000, 2 months 65.7 ( - ) 53.0 (21.1) 40 C, 3 months # 64.7 (0.9) # 52.0 (22.1) Control The figures in parentheses are decomposition percentages.

Example 17 An ultra-low volume composition of the present invention was prepared by adding dodecylbenzene to 100 g of Fenitrothion to give a total volume of 100 ml. This solution had a flash point higher than 70 C and a viscosity of 23.9 cps at 25 C.

Example 18 Cyclosol 63 was added to each of respective 100 g, 80 g, 50 g and 40 g portions of Fenitrothion to give a respective total volume of 100 ml. These solutions, designates as L-100, L-80, L-50 and L-40, respectively, were measured for viscosity to obtain the following results.

Tempera- Vuscosity (cps) ture ( C) L-100 L-80 L-50 L-40 30 10.1 - 2.8 25 11.9 6.0 3.0 1.2 20 # 13.9 # - # 3.5 # 15 17.5 - 3.9 10 22.1 - 11.3 d3030 # 1.20 # - # 1.06 # Example 19 An ultra-low volume composition of the present invention was prepared by mixing 48 g of Fenitrothion and 52 g of butyl cellosolve. One millilitre of this sample was stored under an accelerated storage condition, and change in Fenitrothion content was measured.

Content of Fenitrothion ( ) Accelerated condition Butyl Ethyl cellosolve cellosolve* At the start 48.2 48.5 600c, 10 days 48.3 ( - ) 45.0 (7.2) 500C, 30 days 48.1 (0.2) 47.2 (2.7) 11o0c, 60 days 46.8 (2.8) 115.8 (5.5) Control The figures in parentheses are decomposition percentages.

Example 20 Butyl cellosolve was added to each of respective 100 g, 80 g, 50 g and 40 g portions of Fenitrothion to give a respective total volume of 100 ml. These solutions, designated as L-100, L-80, L-50 and L-40, respectively, were measured for viscosity to obtain the following results.

Tempera- Viscosity (cps) ture ( C) L-100 L-80 L-50 L-40 30 - - - 4.5 25 12.4 8.5 6.0 5.0 20 - 10.3 - 5.9 15 # - # - # - # 6.8 10 - 15.3 - # 8.1 Example 21 Ultra-low volume compositions of the present invention were prepared by mixing 60 g of Fenitrothion and 40 g of ethyl carbitol (and butyl carbitol).One millilitre each of these samples were stored under an accelerated condition, and the content of Fenitrothion was measured.

Accelerated Content of Fenitrothion (%) condition Ethyl Butyl Ethyl carbitol carbitol eellosolve* At the start 60.2 60.1 60.2 60 C, 10 days 59.0 (2.0) 59.2 (1.5) 56.3 (6.5) 20 days 57.7 (4.2) 58.0 (3.5) 54.1 (10.2) 50C, 10 days 60.0 (0.4) 60.0 (0.2) 59.3 (1.5) 20 days 59.8 (0.7) 59.8 (0.5) 58.7 (2.5) 40 C, 30 days 59.7 (0.9) 59.7 (0.7) 58.3 (3.2) 60 days 59.3 (1.5) 59.4 (1.1) 56.9 (5.11) Control The figures in parentheses are decomposition percentages.

Example 22 Ethyl carbitol was added to a respective 100 g, 80 g, 50 g and 40 g portion of Fenitrothion to give a respective total volume of 100 ml. These solutions, designated as L-100, L-80, L-50 and L-40, respectively, were measured for viscosity to obtain the following results.

Tempera- Viscosity (cps) ture ( C) L-100 L-80 L-50 L-40 30 12.8 - 7.5 25 16.2 12.0 9.0 7.1 20 # 20.2 # - # 10.9 # 15 26.3 - 13.2 10 34.7 - 16.1 d3030 # 1.24 # - # 1.06 # - # Example 23 An ultra-low volume composition of the present invention was prepared by adding butyl carbitol to 100 g of Fenitrothion to give a total volume of 100 ml. The viscosity of this composition was 16.9 cps at 25 C Reference Examples will now be given to demonstrate that insecticidal compositions embodying the present invention have an efficacy superior to that of conventional ones.

Reference example 1 Two compositions (1) and (2) of Example 1 stored at40'Cfor3 months, (1) being a cyclohexanone solution and (2) being a benzyl acetate solution, and a conventional composition (ethyl cellosolve solution), a control, were each sprayed onto tea trees on which the smaller tea tortrix (Adoxophyes fasciata) was parasitic, at a rate of 50 g (active ingredient)/10 are, by means of a portable ULV sprayer (produced by Microgen Co.). Two days after spraying, 20 rolled leaves per plot were sampled and unrolled to examine the numbers of dead and alive of the larvae (one tree/plot, 3 replications).

Test composition Mortality (S) Composition of the Example 1 (1) Cyclohexanone 100 Composition of the Example 1 (2) Benzyl acetate 100 Control (ethyl cellosolve) # 83 No treatment 5 Reference Example 2 Two compositions of the present invention stored at 40 C for 1 month, one being prepared in Example 7 and the other in Example 9, and a conventional composition (ethyl cellosolve solution), a control, were each sprayed onto tea trees on which the smal lertea tortrix (Adoxophyes fasciata) was parasitic, at a rate of 50 g (active ingredient)/10 are, by means of a portable ULV sprayer (produced by Microgen Co.).

Two days after spraying, 20 rolled leaves per plot were sampled and unrolled to examine the numbers of dead and alive of the larvae (one tree/plot, 3 replications).

Test composition Mortality (S) Composition or the Example 7 (nonylphenol:Diesel oil A = 1:1) 100 Composition of the Example 9 (linseed oil:Diesel oil A = 8::2) 100 Control (ethyl cellosolve) 90 No treatment 3 Reference Example 3 Two compositions (1) and (2) of Example 13 stored at 50"C for 20 days, (1) being a Solvesso 150 solution and (2) being a Velsicol AR-60 solution, and a conventional composition (ethyl cellosolve solution), a control, were each sprayed on tea trees on which the smaller tea tortrix (Adoxophyes fasciata) was parasitic, at a rate of 50 g (active ingredient)/10 are, by means of a portable ULV sprayer (produced by Microgen Co.). Two days after spraying, 20 rolled leaves per plot were sampled and unrolled to examine the numbers of dead and alive of the larvae (one tree/ plot, 3 replications).

Test composition Mortality (S) Composition of the Example 13 (1) Solvesso 150 100 Composition of the Example 13 (2) Velsicol AR-60 100 Control (ethyl cellosolve) 87 No treatment 0 Reference Example 4 The compositions in Example 22 stored at 400C for 60 days, and a conventional composition (ethyl cellosolve solution), a control, were each sprayed on tea trees on which the smaller tea tortrix (Adoxophyes fasciata) was parasitic, at a rate of 50 g (active ingredient)/10 are, by means of a portable ULV sprayer (produced by Microgen Co.). Two days after spraying, 20 rolled leaves per plot were sampled and unrolled to examine the numbers of dead and alive of the larvae (onetree/plot,3 replications).

Test composition Mortality (S) Ethyl carbitol 100 Butyl carbitol 100 Ethyl cellosolve (control) 90 No treatment 0

Claims (8)

1. A composition which comprises from 40 to 900/c inclusive by weight of Fenitrothion, as hereinbefore defined, and from 10 to 60% inclusive by weight of a component which is one or more of [1] an acetic ester solvent or an alicyclic or aliphatic ketone solvent.

[2] a mixed solvent composed of A group solvent: one or more higher alkyl substituted phenol(s) or vegetable oil(s) and B group solvent: one or more naphthene or paraffin hydrocarbon solvent(s) having a viscos ity of 5 cps or less at 25"C in the A:B ratio of from 50:50 to 95:5 inclusive, [3] an aromatic hydrocarbon solvent having from 9 to 20 carbon atoms inclusive, and [4] one or more of ethylene glycol monobutyl ether, diethlene glycol monoethyl ether, and diethylene glycol monobutyl ether.

2. A composition according to claim 1, wherein the component [1] is an acetic ester solvent which is benzyl acetate, butyl methoxyacetate, ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate or diethylene glycol monobutyl ether acetate.

3. A composition according to claim 1, wherein the component[1] is an alicyclic solvent which is cyclohexanone, 3 - methyl - cyclohexanone or isophorone.

4. A composition according to claim 1, wherein the component[1] is an aliphatic ketone solvent which is a member selected from the group consisting of isobutyl heptyl ketone oracetophenone.

5. A composition according to any one of the preceding claims, wherein the A group solvent is nonylphenol, linseed oil, cotton-seed oil, soybean oil, corn oil or castor oil and the B group solvent is Diesel oil, kerosene, light oil, Shellsol 140, Shellsol 340, Solvent 140 or Ondina oil 17.

6. A composition according to any one of the preceding claims, wherein the aromatic hydrocar bon solvent is dodecylbenzene, methyinaphthalene, trimethylbenzene, methylethylbenzene, dimethylethylbenzene, tetramethylbenzene or a higher alkyl-substituted benzene or a mixture of two or more said aromatic hydrocarbons.

7. A method of knocking down or killing insects which comprises contacting the insects with a com position according to claim 1 by spraying.

8. Acomposition according to claim 1 substan tially as herein described and exemplified.