Activator for herbicide

Abstract

A herbicidal composition comprising an effective amount of a biocide and an effective amount of a herbicide activator selected from the group consisting of an alkyl phosphate, an alkenyl phosphate, a hydroxyalkyl phosphate, a polyoxyalkylene alkyl ether phosphate, a salt thereof, a polyoxyalkylene alkenyl ether phosphate, a salt thereof, a polyoxyalkylene hydroxyalkyl ether phosphate and a salt thereof.

Description

The present invention relates to an activator for biocides.

Biocides such as inseticides, germicides, herbicides and plant growth regulators have been used in the form of an emulsion, wettable powder, flowable product, grains or powder.

The physical properties of the biocides have been modified variously so as to exhibit the activity of the active ingredient sufficiently. However, it has been impossible to further increase the effects of the biocide.

It is quite significant to further increase the effects of known biocides, since the development of new biocides is now very difficult.

After intensive investigations, the inventors have found that specified compounds are effective in further activating various biocides. The present invention has been completed on the basis of this finding.

The invention provides a biocidal composition which comprises an effective amount of a biocide and an effective amount of a biocide activator selected from the group consisting of an alkyl phosphate, an alkenyl phosphate, a hydroxyalkyl phosphate, a polyoxyalkylene alkyl ether phosphate, a salt thereof, a polyoxyalkylene alkenyl ether phosphate, a salt thereof, a polyoxyalkylene hydroxyalkyl ether phosphate and a salt thereof. The invention may be provided in the form of an emulsion concentrate which comprises 10 to 70 weight percent of the biocide and 10 to 50 weight percent of the biocide activator, 3 to 20 weight percent of an emulsifier and 10 to 50 percent weight of an organic solvent, or a dilute composition which comprises 100 to 5,000 ppm of the biocide, 200 to 10,000 ppm, preferably 500 to 5,000 ppm, of the biocide activator and a carrier for dilution. The diluent composition is usually prepared just in advance to use thereof.

The alkyl phosphates, polyoxyalkylene alkyl ether phosphates and salts of them according to the present invention may be prepared by known processes. For example, they are obtained by reacting an alcohol (if necessary, after addition of an alkylene oxide thereto) with phosphorus pentoxide and, if necessary, neutralizing the reaction product.

The starting alcohol has 1 to 22 carbon atoms and contains a straight-chain or branched alkyl group, an alkenyl group having double bond(s) or hydroxyl group(s) in the chain or a hydroxyalkyl group. The alcohol contains preferably 4 to 18 carbon atoms, 0 to 4, preferably 0 to 2 double bonds and 0 to 4, preferably 0 to 2, hydroxyl groups. The alcohols include, for example, butanol, 2-ethylhexanol, lauryl alcohol, stearyl alcohol and oleyl alcohol.

The alkylene oxides to be added to the alcohol to form a polyoxyalkylene chain include ethylene oxide, propylene oxide and butylene oxide. They may be used either alone or in the form of block or random adducts of two or more of them. The mol number of addition is 1 to 100, preferably 1 to 50.

The addition reaction may be carried out by a known process by, for example, introducing an alkylene oxide into an alcohol in the presence of an acid or alkaline catalyst at 50.degree. to 200.degree. C. under 1 to 5 kg/cm.sup.2. The alcohol or polyoxyalkylene alkyl ether may be phosphated by various processes. For example, 3 mol of the alcohol or polyoxyalkylene alkyl ether is reacted with 1 mol of phosphorus pentoxide at 80.degree. to 100.degree. C. for about 6 h to obtain a corresponding phosphate easily. The obtained alkyl phosphate or polyoxyalkylene alkyl ether phosphate is a mixture of a monoester and a diester in substantially equal amounts. Though excellent effects are exhibited when the activator for biocides of the present invention is any of the monoester and the diester, particularly excellent effects are obtained when it is a monoester, particularly a polyoxyalkylene alkyl ether/phosphoric monoester or a salt thereof.

When said phosphate is neutralized with a base, a corresponding polyoxyalkylene alkyl ether phosphate salt is obtained. This ester salt also has an excellent activating effect. The salts include alkali metal, alkaline earth metal, monoethanolamine, diethanolamine, triethanolamine and ammonium salts.

When the activator for biocides of the present invention is used in combination with a biocide, the effect of the biocides can be increased 2 or 3-folds irrespective of the variety of the biocide.

The activator of the present invention is used in an amount of 0.05 to 20, preferably 1 to 15 parts by weight per part by weight of the biocide.

The biocide may be in the form of any of an emulsion, flowable product, wettable powder and powder. Therefore, other additives such as an emulsifying agent, dispersant and carrier may be incorporated therein according to the form of the biocide.

The activator of the present invention may be used by incorporating the same into the biocide of the above-mentioned form according to the formulation or by applying the same to a subject in combination with the biocide at the time of the application of the biocide in a diluted form. The activating effect according to the invention can be obtained in both cases.

Though the mechanism of such a remarkable activation of the biocide by the activator of the present invention has not been fully elucidated yet, it may be presumed that the activator for biocide of the present invention has an extremely high power of solubilizing the biocide irrespective of the structure of the biocide and, therefore, the biocide is finely divided and the penetration thereof through the surfaces of plants or into insects and germs is accelerated.

The present invention provides also a biocidal process characterized by spraying an emulsion (or dispersion) of a biocide containing the above-described activator.

Examples of the biocides which are activated by the activator of the present invention will be given below, which by no means limit the biocides to be activated according to the present invention. The activator of the present invention can be used safely without damaging the farm products. The insecticides include pyrethroid insecticides such a Fenvalerate [.alpha.-cyano-3-phenoxybenzyl-2-(4-chlorophenyl)-3methylvalerate] and Pyrethroid [cyano(4-fluoro-3-phenoxyphenylmethyl-3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropanecarboxylate]; organophosphorus insecticides such as DDVP (2,2-dichlorovinyldimethyl phosphate), Sumithion (dimethyl-4-nitro-m-tolylphosphorothionate), Malathone {S-[1,2-bis(ethoxycarbonyl)ethyl]dimethylphosphorothiol thionate}, Dimethoate [dimethyl-S-(N-methylcarbamoylmethyl)phosphorothios thionate), Elsan {S-[.alpha.-(ethoxycarbonyl)benzyl]dimethylphosphorothiol thionate) and Baycid [O,O-dimethyl-O-(3-methyl-4methylmercaptophenyl)thiophosphate]; carbamate), insecticides such as Bassa (O-butylphenyl methylcarbamate), MTMC (m-tolyl methylcarbamate), Meobal (3,4-dimethylphenyl-N-methylcarbamate), NAC (1-naphthyl-N-methylcarbamate); as well as Methomyl {methyl-N[(methylcarbamoyl)oxy]thioacetimide} and Cartap {1,3-bis(carbamolythio)-2-(N,N-dimethylamino)propane hydrochloride].

Examples of acaricides include Smite {2-[2-(p-tert-butylphenoxy)isopropoxy]isopropyl-2-chloroethyl sulfide}, Acricid (2,4-dinitro-6-sec-butylphenyl dimethylacrylate), Chlormit (isopropyl 4,4-dichlorobenzylate), Acar (ethyl 4,4-dichlorobenzylate), Kelthane [1,1-bis(p-chlorophenyl)-2,2,2-trichloroethanol], Citrazon (ethyl O-benzoyl-3-chloro-2,6-dimethoxybenzohydroxymate), Plictran (tricyclohexyltin hydroxide) and Omite [2-(p-tert-butylphenoxy)cyclohexyl-2-propinyl sulfite].

Example of the germicides include organosulfur germicides such as Dithane (zinc ethylenebisdithiocarbamate), maneo (manganese ethylenebisdithiocarbamate), thiuram [bis(dimethylthiocarbamoyl) disulfide ], Benlate [methyl 1-(butylcarbamoyl)-2-benzimidazole carbamate], Difolatan (N-tetrachloroethylthio-4-cyclohexane-1,2-dicarboxyimide), Daconol (tetrachloroisophthalonitrile), Pansoil (5-ethoxy-3-trichloromethyl-1,2,4-thiadiazole), Thiophanate-methyl[1,2-bis(3-methoxycarbonyl-2-thioureido)benzene], Rabcide (4,5,6,7-tetrachlorophthaloid), Kitazin P (O,O-diisopropyl-S-benzyl phosphorothioate), Hinonsan (O-ethyl-S,S-diphenyldithiophosphate) and Propenazol (3-allyloxy-1,2-benzothiazole 1,1-dioxide).

Examples of the herbicides include Stam (3,4-dichloropropionanilide), Saturn [S-(4-chlorobenzyl) N,N-diethylthiolcarbamate), Lasso (2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide), Glyphosate [N-(phosphonomethyl)glycine isopropylamine salt], DCMU [3-(3,4-dichlorophenyl)-1,1-dimethylurea) and Gramoxone (1,1'-dimethyl-4,4'-dipyridium dichloride].

Example of the plant growth regulating agents include MH (maleic acid hydrazide) and Ethrel (2-chloroethylphosphonic acid).

[EXAMPLES AND EFFECTS ]

The following example will further illustrate the activators for biocides of the present invention.

EXAMPLE 1

A compound of the present invention was dissolved in a commercially available herbicide (Karmex wettable powder, Simazine wettable powder, Paraquat solution or Glyphosate solution) to obtain a 0.2% solution. 10 ml of the solution was sprayed to each pot of crabgrass (a weed of Gramineae) which had been grown uniformly. The herbicidal effects of them were compared with one another. The crabgrasses used were in a three- or four-foliate period having a height of about 10 cm. Each pot had 25 crabgrasses. The dilution rate of said Karmex wettable powder, Simazine wettable powder, Paraquat solution or Glyphosate solution was 1/300. The herbicidal rate was determined by weighing the above-the-ground parts of the crabgrasses 10 days after the spraying and the results were represented by percentage based on the weight of untreated grasses. The results are shown in Table 1.

TABLE 1__________________________________________________________________________ Herbicidal rate (%) Karmex Simazine wettable wettable Paraquat Glyphosate powder powder solution solution__________________________________________________________________________Activator of the present inventionPOE(3) 2-ethylhexyl phosphate 84.0 67.2 98.2 100POE(3) POP(5) 2-ethylhexyl 80.8 68.5 99.1 100phosphate 100POE(3) POP(5) 2-ethylhexyl 81.0 68.9 99.0 100phosphate/diethanolaminePOE(10) octyl phosphate 78.4 70.5 100 100Potassium POE(10) octyl 79.8 72.4 100 100phosphatePOE(30) lauryl phosphate 85.7 80.2 100 100POE(30) lauryl phosphate 86.0 81.5 100 100monoethanolaminePOE(60) POB(10) palmityl 78.8 82.4 100 100phosphateSodium POE(60) POB(10) palmityl 72.1 82.0 100 100phosphatePOE(25) POP(10) oleyl phosphate 89.1 89.5 100 100Ammonium POE(25) POP(10) oleyl 89.5 87.8 100 100phosphatePOE(80) linoleyl phosphate 88.4 88.1 100 100Calcium POE(80) linoleyl phosphate 89.4 89.9 100 1002-Ethylhexyl phosphate 69.0 60.0 95.0 97.2Lauryl phosphate 70.1 72.5 90.4 90.0Oleyl phosphate 75.2 79.0 94.0 92.0No activator used 21.0 18.4 64.2 68.4ComparativePOE(3) 2-ethylhexyl ether 51.2 42.8 69.0 70.0POE(10) octyl ether 49.0 40.4 72.0 78.4POE(30) lauryl ether 52.5 54.5 72.0 80.5POE(25) POP(10) oleyl ether 57.5 52.8 79.5 75.5POE(60) POB(10) palmityl ether 45.4 42.1 72.8 75.6POE(80) linoleyl ether 60.5 55.2 79.2 80.0__________________________________________________________________________ Note: Symbols POE, POP and POB represent polyoxyethylene, polyoxypropylen and polyoxybutylene, respectively. The numerals in the parentheses represent the mol number of addition.

EXAMPLE 2

Third-instar larvae of plant hoppers were cultured and the insecticidal effects of insecticides thereon were examined by the leaf dipping method 3 repetition. Each group consisted of 10 larvae. The insecticidal effects were compared with those in an untreated group 24 h after the treatment. The results are shown in Table 2.

The insecticides used were a Sumithion emulsion and a Malathon emulsion each diluted to a concentration of 1/2000. The concentration of the activator of the present invention was controlled to 0.1% based on the diluted emulsion.

TABLE 2______________________________________ Insecticidal rate (%) 50% 50% Sumithion Malathon emulsion emulsion______________________________________Activator of the present inventionPOE(3) 2-ethylhexyl phosphate 84.5 80.5POE(3) POP(5) 2-ethylhexl phosphate 82.5 78.4POE(3) POP(5) 2-ethylhexyl phosphate 82.5 78.5diethanolaminePOE(10) octyl phosphate 80.5 80.0Potassium POE(10) octyl phosphate 81.2 78.9POE(30) lauryl phosphate 86.4 82.4POE(30) lauryl phosphate 86.9 86.7monoethanolaminePOE(60) POB(10) palmityl 78.5 80.0phosphateSodium POE(60) POB(10) 82.4 81.5palmityl phosphatePOE(25) POP(20) oleyl phosphate 90.1 94.6Ammonium POE(25) POP(10) 86.5 90.0oleyl phosphatePOE(80) linoleyl phosphate 89.5 92.1Calcium POE(80) linoleyl phosphate 90.5 92.62-Ethylhexyl phosphate 68.2 60.0Lauryl phosphate 75.1 72.0Linoleyl phosphate 85.1 80.0No activator used 49.0 40.0ComparativePOE(3) 2-ethylhexyl ether 52.5 41.5POE(10) octyl ether 55.0 40.5POE(30) lauryl ether 55.5 42.8POE(25) POP(10) oleyl ether 49.0 39.5POE(60) POB(10) palmityl ether 50.5 40.0POE(80) linoleyl ether 56.0 45.2______________________________________

EXAMPLE 3

Male imagines of two-spotted red spider were applied to leaf disks of kidney beans in three replications. Each group consisted of 30 imagines. After the culture at 25.degree. C. for 24 h. 0.2 ml per each group of a test sample was sprayed by the chromatospray method. The insecticidal rate was determined by comparison with the results of an untreated group 24 h after the treatment. The acaricides used were Amitraz emulsion and Osadan wettable powder diluted to a concentration of 1/2000. The concentration of the activator of the present invention was controlled to 0.1% based on the diluted product. The results are shown in Table 3.

TABLE 3______________________________________ Insecticidal rate (%) 20% 20% Amitraz OsadanActivator of the present invention emulsion emulsion______________________________________POE(3) 2-ethylhexyl phosphate 92.5 100POE(3) POP(5) 2-ethylhexyl phosphate 96.0 100POE(3) POP(5) 2-ethylhexyl phosphate 96.0 100diethanolaminePIE(10) octyl phosphate 98.0 95.4Potassium POE(10) octyl phosphate 98.5 99.0POE(30) lauryl phosphate 97.5 100POE(30) lauryl phosphate 90.0 100monoethanolaminePOE(60) POB(10) palmityl phosphate 95.0 100Sodium POE(60) palmityl phosphate 92.5 100POE(25) POP(10) oleyl phosphate 100 100Ammonium POE(25) POP(10) oleyl 100 100phosphatePOE(80) linoleyl phosphate 100 100Calcium POE(80) linoleyl 100 100phosphateNo activator used 58.2 64.2______________________________________

It is apparent form Example 1 to 3 that the activators of the present invention have an excellent activating effect. In addition, each composition as prepared in Examples 1 to 3 was diluted with water. The obtained dilute one was effective to improve the biocide activity. Each component content in the dilute compositions is given below.

______________________________________In the compositions of Example 1 activator 2000 ppm Karmex 1660 Simazine 1660 Paraquat 800 Round-Up 660In the compositions of Example 2 activator 1000 ppm Sumithion 250 Malathon 250In the compositions of Example 3 activator 1000 ppm Dani-Cut 100 Osadan 225______________________________________

Claims

1. An agricultural herbicidal composition which consists essentially of an effective amount of an agricultural chemcial herbicide and an effective amount of a substance for increasing the herbicidal rate of said herbicide; said herbicide being 2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide; and said substance being selected from the group consisting of an alkyl phosphate, an alkenyl phosphate, a hydroxyalkyl phosphate, a polyoxyalkylene alkyl ether phosphate, a polyoxyalkylene alkenyl ether phosphate, a polyoxyalkylene hydroxyalkyl ether phosphate and salts thereof, said substance having from 1 to 22 carbon atoms in the alkyl or alkenyl group thereof, the weight ratio of said substance/said herbicide being in the range of 1/1 to 15/1.

2. A composition as claimed in claim 1, in which said substance has 1 to 100 oxyalkylene units and the alkylene group therein has 2, 3 or 4 carbon atoms.

3. A herbicidal composition as claimed in claim 1, in which each of said phosphates is a monoester of phosphoric acid.

4. A herbicidal composition as claimed in claim 1, in which said substance is a polyoxyalkylene alkyl ether phosphate monoester, a salt thereof, a polyoxyalkylene alkenyl ether phosphate monoester, or a salt thereof, said alkyl and alkenyl groups having 4 to 18 carbon atoms and the number of said oxyalkylene units being from 1 to 50.

5. A herbicidal composition as claimed in claim 1, wherein said alkyl is selected from the group consisting of lauryl and palmityl, and said alkenyl is selected from the group consisting of 2-ethylhexyl and linoleyl.

6. A method of controlling weeds which comprises applying to a weed growth medium a herbicidally effective amount of a composition as defined in claim 1.

7. A new composition as claimed in claim 1, in which said substance is anionic and is selected from the group consisting of a polyoxyalkylene alkylether phosphate, a polyoxyalkylene alkenyl ether phosphate, and salts thereof.

8. A composition as claimed in claim 1, in which said substance is selected from the group consisting of an alkyl phosphate and an alkenyl phosphate.

9. A composition as claimed in claim 1, in which said substance is selected from the group consisting of a hydroxyalkyl phosphate and polyoxyalkylene hydroxyalkyl ether phosphate.

10. An agricultural herbicidal composition which consists essentially of an effective amount of an agricultural chemical herbicidal, an effective amount of a substance for increasing the herbicidal rate of said herbicide and an inert carrier; said herbicide being 2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide; and said substance being selected from the group consisting of an alkyl phosphate, an alkenyl phosphate, a hydroxyalkyl phosphate, a polyoxyalkylene alkyl ether phosphate, a polyoxyalkylene alkenyl ether phosphate, a polyoxyalkylene hydroxyalkyl ether phosphate and salts thereof, said substance having from 1 to 22 carbon atoms in the alkyl or alkenyl group thereof, the weight ratio of said substance/said herbicide being in the range of 1/1 to 15/1.

11. A herbicidal composition as claimed in claim 10, in which the herbicide is 2-chloro-2',6'-diethyl-N-(methoxymethyl)acetanilide and the substance is a polyoxyalkylene alkyl ether phosphoric monoester or a salt thereof.

12. A herbicidal composition as claimed in claim 10, which comprises from 100 to 5,000 ppm, based on the composition, of said herbicide, from 200 to 10,000 ppm, based on the composition, of said substance and the balance is an inert carrier.