Biocide Activator

This invention relates to a biocide activator. In this description, the term "biocide" shall mean a material that destroys or inhibits unwanted organisms, such as plants, animals and bacteria.

Biocides, including insecticides, fungicides, herbicides and plant growth regulators, have been used in various forms such as emulsions, wettable powders, flowable agents, granules and dusts. In formulating these biocides numerous attempts have been made to utilize the activity of the active principle thereof sufficiently. However, no activator for such biocides has been disclosed as yet.

As it has become more and more difficult to develop new biocides, it will be highly advantageous if known biocides can be activated by means of an additive activating substance which enhances the activity of the biocide.

We have discovered that particular compounds exhibit an activating effect on various biocides. The present invention provides a biocide activator comprising a product which is prepared by reacting (1) propylene oxide, alone or together with ethylene oxide, with (2) a mixture of at least one fatty acid triglyceride and at least one polyhydric alcohol, under conditions effective to cause addition polymerization of the propylene oxide or propylene oxide and ethylene oxide, with the fatty acid triglyceride and polyhydric alcohol. The present invention further provides a biocidal composition which comprises an effective amount of a biocide such as an insecticide, bactericide, miticide, fungicide, herbicide or plant growth regulator, an effective amount of the foregoing biocide activator, and a carrier. The present invention further provides a dilute biocidal composition formed by diluting the foregoing biocidal composition with water, so that the concentration of the biocide is at least 25 parts per million and the concentration of the activator is at least 50 parts per million. As a preferred form of biocidal composition according to the invention, a biocidal emulsion concentrate is disclosed which contains 10-70 weight percent of the biocide, 10-50 weight percent of the activator, 3-20 weight percent of the emulsifier, and 10-50 weight percent of an organic solvent. In a preferred embodiment, the biocidal emulsion concentrate contains 20-55 weight percent of the biocide, 20-30 weight percent of the activator, 5-10 weight percent of the emulsifier, and 15-45 weight percent of the organic solvent.

The fatty acid triglyceride used in preparing the biocide activator of the present invention is not particularly limited, and triglycerides of higher fatty acids (C.sub.4 -C.sub.22) such as behenic, stearic, oleic, linoleic, palmitic, myristic, lauric and caprylic acid are preferably used. These higher fatty acids can be employed individually, or mixtures of at least two of them can be employed. The fatty acid triglyceride can be either a natural material or a synthetic product. Natural fats and oils which are natural fatty acid triglycerides are readily available and suitable for use in the present invention. Examples of these natural fats and oils are animal fats and oils such as beef tallow, lard, bone oil and mutton tallow, vegetable fats and oils such as coconut oil, palm oil, cottonseed oil, castor oil, rapeseed oil, coconut kernel oil, soybean oil, olive oil, linseed oil and corn oil, and various fish oils.

The polyhydric alcohol used in the present invention is preferably one having 2 to 6 carbon atoms and 2 to 6 hydroxyl groups, wherein the number of the hydroxyl groups does not exceed the number of carbon atoms. Example of these polyhydric alcohols are ethylene glycol, propylene glycol, glycerol, 1,2-, 1,3- and 2,3-butylene glycols, 1,2-, 1,3-, 2,3- and 2,4-pentylene glycols, 1,2-, 1,3-, 2,3- and 2,4-hexylene glycols, butanetriol, pentanetriol, hexanetriol, pentaerythritol, sorbitol, sorbitan, mannitol, xylitol, and dulcitol.

Among these polyhydric alcohols, it is preferable to employ polyhydric alcohols having three carbon atoms, pentaerythritol, or sorbitol. Glycerol is most preferred for achieving the objects of the present invention. A mixture of these polyhydric alcohols may be employed.

The molar ratio of fatty acid triglyceride(s):polyhydric alcohol(s) is from 1:0.1 to 1:5, preferably from 1:0.2 to 1:2.

The alkylene oxide to be added to the mixture of fatty acid triglyceride(s) and polyhydric alcohol(s) is critical in the present invention. This alkylene oxide added to said mixture in the present invention consists of propylene oxide, or consists of both propylene oxide and ethylene oxide. The propylene oxide is preferably added to said mixture in an amount of 1 to 100 mol, most preferably 3 to 50 mol, per 1 mol of the sum of the mols of the fatty acid triglyceride(s) and the mols of the polyhydric alcohol(s).

When both propylene oxide and ethylene oxide are used they can be added to said mixture in any order. Either block addition or random addition can be employed. The ethylene oxide is preferably added in an amount of 1 to 100 mol, most preferably 5 to 60 mol, per 1 mol of the sum of the mols of the fatty acid triglyceride(s) and the mols of the polyhydric alcohol(s).

The addition can be carried out under conventional conditions generally employed for adding an alkylene oxide to a compound having active hydrogen without particular limitation. Thus, the addition reaction can be carried out by adding an alkaline compound such as NaOH, KOH, sodium acetate, CH.sub.3 ONa and CH.sub.3 OK, as a catalyst, to a mixture of triglyceride(s) and polyhydric alcohol(s) in the above mentioned molar ratios and feeding an alkylene oxide thereto, at a temperature of approximately 100.degree. C. to 200.degree. C. and a pressure of 1 to 5 kg/cm.sup.2 gauge over a period of at least about an hour, usually several hours, to thereby allow the materials to react with each other.

The product formed by the above reaction is a mixture of various polymers and the details of its composition are presently unknown. However, it is assumed that the main component thereof is a material in which propylene oxide, alone or together with ethylene oxide, is inserted between (1) the fatty acid constituting part of the original fatty acid triglyceride and (2) a polyhydric alcohol or (3) glycerol originating from the fatty acid triglyceride. Such compounds would contain a linkage of which an example is: ##STR1## wherein n is the number of repeating units derived from the added propylene oxide.

The biocide activator of the present invention is not harmful when it is used with a biocide and it generally enhances the activity of the biocide by two to three times, regardless of the type of biocide with which it is employed. The activator of the present invention is advantageously used in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, per 1 part by weight of the active biocide principle.

A biocide composition containing the activator of the present invention can be formulated into a concentrated form such as a flowable agent, a wettable powder or a dust. Conventional additives such as an emulsifier, dispersant or carrier can be added, depending on the formulation. An emulsifier may be chosen so as to provide the resultant with a good emulsion state. These concentrates are generally diluted with water, before use. The activator of the present invention can be added to the biocide during the formulation of one of the abovementioned biocide compositions or during dilution thereof at the time of use. The activator exhibits activating effects as defined in the present invention in either case.

In the biocidal emulsion concentrate according to the invention, the organic solvent is preferably an aromatic hydrocarbon, most preferably xylene. The emulsifier contained in the biocidal emulsion concentrate preferably contains alkylbenzene sulfonate and at least two different polyoxyethylene compounds from among polyoxyethylene nonylphenol ether, polyoxyethylene oleyl ester, polyoxyethylene styrenated phenol ether and polyoxyethylene tribenzylphenol ether. The emulsifier according to the invention preferably consists of 20-40 weight percent of alkylbenzenesulfonate and 60-80 weight percent of one or more of the foregoing polyoxyethylene compounds.

The mechanism of the remarkable activating effect of the biocide activator of the present invention has not yet been determined. This activating effect might partly be due to the extremely high solubilizing effect of the activator of the present invention on a biocide which would break up the biocide into microparticles to thereby accelerate the penetration thereof through the surfaces of plants or into the bodies of insects or bacteria. In view of this fact, it is preferred to use the biocide activator of the present invention in a concentration of at least 50 ppm when diluted in an aqueous biocide composition.

Accordingly, the present invention further provides a process for controlling organisms which comprises spraying a dilute biocide composition, particularly an emulsion or dispersion, containing at least 50 ppm of a composition prepared by adding propylene oxide, alone or together with ethylene oxide, to a mixture of fatty acid triglyceride(s) and polyhydric alcohol(s) under conditions effective to cause addition polymerization.

Non-limiting examples of the biocides to which the activator of the present invention can be added are as follows. The products of the present invention can be safely applied on a wide variety of crops without harm. Thus, the activator of the present invention can be used with insecticides including pyrethroid insecticides such as Fenvalerate (-cyano-3-phenoxybenzyl 2-(4-chlorophenyl)-3-methylvalerate) and Baisroid (cyano-(4-fluoro-3-phenoxyphenylmethyl)-3-(2,2-dichloroethenyl)-2,2-dimeth ylcyclopropanecarboxylate), organophosphorus insecticides such as DDVP (2,2-dichlorovinyl dimethyl phosphate), Sumithion (dimethyl 4-nitro-m-tolyl phosphorothionate), Malathion (S-[1,2-bis(ethoxycarbonyl)ethyl]dimethyl phosphorothiolothionate), Dimethoate (dimethyl-S-(N-methylcarbamoylmethyl)-phosphorothiolothionate, Elsan (S-[.alpha.-(ethoxycarbonyl)benzyl]dimethyl phosphorothiolothionate, and Baycide (O,O-dimethyl-O-(3-methyl-4-methylmercaptophenyl)thiophosphate), carbamate insecticides such as Bassa (o-butylphenyl methylcarbonate), MTMC (m-tolyl methylcarbamate), Meobal (3,4-dimethylphenyl-N-methylcarbamate) and NAC (1-naphthyl N-methylcarbamate), and bactericides such as Methomyl (methyl-N-((methylcarbamoyl)oxy)thioacetoimide) and Cartap (1,3-bis(carbamoylthio)-2-(N,N-dimethylamino) propane hydrochloride.

The activator of the present invention can also be used with miticides such as Smite (2-(2-p-tert-butylphenoxy)isopropoxy)isopropyl-2-chloroethyl sulfide), Acricid (2,4-dinitro-6-sec-butylphenyl dimethylacrylate), Chlormite (isopropyl 4,4-dichlorobenzilate), Akar (ethyl 4,4-dichlorobenzilate), Kelthane (1,1-bis(p-chlorophenyl)-2,2,2-trichloroethanol), Citrazon (ethyl O-benzoyl-3-chloro-2,6-dimethoxybenzohydroxamate), Plictran (tricyclohexyltin hydroxide) and Omite (2-(p-tert-butylphenoxy)-cyclohexyl 2-propynyl sulfite).

The activator of the invention, can further be used with fungicides including organosulfur fungicides such as Dithane (zinc ethylenebisdithiocarbamate), Maneb (manganese ethylenebisdithiocarbamate), Thiram (bis-(dimethylthiocarbamoyl)disulfide), and other fungicides such as Benlate (methyl 1-(butylcarbamoyl)-2-benzimidazolecarbamate), Difolatan (N-(tetrachloroethylthio)-4-cyclohexene-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), Hinosan (O-ethyl S,S-diphenyl dithiophosphate and Propenasol (3-allyloxy-1,2-benzothiazole-1,1-dioxide).

The activator of the invention can be used with herbicides such as Stam (3,4-dichloropropionanilide), Saturn (S-(4-chlorobenzyl)-N,N-diethylthiolcarbamate), Lasso (2-chloro-2',6'-diethyl-N-(methoxymethyl)-acentanilide), Glyphosate (N-(phosphonomethyl)glycine isopropylamine salt), DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) and Gramoxone (1,1-dimethyl-4,4'-dipyridium dichloride), and with plant growth regulators such as MH (maleic hydrazide) and Ethrel (2-chlor ethyl phosphate).

To illustrate biocide compositions containing the biocide activator of the present invention, the following examples each showing the formulation of concentrated biocide compositions will be given. Unless otherwise state, quantities are expressed in percent by weight.

The effects of the activator of the present invention will be described in the following test examples. In these examples, the biocidal concentrates of the examples and comparative examples were diluted with water so that the concentrations of the biocides were as indicated below in parts per million (ppm).

Ten rice insect larvae of 3rd instar per area were grown triply to examine the effect of the biocide compositions of the examples by a leaf-dipping method wherein insects were allowed to infest each of a number of plant leaves, and the plant leaves infested with the insects were then dipped in the biocide compositions. In the test, the plant leaves having thereon the insects were dipped into the biocide composition solution for about 3 seconds. Then they were taken out and allowed to stand for a while. After a certain period of time had passed, the number of dead insects were calculated and an insecticidal ration was determined. The part of the leaf that was dipped into the biocide composition is referred to as the treated area, and the part thereof that was not dipped is referred to as the non-treated area. The insecticidal ratio was determined by comparing insect density of the treated area with insect density of the non-treated area 24 hours after the treatment. The insecticidal ratio is expressed as the percent reduction in the number of insects in the treated area caused by the biocide composition treatment, as compared to the non-treated area. The other ratios described hereafter in Test Examples 3 to 7 are calculated in the same manner, except that the pests other than insects were treated. The 50% lethal concentration (LC.sub.50) was also determined. The results are shown in Table 1.

Memestra brassicae larvae of 3rd instar per area were grown triply to examine the effect of biocide compositions by the leaf-dipping method described above. The insecticidal ratio was determined by comparison with the non-treated area 24 hours after the treatment. The 50% lethal concentration was also determined. Results are shown in Table 2.

30 female Tetranychus urtiae imagoes per area were inoculated triply and grown at 25.degree. C. for 24 hours to thereafter examine the miticidal effect of biocide compositions by the leaf-dipping method as described above. The miticidal ratio was determined by comparison with the non-treated area 24 hours after the treatment. The 50% lethal concentration was also determined. Results are shown in Table 3.

Young rice plants of pentafoliate stage were inoculated with Pyricularia oryzae and allowed to stand for 24 hours, whereby the plants became infected with Pyricularia oryzae. Then biocide compositions were sprayed thereon and the formed lesions were counted six months after the treatment to calculate the control ratio (%) by comparison with non-treated area of each plant. The control ratio was determined as the percent reduction in the number of lesions in the treated areas as compared to the non-treated areas. The 50% lesion controlling concentration or amount needed to reduce the number of lesions by 50%, was also determined. Results are shown in Table 4.

Young cucumber plants of trifoliate stage were inoculated with Sphaerotheca fuliginea and allowed to stand for 24 hours, whereby the plants became infected with Sphaerotheca filinginea. Then biocide compositions were sprayed thereon and the formed lesions were counted seven days after the treatment to calculate the control ratio (%) by comparison with the non-treated area of each plant. The 50% lesion controlling concentration was also determined. Results are shown in Table 5.

30 crabgrasses of trifoliate stage per pot were treated with biocide compositions of specified concentrations. Seven days after the treatment, the treated plants were weighed on a wet basis to calculate the herbicidal ratio (%) by comparison with the weight of the non-treated plants. The 50% herbicidal concentration was also determined. Results are shown in Table 6.

One tobacco plant (Virginia) per pot (.phi. ca. 13.2 cm) was grown and subjected to topping at the time of 50% flowering. Biocide compositions of specified concentrations were then immediately sprayed thereon and the plants were allowed to stand for 14 days. Subsequently auxillary buds from treated plant areas were weighed on a wet basis to calculate the auxillary bud inhibition ratio by comparison with non-treated areas. The 50% auxillary bud inhibitory concentration was also determined. Results are shown in Table 7.

The foregoing Test Examples 1 to 7 indicate that the biocide activator of the present invention greatly enhances the activity of a wide variety of biocides.

The biocide activator according to the invention comprises a polymeric composition. The polymeric composition is prepared by the process as disclosed before. Embodiments of the process are disclosed below.

A reaction vessel was charged with 370 g of coconut oil, 52 g of glycerol and 1.6 g of potassium hydroxide and purged with nitrogen gas. When the reaction mixture had been heated up to a temperature of 115.degree. to 125.degree. C., 249 g of propylene oxide was added gradually over a period of 3 hours under a pressure of 1.0 to 3.0 kg/cm.sup.2 G. Then the mixture was aged for 3 hours and further heated up to 150.degree. C. Subsequently 328 g of ethylene oxide was added thereto at 150.degree. to 160.degree. C. at a pressure of 1.0 to 3.0 kg/cm.sup.2 G and the mixture was aged for 1 hour. Thereafter the reaction system was allowed to stand at 80.degree. to 90.degree. C. at a reduced pressure of 50 Torr. for 30 minutes. It was then neutralized with 1.7 g of acetic acid. The product was found to be a reaction product between coconut oil and glycerol at a molar ratio of 1 to 1 to which 10 moles of propylene oxide and 10 moles of ethylene oxide had been added, having a formula:

A reaction vessel was charged with 536 g of beef tallow, 110 g of sorbitol and 2.8 g of potassium hydroxide and purged with nitrogen gas. Then propylene oxide was added thereto gradually over a period of 3 hours at 115.degree. to 125.degree. C. at a pressure of 1.0 to 3.0 kg/cm.sup.2 G and the mixture was aged for 3 hours. The reaction product was thereafter allowed to stand at 80.degree. to 90.degree. C. at a reduced pressure of 50 Torr. for 30 minutes. It was neutralized with 1.8 g of acetic acid. The product was found to have a formula:

in which beef tallow and glycerol were reacted with each other at a molar ratio of 1 to 1.