GB2053685A - Systemic insecticidal compositions for controlled diffusion - Google Patents

Abstract

Systemic insecticidal composition which consists of a rigid or flexible, homogeneous mass comprising: A. an oxime carbamate of the formula <IMAGE> in which R1 is a group R'X- or R'-X-C(R'') (R''')-, in which X is a sulfur atom or a sulfonyl radical, R' is a methyl or ethyl radical and R'' and R''' independently of one another are a hydrogen atom or a methyl or ethyl radical, R2 being chosen from the group comprising methyl, ethyl, isopropyl and tert.-butyl radicals, B. a polyvinyl chloride having a molecular weight of more than 10,000, C. a regulator chosen from the group comprising hydrophobic diluents, and D. if appropriate, a complementary regulator chosen from the group comprising hydrophilic diluents and pulverulent fillers. When placed in contact with the moist soil or water, this composition uniformly releases determined amounts of active ingredient over a longer or shorter period of time.

Description

Systemic insecticidal compositions for controlled diffusion The present invention relates to systemic insectic idal compositions which make it possible to achieve controlled diffusion of the active agent into water or into the soil, and also relates to the processes mak ing it possible to obtain the said compositions.

The compositions forming the subject of the pres ent invention contain a polymeric carrier and a systemic insecticidal substance from the family of the oxime carbamates.

It is known to enclose active agents in a polymeric matrix in order to permit slow diffusion into water or into the soil; the following compositions have thus been produced: algidical compositions (ANON, Chem. Eng. News, 197250, no.23,68; and CAR DARELLI & BILLE, Rep. 1, Proj. 121, Creative Biol.

Lab., Baberton, 1976), fungicidal compositions (U.S.

Patents 3,269,900 and 3,278,371), nematicidal compositions (CARDARELLI & FELDMESSER, Proc. Control Rel. Pest. Symp., Dayton, 1975, 386), herbicidal compositions (U.S. Patents 3,269,900 and 3,343,941; British Patent 1,502,441; Canadian Patent 846,785; French Patent 2,016,818; YOUNG & NELSON, Sp.

Study 31.004.69/70, Dept. Army Env. Hyg. Ag., 1969; BARNES & WHITLAW, Proj. 31.004. 69/70 Dept.

Army Env. Hyg. Ag., 1970; HARRIS & al., Weed Sci., 1973,21,318; SINCLAIR, Env. Sci. Technol., 1973,7, 955; and CARDARELLI, Control Rel. Pest. Formul., CRC Press., 1976), molluscicidal compositions (CARDARELLI, Control Rel. Pest. Formul., CRC Press., 1976) and anti-bacterial compositions (U.S.

Patent 4,007,258; and French Patent 2,016,818).

As regards insecticides, this process is less frequently used. Compositions comprising a polymer and dichlorvos (MILES & AL., J. Agr. Food Chem., 1962, 10,240) are known, but they are intended for releasing the insecticidal agent, which is volatile, into the atmosphere.

These compositions cannot be used in water and in the soil because this active substance is very readily and very rapidly hydrolysed. Compositions of this type based on other organophosphorus com pounds, such as azinthos, bromophos, chlorpyrifos, demeton, diazinon, dimefox, dimethoate, fenitroth ion, fenthion, malathion, mevinphos, monocrotophos, naled, parathion, temephos and trichlorfon, or based on organochlorine compounds, such asaldrin, dieldrin, endrin, heptachlor, isodrin, lindane and methoxychlor, have also been described (U. S. Patents 3,269,900 and 3,590,119; Canadian Patent 846,785; French Patent 2,016,818; CLEMENTS & ROGERS, Proc. 35th Ann. Conf. Calif. Mosq. Control. Ass., 1967, page 109; WHITELAW & EVANS, J.

Econ. Entom., 1968,61,889; SCHULTZ & AL., Mosq.

News, 1969,29,38; MILES & WOEHST, Pest, Formul.

Res., Adv. Chem. Series, 1969,86,183; McDONALD & DICKENS, Mosq. News, 1970,30,563; NELSON & BR< AL.,J. Econ. Entom., 1970,63,1870 and 1973,33, 403; MILLER & AL., Mosq. News, 1973,33,148; and ROBERTS & AL., Mosq. News, 1973,33, 155 and 165).

Aryl or heteroaryl carbamates, such as dioxacarb, Isolan, dimetilan, carbofuran and various substituted phenyl carbamates, have also been used (U.S.

Patent 3,269,900; British Patent 1,502,441; Canadian Patent 846,785; and French Patents 2,016,818 and 2,279,336).

In respect of plants, none of these substances is as valuable as the oxime carbamates; they cannot be used in the compositions according to the invention because their release into water or into the soil is much too slow, as is demonstrated in one of the experiments. The oxime carbamates, on the other hand, diffuse very readily from the compositions according to the invention; moreover, they act from the roots of the plants, spread into all their vital parts and thus protect them from attack by insects.

Compositions using aldicarb and a polymeric carriver are known (French Patent 2,279,236; and STOCKES & al., J. Agr. Food. Chem., 1973,21, 103), but this substance is extremely toxic (LD 50 = 0.9 mg/kg), which makes compositions of this type very dangerous and greatly reduces their value. Compositions based on aldicarb which comprise a paper carrier and a polyethylene glycol coating are also known (CIBA-GEIGY, British Patent 1,477,261), but, apart from their high toxicity, they are difficult to process industrially, they are difficult to use in the spreading machines and they are not easy to apply to the areas to be treated, particularly in the presence of wind.

Granules consisting of a polymeic carrier and an oxime carbamate, such as methomyl, have also been used (French Patent 2,016,818), but, in heterogeneous granules of this type, the polymer acts by adsorption and the amount of active substance which can be stored depends on the specific surface area of the said polymer, which must therefore be porous; this results in concentration limits and difficulties in controlling the release.

It has now been found by the Applicant Company that it is possible to produce homogeneous compositions with a polyvinyl carrier, which contain an oxime carbamate of much lowertoxicitythan aldicarb, and that these compositions make it possible to achieve diffusion of the said carbamate, into water or into the soil, afa controlled rate.The invention thus relates to the systemic insecticidal compos itions which consist of a rigid or flexible, homogeneous solid mass comprising: A. an insecticidal material, B. a polyvinyl chloride having a molecular weight of more than 10,000, C. a regulator chosen from the group comprising hydrophobic diluents, and D. if appropriate, a complementary regulator chosen from the group comprising hydrophilic diluents and pulverulent fillers, in which compositions the insecticidal material A consists of an oxime carbamate of the formula::

in which R, is chosen from the group comprising the monovalent groups R'X- and R'-X-C(R") (R"')-, in which X is a sulfur atom or a sulfonyl radical, R' is an ethyl or methyl radical, R" is a hydrogen atom or an ethyl or methyl radical and R"' is a hydrogen atom or an ethyl or methyl radical, R2 being chosen from the group comprising ethyl, isopropyl, methyl and tert. butyl radicals.

The systemic insecticidal materials defined above are described, in particular, in patents in the name of CIBA-GEIGY (French Patent 2,150,185; and U.S.

Patent 3,832,400), Consortium fur Electrochemische Industrie (U.S. Patent 3,816,532), Diamond Sham rock Corp. (U.S. Patent 3,875,232), Dupont de Nemours & Co. (U.S. Patents 3,576, 834,3,639,633 and 3,647,861) and Kumiai Chemical Industry Co.

(Japanese Patent 72/17,993).

The following are examples of the best known of these materials: 2 - (N - methylcarbamoyloxyimino) 2 - methylthio - ethane (METHOMYL), 2 - (N - methyl- carbamoyloxyimino) - 3 - methylthio - butane (BUTOCARBOXIM), 2 - (N - methylcarbamoyloxyimino) - 3 - methylsulfonyl - butane (BUTOXYCAR BOXIM) and 2 - (N - methylcarbamoyloxyimino) - 3,3 - dimethyl - 1 - methylthio - butane (THIOFANOX).

BUTOCARBOXIM, defined above, is the preferred insecticidal material in the compositions according to the invention. The insecticidal material A is preferably present in a proportion by weight of between 5 and 50 parts per 100 parts of composition; more preferably, this proportion is between 10 and 40 parts.

The polyvinyl chloride B is preferably present in a proportion by weight of 20 to 70 parts per 100 parts of composition; more preferably, this proportion is between 30 and 50 parts.

The addition of a regulator chosen from the group comprising hydrophobic diluents makes it possible to vary the rate of release of the insecticidal material as a function of the nature and the amount of these diluents; this regulator must be chemically inert towards the insecticidal material. The hydrophobic diluents are chosen from the group comprising compounds from which hydrophilic groups have been removed and which are known in the plastics industry as having plasticising properties. Examples ofthese compounds are low molecular weight polymers, chlorinated paraffins and long-chain esters. This regulator is preferably present in a proportion by weight of 15 to 70 parts per 100 parts of composition; more preferably, this proportion is between 20 and 55 parts.

Examples of low molecular weight polymers are those originating from the homopolymerisation or the copolymerisation of the following monomers: (1) homopolymerisation: vinyl acetate, isobutylene and chlorinated ethylene; and (2) copolymerisation: acrylonitrile I butadiene, diethyl fumarate I butadiene, ethyl acrylate / butadiene, vinyl acetate I ethylene, vinyl acetate I ethyl acrylate, vinyl acetate/ dimethyl maleate, vinyl acetate I allyl acetate, vinyl chloride /styrene, vinyl chloride/ allyl chloride and vinyl chloride / vinyl acetate.

Further low molecular weight polymers are polyesters, preferably those neutralised by esterification with an alkanol, such as those originating from the following condensation reactions: glycerol / sebacic acid, glycerol / azelaic acid, glycerol I phthalic acid, propylene glycol / adipic acid and propylene glycol / sebacic acid.

The following are examples of long-chain esters: (1) monoesters formed between alkanols and alkanoic or alkenoic acids, for example ethyl, isopropyl, butyl or isobutyt laurate, myristate, palmitate, stearate, undecanoate and oleate; (2) diesters formed between alkanols and dicarboxylic hydrocarbons, for example dialkyl adipates, such as dioctyl adipate and dinonyl adipate, dialkyl, sebacates, such as dibutyl sebacate, dipentyl sebacate and dioctyl sebacate, dialkyl azelates, such as dioctyl azelate, and dialkyl phthalates, such as dibutyl phthalate, dioctyl phthalate, didecyl phthalate, bis - (undecyl) phthalate, bis - (dodecyl) phthalate, bis - (tridecyl) phthalate, bis - (tetradecyl) phthalate and dicetyl phthalate;; (3) diesters formed between phenols which are unsubstituted or substituted by alkyl, and dicarboxylic hydrocarbons, for example diaryl phthalates, such as diphenyl phthalate and dicresyl phthalates; (4) diesters formed between cyclic alkanols which are unsubstituted or substituted by alkyl, and dicarboxylic hydrocarbons, for example dicyclohexyl phthalate and bis - (methylcyclohexyl) phthalates; (5) diesters formed between phenylalkanols and dicarboxylic hydrocarbons, for example dibenzyl sebacate; (6) diesters formed between alkanediols and monocarboxylic hydrocarbons, for example 2,2,4 trimethylpentane - 1,3 - diol di - isobutyrate; (7) triesters formed between phenols which are unsubstituted or substituted by alkyl, and phosphoric acid, for example triphenyl phosphate, tris - (4 - tert. butyl - phenyl) phosphate and tricresyl phosphates; and (8) triesters formed between alkanols and phosphoric acid, for example trioctyl phosphate.

The hydrophilic diluents acting as complementary regulators can be present in a proportion by weight of 0 two 50 parts per 100 parts of composition. They are chosen from the group comprising compounds which are miscible, soluble or dispersible in water and which are physically compatible with the insecticidal material A, the polyvinyl chloride and the hydrophobic diluent The following are examples of hydrophilic diluents: : (1) polymers and copolymers of vinyl alcohol, such as polyvinyl alcohol and the copolymer polyvinyl alcohol/polyvinyl acetate; (2) polyvinylpyrrolidines; (3) alkanediols, such as 2,2 - dimethylpropane - 1,3 diol, propylene glycol"butylene glycol and 2,2 diethylpropane - 1,3 diol; (4) polyalkanediols, such as polyethylene glycols, polypropylene glycols and polybutylene glycols; (5) alkanetriols, such as glycerol, and their monoesters formed with alkanoic ar alkenoic acids; (6) esters formed between aliphatic hydroxyacids and shortchain alkanols, such as trimethyl, triethyl, tripropyl and tributyl citrates; and (7) products resulting from the condensation of propylene oxide or ethylene oxide with alkylphenols, such as butyl-, hexyl-, heptyl-, octyl-, nonyl- and dodecyl - phenols, with fatty alcohols, such as decanol, dodecanol, tetradecanol, hexadecanol, octadecanol and octadecenol, and with vegetable oils, such as palm, peanut, coconut, colza, soya and castor oils.

The pulverulent fillers are chosen from the group comprising those which are inert with respect to water or, on the other hand, those which are soluble or dispersible in water, depending on whether it is desired to retard or accelerate the rate of diffusion of the active ingredient.

Examples of pulverulent fillers are carbon black, rock powders, such as slate, clay, marble, kaolin, talc, silica or attapulgite powders, organic salts, such as the acetates, propionates, citrates, adipates, maleates, sebacates, palmitates and stearates of magnesium, zinc, calcium and sodium, inorganic salts, such as the silicates and carbonates of calcium and magnesium and such as the chlorides of sodium or potassium, the sulfates of sodium or calcium, potassium nitrate and the phosphates of potassium or ammonium; further pulverulent fillers are the sodium orcalcium salts of alkylarylsulfonic acids, cellulose and its derivatives, such as methylcellulose, hydroxymethylcell u lose, hyd roxyethylcellulose and carboxymethylcellulose, carbohydrates, such as cereal flours, starch, dextrin and sugars, aminoacids, such as glutamic acid, casein and protein hydrolysates, and the various organic or inorganic pigments known to those skilled in the art.

The compositions according to the invention are presented as rigid or flexible, compact, homogeneous solid masses, the form of which is not critical.

For example, they can be in the form of plates, sheets, strips, tubes, rods or granules.

The structure of the mass constituting the composition is also not critical; for example, this structure can be compact, fibrous, alveolar or spongy.

When they are placed in contact with the soil or water, the compositions according to the invention release 50% of the insecticidal material in a very uniform manner, over a period varying between about 2 and 200 days. The efficiency of the compositions according to the invention, based on the total amount of insecticidal material contained in the composition, is excellent because virtually all the insecticidal material is released over a longer or shorter period of time.

The compositions according to the invention can be prepared in accordance with several processes.

In accordance with a first process, the constituents are mechanically mixed at ambient temperature, using a powdered polyvinyl chloride. Depending on the proportions of the constituents, a dry powder or a fluid paste, referred to as a "plastisol", is obtained. The dry powder is converted to a homogeneous solid mass by moulding, extrusion, injection moulding or casting, as in the case of an ordinary powdered plastic. In the case of a fluid paste, it is heated to the gelling point and a homogeneous solid mass results on cooling; the rate of diffusion of the active ingredient does not vary substantially as a function of the temperature and/orthe heating time.

In accordance with a second process, the constituents A, B and C of the composition are dissolved in a volatile solvent, it being possible for the pulverulent fillers, if present, to be kept in suspension by stirring. After the volatile solvent has been evaporated off, which can be carried out at a more or less eievated temperature and under a more or less reduced pressure, the mixture solidifies and a homogeneous mass results, which only retains a small part of the solvent.

In accordance with a third process, the polyvinyl chloride is dispersed, in the form of a sol, in a mixture, heated beforehand, of the constituents A and C.

A homogeneous solid mass is obtained on cooling.

In accordance with a fourth process, the constituents A and C are introduced into vinyl chloride or into a liquid semi-polymerofthis compound.

Polymerisation is carried out in accordance with the methods known to those skilled in the art, after a catalyst has been added.

In accordance with a fifth process, a solid mass of polyvinyl chloride, if appropriate having the form desired for the final composition, is placed in a liquid mixture of the constituents A + C. All or part of the constituent C can initially be present in the polyvinyl chloride. If the composition is to contain a pulverulent filler, the latter is incorporated initially into the polyvinyl chloride. The active ingredient A and the adjuvant C, if the latter is mixed with the active ingredient, penetrate into the mass of polyvinyl chloride; this penetration requires a time which is inversely proportional to the temperature at which the operation is carried out.

In accordance with a variant of this process, the mass of polyvinyl chloride and the constituents A + C are introduced into a container serving as packaging, which is impermeable to the said mixture and the internal volume of which is adapted so that the liquid mixture is in contact with the maximum surface area of the mass of polyvinyl chloride. Penetration takes place during the storage period and the pack contains a composition according to the invention at the moment when it is opened for use.

The value of the compositions according to the invention is illustrated by the experiments which follow.

Experiment 1: A mass of polyvinyl chloride plasticised with dibutyl phthalate and having a plasticiser content of the order of 36% by weight was used. This mass was shaped, by extrusion, in the form of a tube of which the external and internal contours of the cross-section were lenticular; the external width was 28 mm and its greatest thickness was 3.2 mm for a length of 45 mm; the width of the internal walls was 20 mm; the weight of this mass was 7.56 grams.

Masses of this type were individually enclosed in a leaktight sachet from which air had been evacuated before it was closed, and which contained one of the following liquids (amounts in grams), depending on the particular case: table!

Composition 1A 1B 1C Pure butocarboxim 5 3.5 2.5 Dibutylphthalate 1.5 2.5 After storage for one month at a temperature of 40"C, the sachets were opened to give, in all cases, a mass of which the homogeneous composition was as follows (percentages by weight):: Table II

Composition 1A 1B 1C Butocarboxim 39.5 27.7 19.8 Polyvinyl Chloride 38.7 38.7 38.7 Dibutyl phthalate 21.8 33.6 41.5 Experiment2:Finely powdered polyvinyl chloride, for a plastisol, was used, and this was mixed with 83% pure, technical-grade butocarboxim and dioctyl phthalate in the following proportions: Technicaiarnde butocarboxim : 20% by weight Polyvinyl chloride : 40% by weight Dioctyl phthalate : 40% by weight The fluid paste obtained was cast into Petri dishes to a depth of 2 mm and the dishes were placed in tempernturncontrnlled ovens for periods varying between 5 and 30 minutes and at temperatures varying between 115 and 135 C. In all cases, a plastic homogeneous mass was obtained and the contents of active ingredient, determined by analysis, were noted, as follows, in percentages of pure active ingredient.

Table III

Heating time 1150C 115 C | 1200C 125 C 1300C 135 C 5 minutes 16.6 16.6 16.6 16.6 16.7 10 minutes 16.6 16.7 16.7 16.7 16.7 15 minutes 16.7 16.7 16.7 16.7 16.7 20 minutes 16.7 16.7 16.7 16.7 16.7 30 minutes 16.7 16.7 16.8 16.8 16.8 These same analyses make it possible to establish :hat only the volatile impurities in the technical3rade material had been lost during heating.

Experiment 3: Three series, 3A, 3B and 3C, of compositions according to the invention were prepared Jsing the process descirbed in Experiment 2, with a :emperature of 125"C and a heating time of 15 ninutes.

The compositions prepared in this way were in the Form of discs of diameter32 mm and thickness 12 mm and had the following constitutions (values in percentages by weight): Table IV

Compositions 3A 3B 3C Technical-grade butocarboxim 10 20 40 Polyvinyl chloride 45 40 30 Dioctyl phthalate 45 40 30 Weight of each disc (grams) 8.53 8.19 7.80 The discs produced in this way were each suspended in a vessel filled with water, and the amount of active ingredient which had passed into the water was measured periodically.

The following table summarisesthe values recorded in this way (the percentages of active ingredient diffused are based on the active ingredient introduced into the composition, and the weights of active ingredient diffused are in milligrams).

Table V

Measurements 3A 3B 1 3C taken after % mg % mg % mg 5 days 12 102 13 211 19 593 9 days 16 137 18 295 25 774 20 days 24 206 26 429 37 1,160 51 days 36 309 41 676 53 1,647 114 days 49 417 54 881 56 2,068 194 days 61 518 65 1,068 77 2,412 Experiment 4: Discs 4A, 4B and 4C, similar to those described in Experiment3 and having respectively the same compositions, were used.

These discs were each placed in sand having a water content of the order of 20%, and the percentages of active ingredient diffused were measured periodically.

The results of the measurement are combined in the following table.

Table Vl

4A 4B 4C Measurements taken after % mg % mg % mg 20 days 11 93 13 237 14 440 51 days 22 188 27 496 31 967 114 days 34 292 38 695 42 1,317 194 days 43 365 47 869 51 1,604 Experiment 5:The following composition was prepared (values in percentages by weight): Technical-grade butoca rboxim 20 Polyvinyl chloride 40 Dioctyl phthalate 40 The process described in Experiment 2 was used (15 minutes at 125"C); discs having a diameter of 90 mm and varying in thickness were obtained: Table VII

Compositions | 5A SB SC SD SE Thickness in mm 1 2 3 3 5 7 Weight in grams 6.8 13.8 20.9 34.8 48.9 These discs were each placed in sand having a water content of the order of 20% and the percentages of active ingredient diffused were measured periodically.

The results of the measurements are combined in the following table.

Table VIII

5A 5B 5C 5D SE Measurements taken after % mg % mg % mg % mg % mg 8 days 19.2 260 13.2 364 9.0 375 8.4 525 7.8 763 15 days 37.1 505 25.7 709 19.7 824 16.8 1,170 14.4 1,407 22 days 54.5 741 37.1 1,024 28.7 1,200 24.5 1,705 21.0 2,054 29 days 65.2 887 46.7 1,289 36.5 1,526 30.5 2,123 25.7 2,515 60 days 80.8 1,100 62.9 1,736 51.5 2,153 43.7 3,040 35.1 3,433 90 days 89.8 1,220 76.6 2,115 67.0 2,800 55.9 3,890 45.3 4,430 Experiment 6: The following compositions 6A to 6D were prepared by following the procedure of Experiment 2 (15 minutes at 125"C); they were in the form of discs ofdiameter 90 mm and thickness 1.5 mm (values in percentages by weight): Table IX

Compositions 6A 6B 6C 6D Technicalgrade butocarboxim 20 20 20 20 Polyvinyl chloride 60 50 40 30 Dioctyl phthalate 20 30 40 9 50 Weight (grams) 13.83 13.75 13.76 13.56 The discs were each placed in sand having a water content of the order of 20%, and the percentages of active ingredient diffused, and also their weight, were measured periodically.

The results of the measurements are combined in the following table.

Table X

6A 6B 6C 6D Measurements taken after % mg % mg % mg % mg 8 days 0.4 11 8.4 231 18.0 495 19.8 537 15 days 3.0 83 15.0 412 32.8 890 37.7 1,023 22 days 6.6 183 22.8 628 45.5 1,251 55.7 1,512 29 days 9.0 249 26.9 740 54.5 1,501 67.7 1,835 60 days 17.9 495 41.3 1,137 71.0 1,954 86.8 2,355 90 days 25.1 693 54.5 1,497 81.1 2,232 98.0 2,659 Experiment7:The following compositions 7A and 7B were prepared by following the procedure of Experiment 2 (15 minutes at 125"C); they were in the form of discs of diameter 90 mm and thickness 2 mm (values in percentages by weight): Table Xl

Compositions 7A 7B Technical-grade butocarboxim 20 20 Polyvinyl chloride 40 40 Dioctyl phthalate 35 20 Tris-(2-butoxyethyl) phosphate 5 20 Weight (grams) The discs were each suspended in a vessel filled with water, and the percentages of active ingredient diffused were measured periodically.

The results of the measurements are combined in the following table.

Table Xll

7A 7B Measurements taken after % mg % mg 2 days 12 323 20 512 5 days 50 1.330 53 1,450 12 days 74 2,025 83 2,273 Experiment 8:The following compositions8A and 8B were prepared by following the procedure of Experiment 2 (15 minutes at 1 250C); they were in the form of discs of diameter32 mm and thickness 12 mm (values in percentages by weight) Table Xlil

Compositions | 8A 8B Technical-grade butocarboxim 40 40 Polyvinyl chloride 25 25 Dioctyl phthalate 25 25 PVA copolymer (al 10 Polyethylene glycol 400 - 10 Weight (grams) (a) Polyvinyl acetate hydrolysed to the extent of 30% to give polyvinyl alcohol and possessing a viscosity of 98 centipoises in a 4% solution in water at 20"C.

The discs were each suspended in a vessel filled with water, and the percentages of active ingredient which had passed into the water were measured periodically.

The results of the measurements are combined in the following table.

Experiment 9: The following compositions 9Ato 9F were prepared by following the procedure of Experiment 2 (15 minutes at 125oC); they were in the form of discs of diameter 90 mm and thickness 2 mm (values in percentages by weight): Table XIV

8A 88 Measurements taken after % mg % mg 5 days 18.2 615 17.5 670 31 days 53.2 1,800 46.4 1,770 93 days 81.4 2,750 66.3 2,530 173 days 98.2 3,320 82.4 3,145 Table XV

Compositions 9A 98 9C 9D 9E 9F Technical-grade carboxim 20 20 20 20 20 20 Polyvinyl chloride 37 37 34 34 30 30 Dioctyl phthalate 37 37 34 34 30 30 PVA polymer (a') 6 - 12 - 20 PVA polymer (a") - 6 - 12 - 20 Weight (grams) 13.60 13.57 13.58 13.60 13.63 13.63 (a') Polyvinyl acetate hydrolysed to the extent of 50% to give polyvinyl alcohol and possessing avis- cosity of 98 centipoises in a 4% solution in water at 20"C.

(a") Polyvinyl acetate hydrolysed to the extent of 70% to give polyvinyl alcohol and possessing avis- cosity of 88 centipoises in a 4% solution in water at 20"C.

The discs were each placed in a vessel filled with water, and the percentages of active ingredient diffused were measured periodically.

The results of the measurements are combined in the following table.

Table XVI

9A 98 9C 9D 9E 9F Measurements taken after % mg % mg % mg % mg % mg % mg % mg %Img 2 days 15 410 22 590 16 440 27 736 18 496 33 897 5 days 28 755 30 817 29 782 48 1,314 34 924 61 1,668 12 days 49 1,340 51 1,390 53 1,445 77 2,090 63 1,712 91 2,473 Experiment 10: The following compositions 10 Ato 10 E were prepared by following the procedure of Experiment 2 (15 minutes atn125"C); they were in the form of discs of diameter 90 mm and thickness 2 mm (values in percentages by weight): Table XVII

Compositions 10A 108 10C 10D 10E Technical-grade butocarboxim 20 20 20 20 20 Polyvinyl chloride 40 40 40 40 40 Dioctyl phthalate 35 35 30 ' 20 20 Polyethylene glycol 400 5 - 10 - 20 Ethyltriethylene glycol - 5 - 20 Weight (grams) 13.57 13.51 13.61 13.32 13.50 The discs were each suspended in a vessel filled with water and the percentages of active ingredient diffused were measured periodically.

The results of the measurements are combined in the following table. Table XVIII

10A 108 10C 10D 10E Measurements -I taken after % mg % mg % mg % mg % mg - 2 days 11 295 13 353 13 354 13 341 40 1,045 3 days 17 466 19 512 87 2,354 5 days 26 714 43 1,160 33 904 46 1,230 100 2,690 12 days 48 1,308 64 1,707 56 1,532 71 1,886 Experiment ii:: The following compositions 11A and 11 B were prepared by following the procedure of Experiment 2 (15 minutes at 125"C); they were in the form of discs of diameter 90 mm and thickness 2 mm (values in percentages by weight). Table XIX

Compositions 11A 118 Technicalgrade butocarboxim 20 20 Polyvinyl chloride 40 40 Dioctyl phthalate 35 20 Tributyl citrate 5 20 Weight (grams) 13.68 13.59 The discs were each suspended in a vessel filled with water, and the percentages of active ingredient diffused were measured periodically.

The results of the measurements are combined in the following table.

Table XX

11A 118 Measurements taken after % mg % mg 2 days 13 350 20 550 5 days 49 1,350 52 1,430 12 days 74 2,030 76 2,080 Experiment 12:The following compositions 1 2A to 12F were prepared by following the procedure of Experiment 2 (15 minutes at 125"C); they were in the form of discs of diameter 90 mm and thickness 2 mm (values in percentages by weight): Table XXI

Compositions 12A 12B 12C 12D 12E 12F Technicalgrade butocarboxim 20 20 20 20 20 20 Polyvinyl chloride 37 37 34 34 30 25 Dioctyl phthalate 37 37 34 34 30 25 Maize cob 6 - 12 - 20 Corn starch 6 6 - 12 - 30 Weight (grams) 13.55 13.60 13.64 13.56 13.70 13.52 The discs were each suspended in a vessel filled with water, and the percentages of active ingredient diffused were measured periodically.

The results of the measurements are combined in the following table. TableXXII

12A 12B 12C 12D 12E 12F Measurements taken after % mg % mg % mg % mg % mg % mg 2days 16 427 17 467 16 431 19 512 16 436 43 1,170 3 days ~ ~ 20 545 - - 26 703 - - 52 1,410 5days 36 980 30 822 43 1,167 41 1,117 52 1,418 80 2,158 12 days 61 1,660 53 1,438 70 1,914 79 2,1 51 96 2,636 100 2,690 Experiment 13: The following compositions 13Ato 13F were prepared by following the procedure of Experiment 2 (15 minutes at 1 25 C); they were in the form of discs of diameter 90 mm and thickness 2 mm (values in percentages by weight): Table XXIII

Compositions 13A 13B 13C 13D 13E 13F Technical-grade butocarboxim 20 20 20 20 20 20 Polyvinyl chloride 37 37 34 34 30 30 Dioctyl phthalate 37 37 34 34 30 30 Methylcellulose 6 - 12 - 20 The sodium salt of carboxymethyl-cellulose - 6 - 12 - 20 Weight (grams) 13.56 13.55 13.56 13.49 13.61 13.48 The discs were each suspended in a vessel filled with water, and the percentages of active ingredient diffused were measured periodically.

The results of the measurements are combined in the following table. Table XXIV

13A 13B 13C 13D 13E 13F Measurements taken after % mg % mg % mg % mg % mg % mg 2 days 13 347 15 412 15 400 25 680 17 463 43 1,163 3 days ~ ~ 22 602 - 33 888 - - 54 1,452 5 days 37 1,006 36 971 39 1,052 43 1,155 65 1,772 87 2,346 12 days 60 1,636 53 1,432 70 1,906 79 2,126 100 2,706 100 2,679 Experiment 14: The following compositions 14A and 14B were prepared by following the procedure of Experiment 2 (15 minutes at 125 C); they were in the form of discs of diameter 90 mm and thickness 2 mm (values in percentages by weight): Table XXV

Compositions 14A 14B Technical-grade butocarboxim 20 20 Polyvinyl chloride 37 25 Dioctyl phthalate 37 15 Casein Weight (grams) 13.5613.76 The discs were each suspended in a vessel filled with water, and the percentages of active ingredient diffused were measured periodically.

The results of the measurements are combined in the following table.

Table XXVI

14A 14B Measurements .

taken after % mg % mg 2 days 13 350 16 446 5 days 35 943 43 1,191 12 days 56 1,510 80 2,213 Experiment 75: The following compositions 15A and 15B were prepared by following the procedure of Experiment 2 (15 minutes at 125 C); they were in the form of discs of diameter 90 mm and thickness 2 mm (values in percentages by weight); Table XXVII

Compositions 15A 15B Technicalgrade butocarboxim 20 20 Polyvinyl chloride 50 34 Dioctyl phthalate 30 34 PVA polymer (a") 12 (a") Polyvinyl acetate hydrolysed to the extent of 70% to give polyvinyl alcohol and possessing a vis- cosity of 88 centipoises in a 4% solution in water at 20 C.

The discs were cut into four equal quarters each having a weight of the order of 3.5 grams. Each quarter was placed, in the open, in a stony, loamenriched clay soil art a depth of 7.5 centimeters. The average rainfall during the period of the experiment was 3.15 millimetres per day. Periodically, one quarter was removed from the soil and the amount of residual butocarboxim was measured by analysis in order to determine the amount which had diffused into the soil.

The results of the measurements are combined in the following table.

Table XX VIII

15A 15B Measurements taken after mg % mg 8 days 5 36 21 150 15 days 9 62 40 278 25 days 12 85 59 414 36 days 19 130 71 495 50 days 26 184 83 579 64 days 31 218 - - 71 days - - 92 646 78 days 39 276 94 660 Experiment 16:Seven series of compositions, 16A to 16G, according to the invention were prepared by using the process described in Experiment 2, with a temperature of 125 C and a heating time of 15 minutes. The compositions prepared in this way were in the form of discs of diameter 90 mm and thickness 2 mm and had the following constitutions (values in percentages by weight):: TableXXlX

16A 168 16C 16D 16E 16F 16G Technical-grade butocarboxim 20 20 20 20 20 20 20 Polyvinyl chloride 38 38 38 38 38 38 38 Dioctyl phthalate 42 - - - - - - Dioctyl adipate - 42 - - 10 10 Dioctyl sebacate Tricresyl phosphate ~ ~ ~ 42 - - - Triethyl citrate - - - - 32 - - Tributyl citrate ~ ~ ~ ~ ~ 32 Tris-(2-butoxyethyl ) phosphate - - - - - - 42 Average weight of a 13.29 13.16 13.25 13.45 13.42 13.57 weight of a disc (grams) 13.29 13.16 13.25 13.45 13A213.5713.03 The discs produced in this way were each placed in sand having a water content of the order of 16.7%, and the percentages and the weights of active ingredient diffused were measured periodically.

The results of the measurements are combined in the following table.

Table XXX

9th day 35th day 60th day % mg % mg % mg 16A 18.1 480 52.1 1,385 62.1 1,650 16B 24.1 635 51.7 1,360 65.0 1,710 16C 26.4 700 48.1 1,275 60.0 1,590 16D 13.8 370 35.3 950 46.7 1,255 16E 22.0 590 43.4 1,165 47.1 1,285 16F 25.1 680 54.9 1,490 66.5 1,805 16G 52.4 1,365 82.3 2,145 89.8 2,340 Experiment 17:Three series of compositions, 17A, 17B and 17C, according to the invention were prepared by using the process described in Experiment 2, with a temperature of 125 C and a heating time of 15 minutes. The compositions prepared in this way were in the form of discs of diameter 90 mm and thickness 2 mm and had the following constitutions (values in percentages by weight):: Table XXXI

17A 17B 17C Butoxycarboxim 20 - - Methomyl - 20 Thiofanox - - 20 Polyvinyl chloride 38 38 38 Dioctyl phthalate 42 42 42 Average weight of a disc (grams) 13.95 13.84 13.93 The discs produced in this way were each placed in sand having a water content of the order of 16.7%, and the percentages and the weights of active ingredient diffused were measured periodically.

The results of the measurements are combined in the following table.

Table XXXII

9th day 35th day 60th day % mg % mg % mg 17A 0.6 17 2.3 64 5.1 142 17B 24.7 685 52.4 1,450 65.6 1,760 17C 4.5 125 17.0 475 21.7 605 Experiment 18: Seven series of compositions,18A 18A to 18G, were prepared by using the process described in Experiment 2 (15 minutes at 125 C)and employing insecticidal substances foreign to the field of the invention.The compositions prepared in this way were in the form of discs of diameter 90 mm and thickness 2 mm and had the following constitutions (values in percentages by weight): Table XXXIII

18A 18B 18C 18D 18E 18F 18G Carbaryl (b) 20- - - - - - Chlorpyrifos (c) - 20 - - - - - Diazinon (d) - - 20 - - - - Fenthion(e) - - - 20 - - - Malathion (f) - - - - 20 - - Naled - - - - - 20 Temephos(h) - - - - - - 20 Polyvinyl chloride 38 38 38 38 38 38 38 Dioctyl phthalate 42 42 42 42 42 42 42 Average weight of a disc (grams) 13.95 13.38 13.98 13.94 14.02 13.86 13.96 (b) Alpha-naphthyl N-methylcarbamate.

(c) O,O - Diethyl 0 - (3,5,6 - trichloropyrid - 2 -yl) thiophosphate.

(d) O,O - Diethyl 0 - (2 - isopropyl - 6 - methyl pyrimidin -4 -yl)thiophosphate.

(e) O,O - Dimethyl 0 - (3 - methyl -4 - methylthiophenyl) thiophosphate.

(f) O,O - Dimethyl S -L1,2 - bis - (ethoxycarbonyl) - ethyl dithiophosphate.

(g) O,O - Dimethyl 0 - (1,2 - dibromo -2,2 - dichloroethyl) phosphate.

(h) O,O,O',O' -Tetramethyl 0,0' - (thiodiphenylene 4,4' - diyl) bis - (thiophosphate); this substance is frequently designated by the name "Abate".

The discs produced in this way were each placed in sand having a water content of the order of 16.7%, and the amounts of active ingredient diffused were measured after 9 days, 35 days and 60 days. It was not possible, in any case or after any period of time, to find a release of active ingredient exceeding 0.05% of the amount employed.

Experiment 19: Acomposition according to the invention was prepared by using the process described in Experiment 2, with a temperature of 125"C and a heating time of 15 minutes and with the following constituents: Butocarboxim :35.5% Polyvinyl chloride :35.0% Dioctyl phthalate : 19.8% PVA polymer (a"') : 9.9% (a"') Polyvinyl acetate hydrolysed to the extent of 88% to give polyvinyl alcohol and possessing avis- cosity of 18 centipoises in a 4% solution in water at 20"C.

This composition was shaped to give plates of thickness 4 mm, which were chopped to give cubic granules with an edge length of 4 mm. The granules were buried near the feet of rosebushes of the Red Favourite variety, placed in a soil containing clay and silica, in the Vienne department of France. Three doses were used, i.e. 30,45 and 67 grams per rosebush. Each rosebush was watered three times per week with 6 litres ofwater. After 15 days, the leaves of the rosebushes were ground and subjected to extraction in order to determine their content of insecticidal material. The following contents could thus be established: 30 gram dose :35 ppm 45 gram dose :60 ppm 67 gram dose :75 ppm Itwas furthermore established thatthese contents were sufficient to prevent the proliferation of aphids on the plants.

Experiment20: The following six compositions, 20A to 20F, according to the invention were prepared by using the process described in Experiment 2, with a temperature of 125"C and a heating time of 15 minutes and with the following constituents (values in percentages): Table XXXIV

20A 20B 20C 20D 20E 20F Techn ica l-grade butocarboxim 35.3 23.5 14.7 35.3 23.5 14.7 Polyvinyl chloride 38.8 45.9 51.2 35.0 35.0 35.0 Dioctyl phthalate 25.9 30.6 34.1 19.8 27.7 33.5 Solubilised maize starch (i) ~ ~ ~ 9.9 13.8 16.8 (i) Starch modified by carboxymethylation and pregelatinisation.

These compositions were shaped to give plates of thickness 4 mm, which were chopped to give cubic granules having an edge length of 4 mm.

The granules of each composition were spread on the surface of the soil in pots of diameter 11 cm, each containing a plant of the species Hibiscus rosasinensis; after spreading, the granules were lightly covered with soil and each pot was watered with one litre of water; the amount of each composition was calculated so as to correspond to 50 mg of butocarboxim per pot: 20A and 20D: : mg 20B and 20E :250 mg 20C and 20F :400 mg The plants were infested with aphids of the species Myzus persicae and the insecticidal effectiveness was measured periodically for 35 days. 5 plants were used for each composition.

The results recorded are summarised in the following table and expressed in percentages of dead insects, based on the amount noted on the first day; the values given are the averages noted for each composition over all five plants: Table XXXV

Measurements taken after 20A 20B 20C 20D 20E 20F 3 days 55 59 49 57 86 69 7 days 71 76 69 79 95 89 12 days 76 75 62 82 91 90 16 days 93 84 79 90 96 94 20 days 90 79 77 89 95 90 24 days D 93 80 85 85 93 95 28 days 87 79 74 77 82 74 35 days 79 74 72 69 79 67

Claims (20)

1. Asystemic insecticidal composition which consists of a rigid or flexible, homogeneous solid mass comprising: A. an insecticidal material, B. a polyvinyl chloride having a molecular weight of more than 10,000, C. a regulator chosen from the group comprising hydrophobic diluents, and D. if appropriate, a complementary regulator chosen from the group comprising hydrophilic diluents and pulverulent fillers, in which composition the insecticidal material A consists of an oxime carbamate of the formula::

in which R1 is chosen from the group comprising the monovalent groups R'X-and R'-X-C(R") (R"')-, in which X is a sulfur atom or a sulfonyl radical, R' is a methyl or ethyl radical and R" and R"' independently of one another are a hydrogen atom or a methyl or ethyl radical, R2 being chosen from the group comprising methyl, ethyl, isopropyl and tert.-butyl radicals.

2. A composition according to claim 1, which contains the insecticidal material A in a proportion by weight of between 5 and 50 parts per 100 parts of composition.

3. A composition according to claim 2, which contains the insecticidal material A in a proportion by weight of between 10 and 40 parts per 100 parts of composition.

4. A composition according to any one of claims 1 to 3, which contains the polyvinyl chloride B in a proportion by weight of 20 to 70 parts per 100 parts of composition.

5. A composition according to claim 4, which contains the polyvinyl chloride B in a proportion by weight of 30 to 50 parts per 100 parts of composition.

6. A composition according to any one of claims 1 to 5, which contains the regulator C in a proportion by weight of 15 to 70 parts per 100 parts of composition.

7. A composition according to claim 6, which contains the regulator C in a proportion by weight of 20to 55 parts per 100 parts of composition.

8. Acomposition according to any one of claims 1 to 7, wherein the insecticidal material A is chosen from the group comprising 2 - (N - methylcarbamoyloxyimino) - 2 - methylthio - ethane, 2 - (N - methylcarbamoyloxyimino) - 3 - methylthio - butane, 2 - (N - methylcarbamoyloxyimino) -3 - methylsulfonyl - butane and 2 - (N - methylcarbamoylox yimino) - 3,3 - dimethyl - 1 - methylthio - butane.

9. A composition according to claim 8, wherein the insecticidal material is 2 (N - methylcarbamoyloxyimino) -3 - methylthio - butane.

10. A composition according to any one of claims 1 to 9, wherein the regulator C is chosen from the group comprising low molecular weight polymers, chlorinated paraffins and long-chain esters.

11. A composition according to any one of claims 1 to 10, which contains, as a complementary regulator, a hydrophilic diluent chosen from the group comprising polymers, polyols and esters which are miscible, soluble or dispersible in water, and polyoxyalkylated products.

12. A composition according to any one of claims 1 to 11, which is in the form of a rigid or flexible, compact, homogeneous solid mass of any shape.

13. A process for the preparation of a composition according to any one of claims 1 to 12, wherein the powdered polyvinyl chloride B is mechanically mixed, at ambient temperature, with the compounds A and C of the composition in order to obtain a dry powder or a fluid paste, and the powder or paste is then converted to a homogeneous solid mass by moulding, injection moulding or casting or by heating to the gelling point of the mixture.

14. A process for the preparation of a composition according to any one of claims 1 to 12, wherein the constituents A, B and C are dissolved in a volatile solvent, and the latter is then evaporated off at a more or less elevated temperature or under reduced pressure.

15. A process for the preparation of a composition according to any one of claims 1 to 12, which comprises dispersing the polyvinyl chloride, in the form of a sol, in a liquid mixture, heated beforehand, of the constituents A and C, and allowing the mixture to cool after a homogeneous dispersion has been obtained.

16. A process for the preparation of a composition according to any one of claims 1 to 12, which comprises introducing the constituents A and C into the vinyl chloride or into a semi-polymer of this compound, and then polymerising the mixture after a catalyst has been added.

17. A process for the preparation of a composition according to any one of claims 1 to 12, which comprises placing a solid mass of polyvinyl chloride, having the form desired for the final composition, in the liquid constituent A, which, if appropriate, contains the constituent C if the latter is not already present in the polyvinyl chloride, and allowing all the liquids to penetrate into the mass of polyvinyl chloride for a period of time which is inversely proportional to the temperature.

18. A process according to claim 17, wherein the constituents A + C are introduced into a container serving as packaging, which is impermeable to the said constituents A and C and the internal volume of which is adapted so that the liquid mixture is in contact with the maximum surface area of the solid mass of polyvinyl chloride, the pack subsequently being closed and then stored for a period of time which is sufficient for it no longer two contain free liquid at the end of the storage period.

19. Use of a composition according to any one of claims 1 to 12 as a systemic insecticidal composition which makes it possible to achieve controlled diffusion of the active agent into water or into the soil.

20. A composition according to Ciaim 1, substantially as hereinbefore described, with reference to any one of the foregoing Examples.