NO753440L - - Google Patents

Description

The invention relates to new preparations with depot gas action based on dimethyl-2,2-dichlorovinylthio-

phosphate as a gas treatment agent acting independently above the gas phase and solid carriers.

The use of dimethyl-2,2-dichlorovinyl phosphate

(DDVP) in formulations acting independently as a gas treatment agent has for a long time been known in pest control. • As a carrier material for the latter active substance, substances of various types were proposed: macromolecular thermo-plastic, duromeric and elastomeric. Plastics or natural substances such as wood, cardboard, asbestos, lime, gypsum, beeswax and montan wax. Examples of suitable carrier materials are natural and synthetic rubber, polyolefins such as polyethylene, polypropylene and copolymers of ethylene and propylene; polyacrylates and copolyacrylates of methyl acrylate, ethyl acrylate, methyl methacrylate;

polyvinyl compounds such as polystyrene, polyvinyltoluene, polyvinyl acetate; polyvinyl and polyvinylidene halides such as polyvinyl chloride, polyvinyl fluoride, polyvinylidene chloride, polyvinyl acetal, such as polyvinyl butyral, linear and branched polyesters and polyethers; cellulose plastics such as cellulose acetate, cellulose propionate, cellulose butyrate, cellulose nitrate; further suitable carrier materials are, for example, unsaturated polyesters, epoxies, polyurethanes, phenol formaldehyde, urea and melamine formaldehyde resins.

Polymers and mixed polymers of vinyl chloride (compare DAS 1,230,259) as well as unsaturated polyester systems (compare DAS 1,694,240 and DOS 2,231,099) were mentioned as particularly preferred carrier materials; furthermore also polymeric acrylates and polymeric vinyl compounds such as polystyrene.

In addition to the active substance, the formulations often also contain, depending on the type of carrier material, auxiliary substances such as softeners, stabilizers, evaporation regulators and fillers. As softeners, there are e.g. namely dioctyl phthalate, alkanesulphonic acid aryl ester, tri-octyl phosphate, triphenyl phosphate, dibutyl adipate, chloroparaffin, di-. isononyl phthalate, di-2-ethylhexyl adipate, di-2-ethylhexyl phthalate, di-2-ethylhexyl sebazinate. Suitable stabilizers are e.g. phenols, ■amines or lower nitrogen-containing heterocycles, further azo and hydrazo compounds, acid anhydrides, epoxides

and elemental sulfur (DOS 2,145,318); further substances that are usually used to stabilize macromolecular substances, such as e.g. organic cadmium and lead compounds as thermo-stabilizers for polyvinyl chloride,

Suitable evaporation regulators are, for example, palmitic acid ethyl ester, myristic acid isopropyl ester, di-n-butyl phthalate, 2-chloronaphthalene, camphor, benzoic acid, biphenyl, iso-butyl benzoate and the like, as they e.g. is mentioned in GDR patent 91,898, further DOS 1,954,501, 2,026,119 and 2,028,226.

Fillers can, for example, be fibers of glass, sisal, hemp, nettle, coconut, flax; further titanium dioxide, iron oxides, kaolin, quartz and other inert materials.

The application of the relevant formulations takes place mostly as shaped bodies such as plates, foils, ribbons, ingots, spheres, foams, strips, films, tablets or granules. When using such a mold body, e.g. in the living room or bedroom of a house or it is converted in the form of a collar of a domestic animal, the DDVP contained in the preparation is released due to its vapor pressure or with the help of a heat source, e.g. electrical energy eventually to the room air and thus exits via the gas phase'automatically the pests in the room and on the domestic animals (compare DAS 1,230,259; British patent 1,015-933; South African patent hr. 62/371; DAS 1,694,240; DOS 1,941,046 and 2,231,099; DAS 1,802,684).

The shaped bodies can thereby either be used directly or be surrounded by housings (sleeves), which can be fully or partially opened or is closed, in this way at time intervals to interrupt the release of DDVP or to regulate the effective amount of substance to be released.

The problem with the use of DDVP in these automatic gas treatment bodies now lies in the fact that the release of the active substance must be controlled so that on the one hand sufficient active substance is released into the room air to safely eradicate the pests, but on the other hand not damage people and pets in the room. Active substances with lower mammalian toxicity than DDVP are therefore very special for this type of application, a major technical advance.

Although, in addition to DDVP, the South African patent 62/371 also mentions combinations with a majority of other phosphoric acid esters and the corresponding thiophosphates, apart from DDVP, no other compounds have so far found practical importance in this respect. With regard to the thiophosphates, it is revealed in DAS 1,230,259 that they are less compatible with the macromolecular substance than the phosphorus esters in question. Furthermore, it is generally known that thiophosphoric acid esters have a lower insecticidal potency than the corresponding phosphates. The inferior insecticidal effect of dimethyl-2,2-dichlorovinylthiophosate, hereafter called thio-DDVP, in relation to DDVP is shown by the following comparative experiments.

Aerosol sample.

Test animals: Musea domestica..

Solvent: Acetone.

To prepare a suitable active substance preparation, the active substance is mixed in a series of concentrations with the specified solvent.

In the middle of a gas-tight glass chamber of 1 m^. size .hanging threads, where there is approx. 25 experimental animals. After the chamber has been closed again, 2 ml of the active substance preparation is atomized into it. The condition of the test animals is constantly checked from the outside through the glass wall, the time required for a knock-down effect of 50$ of the animals is determined.

Active substances, amounts used and time, after which 50% of the animals have gone into the supine position (LT^g) can be seen in the following table 1:

It is therefore not surprising that in the above-mentioned publications there is neither an example of the use of thio-DDVP nor is the active substance mentioned

in some places not even cursorily, for example within the framework of a summary.

It has now been found that, surprisingly, thio-DDVP can advantageously be used instead of DDVP as an active substance in preparations with a depot gas effect, when it is used in combination with solid carrier materials as gas treatment agents acting independently over the gas phase for pest control.

Such preparations include combinations consisting of thio-DDVP and macromolecular. thermoplastic, elastomeric or duromeric plastics or natural substances such as wood, cardboard, asbestos, lime, gypsum, felt, beeswax or montan wax as carrier materials.

In addition to the active substance, the preparations in question may, depending on the type of carrier material, also contain the above-mentioned excipients such as e.g. softeners, stabilisers, evaporation regulators, -inhibitors or - carriers and fillers. The application of the preparation .. takes place as shaped bodies such as plates, foils, ribbons, ingots, spheres, foams, strips, films, tablets, collars or 'granules. They can be surrounded by enclosures and enable an adjustable full or reduced delivery of the active substance. The use according to the invention of thio-DDVP shows that to be particularly advantageous. compared to DDVP, there is little warm-blood toxicity of the active substance, its breakdown, decomposition and any by-products, as shown in the following table 2.

<+>This highest-■possible-concentration in the experiment was tolerated symptom-free by the animals.

The preparations according to the invention based on thio-DDVP as an independently acting gas treatment agent and solid carrier materials can be used to combat the most diverse types of pests. The thio-DDVP used as active substance according to the invention is known from the literature and can, for example, be produced according to the method described in DOS 2.238.. 921.

The invention will be explained in more detail with the help of some examples, with "parts" meaning parts by weight.

In examples 1 and 2, the mixture of 440 parts of an unsaturated polyester (produced by polycondensation of 205.8 parts of maleic anhydride, 725.2 parts of phthalic anhydride, 546.4 parts of 1,2-propanediol and 0.265 parts of hydroquinone) was used as carrier material each time with an acid number of 42)

and 240 parts styrene (polyester blend 1).

For examples 3 and 4, the mixture of 730 parts of an unsaturated polyester (produced by polycondensation of 262.8 parts of maleic anhydride, 926.8 parts of phthalic anhydride, 612 parts of 1,2-propanediol, 35956 parts of dipropylene glycol and 0.214 parts of hydroquinone) is used as carrier material each time with an acid number of 339) and 350 parts of styrene (polyester blend 2).

Example 1.

From 680 parts of polyester mixture • 1,390 parts of thio-DDVP, 230 parts of alkanesulphonic acid aryl ester and 27 parts of maleic anhydride, a homogeneous premix is prepared. After adding 41 parts of a 10% solution of dimethylaniline in toluene, at approx. 30 minutes of heating at 80 to 100°C in a closed mold, in which a glass fiber mat (600 g/m o) was inserted, produced a cast plate with a glass fiber content of 26%. The plate is then cut into shaped bodies with the dimensions 8 x 25 cm. The active substance content amounts to 20 g. E xample la.

(Comparison example 1)

In the same way as described in example 1, however, using DDVP as active substance, molded bodies with dimensions of 8 x 25 cm and an active substance content of 20 g are produced.

Oak sample 2.

A homogeneous premix is prepared from 630 parts of polyester mixture 1 and 450 parts of thio-DDVP. After adding 36 parts benzoyl peroxide in phthalate softener

(50$-ig is produced by approx. 30 minutes of heating with

80 to 100°C in a closed mold in which it had been placed

granular asbestos particles, a cast plate with an asbestos amount

of 3j5weight#. The plate is then cut into shaped bodies with dimensions of 8 x 25 cm, whose•active substance content amounts to 38$. Example 3.

A homogeneous premix is prepared from 665 parts of polyester mixture 2 and 475 parts of thio-DDVP. After adding 38 parts of benzoyl peroxide. in phthalate softener (50%) is produced at approx. 30 minutes of heating at 80 to 100°C in a closed mold, in which a weave of polyacrylonitrile fibers (280 g/m ), a casting plate with a weave portion of 26% by weight, was inserted. The plate is then cut into shaped bodies of dimensions 8 x 25 cm, whose active substance content each time

amount to 24 g.

Example 3a.

(Comparison example).

In the same way as in example 3, however, using DDVP as active substance, a homogeneous premix and the shaped body are produced in the same dimensions and with the same active substance content.

Example 4.

From 438 parts of polyester mixture 2 and 299 parts of thio-DDVP, a homogeneous premix is produced. After adding 26 parts of benzoyl peroxide in phthalate softener (50#-ig) is prepared at approx. 30 minutes of heating at 80 to' 100°C in a closed mold, in which was laid jute fabric (1150 g/m p) a casting plate with a weight amount of 26% by weight. The plate is then cut into shaped bodies with dimensions of 8 x 25 cm, the active substance content of which each time amounts to 25 g.

Example 4a.

(Comparison example).

In the same way as in example 4, however, using DDVP as active substance, a homogeneous premix and shaped bodies are produced in the same dimensions and with the same active substance content. E xample 5-

Mold bodies are cut from a cardboard of 3 mm thickness

in the size of 8 x' 25 cm and impregnated with thio-DDVP. It

• effective amount of substance in the cardboard amounts to 30 g.

Example 6.

Each time a molded body produced according to example 1 and la. is inserted into an envelope of a fine mesh thread and suspended

in the middle of equal space of 50 cnr 3 i.nnhold down from the lid. Four weeks later, 200 Musea domestica flies are released into the room.

In the room with the shaped body according to example 1, the flies fall behind

2 hours, in the room with the mold body according to example laid first

after 3 hours for 100$ in the supine position.

Oak sample 7.

Each time a molded body produced according to examples 3 and 3a is inserted into a net-like holder and suspended in the middle of equally sized rooms of 40 no contents down from the ceiling. Immediately afterwards (0) and after 4, 8 and 12 weeks, 200 flies of the Musea domestica type are released into the rooms each time. - The flies do not come into direct contact with the molded bodies. Every 1 hour after the release of the flies, the percentage of the animals that have fallen in the supine position is determined. The obtained results are shown in the following table 3.

Oak sample 8.

Each time a molded body produced according to examples 4 and 4a is inserted into an open-pore casing and suspended openly in a room. After 2 weeks, the molded body according to example 4 is first brought into a room of 43 contents and 300 flies of the Musea domestica type are released. It is determined

.time after which. 100$ of the flies have fallen over in a supine position. The room is then thoroughly ventilated and the same experiment is carried out with the molded body according to example 4a. The results obtained appear from

Claims (11)

1. Preparations with depot gas action, characterized by a combination of dimethyl-2j 2-dichlorovinylthiophosphate as a gas treatment agent acting independently over the gas phase and solid carriers. 2. Preparations according to claim 1, characterized in that thermoplastic plastics are used as carrier materials. 3. Preparations according to' claim 1, characterized by . that durable plastics are used as carrier materials. 4. Preparations according to claim 1, characterized, t, in that elastomeric substances are used as carrier materials. 5. Preparations according to claim 1, characterized in that natural substances such as cellulose-, ceratin-, asbestos-, lime- and gypsum-containing substances are used as carrier materials. 6. Preparations according to claims 1 and 5> characterized in that cardboard, wood or felt are used as natural substances. 7. Preparations according to claims 1 to 6, characterized in that mixtures of different carriers are used. 8. Preparations according to claims 1 to 7, characterized in that the combination contains additional auxiliaries and/or fillers such as softeners, stabilizers, evaporation inhibitors or - carriers, glass or textile fibres, pigments, dyes, odorants and quartz. 9. Preparations according to claims 1 to 8, characterized in that they are equipped with casings for adjustable full or reduced active substance delivery. 10. Method for producing formulations according to claim 1, characterized in that one ■ combines thio-DDVPP in a manner known per se with the carrier materials. 11. The use of preparations according to claim 1 for pest control.