MXPA00000704A - Improved gel formulations containing insecticide - Google Patents

Abstract

The invention relates to novel insecticide gel formulations which ensure the controlled, long-lasting release of active insecticide agents using a heat source.

Description

Improved gel formulations containing insecticide Description of the invention: The present invention relates to new insecticidal gel formulations for the regulated and prolonged release of insecticidal active ingredients by means of a heat source. These new gel formulations are characterized in that they contain at least one type of an insecticide and at least one vaporization controlling substance (vaporization modifier) in combination with a suitable solid substance as a gelling agent. The present invention is based on known gel formulations, such as those described in EP 0 693 254, in which insecticidal active principles with alternative solvents of a new type together with flavors, colorants and adjuvants do not decompose during the course of a prolonged period will have an optimal activity. The use of this new formulation of active principle must be carried out in plastic or metal containers made by deep drawing or casting which are often closed with fabrics, plastic sheets, eg polypropylene foil or suitable metal foils that are permeable to the components volatile, such as those described in EP 0 693 254. These deep-drawn containers can be used in an electric heating apparatus for the extermination of insects, eg mosquitoes. To kill mosquitoes with an electric heater, REF .: 32483 the so-called plaque vaporizer, it is generally known to impregnate specially selected materials, such as cellulose and cotton board, asbestos, ceramics and / or porous synthetic resins, with pyrethroid insecticides to obtain insecticide inserts in which the insecticide it is vaporized by the action of the heating device for the extermination of mosquitoes, which generates a heat of 120-190 ° C. A notable disadvantage of these platelet vaporizers lies in the unfavorable relation between energy consumption and the active principle to vaporize, since the quantities of active principle in relation to those of adjuvants are considered as low. Furthermore, the high working temperature of these platelet vaporizers causes that only a few active ingredients are generally aerated for them and these also, due to the system, detach irregularly during the predetermined time of active duration. The active duration of these platelet vaporizers is limited here to a maximum of 12 hours. The unfavorable active ingredient / vehicle ratio inevitably finally requires a greater collection of vaporizer inserts, which leads to a considerable expenditure of vehicle materials and packaging materials. Also the apparatuses frequently used for domestic use for the vaporization of an insecticide active ingredient solution by means of a heated wick (GB 2 153 227), in which the active principle is dissolved in a mixture of saturated aliphatic hydrocarbons-kerosine that through the wick is vaporized electrically have significant drawbacks. In addition to the fact that these vaporizer systems also work at service temperatures between 120 and 190 ° C, they need their own distribution system (wick) and considerable quantities of solvents. The overproportional amount of solvent in relation to that of active principle leads to using the product at a high concentration of solvents and coadjuvants in the room, which leads, on the other hand, to a fouling - increasingly observed and claimed by consumers - of walls and objects that are in the vicinity of these devices.

Other drawbacks of these formulations are the large volume of the solvent container and the danger of solvent discharging, which entails considerable problems in transportation and danger in its use. In addition, EP 0 693 254 mentions gel formulations which have the drawback of having residence times in too long interior rooms and also being composed of very expensive components. The novel gel formulations containing insecticide according to the invention comprise mixtures containing at least one type of a pyrethroid insecticide, a vaporizing controlling substance and a suitable inorganic solid substance as a gelling agent.

The active ingredients indicated in document EP 0 693 254 can be used as an active ingredient. In this regard, formulations with the active ingredient transfluthrin (Bayothrin®, (+) -lR-trans-2, 2-dimethyl-3 are especially suitable). - (2,2-dichlorovinyl) -cyclopropylpropane carboxylate 2,3,5,6-tetrafluorobenzyl) with reduced content of active ingredient and in combination with new vaporizing substances, also called vaporization modifiers, which in their use they present a potential of danger strongly reduced and that in addition they degrade quickly in the inner enclosure. Preferred new vaporization modifiers are medicinal white oils CAS No. 8042-47-5 (BP Enerpar M002®) and hydrogenated mineral oils at high pressure CAS No. 8042-47-5 (Enerpar M 1930®). Especially preferred are natural renewable raw materials such as rapeseed oil, methylcocid ester of rapeseed oil and Guerbet alcohol from colorless to slightly yellowish with a liquid / solid consistency with a very weak odor, CAS n °: 67 187-86-0 ( Guerbitol 32/36 * Guerbet alcohol from colorless to slightly yellowish in liquid consistency with very weak odor = 2-hexyldecan-l-ol, CAS n °: 36311-34-9 (Guerbitol 16®). Guerbet from colorless to slightly yellowish with liquid consistency = 2-hexyldecan-1-ol, CAS n °: 36311-34-9 (Guerbitol 16®).

The formulations generally contain between 1.0 and 95% by weight of insecticidal active principle, preferably between 5.0 and 80%, especially from 20 to 50% by weight. The formulations also contain in general between 10 and 90% by weight of vaporization modifiers, preferably between 40 and 80% by weight as well as in general between 1 and "12% of gelling agent, preferably between 6 and 10%.

The ratio active ingredient / vaporization modifier is found in the gel formulations containing insecticide according to the invention between 9 and 0.1, preferably between 2.0 and 0.2. In addition to these mixtures, adjuvants, stabilizers, flavors and organic or inorganic colorants can be added, such as those described, among other places, in EP 0 693 254. The formulations must have an optimum storage stability for a prolonged period. The gel formulations are prepared by stirring, in a corresponding mixing device (planetary stirrer), firstly the active principle with the vaporization modifier and the stabilizer, and optionally additional solvent at room temperature until a clear solution is formed. The gellant is then added in vacuo and stirred vigorously until a homogeneous gel is formed. Before mixing the final gel with the gelling agent, essences and dyes can be added to the present clear solution, stirring until completely homogenized. For use, the film container with the colored gel is inserted into the heating apparatus, the front of which is transparent or is provided with a viewing slot.

During the use of the heating device, the content of the sheet container, which by a colored marking on the container itself or on the heating device is not visible, is dried. Through the transparent front of the heating device or through the viewing slot, it is only observed when the film container is empty. Another variant of the optical determination of the end point can also be carried out by dyes added by changing the color to another color when the active principle and, if appropriate, the solvent have been vaporized. The present invention will be illustrated by the present Examples: Example 1 Formulations with new vaporization modifiers Example 2 The gel formulations containing insecticide can be prepared as follows: 2.1 25 kg of Transfluthrin® (temperature approx 40 ° C) were placed in a stirring device for a 100 kg preparation., 64 kg of Enerpar M002® and 1 kg of BHT and stirred until the formation of a clear solution. In addition, preferably the aurance essences of citronella, C10-C16 aldehyde, birch pitch oil, benzyl salicylate, lavender essence or rose essence in combination with, or without, the yellow dyes can be added to the formulation in the agitation. Hostasol®, bright red Resin BLS®, 1, 4-diaminoanthraquinone, alizarin VK6 / 225, fatty red HKR®, fatty red G®, green Solvaperm G or blue Sudan 670®. To the clear solution, 6 kg of Aerosil 200 were rapidly added to the formation of the gel in vacuo. 2. 2 25 kg of Transfluthrin® (temperature approx 40 ° C), 64 kg of Guerbitoi 16® and 1 kg of BHT were placed in a stirrer for a 100 kg preparation and stirred until a clear solution was formed. In addition, preferably the aurance essences, citronella, C10-C16 aldehyde, birch pitch oil, benzyl salicylate, lavender essence or rose essence in combination with, or without, the yellow dyes Hostasol can be added to the formulation in the agitation. ®, bright red Resin BLS®, 1, 4-diaminoanthraquinone, alizarin VK6 / 225, fatty red HRR®, fatty red G®, green Solvaperm G or blue Sudan 670®. The clear solution was incorporated by rapidly stirring 8 kg of Aerosil COK 84® until the formation of the gel under vacuum. For its application, the gel formulations are filled, according to the duration of application, in general in amounts of 0.2-0.5 g, preferably in quantities of 0.2-0.3, in containers made by deep-drawing or casting and they are sealed with polypropylene sheet. The preferred materials for the containers are aluminum, polyester, polyethylene, metals. The size of the container is chosen so that the bottom surface of the container is the same size as the heating surface of the heating apparatus and transmits temperatures of 70 to 112 ° C. The regulated and prolonged release of the active insecticidal ingredients is represented by the application of Examples 2.1 and 2.2 as follows: 1.6 g of the insecticide-containing gel formulations were distributed in aluminum containers made by deep-drawing of dimensions 4 x 2.5 x 0.4 cm uniformly on the surface, and sealed with PP Walothen C50SE® or Trepaphan 6ND50® sheet. In a heating apparatus with a temperature of 110-112 ° C the container was heated daily for 8 hours and the quantities emitted from the formulation were determined. The results of the vaporization tests are shown in Example 3. Example 3 Emission rates of the formulations of Example 1.1 and 1.2 in [mg / h] Heating temperatures: 105-107 ° C Voltage: 230 V Ambient temperature: 20 -22 ° C Duration of the cycles: 8 h Pause of the cycles: 4 h Weight of the formulation: 1.6 g Example 4 Biological activity on susceptible Aedes aegypti mosquitos Room size: 36 m2 Room type: 1 window remains open temperature: 20-28 ° C humidity reí. of the room: 17-34% heating temperature: 105-110 ° C content of active ingredient: 25% transfluthrin weight of the formulation: 1.6 g On the basis of the present results the biological activity of the formulations indicated here is sufficient.

It is noted that in relation to this date, the best method known to the applicant to carry out said invention is that which is clear from the present description of the invention.

Claims (5)

1. Having described the invention as above, the content of the following claims is claimed as property: 1. Insecticidal gel formulation with regulated and prolonged release of insecticidal active ingredients by a heat source, characterized in that they contain at least one insecticidal active principle of the group of the pyrethroids, a substance controlling the vaporization of the group of medicinal white oils, hydrogenated high pressure mineral oils, rapeseed oil or rapeseed or Guerbet alcohol derivatives as well as gelling agents and customary formulation aids.
2. 2. Gel insecticidal formulations according to claim 1, characterized in that they contain the active substance transfluthrin.
3. 3. Insecticidal active principles according to claim 1, characterized in that they contain at least one vaporizer modifier from the group of natural renewable raw materials such as rapeseed oil, rapeseed oil methyl ester or Guerbet alcohol from colorless to slightly yellowish (CAS n ° : 67 187-86-0) or 2-hexyldecan-1-ol (CAS n °: 36311-34-9).
4. 4. Gel insecticidal formulations according to claim 1, characterized in that they contain from 10 to 90% by weight of vaporization modifiers and from 1 to 12% of gelling agent as well as from 5 to 80% of insecticidal active principle.
5. 5. Process for the preparation of insecticidal gel formulations according to claim 1, characterized in that the insecticidal active principle and the vaporization modifier as well as the stabilizing case and other solvents and coadjuvants are stirred until a clear solution is formed and then, under reduced pressure, gelling agent is added as well as optionally dyes, essences and / or other adjuvants and this is stirred vigorously until the formation of a homogeneous gel and this homogeneous gel formulation is filled into suitable containers.