JPS6139281B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an improved vaporized diffusible substance release control body. Various attempts have been made to gradually release diffusible substances, especially insect pheromones, which are vaporized by steam or sublimation over a long period of time. For example, efforts have already been made to formulate insect pheromones to control their vaporization and provide a sustained effect. Therefore, the desired properties of a sustained-release pheromone composition are: Release of pheromone at a constant rate for a certain period of time; Stable presence of pheromone with little loss; Biodegradability and no environmental pollution. Application Examples include ease of formulation and low cost of formulation, but no drug has been proposed to date that satisfies these requirements. Previously proposed sustained-release compositions for pheromone include microcapsule-based compositions made of gelatin, polyamide resin, etc. (U.S. Patent No.
2800457, 2800458, 3577515, etc.), multilayer film dispenser type (ACS, 33 (1976) p. 283), hollow fiber type consisting of a capillary tube with an open end ( US Patent No.
4017030) are known. However, microcapsule type resins are expensive, gelatin is susceptible to wind and rain, and polyamide resins are not biodegradable. The disadvantage of film dispensers and hollow fibers is that they are not biodegradable and require special sprayers for application. Other diffusible substances that vaporize through evaporation or sublimation include insecticides, fungicides, repellents, other fumigants, and fragrances, but all of them require the achievement of a certain release rate, low cost, and use. It cannot be said that it is sufficient in terms of ease of use. As with pheromones, agricultural and horticultural insecticides, fungicides, and repellents require that the formulations be biodegradable, do not pollute the environment, and be easy to apply. The present invention has been completed as a result of intensive research in view of the conventional technical problems, and is a method of producing a vapor-diffusible substance, which is obtained by coating the surface of solid particles containing a vapor-diffusible substance with a cellulose derivative. This invention relates to non-soluble controlled release substances. According to the present invention, all of the above-mentioned requirements are satisfied, and furthermore, the release rate of the vaporized diffusible substance can be easily designed by changing the surface area, coating thickness, etc. of this control body.
In addition, since it is possible to formulate formulations in minute shapes,
In the case of pheromones, insecticides, fungicides, etc. for agriculture and horticulture, it is possible to spray the preparations with a regular sprayer, and not only does the application not require much labor, but especially in the case of pheromone preparations. In the application of the communication disturbance method, it is possible to more uniformly distribute the pheromone source in the field, release the pheromone continuously at a constant rate, use the pheromone more effectively, and release the pheromone after a certain period of time. The decomposition of the base material provides the advantage of not accumulating in nature and causing no environmental pollution. The vaporizable substance used in the present invention is a substance that vaporizes by steam or sublimation, and examples thereof include pheromones, insecticides, fungicides, repellents, other fumigants, fragrances, and the like. The above-mentioned pheromone may be any pheromone as long as it shows activity as an insect sex pheromone, and it is not limited to a single component, but a mixture of a plurality of active substances can be used. Further, a suitable ultraviolet absorber or a suitable antioxidant can be mixed and used as an additive to the pheromone. The solid particles containing the vaporizable material are prepared by supporting the vaporizable material on an inert carrier, using a binder if necessary. Examples of the inert carrier include inorganic powders such as silicic anhydride and various silicates, cellulose powders, and organic powders such as polysaccharides and polysaccharide derivatives such as starch. Examples of binders include polysaccharides such as starch and polysaccharide derivatives such as cellulose derivatives. Cellulose derivatives used to coat the surface of solid particles containing vapor-diffusible substances include methylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, ethylcellulose, ethylcarboxymethylcellulose, carboxymethylcellulose, etc. Examples include cellulose esters such as cellulose ether, cellulose acetate, and cellulose acetate phthalate, and cellulose ethers such as hydroxypropylmethylcellulose phthalate and hydroxypropylmethylcellulose acetate succinate. These cellulose derivatives have good film-forming properties, and this film has an appropriate permeability to diffusible substances, and is excellent in that it can be decomposed by bacteria, cellulases, etc. and returned to the natural world. The non-soluble release controlled substance of the vaporized diffusible substance obtained using the above cellulose derivative exists stably in water if the cellulose derivative is insoluble in water with a pH around 7; In this case, dissolution of the film can be avoided by subjecting the cellulose derivative to a water-insolubilization treatment such as glyoxal treatment. Stability against water can be obtained. In applications where the controlled release agent does not come into contact with water, the water insolubility of the cellulose derivative is not important. Water insolubility is important for pheromone preparations and the like to avoid dissolution and damage of the film due to rain, etc. The cellulose derivative coating does not need to be a single component, and a plurality of cellulose derivatives can be used in combination as appropriate. It is also possible to use waxes such as stearic acid as a film forming aid. The non-dissolved release controlled body of the vaporized diffusible substance of the present invention is manufactured as follows. First, a liquid or solid vapor-diffusible substance or a mixture of this vapor-diffusible substance and a suitable stabilizer, etc., is added to the inert carrier in a mixing device and mixed, usually 0.3 to 4 times the weight of the inert carrier. By doing so, solid particles containing the vaporized diffusible substance are created. In order to achieve more uniform mixing at this time, it is also possible to dilute or dissolve the vaporized diffusible substance in an appropriate organic solvent. Next, the surface of the solid particles containing the vapor-diffusible substance produced in this way is coated with a cellulose derivative, and the coating method is as follows.
Each method (a) to (c) is exemplified. (a) A method in which solid particles containing a vaporizable substance are granulated by spraying a cellulose derivative solution, or a cellulose derivative coating is formed on the surface without granulation. (b) A binder is usually added to solid particles containing a vapor-diffusible substance in an amount of 0.01 to 1 times the weight of the solid particles, and the mixture is kneaded with an appropriate solvent, or the binder is added in the form of a solution and kneaded. A method of forming a cellulose derivative coating on the surface of the secondary solid particles by subsequently granulating and drying to obtain secondary solid particles, and spraying a cellulose derivative solution onto the secondary solid particles. (c) A method of forming a cellulose derivative film by dispersing the solid particles in (a) or the secondary solid particles in (b) in a cellulose derivative solution and spray drying this dispersion. Known spray coating equipment can be used to spray the cellulose derivative solution, and (b) granulation.

【table】

[Table] From Table 1, sex pheromone continues to be released at a nearly constant rate of 2.1mg/day for 40 days, and the amount that remains unreleased after 60 days is extremely small, about 5% of the amount of pheromone filled, which is ideal. It showed excellent performance. Furthermore, this preparation was left in water at 30°C for 10 days, but there were no abnormalities with the preparation or the sex pheromone contained, confirming that the preparation was highly stable in water. Example 2 30 parts by weight of light silicic anhydride was mixed with 30 parts by weight of Z-11-tetradecenyl acetate, and cellose acetate (trade name L-20 manufactured by Daicel Chemical Industries, Ltd.) was added to this.
A 5% solution of methylene chloride/ethanol (9/1) is sprayed in a fluidizer to granulate and coat the original solid particles, forming a coating of 45% by weight on the original solid particles, and reducing the average particle size. A 0.4 mm formulation was obtained. The obtained preparation was dissolved in acetone, extracted, and analyzed by gas chromatography using an internal standard method. As a result, it was found that Z-11-tetradecenyl acetate was contained in an amount of 23% by weight based on the weight of the entire preparation. Further, when a release rate test and a stability test against water were conducted, almost the same results as in Example 1 were obtained. Example 3 A diazinon-containing preparation with a coating amount of 32% by weight was prepared using 30 parts by weight of the organophosphorus insecticide diazinon in the same manner as in Example 1. 30℃ wind speed
The diazinon residual rate after being left for 30 days under the condition of 0.5 m/sec was 42%, indicating good sustained release properties. Example 4 A naphthalene-containing preparation with a coating amount of 45% by weight was prepared using 30 parts by weight of naphthalene powder in the same manner as in Example 1. The naphthalene residual rate after being left at 30° C. for 15 days at a wind speed of 0.5 m/sec was 48%, indicating good sustained release properties.

Claims (1)

[Scope of Claims] 1. A non-soluble release controlled body for a vaporizable substance, which is obtained by coating the surface of solid particles containing a vaporizable substance with a cellulose derivative. 2. An insoluble release controlled body for a vaporizable substance according to claim 1, wherein the solid particles containing the vaporizable substance are composed of the vaporizable substance and an inert carrier. 3. A non-dissolved controlled release material for a vaporizable substance according to claim 1, wherein the solid particles containing the vaporizable substance are composed of a vaporizable substance, an inert carrier, and a binder. 4. A non-soluble release controlled body for a vaporized diffusible substance according to claim 1, 2 or 3, wherein the vaporized diffusible substance is a pheromone.