JPH0320361B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a novel microcapsule type rodent repellent containing cycloheximide as an active ingredient. More specifically, the present invention provides a microcapsule type rodent repellent that does not impair the physical properties of the molded product material and exhibits stable activity over a long period of time when applied to a desired molded product by kneading, coating, etc. This is related to drugs. Conventional Technology The number of rats in Japan is estimated to be about three times the population, or more than 300 million rats, and the damage they cause is enormous throughout the year. The main types of rodent damage are packaging materials: paper or cloth bags for rice and wheat flour, cardboard cases for packaging various foods, and flexible bags made of polyvinyl chloride or rubber. Container damage, as well as communications materials-related damage, include damage to computers and related communications, power, optical communication cables, signal cables, and other electric wires and cables, as well as nesting inside machines, urination, and defecation. There are disconnections, poor connections, corrosion of parts, etc. In addition, agricultural products,
There is damage to fruit trees and plantations. In order to prevent such rat damage, many rat poisons and rat repellents have been developed, and each has achieved some degree of success. However, when applying these to various materials, it is important to Since direct contact is necessary, it is inevitable that the physical properties of the material will be damaged or new damage will be caused by contamination. Furthermore, these chemicals volatilize within a short period of time or are washed away by rainwater, making it difficult to maintain their effects over a long period of time. On the other hand, in order to make it easier for rodenticides to be ingested by rats, etc., microcapsules with a solid rodenticide as a core material have been proposed, but these capsules are only effective when rats take them into their bellies. It cannot be applied to repellents that emit and eliminate odors disliked by rats, etc. By the way, one of the compounds that has a rat repellent effect is
As one example, 3-[2-(3,5-dimethyl-2-oxocyclohexyl)-2-hydroxyethyl]
Glutarimide, or cycloheximide, is known, but its mechanism of action is that rats extremely dislike the taste of cycloheximide, and once they experience this taste, they memorize the odor, leaving only a faint odor that cannot be detected by humans. It is thought that this is because they learn to avoid it. As an example of the use of this cycloheximide, this crystal is kneaded into polyvinyl chloride,
This is sometimes used for cable coating, but in this case, it is inevitable that the strength will decrease due to heating during molding and free hydrochloric acid contained in polyvinyl chloride, and the cable coating will occur over time. There is a disadvantage that the coating falls off from the cable due to the bleed of cycloheximide into the surface layer. Another use example is dissolving cycloheximide crystals in a solvent and applying it directly to the surface of the desired article; however, if the article is to be left outdoors, cycloheximide is water-soluble. Therefore, it is easily washed away by rainwater,
It has the disadvantage of rapidly losing its rat-proofing effect. Therefore, cycloheximide has heat resistance,
There has been a need for a rodent repellent that provides chemical resistance and water resistance, and that can also exhibit stable effects over a long period of time. Problems to be Solved by the Invention The present invention overcomes the drawbacks of conventional rodent repellents that contain cycloheximide as an active ingredient, has excellent heat resistance, chemical resistance, and water resistance, and can be incorporated into materials. , a cycloheximide rodent repellent that can exhibit stable effects over a long period of time without damaging the original physical properties of the material when applied, and without contamination or loss of potency due to bleeding. It was made for the purpose of providing. Means for Solving the Problems As a result of various studies on rodent repellents containing cycloheximide as an active ingredient, the present inventors have developed a solution in which cycloheximide is dissolved in a specific solvent as a core material, and a specific synthetic resin is used as a wall material. The inventors have discovered that the objective can be achieved by using microcapsules as a material, and based on this knowledge, the present invention has been accomplished. That is, the present invention provides the formula At least 1 cycloheximide represented by
To provide a rodent repellent consisting of microcapsules whose core material is a solution dissolved in a solvent inert to cycloheximide and whose wall material is at least one resin selected from urea resins and melamine resins. It is. In the microcapsules of the present invention, it is necessary to use a solution of cycloheximide dissolved in a solvent that is inert to cycloheximide as the core material. As this solvent, one is used that dissolves cycloheximide well but does not reduce its potency even when it comes into contact with it. Particularly preferred solvents are:
It has a relatively high boiling point of over 250°C, does not volatilize even when heated when forming microcapsules or kneading it into various materials, and is hydrophobic. Typical examples of such solvents include phthalic diesters, low molecular weight epoxy resins, and phosphoric triesters. Examples of this phthalate diester include dimethyl phthalate (bp282℃), diethyl phthalate (b.
p.298°C), dibutyl phthalate (bp340°C), diheptyl phthalate, dioctyl phthalate, di(2-ethylhexyl) phthalate, diisodecyl phthalate, dithylbenzyl phthalate, ditridecyl phthalate, etc. Examples of low molecular weight epoxy resins include epoxy resins with a molecular weight of 400 or less, such as Epicote 815, 816, and 818 (all trade names manufactured by Ciel Chemical Co., Ltd.). Furthermore, examples of phosphoric acid triesters include triphenyl phosphate, trifresyl phosphate, trioctyl phosphate, and octyl diphenyl phosphate. These may be used alone or in combination of two or more. Next, the microcapsule wall material of the present invention is
It should not reduce the efficacy of cycloheximide or be soluble in the above-mentioned solvents.
As a result of various studies based on these conditions, the present inventors have found that at least one resin selected from urea resins and melamine resins satisfies these conditions. If other resins such as polyamide or polyurethane are used, the potency of cycloheximide in the capsule during storage will be significantly reduced. These urea resins and melamine resins may be used alone or as a mixture of two or more resins. To prepare microcapsules in which the cycloheximide-containing solution of the present invention is used as a core material and the core material is covered with a wall material, a method known in the microcapsule production technology can be used, for example, using a solution containing cycloheximide in a solvent in which cycloheximide is dissolved or dispersed. A polymerization reaction is caused at the interface between the soluble monomer and the monomer soluble in the dispersion medium forming the continuous phase to form a polymer microcapsule wall, and a solution containing cycloheximide is formed in the wall. Either an interfacial polymerization method that uses a combination of hydrophobic monomers and hydrophilic monomers that produce encapsulated microcapsules and utilizes the polymerization reaction at the interface to produce microcapsules, or a continuous phase or discontinuous phase method. Methods such as the in-situ method in which monomer is supplied from only one side and a polymerization reaction takes place at the interface to form a microcapsule wall film, as well as coacervation method, in-liquid curing coating method (orifice method),
This can be carried out using a method such as a submerged drying method, a spraying/granulation method, or the like. The concentration of cycloheximide in the cycloheximide solution used as the core material in the microcapsules of the present invention is suitably in the range of 1 to 20% by weight, preferably 3 to 15% by weight. Further, the particle size of the microcapsules is not particularly limited, but is usually selected within the range of 5 to 100 μm. The rodent repellent of the present invention is composed of the above-mentioned microcapsules, which can be used, for example, as shown below. (1) General synthetic resin processed products mainly made of polyvinyl chloride, such as communication/power/optical communication cables, furniture, interior/exterior building materials (walls, sliding doors, etc.), flexible containers, kneading into packaging containers, and coating. Engineering. (2) Impregnation and kneading into yarn in processed textile products. (3) Impregnating, kneading, and coating various tapes (paper and plastic). (4) Kneading into various adhesives. (5) Kneading into various paste products such as sealants. (6) Kneading into various paints. (7) Kneading into various pellets and compounds. Examples Next, the present invention will be explained in more detail with reference to examples. Reference example: Production of microcapsules () 120g of dimethyl phthalate and cycloheximide (product name: Naramycin, manufactured by Tanabe Seiyaku Co., Ltd.)
6g of terephthalic acid chloride and 13g of terephthalic acid chloride were dissolved to obtain a first liquid. Next, the first solution is emulsified in 300 g of a 2% aqueous polyvinyl alcohol solution to prepare an O/W emulsion. Meanwhile, prepare a second liquid by dissolving 4 g of sodium carbonate and 8 g of diethylenetriamine in 80 g of water. While stirring the above O/W emulsion, the second liquid was slowly added and stirring was continued for 24 hours to obtain cycloheximide-encapsulating microcapsules (A) having a polyamide wall and an average particle size of 10 μm. () Using dioctyl phthalate instead of dimethyl phthalate in (), polyamide wall cycloheximide-containing microcapsules (B) were obtained. () 100g contains 25g of diphenylmethane diisocyanate, 6g of cycloheximide, 12g of polyoxypropylene ether, and methylene chloride.
Dissolve 100g to prepare the first solution. Then water
The first is emulsified in the second liquid prepared by dissolving 20g of gum arabic and 2.5g of funnel oil in 100g, and O/
Prepare W emulsion. The obtained emulsion was stirred and reacted at 90° C. to obtain cycloheximide-containing microcapsules (C) having a polyurethane wall and an average particle size of 10 μm. () Dissolve 2 g of cycloheximide in 100 g of dimethyl phthalate to prepare the first. Then,
Emulsify with the first liquid in 400g of 2% gelatin aqueous solution,
Prepare an O/W emulsion. The obtained emulsion was adjusted to pH 8~ with 10% sodium carbonate aqueous solution.
9, 50 g of urea formaldehyde prepolymer (trade name: Euramin P, manufactured by Mitsui Toatsu)
(as a solid content) was added, the pH was adjusted to 5.0 with acetic acid, and the mixture was stirred and reacted at 50° C. for 2 hours to obtain cycloheximide-encapsulating microcapsules (D) having a urea resin wall and an average particle size of 10 μm. () Instead of dimethyl phthalate in (), epoxy resin (product name: Epicote 815, molecular weight
330, manufactured by Ciel Chemical Co., Ltd.) to obtain cycloheximide-encapsulating microcapsules (E) having a urea resin wall and an average particle size of 10 μm. () Instead of dimethyl phthalate in (),
Using dioctyl phthalate, cycloheximide-containing microcapsules (F) with a urea resin wall and an average particle size of 10 μm were obtained. () Dissolve 5 g of cycloheximide in 100 g of dimethyl phthalate to obtain a first solution. Then 2
% polyvinyl alcohol aqueous solution to obtain an O/W emulsion. While stirring the emulsion obtained, 50 g (solid content) of melamine formaldehyde prepolymer (trade name: Sumirez Resin 607syrup, manufactured by Sumitomo Chemical Co., Ltd.) was added, and the pH was adjusted with 20% citric acid aqueous solution.
5.5 and reacted at 60° C. for 2 hours to obtain cycloheximide-containing microcapsules (G) having a melamine resin wall and an average particle size of 10 μm. () Instead of dimethyl phthalate in (),
Using an epoxy resin (trade name: Epicote 828, molecular weight 380, manufactured by Ciel Chemical Co., Ltd.), cycloheximide-encapsulating microcapsules (H) having a melamine resin wall and an average particle size of 10 μm were obtained. () Instead of dimethyl phthalate in (),
Using diethyl phthalate, cycloheximide-encapsulating microcapsules (I) having a melamine resin wall and an average particle size of 10 μm were obtained. Examples 1 to 6, Comparative Examples 1 to 3 After storing the cycloheximide-containing microcapsules obtained in Production Examples for one month at room temperature, approximately
0.5 g was ground in an agate mortar, cycloheximide was extracted with acetone, and the amount of cycloheximide was measured in accordance with the official pesticide inspection method "Preparations containing cycloheximide as a main component". The ratio (%) of the amount of cycloheximide in the capsule thus obtained to the amount of cycloheximide charged at the time of production was determined and determined as the titer. Table 1 shows microcapsules (A) ~
The titer of (I) is shown.

【table】

[Table] As is clear from this table, when urea resin and melamine resin are used as wall materials, the potency of cycloheximide is maintained over a long period of time. Example 7, Comparative Example 4 "CHI Paint N2500" (manufactured by Tanabe Seiyaku Co., Ltd., trade name) containing microcapsules (G) and acrylic resin for comparison was applied to 45 kg of high-quality paper (manufactured by Sanyo Kokusaku Pulp Co., Ltd.). , based on the amount of cycloheximide,
The feed was coated with 10 μg/cm ² and 30 μg/cm ² , respectively, and placed in a breeding case containing 2 male and 3 female Wistar rats, and the feeding damage was measured after 24 hours. The rate was determined as the rate of decrease in the area of the paper specimen. The results are shown in Table 2. In addition,
The control in the table is the case where untreated paper was used.

[Table] As is clear from this table, the rodent repellent of the present invention exhibits a much higher effect than the commercially available rodent repellent containing cycloheximide. Example 8, Comparative Example 5 Microcapsules (D) and cycloheximide crystal powder for comparison were placed on a polyvinyl chloride coated cable wrapped with double-sided tape at 10 μg/cm 2 and 35 μg/cm ² , respectively, based on the amount of cycloheximide.
The sample was coated with powder at a ratio of 2 cm ² and tested in the same manner as in Example 7 to determine the exposure rate of the core of the sample. The results are shown in Table 3.

[Table] As is clear from this table, use of the rodent repellent of the present invention can completely prevent rodent damage to polyvinyl chloride coated cables. Example 9, Comparative Example 6 Microcapsules (F) and cycloheximide crystals for comparison were prepared using a vinyl chloride compound [“Zeon 101EP” (manufactured by Nippon Zeon Co., Ltd., suspension polymerization resin,
Product name) 100 parts by weight, 40 parts by weight of dioctylphenol, 5 parts by weight of tribasic lead sulfate, 1 part by weight of dibasic lead stearate, 7 parts by weight of calcined clay, 0.5 parts by weight of high melting point paraffin] respectively. After adding them at a ratio of 0.05% by weight and 0.2% by weight, they were formed into a sheet and subjected to the eating test in the same manner as in Example 7. The results are shown in Table 4 as polyvinyl chloride weight loss percentages.

[Table] As is clear from this table, when the rodent repellent of the present invention is used, it is possible to completely prevent rodent damage even when it is kneaded into a material. Example 10, Comparative Example 7 Microcapsules (H) and "CHI Paint N2500" (same as that used in Example 6) added with acrylic resin for comparison were each added to 30 μg/cm ² based on cycloheximide. A certain amount of cycloheximide was applied onto the surface of a polyvinyl chloride sheet, and this was left at room temperature, and the amount of cycloheximide transferred was measured after 1 month and 3 months. The results are shown in Table 5.

[Table] As is clear from this table, the rodent repellent of the present invention has no migration properties and can perform safe and effective rodent repellent processing. Example 11, Comparative Example 8 Microcapsules (F) and cycloheximide crystals for comparison were added to a vinyl chloride compound (same as that used in Example) at a proportion of 0.2% by weight based on cycloheximide, and polychloride was added. A vinyl sheet was produced. A polyvinyl chloride sheet of the same type that does not contain cycloheximide was heat-sealed to this sheet and left at room temperature for 1 and 3 months, and the amount of cycloheximide transferred was measured. The results are shown in Table 6.

[Table] As is clear from this table, the rodent repellent of the present invention does not exhibit any migration properties even when kneaded into a material. Example 12, Comparative Examples 9 and 10 Microcapsules (H) and (CHI Emulsion H) for comparison (manufactured by Tanabe Pharmaceutical Co., Ltd., trade name) (Comparative Example 9 and "CHI Paint C-500" (manufactured by Tanabe Pharmaceutical Co., Ltd.) , trade name) (Comparative Example 10) 50μ based on cycloheximide
Coat on a glass plate at a ratio of g/ ^cm2 , 50℃, 85%
The sample was left in an RH atmosphere for 3 months, and the residual rate of cycloheximide over time was measured. The results are shown in Table 7.

[Table] As is clear from this table, the rodent repellent of the present invention exhibits superior stability over time compared to commercially available products. Example 13, Comparative Example 11 Microcapsules (I) and "CHI Paint C-200 (manufactured by Tanabe Seiyaku Co., Ltd., trade name)" for comparison,
Based on cycloheximide, it was applied to a glass plate in an amount of 30μg/ ^cm2 , immersed in water at room temperature, 35℃ and 55℃, taken out after 1 hour, and the amount of cycloheximide remaining on the glass plate was measured. The survival rate was calculated. The results are shown in Table 8.

[Table] As is clear from this table, the rodent repellent of the present invention has excellent water resistance. Effect of the Invention According to the present invention, cycloheximide is made into a solution using a predetermined solvent, and this is microencapsulated using a predetermined wall material, thereby improving chemical resistance, solvent resistance, heat resistance, water resistance, and aging resistance. Not only can the chemical stability be significantly improved, but also the drug efficacy and eradication properties can be improved. Furthermore, there are operational advantages in that handling becomes easier and bleeding into contact materials can be suppressed.

Claims (1)

[Claims] 1 formula At least 1 cycloheximide represented by
A rodent repellent comprising microcapsules whose core material is a solution of cycloheximide dissolved in an inert solvent and whose wall material is at least one resin selected from urea resins and melamine resins.