Sustained-release pheromone preparation

Abstract

To provide a sustained-release pheromone preparation that can be manufactured continuously with an extremely low incidence of defective products during manufacture and that employs a container composed of a biodegradable material.SOLUTION: The present invention provides a sustained-release pheromone preparation comprising at least a carboxylic acid compound that is a sex pheromone substance and a container for enclosing the carboxylic acid compound therein, wherein the container includes, at least in part, a film of a linear aliphatic polyester containing at least one selected from the following repeating units (I) (where X and Y are each independently a divalent hydrocarbon group having 1 to 8 carbon atoms).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a sustained-release pheromone formulation. [Background technology]

[0002] Currently, there is a strong demand for the establishment of mass-trapping and mating disruption methods using sex pheromones as alternative control techniques to insecticide spraying. Mass-trapping and mating disruption methods involve trapping and killing large numbers of adult male pests in the field using traps that are attracted to the sex pheromone substances of the target pests, while mating disruption methods involve releasing large amounts of sex pheromones into the air to disrupt mating between males and females, thereby reducing the mating rate of adult female pests in the field.

[0003] To release a constant amount of sex pheromone substance over a long period of time, sustained-release pheromone formulations are used, in which the sex pheromone substance is encapsulated in a container such as a cap, thin tube, laminated bag, or capsule made of a release-controlling material such as rubber, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, or polyvinyl chloride. Among these, polyolefin-based plastics, such as polyethylene and ethylene-vinyl acetate copolymer (EVA), are available in a wide variety of types and are inexpensive due to their general use. Furthermore, they have excellent moldability, allowing for a wide range of molding processes, including extrusion, film molding, stretch molding, and injection molding. Their mechanical strength, particularly at low temperatures, makes them suitable for use in cold seasons and regions. For example, sustained-release pheromone formulations have been reported in which aldehyde compounds and acetate compounds, well-known as sex pheromone substances of lepidopteran pests, are encapsulated in a container made of a membrane of polyethylene, ethylene-vinyl acetate copolymer, or linear aliphatic polyester, allowing the sex pheromone substance to permeate and be released through the container (Patent Document 1).

[0004] However, carboxylic acid compounds are hardly released from containers made of polyethylene. On the other hand, it has been reported that a sustained-release pheromone formulation using an ethylene-vinyl acetate copolymer with a vinyl acetate content within a specified range as the container can maintain a high release rate of carboxylic acid (Patent Document 2). It has also been reported that the release rate increases as the vinyl acetate content increases. However, no sustained-release pheromone formulation has been reported in which a carboxylic acid compound is encapsulated in a container made of linear aliphatic polyester. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-161058 [Patent Document 2] Japanese Patent Application Laid-Open No. 2012-126692 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 reports that, from the viewpoints of release performance and processability, the vinyl acetate content in the copolymer is preferably 4 to 20% by mass. However, increasing the vinyl acetate content of an ethylene-vinyl acetate copolymer increases its fluidity when heated during processing, resulting in problems such as breakage during extrusion molding of containers or leakage when sealing the edges due to uneven film thickness, resulting in a high number of defective products. This is thought to be due to the low melting point and flexural modulus. For example, an ethylene-vinyl acetate copolymer with a vinyl acetate content of 4% by mass has a melting point of 107°C and a flexural modulus of 200 MPa. Furthermore, an ethylene-vinyl acetate copolymer with a vinyl acetate content of 10% by mass or more has a melting point below 100°C and a flexural modulus of 100 MPa or less.

[0007] In addition, tube formulations, which are the most common containers, are produced by continuously ultrasonically sealing extruded liquid-filled tubes and cutting them to a specified length. Ultrasonic sealing involves pressing a horn, which acts as a vibrator, against the tube, oscillating to fuse and seal the liquid. Therefore, the flexural modulus of the container material plays a major role when the horn is pressed against the tube. Furthermore, as the temperature increases, the flexural modulus decreases, making it more likely to break when oscillating and fusing. Furthermore, the liquid in the sealed area is pushed out both forward and backward, increasing the internal pressure of the tube. In particular, continuous sealing results in continuous movement of liquid to the rear, causing the internal pressure to continue to rise. Therefore, in the above-mentioned continuous production method, if a material with a low flexural modulus and a low melting point is used, the material may be prone to rupture due to the internal pressure.

[0008] Furthermore, in recent years, there has been a strong demand for reducing the environmental impact, and there is a strong demand for the polymers used in sustained-release pheromone preparations to be naturally degradable and biodegradable. Therefore, there has been a demand for the development of a sustained-release pheromone preparation that can be produced continuously with an extremely low rate of defective products during production and that uses a container made of a biodegradable material. [Means for solving the problem]

[0009] As a result of intensive research conducted by the present inventors to solve the above problems, they discovered that by using a carboxylic acid compound sex pheromone substance and a container made of a specified aliphatic polyester, the rate of defective products in the resulting preparation can be reduced, continuous production becomes possible, and further, the carboxylic acid sex pheromone substance can be sustainedly released from the preparation at a constant release rate over an extended period of time, leading to the completion of the present invention. In one embodiment of the present invention, a sex pheromone compound is provided, which comprises at least a carboxylic acid compound as a sex pheromone substance and a container for encapsulating the carboxylic acid compound therein, wherein the container contains the following repeating unit (I): [ka] (In the formula, X and Y are each independently a divalent hydrocarbon group having 1 to 8 carbon atoms.) The present invention provides a sustained-release pheromone preparation that contains, at least in part, a film of a linear aliphatic polyester containing one or more selected from the group consisting of: In another aspect of the present invention, a method for controlling pests can be provided, which includes at least the steps of placing the sustained-release pheromone formulation in a field and releasing the carboxylic acid compound in the sustained-release pheromone formulation. [Effects of the Invention]

[0010] The sustained-release formulation of the present invention can reduce the rate of rejects in the resulting sustained-release pheromone formulation. It also enables continuous production of the pheromone formulation. Furthermore, it can maintain a high level of release of the carboxylic acid sex pheromone substance throughout the adult insect development period. DETAILED DESCRIPTION OF THE INVENTION

[0011] The sustained-release pheromone formulation of the present invention contains at least a carboxylic acid compound as a sex pheromone substance. The carboxylic acid compound may be a natural product extracted from a pest insect, but is preferably a synthetic product from the viewpoint of industrial application. The carboxylic acid compound is not particularly limited as long as it has a carboxy group, but is preferably a medium- or long-chain fatty acid having 6 to 21 carbon atoms, including the carbon atom of the carboxy group. If the number of carbon atoms, including the carbon atom of the carboxy group, is fewer than 6, the sex pheromone substance may permeate through the film too quickly, even if the thickness of the container is increased, and an appropriate release rate may not be achieved. On the other hand, if the number of carbon atoms, including the carbon atom of the carboxy group, exceeds 21, the sex pheromone substance may permeate through the film too slowly, and appropriate release control may not be achieved. In addition, there are few pests that are susceptible to sex pheromone substances with fewer than 6 carbon atoms, including the carbon atom of the carboxy group, or with more than 21 carbon atoms, including the carbon atom of the carboxy group, and therefore these substances are unlikely to be the subject of formulation development.

[0012] Fatty acids are classified as short-chain, medium-chain, and long-chain fatty acids depending on the number of carbon atoms, including the carbon atom in the carboxyl group. Short-chain fatty acids have 5 or fewer carbon atoms, medium-chain fatty acids have 6 to 12 carbon atoms, long-chain fatty acids have 13 to 21 carbon atoms, and very-long-chain fatty acids have 22 or more carbon atoms, including the carbon atom in the carboxyl group. Fatty acids are carboxylic acids with a carboxyl group attached to the end of an aliphatic hydrocarbon skeleton. The carboxylic acid compound may be linear, branched, or cyclic, may have one or more carboxy groups (COOH), and may be a saturated or unsaturated carboxylic acid.

[0013] Specific examples of the carboxylic acid compound include linear or branched saturated fatty acids such as hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, dodecanoic acid, 3,5-dimethyldodecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, icosanoic acid, and heneicosanoic acid; hexenoic acid, heptenoic acid, octenoic acid, octadienoic acid, nonenoic acid, nonadienoic acid, decenoic acid, decadienoic acid, undecenoic acid, E-5-undecenoic acid, Z-5-undecenoic acid, dodecenoic acid, and dodecadienoic acid. Examples of unsaturated fatty acids include enoic acid, tetradecenoic acid, tetradecadienoic acid, pentadecenoic acid, pentadecadienoic acid, hexadecenoic acid, hexadecadienoic acid, hexadecenoic acid, hexadecadienoic acid, hexadecatrienoic acid, heptadecenoic acid, heptadecadienoic acid, octadecenoic acid, octadecadienoic acid, octadecatrienoic acid, nonadecenoic acid, nonadecadienoic acid, icosenoic acid, icosadienoic acid, icosatrienoic acid, heneicosenoic acid, heneicosadienoic acid, and (E,Z)-3,5-tetradecadienoic acid.

[0014] The carboxylic acid compound is more preferably a saturated or unsaturated monocarboxylic acid having 11 to 17 carbon atoms, including the number of carbon atoms in the carboxy group, even more preferably a saturated or unsaturated monocarboxylic acid having 12 to 16 carbon atoms, and particularly preferably a saturated or unsaturated monocarboxylic acid having 13 to 15 carbon atoms.

[0015] Additives such as antioxidants and ultraviolet absorbers may be added to the carboxylic acid compound. Examples of antioxidants include synthetic antioxidants such as BHT (butylhydroxytoluene), BHA (butylhydroxyanisole), isoamyl gallate, propyl gallate, and 2,5-di-t-butylhydroquinone (DBH), and natural antioxidants such as nordihydroguaiaretic acid (NDGA) and guaiac oil. Examples of ultraviolet absorbers include p-aminobenzoic acid derivatives such as octyl p-dimethylaminobenzoate, benzophenone derivatives such as oxybenzone (2-hydroxy-4-methoxybenzophenone) and 2-hydroxy-4-octoxybenzophenone, methoxycinnamic acid derivatives, salicylic acid derivatives, and 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole. The content of each additive is not particularly limited, but is preferably 0.1 to 5 parts by mass relative to 100 parts by mass of the carboxylic acid compound, and the total content thereof is preferably 0.2 to 10 parts by mass.

[0016] Furthermore, since some pest insects utilize both carboxylic acid compounds and other sex pheromone components, a sex pheromone substance other than the carboxylic acid compound may be added to the carboxylic acid compound. The sex pheromone substance other than the carboxylic acid compound is not particularly limited as long as it is released in a fixed amount from the container over a fixed period of time and is highly reactive with the carboxylic acid compound and decomposable, and examples thereof include aldehyde compounds, acetate compounds, alcohol compounds, ketone compounds, and hydrocarbon compounds.

[0017] Examples of pests that have carboxylic acid compounds as sex pheromone substances include the following pests: The names of the pests are followed by the carboxylic acid compounds that are their sex pheromone substances. California prionus( Prionus carifornicus ): 3,5-dimethyldodecanoic acid Himemarukatsuobushimushi ( Anthrenus verbasci ): (Z)-5-undecenoic acid and (E)-5-undecenoic acid Himekatsuobushimushi ( Attagenus unicolor):(E,Z)-3,5-tetradecadienoic acid

[0018] The reason why sustained-release pheromone formulations using carboxylic acid sex pheromone substances and aliphatic polyester containers have not been developed to date is thought to be as follows. Like polyethylene, polyester has acid resistance, and furthermore, its physical properties, such as tensile strength and elongation, which are indicators of mechanical strength, are similar. Therefore, polyethylene and polyester are thought to have similar polymer properties. Therefore, since carboxylic acid compounds could not be released from polyethylene containers, it was expected that release of carboxylic acid compounds would also be difficult from polyester containers. Therefore, polyester was not considered for use in containers intended to release carboxylic acids. However, unexpectedly, when a container containing at least a portion of polyester, particularly a linear aliphatic polyester containing one or more repeating units selected from the following repeating unit (I), was used, a sustained-release pheromone formulation capable of releasing a constant amount of carboxylic acid compounds was obtained, unlike when a polyethylene container was used.

[0019] [ka] (In the formula, X and Y are each independently a divalent hydrocarbon group having 1 to 8 carbon atoms.)

[0020] X and Y are each independently a divalent hydrocarbon group having 1 to 8 carbon atoms. Specific examples of X and Y include a methylene group, an ethylene group, a vinylene group, a propylene group, a propanediyl group, a butanediyl group, a pentanediyl group, a hexanediyl group, a heptanediyl group, and an octanediyl group, with an ethylene group and a butanediyl group being particularly preferred. Preferably, X and Y are each independently a divalent saturated hydrocarbon group having 1 to 5 carbon atoms.

[0021] The method for producing the repeating unit (I) is not particularly limited, but it can be obtained, for example, by condensing a linear dicarboxylic acid with a linear diol. Examples of dicarboxylic acids constituting the dicarboxylic acid unit of repeating unit (I) include linear compounds such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, and fumaric acid. Preferred examples of the dicarboxylic acid unit of repeating unit (I) are succinic acid and adipic acid, from the viewpoints of compatibility with the polarity of the sex pheromone substance, and the molecular diameter of the sex pheromone substance and the crystallinity of the polymer membrane or the gap structure of the polymer chains in the polymer membrane, which are important in terms of the membrane permeation mechanism.

[0022] Examples of diols constituting the diol unit of repeating unit (I) include linear compounds such as ethylene glycol, propylene glycol, propanediol, butanediol, pentanediol, hexanediol, octanediol, decanediol, etc. As an example of a diol constituting the diol unit of repeating unit (I), butanediol is the most preferred, from the viewpoints that compatibility with the polarity of the sex pheromone substance, and the molecular diameter of the sex pheromone substance and the crystallinity of the polymer membrane or the gap structure of the polymer chains in the polymer membrane are important in terms of the mechanism of membrane permeation.

[0023] Polyethylene succinate (PES) is obtained by condensation polymerization using succinic acid as the dicarboxylic acid unit and ethylene glycol as the diol unit. Similarly, polyethylene adipate (PEA) is obtained by condensation polymerization of adipic acid and ethylene glycol. Examples of linear aliphatic polyesters include polyethylene malonate, polyethylene glutarate, polyethylene suberate, polyethylene fumarate, polypropylene succinate, polypropylene malonate, polypropylene adipate, polypropylene glutarate, polypropylene suberate, polypropylene fumarate, polybutylene succinate (PBS), polybutylene malonate, polybutylene adipate (PBA), polybutylene glutarate, polybutylene suberate, polybutylene fumarate, and polypropylene. Examples of the polyisoprene include polypropylene succinate, polypropylene malonate, polypropylene adipate, polypentylene glutarate, polypentylene suberate, polypentylene fumarate, polyhexylene succinate, polyhexylene malonate, polyhexylene adipate, polyhexylene glutarate, polyhexylene suberate, polypropylene fumarate, polyoctylene succinate, polyoctylene malonate, polyoctylene adipate, polyoctylene glutarate, polyoctylene suberate, and polypropylene fumarate. From the viewpoint of plasticity of the molded product, polyethylene succinate (PES), polyethylene adipate (PEA), polybutylene succinate (PBS), and polybutylene adipate (PBA) are preferred, and polybutylene succinate (PBS) is more preferred.

[0024] Examples of linear aliphatic polyesters consisting of two repeating units selected from the repeating unit (I) include linear aliphatic polyesters that are condensation polymers of one dicarboxylic acid and two diols, and linear aliphatic polyesters that are condensation polymers of two dicarboxylic acids and one diol. Preferred are linear aliphatic polyesters that are condensation polymers of two dicarboxylic acids and one diol, such as polyethylene succinate adipate (PESA), polypropylene succinate adipate, and polybutylene succinate adipate (PBSA). From the viewpoint of plasticity of molded articles, polybutylene succinate adipate (PBSA) is more preferred.

[0025] The container of the present invention preferably contains more than 50% by mass and less than 100% by mass, more preferably 70% by mass or more and less than 100% by mass, of the repeating units (I) among all repeating units. A linear aliphatic polyester containing 100% by mass of the repeating units (I) among all repeating units is a linear aliphatic polyester composed of one or more repeating units selected from the repeating units (I), and good results were obtained even at 100% by mass (Examples 1 to 3 described below). On the other hand, when the repeating units (I) are not 100% by mass, a copolymer or blend polymer containing more than 0% by mass and less than 50% by mass, preferably more than 0% by mass and less than 30% by mass, of an aliphatic polyester selected from polylactic acid, polycaprolactone, and polyhydroxybutyric acid may be used. Specific examples of copolymers include poly(caprolactone / butylene succinate), and examples of blend polymers include poly(butylene succinate / adipate) and polycaprolactone.

[0026] The arrangement of the one or more repeating units selected from the repeating unit (I) and the aliphatic polyester selected from polylactic acid, polycaprolactone, and polyhydroxybutyric acid is not particularly limited, and may be, for example, a random copolymer, an alternating copolymer, a block copolymer, or a graft copolymer, but is preferably a random copolymer.

[0027] For example, in the case of polybutylene succinate adipate, which is a copolymer of butylene succinate and butylene adipate, from the viewpoints of the reaction rate of the copolymerization reaction, achieving a high molecular weight, etc., a copolymer in which the molar ratio of butylene succinate units (repeating units) to butylene adipate units (repeating units) is preferably in the range of 95:5 to 5:95, more preferably 90:10 to 70:30, can be exemplified.

[0028] The aliphatic polyester preferably has a flexural modulus of more than 200 Pa, more preferably 300 Pa or more, and even more preferably 330 Pa or more. There is no particular upper limit to the flexural modulus, but it is, for example, 1000 Pa. The flexural modulus is measured at 23°C according to JIS 7171. The aliphatic polyester preferably has a melting point of 50 to 150° C., more preferably 60 to 130° C., and even more preferably 70 to 120° C. The melting point is measured in accordance with JIS K7121. When the aliphatic polyester has a flexural modulus and melting point within the above-mentioned preferred ranges, the rate of defective products resulting from breakage during production of containers or leakage when sealing the ends due to uneven film thickness caused by increased fluidity due to heating during extrusion molding can be reduced to a preferred level.

[0029] The container for enclosing the carboxylic acid compound includes, at least in part, a membrane of a linear aliphatic polyester containing one or more repeating units selected from the repeating unit (I). Since the carboxylic acid compound is released through the membrane of the linear aliphatic polyester, the presence of the membrane in at least part of the container can maintain the sustained release of the carboxylic acid compound. Therefore, the entire container may be composed of a membrane of a linear aliphatic polyester containing one or more repeating units selected from the repeating unit (I). The shape of the container in which the carboxylic acid compound is enclosed is preferably a membrane-permeable pheromone preparation, and examples thereof include a tube, capsule, ampoule, or bag. In particular, in the case of a tube, from the viewpoint of the filling and release of the sex pheromone substance, the inner diameter is preferably in the range of 0.5 mm to 2.5 mm, more preferably 0.6 to 1.6 mm, and the surface area is preferably 600 to 4000 mm.2 , more preferably 690 to 2000 mm 2 The thickness is preferably in the range of 0.20 to 0.75 mm, and more preferably in the range of 0.25 to 0.65 mm.

[0030] A container at least partially comprising a film of a linear aliphatic polyester containing one or more repeating units selected from the repeating unit (I) may contain additives such as colorants, antioxidants, ultraviolet absorbers, anti-locking agents, and lubricants added to the container itself. To prevent deterioration of the sex pheromone substance due to ultraviolet light, a colorant may be added in an amount of preferably 3% or less, more preferably 1% or less, of the mass of the container. Examples of colorants include inorganic colorants and organic colorants. Examples of inorganic colorants include iron oxide, chromium oxide, titanium oxide, and carbon black. Examples of organic colorants include polycyclic pigments and azo pigments.

[0031] Antioxidants and / or UV absorbers may be added in a total amount of preferably 1% or less of the mass of the container to prevent degradation of the polymer during use. Examples of antioxidants include phenol-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants. Examples of UV absorbers include benzotriazole-based and benzophenone-based antioxidants. Antiblocking agents and / or lubricants may be added in a total amount of preferably 1% or less of the mass of the container to improve the processability of the container. Examples of antiblocking agents include metal salts of higher fatty acids and inorganic powders. Examples of lubricants include hydrocarbons, alcohols, higher fatty acids, esters, partial esters of polyhydric alcohols, metal salts of higher fatty acids, natural waxes, fatty acid amides, and polymers.

[0032] A sustained-release pheromone formulation can be obtained by filling a liquid carboxylic acid compound into a container formed by blow molding, extrusion molding, etc., and then sealing it in. In some cases, a method is also available in which the liquid carboxylic acid compound is filled and sealed in using the same route as the route through which air is extruded during molding. A particularly preferred combination of a sex pheromone substance and a container is a container that at least partially comprises a film of a linear aliphatic polyester containing one or more repeating units (I) selected from saturated or unsaturated monocarboxylic acids having 13 to 15 carbon atoms and repeating units (I) in which X and Y are each independently a divalent saturated hydrocarbon group having 1 to 5 carbon atoms. [Example]

[0033] Examples of the present invention will be described in detail below, but the present invention is not limited to these examples. Example 1 Polybutylene succinate (BioPBS FZ91, Mitsubishi Chemical Corporation) was extruded into a tube with an inner diameter of 0.60 mm and a thickness of 0.30 mm, and then cut into 200 mm lengths to obtain polymeric tubules. These polymeric tubules were filled with 50 mg of 3,5-dimethyldodecanoic acid, the sex pheromone of California prionus, and 0.5 mg of the stabilizers 5-di-tert-butylhydroquinone (DBH) and 0.5 mg of 2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole (HBMCBT). Both ends of the polymeric tubule container were then heat-sealed to produce a sustained-release pheromone formulation. Products with pinholes or leaks due to poor fusion were considered defective, and the rate of defective products was calculated. The melting points and flexural moduli of the materials used for the polymeric thin tubes are shown in Table 1, and the results are shown in Table 2. Fifteen tubes of the prepared sustained-release pheromone formulation were left to stand at 30°C and an air velocity of 1.0 m / sec, thereby releasing the mixed liquid inside the sustained-release pheromone formulation. Three tubes of the sustained-release pheromone formulation were collected after 30, 60, 90, 120, and 150 days. The average remaining amount of 3,5-dimethyldodecanoic acid for each tube was calculated using internal standard / gas chromatographic analysis. The difference (decrease) from the average value from the previous time point (the previous time point after 30 days was the start of measurement, and the previous time point after 60 days was 30 days) was divided by the number of days to calculate the daily release rate per tube for each period (0-30 days for the 30-day period, and 30-60 days for the 60-day period). The ratio of the release rate after 150 days to the release rate after 30 days was also calculated. The results are shown in Table 3. The release behavior under these conditions correlated with the release behavior in actual fields, and similar release behavior was observed in actual fields.

[0034] Example 2 A sustained-release pheromone formulation was produced in the same manner as in Example 1, except that the material of the polymeric tubules was changed to polyethylene succinate (Lunare SE, manufactured by Nippon Shokubai Co., Ltd.), and the defective product incidence rate was calculated, followed by a release test. The melting points and flexural moduli of the polymeric tubule materials used are shown in Table 1, and the results of Example 2 are shown in Tables 2 and 3.

[0035] Example 3 A sustained-release pheromone formulation was produced in the same manner as in Example 1, except that the material of the polymeric tubules was changed to polybutylene succinate adipate (BioPBS FD92, manufactured by Mitsubishi Chemical Corporation), and the defective product incidence rate was calculated, followed by a release test. The melting points and flexural moduli of the polymeric tubule materials used are shown in Table 1, and the results of Example 3 are shown in Tables 2 and 3.

[0036] Example 4 A sustained-release pheromone formulation was produced in the same manner as in Example 1, except that the material of the polymeric capillaries was changed to a resin consisting of a mixture of polybutylene succinate adipate (BioPBS FD92, manufactured by Mitsubishi Chemical Corporation) and polycaprolactone (CAPA6800, manufactured by Ingevity) in a mass ratio of 7:3. The defective product incidence rate was calculated, and then a release test was conducted. The melting points and flexural moduli of the polymeric capillary materials used are shown in Table 1, and the results of Example 4 are shown in Tables 2 and 3.

[0037] Example 5 A sustained-release pheromone formulation was produced in the same manner as in Example 1, except that the material of the polymeric capillaries was changed to a resin consisting of a mixture of polybutylene succinate adipate (BioPBS FD92, manufactured by Mitsubishi Chemical Corporation) and polycaprolactone (CAPA6800, manufactured by Ingevity) in a mass ratio of 7:3, and the film thickness of the polymeric capillaries was changed to 0.60 mm. The rate of defective products was calculated, and then a release test was conducted. The melting points and flexural moduli of the polymeric capillary materials used are shown in Table 1, and the results of Example 5 are shown in Tables 2 and 3.

[0038] Comparative Example 1 A sustained-release pheromone formulation was produced in the same manner as in Example 1, except that the material of the polymeric thin tube was changed to high-density polyethylene (Nipolon Hard, manufactured by Tosoh Corporation), and the defective product incidence rate was calculated, followed by a release test. The melting points and flexural moduli of the polymeric thin tube materials used are shown in Table 1, and the results of Comparative Example 1 are shown in Tables 2 and 3.

[0039] Comparative Example 2 A sustained-release pheromone formulation was produced in the same manner as in Example 1, except that the material of the polymeric thin tube was changed to an ethylene-vinyl acetate copolymer with a vinyl acetate content of 4% by mass (Novatec EVA LV113, manufactured by Japan Polyethylene Corporation), and the defective product incidence rate was calculated, followed by a release test. The melting points and flexural moduli of the polymeric thin tube materials used are shown in Table 1, and the results of Comparative Example 2 are shown in Tables 2 and 3.

[0040] Comparative Example 3 A sustained-release pheromone formulation was produced in the same manner as in Example 1, except that the material of the polymeric thin tube was changed to an ethylene-vinyl acetate copolymer with a vinyl acetate content of 10% by mass (Novatec EVA LV342, manufactured by Japan Polyethylene Corporation), and the defective product incidence rate was calculated, followed by a release test. The melting points and flexural moduli of the polymeric thin tube materials used are shown in Table 1, and the results of Comparative Example 3 are shown in Tables 2 and 3.

[0041] [Table 1]

[0042] [Table 2]

[0043] [Table 3]

[0044] When the vinyl acetate content of the formulation capillary material was 4% by mass, the defective rate during production was as high as 5%, and increased further when EVA was 10% by mass. On the other hand, when the containers of Examples 1 to 5 containing at least a linear aliphatic polyester were used, the defective rate was 1% or less, which was lower than the defective rate during production compared to Comparative Examples 2 and 3. Although the formulation materials used in Examples 2 to 5 had lower melting points than vinyl acetate copolymers with a vinyl acetate content of 4%, the defective rate during production was reduced, which is thought to be due to the influence of their high flexural modulus. Furthermore, with the high-density polyethylene of Comparative Example 1, almost no 3,5-dimethyldodecanoic acid was released, whereas with the EVA resins of Comparative Examples 2 and 3, the release rates were significantly higher. In particular, with the latter, the initial release was high and decreased over time. Comparing the release rates after 30 days (a) and 150 days (b), the b / a value was 0.59 or less, indicating relatively low release uniformity and a short effective life of the formulation. On the other hand, with the linear aliphatic polyester, the b / a value was 0.69 or more, indicating high uniformity and a long effective life of the formulation. The release behavior under the conditions of the Examples and Comparative Examples correlated with the release behavior in actual fields, and similar release behavior was observed in actual fields.

Claims

1. The present invention comprises at least a carboxylic acid compound that is a sex pheromone substance and a container for encapsulating the carboxylic acid compound therein, wherein the container contains the following repeating unit (I): 【Chemistry 1】 (In the formula, X and Y are each independently a divalent hydrocarbon group having 1 to 8 carbon atoms.) A sustained-release pheromone preparation comprising, at least in part, a film of a linear aliphatic polyester containing one or more selected from the group consisting of:

2. 2. The sustained-release pheromone formulation according to claim 1, wherein the linear aliphatic polyester is selected from the group consisting of polyethylene succinate, polyethylene adipate, polybutylene succinate, polybutylene adipate, and polybutylene succinate adipate.

3. 2. The sustained-release pheromone formulation according to claim 1, wherein the carboxylic acid compound has 6 to 21 carbon atoms, including the carbon atom of the carboxyl group.

4. A method for controlling pests, comprising at least the steps of placing the sustained-release pheromone formulation according to any one of claims 1 to 3 in a farm field and releasing the carboxylic acid compound in the sustained-release pheromone formulation.

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