JPH1017407A - Biodegradable pheromone dispenser - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a biodegradable pheromone dispenser capable of sustainedly releasing a pheromone for a long period time by using an aliphatic polyester having a specific structure as a controlling layer for the pheromone. SOLUTION: An aliphatic polyester, namely one having the ratio (I/II) of the number (I) of main chain constituent carbons not participating in an ester bond to the number (II) of carbons constituting the ester bond in the repeating structural unit of the aliphatic polyester of Z2 is used. A condensation polymer between a polyfunctional carboxylic acid such as malonic acid or adipic acid and a polyhydric alcohol such as ethylene glycol or butanediol and a ring- opening polymer of a cyclic ester such as ε-caprolactone may be cited as the aliphatic polyester. The shape of the dispenser is preferably a reservoir type for holding a pheromone as a liquid phase. Especially a tubular, bottled or baggy container is preferable. Preferably, the dispenser has >=0.02mm thickness of a release controlling layer and 1cm<2> release surface area.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a biodegradable pheromone dispenser.

[0002] In recent years, as one of the pest control means, a control method using a pheromone has attracted attention because of its safety and lack of resistance. Pheromone dispensers
In order to cope with the long-term occurrence of pests, stable pheromone release for a long period of time is required, and applicability to an object to be treated such as a crop body is also required. Thus, several proposals have been made for pheromone dispensers having both excellent release performance and easy application properties.

[0003] These pheromone dispensers can be broadly classified into three types according to their form. One is for spraying microcapsules or follow fiber,
The third type is a so-called matrix type in which a pheromone is dispersed in a polymer material, and the third type is a so-called reservoir type in which a pheromone is held as a liquid. Microcapsules and follow-fibers can be easily applied by spraying, but have problems such as a short control period. In addition, the matrix type has a problem that the release rate of the pheromone gradually decreases because the release rate of the pheromone depends on the pheromone concentration in the polymer material.
Therefore, as the pheromone dispenser, a reservoir type having a small change in the concentration gradient in the membrane is highly evaluated for its stable release performance over a long period of time.

[0004] However, these pheromone dispensers are rarely collected after being used in a field such as a field, and are actually left in the field. Therefore, a biodegradable pheromone dispenser that is decomposed in soil and does not remain in the field is desired, and several proposals have been made.

For example, JP-A-6-116103 describes a pest control material comprising a biodegradable aliphatic polyester. As a pest control material, microcapsule-shaped active substance surface coated with a biodegradable polymer material, or a biodegradable polymer material in which the active ingredient is dispersed and formed into a sphere, film, ribbon, etc. It describes a molded article or a film processed article provided with a barrier layer on the surface, and further describes an article having an adhesive layer to facilitate application. In addition, a method is described in which an active ingredient is sealed in a capillary tube, and an active substance is released from an opening of the capillary tube. However, it is difficult to ensure stable release over a long period of time with these pest control materials.

The present applicant has already proposed a sustained release pheromone preparation using a polymer containing 3-hydroxybutyric acid as a main component as a release control layer (Japanese Patent Application Laid-Open No. 5-163110). However, since this polymer has a low pheromone permeation rate, there are restrictions such as a need to reduce the thickness of the release control layer or increase the release surface area.

As described above, polyester is a substance having a low pheromone permeability, and is very difficult to use in a reservoir type pheromone dispenser. For example, aromatic polyesters such as polyethylene terephthalate hardly permeate pheromones. In addition, the permeability of the pheromone differs greatly depending on the aliphatic polyester. Under these circumstances, it is not clear what kind of aliphatic polyester should be used and in what thickness, as a release control layer of the reservoir type pheromone dispenser, having both biodegradability and pheromone release controllability. .

[0008]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a stable and sustained release of a pheromone during use for a long period of time, and it is not necessary to collect the pheromone after use because of its biodegradability. Another object of the present invention is to provide a reservoir type biodegradable pheromone dispenser that does not remain in soil.

[0009]

Means for Solving the Problems In the polyester, the ester bond in the structure tightly connects the molecular chains by an electrostatic bond. For this reason, it is difficult for the pheromone molecules to diffuse through the gaps between the polymer segments, and as a result, the permeation of the pheromone in the polyester is reduced. However, the present inventors have found that the release of the pheromone can be controlled by increasing the spacing between the ester bonds in the main chain structure in the aliphatic polyester, and have completed the present invention. That is, in order to achieve the above object, the invention of claim 1 is a biodegradable pheromone dispenser, wherein the number of main-chain constituent carbon atoms (I) not involved in the ester bond and the ester bond in the repeating structural unit are equal to each other. An aliphatic polyester having a ratio (I / II) of more than 2 to the number of carbon atoms (II) is used as a pheromone release control layer incorporated as a liquid phase.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The aliphatic polyester used in the present invention contains a repeating structural unit constituting a polymer.
An aliphatic polyester having a ratio (I / II) of more than 2 between the number of carbon atoms constituting the main chain (I) not involved in the ester bond and the number of carbon atoms constituting the ester bond (II) is used as the pheromone release control layer. . Here, the number of carbon atoms (I) constituting the main chain that does not participate in the ester bond is the number of carbon atoms other than the ester bond in the main chain structure, and does not include the number of carbon atoms in the side chain. The ratio (I / II) between the number of carbon atoms constituting the main chain (I) and the number of carbon atoms constituting the ester bond (II)
Is a value in one repeating structural unit constituting a polymer, and in the case of a polyester having three or more types of monomers, means a weighted average of the repeating structural units according to each monomer composition. That is, to the ratio (I / II) of each monomer,
It means the sum of the values obtained by multiplying the ratio of each monomer composition when the whole is 1. For example, in the case of an aliphatic polyester having the following repeating structural unit, the number of carbon atoms constituting the main chain (I) is the sum of the parts (a), and the number of carbon atoms constituting the ester bond (II) is (b) ) Is the sum of the parts. Number of carbon atoms constituting main chain (I): (I) = (4 + 2) × 0.8 + (4 + 4) × 0.2 =
6.4 Number of carbon atoms constituting ester bond (II) (II) = 2 × 0.8 + 2 × 0.2 = 2 Therefore, ratio (I / II) = 6.4 / 2 = 3.2.

[0011]

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[0012] Such aliphatic polyesters include:
Malonic acid, succinic anhydride, glutaric acid, adipic acid, adipic anhydride, sebacic acid, fumaric acid, maleic acid, dodecane diacid, malic acid, tartaric acid, citric acid, etc. Polyvalent carboxylic acid and ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol,
Examples thereof include polycondensation products with a polyhydric alcohol having up to 20 carbon atoms such as cyclohexanedimethanol, glycerin, and trimethylolpropane, and ring-opening polymers of cyclic esters such as ε-caprolactone.

Although such an aliphatic polyester may have a side chain, the ratio (I) of the number of carbon atoms constituting the main chain (I) which does not participate in the ester bond to the number of carbon atoms (II) constituting the ester bond can be obtained. / II) must be greater than 2.
If the value of (I / II) is 2 or less, the electrostatic binding of the polymer segments becomes strong, the permeation of the pheromone is small, and the release rate required for control cannot be secured. The value of (I / II) is not particularly limited as long as it is larger than 2, but is preferably 20 or less in order to prevent excessive release of pheromone.

These aliphatic polyesters may be of a single composition such as a ring-opening polymer, or may be a polycondensate composed of one dicarboxylic acid and one diol. However, in order to appropriately control the pheromone release performance, an aliphatic polyester composed of three or more types of monomer units is more preferably used. These may be a random copolymer or may have a block copolymer structure by coupling or the like. Further, an aliphatic polyester composed of three or more types of monomer units by a polymer blend may be used.

The shape of the dispenser is not particularly limited, but a reservoir type containing a pheromone as a liquid phase is desirable. This dispenser
It is desirable that the pheromone is sealed and has no opening so that the pheromone is in direct contact with the outside air. A container having a tubular shape, a bottle shape, or a bag shape is suitable as such a shape. There is no problem even if these have separate jigs such as sticks and attachments for attaching the pheromone to an object to be processed such as a crop. In such a reservoir type dispenser, the wall surface of the reservoir itself constitutes a pheromone release control layer.

The pheromone held in the liquid phase is released through the controlled release layer constituting the preparation. In order to perform stable release control, a thickness of at least 0.02 mm is required. A thickness of less than 0.02 mm is not suitable because it causes pinholes and causes excessive release of pheromone. There is no particular problem if the thickness of the release control layer is 0.02 mm or more, but more preferably 0.05 m
m to 5 mm. If it exceeds 5 mm, the release of the pheromone becomes too small and the release area must be too large, which is not practical. The release surface area needs to be 1 cm ² or more, and if it is less than 1 cm ² , it is difficult to secure the release amount of pheromone necessary for control, which is inappropriate. The release surface area is not particularly limited as long as it is 1 cm ² or more, but is more preferably 2 cm 2 to ² m ² . If it exceeds 2 m ² , it is not practical because the installation becomes difficult.

The pheromone contained in the dispenser may be divided and sealed, but at least 1 m
Desirably, the amount is at least 5 g, more preferably at least 5 mg. Filling less than 1 mg is difficult to fill. As the form of the dispenser, a tube-shaped, bottle-shaped, or bag-shaped container is suitable as described above. Tube-shaped containers have an inner diameter of 0.4 mm
10 mm is preferred. If it is smaller than 0.4 mm, it is difficult to fill the pheromone, and if it is larger than 10 mm, it is difficult to seal. Bottles are manufactured by blow molding or injection molding, but those having an internal volume of 0.1 to 200 ml are desirable, and those having less than 0.1 ml are difficult to mold. On the other hand, if the amount is larger than 200 ml, the difference between the charged pheromone amount and the internal volume is large, which is economically wasteful. For bag-like products, the amount of filled pheromone is 1m
g to 100 g is desirable, less than 1 mg or 1
If it is larger than 00 g, it is difficult to fill it, which is not preferable in production.

[0018] The pheromone dispenser needs to have an attachability to an object to be processed such as a crop.
Conventionally known means can be used for this. For example, in the case of a tube-shaped material, a metal wire provided with a metal wire to give shapeability is exemplified. That is, a metal wire is provided along the longitudinal direction of the tube-shaped container body, the metal wire is covered with a resin material constituting the tube-shaped container, and the whole is integrally molded. The material of the metal wire may be any material since it does not affect the performance of the pheromone dispenser. It is preferable to use a material that is easily oxidized and deteriorated, such as an iron wire, so as not to impair the biodegradability characteristics. Further, it is preferable that the pheromone dispenser according to the present invention has a shape which can be attached to a target object in advance.

For example, FIG. 1 shows a possible form of a tubular dispenser. This type of dispenser is formed by bending a tubular reservoir containing a pheromone into an appropriate shape. 11 is a spiral type, 12 is a ring type, 13
Is a square type and 14 is a triangular type. Of course, other polygonal shapes can be used. It can be star-shaped. Reference numeral 15 denotes a spiral type, and reference numeral 16 denotes a 9-shaped type. Furthermore, a pine needle-shaped one connected and integrated at the ends of a plurality of tubes, such as 17, or a ring formed as a whole by connecting and integrating at both ends of a plurality of tubes, such as 18, can be exemplified.

Further, as shown in FIG. 2, the bottle-shaped or bag-shaped one can be constituted by connecting various hooks or annular filaments. In FIG. 2, reference numeral 21 denotes a dispenser of a type having a hook portion 22. The dispenser 21 has a bag 23 for storing a pheromone. The dispenser 21 forms the bag-like portion 23 by laminating an aliphatic polyester film constituting the release control layer, and the hook portion 22 can be integrally formed of the same material. Reference numeral 31 denotes a dispenser provided with a hook portion 32 having another shape, and provided with a bag-shaped portion 33. The basic configuration is the same as that of the dispenser 21. Further, reference numeral 41 denotes a dispenser provided with a hook portion 42 having another shape, and provided with a bag-shaped portion 43. The basic configuration is the same as that of the dispenser 21. Furthermore, reference numeral 51 denotes a dispenser provided with a filament portion 52 having another shape, and provided with a bag-shaped portion 53. The basic configuration is the same as that of the dispenser 21. In addition, the said bag-shaped parts 23, 33, 43, and 53 can also be made into the shape of a bottle.

Further, as shown in FIG. 3, the bag-shaped one is a dispenser 61 having a hole 63 in a film 62 to which the aliphatic polyester constituting the bag is pasted. It is a dispenser that can be wound around an object to be processed. The dispenser 61 includes a storage bag 65 for storing a pheromone.

The pheromone used in the present invention is not particularly limited, and any pheromone such as an alarm pheromone, a signpost pheromone, and a class-differentiated pheromone may be used. Pheromones are preferred, unsaturated aliphatic hydrocarbons having 10 to 20 carbon atoms, known as sex pheromones,
Acetate, aldehyde, alcohol, ketone or epoxy compound is used, and usually used alone or as a mixture of two or more.

More specifically, Z-7-dodecenyl acetate, Z-8-dodecenyl acetate, Z-9-dodecenyl acetate, E, Z-7,9-dodecadienyl acetate , Z, Z-7,9-dodecadienenyl acetate,
E, E-8,10-dodecadienol, E-4-tridecenyl acetate, Z-9-tetradecenyl acetate, Z-9-tetradecenal, Z-11-tetradecenyl acetate, Z-11 -Tetradecenal, Z-9
-Hexadecenal, Z-11-hexadecenal,
Z, E-9,11-tetradecadienyl acetate,
Z, E-9,12-tetradecadienyl acetate, Z
11-hexadecenyl acetate, Z, Z-7, 11
-Hexadecadienyl acetate, Z, E-7, 11-
Hexadecadienyl acetate, E, E, Z-4, 6,
10-hexadecatrienyl acetate, E, E-1
0,12-hexadecadienal, Z, Z-3,13-
Octadecadienyl acetate, E, Z-3,13-octadecadienenyl acetate, Z-7,8-epoxy-
2-methyl-octadecene, Z-13-icosene-10
-One, E, E, Z-10,12,14-hexadecatrienyl acetate, E, E, Z-10,12,14-
Hexadecatrienal, Z-10-tetradecenyl acetate, E, Z-4,10-tetradecadienyl acetate, 14-methyl-1-octadecene, (R, Z)
-5- (1-octenyl) oxacyclopentane-2-
And (R, Z) -5- (1-decenyl) oxacyclopentan-2-one.

Further, the release controlling layer of the biodegradable pheromone dispenser of the present invention needs to maintain its original performance during use, and it is necessary to maintain the original properties of the biodegradable pheromone dispenser. And various stabilizers such as antioxidants. Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited thereto.

Example 1 1,4-butanediol and succinic acid and adipic acid 4:
Of a polycondensate (manufactured by Showa Polymer) consisting of the mixture of
0.1mm thickness by heat pressing at 5 ℃ for 5 minutes
Was prepared. This sheet is 20cm wide and 3cm long
90 mg of Z-11-tetradecenyl acetate, which is a sex pheromone of Coleoptera,
Was charged. Z-11- from the obtained dispenser
The release rate of tetradecenyl acetate was 30 ° C, 1m /
s at 2.0 mg / day was about 40
It was released uniformly over a period of days and had excellent release properties. The discharge surface area of this dispenser was 12 cm ² . The ratio (I / II) of the number of carbon atoms constituting the main chain (I) not involved in the ester bond to the number of carbon atoms (II) constituting the ester bond in the aliphatic polyester was 3.2. Furthermore, when this dispenser was buried in the soil from April to October, it became tattered and hardly retained its original form.

Comparative Example 1 A polylactic acid (manufactured by Cargill) was heat-pressed at 160 ° C. for 5 minutes to produce a sheet having a thickness of 0.1 mm. When the release rate of Z-11-tetradecenyl acetate was measured in the same manner as in Example 1, it was 0.1 m
It showed only a release rate of about g / day and was not practical. The ratio (I / II) of this aliphatic polyester was 1.0.

Comparative Example 2 A polycondensate of 3-hydroxylobutyric acid and 3-hydroxyvaleric acid (manufactured by Zeneca) was heat-pressed at 160 ° C. for 5 minutes to produce a sheet having a thickness of 0.1 mm, as in Example 1. Then Z
When the release rate of -11-tetradecenyl acetate was measured, it showed only a release rate of about 0.5 mg / day and was not practical. The ratio (I / II) of this aliphatic polyester was 2.0.

Comparative Example 3 Hamakikon (trade name: a communication disrupter for snake beetles)
Shin-Etsu Chemical Co., Ltd.) at 30 ° C., 1 m / s
After uniform release at 1.9 mg / day for about 35 days, the release rate gradually decreased. Furthermore, the dispenser was buried in the soil from April to October, but no change was observed.

Example 2 A tube having an inner diameter of 0.8 mm and a wall thickness of 0.5 mm was produced by extrusion molding using the aliphatic polyester used in Example 1. The tube was filled with Z-8-dodecenyl acetate, which is a sex pheromone of the Japanese pear, and heat-sealed and cut every 20 cm to obtain a pheromone dispenser enclosing Z-8-dodecenyl acetate. 30 of this dispenser
When the release rate was measured at 1 ° C. and 1 m / s,
The release was uniform at 1.9 mg / day for about 35 days, which was practical. The discharge surface area of this dispenser was 11 cm ² .

Example 3 An aliphatic polyester (manufactured by Showa Polymer Co., Ltd.), which is a polycondensate of 1,4-butanediol and succinic acid, was extruded with a T-die to form a film having a thickness of 0.06 mm. This film was formed into a bag shape having a width of 25 mm and a length of 30 mm, in which the sex pheromone of codling moth, E, E-8, 10
-100 mg of dodecadienol was charged to obtain a dispenser. When the dispensing rate of this dispenser was measured at 30 ° C. and 1 m / s, the dispenser was uniformly released at 1.4 mg / day for about 65 days, and was practical.
The dispensing surface area of the dispenser was 15 cm ² . The ratio (I / II) of the aliphatic polyester is 3.0.
Met. When this dispenser was buried in the soil from April to October, it was quite tattered and partly lost.

Comparative Example 4 Example 3 was repeated except that a film having a thickness of 0.01 mm was used.
A pheromone dispenser was obtained in the same manner as described above. When the release rate of this dispenser at 30 ° C. and 1 m / s was measured, the dispenser was excessively released at 5.4 mg / day and was unsuitable as a pheromone dispenser. Met.

Example 4 Poly-ε-caprolactone (manufactured by Union Carbide) was blow-molded to form a bottle having a thickness of 1 mm, an inner volume of 0.5 ml, and an outer surface area of about 8 cm ² . A pheromone dispenser was obtained in which 100 mg of a 1: 1 mixture of Z-11-hexadecenyl acetate and Z-11-hexadecenal, which are sex moth pheromones, was filled into the bottle. When the release rate of this dispenser at 30 ° C. and 1 m / s was measured, the dispenser was uniformly released at 1.5 mg / day for about 55 days, and was practical. The ratio (I / II) of this aliphatic polyester was 5.0. When this dispenser was buried in the soil from April to October, no significant change in appearance was observed, but the weight was reduced by 8% due to biodegradation of microorganisms.

Example 5 A polycondensate of 3-hydroxybutyric acid and 3-hydroxyvaleric acid (manufactured by Zeneca) and poly-ε-caprolactone (manufactured by Union Carbide) were kneaded at a ratio of 7: 3 using two rolls. The obtained aliphatic polyester was heat-pressed at 160 ° C. for 5 minutes to form a sheet having a thickness of 0.1 mm. Using this sheet, the release rate of Z11-tetradecenyl acetate was measured in the same manner as in Example 1.
The release was uniform for about 40 days at a release rate of mg / day, and the release was excellent. The discharge surface area of the dispenser was 12 cm ² and the ratio of the aliphatic polyester (I / I
I) was 2.9. In addition, this dispenser
When it was buried in the soil from October to October, it was ragged and almost disappeared.

Example 6 Two tubular dispensers produced in Example 2 were arranged, and both were welded at the heat seal portions at both ends to obtain a dispenser having a ring shape as a whole. Ten dispensers were placed on a peach tree. The installation was performed by opening the two dispensers and covering the annular portion formed from the tip of the branch. Five of them were wound around the branch so that one end of the dispenser passed through the annular portion at the other end. Five were wound. The installation was carried out from April to August, but there was nothing falling and it was practical.

[0035]

As is clear from the above description, the biodegradable pheromone dispenser of the present invention is capable of controlling harmful insects for a long period of time and capable of biodegradation because it can release pheromone stably. It does not need to be collected after use, saving labor. In addition, since it is completely decomposed by microorganisms, it can protect the environment without remaining in the soil.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an embodiment of a tube-shaped dispenser according to the present invention.

FIG. 2 is a perspective view showing an embodiment of a bag-shaped dispenser according to the present invention.

FIG. 3 is a perspective view showing another embodiment of a bag-shaped dispenser according to the present invention.

[Explanation of symbols]

11, 12, 13, 14, 15, 16, 17, 18, 21, 31, 41, 51, 61
Dispensers 22, 32, 42 Hooks 23, 33, 43, 53, 65 Bags

Claims (4)

[Claims] Claims: 1. A fat having a ratio (I / II) of more than 2 in the number of carbon atoms constituting a main chain (I) not participating in an ester bond to the number of carbon atoms (II) constituting an ester bond in a repeating structural unit. A biodegradable pheromone dispenser characterized by using an aromatic polyester as a pheromone release control layer incorporated as a liquid phase. 2. A dispenser in which a pheromone is encapsulated and has no opening, wherein the release control layer has a thickness of 0.02 mm or more and a release surface area of 1 cm ^2.
The biodegradable pheromone dispenser according to claim 1, characterized in that: 3. The biodegradable pheromone dispenser according to claim 1, wherein the aliphatic polyester comprises three or more types of monomer units. 4. The biodegradable pheromone dispenser according to claim 1, wherein the dispenser having a built-in pheromone has a shape that can be attached to an object to be processed in advance.