JPH0688886B2 - Sustained-release pheromone formulation for communication disruption - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sustained-release pheromone formulation for mating disruption, particularly a pheromone capable of gradually releasing a pheromone substance used for pest control at a constant rate for a long period of time. It relates to the formulation.

(Prior Art) Conventionally, many ideas have been proposed and implemented in which a sex pheromone substance or the like effective for controlling pests is enclosed in a container and the release rate thereof is kept constant over time.

In these proposals, the first group is known in which a pheromone substance is supported on an adsorbent, or the adsorbent is mixed and held in a polymer supporting layer. That is, U.S. Pat. No. 4,017,030 shows a pheromone substance carried in a capillary tube having one end opened and released from the open end. This is formulation 1
Since the amount of pheromone supported per book is extremely small, there is a drawback that the life is short. Further, in Japanese Patent No. 4160335, in order to control the release amount from the polymer supporting layer mixed with a pheromone, a layer in which a polymer is laminated is used as a supporting layer. The initial release rate of pheromone is excessively high, and thereafter it decreases over time.
There are drawbacks such as a large amount of pheromone loss that remains adsorbed on the polymer-supporting layer without being released. On the other hand, in German Patent No. 2832248, there is one in which (S) -cis-berbenol and methylbutenol are impregnated in a porous carrier as an attractant of bark beetles, and this is packaged in a plastic film such as polyethylene. No. 2,945,655 shows an example in which a drug for the same purpose is mixed with a paste-like base and the mixture is filled in a plastic bag. Further, in JP-A-59-13701 and US Pat. No. 4,445,641, a porous substance carrier impregnated with a pheromone substance is coated with a control film such as polyethylene to control the permeation of the pheromone substance to the outside. It is shown. All of these preparations have a common drawback in that the pheromone loss that remains adsorbed on the carrier layer without being released in the latter half of the release is large.

Thus, the important characteristics required for a pheromone preparation are that it is released into the pheromone substance at a uniform rate over a long period of time, and that the pheromone loss that remains adsorbed is small. As a formulation form that meets this requirement, a liquid pheromone substance is enclosed in a container provided with a barrier layer having appropriate permeability to the liquid pheromone substance. Many proposals have also been made for this type of formulation. Prior arts belonging to this second group are: A: microencapsulation of a pheromone substance (such as US Pat. Nos. 2800457, 2800458 and 3757515), and B: a pheromone substance made into a polyethylene thin tube. Enclosed inside (JP-A-56-142202, JP-A-57-9705, JP-A-57-451)
01, 57-72904, 57-156403, 59-216802,
No. 60-215367), C: pheromone substance wrapped in a sheet or bag-shaped polymer film (Jo
urnal of Economic Entomology, Vol.62, No.2, (196
9) p.517 to 518).

The type A has not been used much because of its high cost, loss of pheromones during microencapsulation, large surface area, too high release rate and short life. . B
In general, a thick tube made of polyethylene is used for the type (1), and measures such as adding metal wires to improve engagement with trees have been attempted. While this tubular preparation has the advantages of sustained release and long life, it has been reported to have the drawback of a slight decrease in the rate in the latter half of release (Journal of Economic Entomology,
Vol.78, No.6, (1985) p.1431 to 1436). In the document indicated by C, Z-7-dodecenyl acetate, which is a sex pheromone of the nettle buckwheat (Cobbage Looper), is used for the thickness of 50-15.
An example is shown in which it is enclosed with sand in a 3 cm × 5 cm size bag made of 0 μm polyethylene and used as a formulation for communication disruption. Although this has a uniform release rate, it has the drawback that its life is only about 2 weeks due to insufficient barrier properties of polyethylene.

In addition to the above, the third group targets fragrances, repellents, insecticides, etc. other than pheromone substances, and wraps these in a sheet or bag-like polymer film, and permeates this film layer to obtain a constant Various proposals have been made to release at a rate (US Pat. No. 3343).
No. 664, No. 3785556, No. 4161283, etc.).

(Problems to be Solved by the Invention) As described above, although there are many types of pheromone preparations, an example of encapsulating a large amount of pheromone substance of 40 mg or more and using it for the purpose of controlling communication disruption is as described above.
And C type only. Polyethylene is selected as the material for any of these formulations. This is because this material has an appropriate affinity for the pheromone substance, is inert and has a small adsorption amount,
This is due to the excellent processability such as heat-sealing property when encapsulating the pheromone substance, and the excellent strength and water resistance when used as a pheromone preparation.

However, since the tube type has a polyethylene layer with a wall thickness of 300 μm or more, the release can be controlled for 2 months or more, but there is a drawback that the release rate decreases in the latter half, and the bag type has a processability. There is a restriction that the polymer film to be used must be thin with a wall thickness of 200 μm or less, which lacks barrier properties and shortens the service life, so that it is not possible to control the release for more than 2 months like the tube type. It was

Furthermore, this release rate also differs depending on the type of pheromone substance contained in the sustained-release preparation.For example, in the case of pheromone substances consisting of alcohol compounds and pesticides such as DDVP, the equilibrium swelling rate in polyethylene is relatively small, and therefore the release rate is Although it does not require special consideration for the control of pheromones, it does not occur in the pheromone substance consisting of an acetate, aldehyde, or ketone compound having 12 to 20 carbon atoms, which is known as the sex pheromone substance of Phytophthora pests. Since the material and thickness of the polymer that coats the polymer has a great influence, an appropriate one has not been known.

(Means for Solving Problems) The present inventors have found that an unsaturated acetate having 12 to 20 carbon atoms,
As a result of studying a sustained-release preparation that can contain a liquid pheromone substance composed of an aldehyde or ketone compound in a large amount such as a volume of 40 mg or more, as a result of taking advantage of the excellent characteristics of this polyethylene or a similar substance, and using the conventional tube type In order to solve the disadvantages of the bag-shaped product and to secure excellent sustained release properties, a polymer having a low barrier property in the inner layer and imparting processability is used as the coating material, and the main material is used in the outer layer. Focusing on the fact that it is preferable to use a thin laminated film having a controlled release layer using a polymer imparting a barrier property, the present invention has been completed as a result of repeated research, focusing on the fact that it is preferable.

That is, the sustained-release preparation according to the present invention has a thickness of 10 to 110 made of polyethylene or ethylene-vinyl acetate copolymer.
A laminated film composed of an inner control layer having a thickness of 10 to 90 μm and an outer control layer having a thickness of 10 to 90 μm and having a total thickness of 40 to 180 μm is formed into a bag, and the bag is a laminated film. Part is on at least one side of the bag and its actual surface area is 100 to 2
It assumed to be 000 mm ^2, in which the subject matter that it has unsaturated 12 to 20 carbon atoms, acetates, aldehydes or with a liquid pheromone substance consisting of ketone compounds those encapsulated structure, in its bag.

Explaining this, since the liquid pheromone substance has an equilibrium swelling ratio in polyethylene of 3% by weight or more and easily penetrates the polyethylene film, the release rate of these pheromone substances is preferably in a preferable range only by a thin polyethylene film. It is extremely difficult to control.
Stretched or unstretched polypropylene film cannot be put to practical use because it has drawbacks such as a decrease in sealing property and leakage when used alone or cracking during storage at low temperature. Since the equilibrium swelling rate is about 0.5% by weight, a release rate can be set within a preferable range by using this as a laminated film used as an outer control layer of a polyethylene film.
The present invention has been completed based on this finding, and the details thereof will be described below with reference to the accompanying drawings.

In Fig. 1, what is generally indicated by 1 is the sustained-release pheromone preparation according to the present invention. 2 is a bag formed by joining the left and right edges 4 of the laminate film 3,
Reference numeral 5 is a liquid pheromone substance enclosed in the bag 2. As shown in detail in FIG. 2, the laminate film 3 is composed of an inner control layer 6 and an outer control layer 7. The inner control layer 6 is made of polyethylene or ethylene-vinyl acetate copolymer having a thickness of 10 to 110 μm, and the outer control layer 7 is made of stretched or unstretched polypropylene having a thickness of 10 to 90 μm. The thickness of the inner control layer 6 is
If it is less than 10 μm, the workability and strength are poor, and 110
Those having a thickness of more than μm are not preferable because the amount of adsorption of the pheromone substance in the material increases. On the other hand, if the thickness and the material of the outer control layer 7 are other than the above, the desired release rate cannot be obtained.

Laminate film 3 comprising these control layers 6 and 7
Is not only poor in workability if its thickness is too thick,
It is necessary to set the thickness to 40 to 180 μm, because the rigidity becomes too large and the flexibility after forming into a bag impairs the deformation accompanying the release of the pheromone substance, and the uniform release rate cannot be maintained.

As described above, the bag 2 has a shape in which the edge portions (or the edge portions of one laminated film folded in two) 4, 4 of the two laminated films 3, 3 are heat-sealed,
Flat shapes joined to each other by the impulse sealing method, ultrasonic sealing method, etc., specifically FIG. 3 (a)-
A four-sided sealed bag, a three-sided sealed bag, a pillow packaging bag, a stick packaging bag, etc., each exemplified in (d), are preferable. As shown in this bag 2 or a part of it in FIG. 4,
A four-sided seal bag may be used, in which one surface is a laminated film 3 and the other surface is a film 8 made of a material through which a pheromone substance does not pass. These packaging forms are the bag making,
Since the injection and sealing of the pheromone substance 5 into the bag 2 and the cutting for making into individual preparations can be performed using a known filling and packaging machine, mass production is possible and low-cost production is possible. Not only that, even if the amount of pheromone substance enclosed in the latter half of the release decreases, the bag does not flatten and does not create a space inside, and its inner surface is kept wet with the pheromone substance, so it is effective throughout the entire period. The release surface area does not change and maintains a uniform release rate.

The pheromone substance permeates the control layer inside and outside the laminate film and is released to the outside, the rate of which also depends on the surface area of the bag, and the higher the rate, the greater the rate. Therefore, it is necessary to determine the size so that the actual surface area of the laminated film portion excluding the seal portion of the bag is 100 to 2000 mm ² . In the case of the four-sided sealed bag having the laminated film 3 on one side and the film 8 made of a material through which the pheromone substance does not permeate on the other side, the inner volume of the bag can be increased within the range of the actual surface area. It offers the advantage of facilitating the encapsulation of pheromone substances when the real surface area needs to be designed small.

Examples of the film 8 made of a material which does not transmit the pheromone substance include a metal foil such as aluminum, polyvinylidene chloride, polyvinylidene fluoride, polyacrylonitrile, nylon, cellulose acetate, cellophane, polyvinyl alcohol, polyurethane and polyethylene terephthalate. Further, a laminate film of these and a polymer having a heat fusion property, for example, polyethylene, ethylene-vinyl acetate copolymer and the like can be used.

The liquid pheromone substance 5 enclosed in the bag 2 is known as a sex pheromone substance of pests of the order Lysine. 12 carbons
~ 20 unsaturated, acetate, aldehyde, or ketone compounds, including E-5-decenyl acetate, E-4-tridecenyl acetate, n-dodecenyl acetate, Z-7- Dodecenyl acetate, Z-8-
Dodecenyl acetate, Z-9-dodecenyl acetate, E-9-dodecenyl acetate, 11-dodecenyl acetate, E, Z-7,9-dodecadienyl acetate, Z-
7-tetradecenyl acetate, Z-9-tetradecenyl acetate, Z-11-tetradecenyl acetate, Z
-11-hexadecenyl acetate, E, Z-3,13-octadecadienyl acetate, E, Z-2,13-octadecadienyl acetate, Z, Z-3,13-octadecadienyl acetate , Z, E-9,11-tetradecadienyl acetate,
Z, E-9,12-tetradecadienyl acetate, Z, Z / E-7,
Acetate compounds such as 11-hexadecadienyl acetate, Z-7-tetradecenal, Z-9-tetradecenal, Z-11-tetrazecenal, Z-7-hexadecenal, Z-9-hexadecenal, Z-11-hexadecenal, n- Aldehyde compounds such as hexadecanal, Z, Z-11,13-hexadecadienal, and Z-13-octadecenal, ketone compounds such as Z-13-icosen-10-one, and mixtures thereof, and mainly these compounds. As a mixture of components, various antioxidants, ultraviolet absorbers and the like may be added and mixed as necessary.

Further, an ultraviolet absorber may be similarly added to and blended with each of the polymers constituting the inner or outer control layer.

In the case of a bag made of only the laminate film 3, a film made of a material which does not allow the pheromone substance described above to pass through may be provided on the outer surface of the bag in advance, and the film may be peeled off before use.

(Examples) Hereinafter, specific embodiments of the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example 1. Two laminated films with a total thickness of 70 μm, in which the inner control layer is a low-density polyethylene with a thickness of 40 μm and the outer control layer is a biaxially oriented polypropylene with a thickness of 30 μm, are heat-sealed on their four sides. And the inner method is 20 mm x 30 mm
The bag has a surface area of 1200 mm ² excluding the seal part, and contains Z-11- which is the sex pheromone of Chahamaki.
120 mg of tetradecenyl acetate was enclosed.

When this sustained-release preparation was allowed to stand under the conditions of an air temperature of 30 ° C. and a wind speed of 0.5 m / sec and the time-dependent change in the release rate of the pheromone substance was measured, the results shown by the solid line in FIG. 5 were obtained. It was

These results indicate that this sustained-release preparation maintains a uniform release rate of 1.5 mg / day for 70 days or longer, and the amount of pheromone substance that remains adsorbed after release is 2 mg or less. I understood.

Comparative Example 1. As in Example 1, except that only low-density polyethylene with a thickness of 40 μm, which was the same as that used in the inner control layer of Example 1, was used as the material for the bag, the bag was made and the pheromone substance was enclosed. When the release rate was measured, the results shown by the dotted line in Fig. 5 were obtained, and it was found that this preparation did not have sufficient sustained release properties.

Examples 2 to 6 and Comparative Examples 2 to 4. Bag-shaped pheromone preparations having various shapes were obtained using the film materials and pheromone substances shown in the following table. When the release rate of this was measured under the same conditions as in Example 1, the results shown in the table were obtained. The table also shows the results of Example 1 and Comparative Example 1. The contents of abbreviations for pheromone substances and film materials in the table are as follows.

(Pheromone substance) A: Z-11-tetradecenyl acetate B: Z, Z / E-7,11-hexadecadienyl acetate C: Z-13-icosen-10-one D: Z-11-hexadecenal E: Z-9-dodecenyl acetate F: Z-11-hexadecenol (Film material) PE: Polyethylene PP: Polypropylene PET: Polyethylene terephthalate EVA: Ethylene-vinyl acetate copolymer (containing 12% by weight vinyl acetate) Table As shown in Fig. 5, the formulations according to Examples 2 to 6 maintained a uniform release rate for 60 days or more, but comparative examples in which only polyvinyl chloride and ethylene-vinyl acetate copolymer films were used as the material for bag formation, respectively. Both 2 and 3 had too high a release rate to be suitable for use. Further, in Comparative Example 4, Z-11-hexadecenol was used as a pheromone substance by bag-making with the same film material as used in Example 1, but the release rate was too small as 0.1 mg / day, and it was suitable for use. There wasn't.

(Effects of the Invention) According to the sustained-release pheromone preparation for communication disruption of the present invention, the amount of the pheromone substance encapsulated per preparation can be set to 40 mg or more, which enables long-term release.

Since the inner surface of the barrier wall is always uniformly wet with the liquid pheromone substance, there is no change in the release rate with time, and the uniform rate can be maintained for a long period of 2 months or more.

Since the barrier wall is thin, the amount of polymer used in the formulation can be small, and the manufacturing cost is low because a commercially available automatic filling machine can be used.

Since there is no supporting layer for the pheromone substance, the loss of the pheromone substance caused by remaining after being adsorbed remains small, which is an important performance as a sustained release preparation for communication disruption.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 to FIG. 4 exemplify a sustained release pheromone preparation according to the present invention. FIG. 1 is a sectional explanatory view thereof, and FIG.
The figure is a partially enlarged sectional explanatory view of FIG. 1, and FIG.
(D) is a plan view showing a packaging mode of each different mode, and FIG. 4 is a partially enlarged sectional explanatory view of still another mode. FIG. 5 is a graph showing the results of grasping the characteristics of the sustained-release preparations in Example 1 and Comparative Example 1 by measuring the release rate (vertical axis) for each elapsed days (horizontal axis). (Explanation of main symbols in the drawing) 2 …… Bag 3 …… Laminated film 5 …… Pheromone substance 6 …… Inner control layer 7 …… Outer control layer

Claims (2)

[Claims] 1. An inner control layer having a thickness of 10 to 110 μm made of polyethylene or an ethylene-vinyl acetate copolymer and a thickness of 10 to 90 μm made of stretched or unstretched polypropylene.
Composed of an outer control layer and a total thickness of 40-180
Liquid containing an unsaturated acetate, aldehyde, or ketone compound having 12 to 20 carbon atoms in a bag having a laminated film of μm on at least one surface and the actual surface area of that portion is 100 to 2000 mm ^2. A sustained-release pheromone formulation for interfering with communication, which is characterized in that a pheromone substance is encapsulated. 2. The four-side sealed bag according to claim 1, wherein the bag has the laminate film on one surface thereof and a film made of a material that does not transmit a pheromone substance on the other surface thereof. Sustained-release pheromone formulation for communication disruption of.