JPH0791161B2 - Sustained release pheromone formulation - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sustained-release pheromone preparation, and more particularly to a pheromone preparation capable of gradually releasing a pheromone substance used for pest control at a constant rate for a long period of time. Is.

(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 has a disadvantage that the life is short because the amount of pheromone supported per formulation is extremely small. 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. This has the drawbacks that the initial pheromone release rate is too high, and thereafter it decreases over time, and the pheromone loss that remains adsorbed by the polymer-supporting layer without being released is large. On the other hand, in the German Patent No. 2832248, (S) -cis-berbenol and methylbutenol, which are used as attractants for bark beetles, are impregnated in a porous carrier, which is packaged in a plastic film such as polyethylene. See also
No. 2945655 shows an example in which a drug having the same purpose is mixed with a paste-like base and the mixture is filled in a plastic bag. Further, JP-A-59-13701 and U.S. Pat.No. 4,445,641 disclose a porous carrier impregnated with a pheromone substance, which 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 the pheromone substance is released 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 microcapsules of A: pheromone substance (US Pat.
No. 2800457, No. 2800458, No. 3757515, etc.), B: Pheromone substance enclosed in a polyethylene thin tube (JP-A-56-142202, 57-9705, 57-45).
101, 57-72904, 57-156403, 59-216802
No. 60-215367), C: Pheromone substance wrapped in a sheet or bag-shaped polymer film (Journal 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 the release. (Journal of Economic Entomolog
y, Vol. 78, No. 6, (1985) p.1431 to 1436). In the literature indicated by C, Z-7-dodecenyl acetate, which is a sex pheromone of nettle buckwheat (Cabbage Looper), has a thickness of 50-
An example is shown in which a bag of 3 cm × 5 cm size made of polyethylene of 150 μm is enclosed with sand and used as a lumber 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 them in a sheet or bag-shaped polymer film, and permeates this film layer to achieve a constant rate. Various proposals have been made to release it (US Pat. No. 334366).
No. 4, No. 3785556, No. 4161283, etc.).

(Problems to be Solved by the Invention) As described above, although there are many types of pheromone preparations, a pheromone substance composed of an ester, aldehyde, and ketone compound of an unsaturated aliphatic group having 12 to 20 carbon atoms as large as 40 mg. As an example of encapsulating and using for the purpose of controlling communication disturbance, only the types B and C described above are used. Polyethylene is selected as the material for any of these formulations. This is because this material has a proper affinity for the pheromone substance,
It is due to the fact that it is inert and has a small amount of adsorption, has excellent processability such as heat fusion when encapsulating a pheromone substance, and has excellent strength and water resistance when used as a pheromone formulation. .

However, since the tube type has a polyethylene layer with a wall thickness of 300 μm or more, 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. Therefore, if polyethylene is used, the barrier property is small and the life is shortened. It has the drawback of not being able to. Also, when the temperature is high and the wind is weak, the permeation rate through the polyethylene wall of the barrier layer is too fast to evaporate from the membrane surface in time, and the pheromone is leached out on the membrane surface (a sticky and wet state), There was a drawback that dust and dirt stick to each other, which significantly reduces the performance.

Therefore, a pheromone formulation having a thin polymer film of 200 μm or less as a barrier, which has a controlled release for 2 months or more and has no stickiness on the surface, has not been known so far.

The present inventors have studied unsaturated release formulations having 12 to 20 carbon atoms of unsaturated aliphatic, acetate, sex pheromone substance consisting of aldehyde or ketone compound, which can be incorporated in a large amount of 40 mg or more per formulation, We have succeeded in solving the drawbacks of conventional tube-type and bag-type preparations and finding a preparation with excellent sustained release properties.

(Means for Solving the Problem) The sustained-release pheromone preparation according to the present invention comprises: 1) a layer of the first group consisting of 1 or 2 or more layers with a total thickness of 2 to 20 μm. Equilibrium swelling ratio at 20 ° C. to the substance, which is within the range of 0.1 to 1.9% by weight, is composed of the same or different polymer selected from polyamide, polyester, polyacrylonitrile, and polyethylene vinyl alcohol. 2) From one or more layers The second group of
A laminated film having a total thickness of 20 to 200 μm, which has a total thickness of 20 to 200 μm and has a thickness of 10 to 198 μm and which is composed of the same or different polymers in the range of 2 to 20% by weight at the equilibrium swelling rate at 20 ° C. with respect to the incorporated pheromone substance The gist is that a pheromone substance is enclosed in a bag on one surface.

That is, the pheromone preparation according to the present invention exhibits excellent sustained-release properties by using a laminate film composed of two groups of polymer layers having different properties as a packaging material, and the details thereof are attached below. It will be described with reference to the 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 FIGS. 2 to 7, this laminated film 3 is a layer A composed of the above-mentioned first group of polymers.
And a layer B of a second group of polymers. These two layers A and B are arranged in the order of A-B from the outside (second
A) or the reverse order of B-A (Fig. 3), and A and B layers (A ₁ , A ₂ ..., B ₁ , B ₂ ) having different types of polymers. ……) array is also, for example, B ₁ -A-
3 layer laminate in the order of B ₂ (Fig. 4), 4 layer laminate in the order of B ₁ -A-B ₂ -B ₃ (Fig. 5), 4 layer in the order of B ₁ -B ₂ -A-B ₃ Various combinations such as a layer laminate (FIG. 6) and a 5-layer laminate of B ₁ -B ₂ -A-B ₂ -B ₁ (FIG. 7) can be arbitrarily selected.

In the present preparation, by interposing a layer (A layer) composed of the polymer of the first group in this laminated film, the barrier property of pheromone permeation in the conventional bag-shaped dispenser is small, and the controllable period is long. The shortcoming is that when the temperature is high and the wind is weak, the permeation speed of the barrier layer in the polymer is too fast and evaporation from the film surface does not catch up with the pheromone leaching to the film surface (surface stickiness). It was improved that there was a drawback that dust and dirt stick to each other, which reduces the performance. here,
If the total thickness of the layers of the first group consisting of one or more layers exceeds 20 μm, the barrier property becomes too large and the release rate of the pheromone becomes too slow. If it is less than 2 μm, the barrier property becomes insufficient. . The polymer constituting the layer of the first group has an equilibrium swelling ratio at 20 ° C. with respect to the incorporated pheromone substance (measurement method of this value will be described later) is 0.1.
Polyamide, polyester, in the range of up to 1.9% by weight
The same kind or different kinds selected from polyacrylonitrile and polyethylene vinyl alcohol.

On the other hand, the polymer constituting the second group of layers (layer B) in the formulation of the present invention is related to the incorporated pheromone substance.
Equilibrium swelling rate at 20 ℃ consists of the same or different polymers within the range of 2 to 20% by weight, and this layer does not have barrier properties and is permeable to pheromone as the layer made of the first group of polymers described above. Easy to do. By providing this layer, it is possible to solve the drawback that the layer of the first group having a thickness of 2 to 20 μm has low mechanical strength and cannot be used, and since this layer has a high affinity with the pheromone, It has the effect of eliminating the stickiness of the bag surface due to changes in the outside environment such as temperature and wind speed, and when this layer is used on the inside, it has the advantage of improving the heat-sealing property of the laminate film. As shown in FIGS. 7 to 7, it is preferable to provide one or more layers of the same kind or different kinds on both inner and outer sides of the first group A layer, and the total thickness of these layers is
It is necessary to be 10 to 198 μm.

The same or different polymers in the range of 2 to 20% by weight at the equilibrium swelling rate at 20 ° C. with respect to the incorporated pheromone substance are polymers satisfying the above values by the method for measuring the equilibrium swelling rate described later. And this is 2% by weight
If it is less than the above, the above-mentioned buffering ability is not expected due to lack of affinity with pheromones, and if it exceeds 20% by weight, the swelling rate of the bag due to the pheromone is too large and the bag becomes too soft and the mechanical strength is significantly lowered, which is preferable. Absent.

(Measurement method of equilibrium swelling ratio) The polymer film of the sample is placed in the pheromone substance at
After immersing for more than a time, the film is taken out, the pheromone substance attached to the outer surface of the film is washed with a surfactant and then extracted with hexane, and the pheromone substance in the swollen polymer is quantified by gas chromatography, The percentage in the sample was taken as the equilibrium swelling ratio of the polymer.

As a specific example of the polymer having the equilibrium swelling ratio defined as above, the pheromone substance has a carbon number of 12 to 20.
In the case of unsaturated aliphatic hydrocarbon, acetate, aldehyde, or ketone compound, polyethylene, polyolefin such as polypropylene, ethylene-vinyl acetate copolymer, polyvinyl chloride and its copolymer, polyacrylic ester and Examples thereof include copolymers thereof, polymethacrylic acid esters and copolymers thereof, cellulose esters, and cellulose ethers such as ethyl cellulose.

The total thickness of this laminated film is 20 ~ 200μm
Is required to be. This is because if the thickness exceeds 200 μm, not only the processability decreases, but also the uniformity of the release rate, which is a great advantage of the bag-shaped formulation, cannot be maintained. If this is less than 20 μm, the formulation strength is too weak. Performance decreases.

It should be noted that each of the polymers constituting the above first and second groups may optionally contain an ultraviolet absorber, a plasticizer, a stabilizer, a stabilizing aid, a processing aid, a lubricant, and other additives. You may add and mix.

The pheromone substance permeates this laminated film and is released to the outside, but its speed also depends on the surface area of the bag,
The larger this is, the higher the speed becomes. Therefore, it is necessary to determine the size so that the actual surface area of the laminated film part excluding the seal part of the bag is 100 to 3000 mm ² .

The shape of the bag is a four-sided sealed bag, a three-sided sealed bag, a pillow packaging bag, and a stick packaging bag, in which the edges of two laminated films (or both edges of one laminated film folded in two) are joined together. In addition to the 8th
As shown in a part of the figure, a four-sided seal bag may be used, in which one surface is a laminate film 3 and the other surface is a film 9 made of a material through which a pheromone substance does not pass. In this four-way sealed bag, the inner volume of the bag can be increased relative to the actual surface area, so that the advantage of facilitating the encapsulation of the pheromone substance is provided especially when it is necessary to design the actual surface area to be small.

Examples of the film made of a material that does not transmit the pheromone substance include a metal foil such as aluminum, cellophane, polyvinyl alcohol, nylon with a thickness of 20 μm or more, and polyethylene terephthalate. Further, a polymer having heat fusion property with them, for example, A laminated film with polyethylene, an ethylene-vinyl acetate copolymer or the like can be used. In addition, these laminated films can be produced by a conventional method such as bonding with an adhesive or coextrusion molding.

The liquid pheromone substance 5 enclosed in the bag 2 has a carbon number of 12 which is known as a sex pheromone substance of Lycoris pests.
To 20 unsaturated aliphatic hydrocarbon, acetate, aldehyde, or ketone compounds, including hydrocarbon compounds such as Z-9-tricosene-14-methyl-1-octadecene, E-5-decenyl. -Cetate, 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
-Acetate compounds such as tetradecadienyl acetate, Z, E-9,12-tetradecadienyl acetate, Z, Z / E-7,11-hexadecadienyl acetate, Z-7-tetradecenal, Z-9 -Tetradecenal, Z-11-
Tetradecenal, Z-7-hexadecenal, Z-9
-Hexadecenal, Z-11-hexadecenal, n-
Aldehyde compounds such as hexadecanal, Z, Z-11,13-hexadecadienal, Z-13-octadecenal, ketone compounds such as Z-13-icosen-10-one,
Examples thereof include a mixture thereof, and a mixture containing them as a main component, and these may be mixed and added with various antioxidants, ultraviolet absorbers, and the like, if necessary.

A general-purpose filling and packaging machine can be used for bag making from the illustrated laminated film 3, injection / sealing of the pheromone substance 5 in the bag 2, and cutting for making an individual formulation, and the seal can be used. As a method, a heat seal method,
Impulse sealing method, ultrasonic sealing method and the like are preferable.

Alternatively, a film made of a material that does not allow the pheromone substance to pass through may be provided on the outer surface of the bag in advance, and the film can 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 A three-layer laminate film having a total thickness of 82 μm, in which 12 μm-thick polyethylene terephthalate was used for the intermediate layer and 35 μm-thick low-density polyethylene was used for both inner and outer layers,
Heat seal on each other's four sides to make a bag with inner surface of 30 mm x 40 mm and surface area of 2400 mm ² excluding the sealing part.
Then, 160 mg of 14-methyl-1-octadecene, which is the sex pheromone of Pleurotus cornucopiae, was encapsulated.

The sustained-release preparation was allowed to stand under 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 sustained-release preparation showed a uniform release of 1.2 mg / day. To
It was maintained for 120 days or longer, and during this period, no leaching of the pheromone substance to the outer surface of the bag was observed, and good results were obtained.

The equilibrium swelling rates of polyethylene terephthalate and low-density polyethylene at 20 ° C. with respect to the pheromone were 0.3% by weight and 6.3% by weight, respectively.

Comparative Example 1. As the material for the bag, a low-density polyethylene monofilm having a thickness of 60 μm was used in place of the three-layer laminated film of Example 1, the bag was made in the same manner as in Example 1, the pheromone substance was enclosed, and the same conditions were used. When the release rate was measured by leaving it underneath, the pheromone was rapidly leached on the surface and a liquid layer was formed on the surface of the formulation, which was not preferable as a sustained release formulation.

Comparative Example 2. As a material for the bag, a three-layer laminated film having a total thickness of 100 μm, in which the intermediate layer is polyethylene terephthalate having a thickness of 30 μm, both inner and outer layers thereof are low-density polyethylene having a thickness of 35 μm, is used. When the bag was made in the same manner as in Example 1, the pheromone substance was encapsulated, and the release rate was measured by leaving it under the same conditions, the release rate was extremely slow and it was of poor practicality as a pheromone preparation.

Examples 2 to 9. The film materials shown in the following table were each filled with 50 mg of pheromone substance to obtain bag-shaped pheromone preparations of various shapes.
The release rate of this was measured under the same conditions as in Example 1, and the strength and surface condition of the bag were observed. Each formulation shows a uniform release rate of the values listed in the table over 60 days,
No leaching such as stickiness was observed on the surface, and the strength was sufficient, showing good results. The contents of the abbreviations for the film materials and pheromone substances in the table are as follows.

(Film material) A _1: Polyamide (nylon 6,6) A _2: Polyester (polyethylene terephthalate) A _3: Polyethylene vinyl alcohol (EVAL) A _4: polyacrylonitrile Lori Le B _1: Low-density polyethylene B _2: High density polyethylene B _3: ethylene - copolymers of vinyl acetate (88:12) B _4: polypropylene (hereinafter used to the 8-Figure pheromone impermeable layer 9) AL-PE: laminate of aluminum and low density polyethylene (pheromones Substance) HDDA: Z, Z / E-7,11-hexadecadienyl acetate TDA: Z-11-tetradecenyl acetate ICN: Z-13-icosen-10-one HDAL: Z-11-hexadecenal DDA: Z-8-Dodecenyl Acetate Laminated film is described by the type of film, (thickness), [weight of equilibrium swelling rate at 20 ° C for pheromone substance contained in the film, %]] In the order from the outer layer side.

(Effects of the Invention) According to the sustained release pheromone preparation of the present invention, the amount of the pheromone substance encapsulated in each 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 over time, and there is no leaching of the liquid onto the bag surface of the pheromone, maintaining a uniform release for a long period of 2 months or more. it can.

It has excellent workability and can be easily and economically manufactured into bags.

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

[Brief description of drawings]

All of the drawings relate to the sustained release pheromone preparation of the present invention. FIG. 1 is a sectional explanatory view thereof, FIG. 2 is a partially enlarged sectional explanatory view of FIG. 1, and FIGS. FIG. 6 is a partially enlarged cross-sectional explanatory view of FIG. (Explanation of main symbols) 2 ... Bag, 3 ... Laminate film, 5 ... Pheromone substance, A ... Layer composed of first group polymer, B ... Layer composed of second group polymer.

Claims (3)

[Claims] 1. A layer of the first group consisting of one or more layers having a total thickness of 2 to 20 μm and having an equilibrium swelling rate at 20 ° C. with respect to an incorporated pheromone substance at 0.1 to 1.9% by weight. Of the same or different polymers selected from the group consisting of polyamide, polyester, polyacrylonitrile, and polyethylene vinyl alcohol within the range of 2), and 2) the layer of the second group consisting of one or more layers is
A laminated film having a total thickness of 20 to 200 μm, which has a total thickness of 20 to 200 μm and has a thickness of 10 to 198 μm and which is composed of the same or different polymers in the range of 2 to 20% by weight at the equilibrium swelling rate at 20 ° C. with respect to the incorporated pheromone substance A sustained-release pheromone preparation in which a pheromone substance is enclosed in a bag on one side. 2. The sustained-release pheromone preparation according to claim 1, wherein the bag has a laminate film surface having an actual release surface area of 100 to 3000 mm ² and a liquid pheromone substance is enclosed therein. 3. The sustained release pheromone preparation according to claim 1, wherein the pheromone substance is an unsaturated aliphatic hydrocarbon, acetate, aldehyde or ketone compound having 12 to 20 carbon atoms.