JPH04230602A - Sustained release pheromone formulation - Google Patents

Abstract

PURPOSE:To obtain a sustained release pheromone formulation having natural degradability without impairing function as the sustained pheromone formulation such as release control of various pheromones for a long period. CONSTITUTION:The aforementioned sustained release pheromone formulation is obtained by adding 1-40wt.% degradation accelerator composed of a biodegradable or a photodegradable accelerator such as starch or polyepsilon-caprolactone or a combined system thereof to a polymeric material containing a pheromone.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is a pheromone that is used to control insects by storing a pheromone, leaving it in a predetermined place for a long period of time, and continuously volatilizing a certain amount of the pheromone, thereby disrupting the communication of insects. This invention relates to sustained release preparations.

0002

[Prior Art] Recently, the resistance of insect pests to insecticides,
Due to problems such as residual pesticides on agricultural products, the use of pheromones to control pests is attracting attention and practical application is underway. Control of pests using pheromones requires uniform and long-term controlled release of pheromones from sustained-release preparations in order to always ensure the amount of pheromone vapor necessary for pest control within the control area.

Several methods have been proposed for this purpose, one of which is shown in Japanese Patent Publication No. 16361/1983. This is a sustained-release preparation in which a volatile substance is filled in a capillary made of a polymeric material, and a metal wire is attached to the capillary to give it shapeable properties. Also, Unexamined Japanese Patent Publication No. 2-4
No. 9702 proposes a bag-shaped pheromone sustained release preparation. In each of these methods, in order to release pheromones uniformly over a long period of time, the pheromone is filled in liquid form into a container made of polymeric material such as polyolefin, its copolymer, or polyvinylidene chloride, and the release rate is controlled. It is something. However, since these sustained-release preparations are not disintegrating, as they are used over and over again, residue remains in the field, and items buried in the soil remain as they are without decomposing, resulting in environmental destruction. There is. Also, when it comes to collecting to prevent this,
The cost would be enormous.

On the other hand, it is well known that sustained-release preparations can be made from natural disintegrating materials;
Publication No. 21 states that hollow fibers made of biodegradable polymers such as polyhydroxy acids such as polylactic acid and poly(α-amino acids) such as polyglutamic acid are used so that drugs gradually become effective for humans and animals. They have been shown to be loaded with active substances such as pheromones. However, such biodegradable polymers have problems such as difficulty in uniformly controlling the rate of pheromone release, decomposition rates that are too fast to be suitable for long-term use, and limited adaptability to different types of pheromone. There is. Thus, a pheromone sustained release preparation that does not degrade or decompose itself and pollute the environment after uniformly controlling the release of various pheromones over a long period of time has not yet been found.

[0005]

[Problems to be Solved by the Invention] Therefore, the purpose of the present invention is to control the release of various pheromones over a long period of time, etc.
The purpose of the present invention is to provide a pheromone sustained release preparation that has natural disintegrability without impairing its function as a pheromone sustained release preparation.

[0006]

[Means for Solving the Problems] As a result of intensive research, the present inventors have found that disintegration properties can be imparted while taking advantage of the performance of pheromone sustained-release preparations, such as the controllability of pheromone release and the strength of the attachment part of the preparation and the container. In order to achieve this, the inventors have discovered that the above object can be achieved by adding a decomposition accelerator to the polymeric material for forming the pheromone sustained release preparation, and have completed the present invention. That is, the pheromone sustained release preparation according to the present invention is
1 to 10% of a biodegradable or photodegradable decomposition accelerator, or a mixture thereof, is added to the polymeric material containing the pheromone.
It is characterized in that it is made by adding 40% by weight.

To explain this, polyethylene, polyethylene,
There are no particular limitations on commonly used polymeric materials, such as polyolefins such as polypropylene and 4-methylpentene-1, ethylene-vinyl acetate copolymers, polyvinylidene chloride, polyvinyl chloride, polyesters, polyamides, polystyrene, and polycarbonates. However, polyethylene or a copolymer thereof is preferred from the viewpoint of pheromone release control properties, kneading properties with a decomposition accelerator, and processability. Note that the ethylene copolymer desirably has an ethylene content of 70% or more in terms of release rate and strength of the formulation.

[0008] As the decomposition accelerator added to these polymeric materials, many materials among the currently developed naturally degradable materials can be used. Namely, polysaccharides such as starch and cellulose and their derivatives, polyhydroxy acids such as polyε-caprolactone, polyβ-hydroxybutyric acid, polylactic acid, and polyglycolic acid and their derivatives or copolymers, chitin and its derivatives, and polyglutamic acid. Additives that can be degraded by microorganisms, such as polyα-amino acids and their derivatives or copolymers, and
Additives that degrade the polymeric material when exposed to light can be used, such as blends of transition metals and photoactivators and ethylene-carbon monoxide copolymers. Furthermore, among these, polysaccharides such as starch and polyhydroxy acids such as polyε-caprolactone are preferable from the viewpoint of kneading properties with polymeric materials and processability.

[0009] The amount of the decomposition accelerator to be added varies depending on the type of polymer material and decomposition accelerator, the rate of deterioration, the environment of use, etc., but pheromone sustained release preparations can control the release of various pheromones uniformly over a long period of time. It is necessary to decompose it after the decomposition, and for that purpose, it is necessary to add the decomposition accelerator in an amount of 1 to 40% by weight. Since the rate of deterioration greatly depends on the thickness of the polymer material, the amount of decomposition accelerator added may be small for thin materials such as films, but if the amount added is less than 1% by weight, the rate of decomposition will decrease. It's too late,
The purpose of the present invention cannot be achieved. In addition, in areas where strength is required, such as the attachment part of the formulation, the amount added must be increased due to the thick walls, but if the amount added is 40% by weight or more, the decomposition rate will be too fast, making it difficult to use as a formulation. This is undesirable because it affects the period of use and causes large changes in processing conditions and pheromone release rate. More preferably, the amount added is 2 to 30% by weight from the viewpoint of pheromone release control properties and processability.

On the other hand, there is no hindrance to the addition of various stabilizers to improve the stability of the pheromone, fillers to improve the strength of the polymeric material, and the like. The shape of the pheromone sustained release preparation is not particularly limited, and it may be in any form such as a tube, bag, microcapsule, bead, bottle, tape, fiber, or stick. .

[0011]

EXAMPLES Next, specific embodiments of the present invention will be explained with reference to Examples and Comparative Examples, but the present invention is not limited to the description of these Examples. Example 1 10% by weight of Ecostar Plus (manufactured by Hagiwara Kogyo Co., Ltd.), a decomposition accelerator mainly composed of starch that is both biodegradable and photodegradable, was added to various polymeric materials shown in Table 1. T
A sheet with a thickness of 0.5 mm was prepared by die extrusion molding. Further, this sheet was exposed for 15 days in a weather resistance tester to perform an accelerated deterioration test, and then the residual tensile elongation was measured, and the results are also listed in Table 1.

0012

[Table 1]

The results show that polyethylene and its copolymers were good in terms of uniformity of kneading with the decomposition accelerator and processability. Furthermore, the addition of a decomposition accelerator to high-density polyethylene, which has good weather resistance, significantly accelerated deterioration.

Example 2 A tube with an average inner diameter of 0.9 mm and a wall thickness of 0.3 mm was made by adding 12% by weight of Ecostar (same as above), a decomposition accelerator mainly composed of starch, to high-density polyethylene and extrusion molding it. was created. Cut this tube into a length of 20 cm,
This is combined with the sex pheromone 7,11-
After filling 80mg of hexadecadienyl acetate,
The release rate was measured by leaving it outdoors for 2 months and measuring the weight loss. The average release rate at this time is 0.
The amount was 9 mg/day, which was the same value as before adding the decomposition promoter. Further, after the release test was completed, the tube was immersed in activated sludge under aerated conditions for 4 months, and the tube was decomposed by microorganisms and deteriorated to the extent that it could be easily separated by hand.

Comparative Example 1 A high-density polyethylene tube was prepared in the same manner as in Example 1, except that the decomposition accelerator Ecostar was not added, and the release rate of 7,11-hexadecadienyl acetate was determined in the same manner. was measured. Average release rate over 2 months is 0
．． It was 9 mg/day. Furthermore, when this tube was immersed in activated sludge under aerated conditions for 4 months in the same manner as in Example 2, no deterioration of the tube was observed, and the tube was sufficiently strong that it could not be separated by hand. .

Example 3 20% by weight of Ecostar Plus, a decomposition accelerator that is both biodegradable and photodegradable, was added to an ethylene-vinyl acetate copolymer with a vinyl acetate content of 6%, and the mixture was extruded. A tube with an average inner diameter of 1.0 mm and a wall thickness of 0.5 mm was prepared. This tube was made to have a length of 20 cm, and 160 mg of 8,10-dodecadienyl alcohol, which is a sex pheromone for codling moth, was filled into it. When this was attached to a tree for 4 months and the average release rate was measured, it was 1.9 mg/day. Furthermore, when this tube was left for one year, it naturally fell due to deterioration.

Comparative Example 2 An ethylene-vinyl acetate copolymer tube having a vinyl acetate content of 6% was prepared in the same manner as in Example 3, except that the decomposition accelerator Ecostar Plus was not added. This was filled with 160 mg of 8,10-dodecadienyl alcohol, left outdoors for 2 months in the same manner as in Example 3, and the average release rate was measured to be 2.1 mg/day. Furthermore, when this tube was left for one year, almost no deterioration was observed and it remained as it was.

Comparative Example 3 The vinyl acetate content was 6% in the same manner as in Example 3 except that 45% by weight of Ecostar Plus, a decomposition accelerator, was added.
An ethylene-vinyl acetate copolymer tube was prepared. Add 160m of 8,10-dodecadienyl alcohol to this.
When filled with g and left outdoors in the same manner as in Example 3, 2
It was unsuitable for long-term release control, as it deteriorated with cracks and other problems within a few months, and pheromone leaked out.

Examples 4 and 5, Comparative Example 4 Decomposition accelerator A
A 50 μm low-density polyethylene film containing 10% by weight of decomposition accelerator A was laminated on one side of a 10 μm ethylene-vinyl alcohol film containing 2% by weight of
The four sides of this film were sealed so that the release area was 15 cm 2 , and at the same time, 160 mg of 11-tetradecenyl acetate, a sex pheromone of Chahamaki, was filled. Furthermore, a high-density polyethylene having a thickness of 0.5 mm containing 35% by weight of decomposition accelerator B was attached as a hook for attaching this bag-like pheromone sustained release preparation, and the bag was left outdoors for one year. Further, this bag-shaped preparation was immersed in activated sludge under aerated conditions for 4 months to deteriorate it. The above results are shown in Table 2.

[0020]

[Table 2]

[0021]

[Effects of the Invention] According to the pheromone sustained-release preparation of the present invention, after the period of use as a sustained-release preparation has passed, it is decomposed by light, microorganisms, etc., and the form of the preparation is not left behind, so it can be recovered. It is unnecessary and has little impact on the environment. Moreover, since it is possible to easily impart natural disintegrability to materials for controlling the release of pheromone sustained release preparations currently in practical use, its industrial value is extremely large.

Claims (1)

[Claims] Claims 1. A pheromone sustained release preparation comprising a polymeric material containing a pheromone, and 1 to 40% by weight of a biodegradable or photodegradable decomposition accelerator, or a mixture thereof.