JPH0329281Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an insect repellent film. Specifically, the present invention relates to an insect repellent film that has sustained release properties for insecticides or insect repellents and has air permeability.

Microscopic pests such as mites that live on the tatami mats and carpets of houses are the cause of various diseases.
Known countermeasures include spraying insecticides and weaving insecticides into the tatami mats in the form of fibers. Spraying insecticides is not effective in the long term;
Moreover, spraying in large quantities is not good for health. In addition, although the method of mixing insecticides into tatami mats can be expected to have a long-lasting effect, it requires a lot of effort to replace the tatami mats, and is expensive, so it is not versatile, and although it is not simple, it is not a method that has long-term effects. Films and sheets were needed.

Conventionally, a method of mixing and releasing a drug etc. in a film and a method of controlling release using a multilayer resin structure are known. (Japanese Patent Publication No. 56-47881) In this method, even if the release rate from the film surface is constant, if the release rate is set to maintain the drug efficacy at all times, the total amount released will be large, which is healthy and undesirable. However, there is a problem in that when the release rate is small, the insect repellent film becomes less effective. In addition, the lack of air permeability increases humidity and limits the range of use. There is also a known method in which the sheet is made into a three-layer structure, formed into a ribbon shape, etc., and released from the edge of the sheet.
No. 11135) The amount of drug released varies depending on the area of the end, and when used as a continuous sheet, no drug effect is observed, making it impractical.

As a result of intensive studies in view of these current circumstances, the present inventor has developed a resin (hereinafter referred to as resin A) that has a saturated absorption amount of 0.5% or more and 10% or less by weight at 20°C for insecticides or insect repellents. The drug is applied to the layer consisting of
A resin with a saturated absorption amount of 0.3% by weight or less at 20°C (hereinafter referred to as resin B) is mixed in the range of 0.5 to 10.0% by weight.
The inventors devised an insect repellent film that is characterized by the sustained release of drugs from the pores and air permeability by laminating a layer (called ``5'') on both sides of the film and providing a large number of pores to the film. This is what I did.

In such a film, the amount of drug released from the edges of the film is small and most of it is released from the pores, so its performance can be determined by the diameter and aperture ratio of the pores. In order to further increase the precision of the release rate, it is preferable to seal the end of the film so that the drug is not released from the end but only from the through holes. This method uses heat fusion or saturated absorption at 20℃.
A method of sealing with hot melt resin or the like of 0.3% by weight or less is possible.

In the present invention, from the viewpoint of sustained release properties and air permeability, it is preferable that the diameter of the pores be 0.5 mm or more and 9.0 mm or less, and that the aperture ratio relative to the film area be 0.1 to 30%.

The resin that can be used in the present invention is preferably a polyolefin resin or an ethylene copolymer resin from the viewpoint of processability, cost, ease of handling, etc., such as ethylene-vinyl acetate copolymer, low density or high density polyethylene, ethylene-ethylene copolymer resin, etc. Ethyl acrylate copolymer, ethylene-methyl (meth)
Acrylate copolymer, ethylene-vinyl acetate-
Examples include methyl (meth)acrylate.
In particular, it is more preferable to select resin A from among ethylene-vinyl acetate copolymers and select resin B from low-density or high-density polyethylene in terms of perforation workability, durability, texture, and the like.

Various insecticides and insect repellents that can be used in the present invention can be selected depending on the purpose. Organic phosphorus compounds such as sumithion and pyrethroids are effective. Further, by mixing and using insecticides, fungicides, etc. at the same time, a higher synergistic effect can be obtained.

The film used in the present invention can be simultaneously filled with filler to facilitate processing and control release rate. In addition, in order to prevent the odor of the medicine, it is possible to simultaneously mix fragrances or to carry out deodorizing treatment through post-treatment.

The present invention is most effectively used in places where ventilation and insect repellency are particularly required, such as on floors and tatami mats, and between tatami mats and carpets.

Example As resin A, ethylene-vinyl acetate copolymer (vinyl acetate content 15% by weight, density 0.98 g/cc,
Melt index: 1.5 g/10 min) Also, low-density polyethylene (density: 0.92 g/cc, melt index: 1.5 g/10 min) was used as resin B, and resin A
and Sumithion as an insecticide (manufactured by Sumitomo Chemical)
A mixture of 7% by weight of Resin A was mixed with a Banbury-type mixer, and simultaneously mixed with Resin B to which no chemicals were added by the multilayer inflation method to a thickness of approximately 100 μm (the thickness of intermediate layer Resin A was approximately 40 μm, A film with a thickness of approximately 60 μm of inner and outer layer resin B is molded, and the diameter
A through hole with a diameter of 3.0 mm and an aperture ratio of 1.0% was provided. Furthermore, the end surfaces of the film were heat-sealed to prevent release of the drug from the end surfaces. By placing this film between the tatami and the carpet, good insect repellent effects and breathability could be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an insect repellent film, in which 1 is composed of a resin whose saturated absorption amount of an insecticide or repellent at 20°C is 0.5% by weight or more and 10% by weight or less; 2 is a layer made of a resin having a saturated absorption amount of 0.3% by weight or less at 20°C. Figure 2 is a cross-sectional view of the end face of the insect repellent film, and Figure 3 shows the end face exposed to insecticide or insect repellent.
It is sealed with a resin whose saturation absorption at 20°C is 0.3% by weight or less. FIG. 3 is a plan view of the insect repellent film. 4 in each figure indicates a through hole.

Claims (1)

[Scope of claims for utility model registration] (1) A layer consisting of a resin (referred to as resin A) whose saturated absorption amount at 20°C is 0.5% by weight or more and 10% by weight or less for an insecticide or insect repellent. on both sides,
In a multilayer resin film having a layer made of a resin (referred to as resin B) with a saturated absorption amount of 0.8% by weight or less at 20°C, 0.5 to 10.0% by weight of the drug is mixed in the resin layer of resin A. An insect repellent film characterized by having a large number of holes in the film, thereby allowing sustained release of the drug from the holes and having air permeability. (2) The insect repellent film according to claim 1, wherein the end portion of the film is sealed so that the drug is not released from the end portion but only from the through holes. (3) The insect repellent film according to claim 1, wherein the diameter of the through holes is 0.5 mm or more and 9.0 mm or less, and the aperture ratio relative to the film area is 0.1 to 30%. (4) For an insecticide or insect repellent, the resin A is selected from among ethylene-vinyl acetate copolymers and the resin B is selected from low density or high density polyethylene. insect repellent film.