JPS6361063A - Microcapsule insecticide prepatation dispersed in coating compound - Google Patents

Abstract

PURPOSE:To obtain the titled insecticide having long duration period of effect or freely adjusted duration period of effect, by dispersing a microcapsule agent containing an insecticidal component as a core coated with a high polymer membrane substance into an aqueous resin coating compound. CONSTITUTION:A microcapsule containing an insecticidal component as a core coated with a high polymer membrane substance (e.g. gelatin, etc.) is dispersed into an aqueous resin coating compound to give the aimed insecticide. Further the aqueous resin coating compound is blended with two or more microcapsule agent coated with high polymer substance having different release rates to adjust duration of effect freely.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to insecticidal formulations. In detail, insecticidal formulations with a long duration of efficacy in which microcapsules containing an insecticidal ingredient as a core are mixed and dispersed in a water-based resin paint, and two or more types of polymer membrane substances with different release rates each containing an insecticidal ingredient as a core. This invention relates to an insecticidal formulation in which the duration of efficacy can be freely adjusted by mixing and dispersing microcapsules using a water-based resin paint.

PRIOR ART AND PROBLEMS TO BE SOLVED BY THE INVENTION Currently used insecticidal preparations include wettable powders, emulsions, powders, granules,
There are water-based microcapsules, etc. Of these, the first four have the disadvantage of having a short duration of efficacy because the effective insecticidal ingredients are directly exposed to the external environment after spraying, and even water-based microcapsules, which have a relatively long duration of efficacy, The film material may deteriorate due to air or ultraviolet rays,
Due to decomposition by microorganisms, etc., it has been difficult to maintain efficacy for a long period of one to two years. In addition, all of these have low spreading performance, making it difficult to retain them at the application site for a long period of time.

On the other hand, in order to retain the insecticidal ingredients at the application site for a long period of time, active ingredients were mixed with paint or other film-forming materials and applied to the bottoms of ships, aquaculture equipment, fishing nets, underwater structures, etc. (For example, Japanese Patent Publication No. 50-25927, Japanese Patent Publication No. 50-31174, and Japanese Patent Publication No. 51-34416). However, the effective period of these antifouling paints is determined by the rate at which the active ingredient dissolves into water from the surface blade layer, and it has not been possible to adjust the effective duration.

For example, even if this preparation is used as an insecticidal preparation, its efficacy duration is extremely short compared to the preparation according to the present invention (almost equivalent to conventional preparations such as hydrating powders and emulsions).

The object of the present invention is to produce insecticidal formulations with a long duration of efficacy. Another object of the present invention is to produce an insecticidal formulation whose duration of efficacy can be freely adjusted.

Means for Solving the Problems The present inventor has developed a film material of microcapsules in a coating film obtained by mixing and dispersing microcapsules containing an insecticidal ingredient in a water-based resin coating, and then applying the coating to an object and drying it. It was discovered that the metal gradually deteriorates and breaks down over time, leading to the completion of the present invention.

That is, the present invention provides an insecticidal formulation characterized in that microcapsules containing an insecticidal ingredient as a core and coated with a polymer film are mixed and dispersed in an aqueous resin paint, and microcapsules having an insecticidal ingredient as a core and having different release rates. This is an insecticidal formulation characterized in that at least two or more types of microcapsules obtained by coating with a polymer membrane material are mixed and dispersed in an aqueous resin paint.

The insecticidal component that can be used in the present invention is not particularly limited, as long as it has insecticidal properties such as organic phosphorus agents and pyrethroid agents, whether in liquid or powder form.

The polymer membrane material of the microcapsules that can be used in the present invention may be either a natural product or a synthetic polymer material without any particular restriction, and the former generally includes gelatin, casein, agar,
Gelling hydrophilic substances such as pectin and fish glue, and the latter generally include ethyl cellulose, carboxymethyl cellulose, acrylic acid-itaphonic acid copolymers, polyvinyl alcohol, caprolactam, etc., which are most widely used industrially. Regarding water solubility, the former is generally easily soluble in water, and the latter is often poorly soluble in water.As for the release rate of insecticidal ingredients, the former is generally fast and the latter is slow. When mixing capsules with different release rates,
It is preferable to use an acrylic acid and itafonic acid copolymer with gel tar aldehyde or the like as an insolubilizing agent as the membrane material of the fast-acting capsule.

The aqueous resin coating used in the present invention may be of either an aqueous solution type or an aqueous emulsion type without particular limitation.

The concentration range of the insecticidal active ingredient in the aqueous resin paint that can be used in the present invention is not necessarily limited depending on the strength of the insecticidal property, but is usually 0.1 to 3% by weight.

Depending on the purpose and performance of the insecticidal formulation of the present invention, the insecticidal ingredient microcapsules can be mixed and dispersed in the water-based resin paint in advance, or mixed and dispersed immediately before use, the desired method being selected. can.

Effect The mechanism of action of the present invention, which maintains its insecticidal efficacy for a long period of time, is not clear. However, from the outside, the particle interface of the microcapsules is exposed to the resin component in the water-based paint, and when this is dried, it forms a cross-linked film, which double covers the insecticidal component. Conceivable.

As a result of deterioration and destruction of the microcapsule membrane material due to air and ultraviolet rays that have penetrated the molecular gaps of this resin coating, and decomposition and decomposition by microorganisms in the environment, the components in the microcapsules pass through the paint resin coating. This is thought to be due to gradual release into the atmosphere. Therefore, for example, the duration of efficacy will depend on whether the polymer membrane material of the microcapsule is selected to have a fast or slow release rate of the insecticidal component. Furthermore, by blending two or more types of microcapsules with different release rates and changing their blending ratio, the duration of efficacy can be freely adjusted even if a single effective insecticidal ingredient is used.

Effects of the Invention This insecticidal formulation can dramatically increase the duration of efficacy compared to conventional insecticidal formulations, so if the same duration of efficacy is to be maintained, the amount of active ingredients can be reduced to 1/10 or less. Extremely economical.

Moreover, the duration of efficacy can be adjusted at will according to the practical use situation, which was impossible to achieve with conventional insecticidal preparations.

Furthermore, since the insecticidal ingredient is coated with a polymer membrane of microcapsules, the odor peculiar to the insecticidal ingredient is almost completely contained, so the user can be assured of safety against the toxicity of the insecticidal ingredient, and It is a great advantage in use because it does not suffer from inherent bad odors.

EXAMPLES Examples of the present invention will be shown below, but the present invention is not limited thereto. Note that all % expressions mean weight %.

Examples 1 to 3 and Comparative Example 1 Chlorpyrifosethyl (effective insecticidal ingredient) was microencapsulated by a conventional method using water-insoluble gelatin to which geltaraldehyde was added as an insolubilizing agent, and 1% of the active ingredient was added to water-based acrylic resin paint. It was mixed and dispersed in the cedar board and painted once on the surface of the cedar board. (Example 1) The same ingredient was microencapsulated using an acrylic acid/itaconic acid copolymer (Jurimer AC30F manufactured by Nippon Pure Chemical Industries, Ltd.) that was modified to be water-insoluble by adding geltaraldehyde, and 1% of the active ingredient was added. It was dispersed in the above paint and painted once on the surface of a cedar board in the same manner as in Example 1. (Example 2) The same ingredient was microencapsulated with the above water-insoluble gelatin or the above water-insoluble acrylic acid/itaconic acid copolymer, and 0.5% of each as an active ingredient, 1% in total, was mixed and dispersed in the above paint. As in Example 1, the surface of the cedar board was coated once. (Example 3) 1% of the same component was directly dispersed in the above paint and coated once on the surface of a cedar board in the same manner as in Example 1.

(Comparative Example 1) Four types of samples prepared according to the above procedure were left indoors for 10 days, exposed outdoors for 1130 days, and tested using a weatherometer σ2O-M)2.
After a four-stage durability test of 00 hours and 400 hours, the surface of the cedar board was scraped, and the active ingredients were extracted with diacetone at room temperature for 2 hours, and then quantitatively determined by gas chromatography to determine whether or not there was a polymer film on the microcapsules. The effects of differences in the release rate of the insecticidal ingredient on the residual degree of the insecticidal active ingredient were investigated, and the values shown in Table 1 were obtained.

Table 1 Residuality of active ingredients Relative reliability 1) W
-0-M Sunshine Carbon Accelerated Weathering Tester 200 hours corresponds to about 1 year of weathering conditions.

Note 2) 400 hours as above corresponds to approximately 2 years of weather resistance.

Based on the residual determination results in Table 1, Comparative Example 1 was used as the standard, and the sample of Example 1 was tested outdoors for 30 days. However, after 200 hours of W-0-M, which corresponds to one year of outdoor exposure, the wave film of the microcapsules was destroyed and most of the effective fraction was dissipated and disappeared. I understand that.

In comparison, in both the samples of Examples 2 and 3, a considerable amount of the active ingredient remained under the same conditions, and the microcapsule membrane did not deteriorate and break for an extremely long time, and the polymer membrane did not deteriorate and dispersible. It is clear that there is a correlation between

APPLICATION EXAMPLE 20 D. ants were brought into contact with each sample on the four types of samples prepared in Examples 1 to 3 and Comparative Example 1, and the mortality rate after 18 hours was investigated. In addition, the mortality rate of cockroaches was investigated by contacting 20 adult German cockroaches in the same manner, and the insecticidal effect on domestic termites and cockroaches was observed, and the results shown in Table 2 were obtained.

The following can be said from the mortality rate survey results in Table 2. Regarding the insecticidal effect on house termites and cockroaches, the sample of Comparative Example 1 only shows an immediate effect, but the sample of Examples 1 to 3
In the sample, the sustained release effect of the active ingredient due to the microcapsule membrane was observed. The insecticidal effect of the sample of Example 1 on both house termites and cockroaches decreased considerably after 200 hours of W-0-M, but the samples of Examples 2 and 3 had a 4KW-
Efficacy was observed even after 400 hours of 0-M. In particular, in the sample of Example 3, 50% of the total microcapsules (active ingredient)
% gelatin membrane microcapsules show an immediate effect, and acrylic acid/itaphonic acid copolymer membrane microcapsules with a residual content of 50% show a long-lasting effect, making them extremely practical as insecticides and termiticides. It has been revealed that it is a highly effective insecticidal material. Therefore, even if a single insecticidal active ingredient is used, an insecticidal formulation in which a mixture of two or more types microencapsulated with membrane materials with different persistence (degradability) is mixed and dispersed in a water-based resin paint is good. In addition to the excellent spreadability, the release rate of the active ingredient can be fully controlled, and its performance as an insecticide and termite repellent can be dramatically improved.

Claims (2)

[Claims] (1) An insecticidal formulation characterized in that microcapsules containing an insecticidal ingredient as a core and coated with a polymer membrane material are mixed and dispersed in a water-based resin paint. (2) An insecticidal formulation characterized in that two or more types of microcapsules containing an insecticidal ingredient as a core and coated with polymer film materials having different release rates are mixed and dispersed in an aqueous resin paint.