JPH0249707A - Insecticide - Google Patents

Abstract

PURPOSE:To obtain an insecticide made into a readily handleable state without substantially damaging excellent insecticidal effects of boron compound by supporting a boron compound well-known as an inorganic insecticide on porous particles. CONSTITUTION:A boron compound such as orthoboric acid, sodium borate and/or sodium octaborate hydrate, preferably orthoboric acid well-known as an inorganic insecticide having relative slight fear of toxicity to human body and contamination source of water quality and excellent insecticidal effects is supported on a porous particles such as silica, silica alumina or alumina having preferably 10-5,000Angstrom average pore diameter, 0.05-3cc/g average pore volume and 1-300mu average particle diameter to give an insecticide having improved handleability without damaging insecticidal effects of the boron compound, excellent workability and good insecticidal effects. When the compound is sprayed alone as it is, the compound is harmful to human body and inconvenience such as scattering is produced.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides an insecticide, particularly a boron compound, which is a component of the insecticide, by supporting it on a special carrier, thereby making it easy to handle and in a preferable form from the viewpoint of medicinal efficacy. This relates to pesticides that have been imitated.

[Background of the invention] In recent years, various buildings such as houses, buildings, and shops have been constructed using new noncombustible construction materials such as concrete, cellular concrete, blocks, and bricks in addition to wood, but cockroaches still remain in these buildings. Pests such as insects and mites enter the
It causes great damage to the human body.

[Prior Art] Conventionally, as a means to deal with such situations, various organic chlorine agents or organic phosphorous preparations have been used as they are, or various insecticides have been used.

[Problems to be Solved by the Invention] However, the insecticides themselves of these materials are highly toxic to the human body (and may also become a source of water pollution).

On the other hand, boron compounds such as boric acid are known as inorganic insecticides that have relatively few of these drawbacks, and although they have excellent medicinal effects, they may be harmful to the human body if sprayed alone. It becomes toxic and causes inconveniences such as scattering.

[Means for Solving the Problems] As a result of various studies and examinations for the purpose of making such boron compounds into a form that is easy to handle without substantially impairing their medicinal efficacy, the present inventors have discovered that boron is added to porous particles. An object of the present invention is to provide an insecticide characterized by carrying a compound thereon.

The porous particles used in the present invention have physical properties such as an average pore diameter of 10 to 5000 Å, an average pore volume of 0.05 to 3 CC/g, and an average particle diameter of 1 to 300 μm.
It is appropriate to adopt

If each of these physical properties is less than the above ranges, the boron compound cannot be supported sufficiently, making it difficult to sustain the medicinal efficacy over a long period of time.On the other hand, if these properties exceed the above ranges, the mechanical strength will be insufficient and the product may disintegrate or disintegrate. Both are unfavorable because the amount of boron compound supported per volume may be insufficient.

Further, it is desirable that these particles have a sphericity (degree of sphericity when a true sphere is 100) of at least 70%. If the sphericity is lower than this, in extreme cases when using crushed spherical objects or angular irregularly shaped objects,
When a boron compound is supported on this material, the porous particles become entangled with each other and form a lump, resulting in non-uniform support. This is not preferable because it results in the formation of particles.

As the constituent material of such porous particles, any suitable material can be used as long as it does not react with the boron compound and inhibit its medicinal efficacy. Examples include silica, silicalumina, alumina, etc. Among these, silica is particularly preferred because the physical properties can be easily controlled by employing the following manufacturing method. For example, a method is employed in which a silicate is stirred in a nonpolar liquid medium containing a surfactant to form fine droplets, and then the droplets are gelled with carbon dioxide gas.

As the surfactant used, for example, nonionic surfactants such as polyethylene glycol fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid monoester, etc. may be appropriately used. Can be done. The amount of surfactant used is generally about 100 to 50,000 ppm.

Further, as the liquid medium to be used, for example, non-polar organic liquid mediums such as benzene, toluene, xylene, kerosene, trichloroethylene, perchlorethylene, etc. can be used individually or in combination as appropriate. The appropriate amount of these liquid media to be used is about 2 to 20 times the amount of the silicate aqueous solution.

Among these liquid media, it is particularly preferable to use toluene, perchlorethylene, and kerosene because they can be used in small amounts and the amount of surfactant used can be small and high droplet dispersion stability can be obtained.

Further, as the silicate to be used, for example, water vitreous, silicon soda, silica sol, etc. can be used as appropriate. An aqueous silicate solution is then added to the non-polar liquid medium to which a surfactant has been added and stirred to form a sol. If the stirring is carried out too slowly or for too long a time, the dispersibility of the droplets will deteriorate and the particle size may become irregular, which is not preferable.

Generally, it is desirable that the granules have an average particle size of about 1 to 300 μm, and for this reason, the stirring power is 0.2 to 5 K per 1 m of a silicate aqueous solution dispersed and emulsified in a non-polar liquid medium.
It is appropriate to adopt W.

Furthermore, during stirring, if the liquid temperature of the non-polar liquid medium is too high or too low, the viscosity of the liquid will change and the dispersion stability of the droplets will be impaired, which is not preferable;
It is appropriate to adopt 0°C. In addition, in this case, if the silicate is acidic, the silicate will not form the desired fine particles, and some will become lumpy, causing gelation, which is undesirable.
It is appropriate to carry out the test at H9 or above.

The droplet-like sol thus obtained is then gelled with carbon dioxide gas. When carbon dioxide gas is used for gelation, the droplet-like sol produced in a preferred form can be gelled as it is, and the carbon dioxide gas dissolved in the nonpolar medium can reliably cause gelation of the silicate through the emulsion film. becomes possible. When water glass is used as the silicate, the amount of carbon dioxide gas used for gelation is 1 of the theoretical amount required to add all of the sodium to sodium carbonate.
．． It is appropriate to adopt 5 times or more. After separating the gelled granules from the liquid medium by filtration etc.,
The adhering liquid medium is removed by steam distillation or alcohol, and then dried. As specific means for drying, for example, a direct heating method using a combustion flame, a spray dryer type, a fluidized drying force type, etc. can be adopted.

There is no particular restriction on the means for supporting the boron compound on the spherical silica thus obtained, and generally, the spherical silica can be immersed in a solution of the boron compound, and the boron compound can be adsorbed by the capillary effect of the silica.

When supporting a boron compound, it is preferable to use a dissolved substance with as high a concentration as possible, but in addition to adsorption, it is also possible to attach and disperse the boron compound on the surface of the silica.
Generally, it is appropriate to employ a concentration of about 5 to 50% by weight, preferably about 15 to 20% by weight.

Further, an example of the supporting means will be specifically explained using orthoboric acid as a boron compound.

First, the spherical silica is pretreated by drying it at 120° C. or higher for about 2 hours so that it can be easily and sufficiently supported. When using an aqueous solution of orthoboric acid, in order to cause the particles to carry orthoboric acid in an amount higher than the solubility, a method of repeatedly impregnating the particles with a saturated aqueous solution can be adopted. Or 50
It is also possible to increase the solubility and impregnate the water using warm water at about ℃, but for example, 20% by weight of orthoboric acid
When obtaining a supported product, it is easily achieved by mixing the two in a heated atmosphere at a ratio of 2.5 g (10% boric acid aqueous solution) and 7 g (silica). That is, since this ratio is within the adsorption amount range of silica, the mixture of the two does not form a lump, but a cake, and the orthoboric acid aqueous solution can be evenly absorbed and dispersed in the silica due to the capillary effect. When hot water is used in this manner, a good supported product can be obtained with one crosstalk. The thus obtained supported product can be made into a product by air drying or by evaporating moisture at 120° C. or higher.

Next, a case will be described in which orthoboric acid is dissolved in an organic solvent.

Orthoboric acid is an organic compound, and is relatively difficult to dissolve in 7 media, and is best dissolved in glycerol at room temperature. However, glycerol has a sulfur-absorbing property and has a high boiling point. It is extremely difficult to remove glycerol as a solvent.For this reason, glycol ether compounds, especially brobylene glycol monomer (L-A-TIL), are preferred as solvents in terms of overall safety and cost. In the actual loading, it is preferable to carry out the loading under heating, as in the case of the aqueous solution.

As the boron compound used in the present invention, orthoboric acid is preferred from the viewpoint of medicinal efficacy, but sodium borate, sodium octaborate hydrate, etc. can be used alone or in combination as appropriate.

Although the reason for this is not clear, the insecticide according to the present invention has a longer-lasting effect than conventional insecticides of this type, and has virtually no toxicity to the human body.

Examples Spherical silica used in the following examples was prepared as follows.

Liquid composition 5 made by diluting 250g of No. 3 water glass with 500g of water
An aqueous solution containing 1029.7% by weight and 3.2% by weight of Nazo was prepared and used as a reaction solution. Next, in a bulk flask with a capacity of 5°C equipped with a stirrer and a gas blowing nozzle,
Nonionic surfactants Tween 80 and 5pan 60
4000 ppm of 1-luene 3C (weight ratio 3:1) was added thereto, and while stirring at a stirring intensity of 1500 rpm, the above reaction solution was added dropwise to form an emulsion. The average particle size of the sol obtained here was close to a perfect sphere of 6 μm, and then carbon dioxide gas was blown into the sol from a gas blowing nozzle at a rate of 0.2/j2 minutes for 10 minutes, and stirring was continued for an additional 60 minutes. During this time, the liquid temperature was maintained at 30°C. Next, the slurry in the flask was taken out, the solid content was separated in a furnace, and the attached toluene was removed by steam treatment. Since the obtained solid content contained sodium carbonate, this was removed by washing with 2,012 ml of water, and the solid content after washing was dried to obtain silica gel particles.

Example 1 2000 g of spherical silica was air-dried at 120° C. for 2 hours. Add 500g of orthoboric acid to 4500g of water,
The mixture was heated to 0.degree. C. to dissolve it, and added to the treated silica at this temperature for sufficient mixing. During crosstalk, the entire atmosphere was kept at 55°C. When the whole thing becomes cake-like, it is about 3.
After being left for 0 minutes, the orthoboric acid aqueous solution was sufficiently absorbed and dispersed due to the capillary effect of silica. Thereafter, the cake-like silica was air-dried in a drying oven at 120° C., and a product was obtained when there was no weight loss. An average of 20 g of this product was sprinkled on a 1 x 1 m container with a polyester film stretched on the bottom surface through which air could circulate, and German cockroaches were injected into the container.
When 00 mice were placed and observed, they all died out after about 48 hours.

In addition, when 250 woolly spider mites were placed and observed,
It died out after about 24 hours. Further, the above-mentioned product was sprinkled on the surface of a straw tatami floor at an average rate of about 35 g per 1 tatami mat, and a tatami cover was sewn thereon in accordance with a conventional method. I brought this tatami into a 3-tatami room in an apartment where many mites were infested, and replaced it with one of the tatami mats. After about a week, I removed the tatami mat and observed it, and found that there were many dead mites on the straw floor. No mites were found living on the tatami floor.

Example 2 An appropriate amount of woolly spider mites was evenly sprinkled on the surface of a 50X loOcm wool carpet that had been sufficiently absorbed with moisture, and the carpet was wrapped in Japanese paper and left in an atmosphere of 25° C. and 90% RH for 7 days. After 7 days, the Japanese paper was removed and the surface of the carpet was illuminated with an incandescent lamp for 5 minutes to allow the mites to burrow inside the carpet.

This carpet was divided into two equal parts to obtain two samples measuring 50 x 50 cm.

For one of these, surround the periphery with masking tape so that the central part is 30 x 30 cm, vacuum the inside with a powerful vacuum cleaner for 20 seconds, collect dust and mites on the carpet, and remove this dust. The mixture was poured into water containing a neutral detergent, stirred, and filtered with suction. Place the filter paper with dust and mites in the freezer.
The filter was held for 0 minutes to slow down the movement of the mites, and the number of woolly mites living on the filter paper was counted, and the number was approximately 1,800.

On the other hand, the remaining sample was surrounded with masking tape so that the center part was 30 x 30 cm, and then about 3.5 g of the product used in Example 1 was sprinkled on average and rubbed into the carpet. After wrapping this sample in Japanese paper and keeping it in a dark place for 24 hours, the number of mites living there was counted in the same manner as above, and the number was about 150.

Claims (1)

[Claims] 1. An insecticide in which a boron compound is supported on porous particles. 2. Porous particles have an average pore diameter of 10 to 5000 Å, an average pore volume of 0.05 to 3 cc/g, and an average particle diameter of 1 to 300 μ
The insecticide according to claim 1.