JPH0644993B2 - Aqueous suspension composition - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to medical treatment, agricultural chemicals, fertilizers, animal medicines, paints, cosmetics,
The present invention relates to an aqueous suspension composition used for detergents, photographic chemicals, foods and the like.

[Conventional technology]

Conventionally, the aqueous suspension compositions used in these fields are water-insoluble organic compounds that are solid at room temperature as they are,
Alternatively, it is finely pulverized, suspended, and dispersed together with an inorganic powder, a high melting point resin powder, etc., in JP-A-50-76236 and JP-B-53.
-46889, Japanese Patent Publication No. 59-43441, etc., the preparation process by the method described in, such as a water-soluble organic compound that is liquid at room temperature is suspended and dispersed using a high shear stirrer -192810 and Japanese Patent Publication No. 62-52721, etc., or processed into a formulation, or by dissolving a poorly water-soluble organic compound in an organic solvent to form a liquid at room temperature, using a high shear stirrer JP-A-49-54547, JP-A-61-212325, JP-A-61-212326, JP-A-62-167702, JP-B-63-58801, which is suspended and dispersed by
Japanese Patent Publication No. 63-60721, Japanese Patent Publication No. 63-62481, Japanese Patent Publication
It is used after being processed into a pharmaceutical preparation according to the method described in JP-A-63-63256.

[Problems to be Solved by the Invention]

However, in the case of an aqueous suspension composition obtained by suspending and dispersing a water-insoluble organic compound which is a solid at room temperature in the related art, fine particles are dissolved and disappeared due to a change in solubility with a change in temperature during storage. Recrystallize on large particles. By repeating this, the dispersed particle size becomes coarse, causing aggregation and sedimentation separation, and finally the redispersion becomes impossible. Further, a poorly water-soluble organic compound that is liquid at room temperature,
Alternatively, in the case of an aqueous suspension composition in which an organic solvent solution is suspended and dispersed in water, fine droplets suspended and dispersed during storage agglomerate, coalesce, and invert to cause creamy separation. In many cases, the original physical properties are significantly changed by increasing or decreasing the viscosity.

The problem to be solved in the present invention is to solve the problems of recrystallization in a solid particle dispersion-based aqueous suspension composition and droplet coalescence in a droplet dispersion system.

That is, the object of the present invention is excellent in storage stability, and
An object of the present invention is to provide an aqueous suspension composition whose redispersibility after drying can be controlled.

[Means for Solving the Problems]

The present inventors can finely pulverize a poorly water-soluble organic compound into a gel composition and suspend and disperse it as fine gel particles to solve the above-mentioned problems, and a small change in dispersed particle diameter during storage. It has been found that an aqueous suspension composition that can be easily redispersed even when internal separation occurs can be obtained.

The aqueous suspension-like composition of the present invention is a gel-like composition obtained by adding a gelling agent to a liquid poorly water-soluble organic compound or a solution of a solid poorly water-soluble organic compound in an organic solvent (hereinafter referred to as a liquid organic compound). That is, the gel composition is finely pulverized and suspended in water as fine gel particles.

By this method, it is possible to reduce the chances that the organic compound of interest comes into contact with water, suppress the dissolution of fine particles, and prevent the coarsening of the growth of particles due to the recrystallization phenomenon and the destruction of the dispersion system thereby.

Further, by gelling the liquid organic compound, the dispersed particles become solid fine particles from the droplets, so that the particle diameter increases due to coalescence of the droplets during the storage period and the destruction of the dispersion system such as creaming accompanying the increase. Can be prevented.

As the poorly water-soluble organic compound in the present invention, fat-soluble vitamins, fragrances, agricultural chemical raw materials, pharmaceuticals, pigments, natural mineral oils, animal fats and oils, vegetable fats and oils, fatty acids, synthetic oils and the like can be used.

Similarly, as the organic solvent, natural mineral oil, animal fats and oils,
Examples thereof include vegetable oils and fats, fatty acids, esters, ketones, synthetic oils, etc., but are not necessarily limited to those that are liquid at room temperature, and the adhesiveness and spinnability of the target poorly water-soluble organic compound As long as the physical properties such as deterioration can be changed in a desired direction, those solid at room temperature can be used.

Further, as the gelling agent used in the present invention, known oil gelling agents such as metal salts of higher fatty acids, amino acid derivatives, 12-hydroxystearic acid and high melting point waxes may be used alone or in combination of two or more kinds. it can.

Furthermore, an antifreezing agent, an antiseptic agent, a decomposition preventing agent, a fragrance, an antifoaming agent and the like can be added if necessary.

[Action]

The aqueous suspension composition of the present invention having the above-mentioned constitution, in the state of a sol having good fluidity, even if light aggregation occurs,
It has the property of being easily redispersed by light shaking or stirring.

Furthermore, a gel composition obtained by adding a gelling agent is mechanically suspended and dispersed, and then a dispersant and a thickener are added to obtain a more stable aqueous suspension composition. .

Further, since the aqueous suspension composition of the present invention can be easily diluted with water, the use of a surfactant is not essential for its preparation, but a surfactant can be added.

However, when this surfactant is added, for example, when it is used as a pesticide, even if the diluent is sprayed on the crop, the adhering matter is a mixture with the surfactant, so re-emulsification runoff occurs due to rain, and the pesticide The effect of maintaining the effect as a result will be greatly affected by the weather after spraying, and even when used as a vehicle wax, the surfactant will be mixed in the dry film after application and the water resistance will decrease. Therefore, it is important to select a surfactant according to the application.

〔Example〕

The physical properties and stability of Examples 1 to 3 of the aqueous suspension compositions of the present invention obtained by the following method were examined together with the aqueous suspension compositions shown in Comparative Examples 1 to 3.

Example 1 Insecticide fluvalinate, which is a viscous liquid at room temperature: (RS)-
α-Cyano-3-phenoxybenzyl (R) -2- (2
-Chloro-4-fluoromethylanilino) -3-methylbutanoate (10 parts by weight) was added to the aromatic solvent [Solvesso 100
(Trade name of Exxon Chemical Co.)] 10 parts by weight. To this solution, 1 part by weight of 12-hydroxystearic acid was added, heated and dissolved, and then cooled to obtain a transparent gel composition. This gel composition was mixed and dispersed in 59 parts by weight of a 3% polyvinyl alcohol (saponification degree 80%, polymerization degree 1500 or more) aqueous solution using a homogenizer (manufactured by Nippon Seiki Co., Ltd.), and then a wet crusher (manufactured by Dyno Mill WAB). 5 with 0.5 mm beads using
Wet milled for minutes. After the beads were filtered off, 10 parts by weight of a 1% aqueous solution of xanthan gum and 10 parts by weight of ethylene glycol were added and mixed with a stirrer for 5 minutes to obtain an aqueous suspension composition.

Example 2 Insecticide fenitrothion, which is a liquid at room temperature: O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate 10 parts by weight of dibenzylidene sorbitol.
After adding 2 parts by weight of the mixture, the mixture was heated and dissolved, and then cooled to obtain a gel composition. This gel composition was mixed with 64.8 parts by weight of a 3% polyvinyl alcohol (saponification degree 80%, polymerization degree 1500 or more) aqueous solution and 5%.
Methyl cellulose (28% methoxy group, 7% hydroxypropoxy group, 100 degree of polymerization) was mixed and dispersed in a mixed solution of 5 parts by weight using a homogenizer (manufactured by Nippon Seiki Co., Ltd.).
Wet milled for 5 minutes with 5 mm beads. After the beads were filtered off, 10 parts by weight of a 1% aqueous solution of xanthan gum and 10 parts by weight of ethylene glycol were added and mixed with a stirrer for 5 minutes to obtain an aqueous suspension composition.

Example 3 Insecticide etofenprox: 2- (4-ethoxyphenyl) -2-methylpropyl-3-phenoxybenzyl ether, which is solid at room temperature and has a melting point of 34 to 35 ° C., was added to 10 parts by weight of phenylxylylethane system. It was dissolved in 10 parts by weight of the solvent.
To this solution, 2 parts by weight of 12-hydroxystearic acid was added, heated and dissolved, and then cooled to obtain a gel composition. 2% polyvinyl alcohol (saponification degree 80%,
A homogenizer (manufactured by Nippon Seiki Co., Ltd.) was mixed and dispersed in 58 parts by weight of an aqueous solution having a polymerization degree of 1500 or more) and then wet pulverized with 0.5 mm beads for 5 minutes. After the beads were filtered off, 10 parts by weight of a 1% aqueous solution of xanthan gum and 10 parts by weight of ethylene glycol were added and mixed with a stirrer for 5 minutes to obtain an aqueous suspension composition.

Comparative Example 1 10 parts by weight of fluvalinate was dissolved in 10 parts by weight of Solvesso 100 (trade name of Exxon Chemical Co.), and 60 parts by weight of a 3% polyvinyl alcohol (saponification degree of 80%, polymerization degree of 1500 or more) aqueous solution was added to a homogenizer (Nippon Seiki). Manufactured by K.K.), and then wet-milled for 5 minutes together with 0.5 mm beads. After the beads were filtered off, 10 parts by weight of a 1% aqueous solution of xanthan gum and 10 parts by weight of ethylene glycol were added and mixed with a stirrer for 5 minutes to obtain an aqueous suspension composition.

Comparative Example 2 10 parts by weight of fenitrothion and 5 parts by weight of a dispersant containing polyoxyethylene phenyl allyl ether sulfate / dialkyl ester sulfonate were mixed to prepare a 3% polyvinyl alcohol (saponification degree 80%, polymerization degree 1500 or more) aqueous solution.
55 parts by weight and 5% methylcellulose (28% methoxy group, 7% hydroxypropoxy group, 100 degree of polymerization) aqueous solution of 10 parts by weight were mixed and dispersed using a homogenizer (manufactured by Nippon Seiki Co., Ltd.). Wet milled for minutes. After separating the beads, a 1% aqueous solution of xanthan gum 10
Parts by weight and 10 parts by weight of ethylene glycol were added and mixed with a stirrer for 5 minutes to obtain an aqueous suspension composition.

Comparative Example 3 After 10 parts by weight of etofenprox were heated and melted, 5 parts by weight of white carbon: hydrous amorphous silicon oxide (Carplex # 80, manufactured by Shionogi & Co., Ltd.), which is a known liquid absorbent, was absorbed into the liquid to absorb etofenprox. A powdery composition was obtained. This powdery composition was dispersed in 70 parts by weight of an aqueous solution of 2% polyvinyl alcohol (saponification degree 80%, polymerization degree 1500 or more) using a stirrer, and then wet pulverized with 0.5 mm beads for 5 minutes.
After the beads were filtered off, 5 parts by weight of a 1% xanthan gum aqueous solution and 10 parts by weight of ethylene glycol were added and mixed with a stirrer for 5 minutes to obtain an aqueous suspension composition.

The physical properties and stability of each of the above Examples and Comparative Examples are shown in the attached table.

From the table, in the storage stability test that repeats high temperature and low temperature to see the stability during storage normally required for commercial products, not only appearance changes such as separation and aggregation, but also the average particle size of suspended particles From the viewpoint of stability, it can be seen that the aqueous suspension compositions of Examples are significantly superior to the Comparative Examples.

[Effects of the Invention] The following effects can be achieved by the aqueous suspension composition of the present invention.

(1) Recrystallization can be performed for a long period of time without causing instability of the dispersion system due to recrystallization and growth of dispersed particles, which are problems when the dispersion phase is a solid organic compound at room temperature.

(2) Long-term storage is possible without causing destabilization of the dispersion system due to droplet coalescence and phase inversion, which are problems when the dispersion phase is an organic compound at room temperature.

(3) by diluting in a suitable organic solvent and then gelling,
It is possible to approximate the specific gravity of the organic compound to be suspended and dispersed to the specific gravity of the dispersion medium, and it is possible to stabilize the system, and when the organic compound is a biologically active ingredient, it is possible to maintain the action and effect on living organisms. , The effect of reducing mucous membrane irritation to the human body is obtained.

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Claims (5)

[Claims] 1. A sparingly water-soluble gel composition is obtained by adding a gelling agent to a sparingly water-soluble organic compound which becomes liquid at room temperature or a relatively low temperature, or an organic solvent solution containing a sparingly water-soluble organic compound.
An aqueous suspension composition obtained by suspending finely water-insoluble gel particles obtained by finely pulverizing the poorly water-soluble gel composition in water. 2. The aqueous solution according to claim 1, wherein the poorly water-soluble organic compound or a solution thereof exhibits fluidity at room temperature before addition of the gelling agent, and the gel composition after addition of the gelling agent does not exhibit fluidity at room temperature. Suspended composition. 3. The aqueous suspension composition according to claim 1, wherein the gel composition obtained by adding a gelling agent to an organic compound or an organic solvent solution in which the organic compound is dissolved is water-insoluble or sparingly water-soluble. 4. The gelling agent according to claim 1, wherein the added amount of the gelling agent is 0.
Aqueous suspension composition which is 01% to 50%. 5. The gelling agent according to claim 1, wherein the gelling agent is one or more of higher fatty acids, higher fatty acid derivatives, amino acid derivatives, sugar derivatives, high melting point waxes, synthetic polymer oil gelling agents and the like.
An aqueous suspension composition of one or more species.