JPH01207201A - Inspection of hydrated silicic acid for carrier of agricultural chemical - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method for testing hydrated silicic acid for agricultural chemical carriers.

A medicines may be manufactured in the form of powders, granules, water-use agents, etc. depending on the properties of the agricultural chemical substance or the purpose for summer use.

Conventionally, oil absorption has been used as a criterion for determining the superiority or inferiority of agricultural chemical carriers, and those with higher oil absorption have been considered to be superior as agricultural chemical carriers. As pesticide carriers, inorganic compounds with a large oil absorption capacity, such as powdered aqueous silicic acid and diatomaceous earth, are generally used. Particularly recently, powdered aqueous silicic acid has attracted attention as a carrier for agricultural chemicals because of its large oil absorption compared to other inorganic compounds. However, there are many types of powdered water-based silicic acid depending on raw materials and manufacturing methods, and even powdered water-based silicic acid with a large oil absorption capacity is not necessarily satisfactory as a drug carrier. That is, the properties of powdered aqueous silicic acid required for agricultural chemical carriers cannot be judged simply by the amount of oil absorption, and there are no clear criteria for judgment.

Therefore, the present invention is based on the advantages of hydrated silicic acid for agricultural chemical carriers. This paper clarifies the criteria for testing and proposes all testing methods for the water-use silicic acid.

That is, in conducting a complete inspection of hydrated silicic acid for agricultural chemical carriers, the present invention examines at least two types selected from the group consisting of (1) pore volume, (11) oil absorption rate of agricultural chemical raw material, and retention strength of agricultural chemical raw material. This is a method for testing hydrated silicic acid for agricultural chemical carriers, which is characterized by measuring properties. The pore size distribution and pore radius referred to in the present invention are measured by a mercury porosimeter method and calculated by the following formula, and are expressed as nine.

(However, r is the pore radius and P is the pressure.) For the above pore distribution and calculation method of the pore radius, see, for example, "Powder It is sufficient to follow the explanation in "Illustrated Guide to Physical Properties", pages 116 to 117 (published on May 1, 1975). The secondary pore volume refers to the volume occupied by pores smaller than a specific pore.

The powdered water-use silicic acid described above can be obtained in various types depending on the type of raw materials, manufacturing method, etc. Furthermore, the oil absorption amount of the powdered water-use silicic acid can be increased as necessary. However, even if powdered aqueous silicic acid has a large oil absorption capacity, it rarely satisfies its properties as an agricultural chemical carrier as described above. As a result of various statistical experiments, the present inventors have determined that the handling, oil absorption rate, agricultural chemical substance retention force during crushing, etc. are the volume occupied by pores of 150X or less in the pore size distribution of powdered water-based silicic acid. Make sure all that is determined by that ratio.

The properties of the powdered water-based silicic acid required as the agricultural chemical carrier include the pore size distribution of the powdered water-based silicic acid, particularly the pore radius of 75X to 15
Volume occupied by pores between 0X and pore radius 75X to 100X
Shadow by the ratio of the volume occupied by the pores between! The phenomenon of a total loss has been clarified for the first time by the present invention.

Of course, the absolute conditions necessary for a pesticide carrier are that the absorption rate of the agricultural chemical raw material is large and that the oil absorption rate of the agricultural chemical raw material is fast, as described above. In this sense, those with small oil absorption cannot be used, and generally the volume occupied by pores with a pore radius of 10,000X or less in the pore size distribution is Fi2.5 CC7g or more, preferably 2.
7 CC/j; preferably 7 or more. Further, in order to fully increase the rate of adsorption of the agricultural chemical ingredient onto the carrier, it is necessary that the volume occupied by pores in the pore diameter range of 75X to 150X in the pore size distribution is 0.6 CC/g or more. In the above pore size distribution, the volume occupied by pores with a pore radius of 75X to 150χ is preferably as large as possible, for example 0.
It is preferable to select one with a value of 7 CC/i or more, more preferably 0.8 CC/g or more. However, it is industrially difficult to mold all the pores in the pore size distribution where the volume occupied by pores with a radius of 75x to 150x is extremely large. This is probably the upper limit that can be obtained. On the other hand, in the pore size distribution, if the volume occupied by the pores with a pore radius of less than 75X is 7g or more of O16CC, the adsorption of commonly used agricultural chemical ingredients is surprisingly small and the present invention According to a person's confirmation, the amount of pesticide active ingredients adsorbed to pores with a pore radius of less than 751
25% or less of the volume occupied by pores with a pore radius of less than 5X,
The maximum is about 40%. Therefore, the pore radius is 75X-1
The pore radius is 75X compared to the volume occupied by pores between 50X and 50X.
It can be said that a volume occupied by pores of less than 10% has little effect on the properties of the agricultural chemical carrier.

The greatest feature of the agricultural chemical carrier of the present invention is that the volume occupied by pores with a pore radius of 751 to 100X in the pore size distribution accounts for 45% or more of the volume occupied by pores with a pore radius of 75X to 150X. It is a point.

Hydrous silicic acid in which the volume occupied by pores with a pore radius of 75× to 150× in the pore size distribution is 0.6 CC/g or more provides an extremely excellent oil absorption rate of the active pharmaceutical ingredient. However, the carrier that has completely adsorbed the pesticide active ingredient is generally pulverized, and if the active ingredient leaches out during the pulverization process, handling will be affected as mentioned above. It becomes a defect. Moreover, as in recent years, the more attempts are made to increase the use of agricultural chemical ingredients for agricultural chemical carriers, the more the defects become more serious. In this sense, the ability of the agricultural chemical substance to be held in the carrier during crushing is a major factor, along with the overall increase in the amount of pesticide used per unit. The factor of body retention force is pore radius 75X in pore size distribution
It is influenced by the volume occupied by pores between -150X and the ratio of the volume occupied by pores with pore radius between 75X and 100X in this volume. This finding is a completely surprising phenomenon, but as is clear from the example Kurara≠Moe Tsutsuzuma to be described later, it is no exaggeration to say that the properties of the agricultural chemical carrier are 100% determined by the above relationship.

If 45% or more of the volume occupied by pores with a pore radius of 751 to 1501 in the pore distribution is occupied by the volume of pores with a pore radius of 751 to 100 Not only is it possible to increase the amount of agricultural chemicals, but the retention of agricultural chemical ingredients during pulverization is significantly improved. However, if the ratio is less than 45%, the holding power of the agricultural chemical raw material during pulverization is small, and it is impossible to increase the amount of the agricultural chemical raw material used.

In addition, the criterion for determining the quality of insect drug carriers is the oil absorption rate. The oil absorption rate is expressed as the time it takes for a certain amount of hydrosilicic acid to completely absorb one foot of sample oil. As mentioned above, the oil absorption rate is mainly influenced by the volume occupied by the pores between 75X and 150X in the pore size distribution, so when measured instead of or together with the pore volume, it is possible to The quality of the carrier is judged.

Furthermore, the ability to retain agricultural chemical ingredients is a criterion for determining the quality of agricultural chemical carriers. The retention power of the agricultural chemical ingredient is determined by the time from the start of grinding to the time when the coffee mill runs idle when it is ground using a water-based silicic acid coffee mill that has adsorbed a certain amount of sangur oil. can be inspected. As mentioned above, the retention power of agricultural chemical ingredients is determined by the volume occupied by pores with a pore radius of 75X to 150X and the ratio of the volume occupied by pores with a pore radius of 75X to 100X in the pore size distribution. Therefore, if the pore volume is measured instead of or together with the pore volume, the quality of the agricultural chemical carrier can be judged.

The suitability of the water-using silicic acid as a pesticide carrier proposed in the present invention is determined by the pore volume of the water-using silicic acid, the adsorption rate of the agricultural chemical raw material, and the adsorption rate of the agricultural chemical raw material, as is clear from the examples and tests described below. It can be determined by thoroughly testing the properties of at least two types selected from the group consisting of holding power.

EXAMPLES In order to explain the present invention in more detail, Examples will be given below, but the present invention is not limited to these Examples.

In addition, the pore size distribution, pore volume, oil absorption rate, and agricultural chemical substance retention ability during pulverization of the powdered hydrated silicic acid in the examples were measured by the following methods.

Measuring method l) Pore volume The pore size distribution and its pore volume are measured using CARLOE
1520 mercury porosimeter (Dllatometer type SM manufactured by RBA)
3. Capillary: 3
mφ0.07065 m2)' (measured using pore volume of 75 to 1 oool when the pore radius is 50 to 150.

It was expressed as a volume of 75-150X and 50-10000X.

2) Oil absorption rate Figures 1 and 3 are schematic diagrams showing a method for measuring oil absorption rate. Take a sample of water-use silicic acid in a 32 mesh fluid shown in Fig. 1, and while rubbing it with a brush,
The top surface of the sample 3 is opened and the height is 16 m/m. Next, as shown in Fig. 2, a clock mold 4 with a diameter of 120 m and a weight of 51.8 g is gently placed on it.
After 30 seconds, pull up the 4-karat gold watch mold. Next, as shown in FIG. 3, the compressed sample surface 3 is covered with boiling oil 5
．． The total time required from the time when the boiled oil came into contact with the sample until all of the boiled oil was absorbed into the sample was measured and determined as the oil absorption rate. Note that the measurements were performed indoors at room temperature (20° C.).

3) Pesticide drug substance retention test when crushed Place the water-use silicic acid sample into a T-5 evaporation dish. Add 12.5 mt of boiling oil dropwise to this, mix well, and allow it to be absorbed.

This adsorbed sample? Quiliff 12 coffee mill (
Grind using HR2170). As the grinding continues, the boiling oil gradually leaches out, and eventually the ground material becomes a paste, which allows the coffee mill to rotate. The time period 1 from the start of the grinding to idle rotation was measured, and the agricultural chemical substance retention force (hereinafter sometimes simply abbreviated as holding force) during the grinding was determined.

Example 1 7.6 m5 of commercially available sodium silicate (S102/Na20 molar ratio = 3.038IO226, 4%) and Na28
04 (Na2O1, 35%) 37 m% water Q, 4
m' into a 60 m3 internally heated reaction tank with stirring blades, and while stirring, add 1.95 m of sulfuric acid (22 g7100 m/)
Add in about 10 minutes to perform the first stage of acid addition. After the pressurization is finished, water vapor is blown in while stirring to raise the temperature to 95° C. over 20 minutes. After raising the temperature, ripening is performed at the same temperature for 7 minutes. After that, neutralization was completely restarted, and in order to neutralize the remaining alkali, 2.68 mkg of the sulfuric acid was pressurized for 0 minutes, and the pl ('i) of the solution was adjusted to be within the range of 5.5 to 6.5. The reaction is complete.

This solution next? , after drying, the product of water-containing silicic acid is 5.5
p) Prepare I = 4.4 so that it is ~6.5.

The entire solution is filtered and washed with water using a filter press to obtain a filter cake containing aqueous silicic acid. This filter container is made into a slurry again using all the dispersion equipment, and a high-concentration silicic acid suspension is made.The hot air temperature is 400℃, the rotation speed of the rotating disk is 600Or, p, m'''C is spray-dried, and fine granular hydrated silica is produced. Acid was obtained. This hydrosilicic acid was pulverized and degassed to obtain a product. Using this product, pore diameter volume, adsorption retention power, and oil absorption rate were all measured.

The results are shown in Table 1.

Example 2 In Example 1, the addition of sulfuric acid in the first stage was 1,75
Hydrosilicic acid 7 was obtained in the same manner as in Example 1 except that the remaining amount of sulfuric acid was added to m' at t k of 2.95 m'. The same tests and measurements as in Example 1 were carried out using this water-using silicic acid. The results are shown in Table 1.

Example 3 Powdered water-use silicic acid was obtained in the same manner as in Example 2, using the same apparatus as in Example 1, except that the total reaction temperature in Example 2 was changed to 85°C. Using this water-containing silicic acid, the same tests as in Example 1 were carried out. The results are shown in Table 1.

Example 4 Commercially available sodium silicate (Sin□/Na2O-r-ratio=
3.05.8102: 28.4%) 282- and Na2
5O4 (Na2O1, 78%) 1124d, water 594r
Put ntf31 into a glass container and add sulfuric acid (2
2g/100d) 68.1g was pressurized for about 3 minutes to perform the first stage of acid addition. After the pressurization is completed, external heating is performed using a mantle heater, and the temperature is raised to 95°C in about 20 minutes. After raising the temperature, ripening Jli3ETh is performed at the same temperature for 5 minutes.

Thereafter, neutralization was restarted, and the sulfuric acid 126 di was pressurized for about 100 minutes to completely neutralize the remaining alkali.
The reaction is completed so that the value falls within the range of 3.5 to 4.5.

Next, this molten g was filtered through a Puchner funnel, washed with water, dried in a microwave oven, and then ground in a coffee mill manufactured by Philips to obtain powdered aqueous silicic acid. Using this water-containing silicic acid, the same test as in Example 1 and 6111 additions were carried out. As a result, the O shown in January Example 9 Commercially available sodium silicate (SlO□/Na2O molar ratio = 3.0
5.8102: 28.4%) 282- and Na25O4
(Na201.78%) l124*, water 594 goboku3j
into a glass container, and add sulfuric acid (22 g/10
0rnt) 77.6 mjk for about 3 minutes to perform the first stage of acid addition. After the pressurization is completed, external heating is performed using a mantle heater, and the temperature is raised to 70°C in about 20 minutes. After raising the temperature, ripening is performed at the same temperature for 5 minutes. After that, neutralization was fully resumed,
In order to completely neutralize the remaining alkali, the sulfuric acid was heated for 100 minutes and then pressurized until the - of the solution was 3.5 to 4.
5 and complete the reaction.

Next, this reaction solution was transferred to an autoclave with an internal volume of 500-
400 - put it in. While stirring the reaction solution in the autoclave with a magnetic stirrer, the pressure was increased to 3 in about 30 minutes.
Stirring was carried out for 2 hours at the same pressure as the heel pressure at kg 7 cm2G"!.Then, the pressure was reduced to atmospheric pressure by natural slow cooling.Then, the vaginal autoclave-treated liquid was filtered through a Puchner funnel, washed with water, and heated in a microwave oven (home use). After drying it, it was ground in a Philips coffee mill.
Powdered water silicate gold was obtained. The same tests and measurements as in Example 1 were carried out using this water-containing gold silicate. The results are shown in the full table.

Example 6 Using the powdered water-based silicic acid obtained in Example 1, the retention power of agricultural chemical raw materials was measured. The measurement method was as follows, except that in the above 3) "Pesticide API Retention Test during Grinding", the pesticide ingredients for dill oil and boiled oil were used as the pesticide ingredients listed below and in the amounts shown in Table 2. It was carried out in the same manner as in 3) above. The results are shown in Table 2.

Type of agricultural chemical used CH3-CH-CH2-CH.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are all schematic diagrams showing the method for measuring the oil absorption rate, respectively. In the diagram, 1 is a sieve, 2 is a container, and 3
indicates the sample, 4 indicates the clock, and 5 indicates the dill oil vinyl.

Claims (1)

[Claims] (1) When testing hydrated silicic acid for pesticide carriers, (i)
Hydrated silicic acid for use as a pesticide carrier, characterized in that it measures at least two properties selected from the group consisting of pore volume (ii) oil absorption rate of the pesticide active ingredient and (iii) retention power of the active ingredient inspection method.