JP2576749B2 - Paradichlorobenzene composition with improved caking properties and method for preventing caking of paradichlorobenzene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paradichlorobenzene composition having improved caking properties and a method for preventing the caking of paradichlorobenzene.

[0002]

2. Description of the Related Art In general, paradichlorobenzene (hereinafter, referred to as paradichlorobenzene)
“P-DCB” is formed into a tablet shape, a spherical shape, or a donut shape, and is widely used as an insect repellent, a deodorant, or the like. However, p-DCB produced and separated and purified industrially has a property of being easily consolidated. Therefore, p-DCB initially formed in a powder form is transported in a storage hopper in a production plant, and is transported. There is a case where it is solidified into a large lump in a packaging container, a molding hopper of an insect repellent manufacturer, or the like. Therefore, in such a case, for example, when it is subjected to various molding steps, it is necessary to pulverize the pulverized p-DCB and then charge the p-DCB into a molding machine hopper. There is a problem that it is inconvenient and causes a significant decrease in work efficiency. In addition, p-D which was crushed and charged
CB has a disadvantage that it causes bridging in the hopper and remarkably inhibits the flowability of the pulverized product, which is a major obstacle to improving the workability of p-DCB molding.

[0003] In order to prevent the occurrence of such a solidification phenomenon of p-DCB, conventionally, for example, a vapor pressure lower than that of p-DCB such as dioctyl phthalate (DOP) as an anti-solidification agent is added to p-DCB. (Japanese Patent Publication No. 42-1006) in which p-DCB is dissolved in its molten state and does not react with it, or a method of adding a specific diethylene glycol derivative as an anti-caking agent ( Japanese Patent Publication No. 58-23851) and a method of adding a specific diethylene glycol derivative and benzyl alcohol or a derivative thereof in combination as anti-caking agents (Japanese Patent Publication No. 58-11406).

[0004]

However, among the above-mentioned conventional methods for preventing caking, the method described in Japanese Patent Publication No. 42-1006 discloses that the anti-caking agent to be added is particularly p-type.
-P-DCB because of its lower vapor pressure than DCB
Has the disadvantage that it remains as a residue after sublimation of the polymer. That is, when such a residue is present, there is a problem in that the residue causes stains and dirt on clothes and the like due to the residue when the product is used. Further, in any of the above-described anti-caking methods, various anti-caking agents as described above are used in an amount of 100 to 10%.
By adding in the range of 0 ppm, the effect of improving the solidification of p-DCB to some extent is obtained as compared with the case where nothing is added, but in particular, bridging in the hopper during molding is reduced. There is a problem that the effect of the suppression is not sufficient and satisfactory results cannot be obtained. If the bridging in the hopper is not sufficiently suppressed, it is difficult to discharge the hopper from the hopper, which impairs the stable operability of the process in the molding operation. On the other hand, when a conventionally proposed anti-caking agent is used, anti-caking is achieved.However, when tableting is performed, tablet hardness decreases as the amount of addition increases, so that the tablet is crushed when pressed. It is easy and the tablet may be broken during the sales channel. Therefore, it is desirable that the strength is as high as possible from the viewpoint of handleability. That is, the amount of the additive is preferably as small as possible. Also, the grain boundaries of the generated p-DCB flakes grow by adding an anti-caking agent, are easily broken at the grain boundaries at the time of pulverization, have a sharp particle size distribution with little generation of fine particles, and have good flowability and high density. It is also desirable to be able to produce a pulverized product that cannot be filled. Further, when p-DCB is used as an insect repellent or a deodorant, a fragrance is also added at the same time. Therefore, it is desirable that the fragrance also functions for a long time together with p-DCB. It is expected that functions will be added.

The present invention has been made in view of the above-mentioned drawbacks of the prior art. It is an object of the present invention to use a specific anti-caking agent so that even a small amount of p-DC can be added.
B is sufficiently improved, bridging in the hopper during molding is less likely to occur, the strength of the molded article is harder to crack, and p-DCB is a high quality hardly generated residue after sublimation. An object of the present invention is to provide a p-DCB composition and a method for preventing p-DCB from caking.

[0006]

That is, the present invention relates to a process for preparing diethyl phthalate, dimethyl phthalate and 1-phenoxy-2 in para-dichlorobenzene as anti-caking agents.
-One or more selected from propanol in 10-2
It is a paradichlorobenzene composition having improved caking properties, characterized in that it is contained in the range of 000 ppm.

[0007] The present invention also relates to a method for preparing diethyl phthalate, dimethyl phthalate and 1-
One or two selected from phenoxy-2-propanol
A method for preventing the solidification of p-dichlorobenzene, characterized by adding at least a seed in the range of 10 to 2000 ppm.

[0008] Diethyl phthalate, dimethyl phthalate and 1-phenoxy-2-propanol used as anti-caking agents in the present invention may be used alone or in combination of two or more thereof.
The addition amount of these anti-caking agents to p-DCB is 10 to 2000 ppm in total in the flakes, preferably 30 to 2000 ppm.
1000 ppm. When the addition amount is less than 10 ppm, the effect of preventing caking is insufficient, and
When the value exceeds the above, not only is it uneconomical because no further anti-caking effect can be obtained, but also the anti-caking agent etc. oozes out at the molded product stage and oozes the ink on the molded product packaging paper to reduce the product value. There are problems such as remarkable damage and easy breakage of the molded product. Further, a particularly preferable range of the addition amount is 30 to 300 ppm in the case of dimethyl phthalate and diethyl phthalate, and 50 to 300 ppm in the case of 1-phenoxy-2-propanol. is there.

The method of adding the anti-caking agent to p-DCB is not particularly limited. For example, molten p-
Predetermined amounts of additives such as an anti-fixing agent and a fragrance are added to DCB, mixed, and flake-like crystals can be contained by various types of flakers such as a drum flaker and a belt flaker. If desired, p-D
The pulverized CB can be spray-coated with an anti-caking agent. When a drum flaker is used as the above-mentioned flaker, an anti-caking agent is added to the flaker in an amount of about 1.5 to 3 times, preferably about 2 times the above-mentioned addition amount, and the cooling conditions and rotation speed of the flaker are added. By controlling the crystallization rate by adjusting the amount of the solidification inhibitor, p-DCB can be contained in a desired quantitative range in the p-DCB. That is, in this continuous flake forming method, generally, about half of the anti-caking agent dissolved in the melt of p-DCB is taken into the flake or the surface, and the actually obtained anti-caking effect is taken into the flake. It is presumed to be due to the action of the anti-caking agent present.

The p-DCB is preferably of high purity, but is a by-product inevitably produced in the production process.
For example, monodichlorobenzene (MCB), orthodichlorobenzene (ODCB), metadichlorobenzene (m-
DCB), trichlorobenzene (TCB) and the like may partially coexist. However, the concentration of these chlorobenzenes is not more than 400 ppm (when two or more types of chlorobenzenes coexist, each is 200 ppm, in order not to hinder the action and effect of the anti-caking agent to be contained. Must not be exceeded).

[0011] The p-DCB composition having the above-mentioned composition is subjected to a pulverizing step, if necessary, and formed into a predetermined shape such as a tablet shape, a spherical shape, a donut shape or the like by a conventional method. It is said. In this molding, an additive such as a fragrance such as floral or musk or a fragrance may be added as necessary.

[0012]

According to the present invention, the use of the above-described anti-caking agent reduces the mass transfer mechanism due to the presence of the anti-caking agent in the p-DCB particles or on the surface thereof.
The solidification properties of the DCB are sufficiently improved, so that the solidification in the packaging container hardly occurs. In particular, bridging which has conventionally been easily generated in the molding machine hopper can be reliably prevented. The bridging suppression effect of the molding machine hopper according to the present invention satisfies the results of a dropping time of 10 seconds or less and a number of hits of 2 to 3 times or less in a hopper test performed in Examples described later. Moreover, the addition of the anti-caking agent generates an average grain boundary of 0.3 to 1 mm, and the p-DC
When the flaked product of B is pulverized, coarse particles having a preferable particle size can be obtained without being pulverized because the flakes are crushed at the grain boundaries. On the other hand, dimethylphthale
When adding potassium and diethyl phthalate, p-D
Even if the aging time during the process from the CB manufacturing process to the tableting process is reduced to 1/2 to 2/3 of the conventional value, stable operation can be performed, so that production efficiency can be improved. Merits are also exhibited. Further, by using the above anti-caking agent, almost no residue due to the additive after the sublimation of the p-DCB crystal is recognized, and there is a possibility that the residue causes stains and dirt on clothes and the like. No odor is generated, and the fragrance of the separately added fragrance is maintained for a long time.

[0013]

The present invention will be described below in more detail with reference to examples and comparative examples. Examples 1 to 12 and Comparative Examples 1 to 5 Melted p-DCB (purity: 99.96%) was mixed with additives (purity of 98% or more) of the type and amount shown in Table 1 (comparative). Example 1 was not added), and flakes (1 mm thickness × 1 cm length) of the p-DCB composition having the addition amounts shown in Table 1 were obtained using a drum flaker. The p-DCB compositions of Example 4 and Example 7 contained 200 p of o-DCB.
pm. Each of the obtained flakes is pulverized and sieved with a sieve having a mesh size of 2 mm.
The hopper test, the residue after sublimation, the particle size and the hardness were measured and tested. Table 1 shows the results.

[0014]

[Table 1]

* 1: Addition amount: expressed by the concentration of each additive contained in the flake. Its concentration was measured by gas chromatography. * 2: Consolidation force: 30 g of the pulverized product is placed in a cylindrical container that is cut into upper and lower portions with an inner diameter of 3.5 mmφ and can be divided, and 120
After a load of g was applied and left for 16 hours, when the upper cylinder was pulled at a constant speed by a spring balance with the lower cylinder fixed, the force (g) at which the upper cylinder began to move was expressed. The smaller the value of the caking force, the greater the caking preventing effect. * 3: Hopper test: 150 mmφ inlet opening, 110 mm height to the outlet, 18 mmφ inner diameter × 80 mm length, crushed product in a funnel-shaped hopper with an angle of 74 ° 20
After putting in 0 g and leaving it for 1 minute, a test was conducted in which the outlet was opened and the contents were dropped, and the time (second) required until all the contents dropped at that time was measured. If the bridge does not fall for 5 seconds due to bridging, the hopper is dropped by tapping lightly with a spar chill, and the number of hits is shown in the table. * 4: Residue after sublimation: 10 g of the pulverized product was placed in a blast oven at 35 ° C. to be sublimated, and the residue after 7 days was weighed and expressed in terms of concentration (ppm). * 5: Particle size: 100 g of the crushed product is sieved with a low tap, and the average particle size (mm) of the sieved crushed product (Dp
50) and a ratio (%) of 425 μm under were determined. * 6: Size of grain boundary: A micrograph of a flake is taken, the size of the grain boundary is measured, and the minimum and maximum values are indicated as “(minimum value) to (maximum value)”. * 7 Strength: Cracking strength (kg) of a tablet obtained by molding 4 g of a crushed product into a disk having a size of 22 mmφ and a thickness of 7 mm using a tableting machine was measured by a Kiya hardness meter. * 8: Aroma retention: 10 g of the ground product was mixed with 0.5% by weight of a floral flavor and mixed to coat the surface. The mixture was placed in a beaker and left in a 30 ° C air-blower.
The residue after 8 hours was measured and evaluated according to the following criteria. ：: Both p-DCB and fragrance of fragrance remain. Δ: p-DCB perfume remains, but no perfume scent remains. ×: Both p-DCB and fragrance are not present.

From the results shown in Table 1, in Examples 1 to 10, p-DCB was at least as good as the conventionally used anti-caking agent.
It can be seen that the solidification of the composition was definitely improved and bridging in the hopper was well suppressed. Further, in each of the examples, it was confirmed that the residue after the sublimation of p-DCB was as minute as that in the case of no additive (Comparative Example 1). No odor was generated by the additives. Furthermore, it can be seen that the p-DCB composition pulverized product of the examples has a very small number of fine particles due to a large grain boundary, and has an appropriate particle size. Such a property that does not become fine particles is p-
It is useful for the fluidity of the DCB composition in the hopper and the uniformity of the molded article. Furthermore, according to the present invention, there is an effect that the fragrance lasts longer than when no additive is added (Comparative Example 1).

[0017]

According to the p-DCB composition of the present invention, the addition of an anti-caking agent improves the solidification of the composition and suppresses the generation of fine particles. An excellent bridging suppression effect in the hopper at the time of forming into a compact is obtained. At the same time, it is possible to dramatically improve the molding workability, including shortening the aging time until the tableting step, and to achieve a constant density of the molded product. That is, by using the p-DCB composition of the present invention having the improved consolidation property,
Since the handling workability and the molding workability of the p-DCB maker and the tablet maker are good, it is possible to manufacture molded products such as insect repellents and deodorants extremely efficiently. In addition, since the molded article of the composition of the present invention employs the above-mentioned specific anti-caking agent, almost no residue remains after the sublimation of p-DCB, and the fragrance of p-DCB and the fragrance does not remain. There is an effect that the odor can be kept for a long time and a sufficient hardness can be ensured.

Claims (2)

(57) [Claims] 1. An anti-caking agent in p-dichlorobenzene, diethyl phthalate, dimethyl phthalate and 1
One or two selected from phenoxy-2-propanol
A paradichlorobenzene composition having improved caking properties, characterized in that it contains at least one species in the range of 10 to 2000 ppm. 2. Diethyl phthalate, dimethyl phthalate and 1-phenoxy-2 in para-dichlorobenzene.
-One or more selected from propanol in 10
A method for preventing solidification of p-dichlorobenzene, which is added in a range of 2000 ppm.