JP2788558B2 - Method for preventing caking of P-dichlorobenzene - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing the solidification of P-dichlorobenzene, which is widely used as an insect repellent, and for improving the physical properties such as fluidity. More specifically, the present invention provides a method for improving the caking property and flowability by adding a certain compound to P-dichlorobenzene.

[0002]

2. Description of the Related Art P-dichlorobenzene (hereinafter referred to as PDCB)
Abbreviated. ) Is generally formed into a tablet, a ball, or a bar and is widely used as an insect repellent or deodorant for clothing or the like. It is also a useful substance as a raw material for certain polymer compounds.

[0003] PDCB is usually separated and purified from a mixture of chlorobenzene, o-dichlorobenzene, p-dichlorobenzene and the like obtained by chlorinating benzene, and is further taken out in the form of flakes and then directly or granulated. It has been shipped to molding manufacturers.

Although the melting point of PDCB varies depending on the content of trace impurities, its melting point is as low as 53 ° C. even for a pure product, so that the PDCB product shipped in the form of flakes is very hard during storage or transportation. It has the property of being easily tied. Further, the fluidity and the like in the pulverizing and tableting processes by a molding manufacturer are poor, and the workability is extremely poor.

[0005] In order to solve such a problem of solidification of PDCB, various devices have been devised. As a typical method, a method of improving by adding a certain additive is known. For example, a method in which a surfactant is added as disclosed in JP-B-42-10942 and JP-B-42-1006, and a volatile agent as disclosed in JP-A-58-134037 and JP-B-1-34207. This is a method of adding silicon oil. However, these methods are partly due to the very low or negligible vapor pressure of the additives themselves, which can leave the PDCB after sublimation, which can cause problems with fabric staining. It could be. On the other hand, the effect may not be enough.

Japanese Patent Publication No. 57-4615 discloses benzyl alcohol, Japanese Patent Publication No. 58-23851 discloses a diethylene glycol derivative, and Japanese Patent Publication No. 58-11.
No. 406 discloses a method in which both benzyl alcohol and a diethylene glycol derivative are added at a certain ratio to improve the caking property.

[0007] Even in these methods, the method of adding only benzyl alcohol cannot be said to be sufficient for improving the caking property, and the caking property is remarkably improved by using only the diethylene glycol derivative, but Japanese Patent Publication No. 58-11406. As described in Japanese Patent Laid-Open Publication No. H10-163, the hardness of a molded product such as a molded tablet is brittle, and therefore, there is a problem that it is difficult to use it alone as an additive.

A diethylene glycol derivative and benzyl alcohol must be used in order to maintain the hardness of the molded product and to improve the caking property. Since two types of additives are used, it is not necessarily preferable. There is no side.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to improve the solidification properties of PDCB and the fluidity during molding without using a plurality of additives, and to maintain the hardness of molded articles. It is to provide a new additive to obtain.

[0010]

Means for Solving the Problems Based on the prior art relating to the improvement of the solidification properties of PDCB as described above, the present inventors have proposed to prevent the solidification of PDCB and to reduce the pulverizing and tableting process in a molding manufacturer. In order to improve the fluidity at the time, new additives were studied diligently. As a result, the addition of certain ethylene glycol derivatives to PDCB not only significantly improves the solidification and fluidity of PDCB but also maintains the hardness of molded products such as tablets. And completed the present invention.

In the method of the present invention, P-dichlorobenzene is converted to the following formula (1)

[0012]

Embedded image R ¹ O—CH ₂ CH ₂ —OR ² (1)

Wherein R ¹ and R ² are each independently
A hydrogen atom, an aliphatic alkyl group having 1 to 10 carbon atoms or an aliphatic alkylcarbonyl group having 1 to 10 carbon atoms is shown. ]
A method for preventing solidification of P-dichlorobenzene, characterized by adding an ethylene glycol derivative represented by the following formula:

The PDCB obtained by the method of the present invention not only has its consolidation improved remarkably, but also has improved fluidity during molding, thereby significantly improving workability.
Furthermore, the ethylene glycol derivative has a low or almost no odor, so that the quality of the PDCB product is not impaired. Further, the ethylene glycol derivative does not remain after sublimation of the PDCB and does not show any stain on the fabric. Additive.

Specific examples of the ethylene glycol derivative of the formula (1) used in the present invention include ethylene glycol, ethylene glycol monomethyl, monoethyl, and the like.
Monoalkyl ethers such as monopropyl, monobutyl, monopentyl, monohexyl, monoheptyl, monooctyl, monononyl or monodecyl ether, dimethyl, diethyl, dipropyl, dibutyl, dipentyl, dihexyl, diheptyl, dioctyl, dinonyl or didecyl of ethylene glycol Dialkyl ethers such as ethers, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monopentyl ether acetate, ethylene glycol monohexyl ether acetate, ethylene glycol monoheptyl ether acetate, ethylene glycol mono Octyl ether acetate, ethylene Monoalkyl ether alkyl such as recall monononyl ether acetate, ethylene glycol monodecyl ether acetate, ethylene glycol monomethyl ether propionate, ethylene glycol monoethyl ether propionate, ethylene glycol monopropyl ether propionate or ethylene glycol monobutyl ether acetate Carboxylates and ethylene glycol dialkyl carboxylates such as diacetate, dipropionate, dibutyrate, diheptanoate, dihexanoate, dipentanoate, dioctanoate, dinonanoate, and didecanoate of ethylene glycol can be given.

The compounds mentioned here are merely examples and not all. Among these compounds, di-lower alkyl ethers of ethylene glycol, ethylene glycol mono-lower alkyl ether acetate or ethylene glycol diacetate are preferred additives. More preferred additives include ethylene glycol dibutyl ether, ethylene glycol mono n-butyl ether acetate or ethylene glycol diacetate.

The ethylene glycol derivative of the formula (1) used in the present invention is usually used alone, but it is also possible to use two or more compounds in combination. It can also be used in combination with known additives.

If the amount of the ethylene glycol derivative of the formula (1) in the present invention is too small, the anti-caking effect is reduced by half, and if it is too large, it may ooze out of the PDCB product, which is not preferable. Therefore, the amount used is PDCB
0.005 to 0.5% by weight, preferably 0.0
It is in the range of 1 to 0.3% by weight.

By using in this range, not only the physical properties such as the solidification properties of PDCB are remarkably improved, but also the molded product such as a tablet is not brittle and its hardness is sufficiently maintained. Further, no problem such as stain on the fabric is induced at all.

As a method of treating PDCB with the additive in the present invention, for example, a predetermined amount of the compound is added to and dissolved in molten PDCB before taking out a flake-like product, and then the flake-like crystal is used as a flake-like crystal. P may be crystallized or contain no additives
The product of DCB may be sprayed with a predetermined amount of the compound.
Further, when a product of PDCB is taken out by a method such as a recrystallization method, a method of dissolving the silane compound together in a recrystallization solvent, followed by cooling / precipitation may be adopted.

[0021]

The present invention will be described in more detail with reference to the following examples. In the examples, various tests were performed as follows.

1. Melting PDCB at 60 ° C, dissolving a predetermined amount of additives therein, then slowly pour into a stainless steel vat cooled to 10 ° C in advance, crystallize and peel off The flakes were adjusted.

2. Into a cylindrical container having an inner diameter of 5 cm, which has been cut into upper and lower portions, each of the pulverized PDCB products whose particle size has been adjusted to 12 to 20 mesh by pulverizing and sieving with an automatic mortar is put into the container, and 1 kg of this is placed from above on the PDCB pulverized product. After leaving the load for 15 hours, the load was removed, the lower part of the cylinder was fixed, the upper cylinder was pulled in the horizontal direction, and the force when the upper cylinder started to move was measured.

3. 100 g of a flake product of PDCB was placed in an automatic mortar for crushing test, crushed for 5 minutes, and then the mortar was tilted to discharge the crushed product. At this time, the degree of discharge was indicated as follows. ：: The entire amount is easily discharged simply by tilting the mortar. ：: About 80% is easily discharged by tilting the mortar, and about 20% or less remains in the mortar, but the entire amount is discharged by tapping the mortar lightly. △: 50 just by tilting the mortar
% Emissions. X: Even if the mortar is tilted, the discharge is 20% or less, and the mortar adheres remarkably to the mortar.

4. Tablet hardness Various PDCBs are pulverized and molded with a molding machine (tableting machine) to have a diameter of 20 mm and a center thickness of about 9 m.
m is shaped into a drum-shaped tablet, the molded product is placed horizontally on a metal plate, and 13 g of metal balls are dropped from various heights naturally (through a resin cylinder) to determine whether the tablet is cracked. Examined. The judgment was made as follows. ：: The place where the metal sphere fell is only slightly dented and does not crack. Δ: Cracks are formed on the upper surface of the tablet. The crack did not reach the back. X: Cracks are formed on the back surface. XX: The tablet is completely cracked. Further, the hardness of the tablet was measured by a method of measuring the actual hardness using a hardness meter separately.

Examples 1 to 3 and Comparative Example 1 Table 1 shows the results of various tests such as the compaction force and the pulverization test of PDCB flakes produced by adding 0.1% of various ethylene glycol derivatives to PDCB. Shown in As a comparative example, that of an additive-free product is also shown.

[0027]

[Table 1]

Examples 4 to 9 and Comparative Example 2 Table 2 shows the results of various tests on PDCB flake products in which the added amount of the ethylene glycol derivative was changed. As a comparative example, Japanese Patent Publication No. Sho 58
The test results of PDCB to which diethylene glycol monobutyl ether acetate described in No. 23851 is added are also shown.

[0029]

[Table 2]

[0030]

The method of the present invention for preventing the solidification of PDCB by adding a small amount of a certain ethylene glycol derivative to PDCB is not only extremely effective in preventing the solidification of PDCB, but is also effective for molding manufacturers. The fluidity in the pulverizing / tableting process of the pulp is also remarkably improved. Further, the hardness of a molded article such as a tablet is sufficiently maintained, and therefore, the method of the present invention is very valuable industrially.

────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toyohiro Tajiri 30 Asamuta-cho, Omuta-shi, Fukuoka Examiner, Mitsui Toatsu Chemicals Co., Ltd. Examiner Osamu Sato (56) References JP-A-54-154719 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) C07C 25/08, 17/42

Claims (3)

(57) [Claims] 1. A compound represented by the following general formula (1) (formula 1): R ¹ O—CH ₂ CH ₂ —OR ² (1) wherein R ^{1 is}
And R ² are each independently a hydrogen atom, a carbon number of 1 to 1;
0 represents an aliphatic alkyl group or an aliphatic alkylcarbonyl group having 1 to 10 carbon atoms. ] A method for preventing the solidification of P-dichlorobenzene, characterized by adding an ethylene glycol derivative represented by the following formula: 2. The method according to claim 1, wherein the ethylene glycol derivative of the formula (1) is ethylene glycol di-lower alkyl ether, ethylene glycol mono-lower alkyl ether acetate or ethylene glycol diacetate. 3. The use amount of the ethylene glycol derivative of the formula (1) is 0.005 to 0.005 to P-dichlorobenzene.
2. The method according to claim 1, wherein the amount is 0.5% by weight.