JPH05155793A - Method for preventing solidification of p-dichlorobenzene and improving its fluidity - Google Patents

Abstract

PURPOSE:To remarkably improve solidification of the subject compound and its flowability in molding process and simultaneously obtain a molded product having excellent hardness by adding a specific glycol derivative and trichlorobenzene to p-dichlorobenzene at a specified ratio. CONSTITUTION:(A) A glycol derivative (preferably triethyelene glycol, ethylene glycol dibutyl ether, etc.) of the formula [R<1> and R<2> are H, 1-10C aliphatic alkyl, etc.; (n) is 0-2] and (B) trichlorobenzene in a ratio of A/B of 1/10 to 10/1 are added to p-dichlorobenzene(PDCB) so as to provide 0.01-0.5wt.% total amount based on PDCB. As the component (B), e.g. 1,2,4-trichlorobenzene, etc., is used. The addition is carried out by adding the additive to PDCB kept in melted state to dissolve PDCB and crystallizing PDCB in flake state.

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 property of p-dichlorobenzene, which is widely used as an insect repellent, and for improving the physical properties such as fluidity. More specifically, it provides a new combination of additives in the process of adding certain additives to p-dichlorobenzene to improve its physical properties.

[0002]

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

As a method for producing PDCB, it is separated and purified from a mixture of chlorobenzene, o-dichlorobenzene, p-dichlorobenzene and the like obtained by chlorinating benzene, and then taken out in the form of flakes. , Or granulated and shipped to a molding manufacturer.

By the way, PDCB has a melting point as low as 53 ° C., which varies depending on the content of a trace amount of impurities, and since it has a sublimation property, it has a large molecular diffusion on the crystal surface and is basically a solidifying compound. Is. In particular, PDCB products shipped in the form of flakes have a property that they are very easily solidified during storage or transportation. Although the size of the caking property varies depending on the size of the flakes, it is generally considered that the larger the flake is, the more likely the caking property is because the contact area between the flakes increases.

The solidification problem of PDCB is not limited to the problem during storage and transportation, and it basically causes deterioration in the crushing process in the tableting maker and the flow in the tableting line, thus improving workability. It will lead to a marked deterioration.

[0006] In order to solve such a PDCB consolidation problem, various measures have been conventionally made. Of course, it is possible to make the contact area between the particles as small as possible to weaken the caking property, but generally, most of the methods are to add some kind of additive to improve.

For example, as disclosed in Japanese Patent Publication No. 42-10942 and Japanese Patent Publication No. 42-1006, a method of adding a surfactant is disclosed in JP-A-58-134037 and JP-B-1-34207. Methods are known for adding volatile silicone oil as found. However, one of these methods is that the additive itself has a very low or almost no vapor pressure, so that after PDCB sublimates, the additive is liable to remain behind, which causes stain problems on the fabric. May be induced. For one thing, the effect is actually not enough.

Further, JP-B-57-4615 discloses benzyl alcohol, JP-B-58-23851 discloses a diethylene glycol derivative, and JP-B-58-58.
Japanese Patent Publication No. -11406 discloses a method of adding both benzyl alcohol and a diethylene glycol derivative in a certain ratio to improve the caking property.

Even with these methods, the method of adding only benzyl alcohol cannot be said to be sufficient to improve the caking property, and the caking property is improved only with the diethylene glycol derivative, but JP-B-58-11406. As described in (1), the hardness of a molded product such as a molded tablet is fragile, and therefore it is difficult to use it alone as an additive.

In order to maintain the hardness of the molded product and improve the caking property, it is necessary to use a diethylene glycol derivative and benzyl alcohol in combination as disclosed in Japanese Patent Publication No. 58-11406. In addition to the above-mentioned methods, a technique of adding silica or alumina to prevent caking properties, a method of adding a cyclic organic amide, and the like have been proposed.

[0011]

The present invention can prevent the solidification property of PDCB, improve the fluidity in the crushing / tabletting line in the molding process, and can sufficiently maintain the hardness of the tablet. It is to provide a new additive.

[0012]

SUMMARY OF THE INVENTION In view of the current state of the prior art for preventing the solidification of PDCB as described above, the inventors of the present invention did not remain after PDCB sublimates and stain the fabric. A new additive that does not give it, prevents the solidification of PDCB, has good fluidity in the crushing / tabletting line in the molding process, and can sufficiently maintain the hardness of molded products such as tablets Diligently studied.

As a result, (1) certain triethylene glycol derivatives, (2) certain ethylene glycol derivatives, and (3) tetraalkoxysilanes were found as new additives already suited for this purpose. Has proposed a method of using the additive of the above for preventing the caking property of PDCB (Japanese Patent Application No. 3-158048, 3-1614).
25, 3-161421).

The Applicant has further studied variously about the method for achieving the above-mentioned object, and as a result, obtained the extremely interesting knowledge as follows. That is, 1, 2,
P produced by adding 0.1% of 4-trichlorobenzene
As shown in Table 1, the DCB flake product has a higher cohesive strength than that of the PDCB flake product to which the trichlorobenzene is not added, and the hardness when formed into tablets is higher than that of the trichlorobenzene. PDC obtained by adding triethylene glycol diacetate in a certain ratio
It has been found that the flaking product of B has a significantly lower setting force, the flow in the molding step during tableting is extremely good, and the hardness of the tablet is higher than that of the additive-free product. Such a phenomenon has not been known so far. The present invention has been completed based on this finding.

That is, according to the present invention, p-dichlorobenzene has the following general formula (1):

[0016]

Embedded image R ¹ O—CH ₂ CH ₂ (OCH ₂ CH ₂ ) _n —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, n
Represents an integer of 0 to 2. ] The ratio of glycol derivative and trichlorobenzene represented by
(Weight ratio), and 0.01 to 0.5 wt% is added to p-dichlorobenzene in total amount, p
-A method for preventing solidification of dichlorobenzene and improving fluidity.

In the present invention, the glycol derivative of the general formula (1) and trichlorobenzene are added as a measure to prevent the solidification of PDCB. Conventionally, a method for preventing the solidification of PDCB by using trichlorobenzene together is known. Yes, it is a new method.

The glycol derivative of the general formula (1) used in the present invention is specifically ethylene glycol,
Diethylene glycol, triethylene glycol, ethylene glycol monoalkyl ethers having 1 to 10 carbon atoms, diethylene glycol monoalkyl ethers having 1 to 10 carbon atoms, and triethylene glycol having 1 carbon atoms
-10 monoalkyl ethers, ethylene glycol C 1-10 dialkyl ethers, diethylene glycol C 1-10 dialkyl ethers,
Diethylene ethers having 1 to 10 carbon atoms of triethylene glycol, ethylene glycol represented by ethylene glycol mono- or diacetate, and 1 to 10 carbon atoms
Of mono- or diesters with aliphatic carboxylic acids, mono- or diesters of diethylene glycol represented by diethylene glycol mono- or diacetate and aliphatic carboxylic acids having 1 to 10 carbon atoms, triethylene glycol mono- or di-esters. Mono- or diesters of triethylene glycol represented by acetate with aliphatic carboxylic acid having 1 to 10 carbon atoms, monoalkyl ether having 1 to 10 carbon atoms and carbon number of ethylene glycol such as ethylene glycol monobutyl ether acetate 1-10 esters with aliphatic carboxylic acids, esters of ethylene glycol monoalkyl ethers with 1-10 carbon atoms and aliphatic carboxylic acids with 1-10 carbon atoms such as diethylene glycol monobutyl ether acetate, triethylene It can be mentioned esters of recall monoalkyl ethers with aliphatic carboxylic acids having 1 to 10 carbon atoms having 1 to 10 carbon atoms.

Among these compounds of formula (1), more preferable compounds include triethylene glycol, ethylene glycol dibutyl ether, ethylene glycol monobutyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monobutyl ether acetate, ethylene glycol dibutyl ether. Examples thereof include acetate, diethylene glycol diacetate, triethylene glycol diacetate and the like.

The method of the present invention uses the above glycol derivative in combination with trichlorobenzene. As trichlorobenzene, 1,2,4-trichlorobenzene,
1,2,3-trichlorobenzene and 1,3,5-trichlorobenzene can be mentioned.

The glycol derivative of the above formula (1) and trichlorobenzene are usually used as single compounds in combination, but two or more kinds of compounds are used in combination. It is also possible.

In the present invention, the glycol derivative of the formula (1) and trichlorobenzene are used in a ratio of 1: 1.
0-10: 1 (weight ratio), preferably 3: 10-10:
3 (weight ratio). Further, if the total amount is too small, the effect is lowered, and if the total amount is too large, the leaching of the additive from the product may occur, which is not preferable. Therefore, the amount of the additive used is 0.005 relative to PDCB. ~ 0.5% by weight,
It is preferably in the range of 0.01 to 0.3% by weight. By using the additive under such conditions, PD
The solidification property of CB is not only sufficiently prevented, but also the hardness of a molded product such as a tablet is sufficiently maintained.

As a method for treating PDCB with the additive in the present invention, for example, a predetermined amount of the additive is added to and dissolved in PDCB in a molten state before the flaky product is taken out, and then flaked with a flaker or the like. PDCB may be crystallized as crystals, or a method of spraying a predetermined amount of the additive to a product of PDCB containing no additive may be used. Alternatively, when the PDCB product is taken out by the recrystallization method, it is also possible to adopt a method of dissolving the additive together in a recrystallization solvent and cooling / precipitating.

[0025]

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

1. Preparation of flakes (in the case of a small amount) PDCB was melted at 60 ° C., a predetermined amount of additive was dissolved therein, and then gradually poured into a stainless steel vat that had been cooled to 10 ° C. to crystallize. After that, it was peeled off to prepare a flake product.

2. Measurement of solidification force A cylindrical container with an inner diameter of 5 cm, which was cut into upper and lower parts, was charged with each pulverized product of PDCB whose grain size was adjusted to 12 to 20 mesh by pulverizing and sieving with an automatic mortar. After applying a load of 1 kg from the upper part and leaving it 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. Pulverization test 100 g of flakes of PDCB were put in an automatic mortar and pulverized for 5 minutes, then the mortar was tilted and the pulverized product was discharged. that time,
The degree of discharge was indicated as follows. ⊚: The entire amount is easily discharged simply by tilting the mortar. ○: The degree of discharge by tilting the mortar is about 80%, and the remaining 2
About 0% remains in the mortar, but the whole amount is discharged by tapping the mortar. B: About 50% of the discharge is obtained only by tilting the mortar. X: Even if the mortar is tilted, the discharge is 20% or less, and the adhesion to the mortar is remarkable.

4. Tablet hardness After crushing various PDCBs, use a molding machine (tabletting machine) to obtain a diameter of 20.
mm into a drum-shaped tablet with a central thickness of about 9 mm,
The hardness of the molded product was measured using a hardness meter. The numerical value was obtained by averaging 10 balls, and the display in the table was expressed as a numerical value as a ratio represented by the following formula based on the hardness of the additive-free product.

[0030]

[Equation 1]

Examples 1 to 7, Comparative Examples 1 to 2: Various glycol derivatives and trichlorobenzene 1:
Add 1 wt.% Of PDCB to PDCB and add PD
A CB flake product was prepared. Table 1 shows the caking strength of these and the results of the crushing test. In addition, additive-free products and 1,2,4-trichlorobenzene were added to PDCB.
With respect to the flake product prepared by adding 0.1% by weight, the caking force was measured and a crushing test was performed.

[0032]

[Table 1]

Examples 8 to 12 Triethylene glycol diacetate and 1,2,4-trichlorobenzene were used in combination, and flakes were produced by changing the ratio of the amounts of both used and the amount added to PDCB on an actual machine in the field. The hardness of each tablet was measured, the crushing test was performed, and a tablet-shaped tablet-shaped tablet was manufactured to measure the tablet hardness. The results are shown in Table 2.

[0034]

[Table 2]

[0035]

EFFECTS OF THE INVENTION According to the method of the present invention, the solidification property of PDCB is not only prevented by simply adding a very small amount of an industrially inexpensive glycol derivative and trichlorobenzene to PDCB, but also in the molding step. The fluidity is remarkably improved, and at the same time, the hardness of the molded product is improved. Therefore,
It is an industrially extremely valuable method of preventing PDCB from solidifying.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshiro Nagatake 30 Asamu-cho, Omuta-shi, Fukuoka Within Mitsui Toatsu Chemical Co., Ltd. Within

Claims (2)

[Claims] 1. A p-dichlorobenzene having the following general formula (1): R ¹ O—CH ₂ CH ₂ (OCH ₂ CH ₂ ) _n —OR ² (1) [in the formula, R ¹ and R ² Are each independently a hydrogen atom, an aliphatic alkyl group having 1 to 10 carbon atoms or 1 to 10 carbon atoms.
Is an aliphatic alkylcarbonyl group, and n is an integer of 0 to 2. ] The glycol derivative and trichlorobenzene represented by the ratio of both are 1:10 to 10: 1 (weight ratio),
And the total amount is 0.01 to p-dichlorobenzene.
A method for preventing caking of p-dichlorobenzene and improving fluidity, which comprises adding 0.5% by weight. 2. Trichlorobenzene is 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene or 1,3,5-trichlorobenzene, or these 2
The method of claim 1 which is a mixture of more than one species.