JPH05163178A - Caking prevention for p-dichlorobenzene - Google Patents

Abstract

PURPOSE:To accomplish the subject caking prevention leading to improving the fluidity in the forming process for p-dichlorobenzene and the hardness of its processed products by adding a specified amount of a (substituted) phenoxybenzyl alcohol to p-dichlorobenzene. CONSTITUTION:The objective caking prevention can be accomplished by adding (A) 0.005-0.5 (pref. 0.01-0.3)wt.%, based on the p-dichlorobenzene, of a (substituted) phenoxybenzyl alcohol of the formula (R is H or lower alkyl) (pref. m- or p-phenoxybenzyl alcohol) to (B) p-dichlorobenzene.

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, the present invention provides a novel compound in a method for preventing caking property by adding a certain compound to p-dichlorobenzene.

[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.

[0009] 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]

DISCLOSURE OF THE INVENTION The present invention is a new composition which can prevent the solidification of PDCB, improve the fluidity in the crushing / tabletting line in the molding process, and can sufficiently maintain the tablet hardness. To provide an additive.

[0012]

DISCLOSURE OF THE INVENTION The present inventors have made earnest studies on new additives based on the current state of the prior art for preventing the caking property of PDCB as described above. By the way, the physical properties on the additive side required as an additive for improving the physical properties of PDCB not only have the property of having the effect of preventing the solidification of PDCB, but also the insect repellent and deodorant of PDCB. Considering the use as an agent, it is desirable that the cloth does not show stains and that it has an appropriate vapor pressure from the viewpoint of sustaining the effect. In addition, toxicity is one of the conditions that require safety.

As a result of various studies on the anti-caking agent for PDCB from such a viewpoint, phenoxybenzyl alcohols were found as a new additive satisfying the above-mentioned conditions, and the present invention was completed. That is, the present invention is p-
The following general formula (1) is added to dichlorobenzene.

[0014]

[Chemical 2]

[In the formula, R represents a hydrogen atom or a lower alkyl group. ] The substituted or unsubstituted phenoxybenzyl alcohol represented by the following is added 0.005-0.5 weight% with respect to p-dichlorobenzene,
This is a method for preventing the solidification of p-dichlorobenzene.

The phenoxybenzyl alcohol of the general formula (1) of the present invention is a completely new compound as an anti-caking agent for PDCB, and is the first compound found by the present inventors. The PDCB added with the phenoxybenzyl alcohols has remarkably improved solidification property as compared with the unadded PDCB, and at the same time, the fluidity in the crushing / tabletting line in the molding process becomes extremely good. . In addition, the problem of stains on fabric does not occur, and PD for insect repellents
It is an excellent additive as an additive for improving the physical properties of CB.

The substituted or unsubstituted benzyl alcohols of the formula (1) used in the present invention include m-phenoxybenzyl alcohol, p-phenoxybenzyl alcohol, m- (4-methylphenoxy) benzyl alcohol, p- (4-Methylphenoxy) benzyl alcohol, m- (3-methylphenoxy) benzyl alcohol, p- (3-methylphenoxy) benzyl alcohol, m- (2-methylphenoxy) benzyl alcohol, p- (2-methylphenoxy) Examples thereof include benzyl alcohol.

Among these phenoxybenzyl alcohols, m-phenoxybenzyl alcohol and p-phenoxybenzyl alcohol are particularly preferable. These phenoxybenzyl alcohols are usually used alone, but it is also possible to use two or more kinds in combination.

In the present invention, if the amount of the phenoxybenzyl alcohol of the formula (1) used is too small, the effect is not sufficient to prevent the solidification of PDCB, and if it is too large, leaching from the PDCB product occurs. However, the amount used is 0.005 relative to PDCB.
˜0.5 wt%, preferably 0.01 to 0.3 wt%. The effect of the present invention is sufficiently exhibited in the use range.

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 which is 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.

[0021]

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.

Examples 1 to 4 and Comparative Example 1 PDCB flakes were prepared by adding m-phenoxybenzyl alcohol or p-phenoxybenzyl alcohol to molten PDCB while changing the addition amount thereof. Table 1 shows the results of the consolidation test and the crushing test for these.
Shown in. In addition, the results of the additive-free products are also shown as comparative examples.

[0026]

[Table 1]

Example 5 A flake product in which 0.1% by weight of m-phenoxybenzyl alcohol was added to PDCB was produced on an actual machine in the field, and its caking strength was measured and the tablet machine was used on an actual machine. A drum-shaped molded product was manufactured, and the flow conditions on the crushing / tabletting line at that time were compared with those of the additive-free product, and the hardness of the tablet was measured. The results are shown in Table 2.

[0028]

[Table 2]

[0029]

INDUSTRIAL APPLICABILITY According to the method of the present invention, by adding a trace amount of phenoxybenzyl alcohol to PDCB, PDCB
Not only is it possible to sufficiently prevent the caking property of the above, but also the fluidity in the molding process is remarkably improved, and therefore, it is an industrially extremely useful method for preventing the caking of PDCB.

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[Procedure amendment]

[Submission date] August 27, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

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[Claims]

[Chemical 1] [In the formula, R represents a hydrogen atom or a lower alkyl group. ]
A substituted or unsubstituted phenoxybenzyl alcohol represented by
A method for preventing solidification of p-dichlorobenzene, which comprises adding 0.5% by weight.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0013

[Correction method] Change

[Correction content]

As a result of various studies on the anti-caking agent for PDCB from such a viewpoint, phenoxybenzyl alcohols were found as a new additive satisfying the above-mentioned conditions, and the present invention was completed. That is, the present invention is p-
Dichlorobenzene has the following general formula (1)

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

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[0014]

[Chemical 2]

[Procedure amendment 4]

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[Correction target item name] 0017

[Correction method] Change

[Correction content]

The substituted or unsubstituted phenoxybenzyl alcohols of the general formula (1) used in the present invention include m-phenoxybenzyl alcohol, p-phenoxybenzyl alcohol and m- (4-methylphenoxy).
Benzyl alcohol, p- (4-methylphenoxy) benzyl alcohol, m- (3-methylphenoxy) benzyl alcohol, p- (3-methylphenoxy) benzyl alcohol, m- (2-methylphenoxy) benzyl alcohol, p- ( 2-methylphenoxy) benzyl alcohol and the like can be mentioned.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0019

[Correction method] Change

[Correction content]

In the present invention, if the amount of the phenoxybenzyl alcohol of the general formula (1) used is too small, the effect is not sufficient to prevent the solidification of PDCB, and if it is too large, the bleeding from the PDCB product occurs. It is not desirable because it occurs, so the amount used is 0.0 with respect to PDCB.
It is in the range of 05 to 0.5% by weight, preferably 0.01 to 0.3% by weight. The effect of the present invention is sufficiently exhibited in the use range.

Front Page Continuation (72) Inventor Yoshiro Nagatake, Mitsui Toatsu Kagaku Co., Ltd. 30 Asamu-cho, Omuta City, Fukuoka Prefecture (72) Toyohiro Tajiri Inoue 30 Asamu-cho, Omuta-shi, Fukuoka Prefecture Mitsui Toatsu Kagaku Co., Ltd.

Claims (3)

[Claims] 1. A p-dichlorobenzene having the following general formula (1): [In the formula, R represents a hydrogen atom or a lower alkyl group. ]
A substituted or unsubstituted phenoxybenzyl alcohol represented by
A method for preventing solidification of p-dichlorobenzene, which comprises adding 0.5% by weight. 2. The method according to claim 1, wherein the substituted or unsubstituted phenoxybenzyl alcohol of the formula (1) is m-phenoxybenzyl alcohol or p-phenoxybenzyl alcohol. 3. A process as claimed in claim 1, which comprises adding the substituted or unsubstituted phenoxybenzyl alcohol of the formula (1) to molten p-dichlorobenzene and subsequently forming a flaky product.