JPS60105639A - Separation and recovery of condensed brominated acenaphthylene - Google Patents

Abstract

PURPOSE:To recover the titled condensation product obtained by the bromination, condensation and dehydrobromination of acenaphthene, by dissolving the condensation product is a good solvent, adding the solution to a poor solvent having high boiling point, distilling out the good solvent, and separating the objective condensation product from the resultant slurry in the form of powder. CONSTITUTION:The brominated acenaphthylene condensate obtained by the bromination, condensation dehydrobromination of acenaphthene is separated and recovered in the form of powder by the following process. The brominated acenaphthylene condensate is dissolved in a good solvent (preferably a halogenated hydrocarbon or an aromatic hydrocarbon), the solution is added to a poor solvent (preferably a 5-9C saturated aliphatic hydrocarbon) having higher boiling point than the good solvent to effect the reprecipitation of the condensate, the resultant slurry of the condensate is distilled to remove the good solvent, and the residual slurry is filtered to separate and recover the condensate in the form of powder. The filtrate is recycled as the poor solvent. EFFECT:Flame retardant and radiation-resistant agent for various resins.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for separating and recovering powder from a solution obtained in a manufacturing process.

Brominated acenaphthylene condensate (hereinafter abbreviated as Con-BAON) is a compound with excellent flame retardancy and radiation resistance, and has the property of making the resin flame retardant and radiation resistant when blended with various resins. . In addition, since it has a double bond in its molecule, it can be grafted onto resins by subjecting it to free radical generation treatment, and since it is a condensate, it has excellent compatibility with resins, so it can last for a long time. It is attracting attention as a compound that can maintain stable flame retardancy and radiation resistance. (Unexamined Japanese Patent Publication No. 56-122862) Therefore,
Con-BAON can be used in various resin compositions and insulating materials for electric wires and cables used in nuclear reactors, breeder reactors, ionizing radiation generators, etc. that are required to have both flame retardancy and radiation resistance. It is expected.

The purpose of the present invention is to provide C! on-BAC! The present invention provides an industrial method capable of separating and recovering Can-BAON as a powder from a solution containing N. This invention is 5
Con-BAON means that at least one bromine is added to the aromatic ring.
Formally, brominated acenaphthene causes a Friedel-Krach reaction to condense, forming a multimer with a degree of condensation of 2 or more, followed by a dehydrobromation reaction to form Con-BAON. say something

That is, it is a condensate consisting of units represented by the general formula (D or (It) (in the formula, n and n' represent integers of 1 to 5), and the bonding mode is the benzylic carbon of acenaphthylene. This is an intermolecular bond between and the aryl carbon of acenaphthylene. Examples of the bonding point are as follows, but there are also 1 (or 2).

37.1 (or 2), 4'-, 1 (or 2).

Possible bonds include 7'+, 1 (or 2), and B/-. Those with a degree of condensation of 3 or more have the number of constituent units increased by any of these bonds.

The condensate as used in the present invention refers to a condensation product having a degree of condensation of 10 or less and having excellent compatibility with resin.

Con-DAC! N is generally used for bromination of acenaphthene,
Produced by condensation and dehydrobromation reactions.

That is, acenaphthene is brominated and condensed by adding bromine in the presence of a Lewis acid catalyst in a halogenated hydrocarbon solvent, and the resulting halogenated acenaphthene condensate is dehydrobrominated with a base such as caustic potash-methanol. Manufactured by reaction. The dehydrobromination reaction is carried out in a base-inert solvent such as caustic potash-methanol, ie a halogenated hydrocarbon or aromatic hydrocarbon solvent. Therefore, 0o
n-BACN is obtained as a solution of halogenated hydrocarbon or aromatic hydrocarbon, which is a good solvent.

These (!on-BAON solution to con-BAON
Con-BA
A method is known in which a cN solution is added to a solvent in which Con-BAON has a low solubility, that is, a poor solvent to cause reprecipitation.

For example, a method of reprecipitation in acetone ('LMori
ta divination 5 and M, Hagiwara, J Appl, Sci
, 275529 (1982)) and the method of reprecipitation in an aliphatic-hydric alcohol having 3 to 5 carbon atoms, which has already been proposed by the present inventors.

In the former case, the C0n-BAC! obtained in the reaction. Since the N solution is concentrated in advance and then added to cold acetone (θ~-10°C) for reprecipitation, complicated operations are required, and Con-BAC! It had the disadvantage of a low recovery rate of N. In the latter case, although the recovery rate of Con-BACN is high, it has been found that the good solvent and the poor solvent form an azeotropic mixture, making it difficult to separate and recover the solvent, which poses a problem when carried out industrially.

Therefore, the present inventors found that by performing reprecipitation in a saturated aliphatic hydrocarbon having 5 to 9 carbon atoms, reprecipitation can be performed with a simple operation, and since liquid F does not azeotrope, the solvent can be separated and recovered by distillation. We discovered that this was possible and filed a patent application.

However, the Con-BAC! The recovery rate of H is still slightly low at around 80 cm, and after re-precipitation con-BA
0on- contained dissolved in the p liquid from which CN was separated.
Since the treatment of BA(!N) also poses a problem, this method has not yet been satisfactory as an industrial separation and recovery method.

Therefore, the present inventors conducted further intensive studies on the industrial separation and recovery method for con-BAON, and as a result, we used a good solvent solution of Con-BACN obtained in the manufacturing process to After reprecipitating 0on-BACjN as a powder by adding it to a poor solvent of saturated aliphatic hydrocarbons of By filtering Qon-BACjN to separate it as a powder, circulating the p liquid as a poor solvent for the next reprecipitation process, and continuing this operation repeatedly, con-BAON can be obtained with a high recovery rate and in a good manner. The present invention was achieved by discovering that it can be obtained as a powder.

That is, the present invention provides a method for separating and recovering Con-BAON produced by bromination, condensation, and dehydrobromination reactions of acenaphthene as a powder. A step of adding a solution of Con-BACjN dissolved in a good solvent consisting of hydrogen into a poor solvent consisting of a saturated aliphatic hydrocarbon having 5 to 9 carbon atoms and having a boiling point higher than that of the good solvent to reprecipitate Con-BAON. ;(B) Can-obtained in step (A)
Step of distilling the slurry of BA(!N to remove a good solvent: and (C0n-BACN obtained in step (B))
Provided is a method for separating and recovering Con-BAON, which comprises the steps of filtering the slurry, separating and recovering Con-BACN as a powder, and circulating the r liquid as a poor solvent in step (A). It is.

Next, each step of the method of the present invention will be specifically explained.

(A) Step C! produced by bromination, condensation and dehydrobromination reaction of acenaphthene! A good solvent solution of on-BAON is added to a poor solvent whose boiling point is higher than that of the good solvent, and Con-BAON is reprecipitated.

The good solvent used in the present invention is selected from halogenated hydrocarbons or aromatic hydrocarbons that dissolve Con-BACjN and are inert to the dehydrobromation reaction. Examples include carbon tetrachloride, chloroform, methylene chloride, ethylene dichloride, ethylene dipromide, chlorobenzene, benzene, toluene, xylene, and ethylbenzene.

The concentration of Con-BACjN is not particularly limited, but it is preferably kept at a relatively high concentration in order to reduce the burden of distillation in the next step. Usually about 10 to 70% by weight is used.

The poor solvent used in the method of the present invention is a saturated aliphatic hydrocarbon having 5 to 9 carbon atoms, and may be linear, monobranched, or cyclic, such as pentane, hexane, and cyclohexane. , methylcyclopentane, 2-methylpentane.

3-methylpentane, 2,2-dimethylbutane, 2゜6
-dimethylbutane, heptane, methylcyclohexane,
2-Methylhexane, 3-methylhexane, 2,6-dimethylpentane, 2,4-dimethylpentane, octane, 2.25-)dimethylpentane.

2,2.4-) Methylpentane, ethylcyclohexane, nonane, etc. can be mentioned. Pentane, hexane, cyclohexane, heptane, octane, each having 5 to 8 carbon atoms, from the viewpoint of industrial availability and economical aspects; 2.
2,4-trimethylpentane is practically preferred. These may be a mixture of two or more types.

The amount used for reprecipitation of these saturated aliphatic hydrocarbons, Con-BACN, is the amount of C! 1 to 20 times the volume of the on-BACN solution, preferably 2 to 10 times the volume.
Use double the amount. If the amount of saturated hydrocarbon is 0 on-BAON solution under the equidistant plate, the amount of precipitated BACN (!on-BACN) is small, and if the amount is 20 times or more, there is no problem with reprecipitation itself, but it is not economical.The present invention The aliphatic hydrocarbon having 5 to 9 carbon atoms is excellent as a reprecipitating solvent for obtaining a fine powder of (!0n-BACH, and more advantageously, it does not azeotrope with either halogenated hydrocarbons or aromatic hydrocarbons. Therefore, they can be easily separated by distillation and can be reused.

In the method of the present invention, it is necessary that the boiling point of the poor solvent is higher than the boiling point of the good solvent. In the next step (B), the good solvent is separated by distillation, so the boiling point of the poor solvent is usually 55% higher than the boiling point of the good solvent.
It is desired that the temperature be higher than 10°C, preferably 10°C or higher. Therefore, combinations of good and poor solvents with such boiling points are selected, typically benzene (b, p, 8 (
L 1℃)-hebutane (956℃), carbon tetrachloride (7&
8℃) -2,2,4-trimethylpentane (99.2℃)
), ethylene dichloride (855℃)-octane (12
5,7℃). Particularly preferably carbon tetrachloride-2,2,
It is a combination of 4-17 methylpentane. Con-
BAC! The reprecipitation of N is performed by adding a good solvent solution of Coon-BAON into the aliphatic hydrocarbon, and it is preferable that stirring is performed at that time. The temperature during reprecipitation is not particularly limited as long as it is below the melting point of Con-BACN, but usually room temperature is sufficient. When a Con-BAON solution is added to these poor solvents, due to the excellent compatibility 9 dispersibility between the solvents, Con-BAON powder precipitates in a very short time and remains in the Coon-BACH. Since a good solvent is also extracted efficiently, Coon-BAON can be efficiently precipitated.

Therefore, after reprecipitation, a slurry containing fine powder of Con-BAON can be obtained.

(B) Step The Con-BACN slurry obtained in the above step (A) is distilled to remove the good solvent from the slurry.

Distillation can be carried out under normal pressure or reduced pressure.

The distillation temperature is such that Con-BA'ON does not melt and solidify and is sluic I.
The temperature that maintains the J-state is selected, and specifically, the pot temperature needs to be below the melting point of 0on-BAON, that is, below 120°C, preferably below 100°C.

According to the results carried out by the present inventors, (C obtained in the Shu process)
When the on-BAON slurry is distributed door to door and the p-liquid is distilled to recover a good solvent, the Con-
BAON precipitates in the form of a resin and adheres to and solidifies on the inner wall of the distillation pot and stirring blades, making stirring difficult, handling operations difficult, and solvent recovery operations difficult.

On the other hand, in the method of the present invention, since the Con-BACN slurry is distilled, the Con-BAON dissolved in the solution is successfully precipitated on the powder surface of the slurry during distillation, and the above-mentioned resinous caking etc. are not observed at all. Therefore, a good slurry of Can-BAON powder can be obtained, and a good solvent can be easily recovered. The good solvent is removed from the 0on-BACN slurry by distillation, and it is desirable that the removal rate be high, and specifically, it is preferable to remove 50% or more. If the removal rate of the good solvent is as low as 50% or less, (1!on-B
ACH recovery rate is low.

In addition, the F solution obtained after distillation is circulated and reused for the next reprecipitation, but in order to keep the composition ratio of good solvent and poor solvent and the concentration of Con-BACN constant during reprecipitation, p
This method has the disadvantage that it is necessary to draw out a portion of the liquid, and that the rate of drawing must be considerably large. The good solvent obtained by distillation can be purified by rectification and reused for the next bromination, condensation reaction, or dehydrobromination reaction.

(C) Step The slurry of Con-BAcN obtained in the above step (B) is filtered to separate and collect Oo and n-BAON, and
The liquid is recycled to the poor solvent in step (A). Slurry filtration may be carried out by conventional methods such as suction p-filtration and centrifugation.

The resulting Con-BAON is obtained as a fine powder after drying.

The filtrate is recycled to the poor solvent in step (A) and used for reprecipitation. Specifically, some poor solvent was added to the F solution containing the dissolved Con-BACN, so that the composition ratio of good solvent and poor solvent selected in step A was achieved during reprecipitation. Adjust,
Use as a poor solvent.

By implementing the method of the present invention as described above, Can-BAON can be obtained as a fine powder with a high recovery rate from the Con-BAON solution obtained in the manufacturing process.

In addition, because the F solution is recycled and reused, Con-BAO, which is dissolved in the F solution, is
Processing of N is also unnecessary.

Therefore, it is industrially advantageous to use Con-BAC! N can be separated and recovered.

Next, the method of the present invention will be explained in more detail with reference to Examples, but the method is not limited thereto.

Example 1 154 g of acenaphthene and 12 liters of ferric chloride were added to 1.51 g of carbon tetrachloride and kept at 25°C. Bromine 9 in this solution
A solution prepared by dissolving 60 g of carbon tetrachloride in 250 ++ u of carbon tetrachloride was added dropwise over 5 hours. After the dropwise addition, the temperature was raised to 55°C and the reaction was carried out until the color of bromine disappeared. After removing insoluble matter in the reaction solution by filtration and thoroughly washing the reaction solution with water, a solution of potassium hydroxide 729 dissolved in methanol s o o m/ was added dropwise over 1 hour while heating and refluxing, and the reaction was allowed to proceed for another 1 hour. Ta. After cooling the reaction solution, potassium bromide was removed by filtration, methanol was distilled off, and the solution was washed with water. I got it. Hereinafter, this solution will be referred to as a processing solution.

(A) Step The above treated solution was added dropwise to 1-octane 7 and 21 at room temperature for 1 hour while stirring to reprecipitate Con-BAON. Precipitation of fine powder occurred simultaneously with the dropwise addition, and after the completion of the dropwise addition, stirring was continued for an additional 50 minutes to completely precipitate the powder.

(B) Step (A) C obtained in step! The on-BACN slurry was distilled under normal pressure under stirring using a distillation column with an inner diameter of 2.5 crn and a height of 80 crn filled with glass helices (5 dragons φ). Bottle temperature 85~95℃, tower top temperature 76~
Distillation was completed by distilling off a fraction 2.31 containing carbon tetrachloride as a main component at 83°C. Thereafter, the Con-BAC with good dispersibility is cooled to room temperature while stirring. N slurry was obtained.

The composition of the distillate was 511 vol. of carbon tetrachloride. %, i-
Octane 4.2.9vol. In step (C), the Con-BAON slurry obtained in step (B) was suction-filtered to separate the powder and liquid E. The obtained powder was dried to give Con-B, a reddish brown powder with a melting point of 125 to 147°C.
ACN 2609 was obtained.

As a result of analysis, the obtained C0n-BACN had a bromine content of 6
7, and the degree of condensation measured by gel permeation chromatography is less than dimer! fr5%, S-mer 43chi, 4
It was ~8 times and 23 times.

The filtrate contains Con-BAON 50 q, carbon tetrachloride (L35/, 1-octane 58/).

This P solution was mixed with 2.4/ml of 1-octane and circulated to the poor solvent in step (A).

Next, a newly produced treatment liquid was added to this poor solvent to perform reprecipitation in the same manner as in the first operation.

Thereafter, steps (B) and (0) were performed in the same manner as the first time, and this series of operations was repeated a total of 5 times.

1-octane/during reprecipitation in step (A) each time
Table 1 shows the volume ratio of CCl4, the carbon tetrachloride removal rate in the (T3) step, and the recovery rate of Con-BAON.

Note that the recovery rate was expressed as a percentage of the Con-BACN powder obtained by drying each time with respect to the Con-BAON contained in the treatment liquid.

Table 1 Also, the physical properties (melting point, condensation composition, bromine content) of the Con-BAON powder obtained from the second time onwards were almost the same as those of the first time.

Incidentally, the distillates obtained by distillation in Step (B) 1 to 4 times were combined and carbon tetrachloride was rectified to obtain carbon tetrachloride with a purity of 995%. When Con-BAON was synthesized by performing a fifth bromination, condensation, and dehydrobromation reaction using this carbon tetrachloride, no problems were observed.

Comparative Example A carbon tetrachloride solution containing Con-BACN 949 prepared according to Example 1 in 1-octane 21 with stirring [
Con-BAC! N was reprecipitated.

The precipitated powder was separated in a furnace and dried to obtain reddish brown powder Con-BAON 7 & 6 g with a melting point of 126 to 147°C.

Con-BACN from carbon tetrachloride solution (!0n-BA(
! The recovery rate of N corresponds to 81.5 inches.

In addition, when the obtained F solution was distilled to recover carbon tetrachloride, a viscous solid scaled significantly in the distillation pot, making stirring difficult, making it impossible to continue the recovery operation and carbon tetrachloride. could not be recovered satisfactorily.

Patent Applicant Toyo Soda Kogyo Co., Ltd. Procedural Amendment May 11, 1980 Commissioner of the Patent Office Kazuo Wakasugi 1 Case Description 1982 Patent Application No. 213326 2 Name of Invention Separation and recovery of brominated acenaphthylene condensate 6. Person making the amendment 4. Date of the amendment order Voluntary 5. Number of inventions increased by the amendment 0. 6. Subject of the amendment (11. Title of the invention column (2) in the application (2) The description is amended as follows.

Page Line Before amendment After amendment 4 20 10 or less 10 or less (preferably).

1615 dimer or less Monomer 16153jlj body dimer 16164-octamer penta-octamer 8 List of attached documents (1) Corrected patent application (1 copy)

Claims (1)

[Scope of Claims] (1) A method for separating and recovering a brominated acenaphthylene condensate produced by bromination, condensation, and dehydrobromination of acenaphthene as a powder, comprising: (A) a good solvent obtained in the production process; A step of reprecipitating the brominated acenaphthylene condensate by adding a solution of the brominated acenaphthylene condensate dissolved in the brominated acenaphthylene condensate into a poor solvent whose boiling point is higher than that of the good solvent; (B) The brominated acenaphthylene obtained in step (A) A step of distilling the slurry of the condensate to remove a good solvent: and (0) separating and recovering the brominated acenaphthylene condensate by treating the slurry of the brominated acenaphthylene condensate obtained in step (B) with P. A method for separating and recovering a brominated acenaphthylene condensate, which comprises a step of circulating the P solution as a poor solvent in the N step.Q) Using a halogenated hydrocarbon or an aromatic hydrocarbon as a good solvent A separation and recovery method according to claim 1. (3) The separation and recovery method according to claim 1, in which a saturated aliphatic hydrocarbon having 5 to 9 carbon atoms is used as the poor solvent.