JP2567271B2 - Method for producing aromatic dihalide mixture having specific composition - Google Patents

Description

The present invention relates to a novel aromatic dihalide monomer mixture having a specific composition, which is useful as a raw material for an aromatic polyetherketone resin which is a thermoplastic heat-resistant resin. The present invention relates to various manufacturing methods.

(Prior Art) When 2 mol of 4,4'-dihalobenzophenone and 1 mol of 4,4'-dihaloterephthalophenone are reacted with an alkali metal carbonate in the presence of a catalyst, an ether ketone bond is formed. And ether ketone ketone bond The inventors have found a completely new polymerization reaction that gives a polyetherketone copolymer [formula (I)] having a ratio of about 2: 1 and filed a patent application (Japanese Patent Application No. 62-85708, Japanese Patent Application No. 62-85709). .
The copolymer is a known polyether ketone (PEK), Heat resistance is superior to that of polyether ketone ketone (PEKK), It is a well-balanced resin that has the characteristic of being easier to process.

(In the formula, X represents a halogen atom.) 4,4′-dihalobenzophenone and 4,4 ′ which are the starting materials
-Dihaloterephthalophenones are usually synthesized by subjecting the former to the Friedel-Crafts reaction of parahalogenobenzoyl chloride and halobenzene, and the latter by the Friedel-Crafts reaction of terephthalic acid dichloride and halobenzene. Need to be synthesized.

This conventional method has problems that the monomers have to be synthesized separately and that the raw materials, parahalogenobenzoyl chloride and terephthalic acid dichloride, are expensive.

(Problems to be Solved by the Problem) The present invention aims to provide a method for overcoming the drawbacks of conventional methods and synthesizing an aromatic dihalide mixture having the above-mentioned specific composition all at once by using inexpensive raw materials. It was made as.

(Means for Solving the Problems) As a result of intensive studies to achieve the above-mentioned object, the present inventors have used parahalogenobenzotrichloride, which is cheaper than parahalogenobenzoyl chloride, and terephthalic acid dichloride. By using terephthalic acid, which is much cheaper, and reacting both, and further reacting with halobenzene, 4,4'-dihalobenzophenone and 4,4'-dihaloterephthalophenone are obtained at once. It was found that a mixture with a molar ratio of about 2: 1 was obtained, and the present invention was completed based on this finding.

That is, the present invention relates to tere (or iso) phthalic acid 1
After reacting 2.0 to 2.3 moles of parahalogenobenzotrichloride per mole, the reaction product is reacted with 4 moles or more of halobenzene to obtain 4,4'-dihalobenzophenone and 4,4'-dihalobenzophenone.
The present invention provides a process for preparing an aromatic dihalide mixture having a specific composition characterized by synthesizing a mixture having a molar ratio of 4'-dihalotere (or iso) phthalophenone in the range of 1.8: 1 to 2.2: 1. .

 Hereinafter, the present invention will be described in detail.

The phthalic acid used in the method of the present invention is terephthalic acid or isophthalic acid, with terephthalic acid being preferred. It is also possible to use mixtures.

Examples of the parahalogenobenzotrichloride used in the present invention include parafluorobenzotrichloride, parachlorobenzotrichloride, parabromobenzotrichloride, paraiodobenzotrichloride and the like. Moreover, you may use these as a mixture.

Examples of the halobenzene used in the present invention include fluorinated benzene, chlorobenzene, bromobenzene, and iodobenzene.

The reaction of tere (or iso) phthalic acid with para-halogenobenzotrichloride is described as follows.

In this reaction, the molar ratio of tere (or iso) phthalic acid to parahalogenobenzotrichloride is 1: 2.0 to 1:
It is preferably in the range of 2.3. A catalyst can be used for this reaction, and as the catalyst, Friedel-Crafts catalysts such as aluminum chloride, antimony chloride, ferric chloride, titanium tetrachloride, tin tetrachloride and zinc chloride are used, Aluminum chloride and ferric chloride are particularly preferred catalysts. The amount of the catalyst added is not particularly limited, but is 0.01 to 0.5% by weight based on the mixture of para-p-halogenobenzotrichloride and tere (or iso) phthalic acid.

A suitable reaction temperature for this reaction is 0 ° C to 200 ° C, and it is also effective to gradually raise the temperature. In addition, as the reaction time, it is necessary to carry out the reaction until the generation of hydrogen chloride is stopped.

The reaction is preferably carried out without a solvent, but it may be carried out in the presence of a solvent. Examples of the solvent include aliphatic halogen compounds and nitrobenzene.

The reaction mixture thus obtained is subjected to reaction with halobenzene as it is or after once separating and purifying the product.

The number of moles of halobenzene used is at least 4 moles per mole of tere (or iso) phthalic acid.
The higher the amount of halobenzene used, the faster the reaction, and
Since halobenzene acts as an effective solvent, it is a preferred method to use more than 4-fold molar amount. The reaction with halobenzene is represented by the following reaction formula.

For this reaction, various known Friedel-Crafts reaction catalysts are effective, for example, aluminum chloride, antimony chloride, ferric chloride, ferric sulfate, ferrous sulfate, iron oxide,
Examples thereof include titanium tetrachloride, tin tetrachloride and zinc chloride, various heteropoly acids, boron fluoride and the like. This catalyst may be the same as or different from that used in the first-stage reaction.

The reaction temperature is room temperature to 200 ° C, and it is necessary to carry out the reaction until the generation of hydrogen chloride is stopped.

Further, examples of the solvent that can be used in this reaction include aliphatic and aromatic halogen compounds, nitrobenzene and the like, and halobenzene used in the reaction is most preferable.

After completion of the reaction, the reaction solution is subjected to an ordinary method, for example, after pouring it into a large amount of dilute hydrochloric acid, removing the solvent by steam distillation to precipitate the product, or by adding the reaction solution to a large amount of a mixture of dilute hydrochloric acid and methanol. The method of charging and crystallizing the product is used.

Thus, the molar ratio of 4,4'-dihalobenzophenone to 4,4'-dihalotere (or iso) phthalophenone is 1.8: 1.
An aromatic dihalide mixture in the range of ~ 2.2: 1 is formed.

The obtained mixture can be recrystallized to remove impurities, if necessary. As a recrystallization solvent,
It is possible to use toluene, xylene, chloroform and the like.

Also, the molar ratio of 4,4'-dihalobenzophenone and 4,4'-dihalotere (or iso) phthalophenone is 1.8: 1 to 2.
Slightly less than a mixture of aromatic dihalides in the 2: 1 range,
To increase the ratio of 4'-dihalobenzophenone or 4,4'-dihalotere (or iso) phthalophenone,
It is also possible to additionally carry out parahalogenobenzoyl chloride or tere (or iso) phthalic acid dichloride in the latter reaction. In this case, an additional amount of halobenzene corresponding to the additional parahalogenobenzoyl chloride or tere (or iso) phthalic acid dichloride must be added and reacted.

(Effects of the Invention) The present invention is a method of synthesizing an aromatic dihalide mixture having a specific composition, which is a raw material of an aromatic polyether ketone which is an excellent thermoplastic heat-resistant resin, at once using inexpensive starting materials. And has great industrial value.

Example 1 Example 1 Parachlorobenzotrichloride 48.3 g (0.21 mol)
And terephthalic acid 16.61 g (0.1 mol) and ferric chloride 0.0
Add 6g to a 300ml flask and stir from room temperature for 1
The temperature was gradually raised to 00 ° C. Hydrogen chloride gas began to be generated rapidly, and the reaction was performed at that temperature for 80 minutes.
Furthermore, the temperature was raised to 150 ° C. and the reaction was carried out for 30 minutes.

When the reaction product was analyzed by gas chromatography,
Only two peaks of the acid chloride of the product were observed, and no starting material peak was observed.

The obtained reaction product was transferred to a 1000 ml flask, and 224 g (2 mol) of chlorobenzene was added thereto and mixed to form a uniform solution. Furthermore, 66 g (0.5 mol) of aluminum chloride was added thereto, and the temperature was gradually raised from room temperature,
The reaction was completed at the temperature at which chlorobenzene was refluxed for 5 hours to complete the reaction.

300 ml of 3% hydrochloric acid was added to the reaction product and steam distillation was performed to distill off excess chlorobenzene. A precipitate formed which was passed over and separated. When the obtained crude product was analyzed by liquid chromatography, it was a mixture of 4,4'-dichlorobenzophenone and 4,4'-dichloroterephthalophenone in a molar ratio of 2.0: 0.95. The yield of crude product was 96%.

Example 2 A mixture of parafluorobenzoyl chloride and terephthalic acid dichloride was obtained by reacting in the same manner as in Example 1 except that 44.9 g (0.21 mol) of parafluorobenzotrichloride was used instead of parachlorobenzotrichloride. After the synthesis, 192 g (2 mol) of fluorinated benzene was used instead of chlorobenzene to carry out the subsequent reaction in the same manner as in Example 1 to obtain 4,4'-difluorobenzophenone and 4,4'-difluorobenzophenone. 97% yield of an aromatic dihalide mixture with a molar ratio of ′ -difluoroterephthalophenone of 2.0: 1.03
Obtained in.

Example 3 45.98 g (0.2 mol) of parachlorobenzotrichloride
And isophthalic acid 16.61 g (0.1 mol) and ferric chloride 0.0
Add 6g to a 300ml flask and stir from room temperature for 1
The temperature was gradually raised to 00 ° C. Hydrogen chloride gas began to be generated rapidly, and the reaction was carried out at that temperature for 20 minutes.
Furthermore, the temperature was raised to 130 ° C. and the reaction was performed for 30 minutes.

When the reaction product was analyzed by gas chromatography,
Only two peaks of the acid chloride of the product were observed, and no starting material peak was observed.

The obtained reaction product was transferred to a 1000 ml flask, and 224 g (2 mol) of chlorobenzene was added thereto and mixed to form a uniform solution. Furthermore, 66 g (0.5 mol) of aluminum chloride was added thereto, and the temperature was gradually raised from room temperature,
The reaction was completed for 5 hours under reflux conditions to complete the reaction.

300 ml of 3% hydrochloric acid was added to the reaction product and steam distillation was performed to distill off excess chlorobenzene. A precipitate formed which was passed over and separated. When the obtained crude product was analyzed by liquid chromatography, it was a mixture of 4,4'-dichlorobenzophenone and 4,4'-dichloroisophthalophenone in a molar ratio of 2.0: 0.99. The yield of crude product was 96%.

Claims (1)

(57) [Claims] 1. After reacting 2.0 to 2.3 mol of para-halogenobenzotrichloride per mol of tere (or iso) phthalic acid, the reaction product is reacted with 4 mol or more of halobenzene to obtain 4,4'-dicarboxylic acid. The molar ratio of halobenzophenone to 4,4'-dihalotere (or iso) phthalophenone is 1.8: 1 ~
A process for preparing an aromatic dihalide mixture having a specific composition, characterized in that a mixture in the range of 2.2: 1 is synthesized.