JPH0539237A - Production of pure phenol - Google Patents

Abstract

PURPOSE:To provide a method for producing highly pure phenol having excellent hue and storage stability. CONSTITUTION:Industrial phenol (a purity of 99.5wt.%, especially 99.93wt.%) having a water content of <=0.5wt.$, preferably <=0.1wt.%, is brought into contact with a strong acid type ion exchange resin, preferably a gel type resin, distilled under vacuum of 50-600Torr at a temperature of <=185 deg.C to obtain high quality pure phenol containing no coloration-causing substance. The pure phenol is suitable as a washing solvent for the crystalline adduct of bisphenol A with phenol to give the bisphenol A having excellent color tone. The pure phenol is useful as a raw material for producing various phenol derivatives having excellent hues.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a purified phenol having excellent hue and storage stability. High-purity purified phenol having an excellent hue is suitable as a raw material for bisphenol A and alkylphenol, which have excellent hue and storage stability.

[0002]

2. Description of the Related Art Bisphenol A [2,2]
It is known to react excess phenol with acetone in the presence of an acid catalyst to produce [bis (4-hydroxyphenyl) propane]. Further, in order to separate and recover high-purity bisphenol A from this reaction product, the reaction product was cooled to crystallize a crystal adduct of bisphenol A and phenol (hereinafter, also simply referred to as a crystal adduct). It is also known to remove phenol from adduct crystals. In such a method for producing bisphenol A, the purity of bisphenol A recovered as a product obviously depends largely on the removal rate of phenol from the crystal adduct,
It is also affected by impurities other than phenol contained in adduct crystals. A method of washing adduct crystals with liquid phenol in order to remove impurities other than phenol contained in crystal adducts is known (JP-A-1-
146839). This known method is characterized in that the phenol separated from the crystal adduct is used as the liquid phenol for washing, whereby a product bisphenol A having a hue better than that of the industrial phenol is obtained. In this case, the separation of phenol from the crystal adduct is carried out by vaporizing the crystal adduct at a temperature above 180 ° C. and a reduced pressure for 0.1 to 30 minutes, for example, as shown in JP-B-52-42790. Can be carried out by fractionating and condensing the phenol. However, the phenol evaporated from the crystalline adduct is
It is an unsatisfactory cleaning liquid for crystal adducts. That is, impurities such as chroman and 2,4'-bisphenol A contained in the adduct itself and impurities causing coloration such as isopropenylphenol produced by heating in the separation step are mixed in such phenol. This is especially noticeable when the evaporation temperature is high. And
If phenol containing these impurities is used for cleaning the crystal adduct, a product of high purity and good hue, bisphenol A cannot be obtained.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing high-purity phenol which has an excellent hue and is excellent in storage stability as a cleaning liquid for the crystal adduct.

[0004]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies on a method for purifying industrial phenol for obtaining a phenol suitable for washing a crystal adduct, and as a result, the industrial phenol is converted into a strong acid ion exchange resin. The purified phenol obtained by distillation after contact with is excellent in hue and storage stability, and has a crystal adduct washed with this purified phenol. It was found that the product bisphenol A obtained by removing phenol from the product has an extremely excellent hue, and that the alkylphenol obtained using this purified phenol has an extremely excellent hue. The present invention has been completed.

That is, according to the present invention, the water content is 0.5% by weight.
Provided is a method for producing a purified phenol, which comprises subjecting the following industrial phenol to contact with a strong acid ion exchange resin and then subjecting it to a distillation treatment. As the industrial phenol, commercially available products can be used, and generally, phenol having a purity of 99.5% by weight or more, preferably 99.93.
Any weight% or more may be used.

In the present invention, this industrial phenol is treated by contact with a strong acid type ion exchange resin. As the strong acid type ion exchange resin, one having a sulfone group is used, and such a strong acid type ion exchange resin is well known in the art. For example, gel-type ones such as Amberlite and Amberlyst available from Japan and Haas Co., Ltd., and Diaion or the like available from Mitsubishi Kasei Co., Ltd. can be preferably used. As the strong acid type ion exchange resin, a macroporous type can also be used, but unlike the gel type, since this has a decrease in activity over time, its use is not very preferable. The treatment of phenol with this strong acid ion exchange resin is carried out by a method of circulating phenol in a packed column containing a strong acid ion exchange resin, a method of stirring by adding phenol to a stirring tank containing a strong acid ion exchange resin, or the like. Can be implemented. Treatment temperature is 45-150, preferably 50-8
It is 0 ° C. The contact time between the strong acid ion exchange resin and the phenol is 5 to 200 minutes, preferably 15 to 60 minutes. When phenol is treated with this strong acid ion exchange resin, the water content in the phenol is 0.5% by weight.
The following is preferably 0.1% by weight or less. If the water content is larger than this, the effect of removing impurities by the strong acid ion exchange resin deteriorates. The water content up to 0.5% by weight or less can be removed from phenol by azeotropically adding a known azeotropic agent to phenol.

The phenol which has been subjected to the contact treatment with the strong acid ion exchange resin contains high-boiling point impurities, and the high-boiling point impurities are separated by distillation treatment. The operating conditions of the distillation column should be such that phenol and high-boiling impurities can be separated, but it is necessary to do so under conditions that high-boiling impurities are not mixed in the distillate phenol. Is. The operating pressure is arbitrarily set at a temperature of 185 ° C. or lower, but is usually performed under a reduced pressure of 50 Torr to 600 Torr. If the operating temperature exceeds 185 ° C, decomposition of high-boiling impurities and the like will occur and the quality of the purified phenol will deteriorate, which is not preferable. The purified phenol obtained by the above treatment has an APHA standard hue of 10 or less, and even if it adheres to the product bisphenol, the hue is not particularly deteriorated.

[0010]

Industrial Applicability The purified phenol obtained by the present invention is of high quality having excellent hue and storage stability, and is particularly suitable as a cleaning solution for crystal adduct of bisphenol A and phenol. The use of this purified phenol as the cleaning liquid for the crystal adduct has the following advantages. (1) Since a crystal adduct free of impurities, particularly impurities that cause coloring, is obtained, bisphenol A, a product with high purity and excellent hue, can be obtained. (2) Since no solvent other than phenol is mixed in the cleaning liquid, the cleaning liquid can be recycled as it is to the reaction system of bisphenol A and acetone or its crystallization system. As described above, the purified phenol according to the present invention is suitable as a cleaning solution for crystal adducts of phenol and bisphenol A, but since it is a highly pure product excellent in hue, various phenol derivatives having good hue are obtained. For example, it is also suitable as a raw material for producing alkylphenol, phenol resin and the like. The purified phenol obtained in the present invention contains a small amount of oxalic acid or citric acid (0.
0001 to 0.01 wt%), it is possible to suppress the decrease of the hue during storage or reaction.

[0013]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Example 1 Commercially available industrial phenol (water content: 0.1 wt%, impurity concentration: 0.05 wt%) was used at a temperature of 80 ° C. and a contact time of 50 minutes using Amberlite IR-118H + resin manufactured by Rohm and Haas. The mixture was subjected to contact treatment and distilled at a distillation column bottom temperature of 175 ° C. and a column top pressure of 560 torr to obtain a purified phenol having a melt color of 6APHA. On the other hand, a melted color of 50 APH obtained by reacting phenol and acetone in the presence of an acid catalyst.
A mixture of bisphenol A which is A, phenol and impurities was crystallized to deposit a crystal adduct. next,
The slurry of the crystal adduct was filtered under reduced pressure to obtain a solid crystal adduct, which was washed with 2.5 parts by weight of the purified phenol obtained above in 1 part by weight of the crystal adduct. The crystalline adduct thus obtained was steam stripped at 175 ° C. and 25 torr for 30 minutes to substantially completely remove the phenol to obtain bisphenol A. The bisphenol A had an extremely good hue as described below.

Comparative Example 1 A mixture of bisphenol A having a melting color of 50 APHA, phenol and impurities was crystallized to deposit a crystal adduct. The slurry of this crystal adduct is filtered under reduced pressure,
A solid crystal duct was obtained, part of which was decomposed at 190 ° C. to recover phenol. The phenol was washed at a ratio of 2.5 parts by weight to 1 part by weight of the remaining crystal adduct. The washed crystal adduct thus obtained was steam stripped at 175 ° C. and 25 Torr for 30 minutes to remove substantially all of the phenol to obtain bisphenol A, which had a melt color of 20APHA. ..

Comparative Example 2 Phenol was obtained in the same manner as in Example 1 except that the distillation bottom temperature was 200 ° C. when the purified phenol was distilled.
Using this phenol as a cleaning solution for crystal adducts,
Bisphenol A was obtained in the same manner as in Example 1, but had a melt color of 30 APHA. The melting colors at 175 ° C. of bisphenol A obtained in the above Examples and Comparative Examples are summarized in the following table.

[0017]

[Table 1]

Example 2 Water concentration 0.07 wt%, impurity concentration 430 wtppm
Was subjected to contact treatment with Amberlite IR-118H + resin manufactured by Rohm and Haas Co. at a temperature of 80 ° C. for a contact time of 20 minutes. Next, the obtained contact-treated product was distilled at a distillation column bottom temperature of 173 ° C. and a column top pressure of 560 Torr to obtain purified phenol.

Comparative Example 3 Moisture concentration 0.73 wt%, impurity concentration 430 wtppm
An experiment was conducted in the same manner as in Example 2 except that the industrial phenol of No. 1 was used. The properties of the purified phenol obtained as described above are shown in Table 2 together with the properties of the raw material industrial phenol and the properties of the phenol after the ion exchange resin treatment.

[0020]

[Table 2]

Example 3 The ion-exchange resin treatment shown in Example 2 was continuously conducted for 1000 times.
Over time, no benzofuran was detected in the treated phenol in this case.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuo Maejima 2-12-1, Tsurumi Chuo, Tsurumi-ku, Yokohama-shi, Kanagawa Chiyoda Kako Construction Co., Ltd. (72) Koji Sakashita Chuo, Tsurumi-ku, Tsurumi-ku, Yokohama Chome 12-1 Chiyoda Kako Construction Co., Ltd. (72) Inventor Makoto Yasui 2-12-1 Tsurumi Chuo, Tsurumi-ku, Yokohama-shi Kanagawa Chiyoda Kako Construction Co., Ltd.

Claims (3)

[Claims] 1. A method for producing a purified phenol, which comprises contacting an industrial phenol having a water content of 0.5% by weight or less with a strong acid type ion exchange resin and then subjecting it to a distillation treatment. 2. The method according to claim 1, wherein the distillation temperature is 185 ° C. or lower. 3. The method according to claim 1, wherein the strong acid ion exchange resin is a gel type.