JP2796556B2 - Method for producing high-grade bisphenol A / phenol crystal adduct - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-quality bisphenol A. The present invention relates to a method for producing a phenol crystal adduct.

[0002]

BACKGROUND OF THE INVENTION Bisphenol A [2,2
It is known to react acetone with excess phenol 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 the reaction product, the reaction product is subjected to crystallization treatment and a crystal adduct of bisphenol A and phenol (hereinafter, also simply referred to as a crystal adduct). From the resulting crystalline adduct.
It is also known to remove the oil. (Special Publication 66-23
No. 335, JP-B-52-42790). In such a method for producing bisphenol A, the hue of bisphenol A recovered as a product largely depends on the hue of the crystal adduct itself. Therefore, it is desired to develop a method for producing a high-quality crystal adduct. You. Conventionally, in order to obtain a high-purity crystalline adduct, phenol containing bisphenol A
The crystalline adduct slurry obtained by subjecting the crystalline solution to crystallization is filtered, and the separated crystalline adduct is purified with high-purity phenol.
It is known to clean with water. In this case, by increasing the number of crystallization steps, a product crystal adduct with increased purity can be obtained. However, in the production of such a crystal adduct including a plurality of crystallization steps, even if high-purity phenol is used in each of the cleaning liquids for cleaning the crystal adduct obtained in each crystallization step, the crystal adduct has an exceptionally high quality. Purification is not achieved, but rather, there is a problem that the cost for obtaining a large amount of the high-purity phenol increases.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for economically producing a high-quality crystal adduct including a plurality of crystallization steps.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have completed the present invention. That is, according to the present invention, a phenol solution containing bisphenol A is subjected to n (n ≧ 2) crystallization steps,
-Stage solid-liquid separation step, at least one stage of bisphenol A
The method includes a phenol crystal adduct washing step and an n-1 stage crystal adduct re-dissolving step, and solidifies the crystallization product obtained in each of the crystallization steps from the first stage to the (n-1) th stage. Liquid separation,
The obtained crystal adduct is used as it is or after washing with a washing solution, then redissolved by dissolving in phenol and supplied to the next crystallization step, and the crystallization product obtained in the n-th crystallization step In a solid-liquid separation and washing with the obtained crystal adduct washing liquid to obtain a high-purity crystal adduct, wherein (a) n-th
Using purified phenol as at least a part of the washing liquid for the n-th crystal adduct obtained in the solid-liquid separation step of the stage, (b) obtaining at least the solid-liquid separation step of the (n-1) th stage At least a portion of the phenol solution for re-dissolving the crystal adduct thus obtained is washed with the crystal adduct obtained in the n-th solid-liquid separation step, or obtained in the n-th solid-liquid separation step. (C) at least a part of the washing liquid of the crystal adduct obtained in the (n-1) th solid-liquid separation step, the mother liquor obtained in the nth solid-liquid separation step or Using the washed and discharged liquid of the crystal adduct obtained in the n-th solid-liquid separation step; (d) phenol for re-dissolving the crystal adduct in each of the first to n-1 th stages Both the impurity concentration in the solution and the impurity concentration in the crystal adduct cleaning solution Le A · phenol - - bisphenol characterized by high that, than the impurity concentration of the impurity concentration in the Le solution and crystal adduct in the washing liquid - crystalline adduct redissolved for phenol in stage manufacturing method of Le crystalline adduct is provided.

Next, the present invention will be described with reference to the drawings.
FIG. 1 is a flow chart showing the operation of the method of the present invention.
Here is an example. In FIG. 1, A-1, A-2, and A-3 are:
A first crystallization step, a second crystallization step, and a third crystallization step are shown, respectively. B-1, B-2, and B-3 indicate a first solid-liquid separation step, a second solid-liquid separation step, and a third solid-liquid separation step, respectively. C-1 and C-2 are the first of the crystal adduct, respectively.
The redissolving step and the second redissolving step are shown. When a crystal adduct is manufactured in accordance with the flow chart shown in FIG. 1, in a steady state flow, a phenol solution containing bisphenol A, which is a raw material liquid for crystallization, passes through line 1. To the first crystallization step A-1.

The crystallization product obtained in the first crystallization step A-1 is introduced into the first solid-liquid separation step B-1 through the line 2, where the first crystallization adduct D-1 and the first The first mother liquor F-1 is separated into the first mother liquor F-1 and phenol,
Since it contains a useful component such as bisphenol A, it is subjected to an appropriate treatment and then circulated to a reaction step between phenol and acetone. The first crystal adduct separated from the first crystallized product is washed with the second mother liquor F-2 obtained in the next second solid-liquid separation step B-2, and the first mother liquor obtained by this washing is removed. The washing effluent E-1 is circulated to the reaction step between phenol and acetone. As described above, the first washed with the second mother liquor F-2
The crystal adduct D-1 is introduced into the first re-dissolving step C-1, and is dissolved by the second crystal adduct washing and draining liquid E-2 from the second solid-liquid separation step B-2 in the next stage. 3 and introduced into the second crystallization step A-2.

The crystallization product obtained in the second crystallization step A-2 is introduced into the second solid-liquid separation step B-2 through the line 4, where the second crystal adduct D-2 and the second The mother liquor F-2 is separated from the mother liquor F-2, and the second mother liquor F-2 is used to wash the crystal adduct D-1 separated in the first solid-liquid separation step B-1 as described above. On the other hand, the second crystal adduct D-2
Is washed with the third mother liquor F-3 obtained in the subsequent third solid-liquid separation step B-3, and the second washing waste liquid E-2 is subjected to the first re-dissolution step C-3 as described above. -1 as a phenol solution for dissolving the first crystal adduct D-1.
As described above, the second crystal adduct D-2 washed with the third mother liquor F-3 is introduced into the second re-dissolution step C-2, and is supplied from the third solid-liquid separation step B-3 in the next stage. After being dissolved by the third crystal adduct washing drainage E-3, it is introduced into the third crystallization step A-3 through the line 5.

The crystallization product obtained in the third crystallization step A-3 is introduced into the third solid-liquid separation step B-3 through the line 6, where the third crystallization adduct D-3 and the third The mother liquor F-3 is separated from the mother liquor F-3, and the third mother liquor F-3 is used to wash the second crystal adduct D-2 separated in the second solid-liquid separation step B-2 as described above. The third crystal adduct D-3 is
The third washing drainage E-3 is washed with the purified phenol F and used as a phenol solution for dissolving the second crystal adduct D-2 in the second re-dissolving step C-2 as described above. Can be The third crystal adduct D-3 washed with the purified phenol F obtained in the third solid-liquid separation step is recovered as a product.

In the present invention, as the purified phenol F, any one can be used as long as its molten color APHA is preferably 15 or less. Examples of the purified phenol that can be preferably used in the present invention include (i) phenol separated from a reaction product of phenol and acetone, and (ii) phenol containing bisphenol. Phenol separated from the crystallized product, (i
ii) A purified product of at least one phenol selected from spent phenol and industrial phenol after washing the crystal adduct is used. In the reaction product obtained by the reaction between phenol and acetone, phenol is separated from the reaction product in order to concentrate the produced bisphenol A contained therein. Can be used as a washing solution. In addition, when a phenol containing bisphenol A is crystallized to precipitate a crystal adduct, a plurality of crystallization steps and a solid-liquid separation step of a crystallization product are usually employed. A kind of mother liquor (phenol solution) is obtained. In the present invention, a purified product of phenol forming these mother liquors can be used as a washing solution. The purified product of phenol used in the present invention may be a purified product of phenol that forms any of the mother liquors, but is preferably a purified product of phenol separated from the crystallization product obtained in the final crystallization step. It is better to use In the present invention, after washing the crystal adduct,
In the present invention, this used phenol purified product can be advantageously used as a washing solution. As the raw material phenol for obtaining the purified phenol used in the present invention, it is preferable to use a phenol having a purity of 99% by weight or more, preferably 99.5% by weight or more. Further, in the present invention, a purified product of industrial phenol can be used as a washing solution. In this case, as the industrial phenol, one having a phenol purity of 99.5% by weight or more is preferably used.

When the phenol is preferably purified, the raw phenol is first treated by contacting it with a strong acid ion exchange resin. In this case, the strong acid ion exchange resin has a sulfone group. Are used,
Such a strong acid-type ion exchange resin is conventionally well-known. For example, Amberlite and Amberlist available from Rohm and Haas Co., Ltd., and Diaion available from Mitsubishi Kasei Corporation can be preferably used. The phenol treatment using the strong acid-type ion-exchange resin can be performed by flowing phenol through a packed tower containing the strong acid-type ion-exchange resin, or by putting phenol into a stirring tank containing the strong acid-type ion-exchange resin. And can be carried out by a method of stirring. Processing temperature is 45-150 ° C,
Preferably it is 50-100 degreeC. The contact time between the strong acid type ion exchange resin and phenol is about 5 to 200 minutes, preferably about 15 to 60 minutes. When phenol is treated using this strong acid-type ion exchange resin, the water content in the phenol is 0.5% by weight or less, preferably 0.1% by weight or less. If the water content is higher than this, the effect of removing impurities by the strong acid-type ion-exchange resin deteriorates. Removal of water up to 0.5% by weight or less from phenol can be achieved by removing phenol.
A known azeotropic agent can be added to the mixture to cause azeotropic distillation. The phenol that has been contacted with the strong acid-type ion exchange resin contains high-boiling impurities, and the high-boiling impurities are separated as distillation residues by distillation.

The distillation column may be operated under the condition that phenol and high-boiling impurities can be separated, but it is necessary that the distillation column be operated under conditions in which high-boiling impurities are not mixed in the distillate phenol. Is set to 200 ° C. or less. If the temperature is 200 ° C. or lower, the operating pressure is arbitrarily set, but the operation is usually performed under a reduced pressure of 50 Torr to 600 Torr. If the operating temperature exceeds 200 ° C., decomposition of high-boiling impurities and the like will occur, and the quality of the purified phenol will be deteriorated. The purified phenol obtained by the above treatment has an APHA-based hue of 10 or less, and does not particularly deteriorate the hue even when attached to a product crystal adduct.

In the present invention, a mother liquor from the next stage is used for at least a part of the washing liquid for the crystal adduct in each stage. In this case, a part of the washing solution from the next stage is used together if necessary. It is also possible. Further, as the phenol solution for dissolving the crystal adduct in the re-dissolving step of each stage, at least a part of the washing drainage from the next stage is used. In this case, if necessary, the mother liquor from the next stage Can be used in combination. In the cleaning solution used for cleaning the crystal adduct and the phenol solution for dissolving the crystal adduct in the present invention, the impurity concentration contained in each of the cleaning solution and the phenol solution has a downstream side, that is, an n-th concentration from the first crystallization step.
It becomes smaller as it goes to the crystallization step of the step. In other words, the impurity concentrations in the crystal adduct washing solution and the phenol solution for dissolving the crystal add used in each stage are higher than those in the next stage. The impurity concentration in the cleaning liquid used in each of the adjacent stages decreases almost geometrically. Incidentally, the impurities referred to in this specification are bisphenol A by the reaction of phenol with acetone.
Means the by-product when producing. Such impurities include isomers of bisphenol A, chroman compounds, and the like. Furthermore, in the present invention, depending on the required purity of the product adduct, a part of each of the washing steps from the first stage to the (n-1) th stage is omitted, and the crystal adduct obtained in the solid-liquid separation step is It can be directly brought to the next re-dissolution step. In this case, as the phenol solution used in the re-dissolution step, the mother liquor (or the washing waste liquid) obtained in the subsequent solid-liquid separation step is used. As described above, in the present invention, by adjusting the amount of the phenol solution for washing used in each stage according to the required purity of the product adduct, the amount of phenol used as a whole is reduced, and the cost is reduced. Is also possible. The crystallization step in the present invention has two or more steps, and the drawing shows an example including three steps of crystallization steps. However, even in the case of four or more steps, the crystallization step is performed in the same manner as described above. be able to.

[0013]

According to the present invention, a high-quality crystal adduct can be obtained only by using purified phenol for cleaning the crystal adduct in the final stage. Therefore, the present invention has the advantage that the amount of high-purity purified phenol-norno used is small and the production cost of the crystalline adduct is low.

[0014]

Next, the present invention will be described in more detail with reference to examples.

Reference Example 1 A reaction product obtained by reacting acetone and phenol in the presence of an acid catalyst was concentrated and crystallized at 50 ° C. to obtain a bisphenol A.phenol adduct of 20 wt%. -3000 g of the precipitated slurry was obtained. This was filtered at 50 ° C. under reduced pressure (the filtered mother liquor (2250 g) obtained at this time was designated as A), and the crystalline adduct obtained was washed and filtered using 600 g of separately prepared purified phenol (at this time). 580 g of the obtained washing drainage is referred to as B). 1310 g of purified phenol (APHA: 5) separately prepared from the washed crystal adduct
And crystallized at 50 ° C. to give bisphenol A
A slurry of 20 wt% of phenol adduct was obtained and filtered under reduced pressure at 50 ° C. (1430 g of mother liquor obtained at this time)
And C), and then separately prepared purified phenol 60
At 0 g, washing and filtration were performed twice (1 g obtained at this time).
580 g of the second washing and drainage 580 g
g is E). The bisphenol-phenol crystal adduct thus obtained has an impurity concentration of 100 wtpp.
m, melt color was 5 APHA.

Example 1 As in Reference Example 1, the reaction product obtained by reacting acetone and phenol in the presence of an acid catalyst was concentrated and crystallized at a temperature of 50 ° C. to obtain bisphenol A -3000 g of a crystallization slurry containing 20% by weight of a phenol crystal adduct. This was filtered under reduced pressure at 50 ° C., and the obtained crystal adduct was washed with 700 g of the mother liquor C of Reference Example 1. The crystal adduct after washing was replaced with the remaining 730 g of the mother liquor C of Reference Example 1 and the washing drainage D.
After 580 g was added and redissolved, crystallization was performed at 50 ° C.
Bisphenol A / Phenol crystal adduct 20wt%
Was obtained, and this was filtered at 50 ° C. under reduced pressure. Next, the obtained crystal adduct was washed with the washing drainage E of Reference Example 1.
After washing with 580 g, it was further washed with 600 g of purified phenol as a final washing step. The impurity concentration of the bisphenol A phenol crystal adduct obtained at this time was 100 wtppm as in the reference example, and the molten color was 5 wt.
APHA was indicated. Therefore, in this example, the purified phenol was used only for the final step of washing, and the rest used the mother liquor or the washing solution recovered from the later stage of the process. The amount of phenol used can be reduced, and high-quality bisphenol A / phenol crystal adduct, and thus high-quality bisphenol A can be obtained.

[Brief description of the drawings]

FIG. 1 shows an example of a flow sheet for carrying out the method of the present invention.

[Explanation of symbols]

 A-1, A-2, A-3 Crystallization step B-1, B-2, B-3 Solid-liquid separation step C-1, C-2 Re-dissolution step

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Sachio Asaoka 2-1-1, Tsurumichuo, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Chiyoda Kako Construction Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) C07C 39/16 C07C 37/68-37/84

Claims (1)

(57) [Claims] 1. A phenol solution containing bisphenol A is subjected to n (n ≧ 2) crystallization steps, n-stage solid-liquid separation steps,
The method includes at least one stage of washing of a bisphenol A / phenol crystal adduct and a stage of re-dissolving the n-1 stage of the crystal adduct, and is obtained in the crystallization process of each stage from the first stage to the (n-1) th stage. The obtained crystallized product is subjected to solid-liquid separation, and the obtained crystal adduct is washed as it is or with a washing liquid, then redissolved in a phenol solution and supplied to the next crystallization step, and A solid-liquid separation of the crystallized product obtained in the crystallization step of (a), and washing of the obtained crystal adduct with a washing liquid to obtain a high-purity crystal adduct. Using purified phenol as at least a part of the washing liquid for the n-th crystalline adduct obtained in the step, (b) reusing the crystalline adduct obtained in at least the (n-1) -th solid-liquid separation step. The n-th solid-liquid separation is performed on at least a part of the phenol solution for dissolution. Using the washing effluent of the crystal adduct obtained in the above step or the mother liquor obtained in the n-th solid-liquid separation step, (c) at least the crystals obtained in the (n-1) -th solid-liquid separation step (D) using, as at least a part of the washing liquid for the adduct, the mother liquor obtained in the n-th solid-liquid separation step or the washing and draining liquid for the crystal adduct obtained in the n-th solid-liquid separation step; The impurity concentration in the phenol solution for re-dissolving the crystal adduct and the impurity concentration in the cleaning solution for the crystal adduct in each of the first stage to the (n-1) -th stage are all the same. -Hizphenol A phenol, which is higher than the impurity concentration in the crystal solution and the impurity concentration in the crystal adduct cleaning solution.
Manufacturing method of crystal adduct.