JPH0597746A - Production of bisphenol a-phenol crystal adduct powder - Google Patents

Abstract

PURPOSE:To provide a method for producing a readily handleable high-purity crystal adduct powder, having high quality and excellent in hue. CONSTITUTION:A bisphenol A-phenol crystal adduct powder is produced by a method characterized as follows. A solution containing the bisphenol A-phenol crystal adduct in phenol is subjected to solid-liquid separation and the resultant wet cake is then washed with an organic solvent, capable of exhibiting solubility in the phenol and having 60-120 deg.C boiling point. The organic solvent sticking to the cake is subsequently removed and the resultant powder is dried.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing bisphenol A / phenol crystal adduct powder.

[0002]

2. Description of the Related Art 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]. In order to separate and collect high-purity bisphenol A from this reaction product, the reaction product is cooled to precipitate a crystal adduct of bisphenol A and phenol (hereinafter, also simply referred to as a crystal adduct), and the obtained crystal is obtained. It is also known to remove phenol from adducts. In such a method for producing bisphenol A, the purity and hue of bisphenol A recovered as a product largely depend on the purity and hue of the crystal adduct, and a method for producing a crystal adduct with high purity and good hue is desired. .. In order to obtain a high-purity crystal adduct from a phenol solution containing bisphenol A obtained by reacting excess phenol with acetone, the phenol solution is subjected to a crystallization step of a plurality of stages to separate the crystal adduct as necessary. It is known to process by a series of crystallization steps linked through a process and a dissolution process. The crystal adduct obtained by the crystallization treatment in such a plurality of stages of crystallization is of relatively high purity, but its purity is still insufficient and, in particular, it contains a coloring-causing substance, so that it has a hue difference. But it was still unsatisfactory.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a high-quality crystalline adduct powder which has a high purity and an excellent hue and is easy to handle.

[0004]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, according to the present invention, bisphenol A
A wet cake obtained by solid-liquid separation of a phenol solution containing a phenol crystal adduct is washed with an organic solvent having a boiling point of 60 to 120 ° C., which is soluble in phenol, and then the organic solvent attached to the cake is removed. And a bisphenol A / phenol crystal adduct powder are provided.

The crystalline adduct wet cake used in the present invention is produced by a conventionally known method. That is, a phenol solution containing bisphenol A obtained by reacting excess phenol and acetone is subjected to a plurality of stages of crystallization steps to produce a phenol solution containing bisphenol A / phenol crystal adduct (crystal adduct slurry). ,
Then, a wet cake can be obtained by solid-liquid separating this slurry. The wet crystalline adduct cake used in the present invention contains 20 to 30% by weight of free phenol, and the hue APHA of the melt is 100 to 200.
It is a degree.

In the present invention, the wet cake is washed with an organic solvent. As the organic solvent, those having a solubility in phenol, a low solubility in an adduct and a boiling point in the range of 60 to 120 ° C. are used. Examples of such compounds include aromatic hydrocarbons such as benzene and toluene, alicyclic hydrocarbons such as cyclohexane, and aliphatic hydrocarbons such as n-hexane. These organic solvents can be used alone or in the form of a mixture. As a method for washing the wet cake with an organic solvent, there are a method of spraying the surface of the wet cake with the organic solvent, a method of dispersing and stirring the wet cake in the organic solvent, and a refiltration. The washing operation can be repeated multiple times. The amount of the organic solvent used is 100 parts by weight of the wet cake,
It is at least 50 parts by weight, preferably 100 parts by weight or more. By washing the wet cake as described above, the free phenol contained in the wet cake is substantially completely dissolved and removed, and further the impurities adhering to the surface are removed. It is highly purified. Next, the organic solvent adhering to the surface of the wet cake is removed, dried and pulverized. The removal of the organic solvent from the wet cake and the drying of the wet cake can be performed simultaneously or separately. Generally, after holding the wet cake under reduced pressure to evaporate and remove most of the organic solvent adhering to the surface thereof, the temperature is kept at 40 to 60 ° C., preferably under reduced pressure or under inert gas flow. , Heat dry.

In order to preferably carry out the present invention, it is preferable that the wet cake is washed with purified phenol in advance and then with an organic solvent before washing with the organic solvent. In this case, the washing temperature is the same as the temperature of the slurry at the time of solid-liquid separation. The purified phenol, which does not cause coloration of the crystal adduct, may be any as long as the content of impurities is small, in the present invention, as the purified phenol,
Usually, those having a melt color APHA of 10 or less, preferably 5 or less are preferably used. Examples of the purified phenol that can be preferably used in the present invention include (i)
Of phenol separated from the reaction product of phenol and acetone, (ii) phenol separated from the crystallization product of phenol containing bisphenol, (iii) spent phenol and industrial phenol after washing the crystal adduct. A purified product of at least one phenol selected from the above is used. The reaction product obtained by the reaction of phenol and acetone is separated from the reaction product in order to concentrate the produced bisphenol A contained in the reaction product. In the present invention, the purified product of this phenol is used as a washing liquid. Can be used. Further, when crystallization treatment of phenol containing bisphenol A is carried out to precipitate a crystal adduct, usually, a plurality of stages of crystallization steps and a solid-liquid separation step of crystallization products are adopted, and accordingly, a plurality of mother liquors ( Phenol solution) is obtained, but in the present invention, a purified product of phenol forming these mother liquors can be used as a washing liquid. The purified product of phenol used in the present invention may be a purified product of phenol forming any of the mother liquors, but preferably forms a mother liquor separated from the crystallization product obtained in the crystallization step of the first stage. It is preferable to use a purified product of phenol. In the present invention, spent phenol is obtained after washing the crystal adduct, but in the present invention, the purified product of the used phenol can also be advantageously used as a washing liquid. The raw material phenol used for obtaining the purified product of the phenol used in the present invention has a purity of 99% by weight or more, preferably 9% by weight or more.
It is preferable to use 9.5% by weight or more. Further, in the present invention, a purified product of industrial phenol can be used as a cleaning liquid. In this case, as industrial phenol, phenol purity is 99.5% by weight or more, preferably 9
The content of 9.93% by weight or more is used. Next, the preferred method for obtaining purified phenol from the phenol will be described in detail. First, the phenol is contacted with a strong acid ion exchange resin to be treated. 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 Rohm and Haas Company, and Diaion etc. available from Mitsubishi Kasei Co. can be preferably used. 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. Processing temperature is 45-1
The temperature is 50 ° C, preferably 50 to 100 ° C. The contact time between the strong acid ion exchange resin and phenol is 5 to 200 minutes,
It is preferably about 15 to 60 minutes. When phenol is treated using this strong acid ion exchange resin, the water content in phenol is 0.5% by weight or less, preferably 0.1% by weight or less.
Reduce to less than weight%. If the water content is larger than this, the effect of removing impurities by the strong acid ion exchange resin deteriorates. Removal of water from phenol up to 0.5 wt%
It can be carried out by adding a known azeotropic agent to phenol and azeotroping it. The phenol that 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 as a distillation residue by performing a distillation process. The operating conditions of the distillation column should be such that phenol and high-boiling point impurities can be separated, but it is necessary to carry out under conditions where high-boiling point impurities are not mixed in the distilled phenol, and the point to be noted is that the distillation treatment temperature should be 185 ° C or lower. Is. If the temperature is 185 ° C or lower, the operating pressure is arbitrarily set, but normally 50 Torr to 600 To
It is performed under reduced pressure of rr. 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 crystal adduct, the hue is not particularly deteriorated.

[0008]

INDUSTRIAL APPLICABILITY The crystalline adduct powder obtained by the present invention is substantially free of free phenol, and the melt APHA has a hue APHA of 40 or less, usually in the range of 10 to 30.

[0009]

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

Example 1 3 liters of a phenol solution containing 22% by weight of bisphenol A was cooled to a temperature of 50 ° C. with stirring to precipitate a crystal adduct, and the resulting slurry was added to a Buchner funnel kept at 50 ° C. After filtration under reduced pressure, 850 g of a wet cake of crystal adduct was obtained. The hue APHA of the wet cake melt was 50. Next, the wet cake obtained on the funnel as described above was washed and filtered twice by spraying the surface of the cake with 400 cc of purified phenol at 50 ° C. to wash and then filtering under reduced pressure. In this case, the purified phenol was obtained by treating industrial phenol with a strong acid type ion exchange resin and then distilling it.
A hue of APHA5 was used. Next, a washing and filtering operation in which 400 cc of a room temperature toluene / n-hexane mixed solvent (mixing volume ratio: 1/1) is sprayed on the cake surface washed at room temperature with respect to the cake washed with purified phenol and then vacuum filtration is performed. Was performed twice, and then the obtained washed cake was washed and filtered twice with 400 cc of n-hexane in the same manner as above. In this case, the last vacuum filtration operation was continued for 30 minutes to remove as much of the n-hexane remaining in the cake as possible. Next, the funnel-shaped washed crystal adduct was collected in a vat and dried in an oven at 45 ° C. for 2 hours to obtain a crystal adduct powder. The crystalline adduct powder was free-flowing and easy to handle. The hue of the melt of this crystalline adduct APHA
Is 10 and the hue A of the melt of bisphenol A after separating and removing phenol from the crystal adduct
PHA was 15.

Claims (2)

[Claims] 1. A wet cake obtained by solid-liquid separation of a phenol solution containing a bisphenol A / phenol crystal adduct is soluble in phenol and has a boiling point of 60.
A method for producing a bisphenol A / phenol crystal adduct powder, which comprises washing with an organic solvent at 120 ° C, removing the organic solvent attached to the cake, and drying. 2. The method of claim 1, wherein the wet cake is previously washed with purified phenol and then washed with an organic solvent.