JPS62138443A - Production of biscresol - Google Patents

Abstract

PURPOSE:To obtain biscresol A useful as a raw material of polycarbonate resin, etc., from o-cresol and an acetone compound in high purity with simple procedure, by recrystallizing crude product with o-cresol. CONSTITUTION:2,2-Bis(4-hydroxy-3-methyl)propane (biscresol A) is produced by reacting o-cresol with actone or its derivatiee(e.g. 1,1-diacetoxypropane) in the presence of excess o-cresol under the action of e.g. an acid catalyst. In the above process, the produced crude biscresol A is recrystallized with o-cresol. The purification step can be simplified and the objective compound can be economically purified on an industrial scale without using other organic solvent. The amount of o-cresol necessary for the purification of the objective compound is selected to give the crude product having a concentration of 20-60wt% in said compound.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides 2,2-bis(4-hydroxy-3-methylphenyl)propane (hereinafter referred to as bis-cresol A).
Relating to a manufacturing method.

For more details, see 0-cresol and acetone or its rust. The present invention relates to a method for producing high-purity bis-cresol A, which is characterized by recrystallizing crude bis-cresol 8 obtained by reacting with 0-cresol.

Biscresol A is similar to 2,2-bis(4-hydroquinphenyl)propane (hereinafter referred to as bisphenol 8) produced from fluorinol and acetin, as well as polycarbonate, epoxy resin, and aromatic polynitryl. It is used as a raw material for etc.

For such uses, high purity products are used,
Needs to be highly purified.

(Prior Art) Conventionally, several known methods have been applied to produce biscresol.

Most commonly, methods similar to those for the production of bisphenol are applied, for example, condensation dehydration of excess 0-cresol and acetone in the presence of an acid catalyst to obtain the crude product, followed by subsequent treatment with a catalyst. of excess.

-Cresol is removed and, if necessary, the product is purified by distillation, recrystallization from an organic solvent, etc. Specific examples of such methods include Wm, H, Mo
USP 2,211,070 (1941) to 5s et al. describes a method in which it is produced from 0-cresol and acetone using hydrochloric acid as a catalyst and recrystallized with a halogenated hydrocarbon, such as carbon tetrachloride.

In addition, Japanese Patent Publication No. 47-50616 describes a method for producing O-cresol, 〇-tolyl acetate, and acetone as raw materials, and furthermore, Japanese Patent Publication No. 55-1515
No. 12 discloses a method for producing it from 0-cresol and 1,1-diacetoxypropane.

Furthermore, Japanese Patent Publication No. 47-50616 and Japanese Patent Publication No. 55-
No. 151,512 describes that biscresol is isolated by treatment in the same manner as in the production of bisphenol. In this method, bisphenol A is isolated by removing crystals of an adduct of phenol and bisphenol A, and then removing phenol from the adduct by a method such as distillation under reduced pressure and heat.

A similar method was used by Shimauchi (Journal of the Chemical Society of Japan 1982 (8) p.
1363-1370), but here, refined biscresol is obtained by further recrystallizing the crude biscresol obtained by the above method with benzene.

Any of these methods requires a long purification process, uses an aqueous solvent and requires a recovery process, and is extremely complicated to implement industrially.

(Problems to be Solved by the Invention) An object of the present invention is to provide a method for producing biscresol that is simple and highly effective in purification.

(Means for Solving the Problems) In order to achieve the above object, the inventors have conducted extensive studies and found that
Bis-cresol A does not form an addition product with O-cresol, and Bis-cresol A does not form an addition product with O-cresol.
Separation is possible using the difference in solubility in cresol,
The inventors have discovered that the resulting bis-cresol A crystals contain almost no impurities other than the mother liquor adhering to the crystals, and that highly pure bis-cresol A can be produced by a simple method, leading to the present invention.

Of course, the present invention deals with the production of crude 2,2-bis(4-hydroxy-3-methylphenyl)propane from 0-cresol and acetone or its derivatives. -3-methylphenyl)
This method recrystallizes propane with o-cresol and isolates it to produce highly pure 2,2-bis(4-hydroxy-3-methylphenyl)propane.

The present invention will be explained in detail below.

In the process of the invention the phase 2.2-bis(4-hydroxy-3-
Methylphenyl)propane is not particularly limited as long as it can be produced by any method. Most importantly, excess O-cresol or a derivative thereof, such as 0-tolylacetate and acetone or a derivative thereof, such as 1,1-diacetoxypropane, under the action of an acid catalyst,
-obtained in the presence of cresol. It can also be produced from p-isopropenyl-〇-cresol and 0-cresol in a stoichiometric excess of γ.

After completion of the reaction, the reaction product liquid can be directly purified, but of course, crude bisphenol A obtained by isolation by a conventional method may also be used.

Furthermore, bis-cresol 8, which contains impurities and for which sufficient purity cannot be obtained by other purification methods, may be dissolved in 0-cresol.

The amount of O-cresol required to purify crude bisphenol A may be selected within a range such that the content of crude bisphenol A in O-cresol is 20 to 60% heavy mold.

Since bis-cresol Δ has a slight solubility in 0-cresol, the concentration in bis-cresol increases during crystal precipitation. The concentration of the 0-cresol f8 liquid during crystallization is controlled within the temperature range in which bis-cresol A crystals do not precipitate within the above-mentioned bis-cresol A concentration range. For example, when the concentration of biscresol A is 20%, 50%
℃ or higher, and when the concentration of biscresol A is 60%, the temperature is 80℃ or higher.

The 0-cresol solution of crude bis-cresol A may contain water or may not contain water.

When the crude bis-cresol A to be treated is a reaction product liquid that is subsequently treated, the reaction to produce the crude bis-cresol is preferably carried out with a slight excess of 0-cresol. That is, the ratio of bis-cresol A produced and unreacted O-cresol is 1:2.
It is more preferable to carry out the mixing at a ratio of 1:10 to 1:10. After the reaction, the O-cresol-J compound of bis-cresol A can be obtained directly by removing the catalyst or when using a reaction fixed bed catalyst bed.

Crystallization from solution can be carried out using any crystallization method.

One method is to add water to an 0-cresol solution of crude bis-cresol A, and cool it by distilling it under reduced pressure to obtain crystals. Water can be added to the 0-cresol solution in bis-cresol before crystallization, or it can be added to the slurry mixture that is crystallizing.

The latter method is advantageous when crystallization is carried out continuously. In this case, the operating pressure is 20-100 vllg,
Water containing 2 to 20% water, or etc. -0-
Purer crystals of bis-cresol A can be obtained each time the cresol mixture is added and cooled to a temperature in the range of 25 to 70°C.

Cooling for crystallization involves reaction product water, unreacted acetone,
Heat removal by evaporation of 0-cresol itself can also be used.

The crystals thus obtained can be separated using conventional separation methods, i.e.
It is separated from the mother liquor by filtration, centrifugation, etc.

The mother liquor can be dehydrated if necessary, further concentrated if necessary, and used as a raw material for biscresol A newly produced by the method of the present invention.

The separated crystals can be used as products as they are depending on the purpose. If necessary, water, O-cresol,
After washing with a solvent such as an aromatic hydrocarbon or an aliphatic hydrocarbon and then drying, the product can be made into a product. In some cases, it is possible to dissolve the crystals and completely remove the remaining adhering mother liquor by heating, vacuuming, stripping, etc., and then take out the desired product form.

The bis-cresol A thus obtained is pure white and can be used directly in applications requiring high purity bis-cresol, including the production of polycarbonate resins.

(Example) Hereinafter, the present invention will be explained in detail with reference to Examples.

Example-1 O-cresol 162g (1.5 mol), acetone 14
．． 5 g (0.25 mol) was mixed, and a pre-composition reaction was carried out at 45° C. for 8.5 hours while hydrogen chloride was further blown into the mixture. The reaction mixture was heated under reduced pressure to remove hydrochloric acid and water produced by the reaction. This dehydrochloric acid solution was cooled to precipitate crystals. After the crystals were filtered through d0, they were washed with 3 times the amount of Hensen to obtain pure biscresol. As a result of high-speed 'tf1 body chromatography analysis, the purity of the crystals was 99.4%.
and contained 0.6% isomer.

Comparative example-1 The reaction was carried out in the same manner as in Example-■.

The reaction mixture was allowed to stand at room temperature, but at 40
A crystal of g was obtained. The purity of the crystal obtained by treatment in the same manner as in Example-1 was 97.1%.

Example-2 Crude biscresol was prepared in the same manner as in Example-1.
- It was mixed and melted with cresol and cooled to room temperature to obtain crystals. Pure biscresol was obtained with a yield of 85%. As a result of analysis, the purity was 99.6%.

Example-3 O-cresol, acetone, and bis-cresol were produced in the same molar ratio as in Example-1.

Bis-cresol 38% Isomers 2.3% Other impurities 1.8% 0-cresol 57.9% This 0-cresol solution is grown in a crystallization tank of 30 mm and 11 g at a flow rate of 400 kg/hour at 90°C. Water was added at a rate of 30 kg per hour. The internal temperature of the crystallization tank was kept constant at 35°C. A liquid containing crystals was continuously extracted from the crystallization tank and passed through i+. The crystals were continuously washed with 0-cresol, and the composition of the obtained crystals was as follows.

Bis-cresol 92.7% Isomers 0.2% Other impurities 7.1% 0-cresol Only gM detected O-cresol was removed from the crystals by steam treatment and pure white bis-cresol with a purity of 99.8% was obtained. Obtained.

(Effects of the Invention) As described in detail above, the present invention provides a method for producing biscresol with high purity.

This method is characterized by the fact that the product is recrystallized using raw materials, which makes it possible to simplify the process and makes industrial contributions such as eliminating the need to use other organic solvents in the manufacturing process. big.

Claims (1)

[Claims] 1) 2,2-bis(4-hydroxy-3-methylphenyl) from o-cresol and acetone or its derivative
Crude 2,2-bis(
4-Hydroxy-3-methylphenyl)propane to o-
High purity 2,2-bis(4-hydroxy-3-methylphenyl) characterized by recrystallization with cresol
How to make propane.