JP3003294B2 - Method for producing bisphenol A - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a reaction between acetone and phenol (hereinafter abbreviated as PL) to form bisphenol A (2,2-bis (4-hydroxyphenyl) propane, hereinafter 4,4'-BPA). Abbreviated as). 4,4′-BPA is a compound useful as an intermediate material of polycarbonate, polyester, epoxy resin, and a developer for thermal paper.

[0002]

2. Description of the Related Art 4,4'-BPA is usually synthesized by reacting PL with acetone in the presence of an acidic condensing agent, and a sulfur compound such as methyl mercaptan may be added as a co-catalyst. Hydrogen chloride is usually used as an acidic catalyst, but because of its high corrosiveness, a reactor using expensive materials is required for actual production, and purification for removing the catalyst from the reaction mixture is required. There was a problem that a process was required.

Further, the method using an acidic ion exchange resin as a catalyst (Japanese Patent Application Laid-Open No. 36-23334) has a drawback that the activity is reduced by water generated by the reaction.
Although a method of carrying out the reaction while removing water has been studied (Japanese Patent Application Laid-Open No. 61-78741), the ion exchange resin has a problem that the life of the resin is short and the cost is high.

On the other hand, JP-A-2-45439 discloses that
A method for producing a bisphenol using a heteropolyacid as an acidic condensing agent using a PL and a ketone is disclosed. For example, in a reaction between PL and acetone, when a large amount of water of crystallization is contained in the heteropolyacid, a temperature of 60 ° C. There is a drawback that the reaction is very slow with an acetone conversion rate of 2.5% and a yield of 2.0% in 4 hours. This reaction, in which water is produced, was not considered to be an industrially produced catalyst.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a process for producing 4,4'-BPA from PL and acetone without using a special material for the reactor, and in a short time, high selectivity and high yield. It is an object of the present invention to provide a method for producing 4,4′-BPA by the method described above.

[0006]

The present inventors have made it possible to react acetone and PL in the presence of a heteropolyacid and an organic compound having a mercapto group without using corrosive hydrogen chloride. Hardly affected by water generated by the reaction, 4,4 '
-A method for producing BPA has been found. In addition, when a heteropolyacid salt is used, the surface area is increased as compared with a normal heteropolyacid, and the activity is increased. Therefore, it has been found that the reaction proceeds in a shorter time, and the present invention has been achieved.

That is, the present invention provides a method for producing 4,4′-BPA by reacting acetone and PL, wherein the reaction is carried out in the presence of a heteropolyacid or a salt thereof and an organic compound having a mercapto group. 4,4 '
-A method for producing BPA. (Acetone) The acetone used in the present invention is not limited to one purified by distillation, but may be crude acetone obtained from the distillation column bottom in the cumen phenol process. (Heteropolyacid or heteropolyacid salt) The heteropolyacid used in the present invention is at least one oxide selected from molybdenum, tungsten, and vanadium, and phosphorus,
A structure in which an oxyacid selected from silicon, arsenic and germanium is condensed, and the atomic ratio of the former to the latter is 2.5 to
Twelve. As these heteropolyacids, for example, phosphotungstic acid, phosphomolybdic acid, phosphomolybdotungstic acid, phosphomolybdovanadic acid, phosphomolybdung tungstovanadic acid, phosphorus tungstovanadic acid, phosphomolybdniobic acid, silicotungstic acid, Examples include silicomolybdic acid, silicomolybdotungstic acid, silicomolybdo tungstovanadic acid, germanium tungstic acid, arsenic molybdic acid, arsenic tungstic acid, and the like.

Further, sodium of these heteropoly acids,
Alkali metal salts such as potassium and cesium, and ammonium salts can also be used, and among them, cesium salts are particularly effective. These heteropolyacids or heteropolyacid salts can be used as they are, but activated carbon, alumina,
Those supported on a carrier such as silica-alumina and diatomaceous earth may be used.

The amount of the heteropolyacid or heteropolyacid salt used is preferably from 0.01 to 0.1 mol per mol of acetone.
5 mol, particularly preferably in the range of 0.05 to 0.3 mol. (Organic compound having a mercapto group) Specific examples of the organic compound having a mercapto group include alkyl mercaptans such as ethyl mercaptan, propyl mercaptan, and butyl mercaptan; mercapto carboxylic acids such as mercapto propionic acid and mercapto acetic acid; mercapto ethanol; Mercapto alcohols such as mercaptobutanol; mercaptopyridines such as mercaptopyridine, mercaptonicotinic acid, mercaptopyridinoxide, and mercaptopyridinol; thiophenols such as thiophenol and thiocresol; and alkyl mercaptans and the like. Mercaptocarboxylic acids are particularly preferred.

The amount of the organic compound having a mercapto group is preferably 0.1 to 50% by weight, particularly preferably 0.5 to 30% by weight, based on acetone. (Reaction conditions) The amount of PL used was 2 per mol of acetone.
It is at least 3 moles, but preferably 3 to 20 moles. P
When the amount of L used is 2 mol or less, the reaction is slow and, in addition to the target 4,4′-BPA, 2- (2-hydroxyphenyl) -2- (4-hydroxyphenyl) propane (hereinafter referred to as 2 , 4'-BPA) is not preferred because it increases the amount of by-products, and the use of more than 20 moles increases the reaction rate, but increases the amount of unreacted PL recovered and decreases the productivity, which is practical. Not.

The reaction temperature is 30-150 ° C., preferably 4
0-120 ° C. The reaction time depends on the amount of the catalyst and the reaction temperature, but is usually 2 to 12 hours.

[0012]

According to the method of the present invention, 4,4'-BPA can be produced in a short time without using a highly corrosive catalyst such as hydrogen chloride and hardly affected by generated water. It can be produced with high yield and high selectivity.

[0013]

The present invention will be described more specifically with reference to the following examples and comparative examples. The conversion, yield and selectivity in the text are defined by the following equations. Quantification of 4,4′-BPA and the like was performed by high performance liquid chromatography, and quantification of acetone and phenol was performed by gas chromatography.

[0014]

## EQU1 ## Acetone conversion (%) = (Amount of reacted acetone (mol) / Amount of acetone charged (mol)) × 100

[0015]

## EQU2 ## 4,4'-BPA yield (%) = (amount of 4,4'-BPA produced (mol) / amount of acetone charged (mol)). Times.100

[0016]

3,4′-BPA selectivity (%) = (4,4′-BPA yield (%) ÷ acetone conversion (%)) × 100

[0017]

4,4′-BPA position selectivity (%) = {4,4′-BPA (mol)） (4,4′-BPA + 2,4′-BPA (mol))} × 100 (Example) 1) 1 equipped with thermometer, reflux condenser and stirrer
In a 00 ml three-necked flask, 30.1 g of phenol (3
20 mmol), 1.85 g of acetone (32.0 mmol
l) and 0.14 g of butyl mercaptan
8. Silicotungstic acid (H ₄ SiW ₁₂ O ₄₀ .6H ₂ O) which was dried at 0 ° C. under reduced pressure to make crystal water 6 molecules per molecule.
2 g (3.2 mmol) was added and reacted at 60 ° C. for 6 hours. As a result, the conversion of acetone was 94.7%,
The yield of 4′-BPA is 93.1%, the selectivity of 4,4′-BPA is 98.3%, and the selectivity of 4,4′-BPA is 9%.
8.5%. (Example 2) 9.6 g (3.2 mmol) of a cesium phosphotungstate salt in which one proton was replaced with cesium as a heteropolyacid and dried under reduced pressure at 100 ° C. to make 7 molecules of crystallization water per one molecule of the heteropolyacid. The reaction was carried out in exactly the same manner as in Example 1 except that As a result, the conversion of acetone was 100%, the yield of 4,4′-BPA was 97.2%, and the selectivity of 4,4′-BPA was 97.2.
%, 4,4′-BPA position selectivity was 97.3%. Example 3 A reaction was carried out in exactly the same manner as in Example 1 except that 9.0 g (2.7 mmol) of commercially available silicotungstic acid was used as a heteropolyacid without drying under reduced pressure. As a result, the conversion of acetone was 98.8.
%, 4,4′-BPA yield was 86.0%,
The BPA selectivity was 87.0%, and the 4,4′-BPA position selectivity was 95.7%. (Comparative Example 1) A reaction was carried out under the same conditions as in Example 1 except that butyl mercaptan was not added and the catalyst was not dried under reduced pressure. As a result, the conversion of acetone was 65.8.
%, The yield of 4,4′-BPA was 36.4%,
The BPA selectivity was 55.3% and the 4,4'-BPA position selectivity was 89.5%. (Comparative Example 2) A reaction was carried out under the same conditions as in Example 1 except that the reaction was carried out for 4 hours without adding butyl mercaptan. Acetone conversion is 11.2%, 4,4'-B
PA yield was 9.5% and 4,4′-BPA selectivity was 8
4.8% and 4,4′-BPA position selectivity were 85.7%. (Comparative Example 3) A strongly acidic cation exchange resin (Amberlyst 1) vacuum-dried at 80 ° C for 5 hours instead of the heteropolyacid
The reaction was carried out under the same conditions as in Example 1 except that 0.3 g of Rohm & Haas Co., Ltd.) was used. The conversion of acetone was 47.9%, and the yield of 4,4'-BPA was 46.
2%, 4,4′-BPA selectivity is 96.5%, 4,4 ′
-BPA position selectivity was 98.9%.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-4-145039 (JP, A) JP-A-2-45439 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C07C 37/20 C07C 39/16 C07B 61/00 300

Claims (1)

(57) [Claims] 1. A method for producing bisphenol A by reacting acetone and phenol, wherein the reaction is carried out in the presence of a heteropolyacid or a heteropolyacid salt and an organic compound having a mercapto group. .