JPH04290862A - Production of anhydrous phenolsulfonic acid salt - Google Patents

Abstract

PURPOSE:To obtain the subject faintly colored compound having high quality with a simple apparatus while suppressing the production of by-product by removing the hydration water of a phenolsulfonic acid salt hydrate in a specific solvent. CONSTITUTION:Hydrated phenolsulfonic acid salt is dehydrated by heating in a solvent having a solubility parameter of 7.5-13 (e.g. xylene), thereby distilling out the hydration water together with the solvent at 70-220 deg.C. The amount of the solvent is 1-10 pts.wt. based on 1 pt.wt. of the phenolsulfonic acid salt. The phenolsulfonic acid salt is monosalt, disalt or their mixture of sulfonic group and hydroxyl group, e.g. phenolsulfonic acid sodium salt. The dehydration is carried out by using a conventional apparatus furnished with a distillation column and a condenser. It is not necessary to use a particular apparatus such as drying machine.

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 anhydrous phenolsulfonate, and more particularly to a method for producing anhydrous phenolsulfonate by dehydrating the hydration water of phenolsulfonate.

0002

BACKGROUND OF THE INVENTION Phenol sulfonate is usually obtained by reacting phenol with concentrated sulfuric acid and neutralizing it with various alkaline agents. For this reason, reaction water is generated in the product and phenolsulfonate containing crystal water is produced, so dehydration is required to obtain anhydrous phenolsulfonate.

Attempts to dehydrate hydrous phenolsulfonates in air at high temperatures, such as about 200° C., result in discoloration, phenol evolution, and by-product formation. Furthermore, anhydrous phenolsulfonate is heated at 200°C in air.
Decomposes when exposed to high temperatures, producing water and by-products. Attempts to dehydrate this material at lower temperatures result in inefficient and incomplete dewatering.

Drying of commercially available phenol sulfonate dihydrate crystals does not result in less than about 2% water content without excessive heating, resulting in discoloration of the product and the formation of undesirable by-products. The dihydrate can be relatively easily dried to a moisture content approximately equal to the quarter hydrate composition, but when dehydrated at low temperatures in an air atmosphere without color development, by-product formation, or both. It has been found that the moisture content of the material cannot be reduced below a ratio of about 4 moles of phenolsulfonate to 1 mole of water.

[0005] As a method for dehydrating the hydration water of phenolsulfonate, a dry method as shown in JP-A No. 62-106072 is known, but the equipment is large-scale and the dehydrated phenolsulfonate is When the acid salt is in powder form, it is difficult to handle because it exhibits strong hygroscopic properties. moreover,
In the description of JP-A-61-1655 "Method for producing p-isononanoyloxybenzenesulfonate", p-
The dehydration method for sodium phenolsulfonate is said to be ``achieved by drying or azeotropic distillation,'' but it is important to select the most suitable solvent for the dehydration method for phenolsulfonate.

[0006] As used herein, the term "anhydrous phenolsulfonate" refers to the substantial absence of water. However, small amounts of water, up to about 0.5% by weight, are acceptable, and phenol sulfonate salts with such small amounts of water are within the term "anhydrous" as used herein.

[0007] Phenol sulfonate has ortho, meta and para isomers, but ``phenol sulfonate''
The term refers to a para isomer having less than about 30% by weight of other isomers. It should also be noted that inert substances such as sulfates, carbonates, phosphates, etc. may also be present in the paraphenol sulfonate. At least 50 of the materials
% is preferably in the para-form.

[0008] An object of the present invention is to provide a method for producing high quality anhydrous phenol sulfonate with little coloring and by-products using simple equipment.

[0009]

[Means for Solving the Problems] Under the present circumstances, the present inventors have conducted extensive research to solve the above problems, and have found that by adding a hydrate of phenol sulfonate to a specific solvent and heating it, By distilling the solvent out of the system at a temperature of 70 to 220 °C, the hydration water of the phenol sulfonate is distilled out of the system along with the solvent to complete the technology to obtain "anhydrous phenol sulfonate". This led to the completion of the present invention.

[0010] That is, the present invention involves distilling a phenol sulfonate hydrate together with the solvent at a temperature in the range of 70 to 220°C using a solvent with a solubility parameter of 7.5 to 13. The present invention provides a method for producing anhydrous phenol sulfonate, which is characterized by drying and dehydrating.

[0011] Suitable solvents for use in the present invention are as follows: ■ Chemically stable ■ Does not react with phenol sulfonate ■
A solvent that satisfies the azeotrope or entrainment with water and has a solubility parameter (C
．． M. CM Hansen, J. J. Paint Tech., 39,
104 (1967),
SP value) is 7.5 to 13, preferably 8.5 to 12.5.

Examples of solvents satisfying these conditions include toluene, xylene, ethylbenzene, etc. for hydrocarbon solvents, and n-butanol, isobutanol, n-amyl alcohol, isoamyl alcohol, n-hexanol, etc. for alcohol solvents. n-heptanol, cyclohexanol, 2-ethylhexanol, etc., and nitrogen-containing solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, 1,3-dimethyl-2-imidazolidine Examples include, but are not limited to, non-containing substances, and mixtures thereof can also be used.

Solvents with a solubility parameter of less than 7.5 are difficult to handle due to their low boiling points. Also, 1
If it exceeds 3, the affinity with water is too strong, making it difficult to remove water from the solvent. The amount of solvent used is
It is preferably 1 to 10 times the weight of the phenol sulfonate. If it is less than 1 times the weight, it will be distilled out together with water, resulting in poor fluidity in the system, and if it exceeds 10 times the weight, the production efficiency will deteriorate.

[0014] Regarding the distillation temperature of the solvent, it is 70°C to 22°C.
The temperature is preferably 0°C, and more preferably 140°C to 180°C. If the temperature is lower than 70°C, the dehydration efficiency of the hydration water of the phenol sulfonate is very poor, and if the temperature exceeds 220°C, coloration tends to occur. The pressure should be determined by the boiling point of the solvent, and the distillation temperature is preferably 140°C to 180°C.
In order to maintain the temperature within the °C range, low boiling point solvents must be distilled off under pressure, and high boiling point solvents must be distilled off under reduced pressure. Note that the atmosphere is preferably nitrogen or reduced pressure; the presence of air may cause coloring and is dangerous. Although the distillation time does not affect the purity, hue, by-products, etc. of the anhydrous phenol sulfonate, it is usually preferably in the range of 1 to 7 hours.

[0015] As for the dehydration equipment, devices and methods known in the art can be used, which are equipped with a stirrer, a condenser, and a heating and cooling function. Furthermore, if a rectification column is provided, effective dehydration can be expected.

[0016] Types of salts of phenol sulfonate include alkali metal salts, alkaline earth metal salts, amine salts, etc. Examples of the alkali metal salts include sodium and potassium salts, alkaline earth metal salts, etc. Examples of the salts include calcium, magnesium, barium, etc., and amine salts include triethylamine, pyridine, ammonia, etc., but are not limited to these.

Further, as the phenol sulfonate, there are mono-salts and di-salts of a sulfonic group and a hydroxyl group, but mono-salts, di-salts, and any mixtures thereof can be applied to the present invention.

[0018]

[Effects of the Invention] According to the present invention, it is possible to produce high quality anhydrous phenol sulfonate with less coloring and fewer by-products using general reaction equipment without using special equipment such as a dryer. can.

[0019]

EXAMPLES The method of the present invention will be explained in detail with reference to Examples below, but the present invention is not limited thereto. Note that % indicates weight % unless otherwise specified.

Example-1 110 g of 98% concentrated sulfuric acid was added to 100 g of phenol at 40 g.
The mixture was added dropwise under stirring and cooling at a temperature of 90°C to 90°C to obtain 210 g of phenolsulfonic acid. The composition of this thing is that the para body is 77
%, and also contains reaction water, isomers such as ortho form, and unreacted sulfuric acid. This phenol sulfonic acid 100
782 g of 10% calcium hydroxide, 1764 g of 95% methanol was mixed with this neutralized solution, filtered, and the filter cake was dried to obtain 782 g of calcium phenolsulfonate.
3g was obtained. The moisture content of this calcium salt was 14.2%.

[0021] This calcium phenolsulfonate 50
to 300 g of N,N-dimelformamide with a solubility parameter of 12.1, and the mixture was heated to 150 to 15 g under normal pressure.
A 68 g fraction was distilled off and dehydrated at 5°C. The composition of the dehydrated product is 15.2% calcium phenolsulfonate and 84.8% N,N-dimelformamide. The moisture content of this material was 0.012%.

Example 2 50 g (moisture 4.1%) of commercially available sodium phenolsulfonate dihydrate (manufactured by Taoka Chemical Co., Ltd.) was placed in a 500 cc flask equipped with a distillation tube and a condenser, and a solvent (4.1%) was added to the flask.
DMI; 1,3-dimethyl-2-imidazolidinone,
Solubility parameter 11.0) is 4 times the weight of 20
0 g, and while stirring a small amount of nitrogen, the temperature was 1.
48 g of DMI was distilled off at 40° C. and a pressure of 100 mmHg (absolute) for dehydration. The composition of the dehydrated product is 23.7% sodium phenolsulfonate and 76% DMI.
It becomes 3%. The water content of this product was 0.002%.

Example-3 Sodium phenolsulfonate 2 used in Example-2
Water and caustic soda were added to the hydrate to prepare disodium salt of phenolsulfonic acid, which was then dehydrated to obtain a powder. The moisture content of this product was 14.8%. This phenolsulfonic acid disodium salt was added to the flask used in Example-2.
Take 0g and add xylene (solubility parameter 8.8
) was added, and 73 g of xylene was distilled off at 138° C. under normal pressure to attempt dehydration. The composition of the dehydrated product is 24.0% disodium phenolsulfonate and 76.0% xylene. The water content of this mixture is 0
．． It was 0.002%.

Comparative Example-1 Sodium phenolsulfonate 2 used in Example-2
50 g of hydrate was placed in a 500 cc flask equipped with a distillation tube and condenser, and a solvent (solubility parameter 18
．． 1, hydrazine) was added, and 53 g was distilled off under stirring at a temperature of 113° C. to 120° C. and normal pressure. The composition of the dehydrated product is sodium phenolsulfonate: 19
．． At 4%, hydrazine becomes 80.6%. The moisture content of this mixture was 0.8%.

Comparative Example-2 The disodium phenolsulfonic acid salt with a water content of 14.8% used in Example-3 was dried in a shelf dryer (DP manufactured by YAMATO).
22), and dried at 130° C. to 140° C. for 48 hours while passing nitrogen at 1 liter/min. The moisture content of this product was 0.92%.

Claims (3)

[Claims] [Claim 1] A hydrate of phenol sulfonate,
Using a solvent with a solubility parameter of 7.5 to 13,
A method for producing anhydrous phenol sulfonate, which comprises distilling water of hydration together with a solvent and dehydrating it at a temperature in the range of 70 to 220°C. 2. The production method according to claim 1, wherein the phenol sulfonate is a mono- or di-salt of a sulfonic group and a hydroxyl group, or a mixture thereof. 3. The method according to claim 1, wherein the type of salt is an alkali metal salt, an alkaline earth metal salt, or an amine salt.