JPS6013752A - Composition of aromatic sulfonic acid aqueous solution - Google Patents

Abstract

PURPOSE:To provide a composition of an aromatic sulfonic acid aqueous solution useful as a catalyst of an acid-curable resin resistant to the precipitation of crystal even at a low temperature, and containing a specific amount of xylenesulfonic acid and a specific amount of an aromatic sulfonic acid containing ethylbenzenesulfonic acid. CONSTITUTION:10-50wt% xylenesulfonic acid is mixed with 50-90wt% ethylbenzenesulfonic acid, and the mixture is sulfonated to obtain an aromatic sulfonic acid, and an aqueous solution of the aromatic sulfonic acid having the aromatic sulfonic acid concentration of 50-95wt% is prepared therefrom. The composition may be incorporated further with water, an alcohol such as methanol, inorganic acid such as phosphoric acid, a surface active agent, etc. USE:Useful as a synthetic intermediate of various pharmaceuticals. Also useful as a catalyst for the acid-curable resin such as phenolic resin, furan resin, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an aromatic sulfonic acid bath solution composition that prevents crystal precipitation at low temperatures.

Aromatic sulfo/acids have been widely used as intermediates for various synthetic chemicals and as catalysts for acid-curing resins such as phenol resins and 7-run resins.

Particularly in the latter application, xylene sulfonic acid is mainly used, and is generally used in the form of an aqueous solution in most cases.

However, in a xylene sulfonic acid aqueous solution, the higher the sulfonic acid concentration, the more likely sulfonic acid crystals will precipitate at low temperatures. Especially at low temperatures such as winter, acid strength is high, i.e. sulfone 21.
Although it is necessary to use a catalyst with a high temperature of 111 degrees Celsius, there are problems with workability, such as pump clogging due to crystal precipitation.

Generally, the stronger the acidity of a catalyst for an acid-curing resin, the faster the curing reaction. Due to the problem of crystal precipitation at low temperatures, there is a limit to increasing the concentration of sulfonic acid for catalysts that require fast curing in winter, and the lack of acid strength is usually compensated for with an inorganic acid such as sulfuric acid. ing. However, use of a large amount of inorganic acid significantly reduces the physical properties of the cured product.

Although it is possible to speed up the curing reaction by increasing the tsJl, this also reduces the physical properties of the cured product.

The present inventors have attempted to solve this problem (as a result of extensive research), by using an aromatic sulfonic acid containing xylene sulfonic acid and a certain amount or more of ethylbenzenesulfonic acid in a xylene sulfonic acid-based aqueous solution, sulfonate The present invention was achieved by discovering that crystal precipitation at low temperatures can be prevented without reducing acid concentration.

That is, the present invention is directed to crystallization of sulfonic acid at low temperatures characterized by containing 50 to 95% by weight of aromatic sulfonic acids including 10 to 50ii% of xylene sulfonic acid and 50 to 90% by weight of ethylbenzenesulfonic acid. An object of the present invention is to provide an aromatic sulfonic acid aqueous solution composition that prevents

As a method for obtaining the aromatic sulfonic acid aqueous solution composition of the present invention, any of the following methods (1) and (2) may be used.

■ Method of adding and mixing ethylbenzenesulfonic acid to xylene sulfonic acid or its aqueous solution ■ Xylene 10-5
A method for preparing a water bath solution from an aromatic sulfonic acid obtained by sulfonating a xylene/ethylbenzene mixture containing 0% by weight and 50 to 90% by weight of ethylbenzene.Also, the aromatic sulfonic acid aqueous solution of the present invention! Even if components other than water and aromatic sulfonic acid are added to the composition, such as alcohols such as methanol and ethanol, inorganic acids such as phosphoric acid and sulfuric acid, or surfactants, the effects of the present invention will not be lost. .

The present invention will be further explained in detail with reference to Examples below. still,
The aromatic sulfonic acid used in the examples was an aromatic hydrocarbon obtained by blending a predetermined amount of ethylbenzene with industrial xylene containing 77% by weight of xylene (ortho, meta, and It was obtained by sulfonation (see Table 1).

Table 1 Example 1 Ethylbenzenesulfonic acid was blended with sulfone ff1h to obtain an aromatic sulfonic acid containing a predetermined amount of ethylbenzenesulfonic acid. Water was added to this to form an aqueous solution, and precipitation of sulfonic acid crystals at low temperatures was observed. Incidentally, the temperature at which it was allowed to stand was -20 tl'. The results are shown in Table-2.

Table 2: Seed crystal precipitation tends to be improved when the content of heavy ethylbenzenesulfonic acid is high, but the effect is particularly significant at 50 to 90%.

Example 2 Sulfonic acid A-g, xylene sulfonic acid and ethylbenzenesulfonic acid were made into an aqueous solution, and precipitation of sulfonic acid crystals at -200 was observed. The results are shown in Table-6.

The results obtained in Example-2 are totally (same) as the results obtained in Example-1, and the ethylbenzenesulfonic acid content is 50 to 90.
%, particularly good results were obtained.

Example 3 Compressive strength was measured when foundry sand was cured using a 70% aqueous solution of sulfonic acids A to E and xylene sulfonic acid as a catalyst and a 7 run resin as a binder. That is, 0.5 parts by weight of a sulfonic acid water bath solution was added to 100 parts by weight of foundry sand, and the mixture was mixed for one time. Furthermore, add furan resin type 1 foot part,
1.Mix the gaps. This mixed sand was filled into a test piece, and the compressive strength was measured after 1.3 and 24 hours. The results are shown in Table 4.

Table 4 As is clear from Table 4, no deterioration in physical properties was observed when the amount of ethylbenzenesulfonic acid in the aromatic sulfonic acid was increased to 90 wt%.

Applicant's agent Kaoru Furutani

Claims (1)

[Claims] Xylene sulfone M 10-50% by weight Oyohyethylbenzenesulfonic acid 50-9% by weight Aromatic sulfonic acid containing 50-95% by weight to prevent crystal precipitation of sulfonic acid at low temperatures Group sulfo/acid water bath composition.