JPH02208322A - Production of sulfonated resin - Google Patents

Abstract

PURPOSE:To obtain a sulfonated resin of a freely controllable ion exchange capacity by dissolving a polyaryl ether sulfone having specified repeating units in conc. sulfuric acid and sulfonating it by the addition of a sulfonating agent. CONSTITUTION:At least 40wt.% polyaryl ether sulfone having repeating units of the formula is dissolved in conc. sulfuric acid of a concentration >=90wt.% to obtain a solution of a viscosity <=400cp. To this solution is added 0.5-2.5mol of a sulfonating agent (e.g. chlorosulfonic acid) per mol of the repeating units of the polyaryl ether sulfone, and the mixture is sulfonated at 10-60 deg.C with agitation for at most 15hr and then added dropwise to chilled water at 10 deg.C or below to deposit the sulfonated resin. This sulfonated resin is filtered and washed with deionized water while being finely divided to a particle diameter <=1mm.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing sulfonated resins, and in particular, improves chemical and physical properties by sulfonating a polyarylether sulfone having a specific repeating unit. The present invention relates to a method for producing a sulfonated resin having excellent properties with high productivity.

[Prior Art] Conventionally, the conventional method for sulfonating repeating units of type I, type II, and type III described below involves converting polysulfone having repeating units of type I-III to 1,2-dichloroethane, chloroform, etc. It was dissolved in a solvent and sulfonated by adding chlorosulfonic acid, sulfuric anhydride, concentrated sulfuric acid, etc. as a sulfonating agent.

A polyarylether sulfone having repeating unit is provided as a commercial product "rVictrex",
It has superior properties in terms of chemical stability, physical strength, and heat resistance compared to the above-mentioned types (■) to (III) polyaryl ether sulfones.

Therefore, for such boaryaryl ether sulfones,
If an appropriate amount of sulfone group can be introduced, a sulfonated polysulfone resin having better properties than conventional products can be obtained.

[Problems to be Solved by the Invention] However, the above-mentioned I to III in which the repeating unit is a polyaryl ether sulfone
If sulfonation is attempted in the same manner as the sulfonation method for type polysulfone, first, the sulfonating agent is added to this suspension because it is not dissolved in 1,2-dichloroethane or chloroform, but merely suspended. Even if sulfonation is possible by adding , the sulfonation reaction may be considerably heterogeneous. It has been confirmed through experiments by the present inventors that this polyaryl ether sulfone cannot be sulfonated by conventional methods for sulfonating polysulfones of types (1) to (III).

The present invention has been made in view of the above-mentioned conventional circumstances, and it is possible to sulfonate polyarylether sulfone having the above-mentioned specific repeating unit efficiently and in a desired ratio, thereby achieving various properties with high productivity. The purpose of the present invention is to provide a method for producing a sulfonated resin with excellent properties.

[Means for Solving the Problems] The method for producing a polysulfonated resin of the present invention uses a polyaryl ether sulfone (hereinafter sometimes abbreviated as rPEsJ) having a repeating unit represented by the following structural formula.
It is characterized in that after dissolving in concentrated sulfuric acid, a sulfonating agent is added for sulfonation.

The present invention will be explained in detail below.

In the method for producing a sulfonated resin of the present invention, the molecular weight of PES used as a raw material is not particularly limited, and it may have other repeating units or substituents in addition to the repeating units described above. Specifically, Victrex (product name) 3600P and 4100, which are provided as commercial products,
P, 5200P, etc. can be used.

Such raw material PES is first added to concentrated sulfuric acid and sufficiently stirred to uniformly dissolve it. The concentrated sulfuric acid used has a concentration of 90% by weight or more, preferably 98% by weight.

The amount of PES dissolved in concentrated sulfuric acid should be enough to dissolve PES and maintain a solution state.
Sulfonation can be carried out even at low concentrations.

However, in order to cause the sulfonation reaction to occur uniformly, it is preferable that the viscosity of the PE5-concentrated sulfuric acid solution be such that it can be quickly and uniformly stirred when the sulfonating agent is added in the subsequent step. , the PE5-concentrated sulfuric acid solution has a pESIA degree of 40% by weight or less, especially 20% by weight
Hereinafter, the solution viscosity is preferably 400 c,p or less.

If the PES concentration exceeds 40% by weight, the solution may become viscous and the sulfonation reaction may become non-uniform.

Specifically, 3700 g of PE was mixed with concentrated sulfuric acid (97% by weight) 3
When added at 5°C (6440'g), it can be dissolved in about 6 hours, and the resulting solution has a PES concentration of 98% by weight.

Next, a sulfonating agent is added to the obtained PE5-concentrated sulfuric acid solution, followed by stirring at a predetermined temperature for a predetermined time to cause a reaction. The sulfonating agent used is
Any material that can introduce a sulfonic group may be used, and there are no particular limitations, but it is advantageous to use chlorosulfonic acid or sulfuric anhydride. The larger the amount of the sulfonating agent added, the higher the degree of sulfonation of PES, that is, the higher the ion exchange ability of the resulting sulfonated resin, and the lower the amount, the lower the degree of sulfonation.

In the present invention, there is no particular restriction on the addition ratio of the sulfonation agent, but it is preferable that the addition ratio of the sulfonation agent is 0.5 to 2.5 moles per mole of repeating units of PES. The addition ratio of this sulfonating agent is 0.
If it is less than 5 mol, the sulfonation reaction will be difficult to proceed, and 2.
When the amount exceeds 5 mol, the sulfonation rate becomes too high, and the produced sulfonated resin becomes dispersed or dissolved in water, making it difficult to purify and recover the product.

The reaction temperature and reaction time also influence the degree of sulfonation; the higher the reaction temperature and the longer the reaction time, the higher the degree of sulfonation.

In the method of the present invention, if the reaction temperature is less than 10°C, the sulfonation reaction will hardly proceed, and if it exceeds 60°C, the raw material PES
may deteriorate. Further, the reaction proceeds at a relatively high reaction rate until the reaction time is 3 hours, but when it exceeds 3 hours, the reaction rate rapidly decreases, and the reaction does not proceed even if the reaction is continued for 15 hours or more. Therefore, in the present invention, the reaction temperature is 10 to 60°C, and the upper limit of the reaction time is 3 to 15°C.
Preferably, it is an hour.

After the reaction is completed, the reaction solution is slowly dropped into cold water to precipitate the product.

The temperature of the cold water used may be below the reaction temperature, but preferably below 10°C. That is, if the temperature is below 10°C, the sulfonation reaction can be slowed down or stopped depending on the temperature conditions, and during this time the sulfonation agent reacts and decomposes with water.
The sulfonation reaction is completely stopped. The amount of cold water may be such that the product in the reaction solution is quickly solidified and the temperature of the cold water does not rise rapidly due to the heat of dilution of the acid and water. The dropping rate may be, for example, the same as when diluting sulfuric acid with water.

By dropping the reaction solution into cold water in this manner, the product, sulfonated resin, usually precipitates out as a white precipitate.

The obtained precipitate is separated by filtration according to a conventional method, and washed with pure water while being finely ground using a Waring blender or the like. The reason why the product is crushed here is to make the particle size of the product uniform,
This is to facilitate cleaning. The degree of pulverization is not particularly specified, or it is usually a powder with a particle size of about 1 mm, which is preferable in terms of ease of cleaning and handling.

The degree of sulfonation of the sulfonated resin thus obtained can be easily determined by TR analysis or measurement of ion exchange capacity.

[Operation] PES can be sulfonated by adding a sulfonating agent to PES dissolved in concentrated sulfuric acid and causing the reaction to occur. By appropriately selecting the addition ratio of the sulfonating agent, reaction temperature, and reaction time, the degree of sulfonation, that is, the ion exchange capacity of the resulting sulfonated resin, can be easily controlled to a desired value. .

[Example] The present invention will be described in more detail by giving Examples and Comparative Examples below.

Example 1 Victrex 3600p (rV
It is abbreviated as ictrex PE5J. ), add 20g of it to 110mft of concentrated sulfuric acid (98% by weight) and
The mixture was stirred for an hour to obtain a viscous solution (viscosity: 400 c, p, or less). Add chlorosulfonic acid (96% by weight) to this solution 6
mI! , and continued stirring at 25° C. for 12 hours. Next, when this solution was dropped into ultrapure water, a white precipitate was deposited. This white precipitate was filtered off and washed with ultrapure water while pulverizing it using a Waring blender until sulfuric acid or hydrochloric acid was no longer detected. The resulting product was dried in the open at about 80° C. overnight.

As a result of analysis by FT-IR, the product was confirmed to be PES into which a sulfone group had been introduced. When the ion exchange capacity of this product was measured, it was found to be 0.2 meq/g.

Example 2 A product was obtained in the same manner as in Example 1 except that the reaction was carried out at 35°C.

As a result of analysis by FT-IR, the product was confirmed to be PES into which a sulfone group had been introduced. The ion exchange capacity of this product was measured and found to be 0.5 meq/g.

Example 3 520 g of Victrex PE was dissolved in concentrated sulfuric acid (98% by weight)
) 110 mA and stirring for 8 hours to obtain a viscous solution (viscosity 400 c, p, or less).

Add 6.7 m of sulfuric anhydride (γ type, 99.4% by weight) to this solution.
u and continued stirring at 40°C for 15 hours. Next, when this solution was dropped into ultrapure water, a white precipitate was deposited. This white precipitate was filtered off and washed with ultrapure water while pulverizing it finely using a Waring blender until sulfuric acid and hydrochloric acid were no longer detected. The resulting product was dried in an oven at 80° C. overnight.

As a result of analysis by FT-IH, the product was confirmed to be PES into which a sulfone group was introduced. Its ion exchange capacity was found to be 35 meq/g.

Examples 4 to 6 The amount of chlorosulfonic acid added was 1 mol per mol of the repeating unit of Victrex PES, and the reaction temperature was 2.
The product was obtained in the same manner as in Example 1, except that the reaction was carried out at 0°C for 1 hour (Example 4), 2 hours (Example 5), or 3 hours (Example 6). Ta.

The ion exchange capacity of the obtained product was measured and the result was
Shown in the figure.

It is clear from FIG. 1 that the degree of sulfonation can be changed by changing the reaction time, and that the longer the reaction time, the higher the sulfonation rate.

Examples 7 and 8 The amount of chlorosulfonic acid added per mole of repeating units of Victrex PES was changed, and the reaction temperature was adjusted to 20°C.
A product was obtained in the same manner as in Example 1 except that the reaction was carried out at 40° C. (Example 7) or 40° C. (Example 8) for 15 hours.

The ion exchange capacity of the obtained product was measured and the result was
Shown in the figure.

It is clear from FIG. 1 that the higher the reaction temperature, the higher the sulfonation rate, and the higher the proportion of the sulfonating agent used, the higher the sulfonation rate.

Comparative Example I 5700 g of Victrex PE was dissolved in 6440 g of 1,2-dichloroethane, and 209 mj2 of chlorosulfonic acid was added at room temperature. The solution was stirred and reacted, and samples were taken over time after 1,3,615,25,48 hours. After washing each sample, its ion exchange capacity was measured, but like the raw material PES, none of the samples had ion exchange capacity. Further, analysis by FT-IR also confirmed that no sulfone group was introduced.

Comparative Example 2 5700g of Victrex PE was converted into N-methyl-2-
It was dissolved in 6440 g of pyrrolidone, heated to 40°C, and 209 mJ2 of chlorosulfonic acid was added.

While stirring and reacting this solution, the temperature gradually increased to 1°3.2
4. Samples were taken after 48 hours. After washing each sample, its ion exchange capacity was measured, but none of the samples had ion exchange capacity. Further, analysis by FT-IR also confirmed that no sulfone group was introduced.

Comparative Example 3 5700 g of Victrex PE was dispersed in chloroform, and 209 mfl of chlorosulfonic acid was added at room temperature. While stirring and reacting this solution, 1
, 3.18. Samples were taken after 24 hours. After washing each sample, its ion exchange capacity was measured, but none of the samples had ion exchange capacity. Also, FT-
Analysis by IR also confirmed that no sulfone group was introduced.

Comparative Example 4 5700 g of Victrex PE was dissolved in 6440 g of dimethylacetamide, cooled to 0° C., and 209 ml of chlorosulfonic acid was added. While stirring and reacting this solution, samples were taken over time after 1,310.24 hours. After washing each sample, its ion exchange capacity was measured, but none of the samples had ion exchange capacity.

Furthermore, analysis by FT-IR revealed that no sulfone group was introduced.

Comparative Example 5 5700g of Victrex PE was added to 6440g of concentrated sulfuric acid
over time while stirring and reacting at room temperature.
Samples were taken after 1, 3, and 10.24 hours. After washing each sample, the ion exchange capacity was measured, but none of the samples had ion exchange capacity. Also, FT-I
Analysis by R revealed that no sulfone group was introduced.

Comparative Example 6 5700g of Victrex PE was added to 6440g of concentrated sulfuric acid
Dissolved in water, stirred at 40°C, and reacted for 1 hour over time.
．． 3.10. Samples were taken after 24 hours. After washing each sample, the ion exchange capacity was measured, but none of the samples had ion exchange capacity. Also, FT-IR
It was also found that no sulfone group had been introduced.

[Effects of the Invention] As detailed above, according to the method for producing a sulfonated resin of the present invention, polyaryl ether sulfones having specific repeating units, which could not be sulfonated by conventional methods, can be easily and easily produced. Sulfonation can be carried out efficiently, and a high-performance sulfonated resin having ion exchange ability can be produced with high productivity.

Moreover, in its production, the degree of sulfonation, that is, the ion exchange ability, of the resulting sulfonated resin can be arbitrarily controlled by appropriately selecting the reaction temperature, reaction time, usage rate of the sulfonating agent, and the like.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the results of Examples 4 to 8. Agent: Patent attorney Tsuyoshi Shigeno Addition amount of nurefonating agent (mol)

Claims (1)

[Claims] (1) A method for producing a sulfonated resin, which comprises dissolving a polyarylether sulfone having a repeating unit represented by the following structural formula in concentrated sulfuric acid, and then adding a sulfonating agent to sulfonate it. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼