JPS58187405A - Production of strongly acidic cation-exchanging resin - Google Patents

Abstract

PURPOSE:Polymer particles resulting from polymerization styrene, divinyl benzene and acrylic acid are brought into contact with a swelling agent and sulfonated under specific conditions to produce the titled ion-exchange resin with reduced elution of colored components on long-term storage. CONSTITUTION:Styrene, divinyl benzene (0.5-55mol%, preferably 1.5-4.5mol% based on styrene) and acrylic or methacrylic acid or its lower alkyl ester (0.2- 20mol%, preferably 0.5-10mol%) are subjected to suspension polymerization to prepare particles of copolymer. Then, the particles are brought into contact with a swelling agent of organic solvents, then with sulfuric acid at 50-100 deg.C to effect sulfonation.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a strongly acidic cation exchange resin.

Enhanced cation exchange resins are usually produced by swelling copolymer particles obtained by copolymerizing styrene and divinylbenzene with a swelling agent made of an organic solvent, and then contacting them with sulfuric acid to sulfonate them. However, the 4114 fat obtained by this method is colored brown, although there are differences in degree. This is because a colored component of unknown structure is produced during the sulfonation step and is included in the copolymer particles. This coloring of the copolymer particles does not affect its performance as an ion exchange resin, so it is not a problem. When the copolymer particles are stored for a long period of time, a part of the coloring components in the copolymer particles are converted into water-soluble compounds, which have the disadvantage of being eluted into the treated water.

In view of the current situation, the present inventors have investigated various ways to prevent the coloring components from melting when a strongly acidic cation exchange resin is stored for a long period of time. The present invention was completed by using a copolymer consisting of the following and sulfonating it under specific conditions.

That is, the gist of the present invention is that divinylbenzene & h(
3) Copolymer particles obtained by copolymerizing styrene with a copolymer of (meth)acrylic acid or seven moles of lower alkyl ester are brought into contact with a swelling agent consisting of an organic solvent.

Strongly acidic cation exchanger 11 whose % image is sulfonation by contacting with sulfuric acid at a temperature of 5o-ioo°C
#g”) Depends on the manufacturing method.

The following is a detailed review of Honpatsu Hu.

In the present invention, the coelectric polymer particles that are the base material of the cation exchange resin are copolymerized by copolymerizing three monomers consisting of styrene, divinylben(n), (meth)acrylic acid, and/or a lower alkyl ester thereof. coalescence is used.

Examples of (meth)acrylic acid and/or its lower alkyl esters include methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, acrylic acid, methyl acrylate, and ethyl acrylate. The amount of this monomer used is d based on styrene.
J~20 mol, preferably θ, t-/0 mol-
Therefore, if the amount used is too small, not only will it not be possible to uniformly sulfonate the coelectric composite particles in the internal stage with the Wenbin Fan specified in the present invention, but the crystal growth after sulfonation will not be possible for a long period of time. Naturally, it may reduce the amount of coloring components eluted during storage, and if a large amount is used,
Since the proportion of styrene decreases, many exchange groups are not introduced, which is not preferable.

f? , -, the amount of divinylbenzene used is determined by applying an electric current to the target copolymer through Hata-Hashi modification, and θt relative to styrene.
-jj mole, preferably lj to san S mole duck.

In the present invention, the above-mentioned hexamer is suspended in water, and the dispersion medium is usually water, and the amount used is 1 to 10 times that of the monomer. Examples of dispersants used include polyvinyl alcohol and carboxymethyl cellulose. The amount of dispersant used is usually the monomer (
On the other hand, for the at-io heavy molecular zero polymerization initiation ah, known catalysts such as benzoyl peroxide or azo catalysts can be used, and the amount used is QO/
-/! It's heavy.

- Polymerization is usually carried out in a #i reactor at SO to 90°C for about 3 to 30 hours. For example, the Togane operation includes polymerization reaction I
! A predetermined amount of water and a dispersant are added to this, and a polymerization initiator is added to this while stirring! - is added to create an oil-in-water suspension state, and while aerating the 9-gas at a predetermined temperature,
Polymerization can be carried out.

The copolymer particles obtained by suspension polymerization have an overcharge and a particle size of 0/~
The beads are free of cracks on the order of .0%, and are then made into a cation exchange resin using ζhK, which is sulfonated.

In the present invention, the copolymer particles obtained by pressing as described above are used as IjII! which is an organic bath agent. The particles are brought into contact with a 4-agent to swell the particles. As this swelling agent, aromatic hydrocarbons and aliphatic hydrocarbons having a 1-substituted moiety, logenated hydrocarbons, etc. are usually used.

Examples include nitrobenzene, toluene, xylene, chlorobenzene, dichlorobenzene, la carbon chloride, and ethylene dichloride.

This contact treatment with a swelling agent is usually carried out by suspending the copolymer particles in a large excess of an organic solvent, for example, at a temperature of 50 to 100°C.
This can be achieved by stirring at a temperature of /-5 hours.

The copolymer particles swollen with an organic illumination agent are then sulfonated, but sulfonation typically destroys the copolymer particles. j-
This is carried out by stirring in 1009Iil acid. The amount of sulfuric acid used is usually J-JD times the weight of the copolymer. The sulfonated fjA darkness is 5O-tooC,
Preferably it is AO to deθC. If the treatment temperature is too low, the sulfone reaction will not proceed well, and if the temperature is too low, the formation of coloring components will be high (and the degree of coloration of the product itself will be reduced). Not only is this large, but also the elution of coloring components that occurs when the product is stored for a long period of time becomes strange, which is undesirable.
Further, the treatment time for sulfonation is usually 3 to 30 hours.

After the sulfone treatment, the copolymer particles were washed in a conventional manner and then converted into N& type from m@ and recovered.

As described above, even when the cation exchange resin obtained by the method of the present invention is used after being stored in a feed tank after its production, the colored components in the particles will not be eluted. There is no possibility of contaminating the debris. therefore,
By the method of the present invention, a cation exchange resin with a high product price can be obtained.

Next, the present invention will be demonstrated in detail! However, this book is not limited to the following implementation unless it goes beyond its gist.

Example/~2000f of water and polyvinyl alcohol in a 3t flask equipped with a temperature moderator and a nitrous gas inlet; 3.
After adding Of, a mixture of Koretrap Sunalene S 50 f, divinylbenzene tOf, the monomers listed in Table 3 shown in Table 1, and benzoyl peroxide Qlf was added, and the system was aerated with monoatomic gas. Gently, with stirring, Z
Polymerization was carried out for 1 hour at a temperature of OC.

Copolymer particles are collected from the mixture after polymerization.

Of these, 100f is 1# lubricant jO? shown in Table 1. After stirring for 1 hour at 10°C in a mixture of 200°C of sulfonate and water, the copolymer particles were collected, and then treated with sulfonate in 5OOd of periosulfuric acid at a temperature of 10°C for 75 hours. .

After the sulfonated copolymer particles have passed.

lOIg] with SO2- water, and was collected by suspension washing.

The cation exchange obtained in this way is 1M! With IIIK, measurements with 8 exchanges and an elution test of colored components were carried out, and the results shown in No. 1 to 3 were obtained.

Comparative Example 1 In the method of Example 1, during the production of copolymer particles,
Experiments were carried out in the same manner except that the polymerization was carried out without adding the third concentrated liquid, and the results shown in Table 1 were obtained.

Ratio @ Example 3 An experiment was carried out in the same manner as in Example 1 except that the copolymer particles were not treated with a swelling agent and the sulfonation temperature was set to the temperature shown in Table 1. ,! +j/Table V
The results shown in C were obtained.

/-′

Claims (1)

[Claims] (1) ■Styrene, (2) Styrene KN az~
Copolymer particles obtained by copolymerizing SS molar divinylbenzene and (meth)acrylic acid or its lower alkyl ester (aJ to Jθ molar relative to Listerene) with a swelling agent made of organic #l@ contact, then S.O.
~io. A method for producing a strongly acidic cation exchange resin, which is characterized by sulfonation by contacting with sulfuric acid at a temperature of C.