JPS5912683B2 - Method for producing porous ion exchange resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing porous ion exchange resins.

Specifically, a solvent (commonly called a precipitant) that dissolves in the monomer but has no affinity for the resulting copolymer is added to a styrene mixed solution containing divinylbenzene to form a porous crosslinker. polymer (hereinafter referred to as MR copolymer).

), using divinylbenzene, a precipitant, a specific amount of methyl-butylcarbinol, and using a copolymer with a small pore volume but a large surface area, i.e., a small pore size. The present invention relates to a method for producing an ion exchange resin. The ion exchange resin of the present invention has a porous structure and is a well-known MR type ion exchange resin 15.
It has a relatively large surface area comparable to that of the resin, but the pore volume is extremely small, and compared to known MR type ion exchange resins, the water content is lower, the ion exchange capacity per volume is higher, and the physical It is characterized by high strength. 20 Several methods for producing porous cross copolymers are already known, but one of them is that when copolymerizing a mixed solution of monovinyl monomers and polyvinyl monomers, Polymerization is carried out in the presence of a solvent (precipitant) that dissolves but has no affinity with the resulting copolymer, causing complete phase separation during polymerization, and after polymerization, the solvent is removed from the system and the porous cross-copolymer is removed. Methods of producing polymers are known.

Usually, the porous copolymer obtained by such a method has a pore volume of 0.6 to 2.0 CC/θ and a surface area of 10 to 100 m.
30 with /9 is J, Appl, Polym, S
ci, 172835 (1973), etc. According to these, MR copolymers have a large surface area and a large pore volume, and when functional groups are introduced using known techniques, the ion exchanger 35 has a relatively large surface area and a large pore volume.
It is known that the exchange resin generally has a high water content and a small exchange capacity per volume. However, since MR copolymers and MR type ion exchange resins derived from them have several characteristics compared to gel type copolymers and gel type ion exchange resins, ion exchange resins,
It is commercially available and used as an adsorbent.

For example, normal MR type ion exchange resins have less deterioration (0rganicf0u1ing) caused by organic substances, which is seen in gel type ion exchange resins, and have less intra-particle distortion than gel type ion exchange resins with the same degree of crosslinking. It is known that M
The present invention relates to a method for producing an ion exchange resin using a copolymer having an R-like structure and a surface area comparable to that of known MR copolymers, but a pore volume that is particularly smaller than that of MR copolymers. Furthermore, it has been found that it has various characteristics as described below. When comparing the amounts of organic components such as styrene and divinylbenzene in a certain amount of copolymers for copolymers with similar surface areas but different pore volumes, it is obvious that the pore volumes are The larger the copolymer, the lower the amount of organic components, and the smaller the pore volume, the higher the amount of organic components. When such a copolymer with a small pore volume and a high amount of organic components is converted into an ion exchange resin, it has the same MR structure as a known MR type ion exchange resin, but it is different from the known MR type ion exchange resin. In comparison, an ion exchange resin is obtained that has a lower water content and a higher exchange capacity per unit volume.
The present inventors have also discovered that an ion exchange resin with even stronger physical strength can be obtained. That is, although the ion exchange resin obtained from the cross copolymer having the MR structure with a large surface area and small pore volume as described above is an MR type ion exchange resin, it is a gel type ion exchange resin. No literature prior to the present invention has yet described a method for producing an ion exchange resin that has characteristics such as low water content, high exchange capacity per unit volume, and extremely strong physical strength. The present inventors have arrived at the present invention as a result of detailed studies on the physical properties of porous copolymers and their modifying factors, and extensive research into methods for producing ion exchange resins with low porosity and pore diameter.

To explain in more detail, the method for producing a porous copolymer described in Japanese Patent Publication No. 37-13792 involves adding a precipitant to a monomer mixed solution in an amount that causes complete phase separation. , copolymers with large pore volumes as shown above have been obtained.

The copolymer used in the present invention is a well-known system in which a precipitant is added to a mixed solution of monovinyl monomer and polyvinyl monomer and polymerized to obtain a copolymer having an MR-like structure.Divinylbenzene and methyl It has been discovered that by using specific amounts of isobutyl carbinol, a copolymer having an MR structure similar to that of known MR copolymers, a surface area on the same level, and a small pore volume can be obtained. The ion exchange resin obtained by introducing the group has an MR-like structure, which is the same as known MR type ion exchange resins, but it has a higher exchange capacity and physical strength than known MR type ion exchange resins. We found that the copolymer has excellent properties and found industrially useful value for the copolymer. MR with large surface area and large pore volume
MR type ion exchange resin obtained from type copolymer also has
It has a relatively large surface area and pore volume, which makes MR
It is known that type ion exchange resins have a high moisture content and a low exchange capacity per volume. On the other hand, although the ion exchange resin obtained from the copolymer of the present invention has an MR-like structure, the physical properties of the copolymer are different from those of conventionally known MR copolymers. ,
Regarding the exchange capacity and physical strength, which are considered to be particularly important in the performance of ion exchange resins, an ion exchange resin that is extremely superior to known MR type ion exchange resins has been obtained, as is clear from the examples and other examples described below. It will be done. As described above, the present invention provides M
We have established a method for producing R-like copolymers. The porous copolymer of the present invention is characterized by having the same MR structure and surface area value as conventionally known MR copolymers, and having a small pore volume.
It has excellent physical properties as an intermediate for ion exchange resins. The present inventors investigated a polymerization system in which a mixed styrene solution containing divinylbenzene, petatilysobutylcarbinol, was added, and found that divinylbenzene contained 4 to 15%
, methyl isobutyl carbinol in an amount of 20 to 3 of the total weight of all monomers and methyl isobutyl carbinol.
By adding 5% and polymerizing, the pore volume was reduced to 0.3.
It was possible to obtain a copolymer with a small average pore diameter of 0 Cc/9 or less and a surface area of 10 to 100 i/g. In general, a method for producing an MR type copolymer using a precipitant requires a large amount of precipitant when a small amount of divinylbenzene is used, and a relatively small amount of precipitant is required when a large amount of divinylbenzene is used. In a system in which a porous copolymer is obtained by adding and polymerizing a mixed solution of styrene and divinylbenzene, petatyl isobutyl carbinol, divinylbenzene 4 to 1
5%, methyl isobutyl carbinol is 20% of the total weight of all monomers and the weight of methyl isobutyl carbinol.
This objective can be achieved by using divinylbenzene in a range of ~35%, but if the amount of divinylbenzene is used in a larger amount than the amount specified above, a well-known MR type copolymer with a large pore volume will be produced. If the amount is less than that, the resulting copolymer will be a copolymer with extremely small pore volume and surface area, or a gel-like copolymer.
Higher amounts of methyl isobutyl carbinol also produce the well-known MR type copolymers, and lower amounts produce gel-like copolymers with very low pore volume and surface area. That is, the object of the present invention can be achieved by using specific amounts of each of methylisobutylcarbinol and divinylbenzene in a method for producing a porous copolymer using a precipitant, and by polymerizing a mixture of the precipitant and the monomer. can be achieved. Suitable catalysts that provide free radicals to act as initiators for use in preparing the copolymers of this invention include benzoyl peroxide, tertiary butyl hydroperoxide, cumene peroxide, methyl ethyl ketone peroxide, and azoisobutyl peroxide. lonitrile, azoisobutyramide, azobis(α-dimethylvaleronitrino(c),
Azo catalysts such as azobis(α-methylbutyronitrile) can also be used.

The amount of catalyst required is usually from 0.01 to 3%, preferably from 0.2 to 0.15%, relative to the weight of the monomer mixture.
%. Styrene, divinylbenzene, and methylisobutylcarbinol are used as the monovinyl monomer, polyvinyl monomer, and precipitant, respectively. The copolymer obtained here is chloroalkylated, and then the chloroalkylated product is aminated to obtain an anion exchange resin. As amines, primary, secondary and tertiary alkylamines or arylamines are used. Typical amines include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, propylene, diamine, dimethylaminoethanol, and trimethylamine. Cation exchange resins can also be produced by sulfonating the copolymer of the present invention using concentrated sulfuric acid, oleum, sulfur trioxide, or chlorosulfonic acid as a sulfonating agent. Examples, test examples, and reference examples of the present invention will be described below.

Reference example 1 Styrene, industrial divinylbenzene (concentration 58.7%)
, benzoyl peroxide (0.75% based on total monomer weight)
and methyl isobutyl carbinol. 1 and commercially available styrene-maleic anhydride copolymer ammonium salt 39 and water 7
009 in an aqueous solution.

Stir thoroughly to uniformly disperse the monomer phase, and heat for 8 hours to polymerize. After the polymerization is complete, methyl isobutyl carbinol is removed from the polymerization system by azeotroping with water. The produced beads were filtered, thoroughly washed with water, and dried at 125°C for 5 hours to form copolymer piles, [I[), [
], C) Cl and [ are obtained. Table 1 shows the raw materials and physical properties used to obtain these copolymers. Copolymer []1
Add propylene dichloride 450f11 chloromethyl methyl ether 2829 to 069 at room temperature, stir for 30 minutes, add anhydrous aluminum chloride 809 in small portions at 30°C or less for 1 hour, stir at room temperature for 1 hour, and then stir for 30 minutes.
React at ~50°C for 7 hours.

After the chloromethylation reaction is completed, the reaction mixture is cooled and water is added to thoroughly wash the chloromethylation beads with water. Add 300 ml of trimethylamine aqueous solution (concentration 30%) to the washed chloromethylated beads and keep at room temperature for amination reaction. After the amination is completed, the mixture is heated to remove propylene dichloride together with water and thoroughly washed with water. The resulting anion exchange resin has a medium salt decomposition capacity of 3.9 milliequivalents per 19, and an exchange capacity per volume of 0.9 milliequivalents per 19. In addition, copolymer [M [1531 with sulfuric acid (99%)]
Add 5309 and heat at 120° C. for 6 hours with stirring.

The mixture is cooled to about 20°C and diluted with water. Thoroughly wash the resulting resin with water and use 240f! A hydrogen-type sulfonated resin is obtained. The resin is then converted to the sodium form using a slight excess of sodium hydroxide. The neutral salt decomposition capacity of the sodium type sulfonated resin is 4.3 meq/19, and the exchange capacity per volume is 1.5 meq/19. Reference example 2 Styrene 4669 Industrial divinylbenzene (concentration 58.70 t)) 349 Benzoyl peroxide 3
．． A homogeneous mixed solution consisting of 89 and methyl isobutyl carbinol 2709 is charged into an aqueous solution of sodium chloride 279 and commercially available ammonium salt of styrene-maleic anhydride copolymer 39 dissolved in water 7009.

Stir thoroughly to uniformly disperse the monomer phase and heat at 80°C for 5 minutes.
Heat for a period of time to polymerize. After the polymerization is completed, methyl isobutyl carbinol is removed from the polymerization system by azeotroping with water.
The generated beads were filtered, washed thoroughly with water, and incubated at 125°C for 5 minutes.
Dry for an hour. The resulting copolymer was white, opaque, perfectly spherical, and had a yield of 4109. The surface area and pore volume of the copolymer are 59 I/9 and 0.23 CC/9, respectively.
In addition, a white opaque copolymer Cl[1405f1 was obtained using the same conditions and method as above except that methyl isobutyl carbinol 1259 was used, and the surface area and pore volume were 40I/9 and 0.18CC/9. It is. Reference example 3 Styrene 4329, industrial divinylbenzene (concentration 58
．． 7%) 689 and methyl isobutyl carbinol 2709, a white opaque copolymer (Vl4259 was obtained, with a surface area and pore volume of 83'9, 0. .27 CC/9, and when methyl isobutyl carbinol 1259 was used, a white opaque] copolymer CV4l79 was obtained, with a surface area and a pore volume of 48 i/g and 0.20 ec/9.

Reference Example 4 A white opaque copolymer (1! A432
9 was obtained, the surface area and pore volume were 90, but 0.28CC/9
It is.

When methyl isobutyl carbinol 1259 is used, a white opaque copolymer CVIa4299 is obtained, with a surface area and pore volume of 53 i/f! ,0.22CC/9
It is. These results are shown in Table 1. Reference example 5 Styrene 127.39, industrial divinylbenzene 32.
79 (concentration 58.7 (F6)), a homogeneous mixed solution consisting of benzoyl peroxide 19 and t-amyl alcohol 869 was dissolved in water with 7 g of sodium chloride and 0.59 g of commercially available styrene-maleic anhydride copolymer ammonium salt. Charge into solution.

Stir thoroughly to evenly disperse the monomer phase,
Polymerization was carried out at 7° C. for 6 hours, and after the polymerization was completed, the resulting copolymer was filtered and washed with water, and excess water and t-amyl alcohol were removed by heating.

The copolymer produced is white and opaque, and the yield is 1469
It is.

The pore volume is 0.65 CC/9 and the surface area is 41
It is i/9. A mixture of 106.89 styrene, 36.29 ml of industrial divinylbenzene, 1f1 benzoyl peroxide and 629 Sec-butanol was added to 7 g of sodium chloride and 0.61 ml of ammonium salt of a commercially available styrene-maleic anhydride copolymer in water. Pour into a solution dissolved in

Stir thoroughly to disperse the monomer phase and leave at 85-90°C for 6 hours.
Polymerizes at ℃.

The resulting copolymer beads were filtered, washed with water, and incubated at 125°C for 5
Dry for an hour. 1369 white opaque beads are shown.

This has a pore volume of 0.72 CC/9 and a surface area of 39 I/9. Example 1 Copolymer 106 obtained in Reference Example 3
Add propylene dichloride 4509 and chloromethyl methyl ether 2829 to 9 at room temperature, stir for 30 minutes, add anhydrous aluminum chloride 809 little by little at 30°C or less for 1 hour, stir at room temperature for 1 hour, and then add 40 to 50
Incubate at ℃ for 7 hours.

After the chloromethylation reaction is completed, the reaction mixture is cooled, water is added, and the chloromethylation beads are thoroughly washed with water. Add 300 ml of trimethylamine aqueous solution (concentration 30%) to the washed chloromethylated beads and keep at room temperature for amination reaction. After the amination is completed, the mixture is heated to distill off propylene digitalolide together with water and thoroughly washed with water. The neutral salt decomposition capacity of the resulting anion exchange resin is 4.0 milliequivalents per 19, and the exchange capacity per volume is 1.52 milliequivalents per 19. Example 2 Copolymer 53 obtained in Reference Example 3
Add sulfuric acid (99%) 5309 to 9 and add 12 while stirring.
Heat at 0°C for 6 hours.

Claims (1)

[Claims] 1. Surface area 10 to 100 m^2/g, pore volume 0.3
In producing a porous ion exchange resin from a styrene-divinylbenzene porous cross-copolymer having properties of 0 cc/g or less, the total monomer amount of methyl isobutyl carbinol is added to a styrene mixed solution containing 4 to 15% divinylbenzene. Styrene-
A method for producing a porous ion exchange resin, which comprises producing a divinylbenzene porous cross-copolymer and introducing an ion exchange group into it. 2. The manufacturing method according to claim 1, wherein the ion exchange group is a sulfonic acid group. 3. The production method according to claim 1, wherein the ion exchange group is halomethylated and then aminated.