Claims
- 1. A method for producing a weakly acidic cation exchange resin, which comprises hydrolyzing an acrylonitrile crosslinked copolymer obtained by copolymerizing, as polymerizable monomers,
- (a) acrylonitrile
- (b) an alkyl ester of acrylic or methacrylic acid
- (c) a crosslinkable aliphatic or alicyclic unsaturated monomer having at least two allyl groups, and
- (d) an aromatic crosslinkable polyunsaturated monomer, in the presence of from 10 to 45% by weight, based on the total amount of the polymerizable monomers of an inert organic solvent having a specific gravity of at least 1.0, wherein the polymerization reaction is conducted in a state of suspension in an aqueous medium containing a suspension stabilizer.
- 2. The method according to claim 1, wherein the alkyl ester of acrylic acid or methacrylic acid is used in an amount of from 5 to 50% by weight, based on the total amount of the acrylonitrite and the alkyl ester of acrylic acid or methacrylic acid.
- 3. The method according to claim 1, wherein the alkyl ester of acrylic acid or methacrylic acid is a methyl or ethyl ester of acrylic acid or methacrylic acid.
- 4. The method according to claim 1, wherein the aliphatic or alicyclic unsaturated monomer having at least two allyl groups is selected from C.sub.6-10 (cyclo)alkyldienes.
- 5. The method according to claim 4, wherein the aliphatic or alicyclic crosslinkable unsaturated monomer having at least two allyl groups is a C.sub.8-10 (cyclo)alkyldiene.
- 6. The method according to claim 1, wherein the aliphatic or alicyclic crosslinkable unsaturated monomer having at least two allyl groups is used in an amount within a range of from 1 to 10% by weight, based on the total amount of the polymerizable monomers.
- 7. The method according to claim 1, wherein the aromatic crosslinkable polyunsaturated monomer is used in an amount within a range of from 2 to 15% by weight, based on the total amount of the polymerizable monomers.
- 8. The method according to claim 1, wherein the inert organic solvent having a specific gravity of at least 1.0 is selected from dichloroalkanes.
- 9. The method according to claim 8, wherein the inert organic solvent having a specific gravity of at least 1.0 is 1,2-dichloroethane or 1,2-dichloropropane.
- 10. The method for producing a weakly acidic cation exchange resin according to claim 1, wherein the acrylonitrile crosslinked copolymer is hydrolyzed by using an acid or a base after removal of the organic solvent from the polymerization mixture.
- 11. The method for producing a weakly acidic cation exchange resin according to claim 10, wherein the hydrolysis is conducted in a 40-60 wt. % sulfuric acid aqueous solution under a refluxing condition.
- 12. The method for producing a weakly acidic cation exchange resin according to claim 10, wherein the hydrolysis is conducted in a 15-50 wt. % aqueous or alcohol solution of caustic alkali selected from the group consisting of sodium hydroxide and potassium hydroxide, under a refluxing condition.
Priority Claims (1)
Number |
Date |
Country |
Kind |
4-91177 |
Apr 1992 |
JPX |
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Parent Case Info
This is a division of application Ser. No. 08/045,603, filed on Apr. 9, 1993 now U.S. Pat. No. 5,314,974 .
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
3544488 |
Corte et al. |
Dec 1970 |
|
3674728 |
Carbonnel et al. |
Jul 1972 |
|
Foreign Referenced Citations (4)
Number |
Date |
Country |
1360169 |
Mar 1964 |
FRX |
2044630 |
Feb 1971 |
FRX |
2058529 |
May 1971 |
FRX |
1135130 |
Nov 1968 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Patent Abstracts of Japan 7, 219 Sep. 29, 1983, "Cross-linked Rubberg Polymers" (JP 58-117,209A). |
Divisions (1)
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Number |
Date |
Country |
Parent |
45603 |
Apr 1993 |
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