# US 5,350,523 A · Anion exchange method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,350,523 A - Document ID: US5350523A - Status: Granted - Kind: A - Application number: 07/936,337 - Filed: 1992-08-28 - Granted: 1994-09-27 - Earliest claimed: 1990-02-28 - Assignees: Mitsubishi Kasei Corporation; Tohoku Electric Power Co., Inc. - Inventors: Masao Tomoi; Atsuo Kiyokawa; Hiromasa Ogawa; Teruo Onozuka; Tsuyoshi Ito - Web page: https://patentgrep.com/patent/US5350523A ## CPC - B01J 41/14: obtained by reactions only involving unsaturated carbon-to-carbon bonds - B01J 41/05: in the strongly basic form - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract An anion exchange method conducted at a high temperature, which comprises using a crosslinked anion exchanger which comprises structural units having a quaternary ammonium group of the following formula (a) and structural units derived from an unsaturated hydrocarbon group-containing crosslinkable monomer, and of which at least 90% of anion exchange groups are present in the form of a group represented by ##STR1## as defined in the following formula (a): ##STR2## wherein R is a --(CH.sub.2).sub.n --group (n=an integer of from 3 to 18) which may include a cyclic hydrocarbon, each of R.sub.1, R.sub.2 and R.sub.3 which are independent from one another, is a C.sub.1 -C.sub.8 hydrocarbon group or a C.sub.1 -C.sub.8 alkanol group, the benzene ring of the formula (a) may be substituted by an alkyl group or a halogen atom, or may be condensed with other aromatic ring, and X is an anion. ## Claims ### Claim 1 A demineralizign process conducted at a high temperature condition of above 60.degree. C., which comprises treating water with an ion exchanger containing a crosslinked anion exchanger wherein said crosslinked anion exchanger which comprises structural units having a quaternary ammonium group of the following formula (a) and structural units derived from an unsaturated hydrocarbon group-containing crosslinkable monomer, and of which at least 90% of anion exchange groups are present in the form of a group represented by ##STR16## as defined in the following formula (a): ##STR17## wherein R is a --(CH.sub.2).sub.n - group (n=an integer of from 3 to 18) which may include a cyclic hydrocarbon, each of R.sub.1, R.sub.2 and R.sub.3 which are independent from one another, is a C.sub.1 -C.sub.8 hydrocarbon group or a C.sub.1 -C.sub.8 alkanol group, the benzene ring of the formula (a) may be substituted by an alkyl group or a halogen atom, or may be condensed with other aromatic ring, and X is an anion. ### Claim 2 (depends on 1) The method according to claim 1, wherein substantially all of anion exchange groups are present in the form of structural units containing a group represented by ##STR18## as defined in the formula (a). ### Claim 3 (depends on 1) The method according to claim 1, wherein said exchanger contains from 1.5 to 55% by weight of the units derived from an unsaturated hydrocarbon group-containing crosslinkable monomer. ### Claim 4 (depends on 3) The method according to claim 3, wherein said exchanger contains from 1.5 to 25% by weight of the structural units derived from an unsaturated hydrocarbon group-containing crosslinkable monomer. ### Claim 5 (depends on 1) The method according to claim 1, wherein said exchanger has an ion exchange capacity remaining rate of at least 90% and a volume maintaining rate of at least 90% after being heated in a 0.1 N sodium hydroxide aqueous solution at 100.degree. C. for 60 hours as a hydroxide type. ### Claim 6 (depends on 1) The method according to claim 1, wherein R in the formula (a) is a --(CH.sub.2).sub.n --group (n=an integer of from 3 to 10) which may include a cyclic hydrocarbon. ### Claim 7 (depends on 1) The method according to claim 1, wherein each of R.sub.1, R.sub.2 and R.sub.3 in the formula (a) is a methyl group. ### Claim 8 (depends on 1) The method according to claim 1, wherein the unsaturated hydrocarbon group-containing crosslinkable monomer is divinyl benzene. ### Claim 9 (depends on 1) The method according to claim 1, wherein said exchanger comprises from 20 to 98.5% by weight of structural units having a group of the formula ##STR19## as defined in the formula (a), from 1.5 to 55% by weight of structural units derived from an unsaturated hydrocarbon group-containing crosslinkable monomer and from 0 to 20% by weight of structural units derived from other addition polymerizable monomer. ### Claim 10 (depends on 5) The method according to claim 5, wherein said exchanger has an ion exchange capacity remaining rate of at least 95% after being heated in a 0.1N sodium hydroxide aqueous solution at 100.degree. C. for 60 hours as a hydroxide type. ### Claim 11 (depends on 5) The method according to claim 5, wherein said exchanger has a volume maintaining rate of at least 95% after being heated in a 0.1N sodium hydroxide aqueous solution at 100.degree. C. for 60 hours as a hydroxide type. ### Claim 12 (depends on 1) The method according to claim 1, wherein X.sup.- is OH.sup.-. ### Claim 13 (depends on 1) The method according to claim 1, wherein the anion exchanged by the method is CO.sub.3.sup.2-, NO.sub.3 -, Cl.sup.-, SO.sub.4.sup.2-, PO.sub.4.sup.3- or NO.sub.2.sup.2-. ### Claim 14 (depends on 6) The method according to claim 6, wherein n is an integer of from 4 to 8. ### Claim 15 A method for ion exchange-treating hot water in a power plant, which comprises treating water having a temperature of not lower than 60.degree. C. with a crosslinked anion exchanger which comprises structural units having a quaternary ammonium group of the following formula (a) and structural units derived from an unsaturated hydrocarbon group-containing crosslinkable monomer, and of which at least 90% of anion exchange groups are present in the form of a group represented by ##STR20## as defined in the following formula (a): ##STR21## wherein R is a --(CH.sub.2).sub.n - group (n=an integer of from 3 to 18) which may include a cyclic hydrocarbon, each of R.sub.1, R.sub.2 and R.sub.3 which are independent from one another, is a C.sub.1 -C.sub.8 hydrocarbon group or a C.sub.1 -C.sub.8 alkanol group, the benzene ring of the formula (a) may be substituted by an alkyl group or a halogen atom, or may be condensed with other armoatic ring, and X is an anion. ### Claim 16 (depends on 14) The method according to claim 14, wherein substantially all of anion exchange groups are present in the form of structural units containing a group represented by ##STR22## as defined in the formula (a). ### Claim 17 (depends on 14) The method according to claim 14, wherein said exchanger contains from 1.5 to 55% by weight of the units derived from an unsaturated hydrocarbon group-containing crosslinkable monomer. ### Claim 18 (depends on 16) The method according to claim 16, wherein said exchanger contains from 1.5 to 25% by weight of the structural units derived from an unsaturated hydrocarbon group-containing crosslinkable monomer. ### Claim 19 (depends on 14) The method according to claim 14, wherein said exchanger has an ion exchange capacity remaining rate of at least 85% and a volume maintaining rate of at least 90% after being heated in a 0.1N sodium hydroxide aqueous solution at 100.degree. C. for 60 hours as a hydroxide type. ### Claim 20 (depends on 14) The method according to claim 14, wherein R in the formula (a) is a --(CH.sub.2).sub.n --group (n=an integer of from 3 to 10) which may include a cyclic hydrocarbon. ### Claim 21 (depends on 14) The method according to claim 14, wherein each of R.sub.1, R.sub.2 and R.sub.3 in the formula (a) is a methyl group. ### Claim 22 (depends on 14) The method according to claim 14, wherein the unsaturated hydrocarbon group-containing crosslinkable monomer is divinyl benzene. ### Claim 23 (depends on 14) The method according to claim 14, wherein said exchanger comprises from 20 to 98.5% by weight of structural units having a group of the formula ##STR23## as defined in the (a), formula from 1.5 to 55% by weight of structural units derived from an unsaturated hydrocarbon group-containing crosslinkable monomer and from 0 to 20% by weight of structural units derived from other addition polymerizable monomer. ### Claim 24 (depends on 18) The method according to claim 18, wherein said exchanger has an ion exchange capacity remaining rate of at least 90% after being heated in a 0.1N sodium hydroxide aqueous solution at 100.degree. C. for 60 hours as a hydroxide type. ### Claim 25 (depends on 18) The method according to claim 18, wherein said exchanger has a volume maintaining rate of at least 95% after being heated in a 0.1N sodium hydroxide aqueous solution at 100.degree. C. for 60 hours as a hydroxide type. ### Claim 26 (depends on 14) The method according to claim 14, wherein X.sup.- is OH.sup.-. ### Claim 27 (depends on 14) The method according to claim 14, wherein X.sup.- is OH.sup.-, and which is conducted at a temperature of above 60.degree. C. ### Claim 28 (depends on 14) The method according to claim 14, wherein the anion exchanged by the method is CO.sub.3.sup.2-, NO.sub.3.sup.-, Cl.sup.-, SO.sub.4.sup.2-, PO.sub.4.sup.3- or NO.sub.2.sup.2-. ### Claim 29 (depends on 19) The method according to claim 19, wherein n is an integer of from 4 to 8. ### Claim 30 (depends on 1) The process according to claim 1, wherein the crosslinked anion exchanger is present in the form of a mixed bed comprising said anion exchanger and a cation exchanger. ### Claim 31 (depends on 1) The process according to claim 1, wherein the ion exchanger is present in the form of a bed connecting a single bed of said crosslinked anion exchanger with a single bed of a cation exchange resin.