Weakly acidic cation exchange resin and process for producing same
AssigneeMitsubishi Chemical Industries Limited
InventorsTakaharu Itagaki, Hidenaga Ouchi
Life of this patent
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Abstract
A weakly acidic cation exchange resin which is obtainable by a reaction of glyoxylic acid and a polyvinyl alcohol cross-linked by cross-linking groups each containing two or more carbon atoms, and has an exchange capacity of 3 meq/g or greater and a swelling volume of 10 ml/g or smaller, as well as a process for producing such cation exchange resin.
Claims13
A process for producing a weakly acidic cation exchange resin which comprises bringing a polyvinyl alcohol into reaction with a cross-linking reagent capable of forming cross-linking groups each containing two or more carbon atoms to form a cross-linked polyvinyl alcohol and bringing said cross-linked polyvinyl alcohol into reaction with glyoxylic acid in the presence of a mineral acid and a water soluble inorganic salt.
A process for producing a weakly acidic cation exchange resin which comprises:
- suspending an aqueous solution containing a cross-linking reagent capable of forming cross-linking groups each containing two or more carbon atoms, a polyvinyl alcohol and a water soluble inorganic salt, into a dispersing medium thereby making said cross-linking reagent react with said polyvinyl alcohol to form a porous cross-linked polyvinyl alcohol and;
- bringing said porous cross-linked polyvinyl alcohol into reaction with glyoxylic acid in the presence of a mineral acid and a water soluble inorganic salt.
A process for producing a weakly acidic cation exchange resin which comprises:
- forming an aqueous solution in which a cross-linking reagent capable of forming cross-linking groups each containing two or more carbon atoms and a polyvinyl alcohol are dissolved and fine particles of water-insoluble inorganic salt are dispersed;
- suspending said aqueous solution into a dispersing medium thereafter making said cross-linking reagent react with said polyvinyl alcohol to form a cross-linked polyvinyl alcohol containing said fine particles of water-insoluble inorganic salt therein;
- removing said water-insoluble inorganic salt from said resulted cross-linked polyvinyl alcohol and;
- bringing said cross-linked polyvinyl alcohol into reaction with glyoxylic acid in the presence of a mineral acid and a water-soluble inorganic salt.
A process for producing a weakly acidic cation exchange resin which comprises:
- forming an aqueous solution in which a cross-linking reagent capable of forming cross-linking groups each containing two or more carbon atoms and a polyvinyl alcohol are dissolved and fine particles of water-insoluble inorganic salt are dispersed;
- suspending said aqueous solution in a dispersing medium thereafter making said cross-linking reagent react with said polyvinyl alcohol to form a cross-linked polyvinyl alcohol containing said fine particles of water-insoluble inorganic salt therein;
- bringing said cross-linked polyvinyl alcohol thus formed into reaction with glyoxylic acid in the presence of a mineral acid and a water soluble inorganic salt and;
- removing said water-insoluble inorganic salt contained in the inside of the reaction products.
Dependencies are inferred from the claim text.