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US 3,936,399 AGranted
Process of producing phenolic chelate resin using iminodiacetic acid
AssigneeUnitika Ltd.
InventorsMasahide Hirai, Mikio Fujimura, Masahiro Kazigase, Minoru Saito
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Abstract
A phenolic chelate resin having a high heavy-metal chelating ability and capable of being reused is produced by polycondensing a phenol containing an iminodiacetic acid group with an aldehyde.
Claims13
A process of producing a phenolic chelate resin for adsorbing heavy metal ions selectively which comprises the steps of:
- a. heating an acidic mixture of a phenol, an aldehyde and iminodiacetic acid to 20.degree. to 90.degree.C under acidic conditions to introduce an iminoacidic acid group into the phenol;
- and then
- b. adding the phenol or the aldehyde or both such that the total amount of aldehyde is in excess to the iminodiacetic acid and then heating the reaction system at 90.degree. to 110.degree.C thereby polycondensing the entire amount of the phenol and said aldehyde.
Dependencies are inferred from the claim text.