METHOD FOR PREPARING HYPOCHLOROUS ACID AQUEOUS SOLUTION AND METHOD FOR REGENERATING WEAKLY ACIDIC CATION EXCHANGER

    公开(公告)号:US20220371887A1

    公开(公告)日:2022-11-24

    申请号:US17755613

    申请日:2020-11-06

    Inventor: Minoru TERADA

    Abstract: Provided is a method for preparing a hypochlorous acid aqueous solution by which a weakly acidic hypochlorous acid aqueous solution having a pH of about 3.5-7 can be obtained without substantially generating chlorine gas even immediately after regeneration or even with a new weakly acidic cation exchange resin. In a method for preparing a hypochlorous acid aqueous solution wherein an aqueous solution of hypochlorite is brought into contact with a weakly acidic cation exchanger to exchange a cation constituting the hypochlorite with hydrogen ions to increase the concentration of hypochlorous acid in the aqueous solution, a neutral salt solution of a strong acid and a strong base in an amount that may obtain the hypochlorous acid aqueous solution having a pH of at least 3.5 when the hypochlorite aqueous solution is brought into contact with the weakly acidic cation exchanger is brought into contact, prior to the contact between the hypochlorite aqueous solution and the weakly acidic cation exchanger, with a weakly acidic cation exchanger that has been regenerated or has not been substantially subjected to cation exchange.

    Ion exchange membrane for alkali chloride electrolysis, method for its production and alkali chloride electrolysis apparatus

    公开(公告)号:US11066751B2

    公开(公告)日:2021-07-20

    申请号:US16156360

    申请日:2018-10-10

    Applicant: AGC Inc.

    Abstract: To provide an ion exchange membrane for alkali chloride electrolysis which is a membrane having a high water permeability and being capable of maintaining a low electrolysis voltage while suppressing the amount of water supplied to a cathode chamber to be minimum, and which is capable of forming an aqueous alkali hydroxide solution having a high caustic alkali quality. The ion exchange membrane for alkali chloride electrolysis comprises a layer 12 made of a fluorinated polymer having carboxylic acid functional groups, and a layer 14A and a layer 14B made of a fluorinated polymer having sulfonic acid functional groups, wherein a reinforcing material 20 containing reinforcing threads 22 is disposed between the layer 14A and the layer 14B, the thickness when dried, of the layer 12 is from 9 to 28 μm, the layer 14B includes a layer having an ion exchange capacity of from 1.3 to 2.5 meq/g, the thickness when dried, of the layer 14B is from 6 to 100 μm, the layer 14A includes a layer having an ion exchange capacity of from 0.9 to 1.25 meq/g, and the thickness when dried, of the layer 14A is from 40 to 110 μm.

Patent Agency Ranking