Gel including condensation product of organic silicon compound

A method for producing a gel comprising a crosslinked polymer having at least one selected from the group consisting of an acidic dissociative group, an acidic dissociative group in a salt form, and a derivative group of an acidic dissociative group, and a condensate of a compound represented by the following formula (I):

• Si{R1—N(R2)(R3)}(OR4)(OR5)(R6) (I)
• wherein
• R1 is an alkylene group optionally having substituent(s), a cycloalkanediyl group optionally having substituent(s), an arenediyl group optionally having substituent(s), or a divalent group optionally having substituent(s) and being a combination of at least two selected from the group consisting of an alkylene group, a cycloalkanediyl group and an arenediyl group, and one or more —CH2— excluding —CH2— adjacent to Si and —CH2— adjacent to N in said alkylene group and cycloalkanediyl group is/are optionally replaced by at least one selected from the group consisting of —O— and —NR7— wherein R7 is a hydrogen atom, an alkyl group optionally having substituent(s), a cycloalkyl group optionally having substituent(s), an aryl group optionally having substituent(s) or an aralkyl group optionally having substituent(s),
• R2 and R3 are each independently a hydrogen atom, an alkyl group optionally having substituent(s), a cycloalkyl group optionally having substituent(s), an aryl group optionally having substituent(s), or an aralkyl group optionally having substituent(s), or they are bonded to each other to form, together with the adjacent nitrogen atom, a basic nitrogen-containing heterocycle optionally having substituent(s),
• R4 and R5 are each independently a hydrogen atom, an alkyl group optionally having substituent(s), a cycloalkyl group optionally having substituent(s), an aryl group optionally having substituent(s), or an aralkyl group optionally having substituent(s), and
• R6 is an alkyl group optionally having substituent(s), a cycloalkyl group optionally having substituent(s), an aryl group optionally having substituent(s), an aralkyl group optionally having substituent(s), a hydroxy group, an alkoxy group optionally having substituent(s), a cycloalkyloxy group optionally having substituent(s), an aryloxy group optionally having substituent(s), an aralkyloxy group optionally having substituent(s), or a group represented by —R′1—N(R′2)(R′3), wherein
• R′1 is an alkylene group optionally having substituent(s), a cycloalkanediyl group optionally having substituent(s), an arenediyl group optionally having substituent(s), or a divalent group optionally having substituent(s) and being a combination of at least two selected from the group consisting of an alkylene group, a cycloalkanediyl group and an arenediyl group, and one or more —CH2— excluding —CH2— adjacent to Si and —CH2— adjacent to N in said alkylene group and cycloalkanediyl group is/are optionally replaced by at least one selected from the group consisting of —O— and —NR′7— wherein R′7 is a hydrogen atom, an alkyl group optionally having substituent(s), a cycloalkyl group optionally having substituent(s), an aryl group optionally having substituent(s) or an aralkyl group optionally having substituent(s), and
• R′2 and R′3 are each independently a hydrogen atom, an alkyl group optionally having substituent(s), a cycloalkyl group optionally having substituent(s), an aryl group optionally having substituent(s), or an aralkyl group optionally having substituent(s), or they are bonded to each other to form, together with the adjacent nitrogen atom, a basic nitrogen-containing heterocycle optionally having substituent(s), the method comprising drying and heating a mixture comprising at least one selected from the group consisting of a compound represented by the formula (I) and a condensate of a compound represented by the formula (I), water and said crosslinked polymer to form a condensate of the compound represented by the formula (I).