Aromatic polyimine and process for preparing the same, and aromatic oligoimine used for aromatic polyimine and process for preparing the same

A process for preparing an aromatic oligoimine having a recurring unit represented by the general formula (III):

• ##STR22## wherein each of R.sup.1, R.sup.2 and R.sup.3 is independently a hydrogen atom, an alkyl group or an aryl group, the total number of carbon atoms contained in R.sup.1, R.sup.2 and R.sup.3 is at most 10, and X is a single bond, a linear or branched alkylene group having at most 6 carbon atoms, an arylene group, oxygen atom, sulphur atom, --SO.sub.2 --, a group represented by the general formula:
• --Y.sup.1 --Ar--Y.sup.1 -- in which Ar is phenylene group, Y.sup.1 is a single bond, a linear or branched alkylene group having at most 6 carbon atoms, an arylene group, oxygen atom, sulphur atom or --SO.sub.2 --, or a group represented by the general formula:
• --Y.sup.1 --Ar--Y.sup.1 --Ar--Y.sup.1 -- in which Ar and Y.sup.1 are the same as defined above, and a degree of polymerization of 2 to 20,
• which comprises conducting the condensation of an aromatic dialdehyde having a phenolic hydroxyl group, represented by the general formula (I):
• ##STR23## wherein R.sup.1, R.sup.2 and R.sup.3 are the same as defined above and an aromatic diamine represented by the general formula (II):
• ##STR24## wherein X is the same as defined above in the presence of at least one solvent selected from an amido solvent or a phenolic solvent.

An aromatic polyimine having a recurring unit represented by the general formula (III):

• ##STR25## wherein each of R.sup.1, R.sup.2 and R.sup.3 is independently a hydrogen atom, an alkyl group or an aryl group, the total number of carbon atoms contained in R.sup.1, R.sup.2 and R.sup.3 is at most 10, and X is a single bond, a linear or branched alkylene group having at most 6 carbon atoms, an arylene group, oxygen atom, sulphur atom, --SO.sub.2 --, a group represented by the general formula:
• --Y.sup.1 --Ar--Y.sup.1 -- in which Ar is phenylene group, Y.sup.1 is a single bond, a linear or branched alkylene group having at most 6 carbon atoms, an arylene group, oxygen atom, sulphur atom or --SO.sub.2 --, or a group represented by the general formula:
• --Y.sup.1 --Ar--Y.sup.1 --Ar--Y.sup.1 -- in which Ar and Y.sup.1 are the same as defined above,
• made by thermally dehydrating an aromatic oligoimine having a recurring unit represented by the general formula (III):
• ##STR26## wherein R.sup.1, R.sup.2, R.sup.3 and X are the same as defined above and a degree of polymerization of 2 to 20, composed of a reaction product of an aromatic dialdehyde having a phenolic hydroxyl group, represented by the general formula (I):
• ##STR27## wherein R.sup.1, R.sup.2 and R.sup.3 are the same as defined above and an aromatic diamine represented by the general formula (II):
• ##STR28## wherein X is the same as defined above.

A process for preparing an aromatic polyimine having a recurring unit represented by the general formula (III):

• ##STR29## wherein each of R.sup.1, R.sup.2 and R.sup.3 is independently a hydrogen atom, an alkyl group or an aryl group, the total number of carbon atoms contained in R.sup.1, R.sup.2 and R.sup.3 is at most 10, and X is a single bond, a linear or branched alkylene group having at most 6 carbon atoms, an arylene group, oxygen atom, sulphur atom, --SO.sub.2 --, a group represented by the general formula:
• --Y.sup.1 --Ar--Y.sup.1 -- in which Ar is phenylene group, Y.sup.1 is a single bond, a linear or branched alkylene group having at most 6 carbon atoms, an arylene group, oxygen atom, sulphur atom or --SO.sub.2 --, or a group represented by the general formula:
• --Y.sup.1 --Ar--Y.sup.1 --Ar--Y.sup.1 -- in which Ar and Y.sup.1 are the same as defined above,
• which comprises preparing an aromatic oligoimine having a recurring unit represented by the general formula (III):
• ##STR30## wherein R.sup.1, R.sup.2, R.sup.3 and X are the same as defined above and a degree of polymerization of 2 to 20 by reacting an aromatic dialdehyde having a phenolic hydroxyl group, represented by the general formula (I):
• ##STR31## wherein R.sup.1, R.sup.2 and R.sup.3 are the same as defined above with an aromatic diamine represented by the general formula (II):
• ##STR32## wherein X is the same as defined above, and thermally dehydrating said aromatic oligoimine.