Metal particle dispersion for electroconductive substrates, method for producing the same, and method for producing an electroconductive substrate

A method for producing a metal particle dispersion for electroconductive substrates, comprising the steps of:

• preparing a dispersant by preparing a graft copolymer in which at least a monomer represented by the following chemical formula (I′) and a polymerizable oligomer comprising a polymer chain comprising at least one constitutional unit represented by the following chemical formula (IV) or (V) and a group comprising an ethylenically unsaturated double bond at a terminal of the chain, are contained as copolymerizable components and copolymerized, and
• dispersing the thus-obtained dispersant and metal particles in a solvent:
• wherein R1 is a hydrogen atom or a methyl group;
• “A” is a direct bond or a divalent linking group, and the divalent linking group as “A” is at least one selected from the group consisting of an alkylene group comprising 1 to 10 carbon atoms, an arylene group, a —CONH— group, a —COO— group, an ether group comprising 1 to 10 carbon atoms comprising the formula —R′—OR″— wherein R′ and R″ are each independently an alkylene group and combinations thereof;
• wherein R4 is a hydrogen atom or a methyl group;
• R5 is a hydrocarbon group optionally comprising a substituent group, a cyano group or a monovalent group represented by —[CH(R6)—CH(R7)—O]x—R8, —[(CH2)y—O]z—R8, —[CO—(CH2)y—O]z—R8, —CO—O—R9 or —O—CO—R10;
• R6 and R7 are each independently a hydrogen atom or a methyl group;
• R8 is a hydrogen atom, a hydrocarbon group optionally comprising a substituent group, or a monovalent group represented by —CHO, —CH2CHO or —CH2COOR11;
• R9 is a hydrocarbon group optionally comprising a substituent group, a cyano group or a monovalent group represented by —[CH(R6)—CH(R7)—O]x—R8, —[(CH2)y—O]z—R8 or —[CO—(CH2)y—O]z—R8;
• R10 is an alkyl group comprising 1 to 18 carbon atoms, and the alkyl group optionally comprises a substituent group;
• R11 is a hydrogen atom or an alkyl group comprising 1 to 5 carbon atoms;
• the substituent group in R5, R8, R9 and R10 is at least one selected from the group consisting of a nitro group, a halogen atom, an alkoxy group, a hydroxyl group, a carboxyl group, an amino group, an epoxy group and an isocyanate group, and when R5, R8 and R9 are each a group comprising an aromatic ring, the aromatic ring optionally comprises a substituent group of an alkyl or alkenyl group;
• m is an integer of 1 to 5;
• n and n′ are each an integer of 5 to 200;
• x is an integer of 1 to 18;
• y is an integer of 1 to 5;
• and z is an integer of 1 to 18.

A method for producing an electroconductive substrate, comprising the steps of:

• forming a coating film by applying, onto a base material, a coating solution which contains a metal particle dispersion for electroconductive substrates, comprising metal particles, a dispersant and a solvent, wherein the dispersant is a graft copolymer comprising at least a constitutional unit represented by the following chemical formula (I) and a constitutional unit represented by the following chemical formula (II), and
• baking the coating film:
• wherein R1 and R1′ are each independently a hydrogen atom or a methyl group;
• “A” is a direct bond or a divalent linking group, and the divalent linking group as “A” is at least one selected from the group consisting of an alkylene group comprising 1 to 10 carbon atoms, an arylene group, a —CONH— group, a —COO— group, an ether group comprising 1 to 10 carbon atoms comprising the formula —R′—OR″— wherein R′ and R″ are each independently an alkylene group and combinations thereof;
• “L” is a direct bond or a divalent linking group, and the divalent linking group as “L” is at least one selected from the group consisting of an alkylene group, an alkylene group comprising a hydroxyl group, an arylene group, a —CONH— group, a —COO— group, a —NHCOO— group, an ether group (—O— group), a thioether group (—S— group) and combinations thereof;
• and “Polymer” is a polymer chain comprising at least one constitutional unit represented by the following chemical formula (IV) or (V):
• wherein R4 is a hydrogen atom or a methyl group;
• R5 is a hydrocarbon group optionally comprising a substituent group, a cyano group or a monovalent group represented by —[CH(R6)—CH(R7)O]x—R8, —[(CH2)y—O]z—R8, —[CO—(CH2)y—O]z—R8, —CO—O—R9 or —O—CO—R10;
• R6 and R7 are each independently a hydrogen atom or a methyl group;
• R8 is a hydrogen atom, a hydrocarbon group optionally comprising a substituent group, or a monovalent group represented by —CHO, —CH2CHO or —CH2COOR11;
• R9 is a hydrocarbon group optionally comprising a substituent group, a cyano group or a monovalent group represented by —[CH(R6)—CH(R7)—O]x—R8, —[(CH2)y—O]z—R8 or —[CO—(CH2)y—O]z—R8;
• R10 is an alkyl group comprising 1 to 18 carbon atoms, and the alkyl group optionally comprises a substituent group;
• R11 is a hydrogen atom or an alkyl group comprising 1 to 5 carbon atoms;
• the substituent group in R5, R8, R9 and R10 is at least one selected from the group consisting of a nitro group, a halogen atom, an alkoxy group, a hydroxyl group, a carboxyl group, an amino group, an epoxy group and an isocyanate group, and when R5, R8 and R9 are each a group comprising an aromatic ring, the aromatic ring optionally comprises a substituent group of an alkyl or alkenyl group;
• m is an integer of 1 to 5;
• n and n′ are each an integer of 5 to 200;
• x is an integer of 1 to 18;
• y is an integer of 1 to 5;
• and z is an integer of 1 to 18.