Method for producing modified conjugated diene polymer, modified conjugated diene polymer, modified conjugated diene polymer composition, rubber composition and tire

A method of producing a modified conjugated diene polymer comprising

• a polymerization step of obtaining a conjugated diene polymer having an active end by polymerizing a conjugated diene or copolymerizing a conjugated diene with a copolymerizable monomer by use of an alkali metal compound or an alkaline earth metal compound as a polymerization initiator,
• a modification step of modifying the active end by reacting a compound represented by the following formula (I) with the active end of the conjugated diene copolymer, and
• a step of modifying a vinyl group of a main chain of the conjugated diene polymer with a silicon modification group having at least one functional group selected from the group consisting of an amino group, an alkoxysilyl group and a hydroxy group by a hydrosilylation reaction:
• where R21 to R24 each independently represent an alkyl group or aryl group having 1 to 20 carbon atoms;
• R25 represents an alkylene group having 1 to 10 carbon atoms;
• R26 represents an alkylene group having 1 to 20 carbon atoms;
• p is an integer of 1 or 2;
• and q is an integer of 2 or 3.

A modified conjugated diene polymer having a nitrogen atom-containing functional group in a main chain of the polymer, and a functional group having at least one secondary amino group, at least one alkoxysilyl group, and 3 to 6 branches on at least one of ends, wherein

• the modified conjugated diene polymer is modified from a conjugated diene polymer polymerized by copolymerizing a conjugated diene compound and a nitrogen atom-containing vinyl compound or a conjugated diene compound, an aromatic vinyl compound and a nitrogen atom-containing vinyl compound with a modifier, which is a compound represented by the following formula (1), with the active end of the conjugated diene polymer:
• wherein R1 to R4 each independently represent an alkyl group having 1 to 20 carbon atoms or an aryl group having 6 to 20 carbon atoms;
• R5 represents an alkylene group having 3 to 10 carbon atoms;
• R6 represents an alkylene group having 1 to 20 carbon atoms;
• m is an integer of 1 or 2;
• and n is an integer of 2 or 3.

A modified conjugated diene polymer having a nitrogen atom-containing functional group in a main chain of the polymer, and a functional group having at least one secondary amino group, at least one alkoxysilyl group, and 3 to 6 branches on at least one of ends, wherein

• the modified conjugated diene polymer is modified from a conjugated diene polymer polymerized by polymerizing a conjugated diene or copolymerizing a conjugated diene with a copolymerizable monomer by modifying (i) an active end of the conjugated diene polymer by reacting a compound represented by the following formula (I) with the active end of the conjugated diene copolymer,
• wherein R21 to R24 each independently represent an alkyl group or aryl group having 1 to 20 carbon atoms;
• R25 represents an alkylene group having 1 to 10 carbon atoms;
• R26 represents an alkylene group having 1 to 20 carbon atoms;
• p is an integer of 1 or 2;
• and q is an integer of 2 or 3, and (ii) a vinyl group of a main chain of the conjugated diene polymer with a silicon modification group having at least one functional group selected from the group consisting of an amino group, an alkoxysilyl group and a hydroxy group by a hydrosilylation reaction.