Vinyl polymers and processes for producing the same

1. A method for making a vinyl polymer having a terminus to which a functional-group-introducing agent is added, comprising:

supplying the functional-group-introducing agent having a low polymerizability and a functional-group-introducing solvent having a dielectric constant higher than that of the functional-group-introducing agent to a polymerization system after 80 percent by weight or more of a vinyl monomer is consumed by atom transfer radical polymerization in a polymerization solvent in the presence of a polymerization initiator and a transition metal complex functioning as a polymerization catalyst, and

adding the functional-group-introducing agent to the terminus of the vinyl polymer by addition reaction,

wherein 1 to 1,000 parts by weight of the functional-group-introducing solvent to 100 parts by weight of the vinyl monomer is supplied.

2. The method according to claim 1 , wherein the polymerization solvent and the vinyl monomer are removed by reduced-pressure distillation while the ability for atom transfer radical polymerization is maintained, the reduced-pressure distillation being performed after 80 percent by weight or more of the vinyl monomer is consumed and before the functional-group-introducing agent having a low polymerizability and the functional-group-introducing solvent having a dielectric constant higher than that of the functional-group-introducing agent are supplied.

3. The method according to claim 1 , wherein the functional-group-introducing agent is a compound represented by general formula (1):

wherein R 3 represents a hydroxyl group, an amino group, an epoxy group, a carboxylic acid group, an ester group, an ether group, an amido group, a silyl group, a group represented by general formula (2):

wherein R 4 represents a hydrogen atom or a methyl group, or a C 1 -C 20 organic group; R 1 represents a C 1 -C 20 alkylene group or a group represented by general formula (3):

wherein R 5 is a C 1 -C 20 organic group which may contain an oxygen atom or a nitrogen atom; and R 6 s each represent a hydrogen atom or a methyl group and may be the same or different; and R 2 represents a hydrogen atom or a methyl group.

4. The method according to claim 1 , wherein the functional-group-introducing agent is a compound represented by general formula (4):

wherein R 1 represents a C 1 -C 20 alkylene group or a group represented by general formula (3):

wherein R 5 is a C 1 -C 20 organic group which may contain an oxygen atom or a nitrogen atom; and R 6 s each represent a hydrogen atom or a methyl group and may be the same or different; and R 2 and R 4 each represent a hydrogen atom or a methyl group.

5. The method according to claim 1 , wherein the functional-group-introducing agent is a compound represented by general formula (5):

wherein n is an integer between 1 and 20.

6. The method according to claim 1 , wherein the functional-group-introducing agent is 1,5-hexadiene, 1,7-octadiene, or 1,9-decadiene.

7. The method according to claim 1 , wherein R 3 in general formula (1) is selected from a hydroxyl group, an amino group, an epoxy group, a carboxylic acid group, an ester group, an ether group, an amido group, and a silyl group.

8. The method according to claim 1 , wherein an excess amount of the functional-group-introducing agent relative to the propagating termini of the polymer is supplied.

9. The method according to claim 1 , wherein the dielectric constant of the functional-group-introducing solvent is at least 3 higher than the dielectric constant of the functional-group-introducing agent.

10. The method according to claim 1 , wherein the functional-group-introducing solvent is a nitrile compound.

11. The method according to claim 1 , wherein 1 to 10,000 parts by weight of the functional-group-introducing solvent to 100 parts by weight of the functional-group-introducing agent is supplied.

12. The method according to claim 1 , wherein the vinyl polymer is a (meth)acrylic polymer.

13. The method according to claim 1 , wherein the number-average molecular weight of the vinyl polymer is 500 to 100,000.

14. The method according to claim 1 , wherein the molecular weight distribution of the vinyl polymer is less than 1.8.

15. The method according to claim 1 , wherein the central metal of the transition metal complex is a Group VIII, IX, X or XI element in the periodic table.

16. The method according to claim 1 , wherein the ligand of the transition metal complex is a polyamine compound.

17. The method according to claim 1 , wherein the polymerization initiator is a functional-group-containing organohalide compound or a functional-group-containing sulfonyl halide compound.

18. The method according to claim 1 , wherein the polymerization initiator is a polyfunctional initiator.

19. The method according to claim 2 , wherein the polymerization solvent and the monomer removed by the reduced-pressure distillation are recovered and reused as a polymerization solvent and a monomer.

20. The method according to claim 1 , wherein the functional-group-introducing agent or a mixture of the functional-group-introducing agent and the functional-group-introducing solvent is removed by reduced-pressure distillation after the functional group is bound to a terminus of the vinyl polymer by supplying the functional-group-introducing agent.

21. The method according to claim 20 , wherein the functional-group-introducing agent or the mixture of the functional-group-introducing agent and the functional-group-introducing solvent removed by the reduced-pressure distillation is recovered and reused as a functional-group-introducing agent or a mixture of a functional-group-introducing agent and a functional-group-introducing solvent.