Radically polymerizable polyether, method for producing said radically polymerizable polyether, polymerizable composition comprising said radically polymerizable polyether and radically polymerizable vinyl monomer, and copolymer, molded article and film each formed by radical polymerization of said polymerizable composition

1. A radically polymerizable polyether (A) which has a mass average molecular weight of from 20,000 to 1,000,000 and a number average molecular weight of 20,000 to 100,000, comprising a polyalkylene ether backbone having a (meth)acryloyl group as a pendant group and a polytetramethylene ether backbone.

2. The radically polymerizable polyether (A) according to claim 1 , which has a mass average molecular weight of from 20,000 to 1,000,000 and is represented by the following Formula (1):

wherein:

m1 is from 1 to 7000,

m2 is from 0 to 7000,

n is from 1 to 14,000,

R1 is a methyl group or hydrogen, and

R2 and R3 are hydrogen or a hydrocarbon group having from 1 to 20 carbon atoms.

3. The radically polymerizable polyether (A) according to claim 2 , wherein m1, m2, and n in Formula (1) are in a relation of 0.0005≦m1/(m1+m2+n)≦0.20.

4. The radically polymerizable polyether (A) according to claim 2 , wherein m1, m2, and n in Formula (1) are in a relation of 0.001≦m1/(m1+m2+n)≦0.10.

5. A polymerizable composition (C) which comprises the radically polymerizable polyether (A) according to claim 1 and a radically polymerizable vinyl monomer (B), and wherein a composition ratio range of the component (A) to the component (B) is from 1 to 99% by mass of the component (A) and from 99 to 1% by mass of the component (B).

6. The polymerizable composition (C) according to claim 5 , wherein the radically polymerizable vinyl monomer (B) is a (meth)acrylic monomer.

7. A copolymer formed by radical polymerization of the polymerizable composition (C) according to claim 5 .

8. A molded article formed by radical polymerization of the polymerizable composition (C) according to claim 5 after being shaped into a desired shape.

9. A film formed by radical polymerization of the polymerizable composition (C) according to claim 5 .

10. The film according to claim 9 , which has a thickness of from 0.1 to 3000 μm.

11. The film according to claim 9 , which has an elongation at break of 10% or more when a tension speed is 500 mm/min.

12. The film according to claim 9 , which has a haze of 5% or less when a thickness thereof is 0.5 mm.

13. A method for producing a radically polymerizable polyether (A), wherein ring-opening polymerization of tetrahydrofuran is conducted by allowing from 1 to 20 parts by mass of a glycidyl ester (a) represented by the following Formula (2) to react with 100 parts by mass of tetrahydrofuran in the presence of a metal salt hydrate of trifluoromethanesulfonic acid (b) at from 0.1 to 5 parts by mass:

wherein:

R is a straight-chain or branched chain hydrocarbon group having from 1 to 20 carbon atoms and substituted by a hydrocarbon group containing an unsaturated bond and having from 2 to 10 carbon atoms.

14. The method according to claim 13 , wherein a mass ratio (a)/(b) of the glycidyl ester (a) to the metal salt hydrate of trifluoromethanesulfonic acid (b) is from 2 to 9.

15. The method according to claim 13 , wherein the glycidyl ester (a) is glycidyl methacrylate.

16. The method according to claim 13 , wherein the metal of the metal salt hydrate of trifluoromethanesulfonic acid (b) is one or more selected from the group consisting of scandium, yttrium, and lanthanoid.

17. The method according to claim 13 , wherein the metal salt hydrate of trifluoromethanesulfonic acid (b) is ytterbium trifluoromethanesulfonate hydrate.