Organic-inorganic hybrid composition, method for producing the same, molding and optical component

1. An organic-inorganic hybrid composition comprising inorganic fine particles having a refractive index of from 1.90 to 3.00, and a thermoplastic resin having a functional group capable of forming a chemical bond with the inorganic fine particles only at one or more polymer chain terminals and having a number average molecular weight of from 1,000 to 500,000,

wherein the functional group capable of forming a chemical bond with the inorganic fine particles is a functional group selected from the group consisting of

—SO 3 H, —OSO 3 H, and —Si(OR 5 ) m R 6 3-m , wherein R 1 , R 2 , R 3 , R 4 , R 5 and R 6 each independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkenyl group, a substituted or unsubstituted alkynyl group or a substituted or unsubstituted phenyl group, and m is an integer of from 1 to 3,

or its salt.

2. The organic-inorganic hybrid composition according to claim 1 , wherein the thermoplastic resin has a refractive index larger than 1.55.

3. The organic-inorganic hybrid composition according to claim 1 , wherein the inorganic fine particles have a number average particle size of from 1 to 15 nm.

4. The organic-inorganic hybrid composition according to claim 1 , wherein at least one of titanium oxide and zirconium oxide is contained as the inorganic fine particles.

5. The organic-inorganic hybrid composition according to claim 1 , having a light transmittance of 80% or more at a wavelength of 589 nm in terms of the composition having a thickness of 1 mm.

6. The organic-inorganic hybrid composition according to claim 1 , which is thermoplastic.

7. The organic-inorganic hybrid composition according to claim 1 , which is a solvent-free solid.

8. A method for producing an organic-inorganic hybrid composition, comprising mixing inorganic fine particles having a refractive index of from 1.90 to 3.00, and a thermoplastic resin having a functional group capable of forming a chemical bond with the inorganic fine particles at one or more polymer chain terminals and having a number average molecular weight of from 1,000 to 500,000 in an organic solvent.

9. The method for producing an organic-inorganic hybrid composition according to claim 8 , comprising surface-treating inorganic fine particles having a refractive index of from 1.90 to 3.00 in water, an alcohol or a mixture of water and an alcohol in the presence of a surface-treating agent; extracting the surface-treated inorganic fine particles in an organic solvent, and mixing the extracted inorganic fine particles with a thermoplastic resin having a functional group capable of forming a chemical bond with the extracted inorganic fine particles at one or more polymer chain terminals and having a number average molecular weight of from 1,000 to 500,000.

10. The method for producing an organic-inorganic hybrid composition according to claim 8 , comprising mixing an organic solvent dispersion of inorganic fine particles having a refractive index of from 1.90 to 3.00 with a thermoplastic resin having a functional group capable of forming a chemical bond with the inorganic fine particles at one or more polymer chain terminals and having a number average molecular weight of from 1,000 to 500,000, and distilling away a solvent from the resulting mixed liquid.

11. The method for producing an organic-inorganic hybrid composition according to claim 8 , comprising mixing an organic solvent dispersion of inorganic fine particles having a refractive index of from 1.90 to 3.00 with a thermoplastic resin having a functional group capable of forming a chemical bond with the inorganic fine particles at one or more polymer chain terminals and having a number average molecular weight of from 1,000 to 500,000, and reprecipitating the resulting mixed liquid.

12. An organic-inorganic hybrid composition produced by the production method according to claim 8 .

13. A molding comprising the organic-inorganic hybrid composition according to claim 1 , the molding having a maximum thickness of 0.1 mm or more.

14. The molding according to claim 13 , having a light transmittance of 70% or more at a wavelength of 589 nm in terms of the molding having a thickness of 1 mm, and a refractive index of 1.63 or more.

15. An optical component comprising the molding according to claim 13 .

16. The optical component according to claim 15 , which is a lens substrate.