Optical members and compositions for producing them
It is disclosed a polymerizable composition for producing an optical member for 850 nm wavelength comprising: a polymerizable monomer composition and a compound, having a different refractive index from that of the polymerizable monomer composition, whose structure has a benzene ring substituted by a substituent having a Hammett value of not greater than 0.04 or by plural substituents having an average value of Hammett values thereof of not greater than 0.04. It is also disclosed a polymerizable composition for producing an optical member comprising a polymerizable monomer composition comprising at least one selected from the group consisting of C 7-20 alicyclic (meth)acrylates and a compound, having a different refractive index from that of the polymerizable monomer composition and having a solubility parameter of not greater than 10.9, whose structure has a benzene ring substituted by the substituent or the substituents defined above.
1. A polymerizable composition for producing an optical member for 850 nm wavelength comprising:
a polymerizable monomer composition,
a polymerization initiator, and
a compound, having a different refractive index from that of the polymerizable monomer composition, whose structure has a benzene ring substituted by a substituent having a Hammett value of not greater than −0.05 or by plural substituents having an average value of Hammett values thereof of not greater than −0.05.
2. The polymerizable composition of claim 1 , wherein the polymerizable monomer composition comprises at least one selected from the group consisting of esters of a propenoic acid and esters of derivatives thereof in a major proportion.
3. The polymerizable composition of claim 2 , wherein the polymerizable monomer composition comprises at least one selected from the group consisting of esters of a (meth)acrylic acid and esters of derivatives thereof in a major proportion.
4. The polymerizable composition of claim 1 , wherein the polymerizable monomer composition comprises at least one selected from the group consisting of compounds including a C-F bond.
5. The polymerizable composition of claim 1 , wherein the polymerizable monomer composition comprises at least one selected from the group consisting of compounds including a C-D (deuterium) bond.
6. An optical member produced by polymerization of a composition of claim 1 , so as to form a region having a graded refractive index.
7. A process for producing an optical member comprising a step of polymerizing the polymerizable composition of claim 1 .
8. The process of claim 7 , wherein, in said step of polymerizing, the polymerization temperature is 50 degrees Celsius or above.
9. An optical member for 850 nm wavelength comprising:
a polymer composition comprising at least one polymer selected from the group consisting of (meth)acrylates base polymers and
a compound having a different refractive index from that of the polymer composition wherein the compound has an absorption peak attributed to a fourth overtone of C—H bond stretching vibration in a benzene ring at not shorter than 875 nm; and the compound's structure has a benzene ring substituted by a substituent having a Hammett value of not greater than −0.05 or by plural substituents having an average value of Hammett values thereof of not greater than −0.05.
10. The optical member of claim 9 wherein the compound is selected from the group consisting of:
wherein R 1 to R 10 respectively represent a hydrogen, an alkyl, an alkenyl, an alkyloxy, an alkenyloxy, or dialkylamino provided that at least four of them represent an alkyl, alkenyl, alkyloxy, alkenyloxy or dialkylamino.
11. The optical member of claim 9 , which comprises a region having a graded refractive index.
12. The optical member of claim 11 , which comprises a region having a graded refractive index along the direction from the center to the outside.
13. A polymerizable composition for producing an optical member comprising:
a polymerizable monomer composition comprising at least one selected from the group consisting of:
wherein X 1 is hydrogen (H) or deuterium (D) wherein two X 1 may be the same or different; Y 1 represents H, D, CH 3 or CD 3 ; and R 1 represents a C 7-20 alicyclic hydrocarbon group;
a polymerization initiator, and
a compound, having a different refractive index from that of the polymerizable monomer composition and having a solubility parameter of not greater than 10.9, whose structure has a benzene ring substituted by a substituent having a Hammett value of not greater than −0.05 or by groups having an average value of Hammett values thereof of not greater than −0.05.
14. The polymerizable composition of claim 13 wherein the polymerizable monomer composition comprises an alicyclic hydrocarbon methyl methacrylate and methyl methacrylate in a major proportion.
15. The polymerizable composition of claim 14 wherein the polymerizable monomer composition comprises at least one compound including a C-D bond.
16. An optical member produced by polymerization of a composition of claim 13 , so as to form a region having a graded refractive index.
17. The optical member of claim 16 comprising a core region having a graded refractive index, which is produced by polymerization of a composition of claim 11 and a clad region cladding the core region.
18. The optical member of claim 17 , wherein the core region has a graded refractive index along the direction from the center to the outside.
19. The optical member of claim 17 , wherein the clad region is essentially formed of a polymerizable monomer composition comprising a same ingredient or same ingredients in a major portion as those of the core region.
20. The optical member of claim 17 which is an optical fiber, a light guide or an optical lens.