Graded-refractive-index optical plastic material and method for its production

• US 6,166,125 A
• Filed: 10/01/1998
• Issued: 12/26/2000
• Est. Priority Date: 10/02/1997
• Status: Expired due to Term

• Current Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Original Assignee: Asahi Glass Company, Limited (AGC, Inc.)
• Inventors: Irisawa, Jun, Tamura, Masayuki, Okazoe, Takashi, Sugiyama, Norihide, Tatematsu, Shin, Murofushi, Hidenobu
• Primary Examiner(s): Michl, Paul R.
• Application Number:
  US09/164,371
• Time in Patent Office: 817 Days
• Field of Search: 524/462, 524/463
• US Class Current: 524/462
• CPC Class Codes: G02B 1/046 characterised by the core material

Abstract

A graded-refractive-index optical plastic material comprising an amorphous fluorine-containing polymer (A) having substantially no C--H bond, and at least one fluorine-containing polycyclic compound (B) having a refractive index higher by at least 0.005 than the fluorine-containing polymer (A), wherein the fluorine-containing polycyclic compound (B) is distributed in the fluorine-containing polymer (A) with a concentration gradient such that the concentration decreases in a direction of from the center to the periphery, and the fluorine-containing polycyclic compound (B) is at least one fluorine-containing polycyclic compound selected from the group consisting of the following compounds (B1), (B2) and (B3):

(B1) a fluorine-containing non-condensed polycyclic compound having at least two fluorine-containing rings bonded by a bond containing at least one member selected from the group consisting of a triazine ring, an oxygen atom, a sulfur atom, a phosphorus atom and a metal atom, each of said fluorine-containing rings being a carbon ring or a heterocyclic ring and having a fluorine atom or a perfluoroalkyl group, said polycyclic compound having substantially no C--H bond;

(B2) a fluorine-containing non-condensed polycyclic compound having at least three fluorine-containing rings bonded directly or by a bond containing a carbon atom, each of said fluorine-containing rings being a carbon ring or a heterocyclic ring and having a fluorine atom or a perfluoroalkyl group, said polycyclic compound having substantially no C--H bond;

(B3) a fluorine-containing condensed polycyclic compound which is a condensed polycyclic compound composed of at least three carbon rings or heterocyclic rings, and which has substantially no C--H bond.

Claims

1. A graded-refractive-index optical plastic material comprising an amorphous fluorine-containing polymer (A) having substantially no C--H bond, and at least one fluorine-containing polycyclic compound (B) having a refractive index higher by at least 0.005 than the fluorine-containing polymer (A), wherein the fluorine-containing polycyclic compound (B) is distributed in the fluorine-containing polymer (A) with a concentration gradient such that the concentration decreases in a direction of from the center to the periphery, and the fluorine-containing polycyclic compound (B) is at least one fluorine-containing polycyclic compound selected from the group consisting of the following compounds (B1), (B2) and (B3):

(B1) a fluorine-containing non-condensed polycyclic compound having at least two fluorine-containing rings bonded by a bond containing at least one member selected from the group consisting of a triazine ring, an oxygen atom, a sulfur atom, a phosphorus atom and a metal atom, each of said fluorine-containing rings being a carbon ring or a heterocyclic ring and having a fluorine atom or a perfluoroalkyl group, said polycyclic compound having substantially no C--H bond;

(B2) a fluorine-containing non-condensed polycyclic compound having at least three fluorine-containing rings bonded directly or by a bond containing a carbon atom, each of said fluorine-containing rings being a carbon ring or a heterocyclic ring and having a fluorine atom or a perfluoroalkyl group, said polycyclic compound having substantially no C--H bond;

(B3) a fluorine-containing condensed polycyclic compound which is a condensed polycyclic compound composed of at least three carbon rings or heterocyclic rings, and which has substantially no C--H bond.

2. The graded-refractive-index optical plastic material according to claim 1, which has a numerical aperture NA of at least 0.20, when NA=(n² -m²)^1/2, where n is the maximum value of the refractive index in the graded-refractive-index optical plastic material, and m is the minimum value of the refractive index in the graded-refractive-index optical plastic material.

3. The graded-refractive-index optical plastic material according to claim 1, wherein the glass transition temperature of the center portion of the graded-refractive-index optical plastic material is at least 70°

C.

4. The graded-refractive-index optical plastic material according to claim 1, wherein the concentration of the fluorine-containing polycyclic compound (B) at the center portion of the graded-refractive-index optical plastic material is at most 15 wt %.

5. The graded-refractive-index optical plastic material according to claim 1, wherein the optical plastic material is a graded-refractive-index optical fiber or a preform for the production of a graded-refractive-index optical fiber.

6. The graded-refractive-index optical plastic material according to claim 1, wherein the fluorine-containing polymer (A) is a fluorine-containing polymer having a fluorine-containing alicyclic structure in its main chain.

7. The graded-refractive-index optical plastic material according to claim 1, wherein the fluorine-containing polymer (A) has a number average molecular weight of from 1×

10⁴ to 5×

10⁶.

8. The graded-refractive-index optical plastic material according to claim 1, wherein the fluorine-containing polycyclic compound (B) has a refractive index of at least 1.45.

9. The graded-refractive-index optical plastic material according to claim 1, wherein the fluorine-containing polycyclic compound (B) has a number average molecular weight of from 3×

10² to 2×

10³.

10. The graded-refractive-index optical plastic material according to claim 1, wherein each of said carbon rings is an at least 4-membered ring.

11. The graded-refractive-index optical plastic material according-to claim 1, wherein each of said carbon rings is a cyclic saturated hydrocarbon ring or a cyclic unsaturated hydrocarbon ring.

12. The graded-refractive-index optical plastic material according to claim 11, wherein the cyclic saturated hydrocarbon ring is a cyclopentane ring or a cyclohexane ring.

13. The graded-refractive-index optical plastic material according to claim 11, wherein the cyclic unsaturated hydrocarbon ring is a cyclopentene ring, a cyclohexene ring or a benzene ring.

14. The graded-refractive-index optical plastic material according to claim 1, wherein each of said heterocyclic rings is an at least 4-membered ring.

15. The graded-refractive-index optical plastic material according to claim 1, wherein the atoms constituting each of said heterocyclic rings are selected from a carbon atom, a nitrogen atom, an oxygen atom, a sulfur atom and a phosphorus atom.

16. The graded-refractive-index optical plastic material according to claim 1, wherein each of said heterocyclic rings is a heterocyclic ring containing one or two types of hetero atoms.

17. The graded-refractive-index optical plastic material according to claim 16, wherein the heterocyclic ring containing one type of a hetero atom is a thiophene ring, a furan ring, a pyridine ring or a triazole ring.

18. The graded-refractive-index optical plastic material according to claim 16, wherein the heterocyclic ring containing two types of hetero atoms is a triazole ring or an isothiazole ring.

19. The graded-refractive-index optical plastic material according to claim 1, wherein said fluorine-containing non-condensed polycyclic compound is a compound having at least two fluorine-containing rings bonded by a bond containing at least a triazine ring.

20. The graded-refractive-index optical plastic material according to claim 1, wherein said metal atom is a bivalent to tetravalent metal selected from the group consisting of Zn, Sn, Pb, Ge, Si, Ti, Hg, Tl, As, Se, Te and Cd.