Optical film
First Claim
1. A film which comprises a polymer having such a structure that the main chain thereof comprises a hydrocarbon skeleton and some of the hydrogen atoms of the hydrocarbon skeleton are substituted by at least one alicyclic group selected from the group consisting of an alicyclic hydrocarbon group having a 4 or more membered ring and an alicyclic heterocyclic group, the amount of the alicyclic group being 60 to 90 wt %, and which satisfies the following formula (A):
-
R(450)/R(550)<
1
(A) wherein R(450) and R(550) are phase differences on the film plane at a wavelength of 450 nm and a wavelength of 550 nm, respectively.
1 Assignment
0 Petitions
Accused Products
Abstract
A film which is a single polymer film and has a smaller phase difference as the wavelength becomes shorter. This film is made from an olefin-based polymer which has an alicyclic group in the side chain, such as hydrogenated polystyrene, the amount of the alicyclic group in the side chain being 60 to 90 wt % based on the whole polymer, and satisfies the following expression:
R(450)/R(550)<1
wherein R(450) and R(550) are phase differences on the film plane at a wavelength of 450 nm and a wavelength of 550 nm, respectively.
-
Citations
19 Claims
-
1. A film which comprises a polymer having such a structure that the main chain thereof comprises a hydrocarbon skeleton and some of the hydrogen atoms of the hydrocarbon skeleton are substituted by at least one alicyclic group selected from the group consisting of an alicyclic hydrocarbon group having a 4 or more membered ring and an alicyclic heterocyclic group, the amount of the alicyclic group being 60 to 90 wt %, and which satisfies the following formula (A):
-
R(450)/R(550)<
1
(A)wherein R(450) and R(550) are phase differences on the film plane at a wavelength of 450 nm and a wavelength of 550 nm, respectively. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
-
5. The film of claim 1, wherein the polymer is a polymer consisting of a recurring unit represented by the above formula (1).
-
6. The film of claim 1 or 4, wherein the polymer is a hydrogenated product of a block copolymer consisting of a (styrene polymer) block and a (polyconjugated diene) block.
-
7. The film of claim 1 or 5, wherein the polymer is a hydrogenated product of a styrene polymer.
-
8. The film of claim 1 which has a light transmission of 85% or more.
-
9. The film of claim 1 which has an elongation at 25°
- C. of 1 to 50%.
-
10. The film of claim 1 which has a thickness of 3 to 300 μ
- m.
-
11. The film of claim 1 which is a phase difference film.
-
12. The film of claim 11 which is a λ
- /4 film.
-
13. The film of claim 11 which is a λ
- /2 film.
-
14. The film of claim 1 which is a phase difference film for liquid crystal display devices.
-
15. The film of claim 1 which is a cover layer for information recording media.
-
16. The film of claim 11 which has a phase difference of 50 nm or more.
-
17. The film of claim 15 which has a phase difference of 30 nm or less.
-
18. The film of claim 15 which satisfies the following expression (B):
-
K(450)/K(550)<
1
(B)wherein K(450) and K(550) are K values at a wavelength of 450 nm and a wavelength of 550 nm, respectively the K values being represented by the following expression;
K=(nz−
(nx+ny)/2)×
dwherein nx is a refractive index in a mechanical axis direction on the film plane, ny is a refractive index in a direction perpendicular to the mechanical axis direction on the film plane and nz is a refractive index in a direction normal to the film plane, and d is a film thickness (nm).
-
-
19. The film of claim 15 which has an elongation of 1% or more and a shrinkage factor of more than 1% in at least one direction.
Specification