Transparent film
View Patent ↗A film is provided which comprises a thermoplastic resin A having a substituted or non-substituted imide group at a side chain of the resin A, and a thermoplastic resin B having a substituted or non-substituted phenyl group and a nitrile group at a side chain of the resin B. The film has a retardation value of 0 to 1000 nm, a light transmission of 85% or more, and a haze of 2% or less.
1. A transparent film comprising:
(A) a thermoplastic resin having a substituted or non-substituted imide group at a side chain of the resin; and
(B) a thermoplastic resin having a substituted or non-substituted phenyl group and a nitrile group at a side chain of the resin,
wherein a retardation value of the film is from 0 to 1000 nm,
a light transmission of the film is 85% or more, and
a haze of the film is 2% or less.
2. A film according to claim 1 , wherein the thermoplastic resin A consists of an olefin repeating unit, and a repeating unit having a substituted or non-substituted imide group at a side chain of the resin.
3. A film according to claim 1 , wherein the retardation value is less than 20 nm.
4. A film according to claim 1 , wherein the retardation value is 20 nm or more.
5. A film according to claim 1 , wherein an alignment retardation value of the film is 300 nm or less.
6. A film according to claim 1 , wherein the film is a stretched film.
7. A film according to claim 1 , wherein a folding endurance of the film is 30 times or more in at least one direction in a plane of the film.
8. A film according to claim 1 , wherein a tear propagation strength of the film is 150 gf/mm or more in at least one direction in a plane of the film.
9. A film according to claim 1 , wherein a surface energy of at least one surface of the film is 50 dyne/cm or more.
10. A film according to claim 3 , wherein a retardation of the film in a thickness direction of the film is 50 nm or less.
11. A film according to claim 1 , wherein the thermoplastic resin A includes a repeating unit represented by the following formula (1), and another repeating unit represented by the following formula (2):
(where R 1 , R 2 and R 3 independently indicate a hydrogen atom or an alkyl group having 1 to 8 carbon atoms, and R indicates an alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 3 to 12 carbon atoms), and
wherein the content of the thermoplastic resin A is 50 to 90% by weight with reference to the weight of overall resins in the film.
12. A film according to claim 1 , wherein the thermoplastic resin B has a substituted or non-substituted acrylonitrile repeating unit and a substituted or non-substituted styrene repeating unit,
the substituted or non-substituted acrylonitrile repeating unit is 20 to 50% by weight of the thermoplastic resin B, and
the substituted or non-substituted styrene repeating unit is 50 to 80% by weight of the thermoplastic resin B.
13. A method for producing a film according to claim 1 , the method comprising the steps of:
flow-expanding a solution containing the thermoplastic resin A and the thermoplastic resin B on a support; and
drying the solution.
14. An elliptical polarization plate comprising a retardation film according to claim 4 and a polarization plate, wherein the film and the polarization plate are laminated.
15. A circular polarization plate comprising a retardation film according to claim 4 and a polarization plate, wherein the film and the polarization plate are laminated.
16. A polarization plate comprising a polarizer and a protection film protecting at least one side of the polarizer, wherein the protection film is a film according to claim 1 .