Film, film manufacturing method, cover film, and multilayer electronic equipment

1. A film, comprising:

an elastic layer,

wherein the elastic layer has a storage modulus index K SM of 20 to 350 Mpa represented by Equation 1 below, and

wherein the elastic layer has a haze of 3% or less;

K

SM

=

(

SM

-

40

×

SM

80

SM

20

)

-

SM

80

[

Equation

⁢

1

]

where SM −40 is a storage modulus (Mpa) measured at a temperature of −40° C., SM 80 is a storage modulus (Mpa) measured at a temperature of 80° C., and SM 20 is a storage modulus (Mpa) measured at a temperature of 20° C.,

wherein the elastic layer comprises a polymer which has an amide residue as a repeating unit,

wherein a low temperature storage modulus ratio R-40/20 is a ratio of the storage modulus at −40° C. based on the storage modulus at 20° C. and the low temperature storage modulus ratio R-40/20 of the elastic layer is 1.33 or more, and

wherein the storage modulus of the elastic layer at −40° C. is 2000 Mpa or less.

2. The film according to claim 1 ,

wherein the elastic layer has a storage modulus of 3 GPa or less at ambient temperature.

3. The film according to claim 1 ,

wherein the elastic layer has a storage modulus ratio of 0.08 or more, which is the ratio of a storage modulus at 80° C. based on a storage modulus at 20° C.

4. The film according to claim 1 ,

wherein the elastic layer has a difference of a storage modulus at −40° C. and a storage modulus at 20° C., and the difference of a storage modulus ranges from −1500 to +1500 MPa.

5. The film according to claim 1 ,

wherein the elastic layer has a storage modulus of 20 to 2500 Mpa at 0° C.

6. The film according to claim 1 ,

wherein the elastic layer has a storage modulus of at least 5 Mpa or more at 80° C.

7. The film according to claim 1 ,

wherein a thickness of the elastic layer is less than 2000 μm.

8. The film according to claim 1 ,

wherein a recovery force index Rv is represented by Equation 2 below, and the Rv of the elastic layer is greater than 50;

Rv

=

(

X

2

⁢

%

-

Xf

X

2

⁢

%

-

Xo

)

×

100

[

Equation

⁢

2

]

where Xo is a length (mm) of the initial elastic layer, X 2% is a length (mm) of the elastic layer after 2% length stretching, and when 1 cycle is defined as a process consisting of 2% length stretching at a rate of 50 mm/min and restoring to original length at a rate of 50 mm/min, Xf is a length (mm) of the elastic layer after 100 cycles.

9. The film according to claim 1 ,

wherein the elastic layer is an elastomer film comprising a polyether block amide.

10. The film according to claim 9 ,

wherein a content of polyamide contained in the polyether block amide is at least 50 wt % or more based on the total polyether block amide.

11. The film according to claim 1 ,

wherein the elastic layer has a storage modulus ratio of 0.20 or more and 0.7 or less, which is the storage modulus ratio of a storage modulus at 80° C. based on a storage modulus at 20° C.

12. The film according to claim 11 ,

wherein a storage modulus of the elastic layer at 0° C. is 20 Mpa or more.

13. The film according to claim 11 ,

wherein the storage modulus of the elastic layer at −40° C. is 400 Mpa or more.

14. The film according to claim 1 ,

wherein the low temperature storage modulus ratio R-40/20 of the elastic layer is 4.5 or less.

15. A cover film comprising a film according to claim 1 .

16. A multi-layered electronic device comprising a film according to claim 1 as a cover film.

17. The multi-layered electronic device according to claim 16 ,

wherein the multi-layered electronic device comprises a light emitting function layer and the cover film,

wherein the light emitting function layer has a display area which emits or does not emit a light depending on a signal from an outside of the device, and

wherein the cover film is disposed on one surface of the lighting emitting function layer and covers at least a part of the display area.