Thin protective display film
A display film includes a transparent polymeric substrate layer having a 0.2% offset yield stress greater than 110 MPa and a transparent aliphatic cross-linked polyurethane layer having a thickness of 100 micrometers or less disposed on the transparent polymeric substrate layer. The transparent aliphatic cross-linked polyurethane layer has a glass transition temperature in a range from 11 to 27 degrees Celsius and a Tan Delta peak value in a range from 0.5 to 2.5. The display film has a haze value of 2% or less.
1. A display film comprising:
a transparent polymeric substrate layer having an 0.2% offset yield stress greater than 110 MPa; and
a transparent aliphatic cross-linked polyurethane layer having a thickness of 10 to 100 micrometers disposed on the transparent polymeric substrate layer, the transparent aliphatic cross-linked polyurethane layer having a glass transition temperature in a range from 11 to 27 degrees Celsius and a Tan Delta peak value in a range from 0.5 to 2.5;
the display film having a haze value of 2% or less.
2. The display film according to claim 1 , wherein the transparent aliphatic cross-linked polyurethane layer has a cross-link density in a range from 0.34 to 0.65 mol/kg.
3. The display film according to claim 1 , wherein the transparent aliphatic cross-linked polyurethane layer has a Tan Delta peak value in a range from 1 to 2.
4. The display film according to claim 1 , wherein the display film has a thickness of less than 200 micrometers and the transparent polymeric substrate layer has a 0.2% offset yield stress greater than 130 MPa.
5. The display film according to claim 1 , wherein the transparent aliphatic cross-linked polyurethane layer has a glass transition temperature in a range from 17 to 22 degrees Celsius and a Tan Delta peak value in a range from 1.4 to 1.8.
6. The display film according to claim 1 , wherein the display film has a haze of 1% or less.
7. The display film according to claim 1 , wherein the display film has a visible light transmission of 85% or greater.
8. The display film according to claim 1 , further comprising a removable liner disposed on the transparent polymeric substrate layer or the transparent aliphatic cross-linked polyurethane layer.
9. The display film according to claim 1 , further comprising an optical adhesive layer disposed on the transparent polymeric substrate layer and a removable liner disposed on the optical adhesive layer and a second removable liner disposed on the transparent aliphatic cross-linked polyurethane layer.
10. The display film according to claim 1 , wherein the transparent polymeric substrate comprises polyimide.
11. A display film comprising:
a transparent polymeric substrate layer having an 0.2% offset yield stress greater than 110 MPa; and
a transparent aliphatic cross-linked polyurethane layer having a thickness of 10 to 100 micrometers disposed on the transparent polymeric substrate layer, the transparent aliphatic cross-linked polyurethane layer having a glass transition temperature in a range from 11 to 28 degrees Celsius and a Tan Delta peak value in a range from 0.5 to 2.5;
the display film remains intact after at least 100,000 bending cycles about a 3 mm radius.
12. The display film according to claim 11 , wherein the transparent aliphatic cross-linked polyurethane layer has a cross-link density in a range from 0.34 to 0.65 mol/kg.
13. The display film according to claim 11 , wherein the transparent aliphatic cross-linked polyurethane layer has a Tan Delta peak value in a range from 1 to 2.
14. The display film according to claim 11 , wherein the display film has a thickness of less than 200 micrometers and the transparent polymeric substrate layer has a 0.2% offset yield stress greater than 130 MPa.
15. The display film according to claim 11 , wherein the transparent aliphatic cross-linked polyurethane layer has a glass transition temperature in a range from 17 to 22 degrees Celsius and a Tan Delta peak value in a range from 1.4 to 1.8.
16. The display film according to claim 11 , wherein the display film has a haze of 1% or less and a visible light transmission of 85% or greater.
17. The display film according to claim 11 , wherein the transparent polymeric substrate comprises polyimide.
18. An article, comprising:
an optical display;
a protective film disposed on the optical display, the protective film comprising:
a transparent polymeric substrate layer having a 0.2% offset yield stress greater than 110 MPa;
a transparent aliphatic cross-linked polyurethane layer having a thickness of 10 to 100 micrometers disposed on the transparent polymeric substrate layer, the transparent aliphatic cross-linked polyurethane layer having a glass transition temperature in a range from 11 to 28 degrees Celsius and a Tan Delta peak value in a range from 0.5 to 2.5 and a cross-link density in a range from 0.34 to 0.65 mol/kg;
the display film having a haze value of 2% or less;
an optical adhesive layer fixing the transparent polymeric substrate layer to the optical display.
19. The article according to claim 18 , wherein the optical display comprises an OLED display panel.
20. The article according to claim 18 , wherein the optical display and protective film are foldable so that the optical display faces itself and at least a portion of protective film overlaps another portion of the protective film.