MULTILAYER OPTICAL FILM HAVING OVERLAPPING HARMONICS

• US 20160109628A1
• Filed: 10/17/2014
• Published: 04/21/2016
• Est. Priority Date: 10/17/2014
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Weber, Michael F., Kivel, Edward J., Nevitt, Timothy J., O'Neill, Mark B.
• Granted Patent: US 9,823,395 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 1/14 Protective coatings, e.g. hard coatings
• CPC Class Codes: G02B 27/141 using dichroic mirrors
• CPC Class Codes: G02B 5/0816 Multilayer mirrors, i.e. having two or more reflecting layers G02B5/0883, G02B5/0891 take precedence
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
• CPC Class Codes: G02B 5/223 containing organic substances, e.g. dyes, inks or pigments
• CPC Class Codes: G02B 5/26 Reflecting filters G02B5/28 takes precedence
• CPC Class Codes: G02B 5/281 designed for the infrared light
• CPC Class Codes: G02B 5/282 reflecting for infrared and transparent for visible light, e.g. heat reflectors, laser protection
• CPC Class Codes: G02B 5/283 designed for the ultraviolet
• CPC Class Codes: G02B 5/285 comprising deposited thin solid films G02B5/281 - G02B5/289 take precedence; multilayered film filters for fibre optic multiplexing G02B6/29361
• CPC Class Codes: G02B 5/3041 comprising multiple thin layers, e.g. multilayer stacks

Abstract

A multilayer optical film including a stack of microlayers arranged into optical repeat units. At a design angle of incidence, such as normal incidence, the stack provides a 1^st order reflection band, a 2^nd order reflection band, and optionally a 3^rd order reflection band. The 2^nd order reflection band substantially overlaps the 1^st and/or 3^rd order reflection bands to form a single wide reflection band. The wide reflection band may cover at least a portion of visible and infrared wavelengths. The multilayer optical film may include an additional optical layer which maybe be an anti-glare layer and/or may be an absorbing layer. The multilayer optical film is suitable for use as a window film.

Claims

1. A multilayer optical film comprising a packet of microlayers arranged into optical repeat units,

wherein, at a design angle of incidence, the packet provides a single 1^st order reflection band, a 2^nd order reflection band, and optionally a 3^rd order reflection band;

wherein the 1^st order reflection band is disposed at least partially in a wavelength range from 720 to 2000 nm;

wherein the 2^nd order reflection band is disposed at least partially in a wavelength range from 380 to 720 nm;

wherein the 2^nd order reflection band substantially overlaps at least one of the 1^st and 3^rd order reflection bands to form a single wide reflection band; and

wherein the multilayer optical film further comprises an optical layer adjacent the packet of microlayers, the optical layer an anti-glare layer and/or an absorbing layer.

2. The multilayer optical film of claim 1, further comprising one or more of a protective boundary layer and a skin layer between the optical layer and the packet of microlayers.

3. The multilayer optical film of claim 1, wherein the 1^st order reflection band has a first band edge in a range of 760 to 840 nm and a second band edge in a range of 1560 to 1640 nm.

4. The multilayer optical film of claim 1, wherein and the 2^nd order reflection band has a first band edge in a range of 380 to 420 nm and a second band edge in a range of 780 to 820 nm.

5. The multilayer optical film of claim 1, wherein the optical layer is an absorbing layer, the absorbing layer including at least one dye or pigment.

6. The multilayer optical film of claim 5, wherein the at least one dye or pigment includes at least one dichroic dye.

7. The multilayer optical film of claim 5, wherein the at least one dye or pigment includes at least one UV-absorbing dye or pigment, at least one IR-absorbing dye or pigment, at least one visible light absorbing dye or pigment, or a combination thereof.

8. The multilayer optical film of claim 1, wherein the stack is an asymmetric reflector having a low transmission axis and the partially absorbing layer is a partially absorbing polarizer having a block axis substantially parallel to the low transmission axis.

9. The multilayer optical film of claim 1, wherein the 2^nd order reflection band substantially overlaps the 1^st order reflection band.

10. The multilayer optical film of claim 1, wherein the stack provides the 3^rd order reflection band and the optical layer is a partially absorbing layer, the partially absorbing layer including a near infrared absorbing component.

11. The multilayer optical film of claim 1, wherein the multilayer optical film has a Visible Light Transmission (VLT) in a range of 10 percent to 90 percent and a Total Solar Energy Rejected (TSER) is a range of 10 percent to 90 percent.

12. A multilayer optical film comprising a packet of microlayers arranged into optical repeat units,

wherein, at a design angle of incidence, the packet provides a single 1^st order reflection band, a 2^nd order reflection band, and optionally a 3^rd order reflection band;

wherein the 1^st order reflection band is disposed at least partially in a wavelength range from 720 to 2000 nm;

wherein the 2^nd order reflection band is disposed at least partially in a wavelength range from 380 to 720 nm;

wherein the 2^nd order reflection band substantially overlaps at least one of the 1^st and 3^rd order reflection bands to form a single wide reflection band; and

wherein the packet has a first average on-axis reflectivity for visible light polarized in a first plane, and a second average on-axis reflectivity of for visible light polarized in a second plane perpendicular to the first plane, wherein the second average on-axis reflectivity is greater than about 5 percent and less than the first on-axis reflectivity.

13. The multilayer optical film of claim 12, wherein the first average on-axis reflectivity is greater than about 10 percent.

14. The multilayer optical film of claim 12, wherein an average of the first average on-axis reflectivity and the second average on-axis reflectivity is in a range of about 40 percent to about 70 percent.

15. The multilayer optical film of claim 12 further comprising an optical layer adjacent the packet of microlayers, the optical layer including at least one dye or pigment.

16. The multilayer optical film of claim 15, wherein the at least one dye or pigment includes at least one UV-absorbing dye or pigment, at least one IR-absorbing dye or pigment, at least one visible light absorbing dye or pigment, or a combination thereof.

17. The multilayer optical film of claim 14, wherein the 2^nd order reflection band substantially overlaps the 1^st order reflection band.

18. A multilayer optical film comprising a packet of microlayers arranged into optical repeat units,

wherein, at a design angle of incidence, the packet provides a single 1^st order reflection band, a 2^nd order reflection band, and optionally a 3^rd order reflection band;

wherein the 1^st order reflection band is disposed at least partially in a wavelength range from 720 to 2000 nm;

wherein the 2^nd order reflection band is disposed at least partially in a wavelength range from 380 to 720 nm;

wherein the 2^nd order reflection band substantially overlaps at least one of the 1^st and 3^rd order reflection bands to form a single wide reflection band; and

wherein the optical repeat units have a fixed-index f-ratio that varies monotonically across a thickness of the packet of microlayers.

19. The multiplayer optical film of claim 18, wherein the fixed-index f-ratio of the optical repeat units varies in a range from about 0.3 to about 0.4 or varies in a range of about 0.6 to about 0.7.

20. The multilayer optical film of claim 19, wherein a fixed-index optical thickness of the optical repeat units varies monotonically across the thickness of the packet of microlayers and wherein either the fixed-index f-ratio is in the range from about 0.3 to about 0.4 and monotonically decreases from a thinnest optical repeat unit to a thickest optical repeat unit, or the fixed-index f-ratio is in the range from about 0.6 to about 0.7 and monotonically increases from the thinnest optical repeat unit to the thickest optical repeat.

21. The system of claim 18, wherein the multilayer optical film further comprises an optical layer adjacent the packet of microlayers, the optical layer including at least one dye or pigment.

22. The multilayer optical film of claim 21, wherein the at least one dye or pigment includes at least one UV-absorbing dye or pigment, at least one IR-absorbing dye or pigment, at least one visible light absorbing dye or pigment, or a combination thereof.

23. The multilayer optical film of claim 18, wherein the packet is an asymmetric reflector.