Ruggedized switchable glazing comprising a liquid crystal inclusive layer and a multi-layer low-E ultraviolet blocking coating

• US 8,199,264 B2
• Filed: 11/26/2007
• Issued: 06/12/2012
• Est. Priority Date: 11/26/2007
• Status: Active Grant

• Current Assignee: Guardian Glass LLC (KOCH Industries Incorporated)
• Original Assignee: Guardian Industries Corporation (KOCH Industries Incorporated)
• Inventors: Veerasamy, Vijayen S.
• Primary Examiner(s): Robinson, Mark
• Assistant Examiner(s): Kim, Dennis Y
• Application Number:
  US11/987,005
• Publication Number:
  US 20090135319A1
• Time in Patent Office: 1,660 Days
• Field of Search: 349/16, 349/86, 349/183, 359/614
• US Class Current: 349/16
• CPC Class Codes: B32B 17/10005 laminated safety glass or glazing
• CPC Class Codes: B32B 17/10036 comprising two outer glass sheets
• CPC Class Codes: B32B 17/10055 with at least one intermediate air space
• CPC Class Codes: B32B 17/10229 Metallic layers sandwiched by dielectric layers
• CPC Class Codes: B32B 17/10504 Liquid crystal layer
• CPC Class Codes: B32B 17/10761 containing vinyl acetal
• CPC Class Codes: B32B 17/10788 containing ethylene vinylacetate
• CPC Class Codes: B32B 2367/00 Polyesters, e.g. PET, i.e. polyethylene terephthalate
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3639 Multilayers containing at least two functional metal layers
• CPC Class Codes: C03C 17/3644 the metal being silver
• CPC Class Codes: C03C 17/3681 the multilayer coating being used in glazing, e.g. windows or windscreens
• CPC Class Codes: C09K 2323/061 Inorganic, e.g. ceramic, metallic or glass
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: G02F 2201/086 UV absorbing

Abstract

Certain example embodiments of this invention relate to ruggedized switchable glazings, and/or methods of making the same. The PDLC stack of certain example embodiments includes an outer substrate, a low-E UV blocking coating deposited on an inner surface of the outer substrate, a first PVB or EVA laminate, a first PET layer, a first TCO layer, the PDLC layer, a second TCO layer, a second PET layer, a second PVB or EVA laminate, and an inner substrate. The substrates may be glass substrates. The low-E UV blocking coating may include at least two layers of or including silver and/or may include one or more IR layers. Thus, certain example embodiments may advantageously reduce one or more problems associated with residual haze, color change, flicker, structural changes in the polymer and/or the LC, degradations in state-switching response times, delamination, etc. The PDLC stack of certain example embodiments may be used in connection with any form of coated article, such as, for example, windows, windshields, IG units, etc.

Claims

1. A window comprising:

an inner substrate and an outer substrate, the inner and outer substrates being substantially parallel to one another;

a multi-layer low-E ultraviolet (UV) blocking coating supported by an inner surface of the outer substrate, the low-E UV blocking coating blocking significant amounts of UV in the range of from about 380-400 nm;

a liquid crystal inclusive layer disposed between at least the inner and outer substrates, the liquid crystal inclusive layer including liquid crystals whose alignment is dependent upon an electric field, one or more grooves or channels being formed in the liquid crystal inclusive layer so as to attenuate a z-component of compressive stress therein to below 100 MPa;

first and second substantially transparent conductive layers, the first and second substantially transparent conductive layers being provided between the liquid crystal inclusive layer and the outer and inner substrates, respectively;

first and second polymer inclusive laminating layers, the first laminating layer provided between at least the liquid crystal inclusive layer and the outer substrate and the second laminating layer provided between at least the liquid crystal inclusive layer and the inner substrate;

at least one bus bar in electrical communication with at least one of the first and second transparent conductive layer(s) so as to cause the liquid crystal inclusive layer to become activated when a voltage is applied thereto; and

wherein the multi-layer low-E UV blocking coating comprises at least one IR reflecting layer and at least one UV blocking layer so that no more than about 20% of ambient light having a wavelength of from 380-400 nm reaches the liquid crystal inclusive layer, and

wherein the window has a visible transmission of at least about 55% when the liquid crystal inclusive layer is activated.

2. The window of claim 1, wherein the inner and outer substrates are glass substrates, and wherein the liquid crystal inclusive layer comprises PDLC.

3. The window of claim 1, further comprising first and second polymer-based layers provided on opposing sides of the liquid crystal inclusive layer.

4. The window of claim 1, wherein the first and second laminating layers comprise at least one of polyvinyl butyral (PVB) and ethylene-vinyl acetate (EVA).

5. The window of claim 1, wherein the first and second transparent conductive layers comprise transparent conductive oxides.

6. The window of claim 5, wherein the first and/or second transparent conductive layers each comprise one or more of:

zinc oxide, tin oxide and indium-tin-oxide.

7. The window of claim 1, wherein the low-E UV blocking coating includes at least two IR reflecting layers comprising silver.

8. The window of claim 1 wherein the UV blocking layer comprises bismuth oxide.

9. The window of claim 1, wherein the low-E UV blocking coating has at least about 99.5% UV cut-off below about 410 nm.

10. The window of claim 1, wherein the window is a vehicle windshield.

11. The window of claim 1, wherein the window is at least part of an architectural window unit.

12. The window of claim 1, wherein the multi-layer low-E UV blocking coating is arranged so that no more than about 15% of ambient light having a wavelength of about 380-400 nm reaches the liquid crystal inclusive layer.

13. The window of claim 1, wherein the multi-layer low-E UV blocking coating is arranged so that no more than about 10% of ambient light having a wavelength of about 380-400 nm reaches the liquid crystal inclusive layer.

14. The window of claim 1, wherein the multi-layer low-E UV blocking coating is arranged so that no more than about 5% of ambient light having a wavelength of about 380-400 nm reaches the liquid crystal inclusive layer.

15. The window of claim 1, wherein the liquid crystal inclusive layer comprises liquid crystals dispersed in a polymer, and wherein the window further comprises a separate polymer barrier located proximate to peripheral edges of the liquid crystal inclusive layer so as to reduce migration of one or both polymer inclusive laminating layers or movement of the liquid crystal inclusive layer.

16. The window of claim 1, wherein the window appears whitish when the liquid crystal inclusive layer is deactivated as a result of light scattering caused by the liquid crystal inclusive layer, and otherwise is clear.

17. The window of claim 16, wherein the window has a visible transmission of no more than 1.815% when the liquid crystal inclusive layer is deactivated.

18. An insulating glass window unit, comprising:

at least first, second and third substantially parallel substrates;

a multi-layer low-E UV blocking coating supported by a surface of the second substrate facing the third substrate;

a liquid crystal inclusive layer disposed between the second and third substrates, the liquid crystal inclusive layer including liquid crystals whose alignment is dependent upon an electric field, one or more grooves or channels being formed in the liquid crystal inclusive layer so as to attenuate a z-component of compressive stress therein to below 100 MPa;

first and second transparent conductive layers, the first and second transparent conductive layers being provided between at least the liquid crystal inclusive layer and the second and third substrates, respectively;

first and second laminating layers, the first laminating layer being provided between at least the liquid crystal inclusive layer and the second substrate and the second laminating layer provided between at least the liquid crystal inclusive layer and the third substrate;

at least one bus bar electrically connected to at least one of the first and second transparent conductive layer(s) so as to cause the liquid crystal inclusive layer to become activated when at least a predetermined voltage is applied to the bus bar; and

a polymer barrier, separate from the first and second laminating layers, located proximate to peripheral edges of the liquid crystal inclusive layer only, so as to reduce migration of one or both laminating layers over time, as well as inward movement of the liquid crystal inclusive layer,

wherein the first and second substrates are spaced apart from each other,

wherein the multi-layer low-E UV blocking coating comprises at least one UV blocking layer in order to block significant amounts of UV radiation in the range of from 380-400 nm so that no more than about 20% of ambient light having a wavelength of from 380-400 nm reaches the liquid crystal inclusive layer, and

wherein the insulating glass unit has a visible transmission of at least about 50% when the liquid crystal inclusive layer is activated.

19. The insulating glass unit of claim 18, wherein the first, second and third substrates are glass substrates.

20. The insulating glass unit of claim 18, wherein the first and second transparent conductive layers comprise one or more of zinc oxide and tin oxide.

21. The insulating glass unit of claim 18, wherein the low-E UV blocking coating includes at one IR reflecting layer comprising silver, the IR reflecting comprising silver not directly contacting the UV blocking layer of the coating.

22. The insulating glass unit of claim 18, wherein the low-E UV blocking coating has at least about 99.5% UV cut-off below about 410 nm.

23. The insulating glass unit of claim 18, wherein the multi-layer low-E UV blocking coating is provided so that no more than about 15% of ambient light having a wavelength of about 380-400 nm reaches the liquid crystal inclusive layer.

24. The insulating glass unit of claim 18, wherein the UV blocking layer comprises bismuth oxide.

25. The insulating glass unit of claim 18, wherein the UV blocking layer comprises one or more of silver oxide and bismuth oxide.