Switchable mirror glass using magnesium-containing thin film

• US 6,762,871 B2
• Filed: 03/11/2003
• Issued: 07/13/2004
• Est. Priority Date: 03/11/2002
• Status: Expired due to Fees

• Current Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Original Assignee: National Institute of Advanced Industrial Science and Technology (Government of Japan)
• Inventors: Yoshimura, Kazuki
• Primary Examiner(s): Ben, Loha
• Application Number:
  US10/385,111
• Publication Number:
  US 20030169476A1
• Time in Patent Office: 490 Days
• Field of Search: 359/265, 359/267, 359/274, 359/275, 257/1, 257/2, 257/4, 257/107, 257/108, 385/16, 385/18
• US Class Current: 359/265
• CPC Class Codes: E06B 2009/2464 featuring transparency control by applying voltage, e.g. LCD, electrochromic panels
• CPC Class Codes: G02F 1/1523 comprising inorganic material
• CPC Class Codes: G02F 1/19 based on variable-reflection or variable-refraction elements not provided for in groups G02F1/015 - G02F1/169
• CPC Class Codes: G02F 2201/50 Protective arrangements
• CPC Class Codes: G02F 2202/34 Metal hydrides materials

Abstract

The present invention provides a switchable mirror material comprising (1) a magnesium thin film having a thickness of 40 nm or less, or a magnesium-nickel alloy thin film having an alloy composition represented by MgNi_x (0.1<x<0.3), (2) a transparent catalyst layer formed on a surface of the magnesium-containing thin film, and (3) a transparent protective layer optionally formed on the catalyst layer. The switchable mirror material has a chromic property which allows the thin film to be switched from a mirror state into a transparent state by means of hydrogenation of the thin film at about 20° C., and to be switched from the transparent state into the mirror state by means of dehydrogenation of the thin film in the range of about 20° C. to 100° C. The present invention also provides a switchable mirror glass having a surface formed with the switchable mirror material, a switchable mirror window, a method of switching the states of a switchable mirror glass, and an article having the switchable mirror function.

Claims

1. A switchable mirror material comprising:

(1) a magnesium thin film having a thickness of 40 nm or less, or

a magnesium-nickel alloy thin film having an alloy composition represented by MgNix wherein 0.1<

x<

0.3; and

(2) a transparent catalyst layer formed on a surface of said thin film, wherein

said switchable mirror material has a chromic property which allows said thin film to be switched from a mirror state into a transparent state by means of hydrogenation of said thin film at about 20°

C., and to be switched from said transparent state into said mirror state by means of dehydrogenation of said thin film in a temperature range of said about 20°

C. to 100°

C.

2. The switchable mirror material as defined in claim 1, wherein said magnesium thin film has a thickness of about 5 to about 40 nm.

3. The switchable mirror layers as defined in claim 1, wherein said catalyst layer is a palladium or platinum layer having a thickness of 0.5 to 10 nm.

4. The switchable mirror material as defined in claim 1, further comprising a transparent protective layer, wherein said transparent protective layer is formed on said catalyst layer.

5. The switchable mirror material as defined in claim 4, wherein said magnesium thin film has a thickness of about 5 to about 40 nm.

6. The switchable mirror material as defined in claim 4, wherein said catalyst layer is a palladium or platinum layer having a thickness of 0.5 to 10 nm.

7. The switchable mirror material as defined in claim 4, wherein said protective layer is made of a hydrogen-permeable and water-impermeable material.

8. A method of switching the states of a switchable mirror member or glass comprising a switchable layer including the switchable mirror material as defined in claim 1, 2 and 4, comprising a step of adjusting dehydrogenation speed in said switchable layer under a gas atmosphere by controlling the temperature of said gas atmosphere.

9. A switchable mirror member comprising a transparent substrate, and a switchable layer including a switchable mirror material comprising:

(1) a magnesium thin film having a thickness of 40 nm or less, or

a magnesium-nickel alloy thin film having an alloy composition represented by MgNix wherein 0.1<

x<

0.3; and

(2) a transparent catalyst layer formed on a surface of said thin film, wherein

said switchable mirror material has a chromic property which allows said thin film to be switched from a mirror state into a transparent state by means of hydrogenation of said thin film at about 20°

C., and to be switched from said transparent state into said mirror state by means of dehydrogenation of said thin film in a temperature range of said about 20°

C. to 100°

C., and

said switchable layer is formed on a surface of said transparent substrate.

10. The switchable mirror member as defined in claim 9, wherein said magnesium thin film has a thickness of about 5 to about 40 nm.

11. The switchable mirror member as defined in claim 9, wherein said catalyst layer is a palladium or platinum layer having a thickness of 0.5 to 10 nm.

12. The switchable mirror member as defined in any one of claims 9-11, wherein said switchable mirror material further comprises a transparent protective layer, wherein said transparent protective layer is formed on said catalyst layer.

13. The switchable mirror member as defined in any one of claims 9-12, wherein said transparent substrate is a transparent sheet made of acrylic or plastic material.

14. A switchable mirror glass comprising a glass substrate, and a switchable layer including a switchable mirror material comprising:

(1) a magnesium thin film having a thickness of 40 nm or less, or

a magnesium-nickel alloy thin film having an alloy composition represented by MgNix wherein 0.1<

x<

0.3; and

(2) a transparent catalyst layer formed on a surface of said thin film, wherein

said switchable mirror material has a chromic property which allows said thin film to be switched from a mirror state into a transparent state by means of hydrogenation of said thin film at about 20°

C., and to be switched from said transparent state into said mirror state by means of dehydrogenation of said thin film in a temperature range of said about 20°

C. to 100°

C., and

said switchable layer is formed on a surface of said glass substrate.

15. The switchable mirror glass as defined in claim 14, wherein said magnesium thin film has a thickness of about 5 to about 40 nm.

16. The switchable mirror glass as defined in claim 14, wherein said catalyst layer is a palladium or platinum layer having a thickness of 0.5 to 10 nm.

17. The switchable mirror glass as defined in any one of claims 14-16, wherein said switchable mirror material further comprises a transparent protective layer, wherein said transparent protective layer is formed on said catalyst layer.

18. A switchable mirror glass window having an insulating glass structure which includes a plurality of glass plates disposed in parallel with each other to define at least one enclosed space therebetween, wherein at least one of said glass plates is composed of a switchable mirror glass comprising a glass substrate, and a switchable layer including a switchable mirror material comprising:

(1) a magnesium thin film having a thickness of 40 nm or less, or

a magnesium-nickel alloy thin film having an alloy composition represented by MgNix wherein 0.1<

x<

0.3; and

(2) a transparent catalyst layer formed on a surface of said thin film, wherein

said switchable mirror material has a chromic property which allows said thin film to be switched from a mirror state into a transparent state by means of hydrogenation of said thin film at about 20°

C., and to be switched from said transparent state into said mirror state by means of dehydrogenation of said thin film in a temperature range of said about 20°

C. to 100°

C.;

said switchable layer is formed on a surface of said glass substrate; and

said switchable layer faces in the inward direction of said insulating glass structure.

19. The switchable mirror glass window as defined in claim 18, wherein said magnesium thin film has a thickness of about 5 to about 40 nm.

20. The switchable mirror glass window as defined in claim 18, wherein said catalyst layer is a palladium or platinum layer having a thickness of 0.5 to 10 nm.

21. The switchable mirror glass window as defined in any one of claims 18-20, wherein said switchable mirror material further comprises a transparent protective layer, wherein said transparent protective layer is formed on said catalyst layer.

22. The switchable mirror glass window as defined in any one of claims 18-20, wherein said enclosed space is selectively supplied with either one of:

(1) hydrogen gas and (2) heated air or oxygen gas, from an atmospheric-state controller.

23. A method of switching the states of a switchable mirror glass comprising a switchable layer including a switchable mirror material comprising:

(1) a magnesium thin film having a thickness of 40 nm or less, or

a magnesium-nickel alloy thin film having an alloy composition represented by MgNix wherein 0.1<

x<

0.3; and

(2) a transparent catalyst layer formed on a surface of said thin film, wherein

said switchable mirror material has a chromic property which allows said thin film to be switched from a mirror state into a transparent state by means of hydrogenation of said thin film at about 20°

C., and to be switched from said transparent state into said mirror state by means of dehydrogenation of said thin film in a temperature range of said about 20°

C. to 100°

C.,

comprising a step of selectively causing hydrogenation and dehydrogenation in said switchable layer, by means of selectively adjusting the level of said hydrogenation through at least one of a gasochromic process using hydrogen gas and an electrochromic process using electrolyte containing hydrogen, and selectively adjusting the level of the dehydrogenation through at least one of a gasochromic process using air or oxygen gas, an electrochromic process using electrolyte and a thermochromic process based on heating.

24. The method of switching the states of a switchable mirror glass as defined in claim 23, wherein said switchable mirror material further comprises a transparent protective layer, wherein said transparent protective layer is formed on said catalyst layer.

25. A method of switching the states of a switchable mirror member or glass with a switchable layer including a switchable mirror material comprising:

(1) a magnesium thin film having a thickness of 40 nm or less, or

a magnesium-nickel alloy thin film having an alloy composition represented by MgNix wherein 0.1<

x<

0.3; and

(2) a transparent catalyst layer formed on a surface of said thin film, wherein

said switchable mirror material has a chromic property which allows said thin film to be switched from a mirror state into a transparent state by means of hydrogenation of said thin film at about 20°

C., and to be switched from said transparent state into said mirror state by means of dehydrogenation of said thin film in a temperature range of said about 20°

C. to 100°

C.,

comprising a step of presetting a transition temperature of said magnesium thin film at any temperature in a range of about 20°

C. to 100°

C. to allow said magnesium thin film to be automatically switched from the transparent state to the mirror state at said preset temperature in response to a rise in atmospheric temperature.

26. The method as defined in claim 25, wherein said transition temperature is set depending on the thickness of said catalyst layer.

27. An article comprising a switchable layer including the switchable mirror material comprising:

(1) a magnesium thin film having a thickness of 40 nm or less, or

a magnesium-nickel alloy thin film having an alloy composition represented by MgNix wherein 0.1<

x<

0.3; and

(2) a transparent catalyst layer formed on a surface of said thin film, wherein

said switchable mirror material has a chromic property which allows said thin film to be switched from a mirror state into a transparent state by means of hydrogenation of said thin film at about 20°

C., and to be switched from said transparent state into said mirror state by means of dehydrogenation of said thin film in a temperature range of said about 20°

C. to 100°

C.,

and (3) either one of a switchable mirror glass and a switchable mirror member having a transparent substrate, wherein said switchable layer is attached onto the surface of said switchable mirror glass or said transparent substrate.