Light-transmitting electromagnetic wave-shielding material

• US 8,063,391 B2
• Filed: 06/03/2008
• Issued: 11/22/2011
• Est. Priority Date: 06/05/2007
• Status: Active Grant

• Current Assignee: Mitsubishi Gas Chemical Company Incorporated (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Gas Chemical Company Incorporated (Mitsubishi Electric Corporation)
• Inventors: Ohtani, Noboru, Ishikawa, Masahiko, Masuda, Yoshitaka, Masuda, Yoshiyuki, Kimura, Yoshiya, Matsumura, Takatoshi, Kato, Noriyuki
• Primary Examiner(s): Johnston; Phillip A
• Application Number:
  US12/155,404
• Publication Number:
  US 20080302981A1
• Time in Patent Office: 1,267 Days
• Field of Search: 250/515.1
• US Class Current: 250/515.1
• CPC Class Codes: B32B 15/00 Layered products comprising a layer of metal
• CPC Class Codes: G02B 2207/121 Antistatic or EM shielding layer
• CPC Class Codes: H01J 2211/446 Electromagnetic shielding means; Antistatic means
• CPC Class Codes: H01J 2329/869 Electromagnetic shielding
• CPC Class Codes: H05K 9/0096 for television displays, e.g. plasma display panel

Abstract

The present invention provides a light-transmitting electromagnetic wave-shielding material for use in displays or in-vehicle panels each having a polarizing plate or a retardation plate, wherein the light-transmitting electromagnetic wave-shielding material undergoes no generation of light interference fringes and is satisfactory in visibility even through sunglasses, goggles, glare-proof panels or glare-proof window materials having polarizing capability. By using unstretched light-transmitting organic polymer materials low in molecular orientation or small in molecular orientation unevenness as the base substrate of an electromagnetic wave-shielding layer, the light-transmitting electromagnetic wave-shielding material excellent in light interference fringe prevention capability can be obtained.

Claims

1. A light-transmitting electromagnetic wave-shielding material having an electromagnetic wave-shielding layer which shields electromagnetic waves generated from electronic devices and apparatuses, comprising an unstretched polycarbonate resin as a base substrate of the electromagnetic wave-shielding layer;

wherein a retardation value of the unstretched polycarbonate resin is 400 nm or less.

2. The light-transmitting electromagnetic wave-shielding material according to claim 1, wherein the electromagnetic wave-shielding layer comprises a metal thin film mesh or a printed conductive mesh.

3. The light-transmitting electromagnetic wave-shielding material according to claim 2, wherein the metal thin film mesh or the printed conductive mesh comprises a compound including at least one metal components selected from silver, copper, aluminum, nickel, carbon, ITO, ZnO, tin, zinc, titanium, tungsten and stainless steel.

4. The light-transmitting electromagnetic wave-shielding material according to claim 1, wherein an electromagnetic wave-shielding capability of the electromagnetic wave-shielding layer is 30 dB or more.

5. The light-transmitting electromagnetic wave-shielding material according to claim 1 included in a display having a polarizing plate or a retardation plate.

6. The light-transmitting electromagnetic wave-shielding material according to claim 1 included in a car navigation system or an in-vehicle panel comprising a polarizing plate or a retardation plate.