Thermoplastic resin finely-foamed reflective sheet, light-reflecting plate, backlight panel, and method of producing the foamed reflective sheet

Patent metadata

Field	Value
Publication number	US-9908300-B2
Application number	US-201414330325-A
Country	US
Kind code	B2
Filing date	Jul 14, 2014
Priority date	Aug 9, 2012
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

A thermoplastic resin finely-foamed reflective sheet, containing: a foamed layer; and non-foamed layers, each of which has a thickness of 150 μm or less and 30 μm or more, and which are provided one above the other while sandwiching the foamed layer between the non-foamed layers, wherein the thermoplastic resin finely-foamed reflective sheet has an integrated structure, wherein the foamed layer is a thermoplastic resin finely-foamed product having a homogeneous bubble structure, in which an average bubble diameter is 10 μm or less and 0.5 μm or more, and in which a bubble number density is 1×10 6 /mm 3 or more and 1.0×10 12 /mm 3 or less, and wherein at least one of the non-foamed layers comprises a functionality-providing layer.

First claim

The invention claimed is:

1. A thermoplastic resin finely-foamed reflective sheet, comprising:
a foamed layer; and
non-foamed layers, each of which has a thickness of 150 μm or less and 30 μm or more, and which are provided one above the other while sandwiching the foamed layer between the non-foamed layers,
wherein the thermoplastic resin finely-foamed reflective sheet has an integrated structure, wherein the foamed layer is a thermoplastic resin finely-foamed product having a homogeneous bubble structure, in which an average bubble diameter is 10 μm or less and 0.5 μm or more, and in which a bubble number density is 1×10 6 /mm 3 or more and 1.0×10 12 /mm 3 or less,
wherein at least one of the non-foamed layers comprises a functionality-providing layer having a thickness of less than 30 μm,
wherein the integrated structure comprises the non-foamed layer and the foamed layer in this order from the top of the thermoplastic resin finely-foamed reflective sheet, and the non-foamed layer is composed of the functionality-providing non-foamed layer and a non-functionality-providing non-foamed layer in this order from the top of the thermoplastic resin finely-foamed reflective sheet, and
wherein the thermoplastic resin is a polycarbonate.

2. The thermoplastic resin finely-foamed reflective sheet according to claim 1 , wherein the functionality-providing layer contains an antistatic agent, an ultraviolet absorber or an antioxidant.

3. The thermoplastic resin finely-foamed reflective sheet according to claim 2 , wherein the antistatic agent, the ultraviolet absorber or the antioxidant is contained only in the functionality-providing layer, or wherein a content of the antistatic agent, the ultraviolet absorber or the antioxidant which is contained in at least one of the functionality-providing layer is larger than a content thereof which is contained in the remaining layer.

4. The thermoplastic resin finely-foamed reflective sheet, according to claim 2 , wherein a reflectivity thereof at a wavelength of 550 nm (aluminum oxide standard white plate basis) is 98% or more.

5. The thermoplastic resin finely-foamed reflective sheet according to claim 1 , wherein 50% by mass or more of a resin in the functionality-providing layer is composed of the same thermoplastic resin as that of the foamed layer.

6. The thermoplastic resin finely-foamed reflective sheet according to claim 1 , wherein a reflectivity thereof at a wavelength of 550 nm (aluminum oxide standard white plate basis) is 98% or less.

7. The thermoplastic resin finely-foamed reflective sheet according to claim 1 , wherein a reflectivity thereof at a wavelength of 350 nm (aluminum oxide standard white plate basis) is 30% or less.

8. The thermoplastic resin finely-foamed reflective sheet according to claim 1 , wherein a surface specific resistance value thereof is 1×10 12 Ω or less.

9. A light-reflecting plate, comprising the thermoplastic resin finely-foamed reflective sheet according to claim 1 .

10. A backlight panel, having the light-reflecting plate according to claim 9 .

Assignees

• Furukawa Electric Co Ltd

Inventors

• Ikeda Hideyuki
• Inamori Kojiro
• Onda Masaki
• Kimura Kazuhiro

Classifications

• B32B27/36

  comprising polyesters · CPC title

• B32B5/18 Primary

  characterised by features of a layer {of} foamed material · CPC title

• B32B2250/40

  Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA · CPC title

• B32B3/12

  characterised by a layer of regularly- arranged cells, e.g. a honeycomb structure · CPC title

• B32B27/28

  comprising synthetic resins not wholly covered by any one of the sub-groups {B32B27/30 - B32B27/42} · CPC title