Matched-type electromagnetic wave absorber

Patent metadata

Field	Value
Publication number	US-10843445-B2
Application number	US-201615778516-A
Country	US
Kind code	B2
Filing date	Nov 22, 2016
Priority date	Nov 25, 2015
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

A sheet-shaped matched-type electromagnetic wave absorber can obtain electromagnetic wave absorption performance with a relatively small thickness but has a problem that particularly a dimensional change in an electromagnetic wave absorption layer (resin composition layer) has a large influence on the electromagnetic wave absorption performance when being exposed to a high temperature. By laminating a resin composition layer in which a filler with an aspect ratio of 5 or more and a filler with an aspect ratio of less than 5 are dispersed and fixed with an electromagnetic wave reflection layer in a cured product of a resin composition containing an acrylic polymerizable resin and a polymerization initiator, it is possible to provide a matched-type electromagnetic wave absorber having high heat resistant dimensional stability and high electromagnetic wave absorption performance.

First claim

The invention claimed is:

1. A matched-type electromagnetic wave absorber comprising:
a laminated structure including at least a resin composition layer and an electromagnetic wave reflection layer, wherein
in the resin composition layer, a component (C): filler with an aspect ratio of 5 or more and having an average length of 0.5 to 50 μm and a component (D): filler with an aspect ratio of less than 5 are dispersed and fixed in a cured product of a resin composition containing a component (A): acrylic polymerizable resin.

2. The matched-type electromagnetic wave absorber according to claim 1 , wherein
a volume ratio represented by [the component (C)+the component (D)]/resin composition layer is 0.1 to 0.5.

3. The matched-type electromagnetic wave absorber according to claim 1 , wherein
the component (C): filler with an aspect ratio of 5 or more is a conductive filler, and
the component (D): filler with an aspect ratio of less than 5 is aluminum hydroxide and/or magnesium hydroxide.

4. The matched-type electromagnetic wave absorber according to claim 3 , wherein
the conductive filler is conductive titanium oxide.

5. The matched-type electromagnetic wave absorber according to claim 1 , wherein
the component (A): acrylic polymerizable resin contains any one or more selected from an epoxy acrylate, a urethane acrylate, an ester acrylate, a copolymerized acrylate, a butadiene acrylate, a silicone acrylate, and an amino resin acrylate each having a vinyl group.

6. The matched-type electromagnetic wave absorber according to claim 1 , wherein
the resin composition layer further comprises a component (B): polymerization initiator, and the component (B): polymerization initiator is an organic peroxide.

7. The matched-type electromagnetic wave absorber according to claim 1 , further comprising
an adhesive layer between the electromagnetic wave reflection layer and the resin composition layer.

8. The matched-type electromagnetic wave absorber according to claim 1 , wherein
the component (D) is a material different from the component (C).

9. The matched-type electromagnetic wave absorber according to claim 2 , wherein
the component (C): filler with an aspect ratio of 5 or more is a conductive filler, and
the component (D): filler with an aspect ratio of less than 5 is aluminum hydroxide and/or magnesium hydroxide.

10. The matched-type electromagnetic wave absorber according to claim 2 , wherein
the component (A): acrylic polymerizable resin contains any one or more selected from an epoxy acrylate, a urethane acrylate, an ester acrylate, a copolymerized acrylate, a butadiene acrylate, a silicone acrylate, and an amino resin acrylate each having a vinyl group.

11. The matched-type electromagnetic wave absorber according to claim 3 , wherein
the component (A): acrylic polymerizable resin contains any one or more selected from an epoxy acrylate, a urethane acrylate, an ester acrylate, a copolymerized acrylate, a butadiene acrylate, a silicone acrylate, and an amino resin acrylate each having a vinyl group.

12. The matched-type electromagnetic wave absorber according to claim 4 , wherein
the component (A): acrylic polymerizable resin contains any one or more selected from an epoxy acrylate, a urethane acrylate, an ester acrylate, a copolymerized acrylate, a butadiene acrylate, a silicone acrylate, and an amino resin acrylate each having a vinyl group.

13. The matched-type electromagnetic wave absorber according to claim 2 , wherein
the component (D) is a material different from the component (C).

14. The matched-type electromagnetic wave absorber according to claim 3 , wherein
the component (D) is a material different from the component (C).

15. The matched-type electromagnetic wave absorber according to claim 5 , wherein
the component (D) is a material different from the component (C).

16. The matched-type electromagnetic wave absorber according to claim 6 , wherein
the component (D) is a material different from the component (C).

17. The matched-type electromagnetic wave absorber according to claim 7 , wherein
the component (D) is a material different from the component (C).

18. The matched-type electromagnetic wave absorber according to claim 1 , wherein
the component (D) is particles of which an average particle diameter is ranged from 0.01 to 10 μm.

Assignees

• Tomoegawa Co Ltd

Inventors

• Hashimoto Takeshi
• Hattori Takuma
• Tsuruta Kojiro

Classifications

• H05K9/0084

  comprising a single continuous metallic layer on an electrically insulating supporting structure, e.g. metal foil, film, plating coating, electro-deposition, vapour-deposition · CPC title

• C08F299/065

  from polyurethanes with side or terminal unsaturations · CPC title

• C09D175/16

  having terminal carbon-to-carbon unsaturated bonds · CPC title

• B32B27/30

  comprising vinyl {(co)polymers; comprising acrylic (co)polymers} · CPC title

• C09D5/32

  Radiation-absorbing paints {(protection against X-, gamma- or corpuscular radiation G21F)} · CPC title