Carbon fiber recovery method

Patent metadata

Field	Value
Publication number	US-10343305-B2
Application number	US-201816126122-A
Country	US
Kind code	B2
Filing date	Sep 10, 2018
Priority date	Oct 2, 2017
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

A carbon fiber recovery method for recovering carbon fibers from a fiber reinforced plastic member having a carbon fiber reinforced plastic (CFRP) layer on which a glass fiber reinforced plastic (GFRP) layer is formed is provided. This method includes: forming a cut that penetrates through the GFRP layer and reaches the CFRP layer in the fiber reinforced plastic member; causing a heated phosphorus-containing solution to penetrate from the cut and separating the CFRP layer from the GFRP layer in the vicinity of an interface between the CFRP layer and the GFRP layer; and dissolving, by a resin solution, a resin part of the CFRP layer from which the GFRP layer has been removed and then recovering the remaining carbon fibers.

First claim

What is claimed is:

1. A carbon fiber recovery method for recovering carbon fibers from a fiber reinforced plastic member having a carbon fiber reinforced plastic layer on which a glass fiber reinforced plastic layer is formed, the method comprising:
forming a cut that penetrates through the glass fiber reinforced plastic layer and reaches the carbon fiber reinforced plastic layer in the fiber reinforced plastic member;
causing a heated phosphoric acid-containing solution to penetrate into an interface between the glass fiber reinforced plastic layer and the carbon fiber reinforced plastic layer from the cut and separating the carbon fiber reinforced plastic layer from the glass fiber reinforced plastic layer; and
dissolving, by a resin solution, a resin part of the carbon fiber reinforced plastic layer from which the glass fiber reinforced plastic layer has been removed and then recovering the carbon fibers of the carbon fiber reinforced plastic layer.

2. The carbon fiber recovery method according to claim 1 , wherein when the heated phosphoric acid-containing solution penetrates from the cut, the fiber reinforced plastic member is immersed in the phosphoric acid-containing solution.

3. The carbon fiber recovery method according to claim 1 , wherein, when the heated phosphoric acid-containing solution penetrates from the cut, the phosphoric acid-containing solution is applied to a surface of the fiber reinforced plastic member.

4. The carbon fiber recovery method according to claim 1 , wherein a phosphate concentration in the phosphoric acid-containing solution is set to be 60 mass % or higher.

5. The carbon fiber recovery method according to claim 1 , wherein the resin solution contains concentrated sulfuric acid.

Assignees

• Toyota Motor Co Ltd

Inventors

• Kano Akira
• Sakuma Daisuke
• Isomura Keisuke

Classifications

• Y10T156/1911

  Heating or cooling delaminating means [e.g., melting means, freezing means, etc.] · CPC title

• B29B2017/0293

  Dissolving the materials in gases or liquids · CPC title

• B32B43/006

  Delaminating · CPC title

• C08J11/08

  using selective solvents for polymer components · CPC title

• Y10T156/1153

  Temperature change for delamination [e.g., heating during delaminating, etc.] · CPC title