Composite material, prepreg, carbon-fiber-reinforced molded body, and method for manufacturing composite material

Patent metadata

Field	Value
Publication number	US-11370893-B2
Application number	US-201816651590-A
Country	US
Kind code	B2
Filing date	Sep 21, 2018
Priority date	Sep 27, 2017
Publication date	Jun 28, 2022
Grant date	Jun 28, 2022

Abstract

Provided are a composite material that adequately obtains the effect of carbon nanotubes, a prepreg in which the composite material is used, a carbon-fiber-reinforced molded article having greater resistance to the progression of the interlayer peeling crack, and a method for manufacturing the composite material. A composite material includes a carbon fiber bundle in which a plurality of continuous carbon fibers are arranged, carbon nanotubes adhering to respective surfaces of the carbon fibers, and a plurality of fixing resin parts partly fixing the carbon nanotubes on the surfaces of the carbon fibers, where the fixing resin parts cover 7% or more and 30% or less of the surfaces of the carbon fibers to which the carbon nanotubes adhere.

First claim

The invention claimed is:

1. A composite material comprising:
a carbon fiber bundle in which a plurality of continuous carbon fibers are arranged;
carbon nanotubes adhering to respective surfaces of the carbon fibers, wherein at least 50% of the carbon nanotubes intersecting any one of four sides of a frame of 1 μm square in a region of 21 μm in a length direction of the carbon fiber has a length of 1 μm or more, and a standard deviation of the number of the carbon nanotubes intersecting any one of four sides of a frame of 1 μm square in a region of 21 μm is 5 or less; and
a plurality of fixing resin parts partly fixing the carbon nanotubes on the surfaces of the carbon fibers, wherein
the fixing resin parts cover 7% or more and 30% or less of the surfaces of the carbon fibers to which the carbon nanotubes adhere.

2. The composite material according to claim 1 , wherein the fixing resin parts are provided at a rate of 10 to 40 pieces per 5 μm square on the surfaces to which the carbon nanotubes adhere.

3. The composite material according to claim 1 , wherein the fixing resin part is a cured material of reactive curing resin, thermosetting resin, or thermoplastic resin.

4. A prepreg comprising:
the composite material according to claim 1 ; and
a matrix resin impregnated with the composite material.

5. A carbon-fiber-reinforced molded article comprising a cured material of the prepreg according to claim 4 .

6. A method for manufacturing a composite material, the method comprising:
in a carbon fiber bundle in which a plurality of continuous carbon fibers are arranged, attaching carbon nanotubes to respective surfaces of carbon fibers in the plurality of continuous carbon fibers, wherein at least 50% of the carbon nanotubes intersecting any one of four sides of a frame of 1 μm square in a region of 21 μm in a length direction of the carbon fiber has a length of 1 μm or more, and a standard deviation of the number of the carbon nanotubes intersecting any one of four sides of a frame of 1 μm square in a region of 21 μm is 5 or less; and
sizing the carbon fibers to which the carbon nanotubes adhere using a sizing agent, being an emulsion, and thereby forming fixing resin parts that fix the carbon nanotubes partly to the surfaces of the carbon fibers, the fixing resin parts covering 7% or more and 30% or less of the surfaces of the carbon fibers to which the carbon nanotubes adhere.

Assignees

• Nitta Corp

Inventors

• Onizuka Maki
• Komukai Takuji

Classifications

• C08K3/041 Primary

  Carbon nanotubes · CPC title

• C08K2201/003

  Additives being defined by their diameter · CPC title

• C08K9/08

  Ingredients agglomerated by treatment with a binding agent · CPC title

• C08K7/06

  Elements · CPC title

• C08J2300/24

  Thermosetting resins · CPC title