JP-2026076103-A - Graphene inorganic particle composites, compositions, and formed products

Abstract

[Problem] To provide a graphene inorganic particle composite and composition that can produce a graphene-containing material with excellent corrosion resistance. [Solution] A graphene inorganic particle composite in which 10% to 100% of the surface area of non-conductive inorganic particles is coated with surface-modified graphene. [Selection Diagram] None

Inventors

• 平井 善英
• 加藤 智博

Assignees

• 東レ株式会社

Dates

Publication Date

20260511

Application Date

20250630

Priority Date

20241023

Claims (10)

1. A graphene inorganic particle composite in which 10% to 100% of the surface area of non-conductive inorganic particles is coated with surface-modified graphene.
2. The graphene inorganic particle composite according to claim 1, wherein 60% to 100% of the surface area of the non-conductive inorganic particles is coated with surface-modified graphene.
3. The graphene inorganic particle composite according to claim 1, wherein the average thickness of the graphene is 0.3 nm or more and 10 nm or less.
4. The graphene inorganic particle composite according to claim 1, wherein the elemental ratio of oxygen to carbon (O/C ratio) of the graphene, as measured by X-ray photoelectron spectroscopy, is 0.05 or more and 0.60 or less.
5. The graphene inorganic particle composite according to claim 1, wherein the graphene is surface-modified with a nitrogen-containing compound.
6. The graphene inorganic particle composite according to claim 5, wherein the elemental ratio of nitrogen to carbon (N/C ratio) of the graphene, as measured by X-ray photoelectron spectroscopy, is 0.005 or more and 0.200 or less.
7. The graphene inorganic particle composite according to claim 1, wherein the average particle size of the non-conductive inorganic particles is 1 μm or more and 50 μm or less.
8. A composition comprising a graphene inorganic particle composite according to any one of claims 1 to 7, and a curable resin and/or its precursor.
9. The composition according to claim 8, wherein the composition further comprises conductive inorganic particles.
10. A composite material comprising the graphene inorganic particle composite according to any one of claims 1 to 7.

Description

This invention relates to graphene inorganic particle composites and compositions and products using the same. Graphene is a two-dimensional crystal composed of carbon atoms and has been a highly regarded material since its discovery in 2004. The thin sheet structure of graphene possesses functional properties such as electrical and thermal conductivity. One example of an application utilizing graphene's properties is corrosion-resistant paints; further improvements in corrosion resistance are expected through the use of graphene (see, for example, Patent Document 1). For paints requiring particularly high corrosion resistance, rust-preventive paints utilizing the sacrificial corrosion protection effect of zinc particles are used. Graphene possesses electrical conductivity, and adding graphene to such rust-preventive paints can further enhance the rust-preventive effect of zinc particles (see, for example, Patent Document 2). Special Publication No. 2021-512995Japanese Patent Publication No. 2021-175763 <Graphene inorganic particle composite> The graphene inorganic particle composite of the present invention is a composite of surface-modified graphene and non-conductive inorganic particles, wherein 10% to 100% of the surface area of the non-conductive inorganic particles is coated with graphene. In this specification, "graphene" refers to graphene itself, and "graphene inorganic particle composite" refers to a composite material of graphene and non-conductive inorganic particles. Furthermore, even when a surface treatment agent described later is included, it will also be referred to as a graphene inorganic particle composite. In this invention, non-conductive inorganic particles are inorganic particles with a volume resistivity of 1 × 10⁶ Ω·cm or more, in accordance with JIS C2139 (2008). Examples of such non-conductive inorganic particles include bentonite, talc, mica, kaolin, perlite, barium sulfate, barium carbonate, silica, alumina, potassium feldspar, soda feldspar, clay, diatomaceous earth, magnesium hydroxide, aluminum hydroxide, and may be mixtures of multiple types. Examples of inorganic particle shapes include spherical, flake-shaped, flaky, fibrous, and irregular shapes. The graphene inorganic particle composite of the present invention is obtained by coating the surface of non-conductive inorganic particles with surface-modified graphene. By coating the surface of the non-conductive inorganic particles with graphene, conductivity is imparted, and the contact between the graphene inorganic particle composites allows for the formation of conductive paths in a product obtained from a composition containing a curable resin and/or its precursor. From the viewpoint of facilitating the formation of conductive paths, the graphene coverage is 10% or more of the surface area of the non-conductive inorganic particles. Furthermore, to form conductive paths with higher conductivity, a graphene coverage of 20% or more is preferable, 50% or more is more preferable, and 60% or more is even more preferable. On the other hand, a graphene coverage of 100% is the maximum value when the entire surface of the non-conductive inorganic particles is covered. The graphene coverage of the present invention can be measured by the method described in Measurement Example 1 below. Note that the graphene coverage of the present invention can be easily adjusted by the concentration and solid-liquid ratio of the graphene dispersion liquid contacted with the non-conductive inorganic particles. In this invention, the average particle size of the non-conductive inorganic particles is preferably 1 μm or more and 50 μm or less. By setting the average particle size of the non-conductive inorganic particles to 1 μm or more, the graphene does not overlap the surface of the non-conductive inorganic particles in multiple layers, resulting in a uniform coating of the non-conductive inorganic particle surface. More preferably 5 μm or more, and even more preferably 10 μm or more. By setting the average particle size of the non-conductive inorganic particles to 50 μm or less, defects such as pinholes after curing of the composition containing the graphene inorganic particle composite and the curable resin and/or its precursor can be suppressed. From the viewpoint of further improving the corrosion resistance and conductivity of the cured product, 40 μm or less is more preferably, and even more preferably 30 μm or less. The average particle size of non-conductive inorganic particles is determined by observation using a laser microscope, as follows: The non-conductive inorganic particles are diluted to 0.0065% by weight with an organic solvent, dropped onto a glass substrate, and dried. Next, the particle size of the non-conductive inorganic particles on the glass substrate is measured using a laser microscope. The length of the longest part (major axis) and the length of the shortest part (minor axis) of each particle are measured, and the va