Composite lubricating material, engine oil, grease, and lubricant, and method of producing a composite lubricating material
A composite lubricating material include at least a graphite-based carbon material and/or graphene-like graphite exfoliated from the graphite-based carbon material dispersed in a base material. The graphite-based carbon material is characterized by having a rhombohedral graphite layer ( 3 R) and a hexagonal graphite layer ( 2 H), wherein a Rate ( 3 R) of the rhombohedral graphite layer ( 3 R) and the hexagonal graphite layer ( 2 H), based on an X-ray diffraction method, which is defined by following Equation 1 is 31% or more: Rate ( 3 R)=P 3 /(P 3 +P 4 )×100 . . . Equation 1, wherein, P 3 is a peak intensity of a (101) plane of the rhombohedral graphite layer ( 3 R) based on the X-ray diffraction method, and P 4 is a peak intensity of a (101) plane of the hexagonal graphite layer ( 2 H) based on the X-ray diffraction method.
1. A composite lubricating material comprising at least a graphene exfoliated from a graphite-based carbon material dispersed in a base oil,
the graphite-based carbon material having a rhombohedral graphite layer ( 3 R) and a hexagonal graphite layer ( 2 H), wherein a Rate ( 3 R) of the rhombohedral graphite layer ( 3 R) and the hexagonal graphite layer ( 2 H), based on an X-ray diffraction method, which is defined by following Equation 1 is 31% or more:
Rate(3 R )= P 3/( P 3+ P 4)×100 Equation 1
wherein
P 3 is a peak intensity of a (101) plane of the rhombohedral graphite layer ( 3 R) based on the X-ray diffraction method, and
P 4 is a peak intensity of a (101) plane of the hexagonal graphite layer ( 2 H) based on the X-ray diffraction method,
the graphene being a crystal of a mean size of 100 nm or more and formed in a flake-like or sheet-like shape having 10 layers or less.
2. The composite lubricating material according to claim 1 , wherein a weight ratio of the graphite-based carbon material to the base material is 1/10,000 or more to less than 1.
3. The composite lubricating material according to claim 1 , wherein the base oil is derived from mineral, synthetic chemicals, plants or animals.
4. The composite lubricating material according to claim 1 , comprising one or more kinds of additives for a purpose of preventing oxidative deterioration.
5. The composite lubricating material according to claim 4 , wherein the additive is a radioactive substance.
6. Engine oil comprising the composite lubricating material according to claim 1 .
7. Grease comprising the composite lubricating material according to claim 1 .