CN-121986154-A - Conductive composition comprising silicone oil and carbon nanotubes

Abstract

According to the present invention, there is provided a conductive composition comprising a silicone oil as a base oil and carbon nanotubes as a conductive material, wherein the diameter of the carbon nanotubes is 0.4 to 5.0nm, and the content of the carbon nanotubes is 0.5 to 3.0 mass% relative to the total mass of the composition.

Inventors

• Accept the wisdom of mountains
• ICHIMURA RYOSUKE

Assignees

• 协同油脂株式会社

Dates

Publication Date

20260505

Application Date

20241009

Priority Date

20231010

Claims (4)

1. 1. A conductive composition comprising a silicone oil as a base oil and carbon nanotubes as a conductive material, The diameter of the carbon nanotubes is 0.4-5.0 nm, and the content of the carbon nanotubes is 0.5-3.0 mass% relative to the total mass of the composition.
2. 2. The conductive composition of claim 1, wherein the carbon nanotubes are a single layer or two layers.
3. 3. The conductive composition according to claim 1 or 2, wherein a thickener is not contained.
4. 4. The conductive composition of claim 1 or 2, further comprising a thickener.

Description

Conductive composition comprising silicone oil and carbon nanotubes Technical Field The present invention relates to a conductive composition useful for rolling bearings and the like. Background On steel and the lubrication surfaces of steel, damage caused by electricity is known. For example, in the bearing, there is a damage called electrolytic corrosion, which is caused by applying a voltage between the rotating shaft and the bearing to cause discharge. In the case of a bearing, electrolytic corrosion occurs due to a potential difference or a common mode current flowing between an inner ring and an outer ring of the bearing. In detail, the electrolytic corrosion proceeds due to continuous discharge in the lubricating film interposed between the ball and the raceway surface of the bearing. The problem addressed in patent document 1 is to provide a conductive grease having excellent conductivity and being less likely to cause a decrease in conductivity with time, and to provide a rolling device having a small resistance value and being less likely to be charged over a long period of time, and patent document 1 provides a conductive grease having carbon nanotubes as a conductivity-imparting additive. By using the grease, the resistance value of the bearing is reduced. Prior art literature Patent literature Patent document 1 Japanese patent laid-open publication No. 2002-332490 Disclosure of Invention Problems to be solved by the invention The invention aims to provide a conductive composition with low volume resistivity. Means for solving the problems According to the present invention, the following conductive composition is provided. 1. A conductive composition comprising a silicone oil as a base oil and carbon nanotubes as a conductive material, wherein the diameter of the carbon nanotubes is 0.4-5.0 nm, and the content of the carbon nanotubes is 0.5-3.0 mass% relative to the total mass of the composition. 2. The conductive composition according to 1, wherein the carbon nanotube is a single layer or two layers. 3. The conductive composition according to 1 or 2, wherein a thickener is not contained. 4. The conductive composition according to 1 or 2, further comprising a thickener. Effects of the invention According to the present invention, by combining the silicone oil itself having a very high volume resistivity as the insulating oil and a specific amount of the carbon nanotubes of a specific size, the value of the volume resistivity indicating the difficulty in flowing the current can be reduced particularly as compared with the case of using other base oils. Thus, the conductive composition of the present invention can suppress the occurrence of electrolytic corrosion because the conductive composition maintains a good conductive state and charges are less likely to accumulate, thereby suppressing discharge. The composition of the present invention also reduces the dielectric breakdown voltage. Drawings Fig. 1 is a schematic view showing the overall structure of a carbon nanotube. Detailed Description < Base oil > Examples of silicone oils that can be used in the composition of the present invention include dimethyl silicone oil, methyl phenyl silicone oil, methyl hydrogen silicone oil, and modified silicone oil. Among them, simethicone is particularly preferred. The silicone oil of the present invention may be used alone or in combination of 2 or more. But does not contain a base oil other than silicone oil. The kinematic viscosity at 25℃is preferably about 5 to 10000mm 2/s as measured in accordance with JIS K2283. Further preferably, the kinematic viscosity is 10 to 1000mm 2/s. When the kinematic viscosity of the base oil at 25℃is 5mm 2/s or more, evaporation of the base oil at high temperature, oil separation and the like tend to be suppressed, and thus it is preferable. On the other hand, if the kinematic viscosity at 25℃is 10000mm 2/s or less, appropriate fluidity is easily obtained, and thus it is preferable. In addition, if a silicone oil having a relatively high kinematic viscosity at 25 ℃, for example, a silicone oil having a kinematic viscosity of 100mm 2/s or more is used, the conductive composition of the present invention can be made into a paste, and thus leakage or dripping at the application site can be prevented, and the convenience of use can be improved depending on the application. As described later, a thickener and/or a solid lubricant may be added to the conductive composition of the present invention to form a solid or semisolid grease. In this case, the silicone oil may have a relatively low kinematic viscosity at 25 ℃, for example, a silicone oil of 100mm 2/s or less. The content of the silicone oil in the conductive composition of the present invention is preferably 50 to 99.5 mass%, more preferably 60 to 99.4 mass%, and even more preferably 70 to 99.3 mass% based on the total mass of the composition. When the content of the base oil is within such a range, it is preferable