JPS58215494A - Solid lubricant - Google Patents

Abstract

PURPOSE:To provide a solid lubricant consisting mainly of molybdenum bisulfide or tungsten bisulfide and containing a specified amount of a strongly acidic substance, which has a high oxidation temperature and is suitable for application to places exposed to high temperature and high friction. CONSTITUTION:The lubricant consists mainly of molybdenum bisulfide or tungsten bisulfide and contains about 0.1-10wt% strongly acidic substance. It should preferably have a multi-layer structure obtained by alternate lamination of layers consisting of the main component and the strongly acidic substance. The strongly acidic substance includes lead monoxide, vanadium dioxide, lead sulfide, molybdenum oxide, bismuth oxide, manganese oxide, etc. Its addition controls reaction of molybudenum with oxygen in the air which causes decomposition of molybdenum and formation of molybdenum trioxide as shown by the reaction formula.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a solid F4 lubricating material suitable for locations where high temperatures and high frictional pressures occur, such as between a disk and a stylus in a capacitive video disk system. Molybdenum disulfide (MoS2) is a very useful lubricating material in locations where boundary lubrication is not appropriate and where high temperatures and frictional pressures occur. One of the common problems with lubricating materials is seizure and hardening, which occur because #R materials oxidize when heated.

When MoS2 reaches a temperature higher than the oxidation temperature in air, which is a characteristic index, it decomposes into MoS2 +5.502-+M□Q, +2802, and molybdenum trioxide (Mob) is generated, causing baking and hardening. The oxidation temperature of MoS2 is 350'C, but this is a static case; under dynamic friction, the oxidation temperature decreases further (300'C) due to mechanochemical effects.
C) oxidation and seizing will become more difficult.

On the other hand, in order to lubricate a surface having a pattern of fine irregularities, such as a disk in a capacitive video disk system, it is necessary to form a solid lubricant material in the form of a thin film on the surface of the object to be lubricated.

An object of the present invention is to provide a solid lubricant material that eliminates the drawbacks of the prior art described above, increases the oxidation temperature, suppresses baking and hardening, and can be formed into a uniform thin film.

In order to achieve this objective, the present invention uses MoS2 or tungsten disulfide (WS2) as the main component, and adds a strongly acidic substance to it at a predetermined addition rate to form a uniform thin film. The present invention is characterized in that the oxidation temperature is effectively increased by reducing the oxidative decomposition rate of the main component.

Embodiments of the present invention will be described below with reference to the drawings.

The figure is an explanatory view showing one embodiment of the solid lubricant material according to the present invention, in which 1 is an object to be lubricated, 2 is tungsten (WI layer,
3 is Mo32 layer, 4 is boron (81 layer).

Next, this example will be explained.

In the figure, the solid lubricant material has a multilayer structure in which Mo82 layers and a strong acidic substance are alternately laminated to form a thin film. to substantially correspond to that added.

That is, a W layer 2 with a thickness of 200 mm is formed on the object to be lubricated 1, and a Mo82 layer 3 with a thickness of 1 μm is formed thereon. Further, three layers 4 are formed on top of this with a thickness of 200X, and then the 1 μm thick Mo' 82 layer 3 and the 3 layers 4 with a thickness of 200X are alternately laminated to form a multilayer structure of 12 layers as a whole. shall be. The W layer 2 is for ensuring adhesion between the object 1 to be lubricated and the first Mo82 layer 3, but is also a strongly acidic substance. The strongly acidic substance is a substance that easily receives oxygen, is a reducing agent, and prevents the oxidation of MoS2.

Such a multilayer structure is suitable for multi-source RF sputtering equipment.

It can be formed using a multi-source planar magnetron, a sputter gun type sputtering device, a multi-source ion blating device, or the like.

In this example, the addition rate of B to Mob is approximately 2% by weight, but a maximum of 10% is allowable since it does not disturb the properties of MoS. Strongly acidic substances other than B include -lead oxide (PbO).

Vanadium dioxide (VO2), lead sulfide (PbS), molybdenum oxide (MoO), bismuth oxide (BiO).

Manganese oxide (MnO), fluoride steel (CuF), tungsten (W), phosphorus CP), antemon (As).

Bismuth (Bi), cobalt (co), carbon (C)
and so on.

Next, a case will be described in which the solid lubricant material of this example is used in a capacitive video disc system. In this case, the object 1 to be lubricated in the figure is a disk.

When a stylus (not shown) comes into contact with the disk 1, the stylus causes local digging into the soft solid lubricant material, and mobs are trapped in this digging area.

Layer 3 and layer 4 of strongly acidic material are exposed. Then, this dug-in part generates heat locally due to friction, and the temperature rises.
Although the Mo82 layer 3 is easily oxidized, the exposed layer 4 of the strong acidic substance is rather oxidized and suppresses the oxidation effect of the Mo82 layer 3. At this time, the soft Mo82 layer 3 and the strong acidic material layer 4 are mixed, and oxidation is uniformly suppressed.

As described above, the strong acidic substance suppresses the oxidation of MoS2, which is the main component, and reduces the oxidation rate.

In the above embodiment, Mo 82 was explained as the main component, but tungsten disulfide (WS) having the same crystal structure as MoS 2 may be used as the main component. In addition, as a means of mixing the main component and a strong acidic substance, the case where these are laminated in multiple layers has been explained, but the main component and a strong acidic substance are powdered and mixed, and the mixture is applied to the object to be lubricated together with a binder. You may also do so.

As a result of adding a strong acidic substance to the main component as described above, the oxidation temperature of the main component could be effectively increased by 100°C to 150°C.

As explained above, according to the present invention, the main component M
Since it is possible to reduce the oxidation decomposition rate of oS2 or WS2 and effectively raise the oxidation temperature, it is possible to suppress seizure and oxidation even when used at high temperatures and high friction pressures, thus significantly extending the service life. This makes it possible to provide a solid lubricant material with excellent functionality not found in the prior art.

[Brief explanation of drawings]

The figure is an explanatory diagram showing an example of the solid lubricant material according to the present invention. 1... Lubricated object, 2, 4... Layer of strong acidic substance. 3...Layer of main component.

Claims (1)

[Scope of Claims] (1) A solid whose main component is molybdenum disulfide or tungsten disulfide, and which is characterized by having a strongly acidic substance added at a predetermined addition rate to increase the oxidation temperature. Lubricating material. (2. In claim (1), the strongly acidic substance is - lead oxide, vanadium dioxide, lead sulfide, molybdenum oxide, bismuth oxide, manganese oxide, fluorinated steel, tungsten, boron, phosphorus). A solid lubricating material characterized in that it is any one of antimony, bismuth, cobalt, and carbon, and the addition rate is from 0.1 to 10 inches by weight. (3) Claim (1) or item (21), characterized in that layers made of the main component and layers made of the strongly acidic substance are laminated alternately, and the strongly acidic substance is added to the main component. solid lubricating material.