JPS6252794B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to oil-impregnated lubricating members such as oil-impregnated plastics or oil-impregnated sintered bodies used in bearings, etc. The invention is lightweight, has excellent lubricity, and is impregnated with lubricating oil with low volatilization, resulting in low frictional resistance. To provide a component that maintains self-lubricating properties for a long period of time without running out of oil even without lubrication, and that exhibits excellent performance when used in important sliding parts such as bearings of light machines such as sewing machines. The purpose is to Conventionally, sliding parts such as bearings have required excellent lubrication effects, so lubrication has been provided using grease, solid lubricants, forced lubrication equipment, etc., as well as white metals, oil-impregnated plastics, and oil-impregnated sintered materials. Lubrication is performed using self-lubricating members such as bodies. Among these various methods of lubricating important sliding parts, there are oil-impregnated plastics that are formed by impregnating lubricating oil into plastic, and porous bodies that are formed by compacting and sintering plastic powder or metal powder and impregnating lubricating oil. The use of oil-impregnated sintered bodies is an excellent method in terms of both economy and lubrication effect, and is therefore used in many fields. Conventionally, the lubricating oil used for these oil-impregnated plastics and oil-impregnated sintered bodies has been high viscosity mineral oil-based lubricating oil such as turbine oil, machine oil, cylinder oil, etc.
Sliding parts impregnated with such high viscosity oil have high frictional resistance and poor starting performance at low temperatures, so they are not necessarily suitable for smooth operation of light machines with complex mechanisms such as sewing machines. It was hot. Such lubricating oils are used to impregnate oil-impregnated sliding parts because, in order to maintain a good lubrication effect over a long period of time, it is necessary to prevent oil depletion due to volatilization and deterioration due to frictional heat and air oxidation. There is, and also,
In the case of oil-impregnated plastics, it is also inappropriate to use low-viscosity mineral oil-based lubricants in order to avoid volatilization and decomposition due to the heat received during manufacturing and molding.
Naturally, high viscosity mineral oil-based lubricants have been used. In addition, we have attempted to obtain oil-impregnated lubricating parts that can be applied to parts that require light lubrication, such as sewing machine parts, by using synthetic lubricants instead of mineral oil-based lubricants. We have investigated the use of various synthetic lubricating oils, such as those based on synthetic hydrocarbons, but they have some drawbacks such as lubricity, volatility, hydrolyzability, corrosiveness to copper metals, and the ability to corrode plastics. It was not possible to obtain a sliding member. Structural formula

Polyα-olefin represented by the formula is a type of synthetic lubricating oil, and its properties vary depending on the type of alkyl group represented by R and the number of n, but R=C ₈ H ₁₇ , n
= 1 to 6, the viscosity was 18 to 13 cst at 40°C, and it was light and relatively compatible. However, when this lubricating oil was used, it had a high coefficient of friction, poor lubricity, and its volatility was only about half that of light mineral oil-based lubricating oils, so it was not fully satisfactory. As a result of studying the conventional drawbacks, the present invention has found that improvements can be made by adding a specific amount of a specific polyol ester to the polyα-olefin. That is, the structural formula

[Formula] 0.2 to 0.5 volume of tetraester of C ₁₆ to _{C 18} chain monocarboxylic acid and pentaerythritol per 1 volume part of polyα-olefin represented by R = C ₈ H ₁₇ n = 1 to 6. The lubricating oil composition (hereinafter referred to as improved poly-α-olefin) is characterized in that the disadvantages of poly-α-olefin are significantly improved due to the unique addition effect of this polyol ester, and the lubricating oil composition is light (viscosity: 40
℃, 20-30cst) It has low volatility (approximately 1/50 of mineral oil-based light lubricating oil), excellent lubricity, and does not corrode copper-based metals or attack plastics. The present invention relates to oil-impregnated sliding members such as oil-impregnated plastics and oil-impregnated sintered bodies impregnated with this improved poly-α-olefin, which eliminates the drawbacks of conventional oil-impregnated sliding members, and which are lightweight and have good performance over a long period of time. It maintains self-lubricating properties and is extremely effective when applied to light machinery with complex mechanisms such as sewing machines. The method for manufacturing the oil-impregnated sliding member of the present invention is as follows. In other words, the method for producing oleorefin plastics is to melt and knead a predetermined amount of improved poly-α-olefin and plastic powder in a multi-screw extruder, form pellets, and perform injection molding using the pellets. Since it has a high viscosity index and little decrease in viscosity with temperature rise, it can be melt-kneaded easily, and since it has low volatility, it can produce oil-impregnated plastics with high oil content and little variation in oil content. The oil-impregnated sintered body is produced by compacting and sintering metal powder or plastic powder, and then impregnating it with improved poly-α-olefin in vacuum. In addition, it is possible to further improve the properties of improved poly-α-olefin by adding various additives such as extreme pressure additives, antioxidants, and anti-rust additives, just like conventional mineral oil-based lubricating oils. An oil-impregnated sliding member was manufactured using poly-α-olefin with the following improved composition and physical properties to which an extreme pressure additive was added, and the effect was investigated by applying it as a sewing machine part. Examples thereof are as follows.

【table】

[Table] Receiving metal (effects) As mentioned above, the parts formed with the oleoresin-impregnated plastic of the present invention have a high oil content with little variation because there is no volatilization or decomposition of oil during the production and molding of the oleoresin-impregnated plastic. The obtained lubricating oil is light, has a low coefficient of friction,
It has many characteristics such as a high viscosity index, small changes in viscosity due to changes in humidity, and low volatility, so it has superior performance compared to conventional products. In other words, the coefficient of friction has been reduced to less than 1/3 of that of conventional products, and since there is no increase in viscosity as the temperature drops, it has excellent starting characteristics at low temperatures, and runs smoothly over a long period of time without running out of oil. It was possible to guarantee proper operation. In addition, even if this oil-impregnated plastic undergoes a long heat cycle through recycling, it will not volatilize or decompose the oil, so even if recycled materials are used, good molded products can be obtained, making it economical. The effect is also great. In the examples, the oil-impregnated plastic material is PBT, Diuracon, and 66 nylon, but the same applies to all other engineering plastics such as polycarbonate, 6 nylon, Noryl, PPS, etc. It is possible to obtain oil-impregnated plastics with excellent performance. Similarly to the case of oil-impregnated plastics, oil-impregnated sintered bodies retain good lubrication effects over long periods of time, and exhibit particularly remarkable effects when used in motor bearing metals. Conventionally, lubricating oil impregnated in the motor's bearing metal tends to run out as the heat generated by the motor accelerates the volatilization of the oil, and although this increases frictional torque, it is unavoidable because there is no alternative. High viscosity mineral oil-based lubricants and solid lubricants such as molybdenum disulfide have been used, but when the sintered body impregnated with the improved poly-α-olefin of the present invention is used, the friction torque is low, and the lubricant Since there is almost no volatilization, a good lubricating effect can be maintained for a long period of time without running out of oil. As described above, the oil-impregnated lubricating member of the present invention can be applied to light machines with complex mechanisms such as sewing machines, and has a great effect on quality assurance of sewing machines by ensuring good lubrication effects over a long period of time. However, like other office machines and other sewing machines, it requires light lubrication.
Moreover, it is highly effective in fields that require long-term quality assurance.

Claims (1)

[Claims] 1 Structural formula [Formula] n = 1 to 6, R = C ₈ H ₁₇ For 1 volume part of poly-α-olefin, C ₁₆ to _{C 18} chain monocarboxylic acid and penta Tetraester with erythritol
An oil-impregnated lubricating member characterized in that it contains a lubricating oil composition added in an amount of 0.2 to 0.5 parts by volume.