JPS6187792A - Lubricating oil or hydraulic fluid composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. which can prevent external and internal leakage without detriment to the general performance of lubricating oil or hydraulic fluid, by blending polyisobutylene having a high MW with a base oil. CONSTITUTION:A lubricating oil or hydraulic fluid compsn. is obtd. by blending 0.005-1.0wt% polyisobutylene having a high degree of polymn., which has a weight-average MW of 200,000 or above, with a base oil such as mineral or synthetic oil. The compsn. can prevent external and internal leakage without detriment to the general performance of lubricating oil and hydraulic fluid and hence it can contribute to resource and energy saving.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention is based on a base oil [highly polymerized polyisobutylene Q having a weight average molecular weight of 200,000 or more, 005 to 1.0 wt'fR%
It relates to a lubricating oil or hydraulic oil composition that is formulated with The present invention relates to lubricating oil or hydraulic oil compositions.

[Technical background] ゛Since the oil shock, the concepts of energy conservation and resource conservation have become firmly established not only in industry but also among general consumers. Among these, energy conservation, that is, reduction in power consumption and fuel consumption, has become an important issue in the field of lubricating oils and hydraulic oils. As a recent trend, various studies have been conducted to save energy from the perspective of equipment, and studies have also been conducted from the perspective of lubricating oil or hydraulic oil, such as lowering the viscosity, increasing the viscosity index, and reducing friction. It is being said. Decreasing the viscosity of lubricating oil or hydraulic oil increases mechanical efficiency by reducing fluid friction and friction, which can be expected to have an energy-saving effect.On the other hand, it has negative aspects such as a decrease in volumetric efficiency and a decrease in wear resistance. issues need to be considered. In addition, increasing the viscosity index is certainly effective when starting and stopping are frequently performed, but it cannot be expected to be very effective when used at a constant temperature for a long period of time.

Additionally, adding a friction reducer can reduce the coefficient of friction, which can be expected to be effective in saving energy, but it cannot change the physical properties of the oil and cannot be expected to be effective in preventing leakage.

Furthermore, from the perspective of resource saving, reducing the amount of supplementary lubricating oil or hydraulic oil, that is, reducing the number of leaks from the device, is an important issue. Oil leakage is a very troublesome problem, and in order to solve this problem, improvements and improvements from the equipment side are required.
Although improvements have been made, no leak-free device has been developed to date. Looking at existing equipment, leakage tends to increase as it ages, and even replacing parts is not a sufficient countermeasure, and when replacing parts, etc., it is necessary to Since the equipment must be temporarily stopped, replacement during operation is often impossible. Furthermore, as equipment becomes larger, pressurized, or more complex, leaks are more likely to occur.

In general, there are two types of oil leaks: external leaks, in which oil flows out of the equipment system from seals, joints, etc., and internal leaks, which are seen as efficiency losses occurring inside the equipment in the form of pressure loss, flow loss, etc. . External leakage causes oil to leak outside the system, which not only causes oil to flow out onto the floor, but also causes accidents such as fire and slips. Furthermore, it can get mixed into sewage, etc., and sometimes lead to pollution. Furthermore, there is a possibility that products etc. may be contaminated, and there is also the risk of causing serious problems such as burning of the device. Furthermore, it is necessary to replenish the amount of oil corresponding to the amount that has leaked, and the cost required for this is considerable.

On the other hand, if internal leakage increases, the pressure loss in the circuits of hydraulic equipment will increase, and the volumetric efficiency of pumps will also decrease, resulting in an increase in power consumption, which goes against energy conservation. . Furthermore, a complicated problem arises in that it becomes difficult to adjust the pressure maintenance.

As mentioned above, both external leakage and internal leakage are important issues, and although various improvements have been made to the design, structure, materials, and installation of the equipment, there is still no end in sight. ,
X (Hydraullc IPlullIndex
: The value obtained by dividing the annual hydraulic oil consumption by the total capacity of the oil tank) is approximately 1 even at the highest level. In particular, if a leak is discovered while the device is in operation, it is necessary to stop the device to replace or assemble parts, which is often difficult in practice. In addition, replacement of parts in aging equipment,
Assembly alone often does not lead to a fundamental solution.

Therefore, if it were possible to prevent oil leakage by using the oil itself, it would be the best method overall at present, and in particular, it would be an extremely advantageous method economically.

In general, as the viscosity of oil increases, external leakage tends to decrease, which would lead to a decrease in the values of H, ll', and It is not possible to expect a reduction in power consumption. Furthermore, if the viscosity is too high, it can cause various problems such as an increase in temperature due to increased internal friction and an increase in pressure loss in the hydraulic circuit, and simply increasing the viscosity will not solve the problem. . It also runs counter to the goal of lowering viscosity as a way to save energy.

Therefore, the anti-leak agent (
It is desired to develop a method of preventing leakage by adding a substance (substance that prevents leakage by adding it to lubricating oil or hydraulic oil).

Moreover, the anti-leak agent must not impair its original performance as a lubricating oil or hydraulic oil, and it is also necessary to minimize the increase in cost due to its addition. As one method, anti-leak agents containing solid fine particles such as polyfluoroethylene are commercially available, but among these anti-leak agents, those containing particles of a certain size are difficult to prevent from fraying. However, when the particles become large, they have poor dispersibility, can clog filters, cause cavitation, and have many management problems such as the spool of the electromagnetic switching valve sticking. Solid particles such as polyfluoroethylene are currently expensive;
There are economic disadvantages, and it is not necessarily an effective method.

Therefore, when added to lubricating oil or hydraulic oil, if there is an anti-leak agent that does not impair the inherent performance of the lubricating oil or hydraulic oil, has sufficient oil solubility, and is inexpensive, it can be used as an extremely effective substance.

[Purpose of the invention]

In view of these problems, various studies were carried out in the present invention, and the results were obtained by adding 0.05 to 1.0% by weight of highly polymerized polyisobutylene having a weight average molecular weight of 200,000 or more to the base oil.
This is based on the discovery that a lubricating oil or hydraulic oil composition blended in a small amount as shown in FIG. However, the present invention provides a lubricating oil or hydraulic oil composition that can reduce external and internal leakage without impairing its performance as a lubricating oil or hydraulic oil, and can significantly contribute to resource and energy conservation in line with the demands of the times. It is to be.

[Structure of the invention]

The present invention uses mineral oil or synthetic oil as a base oil, and 2
This is a lubricating oil or hydraulic oil composition containing a trace amount of 5 to 1.0% by weight of polyisobutylene having a weight average molecular weight of 00,000 or more.

Hereinafter, the configuration of the present invention will be explained in detail.

Base oils are generally called petroleum-based mineral oils, such as paraffinic hydrocarbon oils and naphthenic hydrocarbon oils, and are tax sources.
It may be obtained by methods such as solvent refining, dewaxing, hydrorefining, and hydrocracking. Also, as a base oil, for example α
-Olefin olicomers, polyethers, diesters, etc., which are generally called synthetic oils, may also be used. High molecular weight polyimbutylene, which is blended into base oil as an anti-leak agent, is synthesized by polymerizing inbutylene alone or a C4 gas containing it at various temperatures using a boron heptafluoride catalyst. can get. Generally, the degree of polymerization will be higher if the temperature is low, there are no impurities that impair the action of the catalyst, and the heat of polymerization is removed well.

For example, if 0.5% boron triseptide is used as a catalyst and polymerization is carried out in boiling ethylene, a polymerization degree of 1000 or more can be obtained. Although it has been known that relatively high molecular weight polymers have leak-preventing properties, it is not known that polymers with a relatively high molecular weight are effective when a very small amount of high molecular weight polyisobutylene is blended. In the present invention, polyisobutylene having a weight average molecular weight of 200,000 or more is o, o o s~
The present invention is characterized in that it has been found that a trace amount of 1.0% by weight can be used as an effective anti-leak agent.

When such anti-leak agents are subjected to shearing, the viscosity decreases significantly and there is a concern that the leak-preventing performance may deteriorate, but the anti-leak agent of the present invention shows excellent leak-preventing performance even after shearing. It is.

The blending ratio of polyisobutylene having a weight average molecular weight of 200,000 or more, preferably 300,000 to 1,500,000 in the lubricating oil or hydraulic oil composition is o, o o s to 1.0 with respect to the lubricating oil or hydraulic oil composition. In % by weight, 0.01 to 0.2 % by weight are particularly suitable for the purposes of the invention. When the blending ratio of high molecular weight polyisobutylene is high, the viscosity decreases due to shearing, and conversely both external leakage and internal leakage increase.

Also, from an economic point of view, it is desirable that the amount added be small.

The lubricating oil or hydraulic oil composition of the present invention contains the above-mentioned high molecular weight polyimbutylene as an essential component, but in addition to this, one or more known lubricating oil or hydraulic oil additives may be used in combination. Specifically, these additives include anti-wear agents (
detergent dispersants (e.g. basic sulfonates), friction modifiers (friction modifiers e.g. molybdenum disulfide), viscosity index improvers (e.g. polymethacrylates, olefin copolymers), antioxidants (e.g. zinc dialkyldithiophosphates), (e.g. amine-based or hindered phenol-based), antifoaming agents (e.g. silicone oil),
pour point depressants (e.g. polymethacrylates), metal deactivators (e.g. benzotriazoles and their derivatives),
Examples include demulsifiers (eg, cationic surfactants).

When blended with high molecular weight polyisobutylene base oil, the viscosity increases, but it has almost no effect on other physical properties. In addition, there is no interaction with other additives, and it becomes possible to further impart new leak prevention performance to lubricating oils or hydraulic oils that are currently widely used.

As described above, lubricating oil or hydraulic oil compositions containing high molecular weight polyisobutylene can save resources by preventing external and internal leakage without impairing the general performance of lubricating oils or hydraulic oils. , can contribute to energy conservation.

Hereinafter, the effects of the composition according to the present invention will be explained in detail using Examples and Comparative Examples regarding hydraulic oil, but the present invention is not limited by these Examples.

[Experiment 1] In order to examine the effect of preventing external leakage of oil containing a polymeric substance as an anti-leak agent, a test was conducted using the device shown in Figure 1, which was made into a U-shape with a % inch iron nipple union sleeve and an elbow. Ta.

The leakage area is 180kl in the gap 13 between the iron nipple 11 and the union sleeve 12? Tighten with a torque of 2.1kg/1M, then add 250mm test oil and apply nitrogen gas from both ends of the U-shape to 2.1kg/1M? apply pressure. The temperature is 25±1
The test oil was kept at 0.degree. C. and left in this state for 20 minutes, and the test oil that flowed out was collected and weighed.

The weight average molecular weight of the blended polymeric substance was determined by gel vermutation chromatography. Note that commercially available standard polystyrene was used for the calibration curve. During experiments, when fluid leaks through a small gap, the leak characteristics (leak rate or leakage amount) are expressed as a function of the gap, fluid pressure, and fluid kinematic viscosity in fluid dynamics. We considered the following.

The test oils used were base oils containing polymeric substances of various molecular weights such as polyisobutylene, polybutene, polymethacrylate, olefin copolymers, and polyalkylstyrene. For comparison, an additive-free base oil that does not contain the above polymer was used as a reference for leakage amount. The results are shown in Table 1, Table 2, and Figure 2 below.

Table 1, Table 2 and Figure 2 show that among various oil-soluble polymers, polyimbutylene with a weight average molecular weight of I200,000 or more is
The oil containing the above amount has an excellent leak-preventing effect.

[Experiment 2] In order to examine the effectiveness of the hydraulic oil composition of the present invention in preventing external leakage under high pressure, leakage was prevented by adjusting the tightening of the male and female threads of an inch NPT pipe made of stainless steel with one side blind. 120±2 mt of additive-free oil that has no effect
The test was conducted by tightening the leakage part so that the leakage amount (initial setting amount) was h. The measurement method is to fill the device with 250-liter test oil, maintain the temperature at 25±1℃,
Apply a pressure of 70kli/J with nitrogen gas.

Leave in this state for 3Q minutes and collect and weigh the spilled test oil. The amount of leakage is converted to the amount per hour and displayed. Repeat this operation several times to see how the leakage prevention effect changes over time.

Examples 1-5 A hydraulic oil composition of the present invention having the following composition was prepared.

Example 1 Example 2 Example 3 Hydraulic oil base oil A1) 9a7 wt%t
t B2) 9&85ii%
9a88ffflfi% polymeric substance A3) [1,0
5p Q, 2 tttt B4) 0.02
tr Pour point depressant 6) 0.5tt Q, 3tt
O,! + tt antifoaming agent 10ppm
10ppm 10ppm1) Additive-free turbine oil So V 52 2) Additive-free turbine oil So
V 46 5) Polyisofethylene 1 double weight → -i 656,0004) Polyisofylene 2
Weight average content → Nanaka Go to 87 0005) Commercially available packaging additive for wear-resistant hydraulic oil 6) Commercially available pour point depressant based on polymethacrylate 7) Silicone oil Comparative Examples 1 and 2 Hydraulic oil compositions shown below as comparative examples (Comparative Example 1) and a hydraulic oil containing polybutene (Comparative Example 2) were prepared. The hydraulic oil base oil used was the same as that shown in the examples.

Comparative Example 1 Comparative Example 2 Hydraulic oil base oil A 50 Tsuru% 95. l is Ti Hydraulic oil base oil B 4&9 Polymer substance C8) -55 Pour point depressant Q,3 0.5 Antifoaming agent 10ppm 10ppm8) Polybutene (Polybutene concentration 2&2H) Weight molecular weight daily 1139,000
Table 3 shows the change over time in the leakage prevention effect.

Table 3 Leakage Example 1 120 86 82 Example 2
120 86 78 Example 5 120
94 90 ratio grain example 1 120 12Q 1
20 1 Comparative Example 2 120 120 119
1 Prevention performance evaluation amount (d/h) 20 1'20 120 120' 020
j19 119 119 1 In Comparative Examples 1 and 2, the amount did not change at all from the initial setting amount throughout the entire period, and no change over time was observed.

On the other hand, those to which a polymeric substance was added (Examples 1.2 and 3) showed a leakage prevention rate (relative value to the leakage amount of oil without additives) of 32 to 48 after 180 minutes.

[Experiment 3] In order to examine the leakage prevention effect of the hydraulic oil composition of the present invention during shear breakage, the test oil after the injection nozzle type shear stability test was evaluated by the method of Experiment 2.

The results are shown in Table 4.

A hydraulic oil composition having the following composition was prepared as a test oil.

The hydraulic base oil and additives used were the same as those used in Experiment 2.

Example 4 Comparative Example 3 Hydraulic oil base oil C9 & 5 Tsuruchi hydraulic oil base oil D2) 9a1% by weight
Polymer substance A O, 4, IF 1.1
p pour point depressant 0.5 # 0.5
1/Antifoaming agent 10ppm 10ppm Among the hydraulic oil compositions of the present invention, those containing a small amount of polymeric substances show only a slight decrease in viscosity even when punched out, and exhibit an excellent anti-sagging effect. When the amount increases, the degree of punching and punching is significantly reduced, and the leakage prevention effect is also reduced. In Comparative Example 3, on the contrary, leakage increased.

[Experiment 4] In order to examine the leakage prevention effect of the hydraulic oil composition of the present invention and the influence on the spool fixation of the electromagnetic switching valve, a test was conducted with a p-pressure cuff of 0 kl//d using a hydraulic device as shown in Fig. 5. I did it.

First, oil was pumped through the pump 3, and the amount of oil leakage (external leakage) from the rod packing a part of the hydraulic cylinder 7 was measured, and the amount of oil leakage (external leakage) from the flange part 8, where the copper packing was similarly scratched, and electromagnetic switching were detected. Internal leakage from the valve was measured and reaction force was measured using a strain gauge. Reaction force measurement using a strain gauge is a method of measuring the force that resists the operation of the spool that occurs when the spool of an electromagnetic switching valve is operated by an external force using a strain gauge, and is used to determine how easily the spool operates. Therefore, the smaller the spool reaction force, the easier it is to operate. The leakage results were organized as a function of temperature. The test oils used are those shown in Example 1 and Comparative Example 1 of Experiment 2.

As shown in Figures 4, 5, 6, and 7, the product of the present invention (Example 1) has a leakage prevention effect of 22 to 35 inches compared to Comparative Example 1 for both external and internal leaks. Is recognized. In addition, regarding the spool reaction force of the electromagnetic switching valve, Example 1 is different from Comparative Example 1.
It is smaller than , and switching is smoother.

From the above results, it is clear that the present invention can provide a hydraulic oil composition that is effective in preventing external leakage and internal leakage. Furthermore, the hydraulic oil composition obtained by the present invention should sufficiently have excellent properties such as general properties, thermal stability, hydrolytic stability, oxidation stability, and wear resistance necessary for a hydraulic oil. has also been confirmed.

In addition, in the above-mentioned example, explanation was given regarding hydraulic oil, but the same effect can be achieved with a lubricating oil that uses the same base oil as the hydraulic oil.

[Brief explanation of the drawing]

FIG. 1 shows a schematic diagram of an external leakage evaluation tester for oil compositions, and FIG. 2 shows the leakage prevention properties of oil added with polymeric substances.
FIG. 3 shows a hydraulic system for measuring internal leakage and external leakage of an oil composition and spool reaction force of an electromagnetic switching valve. Figures 4, 5, and 6 are diagrams showing the oil leakage prevention effect of the present invention, and Figure 7 is a diagram showing the results of the spool reaction force of the electromagnetic switching valve. The axis shows relative comparison based on strain meter readings. 1-1- Dock 2-m-Strainer 3-m-Pump 4--Relief valve 5--4 Boat electromagnetic switching valve 6--Sequence valve with check 7--Hydraulic cylinder 8-- 7 lunge 9-m-strain meter 10-m-pen oscilloscope 1 Figure 4 ijL and 0C 242526272B 29 30 Flare 5 degrees "C" Figure 29 30 31 32 33 34 35 3G Denki On and 0C: Continued from page 1 ■Int, CI, 4 Identification code Internal serial number

Claims (1)

[Scope of Claims] 1. A lubricating oil or hydraulic oil composition containing 0.005 to 1.0% by weight of highly polymerized polyisobutylene having a weight average molecular weight of 200,000 or more in a base oil. 2. The lubricating oil or hydraulic oil composition according to claim 1, wherein the base oil is mineral oil or synthetic oil.