TW201311880A - Silicone-based lubricant composition and sintered oil-containing bearing impregnated therewith - Google Patents

Abstract

[Problem] The purpose of the present invention is to provide a silicone-based lubricant composition wherein excellent rust prevention can be exhibited by stably dispersing a rust inhibitor in a silicone oil that has excellent thermostability, oxidation stability, and a high index of viscosity, and a sintered oil-containing bearing impregnated therewith. [Solution] This silicone-based lubricant composition comprises 90.0 to 99.4 mass% of silicone oil with a kinematic viscosity of 20 to 1000 mm2/s at 25 DEG C, 0.1 to 5.0 mass% of a mixture of one or more types of silica gel with a primary particle average size of 30 nm or less, and 0.5 to 5.0 mass% of a mixture of one or more types of rust inhibitor.

Description

Polyfluorene-based lubricating oil composition and sintered oil-impregnated bearing thereof

The present invention relates to a lubricating oil composition for use in an automobile accessory device, or an electric appliance for an electric appliance, an IT (information technology), or an industrial machine, and a polyfluorene-based lubricating oil composition mainly composed of polyoxygenated oil, and impregnating the same A sintered oil-impregnated bearing of a polyfluorene-based lubricating oil composition.

It is a kind of lubricating oil widely used in various industrial fields because of its excellent thermal stability and oxidation stability, and its high viscosity index.

Further, a lubricating oil composition in which a polyoxygenated oil and a carboxylic acid ester are mixed to improve lubricity and an abrasion preventing agent and/or an oxidation preventing agent can be added is known. The lubricating oil composition is used for sintering oil-impregnated bearings, has stable rotational characteristics in a wide temperature range from low temperature to high temperature, and is excellent in lubricity and volatility, and contains a specific allyl group at 40 ° C the dynamic viscosity of 10 ~ 3000 mm ² / s organopolysiloxane of silicon oxide 20 to 90 wt% alkoxy, and carboxylate 80 to 10 wt% of the composition (see, for example, Japanese Laid-open Patent Publication No. 2003-261892).

It is also known that the grease for bearings is made of polyoxo-oxygen oil mixed metal soap, which acts as a growth agent to form a grease, adding cerium nitrite and sulfonium sulfonate, and a magnesium compound and a gasifying rust inhibitor. A rust inhibitor of an essential component (for example, see JP-A-2004-176075).

Further, a polyfluorene-based grease-based lubricant composition in which a polyfluorene oxide oil, a ruthenium gel having an average particle diameter of 2 to 15 μm, and a solid lubricant are mixed is known. The polyfluorene grease-based lubricant composition is used as a base oil polysulfonated oil, adding an inorganic growth agent and a solid lubricant, and the polyoxyxene oil component is 50-99.9 wt%, and the inorganic growth agent group The content is 0.1~30% by weight, the solid lubricant component is 0.1~49.9% by weight, and the polyoxyxene oil is selected from the group consisting of dimethyl polyfluorene oxide oil and xylyl polyfluorene oxide oil. The dynamic viscosity at 25 ° C is 50 to 1,000,000 mm ² /s, and the inorganic growth agent is a hydrophobic micropowder gel having pores (for example, see JP-A-2010-275384).

However, polyoxygenated oils have poor lubricity or rust resistance, and these disadvantages Although the addition of additives is expected to be improved, it is difficult to disperse the additive in the polyoxo-oxygen oil due to the poor compatibility of the polyoxygenated oil with other components such as additives, and the additives that can be mixed are limited.

In addition, the above lubricating oil composition is suitable for polyoxygenated oil, limited to methylphenyl polyoxyalkylene (phenylmethylpolyoxylate), and dimethylpolyoxyalkylene (dimethylpolyoxygenated oil). The problem is due to the inability to stabilize the dispersing additives.

Further, the above-mentioned bearing grease and rust preventive agent are only limited to grease-like semi-fixed lubricants, and there are problems. Further, in the above-mentioned polyfluorene grease-based lubricant composition, when a lubricating oil having a fluidity of 2 to 15 μm is used to prepare a lubricating oil having fluidity, there is also a problem that the gel is precipitated.

An object of the present invention is to provide a polyfluorene-based lubricating oil composition which is excellent in thermal stability and oxidation stability and which has a high viscosity index and can stably disperse the rust preventive agent. Superior rust preventive properties, as well as sintered oil-impregnated bearings impregnated with this polyfluorene-based lubricating oil composition.

The polyfluorene-based lubricating oil composition of the present invention is characterized in that it has a viscous viscosity of at least 20 to 1000 mm ² /s at 25 ° C of 90.0 to 99.4% by mass, and is selected from a primary average particle diameter of 30 nm. One or a mixture of two or more of the following gel groups is 0.1 to 5.0% by mass, and one or two selected from the group of rust inhibitors and 0.5 to 5.0% by mass of the mixture.

In the polyoxo-based lubricating oil composition, the polysulfonated oil is selected from the group consisting of dimethylpolyphthalide oil, phenylmethylpolyfluorene oil, and modified polyoxyxene oil.

In the polyoxymethane-based lubricating composition, the surface of the ruthenium gel is a hydrophobic ruthenium gel modified with an organic group or a hydrophilic ruthenium gel having a stanol group on the surface.

In the polyoxo-based lubricating oil composition, the rust preventive agent is a sulfonium sulfonate, a carboxylic acid, an ester, or a compound having a hetero ring in a molecule.

Further, the polyfluorene-based lubricating oil composition is preferably used for a sintered oil-impregnated bearing.

The invention further relates to a sintered oil-impregnated bearing characterized by immersing the above-mentioned polyfluorene-based lubricating oil composition.

The ruthenium gel used in the composition of the polyfluorene-based lubricating oil of the present invention can be stably dispersed in the polyoxo-oxygen oil and is a chemically stable compound, and can be used in a wide temperature range similarly to the polyoxygenated oil. The above-mentioned ruthenium gel can be stably dispersed in the polysiloxane oil because of its very small particle size. In particular, in the polyoxo-oxygenated oil of the stable dispersion gel, when the rust inhibitor is mixed, the rust inhibitor is adsorbed to the ruthenium gel, and the rust inhibitor is uniformly dispersed in the polyoxyxene oil. The polyfluorene-based lubricating oil composition thus obtained is a lubricating oil having excellent rust preventive properties. In addition, the sintered oil-impregnated bearing impregnated with the polyfluorene-based lubricating oil composition does not rust even under the condition that the bearing is easily rusted, so it is applicable, and is preferably used in automobile accessory equipment, home appliances, information technology, Bearings for engines such as industrial machines.

The polyfluorene-based lubricating oil composition of the present invention is a lubricating oil used for an electric motor used in a device such as an automobile accessory, a home appliance, an information technology, an industrial machine, or the like, and a lubricating oil having a main component of a polyoxygenated oil, at least a rust inhibitor is added. The bismuth gel is preferably used in a sintered oil-impregnated bearing impregnated with the lubricating oil composition.

The polyoxon-based lubricating oil composition of the present invention and the sintered oil-impregnated bearing impregnated with the polyfluorene-based lubricating oil composition are described in detail below.

The sintered oil-impregnated bearing of the impregnated polyfluorene-based lubricating oil composition of the present invention can be used for internal fans such as refrigerators and freezers, internal fans of oven ovens, LED cooling fans, air conditioners, ventilation fans, and other indoor air conditioner fans, and various fans on the vehicle. (For example, battery pack, DC-DC converter, LED headlight cooling fan, air conditioner blower, etc., air conditioner fan, seat fan, sensor hair dryer, etc.), computer, TV, video recorder, sound-making device, etc. Cooling unit fan, electronic throttle (ETC) unit motor, exhaust gas recirculation unit (EGR) unit motor, engine, unit motor used near the high temperature part of the exhaust system, etc. No brush motor, etc.

First, regarding the composition of the polyfluorene-based lubricating oil of the present invention, the constituent parts thereof include polydecane oxide oil, hydrazine gel and rust inhibitor, and the kinds and compounding ratios thereof are as follows:

(a) About polyoxyl oil

The polyfluorene-oxygen oil used in the composition of the polyfluorene-based lubricating oil of the present invention is selected from the group consisting of dimethylpolyphthalic acid oil having a dynamic viscosity of 20 to 1000 mm ² /s at 25 ° C, and phenylmethyl polyfluorene oxide oil. And one or more (at least one) of the modified polyoxygen group.

The dimethylpolyphthalic acid oil is a compound represented by the following formula: (CH ₃ ) ₃ SiO[Si(CH ₃ ) ₂ O] _n Si(CH ₃ ) ₃

The phenylmethylpolyphthalic acid oil is a compound represented by the following formula: (CH ₃ ) ₃ SiO[Si(CH ₃ ) ₂ O] _n [Si(C ₆ H ₅ ) ₂ O] _m Si(CH ₃ ) ₃

The modified polyoxo oil is a compound represented by the following formula: (CH ₃ ) ₃ SiO[Si(CH ₃ ) ₂ O] _n [Si(CH ₃ )(R)O] _m Si(CH ₃ ) ₃ Wherein R is a functional group selected from the group consisting of an alkyl group, an amine group, a polyether group, a fluoroalkyl group, and an epoxy group. The symbols m and n in the respective formulae are integers of 1 or more.

The polyfluorene oxide oil used in the composition of the polyfluorene-based lubricating oil has a dynamic viscosity of 20 mm ² /s or less at 25 ° C, and is excessively evaporated at a high temperature, so it is not suitable, and when the dynamic viscosity exceeds 1000 mm ² /s, Adding a small amount of bismuth gel will lose fluidity and will not work.

(b) About 矽 gel

In the ruthenium gel used in the composition of the polyfluorene-based lubricating oil of the present invention, since the rust preventive agent is adsorbed on the surface, the purpose of the compounding is to stably disperse the rust preventive agent in the polyfluorene oxide oil.

The ruthenium gel used in the composition of the polyfluorene-based lubricating oil of the present invention is selected from one or a mixture of two or more kinds of ruthenium gel groups having a primary average particle diameter of 30 nm or less. When the primary particle diameter of the ruthenium gel exceeds 30 nm, the ruthenium gel precipitates prominently in the poly oxime oil, and is not suitable as the ruthenium gel used for the composition of the polyfluorene-based lubricating oil of the present invention.

Further, in the ruthenium gel of the polyfluorene-based lubricating oil composition of the present invention, a hydrophilic ruthenium gel having a plurality of stanol groups on the surface or a hydrophobic ruthenium gel whose surface is modified with an organic group may be used.

The polyfluorene-based lubricating oil composition of the present invention is selected from the above-mentioned bismuth gel group The group consists of one or more mixtures of 0.1 to 5.0% by mass.

When the gel content exceeds 5.0% by mass, the polyfluorene-based lubricating oil composition is greased and loses fluidity as a lubricating oil. On the other hand, when the content is 0.1% by mass or less, the effect of the gel is small. The dispersion of the additive is poor.

(c) rust inhibitor as an additive

The rust inhibitor used in the composition of the polyfluorene-based lubricating oil of the present invention may be a sulfonium sulfonate, a carboxylic acid, an ester or a compound having a hetero ring in the molecule.

The sulfonic acid sulfonium has, for example, petroleum sulfonic acid, alkylnaphthalenesulfonic acid, overbased petroleum sulfonic acid, dinonylnaphthalenesulfonic acid, alkylbenzenesulfonic acid, etc., calcium strontium, sodium strontium, barium, magnesium strontium, zinc strontium Wait.

The carboxylic acid is, for example, a C ₇ -C ₅₄ fatty acid, a dimer acid, a trimer acid, a benzoic acid or the like.

The esters are, for example, sorbitan monooleate, sorbitan tristearate, sorbitan laurate, lanolin fatty acid pentaerythritol ester, lanolin fatty acid isobutanol ester, tetrapropene Propylene glycol succinate and the like.

The heterocyclic ring has, for example, a triazole ring, a benzotriazole ring, an imidazole ring, a thiadiazole ring, Oxazole ring and the like.

Specific examples are N,N-bis(2-ethylhexyl)-[(1,2,4-triazol-1-yl)methyl]amine; 1,2,3-benzotriazole; 1-[ N,N-bis(2-ethylhexyl)aminemethyl]benzotriazole; 2-(alkyldithio)benzimidazole; 2,5-bis(alkyldithio)-1,3 , 4-thiadiazole; 2,5-dihydrothio-1,3,4-thiadiazole; 2-heptadecenyl-4,4(5H)- Oxazole dimethanol and the like.

When the amount of the rust inhibitor added is 0.5% by mass or less, the desired rust preventive property cannot be obtained. On the other hand, when the amount of the rust inhibitor added exceeds 5.0% by mass, it is difficult to stably maintain the degree of fluidity of the polyoxyxane oil, that is, the gel amount of 5.0% by mass or less, which is not suitable for the polyfluorene-based lubricating oil composition of the present invention. .

Further, an additive other than the rust preventive agent is also adsorbed to the ruthenium gel and can be dispersed in the composition of the present invention. The additives include anti-oxidants, extreme pressure agents, wear-resistant agents, etc., which are known to be used as lubricants, and may be compounded as needed.

The polyfluorene-based lubricating oil composition of the present invention can be prepared, for example, by the following method. In the polyoxygenated oil, one or two or more kinds of cerium gels, one or two or more kinds of rust inhibitors, may be prepared by fully mixing with a high-speed rotary emulsifier or a high-pressure homogenizer. That is, the polyfluorene-based lubricating oil composition of the present invention can have a viscous viscosity of 20 to 1000 mm ² /s at a temperature of 25 ° C of 90.0 to 99.4% by mass, and is selected from a primary average particle diameter of 30 nm or less. One or more mixtures of the ruthenium gel group are 0.1 to 5.0% by mass, and one or more mixtures selected from the group of rust inhibitors are 0.5 to 5.0% by mass, and are put into a high-speed rotary emulsifier or high-pressure uniform The chemicalizer is prepared by thorough mixing.

Next, the bearing using the polyfluorene-based lubricating oil composition of the present invention will be described in detail. The polyfluorene-based lubricating oil composition of the invention is preferably used as a sintered oil-impregnated bearing lubricating oil.

The so-called sintered oil-impregnated bearing is a sliding bearing which is obtained by compacting a metal powder, heating it into a porous metal body, impregnating a lubricating oil, and using it in a self-supplying state. The material of the sintered oil-impregnated bearing mainly uses bronze, brass, a copper alloy called silver, or an iron-based material. However, due to the high price of copper raw materials in recent years, the proportion of the use of the iron-based material has increased. Accordingly, there has been an increase in the demand for the improvement of the rust prevention performance of the lubricating oil for immersion.

Furthermore, the sintered oil-impregnated bearing has a characteristic of a large specific surface area compared with a sliding bearing of the same diameter and a rotary bearing. Therefore, the lubricating oil impregnated in the sintered oil-impregnated bearing requires strong rust resistance, and the polyfluorene-based lubricating oil composition of the present invention rich in this property is preferably used for sintering oil-impregnated bearings.

Example

In the polyfluorene-based lubricating oil composition of the present invention, various samples, that is, Examples 1 to 16, were prepared, and Comparative Examples 1 to 5 were prepared in comparison with the present invention, and the present invention and comparative products were prepared. Contrast to illustrate its rust-preventing effect.

The samples of Examples 1 to 16 and Comparative Examples 1 to 5 were argon gels as shown in the following 1-1 to 1-7, bismuth gels shown in 2-1 to 2-5, and 3 -1 to 3-5 rust inhibitors, mixed according to the ratio shown in Table 1 to Table 3 The material was prepared by a high-speed rotary emulsifier.

About polyoxyl oil

1-1: Shin-Etsu Chemical Industrial Products KF-96-20CS

[Dimethylpolyphthalic acid oil, dynamic viscosity: 20mm ² / s at 25 ° C]

1-2: Shin-Etsu Chemical Industrial Products KF-96-100CS

[Dimethylpolyphthalic acid oil, dynamic viscosity: 100mm ² / s at 25 ° C]

1-3: Shin-Etsu Chemical Industrial Products KF-96-1000CS

[Dimethylpolyphthalic acid oil, dynamic viscosity: 1000mm ² /s at 25 ° C]

1-4: Shin-Etsu Chemical Industrial Products KF-50-300CS

[Phenylmethyl polyfluorene oxide, dynamic viscosity: 300mm ² / s at 25 ° C]

1-5: Shin-Etsu Chemical Industrial Products KF-4003

[Alkyl modified polyfluorene oxide, dynamic viscosity: 40mm ² / s at 25 ° C]

1-6: Shin-Etsu Chemical Industrial Products FL-100-100CS

[Fluoroalkyl modified polyoxyxide oil, dynamic viscosity: 100mm ² / s at 25 ° C]

1-7: Shin-Etsu Chemical Industrial Products KF-615A

[Polyether modified polyfluorene oxide, dynamic viscosity: 920mm ² / s at 25 ° C]

About 矽 gel

2-1: Hydrophobic bismuth gel (primary average particle diameter: 16 nm)

2-2: Hydrophobic bismuth gel (primary average particle diameter: 12 nm)

2-3: hydrophilic bismuth gel (primary average particle diameter: 30 nm)

2-4: Hydrophilic gelatin gel (primary average particle diameter: 12 nm)

2-5: hydrophilic bismuth gel (primary average particle diameter: 40 nm)

About rust inhibitor

3-1: Carboxylic acid rust inhibitor ( Acid, HOOC(CH ₂ ) ₃₄ COOH)

3-2: ester-based rust inhibitor (sorbitan monooleate)

3-3: sulfonium sulfonate rust inhibitor (calcium sulfonate sulfonate)

3-4: Heterocyclic rust inhibitor A

(1-[N,N-bis(2-ethylhexyl)aminemethyl]benzotriazole)

3-5: Heterocyclic rust inhibitor B

[2,5-bis(alkyldithio)-1,3,4-thiadiazole]

These samples were judged according to the following test methods.

Exterior

After the preparation, the mixture was allowed to stand for 1 week, and the separation and precipitation of the gel were visually confirmed.

Rust test

The iron-based sintered oil-impregnated bearings (outer diameter 7 mm, inner diameter 3 mm, height 11.5 mm) of two impregnated samples were placed in a Φ30 petri dish containing 4 ml of tap water, and allowed to stand at room temperature for 100 hours. After 100 hours, confirm the bearing rust.

The test results of Examples 1 to 16 are shown in Tables 1 to 3, and the test results of Comparative Examples 1 to 5 are shown in Table 4. In addition, Figures 1 and 2 show photographs of petri dishes with tap water and bearings after 100 hours of rust test.

In the polyfluorene-based lubricating oil composition of the present invention, for each of the samples of Examples 1 to 16, no antimony gel and rust preventive agent were separated from the polyfluorene oxide oil, and no precipitation was observed, and no rust test was found. Rusty. That is, as shown in Figure 1, with a dip The sintered oil-impregnated bearing of the polyfluorene-based lubricating oil composition of the present invention and the petri dish of the tap water, the sintered oil-impregnated bearing is not rusted, and the tap water contained in the petri dish does not contain rust and remains transparent.

In contrast, in Comparative Example 1, since the sintered oil-impregnated bearing of only the immersed polyoxygenated oil was used, the rust-preventing force was weak, and the rust-impregnated bearing was rusted during the rust test, so that the tap water contained in the petri dish was turbid (ie, FIG. 2) Show black). In Comparative Example 2, no ruthenium gel was added to the polyfluorene oxide, and only a rust preventive agent was added. Therefore, the rust preventive agent was separated and precipitated from the polyfluorene oxide oil, and the bearing was rusted in the rust test, and the rust of the bearing was made to the petri dish. The water is turbid (ie blackened as shown in Figure 2). In Comparative Example 3, the amount of the ruthenium gel added to the polyoxygenated oil was slightly excessive, and the rust preventive agent was separated and precipitated from the polyfluorene oxide oil. In the rust preventive test, the bearing was rusted, and the rust of the bearing was used to supply the petri dish with tap water. Turbid (ie blackened as shown in Figure 2). Therefore, Fig. 2 shows photographs of Comparative Examples 1 to 3 after 100 hours of the rust test, and rust caused the test tap water to become black and turbid.

In Comparative Example 4 which is not shown in the drawing, since the amount of the cerium gel added to the polyoxygenated oil is too large, the lubricating oil becomes a grease, and the lubricating oil fluidity is lost. Further, in Comparative Example 5, since the particle size of the ruthenium gel was too large, the dispersion stability of the ruthenium gel in the polyxanthene oil was poor, and the ruthenium gel and the rust preventive agent precipitated, and it was impossible to immerse in the bearing.

From the test results of the above Examples 1 to 16 and Comparative Examples 1 to 5, it is understood that the polyfluorene-based lubricating oil composition of the present invention is 90.0 to 99.4% by mass based on the polyoxygenated oil, and the mixed gel is 0.1 to 5.0. The mass%, and the rust inhibitor 0.5~5.0% by mass, can improve the rust resistance of the lubricating oil, and is the best compounding ratio.

Fig. 1 is a photograph of the immersion test of each of the examples in which the bearing of the polyfluorene-based lubricating oil composition of the present invention was immersed in tap water for 100 hours, showing that the bearings were not rusted, and the test tap water was in a transparent state; The photographs of Comparative Examples 1 to 3, which do not contain a predetermined amount of rust inhibitor and/or ruthenium gel, are impregnated with the bearing and immersed in tap water for rust test, showing that the bearings are rusted, so that the test tap water is black and turbid. status.

Claims (6)

A polyfluorene-based lubricating oil composition characterized in that it comprises 90.0-99.4% by mass of a polyoxygenated oil having an kinetic viscosity of 20 to 1000 mm ² /s at 25 ° C, and is selected from the group consisting of tannins having an average particle diameter of 30 nm or less. One or a mixture of two or more of the groups is 0.1 to 5.0% by mass, and one or a mixture of two or more selected from the group of rust inhibitors is 0.5 to 5.0% by mass. The polyfluorene-based lubricating oil composition according to claim 1, wherein the polyoxyxene oil is selected from the group consisting of dimethyl polyphthalic acid oil, phenylmethyl polyfluorene oxide oil, or modified polyoxygenated oil. Group of people. The polyfluorene-based lubricating oil composition according to claim 1, wherein the cerium gel is a hydrophobic cerium gel whose surface is modified with an organic group, or a hydrophilic cerium gel having a stanol group on the surface. The polyfluorene-based lubricating oil composition according to claim 1, wherein the rust preventive agent is a sulfonium sulfonate, a carboxylic acid, an ester, or a compound having a heterocyclic ring in the molecule. For example, the polyfluorene-based lubricating oil composition of claim 1 is used for a sintered oil-impregnated bearing. A sintered oil-impregnated bearing characterized by being immersed in the polyfluorene-based lubricating oil composition according to any one of the above claims.