JP2005036212A - Lubricant composition for rolling device and rolling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant composition for rolling devices that is hard to be degraded, has its performance hard to be lowered, and hardly corrodes the rolling devices, and also to provide a long-life rolling device with excellent lubricating properties. <P>SOLUTION: In this rolling device, a lubricant composition 15 containing microcapsules that encapsulate an additive is supplied into the inside of a cylindrical roller bearing, and lubrication is performed between two orbit surfaces 10a and 11a, and a roller 12. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lubricant composition suitable for a rolling device, and more particularly to a lubricating oil or grease. The present invention also relates to a rolling device such as a rolling bearing, a linear guide device, a ball screw, and a linear motion bearing.

In rolling bearing lubrication, the coefficient of friction between the two contacting metal surfaces varies depending on the absolute viscosity of the lubricating oil used, the bearing load, and the rotational speed. That is, in a completely lubricated state in which a thick oil film is formed between the friction surfaces, the contact between the two metal surfaces hardly occurs, so the friction coefficient is extremely small.
However, in a mixed lubrication state in which metal-metal contact is partially generated or in an environmental lubrication state in which the oil film is broken and metal-metal contact occurs, damage such as seizure may occur on the friction surface. In order to prevent such damage, additives such as an extreme pressure agent and an antiwear agent are added to the lubricant.

By the way, the contact portion between the two metal surfaces has a high temperature and high surface pressure, and is in a highly reactive state. Therefore, an additive (for example, an organic compound containing chlorine, sulfur, phosphorus, etc., such as chlorinated paraffin, dibenzyl sulfide, tricresyl phosphate, etc.) in the lubricant supplied to the contact portion is easily combined with a metal. In response to this, a metal chloride, a metal sulfur compound, a metal phosphorus compound, or the like is generated at the contact portion. And this metal compound suppresses that a seizure and abrasion arise in the said contact part.
JP 7-233362 A JP 2001-234188 A Japanese Patent No. 2969700

However, extreme pressure agents, friction modifiers, and anti-wear agents are generally compounds with strong chemical activity, so when added directly to lubricating oil or grease, especially when used for a long period of time, There was a risk of causing such inconvenience.
(1) Promote deterioration of lubricating oil and grease base oil (2) React with other additives added to lubricating oil and grease (3) Rolling bearing components (bearing rings, rolling elements, holding) (4) In grease, the grease is softened or hardened due to the interaction with the thickener. (5) When chemically active additives come into contact with air or base oil Since the chemical reaction is likely to occur, the effect of the additive is reduced when the lubricant is used. (6) When two or more additives are used in combination, the additives react with each other, and when the lubricant is used. The effect of the additive is reduced

  These inconveniences are caused by the strong chemical activity of the extreme pressure agent. Conversely, if the chemical activity is weak, the effect as the extreme pressure agent is also weakened. Therefore, when extreme pressure performance is important, it is necessary to replace the lubricant frequently, and when long-term maintenance-free use is desired, the number of rolling bearings is increased or the size is increased. Needs arise and all measures are costly.

On the other hand, a method of providing a chemical reaction film in advance on the raceway surface or rolling element surface of a rolling bearing has been proposed in order to prevent the above-described inconvenience (see Patent Document 3), but a rolling bearing is manufactured. There is a problem that the number of man-hours required to increase the cost increases. Further, when the chemical reaction film is damaged by using the rolling bearing, there is a problem that the entire rolling bearing needs to be replaced.
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems of the prior art, and to provide a lubricant composition for a rolling device that is unlikely to deteriorate or deteriorate in performance and that hardly corrodes the rolling device. . Another object is to provide a long-life rolling device with excellent lubricity.

In order to solve the above problems, the present invention has the following configuration. That is, the lubricant composition for a rolling device according to claim 1 according to the present invention is a lubricant composition for a rolling device containing a base oil and an additive, and at least a part of the additive includes: It is contained in a microcapsule having a particle size of 0.01 to 5 μm, and the amount of the microcapsule is 0.1 to 50% by mass of the whole composition.
The rolling device lubricant composition of claim 2 according to the present invention is the rolling device lubricant composition of claim 1, wherein the microcapsule contains the additive. Is included.

  In the lubricant composition for a rolling device according to claim 1, the microcapsule containing the additive is contained in the lubricant composition for the rolling device, and the lubricant composition for rolling device according to claim 2, Microcapsules enclosing a lubricant to which an additive has been added are contained in the lubricant composition for a rolling device. As described above, the lubricant composition for a rolling device according to the present invention includes other substances (base oil, thickener, other additives, and configuration of the rolling device) in which the additive is isolated in the microcapsule. (1) to (6) are less likely to occur.

Moreover, since the microcapsule is physically destroyed in the load zone of the rolling device, the contained additive is reliably supplied to the load zone. In the state where an oil film having a thickness equal to or larger than the particle size of the microcapsules is formed in the load zone, the microcapsules are not broken, so that no excessive additive is released.
The particle size of the microcapsules needs to be 0.01 to 5 μm. If it exceeds 5 μm, it may act as a foreign substance on the rolling device. In addition, it is often difficult to stably disperse in the lubricant composition, or the microcapsules are destroyed at sites other than the load zone of the rolling device (the contact portion between the raceway surface and the rolling element). Increases the release of substances. Furthermore, in the case of the lubricating oil used in the circulating oil supply system, there is a risk of adversely affecting the filtration device.

On the other hand, if the particle size is less than 0.01 μm, there is a high possibility that the microcapsules will not be broken even in the load zone of the rolling device, so that the additive effect may be insufficient.
Moreover, the compounding quantity of a microcapsule needs to be 0.1-50 mass% of the whole lubricant composition for rolling devices. If the amount is less than 0.1% by mass, the number of microcapsules that reach the load zone decreases, so that the additive effect may be insufficient. On the other hand, if it exceeds 50% by mass, the number of microcapsules destroyed in the load zone becomes excessive, so that the above disadvantages (1) to (6) are likely to occur.

Furthermore, the lubricant composition for a rolling device according to a third aspect of the present invention is the lubricant composition for a rolling device according to the first or second aspect, wherein the lubricant composition is a liquid lubricant, and the base The kinematic viscosity at 40 ° C. of the oil is 1-1500 mm ² / s.
When the lubricant composition for a rolling device of the present invention is a liquid lubricant, the base oil preferably has a kinematic viscosity at 40 ° C. of 1 to 1500 mm ² / s. If it is less than 1 mm ² / s, evaporation or the like increases, so that the wear of the lubricating oil is large, and if it exceeds 1500 mm ² / s, the shear resistance of the base oil becomes too large, making it unsuitable for a rolling device.

Furthermore, the lubricant composition for a rolling device according to claim 4 according to the present invention is the lubricant composition for a rolling device according to claim 1 or 2, wherein the blending degree is 150 to 400. It is a solid grease, and the base oil has a kinematic viscosity at 40 ° C. of 15 to 1500 mm ² / s.
When the lubricant composition for a rolling device of the present invention is a semi-solid grease, it is preferable that the grease has a blending degree of 150 to 400, and the base oil has a kinematic viscosity at 40 ° C. of 15 to 1500 mm. ² / s is preferable.

In the case of grease, it is often heated during the manufacturing process, and since it is rarely supplied continuously during use, a certain degree of heat resistance is required. Therefore, the kinematic viscosity at 40 ° C. of the base oil is preferably 15 mm ² / s or more. However, if it exceeds 1500 mm ² / s, the shear resistance of the base oil becomes too large, which is not suitable for a rolling device.
On the other hand, if the penetration is less than 150, the grease is too hard and the fluidity is poor. If the fluidity is inferior, the grease does not reach the place where the grease is required, so the microcapsule does not reach the place and the effect of adding the additive becomes insufficient. On the other hand, when the blending degree exceeds 400, the fluidity becomes excessive, so that grease leaks from a necessary portion, and the additive effect of the additive becomes insufficient.

  In addition, when the lubricant composition for rolling devices is grease, it is preferable to enclose the lubricating oil containing an additive in a microcapsule. In the case of grease lubrication, the supply of base oil itself to the load zone is likely to be insufficient compared to the case of oil lubrication, and damage may occur early in the load zone. Therefore, if the base oil component is encapsulated in the microcapsule, the base oil can be supplied to the load zone, so that damage can be suppressed.

Furthermore, the lubricant composition for rolling devices of Claim 5 which concerns on this invention is a lubricant composition for rolling devices in any one of Claims 1-4, The said additive contains sulfur. It is at least one of an extreme pressure agent composed of a compound, an extreme pressure agent composed of a compound containing phosphorus, and an extreme pressure agent composed of a compound containing halogen.
Such extreme pressure agents are particularly strong in chemical activity, so the disadvantages (1) to (6) described above are more likely to occur among various additives. Inconvenience is suppressed.

Furthermore, the lubricant composition for a rolling device according to claim 6 of the present invention is the lubricant composition for a rolling device according to any one of claims 1 to 5, wherein the ratio of the inclusion substance in the microcapsule Is characterized by being 10 to 98% by mass.
If the ratio of the inclusion substance (additive or lubricant containing the additive) is less than 10% by mass, the ratio of the inclusion substance is too low to obtain the expected effect (addition effect of the additive, etc.) on the inclusion substance. It's hard to be done. On the other hand, if it exceeds 98% by mass, the outer shell of the microcapsule becomes relatively thin, and therefore the microcapsule may be destroyed when the lubricant composition for a rolling device containing the microcapsule is produced. In order to make such inconvenience less likely to occur, the ratio of the inclusion substance in the microcapsule is more preferably 20 to 98% by mass.

Furthermore, the lubricant composition for a rolling device according to claim 7 according to the present invention is the lubricant composition for a rolling device according to any one of claims 1 to 6, wherein the microcapsule is composed of a resin composition. It is characterized by being.
Furthermore, the rolling device according to claim 8 of the present invention includes an inner member having a raceway surface on the outer surface, and a raceway surface facing the raceway surface of the inner member, and is disposed outside the inner member. And a plurality of rolling elements arranged so as to be freely rollable between the both raceway surfaces, wherein lubrication between the raceway surfaces and the rolling elements is provided. It is performed with the lubricant composition for rolling devices in any one of claim | item 1 -7.
Such a rolling device is excellent in lubricity and has a long life because it is lubricated with a lubricant composition that is unlikely to deteriorate or deteriorate in performance and corrodes the rolling device.

Furthermore, a rolling device according to a ninth aspect of the present invention is the rolling device according to the eighth aspect, wherein the rolling device is a rolling bearing.
In addition, this invention is applicable not only to a rolling bearing but to various rolling devices, such as a linear guide apparatus, a ball screw, and a linear motion bearing.
Here, in the present invention, the inner member means an inner ring when the rolling device is a rolling bearing, a screw shaft when the ball screw is also used, a guide rail when the linear guide device is used, and a linear bearing. In the case of, each means an axis. The outer member is an outer ring when the rolling device is a rolling bearing, a nut when it is a ball screw, a slider when it is a linear guide device, and an outer cylinder when it is also a linear bearing. Means each.

  Since the lubricant composition for a rolling device of the present invention contains the additive contained in the microcapsule, the rolling device is less likely to be deteriorated or deteriorated in performance and hardly corroded. Moreover, since the rolling device of this invention is equipped with the lubricant composition for rolling devices which is hard to produce deterioration and a performance fall and to be hard to corrode a rolling device, it is excellent in lubricity and is long life.

DESCRIPTION OF EMBODIMENTS Embodiments of a lubricant composition for a rolling device and a rolling device according to the present invention will be described in detail with reference to the longitudinal sectional view of FIG.
1 is a cylindrical roller bearing (inner diameter: 25 mm, outer diameter: 52 mm) manufactured by NSK Ltd., and an inner ring 10 having a raceway surface 10a on the outer peripheral surface and a raceway surface 11a facing the raceway surface 10a are arranged on the inner periphery. An outer ring 11 on the surface, a plurality of rollers 12 disposed between the raceway surfaces 10a and 11a so as to be freely rotatable, and a cage 13 for holding the plurality of rollers 12 between the inner ring 10 and the outer ring 11, It consists of

  Further, a lubricant composition 15 is supplied into a gap formed between the inner ring 10 and the outer ring 11 and provided with rollers 12, and lubrication between both the raceway surfaces 10a, 11a and 12 is performed. It is like that. When the lubricant composition 15 is a liquid lubricating oil, a lubricating method such as oil bath lubrication, jet lubrication, oil-air lubrication, oil mist lubrication, or plating can be applied to the lubrication form.

The lubricant composition 15 may be a liquid lubricating oil or a semi-solid grease. However, microcapsules having a particle size of 0.01 to 5 μm are used as 0% of the entire lubricant composition 15. .1 to 50% by mass.
The kinematic viscosity at 40 ° C. of the base oil of the lubricant composition 15 is 1-1500 mm ² / s when the lubricant composition 15 is a lubricant, and 15-1500 mm ² / s when the grease is a grease. Further, in the case of grease, the blending degree is 150 to 400.

  This microcapsule (see FIG. 2) contains an additive or a lubricant containing the additive (which may be a lubricating oil or a grease), and usually this inclusion substance. Is isolated in the microcapsule, but when the lubricant composition 15 reaches the load zone of the cylindrical roller bearing (contact portion with the raceway surfaces 10a, 11a and 12), the microcapsule is physically destroyed. Then, the inclusion substance is released, and the additive is supplied to the load zone. In addition, the ratio of the inclusion substance to a microcapsule is 10-98 mass%.

  Since the additive is a compound with high chemical activity, it may react with base oils, thickeners, and other additives and deteriorate, or it may react with air and lose its performance as an additive. is there. As a result, the performance of the lubricant composition 15 may be deteriorated. Further, the additive may corrode the constituent members (inner ring 10, outer ring 11, roller 12, and cage 13) of the cylindrical roller bearing.

In particular, an extreme pressure agent composed of a compound containing sulfur, an extreme pressure agent composed of a compound containing phosphorus, and an extreme pressure agent composed of a compound containing halogen are compounds having extremely high chemical activity. Such inconveniences are likely to occur.
However, if the additive is isolated in the microcapsule as in this embodiment, the above disadvantages are unlikely to occur, and the performance of the lubricant composition 15 is maintained over a long period of time. Excellent lubricity and long service life.

Below, the lubricant composition of this embodiment is demonstrated in detail.
[About microcapsules]
Although the material which comprises a microcapsule is not specifically limited, The resin composition containing resin, such as a thermoplastic resin and a thermosetting resin, is preferable. Specific examples include polyurethane resin compositions, polyester resin compositions, polyamide resin compositions, polyurea resin compositions, phenol resin compositions, polyvinyl alcohol resin compositions, melamine resin compositions, and polyethylene resins. Examples thereof include a resin composition, a polystyrene resin composition, cellulose, and gelatin.

The method for producing the microcapsule is not particularly limited, and is selected in consideration of the nature of the encapsulated substance, the nature of the material constituting the microcapsule, and the like. Specific examples include an interfacial polymerization method, an in situ polymerization method, a phase separation method, a liquid drying method, an orifice method, a spray drying method, an air suspension coating method, a hybridizer method, and the like.
In order to produce a microcapsule having a uniform particle size, it is preferable to appropriately adjust the production conditions of the microcapsule, but the microcapsule having a particle size distribution has a uniform particle size by a centrifugal separation method or a filter method. Microcapsules may be separated.

[About base oil]
The type of the base oil of the lubricant composition and the base oil of the lubricant encapsulated in the microcapsule is not particularly limited as long as it is a base oil generally used as a base oil of grease or lubricating oil. Can be used without problems.
Specific examples of the base oil include mineral oil, synthetic oil, and animal and vegetable oils. Mineral oil refined to a viscosity index of 100 or more by appropriately combining vacuum distillation, solvent removal, solvent extraction, hydrocracking, solvent dewaxing, sulfuric acid washing, clay refining, hydrorefining, etc. preferable. And what is called highly refined mineral oil refine | purified so that a viscosity index may be 120 or more is more preferable.

Synthetic oils include synthetic hydrocarbon oils, ester oils, ether oils, silicone oils, fluorine oils and the like.
Examples of the synthetic hydrocarbon oil include poly α-olefins such as normal paraffin, isoparaffin, polybutene, polyisobutylene, 1-decene oligomer, 1-decene and ethylene co-oligomer, and hydrides thereof. Further, alkylbenzenes such as monoalkylbenzene, dialkylbenzene, and polyalkylbenzene, and alkylnaphthalenes such as monoalkylnaphthalene, dialkylnaphthalene, and polyalkylnaphthalene are also included.

  Examples of ester oils include dibutyl sebacate, di (2-ethylhexyl) sebacate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, ditridecyl glutarate, and methyl acetyl ricinolate, trioctyl trimellitate, trioctyl trimellate. Aromatic ester oils such as decyl trimellitate and tetraoctyl pyromellitate, polyol ester oils such as trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, and pentaerythritol pelargonate Examples thereof include complex ester oils, which are oligoesters of mixed fatty acids of basic and dibasic acids and polyhydric alcohols.

  Further, as ether oils, polyglycols such as polyethylene glycol, polypropylene glycol, polyethylene glycol monoether, polypropylene glycol monoether, monoalkyl triphenyl ether, alkyl diphenyl ether, dialkyl diphenyl ether, tetraphenyl ether, pentaphenyl ether, monoalkyl tetra Examples thereof include phenyl ether oils such as phenyl ether and dialkyl tetraphenyl ether. In view of heat resistance, a thioether ether oil is also suitable. Examples thereof include (di) alkyl diphenyl thioether oil, (di) alkyl polyphenyl thioether oil, tetraphenyl thioether oil, and pentaphenyl thioether oil.

Synthetic oils other than the above include tricresyl phosphate, perfluoroalkyl ether oil and the like.
Examples of animal and vegetable oils include beef tallow, pork tallow, soybean oil, rapeseed oil, rice bran oil, coconut oil, palm oil, palm kernel oil, and other oils or hydrides thereof.
These base oils may be used alone or in combination of two or more.

[About thickener]
If the lubricant composition is grease, it is necessary to use a thickener. The type of the thickener is not particularly limited, and can be appropriately selected depending on the application and use conditions.
For example, metal soap (metal is aluminum, barium, calcium, lithium, sodium, etc.) and metal composite soap (metal is lithium, calcium, aluminum, etc.) can be mentioned. Urea compounds (diurea, triurea, tetraurea, polyurea, etc.), inorganic compounds (silica gel, bentonite, etc.), urethane compounds, urea / urethane compounds, sodium terephthalamate compounds, fluororesins, and the like can also be used.

[About extreme pressure agents]
The type of extreme pressure agent included in the microcapsule is not particularly limited, but (a) an extreme pressure agent composed of a compound containing sulfur, (b) an extreme pressure agent composed of a compound containing phosphorus, (c It is preferably at least one of extreme pressure agents composed of a halogen-containing compound.
Examples of the extreme pressure agent (a) include sulfurized oils and fats such as sulfurized whale oil, organic sulfur compounds such as sulfurized olefins, mercaptans, sulfides, sulfoxides, sulfones, dithiocarbamic acid and dithiophosphonic acid. Among these, sulfurized olefins, mercaptans, sulfides, sulfoxides, sulfones, dithiocarbamic acid, and dithiophosphonic acid are more preferable.

The sulfurized olefins are, for example, olefins having 2 to 8 carbon atoms or low molecular weight polyolefin sulfides derived therefrom, and sulfurized pentene, sulfurized butylene, sulfurized octene and the like are preferable.
Mercaptans are, for example, alkyl mercaptans and mercapto fatty acid esters having 4 to 20 carbon atoms, and include n-butyl mercaptan, isobutyl mercaptan, tertiary butyl mercaptan, n-octyl mercaptan, tertiary nonyl mercaptan, tertiary dodecyl mercaptan, thiol. Preferred are butyl glycolate, ethyl thiopropionate, octyl 3-mercaptopropionate, and the like.

  Examples of the sulfides include monosulfide (-S-), disulfide (-S-S-), polysulfide (-) of hydrocarbons having 4 to 18 carbon atoms (for example, alkyl, phenyl, benzyl, cinnamyl, allyl). S-SS-), and dibutyl monosulfide, dibutyl disulfide, diphenyl sulfide, dibenzyl sulfide and the like are preferable.

The sulfoxides are, for example, sulfoxides of hydrocarbons having 4 to 20 carbon atoms (for example, alkyl, phenyl, benzyl, cinnamyl, allyl), and dibutyl sulfoxide, dibenzyl sulfoxide and the like are preferable.
The sulfones are, for example, sulfones of hydrocarbons having 4 to 20 carbon atoms (eg, alkyl, phenyl, benzyl, cinnamyl, allyl), and dibutyl sulfone, didodecyl sulfone, phenyl sulfone and the like are preferable.

Examples of dithiophosphoric acid and dithiophosphonic acid include metal compounds such as metal dihydrocarbyl dithiophosphates and metal dihydrocarbyl dithiocarbamates.
Metal dihydrocarbyl dithiophosphates are metal dihydrocarbyl dithiophosphates in which each hydrocarbyl group is a hydrocarbon having 4 to 20 carbon atoms, such as zinc dimethyl dithiophosphate, zinc butyl isooctyl dithiophosphate, and zinc dithiophosphate. (4-methyl-2-pentyl) dithiophosphate, zinc di (tetrapropenylphenyl) dithiophosphate, zinc (2-ethyl-1-hexyl) dithiophosphate, zinc (isooctyl) dithiophosphate, zinc (ethylphenyl) ) Dithiophosphate, zinc (amyl) dithiophosphate, zinc di (hexyl) dithiophosphate and the like.

The metal of the metal dihydrocarbyl dithiophosphate is preferably zinc (Zn), lead (Pb), cadmium (Cd), antimony (Sb), molybdenum (Mo), nickel (Ni), bismuth (Bi) or the like. .
Metal dihydrocarbyl dithiocarbamates are metal dihydrocarbyl dithiocarbamates in which each hydrocarbyl group is a hydrocarbon having 4 to 20 carbon atoms, such as zinc dimethyldithiocarbamate, zinc butylisooctyl dithiocarbamate, zinc di (4-methyl). -2-pentyl) dithiocarbamate, zinc di (tetrapropenylphenyl) dithiocarbamate, zinc (2-ethyl-1-hexyl) dithiocarbamate, zinc (isooctyl) dithiocarbamate, zinc (ethylphenyl) dithiocarbamate, zinc (amyl) Examples include dithiocarbamate and zinc di (hexyl) dithiocarbamate.

The metal of the metal dihydrocarbyl dithiocarbamate is preferably zinc (Zn), lead (Pb), cadmium (Cd), antimony (Sb), molybdenum (Mo) or the like.
Examples of the extreme pressure agent (b) include phosphorus compounds such as phosphate esters, phosphites, orthophosphoric acids, acidic phosphate esters, dithiophosphates, and among these, phosphites , Orthophosphates, acidic phosphates and the like are preferred.

  Phosphites are, for example, phosphites of hydrocarbons having 1 to 18 carbon atoms (for example, alkyl, phenyl, benzyl, cresyl, cinnamyl, allyl), trioctyl phosphite, triphenyl phosphite. , Tricrane phosphite, bis-2-ethylhexyl phosphite, tridecyl phosphite, dibutyl hydrogen phosphite, tris (nonylphenyl) phosphite, dilauryl hydrogen phosphite, diphenyl monodecyl phosphite, trilauryl trithiophos Phyto, diphenyl hydrogen phosphite and the like are preferable.

  The orthophosphate esters are, for example, orthophosphate esters of hydrocarbons having 1 to 18 carbon atoms (eg, alkyl, phenyl, benzyl, cresyl, cinnamyl, allyl), triphenyl phosphate, triethyl phosphate, Tributyl phosphate, tris (2-ethylhexyl) phosphate, tridecyl phosphate, diphenyl mono (2-ethylhexyl) phosphate, tricresyl phosphate, trioctyl phosphate, tristearyl phosphate and the like are preferable.

Examples of the acid phosphate esters include mono- or dihydrocarbyl acid phosphates having 1 to 20 carbon atoms, such as methyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, 2-ethylhexyl acid phosphate, and isodecyl acid. Phosphate, tridecyl acid phosphate, lauryl acid phosphate and the like are preferable.
Examples of the extreme pressure agent (c) include organic halogen compounds, and among them, organic chlorine compounds such as chlorinated paraffins and chlorinated oils and fats are preferable. Examples of chlorinated paraffins include n-octyl chloride, paraffin chloride, and octadecyl chloride. Examples of chlorinated fats and oils include chlorinated whale oil.

[Other additives]
The lubricant composition for a rolling device is not limited to an extreme pressure agent, and various additives generally used for lubricants can be used (the lubricant composition for a rolling device enclosed in a microcapsule). It may be added to the product or may be added directly without being encapsulated in the microcapsule). In particular, antioxidants, rust inhibitors, and metal corrosion inhibitors are preferred. Further, if necessary, an antifoaming agent, a colorant, a solid lubricant, a pour point depressant, a viscosity index improver, a cleaning dispersant and the like may be used. These additives may be used alone or in appropriate combination of two or more.

  Examples of the antioxidant include amine-based antioxidants, phenol-based antioxidants, dialkyldithiocarbamate compounds, and the like. Specific examples of the amine antioxidant include phenyl-α-naphthylamine, alkylated phenyl-α-naphthylamine, alkyldiphenylamine, diphenyl-p-phenylenediamine, dipyridylamine, phenothiazine, N-methylphenothiazine, N-ethylphenothiazine, 3,7-dioctylphenothiazine, p, p'-dioctyldiphenylamine, N, N'-di-2-naphthyl-p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, N, N'-diisopropyl- Examples include p-phenylenediamine, N, N′-di-sec-butyl-p-phenylenediamine, and the like. Of these, phenyl-α-naphthylamine is particularly preferred.

Specific examples of the phenolic antioxidant include 2,6-di-tert-dibutylphenol and di-tert-butylcresol. Among these, 2,6-di-tert-dibutylphenol is particularly preferable.
Specific examples of dialkyldithiocarbamate compounds include zinc dialkyldithiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, sodium dibutyldithiocarbamate, diethyldithiocarbamine. Examples thereof include nickel oxide, nickel dibutyldithiocarbamate, copper dimethyldithiocarbamate, iron diethyldithiocarbamate, selenium diethyldithiocarbamate, telenium diethyldithiocarbamate, and zinc butylxanthate. Of these, zinc dialkyldithiocarbamate is particularly preferred.

Specific examples of the rust inhibitor include alkenyl succinic acid derivatives, sulfonates, sorbitan monooleate and the like.
Furthermore, specific examples of the metal corrosion inhibitor include benzotriazole and derivatives thereof, and specific examples of the oiliness improver include fatty acids such as oleic acid and aliphatic alcohols such as oleyl alcohol. Furthermore, specific examples of the solid lubricant include graphite, molybdenum disulfide, and polytetrafluoroethylene (PTFE), and specific examples of the viscosity index improver include polymethacrylate and polyisobutylene.

In addition, this embodiment shows an example of this invention and this invention is not limited to this embodiment.
For example, in this embodiment, a cylindrical roller bearing has been described as an example of a rolling device, but the present invention can be applied to various types of other rolling bearings. For example, radial rolling bearings such as deep groove ball bearings, angular contact ball bearings, self-aligning ball bearings, tapered roller bearings, needle roller bearings, and self-aligning roller bearings, and thrust types such as thrust ball bearings and thrust roller bearings This is a rolling bearing.

The present invention can be applied not only to rolling bearings but also to various other types of rolling devices. For example, a ball screw, a linear guide device, a linear motion bearing, or the like.
Furthermore, the microcapsules added to the lubricant composition are not limited to those containing an extreme pressure agent, and may be those containing other additives (antioxidants and the like) described above. Furthermore, it may include a powder such as titanium oxide (TiO ₂ ). In this way, necessary and sufficient additives can be supplied to the load zone, so even if there is little movement of the base oil or grease present in the load zone as in the case of grease lubrication, the necessary additives are supplied to the load zone. it can. Moreover, it is good to use the microcapsule which includes a metal deactivator for the rolling device comprised with the material which is easy to corrode, such as copper and aluminum.

  Alternatively, two or more kinds of microcapsules (microcapsules containing different kinds of additives) may be used in combination. If the additive is added directly to the lubricant composition without being encapsulated in the microcapsule, a different type of additive may cause a chemical reaction, resulting in a decrease in additive effect or precipitation over time. However, if different types of additives are encapsulated and separated in separate microcapsules, such inconveniences are unlikely to occur. Two or more kinds of microcapsules having different particle diameters and outer wall materials may be used in combination.

  Furthermore, the microcapsules are preferably such that they are physically destroyed when they reach the load zone. For example, the microcapsules may be sensitive to temperature and destroyed at a predetermined temperature. . When an antioxidant is encapsulated in such a microcapsule, the antioxidant can be supplied only at a temperature at which the lubricant composition may be oxidized and deteriorated. The microcapsules may be broken in response to light.

Furthermore, the microcapsules may be broken in response to hydrogen ion concentration, metal ion concentration, or a concentration of a specific chemical (eg, hydroperoxide). If an alkaline substance is encapsulated in such a microcapsule, neutralization can be performed by releasing the alkaline substance when the acidic substance has entered the lubricant composition.
Furthermore, when adding a microcapsule to base oil to make a lubricant composition, a dispersion stabilizer such as a surfactant may be used.

  Furthermore, the microcapsule may have pores that allow the void portion containing the additive to communicate with the outside. Then, the inclusion substance is gradually released from the pores. Therefore, the lubricant composition existing in a region other than the load zone gradually supplies the additive as described above, and the lubricant composition present in the load zone receives a large amount of additive due to the destruction of the microcapsules. Will be supplied.

  Further, the microcapsules may have a nested structure. The hierarchy of the nested structure is not particularly limited, but a double-structured microcapsule as shown in FIG. 3 is preferable. If two kinds of substances that cause an endothermic reaction when mixed are divided into an inner capsule and an outer capsule, and the inner capsule breaks at a lower temperature than the outer capsule, The capsules are broken and the two substances are mixed to cause an endothermic reaction inside the outer microcapsules. As a result, the temperature of the lubricant can be lowered.

  Further, various surface modification treatments may be applied to the surface of the microcapsule. For example, the surface of the microcapsule may be held with adsorptivity and non-adsorptivity to the raceway surface and the rolling surface of the rolling device. For example, when both a microcapsule having adsorptive properties and a microcapsule having non-adsorbing properties or weakly adsorbing properties are contained in the lubricant, the former is adsorbed on the raceway surface or rolling surface of the rolling device, and the latter is lubricated. Since it is dispersed in the agent, the lubricity of the lubricant is improved.

Hereinafter, the present invention will be described with reference to more specific examples.
[Example A]
A method for producing a microcapsule containing the additive will be described below. The additive is tridecyl acid phosphate which is an acidic phosphate ester, and the microcapsule is composed of a urethane elastomer synthesized from hexamethylene diisocyanate and pentaerythritol.

After mixing 1 part by mass of tridecyl acid phosphate, 1 part by mass of hexamethylene diisocyanate, and 10 parts by mass of pentaerythritol, the mixture was dispersed in pure water and heated to 60 ° C. The microcapsules thus obtained were separated and dispersed in ester oil (Kao Lube 268 manufactured by Kao Corporation, kinematic viscosity at 40 ° C. is 33 mm ² / s) to obtain a lubricating oil. In addition, the compounding quantity of a microcapsule is 3 mass% of the whole lubricating oil.

20 μL of the lubricating oil thus obtained was supplied into a cylindrical roller bearing having the same configuration as described above. The cylindrical roller bearing was evaluated for seizure resistance and the state of corrosion due to additives.
First, a method for evaluating seizure resistance will be described. A cylindrical roller bearing was loaded with a radial load of 2000 N and an axial load of 1000 N, and was rotated at a rotational speed of 3000 min ⁻¹ . The outer ring temperature was measured while gradually increasing the rotation speed, and the seizure resistance was evaluated based on the rotation speed when the outer ring temperature reached 160 ° C. (seizure).

Next, a method for evaluating the corrosion state will be described. The cylindrical roller bearing was left in an environment of temperature 70 ° C. and humidity 90% RH for 168 hours. And the rolling surface of the roller was observed visually and the degree of corrosion was evaluated by the number of corrosion marks.
These results are shown together in Table 1 together with the particle size of the microcapsules. As can be seen from Table 1, the seizure resistance of the cylindrical roller bearings of each example is higher than that of Comparative Example A2, which is an example using a lubricant composition not containing microcapsules (an example in which no additive is added). Excellent and no seizure occurred until high speed. And it was comparable as Comparative Example A3 which is an example using the lubricant composition added directly without encapsulating the additive in the microcapsule.
Further, in the cylindrical roller bearings of the respective examples, no corrosion marks were observed, whereas in Comparative Example A3, many corrosion marks were observed.

[Example B]
Next, a lubricating oil in which microcapsules encapsulating molybdenum dithiophosphate (MoDTP) as an additive is dispersed will be described. As the MoDTP, a cherry lube 300 manufactured by Asahi Denka Co., Ltd. was used. The microcapsules are made of a urethane-urea resin produced by an interfacial polymerization method. Further, the mass ratio of MoDTP in the entire microcapsule is 50%, and the average particle size of the microcapsule is 5 μm.
Such microcapsules were dispersed in a synthetic hydrocarbon oil (SHF-61 manufactured by ExxonMobil, kinematic viscosity at 40 ° C. of 30 mm ² / s) to obtain a lubricating oil. In addition, the compounding quantity of a microcapsule is 5 mass% of the whole lubricating oil.

  The lubricating oil thus obtained was subjected to a reciprocating frictional wear test. First, the reciprocating frictional wear test apparatus shown in FIG. 4 will be described. A mirror-polished flat plate 30 is placed on the test table 20, and a JIS G5 grade ball bearing steel ball 35 (manufactured by Tengu Steel Ball Manufacturing Co., Ltd.) is disposed on the flat plate 30. The ball bearing steel balls 35 are configured to reciprocate horizontally on the flat plate 30 by the cam 50 in a state where a vertical load is applied and pressed against the flat plate 30. The material of the flat plate 30 is bearing steel SUJ2, and the hardness is HRC62. The ball bearing steel ball 35 is made of bearing steel SUJ2 and has a diameter of 10 mm. Further, reference numeral 40 in FIG. 4 represents a heater, reference numeral 41 represents a thermocouple, and reference numeral 45 represents a load cell.

  In the reciprocating frictional wear test, 0.01 ml of the above-described lubricating oil was applied to the flat plate 30. The test conditions were a vertical load of 198 N, a reciprocating amplitude of 2 mm, a reciprocating frequency of 50 Hz, an ambient temperature of 50 ° C., and a test time of 10 minutes. And after completion | finish of a test, the abrasion depth of the flat plate 30 was measured and the wear part was observed with an electron microscope (SEM), and the wear resistance of the lubricating oil was evaluated from these results. The results are shown in Table 2.

  In Example B1 using the above-described lubricating oil, the wear depth was as small as 0.1 μm, and the surface state of the flat plate 30 observed by SEM was almost the same as that before the test. By encapsulating a relatively strong extreme pressure agent such as MoDTP in the microcapsule, the additive can be supplied to the wear surface in a necessary amount, so it is considered that the deterioration of the surface condition due to the additive was small.

On the other hand, Comparative Example B1 using the lubricating oil added directly without encapsulating the additive in the microcapsule (the additive content is 2.5% by mass of the whole lubricating oil) has a wear depth. Was about the same as Example B1, but the surface condition was worse. This is probably because the surface condition deteriorated although the wear depth was small because the supply of the extreme pressure agent to the wear surface was excessive.
In addition, Comparative Example B2 using a microcapsule and a lubricating oil containing no additive had a large wear depth of 0.5 μm.

[Example C]
Next, a lubricating oil in which microcapsules containing an antioxidant as an additive are dispersed will be described.
The effect of the antioxidant is remarkably superior when the antioxidant is added in the microcapsule rather than directly added to the lubricant. In particular, the antioxidant is preferably at least one of an amine-based antioxidant, a phenol-based antioxidant, and a dialkyldithiocarbamate compound. Further, it is preferable that 20% by mass or more and 95% by mass or less of the antioxidant in the lubricant is contained in a state of being encapsulated in the microcapsule. More preferably, they are 30 mass% or more and 70 mass% or less.

Below, the manufacturing method of the microcapsule which encloses antioxidant is shown. In 40 parts by mass of the base oil, 60 parts by mass of the antioxidant was dissolved, and further 80 parts by mass of the isocyanate was dissolved. The hydrophobic liquid thus obtained was added to a hydrophilic liquid obtained by dissolving 9 parts by mass of polyvinyl alcohol in 900 parts by mass of water, and emulsified by stirring at 8000 min ⁻¹ . To this emulsion, 35 parts by mass of trimethylolpropane, which is a polyhydric alcohol, was added with stirring, and the temperature was raised to 60 ° C. Then, 10 parts by mass of methylenebischloroaniline as a crosslinking agent was added and reacted for 30 minutes. The obtained reaction solution was put into a centrifuge to separate microcapsules containing an antioxidant, followed by washing with water and drying. The average particle size of the microcapsules was 1 μm.

The microcapsules thus obtained are dispersed in a grease containing ester oil (Kao Lube 268 manufactured by Kao Corporation, kinematic viscosity at 40 ° C. is 33 mm ² / s) and lithium 12-hydroxystearate, and a lubricant. Got. The content of the antioxidant in the lubricant is 4% by mass, and in the case of Examples C1 to C3, 2% by mass of the half is contained in the lubricant in the state of being encapsulated in the microcapsule, and the rest 2% by mass of is directly added to the lubricant. In Examples C4 to C6, the entire amount is contained in a state of being encapsulated in microcapsules. In the case of Comparative Examples C2 to C4, the entire amount is added directly. About 50% of the mass of one microcapsule is the outer wall and about 50% is the inclusion substance, so that the antioxidant added in the state of being encapsulated in the microcapsule has the aforementioned value. The microcapsules were added to the lubricant.

In addition, as an antioxidant, phenyl-α-naphthylamine (a reagent manufactured by Tokyo Chemical Industry Co., Ltd.), 2,6-di-tert-dibutylphenol, or zinc dialkyldithiocarbamate (vanrubbe AZ manufactured by vanderbilt) was used. .
About such lubricant (grease), the heat deterioration property (oxidation deterioration property) showing the addition effect of antioxidant was evaluated. First, in order to cause oxidative degradation in the lubricant, a predetermined heat treatment was performed. The base oil was extracted with petroleum ether from the lubricant after the heat treatment, the total acid value and the viscosity thereof were measured, and the heat deterioration property (oxidation deterioration property) was evaluated based on the difference from both characteristic values before the heat treatment.

  The total acid value was measured by the method defined in JIS K2501. And the difference of the total acid value before and behind heat processing was calculated | required. The results are shown in Table 3. The total acid value is a relative value when the difference between the total acid values before and after the heat treatment in Comparative Example 1 is 1, and in Table 3, when the relative value is less than 0.1, ◎, The case of 1 or more and less than 0.3 is indicated by ◯, the case of 0.3 or more and less than 0.5 is indicated by Δ, and the case of 0.5 or more is indicated by ×.

  Further, the viscosity (viscosity at 40 ° C.) was measured by the method defined in JIS K2283. And the difference of the viscosity before and behind heat processing was calculated | required. The results are shown in Table 3. The viscosity is a relative value when the difference in viscosity before and after the heat treatment in Comparative Example 1 is 1, and in Table 3, when the relative value is less than 0.1, ◎, 0.1 or more and 0.1. The case of less than 3 is indicated by ◯, the case of 0.3 or more and less than 0.5 is indicated by Δ, and the case of 0.5 or more is indicated by ×.

As can be seen from Table 3, the lubricants of Examples C1 to C6 were less susceptible to heat deterioration (oxidation deterioration) than the lubricants of Comparative Examples C1 to C4.
Next, in the lubricant of Example C1, the content of the total antioxidant in the lubricant was fixed to 4% by mass and added directly with the antioxidant contained in the microcapsule. What changed the ratio with the antioxidant which is variously prepared was prepared, and the difference of the total acid value before and behind heat processing was calculated | required similarly to the above-mentioned. The results are shown in the graph of FIG. The difference between the total acid values before and after the heat treatment in the graph of FIG. 5 is shown as a relative value when the difference between the total acid values before and after the heat treatment in Comparative Example C1 is 1.

  From this graph, it can be seen that it is preferable to contain 30% by mass or more and 70% by mass or less of the total antioxidant contained in the lubricant in a state of being encapsulated in microcapsules. This is because the microcapsule itself has heat resistance, so that the microcapsule is gradually destroyed and the antioxidant is released, and as a result, the effect of the antioxidant is fully exhibited. It is thought that. However, about 20 to 30% by mass is preferably added directly to the lubricant.

Example D
An example of a method for producing an adsorbent microcapsule is shown below. What melt | dissolved 20 mass parts of polyvinyl alcohol in 250 mass parts of water and what disperse | distributed 1 mass part of pyromellitic dianhydride to 10 mass parts of MoDTP were mixed. While stirring at a rotational speed of 3000 min ⁻¹ , 1 part by mass of phenylenediamine was gradually added to the mixture and heated to 90 ° C. And it stirred for further 4 hours. Then, when it dried under reduced pressure, the adsorptive microcapsule which was comprised with the polyimide resin and included MoDTP was obtained. Next, an example of a method for producing non-adsorbing microcapsules will be described below. MoDTP was added to low molecular weight polyethylene melted at 140 ° C., and the emulsion was prepared by stirring while keeping the temperature at 130 ° C. The emulsion was sprayed with a two-fluid nozzle atomizer and coagulated and granulated to obtain a non-adsorbing microcapsule composed of polyethylene and encapsulating MoDTP.

Example E
An example in which two or more kinds of microcapsules having different particle diameters and outer wall materials are used in combination will be described. Since the outer wall of a microcapsule is destroyed under certain conditions (physical energy such as load, thermal energy, or chemical reaction), a specific condition may occur when there is only one type of microcapsule contained in the lubricant. Almost all microcapsules can be destroyed. However, when two or more types of microcapsules having different particle sizes and outer wall materials are used in combination, the outer wall can be destroyed under a plurality of conditions, so that the microcapsules can be destroyed at a plurality of timings. it can. As a result, since the effect of the additive which is an inclusion substance can be maintained for a long time, the life of the rolling device can be further extended. For example, if two or more types of microcapsules with different hardness, heat resistance, etc., are used in combination, the surface pressure changes due to differences in the operating conditions of the rolling device, the temperature rises, the oil film thickness changes, etc. Microcapsules can be broken in stages. In addition, the inclusion substance to be included in each type of microcapsule may be the same or different.

  Below, the manufacturing method of 2 types of microcapsules (capsule A and capsule B) from which the material of an outer wall differs is shown, respectively. The additive is molybdenum dithiophosphate (Sakura Lube 300 manufactured by Asahi Denka Kogyo Co., Ltd.). The outer wall material is a urethane elastomer synthesized from hexamethylene diisocyanate and trimethylolpropane in the case of capsule A, and is synthesized from gelatin and gum arabic in the case of capsule B. Note that the capsule A composed of urethane elastomer has good heat resistance, but the capsule B composed of gelatin and gum arabic is slightly inferior in heat resistance.

  First, the manufacturing method of the capsule A will be described. A solution in which 80 parts by mass of hexamethylene diisocyanate was dissolved in 100 parts by mass of molybdenum dithiophosphate and a solution in which 9 parts by mass of polyvinyl alcohol was dissolved in 900 parts by mass of pure water were mixed and emulsified by stirring. To this emulsion, 35 parts by mass of trimethylolpropane, which is a polyhydric alcohol, was added with stirring, and the temperature was raised to 60 ° C. Then, 10 parts by mass of 4,4′-methylenebis (2-chloroaniline) as a crosslinking agent was added and reacted for 30 minutes to obtain microcapsules.

  Next, a method for manufacturing the capsule B will be described. 30 parts by weight of a 10% by weight gelatin aqueous solution and 9 parts by weight of molybdenum dithiophosphate were heated to 40 ° C., mixed, stirred and emulsified. To this emulsion, 30 parts by mass of a 10% by mass aqueous gum arabic solution heated to 40 ° C. was added while stirring, and 140 parts by mass of pure water heated to 40 ° C. was gradually added. After adjusting the pH to 4 with a 10% by mass acetic acid aqueous solution, the liquid temperature was cooled to 10 ° C., and 3 parts by mass of a 50% by mass glutaraldehyde aqueous solution was added. And it adjusted to pH7 with 1 mol / L NaOH, and obtained the microcapsule.

The microcapsules thus obtained were separated and dispersed in a poly α-olefin oil (SHF 61, manufactured by Mobil, kinematic viscosity at 40 ° C. is 30 mm ² / s) to obtain a lubricating oil. In addition, the compounding quantity of the microcapsule (the total of the capsule A and the capsule B) is 3% by mass of the whole lubricating oil, and five kinds of lubricating oils having different ratios of the capsule A and the capsule B were prepared. The average particle size of the microcapsules is 1 μm for both capsule A and capsule B.

20 μL of the lubricating oil thus obtained was supplied into the cylindrical roller bearing in the same manner as in Example A. And about this cylindrical roller bearing, it carried out similarly to Example A, and evaluated the seizure resistance and the condition of the corrosion by an additive.
Table 4 shows the test results. As can be seen from Table 4, the cylindrical roller bearings of Examples E2 to E4 using the lubricating oil containing two types of microcapsules are the same as those of Examples E1 and E5 using the lubricating oil containing one type of microcapsule. Seizure resistance was superior to that of cylindrical roller bearings, and seizure hardly occurred.

[Example F]
If the metal deactivator is encapsulated in the microcapsule and added to the lubricant, the effect of preventing the deterioration of the acoustic performance is obtained even if the rust preventive oil enters the inside of the rolling device. When the rust preventive oil applied to the outer surface of the rolling device enters the inside of the rolling device and the rust preventive agent in the rust preventive oil and the metal deactivator in the lubricant are mixed, both May react to form crystals. And when this crystal | crystallization becomes a magnitude | size exceeding 2 micrometers, it will become a narrow thing and acoustic performance will deteriorate. However, if the metal deactivator in the lubricant is encapsulated in the microcapsule, the microcapsule is broken and the metal deactivator is supplied into the lubricant as the rolling device is driven. Such inconveniences are unlikely to occur.

  Below, the manufacturing method of the lubricant which disperse | distributed the microcapsule which includes a metal deactivator is demonstrated. To 50 parts by mass of water, 2 parts by mass of polyvinyl alcohol and 0.5 parts by mass of sodium dodecyl sulfate were added and dissolved, and further 20 parts by mass of oil-soluble benzotriazole as a metal deactivator was added and dissolved. By adding 35 parts by mass of an aqueous urea prepolymer solution (concentration: 20% by mass), a film was formed on the surface of the O / W emulsion to produce microcapsules. After washing with water, filtration and drying were performed to isolate microcapsules having a particle size of 5 μm or less.

The microcapsules thus obtained were dispersed in grease to obtain a lubricant. In this grease, the base oil is a tetraester (the kinematic viscosity at 40 ° C. is 30 mm ² / s), the thickener is lithium 12-hydroxystearate, and the consistency is 280. Moreover, 4.45 mass% calcium sulfonate is contained as a rust preventive agent, and 0.03 mass% phenylenediamine and 0.02 mass% hindered phenol are contained as antioxidants, respectively. Furthermore, the content of microcapsules in the lubricant is 0.1% by mass.

Such lubricant is applied to a single row deep groove ball bearing having a bearing number of 695 (inner diameter 5 mm, outer diameter 13 mm, width 4 mm, rolling element diameter 2.0 mm, with non-contact rubber seal (V type)) of 10 Volume% encapsulated, and a mineral oil rust preventive oil was applied to the outer surface of the deep groove ball bearing. Then, the obtained deep groove ball bearing was stored under the following conditions or rotated under the following conditions (outer ring rotation), and then the acoustic characteristics were evaluated.
The storage condition is such that a cycle of leaving in an environment of 30 ° C. and 80% RH for 5 days and then leaving in an environment of 30 ° C. and 40% RH is performed continuously for 5 cycles. The rotation conditions are a rotation speed of 7200 min ⁻¹ , an axial load of 20 N, an ambient temperature of 80 ° C., and a rotation time of 5000 hours.

  The evaluation method of acoustic characteristics is as follows. The Anderon value is measured before the storage or rotation described above and compared with the Anderon value after storage or rotation. And the case where the increase amount of the Anderon value was less than 1 was set as the pass, and the case where it was 1 or more was set as the failure. The evaluation results of the acoustic characteristics are shown in Table 5. The numerical values shown in Table 5 are the number of bearings that were evaluated for acoustic characteristics of 100 bearings and failed. Note that Example F1 is an example of a lubricant in which a metal deactivator is encapsulated in a microcapsule, and Comparative Example F1 is a direct example without encapsulating a metal deactivator in a microcapsule. It is an example of the added lubricant.

  From Table 5, in addition to the fact that the acoustic characteristics of the bearing of Example F1 do not deteriorate even when rotated for a long period of time, the acoustic characteristics even if rust preventive oil applied to the outer surface or the like enters the bearing during storage. It can be seen that does not decrease. On the other hand, the bearing of Comparative Example F1 does not deteriorate the acoustic characteristics even when rotated for a long period of time, but the rust preventive oil applied to the outer surface or the like enters the bearing during storage and the acoustic characteristics deteriorate. I understand that.

[Example G]
The lubricant for rolling devices and the rolling device of the present invention are used for automobile electrical parts and engine auxiliary machines (alternators, intermediate pulleys, car air conditioner electromagnetic clutches, car air conditioner pulleys, etc.) used under high speed and high load conditions. ).
In the lubricant for rolling devices used in such applications, the type of base oil is not particularly limited, but avoids noise generation at low temperature startup due to low temperature fluidity and seizure due to insufficient oil film at high temperature. for, it preferably has a kinematic viscosity at 40 ° C. is 10~400mm ² / s, more preferably 20~250mm ² / s, further preferably 40~150mm ² / s. Specific examples of the base oil are as described above, and any of the above kinematic viscosities may be used singly or in appropriate combination of two or more.

  Further, the type of the thickener is not particularly limited, and the above-described thickener can be used without any problem. However, considering the heat resistance of the lubricant for rolling devices, a urea compound, a urethane compound, a urea / urethane compound, or a mixture thereof is preferable, and a diurea compound as shown in the following chemical formula is particularly preferable.

In this chemical formula, R ₂ represents an aromatic hydrocarbon group having 6 to 15 carbon atoms, and R ₁ and R ₃ represent an aliphatic hydrocarbon group or alicyclic hydrocarbon group (cyclohexyl group) having 6 to 18 carbon atoms. Or an alkylcyclohexyl group having 7 to 12 carbon atoms) or an aromatic hydrocarbon group having 7 to 12 carbon atoms. Diurea compounds used for lubricants for rolling devices are diurea compounds in which R ₁ and R ₃ are alicyclic hydrocarbon groups, and diurea compounds in which R ₁ and R ₃ are C 7-12 aromatic hydrocarbon groups , And R ₁ is preferably at least one of diurea compounds in which R ₁ is an alicyclic hydrocarbon group and R ₃ is an aromatic hydrocarbon group having 7 to 12 carbon atoms. When used as a mixture of two or more of the three types, and the proportion of aromatic hydrocarbon group having 7 to 12 carbon atoms in R _1, R ₃ that all diurea compound having 55 mol% or less It is preferable to do. Furthermore, it is preferable that content of the urea compound in the lubricant for rolling devices shall be 10-35 mass%.

Below, the manufacturing method of the lubricant for rolling devices suitable for the electrical component of a motor vehicle or an engine auxiliary machine is demonstrated.
What dissolved 20 mass parts of polyvinyl alcohol in 250 mass parts of water and what disperse | distributed 1 mass part of pyromellitic dianhydrides to 10 mass parts of dialkyl dithiocarbamate zinc (ZnDTC) were mixed. While stirring at 3000 min ⁻¹ , 1 part by mass of phenylenediamine was gradually added to the mixture and heated to 90 ° C. Then, after 12 hours, the temperature was raised to 220 ° C. and further stirred for 4 hours. Then, when it dried under reduced pressure, the microcapsule which comprised a polyimide resin and included ZnDTC was obtained.

The microcapsules thus obtained are dispersed in a grease whose base oil is a dialkyldiphenyl ether oil (kinematic viscosity at 40 ° C. is 100 mm ² / s) and the thickener is a diurea compound to obtain a lubricant. It was. In addition, the manufacturing method of this grease is as follows. A dialkyldiphenyl ether oil was charged into the container, and equimolar cyclohexylamine and p-toluidine were added, and the mixture was heated to 70 to 80 ° C. In a separate container, the same amount of dialkyl diphenyl ether oil and diphenylmethane diisocyanate were charged, heated to 70-80 ° C., added to the container and stirred. Although the temperature of the reaction product increased due to the heat of reaction, stirring was continued for about 30 minutes, and after sufficient reaction, the temperature was raised to 170-180 ° C. and held for 30 minutes, and then cooled. Thereafter, an additive was added and sufficiently kneaded to obtain a grease.

2.3 g of such a lubricant was sealed in a deep groove ball bearing (inner diameter 17 mm, outer diameter 52 mm, width 16 mm) provided with a contact-type rubber seal, and a rotation test (inner ring rotation) was performed. The conditions of the rotation test are a rotational speed of 20000 min ⁻¹ , a bearing temperature of 170 ° C., and a radial load of 98N. When the outer ring temperature rose to 180 ° C. or higher, the bearing was seized and reached the end of its life. The content of ZnDTC in the lubricant and the result of the rotation test (seizure life) are shown in Table 6, and a graph of this is shown in FIG. Note that the seizure life shown in Table 6 and FIG. 6 is a relative value when the seizure life of Comparative Example G1 is 1.

As can be seen from Table 6 and FIG. 6, when the content of ZnDTC in the lubricant is 0.1% by mass or more and 10% by mass or less, the seizure life is more than twice that of Comparative Example G1, which is acceptable. .
[Example H]
The lubricant and rolling device for a rolling device according to the present invention includes a hard disk drive (HDD), a flexible disk drive (FDD), an optical disk drive (MOD), a video tape recorder (VTR), a digital audio tape recorder (DAT), and a laser. It is suitable for rotation support parts such as a beam printer (LBP), a small cooling fan motor for information equipment, and an air conditioner (air conditioner).

  It is preferable that the lubricant for rolling devices used for such applications contains microcapsules containing at least one of a fatty acid and a fatty acid derivative. The content of the inclusion substance (at least one of fatty acid and fatty acid derivative) encapsulated in the microcapsule is preferably 0.1% by mass or more and 10% by mass or less of the lubricant. Examples of the fatty acid include oleic acid, naphthenic acid, lanolinic acid, succinic acid, stearic acid, and the like, and examples of the fatty acid derivative include derivatives of the aforementioned fatty acids.

Moreover, in the lubricant for rolling devices used for such applications, the type of base oil is not particularly limited, but ester oil is preferable, and in order to achieve low torque, the kinematic viscosity at 40 ° C. is It is preferably 30 mm ² / s or less. Specific examples of the base oil are as described above, and any of the above kinematic viscosities may be used singly or in appropriate combination of two or more.

  Further, the type of thickener is not particularly limited, and the above-described thickener can be used without any problem, but metal soap is particularly preferable. Further, when considering the above-mentioned applications (the lubricant needs to remain in the lubrication-necessary portion, it is necessary to provide a certain degree of shape retaining property), the consistency specified in JIS K2220 is 200 to 300. Preferably there is. If it exceeds 300, the lubricant is too soft, so that it flows during driving of the rolling device, and part of it adheres to the raceway surface, restricting the rotation of the rolling element and causing slippage, which causes surface damage. There is a fear. Moreover, when it is less than 200, fluidity is inferior, there is a risk that the microcapsules will not reach the location where the lubricant is not required.

Next, a lubricant containing microcapsules containing at least one of a fatty acid and a fatty acid derivative was prepared (see Table 7), sealed in a rolling bearing, and its acoustic characteristics were evaluated. This lubricant is a grease in which the base oil is a polyol ester oil (kinematic viscosity at 40 ° C. is 30 mm ² / s), and the thickener is lithium stearate. And the fatty acid or fatty acid derivative as shown in Table 7 is included in the microcapsule, and the amount (content of only the inclusion substance excluding the weight of the microcapsule) is 5% by mass of the whole lubricant. is there.

  This lubricant includes calcium sulfonate as a rust preventive agent, phenyl-α-naphthylamine and 2,6-di-tert-butyl-p-phenylphenol as an antioxidant, sorbitan trioleate as a dispersant, and an antiwear agent. Tricresyl phosphate is added in an amount of 2% by mass.

  Further, the rolling bearing is a single row deep groove ball bearing having a non-contact type rubber seal (V type) with a nominal number of 694 (inner diameter: 4 mm, outer diameter: 10 mm, width: 2 mm, rolling element diameter: 1.0 mm). And a lubricant of 15 to 35% by volume of the bearing space volume is enclosed. When encapsulating the lubricant, it is encapsulated from the back side at an appropriate position of the cage so as not to contact the surface of the rolling element as much as possible. Here, the bearing space volume is a volume obtained by subtracting the volumes of the rolling elements and the cage (in some cases, a seal member in some cases) from the volume of the ring-shaped space formed between the outer ring and the inner ring. If the amount of the lubricant is less than 15% by volume of the bearing space volume, the absolute amount is too small and the effect of the lubricant becomes insufficient. On the other hand, if it exceeds 35% by volume, the lubricant may hinder the rolling motion of the rolling elements and may cause sliding of the rolling elements. Further, the rolling element may be made of ceramics.

Such a rolling bearing was rotated (outer ring rotation), and the acoustic characteristics (Anderon value) during rotation were evaluated using an Anderon meter. The rotation conditions are a rotation speed of 7200 min ⁻¹ , an atmospheric temperature of 80 ° C., and an axial load of 10 N. A comparison was made between the Anderon value (initial Anderon value) immediately after encapsulating the lubricant and the Anderon value after 5000 hours of rotation (Anderon value after rotation). . Then, 1000 tests were conducted for each type of bearing, and the rejection rate (%) was calculated.

The results are shown in Table 7. In addition, the failure rate of Table 7 is shown by the relative value when the failure rate of Comparative Example H1 is 1. As can be seen from Table 7, Examples H1 to H3 had a lower rejection rate than Comparative Examples H1 and H2.
Next, the bearing of Example 1 with various fatty acid contents prepared was prepared, the acoustic characteristics were evaluated in the same manner as described above, and the rejection rate was calculated. The result is shown in the graph of FIG. In addition, the failure rate described in the graph of FIG. 7 is shown as a relative value when the failure rate of Comparative Example H1 is 1.
As can be seen from FIG. 7, the failure rate was low when the fatty acid content was 0.1 mass% or more and 10 mass% or less of the entire lubricant.

It is a longitudinal section showing the composition of the cylindrical roller bearing which is one embodiment of the rolling device concerning the present invention. It is sectional drawing which shows the structure of a microcapsule. It is sectional drawing of the microcapsule of a double structure. It is a figure which shows the structure of a reciprocating friction wear test apparatus. It is a graph which shows the correlation with the ratio of the antioxidant contained in the state enclosed by the microcapsule, and the difference of the total acid value before and behind heat processing. It is a graph which shows the correlation with content of ZnDTC in a lubricant, and the seizure life of a bearing. It is a graph which shows the correlation with content of the fatty acid in a lubricant, and the rejection rate of an acoustic characteristic test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Inner ring 10a Raceway surface 11 Outer ring 11a Raceway surface 12 Roller 15 Lubricant composition

Claims (9)

  In the lubricant composition for a rolling device containing a base oil and an additive, at least a part of the additive is contained in a microcapsule having a particle diameter of 0.01 to 5 μm, The lubricant composition for a rolling device, wherein the amount of the microcapsule is 0.1 to 50% by mass of the whole composition.   The lubricant composition for a rolling device according to claim 1, wherein the microcapsule contains a lubricant containing the additive. 3. The lubricant composition for a rolling device according to claim 1, wherein the lubricant composition is a liquid lubricating oil, and the base oil has a kinematic viscosity at 40 ° C. of 1 to 1500 mm ² / s. The semi-solid grease having a blending degree of 150 to 400, wherein the base oil has a kinematic viscosity at 40 ° C of 15 to 1500 mm ² / s. A lubricant composition for a rolling device.   The additive is at least one of an extreme pressure agent composed of a compound containing sulfur, an extreme pressure agent composed of a compound containing phosphorus, and an extreme pressure agent composed of a compound containing halogen. The lubricant composition for a rolling device according to any one of claims 1 to 4.   The lubricant composition for a rolling device according to any one of claims 1 to 5, wherein a ratio of the inclusion substance in the microcapsule is 10 to 98% by mass.   The lubricant composition for a rolling device according to any one of claims 1 to 6, wherein the microcapsule is composed of a resin composition. An inner member having a raceway surface on the outer surface, an outer member having a raceway surface opposite to the raceway surface of the inner member and disposed outside the inner member, and rolling between the raceway surfaces A rolling device comprising a plurality of freely arranged rolling elements,
A rolling device characterized in that the lubrication between the both raceway surfaces and the rolling element is performed by the lubricant composition for a rolling device according to any one of claims 1 to 7.   The rolling device according to claim 8, wherein the rolling device is a rolling bearing.

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