JP2008297375A - Lubricating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating system which is improved in the lubricating component-holding force of a foamed solid lubricant holding the lubricating component, can control the oozing amount of the lubricating component by the deformation of the foamed solid lubricant, to a necessary minimum amount, can supplement the lubrication function, even when the lubricating component oozed from the foamed solid lubricant is insufficient, has a long life, and can respond to the demand of cost reduction. <P>SOLUTION: This lubricating system has a foamed solid lubricant containing a lubricating component in a foamed cured porous resin, and an auxiliary lubricant at a lubrication target site. The auxiliary lubricant is a solid lubricant such as molybdenum disulfide, tungsten disulfide, melamine cyanurate, boron nitride, or solid molybdenum dithiocarbamate. As an example, the foamed cured porous resin 9 and the auxiliary lubricant 10 coexit on the inside of a universal joint in which a rotation torque is transmitted by the engagement of a steel ball 5 with track grooves 3, 4 disposed in the outer member 2 and the inner membrane 1, and the steel ball 5 is rolled along the track grooves 3, 4 in the axial direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lubrication system capable of supplying a lubricant to a sliding part and a rotating part of a mechanical device.

Generally, a lubricant is used in a sliding part and a rotating part of most machines represented by automobiles and industrial machines. Lubricants can be broadly divided into liquid lubricants and solid lubricants. Grease with increased lubricating oil and shape retention, and solids that retain liquid lubricant and prevent its splashing and dripping. Lubricants are also known.
For example, a solid lubricant in which ultra-high molecular weight polyolefin or urethane resin and its curing agent are mixed in lubricating oil or grease, and a liquid lubricant component is held between the resin molecules to gradually exude physical properties. It is known (see Patent Documents 1 to 3).
Also known is a self-lubricating polyurethane elastomer obtained by reacting a polyol, which is a polyurethane raw material, with a diisocyanate in a lubricating component in the presence of a lubricant (see Patent Document 4).
When such solid lubricant is sealed in a bearing and solidified, it gradually exudes lubricating oil. If this is used, maintenance for replenishing the lubricating oil becomes unnecessary, and there is a lot of moisture. It is intended to be useful for extending the life of the bearing even in environments where it is used or where inertia is strong.

When such a solid lubricant is used in a part where external stress such as compression or bending is frequently applied, such as a drive part of a constant velocity joint, a very large force is required to deform following the compression or bending. Or a very large stress is applied to the solid lubricant, and the mechanical strength is also required for the portion holding the solid lubricant.
However, since the strength and filling rate of the solid lubricant are usually compensatory, it is difficult to keep the lubricant at a high filling rate, which may hinder a longer life.
Therefore, there is a demand for a solid lubricant that can be easily used even at sites where external stress such as compression and bending repeatedly occurs at a high frequency.
As this solid lubricant, for example, a soft resin that is foamed to form continuous vents is impregnated with lubricating oil, and the solid foam lubricant that holds the lubricating oil in the pores is also filled in the bearings and constant velocity joints. It is known that it is used (see Patent Document 5).

  Further, grease has been conventionally used for lubrication of constant velocity joints, and various greases have been proposed in order to improve their functions (for example, vibration characteristics, durability, etc.). Although functions can be improved by selecting thickeners and base oils, many patents have been proposed that suggest improvements by selecting additives. For example, grease that uses alicyclic and / or aromatic diurea compounds as thickeners to prevent flaking and improve heat resistance, and combines melamine cyanurate, molybdenum dithiocarbamate, molybdenum disulfide, and sulfur-based additives. For the purpose of improving durability (see Patent Document 6) and grease, a grease (see Patent Document 7) in which melamine cyanurate, molybdenum disulfide, a sulfur-based additive, and calcium sulfonate are combined is known.

  However, the solid lubricant according to Patent Documents 1 to 5 can have a longer life than the case of using a grease alone. However, in the case of the solid lubricant according to Patent Documents 1 to 4, the lubricating oil retention force Although it is excellent, it lacks flexible deformability. Further, the solid foamed lubricant of Patent Document 5 has a flexible deformability depending on external force and can follow compression and bending deformation, but has a smaller lubricating oil retaining force than the solid lubricant of Patent Document 1 and the like. When used under high-speed conditions such as bearings, there is a possibility that the lubricating oil will rapidly escape and be exhausted. This foamed solid lubricant can be used in short-time lubrication and sealed spaces, but if used in parts that require long-term lubrication or in open spaces, the supply of lubricating oil will be insufficient, or the oil holding power will be reduced. If it is weak, excess lubricating oil will be repeatedly released and absorbed from the pores and will endure and flow in the space.

  When the lubricant exuded excessively from such a solid lubricant or foamed solid lubricant comes into contact with an exterior such as rubber, the lubricant and its additives may be chemically corroded or deteriorated. In addition, in the process of manufacturing the lubricant, many manufacturing processes are required for reliably impregnating the lubricant and grease, and it is difficult to meet the demand for cost reduction.

In addition, when using the above grease, it may be possible to mix solid lubricants such as molybdenum disulfide and melamine cyanurate, which are added to prevent flaking and improve heat resistance, into the solid lubricant and foamed solid lubricant. However, the solid lubricant that has been incorporated into the resin component is difficult to be released, and it is difficult to obtain an effect commensurate with the amount added.
JP-A-6-41569 JP-A-6-172770 JP 2000-319681 A JP-A-11-286601 Japanese Patent Laid-Open No. 9-42297 Japanese Patent Laid-Open No. 9-255983 JP 2004-123858 A

  The present invention has been made in order to address such problems, and improves the lubricant retention of the foamed solid lubricant that retains the lubricating component, and also causes the bleeding of the lubricant due to deformation of the foamed solid lubricant. It is an object of the present invention to provide a long-life and low-cost lubrication system that can keep the output amount to the minimum necessary and can supplement the lubrication function even when the lubrication component from the foamed solid lubricant is insufficient.

The lubrication system of the present invention is a lubrication system in which a foamed solid lubricant and an auxiliary lubricant coexist at a site to be lubricated. The foamed solid lubricant includes a lubrication component, a resin component, a curing agent, and foaming. A foamed solid lubricant obtained by foaming and curing a mixture containing an agent, wherein the auxiliary lubricant contains at least a solid lubricant.
In particular, the solid lubricant is at least one selected from molybdenum disulfide, tungsten disulfide, melamine cyanurate, boron nitride, and solid molybdenum dithiocarbamate (hereinafter referred to as MoDTC). .

Among the solid foam lubricants, the first solid foam lubricant is at least one lubricating component whose lubricating component is selected from hydrocarbon-based lubricants and hydrocarbon-based greases, and the resin component is a polymer main component. A liquid rubber having a chain composed of hydrocarbons and having a hydroxyl group amount of 25 mgKOH / g to 110 mgKOH / g at the end of the main chain, and the curing agent is an organic compound having an isocyanate group in the molecule The ratio of the liquid rubber and the curing agent is such that the hydroxyl group contained in the liquid rubber and the isocyanate group contained in the curing agent are equivalent (OH / NCO) = 1 / (1.0 to 2.0), and the mixture contains 40% to 80% by weight of the lubricating component and 5% to 45% by weight of the liquid rubber with respect to the whole mixture. To do.
Further, the liquid rubber is a hydroxyl group-terminated diene polymer having a number average molecular weight of 1000 to 3500 having a hydroxyl group at the main chain terminal of a butadiene or isoprene polymer, or a modified hydroxyl group-terminated diene system obtained by hydrogenating the diene polymer. It is a polymer.
The organic compound having an isocyanate group in the molecule is a prepolymer having two or more isocyanate groups in the molecule and a ratio of the isocyanate group of 2.5 NCO% to 5.0 NCO%, or aromatic. It is a polyisocyanate.

Among the foamed solid lubricants, the second foamed solid lubricant is at least one lubricating component in which the lubricating component is selected from lubricating oil and grease, and the resin component has an isocyanate group content of 2% by weight. More than 6% by weight of urethane prepolymer, the foaming agent is water, and the mixture contains 30% to 70% by weight of the lubricating component with respect to the whole mixture, and the open cell ratio after foaming is It is characterized by being 50% or more. The urethane prepolymer is at least one urethane prepolymer selected from an ester urethane prepolymer, a caprolactone urethane prepolymer, and an ether urethane prepolymer.
Further, the ratio of the isocyanate group to the functional group of the curing agent that reacts with the isocyanate group is an equivalent ratio (functional group of the curing agent / NCO) = 1 / (1.1 to 2.5). And
The ratio of the hydroxyl group of water to the functional group of the curing agent is an equivalent ratio (hydroxyl group of water / functional group of the curing agent) = 1 / (0.7 to 2.0).
The curing agent is an aromatic polyamino compound, particularly an aromatic polyamino compound having a substituent at a position adjacent to an amino group.

The lubrication system of the present invention is a lubrication system in which a foamed solid lubricant containing a lubrication component in a resin that is foamed and cured to become porous, and an auxiliary lubricant coexist at a site to be lubricated. The lubricant contains a solid lubricant such as molybdenum disulfide, tungsten disulfide, melamine cyanurate, boron nitride, solid MoDTC, etc., so that the solid lubricant is not taken into the foamed solid lubricant and lubricated. The auxiliary lubricant is present in the sliding part and has a lubricating function even when there is a shortage of the lubricating component that exudes from the foamed solid lubricant during initial lubrication or when there is no lubricating component. Can do.
For this reason, in sliding parts such as bearings and universal joints filled with foamed solid lubricant, it is excellent in initial conformability, prevents flaking, improves heat resistance, and does not run out of lubricant. The lubrication function can be sufficiently performed continuously.

  In this invention, since the lubricating component is occluded in the resin, the lubricating component oozes out by deformation due to external force such as compression, expansion, bending, and twisting due to the flexibility of the resin, and is gradually released from between the molecules of the resin. it can. At this time, the amount of the lubricating component that oozes out can be minimized by changing the degree of elastic deformation according to the magnitude of the external force by selecting the resin component. In the present invention, “occlusion” means that a liquid / semi-solid lubricating component does not react with other compounding components and is contained in a solid resin without becoming a compound.

Further, in the foamed solid lubricant used in the lubrication system of the present invention, the resin has a large surface area due to foaming, and the excess lubricating component that has oozed out can be temporarily held in the foam bubbles again. The amount of the lubricating component that oozes out is stable, and the lubricating component is stored in the resin and impregnated in the bubbles of the foam, so that the amount of the lubricating oil or the like is increased as compared with the non-foamed state.
In addition, the foamed solid lubricant used in the present invention requires very little energy when bent compared to a non-porous body, and can be flexibly deformed while maintaining a high density of lubricating components. Moreover, since it has many porous parts, it is advantageous also at the point of weight reduction.

  The example which applied the lubrication system of this invention to the universal joint is demonstrated concretely using drawing. FIG. 1 is a cross-sectional view showing a constant velocity universal joint. As shown in FIG. 1, the constant velocity universal joint includes an inner member (also referred to as an inner ring) 1, an outer member (also referred to as an outer ring) 2, an inner member side track groove 3, an outer member side track groove 4, and a steel ball 5. , Cage 6, shaft 7, boot 8, foamed solid lubricant 9, auxiliary lubricant 10 in which a solid lubricant is blended with grease, and other accessory parts. At this time, in the constant velocity universal joint, the auxiliary lubricant 10 is accommodated in the bottom of the outer member 2, and the foamed solid lubricant 9 coexists in the form of being disposed in the vicinity of the steel ball 5.

  The foamed solid lubricant 9 contains a lubricating component in a foamed, hardened porous resin, and is generated when the centrifugal force accompanying the rotational motion of the constant velocity universal joint or the constant velocity universal joint takes an angle. The inner member side track groove 3, outer member side track groove 4, steel ball 5 surface and cage 6 surface which are sliding parts from the foamed solid lubricant due to external stress such as compression, bending, expansion and capillary action For example, the lubricating component is gradually released. Further, unlike the lubricating component in the foamed solid lubricant 9, the auxiliary lubricant 10 accommodated in the bottom portion of the outer member 2 is not contained in the resin, so that it can move in the constant velocity universal joint together with the grease. And can reach the sliding portion of the constant velocity universal joint. Further, since the solid lubricant is contained in the auxiliary lubricant 10 and is not taken into the foamed solid lubricant 9, it can effectively contribute to preventing flaking and improving heat resistance. As a result, the auxiliary lubricant 10 contributes to improving the lubricity of the sliding portion of the constant velocity universal joint even when the lubricating component in the foamed solid lubricant 9 does not ooze out or when the oozing amount is insufficient. be able to.

  The foamed solid lubricant releases the lubricating component to the outside due to external stresses such as centrifugal force, compression, bending, and expansion. When depleted, the lubricating component may not be sufficiently present in the sliding portion. In the present invention, by using an auxiliary lubricant in combination, it is possible to compensate for the shortage of the lubricating component that exudes from the foamed solid lubricant, and the solid lubricant is included in the auxiliary lubricant, so that the solid lubricant suitable for the amount added The effect is obtained.

In addition, the foamed solid lubricant used in the present invention requires much less energy when bent compared to non-foamed materials, and can be flexibly deformed while maintaining a high density of lubricating components such as lubricating oil. . Therefore, even if the foamed solid lubricant shrinks in the process of cooling after solidifying the foamed solid lubricant inside the constant velocity universal joint, for example, it is necessary for bending and deformation even if the steel ball of the constant velocity universal joint is embraced Since the energy is small, it can be easily deformed and the problem of increased rotational torque can be prevented. Moreover, since it has many foamed parts, ie, a porous part, it is advantageous also at the point of weight reduction.
In addition, since the foamed solid lubricant used in the present invention only foams and hardens a mixture containing a lubricating component and a resin, no special equipment is required, and it can be filled and molded in any place. It is.
Further, the density of the foamed solid lubricant can be changed by controlling the blending amount of the blending components of the mixture.

In the present invention, the resin that forms a foamed solid lubricant and is made porous by curing and foaming preferably has a rubber-like elasticity after foaming and curing, and has a leaching property of a lubricating component due to deformation.
Foaming / curing may be in a form in which foaming / curing is performed when the resin is produced, or in a form in which a foaming agent is blended with the resin and foaming / curing is performed in molding. Here, curing means a cross-linking reaction and / or a phenomenon in which a liquid is solidified. The rubber-like elasticity means rubber elasticity and means that deformation applied by an external force returns to the original shape by eliminating the external force.

For the resin component of the foamed solid lubricant used in the present invention, it is preferable to use a urethane resin that is excellent in heat resistance and flexibility and can be reduced in cost. As the resin component, a first foamed solid lubricant using a liquid rubber having a hydroxyl group in the molecule described below and a second foamed solid lubricant using a urethane prepolymer containing a predetermined NCO are preferable.
Moreover, the resin component obtained by making the polyether polyol and polyisocyanate as a polyol react can be used.

As the resin component used in the first foamed solid lubricant that can be used in the present invention, it is preferable to use a urethane resin that is excellent in heat resistance and flexibility and can be reduced in cost. The hydroxyl group-containing component that forms the urethane resin is preferably a liquid rubber having a hydroxyl group in the molecule. This liquid rubber has a polymer main chain composed of hydrocarbons, and a hydroxyl value of 25 to 110 mg KOH at the end of the main chain. A liquid rubber having a hydroxyl group in an amount of / g 2 is preferable. When the hydroxyl value is less than 25 mg KOH / g, foaming / curing is not sufficient, and when the hydroxyl value exceeds 110 mg KOH / g, the elasticity of the foamed solid lubricant may be lost.
This liquid rubber is a hydroxyl group-terminated diene polymer having a number average molecular weight of 1000 to 3,500 having a hydroxyl group at the main chain terminal of a butadiene or isoprene polymer, or a modified hydroxyl group-terminated diene polymer obtained by hydrogenating the diene polymer. Coalescence can be used.
Examples of the hydroxyl-terminated liquid polybutadiene include poly-bd R45HT (manufactured by Idemitsu Kosan Co., Ltd.), poly-bd R15HT (manufactured by Idemitsu Kosan Co., Ltd.), NISSO-PB G-1000, G-2000, and G-3000 (manufactured by Nippon Soda Co., Ltd.). Examples of the hydroxyl-terminated liquid polyisoprene include poly-ip (manufactured by Idemitsu Kosan Co., Ltd.), and examples of the hydrogenated hydroxyl-terminated polydiene compound include Epol (manufactured by Idemitsu Kosan Co., Ltd.), NISSO-PB GI-1000, GI-2000, GI-3000 (made by Nippon Soda Co., Ltd.), etc. are mentioned.

  In addition, the hydroxyl group-terminated polydiene compound or the hydroxyl group-terminated polydiene compound obtained by partially modifying the hydroxyl group-terminated polydiene compound or the hydrogenated hydroxyl group-terminated polydiene compound with an isocyanate group or an epoxy group or the hydrogenated hydroxyl group-terminated polydiene compound are also included at the terminal. If it can be used. Two or more of these compounds may be mixed and used for the purpose of controlling the physical properties of the produced foam.

  The hydroxyl group-terminated polydiene polymer or the hydrogenated hydroxyl group-terminated polydiene polymer has a molecular structure similar to that of a lubricating component composed of paraffinic or naphthenic mineral oil composed of hydrocarbons, which will be described later. It is considered that the hydroxyl group-terminated polydiene polymer or the hydrogenated hydroxyl group-terminated polydiene polymer and the lubricating component molecule are intertwined by a relatively weak interaction. Therefore, many lubricating components can be impregnated in the molecule of the hydroxyl-terminated polydiene polymer or the hydrogenated hydroxyl-terminated polydiene polymer, and high lubricating component retention can be exhibited. By applying a strong force such as heat or centrifugal force to this, the interaction between the hydroxyl-terminated polydiene polymer or the hydrogenated hydroxyl-terminated polydiene polymer and the lubricating component is broken, and the lubricating component can be released gradually. it can.

The organic compound having an isocyanate group in the molecule as a curing agent for curing the liquid rubber can be used without particular limitation as long as it is an isocyanate compound that reacts with a hydroxyl group in the liquid rubber to extend the molecular chain or crosslink. Preferred isocyanate compounds include polyisocyanates. Polyisocyanates are particularly preferable because they can react with water to be a foaming agent described later to generate gas.
Examples of the polyisocyanates include polyisocyanates and / or prepolymers having two or more isocyanate groups in the molecule.

Polyisocyanates can include aromatic, aliphatic, or alicyclic polyisocyanates.
Aromatic polyisocyanates include tolylene diisocyanate (hereinafter referred to as TDI), diphenylmethane diisocyanate (hereinafter referred to as MDI), TDI multimer, MDI multimer, naphthalene diisocyanate (NDI), phenylene diisocyanate, diphenylene. Diisocyanate etc. are mentioned.
Examples of the aliphatic polyisocyanates include octadecamethylene diisocyanate, decamethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, and xylylene diisocyanate.
Examples of the alicyclic polyisocyanates include isophorone diisocyanate and dicyclohexylmethane diisocyanate.
Also, an adduct of the polyisocyanate and a polyol such as trimethylolpropane can be used.
When the reaction with the hydroxyl group that is the terminal functional group of the liquid rubber is performed at a high temperature, a blocked isocyanate in which an isocyanate group is blocked with a blocking agent such as phenols, lactams, alcohols, and oximes can be used. .

  In the case of reacting with a hydroxyl group-terminated polydiene polymer, aromatic polyisocyanates are preferred among the polyisocyanates, and TDI having excellent foamability and reactivity with the hydroxyl group-terminated polydiene polymer is preferred.

As the prepolymer having two or more isocyanate groups in the molecule, any prepolymer having an isocyanate group ratio of 2.5 to 5.0 NCO% can be used. In addition, NCO% is the weight% as an NCO group in a prepolymer. A 2.5 to 5.0 NCO% prepolymer can react with a hydroxyl group-terminated polydiene polymer or the like to obtain a urethane having high elasticity.
Prepolymers are classified into PPG type, PTMG type, ester type, caprolactone type, etc., depending on the type of monomer to be polymerized. There are Takenate L-1170 (manufactured by Mitsui Chemicals Polyurethane) and P-1158 (manufactured by Mitsui Chemicals Polyurethanes) in the PPG system, and Coronate 4090 (manufactured by Nippon Polyurethanes) in the PTMG system. Coronate 4047 (manufactured by Nippon Polyurethane Co., Ltd.) is used as the ester system, and Takenate L-1350 (manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.), Takenate L-1680 (manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.), and Sianaprene 7-QM are used as caprolactones. (Mitsui Chemical Polyurethane Co., Ltd.), Plaxel EP1130 (Daicel Chemical Industries Co., Ltd.) and the like. Two or more kinds of the above prepolymers can be mixed and used according to the purpose.

  The blending ratio of the hydroxyl group-terminated polydiene polymer having a terminal hydroxyl group or the hydrogenated hydroxyl group-terminated polydiene polymer and the isocyanate compound having an isocyanate group is equivalent ratio of hydroxyl group (—OH) to isocyanate group (—NCO). The range of (OH / NCO) = 1 / (1.0 to 2.0) is preferable, and the range of (OH / NCO) = 1 / (1.1 to 1.9) is preferable in consideration of particularly excellent foamability and elasticity. When (OH / NCO) is smaller than 1 / 2.0, the isocyanate group becomes excessive, the crosslink density is large, and the elasticity may be poor. On the other hand, when (OH / NCO) is greater than 1 / 1.0, the crosslinking is insufficient and curing becomes insufficient.

The lubricating component that can be used for the first foamed solid lubricant can be used as long as it does not dissolve the solid component that forms the foam. Examples of the lubricating component include hydrocarbon-based lubricants, hydrocarbon-based greases, and mixtures of hydrocarbon-based lubricants and hydrocarbon-based greases.
Examples of the hydrocarbon-based lubricating oil include paraffinic and naphthenic mineral oils, hydrocarbon-based synthetic oils, GTL base oils, and the like. These can be used alone or as a mixed oil.
The hydrocarbon-based grease is a grease having a hydrocarbon oil as a base oil, and examples of the base oil include the above-described hydrocarbon-based lubricating oil. Examples of the thickener include lithium soaps, lithium complex soaps, calcium soaps, calcium complex soaps, aluminum soaps, aluminum complex soaps, and other urea compounds such as diurea compounds and polyurea compounds. It is not a thing. The diurea compound is obtained by the reaction of diisocyanate and monoamine, and the polyurea compound is obtained by the reaction of diisocyanate and polyamine.

  As the lubricating component, hydrocarbon synthetic wax, polyethylene wax, higher fatty acid ester wax, higher fatty acid amide wax, ketone / amines, hydrogenated oil, and the like can be mixed and used.

  Since the means for foaming the first foamed solid lubricant uses an isocyanate compound as a raw material, it is preferable to use water that reacts with the isocyanate compound to generate carbon dioxide gas.

The first solid foam lubricant is obtained by foaming and curing a mixture containing the above-described lubricating component, liquid rubber, a curing agent, and a foaming agent.
The blending ratio of the lubricating component is 40 to 80% by weight based on the entire mixture. If the lubricating component is less than 40% by weight, the supply amount of lubricating oil and the like is so small that it cannot function as a foamed solid lubricant, and if it exceeds 80% by weight, it will not solidify.
The blending ratio of the liquid rubber is 5 to 45% by weight, preferably 9 to 42% by weight, based on the entire mixture. When it is less than 5% by weight, it does not solidify, so it does not have a function as a foamed solid lubricant. When it is more than 45% by weight, the supply of the lubricant is small and it does not function as a foamed solid lubricant.

  In the first foamed solid lubricant, the expansion ratio is preferably 1.1 to 50 times, more preferably 1.1 to 10 times. When the expansion ratio is less than 1.1 times, the bubble volume is small and deformation cannot be allowed when external stress is applied. If it exceeds 50 times, it will be difficult to obtain the strength to withstand external stress.

  Moreover, in order to accelerate the curing rate of the first foamed solid lubricant, a tertiary amine catalyst, an organometallic catalyst, or the like can be used. Examples of the tertiary amine catalyst used include monoamines, diamines, triamines, cyclic amines, alcohol amines, ether amines and the like. Examples of the organometallic catalyst include stanaoctaate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin maleate, dioctyltin dimercaptide, dioctyltin thiocarboxylate and the like. Moreover, you may mix and use these multiple types for the purpose of adjusting the balance of reaction.

In the present invention, the urethane prepolymer that can be used as the resin component of the second foamed solid lubricant is obtained by a reaction between a compound having an active hydrogen group and a polyisocyanate, and the isocyanate group may be a molecular chain terminal, or It may be contained at the end of the side chain branched from the molecular chain. The urethane prepolymer may have a urethane bond in the molecular chain.
Depending on the type of monomer (= compound having an active hydrogen group) to be reacted, it is classified into caprolactone, ester and ether. Ether ethers include Takenate L-1170 (Mitsui Chemical Polyurethane), L-1158 (Mitsui Chemical Polyurethane), and Coronate 4090 (Nippon Polyurethane). Coronate 4047 (manufactured by Nippon Polyurethane Co., Ltd.) is used as the ester system, and Takenate L-1350 (manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.), Takenate L-1680 (manufactured by Mitsui Chemicals Polyurethanes Co., Ltd.), and Sianaprene 7-QM are used as caprolactones. (Manufactured by Mitsui Chemicals Polyurethane), Plaxel EP1130 (manufactured by Daicel Chemical Industries) and the like.
Moreover, the oligomer and prepolymer compound which modified the terminal group into the isocyanate group can also be used. Examples of such a compound include a terminal isocyanate-modified polyether polyol and an isocyanate-modified product of a hydroxyl group-terminated polybutadiene. Examples of the terminal isocyanate-modified polyether polyol include Coronate 1050 (manufactured by Nippon Polyurethane Co., Ltd.). Moreover, poly-bd MC50 (made by Idemitsu Kosan Co., Ltd.) and poly-bd HTP9 (made by Idemitsu Kosan Co., Ltd.) are mentioned as the isocyanate modified body of hydroxyl-terminated polybutadiene.
These urethane prepolymers can be used in combination of two or more depending on the intended mechanical properties.

As the second foamed solid lubricant, a urethane prepolymer having an isocyanate group content of 2 wt% or more and less than 6 wt% can be used. If the isocyanate group (NCO) content is less than 2% by weight, it will be difficult to achieve both foamability and elasticity, and if it is more than 6% by weight, the hardness will be too high and the rebound resilience will increase and deformation due to external force will occur. It becomes easy to generate heat when receiving.
Moreover, the isocyanate group can use the block isocyanate etc. which blocked the isocyanate group with blocking agents, such as phenols, lactams, alcohols, and oximes.

The curing agent for curing the urethane prepolymer is preferably a compound having active hydrogen, and examples thereof include a polyamino compound having a functional group as an amino group and a polyol compound having a functional group as a hydroxyl group.
Polyamino compounds include 3,3'-dichloro-4,4'-diaminodiphenylmethane (hereinafter referred to as MOCA), 3,3'-dimethyl-4,4'-diaminodiphenylmethane, and 3,3'-dimethoxy-4. , 4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, trimethylene-bis- (4-aminobenzoate), bis (methylthio) -2,4- Aromatics typified by toluenediamine, bis (methylthio) -2,6-toluenediamine, methylthiotoluenediamine, 3,5-diethyltoluene-2,4-diamine, 3,5-diethyltoluene-2,6-diamine Examples include polyamino compounds.

  Among the polyamino compounds, aromatic amino compounds are preferable because of low cost and excellent physical properties, and aromatic diamino compounds having a substituent at the position adjacent to the amino group are particularly preferable. In the 2nd foaming solid lubricant, since it passes through the process of hardening with foaming, it is thought that the reactivity of an amino group is suppressed by the substituent of an adjacent position.

  When the urethane prepolymer is cured with a polyamino compound, it becomes a foamed solid lubricant having urethane and urea bonds in the molecule. By generating urea bonds, the urethane bond density in the molecule is lowered, and elongation and impact resilience are improved. Moreover, rigidity can be provided by generating a urea bond.

  Examples of the polyol compound include low molecular polyols such as 1,4-butane glycol and trimethylolpropane, polyether polyols, castor oil polyols, and polyester polyols. Among the polyol compounds, polyether polyol and trimethylolpropane are preferable.

The ratio of the isocyanate group (—NCO) contained in the urethane prepolymer and the functional group of the curing agent that reacts with the isocyanate group is an equivalent ratio when the functional group is an amino group or a hydroxyl group (functional group of the curing agent). /NCO)=1/(1.1 to 2.5).
The foamability of the foamed solid lubricant is determined by the ratio of the isocyanate group contained in the urethane prepolymer to the amino group (—NH ₂ ) or hydroxyl group (—OH) of the curing agent and the hydroxyl group of water (—OH) as the foaming agent. Flexibility, elasticity, etc. are determined. When the amino group (—NH ₂ ) or hydroxyl group (—OH) of the curing agent is reacted with the isocyanate group (—NCO) of the urethane prepolymer in an equivalent amount, an isocyanate group (—NCO) that reacts with water as the foaming agent is formed. Since it will disappear, the range of (functional group of curing agent / NCO) = 1 / (1.1 to 2.5) is preferable. Moreover, the ratio of the hydroxyl group of water which is a foaming agent and the functional group of a hardening | curing agent is the range of (hydroxyl group of water / functional group of a hardening | curing agent) = 1 / (0.7-2.0) by an equivalent ratio.
If the amount of the curing agent is less than the above range, not only the physical properties such as the strength of the foamed solid lubricant are remarkably lowered, but also the urethane elastomer may not be cured.

The lubricating component that can be used in the second foamed solid lubricant can be used as long as it does not dissolve the solid component that forms the foam, like the first foamed solid lubricant. As the lubricating component, for example, lubricating oil, grease, wax or the like can be used alone or in combination. Particularly preferred are hydrocarbon-based lubricants, hydrocarbon-based greases, or mixtures of hydrocarbon-based lubricants and hydrocarbon-based greases.
As the hydrocarbon-based lubricant, the same one as the first foamed solid lubricant can be used. In addition, ester synthetic oils, ether synthetic oils, fluorine oils, silicone oils and the like can also be used. These can be used alone or as a mixed oil.
As the grease, in addition to the grease similar to the first foamed solid lubricant, a grease based on ester synthetic oil, ether synthetic oil, GTL base oil, fluorine oil, silicone oil or the like can be used.
In addition, the same hydrocarbon-based synthetic wax, polyethylene wax, higher fatty acid ester-based wax, higher fatty acid amide-based wax, ketone / amines, hydrogenated oil, and the like as the first foamed solid lubricant may be used. it can.

As the foaming agent for foaming the second foamed solid lubricant, since an isocyanate compound is used as a raw material, it is preferable to use water that reacts with the isocyanate compound to generate carbon dioxide gas.
Moreover, in order to accelerate the curing rate of the second foamed solid lubricant, the above-described tertiary amine catalyst, organometallic catalyst, or the like can be used.

The second foamed solid lubricant is obtained by foaming and curing a mixture containing the lubricating component, the resin component, the curing agent, and the foaming agent.
The blending ratio of the lubricating component is 30% to 70% by weight, preferably 40% to 60% by weight, based on the entire mixture. If the lubricating component is less than 30% by weight, the supply amount of lubricating oil and the like is so small that it cannot function as a foamed solid lubricant, and if it exceeds 70% by weight, it does not solidify.

  The open cell ratio of the second foamed solid lubricant after foaming is 50% or more, preferably 50% or more and 90% or less. When the open cell ratio is less than 50%, the ratio of the resin component (solid component) lubricating oil temporarily taken up into the closed cells increases and may not be supplied to the outside when necessary. If it exceeds 90%, the oil retention of the lubricant will decrease and the amount of lubricant released will increase, which will be disadvantageous for long-term use, and the strength (durability) of the foamed solid lubricant itself will decrease. There is a fear.

The open cell ratio of the second solid foam lubricant can be calculated by the following procedure.
(1) The foamed solid lubricant that has been foam-cured is cut into an appropriate size to obtain sample A. The weight of sample A is measured.
(2) A is soxhlet washed (solvent: petroleum benzine) for 3 hours. Thereafter, the sample is left in a thermostatic bath at 80 ° C. for 2 hours to completely dry the organic solvent, and sample B is obtained. The weight of sample B is measured.
(3) The open cell ratio is calculated by the following procedure.
Open cell ratio = (1− (weight of resin component of sample B−weight of resin component of sample A) / weight of lubricating component of sample A) × 100
The resin component weight and the lubrication component weight of Samples A and B are calculated by multiplying the weights of Samples A and B by the composition charge ratio.
Lubricating components taken into discontinuous closed cells are not released to the outside by Soxhlet cleaning for 3 hours, so the weight of sample B is not reduced. The open cell ratio can be calculated as a result of the release of the lubricating component.

The first and second foamed solid lubricants may contain various additives such as pigments, antistatic agents, flame retardants, antifungal agents, reinforcing agents, inorganic fillers, anti-aging agents, and fillers as necessary. Can be added. Examples of the reinforcing agent include carbon black, white carbon, colloidal silica, and examples of the inorganic filler include calcium carbonate, barium sulfate, talc, clay, and meteorite powder.
In addition, solid lubricants such as molybdenum disulfide and graphite, friction modifiers such as organic molybdenum, oily agents such as amines, fatty acids, and fats, antioxidants such as amines and phenols, petroleum sulfonates, dinonylnaphthalene sulfone Antirust agents such as nates and sorbitan esters, extreme pressure agents such as sulfur and sulfur-phosphorus, antiwear agents such as organic zinc and phosphorus, metal deactivators such as benzotriazole and sodium nitrite, polymethacrylate, polystyrene Various additives such as a viscosity index improver such as

For the first and second foamed solid lubricants, it is possible to use a reactive impregnation method in which a foaming reaction and a curing reaction are simultaneously performed in the presence of a lubricating component such as a lubricating oil. It is desirable to achieve both elongation simultaneously. This is because the lubricant is uniformly impregnated into the foam formed in the foam during the foam formation stage, and the lubricant is occluded in the foamed / cured solid component, so that the lubricant is highly filled and the material properties It is considered that the high elongation of both is compatible.
On the other hand, after the foam is manufactured in advance, the post-impregnation method in which the lubricant is impregnated does not have sufficient lubricant holding power, and the lubricant is released in a short period of time and supplied when used for a long time. It becomes insufficient.

The first and second methods for producing the solid foamed lubricant include a mixing step of mixing a component including a lubricating component, a resin component, a curing agent, and a foaming agent to obtain a mixture, and foaming and curing of the mixture. Before completion of the process, a filling step of filling the mixture around the sliding member or in a molding die and a foaming / curing step of foaming / curing the filled mixture are provided.
In the mixing step, the method of mixing the resin component, the curing agent, the lubricating component, and the foaming agent is not particularly limited, and a commonly used stirrer such as a Henschel mixer, a ribbon mixer, a juicer mixer, or the like is used. Can be used and mixed.
Since the mixture is quickly cured by the curing agent and the foaming agent, it is desirable to add the other components except the curing agent and the foaming agent to the stirrer and finally the curing agent and the foaming agent.

  In the filling step, the mixture containing the resin component, the curing agent, the lubricating component, and the foaming agent is filled around the sliding member or in the molding die before the foaming and curing of the mixture is completed. Foaming of resin component using carbon dioxide generated by chemical reaction between isocyanate and water in the mixture filled in the mold around the sliding member or in the mold, and the resin component in the mixture and curing The curing reaction with the agent proceeds at the same time, and a foam, which is a foamed / cured product having the shape of the filling space, is formed around the sliding member or in the molding die. The foams impregnated with this lubricating component are the first and second foamed solid lubricants.

  In the above production method, it is desirable to use a surfactant such as a commercially available silicone foam stabilizer and to uniformly disperse each raw material molecule. Further, the surface tension can be controlled by the type of the foam stabilizer, and the type of the generated bubbles can be controlled to open cells or closed cells. Examples of such surfactants include anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, silicone surfactants, and fluorine surfactants.

In the lubricating system of the present invention, the foamed solid lubricant is foamed and cured after pouring a mixture containing a lubricating component and a resin component into bearings and universal joints in bearings and universal joints to which the lubricating system is applied. Alternatively, after foaming and curing at normal pressure, it can be post-processed into a desired shape by cutting or grinding, and incorporated into a bearing or a universal joint.
In the present invention, it is possible to easily fill any part in a bearing or universal joint having a complicated shape, and a molding die or a grinding process for obtaining a foam molded article is unnecessary. It is preferable to employ a method in which the mixture is poured into a bearing or a universal joint before foaming / curing and foamed / cured in the bearing or universal joint. By adopting this method, the manufacturing process is simplified and the cost can be reduced.

  It is preferable that the air bubbles to be generated when foamed by foaming at the time of foaming / curing are open air bubbles, and the lubricating component is directly transferred from the surface of the resin to the outside through the open air cells by external stress. This is to supply. In the case of closed cells that do not communicate with each other, the entire amount of lubricating oil in the solid component is temporarily isolated in the closed cells, making it difficult to move between the bubbles. May not be supplied.

  In addition, the lubricating component contained in the state of being impregnated in the foamed solid lubricant does not exude suddenly even when the foam is deformed by an external force, and the lubricating component can be efficiently exuded and used. As a result, the amount of the lubricating component may be the minimum necessary, and the lubricating performance can be maintained for a long period.

  The form of the auxiliary lubricant containing the solid lubricant in the present invention is not particularly limited. For example, as illustrated in FIG. 1, a grease containing a solid lubricant may be used, or a paste or slurry substance in which a solid lubricant is dispersed in oil or the like at a high concentration may be used. What is necessary is just to take the method according to the property of the solid lubricant to be used. In the case of grease, the lubricating component released from the foamed solid lubricant circulates within the lubrication target part such as a universal joint by centrifugal force or bending motion, and is a relatively hard (high viscosity) paste or slurry. It can be mixed with and diffused inside the lubrication target part and moved to the sliding part.

When grease is selected as the form of the auxiliary lubricant, as the thickener and base oil for obtaining the grease, those exemplified as an example of the above-described lubricating component can be used. Similarly, various additives other than the solid lubricant can be added to the grease.
When a paste or a slurry-like substance is selected as the form of the auxiliary lubricant, the base oil for obtaining the paste or slurry can be the one exemplified as the above-mentioned lubricating component. Similarly, various additives other than the solid lubricant can be added to the paste or slurry.
In addition, it is desirable to include a solid lubricant in these greases, pastes, and slurries in an amount of 0.5% by weight or more based on the total components. It is difficult to obtain the expected effect when the solid lubricant content is less than this.

  As the solid lubricant that can be used in the present invention, those having cleavage properties such as molybdenum disulfide, tungsten disulfide, melamine cyanurate, polytetrafluoroethylene resin, boron nitride, and graphite are preferable. Further, although it is not cleaved, a solid MoDTC is also preferable because it can react at the sliding interface and form a molybdenum disulfide film on the sliding surface. These solid lubricants may be composed of only one type, or may be used in combination of two or more types.

  In the present invention, when the auxiliary lubricant is sealed, the auxiliary lubricant is preferably 1 to 40% by volume of the space volume inside the object to be lubricated. More preferably, it is 3 to 30% by volume. If it is less than 1% by volume, it is insufficient as an auxiliary lubricant, and if it exceeds 40% by volume, the amount of foamed solid lubricant that contributes to lubrication over a long period of time will be reduced, resulting in a problem in durability. .

In the present invention, the method for enclosing the auxiliary lubricant is not limited. Before filling the part to be lubricated with the foamed solid lubricant, grease, paste or slurry-like substance containing the solid lubricant may be applied to the part to be lubricated or its parts, or foamed to the part to be lubricated. After filling with a solid lubricant, it may be injected into the target location with a syringe (or similar).
The place where the auxiliary lubricant is enclosed or applied in the lubrication system is not particularly limited, but it is preferable to enclose or apply the auxiliary lubricant near the sliding portion of the lubrication target part. When used for a constant velocity universal joint, the outer member bottom is also preferable as described above. The enclosed or applied auxiliary lubricant is gradually moved to the sliding portion of the lubrication target site by the centrifugal force or bending motion of the lubrication target site, and can contribute to lubrication.

<Preparation of auxiliary lubricant (grease)>
Solid lubricant-containing greases A to D used in Examples 1 to 4 were produced by the following method. In addition, the penetration degree represents the 60-time penetration penetration degree measured based on JIS K 2220 5.3.

[Solid lubricant containing grease A]
In 92 g of mineral oil (turbine 100: manufactured by Nippon Oil Corporation), 3.94 g of diphenylmethane-4,4-diisocyanate and 4.07 g of octylamine were reacted, and the resulting diurea compound was uniformly dispersed to form a base grease. Obtained. The amount of thickener in the base grease was 8% by weight, and the consistency was measured to be 320. This was mixed with 1.5% by weight of molybdenum disulfide (average particle size 0.45 μm, manufactured by CLIMAX MOLYBDENUM COMPANY) to obtain a solid lubricant-containing grease A.

[Grease B containing solid lubricant]
In 92 g of mineral oil (turbine 100: manufactured by Nippon Oil Corporation), 3.94 g of diphenylmethane-4,4-diisocyanate and 4.07 g of octylamine were reacted, and the resulting diurea compound was uniformly dispersed to form a base grease. Obtained. The amount of thickener in the base grease was 8% by weight, and the consistency was measured to be 320. This was mixed with 1.5% by weight of tungsten disulfide (average particle size 1 μm, manufactured by Nippon Lubricant Co., Ltd.) to obtain a solid lubricant-containing grease B.

[Grease C containing solid lubricant]
Mineral oil (turbine 100: manufactured by Nippon Oil Co., Ltd.) Base grease by reacting 12.39 g of diphenylmethane-4,4-diisocyanate and 10.61 g of p-toluidine to uniformly disperse the produced diurea compound Got. The amount of thickener in the base grease was 23% by weight, and the consistency was measured to be 270. To this, 1.0 wt% of melamine cyanurate (Mitsubishi Chemical Co., Ltd.) and 1.0 wt% of MoDTC (trade name: Sakura Rube 600 Adeka Co., Ltd.) were blended to obtain a solid lubricant containing grease C.

[Grease D containing solid lubricant]
Mineral oil (turbine 100: manufactured by Nippon Oil Co., Ltd.) Base grease by reacting 12.39 g of diphenylmethane-4,4-diisocyanate and 10.61 g of p-toluidine to uniformly disperse the produced diurea compound Got. The amount of thickener in the base grease was 23% by weight, and the consistency was measured to be 270. Boron nitride (average particle size 5 μm, manufactured by Denki Kagaku Kogyo Co., Ltd.) was blended with 2.0% by weight of this to obtain a solid lubricant-containing grease D.

Examples 1 to 15 and Comparative Examples 1 to 4
The lubricating components, liquid rubber, curing agent, foaming agent, and catalyst used in Examples 1 to 15 and Comparative Examples 1 to 4 are shown below. In addition, () represents an abbreviation in the table.
Lubricating component Lubricating oil (lubricating oil): Turbine 100 (manufactured by Nippon Oil Corporation)
Lubricating grease (Grease 1): NTG2218M (manufactured by Kyodo Yushi Co., Ltd.)
Liquid rubber Hydroxyl-terminated polybutadiene (PBOH1): Poly-bd R45HT (hydroxyl value: 46.6 mgKOH / g, number average molecular weight: 2,800, manufactured by Idemitsu Kosan Co., Ltd.)
Hydroxyl-terminated polybutadiene (PBOH2): Poly-bd R15HT (hydroxyl value: 102.7 mgKOH / g, number average molecular weight: 1,200, manufactured by Idemitsu Kosan Co., Ltd.)
Hydroxyl-terminated polyisoprene (PipOH): Poly-ip (hydroxyl value: 46.6 mgKOH / g, number average molecular weight: 2,500, manufactured by Idemitsu Kosan Co., Ltd.)
Hydrogenated hydroxyl-terminated polyisoprene (HPipOH): Epol (hydroxyl value: 50.5 mgKOH / g, number average molecular weight: 2,500, manufactured by Idemitsu Kosan Co., Ltd.)
Curing agent Isocyanate compound (TDI): Coronate T-80 (manufactured by Nippon Polyurethane Co., Ltd.)
Elastomer 1 (UE1): Coronate 4090 (4.4 NCO% made by Nippon Polyurethane)
Elastomer 2 (UE2): Plaxel EP1130 (3.3NCO% manufactured by Daicel Chemical Industries)
Foaming agent (foaming agent) Ion exchange water Foam stabilizer (foam stabilizer) SRX298 (manufactured by Toray Dow)
Catalyst (Catalyst 1) DM70 (manufactured by Tosoh Corporation)

Mix well the compounding materials except the curing agent (isocyanate) at the blending ratios shown in Tables 1 to 3, and finally add 40 g of the mixture that was quickly mixed by adding the curing agent to a polytetrafluoroethylene resin container (70 mm in diameter). × Height 150 mm). After a few seconds, the foaming reaction started and allowed to stand at room temperature for several hours to be cured to obtain a cylindrical test piece. This test piece was observed visually and using an optical microscope. Evaluated as an excellent foamed solid lubricant that is an elastic rubber foam in which oil oozes out when a force of 30 N is applied to the specimen in the direction of the cylinder axis of the specimen. Further, when not cured as a foam, cases where the lubricating oil does not separate or release are marked with “x” and are also shown in Tables 1 to 3.
In addition, the test piece evaluated as “◯” showed no oil oozing even when it was stretched by 20% in the cylindrical axis direction of the test piece.

As shown in Tables 1 to 3, the foamed solid lubricants of Examples 1 to 15 are elastic rubber foams in which oil oozes out when a corresponding force is applied when pressed with a finger. Although it was recognized as an excellent foamed solid lubricant, in Comparative Examples 1 to 4, it was found that although foamed, it did not partially solidify and function as a foamed solid lubricant.
Next, the auxiliary lubricating component of Examples 1 to 15 is sealed in the bottom of the outer member 2 of the constant velocity universal joint shown in FIG. 1, and then the foamed solid lubricant component is shown in FIG. Was poured around the steel ball 5 and allowed to stand at room temperature for several hours to be cured, thereby obtaining a constant velocity universal joint in which a foamed solid lubricant was enclosed.
In this constant velocity universal joint, the foamed solid lubricant is enclosed around the steel ball 5, so that it is possible to effectively prevent scattering and leakage of the lubricating oil to the outer member opening end side (boot 8 side), Lubricating components could be accurately supplied around the steel balls 5 serving as torque transmitting members, and deterioration of the lubricating characteristics could be suppressed.

The lubricating components, urethane prepolymers, curing agents, foaming agents, and catalysts used in Examples 16 to 35 and Comparative Examples 5 to 7 are shown below. In addition, () represents an abbreviation in the table.
Lubricating component Lubricating oil (lubricating oil 1): Turbine 100 (paraffinic mineral oil, manufactured by Nippon Oil Corporation)
Lubricating oil (lubricating oil 2): Crisef 150 (Naphthenic mineral oil, manufactured by Nippon Oil Corporation)
Lubricating oil (lubricating oil 3): Sinfluid 801 (poly-α-olefin, manufactured by Nippon Steel Chemical Co., Ltd.)
Lubricating grease (Grease 2): Pyronock Universal N6C (manufactured by Nippon Oil Corporation)
Urethane prepolymer Caprolactan-based urethane prepolymer 1 (prepolymer 1): Plaxel EP1130 (NCO 3.3%, manufactured by Daicel Chemical Industries)
Ether-based urethane prepolymer (Prepolymer 2): Coronate 4090 (NCO 4.3%, manufactured by Nippon Polyurethane Co., Ltd.)
Ester urethane prepolymer (Prepolymer 3): Coronate 4047 (NCO 4.3%, manufactured by Nippon Polyurethane Co., Ltd.)
Caprolactan urethane prepolymer (Prepolymer 4): Takenate L-1350 (NCO 2.3%, manufactured by Mitsui Chemicals Polyurethanes)
Ether-based urethane prepolymer (Prepolymer 5): Takenate L-1170 (NCO 2.4%, manufactured by Mitsui Chemicals Polyurethanes)
Caprolactan urethane prepolymer (Prepolymer 6): Takenate L-1680 (NCO 3.2%, manufactured by Mitsui Chemicals Polyurethanes)
Caprolactan urethane prepolymer (Prepolymer 7): Cyanaprene 7-QM (NCO 2.3%, manufactured by Mitsui Chemicals Polyurethanes)
Ether-based urethane prepolymer (Prepolymer 8): Takenate L-1158 (NCO 4.4%, manufactured by Mitsui Chemicals Polyurethanes)
Hardener MOCA (MOCA): Iharacamine MT (manufactured by Ihara Chemical)
Trimethylene-bis- (4-aminobenzoate) (CUA-4): CUA-4 (manufactured by Ihara Chemical)
Mixture of bis (methylthio) -2,4-toluenediamine, bis (methylthio) -2,6-toluenediamine and methylthiotoluenediamine (Etacure 300): Etacure 300 (manufactured by Albemarle)
Trimethylolpropane: Reagent blowing agent (foaming agent) Ion exchange water foam stabilizer (foam stabilizer) SRX298 (manufactured by Toray Dow)
Catalyst (Catalyst 1)

Examples 16-18, 21, 22, 24, 25, 27-32, 34-35, Comparative Examples 5-7
In a polytetrafluoroethylene beaker (diameter 70 mm × height 150 mm) at 80 ° C., the raw materials excluding the curing agent, amine catalyst and blowing agent were mixed well in the blending ratios shown in Tables 4 to 6. Next, MOCA dissolved at 120 ° C. was put into a beaker and well stirred. Subsequently, an amine catalyst and a foaming agent (only Comparative Example 6 had no foaming agent) were added and stirred. After a few seconds, the foaming reaction started, and it was allowed to stand at 100 ° C. for 30 minutes to cure to obtain a cylindrical test piece. This test piece was observed visually and using an optical microscope. Evaluated as an excellent foamed solid lubricant that is an elastic rubber foam in which oil oozes out when a force of 30 N is applied to the specimen in the direction of the cylinder axis of the specimen. In other cases, “Δ” mark or comments are also shown in Tables 4 to 6.
Further, the open cell ratio was measured by the above-described method, and the centrifugal oil separation evaluation was measured by the following method. The results are shown in Tables 4-6.
Centrifugal oil separation evaluation test Centrifugal oil separation was measured in order to examine the sustained release of the lubricant. Centrifugal oil separation showed the oil reduction rate relative to the oil filling amount when rotated for 1 hour under the conditions of a rotor radius of 75 mm and a rotation speed of 1500 rpm.

Example 19
In a polytetrafluoroethylene beaker (diameter 70 mm × height 150 mm) at 100 ° C., the raw materials excluding the curing agent, amine catalyst and blowing agent were mixed well in the blending ratio shown in Table 4. Next, trimethylene-bis (4-aminobenzoate) dissolved at 140 ° C. was put into a beaker and stirred well. Subsequently, an amine catalyst and a blowing agent were added and stirred. After a few seconds, the foaming reaction started, and it was allowed to stand at 100 ° C. for 30 minutes to cure to obtain a cylindrical test piece. This test piece was observed visually and using an optical microscope. Evaluated as an excellent foamed solid lubricant by an elastic rubber foam that exudes oil when a force of 30 N is applied to the specimen in the direction of the cylinder axis of the specimen. Is also shown in Table 4.

Examples 20, 26, 33
In a polytetrafluoroethylene beaker (diameter 70 mm × height 150 mm) at 80 ° C., the raw materials excluding the curing agent, amine catalyst and blowing agent were mixed well in the blending ratios shown in Tables 4 to 6. Next, Etacure 300 was put into a beaker and stirred well. Subsequently, an amine catalyst and a blowing agent were added and stirred. After a few seconds, the foaming reaction started, and it was left to cure at 100 ° C. for 30 minutes to obtain a cylindrical test piece. This test piece was observed visually and using an optical microscope. Evaluated as an excellent foamed solid lubricant by an elastic rubber foam that exudes oil when a force of 30 N is applied to the specimen in the direction of the cylinder axis of the specimen. Are also shown in Tables 4-6.

Example 23
In a polytetrafluoroethylene beaker (diameter 70 mm × height 150 mm) at 100 ° C., raw materials excluding the curing agent, amine catalyst and blowing agent were mixed well in the blending ratio shown in Table 5. Next, trimethylolpropane was put into the beaker and stirred well. Subsequently, an amine catalyst and a blowing agent were added and stirred. After a few seconds, the foaming reaction started, and it was allowed to stand at 100 ° C. for 30 minutes to cure to obtain a cylindrical test piece. This test piece was observed visually and using an optical microscope. Evaluated as an excellent foamed solid lubricant that is an elastic rubber foam in which oil oozes out when a force of 30 N is applied to the specimen in the direction of the cylinder axis of the specimen. Is also shown in Table 5.

As shown in Tables 4 to 6, Examples 16 to 35 are elastic rubber foams in which oil oozes out when a corresponding force is applied when pressed with a finger, and excellent foam solid lubrication. In Comparative Example 5, it was found that although foamed, it did not partially solidify, and in Comparative Example 6, the resin component and the lubricant were separated and did not function as a foamed solid lubricant. . Comparative Example 7 lacked elasticity. Further, in Examples 16 to 35, it was found that the lubricant component was gradually released under the centrifugal force (without immediately leaving the foam).
Next, the auxiliary lubricating components of Examples 16 to 35 are sealed in the bottom of the outer member 2 of the constant velocity universal joint shown in FIG. 1, and then the foamed solid lubricant component is shown in FIG. Was poured around the steel ball 5 and allowed to harden at 100 ° C. for 30 minutes to obtain a constant velocity universal joint encapsulating a foamed solid lubricant.
In this constant velocity universal joint, the foamed solid lubricant is enclosed around the steel ball 5, so that it is possible to effectively prevent scattering and leakage of the lubricating oil to the outer member opening end side (boot 8 side), Lubricating components could be accurately supplied around the steel balls 5 serving as torque transmitting members, and deterioration of the lubricating characteristics could be suppressed.

Examples 36 to 37 and Examples 39 to 40
First, as shown in FIG. 1, the outer side of an outer member 2, an inner member 1, a cage 6 and a steel ball 5 and a fixed 8-ball joint sub-assembly (EBJ82 outer diameter size 72.6 mm manufactured by NTN Corporation). At the bottom of the member, 3 g of the solid lubricant-containing grease shown in Table 1 or 2 g of the solid lubricant-containing paste was sealed. Next, among the compositions shown in Table 7, (a), (d), (e), and (i) were mixed well at 80 ° C, and then (b) dissolved at 120 ° C was added and mixed rapidly. Finally, (c) and (h) were added and stirred, and then 18.0 g was sealed in the above-mentioned joint sub-assembly in which grease or paste was sealed. After a few seconds, the foaming reaction begins, and is allowed to stand for 30 minutes in a thermostatic chamber set at 100 ° C to be cured, and other parts such as boots and shafts are assembled, and the constant velocity universal joint where the foamed solid lubricant and auxiliary lubricant coexist in the interior. The test piece was obtained.
The obtained test piece was subjected to the durability test shown below, and the lifetime was measured. Further, the open cell ratio of the foamed solid lubricant was measured based on the above-mentioned method for calculating the open cell ratio. The results are also shown in Table 7.

<Durability test using constant velocity universal joint>
In order to evaluate whether or not the target durability has been improved, the constant velocity universal joint test piece was evaluated under the following conditions. If the outer member surface temperature exceeded 100 ° C during the test, the test was terminated due to an abnormal temperature rise. In addition, after the test, the inside of the test piece is inspected, and if there is no internal damage such as wear or peeling, it is judged as acceptable. It is judged that it is impossible, and “x” is recorded.
・ Torque 451 N ・ m
・ Angle 6 deg
・ Rotation speed 580 rpm
・ Test time 300 hours

Example 38 and Example 41
First, as shown in FIG. 1, the outer side of an outer member 2, an inner member 1, a cage 6 and a steel ball 5 and a fixed 8-ball joint sub-assembly (EBJ82 outer diameter size 72.6 mm manufactured by NTN Corporation). 3 g of grease containing a solid lubricant shown in Table 1 was sealed at the bottom of the member. In the component amounts (composition) shown in Table 1, silicone-based foam stabilizer, mineral oil, amine-based catalyst, and water as a blowing agent were added to the polyether polyol, and the mixture was heated at 90 ° C. and stirred well. After adding isocyanate to this and stirring well, 16.0 g was sealed in the above-mentioned joint subassembly filled with grease. After a few seconds, the foaming reaction begins, and is allowed to stand for 15 minutes in a thermostatic chamber set at 90 ° C to cure. The constant velocity universal joint in which other parts such as boots and shafts are assembled and the solid foam lubricant and auxiliary lubricant coexist in the interior. The test piece was obtained. The same items as in Example 36 were measured. The results are also shown in Table 7.

Comparative Example 8
A constant velocity universal joint specimen with the composition shown in Table 7 was prepared in the same procedure as in Example 37, but no auxiliary lubricant-containing grease was enclosed. The same items as in Example 36 were measured. The results are also shown in Table 7.

Comparative Example 9
A constant velocity universal joint test piece having the composition shown in Table 7 was prepared in the same procedure as in Example 38, but no auxiliary lubricant-containing grease was enclosed. The same items as in Example 36 were measured. The results are also shown in Table 7.

Comparative Example 10
A constant velocity universal joint specimen was prepared in the same procedure as in Comparative Example 9 except that no silicone foam stabilizer was used. The same items as in Example 36 were measured. The results are also shown in Table 7.

  In Examples 36 to 41, wear due to lack of lubricant was not confirmed in the durability test using the constant velocity universal joint, and good results were shown.

  The lubrication system of the present invention improves the lubricant holding power of the foamed solid lubricant that retains the lubricating component, and can suppress the amount of lubricant oozing out due to deformation of the foamed solid lubricant, and Even when the lubrication component from the foamed solid lubricant is insufficient, the lubrication function can be supplemented, and a long life and cost reduction can be met. Therefore, it can be suitably used as a lubrication system for various rolling bearings and universal joints used for various industrial machines and automobiles.

It is sectional drawing which shows a constant velocity universal joint.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner member 2 Outer member 3 Inner member side track groove 4 Outer member side track groove 5 Steel ball 6 Cage 7 Shaft 8 Boot 9 Foamed solid lubricant 10 Auxiliary lubricant

Claims (12)

A lubrication system in which a foamed solid lubricant and an auxiliary lubricant coexist in a lubrication target part,
The foamed solid lubricant is a foamed solid lubricant obtained by foaming and curing a mixture containing a lubricating component, a resin component, a curing agent, and a foaming agent,
The lubrication system, wherein the auxiliary lubricant contains at least a solid lubricant. The lubricating component is at least one lubricating component selected from a hydrocarbon-based lubricating oil and a hydrocarbon-based grease;
The resin component is a liquid rubber in which the polymer main chain is composed of hydrocarbons and has hydroxyl groups in an amount such that the hydroxyl value is 25 to 110 mgKOH / g at the ends of the main chain.
The curing agent is an organic compound having an isocyanate group in the molecule,
The blowing agent is water;
The ratio of the liquid rubber and the curing agent is such that the hydroxyl group contained in the liquid rubber and the isocyanate group contained in the curing agent are in an equivalent ratio of (OH / NCO) = 1 / (1.0 to 2.0). ,
The lubricating system according to claim 1, wherein the mixture contains 40 to 80% by weight of the lubricating component and 5 to 45% by weight of the liquid rubber with respect to the whole mixture.   The liquid rubber is a hydroxyl group-terminated diene polymer having a number average molecular weight of 1000 to 3,500 having a hydroxyl group at the main chain end of a butadiene or isoprene polymer, or a modified hydroxyl group-terminated diene polymer obtained by hydrogenating the diene polymer. The lubrication system according to claim 2, wherein:   The organic compound having an isocyanate group in the molecule is a prepolymer having two or more isocyanate groups in the molecule and a ratio of isocyanate groups of 2.5 to 5.0 NCO%. The lubrication system according to claim 3.   The lubricating system according to claim 2 or 3, wherein the organic compound having an isocyanate group in the molecule is an aromatic polyisocyanate. The lubricating component is at least one lubricating component selected from lubricating oil and grease;
The resin component is a urethane prepolymer having an isocyanate group content of 2 wt% or more and less than 6 wt%,
The blowing agent is water;
The lubricating system according to claim 1, wherein the mixture contains 30 to 70% by weight of the lubricating component with respect to the whole mixture, and the open cell ratio after foaming is 50% or more.   The lubrication system according to claim 6, wherein the urethane prepolymer is at least one urethane prepolymer selected from an ester urethane prepolymer, a caprolactone urethane prepolymer, and an ether urethane prepolymer.   The ratio of the isocyanate group and the functional group of the curing agent that reacts with the isocyanate group is an equivalent ratio (functional group of the curing agent / NCO) = 1 / (1.1 to 2.5). The lubrication system according to claim 6 or 7.   The ratio of the hydroxyl group of the water and the functional group of the curing agent is an equivalent ratio (water hydroxyl group / functional group of the curing agent) = 1 / (0.7 to 2.0). The lubrication system according to any one of claims 8 to 9.   The lubricating system according to any one of claims 6 to 9, wherein the curing agent is an aromatic polyamino compound.   11. The lubricating system according to claim 10, wherein the aromatic polyamino compound is an aromatic polyamino compound having a substituent at a position adjacent to an amino group.   12. The solid lubricant according to claim 1, wherein the solid lubricant is at least one selected from molybdenum disulfide, tungsten disulfide, melamine cyanurate, boron nitride, and solid molybdenum dithiocarbamate. A lubrication system according to claim 1.

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