JP2002069473A - Composition for sliding member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide composition for a sliding member which has lower friction coefficient, superior wear resistance and better seizure resistance as compared with the existing composition for sliding members which consists of base resin and solid lubricant dispersed in the resin. SOLUTION: This composition for a sliding member contains polyamideimide(PAI) resin and microcapsules dispersed in the polyamideimide resin which consist of film made of resin and lubricant made of oil or grease contained in the film. In other words, this composition for a sliding member makes use of PAI resin as base material and microcapsules containing liquid lubricant, i.e., oil or grease, are dispersed in the PAI.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composition for a sliding member capable of forming a sliding surface having excellent friction characteristics.

[0002]

2. Description of the Related Art Sliding members are roughly divided into members such as brake discs, which increase the frictional force with a mating material and convert the kinetic energy of the mating material into frictional heat energy to suppress the motion of the mating material. And a type, such as a piston and a cylinder, which reduces the frictional force with the mating material to prevent a decrease in the kinetic energy of the mating material and maintain the motion of the mating material. The sliding surface of the sliding member corresponding to the latter is required to have good friction characteristics, such as a low friction coefficient, high wear resistance, and low opponent aggression. For this reason, the sliding surface of the sliding member is often formed of a composition having good friction characteristics (hereinafter, referred to as “composition for the sliding member”).

[0003] For example, the skirt portion of the piston and the inner wall surface of the cylinder slide during normal operation with an oil film interposed therebetween, but they come into direct contact with each other when the engine is started. In many cases, a sliding surface composition is formed by coating the surface of a skirt portion of a piston with a composition for a sliding member such as a fluororesin. For example, Japanese Patent Application Laid-Open No. 54-162014 discloses that the surface of a skirt of a piston is coated with a composition for a sliding member comprising a fluororesin as a base material and a solid lubricant dispersed in the base material, and the friction of the skirt portion is reduced. Techniques for improving characteristics are introduced. Since the fluororesin has a small friction coefficient and the solid lubricant has a high self-sliding property, the composition for a sliding member has good friction characteristics as a solid.

[0004]

However, Japanese Patent Application Laid-Open No.
The technology introduced in Japanese Patent No. 162014 has the following problems. First, the composition for a sliding member introduced in the above-mentioned publication has excellent friction characteristics, but the level is not satisfactory. That is, as compared with a conventional sliding member composition such as a fluororesin in which no solid lubricant is dispersed, the friction characteristics are improved by the effect of dispersing the solid lubricant, but the fluororesin and Solid lubricants may not have a lower coefficient of friction than fluid lubrication, and have inferior friction characteristics as compared to the case where a liquid oil film exists between the skirt and the cylinder.

[0005] Further, crystals of a substance generally forming a solid lubricant such as graphite have a layered structure, and a bond (for example, van der Waals bond) between layers having a weak bonding force is broken to cause a layer slip. This ensures self-sliding. Therefore, the solid lubricant itself has low abrasion resistance, and depending on the compounding ratio of the solid lubricant, the durability of the film coated on the skirt may be deteriorated. In addition, the solid lubricant that has fallen off the coating is present in the cylinder as sludge, which may adversely affect engine characteristics.

The inventor of the present invention has intensively studied to solve the above-mentioned problems, and formed the sliding surface with a composition for a sliding member in which a liquid lubricant was blended. It has been found that the friction characteristics of the steel can be improved. The present invention has been completed based on such knowledge,
An object of the present invention is to provide a composition for a sliding member capable of forming a sliding surface having good friction characteristics.

[0007]

In order to solve the above-mentioned problems, a composition for a sliding member according to the present invention comprises a polyamide-imide resin, a resin dispersed in the polyamide-imide resin, and a film made of the resin and wrapped in the film. And a microcapsule made of a lubricant made of oil or grease. That is, the composition for a sliding member of the present invention comprises a polyamide (imide) resin (PAI)
And microcapsules containing oil or grease as a liquid lubricant are dispersed in the PAI. In other words, microcapsules containing oil or grease are bound by PAI.

P serving as a base material of the composition for a sliding member of the present invention
AI has excellent wear resistance. In the composition for a sliding member of the present invention, a liquid lubricant is filled in microcapsules and dispersed in PAI. Therefore, when a sliding surface is formed with the present composition and the surface is slid, The released microcapsules are broken by friction with the mating material, and oil or grease flows out to cover the sliding surface, thereby ensuring lubrication. The lubricant used in the composition for a sliding member of the present invention is in a liquid state, and has a lower coefficient of friction and aggressiveness with respect to a solid lubricant than a solid lubricant, and there is no possibility of generation of sludge or the like.

Accordingly, the composition for a sliding member of the present invention is characterized by a combination of good abrasion resistance of PAI as a base material, a small coefficient of friction of a liquid lubricant and a small aggressiveness of a mating agent. Is a composition for a sliding member capable of forming an extremely good sliding surface. Further, in the composition for a sliding member of the present invention, as the wear of the sliding surface progresses, new microcapsules are exposed, so that a steady supply of the liquid lubricant to the sliding surface becomes possible. The sliding surface formed of the composition for a sliding member can stably maintain excellent friction characteristics.

The composition for a sliding member of the present invention is based on a thermosetting resin, and is used for sliding a mechanical part or the like having a surface to be slid (hereinafter referred to as a "sliding member"). It can be easily formed (coated) as a film by applying it to the surface to be cured and thermally curing it. Therefore, the wear characteristics of various sliding members can be improved and can be applied to a wide range of applications.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the composition for a sliding member of the present invention are divided into the following items: the basic composition of the composition, the mode including a solid lubricant, the manufacturing method, and the mode as a coating film. Each will be described.

(1) Basic Structure of Composition The basic structure of the composition for a sliding member of the present invention is a polyamide-imide resin, a film dispersed in the polyamide-imide resin, and a film made of the resin and wrapped in the film. Microcapsules comprising a lubricant comprising oil or grease (corresponding to claim 1). Hereinafter, polyamide-imide resin,
Each of the microcapsules will be described.

(A) Polyamide imide resin The polyamide imide resin (PAI) serving as a base material has a function of dispersing and binding microcapsules and a function of ensuring abrasion resistance. Therefore, it is necessary to have excellent mechanical strength, and in particular, it is required that the tensile strength is appropriately high. PAI has excellent mechanical strength as compared with the same thermosetting resin such as epoxy resin and polyimide resin, and satisfies this requirement.

The polyamide-imide resin has a tensile strength of 7
8.4 to 98 MPa and a longitudinal elastic modulus of 1960 to 2
940 MPa, and the elongation is preferably 10 to 20% (corresponding to claim 2). Tensile strength 78.4M
If it is Pa or more, even when the present composition is formed as a film, sufficient abrasion resistance can be obtained in a practical range, and the film is less likely to be broken.
This is because even if it exceeds MPa, the effect of further improving the wear resistance is small.

The modulus of longitudinal elasticity is particularly affected when the composition is formed as a coating on the surface of a sliding member. When the longitudinal modulus is low, the coating is easily deformed, and the contact stress with the counterpart material can be dispersed. That is, since the contact stress can be dispersed and received over a wide area of the coating, the contact stress per unit area (that is, the contact pressure) is reduced,
The coefficient of friction also decreases. However, if the coating is excessively deformed, there is a possibility that the adhesiveness to the sliding member as the base material is deteriorated. On the other hand, when the modulus of longitudinal elasticity is high, the amount of deformation of the coating film is small, but the contact pressure with the mating material is large, so that the coefficient of friction is large, and there is a possibility that seizure is likely to occur and wear is likely. For these reasons, the longitudinal elastic modulus of the PAI is preferably in the range of 1960 to 2940 MPa.

The elongation is a percentage of the deformation (elongation) of the loaded material relative to the length of the unloaded material. When the composition of the present invention is coated on a sliding member, if the elongation of the PAI serving as the base material is large, the coating film is easily deformed, and the contact stress with the partner material can be dispersed. That is, since the contact stress can be dispersed and received over a wide range of the surface of the coating film, the contact pressure decreases and the friction coefficient decreases. However, if the coating is excessively deformed, the adhesiveness to the sliding member may be deteriorated. On the other hand, when the elongation percentage is small, the amount of deformation of the coating film is small, but the contact pressure with the counterpart material is large, so that the coefficient of friction may be large, and seizure or wear may easily occur. For these reasons, the elongation percentage of PAI is preferably in the above range of 10 to 20%.

(B) Microcapsules Microcapsules are composed of a film made of resin and a lubricant made of oil or grease encapsulated in the film. And, in the PAI serving as the base material, as if
It exists in the form of a foam containing a liquid or semi-liquid lubricant, and when the foam breaks, the lubricant covers the sliding surface, ensuring lubricity of the sliding surface. The shape of the microcapsule is not particularly limited as long as it fulfills this function. For example, it may be spherical or disk-shaped.
Also, the film may have holes, grooves, or the like, and the lubricant may not be completely sealed by the film.

The film constituting the microcapsules is made of resin. The resin is not particularly limited, but is preferably a mixed resin composed of two or more resins.
(Corresponding to claim 3). As clarified by experiments, when the microcapsule film is formed from a single resin, grooves and holes are formed in the film, and oil and grease, which are lubricants, are hermetically sealed inside the film. Doing it involves some difficulty. When the capsule film is formed of a mixed resin, it is difficult for grooves and holes to be formed in the film.
The grease can be easily sealed and included, and a film having excellent liquid tightness can be formed. When the film is excellent in liquid tightness, oil and grease do not leak from the capsule film inside the composition, and the microcapsules can be broken by friction with the partner material. For this reason, the favorable friction characteristics of the composition for a sliding member of the present invention can be maintained for a long period of time.

When the capsule film is formed of a mixed resin, the mixed resin is preferably a mixed resin formed of any two of urea resin, melamine resin and benzoguanamine resin (corresponding to claim 4). These resins have thermosetting properties and are collectively called amino resins. Urea resin (UF) has heat resistance and high hardness. Melamine resin (MF) has excellent impact resistance,
It has heat resistance and flame resistance. In addition, benzoguanamine resin (UBGF) is obtained by improving the crack resistance of MF. By using a resin mixture of these resins, a capsule film having better characteristics can be easily formed. in this case,
More preferably, the mixing ratio (mass ratio) of any two of UF, MF, and UBGF in the mixed resin is 3: 7 to 7: 3. By setting the compounding ratio within this range, a film having more excellent sealing properties can be formed as compared with those outside this range.

The oil and grease encapsulated in the microcapsules are usually used as a lubricant, are compatible with the ambient temperature of use of the composition for a sliding member of the present invention, and Any kind of liquid or semi-liquid may be used. What has a viscosity etc. according to the friction characteristic required for a sliding surface should just be selected suitably and used.

The proportion of microcapsules in PAI is preferably 1 to 60 parts by weight of microcapsules per 100 parts by weight of PAI. When the amount of the microcapsules is less than 1 part by weight, the effect of reducing the friction coefficient and the effect of improving seizure resistance are small when the amount of the microcapsules is less than 1 part by weight. This is because the relative amount decreases, so that the strength of the composition itself decreases and the abrasion resistance decreases.

(2) Embodiment Including a Solid Lubricant The composition for a sliding member of the present invention comprises, in addition to a polyamideimide resin as a base material and microcapsules dispersed in the polyamideimide resin and containing a lubricant, The present invention can be implemented in a mode including a solid lubricant dispersed in a polyamideimide resin (corresponding to claim 5). Since the solid lubricant has a self-sliding property, the composition for a sliding member implemented in this embodiment has a smaller coefficient of friction and a lower aggressiveness to a partner.

The kind of the solid lubricant is not particularly limited. For example, a general lubricant such as graphite, sulfide, fluorine compound, hexagonal BN or the like can be appropriately selected and used according to the friction characteristics to be obtained.
However, the solid lubricant is desirably at least one selected from sulfides, fluorine compounds, and graphite (corresponding to claim 6). The composition for a sliding member is often used under a wide range of temperature conditions. For example, a piston for an automobile engine is used under a normal temperature environment when the engine is started, but is used under a high temperature condition when the engine is heated. Therefore, the solid lubricant contained in the composition of the present invention may be required to stably maintain high self-slidability under a wide range of temperature conditions. Among solid lubricants, sulfides, fluorine compounds, and graphite are particularly excellent in self-sliding properties as compared with other solid lubricants, and exhibit excellent self-sliding properties over a relatively wide temperature range. In the above, it can be stably maintained.

When sulfide is used as the solid lubricant, the sulfide is desirably at least one of molybdenum disulfide and tungsten disulfide. They are,
Among sulfides, it is particularly excellent in self-sliding property, and it is possible to stably maintain this excellent self-sliding property under a relatively wide temperature condition.

When a fluorine compound is used as a solid lubricant, the fluorine compound may be polytetrafluoroethylene, a tetrafluoroethylene-va-fluoroalkylvinyl ether copolymer, a tetrafluoroethylene-hexafluoropropylene copolymer, or a tetrafluoroethylene. -Ethylene copolymer, polyvinylidene fluoride,
Desirably, at least one selected from polychlorotrifluoroethylene. These compounds or a mixture of these compounds are particularly excellent in self-slidability among fluorine compounds, and it is possible to stably maintain this excellent self-slidability under a relatively wide temperature range.

When working in an embodiment containing a solid lubricant,
The proportion of the solid lubricant in the PAI is preferably 1 to 500 parts by weight of the solid lubricant based on 100 parts by weight of the PAI. If the amount is less than 1 part by weight, sufficient effect of reducing the coefficient of friction and the effect of improving seizure resistance cannot be obtained, and if it exceeds 500 parts by weight, the amount of PAI relatively serving as the base material is reduced. This is because sufficient strength cannot be obtained due to the decrease in the amount of sludge, and sludge may increase due to falling off of the solid lubricant.

The composition for a sliding member of the present invention can be carried out in a mode further containing hard particles. Since the hardness characteristics of the hard particles appear in the entire composition, the composition for a sliding member of this embodiment is a composition for a sliding member having higher wear resistance. Here, cubic boron nitride (BN), silicon nitride (Si ₃ N ₄ ), alumina (Al
₂ O ₃ ) can be used.

(3) Production Method The composition for a sliding member of the present invention is not particularly limited in its production method, and may be produced by making full use of the technology relating to composition production that has already been carried out. Hereinafter, an example of the manufacturing method will be described.

Polyamide-imide (PAI) serving as a substrate
Can be produced by various methods usually used for producing PAI, for example, by reacting diisocyanate with a tricarboxylic anhydride such as trimellitic anhydride. Also, microcapsules,
It can be formed by various methods usually used for forming microcapsules. For example, a resin material for forming a capsule film is added to an aqueous mixed solution in which oil or grease as a lubricant is added and dispersed, pH is adjusted, and condensation polymerization is performed.

When mixing and dispersing microcapsules in PAI, in order to adjust the viscosity of PAI and to facilitate mixing,
An appropriate organic solvent can be selected and added. This organic solvent is not particularly limited as long as it can dissolve PAI. For example, N-methyl-2
-Pyrrolidone (NMP) can be used. Also,
A mixed solvent obtained by adding an appropriate amount of an aromatic solvent (such as xylene) or a ketone solvent (such as methyl ethyl ketone) to NMP can also be used. When a solid lubricant (MoS ₂ , PTFE, etc.) is put into the PAI whose viscosity has been adjusted, the PAI and the solid lubricant are dispersed by a ball mill or the like, and then microcapsules are added, followed by stirring and dispersion by a propeller stirrer or the like.
When only the microcapsules are added, the precursor of the composition for a sliding member can be prepared by adding the microcapsules to the PAI, stirring with a propeller, and mixing for an appropriate time. In the case of a composition for a sliding member containing a solid lubricant, it may be added and mixed at the same time as mixing and dispersing the microcapsules.

By heating the precursor thus obtained and thermally curing the PAI serving as a base material, the composition for a sliding member of the present invention in which microcapsules and, if necessary, a solid lubricant are dispersed in the PAI. Can be manufactured.

(4) Embodiment as Coating Film The composition for a sliding member of the present invention is not particularly limited in its shape. For example, it is possible to form the present composition into various shapes and to carry out the present invention in the form of a sliding member composed only of the present composition. As a practical embodiment, for example, the present invention can be carried out as a coating film formed by coating the composition of the present invention on a sliding surface portion of a sliding member made of metal, ceramic, or the like. 7).

The coating method for forming a coating film is not particularly limited, and a known method used for ordinary resin coating may be employed. For example, the composition precursor prepared as described above is applied to a sliding member by air spray or a brush and attached to the sliding member, and then the PAI is thermally cured using a heating device such as an electric furnace to perform coating. A coating can be formed.

When a thin film is formed, it is desirable to heat the PAI to a temperature of 180 to 270 ° C. in order to cure the PAI at a stretch. When forming a thick film, for example, the precursor is first preheated to a temperature of about 80 ° C. to form a semi-cured film, and then the precursor is further laminated on the film by air spray or the like. And further heating. In this method, when laminating a film to be an intermediate layer, it is heated to a temperature of about 80 ° C.
After laminating the uppermost film, the film may be heated to a temperature of 180 to 270 ° C. By appropriately repeating the lamination, a coating film having a desired thickness can be easily formed.

In coating, it is preferable to remove dirt, oil and the like by previously cleaning and degreasing the surface of the sliding member in order to improve the adhesiveness of the coating. Further, in order to reduce repelling and dripping of the coated film and to form a uniform film, the surface of the sliding member is, for example, 50 to 1
It is preferable to preheat to a temperature of 20 ° C. in advance.

When the embodiment is carried out as a coating film, the diameter of the microcapsules is preferably 10 to 100% of the thickness of the coating film (corresponding to claim 8). If the diameter of the microcapsules is less than 10% of the thickness of the coating as compared with the preferred range, a sufficient effect of reducing the coefficient of friction and an effect of improving seizure resistance may not be obtained. If it exceeds 100%, the microcapsules will protrude from the sliding surface, and all the microcapsules will break at once by the first contact with the counterpart material. For example, the thickness of the coating used for the skirt of the piston is 20 μm.
In many cases, the microcapsules have a diameter of 2 to 20 μm. In addition, considering that the microcapsules are successively broken, the diameter of the microcapsules with respect to the thickness of the coating is 10 to 10.
More preferably, it is 66%. Note that the diameter of the microcapsules may be practically controlled by the average particle diameter.

When a coating film is formed containing a solid lubricant, the solid lubricant preferably has a particle size of 2.5 to 75% of the film thickness. If it is less than 2.5% as compared with the preferred range, the effect of reducing the friction coefficient and the effect of improving seizure resistance due to the addition of the solid lubricant cannot be obtained, and exceeds 75%. In such a case, the solid lubricant may easily fall off the coating due to friction with the partner material. In addition, the particle size of the solid lubricant may be practically controlled by the average particle size.

(5) Although the embodiment of the composition for a sliding member of the present invention has been described above, the above-described embodiment is merely an embodiment, and the composition for a sliding member of the present invention is not limited to the above-described embodiment. The present invention can be embodied in various forms including various modifications and improvements based on the knowledge of those skilled in the art.

[0039]

EXAMPLES Samples in which the composition for a sliding member of the present invention was coated on a sliding member, an experimental method for measuring the coefficient of friction, seizure load, and abrasion loss of the composition forming a coating film of these samples, and The experimental apparatus and the experimental results will be described in the section of this embodiment.

<Production of Sample> (1) Sample of Example 1 The composition for the sliding member to be coated on the sliding member was PA
I (manufactured by Hitachi Chemical Co., Ltd., trade name: HPC4250)
It consists of microcapsules dispersed in this PAI.

The tensile strength of PAI is 88.2 MPa,
The longitudinal modulus was set to 2009 MPa and the elongation was set to 17%.
Microcapsules are made of benzoguanamine resin (UB
A film formed by enclosing an oil (trade name: Castle Neo SJ30 with additives removed) in a film made of a mixed resin of GF) and a melamine resin (MF) was used. The average particle size of the microcapsules was 4 μm,
The added amount of the microcapsules was 3 parts by weight based on 100 parts by weight of PAI. When the oil is 100 parts by weight, the film is 50 parts by weight, and UBGF and MF forming the film are used.
Was set to 1: 1.

This composition was prepared by adding 400 parts by weight of N-methyl-2-pyrrolidone (NM) to 100 parts by weight of PAI.
After the addition of P), the microcapsules were charged, and the mixture was stirred by a propeller stirrer for 8 hours to prepare. The prepared composition was applied to the sliding surface of a plate-shaped sliding member preheated to 100 ° C. after degreasing by air spray,
The coating film was formed by baking at 180 ° C. to 200 ° C. for 100 minutes using an electric oven. The thickness of the coating film was about 15 μm. The sample manufactured in this manner was used as a sample of Example 1.

(2) Sample of Example 2 The composition for coating the sliding member was the same as that of Example 1. The composition for a sliding member was sprayed on the sliding surface of the block-shaped sliding member in the same manner as in the case where the sample of Example 1 was prepared, to form a coating film. The sample manufactured in this manner was used as a sample of Example 2.

(3) Sample of Example 3 The composition to be coated on the sliding member was PAI (HPC4250, manufactured by Hitachi Chemical Co., Ltd.) and this PAI
And a solid lubricant further dispersed in the PAI.

The tensile strength of PAI is 88.2 MPa,
The longitudinal modulus was set to 2009 MPa and the elongation was set to 17%.
The microcapsules used were formed by encapsulating oil (made by Idemitsu Petrochemical Co., Ltd., trade name: Idemitsu Polybutene 15R) in a film made of a mixed resin of UF and MF. The average particle size of the microcapsules is 10 μm
The amount of microcapsules added was 20 parts by weight based on 100 parts by weight of PAI. When the oil is 100 parts by weight, the film is 100 parts by weight, and the UF for forming the film is used.
And the mixing ratio (mass ratio) of MF to 1: 2.

Further, molybdenum disulfide (MoS ₂ ) (trade name: Ultrapure) was used as the solid lubricant.
The average particle size of this solid lubricant was 1 μm,
The AI was 100 parts by weight and 200 parts by weight. That is, the composition for forming the coating film of the sample of this example is obtained by further dispersing MoS ₂ as a solid lubricant in the composition of the sample of Example 1.

The method for producing the composition for a sliding member is described in PAI1
After adding 400 parts by weight of NMP to 00 parts by weight, the resultant was dispersed by a ball mill, microcapsules were added, and the mixture was stirred and dispersed by a propeller stirrer for 5 hours.

The composition for a sliding member was sprayed on the sliding surface of the plate-like sliding member in the same manner as in the case of preparing the sample of Example 1 to form a coating film. The sample manufactured in this manner was used as a sample of Example 3.

(4) Sample of Example 4 The composition to be coated on the sliding member was the same as that of Example 3. The composition for a sliding member was sprayed on the sliding surface of the block-shaped sliding member in the same manner as in the case of preparing the sample of Example 3 to form a coating film. The sample manufactured in this manner was used as a sample of Example 4.

(5) Sample of Example 5 The composition for coating the sliding member was the same as that of the sample of Example 1, except that the amount of microcapsules added was P
The AI was 100 parts by weight and 8 parts by weight. The used PAI, the material of the microcapsules, the method of preparing the composition, the method of forming the coating film, and the like are the same as those in the case of preparing the sample of Example 1. The sample manufactured in this manner was used as a sample of Example 5.

(6) Sample of Example 6 The composition for coating the sliding member was the same as the composition of the sample of Example 1, except that the amount of microcapsules added was P
AI was 100 parts by weight and 20 parts by weight.
The used PAI, the material of the microcapsules, the method of preparing the composition, the method of forming the coating film, and the like are the same as those in the case of preparing the sample of Example 1. The sample manufactured in this manner was used as a sample of Example 6.

(7) Sample of Example 7 The composition for coating the sliding member was the same as that of the sample of Example 1, except that the amount of microcapsules added was P
The AI was 30 parts by weight as 100 parts by weight.
The used PAI, the material of the microcapsules, the method of preparing the composition, the method of forming the coating film, and the like are the same as those in the case of preparing the sample of Example 1. The sample manufactured in this manner was used as a sample of Example 7.

(8) Sample of Example 8 The composition for coating the sliding member was the same as the composition of the sample of Example 1, except that the amount of microcapsules added was P
The AI was 100 parts by weight and 50 parts by weight.
The used PAI, the material of the microcapsules, the method of preparing the composition, the method of forming the coating film, and the like are the same as those in the case of preparing the sample of Example 1. The sample manufactured in this manner was used as a sample of Example 8.

(9) Sample of Example 9 The composition to be coated on the sliding member was the same as the composition of the sample of Example 3 except that the solid lubricant was dispersed in the composition of the sample of Example 1. , PA
I was 3 parts by weight as 100 parts by weight. The used PAI, the material of the microcapsules, the method of preparing the composition, the method of forming the coating film, and the like are the same as those in the case of preparing the sample of Example 3. The sample manufactured in this manner was used as a sample of Example 9.

(10) Sample of Example 10 The composition for coating the sliding member was the same as that of the sample of Example 3, except that the amount of microcapsules added was P
The AI was 100 parts by weight and 5 parts by weight. PAI used, microcapsules, material of solid lubricant,
The method for preparing the composition, the method for forming the coating film, and the like are the same as those in the case of preparing the sample of Example 3. The sample manufactured in this manner was used as a sample of Example 10.

(11) Sample of Example 11 The composition for coating the sliding member was the same as that of the sample of Example 3 except that the amount of microcapsules added was P
AI was 100 parts by weight and 10 parts by weight.
The materials used for the PAI, the microcapsules, the solid lubricant, the method for preparing the composition, the method for forming the coating film, and the like are the same as those in the case of preparing the sample of Example 3. The sample manufactured in this manner was used as a sample of Example 11.

(12) Sample of Example 12 The composition for coating the sliding member was the same as that of the sample of Example 3 except that the amount of microcapsules added was P
The AI was 35 parts by weight as 100 parts by weight.
The materials used for the PAI, the microcapsules, the solid lubricant, the method for preparing the composition, the method for forming the coating film, and the like are the same as those in the case of preparing the sample of Example 3. The sample manufactured in this manner was used as a sample of Example 12.

(13) Sample of Comparative Example 1 The composition to be coated on the sliding member comprises the same PAI as in Example 3 and a solid lubricant (MoS ₂ ). In other words, the composition of the sample of Example 3 for forming a coating film is the same as the composition without microcapsules. The amount of the solid lubricant added is 100
The weight was 230 parts by weight. The composition was prepared by adding a solid lubricant to PAI and stirring for 8 hours in a ball mill. The method of forming the coating film and the like are the same as in the case where the sample of Example 3 was manufactured. The sample manufactured in this manner was used as a sample of Comparative Example 1.

(14) Sample of Comparative Example 2 The composition for coating the sliding member was the same as the sample of Comparative Example 1. The composition for a sliding member was sprayed on the sliding surface of the block-shaped sliding member in the same manner as in the case where the sample of Comparative Example 1 was prepared, to form a coating film. Comparative Example 2
Sample.

(15) Sample of Comparative Example 3 The composition to be coated on the sliding member comprises only the same PAI as in Example 1. That is, the composition for forming the coating film of the sample of Example 1 is the same as the composition without adding microcapsules. The method for preparing the composition, the method for forming the coating film, and the like are the same as those in the case of preparing the sample of Example 1. The sample manufactured in this manner was used as a sample of Comparative Example 3.

<Experimental Method and Experimental Apparatus> (1) The experimental conditions were such that there was no lubricant between the coating film coated on the surface of the sliding member and the mating material (hereinafter referred to as “non-lubricating condition”). ) And a condition in which an oil (a product obtained by removing an additive from Castle Neo SJ30) is present between the coating film and the mating material (hereinafter referred to as “lubrication condition”). . The reason why the additive was removed was to clarify the effect of the microcapsule.

The measurement items were three items: coefficient of friction, seizure load, and wear amount. A thrust tester was used to measure the friction coefficient and the seizure load. FIG. 1 shows an outline of the thrust tester. As shown in FIG. 1, the testing machine presses a fixed steel circular surface 20 of a hollow cylindrical member (hardness 500 Hv) 2 having an outer diameter of 25 mmφ and an inner diameter of 20 mmφ against a coating surface 10 of a rotating plate-shaped sample 1. In this way, the coefficient of friction and the seizure load of the composition for a sliding member forming a coating film are measured.
In this experiment, the pressing load was gradually increased while stepping up every 196N. The rotation speed of the plate-shaped sample 1 was 1000 rpm under lubricating conditions, and 100 rpm under non-lubricating conditions. The samples used for measuring the seizure load are the samples of Example 1, Example 3, Examples 5 to 12, Comparative Example 1, and Comparative Example 3. The samples used for measuring the coefficient of friction are the samples of Example 1, Example 3, and Comparative Example 1.

Here, seizure means that when the hollow cylindrical member is pressed against the rotating coating surface, the coefficient of friction exceeds 0.3 when it is judged to be seizure. It is in a state of abrasion and peeling). The value at a pressing load of 1960 N was used as the friction coefficient.

(2) A wear amount was measured using a block-on-ring tester and a surface roughness meter. FIG. 2 shows an outline of the block-on-ring tester. As shown in FIG. 2, the block-on-ring tester is a rotating steel ring member having an outer diameter of 35 mmφ (hardness 500 to 600H).
v) A composition for forming a coating film is slid and worn by pressing the coating surface 40 of the block-shaped sample 4 fixed on the circumferential surface 30 of 3.

In this experiment, the pressing load of Sample 4 was 98 Pa, and the pressing time was 20 minutes. The number of rotations of the ring was 30 rpm. The samples used for measuring the wear amount are the samples of Example 2, Example 4, and Comparative Example 2.

After the experiment, the coating surface was scanned with a surface roughness meter, and the depth of the sliding portion in the direction perpendicular to the coating surface relative to the non-sliding portion of the coating surface was measured.

<Experimental Results> Tables 1 and 2 show the composition, the seizing load, the coefficient of friction, and the composition of the sliding member composition for forming the coating film of the sample of the example and the sample of the comparative example.
Shows the amount of wear.

[0068]

[Table 1]

[0069]

[Table 2]

(1) First, in a lubricating condition and a non-lubricating condition, 1) PAI + solid lubricant, 2) PAI + microcapsule, 3) PAI + microcapsule + solid lubricant, each having a different composition for a sliding member. Consider the seizure load. The sample used in the experiment is Example 1.
(PAI + microcapsule), Example 3 (PAI + microcapsule + solid lubricant), and Comparative Example 1 (PAI + solid lubricant). FIG. 3 shows the results of measuring the seizure load of a composition for a sliding member forming a coating film of these samples (hereinafter, simply referred to as “sample”) using a thrust tester. Note that the sample of Comparative Example 1 was seized at 196 (N) which is the initial step value of the pressing load under non-lubricated conditions, so that the seizing load could not be measured.

First, the difference in seizure load depending on the presence or absence of microcapsules will be examined. From FIG. 3, it was found that under the lubricating condition and the non-lubricating condition, the samples of Examples 1 and 3 to which microcapsules were added had a higher seizure load than the sample of Comparative Example 1 to which microcapsules were not added. That is, it was found that the seizure load of the composition was higher when microcapsules were added. A high seizure load means that seizure does not occur up to that load, meaning that the frictional force is small.

Next, the difference in the seizure load depending on whether or not the solid lubricant is added will be examined. In FIG. 3, when comparing the sample of Example 1 in which the solid lubricant was not added and the sample of Example 3 in which the solid lubricant was added, under the lubrication condition, the seizure load was 4704 (N) (Table). 1), no difference was found. On the other hand, under the non-lubricating condition, it was found that the sample of Example 3 had a higher seizure load than the sample of Example 1. That is, it was found that the seizure load of the composition was higher when the solid lubricant was added, particularly under non-lubricating conditions.

(2) Next, the friction coefficients (values under a load of 1960 N) of the compositions having different constitutions 1), 2) and 3) under lubricating and non-lubricating conditions will be examined. The samples used in the experiment are Example 1 (PAI + microcapsule), Example 3 (PAI + microcapsule + solid lubricant), and Comparative Example 1 (PAI + solid lubricant). FIG. 4 shows the results of measuring the friction coefficient of these samples using a thrust tester. Comparative Example 1
The coefficient of friction of the sample of Comparative Example 1 under non-lubricated conditions could not be measured because the sample of Comparative Example 1 was seized with a load of 196 (N) or less.

First, the difference in the coefficient of friction between the presence and absence of microcapsules will be examined. From FIG. 4, it was found that, under the lubricating condition and the non-lubricating condition, the samples of Examples 1 and 3 to which microcapsules were added had a smaller coefficient of friction than the sample of Comparative Example 1 to which microcapsules were not added. That is, it was found that the friction coefficient of the composition was smaller when microcapsules were added.

Next, the difference in the coefficient of friction between the presence and absence of the solid lubricant will be examined. In FIG. 4, when comparing the sample of Example 1 in which the solid lubricant was not added and the sample of Example 3 in which the solid lubricant was added, under the lubricating condition, the coefficient of friction of the sample of Example 1 was 0.033. Whereas the coefficient of friction of the sample of Example 3 is 0.0
28 (see Table 1), and it was found that the sample of Example 3 had a slightly lower coefficient of friction. It was also found that the sample of Example 3 had a smaller coefficient of friction than the sample of Example 1 even under non-lubricated conditions. That is, it was found that the friction coefficient of the composition was smaller when the solid lubricant was added under both the lubricating condition and the non-lubricating condition.

(3) Next, the amount of wear of the compositions having different constitutions 1), 2) and 3) will be examined under lubricating conditions. The sample used in the experiment was Example 2.
(PAI + microcapsule), Example 4 (PAI + microcapsule + solid lubricant), and Comparative Example 2 (PAI + solid lubricant). FIG. 5 shows the results of measuring the amount of wear of these samples using a block-on-ring tester and a surface roughness meter.

First, the difference in wear amount between the presence and absence of microcapsules will be examined. From FIG. 5, the samples of Examples 2 and 4 to which microcapsules were added were
It was found that the abrasion loss was smaller than that of the sample of Comparative Example 2 in which microcapsules were not added. That is, it was found that when the microcapsules were added, the amount of abrasion of the composition was smaller and the abrasion resistance was better.

Next, the difference in the amount of wear depending on the presence or absence of the solid lubricant will be examined. In FIG. 5, comparing the sample of Example 2 in which the solid lubricant was not added and the sample of Example 4 in which the solid lubricant was added, the sample of Example 2 was more worn than the sample of Example 4. The amount was found to be small. That is, it was found that the abrasion resistance of the composition was higher when the solid lubricant was not added.

(4) Next, the relationship between the added amount of microcapsules (hereinafter simply referred to as “added amount”) and the seizure load under non-lubricated conditions will be examined. The samples used in the experiment were Example 1 (addition amount 3 parts by weight), Example 5 (addition amount 8 parts by weight), Example 6 (addition amount 20 parts by weight), Example 7 (addition amount 30 parts by weight). Example 8 (addition amount: 50 parts by weight) and Comparative Example 3 (no addition). Note that no solid lubricant was added to these samples. FIG. 6 shows the results of measuring the seizure load of these samples using a thrust tester. The sample of Comparative Example 3 has an initial step value of 196 (N) of the pressing load.
, The seizure load could not be measured.

From FIG. 6, it was found that the samples of Examples 1, 5, 6, 7, and 8 to which microcapsules were added had a higher seizure load than the sample of Comparative Example 3 to which no microcapsules were added. Further, it was found that even a sample having a relatively small amount of addition (Example 1) can have a certain degree of image sticking suppression effect. In other words, it was found that under non-lubricated conditions, the addition of microcapsules can suppress seizure, and this effect can be obtained to some extent even with a small amount of addition.

(5) Next, the relationship between the amount of addition and the seizure load under lubricating conditions will be examined. The samples used in the experiments were Example 9 (addition amount 3 parts by weight), Example 10 (addition amount 5 parts by weight), Example 11 (addition amount 10 parts by weight), Example 3 (addition amount 20 parts by weight). Example 12 (addition amount: 35 parts by weight) and Comparative Example 1 (no addition). In addition,
These samples have a solid lubricant added. FIG. 7 shows the results of measuring the seizure load of these samples using a thrust tester.

From FIG. 7, it was found that the samples of Examples 9, 10, 11, 3 and 12 to which microcapsules were added had a higher seizure load than the sample of Comparative Example 1 to which no microcapsules were added. In addition, it was found that even with a sample having a relatively small amount of microcapsules (Example 9), a sufficient image sticking suppression effect was obtained.
That is, it was found that, even under the lubricating conditions, the seizure can be suppressed by adding the microcapsules, and this effect can be obtained even with a small amount of addition.

<Conclusion> From the above experiments, the seizure load is increased according to the composition comprising PAI to which the microcapsules of the present invention are added, as compared with the composition comprising PAI to which conventional solid lubricant is added. It was found that the coefficient of friction could be reduced and the amount of wear could be reduced.

Further, it was found that according to the composition comprising PAI to which the microcapsules and the solid lubricant of the present invention were added, the seizure load could be further increased and the friction coefficient could be reduced.

[0085]

EFFECT OF THE INVENTION P containing microcapsules of the present invention
According to the composition for a sliding member made of AI, it is possible to provide a composition for a sliding member having a small friction coefficient, excellent abrasion resistance, and low aggressiveness to a partner. In addition, it is possible to provide a composition for a sliding member that can stably maintain the above-mentioned excellent friction characteristics and continuously maintain it. In addition, since oil enters the broken microcapsules during sliding and is retained by capillary action, even if the oil does not operate for a long time and the amount of oil decreases, the oil in the capsule acts and seizure occurs, resulting in problems such as high μ. Is difficult to occur.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of a thrust tester.

FIG. 2 is a diagram showing an outline of a block-on-ring tester.

FIG. 3 is a diagram showing a seizure load under lubricating and non-lubricating conditions.

FIG. 4 is a diagram showing a coefficient of friction under lubricated and non-lubricated conditions.

FIG. 5 is a diagram showing the amount of wear under lubrication conditions.

FIG. 6 is a graph showing the relationship between the amount of microcapsules added and the seizure load under non-lubricated conditions.

FIG. 7 is a diagram showing the relationship between the amount of microcapsules added and the seizure load under lubrication conditions.

[Description of Signs] 1: Plate sample 2: Hollow cylindrical member 3: Ring member 4: Block sample 10: Coating surface 2
0: circular surface 30: circumferential surface 40: coating surface

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C10M 103/02 C10M 103/02 Z 103/06 103/06 C 107/38 107/38 149/16 149 / 16 149/18 149/18 149/20 149/20 // F16J 1/01 F16J 1/01 C10N 10:12 C10N 10:12 20:00 20:00 Z 30:06 30:06 40:02 40:02 50:08 50:08 50:10 50:10 (72) Inventor Yoshio Fuwa 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Automobile Co., Ltd. (72) Inventor Shoichi Seki 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto Inside (72) Inventor Noriyuki Ikeda 84 Takata Building Estate Co., Ltd., Naze-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Takehiro Kawata Within 84 Takata Building-Nase-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 3J044 AA02 BB37 BC04 DA09 4F071 AA55 AA71 AB03 AB23 AB27 AD04 AH18 EA01 4H104 AA04A AA19A AA26A CD01A CD02A CE12C CE13C CE14C EA01C FA06 LA03 PA01 QA11 QA18 QA22 QA27 4J002 AE002 AE052 AE05 AE052

Claims (8)

[Claims] 1. A sliding member comprising: a polyamide-imide resin; and microcapsules dispersed in the polyamide-imide resin and comprising a film made of a resin and a lubricant made of oil or grease encapsulated in the film. Composition. 2. The polyamide-imide resin has a tensile strength of 78.4 to 98 MPa and a longitudinal modulus of 19.
The composition for a sliding member according to claim 1, wherein the composition is 60 to 2940 MPa and the elongation is 10 to 20%. 3. The resin constituting the microcapsule is a mixed resin comprising two or more resins.
Or the composition for a sliding member according to claim 2. 4. The composition for a sliding member according to claim 3, wherein the mixed resin is a mixed resin formed from any two of urea resin, melamine resin, and benzoguanamine resin. 5. The composition for a sliding member according to claim 1, further comprising a solid lubricant dispersed in the polyamide-imide resin. 6. The composition for a sliding member according to claim 5, wherein the solid lubricant is at least one selected from a sulfide, a fluorine compound, and graphite. 7. The composition for a sliding member according to claim 1, wherein the composition is formed as a coating film coated on the sliding member. 8. The composition for a sliding member according to claim 7, wherein the diameter of the microcapsules is 10 to 100% of the thickness of the coating film.