JP3054291B2 - Composition for sliding members - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a composition for a sliding member using a heat-resistant synthetic resin as a binder. The sliding member obtained by using the composition for a sliding member is suitable for use in a portion which is slid particularly under lubrication in oil, such as a skirt portion of an engine piston.

[0002]

2. Description of the Related Art Conventionally, a slide using a heat-resistant synthetic resin as a binder has been used.
As a proposal to improve the sliding characteristics of moving members, the mineral Mo
S_Two, PTFE, C (graphite) and other solid lubricants
Formulation is being done. For example, (1) polyamide imide
Containing PTFE to reduce wear
-162014), (2) Mineral M in epoxy resin
oS _Two(JP-A-57-39916)
Report), (3) C (graphite) compounded with epoxy resin
(JP-A-59-190455), (4)
Mineral MoS to polyamideimide_TwoCompounded with
JP-A-63-125821) is known.

As a proposal for improving the sliding characteristics of a magnetic recording medium, (5) a magnetic layer in which a ferromagnetic powder is dispersed in a binder has a general formula:

[0004]

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(Where R is an alkyl group having 1 to 20 carbon atoms) containing an organic molybdenum compound (JP-A-60-195729);

[0006]

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(Where R is an alkyl group having 1 to 20 carbon atoms) containing an organic molybdenum compound (JP-A-60-195731);

[0008]

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A compound containing an organic molybdenum compound represented by the formula (where R is an alkyl group having 1 to 20 carbon atoms) is known (Japanese Patent Application Laid-Open No. 60-195,731).

[0010]

However, the above (1) to (1)
Minerals MoS ₂ , PTFE, C in each proposal of (4)
Solid lubricants such as (graphite) are commercially available having a particle size of, for example, 10 to 30 μm for mineral MoS ₂ and 5 for PTFE.
It is relatively large, such as 10 μm to 10 μm, and tends to be non-uniformly dispersed in the liquid when it is simultaneously dissolved in a solvent together with a binder serving as a matrix.

For this reason, if a coated sliding member is manufactured by coating the base material with such a composition, local absence of the solid lubricant occurs on the sliding surface, and the local frictional force increases. It also becomes the starting point of the occurrence of wear and peeling. Thus, the non-uniform dispersion of the solid lubricant not only impairs the wear characteristics and the seizure characteristics, but also does not reduce the friction characteristics for the mixing ratio of the solid lubricant, and causes variations in these characteristics. . In the worst case, there is a possibility that the coat sliding member is broken.

When a molded sliding member is manufactured using such a composition, for example, when an external force such as a bending stress or a tensile stress is applied, the solid lubricant dispersed non-uniformly in the molded sliding member. May cause stress concentration in the resulting material, and there is a possibility that the molded sliding portion agent is broken. Of course, means for reducing the particle size of the solid lubricant in the coated sliding member and the molded sliding member as much as possible can be considered. However, in order to reduce the particle size of the solid lubricant, a sand mill, a roll mill, a homogenizer, etc. , The minerals MoS ₂ , PTFE, C (graphite), etc. are reduced to about 1 to 4 μm, but still cannot be sufficiently dispersed uniformly in the solvent together with the binder.

On the other hand, it has been found that the sliding member in which only the organic molybdenum compound is blended in the binder, as in the proposals (5) to (7) above, has insufficient sliding characteristics at the initial stage of sliding. That is, in the sliding member obtained by dispersing the organic molybdenum compound in the binder, Mo in the molecules of the organic molybdenum compound on the sliding surface and S in the same molecule are activated by heat during sliding, MoS ₂ is produced by an intermolecular reaction. Since the generated MoS ₂ adheres to the sliding member and the surface of the mating material, the frictional force is reduced, the friction coefficient is reduced, and accordingly, the wear resistance and the seizure surface pressure are improved. In particular, in the lubricating oil, S in the lubricating oil also contributes to the generation of MoS ₂ , and the sliding characteristics of the sliding member are further improved.

However, the inventors of the present invention have found that a sliding member containing only an organic molybdenum compound in a binder has a relatively low starting temperature or a low lubricating oil temperature (about 40 to 50) at the beginning of sliding. (Less than ° C.), it was found that Mo in the molecules of the organic molybdenum compound and S in the same molecules or S in the lubricating oil were hardly activated, and it was difficult to generate MoS ₂ by an intermolecular reaction. Therefore, a sliding member in which only an organic molybdenum compound is blended in a binder does not have sufficient sliding characteristics at the initial stage of sliding.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to produce a sliding member which exhibits excellent wear characteristics, seizure characteristics and friction characteristics from the initial stage of sliding, and is hard to break. It is an object of the present invention to provide a composition for a sliding member that can be used.

[0016]

The composition for a sliding member according to the present invention comprises a binder made of a heat-resistant synthetic resin, an organic molybdenum compound dispersed in the binder, and a solid lubricant. Things. Examples of the binder made of a heat-resistant synthetic resin include polyimide (PI), phenol (PF) resin, polyamide (PA66), polyetheretherketone (PEEK), polyamideimide (PAI), epoxy (EP) resin, and the like. These resin mixtures can be employed for the purpose of strengthening the binder or accelerating the curing.

As the organic molybdenum compound,

[0018]

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(Where R is an alkyl group, X is O or S),

[0020]

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(Where R is an alkyl group),

[0022]

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(Where R is an alkyl group, x, y, z ≦
3),

[0024]

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(Where R is an alkyl group, x, y, z ≦
3) can be adopted. Specifically, "Sakura Lube 230" and "Sakura Lube 3" manufactured by Asahi Denka Kogyo Co., Ltd.
00, the Sakura Lube 474, the Sakura Lube 500, the Sakura Lube 600, and the Sakura Lube 700. This organic molybdenum compound is contained in a coating film in an amount of 0.01 to 40 weight (wt).
%, And 0.01 to 20 wt% in the molded product. Solid lubricants include mineral MoS ₂ , PTF
E, C (graphite), WS _{2 and the} like can be adopted. This solid lubricant is 1 to 60 wt% in the coating film,
It is preferable that the content is 1 to 30% by weight in the molded product, and the total amount when both the solid lubricant and the organic molybdenum compound are mixed is less than 60.01% by weight in the coating film at the maximum.
It is preferably less than 30.01 wt% in the molded product. When the amount of the organic molybdenum compound is less than 0.01% by weight and the amount of the solid lubricant is less than 1% by weight, the lubricant does not easily exist on the sliding surface, and the binder serving as a matrix easily controls the sliding surface. And the shearing force on the sliding surface is large, causing seizure at an early stage. Conversely, if the amount of the organic molybdenum compound and the amount of the solid lubricant exceed the above-mentioned ratio, the strength of the binder serving as a matrix is significantly reduced, and the wear characteristics are deteriorated. As a result, the sliding surface is actively worn, so that the roughness increases, and as a result, the friction coefficient increases and the seizure pressure decreases.

The composition for a sliding member of the present invention can be manufactured into a coated sliding member or a molded sliding member. When manufacturing a coated sliding member, a heat-resistant synthetic resin is dissolved in a solvent, an organic molybdenum compound and a solid lubricant are simultaneously mixed into the solution to obtain a composition, and the composition is coated on a base material, and coated. The layer can be heat cured. In the case of producing a molded sliding member, a composition can be obtained by simultaneously mixing an organic molybdenum compound and a solid lubricant into the solution during injection molding, and the composition can be produced by molding into a predetermined shape. .

[0027]

When the organic molybdenum compound is dispersed in the binder, the organic molybdenum compound is uniformly dispersed. In the sliding member obtained in this way, at the initial stage of sliding when the starting temperature is relatively low or when the lubricating oil temperature is low (less than about 40 to 50 ° C.), the sliding characteristics by the solid lubricant can be obtained. After reaching the MoS ₂ generation temperature of 40 to 50 ° C., the sliding characteristics can be improved by the organic molybdenum compound.

[0028]

【Example】

(1) Examples 1 to 1 in which the present invention is embodied in a molded sliding member
9 will be described together with Comparative Examples 1 to 14. First, “Sakura Lube 300”, “Sakura Lube 500” and “Sakura Lube 600” manufactured by Asahi Denka Kogyo KK are prepared as organic molybdenum compounds.

Of these, "Sakura Lube 500" and "Sakura Lube 600" are powdered at normal temperature.
On the other hand, "Sakura Lube 300" is liquid at normal temperature and has solubility with methyl ethyl ketone or polyglycol monoethyl ether acetate which dissolves the binder. Here, “Sakura Lube 500” and “Sakura Lube 600” are molybdenum dithiocarbamate (Mo-D
TC). As shown in the above Chemical Formula 5, "Sakura Lube 300" is molybdenum dithiophosphate (Mo-
DTP).

As binders, PI (manufactured by Toshiba Chemical Co., Ltd., "Imidalloy KIR"), PF (manufactured by Toshiba Chemical Co., Ltd., "KM-960"), PA66 (manufactured by Polyplastics Co., Ltd., "1000") )) And PEEK (“GK3440”, manufactured by Sumitomo Chemical Co., Ltd.). As shown in Tables 1 to 3, the above organic molybdenum compound is mixed to prepare a composition.

[0031]

[Table 1]

[0032]

[Table 2]

[0033]

[Table 3]

The composition is formed into a predetermined shape under the conditions shown in Tables 1 to 3. Here, in the casting method, 150 kgf /
Molding was performed at 170 ° C. × 10 minutes under a pressure of ² cm ² ,
Adjust at 0 ° C for 3 hours. In the injection molding, 780
injection pressure of kgf / cm ^2, a holding pressure of 750 kgf / cm ^2. However, during injection molding, the cylinder temperature is 30
If the temperature is 0 ° C. or more, the organic molybdenum compound may be decomposed. Therefore, the heating is not performed at 300 ° C. or more for 10 minutes or more. Thus, Examples 1 to 19 and Comparative Example 1
To 14 molded sliding members are obtained.

In the molded sliding members of Examples 1 to 19, the organic molybdenum compound was uniformly dispersed in the binder. Therefore, it can be seen that these formed sliding members hardly cause a local increase in frictional force and hardly cause variations in characteristics. Further, the friction coefficient, the wear amount (μm) and the seizure surface pressure (MPa) of each obtained molded sliding member are measured. Here, as the friction coefficient, the initial sliding S (Tables 1-3)
The temperature at this time is shown in parentheses. ) And in the latter stage of sliding E (the temperatures at this time are shown in parentheses in Tables 1 to 3).

Here, the friction coefficient is determined by a thrust type testing machine: sliding speed: 60 m / min, surface pressure: 9.8 MPa, mating material: gray cast iron FC25, lubricating oil: mineral oil without additives under lubrication. It is. The amount of wear was as follows: a sliding speed of 5 m / min with a ring-on-block type testing machine, and a surface pressure of 0.5 MP.
a, mating material: gray cast iron FC25, test time: 5 minutes, lubricating oil: under the lubrication of mineral oil without additives. The baking surface pressure was determined by the sliding speed of a thrust type testing machine: 60 m /
Min, partner material: gray cast iron FC25, lubricating oil: under the lubrication of mineral oil without additives, when the surface pressure is increased at a certain period,
This is the surface pressure at which seizure occurred. The results are also shown in Tables 1 to 3.

From Tables 1 to 3, it can be seen that in the molded sliding members of Examples 1 to 19, the sliding characteristics by the solid lubricant can be obtained at the beginning of sliding. In the latter stage of the sliding, Mo in the molecules of the organic molybdenum compound on the sliding surface is removed.
And S in the same molecule or S in the lubricating oil are activated by heat at the time of sliding, and MoS ₂ is generated by an intermolecular reaction. Since the generated MoS ₂ adheres to the formed sliding member and the surface of the mating material, the frictional force is reduced, the friction coefficient is reduced, and the abrasion resistance and the seizure surface pressure are also improved. Therefore, M
It can be seen that after reaching the oS ₂ formation temperature, the organic molybdenum compound can also improve the sliding characteristics.

Further, in the molded sliding members of Examples 1 to 19, even when an external force such as a bending stress or a tensile stress is applied, stress concentration hardly occurs, and it is expected that the molded sliding members are hardly broken. . (2) Embodiment 20 in which the present invention is embodied in a coated sliding member
To 40 will be described together with Comparative Examples 15 to 26.

As the organic molybdenum compound, the same type as above is prepared. As binders, PAI (HI-400 "manufactured by Hitachi Chemical Co., Ltd.), EP resin (" H-303 "manufactured by Dainippon Ink and Chemicals, Inc.), PI
(Mitsubishi Gas Chemical Co., Ltd., “BIM-450”), xylene resin (Mitsubishi Gas Chemical Co., Ltd., “Nicanol DL-
15 ") and a vinyl resin (" SREC BL-2 ", manufactured by Sekisui Chemical Co., Ltd.).

Using methyl ethyl ketone, propylene glycol methyl ether acetate or N-methyl-2-pyrrolidone as a solvent, each binder is prepared as shown in Tables 4 to 6. In Table 5, the binder composed of the resin mixture was obtained by weight ratio. As shown in Tables 4 to 6, the above organic molybdenum compound is mixed to prepare a composition.

The composition is sprayed to a thickness of 10 μm.
And heat-curing at 210 ° C. for 90 minutes. Thus, Examples 20 to 40 and Comparative Examples 15 to
26 coat sliding members are obtained.

[0042]

[Table 4]

[0043]

[Table 5]

[0044]

[Table 6]

The friction coefficient, wear amount (μm) and baking surface pressure (MPa) of each of the obtained coated sliding members are measured in the same manner as described above. The results are also shown in Tables 4 to 6. From Tables 4 to 6, it can be seen that the same results as the molded sliding members can be obtained with the coated sliding members. It is also expected that the coated sliding members of Examples 20 to 36 are unlikely to break.

[0046]

As described above in detail, in the composition for a sliding member of the present invention, an organic molybdenum compound and a solid lubricant are dispersed in a binder made of a heat-resistant synthetic resin. It is possible to manufacture a sliding member that reliably exhibits wear characteristics, seizure characteristics, and friction characteristics and is less likely to break.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C10M 147: 02 125: 02 125: 22) C10N 30:06 40:02 50:08 (72) Inventor Yoshiyuki Hirokawa Yokosuka, Kanagawa Prefecture 3-69-3, Kogocho, City (72) Inventor, Isao Tomura 1007-2, Hikotomicho, Hikone City, Shiga Prefecture (72) Inventor, Masahiro Nagasaki 883, Kadayamacho, Hikone City, Shiga Prefecture (56) References 4-202470 (JP, A) JP-A-61-73723 (JP, A) JP-A-63-293322 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16C 33/20

Claims (1)

(57) [Claims] 1. A composition for a sliding member, comprising: a binder made of a heat-resistant synthetic resin; an organic molybdenum compound dispersed in the binder; and a solid lubricant.