JPS60224529A - Member of polyamide resin - Google Patents

Abstract

PURPOSE:To obtain satisfactory sliding property by constituting a surfacial shape with a substantially flat and continuous plane and a shallow cave-in type concave part. CONSTITUTION:The member has a surfacial shape consisting of a substantially flat and continuous plane with an average coarseness of less than 0.2mum in a medium line and independent concave parts with a diameter of less than 3,000mum and a depth of more than 0.5mum. The average number of said concave parts is more than one per one square cm of surface. In addition, the surfacial characteristics are less than 0.35 of coefficient of friction (no unit), less than 250X10<-6> (cm)/(kg/cm<2>).(m/sec).(hr) of coefficient of abrasion and 2-22(kg/cm<2>).(m/sec) of PV value. If the diameter of the concave part is large or more than 3,000mum and the depth short or not more than 0.5mum, the surface happens to be close to a plane so that the function of the concave part is not fully achieved. The average number of concave parts should be more than one per square cm of surface (not limited to the integer) and preferably be more than 10.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The polyamide resin backing member according to the present invention has good sliding properties and is suitable for sheet-like or plate-like resin members that are subjected to rotational contact or reciprocating contact, for example. In particular, it is suitably used as a thrust washer for resin machine parts.

BACKGROUND ART Resin thrust washers have been known for a long time, and many resin compositions and molding methods for manufacturing them have been reported (for example, Japanese Patent Application Laid-open Nos. 157445-1982 and
0-158643).

However, conventional resin thrust washers do not necessarily fully satisfy the required functions.

Problems to be Solved by the Invention Therefore, the present inventors have developed a member made of polyamide Js4 resin,
In particular, we were satisfied with the thrust washer (after examining both the surface shape and surface characteristics in order to obtain a product, we succeeded in developing a thrust washer that suited the purpose.

Means for Solving the Problems That is, the present invention provides a surface shape consisting of a substantially flat continuous plane portion with a centerline average roughness of 02 μm or less and an independent recessed portion with a diameter of 3000 μm or less and a depth of 0.5 μm or more. , the number of recesses is on average 1 or more per surface, the coefficient of friction is 15!0.35 or less (no unit), and the coefficient of wear is 250 x 10 "6 (=-+) / (surprising) mAec
)・(hr) The following is a polyamide resin member with good sliding properties and surface characteristics with a pv value of 2 to 22 (pv value).

The member of the present invention has the above-mentioned specific surface shape and surface characteristics, and in particular, the sheet-like or plate-like member thereof exhibits a superior function as a thrust washer compared to conventional products, so it is extremely useful. be.

In the member of the present invention, the surface, that is, the contact surface as a mechanical part, for example, one or both sides of a sheet-like object, has a substantially flat continuous shape with a centerline average roughness of 0.2 μm or less flat part with a diameter of 3000μ
It consists of independent recesses with a depth of 0.5 μm or less. Such a Kff surface shape needs to have a substantially flat continuous plane part and a sinkhole-like recess with a shallow bottom, and a mere rough surface is inconvenient. If the centerline average roughness of the flat portion of the surface exceeds 0.2 μm and is not substantially flat, the flat portion becomes sawtooth-like, which is disadvantageous.

Further, the recesses on the surface have a diameter of 3000 μm or less, preferably 1000 to 10 μm, and a depth of 0.5 μm or more, preferably 1 to 10 μm. There is no guarantee that the diameter of the recess is uniform. When the diameter of the recess becomes large, exceeding 3000 μm, and the depth becomes shallow, less than 0.5 μm, the surface becomes almost flat, and the recess cannot perform its full function. (not limited to an integer), and preferably 10 or more. If it is less than 1, the recess is almost non-existent and the existence of the recess loses its significance. The plane of the recess The shape is generally approximately circular, but not necessarily a perfect circle. If it is not a perfect circle, the diameter means the apparent diameter. The cross-sectional shape of the recess is, for example, 3000 μm in diameter9. If the diameter is 0.5 μm Since the depth is significantly smaller than the east longitude, it is generally an elongated rectangle, but it is not limited to this, and may be, for example, a three-pronged shape, a crushed inverted triangle, or other irregular shapes.The cross-sectional shape is They do not have to be uniformly the same, and may be a mixture of d().

In the uninvented member, by having a specific number of four parts with a specific shape along with a flat part on the surface, when used as a thrust washer, for example, in the +yM plane,
Wear particles are effectively captured in the recesses and do not get caught in the sliding interface (in addition, the air gap effect on the four parts prevents vacuum adsorption and reduces frictional resistance.
Due to the presence of four parts, the line of frictional action is discontinuous, which is thought to provide functions such as preventing stick-slip.

The member of the present invention has surface characteristics such as a friction coefficient of 0.35 or less (no unit) and a wear coefficient of 250 x 10"6 (country)/(luxury)"
(1'Q/5ee) H (hr) below, Pvnq
It must be 2 to 22 (M) (■-).

When the friction coefficient exceeds 0.35, the surface quality loses its smoothness, which is disadvantageous, and the wear coefficient becomes inferior (the smaller the wear coefficient, the greater the wear resistance), and the durability deteriorates. This is inconvenient in some respects.

Furthermore, if the pv value (N Buddha load limit value) is within the appropriate range of 2 to 22 (the above unit), #J melting and fusion will occur due to frictional heat at the contact interface even when the R bonito becomes intense. However, when the pv value is less than 2*U), melting and fusion occur and the thrust washer cannot function.

On the other hand, when the pv value exceeds 22 (same), when parts are manufactured by molding polyamide resin as paulownia wood, due to the physical properties of the resin itself, parts with a PV value exceeding 22 (same) are industrial. The inventors of the present invention are convinced that this is not possible in practice.

The pv value generally refers to a certain load (
If the speed exceeds P) and circumferential speed (B), the material will melt or burn, but this is the limit value of the load that will not cause this. Compared to metals, plastics have a smaller M stop coefficient and are less annoying, but on the other hand, they have the disadvantage of a lower pv value.

Regarding the present invention, the friction coefficient, abrasion coefficient, and pv value are all measured by "Saishi, Abrasion Tester-EFM-11 [-E.

U-738J■ Made by Toyo Baldwin was used and was fixed offshore as shown below.

■ # part coefficient The end face of an iron cylinder with an outer diameter of 25m and an inner diameter of 20++m has been polished with 800 band sandpaper, and a polyamide resin sheet member is pressed with a surface pressure of 2.5υ and a peripheral speed of 1
The molded product was rotated at rrVsec and the coefficient of kinetic friction (unitless) between the molded product and the amount of iron was measured.

■Wear coefficient: 1 constant pressure according to the above (■), and the suppressed rotation condition is set to a surface pressure of 10.
When the circumferential speed is 0.5 mm and the rotation time is 2 hours, the wear depth Dcm of the surface of the polyamide resin sheet-like member is measured, and the wear coefficient K [unit is (LM)] is calculated by the following formula. /(a))・(instant insurance)・(hr)) was calculated.

K = D/(PVT) [Here, P is surface pressure (Yi), ■ is peripheral speed (rnAM,
), T represents time (hr). ] ■In the measurement of ■, just before pv1, by changing both the surface pressure P (υ) and circumferential velocity V (war secret) conditions and performing a pressure rotation test, the material will not melt or burn. The limit value of the load, that is, the maximum value of pxv, is fA, and this is set as p
v fN Il, the unit is (1).(le bale)] The member of the present invention is of a shape suitable for mechanical parts subject to rotational contact or reciprocating contact, and is preferably is a sheet-like object or a plate-like object.

The member of the present invention is made of a polyamide resin, and the polyamide resin here refers to a polyamide resin to which other crushing properties such as a polyolefin resin, a carboxyl group-containing polyolefin resin, etc. are added.

Polyamide resins include all known polyamide resins, specifically nylon 6, nylon 11,
Examples include nylon 12, nylon 66, nylon 610, and nylon 612. Examples of the polyolefin resin include polyethylene, polypropylene, polybutene, etc., and high-density polyethylene and polypropylene are particularly suitable. The polyamide resin may contain other additives such as fatty acids, fatty acid amides, oils and fats, graphite, carbon black, molybdenum disulfide, and the like.

Next, the manufacturing method for obtaining the member of the present invention will be described.

As a raw material, for example: 100 parts by weight of polyamide resin;
1 to 20 parts by weight of polyolefins such as polyethylene, polypropylene, and polybutene, and 1 to 20 parts by weight of graphite
1 or 2 or more of the above-mentioned materials include fatty acids (stearic acid, etc.), fatty acid amides, nanthenic acid oils, etc. (having the property of volatilizing below the melting point of the polyamide thread resin). A composition containing 1 to 10 parts by weight of the compound is suitably used.

For example, this raw material is extruded into a sheet using a general extruder at a temperature within the melting point of the polyamide resin used or approximately 30°C higher than the melting point. regulate. The roll hot water temperature varies depending on the thickness of the sheet material, but is approximately 90 to 200°C.

Nip rolls are usually composed of two rolls,
In this case, the temperatures of the upper roll and the lower roll do not necessarily have to be the same, and when the temperatures are different, different properties can be obtained on the upper and lower surfaces of the sheet-like material.

The diameter of the roll that constitutes the nip roll is 120 to 17 mm.
When using 0mm, the thickness of the sheet material is 0.5
When picking up gourds, the picking speed is set to 1 to 6φ. Further, when picking up a piece with a thickness of 0.1 am, the picking speed is 10 to 27 m/min. In either case, if the take-up speed deviates from each of the above ranges, the member of the present invention cannot be obtained. The sheet-like material obtained here has the surface shape and surface characteristics specified in the present invention, and the recesses have a predetermined diameter and depth, but the mechanism of their formation has not been fully elucidated. It is thought that factors such as diameter of the hole, roll temperature, take-up speed, etc. are related to its formation. Note that if the sheet-like product after extrusion and before rolling is cooled with water or left to cool at room temperature, the desired sheet-like product cannot be obtained.

The members of the present invention may be used alone, but may be processed and cut into appropriate shapes.

Examples of the present invention are listed below along with comparative examples. In the example “
%" is 6 collapse, chi.

Example 1 Polyamide (nylon 66, melt index MI=2
．． 8) 91%, high density polyethylene (specific gravity = 0.95,
M I = 0.03) 4%, graphite (jl1
A mixture of 2% stearic acid and 2% stearic acid was mixed in a rolling tumbler to obtain a mixture. On this occasion,
When the polyamide was preheated to about 80° C., the surface of the polyamide was coated with a mixture of graphite and stearic acid, and graphite dust was suppressed, making it suitable for post-process operations.

This mixture was charged into an extruder equipped with a pelletizer and first formed into pellets at a processing temperature of 270°C. After drying this pellet under reduced pressure at 80° C. for 8 hours, it was charged into an extruder equipped with a court nozzle die and extruded, and then a sheet with a thickness of 0.5 mm was produced using heated nip rolls.

The sheet manufacturing conditions are extrusion temperature 275℃, die temperature 270℃.
℃, upper nip roll 150℃, lower nip roll 19
The temperature was 0°C and the speed was 5 minutes. The properties of this sheet are shown in Table 1 below.

Example 2 Using the mixture pellet of Example 1, sheet manufacturing conditions were set as extrusion temperature 275°C, die temperature 270°C, upper nip roll 90°C, lower nip roll 130°C, and speed 2m10 to produce a 0.5cm thick sheet. was manufactured. The properties of this sheet are shown in Table 1 below.

Example 3 Using the mixture pellet of Example 1, the sheet manufacturing conditions were set as extrusion temperature 275°C, die temperature 270°C, upper nip roll 160°C, lower nip roll 190°C, and speed 5.4 l. , 5 was)-9-(n Sheetra H was manufactured. The properties of this sheet are shown in Table 1 below.

Comparative Example 1 Using the mixture pellet of Example 1, sheet manufacturing conditions were set at extrusion temperature of 275°C, die temperature of 270°C, upper nip roll of 90°C, lower nip roll of 110°C, speed of 1 m10, and a thickness of 0.5 mm. sheets were manufactured. The properties of this sheet are shown in Table 1 below.

Comparative Example 2 Using the mixture pellet of Example 1, the sheet manufacturing conditions were an extrusion temperature of 275°C and a die temperature of 2.7'0. )°C, upper nip roll 170°C, lower nip roll 195°C, and speed 7 min to produce a sheet with a thickness of 0.5+o+. The properties of this sheet are shown in Table 1 below.

Comparative Example 3 Using the mixture pellet of Example 1, sheet manufacturing conditions were set as extrusion temperature 275°C, die temperature 270°C, upper nip roll 120°C, lower nip roll 130°C, and speed 3 m/min. A sheet of ms thickness was produced. The properties of this sheet are shown in Table 1 below.

Claims (3)

[Claims] (1) Substantially flat continuous plane part with a center line average roughness of 0.2 μm or less and a diameter of 3000 μm or less and a depth of 0.5 μm
It has a surface shape consisting of the above independent recesses, the number of the recesses is on average 1 or more per surface 1+d, and the friction coefficient is 0.35 or less (portion ratio (2), wear coefficient 250
10-' he/(M) ・(m/5ee) ・(h
r) A polyamide resin member with good sliding properties and surface characteristics with a Pv value of 2 to 22 (V). (2) The diameter of the recess is 100o~10μm, and the depth is 1~1
The member according to claim (1), which has a diameter of 0 μm. (3) Claims that are sheet-like products or plate-like products (1)
) members.