KR20180088126A - Method for preparing of low friction polymer powder and low friction polymer powder obtained thereby - Google Patents

Abstract

The present invention relates to a method for producing a low friction polymer powder and to a low friction polymer powder obtained by the method, wherein the method comprises the following steps: (A) pulverizing a polymer with a low-temperature high-speed pulverizer; (B) producing a spherical polymer powder by treating the polymer powder pulverized with the low-temperature with a high-temperature high-speed pulverizer; and (C) obtaining a spherical polymer powder having a particle size of 25 to 150 μm using a difference in settling velocity with rotation, and a friction reducing effect is excellent, so that the low friction polymer powder can alleviate automobile noise when used in automobile parts and can be used in various products requiring excellent frictional force.

Description

TECHNICAL FIELD The present invention relates to a method of preparing a low-friction polymer powder and a low-friction polymer powder obtained by the method,

The present invention relates to a method for producing a low-friction polymer powder having an excellent friction reducing effect and a low-friction polymer powder produced thereby.

Generally, a typical noise introduced into the automobile interior is a noise generated by friction between components, noise emitted from the engine room, noise transmitted through the vehicle body, friction fingers between the wheel and the ground, and small sand, Noise generated by hitting the underside of the housing, and a noise generated due to improper fixing of accessories such as internal wiring. Among these, the noise caused by the friction noise caused by the friction between the components is the biggest problem.

In order to prevent the noise generated during the running of the vehicle from entering into the automobile, an automobile sound absorbing material excellent in sound absorption property and car sound has been developed and applied to automobiles.

The sound-absorbing property is a property of absorbing the sound of an object, and examples of the material having excellent sound-absorbing properties include porous materials having many small holes in the interior such as glass fiber and rock surface. Also, the sound insulation (sound insulation property) means a property of blocking sound transmitted from an object, and an object having no hole inside can be mentioned as a material excellent in sound insulation.

An engine cover or a hood insulator is used to suppress the noise of the automobile. However, since the effect of removing the noise is insufficient, the dash outer and the dash inner attached to the outside of the vehicle, And floor carpet have been used to remove most of the noise.

Conventionally, in the case of a sound absorbing material for automobiles, a method of using a soft material as a sound absorbing layer and a hard material as a sound insulating layer in accordance with a method of blocking noise, a method of using a hard material as a sound insulating layer between soft materials composed of a sound absorbing layer And a method of using a composite sound-absorbing layer in which the density of soft materials is different. However, in the conventional structures, the sound-absorbing layer and the sound-insulating layer There is a problem that the weight must be increased.

Specifically, conventional sound absorbing materials used in automobiles include low melting point polyethylene terephthalate (LM PET) serving as a binder with polyethylene terephthalate (PET) fibers, polypropylene (PP) fibers and jute fibers for rigidity or moldability, Fiber, etc. However, since the constituent components are in the form of fibers, there is a problem in that it is not easy to disperse during mixing, and since the low melting point polyethylene terephthalate (LMPET) fiber serving as a binder is not dispersed evenly, There is a problem that a variation in bonding force occurs.

Accordingly, there is a demand for a technique for reducing noise of automobiles by reducing the frictional force between parts, not by using the sound damping materials or sound insulating materials.

Korean Patent No. 1488320 Korean Patent No. 1458668

It is an object of the present invention to provide a method for producing a low-friction polymer powder having an excellent friction reducing effect.

Another object of the present invention is to provide a low-friction polymer powder produced according to the above-mentioned production method.

Still another object of the present invention is to provide a low-friction composite polymer composition containing the low-friction polymer powder.

It is still another object of the present invention to provide an automobile part containing the low-friction composite polymer composition.

In order to accomplish the above object, the present invention provides a method for producing a low-friction polymer powder, comprising the steps of: (A) pulverizing a polymer with a low-temperature high-speed pulverizer to prepare a non- (B) treating the non-spherical polymer powder with a high-temperature high-speed pulverizer to prepare a spherical polymer powder; And (C) obtaining a spherical polymer powder having a particle size of 25 to 150 mu m using the difference in settling velocity with rotation.

The polymer may be at least one selected from the group consisting of polyethylene, polyester and nylon.

In the step (A), the polymer is cooled in a settling tank of a low-temperature high-speed pulverizer to -150 to -70 ° C, then is firstly pulverized in a pulverizing tank of a low-temperature pulverizer and then cooled again to -150 to -70 ° C in a settling tank, To thereby produce a non-spherical polymer powder.

In the step (B), the non-spherical polymer powder may be processed into spherical polymer powder at a rate of 500 to 3000 rpm when the internal temperature of the high-speed high-speed pulverizer is 60 to 90 ° C.

Stirring into the high temperature high speed pulverizer can be performed for 5 to 30 minutes.

According to another aspect of the present invention, there is provided a low-friction polymer powder according to the present invention.

According to another aspect of the present invention, there is provided a low-friction composite polymer composition comprising 2 to 20% by weight of the low-friction polymer powder.

The low-friction polymer composition may be one obtained by adding at least one selected from the group consisting of polypropylene pellets and polyamide pellets to the low-friction polymer powder of claim 6.

The low friction polymer composition may include 2 to 20 wt% of the low friction polymer powder, 20 to 40 wt% of polypropylene pellets, and 40 to 60 wt% of polyamide pellets.

In order to achieve the above-mentioned further object, the automobile part of the present invention may contain the low friction composite polymer composition.

The low-friction polymer powder of the present invention is produced by a physical method without using chemical agents, and is environmentally friendly. It has excellent friction reducing effect and mechanical properties, and therefore can provide automobile noise (BSR, buzz, squeak, rattle) It can be dramatically reduced. The automobile parts are an automobile interior material, a car frame (body), a chassis, a bush for a vehicle, and a vehicle accessory.

The low-friction polymer powder of the present invention can be used in various products requiring excellent frictional force besides automobile parts.

FIG. 1A is a particle size-spherical distribution chart of spherical polyethylene powder prepared according to Example 1, and FIG. 1B is a particle size-spherical distribution graph of non-spherical polyethylene powder prepared according to Comparative Example 1. FIG.
FIG. 2A is a sphericity distribution graph of spherical polyethylene powder prepared according to Example 1, and FIG. 1B is a graph of sphericity distribution of non-spherical polyethylene powder prepared according to Comparative Example 1. FIG.
FIG. 3A is an image of spherical polyethylene powder prepared according to Example 1, and FIG. 3B is an image of non-spherical polyethylene powder prepared according to Comparative Example 1. FIG.

The present invention relates to a method for manufacturing a low-friction polymer powder which is excellent in friction reducing effect and can improve automobile noise when used as an automobile interior material, and a low-friction polymer powder produced thereby.

Hereinafter, the present invention will be described in detail.

The method for producing the low-friction polymer powder of the present invention comprises the steps of (A) preparing a non-spherical polymer powder by pulverizing a polymer with a low-temperature high-speed pulverizer; (B) treating the non-spherical polymer powder with a high-temperature high-speed pulverizer to prepare a spherical polymer powder; And (C) obtaining a spherical polymer powder having a particle size of 25 to 150 mu m using the difference in settling velocity with rotation.

First, in the step (A), the polymer is pulverized by a low-temperature high-speed pulverizer to prepare an unsialented polymer powder.

The polymer may include at least one selected from the group consisting of polyethylene, polyester and nylon, but it is preferable to use polyethylene for excellent low friction properties.

The low-temperature high-speed pulverizer includes a settling tank for cooling the polymer material, and a grinding tank for pulverizing the cooled polymer while maintaining the cooled state. Specifically, the polymer is cooled in the settling tank by liquid nitrogen at -150 to -70 占 폚, preferably -100 to -70 占 폚, and then transported to a mill to perform primary milling and then to the settling tank again After cooling again to -150 to -70 캜, a second milling is carried out in a mill. The rotation speed of the rotary blade during the primary and secondary pulverization is 3000 to 10000 rpm, preferably 5000 to 7000 rpm, and is pulverized at the above rotation speed for 10 to 50 minutes, preferably 20 to 30 minutes.

In the case of performing only the first pulverization in the low-temperature high-speed pulverizer, it is difficult to obtain a fine powder and a desired effect can not be achieved. In addition, in the case of using the polymer material which is not cooled at a low temperature even in one of the primary and secondary pulverization processes, the low friction property can not be exhibited, and the tensile strength and elongation can be lowered. Of the polymer powder is not formed into a spherical shape, so that the amount of the polymer powder that can be used in the present invention may be drastically reduced.

The pulverized polymer powder is a non-spherical powder.

If the temperature at which the polymer is frozen in the settling tank of the low-temperature high-speed pulverizer is out of the above-mentioned range, it may be difficult to obtain excellent low friction characteristics.

When the crushing rate and crushing time in the crushing tank are less than the lower limit, a small amount of polymer powder having a desired particle size can be obtained. If the crushing rate is higher than the upper limit, most of the polymer powder is formed into a spherical shape in a high- .

Next, in the step (B), the polymer powder prepared in the step (A) is treated with a high-temperature high-speed pulverizer to prepare a spherical polymer powder.

The polymer powder obtained in the step (B) is spherical. When the non-spherical polymer powder or the flat polymer powder prepared in the step (A) is used instead of the spherical polymer powder in the present invention, And mechanical properties such as tensile strength may also be deteriorated.

The high-temperature and high-speed pulverizer is used to make non-spherical polymer powder as a spherical polymer powder. The high-temperature and high-speed pulverizer is equipped with a regulating device for controlling the rotation speed and temperature inside, , Preferably 10 to 15 minutes, so that the non-spherical polymer powder can be made into spherical polymer powder due to collision between the particles.

The specific temperature may be 60 to 90 ° C, preferably 70 to 80 ° C. When the temperature is lower than the lower limit, the shape of the non-spherical powder may not be deformed into a spherical shape. If the temperature is above the upper limit, Type polymer powder may be formed to lower the low friction property and the mechanical properties.

The specific rotation speed is 500 to 3000 rpm, preferably 800 to 1500 rpm. When the speed is below the lower limit value, the shape of the non-spherical powder may not be deformed into a spherical shape. If the speed is above the upper limit, A large amount of polymer powder in a geometric form can be formed.

When the stirring time in the high-temperature high-speed pulverizer is less than the lower limit value, the mechanical properties may be deteriorated. If the stirring time exceeds the upper limit value, no excellent low friction property can be obtained.

Next, in the step (C), the spherical polymer powder present in various particle sizes is dispersed in a solution having a particle size of 25 to 150 탆, preferably 50 to 140 탆, more preferably 50 Lt; / RTI > to 100 < RTI ID = 0.0 > pm. ≪ / RTI >

Specifically, while rotating the rotating blade at 4000 to 10000 rpm to flow the powder through the air stream, the spherical polymer powder having a large particle size and the particle size Is separated into a relatively small spherical polymer powder. For example, a spherical polymer powder having a large particle size and a heavy specific gravity falls down without passing through the rotation speed, and a spherical polymer powder having a small particle size and a light particle size is pulled by the blower through the rotation speed And is collected in a bag filter. This process is repeated to obtain a spherical polymer powder having a particle size of 25 to 150 mu m, preferably 50 to 140 mu m, more preferably 50 to 100 mu m.

When the particle size of the spherical polymer powder used in the present invention is less than the above lower limit value, not only the excellent low friction property can be obtained but also the mechanical properties such as tensile strength may be lowered. When the particle size exceeds the upper limit value, Can be degraded.

The present invention also provides a low-friction composite polymer composition containing the spherical polymer powder.

In the low-friction composite polymer composition of the present invention, one or more polymer pellets selected from the group consisting of polypropylene pellets and polyamide pellets may be added to the spherical polymer powder prepared above.

For example, the low friction composite polymer composition of the present invention comprises 2 to 20% by weight, preferably 2.5 to 15% by weight, of the spherical polymer powder prepared above; 20 to 40% by weight, preferably 30 to 40% by weight, of polypropylene pellets; And 40 to 60 wt%, preferably 45 to 55 wt%, of the polyamide pellets.

When the content of the spherical polymer powder is out of the above range, it can not have an excellent low friction property and mechanical properties such as tensile strength may be lowered. Also, when a polymer powder such as a non-spherical or flat plate-like polymer powder is used instead of a spherical polymer powder, it can not have an excellent low friction property and mechanical properties such as tensile strength may be lowered.

When the content of the polypropylene pellets is less than the lower limit value, the low friction property may not be improved. When the content of the polypropylene pellets is higher than the upper limit value The low friction characteristics are not improved and the elongation can be rapidly lowered.

The polyamide pellets may be used with spherical polymer powders to further improve low friction characteristics and improve tensile strength and elongation. When the content is less than the lower limit, tensile strength and elongation may be drastically lowered, If the upper limit is exceeded, the low friction characteristics may not be improved.

When the polypropylene pellets and the polyamide pellets used in the low friction polymer composition of the present invention are in the form of powders, the tensile strength and elongation can be drastically lowered.

In addition, when other resins such as ethylene vinyl acetate, polysulfone, and polystyrene are used in place of the polypropylene pellets and the polyamide pellets in the low-friction composite polymer composition of the present invention, the low friction properties may be deteriorated.

Further, the present invention can provide an automobile part containing the low-friction composite polymer composition.

As the automobile parts, the automobile parts include an automobile interior material, a car frame (body), a chassis, a bush for a vehicle, and accessories for a vehicle. The vehicle accessory is not particularly limited as long as it can generate a rubbing sound with other objects such as briquettes, wiring, connectors, assays, audio cases, and the like.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Control group.

Mipelon (mitsui-chem, Japan, polyethylene powder, particle diameter 25-30 탆) manufactured by a chemical method was used.

Example 1. Spherical polyethylene powder-100 占 퐉

The polyethylene was cooled in a settling tank of a low-temperature high-speed pulverizer (JEESSTECH) using liquid nitrogen at -80 DEG C and then transferred to a mill, and pulverized at 6000 rpm for 10 minutes. Subsequently, And then pulverized in a grinding tank for 10 minutes to obtain an aspherical powder, which was then transferred to a high-temperature high-speed pulverizer having an internal temperature of 70 DEG C and stirred at 800 rpm for 10 minutes to obtain spherical powder.

Spherical powder having various sizes was obtained by using a sedimentation velocity difference to obtain a spherical polyethylene powder having a particle size of 100 탆.

Example 2. Spherical polyethylene powder-140 占 퐉

A spherical polyethylene powder having a particle size of 140 탆 was obtained in the same manner as in Example 1.

Example 3. Spherical nylon powder _ 100 ㎛

A spherical nylon powder having a particle size of 100 mu m was obtained in the same manner as in Example 1 except that nylon was used instead of polyethylene.

Comparative Example 1. Non-spherical Polyethylene powder_100 ㎛

The non-spherical powder obtained above was treated in the same manner as in Example 1 except that the high-temperature high-speed pulverizer was used to immediately obtain a non-spherical polyethylene powder having a particle size of 100 탆 by using the sedimentation rate difference.

Comparative Example 2. Spherical polyethylene powder 30 占 퐉

A spherical polyethylene powder having a particle size of 30 탆 was obtained in the same manner as in Example 1.

Comparative Example 3. Spherical polyethylene powder-200 占 퐉

A spherical polyethylene powder having a particle size of 200 탆 was obtained in the same manner as in Example 1.

Comparative Example 4. Plate-shaped polyethylene powder _ 100 占 퐉

The obtained non-spherical powder was compressed in the same manner as in Example 1, but without being treated with a high-temperature high-speed pulverizer to obtain a flat-plate type polyethylene powder. At this time, the width of the particles is 100 탆.

Comparative Example 5. Spherical polyethylene powder _ 140 占 퐉

The same procedure as in Example 1 was carried out except that polyethylene was cooled in a settling tank at a low temperature and high speed pulverizer in a settling tank at -80 ° C using liquid nitrogen and then moved to a grinding tank and pulverized at 6000 rpm for 10 minutes, A spherical powder was obtained. That is, only one freezing and one crushing were performed in a low-temperature high-speed crusher.

<Test Example _1>

Test example 1. Measurement of spherical distribution

The sphericity of the spherical polyethylene powder prepared in Example 1 and that of the non-spherical polyethylene powder prepared in Comparative Example 1 were analyzed using a particle image analyzer (PITA-1, Seishin).

FIG. 1A is a particle size-spherical distribution chart of spherical polyethylene powder prepared according to Example 1, and FIG. 1B is a particle size-spherical distribution graph of non-spherical polyethylene powder prepared according to Comparative Example 1. FIG.

2A is a graph of a sphericity distribution obtained by measuring spherical polyethylene powder prepared according to Example 1, and FIG. 1B is a graph of sphericity distribution obtained by measuring non-spherical polyethylene powder produced according to Comparative Example 1. FIG.

In FIGS. 1 and 2, the spherical distribution means that the closer to 1.0 the particles are spherical.

As shown in FIGS. 1A and 1B, the polyethylene powder prepared according to Example 1 shows that most of the particles are spherical, since the sphericality of the particles is more than 0.7 (FIG. 1A).

On the other hand, the polyethylene powder prepared according to Comparative Example 1 shows a mixture of spherical polyethylene and non-spherical polyethylene because a large number of particles are distributed in a wide region (FIG. 1B).

As shown in FIGS. 2A and 2B, the amount of the polyethylene powder of Comparative Example 1 which was not treated with the high-temperature high-speed pulverizer was found to be as large as 0.2 to 0.6. However, the polyethylene powder of Example 1 contained particles And the spherical shape as a whole is dense with a narrow distribution pattern close to 0.8. Further, when the ratio of the spherical shape was 0.8 or more, it was confirmed that the polyethylene powder of Comparative Example 1 was 46.0%, while the polyethylene powder of Example 1 was 89.3%.

Test Example 2. Powder image measurement

Images of the spherical polyethylene powder prepared in Example 1 and the non-spherical polyethylene powder prepared in Comparative Example 1 were analyzed using a particle image analyzer (PITA-1, Seishin).

FIG. 3A is an image of spherical polyethylene powder prepared according to Example 1, and FIG. 3B is an image of non-spherical polyethylene powder prepared according to Comparative Example 1. FIG.

As shown in FIGS. 3A and 3B, it was confirmed that the polyethylene powder prepared according to Example 1 had a particle shape close to a sphere (FIG. 3A).

On the other hand, it was confirmed that the polyethylene powder prepared according to Comparative Example 1 existed in various forms such as a elliptical shape or a rectangular shape (Fig. 3B).

As a result, it was confirmed that the non-spherical powder was converted into a spherical powder when treated with a high-temperature high-speed pulverizer.

Test Example 3. Measurement of Friction Coefficient

In order to measure the coefficient of friction of the powders prepared according to the control, the examples and the comparative examples, each powder, polypropylene pellets and polyamide pellets prepared according to the control group, the examples and the comparative examples were mixed to prepare injection specimens. When the contents of the powders prepared according to the control, the examples and the comparative examples were 2.5 wt%, 5 wt%, 10 wt%, 15 wt% and 20 wt%, the content of the polypropylene pellets was respectively 40 wt% , And the polyamide pell is added in the balance.

The prepared specimens were measured for friction coefficient using a multiaxial friction coefficient meter (tactile evaluator). The multiaxis friction coefficient measuring device (Touch Meter, manufactured by Heidon) is capable of quantifying the touch, feeling and affinity which have been difficult to quantify so far. It detects the deflection in X, Y and Z directions by using three stereo gauges And it is a device that can measure the coefficient of friction between X axis and Y axis.

Table 1 shows the X-axis friction coefficient (μ), and Table 2 below shows the Y-axis friction coefficient ().

division Control group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 2.5 wt% 0.1120 0.1101 0.1187 0.1201 0.1289 0.1301 0.1349 0.1486 0.1351 5
weight% 0.1126 0.1124 0.1175 0.1195 0.1246 0.1288 0.1302 0.1451 0.1315 10 wt% 0.1181 0.1153 0.1184 0.1204 0.1188 0.1240 0.1284 0.1400 0.1300 15 wt% 0.1120 0.1130 0.1207 0.1210 0.1219 0.1291 0.1342 0.1468 0.1371 20 wt% 0.1129 0.1201 0.1164 0.1206 0.1211 0.1299 0.1360 0.1511 0.1429

division Control group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 2.5 wt% 0.1071 0.0930 0.1014 0.1054 0.1091 0.1165 0.1245 0.1398 0.1299 5
weight% 0.1126 0.0961 0.0987 0.1016 0.1032 0.1130 0.1200 0.1374 0.1253 10 wt% 0.1081 0.1015 0.1059 0.1055 0.1054 0.1148 0.1218 0.1402 0.1241 15 wt% 0.1059 0.0941 0.1018 0.1017 0.1022 0.1101 0.1199 0.1359 0.1281 20 wt% 0.1008 0.1009 0.0975 0.1084 0.1115 0.1201 0.1205 0.1387 0.1305

As shown in the above Tables 1 and 2, it was confirmed that the test piece using the spherical polymer powder prepared according to Examples 1 and 3 of the present invention showed similar friction coefficient to that of the test piece using the control group. In Comparative Examples 1 to 5 It was confirmed that the friction coefficient was much lower than that of the specimen using the polymer powder.

For example, it was confirmed that the group containing the spherical polymer powder having a particle size of 100 占 퐉 (Example 1) and 2.5 to 15% by weight was excellent in the friction reducing effect.

Test Example 4. Mechanical Properties _ Tensile Strength Measurement

The tensile strength of the specimen prepared in Test Example 3 was measured. The tensile gauge was measured using a tensile tester (Tensometer 2000, manufactured by Myji Tech Co., Ltd.), and the specimens were processed according to ASTM D638. The test conditions are 23 캜, 50 mm / min.

division
(Unit: kgf / cm ² ) Control group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 2.5 wt% 394.42 381.74 379.55 370.12 340.51 336.15 348.12 300.51 316.81 5
weight% 401.53 399.46 384.69 376.15 343.51 340.26 351.11 304.15 336.95 10 wt% 412.60 410.68 399.11 388.44 342.49 343.66 359.08 308.67 342.10 15 wt% 416.55 416.51 405.21 391.68 349.17 349.05 362.65 307.49 338.05 20 wt% 420.68 418.10 409.64 403.12 351.11 353.47 374.49 315.47 351.00

As shown in Table 3, it was confirmed that the specimens using the spherical polymer powders prepared according to Examples 1 and 3 of the present invention exhibited similar tensile strengths to those of the specimens using the control group, It was confirmed that the tensile strength was much improved compared with the specimen using the polymer powder.

Test Example 5. Mechanical Properties _ elongation measurement

The tensile strength of the specimen prepared in Test Example 3 was measured. The elongation was measured using a tensile tester (Tensometer 2000, manufactured by Myji Tech Co., Ltd.), and the specimens were processed according to ASTM D638 standard. The test conditions are 23 캜, 50 mm / min.

division
(unit: %) Control group Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 2.5 wt% 39.0 38.7 38.0 37.3 33.4 31.5 32.4 27.5 30.4 5
weight% 40.8 40.6 38.8 38.1 34.1 32.8 33.9 28.9 31.6 10 wt% 41.9 42.1 41.5 40.5 34.9 34.1 34.4 30.5 31.1 15 wt% 43.5 43.0 42.7 41.6 35.9 34.9 35.1 31.6 32.5 20 wt% 45.9 44.8 44.3 43.0 37.0 35.9 36.3 32.0 34.6

As shown in Table 4, it was confirmed that the specimens using the spherical polymer powders prepared according to Examples 1 and 3 of the present invention had elongation similar to that of the specimen using the control group, and the polymers prepared according to Comparative Examples 1 to 5 It was confirmed that the elongation was much improved as compared with the specimen using powder.

Claims (10)

(A) preparing a non-spherical polymer powder by pulverizing the polymer with a low-temperature high-speed pulverizer;
(B) treating the non-spherical polymer powder with a high-temperature high-speed pulverizer to prepare a spherical polymer powder; And
And (C) obtaining a spherical polymer powder having a particle size of 25 to 150 탆 by using the difference in settling velocity with rotation. The method according to claim 1, wherein the polymer is at least one selected from the group consisting of polyethylene, polyester and nylon. The method according to claim 1, wherein in the step (A), the polymer is cooled in a settling tank of a low-temperature high-speed pulverizer to -150 to -70 ° C, then pulverized first in a pulverizing tank of a low- And then pulverized in a pulverizing tank to obtain a non-spherical polymer powder. The method of claim 1, wherein in the step (B), the non-spherical polymer powder is processed at a speed of 500 to 3000 rpm at a high temperature and high-speed pulverizer at an internal temperature of 60 to 90 ° C to produce spherical polymer powder (Method for producing low friction polymer powder). 5. The method for producing a low-friction polymer powder according to claim 4, wherein the stirring with the high-temperature high-speed pulverizer is performed for 5 to 30 minutes. A low-friction polymer powder produced by the manufacturing method according to any one of claims 1 to 5. A low-friction composite polymer composition comprising the low-friction polymer powder of claim 6 in an amount of 2 to 20% by weight. The low friction composite polymer composition of claim 7, wherein the low friction polymer composition further comprises one or more selected from the group consisting of polypropylene pellets and polyamide pellets. The low friction polymer composition according to claim 7, characterized in that it comprises 2 to 20% by weight of the low friction polymer powder of claim 6, 20 to 40% by weight of polypropylene pellets and 40 to 60% by weight of polyamide pellets. Friction composite polymer composition. An automobile part containing the low-friction composite polymer composition of claim 7.

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