JPH0769015B2 - Material of seal part for scroll type compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a material for a seal portion for a scroll type compressor.

[Conventional technology]

The scroll type compressor is provided with a pair of scroll members each having a spiral wall formed on one surface of the substrate, and the spiral walls of the respective scroll members are engaged with each other in an eccentric state, thereby performing a relative revolution motion. The fluid is compressed while moving the closed space between the spiral walls toward the center, and the fluid is discharged from the central portion. For example, JP-A-50-32512 and JP-A-55-81296 disclose the same. Is already well known.

1 and 2 show a conventionally known scroll member 1, in which a groove 3 is formed at the tip of a spiral wall 2 and a seal material 4 is attached to the groove 3. FIG. 3 shows a state in which the scroll member 1 is on the movable side and is eccentrically engaged with the fixed scroll member 1 ', and the respective seal portion materials 4 of both spiral walls 2 are mutually interfering with each other. The materials 1,1 'are slidably contacted with the bottom of the spiral groove to achieve mutual sealing.

In the scroll type compressor as described above,
Recently, in order to reduce its weight, the scroll member 1 is made of a light metal such as aluminum or an aluminum alloy, and a tetrafluoroethylene resin (abbreviated as PTFE) is used for the seal material 4 which is always in sliding contact. It has come to be used. This PTFE is a resin that has extremely excellent properties such as heat resistance, chemical resistance, flame retardancy and other self-lubricating properties, non-adhesiveness, and a low coefficient of friction, so it can be used in sliding parts such as bearings, pipes, valves and other materials. Widely used in various fields such as molded products. However, such resins are not always satisfactory in wear resistance and creep resistance, and even if a filler is added to PTFE to improve these properties, the metal surface of the mating material may be scratched or There is a risk that the wear resistance will gradually decrease when sliding for a period of time. Therefore, in order to solve such a drawback, the inventors of the present invention have proposed Japanese Patent Application No.
−254481 new sealing material, namely PTFE
Organic fillers (eg polyphenylene sulphate,
Polyimide, aromatic polyester, aromatic polyamide, polyamide, polyetherketone, etc.) and an injection-moldable fluorine resin powder were added and mixed, but such a seal part material has creep resistance. Even if the improvement is recognized, a considerable dimensional change may occur when used under a high load, and a dimensional change due to swelling may occur when used in a refrigerant, resulting in a decrease in operating efficiency of the compressor. Become. Furthermore, the main component is PT
A composition which is FE is not preferable because it cannot be injection-molded, the productivity is poor, and the product cost is naturally high.

[Problems to be solved by the invention]

In this way, in the conventional technology, materials that are excellent in heat resistance, chemical resistance, flame retardancy, lubricity, wear resistance, dimensional stability, creep resistance, etc. However, there is a problem in that a material for a seal portion made of was not obtained.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention adopts means for adding a fluorocarbon polymer, carbon fiber and metal powder to an aromatic polyether ketone resin to prepare a seal part material for a scroll type compressor. The details will be described below.

First, the aromatic polyether ketone used in the present invention is a repeating unit. Alone or together with other repeating units and having an intrinsic viscosity of 0.7 to 2.6, preferably 0.8 to 1.8. Here, as another repeating unit, For example, a polymer containing 25% by weight or more is not preferable because the intrinsic properties of polyetherketone are lost. Further, the intrinsic viscosity shall apply an intrinsic viscosity measured for the polymer solution in concentrated sulfuric acid density of 1.84 g / cm ³ containing a solution 100 cm ³ per polymer 0.1 g, viscosity solvent efflux time of about 2 minutes for the measurement The total was used. This intrinsic viscosity is a value that uniquely corresponds to the molecular weight of the polymer, and the intrinsic viscosity is 0.
Polyetherketone lower than 7 has low heat resistance and is very brittle even when a molded product is obtained. On the contrary, those exceeding 2.6 have too high melt viscosity and poor workability, and cannot be generally used.

Next, the fluorocarbon polymer in this invention is
Polytetrafluoroethylene, polytetrafluoroethylene / hexafluoropropylene copolymer, polytrichlorofluoroethylene, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer and the like are included, but the above-mentioned PTFE is particularly preferable. Further, PTFE is also preferably a lubricant grade powder having an average particle size of less than 20 μm, and examples of commercially available products include Fluon (trademark) L169, L170, L171 and Daikin Industries Ltd. Lubron (trademark) L-2, L-5, LD-1, Teflon (trademark) TLP-10, TLP-10F-1 manufactured by Dupont, USA, and the like can be mentioned.

Further, the carbon fibers that can be used in the present invention may be any of acrylonitrile-based, pitch-based, cellulose-based, etc., and since the fiber length is preferably 0.1 to 10 mm, it is usually about 6 mm used as a resin filler. It is possible to use a long length fiber, roving or the like. It is preferable to use the carbon fiber whose surface is treated with a treating agent such as an epoxy resin, a polyamide resin, a polycarbonate resin, and a polyacetal resin, but the carbon fiber is not limited thereto. Examples of such carbon fibers are MAGNAMITE AS and MAGNAMITE HM manufactured by Herquilles.
S, trading card T300A manufactured by Toray Co., Vesufite HTA manufactured by Toho Rayon, Veshuite 1000, Creca M, Creca C manufactured by Kureha Chemical Industry Co., Ltd., and the like.

Further, the metal powder used in the present invention has a thermal conductivity of 0.6 to 1
It is 2.0 kcal / (m · h · ° C), and a copper alloy is preferable, but it is not limited to this. Examples of such metal powder include bronze powder Bro-At-350 manufactured by Fukuda Metal Foil Industry Co., Ltd., bronze powder S91-120 manufactured by Nippon Atomize Co., Ltd., and the like.

In blending the above aromatic polyether ketone, fluorocarbon polymer, carbon fiber and metal powder,
It is desirable to use 20 to 80% by weight of aromatic polyether ketone, 5 to 25% by weight of fluorocarbon polymer, 5 to 15% by weight of carbon fiber, and 10 to 40% by weight of metal powder. This is because when the total amount of fluorocarbon polymer, carbon fiber and metal powder exceeds 80% by weight of the resin composition and the amount of aromatic polyether ketone is less than 20% by weight, the fluidity of the resin composition is low. Is lost, and even if a molded product is obtained by injection molding, its mechanical strength becomes extremely low and brittle. Carbon fibers have insufficient mechanical strength in a small amount of less than 5% by weight. When the amount exceeds 15% by weight, the soft mating material is worn out and good sealing properties cannot be obtained, and the thermal conductivity of metal powder is less than 0.6 kcal / (m · h · ° C). When the compounding amount is less than 10% by weight, the thermal conductivity of the composition itself cannot be expected to be improved, and the heat dissipation effect on the sliding surface cannot be obtained. If the amount exceeds the limit, the friction coefficient will be large and the fluorocarbon If the amount of the Bon polymer is less than 5% by weight, the lubricity is insufficient, and conversely, if the amount is more than 25% by weight, the dispersibility and compatibility are deteriorated and it is difficult to obtain a homogeneous composition. Because.

Various operations such as blending, heating, melting, and mixing of these raw materials utilize a heat roller, Banbury mixer, brabender, extruder, etc., and a homogeneous mixture is usually obtained at 340 to 400 ° C, preferably 350 to 380 ° C. It may be carried out continuously until, but mortar, Hensiel mixer, ball mill, 300-400 ℃ using a melt mixer, an injection molding machine, an extrusion molding machine and the like after premixing them with a ball mill, a ribbon blender, etc. Pellets, wires, rods, plates, sheets, or any other shape may be appropriately molded at a temperature of 320 to 380 ° C.

〔Example〕

The raw materials used in Examples and Comparative Examples are summarized below. That is, aromatic polyether ketone resin (Udel-PEEK150P manufactured by UK IC) [abbreviated as PEEK], fluorocarbon polymer (Lubron L-5 manufactured by Daikin Industries, Ltd.) [PTFE], carbon fiber (Kureha) Chemical company: Kureha M207S) and bronze powder (Fukuda Metal Foil Powder company: AT-350 mesh).

Examples 1 to 5: The above raw materials were blended in the proportions shown in Table 1, thoroughly mixed with a Henschel mixer, and then fed to a twin-screw melt extruder (Ikegai Iron Works Co., Ltd .: PCM-30 type). Extruded from a strand die having a temperature of 365 ° C., a screw rotation speed of 150 rpm, and a diameter of 2 mm and seven holes, and granulated into pellets. Barrel temperature 310-370 ℃, metal temperature 200 ℃, injection pressure 1500kg /
A predetermined test piece is prepared by applying an injection molding machine of cm ² , and the bending strength kg / cm ² of the obtained test piece is based on ASTM-D790, and the Izod impact strength kg / cm / cm is based on ASTM-D256. Friction coefficient is 17m inside diameter using Suzuki-Matsubara friction and wear tester
m, outer diameter 21 mm, length 10 mm wear ring specimen pressure 10 kg / cm
² , the value under the condition of speed 10m / min
kg / cm ² For the m / min, the Suzuki-Matsubara friction and wear tester and a wear ring test piece of the same size were used, the speed V was kept constant at 308 m / min, and the pressure P was set to 5000, 6000, 700 in the suniso 4GS oil.
0 …… kg / cm ² · m / min As the sample starts to undergo abnormal wear accompanied by melting, or the wear coefficient suddenly becomes unstable, while increasing so as to increase by 1000 every 5 minutes of
The PV value and the heat resistance of the actual machine were formed by molding the seal material 4 shown in Fig. 1, the number of revolutions was 5500 revolutions per minute, atmosphere freon gas 5% by volume + oil 95% by volume, temperature 300 ° C or more, operating time 1
During the test under the condition of 0 hours, the seal part material 4 was evaluated for the time during which abnormal wear accompanied by melting occurred or the friction coefficient suddenly became unstable. For injection moldability, using Labo Plastomill manufactured by Toyo Seiki, when the screw speed is 50 rpm and the cylinder temperature is 380 ° C, the torque value m · kg is 300 to 350, ◎ mark, 350 to 400 ○, 40
When the value was 0 to 450, the mark was Δ, and when the value was more than 450, the mark was ×. The measured values obtained are summarized in Table 2.

Comparative Examples 1 to 5 The same operations as in Examples 1 to 5 were carried out except that the raw materials were mixed in the proportions shown in Table 3. Then, a test piece was prepared, and its bending strength, Izod impact strength, friction coefficient, limit PV value, actual machine durability, and injection moldability were measured. The results obtained are summarized in Table 4.

Here, when comparing Examples 1 to 5 and Comparative Examples 1 to 5, since the compounding ratios of Examples 1 to 5 are all in the ranges considered to be desirable, mechanical characteristics, lubrication characteristics, limit PV values,
Excellent in all aspects of actual machine durability test and injection moldability. However, in Comparative Examples 1 to 5, all the characteristics described in the examples are satisfied by the fact that even one compounding ratio of the aromatic polyether ketone, the fluorocarbon polymer, the carbon fiber and the metal powder deviates from the desirable range. Is impossible. For example, in Comparative Example 1, when the amount of bronze powder exceeds 40% by weight, the friction coefficient is high, the mechanical strength is low, and the injection moldability is also very poor. In each of Comparative Examples 2, 4, and 5, the limit PV value is low, and the durability of the actual machine is considerably poor. Comparative Example 3 has a high friction coefficient and is inferior in terms of the limit PV value and the durability of the actual machine.

〔effect〕

As is clear from the above, the seal part material of the present invention has a sliding property under high speed and a high load, which significantly improves the limit PV value, and since it can be injection-molded, it can be mass-produced rather than compression-molded. It is much easier to commercialize and will greatly contribute to the price reduction of molded products. Therefore, it can be said that the significance of the present invention is extremely great.

[Brief description of drawings]

FIG. 1 is a perspective view of a scroll member, FIG. 2 is a cross-sectional view of an essential part of FIG. 1, and FIG. 3 is a cross-sectional view illustrating an internal structure of a compressor in which scroll members are engaged with each other. 1, 1 '... scroll member, 2 ... spiral wall, 3 ... groove, 4 ...
Seal material

Claims (1)

[Claims] 1. A fluorocarbon polymer in an amount of 20 to 80% by weight of an aromatic polyetherketone resin, an amount of 5 to 25% by weight of a fluorocarbon polymer, and 5 carbon fibers.
-15% by weight and 10 to 40% by weight of metal powder are added to the seal part material for scroll type compressors.