JPS63158362A - Seal part material for scroll type compressor - Google Patents

Abstract

PURPOSE:To improve a sliding characteristic, by adding a fluorocarbon polymer, a carbon fiber and metal powder to aromatic polyether ketone resin. CONSTITUTION:A seal member 4 is attached to a groove at a tip of a volute wall 2 of a scroll member 1. This seal member 4 is made up of adding a fluorocarbon polymer of 5-25 wt%, a carbon fiber of 5-15 wt% and a metal powder of 10-40 wt% to aromatic polyether ketone resin 20-80 wt%. Therefore, it can be made into such one excellent in heat resistance, chemical resistance, flame resistance, wear resistance, creep-proof, etc., thus a sliding characteristic is improvable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a sealing material for a scroll compressor.

[Conventional technology]

A scroll type compressor has a pair of scroll members each having a spiral winding formed on one side of a base plate, and the spiral windings of each scroll member are eccentrically engaged with each other to perform relative orbital motion. The fluid is compressed while moving the sealed space between the chambers toward the center, and the fluid is discharged from the center. It is 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 winding 2, and a seal member material 4 is mounted in the groove 3. Further, FIG. 3 shows a state in which the scroll member 1 is on the movable side and eccentrically engaged with the fixed scroll member 1', and each sealing part material 4 of both spiral windings 2 is mutually connected to the other scroll part. They are brought into sliding contact with the bottom of the spiral groove of the material 1.1' to form a mutual seal.

In a scroll type compressor like the one above,
Recently, in order to reduce the weight, the scroll member 1 has been made of light metals such as aluminum or aluminum alloy, and the seal part material 4, which is in constant sliding contact, is made of polytetrafluoroethylene resin (abbreviated as PTFE). It has come to be used. PTFE is a resin with extremely excellent properties such as heat resistance, chemical resistance, flame retardancy, self-lubricating property, non-adhesiveness, and low coefficient of friction. It is widely used in various fields such as molded products. However, the abrasion resistance and creep resistance of such resins are not necessarily satisfactory, and even if fillers are added to PTFE to improve these properties, they may cause scratches on the metal surface of the mating material. , there is a risk that the wear resistance will gradually decrease when sliding for a long time.

In order to solve these drawbacks, the inventors proposed a new sealing material in Japanese Patent Application No. 60-254481, in which organic fillers (such as polyphenylene sulfide, polyimide, aromatic polyester, aromatic disclosed a composition in which an injection-moldable fluororesin powder is added and mixed (such as polyamide, polyamide, polyetherketone, etc.), but even though such sealing material has improved creep resistance, Significant dimensional changes occur when used under load, and when used in a refrigerant, dimensional changes may occur due to swelling, leading to a reduction in the operating efficiency of the compressor. Furthermore, compositions whose main component is PTFE cannot be injection molded, resulting in poor productivity and, of course, high product costs, which is not desirable.

[Problem that the invention seeks to solve]

In this way, in conventional technology, materials are made of materials that have excellent heat resistance, chemical resistance, flame retardancy, lubricity, abrasion resistance, dimensional stability, creep resistance, etc., and can be injection molded. There was a problem in that the material for the sealing part could not be obtained.

[Means for solving problems]

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

First, the aromatic polyetherketone used in the present invention contains a repeating unit alone or together with other repeating units, and has an intrinsic viscosity of 0.7 to 2.6, preferably 0.8 to 1. 8. Here, other repeating units may be contained, such as less than 25% by weight, but a polymer containing more than 25% by weight is not preferred because the original properties of polyetherketone are lost. In addition, the intrinsic viscosity is the intrinsic viscosity measured for a polymer solution in concentrated sulfuric acid with a density of 1.84 g/cm3 containing 0.1 g of polymer per 100 cm3 of solution, and the measurement requires a solvent outflow time of about 2 minutes. A viscometer was used. This intrinsic viscosity is a value that uniquely corresponds to the molecular weight of the polymer, and polyetherketones with an intrinsic viscosity lower than 0.7 have low heat resistance and are extremely brittle even if molded products are obtained; .6
Those exceeding this amount have too high a melt viscosity and have poor processability, so they cannot be used generally.

Next, in this invention, the fluorocarbon polymer includes polytetrafluoroethylene, polytetrafluoroethylene/hexafluoropropylene copolymer, polytrichlorofluoroethylene, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, etc. In particular, the above-mentioned PTFE is preferred. In addition, for PTFE, a lubricant-edge powder with an average particle size of less than 20 μm is preferable, and examples of commercially available products include Fluon (trademark) L169, Fluon L170, and Fluon L17 manufactured by ICI Ltd. in the UK.
1. Daikin Industries, Ltd.'s LeBlon (trademark) L-2, L-
5. LD-1, Teflon (trademark) TL from DuPont, USA
Examples include P-1o and TLP-10F-1.

Furthermore, the carbon fibers that can be used in this invention may be any of acrylonitrile-based, pitch-based, cellulose-based, etc., and those with a fiber length of 0.1 to 10 mm are preferable. Chopped fibers, rovings, etc. of a certain length can be used. It is preferable to use carbon fibers whose surfaces have been treated with a treatment agent such as epoxy resin, polyamide resin, polycarbonate resin, or polyacetal resin, but are not limited thereto. Examples of such carbon fibers include Magnamite AS and Magnamite HMS manufactured by Percules, Trading Card T300A manufactured by Toshisha Co., Ltd., and Besphite HTA and Besphite 1000 manufactured by Toho Rayon Co., Ltd.
, Kreka M, and Kreka C manufactured by Kenbetsu Kagaku Kogyo Co., Ltd.

Furthermore, the metal powder used in this invention has a thermal conductivity of 0.6.
~12.0 kcal/(m-h·'C), and is preferably a copper alloy, but is not limited thereto. An example of such metal powder is copper powder Br manufactured by Fukuda Metal Foil Industry Co., Ltd.
o-At-350, bronze powder 591-120 manufactured by Nihon Atomize Kako Co., Ltd., and the like.

When blending the above aromatic polyether ketone, fluorocarbon polymer, carbon fiber and metal powder,
Desirably, the content is 20 to 80% by weight of aromatic polyetherketone, 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 polyetherketone is a small amount of less than 20% by weight, the fluidity of the resin composition is lost, and even if a molded product is obtained by injection molding, its mechanical strength will be very low and it will be brittle. Carbon fiber has insufficient mechanical strength in a small amount of less than 5% by weight; If the amount exceeds % by weight, the soft mating material will be damaged and good sealing properties will not be obtained, and the thermal conductivity of metal powder will be 0.6 kcal/
When the value is smaller than (m-h・℃) or when the amount is small (less than 10% by weight), the thermal conductivity of the composition itself cannot be improved and the heat dissipation effect on the sliding surface cannot be obtained. No improvement in the critical pv value can be expected; conversely, if the amount exceeds 40% by weight, the coefficient of friction becomes large; if the amount of fluorocarbon polymer is less than 5% by weight, the lubricity is insufficient; conversely, if the amount exceeds 25% by weight, This is because, if the amount is too large, many problems will occur, such as a decrease in dispersibility and compatibility, making it difficult to obtain a homogeneous composition.

Various operations such as blending, heating, melting, and mixing of these raw materials are performed using a maturing roller, a Banbury mixer, a Brabender, an extruder, etc., and the temperature is usually 340 to 400°C, preferably 350°C.
The process may be continued until a homogeneous mixture is obtained at ~380°C, but the raw materials may be mixed in a mortar, Henschel mixer,
After pre-mixing with a ball mill, ribbon blender, etc., using a melt mixer, injection molding machine, extrusion molding machine, etc.
It may be suitably formed into pellets, wires, rods, plates, sheets, or other arbitrary shapes at a temperature of 400°C, preferably 320 to 380°C.

〔Example〕

The raw materials used in the Examples and Comparative Examples are listed below. Namely, ■ Aromatic polyetherketone resin (manufactured by ICI, UK: TJdel-
PEEK 150P), abbreviated as CPEEK], ■Fluorocarbon polymer (Daikin Industries Co., Ltd.'s CPTFE), ■Carbon fiber (manufactured by Kureha Chemical Co., Ltd.: Kureha M2O7S), ■Bronze powder (manufactured by Fukuda Metal Foil and Powder Co., Ltd.: AT-350 mesh).

Examples 1 to 5: The above raw materials ■ to ■ were blended in the proportions shown in Table 1, thoroughly mixed using a Henschel mixer, and then mixed using a twin-screw melt extruder (
Ikegai Tekko Co., Ltd.: PCM-30 type) and the temperature was 365.
°C, screw rotation speed 15 Orpm, diameter 2rrrn hole 7
It was extruded through several strand dies and granulated into pellets. This pellet was applied to an injection molding machine with a barrel temperature of 310 to 370°C, a mold temperature of 200°C, and an injection pressure of 1500 kg/cm2 to produce a specified test piece, and the bending strength of the obtained test piece was determined according to ASTM-D790. Also, the Izot impact strength kg-cm/cm is ASTM-D2
56, and the friction coefficient was measured using the Matsubara type friction and wear test using precious wood.The inner diameter was 17 mm, the outer diameter was 21 mm, and the length was 10 mm.
The value under the conditions of a pressure of 10 kg/cm2 and a speed of 101 TI per minute for a wear ring specimen of mm is further calculated as the limit P.
V value kg/Cm"・Table 1 The pressure P in Suniso 4GS oil was determined using the aforementioned precious wood/Matsubara type friction and wear tester and the wear ring specimen of the same size, with the speed V constant at 308 m/min. PV is 500
0.6000.7000-・kg/cm2・-min and 5
While increasing the temperature by 1000r per minute, the PV value is determined when the specimen begins to undergo abnormal wear accompanied by melting or when the wear coefficient suddenly becomes unstable, and the actual heat resistance is the first. The seal material 4 shown in the figure was molded, and the seal material 4 was tested under the conditions of 5,500 revolutions per minute, an atmosphere of 5 volumes of Freon gas + 95 volumes of oil, a temperature of 300°C or more, and an operating time of 10 hours. Each test was evaluated based on the time at which abnormal wear accompanied by melting occurred or the friction coefficient suddenly became unstable. In addition, injection moldability was measured using Toyo Seiki Labo Plast Mill with a screw rotation speed of 50 per minute.
When the rotation and cylinder temperature exceeded 380, it was marked with an X and evaluated on a four-level scale. The obtained measurement values are summarized in Table 2.

Table 2 Comparative Examples 1 to 5 Test pieces were prepared in the same manner as in Examples 1 to 5 except that the raw materials ■ to ■ were blended in the proportions shown in Table 3. Shiso bending strength, isot 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, it is found that the blending ratios of Examples 1 to 5 are all within desirable ranges, so the mechanical properties, lubricating properties, limit pv value, Excellent in all aspects of injection moldability in the Miso Mukuhisa test. However, in Comparative Examples 1 to 5, even if the blending ratio of aromatic polyether ketone, fluorocarbon polymer, carbon fiber, and metal powder is out of the desired range, it is not possible to satisfy all the characteristics described in the examples. It's impossible. For example, in Comparative Example 1, bronze powder was
When the amount exceeds 0 weight, the friction coefficient is high, the mechanical strength is low, and the injection molding ratio is also very poor. Comparative example 2.4.
Comparative example 3 has a high coefficient of friction and has a low limit PV value, and is considerably inferior in terms of actual machine durability.
It is also inferior in terms of value and actual machine durability.

〔effect〕

As is clear from the above, the seal material of the present invention has sliding properties at high speeds and high loads that significantly improve the limit Pv value, and since injection molding is possible, it is easier to mass produce than compression molding. This is much easier to do, and will greatly contribute to reducing the cost of molded products. therefore,
It can be said that the significance of this invention is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a scroll member, FIG. 2 is a sectional view of a main part of FIG. 1, and FIG. 3 is a sectional view illustrating the internal structure of a compressor in which the scroll members are engaged. 1.1'... Scroll member, 2... Spiral winding, 3
...Groove, 4...Seal part material

Claims (1)

[Claims] 20-80% by weight of aromatic polyetherketone resin, 5-25% by weight of fluorocarbon polymer, and 5-1% by weight of carbon fiber.
A sealing part material for a scroll compressor, characterized in that it contains 5% by weight and 10 to 40% by weight of metal powder.