JPH05295162A - Resin composition for sliding material - Google Patents

Abstract

PURPOSE:To obtain a resin composition which does not deteriorate in the presence of a heavy metal and can prevent the corrosion of a heavy metal of the mating material during sliding by adding a metal inactivator having a specified weight loss temperature in heat decomposition to a heat-resistant resin having a specified molding temperature. CONSTITUTION:The composition is prepared by adding a metal inactivator having a 50% weight loss temperature of 350 deg.C or above when heat-decomposed to a heat-resistant resin having a molding temperature of 300 deg.C or above. When this composition is molded into a sliding member, the metal inactivator is not heat-decomposed at the molding temperature of the heat-resistant resin and can be uniformly dispersed in the heat-resistant resin. Therefore, when this molding slides on a heavy metal, the sliding material itself does not deteriorate and further has a function of protecting the surface of the mating material and preventing its corrosion through the contained metal inactivator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for sliding materials used as a molding material for sliding members.

[0002]

2. Description of the Related Art Generally, it is known that natural or synthetic high molecular weight polymers such as rubber and resin are accelerated in decomposition and deterioration in the presence of manganese, cobalt, copper, iron or lead and other heavy metals. There is.

For example, the presence of metal ions is considered to be a cause of oxidative deterioration with respect to general-purpose synthetic resins such as polypropylene and polyamide used as electrical insulating materials for copper wire coating materials and printed wiring boards. An antioxidant having a deactivating effect called a metal deactivator was blended.

As the metal deactivator, hydrazine compounds such as N-salicyloyl-N'-aldehyde hydrazine or N-salicyloyl-N'-acetylhydrazine and oxamide compounds such as N, N'-diphenyloxamide. and so on.

[0005]

However, since such a metal deactivator is easily decomposed by heat,
It was thought that it could not be added to a heat-resistant synthetic resin with a molding temperature of 300 ° C or higher.

On the other hand, as a sliding material used under the condition of sliding with heavy metals, a synthetic resin such as tetrafluoroethylene having excellent heat resistance and sliding characteristics is used. Below, there is a problem that the mechanical and chemical properties of this product are easily deteriorated, and the slidability is also deteriorated by the corrosion of a heavy metal as a mating material.

In order to maintain the sliding characteristics of the above-mentioned sliding material, a method of applying a metal deactivator to the surface of a heavy metal has been adopted so far, but the metal deactivator on the application surface easily falls off. However, it could not be slid under stable low friction conditions.

The present invention solves the above-mentioned problems of the heat-resistant resin composition for a sliding material, which is caused by deterioration such as oxidation under the coexistence condition with the heavy metal, and the heat-resistant resin itself deteriorates in the presence of the heavy metal. It is an object of the present invention to prevent the corrosion of heavy metal which is a mating material during sliding and to maintain the friction coefficient of the sliding surface at a low level stably.

[0009]

In order to solve the above-mentioned problems, in the present invention, a heat-resistant resin having a molding temperature of 300 ° C. or higher has a 50% by weight reduction temperature of 3 due to thermal decomposition.
The resin composition for a sliding material was prepared by adding a metal deactivator at 50 ° C. or higher.

The details will be described below.

The heat-resistant resin in the present invention is a synthetic resin having a molding temperature of 300 ° C. or higher, for example, tetrafluoroethylene resin (hereinafter referred to as PTFE), molten fluororesin, polyimide resin, aromatic polyether ketone. Examples thereof include resins, polyether nitrile resins, liquid crystal polymers, polyphenylene sulfide resins and the like. Among these, PTFE or other meltable fluororesin is preferable because it becomes a sliding material having a stable friction coefficient.

The metal inert material according to the present invention is
A material having a 50% weight loss temperature of 350 ° C. or higher due to thermal decomposition is used. Here, the 50 wt% weight loss temperature due to thermal decomposition means the temperature according to the test method described below.

That is, using a thermogravimetric analyzer which is usually used, the temperature was raised from room temperature to 600 ° C. in nitrogen gas under the condition of a temperature increase of 10 ° C./min, and the weight loss% at each temperature was examined. The temperature corresponding to 50% by weight was defined as the 50% by weight reduction temperature due to thermal decomposition. Among the metal deactivators that meet these conditions, it is a hydrazine-based metal deactivator that functions as a copper damage inhibitor, especially for the purpose of preventing corrosion of the sliding mating material copper or copper alloy. Those that do are preferred.

Examples of such a metal deactivator include those manufactured by Asahi Denka Kogyo Co., Ltd. represented by the following formula [Chemical formula 1]: Adeka Stab CDA-6 or manufactured by Ciba-Geigy Co. represented by the following formula [Chemical formula 2]. : Irganox MD1024 or the like may be used.

[0015]

[Chemical 1]

[0016]

[Chemical 2]

The addition amount of the above metal deactivator is preferably less than 7% by weight of the total amount. Because 7% by weight
This is because the above is not sufficiently dispersed in the heat resistant resin, and a large amount of gas is generated by thermal decomposition, which causes cracks or cavities during molding.

In addition to the metal deactivator, various fillers may be added to the heat-resistant resin used in the present invention for the purpose of improving wear resistance and stability of friction coefficient.

As the above-mentioned filler, polyether imide resin, polyether sulfone resin, polyamide imide resin, aromatic aramid resin, heat resistant polyamide resin, phenolic resin, aromatic polyester resin, silicone which is an organic resin material. Resin, zinc, aluminum, magnesium, metal powder such as molybdenum or inorganic powder for improving heat conduction, glass beads, glass flakes, silica balloons, diatomaceous earth, asbestos, magnesium carbonate, calcium carbonate, calcium oxide, calcium fluoride, Inorganic powder such as calcium hydroxide, graphite,
Inorganic powder for improving lubricity, such as lead oxide, fluorinated graphite, kaolin, carbon, mica, talc and molybdenum trioxide,
Inorganic fibers and whiskers such as glass fiber, carbon fiber, graphite fiber, wollastonite, potassium titanate whiskers, silicon carbide whiskers, sapphire whiskers, metal fibers such as steel wire, copper wire, stainless wire, tungsten core wire or So-called boron fiber obtained by vapor deposition of boron, silicon carbide, etc. on carbon fiber, organic fiber such as aromatic aramid fiber, polyethylene fiber, phenol fiber and inorganic pigments such as iron oxide, cadmium sulfide, cadmium selenide and carbon black, silicone oil Examples thereof include ester oils, fluorine oils, polyphenylene ether oils, waxes, and internal lubricant additives such as zinc stearate.

Further, these heat resistant resins, metal deactivators,
As for the method of mixing and molding the other fillers, in the case of PTFE, the molding may be carried out under the usual molding conditions of the commonly used filler-containing PTFE. For example, a tumbler mixer, a Henschel mixer, or other mixer may be used to mold the PTFE and the metal mixture. The activator and other fillers are dry-mixed, put in a mold and pre-molded by applying a pressure of 380 to 600 kg / cm ² , and then the compression molded body taken out from the mold is 3
Any of a method of sintering at 70 ° C., a method of compression-molding batchwise while applying heat and pressure, a method of continuous molding with a ram extruder, or the like may be used.

When a non-thermoplastic polyimide resin is used, it is mixed by the same mixing method as in the above PTFE, and the molding conditions are as follows: the mixture is put in a mold at 320 to 370 ° C.
A method of heat-pressing under a condition of 500 to 1200 kgf / cm ² can be adopted.

Further, in the case of a heat resistant resin other than PTFE or a non-thermoplastic polyimide resin, the raw materials may be individually supplied to a melt mixer, or a mixer such as a Henschel mixer, a ball mill or a tumbler mixer may be used in advance. After dry-mixing, the mixture may be melt-mixed with a hot roll, a kneader, a Banbury mixer, a screw extruder or the like to form a pellet as a molding material. As a molding method, it goes without saying that compression molding, sintering molding, etc. can be applied.
In the present invention, in particular, a uniform melt blend is formed,
It is possible to perform injection molding or extrusion molding with high productivity.

[0023]

The resin composition for a sliding material of the present invention becomes a sliding material in a state where the metal deactivator is not thermally decomposed at the molding temperature of the heat resistant resin and is uniformly dispersed in the heat resistant resin. Therefore, when this material slides against a heavy metal, the sliding material itself does not deteriorate, and moreover, the surface of the mating material is protected by the metal deactivator and corrosion is prevented.

[0024]

[Examples and Comparative Examples] The raw materials used in Examples and Comparative Examples are summarized below. In addition,
The abbreviations are shown in parentheses, and the blending ratios are all represented by weight%.

(I) Heat resistant resin (1) PTFE (PTFE-1) manufactured by Daikin Industries: Polyflon M-15 (2) Molten fluororesin (PFA-1) manufactured by Mitsui DuPont Fluorochemicals: PFA340J (3) Aromatic Polyether Ketone Resin (PEEK-1) ICI: Victrex PEEK150P (4) Polyether Nitrile Resin (PEN) Idemitsu Kosan: Polyether Nitrile ID300 (5) Liquid Crystal Polymer (LCP) Nippon Petrochemical Co., Ltd. Made: Zaider SRT300 (6) Polyphenylene sulfide (PPS) Made by Topren: T-4AG (7) Thermoplastic polyimide resin (PI-1) Made by Mitsui Toatsu Chemicals: New-TPI450 (8) Non-thermoplastic polyimide resin ( PI-2) Ube Industries, Ltd .: Upilex R type (II) Metal deactivator (9) Asahi Denka Kogyo Co., Ltd. : STAB CDA-6 (CDA
-6) 50% weight loss temperature due to thermal decomposition 400 ° C. (10) Ciba Geigy Co .: Irganox MD1024
(MD1024) 50% weight loss temperature 370 ° C due to thermal decomposition (11) Asahi Denka Kogyo KK: ADEKA STAB CDA-1 (CDA
-1) 50% weight reduction temperature due to thermal decomposition 320 ° C (III) Filler (12) Aromatic polyester resin (OBP) Sumitomo Chemical Co., Ltd .: Econol E101SS (13) Aromatic polyetherketone resin (PEEK-2) IC Ai: Victrex PEEK150P frozen and pulverized into powder (14) Aromatic aramid resin (aramid) Asahi Kasei: Aramid powder MP (15) Molten fluororesin (PFA-2) Mitsui DuPont Fluorochemicals Made: MP-10 (16) PTFE (PTFE-2) Kitamura Co., Ltd .: KT400H (17) Calcium Carbonate (CaCO ₃ ) Nihon Kogyo Co., Ltd .: NA600 (18) Talc Matsumura Sangyo Co., Ltd .: Crown Talc PP After mixing the raw materials in the proportions shown in Table 1, molding the sliding material by molding under the normal molding conditions of the heat-resistant resin that serves as the matrix. The following test was conducted and the results are shown in Table 1.
It was also written inside.

(1) Wear coefficient and friction coefficient Sliding speed by a thrust type friction wear tester was 18 m / min,
Load 8.5 kgf / cm ² , mating material phosphor bronze C519
1. The wear coefficient (× 10 ⁻¹⁰ cm ³ / kg · m) after 100 hours and the friction coefficient after 5 minutes and 120 minutes under a humidified condition of a temperature of 60 ° C. and a humidity of 70% were obtained.

(2) Degree of deterioration of mating material (phosphor bronze) due to sliding Observing the degree of deterioration of the mating material sliding surface after the friction and wear test of (1) above for 100 hours, the amount of rust generated The evaluation was made in two stages, large (x) and small (○).

[0028]

[Table 1]

As is clear from the results shown in Table 1, in Comparative Examples 14, 16 and 17 in which the metal deactivator was not added, rust was remarkably generated from the sliding surface of the phosphor bronze as the mating material.
Along with this, the heat resistance of the heat resistant resin is also inferior. Further, in Comparative Examples 13 and 15 to which the metal deactivator having a 50% weight loss temperature of 350 ° C. or less due to thermal decomposition was added, a large amount of gas was generated during molding, and molding was impossible.

On the other hand, the heat resistant resin sliding materials of Examples 1 to 12 have a stable friction coefficient and a small wear coefficient. In addition, even though the test was performed in a humidified atmosphere, the occurrence of rust was small on the sliding surface of the phosphor bronze which was the mating material.

[0031]

As described above, the sliding material resin composition of the present invention is excellent in heat resistance, wear resistance and friction characteristics, and is resistant to deterioration when it slides against a heavy metal, and at the same time, the mating material. It has the advantage of protecting heavy metals, which are

Claims (1)

[Claims] 1. A resin composition for a sliding material comprising a heat-resistant resin having a molding temperature of 300 ° C. or higher and a metal deactivator having a 50% weight loss temperature of 350 ° C. or higher due to thermal decomposition.