KR100586079B1 - Rubber compostion of a packing for timing chain cover module - Google Patents

Abstract

The present invention relates to a rubber composition for packing the timing chain cover module (TCCM), and more particularly to 80 to 95% by weight in consideration of the fact that the packing used for the timing chain cover module is in contact with the engine oil and the antifreeze at the same time. By preparing a rubber composition based on a polymer blended with hydrogenated acrylonitrile butadiene rubber and 5 to 20% by weight of ethylene vinyl acetate copolymer, a packing excellent in long-term durability, heat resistance, hot water resistance, oil resistance, and compression resistance can be produced. And a rubber composition for packing the timing chain cover module.

Timing Chain Cover Module, Hydrogenated Acrylonitrile Butadiene Rubber, Engine Oil, Antifreeze

Description

Rubber composition for timing chain cover module packing {Rubber compostion of a packing for Timing Chain Cover Module}

The present invention relates to a rubber composition for packing the timing chain cover module (TCCM), and more particularly to 80 to 95% by weight in consideration of the fact that the packing used for the timing chain cover module is in contact with the engine oil and the antifreeze at the same time. By preparing a rubber composition based on a polymer blended with hydrogenated acrylonitrile butadiene rubber and 5 to 20% by weight of ethylene vinyl acetate copolymer, a packing excellent in long-term durability, heat resistance, hot water resistance, oil resistance, and compression resistance can be produced. And a rubber composition for packing the timing chain cover module.

The timing chain is a drive chain connecting the crankshaft of the automobile and the camshaft for opening and closing the intake / exhaust valve of the cylinder head, and serves to adjust the opening and closing timing of the valve according to the position of the piston.

In the past, timing belts made of rubber were used instead of timing chains. Conventional rubber timing belts have the advantage of low noise, but the tension of the belt may be reduced during long-term driving, and there is a risk of disconnection due to hardening of the rubber, which requires regular replacement. In order to solve these problems, a timing chain method is used without using a timing belt.

Timing chains and chain covers are semi-permanent as they are made of metal, while driving noise is generated and requires lubrication and cooling. The timing chain cover acts as a passage and seal for engine oil and antifreeze for reducing noise and lubricating and cooling the timing chain. Therefore, airtightness of the timing chain cover is one of the important factors for the performance of the timing chain. However, since the material of the timing chain cover is made of metal, the actual sealing role is played by the packing mounted on the cover.

In general, acrylonitrile butadiene rubber and ethylene propylene diene rubber are typically used for rubber compositions requiring water resistance. However, there is a limit to satisfying long-term durability, which is the current trend of the industry. Hydrogenated acrylonitrile butadiene rubber, silicone rubber, fluorine rubber, and the like are used to compensate for the disadvantages of the two rubbers having low compatibility at high temperatures.

In particular, hydrogenated acrylonitrile butadiene rubber is a rubber material having excellent heat resistance and oil resistance. Sealants made of this hydrogenated acrylonitrile-butadiene rubber have been applied to seal a relative fluid under severe conditions. In the aspect of securing long-term durability, which is a trend in the market, it is being widely applied to general devices.

Since a timing belt has conventionally been used and thus no packing is required, a technique for rubber compositions that is optimal for timing chain cover module packing has not been proposed yet. Therefore, in consideration of the fact that the packing used for the timing chain cover module is in contact with the engine oil and the antifreeze at the same time, it was necessary to develop a packing composition excellent in long-term durability, heat resistance, hot water resistance, oil resistance and compression resistance.

Accordingly, the present inventors have conducted research and efforts to solve the conventional problems, and as a result, hydrogenated acrylonitrile butadiene rubber (H-NBR) having excellent heat resistance, hot water resistance, and oil resistance and ethylene vinyl acetate copolymer having excellent heat resistance, compression resistance, and weather resistance When the rubber composition for packing is prepared by including a polymer blended with EVA, the present invention finds excellent long-term durability, heat resistance, hot water resistance, oil resistance, and compression resistance even when the packing contacts the engine oil and the antifreeze at the same time. Was completed.

Accordingly, an object of the present invention is to provide a rubber composition for packing a timing chain cover module comprising a hydrogenated acrylonitrile butadiene rubber and an ethylene vinyl acetate copolymer in a certain weight ratio.

The present invention is characterized by a rubber composition for packing a timing chain cover module comprising a polymer blended with 80 to 95 wt% of hydrogenated acrylonitrile butadiene rubber and 5 to 20 wt% of ethylene vinyl acetate copolymer.

The present invention will be described in more detail as follows.

In view of the fact that the packing used in the timing chain cover module is in contact with the engine oil and the antifreeze at the same time, 80 to 95% by weight of hydrogenated acrylonitrile butadiene rubber and 5 to 20% by weight of ethylene vinyl acetate copolymer are used. The present invention relates to a rubber composition for timing chain cover module packing that can produce a packing excellent in long-term durability, heat resistance, hot water resistance, oil resistance, and compression resistance by producing a rubber composition based on a blended polymer.

The composition of the present invention comprises a polymer, a filler, a crosslinking agent, a crosslinking aid and a plasticizer.

The present invention is characterized by using a blend of a copolymer of hydrogenated acrylonitrile butadiene rubber and ethylene vinyl acetate as a polymer. The hydrogenated acrylonitrile butadiene rubber is widely known under the trade name "Therban ^® ", and the ethylene vinyl acetate copolymer under the trade name "Levapren ^® ".

Since the packing used for the timing chain cover module should play a role of preventing leakage and leakage in the situation of directly contacting water of 100 ° C. or higher and engine oil of 130 ° C. or higher, the present invention provides heat resistance, chemical resistance, oil resistance, and hot water resistance. The combination of good hydrogenated acrylonitrile butadiene rubber and ethylene vinyl acetate copolymer with excellent flame resistance, compression resistance, weather resistance and ozone resistance can improve the heat resistance, hot water resistance and compression resistance of the packing.

It is preferable that 80-95 weight% of hydrogenated acrylonitrile butadiene rubbers are contained in the said polymer, and 5-20 weight% of ethylene vinyl acetate copolymers are included. When the content of ethylene vinyl acetate is more than 20% by weight can lower the tensile strength and elongation, less than 5% by weight is not expected to improve the mechanical properties.

The filler is used to supplement the water resistance, mechanical properties, etc., it is preferable to use carbon black. Carbon black is not limited to a specific type, and carbon black HAF (particle size: 26 to 30 nm), carbon black FEF (particle size: 40 to 48 nm), carbon black SRF (particle size: 61 to 100 nm), carbon black MT (particle size) : 201 to 500 nm) can be preferably used. More preferably, carbon black MT is preferable.

The filler may be included in 10 to 30 parts by weight, preferably 20 to 25 parts by weight based on 100 parts by weight of the polymer of the present invention. If the content of the filler is less than 10 parts by weight, it is difficult to expect the effect of improving mechanical properties. If the content of the filler exceeds 30 parts by weight, there is a problem that the crack is likely to occur during an external impact and adversely affect the water resistance.

The crosslinking agent is a compounding agent used to make crosslinks between the polymer chains when the kneaded rubber is heated to an appropriate temperature. Types of crosslinking agents include sulfur and peroxide, and in general, peroxide vulcanization is preferred in order to obtain better heat resistance and compression resistance.

The crosslinking agent may be included in an amount of 4 to 8 parts by weight, and preferably 5 to 7 parts by weight, based on 100 parts by weight of the polymer of the present invention. If the content of the crosslinking agent is less than 4 parts by weight, it is difficult to obtain a crosslinking effect between the polymers. If the content of the crosslinking agent is more than 8 parts by weight, the tensile strength, the elongation, etc. are worsened, and there is a problem in that the bending resistance is poor and brittleness occurs.

The crosslinking aid is used to assist the crosslinking and to improve the durability and heat resistance of the long term packing. In the present invention, a metal oxide is used. The metal oxide includes zinc oxide, magnesium oxide, titanium oxide and the like.

The crosslinking aid is preferably contained 5 to 20 parts by weight based on 100 parts by weight of the polymer.

In the composition of the present invention, in addition to the additives used above, other various additives such as anti-aging agents and processing aids can be used within the scope of the object of the present invention.

Anti-aging agents can be used without limitation conventional ones used in the rubber composition for packing, for example, 4.4'-bis (4-α, α'- dimethylbenzyl) diphenylamine, diphenylamine, 2-mercaptomethylbenzo Imidazole and the like.

Antioxidant may be included 2 to 5 parts by weight based on 100 parts by weight of the polymer.

Processing aids can be used without limitation conventional ones used in the rubber composition for packing, stearic acid, fatty acid resins, fatty acid esters and the like can be used.

Meanwhile, the manufacturing method of the timing chain cover module packing will be described in more detail as follows.

The production of the rubber packing of the present invention is not limited to a particular method, and can be produced by a conventional mechanical kneading method or the like. The kneader, for example, using a common kneader such as kneader, Banbury mixer, Open mill, and the like to mix the composition, it is carried out at a kneading temperature of 100 ~ 150 ℃ and the most within the temperature range It can have effective physical properties.

In addition, the packing rubber composition kneaded above is molded by a molding process such as cutting, extrusion molding.

Hereinafter, the present invention will be described in more detail based on Examples, but the present invention is not limited to the following Examples.

Example

The rubber composition for timing chain cover module packing was prepared using the components and contents shown in the following Table 1. Although there is no prior art of the present invention, in order to confirm the superiority of the polymer of the present invention, an example in which the polymer is changed is used as a comparative example.

Component (parts by weight) Example Comparative example Polymer H-NBR ¹ 92 wt% - NBR ² - 92 wt% EVA ³ 8 wt% 8 wt% Filler N990 ⁴ 23 23 Crosslinking agent TY-13 ⁵ 6 6 Crosslinking aid ZnO KS-1 ⁶ 13 13 Plasticizer RS-700 ⁷ 7 7 Anti-aging Naugard 445 ⁸ 3 3 Processing aid ST / A ⁹ 2 2  1.H-NBR: Therban A3907, Bayer 2.NBR: NT3481VP, Bayer 3. EVA: Levapren 600HV, Bayer 4.N990: MT, Cancarb 5.TY-13: 1,3 bis (2-t-butylperoxy Isopropyl) benzene, Akzo 6. ZnO KS-1: ZnO, tribozinc 7. RS-700: ether ester, ADK 8. Naugard 445: 4.4'-bis (4-α, α'-dimethylbenzyl) diphenyl Amine, emerging emerging 9. ST / A: stearic acid, Natoleo

Experimental Example

In order to measure the physical properties of the prepared composition, a specimen was prepared by cooling after extrusion molding. Physical properties of hardness, tensile strength, elongation, heat resistance, oil resistance, internal fluid resistance, cold resistance, compressive permanent shrinkage, and the like were measured using the specimen prepared from the composition of the above example, and the results are shown in Table 2 below. Shown in

[How to measure]

1. Hardness: According to KS M6518, Clause 7

2. Tensile strength: According to KS M6518, Clause 5

3. Elongation: According to KS M6518, Clause 5

4. Heat resistance: According to KS M6518, Clause 8 of KS Standard

5. Oil resistance: According to KS M6518, Clause 13

6. Inner fluid: According to KS standard KS M6789

7. Cold resistance: According to KS standard KS M6676

8. Compressive permanent shrinkage: According to KS M6518, Clause 11

Item Example Comparative Example State property Hardness (Hs) 71 70 Tensile strength (kgf / ㎠) 198 205 % Elongation 328 383 Heat resistance Hardness change (Point) +4 +17 Tensile Strength Change Rate (%) +13 -69 Elongation rate of change (%) -10 -85 Compressed permanent reduction rate (%) 17 30 Oil Resistance ASTM No.1 Hardness change (Point) +2 +4 Tensile Strength Change Rate (%) -2 -8 Elongation rate of change (%) -8 -19 Volume change rate (%) -2.2 -3.1 Oil resistant IRM 903 Hardness change (Point) -5 -7 Tensile Strength Change Rate (%) -One -5 Elongation rate of change (%) -7 -9 Volume change rate (%) +14.2 +16.9 Oil Resistance Engine Oil (5W-30) Hardness change (Point) +2 +7 Tensile Strength Change Rate (%) -4 -12 Elongation rate of change (%) -11 -14 Volume change rate (%) +8.8 +12.6 Internal synergism Hardness change (Point) -3 -6 Tensile Strength Change Rate (%) -One -16 Elongation rate of change (%) -6 -19 Volume change rate (%) +2.7 +5.2 Cold resistance Low temperature destruction Nondestructive Nondestructive

As shown in Table 2, the packing made of the composition of the present invention has a 43% improvement in compressive permanent shrinkage, which is the most important characteristic of the packing. In addition, the timing chain cover module is in contact with engine oil and antifreeze at the same time. As the engine of a car is gradually getting smaller and smaller in size, the inside of the engine room is in a high temperature atmosphere. The embodiment is more than 80% improved in heat resistance compared to the comparative example and is suitable for a timing chain cover module applied to a high performance engine.

In particular, the blend polymer of the present invention showed an excellent effect that the change in physical properties such as hardness in the heat resistance and oil resistance test was smaller than in the case of using other polymers, and the physical properties in the internal copper fluid test were significantly improved.

As described above, the rubber composition for packing the timing chain cover module (TCCM) of the present invention is 80 to 95% by weight of hydrogenated acrylic in consideration of the fact that the packing used for the timing chain cover module is in contact with the engine oil and the antifreeze at the same time. By producing a rubber composition based on a polymer blended with nitrile butadiene rubber and 5 to 20% by weight of ethylene vinyl acetate copolymer, a timing capable of producing a packing excellent in long-term durability, heat resistance, hot water resistance, oil resistance and compression resistance is obtained. A rubber composition for chain cover module packing.

Claims (6)

A rubber composition for packing a timing chain cover module, comprising a polymer blended with 80 to 95 wt% hydrogenated acrylonitrile butadiene rubber and 5 to 20 wt% ethylene vinyl acetate copolymer. The rubber composition for packing the timing chain cover module according to claim 1, further comprising 10 to 30 parts by weight of carbon black based on 100 parts by weight of the polymer. The rubber composition for packing a timing chain cover module according to claim 2, wherein the carbon black has a particle diameter of 201 to 500 nm. The rubber composition for packing the timing chain cover module according to claim 1, further comprising 4 to 8 parts by weight of peroxide, based on 100 parts by weight of the polymer. The rubber composition for packing a timing chain cover module according to claim 1, further comprising 5 to 20 parts by weight of a metal oxide with respect to 100 parts by weight of the polymer. 6. The rubber composition for packing the timing chain cover module according to claim 5, wherein the metal oxide is selected from the group consisting of zinc oxide, magnesium oxide and titanium oxide.