KR20140078243A - Rubber composition improving heat-resisting and vibration-proof - Google Patents

Abstract

The present invention relates to a driving system vibration resistant rubber composition of a vehicle and, more specifically, to a vibration resistant rubber composition used for a driving system of a vehicle, in which sulfur or peroxide is used in ethylidene norbornene (ENB) and an ethylene propylene diene rubber (EPDM) as a vulcanizing agent and a particular content of carbon black having different particle sizes and carbon nanotubes are contained as a filling agent, thereby having improved heat and vibration resistance and less modulus variance under ambient temperature.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a vibration-

The present invention relates to a vibration damping rubber composition for a driving system of a vehicle, and more particularly, to a vibration damping rubber composition for a vehicle that uses sulfur or peroxide as a vulcanizing agent in ENB (ethylidene norbornene) and EPDM (ethylene propylene diene rubber) And carbon nanotubes in a specific amount to improve drivability and vibration resistance.

In recent years, interest in environment and energy has increased in the automobile industry, and many automakers are developing technologies for light weight and miniaturization of the vehicle to improve fuel efficiency. At the same time, powertrain (power train) The technology related to the high power output is also being developed.

With the development of the above-mentioned technology, the output of the automobile engine has been continuously increased to be much higher than the engine output of the previous generation. As the size and weight of the vehicle body have become smaller and smaller, vibration and noise from the engine with high output have been reduced, The problem is that it is easily transmitted to the user.

In order to solve the above problems, automobile companies are developing technologies for improving the vibration resistance performance of miniaturized and lightweight automobile parts themselves. The improvement of the vibration resistance performance has become a very important factor in the development of a so-called sensible car and has become an unavoidable global trend. In addition, consumer complaints about vibration and noise are constantly being received, and automakers are devoting themselves to developing technologies for vibration and noise reduction.

Generally, in automobiles, a vibration proof rubber is provided at a portion for supporting a connection portion or a driven motion portion between respective components, and the vibration proof rubber absorbs impact generated from the outside or motion.

That is, since the anti-vibration rubber of the vehicle plays a role of suppressing the transmission of the vibration generated from the engine and the drive shaft, it must be capable of supporting a heavy load and have durability against repeated fatigue. In addition, since it is mounted around a high-temperature engine room, it has a technical feature that heat resistance performance must be secured at the same time.

However, in the case of conventionally used anti-vibration rubber materials, the anti-vibration characteristic shows a reaction sensitive to the change of temperature, and shows a high rate of change of modulus under the atmospheric temperature. Accordingly, if the impact value is excessively higher than the initially set impact value, The shock can not be absorbed and thus the impact is transmitted to the occupant through the vehicle body.

Therefore, there is a need to develop a vibration damping rubber composition having low temperature dependency and excellent vibration damping properties.

It is an object of the present invention to solve the above-mentioned problems, and an object of the present invention is to provide an anti-vibration rubber composition for use in a driving system of an automobile, in which various kinds of EPDM rubber are mixed with a specific component and a crosslinking agent and a filler in an amount, Which is less susceptible to changes in the rubber composition of the present invention.

To achieve the above object, the present invention provides a drivetrain vibration damping rubber composition having improved heat resistance and vibration damping properties, which comprises a raw rubber, a filler, an activator, an antioxidant, a processing oil and a crosslinking agent, (ethylene propylene diene rubber) including ethylidene norbornene.

The raw material rubber preferably contains ethylidenenorbornene in an amount of 4 to 6% by weight based on the total weight of the raw material rubber, and the raw material rubber preferably contains ethylene in an amount of 50 to 70% by weight based on the total weight of the raw material rubber.

The filler is carbon black or a carbon nanotube. The carbon black is contained in an amount of 10 to 30 wt% based on the total weight of the raw rubber, and the carbon nanotube is included in an amount of 5 to 30 wt% .

The activator is zinc oxide (ZnO) or stearic acid. The zinc oxide is contained in an amount of 4.9 to 5.2% by weight based on the total weight of the starting rubber, and the stearic acid is contained in an amount of 0.9 to 1.2% .

The antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline, and it is preferable that the antioxidant is contained in an amount of 1.9 to 2.2% by weight based on the total weight of the starting rubber.

The processed oil is naphthenic oil, and it is preferable that the processed oil is contained in an amount of 49 to 52% by weight based on the total weight of the raw rubber.

Further, the cross-linking agent is diacetyl peroxide, and it is preferable that the cross-linking agent is contained in an amount of 4.9 to 5.2% by weight based on the total weight of the raw rubber.

The effect of the present invention having such a constitution as described above can be attained by changing the combination of the constituent components to ensure excellent mechanical properties of the rubber composition and to improve the vibration damping performance by using various kinds of fillers, There is an advantage to be improved.

In addition, vibration and noise introduced into the automobile interior are reduced, thereby improving the ride quality and improving the sensibility and the commerciality of the automobile.

In addition, since the modulus of change of the modulus is low in a wide temperature range, it is possible to minimize vibrations transmitted from a driving system of an automobile, so that it can be applied not only to a driving system of an automobile but also to various devices for preventing vibration transmission.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

The vibration damping rubber composition of the present invention having improved heat resistance and vibration damping properties comprises a raw rubber, a filler, an activator, an antioxidant, a processing oil and a crosslinking agent, wherein the raw rubber comprises ethylidene norbornene (ENB) And is characterized by being ethylene propylene diene rubber (EPDM).

That is, the present invention relates to a drivetrain vibration-damping rubber composition using various types of carbon black and carbon nanotubes as fillers in various kinds of EPDM rubbers, using EPDM rubber using sulfur or DCP as a cross-linking agent, The ratio of the cross-linking agent to the filler is improved to improve the heat resistance and the dust-proof property by including a specific content.

Thus, by manufacturing the rubber composition of the EPDM material using the same material as that of the present invention, the EPDM rubber composition having high heat resistance and low modulus change rate at a wide range of temperatures can be used to improve the characteristics of the drivetrain rubber composition .

To this end, the raw material rubber preferably contains ethylidenenorbornene in an amount of 4 to 6% by weight based on the total weight of the raw material rubber, and the raw material rubber preferably contains ethylene in an amount of 50 to 70% by weight based on the total weight of the raw material rubber.

Sulfur or peroxide may be used as the vulcanizing agent added thereto.

The filler is carbon black or a carbon nanotube. The carbon black is contained in an amount of 10 to 30 wt% based on the total weight of the raw rubber, and the carbon nanotube is included in an amount of 5 to 30 wt% .

Accordingly, by using a filler containing carbon black and carbon nanotubes different in particle size from each other in a specific amount, the respective compositions contained in the anti-vibration rubber composition are formed at an optimum blend ratio, and have excellent heat resistance, It is possible to provide a drivetrain vibration damping rubber composition using an EPDM rubber composition having a low rate of change of lower modulus.

In addition to the above-mentioned raw rubber and filler, an activator, an anti-aging agent, a processing oil, a cross-linking agent and the like are used in the vibration damping rubber composition for driving system used in the present invention. Dibenzothiazyl disulfide or tetramethyl A promoter such as Tetramethylthiuram disulfide is used. In contrast, the present invention is characterized in that the above promoter is not used.

Wherein the activator is zinc oxide (ZnO) or stearic acid, the zinc oxide is contained in an amount of 4.9 to 5.2 wt% based on the total weight of the raw rubber, and the stearic acid is contained in an amount of 0.9 to 1.2 wt% desirable.

The antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline, and it is preferable that the antioxidant is contained in an amount of 1.9 to 2.2% by weight based on the total weight of the starting rubber.

The processing oil is naphthenic oil, and it is preferable that the processing oil is contained in an amount of 4.9 to 5.2% by weight based on the total weight of the starting rubber.

Further, the cross-linking agent is diacetyl peroxide, and it is preferable that the cross-linking agent is contained in an amount of 4.9 to 5.2% by weight based on the total weight of the raw rubber.

Hereinafter, various embodiments of the present invention will be described in detail.

The vibration damping rubber composition of the present invention having improved heat resistance and vibration damping properties is used as raw rubber, filler, activator, antioxidant, processing oil and crosslinking agent. Experiments are carried out while varying the specific components and content of each composition Respectively.

≪ Example 1 >

Ethylene propylene diene rubber (EPDM) containing ethylidene norbornene (ENB) was used as raw material rubber, and ENB was contained in an amount of 4.7 wt% based on the total weight of the starting rubber, ethylene was 57.5 wt% % (KUMHO POLYChem, KEP-2320 EPDM) were used.

In addition, carbon black was used as the filler. Among the various types of carbon black, Black Pearl (BP120) was used. Particularly, 20 parts by weight of EPDM was added to 100 parts by weight of the carbon black, and zinc oxide (ZnO) and stearic acid Steric acid) was used, and in particular, 5 parts by weight of oxidized bottoms and 1 part by weight of stearic acid were added to 100 parts by weight of EPDM.

As the antioxidant, 2,2,4-trimethyl-1,2-dihydroquinoline was used in an amount of 2 parts by weight based on 100 parts by weight of EPDM, 50 parts by weight of europa naphthenic oil was used for 100 parts by weight of EPDM, and 5 parts by weight of dicumyl peroxide as a crosslinking agent was added to 100 parts by weight of EPDM. No accelerator was used.

≪ Example 2 >

The raw rubber, the activator, the antioxidant, the processing oil and the cross-linking agent were the same as those of Example 1, except that 20 parts by weight of black powder and 20 parts by weight of CNT (carbon nanotube) were mixed in the carbon black used in Example 1 I used it.

≪ Example 3 >

The raw rubber, activator, antioxidant, processing oil and cross-linking agent were the same as those in Example 1, except that 15 parts by weight of black puff in the carbon black used in Example 1 and another carbon black, HAF (High abrasion furnace) 10 parts by weight were used.

<Example 4>

The ethylene-propylene diene rubber (EPDM) containing ethylidene norbornene (ENB) was used as the starting rubber for the raw rubber. The ENB was contained in an amount of 4.5 wt% (KEMPO POLYChem, KEP-7141 EPDM) containing 51.0% by weight was used. The filler was used in the same manner as in Example 3, and the activator, antioxidant, processing oil and crosslinking agent were the same as those in Example 1.

division Compound Weight portion Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Raw rubber EPDME 100 100 100 - - - EPDM B - - - 100 - - NR - - - - 100 60 IIR 40 Filler Carbon black A - - 10 10 45 40 Carbon black B 20 20 15 15 - - CNT - 20 - - - - Activator ZnO 5 5 5 5 8 8 Stearic acid One One One One 2 2 Antioxidant TMQ 2 2 2 2 2 2 N-isopropyl-N'-phenyl-p-phenylenediamine - - - - 2 2 N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine - - - - 2 2 2-mercaptobenzimidazole - - - - 1.5 1.5 Sunnoc - - - - 2 2 Processing oil N-2 50 50 50 50 - - Cross-linking agent S - - - - 0.5 0.4 DCP 5 5 5 5 - - accelerant DM - - - - 1.5 1.5 TT - - - - 1.5 1.5 EPDM A: ethylene propylene diene rubber, Kumho Polychem, KEP-2320
EPDM B: ethylene propylene diene rubber, Kumho Polychem, KEP-7141
NR: natural rubber, Kumho Polychem, SMR CV60
IIR: isobutylene-isoprene rubber, Kumho Polychem, BR-IIR 2244
Carbon black A; HAF, Dongyang Steel Chemical, N330
Carbon black B: Black Pearl, CABOT, BP120
CNT: Carbon nanotubes, JEIO
ZnO: zinc oxide, SBC
Staric acid: Stearic acid, Natoleo
TMQ: 2,2,4-trimethyl-1,2-dihydroquinoline, RT Vanderbilt
N-isopropyl-N'-phenyl-p-phenylenediamine, Crompton
N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, Crompton
2-mercaptobenzimidazole, Qingdao rubber chemical
Sunnoc: Sunnox wax, Yongjin oil painting
N-2: Naphthenic oil, Mingchang oil industry
S: Hwang, Miwon Chemical
DCP: dicumyl peroxide, NOF
DM: dibenzothiazyl disulfide, Crompton
TT: tetramethylthiuram disulfide, Dongyang Iron and Steel Chemical

The physical properties of the rubber specimens and products prepared according to the above examples were measured for the following items.

division Evaluation results Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Hardness (Hs) 48 60 44 40 50 46 Tensile strength (kgf / cm ² ) 80 66 95 78 201 185 Elongation (%) 676 442 891 894 670 710 After aging
Rate of change Hardness (Hs) +4 +4 +6 +5 Not measurable Not measurable The tensile strength -12 -8 -6 -8 Not measurable Not measurable Elongation -13 -14 -7 -10 Not measurable Not measurable Ambient temperature Modulus change rate (%) -20 ° C 253 223 176 161 189 342 20 ℃ 100 100 100 100 100 100 100 ℃ 59 59 50 54 51 43 Loss factor 0.10 0.12 0.12 0.14 0.05 0.18

* Change rate after aging: 130 ° C x 240 hours Physical properties after thermal aging

In the above experiment, the hardness of the anti-vibration rubber composition was measured in accordance with KS M 6784. The tensile strength and elongation of the anti-vibration rubber composition were measured in accordance with KS M 6782 with a dumbbell type No. 3. The evaluation of the aging properties of the dynamic damper rubbers was performed after aging at 130 ° C for 240 hours. The loss factor of the anti-vibration rubber composition was measured by using a DMTA apparatus, and the values were recorded under the conditions of a static strain of 3% and a dynamic strain of 0.1% while being heated from -70 ° C to 120 ° C.

As can be seen from Table 2, the hardness, tensile strength and elongation of the material were different from those of the comparative example, but the change rate of the atmospheric temperature modulus in Example 4 was the lowest and showed good results in terms of the rate of change after aging.

In Comparative Example 1 and Comparative Example 2, the rate of change in physical properties after aging was 240 ° C after 240 hours of heat aging, but the test pieces were broken and the measurement was impossible. In Examples 1 to 4, however, the rate of change in physical properties was exhibited.

That is, according to the vibration-damping rubber composition of the present invention, excellent mechanical properties are ensured, heat resistance is excellent, the modulus of the modulus does not change largely according to the temperature change, and an excellent loss factor is secured. And it is possible to provide a driving system vibration damping rubber composition improved in heat resistance and vibration damping properties by applying the present invention to a vibration damping rubber having low temperature dependency.

Although the present invention has been described in connection with the specific embodiments of the present invention, it is to be understood that the present invention is not limited thereto. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. Various modifications and variations are possible.

Claims (13)

In the rubber composition,
A raw material rubber, a filler, an activator, an antioxidant, a processing oil and a crosslinking agent,
Wherein the raw material rubber is ethylene propylene diene rubber including ethylidene norbornene, wherein the heat resistant and anti-vibration property is improved.
The method according to claim 1,
Wherein the raw rubber comprises ethylidene norbornene in an amount of 4 to 6% by weight based on the total weight of the raw rubber, wherein the heat resistant and anti-vibration property is improved.
The method according to claim 1,
Wherein the raw material rubber comprises ethylene in an amount of 50 to 70% by weight based on the total weight of the raw material rubber, wherein the heat resistant and anti-vibration property is improved.
The method according to claim 1,
Wherein the filler is carbon black or carbon nanotube.
5. The method of claim 4,
Wherein the carbon black is contained in an amount of 10 to 30% by weight based on the total weight of the raw rubber.
5. The method of claim 4,
Wherein the carbon nanotubes are contained in an amount of 5 to 30 wt% based on the total weight of the raw rubber.
The method according to claim 1,
Wherein the activator is zinc oxide (ZnO) or stearic acid. The vibration damping rubber composition of claim 1, wherein the activator is zinc oxide (ZnO) or stearic acid.
8. The method of claim 7,
Wherein the zinc oxide comprises 4.9 to 5.2 wt% of the total weight of the raw rubber.
8. The method of claim 7,
Wherein the stearic acid is contained in an amount of 0.9 to 1.2% by weight based on the total weight of the starting rubber.
The method according to claim 1,
Wherein the antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline, and the antioxidant is 1.9 to 2.2% by weight based on the total weight of the starting rubber.
The method according to claim 1,
Wherein the processing oil is naphthenic oil and is contained in an amount of 49 to 52% by weight based on the total weight of the starting rubber.
The method according to claim 1,
Wherein the crosslinking agent is dicumyl peroxide, and the crosslinking agent is contained in an amount of 4.9 to 5.2% by weight based on the total weight of the starting rubber.
An anti-vibration rubber characterized by being manufactured from the anti-vibration rubber composition according to any one of claims 1 to 12.