KR102417538B1 - Rubber composition having high stiffness for absorbing vibration of engine - Google Patents

Abstract

The present invention relates to a rubber composition for a high rigidity engine mount, and more particularly, to 100 parts by weight of natural rubber, 20 to 90 parts by weight of a filler consisting of 5 to 15 parts by weight of carbon black and 15 to 75 parts by weight of silica, and an average particle diameter of 5 2-8 parts by weight of alumina of ~45 μm, 1-12 parts by weight of a silane coupling agent, 9-13 parts by weight of an activator, 5-9 parts by weight of an antioxidant, 0.3-0.6 parts by weight of a vulcanizing agent, and 2-4 parts by weight of a vulcanization accelerator It relates to a rubber composition for a high rigidity engine mount comprising a part.

Description

Rubber composition for high rigidity engine mount {RUBBER COMPOSITION HAVING HIGH STIFFNESS FOR ABSORBING VIBRATION OF ENGINE}

The present invention relates to a rubber composition for high rigidity engine mounts, and more particularly, by mixing alumina having a specific average particle diameter with a filler in which natural rubber is mixed with carbon black and silica in an optimal component ratio, the same magnification required for the material can be obtained. It relates to a rubber composition for a high-rigidity engine mount that can simultaneously secure NVH performance and driving stability of a vehicle by improving rigidity while maintaining it.

For environmental reasons such as depletion of limited resources and greenhouse gas emissions, automobile engine technology has developed into a downsized, high-efficiency engine. Accordingly, attention has been focused on the development of heat-resistant components that can withstand the temperature rise of the engine room atmosphere due to the high-efficiency engine.

In particular, engine mount parts are related to the steering part and NVH (noise, vibration, harshness) part as they not only withstand the temperature rise of the engine room atmosphere, but also support the engine and insulate the transmitted energy source.

During the development of parts, the requirements of the steering part and the NVH part affect the hardness and the same magnification characteristics of the rubber material. The NVH performance part is required to lower the same magnification.

However, in the existing rubber material for engine mounts, the hardness was adjusted by filling the filler to induce an increase in hardness, but this increase in hardness had a problem in that the same magnification increased.

Conventional Korean Patent Application Laid-Open No. 2004-0000241 discloses a heat-resistant anti-vibration rubber composition comprising FEF carbon black and silica in a base rubber made of natural rubber and isoprene rubber, but the main purpose is to improve performance such as heat resistance and creep amount There is only this, and there is a problem in that the physical properties such as improving the hardness and appropriately lowering the same magnification are not satisfied.

Therefore, research and development is required for a material that can prevent the engine weight from being biased by simultaneously controlling the hardness and magnification characteristics of the rubber material while applying the existing natural rubber as a basic material.

Korean Patent Publication No. 2004-0000241

In order to solve the above problems, the present invention provides a low magnification ratio by mixing a filler made of carbon black and silica, alumina having a specific average particle diameter, a silane coupling agent, an activator, an anti-aging agent, etc. in an appropriate amount with natural rubber, which is a base rubber. The invention was completed by discovering that a rubber composition for an engine mount having excellent rigidity while having

Accordingly, an object of the present invention is to provide a rubber composition for a high rigidity engine mount with improved NVH performance and driving stability of a vehicle.

The present invention relates to 100 parts by weight of natural rubber, 20 to 90 parts by weight of a filler consisting of 5 to 15 parts by weight of carbon black and 15 to 75 parts by weight of silica; 2 to 8 parts by weight of alumina having an average particle diameter of 5 to 45 μm; 1 to 12 parts by weight of a silane coupling agent; 9-13 parts by weight of an activator; 5 to 9 parts by weight of an antioxidant; 0.3-0.6 parts by weight of a vulcanizing agent; And 2 to 4 parts by weight of a vulcanization accelerator; provides a rubber composition for a high rigidity engine mount comprising.

The rubber composition for an engine mount according to the present invention improves mechanical properties while maintaining a low magnification ratio by mixing alumina having a specific average particle diameter with a filler in which carbon black and silica are mixed in an optimal component ratio to natural rubber. A rubber composition for a mount can be prepared.

In addition, it is possible to increase the NVH performance of the vehicle by improving the insulation performance through a low copper magnification, and it has the effect of securing driving stability with high rigidity at the same time.

Hereinafter, the present invention will be described in more detail by way of an embodiment.

The rubber composition for a high-rigidity engine mount of the present invention comprises: 20 to 90 parts by weight of a filler composed of 100 parts by weight of natural rubber, 5 to 15 parts by weight of carbon black and 15 to 75 parts by weight of silica; 2-8 parts by weight of alumina having an average particle diameter of 5 to 45 μm; 1 to 12 parts by weight of a silane coupling agent; 9-13 parts by weight of an activator; 5 to 9 parts by weight of an antioxidant; 0.3-0.6 parts by weight of a vulcanizing agent; and 2 to 4 parts by weight of the vulcanization accelerator.

Specifically, the rubber composition for an engine mount can increase the initial rigidity by inducing an increase in hardness while maintaining a low copper magnification (vibration insulation) of the material by mixing alumina with a filler made of carbon black and silica to natural rubber.

According to a preferred embodiment of the present invention, the natural rubber has excellent elongation, tensile strength, elasticity, and the like, and has high strength during vulcanization, so that it can be used as a rubber for engine mount.

According to a preferred embodiment of the present invention, the filler can improve durability and mechanical properties of the product by using a mixture of carbon black and silica. As the filler, 5 to 15 parts by weight of carbon black and 15 to 75 parts by weight of silica may be used. That is, it is preferable to use a filler in which the carbon black and silica are mixed in a weight ratio of 1:3 to 5. Preferably, the filler is mixed with 5-10 parts by weight of carbon black and 15-50 parts by weight of silica, and more preferably, it is preferable to use a mixture of 7-10 parts by weight of carbon black and 21-50 parts by weight of silica. .

As the carbon black, it is preferable to use SRF (Corax N774, Orion Engineered Carbons Co., Ltd.) having an average particle diameter of 11 to 19 nm. The reason is that if the particle size is less than 11 nm, the reinforcing effect may be insignificant, and if it exceeds 19 nm, the dispersibility may be deteriorated because the particle size is too large. The SRF carbon black used in the present invention has good workability and dispersibility, and the reinforcing property does not decrease significantly even when mixed in large amounts, has good rebound elasticity and flex resistance of vulcanized rubber, and has low heat generation, so it acts as a filler and reinforcing agent. There is an advantage.

When the content of the carbon black is less than 5 parts by weight, there is a problem of deviating from the physical property specifications required for engine mount rubber products due to deterioration of mechanical properties. If it exceeds 15 parts by weight, problems with dispersion and distribution of silica may occur. In addition, it is undesirable because there is a problem of defects and processability during product production due to a sudden decrease in mechanical properties.

In addition, the silica can be used to improve the compression set with excellent restoring force. If the content is less than 10 parts by weight, the effect of improving physical properties on the silica content is insignificant, and if it exceeds 60 parts by weight, the problem of dispersion and distribution of silica This is undesirable because it can cause deterioration of mechanical properties, increase in defects in the production of vibration-proof products, and workability problems due to over-spec of hardness.

According to a preferred embodiment of the present invention, the alumina (Al ₂ O ₃ ) is used to improve mechanical properties and impart excellent thermal conductivity and uniform vulcanization to the product, and has a spherical shape with an average particle diameter of 5 to 45 μm. It is better to use alumina powder. In particular, if alumina having a size larger than the average particle diameter is used, mechanical properties may be rather impaired due to the occurrence of voids in the formulation. If the content of the alumina is less than 2 parts by weight, the effect of improving mechanical properties is insignificant, and if it is more than 8 parts by weight, there is an effect of improving the modulus of the product, but the same magnification may be inhibited.

According to a preferred embodiment of the present invention, the silane coupling agent can improve dispersion and further improve workability by modifying the interface of polar silica, and can increase mechanical properties when using a bifunctional silane coupling agent. can The silane coupling agent may be used in an amount of 1 to 12 parts by weight based on 100 parts by weight of the natural rubber. If the content is less than 1 part by weight, the modification reaction and dispersion effect of the silica interface may be insignificant, and if it exceeds 12 parts by weight, coupling Excessive reaction may cause deterioration of mechanical properties. Preferably, the silane coupling agent is mixed with the silica contained in the filler in a mixing ratio of 1:5.

According to a preferred embodiment of the present invention, the activator serves to activate the vulcanization accelerator, and stearic acid, zinc oxide, or a mixture thereof may be used. 9 to 13 parts by weight of the activator may be added. If the content is less than 9 parts by weight, the crosslinking reaction is slow, and if it is more than 13 parts by weight, the crosslinking reaction is too fast, which may cause problems in productivity.

According to a preferred embodiment of the present invention, the antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline (2,2,4-trimethl-1,2-dihydroquinoline), acetone diphenylamine (Acetone) diphenylamine), 2-Mercapto benzoimidazole, N-(1,3-dimethylbutyl)-N'phenyl-phenylene diamine (N-(1,3-Dimethylbutyl)-N'phenyl- phenylene diamine) and at least one selected from the group consisting of paraffin wax may be used.

Specifically, the 2,2,4-trimethyl-1,2-dihydroquinoline is excellent in preventing aging due to heat, and there is no blooming during mixing and no influence on the vulcanization accelerator. For example, Kumho Monsanto You can use Kumanox RD on The acetone diphenylamine is an anti-aging agent that is particularly excellent in heat resistance and bending resistance. It is hardly affected by the vulcanization accelerator and can be mainly used in parts that are aged by cracking under physical force. For example, Kumanox BLE- N can be used.

The 2-mercapto benzoimidazole is used as a stabilizer for engineering plastics, such as polyimide-based and polyamide-based resins, and when combined with other phenol-based and amine-based primary antioxidants, excellent effects can be obtained, and non-pollution properties of rubber There is an excellent advantage when used as a secondary anti-aging agent, for example, Miwon Chemical's MB (2-Mcrcaptobenzimidazole) can be used.

The N-(1,3-dimethylbutyl)-N'phenyl-phenylene diamine is effective in bending resistance, oxidation resistance, ozone uniformity, and anti-freeze protection. It has an excellent advantage in preventing bending cracks, and Kumanox 13 of Kumho Monsant can be used as an example. As the paraffin wax, Rhein Chemie Additives' ANTILUX 654 may be used as an anti-check wax that protects rubber products against cracking due to ozone and weathering.

5 to 9 parts by weight of the antioxidant may be used based on 100 parts by weight of the natural rubber. If the content is less than 5 parts by weight, the anti-aging effect may be insignificant, and if it exceeds 9 parts by weight, blooming occurs excessively. As a result, mechanical properties may be deteriorated.

According to a preferred embodiment of the present invention, 0.3 to 0.6 parts by weight of the vulcanizing agent may be used with respect to 100 parts by weight of natural rubber. There is a problem, and when it is more than 0.6 parts by weight, there is a problem that heat resistance cannot be satisfied. Sulfur may be used as the vulcanizing agent, and MIDAS 101 manufactured by Miwon Chemical Company may be used as an example.

According to a preferred embodiment of the present invention, as the vulcanization accelerator, it is preferable to use a monosulfide-based or disulfide-based accelerator to which sulfur is added in a small amount for heat resistance. Specific examples include N-cyclohexylbenzothiazole-2-sulfenamide (N-cyclohexylbenzothiozole-2-sulfenamide, CZ), tetramethylthiuram disulfide (Tetramethylthiuram disulfide, TT), or a mixture thereof. 2 to 4 parts by weight of the vulcanization accelerator may be mixed with respect to 100 parts by weight of natural rubber. If the content is less than 2 parts by weight, the vulcanization time is too long and productivity is lowered. If it exceeds 4 parts by weight, scorch (Scorch) ), which may cause process defects. The vulcanization accelerator may serve to shorten the vulcanization time, lower the vulcanization temperature, and reduce the amount of the vulcanizing agent.

According to a preferred embodiment of the present invention, 2 to 10 parts by weight of an additive comprising 1 to 5 parts by weight of a softener and 1 to 5 parts by weight of a dispersant may be further included in 100 parts by weight of the natural rubber. The dispersing agent serves to further facilitate the dispersion of the rubber and the filler made of carbon black and silica, and may be used without limitation as long as it is a generally used dispersing agent. Preferably, as the dispersant, Struktol WB212 products made of fatty acids with a developed structure can be used.

Therefore, the rubber composition for an engine mount according to the present invention uses natural rubber as a base rubber, and alumina having a specific average particle diameter is mixed with a filler in which carbon black and silica are mixed in an optimal component ratio to this natural rubber, thereby achieving a low same magnification. It has the effect of improving the NVH performance of the vehicle by improving mechanical properties while maintaining it, and securing driving stability by preventing the bias of the engine weight due to its high rigidity.

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

Production Examples 1 to 5

In order to check the optimum mixing ratio and influence of the filler consisting of carbon black (C/B) and silica, the filler in the ratio shown in Table 1 below was added to a conventional rubber composition for engine mounts, and the rubber was subjected to a conventional method. Specimens were prepared. Then, physical properties were measured in the same manner as in Table 4 below. At this time, carbon black is Orion Engineered Carbons Co., Ltd. Corax N774 (SRF) manufactured by Corporation was used, and Nipsil RS-150 manufactured by Tosoh Silica Corporation was used as the silica.

Category (wt%) Preparation Example 1 Preparation 2 Preparation 3 Preparation 4 Preparation 5 C/B
(100) C/B: Silica
(80:20) C/B: Silica
(60:40) C/B: Silica
(40:60) C/B: Silica
(20:80) Hardness 56 56 56 56 56 The tensile strength 229 240 233 225 232 elongation 656 663 654 644 650 Modulus 300 65.38 68.63 66.50 66.23 67.38 DMTA equivalence 2.45 2.28 2.20 2.27 1.89 DMTA modulus 2.874 2.776 2.721 2.774 2.607

According to the results in Table 1, when the mixing ratio of carbon black and silica was mixed in the same ratio as in Preparation Example 5, the same as in Preparation Example 1 using only carbon black as a filler and Preparation Examples 2 to 4 using a different mixing ratio It was confirmed that a low copper magnification ratio of 2.0 or less could be secured while maintaining the hardness. Through this, it was found that the durability and mechanical properties were improved when mixed with carbon black in an optimal ratio due to the excellent restoring force of silica.

Production Examples 6-8

In order to confirm the optimal mixing ratio of the silane coupling agent (Si-69 (50%) of EVONIK Co., Ltd.) and the silica used as a filler, the silane coupling agent and silica were used in the weight ratio as shown in Table 2 below, and Preparation Example 5 and In the same manner, a rubber specimen was prepared and the physical properties were measured.

Category (weight ratio) Preparation 6 Preparation 7 Preparation 8 Silane Coupling Agent: Silica
(1:10) Silane Coupling Agent: Silica
(1:5) Silane Coupling Agent: Silica
(1:2.5) Hardness 56 56 51 The tensile strength 232 237 237 elongation 650 640 641 Modulus 300 67.38 70.88 58.48 DMTA equivalence 1.89 1.87 1.62 DMTA modulus 2.607 2.772 2.476

According to the results of Table 2, in the case of Preparation Example 7, it was confirmed that the silica interface was uniformly modified to improve dispersibility, thereby preventing deterioration of physical properties such as hardness and modulus while having a low magnification ratio. On the other hand, in the case of Preparation Example 6, the tensile strength and modulus were lowered due to excessive silica, and in the case of Preparation Example 8, the modification reaction of the silica interface using less silica was insignificant, indicating poor physical properties as a whole.

Example 1

100 parts by weight of natural rubber was used for 1 minute by using a Banbary Mixer, and then, as shown in Table 3 below, a silane coupling agent was added and the Soviet Union was further performed for 4 minutes. Then, kneading was performed for 4 minutes after adding silica and for 1 minute after adding alumina. Thereafter, carbon black, a softener, a dispersant, an activator and an anti-aging agent were mixed and kneaded for 2 minutes to prepare a carbon master batch. In the final master batch, the prepared carbon masterbatch was stirred in Banbury for 1 minute, and then a vulcanizing agent and a vulcanization accelerator as a crosslinking agent were added and kneaded for 2 minutes.

The final master batch kneaded in the Banbury mixer was dispersed and mixed for 2 minutes using an open roll mixer. For the prepared rubber composition, an appropriate vulcanization time was measured using a rheometer, and then, a rubber specimen for engine mount was prepared at 160° C. under a pressure of 150 Kgf/Cm ² using a thermo-pressing machine.

Examples 2-4 and Comparative Examples 1-6

It was carried out in the same manner as in Example 1, but was added in the ratio of the components shown in Table 3 to prepare a rubber specimen for an engine mount.

<Ingredients>

(1) natural rubber

(2) Activators: Zincide (zinc oxide) and stearic acid

(3) Anti-aging agent: Kumanox RD (Polymer of 2,2,4-trimethl-1,2-dihydroquinoline) from Kumho Monsanto, Kumanox BLE-N (Acetone diphenylamine) from Kumho Monsanto, MB (2-Mercapto benzoimidazole) from Miwon Chemical ), Kumanox 13 (N-(1,3-Dimethylbutyl)-N'phenyl-phenylene diamine) from Kumho Monsanto and ANTILUX654 from Rhein Chemie Additives were used.

(4) Softener: N-2 of Kukdong Manufacturing Co., Ltd.

(5) dispersant: Struktol WB 212 from Schill+Seilacher GmbH

(6) Filler: Carbon black is manufactured by Orion Engineered Carbons Co., Ltd. Corporation's Corax N774 (SRF) was used, and for silica, Nipsil RS-150 from Tosoh Silica Corporation was used.

(7) Silane coupling agent: EVONIK Si-69 (50%)

(8) Alumina: DAW-05 from Denka Company Limited

(9) Vulcanizing agent: Miwon Chemical's MIDAS 101 (Sulfur)

(10) Vulcanization accelerator: TBzTD-70 (Tetrabenzyl thiuram disulfide) from Rhein Chemie Additives and ORICEL CZ (N-Cyclohexyl benzothiazole-2-Sulfenamide) from Dongyang Chemical

Category (parts by weight) Example comparative example One 2 3 4 One 2 3 4 5 6 raw rubber natural rubber (NR) 100 100 100 100 100 100 100 100 100 100 activator zinc oxide 10 10 10 10 10 10 10 10 10 10 stearic acid One One One One One One One One One One antioxidant RD 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 BLE-N One One One One One One One One One One MB One One One One One One One One One One Kumanox 13 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 1.5 ANTILUX654 2 2 2 2 2 2 2 2 2 2 emollient N-2 2 2 2 2 2 2 2 2 2 2 dispersant WB 212 2 2 2 2 2 2 2 2 2 2 filler carbon black 8.75 8.75 8.75 8.75 8.75 51 8.75 8.75 8.75 8.75 silica 35 35 35 35 35 - 35 35 17.5 52.5 Silane coupling Si-69 (50%) 7 7 7 7 7 - 7 7 3.5 10.5 alumina Al ₂ O ₃
(Average particle diameter 45 ㎛) 2 4 8 - - - One 10 8 8 Al ₂ O ₃
(average particle diameter 5 ㎛) - - - 2 - - - - - - vulcanizing agent S 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6 vulcanization accelerator TBzTD-70 2 2 2 2 2 2 2 2 2 2 CZ One One One One One One One One One One

Experimental example

In order to confirm the physical properties of the rubber specimens prepared in Examples 1 to 4 and Comparative Examples 1 to 6, an experiment was performed with the following items, and the results are shown in Table 5 below.

<Experiment method>

(1) Hardness: It was measured according to KS M 6784.

(2) Tensile strength, elongation and modulus: measured with dumbbell type No. 3 according to KS M 6782.

(3) DMTA magnification and modulus: The modulus and magnification were measured by the method of Table 4 below.

Item Example comparative example One 2 3 4 One 2 3 4 5 6 Psalter Hardness (Hs) 56 56 56 56 56 56 56 56 49 64 The tensile strength
(kgf/cm ² ) 226 227 214 232 237 229 230 243 225 214 Elongation (%) 611 617 613 632 640 656 643 580 644 528 Modulus 50 11.35 11.13 11.18 11.7 10.45 11.93 9.7 12.93 10.38 15.6 Modulus 100 17.93 17.43 16.98 18.38 16.38 17.7 15.75 18.48 15.98 25.4 Modulus 300 76.18 75.48 72.1 76.23 70.88 65.38 68.63 76.5 58.4 101.7 DMTA equivalence 1.98 1.9 1.89 1.87 1.87 2.45 2.18 2.32 1.69 2.57 DMTA modulus 2.963 2.805 2.854 2.981 2.772 2.874 2.776 2.921 2.434 4.28

According to the results of Table 5, in Examples 1 to 4 and Comparative Examples 1 to 6, it was confirmed that hardness, tensile strength, and elongation showed almost similar results. However, looking at the measurement results of the same magnification and modulus in the DMTA equipment, it was confirmed that in Comparative Example 1 in which no alumina was used, the same magnification was low, but the overall modulus value was low.

In addition, in the case of Comparative Example 2, the same magnification showed a high value due to the use of only carbon black as a filler, and Comparative Examples 3 and 4, which were out of the amount of alumina used, similarly showed a high value of 2.0 or more of the same magnification. it was In particular, in Comparative Example 4, deterioration of physical properties occurred.

In addition, in Comparative Examples 5 and 6, in which the weight ratio of carbon black and silica were 1:2 and 1:6, respectively, it was confirmed that the same magnification was very high compared to the increase or decrease of the modulus.

On the other hand, in the case of Examples 1 to 4, while having the physical properties of hardness and tensile strength similar to those of Comparative Examples 1 to 6, the modulus was improved, and it was confirmed that the same magnification was maintained as low as 2.0 or less.

Therefore, the rubber compositions for engine mounts prepared in Examples 1 to 4 can improve mechanical properties such as hardness, tensile strength and modulus to prevent engine weight bias, and lower the same magnification to improve NHV performance. It was confirmed that there is an effect.

Claims (5)

100 parts by weight of natural rubber,
20-90 parts by weight of a filler consisting of 5-15 parts by weight of carbon black and 15-75 parts by weight of silica;
2-8 parts by weight of alumina having an average particle diameter of 5 to 45 μm;
1 to 12 parts by weight of a silane coupling agent;
9-13 parts by weight of an activator;
5 to 9 parts by weight of an antioxidant;
0.3-0.6 parts by weight of a vulcanizing agent; and
2-4 parts by weight of a vulcanization accelerator;
A rubber composition for a high rigidity engine mount comprising a.
According to claim 1,
The activator is a rubber composition for high rigidity engine mount, characterized in that stearic acid, zinc oxide, or a mixture thereof.
According to claim 1,
The antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline (2,2,4-trimethl-1,2-dihydroquinoline), acetone diphenylamine (Acetone diphenylamine), 2-mercapto benzoimi group consisting of dazole (2-Mercapto benzoimidazole), N-(1,3-dimethylbutyl)-N'phenyl-phenylene diamine (N-(1,3-Dimethylbutyl)-N'phenyl-phenylene diamine) and paraffin wax A rubber composition for high rigidity engine mount, characterized in that at least one selected from
According to claim 1,
The vulcanization accelerator is N-cyclohexylbenzothiazole-2-sulfenamide (CZ), tetramethylthiuram disulfide (TT), or a rubber composition for high rigidity engine mount, characterized in that a mixture thereof.
According to claim 1,
The rubber composition for high rigidity engine mount, characterized in that it further comprises 2 to 10 parts by weight of an additive comprising 1 to 5 parts by weight of a softener and 1 to 5 parts by weight of a dispersant to 100 parts by weight of the natural rubber.