KR100537104B1 - Cold-resistant polymer blend for absorbing shock comprising dioctylphthalate - Google Patents

Abstract

The present invention relates to a cold-proof anti-vibration rubber composition containing dioctyl phthalate, which is dust-proof by adding dioctyl phthalate, which is an anti-plasticizer, to a natural rubber, a blend of natural rubber and styrene-butadiene rubber, or a blend of natural rubber and butadiene rubber. After the rubber composition is prepared, it is effective to provide a dustproof rubber composition having excellent cold resistance properties by investigating the change in the cold resistance impact temperature and the dynamic characteristics of the dustproof rubber composition.

Description

Cold-resistant anti-vibration rubber composition containing dioctyl phthalate {Cold-resistant polymer blend for absorbing shock containing dioctylphthalate}

The present invention relates to a cold-proof anti-vibration rubber composition containing dioctylphthalate, a cold-resistant plasticizer, and more particularly, to dioctyl phthalate in a blend of purified natural rubber, a blend of natural rubber and styrene-butadiene rubber, or a blend of natural rubber and butadiene rubber. It relates to a cold-resistant dust-proof rubber composition, characterized in that for producing by mixing.

Today, with the development of the automobile industry, the rubber industry has also grown a lot, and dust-resistant rubber also plays a role.

Anti-vibration rubber is a vulcanized rubber product used for the purpose of preventing or mitigating the transmission of vibration and shock. It can be called a rubber spring. Anti-vibration rubber is used to prevent the vibration or impact from machine operation on the foundation. For example, supporting a diesel generator, a conveyor, a forging machine, a hydraulic press, etc. with anti-vibration rubber is widely used as a countermeasure against pollution by vibration. On the contrary, the anti-vibration rubber is also used to prevent the vibration and impact of the foundation from being transmitted to the machine. For example, the spring system installed on the railcar of the railway vehicle, the suspension system of the automobile, the elastic support of the precision machine tool, and the like. The dust-proof rubber has a compression type, shear type, and complex type, and can be selected appropriately according to the purpose. Anti-vibration rubber is characterized by adjusting the spring constants in three directions: up, down, left and right, to the desired value if the shape and dimensions are properly selected. In addition, since the internal friction of rubber is more than 1000 times larger than that of metal, it is also good for suppressing the amplitude at resonance or quickly attenuating free vibration caused by impact. It also has the advantage of absorbing high frequency vibration. However, there is a problem in high temperature and low temperature, and when wetted with oil, it expands, so use oil-resistant rubber (urethane rubber, etc.) at this time.

Rubber is the most suitable material for dust protection because it has the property of blocking vibration and noise. Compared with metal buffers such as spring, the deformation property is very large and reversible, but the modulus of elasticity is significantly smaller than that of metal, and the shape can be freely selected. The elastic modulus of each direction can be selectively designed, and the internal loss is much higher than that of metal, so the vibration attenuation is excellent, there is little surging phenomenon due to the secondary vibration (vibration amplification), and Since the adhesion is easy, the shape can be diversified.

Natural rubber is widely used as dustproof rubber among various raw material rubbers because of its excellent workability. However, natural rubber has poor heat resistance and ozone resistance and poor oil resistance due to the high unsaturation of cis-1 and 4-polyisoprene structures. Since the maximum allowable temperature for continuous use of rubber products is generally around 70 ° C, improvement of these fragile properties including heat resistance is required, and the specific physical property ratio is required or one rubber material meets the physical, chemical and mechanical conditions of the product. If this is not possible, a method of compensating for the disadvantages of their physical properties by blending two or more rubbers may be considered.

In the rubber industry, rubber / rubber blends are common, and general-purpose rubbers are often blended with natural rubber (NR), stylene butadiene rubber (SBR) and butadiene rubber (BR). Of the various blending methods for rubber materials, mechanical blending methods such as master batch kneading, conventional kneading and one-side kneading are the most widely used due to economic reasons.

As the temperature inside the engine increases with the increase of medium and large sized passenger cars, the heat resistance characteristics are important and are now generalized, but there are few studies on the cold resistance characteristics of products.

In view of the above, the present inventors added a dioctylphthalate, a cold-resistant plasticizer, to a natural rubber, a blend of natural rubber and styrene-butadiene rubber, or a blend of natural rubber and butadiene rubber to prepare a dustproof rubber composition. The present invention has been completed by investigating the change in the dynamic characteristics of the anti-vibration rubber composition according to the cold shock temperature and temperature.

Accordingly, an object of the present invention is to provide a cold-resistant dustproof rubber composition containing dioctylphthalate, which is a cold-resistant plasticizer.

The object of the present invention is to prepare a dustproof rubber composition by adding dioctylphthalate, a cold-resistant plasticizer, to a natural rubber, a blend of natural rubber and styrene-butadiene rubber, or a blend of natural rubber and butadiene rubber. Achievement was achieved by investigating the change of cold resistance temperature and dynamic characteristics with temperature.

Hereinafter, the configuration of the present invention.

The present invention comprises the steps of preparing a dust-proof rubber composition by adding dioctylphthalate, a cold-resistant plasticizer, to a natural rubber, a blend of natural rubber and styrene-butadiene rubber, or a blend of natural rubber and butadiene rubber; Measuring the cold shock temperature of the anti-vibration rubber composition of the step; And investigating the change in dynamic properties with temperature of the anti-vibration rubber composition of the step.

The present invention is a dustproof rubber composition containing dioctylphthalate (Dioctylphthalate) as an active ingredient.

The present invention is a cold-resistant dust-proof rubber composition characterized in that 5 to 15 parts by weight of dioctylphthalate is mixed with respect to 100 parts by weight of purified natural rubber.

The present invention is a cold-resistant dust-proof rubber composition characterized in that 5 to 15 parts by weight of dioctyl phthalate is mixed with 100 parts by weight of the base rubber consisting of 80 to 90 parts by weight of purified natural rubber and 10 to 20 parts by weight of styrene-butadiene rubber.

The present invention is a cold-resistant dust-proof rubber composition characterized in that 5 to 15 parts by weight of dioctylphthalate is mixed with 100 parts by weight of the base rubber consisting of 80 to 90 parts by weight of purified natural rubber and 10 to 20 parts by weight of butadiene rubber.

As for the addition amount of the dioctyl phthalate which is a cold-resistant plasticizer in this invention, 5-15 weight part is preferable with respect to 100 weight part of rubber | gum. If the added amount of dioctyl phthalate is less than 5 parts by weight, cold resistance is inferior, and if more than 15 parts by weight, there is a disadvantage in that physical properties such as durability.

The cold-resistant anti-vibration rubber composition of the present invention contains styrene butadiene rubber or butadiene rubber, which is a purified natural rubber and synthetic rubber, and has a cold-resistant property by adding dioctylphthalate, which is a cold-resistant plasticizer. Purified natural rubber is free of impurities such as protein, and especially helps to improve heat resistance.By styrene butadiene rubber or butadiene rubber, which is a synthetic rubber, is mixed with natural rubber, butadiene rubber blend improves cold resistance temperature and dynamic characteristics, and styrene butadiene rubber Blends improve the cold-loss coefficient and the attenuation coefficient.

In the present invention, the composition ratio of natural rubber and synthetic rubber is preferably 80 to 90:10 to 20 parts by weight to 100 parts by weight in total. If the weight ratio of the synthetic rubber is less than 10 parts by weight, cold resistance is inferior, and if more than 20 parts by weight, there is a disadvantage in that physical properties such as durability. In this case, it is preferable to use styrene butadiene rubber or butadiene rubber for synthetic rubber.

In addition, even when only natural rubber is used without the addition of synthetic rubber, the addition of dioctylphthalate, which is a cold-resistant plasticizer, has cold resistance.

In addition to the above components, the anti-vibration rubber composition of the present invention contains various auxiliary additives such as zinc oxide, stearic acid, carbon black, sulfur and a vulcanization accelerator.

Hereinafter, the specific method of the present invention will be described in detail with reference to Examples and Comparative Examples, but the scope of the present invention is not limited only to these Examples.

Examples 1 to 3 and Comparative Examples 1 to 3 Preparation of Dustproof Rubber Composition

To prepare a dustproof rubber composition consisting of the components and the composition ratio as shown in Table 1 by a conventional method.

matter division Comparative Example 1 Example 1 Comparative Example 2 Example 2 Comparative Example 3 Example 3 SMR CV 60 100.00 100.00 80.00 80.00 80.00 80.00 SBR # 1502 0 0 20.00 20.00 0 0 BR # 01 0 0 0 0 20.00 20.00 ZnO 5.00 5.00 5.00 5.00 5.00 5.00 ST / A 2.00 2.00 2.00 2.00 2.00 2.00 FEF 40.00 40.00 40.00 40.00 40.00 40.00 DOA 0 10.00 0 10.00 0 10.00 CZ 1.20 1.20 1.20 1.20 1.20 1.20 D 0.50 0.50 0.50 0.50 0.50 0.50 S 2.00 2.00 2.00 2.00 2.00 2.00 Sum 150.70 160.70 150.70 160.70 150.70 160.70 1. SMR CV 60: Natural rubber, Manufacturer: Malaysia (Malaysia) 2. SBR # 1502: Styrenebutadiene rubber, Manufacturer: Kumho Petrochemical (Korea) 3. BR # 01: Butadiene rubber, Manufacturer : Kumho Petrochemical (Korea) 4. ZnO: Zinc oxide, Manufacturer: Gilcheon (Korea) 5. ST / A: Stearic acid, Manufacturer: Peacekeeping (Korea) 6. FEF: Carbon, Product Name : N550, Manufacturer: Degussa (Germany) 7. DOA: Dioctylphthalate, Manufacturer: Songwon Industry (Korea) 8. CZ: N-Cyclohexylbenzothiazole-2-sulfenamide (N-Cyclohexylbenzothiazole -2-Sulfenamide), Manufacturer: Dongyang (Korea) 9. D: 1,3-Diphenylguanidine, Manufacturer: Kumho (Korea) 10. S: Sulfur, Manufacturer: Sekwang Chemical (Korea)

The natural rubber used in the present invention is SMR CV 60 (natural rubber, Standard Malaysian Rubber CV 60), and styrene butadiene rubber or butadiene rubber was used by purchasing Kumho Petrochemical (Korea).

Zinc oxide was produced by Gilcheon Co., Ltd. (Korea) and has a specific gravity of 5.5g / cm 3, zinc oxide content of 99.4% by weight, and water content of 0.12% by weight. Usually, zinc oxide is normally used 3 to 8 parts by weight based on 100 parts by weight of rubber. The role of zinc oxide is to make sulfur free radicals. Rubber compound that requires heat resistance is used in an excessive amount of about 10 to 30 parts by weight, but there is a problem in that hysteresis increases when a large amount is put. Zinc oxide must be well dispersed because it is not well dispersed.

Stearic acid (ST / A; stearic acid) is manufactured by Pyung Hwa Oil Co., Ltd. (Korea) and is used as an activator, softener, and dispersant. It is made of zinc stearate in combination with zinc oxide to facilitate zinc oxide dispersion. It helps to reduce the property error for each batch.

FEF is a kind of carbon black and used as rubber reinforcement. Among various carbon blacks, FEF is mainly used for extrudates.

Sulfur is manufactured by Sekwang Chemical Co., Ltd. (Korea), and is used in NR, diene-based synthetic rubber (IR, BR, SBR, NBR), unsaturated synthetic rubber (IIR, EPDM), etc. As it is easy to use and easy to use, it is an important additive for various rubber products.

CZ is a vulcanization accelerator as N-cyclohexylbenzothiazole-2-sulfenamide, and was used by Dongyang Chemical Co., Ltd. (Korea). D is a 1,3-diphenylguanidine, a vulcanization accelerator, and Kumho Monsanto Co., Ltd. product was used.

The vulcanization accelerator is used together with the vulcanizing agent in the vulcanization of raw rubber, and it is a substance used to lower and shorten the temperature and time required for vulcanization by increasing the vulcanization rate with a small amount in the presence of auxiliary materials. There are acid accelerators and neutral accelerators. According to the speed, vulcanization accelerators are classified into weak, medium, steel, and super-steel, and many vulcanization accelerators improve physical properties of vulcanized rubber and improve aging. Therefore, it occupies an important position among rubber compounding chemicals.

Experimental Example 1: Cold Resistance Test

The cold shock test of the anti-vibration rubber composition prepared according to Examples 1 to 3 and Comparative Examples 1 to 3 was carried out using a Test Brittleness Point.

Specimen for cold shock test was prepared and used as shown in FIG.

The test press used Comet Machinery (Korea) and the capacity was 100 tons. Test Mold and Test Cutter were also used by Comet Machine (Korea). The thermometer was used to be able to measure from -80 ℃ to 100 ℃.

Ethyl alcohol used in the test was 98% and dry ice was used consisting of 98% CO ₂ .

The test conditions were frequency of 15 Hz, initial load (P-Load) of 30 kg, and variation (Disp.) Of ± 0.5 mm, and KSM 6676 or ASTM D2137-94 was used as the cold resistance tester.

Cold resistance temperature for each polymer blend of Comparative Examples 1 to 3 was as shown in Table 2 and FIG.

Cold resistance impact temperature (unit: ℃) for each polymer blend of Comparative Examples 1 to 3 division Comparative Example 1 Comparative Example 2 Comparative Example 3 Low Temp. (TL, ℃) -58 -58 -68 Temperature resistance (Brittleness Temp .; Tb, ℃) -54 -54 -64

Cold resistance temperatures for the polymer blends of Examples 1 to 3 were as shown in Table 3 and FIG. 4.

Cold-resistant impact temperature for each polymer blend of Examples 1-3 (unit: ℃) division Example 1 Example 2 Example 3 Low Temp. (TL, ℃) -64 -61 -72 Temperature resistance (Brittleness Temp .; Tb, ℃) -61 -60 -70

As can be seen from the test results, the cold shock temperature was significantly reduced by adding a plasticizer, dioctylphthalate, to the dustproof rubber composition. The cold shock temperature was lower in the BR blend than in NR alone.

Experimental Example 2: Dynamic Characteristic Test

Heat and cold resistance dynamic characteristics tests of the anti-vibration rubber composition prepared according to Examples 1 to 3 were carried out using a dynamic characteristic tester (Dynamic Servo).

Dynamic Servo was used to load up to 3 tons and was manufactured by SAGInoMIYA (Japan).

Specimens for dynamic characteristics test were prepared and used as shown in FIG.

The change in heat resistance dynamic characteristics of each polymer blend of Examples 1 to 3 was as shown in Table 4 below.

Heat resistance dynamic characteristics change Temperature (℃) Item Example 1 Example 2 Example 3 10 Kd (15 Hz) [kg / mm] 90.46 91.79 82.04 C (15 Hz) [kg.s / mm] 0.1016 0.0934 0.0709 Tanδ (15 Hz) 0.1059 0.0959 0.0815 20 Kd (15 Hz) [kg / mm] 83.15 89.46 82.23 C (15 Hz) [kg.s / mm] 0.0805 0.1002 0.0697 Tanδ (15 Hz) 0.0913 0.1056 0.0799 50 Kd (15 Hz) [kg / mm] 84.18 83.62 77.96 C (15 Hz) [kg.s / mm] 0.0680 0.0694 0.0493 Tanδ (15 Hz) 0.0762 0.0783 0.0597 80 Kd (15 Hz) [kg / mm] 73.15 77.55 80.35 C (15 Hz) [kg.s / mm] 0.0408 0.0577 0.0482 Tanδ (15 Hz) 0.0526 0.0701 0.0566 100 Kd (15 Hz) [kg / mm] 78.34 72.87 74.45 C (15 Hz) [kg.s / mm] 0.0521 0.0445 0.0296 Tanδ (15 Hz) 0.0627 0.0576 0.0374 Note: Kd: Dynamic spring constant C: Attenuation coefficient Tanδ: Cold loss loss coefficient

The changes in cold resistance dynamic characteristics of the polymer blends of Examples 1 to 3 were as shown in Table 5 below.

Cold characteristics change Temperature (℃) Item Example 1 Example 2 Example 3 0 Kd (15 Hz) [kg / mm] 83.04 95.87 85.15 C (15 Hz) [kg.s / mm] 0.1123 0.1264 0.0812 Tanδ (15 Hz) 0.1275 0.1243 0.0898 -10 Kd (15 Hz) [kg / mm] 93.42 102.20 85.64 C (15 Hz) [kg.s / mm] 0.1530 0.1707 0.1049 Tanδ (15 Hz) 0.1544 0.1574 0.1155 -20 Kd (15 Hz) [kg / mm] 97.94 111.40 93.04 C (15 Hz) [kg.s / mm] 0.2148 0.2862 0.1692 Tanδ (15 Hz) 0.2067 0.2421 0.1714 -30 Kd (15 Hz) [kg / mm] 118.50 140.20 102.20 C (15 Hz) [kg.s / mm] 0.5281 0.6500 0.2999 Tanδ (15 Hz) 0.4199 0.4370 0.2765 -40 Kd (15 Hz) [kg / mm] 162.30 171.10 122.20 C (15 Hz) [kg.s / mm] 1.1210 1.0680 0.5839 Tanδ (15 Hz) 0.6506 0.5886 0.4502 Note: Kd: Dynamic spring constant C: Attenuation coefficient Tanδ: Cold loss loss coefficient

The dynamic spring constants, cold-loss loss coefficients, and attenuation coefficients of polymer blends of Examples 1 to 3 were the same as those of FIGS. 5, 6, and 7.

As can be seen from the experimental results, the dynamic spring constant showed a low value of the BR blend, and the cold resistance loss coefficient and the attenuation coefficient showed a high value of the SBR blend.

In summary, when the anti-plasticizer DOA was added, the cold shock temperature and dynamic characteristics were excellent in the BR blend, that is, the dustproof rubber composition of Example 3, and the coldproof loss coefficient and the attenuation coefficient were excellent in the SBR blend, that is, the dustproof rubber composition of Example 2. .

As described above, the cold-proof anti-vibration rubber composition containing the dioctyl phthalate of the present invention as described through the above embodiment is an extremely useful invention for the automobile industry and the chemical industry because it has an excellent cold-resistant property compared to the conventional anti-vibration rubber composition.

1 is a photograph showing the appearance of the cold resistance temperature test specimen.

2 is a photograph showing the state of the specimen for dynamic characteristics test.

3 is a graph comparing cold shock temperature values of polymer blends without adding plasticizer.

4 is a graph comparing cold shock temperature values of polymer blends to which plasticizers are added.

5 is a graph showing the change of the dynamic spring constant for each polymer blend added with a plasticizer.

6 is a graph showing the change in cold loss coefficient for each polymer blend to which a plasticizer is added.

7 is a graph showing a change in attenuation coefficient for each polymer blend added with a plasticizer.

Claims (3)

In the anti-vibration rubber composition, dust-proof rubber composition having cold resistance by mixing 5 to 15 parts by weight of dioctylphthalate with respect to 100 parts by weight of purified natural rubber. In the anti-vibration rubber composition, dust-proof having 80 to 90 parts by weight of purified natural rubber and 5 to 15 parts by weight of dioctylphthalate based on 100 parts by weight of the base rubber consisting of 10 to 20 parts by weight of styrene-butadiene rubber. Rubber composition. In the anti-vibration rubber composition, anti-vibration rubber having 80 to 90 parts by weight of purified natural rubber and 5 to 15 parts by weight of dioctylphthalate based on 100 parts by weight of the base rubber consisting of 10 to 20 parts by weight of butadiene rubber. Composition.