JPH06136203A - Vibration damping rubber composition and vibration damping vulcanized rubber composition - Google Patents

Abstract

PURPOSE:To obtain a vibration damping rubber composition and a vulcanized one excellent in dynamic magnification characteristics by compounding mono- or polyalkylene glycol with an ethylene-alpha olefin copolymer rubber without decreasing processability. CONSTITUTION:(A) 100 pts.wt. ethylene-alpha, olefin copolymer rubber and/or ethylene-alpha olefin-non-conjugated diene copolymer rubber having 50-250, preferably 70-240 Mooney viscosity (at 100 deg.C), and 2-10, preferably 2.2-5 ratio of weight average molecular weight/number average molecular weight, is compounded with (B) 2-20 pts.wt., preferably 2-10 pts.wt. monoalkylene glycol or polyalkylene glycol (preferably polypropylene glycol, etc.) having 62-2000000, preferably 200-500000 molecular weight and, when needed, with carbon black, an organic peroxide, sulfur, a vulcanization accelerator, a filler, a plasticizer, etc., to obtain a vibration damping rubber composition. The vibration damping rubber composition is vulcanized at >=120 deg.C to obtain a vulcanized vibration damping rubber composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration damping rubber composition and a vulcanized vibration damping rubber composition.

[0002]

2. Description of the Related Art Conventionally, ethylene-propylene rubber (EP
M) or ethylene-propylene-non-conjugated diene rubber (E
It is known that ethylene-α-olefin copolymer rubber or ethylene-α-olefin-non-conjugated diene copolymer rubber represented by PDM) is excellent in heat aging resistance, ozone resistance, polar solvent resistance and the like. .

By the way, one of the important characteristics required of a vibration-proof rubber is a dynamic magnification characteristic, that is, a braking characteristic. The dynamic magnification is defined by the ratio of the dynamic spring constant / static spring constant of the anti-vibration rubber and is a characteristic corresponding to the frequency dependence of the anti-vibration performance. That is, the dynamic magnification becomes a value of 1 or more, but it can be said that the larger the dynamic magnification, the greater the frequency dependence of the image stabilization performance. The large frequency dependence of the vibration isolation performance is extremely inconvenient for a vibration isolation rubber.
This is because the anti-vibration rubber designed to exhibit the maximum anti-vibration performance near a certain frequency has its anti-vibration performance reduced when a vibration of a frequency outside the design point is applied. Because it does. That is, the anti-vibration rubber is required to exhibit sufficient anti-vibration performance against vibrations in a wide range of frequencies, in other words, to have a small dynamic magnification. In particular, this means that the anti-vibration rubber used in an environment where the frequency of vibration changes depending on the usage conditions, such as anti-vibration rubber for automobiles whose frequency of vibration changes depending on the number of times of the engine, For anti-vibration rubber for washing machines whose frequency changes,
This is a very important property.

Conventionally, as a method for improving the dynamic ratio of a vibration-proof rubber, a method is known in which a rubber having a high molecular weight and a narrow molecular weight distribution is used and the compounding ratio is as low as possible. However, this method has a problem that the workability of rubber is deteriorated, which is extremely inconvenient in practical use.

[0005]

In view of the present situation, the problem to be solved by the present invention is to use an ethylene-α-olefin copolymer rubber and / or an ethylene-α-olefin-non-conjugated diene copolymer rubber as a rubber component. The purpose of the present invention is to provide a vibration-damping rubber composition and a vulcanized vibration-damping rubber composition having excellent dynamic magnification characteristics without deteriorating processability.

[0006]

The present inventors have arrived at the present invention as a result of intensive studies to solve the above problems. That is, one of the inventions is an anti-vibration rubber composition containing an ethylene-α-olefin copolymer rubber and / or an ethylene-α-olefin-non-conjugated diene copolymer rubber and a monoalkylene glycol or a polyalkylene glycol. It relates to things.

Another aspect of the present invention is the ethylene-α-olefin copolymer rubber and / or the ethylene-α-olefin rubber.
The present invention relates to a vulcanized anti-vibration rubber composition obtained by vulcanizing a rubber composition containing an olefin-non-conjugated diene copolymer rubber and a monoalkylene glycol or a polyalkylene glycol.

The details will be described below. Examples of the α-olefin in the ethylene-α-olefin copolymer rubber and the ethylene-α-olefin-non-conjugated diene copolymer rubber of the present invention include propylene, 1-butene, 1-pentene, 1-hexene and 4-methyl-1. -Pentene, 1-octene, 1-decene and the like are mentioned, and among them, propylene is preferable. Examples of the non-conjugated diene include 1,4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene. Chain non-conjugated dienes such as; cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5
-Cyclic non-conjugated dienes such as methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene;
2.3-Diisopropylidene-5-norbornene, 2-
Ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2.2-norbornadiene, 1.
Trienes such as 3,7-octatriene and 1,4,9-decatriene are mentioned, and among them, 1,4-hexadiene, dicyclopentadiene and 5-ethylidene-2-
Norbornene is preferred. These non-conjugated dienes can be used alone or in combination of two or more.

The molecular weight of the ethylene-α-olefin copolymer rubber and the ethylene-α-olefin-non-conjugated diene copolymer rubber is usually 50 at a Mooney viscosity ML _{1 + 4 of} 100 ° C.
-250, preferably 70-240. If the molecular weight is too small, the dynamic magnification characteristic and durability may be poor, while if the molecular weight is too large, processability may be poor. The ratio of weight average molecular weight / number average molecular weight is usually 2 to 10, preferably 2.
2-5. If the ratio is too small, the workability may be poor. On the other hand, if the ratio is too large, the dynamic magnification characteristic may be poor. An oil-extended rubber may be used as the ethylene-α-olefin copolymer rubber and the ethylene-α-olefin-non-conjugated diene copolymer rubber.

In the present invention, monoalkylene glycol or polyalkylene glycol is used. Specific examples of monoalkylene glycol or polyalkylene glycol are not particularly limited, but preferable examples include polyethylene glycol and polypropylene glycol. Also, a block copolymer of polyethylene glycol and polypropylene glycol can be used, and a graft copolymer obtained by copolymerizing polyethylene glycol or polypropylene glycol in a branched form can also be used.

The molecular weight of monoalkylene glycol or polyalkylene glycol is usually 62 to 2,000,0.
00, preferably 200 to 500,000. If the molecular weight is too small, the effect of improving the dynamic magnification characteristic becomes insufficient, while if the molecular weight is too large, poor dispersion may occur and the strength of the rubber may decrease. As the monoalkylene glycol or polyalkylene glycol, one kind thereof may be used alone, or two or more kinds thereof may be mixed and used.

The amount of monoalkylene glycol or polyalkylene glycol used is ethylene-α-olefin copolymer rubber and / or ethylene-α-olefin-non-conjugated diene copolymer rubber (hereinafter sometimes referred to as "rubber component"). 0.5 to 20 per 100 parts by weight in total.
Parts by weight, preferably 2 to 10 parts by weight. If the amount of monoalkylene glycol or polyalkylene glycol is too small, the effect of improving the dynamic magnification characteristic becomes insufficient, while if the amount of monoalkylene glycol or polyalkylene glycol is too large, the properties and mechanical properties of rubber as an elastomer are improved. The characteristics may deteriorate. In addition, when the oil-extended rubber is used, the above-mentioned usage amount is based on the amount of the rubber component containing no extension oil.

The rubber composition of the present invention is finally used as a vulcanized vulcanized rubber composition. To obtain the vulcanized rubber composition, for example, in addition to the rubber component and the monoalkylene glycol or the polyalkylene glycol, if necessary, carbon black, organic peroxide, sulfur, an antioxidant, a vulcanization accelerator, A vulcanizable rubber composition is prepared by mixing a processing aid, a stearic acid, a reinforcing agent, a filler, a plasticizer, a softening agent and the like using an ordinary kneading machine such as a roll or Banbury, which is usually 120 ° C. As described above, a vulcanized rubber composition can be obtained by vulcanizing at a temperature of 150 to 220 ° C. for about 1 to 30 minutes. In addition,
Vulcanization includes press vulcanization, steam vulcanization, injection molding vulcanization, etc.
Either can be applied, and either sulfur vulcanization or organic peroxide vulcanization may be used.

In the present invention, JP-A-63-2394 is used.
The amine derivatives disclosed in Japanese Patent No. 2, for example N, N '
-Bis (2-methyl-2-nitropropyl) -1,6-
By using diaminohexane (Sumifine 1162, trade name, manufactured by Sumitomo Chemical Co., Ltd.) in combination, the durability of the rubber can be further improved.

The vulcanized rubber composition obtained by the rubber composition of the present invention maintains the excellent properties and processability of the ethylene-α-olefin copolymer rubber or the ethylene-α-olefin-non-conjugated diene copolymer rubber. In addition, it has excellent dynamic magnification characteristics, and can be applied to a wide range of fields utilizing its characteristics, for example, anti-vibration rubber for automobile engine mounts, muffler hangers for automobiles, anti-vibration rubber for washing machines, and the like.

[0016]

EXAMPLES The present invention will be described with reference to Examples and Comparative Examples. Examples 1 to 13 and Comparative Examples 1 to 2 The formulations shown in Tables 1 to 4 (however, alkylene glycol,
Excludes sulfur and vulcanization accelerators. ) Was adjusted to 90 ° C. 1
Using a 500 ml Banbury mixer, kneading was carried out for 5 minutes at a rotor rotation speed of 60 rpm. Then, using an 8-inch open roll, alkylene glycol, sulfur and a vulcanization accelerator were added and kneaded to obtain a rubber composition. Next, the rubber composition was press-vulcanized at 160 ° C. for 10 minutes to obtain a vulcanized rubber composition. The obtained vulcanized rubber composition was evaluated as follows. The results are shown in Tables 1 to 4.

(1) Vibration characteristics (static spring constant and dynamic spring constant) The static spring constant (Ks) is measured by the low elongation stress test of JIS K 6301 to measure 25% elongation stress σ ₂₅ , I asked from. Ks = 3 × 1.639σ _{25 Further} , the dynamic spring constant (Kd ₁₀₀ ) is 2 mm in thickness and 5 in width.
Using a test piece of vulcanized rubber of mm, a frequency of 1 at a 10% initial extension state by a Toyo Seiki Rheograph.
Kd ₁₀₀ , which is a dynamic spring constant, was measured when a sine wave vibration with an amplitude of 0.5% at 00 Hz was applied in the axial direction.

(2) Physical Properties of Vulcanized Material (Tensile Strength, Elongation, Hardness) Measured in accordance with JIS K 6301. From the results,
You can see the following. That is, all of the examples using the polyalkylene glycol of the present invention are superior in dynamic magnification characteristic as compared with the comparative example not using the polyalkylene glycol.

[0019]

[Table 1] ------------------ Comparison Example 1 1 2 3 Formulation * 1 (parts by weight) Rubber component * 2 types A ← ← ← amount 100 ← ← ← PAG * 3 types-PEG ← ← # 4000 ← ← amount 0 1 3 5 Evaluation Vibration characteristics Static spring constant K _S kgf / cm ² 20.5 21.2 21.3 21.3 Dynamic Spring constant K _d100 kgf / cm ² 67.7 65.7 56.8 53.4 Dynamic ratio K _d100 / K _S 3.3 3.1 2.7 2.5 Physical properties of vulcanizate Kgf / cm ² 151 151 155 150 Elongation% 740 760 740 740 Hardness JIS-A 56 56 55 54 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

[0020]

[Table 2] ------------------ Comparison Example 2 4 5 6 Formulation * 1 (parts by weight) Rubber component * 2 types B ← ← ← amount 100 ← ← ← PAG * 3 types-PEG ← ← # 4000 ← ← amount 0 1 3 5 Evaluation vibration characteristics Static spring constant K _S kgf / cm ² 17.8 18.1 17.2 17.0 Dynamic Spring constant K _d100 kgf / cm ² 41.1 40.0 32.2 30.5 Dynamic ratio K _d100 / K _S 2.3 2.2 1.9 1.8 Physical properties of vulcanizate Tensile strength Kgf / cm ² 178 170 169 160 Elongation% 830 810 820 800 Hardness JIS-A 50 49 48 48 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

[0021]

[Table 3] −−−−−−−−−−−−−−−−−−−−−−−−−− Actual Example 7 8 9 Compounding * 1 (parts by weight) Rubber component * 2 Types ← ← ← Quantity ← ← ← PAG * 3 Types DEG PEG PEG # 200 # 1000 Quantity 3 3 3 Evaluation Vibration characteristics Static spring constant K _S kgf / cm ² 21.3 21.5 21.3 Dynamic spring constant K _d100 kgf / cm ² 60.6 55.5 57.5 Dynamic Magnification K _d100 / K _S 2.9 2.6 2.7 Physical properties of vulcanizate Tensile strength Kgf / cm ² 147 150 149 Elongation% 760 770 760 Hardness JIS-A 55 54 54 −−−−−−−−−−−−−−−−− −−−−−−−−−−

[0022]

[Table 4] ------------------ Example 10 11 12 13 Formulation * 1 (parts by weight) Rubber component * 2 Type A ← ← ← Amount 100 ← ← ← PAG * 3 Type PEG PEG PPG PPG # 20000 # 500000 # 1000 # 4000 Amount 3 3 3 3 Evaluation Vibration characteristics Static spring constant K _S kgf / cm ² 21.4 21.6 20.1 20.7 Dynamic spring constant K _d100 kgf / cm ² 55.6 59.2 61.5 54.8 Dynamic ratio K _d100 / K _S 2.6 2.7 3.1 2.7 Physical properties of vulcanizate Tensile strength Kgf / cm ² 147 136 143 143 Elongation% 760 710 770 770 770 Hardness JIS-A 54 54 54 54 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−

* 1 Formulation: In addition to those shown in Table 1, a common formulation is Diablack EX (F manufactured by Mitsubishi Kasei Co., Ltd.).
EF black) 150 parts by weight, PW90 (Idemitsu Kosan Co. paraffin oil) 60 parts by weight, zinc flower 5 parts by weight,
Stearic acid 1 part by weight, Escoletz 1102B (ES
SO Petroleum Company's petroleum resin) 5 parts by weight, Stractor W
3 parts by weight of B212 (processing aid manufactured by Schill & Seiracher), 2.0 parts by weight of Sox TS (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.), Sox CZ (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.) 2.5 Parts by weight, Sox TE
1.0 parts by weight of T (Sumitomo Chemical Co., Ltd. vulcanization accelerator), S
2.0 parts by weight of ox TT (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.) and 1.5 parts by weight of sulfur were used. However, for Comparative Example 1, Examples 1 to 3 and Examples 7 to 13, So
xTT was not used. In addition, Comparative Example 2 and Example 4
For No. 6 to No. 6, Sox TS and Sox TET were not used, and Diamond Black EX was set to 80 parts by weight, and PW90 was used.
Was 50 parts by weight.

* 2 Rubber component A: Esprene 671F (Sumitomo Chemical Co., Ltd. ethylene-propylene-ethylidene norbornene copolymer rubber, Mooney viscosity ML _{1 + 4} 121 ° C. 63, weight average molecular weight /
Number average molecular weight = 2.6, ethylene content 60% by weight, iodine value 12 and 70 parts by weight of extender oil per 100 parts by weight of rubber copolymer) B: Esplen 671F (oil extended product) 85 parts by weight (rubber Polymer 50 parts by weight + extender oil 35 parts by weight) and Esplen 501A (Sumitomo Chemical Co., Ltd. ethylene-propylene-
Ethylidene norbornene copolymer rubber, Mooney viscosity ML
_{1 + 4} 100 ° C 43, weight average molecular weight / number average molecular weight =
9. Mixture of ethylene content 50% by weight, iodine value 11) 50 parts by weight Amount of rubber component: parts by weight of rubber component are shown by parts by weight of a rubber copolymer containing no extender oil.

* 3 PAG: Polyalkylene glycol, specifically as follows. PEG: polyethylene glycol DEG: diethylene glycol PPG: polypropylene glycol The number with # represents the average molecular weight.

[0026]

As described above, according to the present invention, the ethylene-α-olefin copolymer rubber and / or the ethylene-α-olefin-non-conjugated diene copolymer rubber is used as a rubber component without deteriorating the processability. It was possible to provide a vibration-damping rubber composition and a vulcanized vibration-damping rubber composition having excellent dynamic magnification characteristics.

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Claims (2)

[Claims] 1. An anti-vibration rubber composition containing an ethylene-α-olefin copolymer rubber and / or an ethylene-α-olefin-non-conjugated diene copolymer rubber and a monoalkylene glycol or a polyalkylene glycol. 2. A rubber composition obtained by vulcanizing a rubber composition containing an ethylene-α-olefin copolymer rubber and / or an ethylene-α-olefin-non-conjugated diene copolymer rubber and a monoalkylene glycol or polyalkylene glycol. Sulfur-proof anti-vibration rubber composition.