JP3221097B2 - Vibration-proof rubber composition and vulcanized vibration-proof rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration rubber composition and a vulcanized anti-vibration 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 an ethylene-α-olefin copolymer rubber or an 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. .

Incidentally, one of the important characteristics required for the 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 vibration isolating rubber, and is a characteristic corresponding to the magnitude of the frequency dependence of the vibration isolating performance. That is, although the dynamic magnification is a value of 1 or more, it can be said that the greater the dynamic magnification, the greater the frequency dependence of the vibration isolation performance. The fact that the frequency dependency of the vibration isolation performance is large is extremely inconvenient as a vibration isolation rubber.
Because, when a vibration of a frequency outside the design point is applied to the vibration isolating rubber designed to exhibit the maximum vibration isolating performance near a certain frequency, the vibration isolating performance of the rubber is reduced. Because you do. That is, it is required that the anti-vibration rubber be able to exhibit sufficient anti-vibration performance against vibrations in a wide range of frequencies, in other words, that the dynamic magnification be small. In particular, this means that the vibration isolation rubber used in an environment in which the frequency of vibration changes according to the use situation, for example, an anti-vibration rubber for automobiles in which the frequency of vibration changes with the number of times of the engine, and the vibration of the motor with the number of times of the motor. For anti-vibration rubber for washing machines whose frequency changes,
This is a very important property.

Heretofore, as a method for improving the dynamic magnification of a vibration-proof rubber, there has been known a method 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 practically extremely disadvantageous problem that the processability of rubber is reduced.

[0005]

In view of the above situation, an object of the present invention is to provide an ethylene-α-olefin copolymer rubber and / or an ethylene-α-olefin-non-conjugated diene copolymer rubber as a rubber component. The present invention is intended to provide a vibration-proof rubber composition and a vulcanized vibration-proof rubber composition having excellent dynamic magnification characteristics without lowering workability.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the present invention. That is, among the present invention, one invention 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 relates to an ethylene-α olefin copolymer rubber and / or ethylene-α
The present invention relates to a vulcanized vibration-proof 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, for example, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1 -Pentene, 1-octene, 1-decene and the like, among which propylene is preferred. Examples of the non-conjugated diene include 1,4-hexadiene, 1.6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, and 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-isopropylenyl-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, among which 1,4-hexadiene, dicyclopentadiene and 5-ethylidene-2-ene.
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 has a Mooney viscosity ML _{1 + 4}
２５０250, preferably 70-240. If the molecular weight is too small, the dynamic magnification characteristics 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 processability is poor, while if the ratio is too large, the dynamic magnification characteristics may be poor. Oil-extended rubber can also be used as the ethylene-α-olefin copolymer rubber and the ethylene-α-olefin-non-conjugated diene copolymer rubber.

In the present invention, a monoalkylene glycol or a polyalkylene glycol is used. Specific examples of the monoalkylene glycol or polyalkylene glycol are not particularly limited, but preferred examples include polyethylene glycol and polypropylene glycol. In addition, a block copolymer of polyethylene glycol and polypropylene glycol can be used, and further, a graft copolymer in which polyethylene glycol or polypropylene glycol is copolymerized in a branch shape can be used.

The molecular weight of the monoalkylene glycol or the polyalkylene glycol is usually from 62 to 2,000,000.
00, preferably 200 to 500,000. If the molecular weight is too small, the effect of improving the dynamic magnification characteristics will be insufficient, while if the molecular weight is too large, poor dispersion may occur and the rubber strength may decrease. In addition, as the monoalkylene glycol or the polyalkylene glycol, one kind thereof may be used alone, or two or more kinds thereof may be used as a mixture.

The amount of the monoalkylene glycol or the polyalkylene glycol used may be defined as ethylene-α-olefin copolymer rubber and / or ethylene-α-olefin-non-conjugated diene copolymer rubber (hereinafter, referred to as “rubber component”). ) Is usually 0.5 to 20 per 100 parts by weight of the total amount of
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 characteristics becomes insufficient, while if the amount of monoalkylene glycol or polyalkylene glycol is too large, the properties and mechanical properties of the rubber as an elastomer are reduced. The characteristics may deteriorate. When oil-extended rubber is used, the above-mentioned amount is based on the amount of the rubber component not containing the extended oil.

[0013] The rubber composition of the present invention is finally used as a vulcanized rubber composition. To obtain the vulcanized rubber composition, for example, in addition to the rubber component and monoalkylene glycol or polyalkylene glycol, if necessary, carbon black, organic peroxide, sulfur, antioxidant, vulcanization accelerator, By mixing a processing aid, stearic acid, a reinforcing agent, a filler, a plasticizer, a softening agent, and the like using a usual kneader such as a roll or a Banbury, a vulcanizable rubber composition is obtained, usually at 120 ° C. As described above, preferably vulcanized at a temperature of 150 to 220 ° C. for about 1 to 30 minutes to obtain a vulcanized rubber composition. In addition,
Vulcanization includes press vulcanization, steam vulcanization, injection molding vulcanization, etc.
Any of them can be applied, and either sulfur vulcanization or organic peroxide vulcanization may be used.

In the present invention, JP-A-63-2394 is disclosed.
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.), the durability of the rubber can be further improved.

The vulcanized rubber composition obtained from 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-nonconjugated diene copolymer rubber. In addition, it has excellent dynamic magnification characteristics and can be applied to a wide range of fields utilizing the characteristics, for example, anti-vibration rubber for automobile engine mounts, muffler hangers for automobiles, anti-vibration rubber for washing machines, and the like.

[0016]

Next, the present invention will be described with reference to Examples and Comparative Examples. Examples 1 to 13 and Comparative Examples 1 to 2 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, the mixture was kneaded at a rotor rotation speed of 60 rpm for 5 minutes. Thereafter, an alkylene glycol, sulfur and a vulcanization accelerator were added and kneaded using an 8-inch open roll 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 obtained by measuring a 25% elongation stress σ ₂₅ by a low elongation stress test according to JIS K6301, and Asked from. Ks = 3 × 1.639σ ₂₅ The dynamic spring constant (Kd ₁₀₀ ) is 2 mm in thickness and 5 in width.
using a vulcanized rubber test piece with a rheograph manufactured by Toyo Seiki Co., Ltd. at a frequency of 1 under an initial elongation of 10%.
Kd ₁₀₀ , which is a dynamic spring constant when a sine wave vibration having a frequency of 00 Hz and an amplitude of 0.5% is applied in the axial direction, was measured.

(2) Physical properties of vulcanized product (tensile strength, elongation, hardness) Measured according to JIS K6301. From the results,
The following can be seen. That is, all Examples using the polyalkylene glycol of the present invention are superior in dynamic magnification characteristics as compared with Comparative Examples not using the polyalkylene glycol.

[0019]

Table 1---------------------------------------------------------------------------------Comparison Rubber component * 2 type A ← ← ← Amount 100 ← ← ← PAG * 3 type-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 magnification K _d100 / K _S 3.3 3.1 2.7 2.5 Vulcanizate properties Tensile strength Kgf / cm ² 151 151 155 150 Elongation% 740 760 740 740 Hardness JIS-A 56 56 55 54 -------------------------------------------

[0020]

[Table 2] ------------------------ Rubber component * 2 type B ← ← ← Amount 100 ← ← ← PAG * 3 type-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 magnification K _d100 / K _S 2.3 2.2 1.9 1.8 Vulcanizate properties Tensile strength Kgf / cm ² 178 170 169 160 Elongation% 830 810 820 800 Hardness JIS-A 50 49 48 48 -------------------------------------------

[0021]

Table 3 −−−−−−−−−−−−−−−−−−−−−−−−−−−−− Example 7 8 9 Formulation * 1 (parts by weight) Rubber component * 2 Type ← ← ← Amount ← ← ← PAG * 3 Type DEG PEG PEG # 200 # 1000 Amount 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 vulcanized material 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 ← ← ← Volume 100 ← ← ← PAG * 3 Type PEG PEG PPG PPG # 20000 # 500000 # 1000 # 4000 Volume 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 magnification K _d100 / K _S 2.6 2.7 3.1 2.7 Vulcanizate properties 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 formula is Diablack EX (F by Mitsubishi Kasei Co., Ltd.).
EF black) 150 parts by weight, PW90 (paraffin oil manufactured by Idemitsu Kosan Co., Ltd.) 60 parts by weight, zinc white 5 parts by weight,
1 part by weight of stearic acid, ESCOLETZ 1102B (ES
SO Petroleum Co., Ltd. petroleum resin) 5 parts by weight, Structor W
B212 (processing aid manufactured by Schill & Seilacher) 3 parts by weight, Sox TS (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.) 2.0 parts by weight, Sox CZ (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.) 2.5 Parts by weight, Sox TE
1.0 parts by weight T (vulcanization accelerator manufactured by Sumitomo Chemical Co., Ltd.)
2.0 parts by weight of oxTT (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. Comparative Example 2 and Example 4
About No. 6 to 6, the Sox TS and Sox TET were not used, the diamond black EX was 80 parts by weight, and the PW90
Was 50 parts by weight.

* 2 Rubber component A: Esplen 671F (Ethylene-propylene-ethylidene norbornene copolymer rubber manufactured by Sumitomo Chemical Co., Ltd., 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, including 70 parts by weight of extending oil per 100 parts by weight of rubber copolymer) B: 85 parts by weight of Esplen 671F (oil-extended product) 50 parts by weight of polymer + 35 parts by weight of extension oil) and Esprene 501A (ethylene-propylene-supplied by Sumitomo Chemical Co., Ltd.)
Ethylidene norbornene copolymer rubber, Mooney viscosity ML
_{1 + 4} 100 ° C. 43, weight average molecular weight / number average molecular weight =
9, a mixture of ethylene content 50% by weight and 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: a polyalkylene glycol, specifically as follows. PEG: polyethylene glycol DEG: diethylene glycol PPG: polypropylene glycol The numbers with # indicate 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 are used as the rubber component without deteriorating the processability. A vibration-proof rubber composition and a vulcanized vibration-proof rubber composition having excellent dynamic magnification characteristics could be provided.

────────────────────────────────────────────────── (5) Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C08L 71:02) C08L 71:02) (56) References JP-A-62-194044 (JP, A) JP-A-2-199147 (JP, A) JP-A-5-278804 (JP, A) Patent 2890944 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 23/00-23/36 C08K 5 / 00-5/59 C08L 71/00-71/14 F16F 1/36 F16F 15/08 CA (STN)

Claims (2)

(57) [Claims] An anti-vibration rubber composition comprising 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 obtained by vulcanizing an ethylene-α-olefin copolymer rubber and / or an ethylene-α-olefin-non-conjugated diene copolymer rubber and a rubber composition containing a monoalkylene glycol or a polyalkylene glycol. Sulfurized vibration-proof rubber composition.