JPH0586236A - Rubber composition for heat-resistant and vibration damping rubber - Google Patents

Abstract

PURPOSE:To obtain the subject composition, composed of a high-molecular weight component composed of a specific ethylene-alpha-olefin-diene copolymer rubber and a low-molecular weight component composed of a liquid ethylene-alpha- olefin copolymer, and suitable as automotive engine mounts, etc. CONSTITUTION:The objective composition consisting essentially of a rubber composed of (A) 90-60wt.% high-molecular weight component composed of an ethylene-alpha-olefin-diene copolymer rubber, composed of ethylene, a 3-20C alpha-olefin and a nonconjugated diene and having 60-73mol% ethylene content, <4 value of the molecular weight distribution Q (Mw/Mn), 2.7-5.0dl/g intrinsic viscosity [eta] and 10-40 iodine value and (B) 10-40wt.% low-molecular weight component composed of a liquid ethylene-alpha-olefin copolymer, composed of ethylene and a 3-20C alpha-olefin and having 50-78mol% ethylene content and 0.2-0.4dl/g intrinsic viscosity [eta]. The Mooney viscosity of the rubber is 20-150 and the ratio (IV1/IV2) between the iodine value (IV1) of the low-molecular weight component and the iodine value (IV2) of the high-molecular weight component is <=0.1.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a rubber composition for heat-resistant and vibration-proof rubber, and more specifically, it is suitable for use as a vibration-proof rubber material which is particularly required to have heat resistance in automobile engine mounts and the like. The present invention relates to a rubber composition for rubber.

[0002]

BACKGROUND OF THE INVENTION In recent years, the physical properties required for anti-vibration rubber, particularly heat resistance and anti-vibration properties, have become extremely severe.

At present, polymers used for anti-vibration rubber are natural rubber (NR), butadiene rubber (BR), styrene-butadiene rubber (SBR) and chloroprene rubber (C).
R), butyl rubber (IIR) and the like are used, and two or more polymers are blended and used depending on the application. However, these polymers basically have poor heat resistance because they have a double bond in the main chain. Therefore, attempts have been made to control the cross-linking form by studying the type and combination of vulcanization accelerators. However, under the condition of being exposed to a high temperature of 120 ° C. or higher for a long time, for example, in the engine room of an automobile. The surface of the anti-vibration rubber may crack and eventually break. Therefore, the improvement of heat resistance has been a problem in anti-vibration rubber.

The anti-vibration property is an important physical property because it is greatly related to the riding comfort of the vehicle and the muffled noise in the vehicle.
The engine mount acts as a dynamic damper for the engine transmission to reduce the vibration of the vehicle body due to the input from the road surface, and recently, it can reduce the low frequency such as idle vibration, shake, and muffled sound to a higher level. Is desired. For example, it is required to reduce the transmission rate in the frequency band of 100 Hz or higher for vehicle interior noise such as muffled noise while suppressing vibration transmission in the frequency band of 7 to 15 Hz related to engine shake.

Therefore, in order to attenuate a high-amplitude input at a low frequency (7 to 15 Hz), the loss tangent (tan δ), which is a measure of the riding comfort of an automobile, should be increased.
A polymer having a large an δ or a compound thereof has a large dynamic ratio (dynamic shear modulus / static shear modulus), which causes a problem of muffled sound during high-speed operation. Further, although the liquid-filled type anti-vibration rubber exhibits excellent anti-vibration properties, it has the drawbacks that the structure is complicated and the cost is significantly increased.

Therefore, a vulcanized rubber having excellent properties such as heat resistance and anti-vibration properties, which has solved the above problems, and has a small rate of change in anti-vibration properties due to thermal deterioration, that is, excellent aging resistance to heat. The appearance of a rubber composition for a heat-resistant and vibration-proof rubber that can provide a molded article has been conventionally desired.

[0007]

It is an object of the present invention to solve the problems associated with the prior art as described above, and to provide a vulcanizate which has excellent properties such as heat resistance and anti-vibration properties as well as excellent heat aging resistance. It is an object of the present invention to provide a rubber composition for heat-resistant and vibration-proof rubber, which can give a rubber molded body.

[0008]

SUMMARY OF THE INVENTION A rubber composition for heat and vibration resistant rubber according to the present invention comprises ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated diene, and has an ethylene content of 60 to
73 mol%, the molecular weight distribution (Mw / Mn) Q value determined by GPC method is less than 4, and the intrinsic viscosity [η] measured in decalin at 135 ° C. is 2.7 to 5.0 d.
ethylene having an iodine value of 10 to 40, which is 1 / g.
High molecular weight component (A) consisting of α-olefin / diene copolymer rubber: 90 to 60% by weight, consisting of ethylene and α-olefin having 3 to 20 carbon atoms, and having an ethylene content of 50 to 78 mol. %, And the intrinsic viscosity [η] measured in decalin at 135 ° C. is 0.2 to 0.4 dl /
A low molecular weight component (B) consisting of a liquid ethylene / α-olefin copolymer of g: 10 to 40% by weight of an ethylene / α-olefin / diene rubber having a Mooney viscosity ML _{1 + 4} (100 ° C.). ) Is in the range of 20 to 150 and has a molecular weight of 3,000 to 15,000.
The ratio (IV ₁ / IV ₂ ) of the iodine value (IV ₁ ) of the olefin / diene rubber to the iodine value (IV ₂ ) of the ethylene / α-olefin / diene rubber having a molecular weight of 80,000 to 120,000 is It is characterized in that it contains ethylene / α-olefin / diene rubber having a content of 0.1 or less as a main component.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The rubber composition for heat and vibration resistant rubber according to the present invention will be specifically described below. The rubber composition for heat and vibration resistant rubber according to the present invention contains a specific ethylene / α-olefin / diene rubber as a main component. This ethylene / α-olefin / diene rubber is
It is composed of a high molecular weight component (A) composed of an α-olefin / diene copolymer rubber and a low molecular weight component (B) composed of a specific liquid ethylene / α-olefin copolymer.

High molecular weight component (A) The high molecular weight component (A) used in the present invention is an ethylene / α-olefin / diene co-polymer comprising ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated diene. It is a united rubber.

The ethylene / α-olefin / diene copolymer rubber used in the present invention has an ethylene content of 60 to 7
It is 3 mol%, preferably 65 to 70 mol%. Specific examples of the α-olefin having 3 to 20 carbon atoms include propylene, butene-1, hexene-1, pentene-
1,4-methylpentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, undecene-1, dodecene-1, tridecene-1, tetradecene-1, pentadecene-
1, hexadecene-1, heptadecene-1, octadecene-
1, nonadecene-1, eicosene-1 and the like. These α-olefins are used alone or in combination. Among these, especially propylene and butene-1
Is preferred.

Specific examples of the non-conjugated dienes include 1,4-hexadiene, 1,6-octadiene and 2-methyl-diene.
1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-
Chain-like non-conjugated dienes such as methyl-1,6-octadiene, cyclohexadiene, dicyclopentadiene, methyltetrahydroindene, 5-vinylnorbornene, 5-ethylidene
-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-
Cyclic non-conjugated dienes such as 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 can be mentioned. Of these, 1,4-hexadiene and cyclic non-conjugated dienes, particularly dicyclopentadiene and 5-ethylidene-2-norbornene are preferably used.

Further, ethylene / α-used in the present invention
The olefin / diene copolymer rubber has an iodine value of 10 to 40, which is one index of the non-conjugated diene content, preferably 15
~ 25.

The ethylene / α-olefin / diene copolymer rubber used in the present invention has a molecular weight distribution (Mw / Mn) Q value determined by GPC measurement of less than 4, preferably 3 or less. By using the ethylene / α-olefin / diene copolymer rubber having such a molecular weight distribution as the high molecular weight component (A), excellent shape retention during vulcanization, mechanical strength characteristics and low compression set are obtained. It is possible to obtain an ethylene / α-olefin diene rubber capable of providing a vulcanized rubber molded product having excellent strain characteristics, dynamic fatigue resistance, and wear resistance.

Further, ethylene / α-used in the present invention
The olefin / diene copolymer rubber has an intrinsic viscosity [η] measured in decalin at 135 ° C. of usually 2.7 dl / g or more, preferably 2.7 to 5.0 dl / g, and more preferably 3.5 to 4. It is 0.5 dl / g. When an ethylene / α-olefin / diene copolymer rubber having an intrinsic viscosity [η] in the above range is used, an ethylene / α-olefin diene rubber having excellent dynamic fatigue resistance can be obtained.

Molecular weight distribution (Mw / Mn) Q as described above
Among the ethylene / α-olefin / diene copolymer rubbers having values, ethylene / α-olefin / diene rubbers obtained by using the ethylene / α-olefin / diene copolymer rubbers having the above-mentioned intrinsic viscosity Shows a remarkable effect of improving the above-mentioned physical properties.

The above-mentioned ethylene / α-olefin /
The diene copolymer rubber is, for example, Japanese Patent Publication Sho 59-1449.
It can be produced by the method described in Japanese Patent Publication No. That is, in the presence of a Ziegler catalyst, hydrogen is used as a molecular weight regulator, and ethylene and C 3-20 are used.
By copolymerizing α-olefin with a diene of
An ethylene / α-olefin / diene copolymer rubber can be obtained.

Low Molecular Weight Component (B) The low molecular weight component (B) used in the present invention is a liquid ethylene / α-olefin copolymer composed of ethylene and an α-olefin having 3 to 20 carbon atoms, and is a diene. Contains no ingredients.

The above liquid ethylene / α-olefin copolymer is a random copolymer of ethylene and an α-olefin having 3 to 20 carbon atoms. 3 to 3 carbon atoms
Specific examples of the α-olefin of 20 include propylene, butene-1, pentene-1, 4-methylpentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-
1, undecene-1, dodecene-1, tridecene-1, tetradecene-1, pentadecene-1, hexadecene-1, heptadecene-1, octadecene-1, nonadecene-1, eicosene-1.
And so on. These α-olefins are used alone or in combination. Of these, propylene and butene-1 are particularly preferable.

In the present invention, the high molecular weight component has the effect of improving heat resistance, mechanical strength characteristics, low compression set characteristics, dynamic fatigue resistance, wear resistance, shape retention, etc. The molecular weight component was quality-designed so as to be effective in improving vibration-damping properties, heat aging resistance, processability (fluidity), and surface smoothness of the vulcanized rubber molded product.

However, ethylene, which is simply bimodal, that is, which exhibits a molecular weight distribution with two modes,
In the α-olefin / diene rubber, since the ratio of the effect of improving the physical properties by the high molecular weight component and the ratio of the effect of improving the properties by the low molecular weight component are in a tug of war,
For example, even if the amount of low molecular weight components is increased and the processability is excellent,
It is not possible to provide a vulcanized rubber molded product having dramatically improved physical properties such as fatigue resistance.

Therefore, the inventors of the present invention have further studied this low molecular weight component, and found that when a vulcanized rubber molded product was obtained from an ethylene / α-olefin / diene rubber showing a bimodal molecular weight distribution. The inventors have found that it is necessary that the low molecular weight component constituting the vulcanized rubber molded body is not crosslinked as a polymer. That is, in the present invention, a liquid ethylene / α-olefin copolymer containing no diene is used as the low molecular weight component.

The ethylene content of the liquid ethylene / α-olefin copolymer used in the present invention is usually 50 to 78 mol%, preferably 50 to 70 mol%, more preferably 50 to 60 mol%. .. Since the liquid ethylene / α-olefin copolymer having an ethylene content in the above range has good thermal stability, it is recommended that the amount be reduced during the kneading operation with the high molecular weight component (A) as described above. It does not occur, nor does it carbonize during molding to contaminate the molded product.

The low molecular weight component (B) used in the present invention,
That is, the liquid ethylene / α-olefin copolymer has 1
The intrinsic viscosity [η] measured in decalin at 35 ° C is 0.2 to
0.4 dl / g, preferably 0.24 to 0.4 dl / g
Is.

When a liquid ethylene / α-olefin copolymer having an intrinsic viscosity [η] in the above-mentioned narrow range is used as the low molecular weight component (B), ethylene / α-olefin excellent in processability (fluidity) is obtained. Olefin / diene rubber can be provided, and tan δ can be increased without changing the dynamic magnification, so the vibration transmissibility related to engine shake can be reduced, and moreover, muffled noise at high speed operation can be prevented. can do. Since the dynamic ratio depends on the product hardness, it is important to design the ratio of carbon to oil, and the lower limit strength (hardness) that can safely support the target vibration support is designed. The above characteristics are exhibited at any hardness designed there.

The liquid ethylene / α-olefin copolymer as the low molecular weight component (B) used in the present invention has poor processability (fluidity) when the intrinsic viscosity [η] is less than 0.2 dl / g. Become. On the other hand, when the intrinsic viscosity [η] of the liquid ethylene / α-olefin copolymer exceeds 0.4 dl / g, it becomes impossible to reduce vibration at resonance and prevent muffled noise at high speed operation.

The above-mentioned liquid ethylene / α-olefin copolymer is similar in composition to oil, but has a limiting viscosity [η] in the range of 0.2 to 0.4 dl / g. In the α-olefin copolymer, even if the molecular weight (intrinsic viscosity [η]) of the high molecular weight component (A) used in combination with the low molecular weight component (B) is very high, the liquid ethylene / α-olefin copolymer By increasing the use ratio of the coalescence, it is possible to secure the processability (fluidity) required in the kneading process and the molding process using a roll, a Banbury mixer, or the like.

[0028] It should be noted that there is a limit to the effect of improving the processability of ethylene / α-olefin / diene rubbers, which have been conventionally used and in which oils such as process oils, paraffin oils and naphthene oils have been spread. Further, in the oil-extended ethylene / α-olefin / diene copolymer rubber having an intrinsic viscosity [η] of 3.5 dl / g or more, the processability is improved by keeping the product hardness within a predetermined range. In addition, even if an attempt is made to reduce the viscosity at the time of processing by using a large amount of oil, it is not possible to obtain a vulcanized rubber molded product having excellent dynamic fatigue resistance because of poor dispersibility of carbon and the like.

The liquid ethylene / α-olefin copolymer as described above can be produced, for example, by the method described in Japanese Patent Publication No. 2-1163. That is, in the presence of a Ziegler catalyst, hydrogen is used as a molecular weight modifier, and ethylene is randomly copolymerized with an α-olefin having 3 to 20 carbon atoms to obtain a liquid ethylene / α-olefin copolymer. You can

Ethylene / α-olefin / diene-based rubber In the ethylene / α-olefin / diene-based rubber according to the present invention, the ethylene / α-olefin / diene copolymer rubber as the high molecular weight component (A) has a high molecular weight. Liquid ethylene as the low molecular weight component (B) is present in a proportion of 90 to 60% by weight, preferably 80 to 65% by weight, based on 100% by weight of the total amount of the component (A) and the low molecular weight component (B).
The α-olefin copolymer is present in a proportion of 10 to 40% by weight, preferably 35 to 20% by weight, based on 100% by weight of the total amount of the above (A) and (B).

Ethylene according to the present invention comprising the high molecular weight component (A) and the low molecular weight component (B) as described above.
α-olefin / diene rubber has Mooney viscosity ML
_{1 + 4} (100 ° C) is 20 to 150, preferably 30 to 1
35 and an ethylene / α-olefin / diene rubber having an iodine value (IV ₁ ) of ethylene / α-olefin / diene rubber having a molecular weight of 3,000 to 15,000 and a molecular weight of 80,000 to 120,000. Iodine value (I
V ₂₎ ratio of (IV ₁ / IV ₂₎ is 0.1 or less, preferably 0. The ethylene / α-olefin / diene rubber having a Mooney viscosity ML _{1 + 4} (100 ° C.) and the above iodine value ratio (IV ₁ / IV ₂ ) within the above range is kneadable with a Banbury mixer or the like. Is excellent in

The ethylene / α-olefin / diene rubber of the present invention is prepared by mixing a solution or suspension of the high molecular weight component (A) with a solution or suspension of the low molecular weight component (B) and then solidifying the mixture. It can be obtained by collecting the substance. In addition, a high molecular weight component (A) or a low molecular weight component (B) is first obtained by polymerization, and then other components are obtained by polymerization in the presence of the polymer. The ethylene / α-olefin / diene rubber according to the invention can be obtained.

Rubber Composition for Heat-Resistant Anti-Vibration Rubber The rubber composition for heat-resistant anti-vibration rubber according to the present invention contains the above ethylene / α-olefin / diene rubber as a main component. In the present invention, in addition to the above ethylene / α-olefin / diene rubber, a softening agent, a filler, and a vulcanization agent which have been widely and generally used conventionally in the production of a vulcanized rubber molded product made of ethylene / propylene rubber or the like. Compounding agents such as agents, vulcanization accelerators, vulcanization aids and the like can be used within the range not impairing the object of the present invention. For example, when carbon black is used as the filler, the addition amount thereof is in the range of 5 to 90 parts by weight, preferably 40 to 85 parts by weight, relative to 100 parts by weight of the ethylene / α-olefin / diene rubber. ..

The above-mentioned compounding agent and the ethylene of the present invention
The kneading with the α-olefin / diene rubber is carried out by using an ordinary rubber kneading machine such as a Banbury mixer, an open roll, a kneader and the like.

To obtain a vulcanized rubber from the rubber composition for heat-resistant and vibration-proof rubber according to the present invention, an unvulcanized compounded rubber (heat-resistant and The rubber composition for vibrating rubber) may be adjusted once, and then the compounded rubber may be molded into an intended shape and then vulcanized.

When producing a vulcanized rubber, the above-mentioned ethylene
In addition to the α-olefin / diene rubber, types and blending amounts of softening agents, and further types and blending amounts of compounds constituting the vulcanizing system such as vulcanizing agents, vulcanization accelerators and vulcanization aids, and The process for producing the vulcanized rubber is appropriately selected.

As the above-mentioned softening agent, a softening agent generally used for rubber is used. Specifically, petroleum-based softening agents such as process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt and vaseline; coal. Coal tar type softeners such as tar and coal tar pitch; Fat oil type softeners such as castor oil, linseed oil, rapeseed oil and coconut oil; tall oil; sub; waxes such as beeswax, carnauba wax and lanolin; ricinoleic acid , Palmitic acid, barium stearate,
Fatty acids and fatty acid salts such as calcium stearate and zinc laurate; synthetic polymer substances such as petroleum resin, atactic polypropylene and coumarone indene resin are used. Among them, petroleum-based softeners are preferably used, and process oils are particularly preferably used.

In producing a vulcanized rubber, as a vulcanizing agent,
The following sulfur compounds are used. Specific examples of the sulfur compound include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide,
Selenium dimethyldithiocarbamate or the like is used, and among them, sulfur is preferably used.

The above sulfur compounds are the above ethylene / α
-For 100 parts by weight of olefin / diene rubber,
It is used in a proportion of 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight.

When a sulfur compound is used as a vulcanizing agent in producing a vulcanized rubber, it is preferable to use a vulcanization accelerator together. As the vulcanization accelerator, specifically, N-cyclohexyl-2-benzothiazole-sulfenamide, N-oxydiethylene-2-benzothiazole-sulfenamide, N, N-diisopropyl-2-benzothiazole- Sulfenamide, 2-mercaptobenzothiazole, 2- (2,4-
Dinitrophenyl) mercaptobenzothiazole, 2-
Thiazole compounds such as (2,6-diethyl-4-morpholinothio) benzothiazole and dibenzothiazyl-disulfide; diphenylguanidine, triphenylguanidine, diorthotolylguanidine, orthotriyl-by-
Guanidine compounds such as guanide and diphenylguanidine phthalate; acetaldehyde-aniline reaction products, butyraldehyde-aniline condensates, hexamethylenetetramine, acetaldehyde-ammonia reaction products and other aldehyde-amine or aldehyde-ammonia compounds; 2-mercaptoimidazoline And other imidazoline compounds; thiocarbanilide, diethylthiourea, dibutylthiourea, trimethylthiourea, diorthotolylthiourea, and other thiourea compounds; tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide , Thiuram compounds such as pentamethylene thiuram tetrasulfide; zinc dimethyldithiocarbamate, diet Zinc dithiocarbamate, di
-Dithioate compounds such as zinc n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, tellurium diethyldithiocarbamate; xanthate compounds such as zinc dibutylxanthate. Compound; In addition, a compound such as zinc white is used.

The vulcanization accelerator is used in an amount of 0.1 parts by weight per 100 parts by weight of the ethylene / α-olefin / diene rubber.
-20 parts by weight, preferably 0.2-10 parts by weight.

The unvulcanized compounded rubber is prepared by the following method. That is, the above ethylene / α-olefin / diene rubber and the softening agent are kneaded at a temperature of 80 to 170 ° C. for 3 to 10 minutes using a mixer such as a Banbury mixer, and then rolls such as an open roll are used. , A vulcanizing agent and, if necessary, a vulcanization accelerator or a vulcanization aid are additionally mixed and kneaded at a roll temperature of 40 to 80 ° C. for 5 to 30 minutes, and then the kneaded product is extruded to form a ribbon or a sheet. Prepare the rubber.

The compounded rubber thus prepared is molded into an intended shape by an extruder, calender roll, or press. Simultaneously with molding or by introducing the molded product into a vulcanizing tank, the compounded rubber is heated at 150 to 270 ° C. Heat at a temperature for 1 to 30 minutes to obtain a vulcanized rubber. When performing such vulcanization, a mold may or may not be used.

[0044]

The rubber composition for heat and vibration resistant rubber according to the present invention comprises a high molecular weight component (A) consisting of a specific ethylene / α-olefin / diene copolymer rubber and a specific liquid ethylene / α-olefin. The low molecular weight component (B) composed of a copolymer is contained in a specific ratio, and the Mooney viscosity ML
_{1 + 4} (100 ° C) and molecular weight 3,000 to 15,000
The ratio (IV ₁ ) of the iodine value (IV ₁ ) of the ethylene / α-olefin / diene rubber having a molecular weight of 0 to the iodine value (IV ₂ ) of the ethylene / α-olefin / diene rubber having a molecular weight of 80,000 to 120,000. / IV ₂ ) is a composition containing ethylene / α-olefin / diene-based rubber as a main component with a specific range of / IV ₂ ), it has excellent heat resistance, anti-vibration properties, and heat aging resistance, as well as processability (fluidity). ), It is possible to provide a vulcanized rubber molded article which is excellent in shape-retaining surface smoothness during vulcanization molding, mechanical strength characteristics, low compression set characteristics, wear resistance and dynamic fatigue resistance.

Since the rubber composition for heat-resistant and vibration-proof rubber according to the present invention has the above-mentioned effects, the heat-resistant and vibration-proof rubber, particularly for automobile engine mounts, torsional dampers,
It can be used as a rubber composition such as a tension rod push, a steering rubber coupling, a center bearing support, a lower ring bush, a pump stopper and a muffler hanger.

The present invention will be described below with reference to examples.
The present invention is not limited to these examples. The methods of evaluating the characteristics of the ethylene / α-olefin / diene rubber and the vulcanized rubber molded product in the examples and comparative examples are as follows.

[1] Molecular weight distribution (Mw / Mn) Q value The molecular weight distribution (Mw / Mn) Q value was measured according to "Gel Permeation Chromatography" published by Maruzen Co., Ltd. by Takeuchi. It was (1) Using standard polystyrene of known molecular weight (monodisperse polystyrene manufactured by Tosoh Corporation), molecular weight M and its GPC
(Gel Permeation Chromatog
Raphy) count is measured, molecular weight M and elution volume E
A correlation diagram calibration curve with V (Elution Vlume) is created. The polystyrene concentration at this time is 0.02% by weight. (2) The GPC pattern of the sample is taken by the GPC measurement method, and the molecular weight M is known from the above (1). The sample preparation conditions and GPC measurement conditions in that case are as follows.

Sample preparation conditions (a) Samples are collected in an Erlenmeyer flask together with an o-dichlorobenzene solvent so that the concentration thereof will be 0.04% by weight. (B) Anti-aging agent 2,6-in the Erlenmeyer flask containing the sample
Di-tert-butyl-p-cresol is added at 0.1% by weight based on the polymer solution. (C) The Erlenmeyer flask is heated to 140 ° C. and stirred for about 30 minutes to dissolve the sample. (D) Then, the Erlenmeyer flask is kept at 135 to 140 ° C. and filtered with a pore filter having a diameter of 1 μm. (E) The filtrate is subjected to GPC analysis.

GPC measurement conditions (a) Device: Waters type 200 (b) Column: Tosoh Corp. S-type (Mix type) (c) Sample amount: 2 ml (d) Temperature: 135 ° C. (e) Flow rate: 1 ml / mm (he) Total theoretical plate number of the column: 2 × 10 ⁴ to 4 × 10 ⁴ (measured value with acetone) [2] Tensile test JIS K 6301 (198)
No. 3 type dumbbell test piece described in 9 years) was obtained, and the test piece was used in accordance with the method defined in the same JIS K 6301 Clause 3 to measure temperature 25 ° C. and pulling speed 500 mm /
Subjected to tensile test at a minute conditions, the 100% modulus (M _100), 200% modulus (M _200), 300%
The modulus (M ₃₀₀ ), tensile stress at break T _B and tensile elongation at break E _B were measured.

[3] Hardness Test The hardness test was carried out according to JIS K 6301 (1989), and the spring hardness H _S (JIS A hardness) was measured.

[4] Compression set test The compression set test was conducted according to JIS K 6301 (1989).
Then, the compression set (%) was determined.

[5] Low elongation stress test The low elongation stress test is performed according to JIS K 6301 (1989).
Then, the 25% elongation stress σ ₂₅ was obtained. The static shear elastic modulus G _s (kg / cm ² ) can be calculated by the following formula.

G _s = 1.639 × σ ₂₅ [6] Dynamic viscoelasticity test The dynamic viscoelasticity test was carried out using a viscoelasticity tester (Model RDS-2) manufactured by Rheometric Co. at a measurement temperature of 25 ° C. The dynamic shear modulus (kg / cm ² ) was determined under the conditions of a frequency of 15 Hz and a strain rate of 1%. In addition, the dynamic ratio (index of vehicle interior noise) and the loss tangent tan δ (index of riding comfort) were calculated by the following formulas.

G _s = G ′ + ιG ″ (G _s : static shear modulus, real number G ′: dynamic shear modulus,
Imaginary number G ″: Dynamic loss elastic modulus) Dynamic magnification = G ′ / G _s tan δ = G ″ / G ′ [7] Heat aging resistance The heat aging resistance is as follows according to 6.5 of JIS K 6301 (1975). The stress retention at break A _R (T _B ) and the elongation at break A _R (E _B ) are evaluated.

A dumbbell No. 1 type tensile test piece of JIS K 6301 was punched out from the longitudinal direction of the sheet, the test piece was allowed to stand at 100 ° C., 120 ° C. and 150 ° C. for 70 hours, then returned to room temperature and 200 mm / min. A tensile test is performed at speed to measure stress at break (T Baged) and elongation at break (E Baged). On the other hand, the stress at break (T Borig) and the elongation at break (E Bori) of the sample before heat aging
g) is measured beforehand, and the stress retention at break and elongation retention at break are calculated.

A _R (T _B ) [%] = (T Baged / T Borig) × 100 A _R (E _B ) [%] = (E Baged / E Borig) × 100 First, in Examples and Comparative Examples. Two kinds of high molecular weight components and five kinds of low molecular weight components were prepared. The characteristics of these components are shown below.

[High molecular weight component-1 (EPT-1)] Ethylene content: 70 mol Non-conjugated diene: 5-ethylidene-2-norbornene (E
NB) Iodine number: 20 Intrinsic viscosity [η] measured in 135 ° C decalin: 2.7
dl / g molecular weight distribution (Mw / Mn) Q value: 2.8 [high molecular weight component-2 (EPT-2)] ethylene content: 70 mol% non-conjugated diene: 5-ethylidene-2-norbornene (E
NB) Iodine number: 20 Intrinsic viscosity [η] measured in decalin at 135 ° C .: 4.0
dl / g Molecular weight distribution (Mw / Mn) Q value: 3.2 [Low molecular weight component-1 (EP-1)] Ethylene content: 75.0 mol% Intrinsic viscosity [η]: 0 measured at 135 ° C decalin .2
4 dl / g Molecular weight distribution (Mw / Mn) Q value: 2.2 [Low molecular weight component-2 (EP-2)] Ethylene content: 60 mol% Intrinsic viscosity [η]: 1.0 measured in decalin at 135 ° C.
dl / g Molecular weight distribution (Mw / Mn) Q value: 2.1 [Low molecular weight component-3 (EP-3)] Ethylene content: 60 mol% Intrinsic viscosity [η]: 1.2 measured at 135 ° C decalin
dl / g molecular weight distribution (Mw / Mn) Q value: 2.2 [low molecular weight component-4 (EPT-3)] ethylene content: 70 mol% non-conjugated diene: 5-ethylidene-2-norbornene (E
NB) Iodine value: 13 Intrinsic viscosity measured in decalin at 135 ° C. [η]: 0.2
5 dl / g Molecular weight distribution (Mw / Mn) Q value: 2.4 [Low molecular weight component-5 (EP-4)] Ethylene content: 68 mol% Intrinsic viscosity [η]: 0.3 measured in decalin at 135 ° C.
0 dl / g molecular weight distribution (Mw / Mn) Q value: 2.2

[0058]

Example 1 High molecular weight component-1 (EPT-1) 10
0 parts by weight, 30 parts by weight of the above low molecular weight component-1 (EP-1), and paraffin-based process oil [Idemitsu Kosan Co., Ltd.
Manufactured by Diana Process Oil PW-380] and melt-kneaded with 30 parts by weight to obtain Mooney viscosity ML _{1 + 4} after oil extension.
(100 ° C) is 42 and IV ₁ / IV ₂ is 0.
A propylene / diene rubber was obtained.

100 parts by weight of the obtained ethylene / propylene / diene rubber, 5 parts by weight of Zinc Hua No. 1, 1 part by weight of stearic acid, and FEF carbon black [Asahi Carbon Co., Ltd., Asahi 60HG] 60 parts by weight Were mixed with a Banbury mixer (manufactured by Kobe Steel, Ltd.) having a capacity of 4.3 liters.

The kneaded material obtained in this manner was mixed with about 5
After cooling to 0 ° C., 0.5 parts by weight of sulfur, 3.0 parts by weight of NOXCELLER M [MBT manufactured by Ouchi Shinko Chemical Industry Co., Ltd., vulcanization accelerator], NOXCELLER BZ [Ouchi Shinsei Chemical Co., Ltd.] were added to the kneaded product. ZnBDC manufactured by Kogyo Co., Ltd., vulcanization accelerator] 1.5 parts by weight and NOXCELLER TT [TMTD manufactured by Ouchi Shinko Chemical Co., Ltd.,
Vulcanization accelerator] After adding 0.75 parts by weight and kneading with an 8-inch roll (front and rear roll temperature: 55 ° C.), the mixture is dispensed into a sheet and pressed at 150 ° C. for 18 minutes to obtain a vulcanized sheet having a thickness of 2 mm. And a physical property test was conducted on this vulcanized sheet.

Further, the above pressing conditions were changed to 150 ° C. for 20 minutes to obtain a thick vulcanized rubber molded product for compression set test,
A compression set test was conducted on this thick vulcanized rubber molded product.

The results are shown in Tables 1 and 2.

[0063]

Comparative Example 1 In Example 1, the low molecular weight component-1 (E
Example 1 except that the compounding amounts of P-1) and the paraffinic process oil were 0 parts by weight and 60 parts by weight, respectively.
It carried out similarly to.

The obtained ethylene / propylene / diene rubber had a Mooney viscosity ML _{1 + 4} (100
C.) was 42 and IV ₁ / IV ₂ was 18. The results are shown in Tables 1 and 2.

[0065]

Example 2 In Example 1, the low molecular weight component-1 (E
Example 1 except that the compounding amount of P-1) was 60 parts by weight.
It carried out similarly to.

The obtained ethylene / propylene / diene rubber had a Mooney viscosity ML _{1 + 4} (100
C.) was 41 and IV ₁ / IV ₂ was 0. The results are shown in Tables 1 and 2.

[0067]

Comparative Example 2 In Example 2, the low molecular weight component-1 (E
It carried out like Example 2 except having used low molecular weight ingredient-2 (EP-2) instead of P-1).

The ethylene / propylene / diene rubber thus obtained had a Mooney viscosity ML _{1 + 4} (100
C.) was 50 and IV ₁ / IV ₂ was 0. The results are shown in Tables 1 and 2.

[0069]

Comparative Example 3 In Example 2, the low molecular weight component-1 (E
It carried out like Example 2 except having used low molecular weight ingredient-3 (EP-3) instead of P-1).

The obtained ethylene / propylene / diene rubber had a Mooney viscosity ML _{1 + 4} (100
C.) was 52 and IV ₁ / IV ₂ was 0. The results are shown in Tables 1 and 2.

[0071]

Comparative Example 4 In Example 2, the low molecular weight component-1 (E
Instead of P-1), low molecular weight component-4 (EPT-3)
Example 2 was repeated except that was used.

The obtained ethylene / propylene / diene rubber had a Mooney viscosity ML _{1 + 4} (100
° C.) is 42, IV ₁ / IV ₂ was 0.65. The results are shown in Tables 1 and 2.

[0073]

Comparative Example 5 70 parts by weight of natural rubber (NR) [RSS No. 1], 30 parts by weight of styrene-butadiene rubber (SBR) [manufactured by Nippon Zeon Co., Ltd., trade name: Nipol 1502], and stearic acid 0. 5 parts by weight, Zinc Hua No. 1 5 parts by weight, HAF carbon [Tokai Carbon Co., Ltd., Seast 3] 40 parts by weight, paraffin-based process oil [Kyodo Oil Co., Ltd., Sonic Process Oil P-30]
0] 20 parts by weight were kneaded with a 4.3 Banbury mixer [made by Kobe Steel, Ltd.].

The kneaded material thus obtained was mixed with sulfur 1
Parts by weight, 1.5 parts by weight of a vulcanization accelerator [manufactured by Ouchi Shinko Chemical Industry Co., Ltd., NOXCELLER CZ] and 3 parts by weight of an antiaging agent [manufactured by Ouchi Shinko Chemical Industry Co., Ltd., NOCRAC AD] After kneading with a roll, it is dispensed into sheet form and 150 ℃
Was pressed for 30 minutes to obtain a vulcanized sheet having a thickness of 2 mm, and the vulcanized sheet was evaluated.

Further, the above press conditions were changed to 150 ° C. for 13 minutes to obtain a thick vulcanized rubber molded product for compression set test.
A compression set test was conducted on this thick vulcanized rubber molded product.

The results are shown in Tables 1 and 2.

[0077]

Example 3 In Example 2, the low molecular weight component-1 (E
Example 2 was repeated except that low molecular weight component-5 (EP-4) was used instead of P-1).

The obtained ethylene / propylene / diene rubber had a Mooney viscosity ML _{1 + 4} (100
C.) was 42 and IV ₁ / IV ₂ was 0. The results are shown in Tables 1 and 2.

[0079]

[Table 1] FIG. 1 shows the relationship between the dynamic magnification and tan δ of the vulcanized rubbers of Examples 1 to 3 and Comparative Examples 1 to 5. As is clear from FIG. 1, an ethylene / α-olefin composed of a high molecular weight component-1 having an intrinsic viscosity [η] of 2.7 dl / g and a low molecular weight component-1 having an intrinsic viscosity of [η] of 0.24 dl / g. In Example 1 using a diene-based rubber, a vulcanized rubber having substantially the same dynamic magnification as in Comparative Example 1 but having a large tan δ vibration-damping property was obtained. Further, in Example 2, in which the ethylene / α-olefin / diene-based rubber in which a large amount of the low molecular weight component-1 was blended was used, compared to Example 1, vibration damping with a larger tan δ was achieved. A vulcanized rubber having characteristics is obtained. As described above, in the present invention, the vibration damping property of rubber can be controlled by the blending amount of the low molecular weight component. Regarding the above-mentioned vibration damping property, the molecular weight of the low molecular weight component is a decisive factor, and when a low molecular weight component having an intrinsic viscosity [η] which is an index of the molecular weight exceeds 0.4 dl / g is used, the control of the vibration damping property becomes unsuccessful. This is possible, and this is made clear by Comparative Examples 2 and 3.

[0080]

[Table 2]

In Table 2, Examples 1 to 3 and Comparative Example 5
As is clear from comparison with, the vulcanized rubber using the rubber composition for heat-resistant and vibration-proof rubber of the present invention is compared with NR-SBR vulcanized rubber currently used as a polymer for vibration-proof rubber materials. And the heat aging resistance is remarkably excellent, 120 ℃ × 7
2 hrs. Under aging conditions of about 2 times better.
This means that the vulcanized rubber using the rubber composition for heat-resistant and vibration-proof rubber of the present invention has a smaller rate of change in the vibration-proof property than the NR-SBR-based vulcanized rubber, and the It has excellent heat stability.

As is clear from comparison between Comparative Example 4 in Table 2 and Examples 1 to 3, the intrinsic viscosity [η] of the low molecular weight component is shown.
Is in the range of 0.2 to 0.4 dl / g, but when the diene component is copolymerized in the low molecular weight component, only a vulcanized rubber having a particularly deteriorated compression set is obtained. Absent. Therefore, in the present invention, the rubber composition using the above-mentioned low-molecular weight component instead of the low-molecular-weight component of the present invention cannot be used for a vibration-proof rubber for supporting an engine, and The vibration damping characteristics as seen in the examples are not sufficiently exhibited.

[Brief description of drawings]

FIG. 1 is a graph showing the relationship between tan δ and the dynamic magnification of vulcanized rubbers of Examples 1 to 3 and Comparative Examples 1 to 5.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor, Michihiro Harada, 330, Naganuma-cho, Chiba-shi, Chiba Kinugawa Rubber Industrial Co., Ltd.

Claims (1)

[Claims] 1. A molecular weight distribution (Mw / Mw) determined by GPC measurement, comprising ethylene, an α-olefin having 3 to 20 carbon atoms and a non-conjugated diene, and having an ethylene content of 60 to 73 mol%. Mn) Q value is less than 4 and 1
Intrinsic viscosity [η] measured in decalin at 35 ° C is 2.7-
High molecular weight component (A) consisting of ethylene / α-olefin / diene copolymer rubber having 5.0 dl / g and an iodine value of 10 to 40: 90 to 60% by weight, and ethylene and 3 to 3 carbon atoms. Consisting of 20 α-olefins,
And has an ethylene content of 50 to 78 mol%,
The intrinsic viscosity [η] measured in decalin at 0.2 ° C is 0.2 to 0.
Low molecular weight component (B) consisting of liquid ethylene / α-olefin copolymer of 4 dl / g: 10 to 40% by weight of ethylene / α-olefin / diene rubber having Mooney viscosity ML _{1 + 4} ( 100 ° C.) is in the range of 20 to 150 and the iodine value (I) of the ethylene / α-olefin / diene rubber having a molecular weight of 3,000 to 15,000.
V ₁ ) and the iodine value (I) of an ethylene / α-olefin / diene rubber having a molecular weight of 80,000 to 120,000.
V ₂₎ and the ratio (IV ₁ / IV ₂₎ heat rubber cushion rubber composition, characterized in that a main component of ethylene-alpha-olefin-diene rubber is 0.1 or less.