JP2003027037A - Damping rubber composition and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new damping rubber composition that can furnish a damping member having a good performance similar to a silica type damping member, even though it uses a carbon black and a rubber softening agent, and to provide a method for manufacturing the composition with a high productivity, and with a consistent quality realized by effectively preventing slips during the kneading. SOLUTION: This damping rubber composition comprises 100 pts.wt. of a base rubber having >=50 wt.% of a styrene-butadiene copolymer rubber, >=100 pts.wt. of carbon block, and >=80 pts.wt. of a rubber softening agent. In the manufacturing method therefor, a solid base rubber extended with a part of the rubber softening agent is kneaded with the carbon black soaked with at least a part of the residual rubber softening agent, and further with the remaining rubber softening agent, if present.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a vibration damping rubber composition suitable for forming a vibration damping member such as a cable damper, and a method for producing the same.

[0002]

2. Description of the Related Art A damping member such as a cable damper used for attenuating a vibration of a cable in a bridge such as a cable-stayed bridge or a suspension bridge is generally formed by vulcanizing a rubber composition. Examples of the rubber composition (damping rubber composition) that forms the basis of the vibration damping member include, for example, a base rubber mainly composed of natural rubber or isoprene rubber, and silica as a reinforcing agent.
It is known that an alkoxysilane is used as a coupling agent (Japanese Patent Laid-Open No. 10-81787).

A damping member obtained by vulcanizing the above damping rubber composition has an elastic modulus suitable as a cable damper and the like.
It has the advantages of excellent vibration damping performance, small temperature dependence of these characteristics, and stable performance over a wide temperature range. The preferable range of the characteristics of the damping member is
Although it depends on the shape and structure of the vibration damping member, for example, in a typical shear type damper structure as a cable damper for a bridge, the shear elastic modulus at 10% to 20% shear deformation at the measurement temperature + 20 ° C. is 0. .98 to 3.43 MPa
Is preferred. As the vibration damping ability, it is preferable that the loss tangent tan δ at the measurement temperature + 20 ° C. is 0.45 or more, particularly 0.5 or more. As the temperature dependence of the characteristics, for example, the shear elastic modulus G [-10 ° C] at 12.5% shear deformation at the measuring temperature -10 ° C and the measuring temperature +
Shear modulus G at 12.5% shear deformation at 20 ℃
The ratio G [−10 ° C.] / G [+ 20 ° C.] with [+ 20 ° C.] is preferably 3 or less.

The damping member formed from the above composition is
All of these characteristics can be satisfied. However, in the process of blending the above-mentioned components and kneading to produce a vibration-damping rubber composition, silica and alkoxysilane react with each other, resulting in volatility,
There is a problem that alcohol having a flammability is generated, which easily pollutes the environment in the work place or causes a risk of ignition or explosion.

Further, since the degree of progress of the above reaction greatly varies depending on the kneading conditions and the environmental conditions at the time of kneading, there is also a problem that the characteristics of the vibration damping member are likely to largely change. Therefore, it is difficult to stabilize the quality of the vibration damping member.

[0006]

A rubber composition using carbon black as a reinforcing agent has been known for a long time. Even if a rubber composition is vulcanized to form a vibration damping member, silica and an alkoxy compound are used. There is a problem that the vibration damping performance is not sufficient as compared with that using silane. Therefore,
Based on the finding that the vibration damping performance is improved by increasing the blending ratio of carbon black, it was studied to increase the blending ratio of carbon black more than ever, but as the blending ratio increases, the elastic modulus increases. The damping member tends to rise and become hard.

In particular, in the above-mentioned system using natural rubber or isoprene rubber as the base rubber, the compounding ratio of carbon black is set to be larger than before so that good vibration damping performance can be obtained as the vibration damping member. When the vibration damping member is formed in this manner, the elastic modulus of the vibration damping member far exceeds an appropriate range as the vibration damping member, and the vibration damping member becomes extremely hard. For this reason, there arises a problem that it cannot be used as a vibration damping member. If a rubber softening agent is added, the vibration damping member can be softened to some extent. However, since the composition is likely to cause slip during kneading, the quality of the composition is likely to vary greatly depending on the level of skill of the operator or a slight change in the conditions during kneading. In particular, the degree of dispersion of carbon black is likely to change greatly, which causes another problem that a vibration-damping rubber composition having stable quality cannot be produced with high productivity.

Further, it has been studied to use silica and carbon black together, but the damping member formed is not yet sufficient in vibration damping performance, especially for cable dampers, and there is a problem of vulcanization delay due to silica. There is also. A first object of the present invention is to provide a novel vibration damping member capable of producing a vibration damping member having good performance equivalent to that of a silica-based material, even though carbon black and a rubber softening agent are used. To provide a rubber composition.

A second object of the present invention is to more reliably prevent the occurrence of slip during kneading, and to manufacture the above-mentioned vibration-damping rubber composition with stable quality and high productivity. To provide a method.

[0010]

Means for Solving the Problems In order to achieve the above-mentioned object, the inventor has made various studies on each component constituting a vibration damping rubber composition. As a result, styrene-butadiene copolymer rubber (hereinafter referred to as "SBR") as the base rubber
When used in combination with carbon black and a rubber softening agent, it exhibits excellent vibration damping performance at around room temperature (+ 20 ° C.), has an appropriate elastic modulus, and has a temperature dependence of these characteristics. It has been found that a relatively small damping member can be obtained. Then, as a result of further studying the optimum blending ratio of each of the above components, the present invention has been completed.

That is, according to the first aspect of the invention, 100 parts by weight of a base rubber containing a styrene-butadiene copolymer rubber in a proportion of 50% by weight or more and 100 parts by weight of carbon black are used.
It is a vibration-damping rubber composition characterized in that a rubber softening agent is blended in an amount of 80 parts by weight or more by weight. Claim 1
According to the vibration-damping rubber composition of No. 4, the vibration-damping rubber composition having stable and good performance in a wide temperature range is obtained by the synergistic effect of the function of the SBR and the blending ratio of the carbon black and the rubber softening agent combined with the SBR. It becomes possible to manufacture the member.

The invention according to claim 3 for producing the above-mentioned vibration damping rubber composition comprises at least one of a solid base rubber oil-extended with a part of a rubber softening agent and the balance of the rubber softening agent. A method for producing a vibration-damping rubber composition, which comprises kneading carbon black whose part is oil-absorbed, and the remaining part of the rubber softening agent, if any, with the remaining part of the rubber softening agent. According to the manufacturing method of claim 3, a part of the rubber softening agent is used for oil extension of the base rubber so as to be solidified, and at least a part, preferably all of the remaining part of the rubber softening agent is absorbed by the carbon black. It is solidified with and is used for kneading.
Therefore, for example, even if the rubber softening agent remains in the balance and is used for kneading as it is, most of the kneading system is solid, so that slip is less likely to occur particularly in the initial stage of kneading.

Therefore, according to the manufacturing method of claim 3,
The vibration-damping rubber composition according to claim 1 can be manufactured more efficiently and with high productivity while stabilizing the quality, regardless of the skill of the operator, the conditions during kneading, and the like.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below. <Damping rubber composition> As described above, the damping rubber composition of the present invention comprises 100 parts by weight of the base rubber containing SBR in an amount of 50% by weight or more, 100 parts by weight or more of carbon black, and softening the rubber. The agent is blended at a ratio of 80 parts by weight or more.

Of these, the content ratio of SBR in the base rubber is limited to 50% by weight or more. If the content is less than this range, the above-mentioned function of SBR cannot be sufficiently exhibited.
This is because it is not possible to form a vibration damping member having stable and good performance in a wide temperature range. In order to more fully exert the function of SBR, the content ratio of SBR is preferably higher even within the above range. Particularly, when the total amount of the base rubber is SBR, that is, when the content ratio of SBR is 100% by weight. Preferably.

Other rubbers which may be used in combination with SBR include, for example, natural rubber, acrylonitrile butadiene copolymer rubber, butyl rubber, halogenated butyl rubber, brominated paramethylstyrene-isobutylene copolymer rubber, ethylene propylene copolymer rubber, ethylene. One or more of propylenediene copolymer rubber, isoprene rubber, chloroprene rubber, polysulfide rubber, epichlorohydrin rubber, fluororubber, silicone rubber and the like can be mentioned.

Further, the mixing ratio of carbon black is limited to 100 parts by weight or more with respect to 100 parts by weight of the base rubber. Below this range, the base rubber mainly composed of SBR is sufficiently reinforced. This is because high vibration damping performance cannot be imparted to the vibration damping member. In consideration of further improving the vibration damping performance, the compounding ratio of carbon black to 100 parts by weight of the base rubber is particularly preferably 110 parts by weight or more, and is 120 parts by weight or more, even within the above range. Is more preferable.

However, considering that the elastic modulus is maintained in a suitable range so that the vibration damping member does not become too hard, the blending ratio of carbon black to 100 parts by weight of the base rubber is particularly within the above range. The amount is preferably 200 parts by weight or less, more preferably 180 parts by weight or less, still more preferably 150 parts by weight or less.
As the carbon black, any of various carbon blacks known as a rubber reinforcing agent can be used. However, especially for damping members such as cable dampers,
Considering that it is stable in a wide temperature range and imparts good performance, it is preferable to use carbon black having a primary particle diameter of 20 nm or less and a DBP oil absorption of 110 ml / 100 g or more.

As the blending amount of carbon black increases, the vibration damping member has improved vibration damping performance as described above, but tends to have a higher elastic modulus and become harder.
Further, as the particle size of carbon black is made smaller, the vibration damping performance of the vibration damping member can be improved, but the dispersibility of carbon black in the base rubber tends to decrease. The vibration damping performance of the vibrating member may be reduced. Therefore, in consideration of the balance between the vibration damping performance of the damping member and the elastic modulus, S is used as the base rubber.
In consideration of improving the vibration damping performance while maintaining the blending ratio of carbon black to a value as small as possible within the above range in the system using BR to prevent the elastic modulus from rising, the carbon black as described above is used. The primary particle size of black is 2
0 nm or less, and DBP oil absorption is 110 ml / 100
It is preferably at least g.

The lower limit of the primary particle diameter of carbon black and the upper limit of the DBP oil absorption are not particularly limited.
Currently, the primary particle size is slightly above 10 nm, and DB
If the P oil absorption is a little below 130 ml / 100g,
It is the finest carbon black available, but when finer ones become available in the future, such carbon black can also be used, and further improvement in performance can be achieved by using such carbon black. Can be expected.

Specific examples of carbon black include N-11 defined in ASTM D1765-82a.
0 (Type name SAF, primary particle size 11 to 19 nm, DB
P oil absorption 113 ml / 100 g), N-220 (type name ISAF, primary particle size 20-22 nm, DBP oil absorption 106-117 ml / 100 g), N-339 (primary particle size 24-26 nm, DBP oil absorption 118). ~ 123 ml
/ 100g), N-285 (type name ISAF-HS,
Primary particle size 22 to 24 nm, DBP oil absorption 124 to 12
9 ml / 100 g), N-347 (type name HAF-H
S, primary particle diameter 27 to 30 nm, DBP oil absorption 126 to
128ml / 100g), N-550 (type name FE
F, primary particle diameter 39 to 50 nm, DBP oil absorption 105 to 105
127 ml / 100 g), N-660 (type name GP
F, primary particle size 62 to 80 nm, DBP oil absorption 80 to 9
2 ml / 100 g), N-770 (type name SRF, 1
Secondary particle size 70-75nm, DBP oil absorption 63ml / 10
0 g) and the like. Especially, the primary particle size is 2
0 nm or less and DBP oil absorption is 110 ml / 100
N-110 which falls within the range of g or more is preferable.

In the present invention, the compounding ratio of the rubber softening agent is 8 with respect to 100 parts by weight of the base rubber as described above.
The reason why the amount is limited to 0 parts by weight or more is that if the amount is less than this range, it is not possible to impart a good flexibility to the vibration damping member by suppressing an increase in elastic modulus due to the reinforcement with carbon black. In addition, it is possible to prevent slippage during kneading, which makes it impossible to knead, or insufficient dispersion of carbon black, and to prevent the vibration damping performance from decreasing because the elastic modulus of the vibration damping member becomes too low. Considering prevention, the compounding ratio of the rubber softening agent is preferably 150 parts by weight or less even within the above range.

Examples of the rubber softener include, for example, mineral oil-based softeners such as aromatic process oil, naphthene-based process oil, paraffin-based process oil, and vegetable oil-based softeners such as castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil and palm. Examples include oil. Further, sub, fatty acids and fatty acid salts can also be used as a rubber softening agent.
These may be used alone or in combination of two or more. Among them, aroma-based process oil and naphthene-based process oil, which have good compatibility with the base rubber and are inexpensive, are preferably used.

In addition to the above-mentioned components, the vibration-damping rubber composition contains a vulcanizing agent, a vulcanization accelerator, a vulcanization accelerating aid, a vulcanization retarder, an antiaging agent, a filler, and an adhesive property in the same manner as before. Various additives such as an imparting agent and an anti-scorch agent can be added. Among these, examples of the vulcanizing agent include sulfur, organic sulfur-containing compounds, and organic peroxides. Examples of the vulcanization accelerator include sulfenamide-based, guanidine-based,
Examples thereof include thiuram-based, dithiocarbamic acid-based, thiazole-based, and thiourea-based organic accelerators.

Examples of the vulcanization accelerator include fatty acids such as stearic acid, oleic acid and cottonseed fatty acid, and metal oxides such as zinc white. Examples of the vulcanization retarder include aromatic organic acids and nitroso compounds. Examples of the antiaging agent include imidazoles, amines, phenols and the like.

Examples of the filler include calcium carbonate, clay, barium sulfate, diatomaceous earth and the like.
Examples of the tackifier include coumarone / indene resin, aromatic resin, aromatic / aliphatic mixed resin, rosin resin, cyclopentadiene resin, and the like.
Further, examples of the anti-scorch agent include organic acid-based and nitroso compound-based anti-scorch agents. In particular, N- (cyclohexylthio) phthalimide, which is a nitroso compound type, is a strong early vulcanization inhibitor, and has the advantage of being able to control processing safety when used in combination with a sulfenamide type or thiazole type vulcanization accelerator. Have.

In addition to the above, the damping rubber composition may be appropriately blended with a dispersant, a solvent and the like. <Method for producing damping rubber composition> The damping rubber composition of the present invention is produced by kneading the above components. In particular, while preventing the slip due to the rubber softener described above,
In order to efficiently produce a vibration damping rubber composition having uniform properties, as described above, a solid base rubber oil-extended with a part of a rubber softening agent and at least a part of the remaining part of the rubber softening agent are used. Kneading the oil-absorbed carbon black and the remaining portion of the rubber softening agent, if any,
It is preferable to adopt the manufacturing method of the present invention.

In the above manufacturing method, the base rubber 10
A small amount of 30 parts by weight or less, preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 0 parts by weight prevents slippage even when the rubber softening agent is added alone, and provides a uniform level. It is possible to efficiently produce a vibration damping rubber composition having characteristics. However, after the base rubber is oil-extended, carbon black absorbs all the remaining amount of the rubber softening agent to minimize the addition of the rubber softening agent alone.
It is most preferable in preventing slippage during kneading.

For kneading, a kneader or the like having various capacities may be used as in the conventional case. The vibration-damping rubber composition of the present invention thus produced should be used as a raw material for forming various conventionally known vibration-damping members, such as a cable damper having a general shear-type damper structure for bridges as described above. You can When manufacturing the damping member, as in the conventional case, a mold corresponding to the shape of the damping member is filled with a predetermined amount of the damping rubber composition, and heated under pressure to vulcanize the base rubber. Good.

[0030]

EXAMPLES The present invention will be described below based on Examples and Comparative Examples. Example 1 Carbon black N-110 described above and an aroma-based process oil [Diana Process Oil X manufactured by Idemitsu Kosan Co., Ltd.]
-140] in a weight ratio of 4: 6 and kneaded using a kneader to cause carbon black N-110 to absorb the aroma process oil to obtain a kneaded product.

Next, the oil exhibition SBR [SB manufactured by Sumitomo Chemical Co., Ltd.
R1712 and SBR 100 parts by weight of oil softening agent oil extension 37.5 parts by weight] 137.5 parts by weight, the above kneaded product 138 parts by weight, and 80 parts by weight of carbon black N
-110 and each of the following additives were kneaded using a 3L kneader to obtain a vibration damping rubber composition. (Additives) (parts by weight) Zinc oxide 5 Anti-aging agent 6PPD 2 Anti-aging agent FR 2 Stearic acid 1 Vulcanization accelerator (sulfenamide type) 1 Vulcanization accelerator (guanidine type) 0.5 N- (cyclohexyl) Thio) phthalimide 0.3 In the vibration damping rubber composition, the total compounding ratio of carbon black N-110 to 100 parts by weight of SBR is 13
5.2 parts by weight, and the total compounding ratio of the rubber softening agent was 120.
It was 3 parts by weight.

Examples 2 and 3, Comparative Example 1 An example except that a kneaded product of carbon black N-110 and an aroma-based process oil and carbon black N-110 were blended at the blending ratios shown in Table 1, respectively. A vibration damping rubber composition was obtained in the same manner as in 1. Example 4 A kneaded product of carbon black N-110 and an aroma-based process oil, and carbon black N-110 were blended at the blending ratios shown in Table 1, respectively. A vibration damping rubber composition was obtained in the same manner as in Example 1 except that the compounding ratio was as shown.

[0033]

[Table 1]

Conventional Example 1 100 parts by weight of natural rubber, 135 parts by weight of silica, and triethoxyphenylsilane [KBE10 manufactured by Shin-Etsu Chemical Co., Ltd.]
3] 20 parts by weight and the following additives were kneaded using a 3L kneader to obtain a silica-based vibration damping rubber composition. (Additives) (parts by weight) Zinc oxide 5 Anti-aging agent 6PPD 2 Anti-aging agent FR 2 Stearic acid 1 Vulcanization accelerator (sulfenamide type) 1 Vulcanization accelerator (thiuram type) 0.7 N- (cyclohexyl) Thio) phthalimide 0.3 The following tests were conducted on the vibration damping rubber compositions of the above Examples and Comparative Examples to evaluate their properties.

<Shear Dynamic Viscoelasticity Test> Each of the above examples,
To the vibration-damping rubber composition of Comparative Example, 1.5 parts by weight of sulfur was added to 100 parts by weight of the base rubber, respectively, and the mixture was kneaded with a roll, and then, using a predetermined mold, a diameter of 25 mm (= 25 × 1).
While press vulcanizing into a disk shape having a thickness of 0 ⁻³ m) × a thickness of 5 mm (= 5 × 10 ⁻³ m), at the same time as this press vulcanization,
As shown in (a) and (b), the plate-shaped metal fittings 11 and 12 for mounting to the measuring device are vulcanized and adhered to the upper and lower surfaces of the disk 10, respectively, to form a shearing type vibration damping member. A model of a cable damper having a damper structure was made. Vulcanization condition is 1
It was set to 60 ° C. × 25 minutes.

Then, the shear dynamic viscoelastic property of this model was measured using a 1.5 ton dynamic tester (manufactured by Tokyo Hoki Co., Ltd.). That is, the model of the cable damper, which was stored in a + 20 ° C or -10 ° C constant temperature tank for 3 hours or more to stabilize the temperature, was set in the constant temperature constant temperature tank of the same temperature of 1.5 tons. Two metal fittings 11 and 12
Attached through. Next, with the lower fixing metal fitting 12 fixed, the upper fixing metal fitting 11 was repeatedly displaced in the horizontal direction indicated by the white arrow in the figure to shear-deform the disk 10.

The shear deformation is caused by the horizontal displacement d (m) of the upper fixing member 11 and the height t (= 5 ×) of the disk 10.
10 ⁻³ m) and the following formula (i):

[0038]

[Equation 1]

The horizontal displacement at which the maximum value of the shear deformation D (%) determined by 12.5% was 12.5% was repeated 4 cycles with a sine wave. Then, the relationship between the shear deformation D (%) and the horizontal load in the horizontal displacement at the third cycle was measured. Next, as shown in FIG. 2, obtained by measuring as described above,
From the hysteresis loop curve showing the relationship between shear deformation D (%) and horizontal load, the following formula (ii):

[0040]

[Equation 2]

Thus, the equivalent damping constant he was obtained. Note that ΔW in the equation (ii) represents the energy loss per displacement cycle (the area of the entire region surrounded by the hysteresis loop curve in FIG. 2), and W is the elastic strain energy accumulated until the maximum amplitude is reached. (The area of the hatched area in FIG. 2) is shown. Further, F in FIG. 2 indicates a horizontal load at the maximum elongation (in this case, elongation D = 12.5%). Further, the curve L is an intermediate point (point b) between the horizontal load at the point a and the horizontal load at the point c on the hysteresis loop curve at a predetermined elongation.
From the time of no elongation (D = 0%) to the time of maximum elongation (D = 1
Curve plotted over the entire range up to 2.5%).

The displacement amount d at the maximum value (= 12.5%) of the horizontal displacement D in the above hysteresis loop curve.
From (m) and the horizontal load F (N) at this maximum horizontal displacement, the following formula (iii):

[0043]

[Equation 3]

The horizontal spring constant Kh is obtained from the above, and the horizontal spring constant Kh and the height t of the disk 10 (= 5 × 10 ⁻³ m)
And the horizontal sectional area A of the disk 10 (= 4.9 × 10 ⁻⁴
m ² ) and the following formula (iv):

[0045]

[Equation 4]

The shear modulus G was determined by Also, the following formula (v):

[0047]

[Equation 5]

The loss tangent tan δ was calculated by Then, the flexibility of the model of the cable damper was evaluated by the shear elastic modulus G [+ 20 ° C.] at 12.5% shear deformation at the measurement temperature of + 20 ° C. That is, in the cable damper having the shear type damper structure, the measured temperature +20 as described above.
Shear modulus at 10 to 20% shear deformation at 0.
Since it is preferably 98 to 3.43 MPa, whether the flexibility of each model is good or bad was judged depending on whether or not the above measurement result falls within this range.

The loss tangent tan at the measurement temperature + 20 ° C.
The vibration damping performance was evaluated according to the size of δ. That is, in the cable damper having the shear type damper structure, the loss tangent tan δ at the measurement temperature of + 20 ° C. is 0.
Since it is preferably 45 or more, particularly 0.5 or more, depending on whether or not the above measurement result falls within this range,
The quality of vibration damping performance of each model was judged. Further, the shear elastic modulus G [+ 20 ° C.] at 12.5% shear deformation at the measurement temperature + 20 ° C. and the shear elastic modulus G [−10 ° C.] at 12.5% shear deformation at the measurement temperature −10 ° C. Ratio G [-1
[0 ° C.] / G [+ 20 ° C.] was obtained to evaluate the temperature dependence of the characteristics of the model of the cable damper. That is, in the cable damper having the shear type damper structure, it is preferable that the ratio G [−10 ° C.] / G [+ 20 ° C.] is 3 or less as described above, so whether or not the calculation result falls within this range. The quality of the temperature dependence of the characteristics of each model was determined by.

<Manufacturing Workability Test> Workability in manufacturing the vibration damping rubber compositions of Examples and Comparative Examples by kneading the respective components,
The time required for obtaining a uniform composition by kneading and the presence or absence of alcohol generation during kneading were evaluated. The above results are shown in Table 2.

[0051]

[Table 2]

From the table, it is possible to form a cable damper having good characteristics by using the vibration damping rubber composition of Conventional Example 1 using silica and alkoxysilane, but alcohol is generated when the composition is kneaded. confirmed. In the system using carbon black and a rubber softening agent, the damping rubber composition of Comparative Example 1 in which the compounding ratio of carbon black was less than 100 parts by weight relative to 100 parts by weight of the base rubber was used. , It was found that the vibration damping performance was insufficient although the cable damper had good flexibility.

On the other hand, it was found that the use of the vibration damping rubber compositions of the respective examples makes it possible to form a cable damper having good characteristics equivalent to those of Conventional Example 1 without producing alcohol during kneading of the composition. . It was also found that the vibration damping rubber composition of each of the above examples can be produced in a shorter kneading time as compared with Conventional Example 1. Example 5 A kneaded product of carbon black N-110 and an aroma-based process oil, and carbon black N-110 were blended at the blending ratios shown in Table 1, respectively, and further, the aroma-based process oil alone was used in Table 1. A vibration-damping rubber composition was obtained in the same manner as in Example 1 except that the compounding ratio was as shown in.

Comparative Example 2 Carbon black N-110 was used without blending a kneaded product of carbon black N-110 and aroma process oil.
Was blended at the blending ratio shown in Table 1 above, and an aroma-based process oil alone was blended at the blending ratio shown in Table 1 to obtain a vibration damping rubber composition in the same manner as in Example 1. did. However, even if the kneading was continued for 60 minutes, a uniform composition could not be obtained, so the work was abandoned.

The shear dynamic viscoelasticity test and the manufacturing workability test for the above Example 5 were conducted. The results are shown in Table 3 together with the results of Example 1.

[0056]

[Table 3]

From the table, in Comparative Example 2, the kneading had to be abandoned as described above. On the other hand, in Examples 1 and 5 in which the manufacturing method according to the present invention was carried out, a uniform composition could be manufactured. However, when comparing the two examples, it was confirmed that the kneading time can be shortened in Example 1 in which the blending ratio of the aromatic process oil alone is smaller than that in Example 5.

[Brief description of drawings]

FIG. 1 is a view showing a model of a cable damper as a vibration damping member formed by using the compositions of Examples and Comparative Examples of the present invention, FIG. 1 (a) is a front view and FIG. ) Is a plan view.

FIG. 2 is a graph showing a hysteresis loop curve showing the relationship between shear deformation D (%) and horizontal load, which is obtained when the shear dynamic viscoelastic characteristics of the model of the cable damper is measured.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3J048 AA01 AD05 AD12 BD04 DA07                       EA39                 4J002 AC081 AE002 DA036 EA017                       EA027 EA037 GM00

Claims (3)

[Claims] 1. A blend of 100 parts by weight of a base rubber containing 50% by weight or more of styrene-butadiene copolymer rubber with 100 parts by weight or more of carbon black and 80 parts by weight or more of a rubber softening agent. A vibration-damping rubber composition characterized by: 2. A DBP having a primary particle size of 20 nm or less
The damping rubber composition according to claim 1, wherein carbon black having an oil absorption of 110 ml / 100 g or more is blended. 3. A method for producing the vibration damping rubber composition according to claim 1, wherein a solid base rubber oil-extended with a part of the rubber softening agent and at least a part of the remaining part of the rubber softening agent are used. A method for producing a vibration-damping rubber composition, which comprises kneading an oil-absorbed carbon black and, if there is a balance of a rubber softening agent, the balance of the rubber softening agent.