JP2005344086A - High-damping rubber composition and earthquake-proof structure using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-damping rubber composition suitable for earthquake-proof structure compounded with much carbon black to make high-damping performance and processability compatible with each other, and to provide such an earthquake-proof structure good in damping performance. <P>SOLUTION: The high-damping rubber composition comprises 100 pts. wt. of a rubber component consisting of a diene rubber, 40-95 pts. wt. of carbon black and 10-50 pts. wt. of a resin. In this composition, the carbon black comprises (A) carbon black 100-170 m<SP>2</SP>/g in cetyl trimethylammonium bromide adsorption specific surface area(CTAB) and (B) carbon black 100-170 m<SP>2</SP>/g in CTAB and ≤90 mL/100mg in DBP oil absorption, wherein the carbon black B accounts for 10-50 wt.% of the total carbon black. The earthquake-proof structure 1 is obtained using the high-damping rubber composition 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a high-damping rubber composition, and relates to a high-damping rubber composition that is excellent in damping performance and breaking strength, and that can be processed with good rigidity while being highly rigid.

  For base isolation of buildings and support of structures such as bridges and elevated roads, seismic isolation structures in which rubber compositions and hard plates such as steel plates are alternately stacked are used. This seismic isolation structure is an elastic structure with high rigidity in the vertical direction and low rigidity in the shear direction. By reducing the natural frequency of the building against the vibration frequency of the earthquake, the vibration input can be reduced. It reduces acceleration and minimizes damage to buildings, people in them, and equipment.

  As a rubber composition for such applications, diene rubber is used as a rubber component, and a large amount of fine particle carbon black and petroleum resin are blended in order to impart high damping properties (Patent Document 1, Patent Document 1). 2).

  However, a large amount of carbon black can improve the rigidity of the rubber and give it a high damping property, but the increase in rubber viscosity has an adverse effect on the refining process such as kneading and extrusion of unvulcanized rubber, and the workability is significantly reduced. In addition, there is a problem in that the fracture strength and elongation at break due to an increase in rubber hardness are reduced, and a balance between the damping performance and workability and rubber properties in a high damping rubber composition is required.

In addition, in order to improve the damping property of rubber composition and supplement and improve processability, petroleum resin is blended with carbon black. However, if a large amount of petroleum resin is blended, the creep characteristics deteriorate and long-term durability is achieved. The problem of inferiority occurs.
Japanese Patent Laid-Open No. 10-110064 Japanese Patent Laid-Open No. 10-176083

  In view of the above situation, the present invention is excellent in damping performance, strength and elongation characteristics, can adjust the rigidity (elastic modulus) of the rubber composition, and can process the unvulcanized rubber even in the case of high rigidity blending. It is an object of the present invention to provide a highly damped rubber composition that can be suitably used for a seismic isolation structure that does not damage.

  The inventors of the present invention have given rubber composition a high damping property due to a large amount of carbon black by using carbon black having a specific colloidal characteristic in combination with a high rigidity of the rubber composition due to a large amount of carbon black. However, the present invention has been completed by finding that the viscosity of the unvulcanized rubber is suppressed and the processability is kept good.

That is, the present invention relates to a high-damping rubber composition containing 40 to 95 parts by weight of carbon black and 10 to 50 parts by weight of resin with respect to 100 parts by weight of a rubber component made of a diene rubber. trimethyl ammonium bromide adsorption specific surface area (CTAB) is a carbon black (a) is a 100~170m ² / g, cetyltrimethylammonium bromide adsorption specific surface area (CTAB) is 100~170m ² / g and DBP oil absorption amount 90ml / 100 mg or less of carbon black (B), wherein the carbon black (B) comprises 10 to 50% by weight of the total carbon black content.

According to the highly damped rubber composition of the present invention, by containing fine particle carbon black having a CTAB of 100 to 170 m ² / g, the rigidity (elastic modulus) of the rubber is improved and high damping properties are imparted to the rubber composition. In combination with carbon black (B) having a CTAB of 100 to 170 m ² / g and a DBP oil absorption of 90 ml / 100 mg or less, it is possible to suppress an increase in Mooney viscosity of the unvulcanized rubber and improve workability. It is possible to improve and suppress a decrease in strength and elongation at break. As a result, even in the case of high-rigidity compounding with a large amount of fine particle carbon black, processability of unvulcanized rubber is improved to maintain process stability, and a rubber composition having excellent damping performance and rubber physical properties is obtained. be able to.

  And in the seismic isolation structure using the high-damping rubber composition, the high-damping rubber composition absorbs and attenuates vibration energy such as earthquakes, and protects buildings, internal people, mechanical devices, etc. The vibration damping effect is excellent for long-term durability.

  The high-damping rubber composition of the present invention is excellent in damping performance and fracture characteristics, and can adjust the rigidity (elastic modulus) of the rubber composition. Especially in the case of blending with high rigidity, the processability of unvulcanized rubber is improved. It is possible to improve the process stability. Therefore, it can be suitably used for a seismic isolation structure having excellent vibration energy absorption effects such as various types of seismic isolation, seismic isolation, and seismic isolation.

  Hereinafter, embodiments of the present invention will be described.

  The high-damping rubber composition of the present invention contains a resin and at least two types of carbon blacks (A) and (B) having specific colloidal characteristics in a diene rubber component, and in addition, a vulcanizing agent and a vulcanizing agent. It is a rubber composition formed by blending compounding agents such as an accelerator, zinc white, and anti-aging agent.

  Diene rubbers include natural rubber (NR), isoprene rubber (IR), various styrene butadiene rubbers (SBR), various butadiene rubbers (BR), cis-1, modified with syndiotactic-1,2 polybutadiene, 4-Butadiene rubber (VCR), nitrile butadiene rubber (NBR), chloroprene rubber (CR) and the like can be mentioned, and these can be used alone or in combination of two or more.

  Of these, NR and IR natural rubber rubber components are preferred from the viewpoint of the balance of mechanical strength characteristics, damping properties, processability, etc., and NR and / or IR is the main component and BR or VCR is blended to attenuate. It may be possible to improve the properties and low temperature characteristics.

  In the high damping rubber composition of the present invention, 10 to 50 parts by weight of the resin is blended with 100 parts by weight of the diene rubber component.

  Examples of the resin used in the present invention include petroleum resins obtained by polymerizing C5 and C9 petroleum fractions such as olefins and diolefins, and mixed products of coumarone / indene resin and coumarone resin / naphthene oil / phenol resin / rosin. Such as coumarone resin, phenol / acetylene resin, phenol / formaldehyde resin, terpene / phenol resin, polyterpene resin, phenol / terpene resin such as xylene / formaldehyde resin, aromatic hydrocarbon resin, aliphatic hydrocarbon resin And petroleum hydrocarbon resins such as aliphatic / aromatic petroleum resins, rosin, rosin derivative resins, terpene resins, and the like. These may be used alone or in combination of two or more.

  If the amount of the resin is less than 10 parts by weight, the effect of improving the damping property by the resin cannot be obtained, and if it exceeds 50 parts by weight, the viscosity of the unvulcanized rubber is lowered and the refining process such as rubber kneading and extrusion becomes difficult. In addition, the tackiness of the rubber composition becomes excessive, the workability such as roll adhesion is deteriorated, and the creep property of the vulcanized rubber is also increased, so that the damping property and durability are lowered.

  The high damping rubber composition of the present invention contains 40 to 95 parts by weight of fine carbon black with respect to 100 parts by weight of the diene rubber component.

The carbon black has a cetyltrimethylammonium bromide adsorption specific surface area (CTAB) of 100 to 170 m ² / g, and a cetyltrimethylammonium bromide adsorption specific surface area (CTAB) of 100 to 170 m ² / g. And carbon black (B) having a DBP oil absorption of 90 ml / 100 mg or less, and the amount of carbon black (B) is 10 to 50% by weight of the total carbon black content. The Of course, it may contain a small amount of other carbon black.

  If the blending amount of carbon black is less than 40 parts by weight with respect to 100 parts by weight of the diene rubber component, it is difficult to obtain desired damping performance and rubber physical properties, and if it exceeds 95 parts by weight, the dispersibility of carbon black deteriorates and the strength and elongation increase. It is not preferable because the physical properties of rubber and the like are deteriorated, and the workability is decreased with increasing viscosity.

In the present invention, by blending fine carbon black having a CTAB of 100 to 170 m ² / g, the rubber composition is adjusted to high rigidity (high elasticity) according to the blending amount, and excellent in damping properties It can be.

If the CTAB of the carbon black is less than 100 m ² / g, the particle size becomes large and good damping properties cannot be obtained, and if it exceeds 170 m ² / g, the Mooney viscosity of the unvulcanized rubber increases rapidly and the processability is increased. When the upper limit is exceeded, it becomes difficult to achieve both damping performance, workability and rubber physical properties. CTAB is a measured value based on ASTM D3765.

When a fine carbon black having a CTAB of 100 to 170 m ² / g is blended, the rubber composition can obtain a high damping property, but on the other hand, since the rubber hardness is increased, kneadability, extrudability, etc. Reduces workability. Therefore, when only carbon black (A) that defines only the range of CTAB is blended, there arises a problem that high damping property and workability and rubber physical properties are not compatible.

Therefore, in the present invention, 10 to 50% by weight of the total content of carbon black blended in the highly attenuated rubber composition is CTAB of 100 to 170 m ² / g and DBP oil absorption of 90 ml / 100 mg or less. A certain carbon black (B) is blended and used. That is, 10 to 50% by weight of the total amount of carbon black (A) and (B), or when other carbon black is blended, carbon black (A) and (B) and other carbon black Carbon black (B) is blended in a blending amount of 10 to 50% by weight of the total blending amount, and used in combination with carbon black (A).

Carbon black (B) having a CTAB of 100 to 170 m ² / g and a DBP of 90 ml / 100 mg or less has a small particle size and a low aggregation state of the structure. It has the effect of suppressing the viscosity increase of vulcanized rubber, can maintain strength and elongation at break, and maintains the good processability of the rubber composition by making up for the disadvantage of the processability of carbon black (A) that defines CTAB. To be.

  When the DBP of the carbon black (B) exceeds 90 ml / 100 mg, it is difficult to secure processability because the effect of suppressing the increase in Mooney viscosity cannot be obtained. The lower limit value of DBP is not particularly limited, but about 40 ml / 100 mg or more is a practical range at present from the viewpoint of carbon black production technology. DBP is a measured value based on JIS K6217.

  When the blending amount of the carbon black (B) is less than 10% by weight of the total carbon black content, the increase in Mooney viscosity of the rubber composition cannot be suppressed and it becomes difficult to maintain processability. If it exceeds, the rigidity of the rubber composition cannot be obtained, and the damping performance is lowered.

  Therefore, the carbon black (A) that limits the CTAB and the carbon black (B) that limits the DBP and CTAB is in the same range as the carbon black (A) are used together, so that a large amount of carbon black is blended. Even in the case of high-rigidity blending, the increase in Mooney viscosity of unvulcanized rubber is suppressed to ensure processability, and the rubber properties such as damping performance, strength, and elongation after vulcanization, and the rubber properties and durability are balanced and balanced. Can do.

  Also, by adjusting the total blending amount and blending ratio of carbon black (A) and carbon black (B), the rigidity (elastic modulus) of the rubber composition can be set arbitrarily, and used for various seismic isolation devices. A suitable rubber composition can be obtained.

  In addition to the rubber component, resin, and carbon black, the high damping rubber composition of the present invention includes a vulcanizing agent such as sulfur that is usually used in the rubber industry, a vulcanization accelerator, silica, Silane coupling agents, anti-aging agents, softeners such as zinc white, stearic acid, oil, etc., compounding agents such as waxes, various fillers, plasticizers, various resins, etc. can be appropriately blended within the normal blending amount range. it can.

  The high-damping rubber composition of the present invention can be obtained by mixing the above components using a rubber mixer usually used in the rubber industry such as a Banbury mixer or a kneader.

  The seismic isolation structure of the present invention is a structure comprising a rubber member made of the high damping rubber composition and a hard plate such as a steel plate.

  As this seismic isolation structure, there is provided a seismic isolation structure 1 having a high damping rubber layer 2 and a hard plate 3 alternately laminated as shown in FIG. 1 and having flanges 4 and 4 'on the upper and lower surfaces. The internal structure, shape, size, and the like are not limited, and the shape can be selected depending on the use such as a rectangular column shape, a polygonal column shape, an elliptical column shape in addition to a columnar shape, and the hard plate and the flange can be a cold rolled steel plate, Various materials such as various metal plates, ceramic materials, and reinforced plastic materials such as FRP are used.

  The manufacturing method of the seismic isolation structure is a method of laminating a sheet-like rubber member obtained by molding and vulcanizing a high-damping rubber and a hard plate or a flange and bonding them with an adhesive, or an unmolded sheet-like structure. It can be manufactured by laminating vulcanized high damping rubber with a hard plate or flange and vulcanizing and bonding.

  This seismic isolation structure has a stable effect on the absorption of vibration energy such as base isolation of buildings and detached buildings, isolation of bridges and road supports, vibration isolation, vibration isolation, etc. be able to.

  Hereinafter, the present invention will be described in more detail with reference to examples.

  For each of the examples and comparative examples shown in Table 1, carbon black (A) (B) having the following CTAB and DBP, resin, and plasticizer are represented with respect to 100 parts by weight of natural rubber (NR, equivalent to RSS # 3). 1 was blended in the blending amount (parts by weight) described in 1.

[Carbon black and resin, plasticizer]
Carbon black (A): CTAB = 135 m ² / g, DBP = 110 ml / 100 mg
Carbon black (B): CTAB = 120 m ² / g, DBP = 70 ml / 100 mg
-Resin: ZEON Corporation Quinton 1345
・ Plasticizer: Aroma-based process oil

  The following common compounding ingredients were blended (parts by weight) with the above NR, carbon black, resin, and plasticizer, and each rubber composition of each Example and Comparative Example was kneaded and adjusted using a normal hermetic Banbury mixer. .

[Common ingredients and amounts]
・ Zinc flower: 3 parts by weight (No. 3 zinc flower)
・ Stearic acid: 2 parts by weight (industrial stearic acid)
-Anti-aging agent: 3 parts by weight (Santo flex 13 from Flexis Co., Ltd.)
・ Sulfur: 2 parts by weight (5% oil-treated powdered sulfur)
・ Vulcanization accelerator: 1.2 parts by weight (Ouchi Shinsei Chemical Co., Ltd. Noxeller CZ)

  Each rubber composition obtained was evaluated for processability, basic physical properties (tensile strength, elongation at break), and seismic isolation characteristics according to the following methods, and the results are shown in Table 1.

[Machinability]
The Mooney viscosity (ML (1 + 4), temperature 100 ° C.) of each highly damped rubber composition was measured according to JIS K6300 and used as an index of processability. The smaller the value, the better the workability.

[Tensile strength, elongation at break]
The tensile strength (TB) and elongation at break (EB) of each high-damping rubber composition were measured according to JIS K6251 (using No. 3 dumbbell). The higher the number, the better.

[Seismic isolation characteristics]
A "2-block lap shear type" specimen (rubber part: width 25 mm, length 25 mm, thickness 5 mm) shown in FIG. 2 is vulcanized using each rubber composition, and then using a hydraulic vibration tester. Shear excitation was applied at a frequency of 0.5 Hz under the following three series of strain conditions to obtain a stress-strain curve as shown in FIG. 3, and the shear elastic modulus (Geq) and vibration absorption characteristics (Heq) were determined. The measurement temperature was 20 ° C.

Strain excitation condition 1st series: Excitation is performed 10 times with a strain of 100%.
Second series: Excitation is performed 10 times with a strain of 200%.
3rd series: Excitation twice with 100% strain.

  For the tenth vibration in the first series and the second vibration in the third series, Geq and Heq are calculated from the following equations (1) and (2) from the stress-strain curve shown in FIG. Table 1 shows Geq and Heq of the rubber composition. Geq is an index of rigidity and is set to an arbitrary value, and Heq is an index of attenuation, and the larger the better.

Geq (Kgf / cm ² ) = F / 2 (1)
Heq (%) = (ΔW / (W1 + W2)) × 1 / 2π × 100 (2)
Here, ΔW is the area in the loop of the stress-strain curve in FIG. 3, and W1 and W2 are the areas of the triangular regions in FIG.

  In Comparative Examples 1, 2, and 3 containing only carbon black (A), Geq and Heq increase as the compounding amount increases to improve rigidity and damping. On the other hand, Mooney viscosity increases and uncured rubber increases. Workability deteriorates and strength and elongation at break also show a tendency to decrease, which is unfavorable because it affects durability.

  On the other hand, each Example using a predetermined amount of carbon black (B) maintains Mooney viscosity at a low level to improve processability, and maintains Geq and Heq to ensure high attenuation. It turns out that both have the performance which balances.

  In Comparative Example 4 in which the blending amount of carbon black (B) is small, the Mooney viscosity increases and processability is not improved. Conversely, in Comparative Example 5 in which the blending amount is too large, the Mooney viscosity is at a low level. , Heq is lowered and sufficient rigidity and damping performance cannot be obtained.

  As described above, the highly damped rubber composition according to the present invention maintains the processability at the time of rubber kneading by blending a specific carbon black and a resin, obtains process stability, and has good rubber properties and damping performance. Can be suitably used for various seismic isolation structures such as building structures such as buildings, bridges and road supports.

It is a seismic isolation structure to which the high damping rubber composition of the present invention is applied. It is a perspective view of a "2 block lap shear type" test body. It is explanatory drawing of a stress-strain curve.

Explanation of symbols

1 …… Seismic isolation structure 2 …… High damping rubber 3 …… Hard plate 4, 4 ′ …… Flange

Claims (2)

In the high damping rubber composition containing 40 to 95 parts by weight of carbon black and 10 to 50 parts by weight of resin with respect to 100 parts by weight of the rubber component made of diene rubber,
The carbon black has a cetyltrimethylammonium bromide adsorption specific surface area (CTAB) of 100 to 170 m ² / g and a cetyltrimethylammonium bromide adsorption specific surface area (CTAB) of 100 to 170 m ² / g. And a carbon black (B) having a DBP oil absorption of 90 ml / 100 mg or less, wherein the carbon black (B) comprises 10 to 50% by weight of the total carbon black content. Composition. A base-isolated structure comprising the high-damping rubber composition.

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