JP3469621B2 - High damping rubber composition and seismic isolation structure using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition having a high damping property, which is very effective for absorbing vibration energy such as seismic isolation, vibration isolation or vibration isolation, and a seismic isolation structure using the same. .

[0002]

2. Description of the Related Art In recent years, a seismic isolation construction method using a seismic isolation structure has been attracting attention for the purpose of reducing the input acceleration of vibration generated by an earthquake in a building. This isolates the ground from the building with a soft layer and reduces the natural frequency of the building to the frequency of the ground at the time of an earthquake, thereby reducing the input acceleration of vibration, which is contained in the building or in it. It minimizes damage to people and machines.

The seismic isolation structure used here is a combination of alternating soft layers (rubber) and hard layers (iron plate, etc.),
It is hard in the vertical direction to support the building, and conversely soft in the horizontal direction to moderate the input acceleration of vibration, and has the property of not breaking even during large lateral deformation.

However, since the seismic isolation rubber composition used conventionally has a very small hysteresis loss, the seismic isolation structure using this rubber composition itself has the ability to damp the vibration of the upper structure. There was nothing at all, so vibration was measured by various dampers such as viscous dampers. However, this has the drawbacks that the structure becomes complicated as a building, and the construction period and cost are relatively high.

Therefore, in order to simplify the whole seismic isolation construction method, the applicant of the present invention has proposed that the conventional seismic isolation structure itself has a high damping capacity and the damper can be removed, 1,2- or 3,4- Method using polyisoprene having a bond (JP-A-2-32
No. 135), but this method still requires low creep properties, which are required properties for the seismic isolation rubber composition,
It was difficult to provide higher damping while satisfying the cold resistance, fracture resistance, and long-term stability of performance.

Conventionally, in order to increase the loss characteristic of a rubber composition, the amount or grade of carbon black has been improved or a resin or a softening agent has been added. In many cases, characteristics and long-term stability deteriorate. Moreover, no high-damping rubber composition excellent in cold resistance has hitherto been known.

[0007]

The object of the present invention is to use a rubber composition having a high damping property and also excellent in cold resistance, fracture resistance, processing property and long-term stability, and a rubber composition thereof. To provide unnecessary seismic isolation structures such as dampers.

[0008]

The present invention comprises (a) 100 parts by weight of a rubber component containing a synthetic polyisoprene rubber as a main component, and (b) 40 to 100 parts by weight of surface-untreated silica as a filler. The present invention relates to a high damping rubber composition containing all or a main component of the agent .

Further, according to the present invention, in a seismic isolation structure in which a plurality of hard layers and soft layers are alternately laminated, the soft layer contains 100 parts by weight of a rubber component containing synthetic polyisoprene rubber as a main component, and a surface-free filler. The present invention relates to a seismic isolation structure characterized by being obtained from a high damping rubber composition containing 40 to 100 parts by weight of treated silica as a whole or a main component of a filler .

Further, according to the present invention, in a seismic isolation structure in which a plurality of hard layers and soft layers are alternately laminated, a cylindrical space is provided at the center of the laminated structure, and polybutadiene rubber is the main component in this space. 100 parts by weight of rubber component and 40-100 parts by weight of untreated silica as a filler
The present invention relates to a seismic isolation structure characterized by being filled with a high-damping rubber composition containing all or a main component of the agent .

Furthermore, in the present invention, in a seismic isolation structure in which a plurality of hard layers and soft layers are alternately laminated, the soft layer contains 100 parts by weight of a rubber component containing synthetic polyisoprene rubber as a main component and a surface-free filler. It is obtained from a high damping rubber composition containing 40 to 100 parts by weight of treated silica as the whole or a main component of a filler , and a cylindrical space is provided in the center of the laminated structure, and this space is provided. In addition, 100 parts by weight of a rubber component containing polybutadiene rubber as a main component and 40 to 100 parts by weight of surface-untreated silica as a filler
The present invention relates to a seismic isolation structure which is filled with a high damping rubber composition contained as a part or a main component .

Incidentally, Japanese Patent Application Laid-Open No. 64-48952, Japanese Patent Application Laid-Open No. 5-59216, which is a prior application of the present applicant, describes a soft layer in which silica is used as a filler. In fact, carbon black is used in the examples, and silica is listed only as an example, and silica is not used as the whole or main component of the filler as in the present invention. Further, in JP-A-5-222248, a high loss rubber composition using a large amount of silica as a filler is disclosed in the examples. As a rubber component of this rubber composition, a special synthetic rubber having high polarity is used. In addition, an aromatic hydrocarbon formaldehyde resin is an essential additive component.

The rubber component of the high damping rubber composition according to claim 1 of the present invention is a rubber component containing a synthetic polyisoprene rubber (synthetic IR) as a main component, and examples of other rubbers include natural rubber (NR) and styrene. Examples thereof include butadiene rubber (SBR), nitrile butadiene rubber (NBR), polybutadiene rubber (BR), butyl rubber (IIR), halogenated butyl rubber (X-IIR) and chloroprene rubber (CR). The synthetic IR is usually contained in an amount of 50 to 100 parts by weight, preferably 70 to 100 parts by weight, based on 100 parts by weight of the rubber component. When NR is used, it is less than 30 parts by weight.

In the present invention, 40 to 100 parts by weight of surface-untreated silica is blended as a filler with 100 parts by weight of the above rubber component. Silica is preferably used in the range of 50 to 90 parts by weight with respect to 100 parts by weight of the rubber component. In the present invention, when the amount of silica is less than 40 parts by weight, good damping property is not obtained, and 10
If it exceeds 0 part by weight, the unvulcanized viscosity of the rubber composition becomes high and the processability deteriorates. This can be solved by adding a large amount of a softening agent such as oil, but migration of the softening agent, there is a possibility of accompanying problems such as volatilization, is preferable for the rubber composition of the present invention that may be used for a long time Absent.

The rubber composition of the present invention contains known vulcanizing agents, vulcanization accelerators, vulcanization accelerating aids, vulcanization retarders, organic peroxides,
It goes without saying that colorants, reinforcing agents, antiaging agents, fillers, softening agents, plasticizers, activators, tackifiers, lubricants and the like can be added.

Examples of the filler include, in addition to silica, carbon black, clay, talc, mica, calcium carbonate, magnesium carbonate, barium sulfate, aluminum hydroxide, zinc oxide, and various natural or artificial fibers. The mixing ratio is preferably 0 to 50 parts by weight with respect to 100 parts by weight of silica. The present invention is characterized in that a large amount of silica is used as a filler.

Examples of the softening agent include tall oil mainly containing linoleic acid, oleic acid and abietic acid, pine tar, rapeseed oil, cottonseed oil, peanut oil, castor oil, palm oil,
Plant softeners such as Factis, paraffin oils, naphthenic oils, mineral oil softeners such as aromatic oils, and the like,
The mixing ratio is preferably 1 to 150 parts by weight with respect to 100 parts by weight of rubber.

Examples of the plasticizer include phthalic acid type, sebacic acid type, adipic acid type, phosphoric acid ester type, epoxy type, chlorinated paraffin type, ether type, thioether type, polyester type and polyether type plasticizers. The compounding ratio is preferably 1 to 150 parts by weight with respect to 100 parts by weight of rubber.

Examples of the tackifier include alkylphenol formaldehyde resin, alkylphenol acetylene resin, coumarone indene resin, xylene formaldehyde resin, polybutene, rosin derivative, etc., and the compounding ratio thereof is 100 parts by weight of rubber. It is preferably 1 to 50 parts by weight.

Examples of the lubricant include stearic acid, stearic acid metal soap, high melting point wax, low molecular weight polyethylene, polyethylene glycol, octadecylamine, and the like, and the mixing ratio thereof is 1 to 100 parts by weight of rubber.
It is preferably 50 parts by weight.

The rubber composition of the present invention can be obtained by kneading the above components with a conventional processing device such as a roll, a Banbury mixer or a kneader.

The present invention further provides a seismic isolation structure in which a plurality of hard layers and soft layers are alternately laminated, wherein the soft layer is a rubber component containing the synthetic polyisoprene rubber of claim 1 as a main component.
There is provided a seismic isolation structure which is obtained from a high damping rubber composition containing 100 parts by weight and 40 to 100 parts by weight of silica as a filler. It is preferable to provide flanges on the upper and lower surfaces of the laminated structure in which the soft layers and the hard layers are alternately laminated, and it is optional to cover the laminated structure with a coating layer.

In the present invention, as the material of the hard layer, metal, ceramics, plastics, FRP, polyurethane, wood, paper board, slate board, decorative board and the like can be used, and among them, steel sheet is preferable. The shape of the hard layer and the soft layer may be a polygon such as a circle, a rectangle, a pentagon, and a hexagon. To bond such a hard layer and a soft layer, an adhesive may be used or co-vulcanization may be performed.

Further, in the present invention, in order to impart a higher seismic isolation effect to the seismic isolation structure, a cylindrical space is provided at the center of the laminated structure composed of the soft layer and the hard layer, and a high space is provided in this space. It may be filled with a material having loss characteristics. It is preferable to use a high damping rubber composition containing 100 parts by weight of a rubber component containing polybutadiene rubber (BR) as a main component and 40 to 100 parts by weight of silica as a filler as the high loss property material to be filled. The rubber containing BR as a main component is, for example, natural rubber (N
R), styrene butadiene rubber (SBR), nitrile butadiene rubber (NBR), butyl rubber (IIR), halogenated butyl rubber (X-IIR), chloroprene rubber (CR) and the like. BR is usually a rubber component
In 100 parts by weight, 50 to 100 parts by weight, preferably 70 to 100 parts by weight is contained. This rubber composition also includes the same known vulcanizing agents, vulcanization accelerators, vulcanization accelerating aids, vulcanization retarders, organic peroxides, colorants, reinforcing agents, antioxidants, and fillers as described above. Needless to say, a softener, a plasticizer, an activator, a tackifier, a lubricant and the like can be added. Furthermore, when the high damping rubber composition according to claim 1 of the present invention is used for the soft layer in this seismic isolation structure, the outer diameter of the seismic isolation structure can be made small while obtaining the same damping property. It is more suitable.

[0025]

EXAMPLES Examples and comparative examples will be described below.
Incidentally, "parts" means "parts by weight".

For the unvulcanized viscosity ratio, the Mooney viscosity (ML _{1 + 4} 100 ° C.) of the obtained rubber composition was measured, and the compounding No. 1 was 10
Expressed as 0 as an index.

As a cold resistance test, each at -20 ° C and + 40 ° C
100% module, M ₁₀₀ (−20 ° C.) and M ₁₀₀ (40 ° C.) were measured according to the JIS tensile test and expressed as the ratio.

Examples and Comparative Examples (I) 100 parts of rubber components shown in Tables 1 to 2, silica parts, carbon black parts, aromatic oil parts, petroleum resin parts, zinc flower 5 parts, stearic acid 2 parts , Wax 2 parts, antioxidant 8 parts, sulfur 1 part and accelerator (CBS)
Two parts were kneaded with a Banbury mixer to obtain a rubber composition. The properties of the obtained rubber composition are shown in Tables 1 and 2. Formulation Nos. 5 to 10 are examples, and the others are comparative examples.

The damping properties of the rubber composition are as follows: 135 layers of rubber of 135φ × 1 mm and 133φ × made of the obtained rubber composition.
Equivalent damping factor (heq) of seismic isolation structure in which 29 layers of 1 mm steel plates are alternately laminated is included in "Life and reliability report of laminated rubber for seismic isolation structure" (Seismic Isolation Structure Laminated Rubber Special Committee) It was measured and evaluated by the described method. The composition No. 1 was set as 100 and expressed as an index.

[0030]

[Table 1]

[0031]

[Table 2]

Formulation No. 1 has good temperature dependence,
Indicates that there is no damping. Formulation No. 2 has good damping properties, but has large temperature dependence and poor cold resistance. Compound No. 3
The compound No. 4 has a large amount of silica and has a high unvulcanized viscosity.

On the other hand, Formulation Nos. 5 to 10 are good overall, and Formulation Nos. 6 to 10 show that BR and SBR can be blended with synthetic IR.

Examples and Comparative Examples (II) 100 parts of rubber components shown in Table 3, parts of silica, parts of carbon black, 5 parts of aromatic oil, 5 parts of zinc white, 2 parts of stearic acid, 2 parts of wax, Anti-aging agent 8
Parts, 1 part of sulfur and 2 parts of accelerator (CBS) were kneaded with a Banbury mixer to obtain a rubber composition. The obtained rubber composition was used as a rubber filling a cylindrical space provided at the center of a laminated structure composed of a soft layer and a hard layer. On the other hand, as the rubber composition for the soft layer, the rubber composition having the composition No. 11 was used. Formulation Nos. 14 to 18 are examples, and the others are comparative examples. The heq ratio is φ135 × 1 mm, hollow 60 mm thick donut-shaped rubber 30 layers of the above soft layer, and φ135 × 1 mm, hollow 60 mm donut-shaped steel sheet 29 layers are laminated in the cylindrical hollow part of Table 2 The equivalent damping constant of the base-isolated structure filled with the rubber composition was measured and evaluated. The composition No. 11 was set as 100 and expressed as an index.

[0035]

[Table 3]

The compound Nos. 11 and 12 have low damping properties, and the compound Nos.
Although No. 13 was aimed at high damping, it was impossible to measure the heq because the unvulcanized viscosity was high and it was difficult to make a seismic isolation structure. On the other hand, in compound Nos. 14 to 18, heq and unvulcanized viscosity ratio were good overall, and in compound Nos. 15 to 18, blending IR, NR, and SBR with BR reduced the unvulcanized viscosity ratio. It shows that the workability is improved. Formulation No. 17 indicates that part of the silica may be replaced with carbon black.

Example and Comparative Example (III) A rubber composition and a seismic isolation structure were obtained in the same manner as in Example (II) except that the soft layer rubber and the cylindrical hollow part filling rubber shown in Table 4 were used. . Formulation No. 19 is a comparative example, and formulation No. 20 is an example. Heq ratio is φ124 × 1mm, hollow φ27.4mm, 30 layers of soft rubber in a donut shape, φ124 × 1mm, hollow φ2
The equivalent damping constant of the seismic isolation structure in which the cylindrical hollow part of the laminated body in which 29 layers of 7.4 mm donut-shaped steel plates were stacked was filled with the cylindrical hollow part filling rubber was measured and evaluated. The composition No. 11 was set as 100 and expressed as an index.

[0038]

[Table 4]

Formulation No. 19 has a low damping property. On the other hand, compound N
o.20 has a high damping property and is good. Formulation No. 20 is the case where a rubber composition having no damping property is used when the rubber composition of claim 1 having a high damping property is used for the doughnut-shaped soft layer (compound No.
It is shown that the outer diameter of the seismic isolation structure can be made smaller in order to obtain the same damping property as compared with (14-18).

[0040]

EFFECT OF THE INVENTION The rubber composition of the present invention has a high damping property, and is excellent in cold resistance, fracture resistance and long-term stability, so that it can be used for absorbing vibration energy such as seismic isolation, vibration isolation, or earthquake prevention. It is very effective. Further, since the seismic isolation structure of the present invention itself has a high damping property, it does not require a damper or the like to damp vibration, which is advantageous in terms of construction period and cost.

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-5-5048 (JP, A) JP-A-64-48952 (JP, A) JP-A-7-41603 (JP, A) JP-A-6- 32945 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08L 9/00-9/10

Claims (4)

(57) [Claims] 1. A (a) a rubber component 100 parts by weight of a main component synthetic polyisoprene rubber, and as (b) a filler Table
40 to 100 parts by weight of untreated silica is added to all or the filler.
A high damping rubber composition containing as a main component . 2. A seismic isolation structure in which a plurality of hard layers and soft layers are alternately laminated, wherein the soft layer is 100 parts by weight of a rubber component containing synthetic polyisoprene rubber as a main component, and a surface-untreated filler is used. 40 to 100 parts by weight of silica as a filler
A seismic isolation structure obtained by a high-damping rubber composition containing all of or as a main component . 3. A seismic isolation structure in which a plurality of hard layers and soft layers are alternately laminated, a cylindrical space is provided in the center of the laminated structure, and a rubber containing polybutadiene rubber as a main component is provided in this space. 100 parts by weight of ingredients and as filler
40 to 100 parts by weight of surface-untreated silica is added to the filler.
Is a seismic isolation structure characterized by being filled with a high damping rubber composition which is contained as a main component . 4. The soft layer comprises 100 parts by weight of a rubber component containing synthetic polyisoprene rubber as a main component, and a surface-free filler.
Treated silica with 40-100 parts by weight of the filler as a whole or main component
Seismic isolation structure according to claim 3 is obtained from the high damping rubber composition containing as a minute.