JP2009286997A - Elastomer composition for plug of base-isolation structure, composition for plug of base-isolation structure, plug for base-isolation structure and the base-isolation structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastomer composition used for preparing a plug of base-isolation structures having sufficient dumping performance, displacement following capability and the like and excellent in dumping performance in high strain areas. <P>SOLUTION: The elastomer composition for the plug of base-isolated structures comprises an elastomer component and a resin having a 80-170°C softening point. The elastomer composition preferably comprises at least 2 of resins each having a different softening point, and the amount of the resin to be blended preferably is 20-100 pts.mass based on 100 pts.mass of the elastomer component. In addition, the elastomer composition preferably contains a reinforcing filler, wherein the amount of the reinforcing filler to be blended preferably is 60-150 pts.mass based on 100 pts.mass of the elastomer component. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an elastomer composition for a plug of a base isolation structure, a composition for a plug of a base isolation structure including the elastomer composition, a plug for a base isolation structure using the plug composition, and the plug. In particular, the present invention relates to an elastomer composition used for the production of a plug for a seismic isolation structure having sufficient damping performance, displacement followability, etc., and excellent damping performance in a high strain region. is there.

  2. Description of the Related Art Conventionally, seismic isolation structures in which soft plates having viscoelastic properties such as rubber and hard plates such as steel plates are alternately stacked have been used as bearings for seismic isolation devices. Among such seismic isolation structures, for example, there is a structure in which a hollow portion is formed at the center of a laminated body made of a soft plate and a hard plate, and a plug is press-fitted into the hollow portion.

  As the plug, a plug made entirely of lead is often used, and when the laminated body undergoes shear deformation, the plug is plastically deformed to absorb vibration energy. However, lead has a large environmental load and a high cost for disposal. For this reason, an attempt has been made to develop a plug having sufficient damping performance, displacement followability, etc., using a lead substitute material. For example, in Japanese Patent Publication No. 7-84815, there is a seismic isolation device in which a viscous material and a solid material are sealed in a hollow portion of a laminate instead of a lead plug, and a gap between the solid materials is filled with the viscous material. Proposed.

  However, Japanese Patent Publication No. 7-84815 exemplifies liquid substances such as mineral oils and vegetable oils as viscous bodies. However, when used for a long period of time, solid substances precipitate in the liquid substances and the dispersibility deteriorates. End up. As a result, there is a problem that the attenuation performance is locally changed and stable attenuation performance cannot be exhibited.

  In response to this problem, Japanese Patent Application Laid-Open No. 2006-316990 discloses a seismic isolation device in which a hollow portion of a laminate is filled with a plastic fluid material and a hard filler. In addition, this publication exemplifies that a plastic fluid material is preferably a material having a shear yield stress in a specific range, and further, examples of a hard filler include metal, hard resin, and hard fiber.

Japanese Patent Publication No. 7-84815 JP 2006-316990 A

  However, with the above-described lead plug alternative technology, it has not been possible to obtain a plug for a seismic isolation structure having sufficient damping characteristics, displacement followability, etc. as a plug. On the other hand, as a result of intensive studies, the present inventors have used a composition containing an elastomer composition and a powder for a plug of the seismic isolation structure, thereby reducing the damping performance and displacement of the seismic isolation structure. It has been found that followability is improved. However, as a result of further investigations by the present inventors, it has been found that there is room for improvement in the damping performance in the high strain region even with a base-isolated structure using such a plug.

  Accordingly, an object of the present invention is to provide an elastomer composition that is used for the production of a plug for a base-isolated structure that has sufficient damping performance, displacement followability, and the like, and that is excellent in damping performance in a high strain region. is there. Another object of the present invention is to provide a plug composition for a base isolation structure including the elastomer composition and powder, a plug for a base isolation structure using the plug composition, and the plug. It is to provide a seismic isolation structure.

  As a result of intensive studies to achieve the above object, the present inventors have exempted a composition for a plug of a seismic isolation structure including an elastomer composition containing a resin having a softening point in a specific range and a powder. The use of the plug for a seismic structure finds that a seismic isolation structure having sufficient damping performance, displacement followability, etc. and excellent damping performance in a high strain region can be obtained, and the present invention is completed. It came to.

  That is, the elastomer composition for plugs of a seismic isolation structure according to the present invention is characterized by including an elastomer component and a resin having a softening point of 80 to 170 ° C.

The elastomer composition for plugs of the present invention preferably contains two or more resins having different softening points. When two or more resins are blended, the softening point of each resin is different, so that it is possible to cover a wide temperature range. As a result, the temperature of the intercept load Q _d and the equivalent damping constant Heq, which are generally used as indicators of damping performance The dependency can be reduced.

  In a preferred example of the elastomer composition for plug of the present invention, the amount of the resin is 20 to 100 parts by mass with respect to 100 parts by mass of the elastomer component. In this case, the processability of the elastomer composition is good, and the effect of improving the damping performance of the plug is sufficiently improved.

  The elastomer composition for plugs of the present invention preferably further contains a reinforcing filler. In this case, the viscosity of the elastomer composition increases and energy loss increases. As a result of the increased energy loss, the plug attenuation performance, particularly in the low distortion region, is improved.

  In the elastomer composition for plugs of the present invention, the reinforcing filler is preferably carbon black and silica. Since carbon black and silica have a large effect of improving the viscosity of the elastomer composition by interaction with the elastomer component, the flow resistance of the plug is increased, and as a result, the plug damping effect is increased.

  In the plug elastomer of the present invention, the amount of the reinforcing filler is preferably in the range of 60 to 150 parts by mass with respect to 100 parts by mass of the elastomer component. In this case, the viscosity of the elastomer composition is sufficiently high, the plug can exhibit a sufficient damping effect, and kneading is easy, and a uniform composition can be easily obtained.

  The elastomer composition for plugs of the present invention preferably has a Mooney viscosity [ML (1 + 4) 127 ° C.] at 127 ° C. of 20 to 170. Here, the Mooney viscosity [ML (1 + 4) 127 ° C.] of the elastomer composition is measured according to JIS K6300-1.

  In another preferred embodiment of the elastomer composition for plugs of the present invention, the elastomer component is natural rubber and / or synthetic rubber. In this case, the damping performance of the plug is improved and the durability is also improved.

  In another preferred embodiment of the elastomer composition for plugs of the present invention, at least a part of the elastomer component is uncrosslinked. In this case, after the plug receives a history of large deformation, when the position of the plug returns to the origin again, the plug can return to its original shape. Can be maintained.

  Further, a plug composition for a base isolation structure according to the present invention comprises the above elastomer composition and a powder, preferably a metal powder and / or a metal compound powder, and the base isolation system according to the present invention. The structure plug is manufactured from the plug composition, and the seismic isolation structure according to the present invention is formed by alternately laminating a rigid plate having rigidity and an elastic plate having elasticity. And a laminated body having a hollow portion extending in the laminating direction, and a plug press-fitted into the hollow portion of the laminated body, wherein the plug is the plug for the seismic isolation structure.

  ADVANTAGE OF THE INVENTION According to this invention, the composition for plugs of the seismic isolation structure which can produce the plug for seismic isolation structures which has sufficient damping performance, displacement followability, etc., and was excellent in the damping performance in a high distortion region. And an elastomer composition used for the plug composition of the seismic isolation structure. Moreover, the plug for seismic isolation structures using the said composition for plugs of the said base isolation structure and the seismic isolation structure using this plug can be provided.

<Elastomer composition for plug>
Below, the elastomer composition for plugs of this invention is demonstrated in detail. An elastomer composition for plugs of a seismic isolation structure according to the present invention comprises an elastomer component and a resin having a softening point of 80 to 170 ° C., and a plug composition comprising the elastomer composition and a powder. By using it as a plug for a seismic isolation structure, it is possible to obtain a seismic isolation structure having sufficient damping performance, displacement followability, etc., and excellent damping performance in a high strain region. When the elastomer composition contains a resin, a decrease in viscosity at the time of large deformation can be suppressed and the viscosity can be kept large, so that energy loss is increased. As a result, the damping performance of the plug (in particular, the section load Q) _d ) can be improved. The resin also acts as a processing aid, and can facilitate kneading of the plug composition. If the softening point of the resin blended in the elastomer composition is less than 80 ° C., the temperature repeatedly rises and the temperature rises, and the elastomer composition softens rapidly, making it difficult to maintain the plug damping performance. On the other hand, since the kneading temperature of the elastomer composition is about 170 ° C., if the softening point of the resin blended in the elastomer composition exceeds 170 ° C., the resin does not disperse well in the elastomer component during kneading. As a result, it will not be possible to fully demonstrate the performance. From these viewpoints, the softening point of the resin used is preferably in the range of 80 to 150 ° C.

  As said resin, what has the effect | action as a tackifier is preferable, More specifically, a phenol resin, a rosin resin, a dicyclopentadiene (DCPD) resin, a dicyclopentadiene-isoprene copolymer, C5 type | system | group Petroleum resins, C9 petroleum resins, alicyclic petroleum resins, petroleum resins obtained by copolymerizing C5 and C9 fractions, xylene resins, terpene resins, ketone resins, modified resins of these resins, etc. Can be mentioned. These resins may be used alone or in combination of two or more.

In the elastomer composition of the present invention, it is more preferable to use two or more resins having different softening points. When the elastomer composition contains two or more kinds of resins having different softening points, the softening points of the resins are different, so that a wide temperature range can be covered. As a result, the temperature of the intercept load Q _d and the equivalent damping constant Heq Dependency is reduced.

  The amount of the resin in the elastomer composition is preferably in the range of 20 to 100 parts by mass with respect to 100 parts by mass of the elastomer component. When the amount of the resin is less than 20 parts by mass, the effect of improving the damping performance of the plug is small. On the other hand, when the amount exceeds 100 parts by mass, the processability of the elastomer composition decreases.

The elastomer composition of the present invention preferably further contains a reinforcing filler. In the present invention, the reinforcing filler is a substance that reinforces the elastomer component and has a strong cohesive strength between itself and the elastomer component. The bonding force has the effect of improving the viscosity of the entire elastomer composition and, as a result, improving the damping performance of the plug. Generally, a plug of a seismic isolation structure absorbs energy generated by an earthquake (for example, converts it into heat, etc.) to exhibit a damping effect. Therefore, the damping effect increases as the flow resistance of the plug increases. Become. On the other hand, when a reinforcing filler is blended with the elastomer component, the flow resistance of the elastomer composition increases, and the displacement followability when deformed deteriorates, resulting in increased energy loss. It is possible to improve the damping performance of the plug such as the intercept load Q _d and the equivalent damping constant Heq in the curve, particularly the damping performance in the low strain region.

  As the reinforcing filler, carbon black and silica are preferable, and carbon black is particularly preferable in that the effect of improving the viscosity of the elastomer composition by interaction with the elastomer component is great. Here, examples of the carbon black include SAF, ISAF, and HAF grades. Among these, fine particles such as SAF and ISAF grades having a large surface area are preferable. Examples of silica include wet silica, dry silica, and colloidal silica. These reinforcing fillers may be used alone or in combination of two or more.

  The blending amount of the reinforcing filler in the elastomer composition of the present invention is preferably in the range of 60 to 150 parts by mass with respect to 100 parts by mass of the elastomer component. When the compounding amount of the reinforcing filler is less than 60 parts by mass, the viscosity and flow resistance of the elastomer composition are low, and the damping performance of the plug tends to be insufficient. On the other hand, when the compounding amount of the reinforcing filler exceeds 150 parts by mass, the processability is poor, so that kneading is difficult and it is difficult to obtain a uniform composition.

  The elastomer composition of the present invention preferably has a Mooney viscosity [ML (1 + 4) 127 ° C.] at 127 ° C. of 20 to 170. When the Mooney viscosity [ML (1 + 4) 127 ° C.] of the elastomer composition for plugs is less than 20, the damping performance (particularly equivalent damping) of the plug produced using the composition containing the elastomer composition and powder is used. The constant Heq) is insufficient. On the other hand, if the Mooney viscosity [ML (1 + 4) 127 ° C.] of the elastomer composition for plugs exceeds 170, the elastomer composition is too hard and the processability of the elastomer composition is poor, and the plug containing the elastomer composition and powder The processability of the composition for use also deteriorates.

  As the elastomer component used in the elastomer composition of the present invention, those exhibiting rubber elasticity at room temperature, for example, rubbers such as natural rubber and synthetic rubber, and thermoplastic elastomers can be used. Among these, natural rubber and synthetic rubber can be used. It is preferable to use rubber such as rubber. Natural rubber and synthetic rubber-based polymers are viscoelastic and show some elasticity, but have great plasticity, can follow large deformations, and can re-aggregate in the same state again when returning to the origin after vibration. When the elastomer component is rubber (that is, when the elastomer composition is a rubber composition), the damping performance of the plug is improved and the durability is also improved. More specifically, the elastomer component includes natural rubber (NR), polyisoprene rubber (IR), polybutadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), ethylene-propylene rubber, nitrile. Rubber, butyl rubber, halogenated butyl rubber, acrylic rubber, polyurethane, silicone rubber, fluorinated rubber, polysulfide rubber, hyperon, ethylene vinyl acetate rubber, epichlorohydrin rubber, ethylene-methyl acrylate copolymer, styrene elastomer, urethane elastomer, polyolefin Based elastomers and the like. These elastomer components may be used alone or in a blend of two or more.

  The elastomer component is preferably at least partially, preferably all uncrosslinked, and more specifically unvulcanized. When the elastomer component is completely cross-linked, it deforms when subjected to a large deformation, but the position of the filler cannot be changed during the deformation, and it is impossible to follow the deformation at a certain limit point. The elastomer part is broken or tries to return to its original shape by the repulsive force of the crosslinked elastomer part. If the cross-linked elastomer part breaks, the plug will not return to its original shape even if the plug position returns to the origin, so that the damping performance gradually decreases, and the repulsive force of the cross-linked elastomer part works. The original attenuation performance cannot be exhibited. On the other hand, if the elastomer component is uncrosslinked, it is possible to follow deformation, and when the plug returns to the origin again after receiving a history of large deformation, hydrostatic pressure is applied to the entire plug. As a result, the plug can return to its original shape, and as a result, the same performance as the initial stage can be maintained for a long time. When the number of crosslinking points is very small, or when only the plug surface is crosslinked, the original shape can be restored after the plug is deformed. The state which has not passed through includes a partially crosslinked state.

  In addition to the elastomer component, resin, and reinforcing filler, additives generally added to the elastomer composition such as an anti-aging agent, wax, plasticizer, and softener can be added to the elastomer composition. By blending the anti-aging agent with the elastomer composition, it is possible to suppress the change in physical properties of the plug even after a long period of time. For such purposes, it is particularly effective to mix an antioxidant, an ozone degradation inhibitor, a stabilizer and the like with the anti-aging agent.

  Examples of the plasticizer include phthalic acid, isophthalic acid, adipic acid, tetrahydrophthalic acid, sebacic acid, azelaic acid, maleic acid, fumaric acid, trimellitic acid, citric acid, itaconic acid, oleic acid, ricinoleic acid, stearic acid, Derivatives (for example, esters) such as phosphoric acid and sulfonic acid; glycols, glycerin, epoxy derivatives, and polymerization plasticizers. These plasticizers may be used alone or in a blend of two or more.

  As the softener (oil), aroma oil, naphthenic oil, paraffinic oil and other mineral oil softeners; castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, peanut oil, rosin, Examples include vegetable oil-based softeners such as pine oil; and low molecular weight oils such as silicone oil. These softeners may be used alone or in a blend of two or more.

  The above-described elastomer composition for a plug of the present invention can be produced, for example, by adding a resin having a softening point of 80 to 170 ° C. to the elastomer component and various kneading agents appropriately selected as necessary, and kneading them. Here, a normal kneading apparatus such as a kneader or a Banbury mixer can be used for producing the elastomer composition. Also, the kneading conditions are not particularly limited, and the conditions that are normally used in the technical field can be appropriately modified to set conditions that allow the composition of the present invention to be sufficiently kneaded. it can. For example, as kneading conditions, the rotational speed is preferably in the range of 20 to 40 rpm, and the temperature is preferably about 100 ° C. Moreover, in order to suppress the viscosity fall of an elastomer component, the one where a rotation speed is lower is preferable.

<Composition for plug>
The composition for plugs of a seismic isolation structure according to the present invention is characterized by containing the above-described elastomer composition and powder. The powder used for the plug composition of the present invention is a material mainly responsible for the damping performance of the plug. Specifically, the vibration is attenuated by friction between the powders and friction between the powder and the elastomer component. Here, in this invention, a powder refers to things other than a reinforcing filler, for example, a metal powder, a silicon carbide powder, etc. are included. When the plug composition does not contain powder, the damping performance of the plug is greatly reduced, and sufficient damping performance, displacement followability, etc. cannot be obtained.

  The powder is preferably a metal powder, and the metal powder preferably has a low environmental load. For example, iron powder, stainless steel powder, zirconium powder, tungsten powder, bronze (CuSn) powder, aluminum Powder, gold powder, silver powder, tin powder, tungsten carbide powder, tantalum powder, titanium powder, copper powder, nickel powder, niobium powder, iron-nickel alloy powder, zinc powder, molybdenum powder, and the like. One species may be used alone, or two or more species may be used in combination. In addition, since these metal powders may be metal oxide powders, metal compound powders such as metal oxide powders can also be suitably used as the powder. Among these powders, iron powder is particularly preferable. Iron powder is inexpensive and has high fracture strength compared to other metal powders, and the plug for seismic isolation structures based on iron powder is neither too hard nor too brittle. Excellent damping performance can be demonstrated over a long period of time. Examples of the iron powder include reduced iron powder, electrolytic iron powder, sprayed iron powder, pure iron powder, and cast iron powder.

  In the plug composition of the present invention, the content of the powder is preferably in the range of 50 to 74% by volume, more preferably in the range of 60 to 74% by volume (that is, the volume ratio of the elastomer composition / powder is 50). / 50 to 26/74 is preferable, and 40/60 to 26/74 is more preferable. If the content of the powder in the plug composition is less than 50% by volume, the distance between the powders is too wide, the friction between the powders during deformation, and the flow resistance between the powder and other components is small. Therefore, the attenuation performance is insufficient. On the other hand, when the content of the powder in the plug composition exceeds 74% by volume, the contact between the powders increases and the durability repeatedly decreases, and when the plug is molded from the plug composition, It is difficult to sufficiently remove air from the composition for use, and the volume of the plug becomes significantly larger than the ideal volume (the volume in the case where no air is mixed), so that the damping performance of the plug is lowered. If the content of the powder in the plug composition is 60 to 74% by volume, the damping performance can be maintained well, and the followability, repeat stability, and workability are also good.

  The particle size of the powder is preferably in the range of 0.1 μm to 2 mm, and more preferably in the range of 1 μm to 150 μm. When the particle size of the powder is less than 0.1 μm, handling is difficult. On the other hand, when the particle size of the powder exceeds 2 mm, the friction between the powders tends to decrease and the damping effect tends to decrease. When the particle diameter of the powder is 1 μm or more, handling is easy, and when the particle diameter of the powder is 150 μm or less, the plug damping performance is sufficiently high.

  The shape of the powder is preferably indefinite. Here, the indefinite shape means that not only one type of shape such as a spherical shape but also shapes having various forms such as those having irregularities and protrusions are mixed. The shape of the powder obtained by pulverizing the bulk is naturally indeterminate, but when compared to the case of using a spherical powder, the use of the amorphous powder has a better damping effect. Obtained. This is because when an amorphous powder is used, a frictional effect occurs between the powder and between the powder and the elastomer component, and the friction is lower than when a spherical one is used. This is considered to be due to the fact that the attenuation performance is improved.

  The plug composition of the present invention can be produced by adding powder to the elastomer composition and further kneading. In the production of the plug composition, it is preferable to mix the powder into a plurality of times, and it is possible to produce a uniform plug composition by mixing the powder into a plurality of times. It becomes.

  For the production of the plug composition, a conventional kneading apparatus such as a kneader or a Banbury mixer can be used. Also, the kneading conditions are not particularly limited, and the conditions that are normally used in the technical field can be appropriately modified to set conditions that allow the composition of the present invention to be sufficiently kneaded. it can. For example, as kneading conditions, the rotational speed is preferably in the range of 20 to 40 rpm, and the temperature is preferably about 100 ° C. In addition, in order to suppress the viscosity fall of an elastomer component, the one where a rotation speed is lower is preferable. The temperature is preferably a temperature sufficient to soften the elastomer composition in order to improve the dispersion of the powder in the elastomer composition. However, if the temperature is too high, the elastomer component deteriorates or is cooled. Takes too much time to reduce productivity. In addition, before discharging the kneaded composition, it is preferable to release the pressure and knead without pressure. By kneading without pressure, the composition does not solidify and the composition can be taken out. It becomes easy.

<Seismic isolation structure plug>
The seismic isolation structure plug of the present invention is characterized by being manufactured from the above-described plug composition, has sufficient damping performance, displacement followability, etc., and is particularly excellent in damping performance in a high strain region. The plug for a seismic isolation structure of the present invention can be produced, for example, as follows using the plug composition.

The plug composition prepared as described above is taken out from the kneading apparatus, transferred to a molding apparatus, and pressed into a plug by applying temperature and pressure. As a press machine used in this step, a machine that is usually used in the technical field can be adopted. Further, the press working conditions are not particularly limited, and conditions suitable for molding of the plug can be set by appropriately modifying the conditions normally used in the technical field. For example, as the conditions for pressing, the pressing temperature is preferably in the range of room temperature to 150 ° C., and the molding pressure is preferably 0.7 t / cm ² or more.

<Seismic isolation structure>
The seismic isolation structure of the present invention includes a laminate having a rigid plate having rigidity and an elastic plate having elasticity stacked alternately, and having a hollow portion extending in the lamination direction, and press-fitting into the hollow portion of the laminate. The plug is a plug for a seismic isolation structure as described above. Below, the seismic isolation structure of this invention is demonstrated in detail, referring a figure.

  A seismic isolation structure 1 shown in FIG. 1 is formed by alternately laminating rigid plates 2 having rigidity and elastic plates 3 having elasticity, and has a cylindrical hollow portion extending in the laminating direction (vertical direction) as a central portion. The laminate 4, the plug 5 press-fitted into the hollow portion of the laminate 4, and the flange 4 fixed to both ends (upper and lower ends) of the laminate 4 and the plug 5. The outer peripheral surface is covered with a covering material 7.

  Also, the base isolation structure 1 shown in FIG. 2 includes a laminate 4 similar to the base isolation structure shown in FIG. 1, a plug 5 that is mostly press-fitted into the hollow portion of the laminate 4, and the laminate 4. And the flange board 6 fixed to the both ends (upper end and lower end) of the plug 5 is provided, and the outer peripheral surface of the laminated body 4 is covered with the coating | covering material 7 similarly to the seismic isolation structure shown in FIG. In FIG. 2, the plug 5 is longer in the vertical direction than the laminated body 4, and a part thereof extends into the flange plate 6. Further, a closing plate 8 having a diameter larger than that of the plug 5 is arranged at the center of the flange plate 6. For example, the closing plate 8 is fixed to the lower flange plate 6 and the plug is inserted into the hollow portion of the laminate 4. After press-fitting 5, the plug 5 can be sealed by fixing the closing plate 8 to the upper flange plate 6.

  The rigid plate 2 and the elastic plate 3 constituting the laminated body 4 are firmly bonded by, for example, vulcanization adhesion or an adhesive. In the vulcanization adhesion, the rigid plate 2 and the unvulcanized rubber composition are laminated and then vulcanized, and the vulcanized product of the unvulcanized rubber composition becomes the elastic plate 3. Here, as the rigid plate 2, a metal plate such as a steel plate, a ceramic plate, a reinforced plastic plate such as FRP, or the like can be used. On the other hand, as the elastic plate 3, a vulcanized rubber plate or the like can be used. Moreover, the laminated body which comprises the seismic isolation structure of this invention does not need to be covered with the coating | covering material 7, but when the outer peripheral surface of the laminated body 4 is covered with the coating | covering material 7, the laminated body 4 Rain and light do not reach from the outside, and deterioration of the laminate 4 due to oxygen, ozone, and ultraviolet rays can be prevented. As the covering material 7, the same material as the elastic plate 3, for example, vulcanized rubber can be used.

  When the laminated body 4 receives a shearing force in the horizontal direction due to vibration, the laminated body 4 undergoes shear deformation and absorbs vibration energy. Further, since the laminate 4 is formed by alternately laminating the rigid plates 2 and the elastic plates 3, the compression is suppressed even when a load is applied in the lamination direction (vertical direction).

  In the seismic isolation structure 1, the plug 5 is press-fitted into the hollow part of the laminated body 4, and when the horizontal shearing force is received by vibration, the plug 5 is sheared and deformed together with the laminated body 4. The energy can be effectively absorbed, and the vibration can be quickly damped. Here, in the seismic isolation structure of the present invention, a plug manufactured from a composition containing an elastomer composition containing an elastomer component and a resin having a softening point of 80 to 170 ° C. and a powder is used as the plug 5. Therefore, it has sufficient damping performance, displacement followability, etc., and is particularly excellent in damping performance in a high strain region.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

<Preparation of elastomer composition and measurement of Mooney viscosity>
Using a kneader, an elastomer composition having a formulation shown in Table 1 was prepared, and Mooney viscosity [ML (1 + 4) 127 ° C.] was measured in accordance with JIS K6300-1. Tables 2 and 3 show the amounts of carbon black and resin in each example.

<Production of plug for seismic isolation structure>
Next, using a kneader, the volume ratio of 35/65 (Table 2) or 40/60 (Table 3) of the obtained elastomer composition and iron powder (particle size = 40 μm, amorphous reduced iron powder). A plug composition was prepared by kneading with (elastomer composition / iron powder). Next, the plug composition was pressed at a temperature of 100 ° C. and a pressure of 1.3 ton / cm ² to produce a columnar seismic isolation structure plug having a diameter of 45 mm.

<Production of seismic isolation structure>
Cylindrical hollow part in the center, outer diameter is 225 mm, rigid rigid plate [iron plate] and elastic elastic plate [vulcanized rubber (G ′ = 0.4 MPa)] are laminated alternately The above seismic isolation structure plug was press-fitted into the hollow portion of the laminated body, thereby producing the seismic isolation structure having the structure shown in FIG. The volume of the plug was 1.01 times the volume of the hollow part of the laminate. The damping performance of the above seismic isolation structure plug was evaluated by the following method. The results are shown in Tables 2 and 3.

<Evaluation of damping performance>
The seismic isolation structure was subjected to a horizontal deformation with a reference surface pressure applied in the vertical direction using a dynamic testing machine to cause shear deformation with a specified displacement. The vibration displacement was set such that the total thickness of the laminate was 100%, the strain was 50 to 250%, the vibration frequency was 0.33 Hz, and the vertical surface pressure was 10 MPa. FIG. 3 shows the relationship between the horizontal deformation displacement (δ) and the horizontal load (Q) of the seismic isolation structure. As the area ΔW of the region surrounded by the hysteresis curve in FIG. 3 increases, it means that more vibration energy can be absorbed.

In this test, first, an intercept load Q _d (horizontal load value at zero displacement) at strains of 150% and 250% was obtained. The intercept load Q _d is expressed by the following formula using the loads Q _d1 and Q _d2 at the point where the hysteresis curve intersects the vertical axis:
Q _d = (Q _d1 + Q _d2 ) / 2
Calculated from As Q _d increases, the area of the region surrounded by the hysteresis curve increases, indicating that the attenuation performance is excellent. Further, using the section load Q _d and the cross-sectional area S of the plug, the following formula:
τd = Q _d / S
From this, the intercept stress τd (horizontal stress value at zero displacement) was calculated.

Further, from the point A (δ ₁ , Q ₁ ) giving the maximum load value and the point B (−δ ₁ , -Q ₂ ) giving the minimum load value in FIG.
W = (δ ₁ + δ ₁ ) × (Q ₁ + Q ₂ ) / 2
The area W of the triangle ABC in FIG. Next, from the area W and the area ΔW of the region surrounded by the hysteresis curve in FIG.
Heq = ΔW / (W × π)
The equivalent damping constant (Heq) was determined according to A large Heq indicates that the energy absorption rate of vibration is large.

* 1 Natural rubber, unvulcanized, RSS # 4
* 2 Polybutadiene rubber (low cis), unvulcanized, "Diene NF35R" manufactured by Asahi Kasei
* 3 Carbon Seed 6P, ISAF, Tokai Carbon
* 4 Resin A, “Zeofine” manufactured by Nippon Zeon, softening point = 100 ℃
* 5 Resin B, “Marcaretz M-890A” manufactured by Maruzen Petrochemical Co., Ltd., softening point = 100 ° C
* 6 Resin C, “Nisseki Neopolymer 140” manufactured by Nippon Petrochemical, softening point = 145 ℃
* 7 Plasticizer, Dioctyl adipate (DOA)
* 8 Other compounding agents, zinc white, stearic acid, anti-aging agent (“Unstage 6C” manufactured by Sumitomo Chemical), wax [“Proto Wax 1” manufactured by Nippon Oil Corporation], zinc white: stearic acid: anti-aging agent: wax = 4: 5: 3: 1 (mass ratio)

Comparison between Example A-1 and Comparative Example A-2 in Table 2, Comparison between Example A-2 and Comparative Example A-1, and Example B-1 and Comparative Example B-2 in Table 3 As is clear from the comparison between Example B-2 and Comparative Example B-1, by using an elastomer composition containing a resin having a softening point of 80 to 170 ° C., in a high strain region of the plug It can be seen that the damping performance is improved, and Q _d and τ _{d in} the high strain region of the base-isolated structure are improved.

Moreover, the softening point is 80-170 degreeC from the comparison with Example A-1 and Example A-2 in Table 2, and the comparison with Example B-1 and Example B-2 in Table 3. It can be seen that by using an elastomer composition containing a reinforcing filler such as carbon black in addition to the resin, Q _d , τd and Heq of the base isolation structure are improved.

It is sectional drawing of an example of the seismic isolation structure of this invention. It is sectional drawing of the other example of the seismic isolation structure of this invention. It is a graph which shows the relationship between horizontal deformation displacement (delta) and horizontal direction load (Q) in the seismic isolation structure using a plug.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seismic isolation structure 2 Rigid board 3 Elastic board 4 Laminated body 5 Plug 6 Flange board 7 Cover material 8 Closure board

Claims (13)

  An elastomer composition for a plug of a base-isolated structure comprising an elastomer component and a resin having a softening point of 80 to 170 ° C.   The elastomer composition for plugs of a seismic isolation structure according to claim 1, comprising two or more resins having different softening points.   The elastomer composition for a plug of a seismic isolation structure according to claim 1, wherein the amount of the resin is 20 to 100 parts by mass with respect to 100 parts by mass of the elastomer component.   The elastomer composition for a plug of the seismic isolation structure according to claim 1, further comprising a reinforcing filler.   The elastomer composition for a plug of a seismic isolation structure according to claim 4, wherein the reinforcing filler is carbon black and / or silica.   5. The elastomer composition for a plug of a seismic isolation structure according to claim 4, wherein the compounding amount of the reinforcing filler is 60 to 150 parts by mass with respect to 100 parts by mass of the elastomer component.   2. The elastomer composition for a plug of a seismic isolation structure according to claim 1, wherein Mooney viscosity [ML (1 + 4) 127 ° C.] at 127 ° C. is 20 to 170. 3.   The elastomer composition for a plug of a seismic isolation structure according to claim 1, wherein the elastomer component is natural rubber and / or synthetic rubber.   The elastomer composition for a plug of a seismic isolation structure according to claim 1, wherein at least a part of the elastomer component is uncrosslinked.   A composition for a plug of a base-isolated structure comprising the elastomer composition according to any one of claims 1 to 9 and a powder.   The said powder is a metal powder and / or a metal compound powder, The composition for plugs of the seismic isolation structure of Claim 10 characterized by the above-mentioned.   A plug for a base isolation structure manufactured from the plug composition for a base isolation structure according to claim 10 or 11. A seismic isolation comprising a laminate having a hollow portion extending in the laminating direction and a plug press-fitted into the hollow portion of the laminate, wherein a rigid plate having rigidity and an elastic plate having elasticity are alternately laminated. In the structure,
A base isolation structure, wherein the plug is the plug for base isolation structure according to claim 12.

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