JP5350773B2 - Manufacturing method of seismic isolation structure plug - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a plug for a base isolation structure having sufficient damping performance, deformation followability and the like, at a uniform density, without generating a cavity, and the base isolation structure using the plug for the base isolation structure manufactured by the method. <P>SOLUTION: This method of manufacturing the plug for the base isolation structure comprising a plug composition containing at least an elastomer composition with a reinforcing filler and a thermoplastic resin blended in an elastomer component, and powder, includes a process for feeding the plug composition into a molding die, and a process for molding, in the die, the plug composition at a temperature of -30&deg;C or higher that is softening point of the thermoplastic resin. The present invention discloses the plug for the base isolation structure manufactured by the method, and the base isolation structure using the plug for the base isolation structure. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to a method for producing a plug for base-isolated structure.

  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. In such a base-isolated structure, for example, a plug formed by forming a hollow portion at the center of a laminate composed of a soft plate and a hard plate, and forming a uniform composition inside the hollow portion There is something that has been press-fitted.

  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, instead of a lead plug, a solid material and a viscous material made of a liquid material such as mineral oil or vegetable oil are sealed in the hollow portion of the laminate, and the gap between the solid materials is made viscous. A seismic isolation device has been proposed that is filled with the body.

  However, in this seismic isolation device using a liquid material such as mineral oil or vegetable oil as a viscous material, a solid material precipitates in the liquid material when used for a long time, and dispersibility deteriorates. As a result, there is a possibility that the attenuation performance changes locally and stable attenuation performance cannot be exhibited.

In contrast, JP 2006-316990 A fills the hollow portion of the laminate with a plastic fluidizing material and a hard filler made of metal, hard resin, hard fiber or the like so that the composition is uniform. It has been disclosed that a material having a shear yield stress in a specific range is preferable as the plastic fluidizing material.
Japanese Patent Publication No. 7-84815 JP 2006-316990 A

  However, in the conventional alternative techniques as described above, there is room for improvement in terms of performance because it is impossible to obtain a plug for a base isolation structure having sufficient damping characteristics, displacement followability, etc. as a plug.

  On the other hand, the present inventors, as a plug for a seismic isolation structure having sufficient damping characteristics and displacement followability, an elastomer composition obtained by blending an elastomer component with a reinforcing filler and a thermoplastic resin, and a powder The plug which pressure-molded the composition for plugs containing a body was newly created. However, when such a plug is manufactured by pressure molding, the friction between the mold and the material, the fluidity of the powder, as in the case of manufacturing a molded body by pressure molding only the powder. There is room for improvement in the manufacturing method in that it is difficult to obtain a plug having a uniform density due to the low density in the lower part and the outer peripheral part of the molded body due to gaps caused by the shortage and the like.

An object of the present invention is to advantageously solve the above-mentioned problems, and a method for manufacturing a plug for a seismic isolation structure according to the present invention is obtained by blending a reinforcing filler and a thermoplastic resin with an elastomer component. A method for manufacturing a plug for a base-isolated structure comprising a composition for a plug containing at least an elastomer composition and a powder, the step of introducing the plug composition into a mold for molding, in, see contains a step of molding the plug composition in the thermoplastic temperature of the softening point -30 ° C. or more resins, the powder is metal powder, that the metal oxide powder or silicon carbide powder Features. Thus, by molding an elastomer composition obtained by blending a reinforcing filler and a thermoplastic resin into an elastomer component, and a plug composition containing powder, sufficient damping performance, displacement followability, etc. can be obtained. It is possible to manufacture a plug for a base isolation structure that can provide the base isolation structure. Moreover, the plug composition is formed by molding the plug composition at a temperature equal to or higher than a softening point of the thermoplastic resin of −30 ° C. (a temperature equal to or higher than 30 ° C. below the softening point), preferably a temperature equal to or higher than the softening point. Since molding can be performed in a state where the fluidity of the object is increased, a plug for a base-isolated structure having a low porosity and a uniform density can be obtained. Furthermore, when molding is performed by press molding, the pressure (molding pressure) required for molding can be reduced.

  Here, the softening point of the thermoplastic resin is a value measured by a ring and ball method (JIS K5601-2-2).

Method for producing a plug for a seismic isolation structure of the present invention, it is particularly preferred that the powder is iron powder. Iron powder is inexpensive and has high breaking strength, and by using iron powder, the plug can exhibit excellent damping performance over a long period of time.

  In the method for manufacturing a plug for a seismic isolation structure according to the present invention, the temperature is preferably -30 ° C or higher and 150 ° C or lower with respect to the softening point. If the temperature of the plug composition at the time of molding is too high, cooling takes time and the elastomer component deteriorates. In addition, since the adhesiveness between the powders becomes low, the molded plug becomes a brittle plug under high temperature conditions. On the other hand, if the temperature is too low, the porosity of the molded product will be high.

  In the method for manufacturing a plug for a seismic isolation structure according to the present invention, the molding is performed at a temperature of the softening point of −30 ° C. or higher by heating the mold after the plug composition is put into the mold. May be. By heating the plug composition in the mold, the plug composition can be sufficiently heated to be molded.

  Moreover, the manufacturing method of the plug for seismic isolation structure of this invention is made to perform the said shaping | molding at the temperature more than the said softening point -30 degreeC by throwing the said composition for plugs heated beforehand into the said type | mold. Also good. By heating the plug composition in advance, rapid molding becomes possible, and heating and cooling of the mold are not necessary.

In another preferred embodiment of the method for producing a plug for a seismic isolation structure of the present invention, at least a part of the elastomer component is uncrosslinked, and preferably, the elastomer composition comprises an unvulcanized rubber composition. 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.

ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing the plug for seismic isolation structures which has sufficient damping performance, displacement followability, etc. with uniform density, reducing a space | gap can be provided .

<Composition for plug>
Below, the composition for plugs used for manufacture of the plug material which comprises the plug for seismic isolation structures is demonstrated in detail. This plug composition is characterized by containing an elastomer composition obtained by blending a reinforcing filler and a thermoplastic resin with an elastomer component, and powder.

  As the elastomer component used in the plug composition, 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 a rubber such as 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 large deformation, but the position of the powder cannot be changed during deformation, and it becomes 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.

  The reinforcing filler used in the plug composition is a substance that reinforces the elastomer component and has a strong cohesive strength and bonding strength with the elastomer component, and is blended in the elastomer component. The bonding force increases the viscosity of the entire elastomer composition, and as a result, has an effect of 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 in the elastomer component, the flow resistance of the elastomer composition increases, and a plug having sufficient damping performance, displacement followability, and the like can be obtained.

  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 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, kneading is difficult, it becomes difficult to obtain a uniform composition, and the repeated stability of the plug is lowered.

  The thermoplastic resin used for the plug composition has an effect of improving the damping performance of the plug even in the case of large deformation. The resin also acts as a processing aid and can facilitate kneading of the plug composition.

  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 addition, the compounding 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.

  In addition to the elastomer component, the reinforcing filler, and the resin, additives generally added to the elastomer composition such as an anti-aging agent, a wax, a plasticizer, and a softening agent 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, a flame retardant and the like together 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 powder used for the plug composition is a material mainly responsible for the damping performance of the plug. Specifically, the vibration is damped by friction between the powders and friction between the powder and the elastomer component. Here, the powder refers to a material other than the reinforcing filler, and includes, for example, metal powder, silicon carbide powder and the like.

  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. Among these, reduced iron powder is preferable.

  In the plug composition, the content of the powder is preferably in the range of 50 to 74% by volume. When 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 powders and other components. Since it becomes small, 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.

  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. Here, the particle diameter of the powder is determined by particle diameter measurement by laser diffraction (JIS Z8825-1), and in the method by laser diffraction, the average of the major axis and the minor axis of the powder particles (taken as a spherical shape). ) Is a value obtained by measuring.

  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 described above is not particularly limited except that an elastomer composition obtained by blending a reinforcing filler and a thermoplastic resin with an elastomer component and powder are used. For example, the plug composition is manufactured as follows. Can do.

  First, in the first step, an elastomer composition is prepared by adding a reinforcing filler, a thermoplastic resin, and various compounding agents appropriately selected as necessary to the elastomer component and kneading them.

  Next, in the second step, powder is added to the elastomer composition and further kneaded. In the second step, it is preferable to mix the powder into a plurality of times, and by mixing the powder into a plurality of times, a uniform plug composition can be produced.

  In the first and second steps for producing the plug composition, a normal kneader such as a kneader or a Banbury mixer can be used. Further, the conditions for kneading are not particularly limited, and the conditions that are usually used in the technical field can be appropriately modified to set conditions for sufficiently kneading the composition of the present invention. . For example, the kneading conditions in the second step are preferably in the range of 20 to 40 rpm and a temperature of about 100 ° C. In order to suppress a decrease in the viscosity of the elastomer component, it is preferable that the rotational speed is low. 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. It 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>
By the method for manufacturing a plug for a base isolation structure of the present invention, the plug for a base isolation structure can be manufactured from the above-described plug composition, for example, as follows.

The plug composition prepared as described above is taken out of the kneading apparatus, transferred to a molding apparatus, and pressed by applying, for example, temperature and pressure. Specifically, the plug composition is pressed at a temperature of a softening point of a thermoplastic resin contained in the plug composition of −30 ° C. or higher (150 ° C. or lower). As described above, in the present invention, two or more kinds of thermoplastic resins can be used in combination. In that case, the press working is performed at a temperature of the softening point of the resin having the lowest softening point of −30 ° C. or higher. It takes a thing. Then, the molded plug is taken out from the apparatus and used as a seismic isolation structure plug. In addition, as a press machine used at this process, what is normally used in the said technical field is employable. Also, the press working conditions are not particularly limited except for the temperature, 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 a press working condition, the molding pressure is preferably 0.7 t / cm ² or more.

  Here, in order to perform the press working at a softening point of the thermoplastic resin of −30 ° C. or higher, the plug composition is transferred to the molding apparatus and then heated in the molding apparatus (mold) to perform the pressing process. Alternatively, the plug composition may be heated in advance to a temperature equal to or higher than the softening point of −30 ° C., and the heated plug composition may be put into a molding apparatus and pressed.

<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 laminated alternately, and having a hollow portion extending in the stacking direction, and a hollow portion of the laminate. The plug is a plug for the above-mentioned seismic isolation structure, and has high damping performance, displacement followability, and the like. Hereinafter, the seismic isolation structure of the present invention will be described in detail with reference to FIG.

  The seismic isolation structure 1 according to the present invention is a substantially donut plate-like structure in which a rigid plate 2 having rigidity and an elastic plate 3 having elasticity are alternately stacked, and extends in the stacking direction (vertical direction). The laminated body 4 which has a hollow part in the center part, the plug 5 provided in the hollow part of this laminated body 4, and the flange board 6 fixed to the both ends (upper end and lower end) of the laminated body 4 and the plug 5 are provided. The outer peripheral surface of the laminate 4 is covered with a laminate covering material 7.

  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. The laminated body 4 constituting the seismic isolation structure 1 of the present invention may not be covered with the laminated body covering material 7, but the outer peripheral surface of the laminated body 4 is covered with the laminated body covering material 7. In this case, rain and light do not reach the laminate 4 from the outside, and deterioration of the laminate 4 due to oxygen, ozone, and ultraviolet rays can be prevented. In addition, as the laminated body covering material 7, the same material as the elastic plate 3, for example, vulcanized rubber can be used.

  And when the laminated body 4 receives the shearing force of the horizontal direction by vibration, it will carry out shear deformation and will absorb the energy of vibration. 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).

  When the seismic isolation structure 1 in which the plug 5 is press-fitted into the hollow portion of the laminated body 4 is subjected to a horizontal shearing force due to vibration, the plug 5 and the laminated body 4 are shear-deformed to cause vibration. Energy can be absorbed effectively and vibration can be damped quickly.

  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.

<Evaluation of porosity>
(Examples 1-4)
Using a kneader, an elastomer composition having a formulation shown in Table 1 was prepared, and then the elastomer composition and iron powder were kneaded at a volume ratio shown in Table 1 to prepare a plug composition. Then, the plug composition was pressed under the conditions shown in Table 1 to produce a columnar seismic isolation structure plug having a diameter of 45 mm and a plug length of 90 mm.

(Comparative Example 1)
Using a kneader, an elastomer composition having the same formulation as in Examples 1 to 4 was prepared, and the elastomer composition was pressed under the conditions shown in Table 1 to form a column-shaped relief having a diameter of 45 mm and a plug length of 90 mm. A plug for a seismic structure was prepared.

(Evaluation)
The porosity was calculated using the following formulas (1) to (4) for the plug for the base isolation structure. The results are shown in Table 1.
Porosity (%) = {1− (specific gravity of plug / calculated specific gravity of composition for plug)} × 100 (1)
Plug specific gravity = Plug weight / Plug volume (2)
Plug volume = {(plug radius) ² × π} × plug height (3)
Calculated specific gravity of the plug composition = (powder volume fraction × powder specific gravity) + (elastomer composition volume fraction × elastomer composition specific gravity) (4)

* 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, “Zeofine” manufactured by Nippon Zeon, “Nisseki Neopolymer 140” manufactured by Nippon Petrochemical Co., Ltd., “Marcaretz M-890A” manufactured by Maruzen Petrochemical, “Zeofine”: “Nisseki Neopolymer 140”: “Marcaretz M” −890A ”= 40: 40: 20 (mass ratio)
* 5 Plasticizer, Dioctyl adipate (DOA)
* 6 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)
* 7 Volume ratio of elastomer component and irregular reduced iron powder with particle size = 40μm

  From Examples 1 to 4 and Comparative Example 1 in Table 1, the softening point of the resin ("Zeofine" manufactured by Nippon Zeon: 100 ° C, "Marcaretz M-890A" manufactured by Maruzen Petrochemical Co., Ltd .: 100 ° C, "Nippon Petrochemical's" Japan It can be seen that the plug for a base-isolated structure that has been pressed at a temperature of −30 ° C. or higher has a low porosity and an overall uniform density. From this, it can be seen that a good seismic isolation structure plug can be obtained by molding the plug at a temperature equal to or higher than the softening point of the resin of −30 ° C.

<Evaluation of damping performance>
(Examples 5 to 13)
Using a kneader, an elastomer composition having a formulation shown in Table 2 was prepared, and then the elastomer composition and powder were kneaded at a volume ratio shown in Table 2 to prepare a plug composition. Next, the plug composition was pressed at a temperature of 100 ° C. and a pressure of 1.3 ton / cm ² to prepare a cylindrical seismic isolation structure plug having a diameter of 45 mm.

(Comparative Example 2)
Using a kneader, an elastomer composition having a formulation shown in Table 2 was prepared, and the elastomer composition was pressed in the same manner as in Examples 5 to 13 to produce a plug for a seismic isolation structure.

(Evaluation)
Cylindrical hollow part in the center, outer diameter is 225mm, rigid rigid plate [iron plate] and elastic elastic plate [vulcanized rubber (G '= 0.4MPa)] are laminated alternately The above plug for a seismic isolation structure was press-fitted into the hollow portion of the laminated body to produce 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. With respect to the above-mentioned plug for seismic isolation structure, the damping performance, followability, repeatability and moldability were evaluated by the following methods. The results are shown in Table 2.

(Attenuation 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. 2 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. 2 becomes wider, it means that more vibration energy can be absorbed. Here, for the sake of simplicity, the damping performance of the plug was evaluated based on an intercept load Q _{d at} a strain of 200% (a horizontal load value at a displacement of 0). 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.

(Followability)
When the laminate was subjected to shear deformation, it was evaluated whether or not the plug could follow the deformation. A case where the plug could follow the deformation was evaluated as ◯ (good), and a case where the plug could not be followed was evaluated as x (bad).

(Repetitive stability)
As a preliminary test, shear deformation was performed for each of three cycles of 50%, 100%, 150%, 200%, and 250% strain. Next, when shear deformation was applied in the order of 100% strain (1), 200% strain, and 100% strain (2) for 3 cycles each, Q _d (third cycle of 100% strain (2)) / Q _d A case where (the third cycle of 100% strain (1)) was 0.5 or more was evaluated as ◯ (good), and a case where it was less than 0.5 was evaluated as x (defective).

(Processability)
The workability at the time of producing a plug for a base-isolated structure by pressing the plug composition was evaluated. The case where the workability was good was evaluated as ○, and the case where the workability was poor was evaluated as ×.

* 8 Iron powder 1, particle size = 40μm, irregular reduced iron powder
* 9 Iron powder 2, particle size = 45μm, spheroidal cast iron powder
* 10 Iron powder 3, particle size = 8μm, irregular reduced iron powder
* 11 Iron powder 4, particle size = 8μm, spherical carbonyl iron powder
* 12 Alumina powder, particle size = 50μm
* 13 Silicon carbide powder, particle size = 1μm
* 14 Volume ratio of elastomer component / powder

  From Examples 5 to 13 in Table 2, by using a plug produced from an elastomer composition obtained by blending a reinforcing filler and a thermoplastic resin into an elastomer component, and a plug composition containing iron powder, It can be seen that the damping performance of the seismic isolation structure can be secured sufficiently. Moreover, it can be seen from Comparative Example 2 in Table 2 that the powder greatly contributes to the damping effect.

  From Examples 5 to 7 in Table 2, it can be seen that when the content of the powder in the plug composition is 50 to 74% by volume, a plug having excellent workability and damping performance can be obtained.

  From Examples 8 to 13 in Table 2, it can be seen that the damping performance is improved by using metal powder, particularly iron powder, as the powder.

It is sectional drawing of an 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 Covering material

Claims (6)

A method for producing a plug for a seismic isolation structure comprising an elastomer composition obtained by blending a reinforcing filler and a thermoplastic resin with an elastomer component, and a plug composition containing at least powder.
Charging the plug composition into a mold for molding;
In the mold, the plug composition is molded at a temperature of a softening point of the thermoplastic resin of −30 ° C. or higher;
Only including,
The method for producing a plug for a seismic isolation structure, wherein the powder is metal powder, metal oxide powder, or silicon carbide powder .   The method for manufacturing a plug for a seismic isolation structure according to claim 1, wherein the powder is iron powder.   The method for manufacturing a plug for a seismic isolation structure according to claim 1, wherein the elastomer composition is an unvulcanized rubber composition.   The method for manufacturing a plug for a seismic isolation structure according to claim 1, wherein the temperature is a temperature of -30 ° C or higher and 150 ° C or lower with respect to the softening point.   2. The base-isolated structure according to claim 1, wherein the molding is performed at a temperature of the softening point of −30 ° C. or more by heating the mold after the plug composition is put into the mold. 3. Manufacturing method for a plug.   2. The plug for a seismic isolation structure according to claim 1, wherein the molding is performed at a temperature of the softening point of −30 ° C. or more by introducing the preheated composition for a plug into the mold. 3. Production method.

Images