JP4120602B2 - Seismic isolation rubber laminate - Google Patents

Description

  The present invention relates to a seismic isolation rubber laminate, and in particular, a seismic isolation rubber laminate that supports structures such as civil engineering and construction, and more particularly, a seismic isolation rubber for a bridge that is suitably used for supporting a bridge pier. The present invention relates to a laminate (support).

  Conventionally, a rubber bearing body, which is a seismic isolation rubber laminate used for supporting structures in the fields of civil engineering and construction, is disposed between an upper structure and a lower structure. However, since the weight of these structures is usually extremely large, it has a laminated structure in which rigid plates such as metal plates and rubber layers are alternately laminated, thereby The function as a rubber bearing body such as a vibration isolating support for a building, a base isolation support, a load support for a bridge, and a base isolation support can be effectively performed.

  Specifically, for example, as shown in FIG. 1, the seismic isolation rubber laminate 10 includes a rubber block 12 in which a plurality of metal plates 14 as hard plates are embedded at predetermined intervals. Such a metal plate 14 and a rubber layer 16 that is a portion of the rubber block 12 positioned between the metal plates 14 and 14 have a structure in which they are alternately and integrally laminated, and the rubber block 12 A metal upper mounting plate 18 and a lower mounting plate 20 are fixed to the upper and lower portions, respectively. The seismic isolation rubber laminate 10 is sandwiched and disposed between an upper structure such as a bridge and a lower structure such as a pier on the upper mounting plate 18 and the lower mounting plate 20 and fixed. Therefore, it is designed to support a large weight superstructure such as a concrete pier, so that the original function as a seismic isolation rubber laminate can be achieved. That is, bending and displacement caused by the influence of weight, acceleration, etc. caused by earthquakes, strong winds or vehicles passing over the bridge are absorbed by the buffering action in the shearing direction of the rubber laminate, and vertical vibration is also absorbed by the buffering of the rubber laminate. It can be absorbed by the action.

  By the way, it is desirable that the seismic isolation rubber laminate having the structure as described above should originally have a high damping characteristic, and a wide temperature range from a low temperature to a high temperature from the installation location. In particular, bridge supports used for supporting piers of bridges should be placed in a harsh natural environment from temperatures below freezing to temperatures exceeding 30 ° C. Therefore, it is desirable that the temperature dependence of the elastic modulus is small.

  However, in the conventional seismic isolation rubber laminate, as a rubber composition for providing the rubber layer (rubber block), an appropriate vulcanizing agent is simply blended with a rubber material such as natural rubber (NR). In addition to the fact that ordinary rubber compositions are used, in addition to the fact that the damping characteristics are not sufficient yet, adding a conventionally known component that is supposed to improve such damping characteristics, the elastic modulus of Due to the relatively large temperature dependence, there was an inherent problem that the properties of the seismic isolation rubber laminate, particularly the elastic properties, depend on the ambient temperature.

  Here, the present invention has been made in the background of such circumstances, and the problem to be solved is that it has high damping characteristics for use in seismic isolation bearings and has low temperature dependence of elastic characteristics. The object is to provide a seismic rubber laminate.

And in the present invention, in order to solve such a problem, a seismic isolation rubber laminate formed by alternately laminating rigid hard plates and rubber layers, the rubber layer comprises: , with respect to 100 parts by weight of the rubber material, natural asphalt having a softening point of above 110 ° C., will be formulated in a proportion of 1 to 50 parts by weight, and with respect to 100 parts by weight of the rubber material, 10 to The gist of the present invention is a base-isolated rubber laminate formed by using a rubber composition further containing 150 parts by weight of SAF carbon black.

Thus, in the seismic isolation rubber laminate according to the present invention, the rubber composition that gives the rubber layer positioned between the hard plates such as the metal plates is blended with a predetermined ratio of specific asphalts. This is a seismic isolation rubber that can exhibit high damping characteristics by blending a specific amount of such components and has good temperature dependence, that is, low temperature dependence of elastic characteristics such as elastic modulus. Laminates can be realized advantageously.

  In addition, according to the present invention, the rubber composition further includes SAF carbon black in a ratio of 10 to 150 parts by weight with respect to 100 parts by weight of the rubber material. Thus, the influence on the temperature dependency due to the inclusion of the component can be buffered or avoided.

  According to one of the desirable embodiments of the seismic isolation rubber laminate according to the present invention, the rubber material contains natural rubber and / or diene synthetic rubber as a main component.

Further, in the seismic isolation rubber laminate according to the present invention, before Symbol asphalts is Ru der those having a softening point of above 110 ° C.. By adopting such asphalts , it is possible to achieve both a further improvement in damping characteristics and an extremely small temperature dependence. In the present invention, as asphalt, natural asphalt having such characteristic properties, and thus be needed use.

  Furthermore, according to one of the preferable aspects in the seismic isolation rubber laminate according to the present invention, the plasticizer having a freezing point of −30 ° C. or less is based on 100 parts by weight of the rubber material with respect to the rubber composition. In the proportion of 1 to 50 parts by weight, it can be further blended. That is, by adding such a specific plasticizer at a predetermined ratio to a rubber composition containing components such as asphalts as described above, effective damping characteristics exhibited by blending asphalts and the like can be obtained. While maintaining a high level, the temperature dependence can be made as small as possible.

  In such a base-isolated rubber laminate according to the present invention, the damping characteristic is remarkably improved without deteriorating the temperature dependence, and therefore it can be advantageously used as a high-attenuating bearing for seismic isolation bearings. Bending and displacement caused by the influence of weight, acceleration, etc. caused by earthquakes, strong winds, vehicles passing over the bridge, etc. can be effectively absorbed by the buffering action in the shearing direction of the rubber laminate. It has the feature that it can be advantageously absorbed by the buffering action of the laminate.

  By the way, the seismic isolation rubber laminate according to the present invention typically has a structure as shown in FIG. 1 and is a hard plate having rigidity in the rubber block 12 with a predetermined interval. A rubber layer 16 is formed between the metal plates 14 and 14 by the plurality of arranged metal plates 14, and thus a laminated structure in which the metal plates 14 and the rubber layers 16 are alternately laminated. Here, the rubber block 12 (specifically, the rubber layer 16) constituting the same is formed using a specific rubber composition according to the present invention.

That is, such a rubber composition is obtained by blending a specific asphalt at a predetermined ratio with respect to 100 parts by weight of the rubber material. In particular, such asphalt is temperature-dependent. It is blended as a component for improving the damping characteristics while preventing or suppressing the decrease of the above.

Of the such damping property enhancing component of nuclear, the asphalts, each species of natural asphalt is being targeted in the present invention, as the damping property enhancing component, among others of such asphalts, in particular, it is the softening point are the use of Ru natural asphalt der 110 ° C. or higher, by this, the higher damping characteristics, and a remarkably better temperature dependence, be achieved by both It can be done.

  The blending amount of this type of damping characteristic improving component is appropriately determined according to the target damping characteristic. In order to achieve sufficient damping characteristics improvement by the blending, rubber is used. It is necessary to add at least 1 part by weight, preferably 5 parts by weight or more, with respect to 100 parts by weight of the material. However, if the amount is too large, the elastic properties of the rubber block (12) to be formed Therefore, the blending ratio is 50 parts by weight or less, preferably 30 parts by weight or less with respect to 100 parts by weight of the rubber material.

  In addition, in the present invention, it is necessary to add a predetermined carbon black in addition to such a specific damping characteristic improving component, thereby preventing or avoiding deterioration of temperature dependency. I can do it. In particular, such carbon black is compounded in a ratio of 10 to 150 parts by weight with respect to 100 parts by weight of the rubber material. Further, as such carbon black, those having a small primary particle diameter, generally about 30 nm or less are desirable, and among these, SAF carbon having a smaller particle diameter is particularly advantageously used. Such a carbon black having a small particle size also contributes advantageously to the improvement of the attenuation characteristics.

  Furthermore, in the present invention, a plasticizer having a freezing point of −30 ° C. or lower is added to the rubber composition in combination with the above-described damping characteristic improving component, thereby providing the damping characteristic improving component. It is also possible to reduce the temperature dependence as much as possible by effectively buffering the influence of such components on the temperature dependence while maintaining an effective function. Examples of such plasticizers include phthalate plasticizers such as dibutyl phthalate (DBP) and dioctyl phthalate (DOP); dioctyl adipate (DOA), diisodecyl adipate (DIDA), dibutyl glycol adipate, dibutyl carbitol adipate Adipate plasticizers such as dioctyl sebacate (DOS), dibutyl sebacate (DBS), etc .; tricresyl phosphate (TCP), cresyl phenyl phosphate (CDP), tributyl phosphate (TBP) ), Tri-octyl phosphate (TOP), tributoxyethyl phosphate (TBXP) and other plastic plasticizers, di-2-ethylhexyl azelate (DOZ), di-2-ethylhexyl decandio It can be mentioned chromatography bets (dODN), etc., thereof one or so that the two or more may be used in combination.

  Moreover, in the plasticizer having such specific properties, it is blended in a proportion of 1 to 50 parts by weight, more preferably in a proportion of 2 to 25 parts by weight with respect to 100 parts by weight of the rubber material. It is something to be damned. However, if the blending amount is too small, the effect of improving the temperature dependence cannot be sufficiently expressed. On the other hand, if the blending amount is too large, the compatibility deteriorates, and the seismic isolation according to the present invention. This is because in the rubber laminate 10, the plasticizer oozes out from the outer surface of the rubber block 12 (rubber layer 16), so-called bleed is caused.

  In addition, the rubber material which is one of the components constituting the rubber composition for providing the rubber layer 16 constituting the seismic isolation rubber laminate 10 according to the present invention together with the damping characteristic improving component as described above is conventionally seismic isolation rubber laminate. The rubber material is appropriately selected from various rubber materials used for the production of the body, but is advantageously composed mainly of at least one of natural rubber and diene synthetic rubber. As the diene synthetic rubber, synthetic polyisoprene rubber, styrene / butadiene rubber, polybutadiene rubber, butyl rubber, halogenated butyl rubber, acrylonitrile-butadiene rubber, and the like are used.

  Thus, a rubber composition in which a specific damping property improving component is blended in a predetermined ratio to a predetermined rubber material, and carbon black or a plasticizer is blended in a predetermined ratio. As in the prior art, a vulcanizing agent such as sulfur is added, and if necessary, a suitable vulcanization accelerator, a vulcanization accelerating aid such as stearic acid or zinc white, a softening agent such as oil, and a wax. Various known rubber compounding agents such as anti-aging agents are compounded within a normal range and used to form the rubber block 12 that gives the target rubber layer 16.

  Further, when producing the seismic isolation rubber laminate according to the present invention using such a rubber composition, various conventionally known methods are appropriately employed. For example, the seismic isolation rubber as shown in FIG. In order to obtain the laminated body 10, a rubber block 12 is formed by injecting a predetermined rubber composition in the presence of the upper and lower mounting plates 18 and 20 together with the metal plate 14 or using a vulcanization mold. By using vulcanization molding, the rubber plate 16 is interposed between the metal plates 14 and 14 and the vulcanization is integrally performed, or the metal plate 14 is used by using a suitable adhesive. For example, a method of forming a laminated body by alternately laminating and adhering the rubber layers 16 formed from the rubber composition and bonding them together is adopted.

  In the seismic isolation rubber laminate according to the present invention, as the metal plate 14 used as the rigid hard plate, an iron plate or a steel plate excellent in compression resistance can be suitably used. Even if it is a thing, even if it is a hard plastic board material etc., if it is excellent in compression resistance, it can be used similarly.

  Further, as the overall shape of the seismic isolation rubber laminate 10, an appropriate shape according to the installation form is adopted. For example, in a planar form, in addition to a rectangular shape and a disk shape, an elliptical shape, a pentagonal shape, a hexagonal shape It is also possible to use a polygonal shape such as the above, and even if the number of the metal plates 14 and the rubber layers 16 is laminated, it is appropriately determined according to the use of the seismic isolation rubber laminate.

  Examples of the present invention will be shown below to clarify the present invention more specifically. However, the present invention is not limited by the description of such examples. Needless to say. In addition to the following examples, the present invention includes various changes, modifications, and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention, in addition to the above specific description. It should be understood that improvements and the like can be added.

First, rubber compositions having various compounding compositions shown in Tables 1 to 3 below were prepared. Next, from each rubber composition, a vulcanization condition of 150 ° C. × 30 minutes was adopted, and a characteristic evaluation test according to JIS-K-6394-1976 “Method for testing dynamic properties of vulcanized rubber”. after producing a vulcanized rubber test piece (S ₁ form), by performing characterization tests for the purpose, and the results are shown together in table 1 to table 3.

In preparing the rubber composition, natural rubber (NR), butadiene rubber (BR), or synthetic isoprene rubber (IR) is used as the rubber material, and naphthenic process oil or aroma is used as the softening agent. an oil, as the or asphalt, straight asphalt 80-100, or softening point of 120 ° C. natural asphalt, had use. DOP in the table indicates dioctyl phthalate (freezing point: −50 ° C.) as a plasticizer, while MSA and TBT indicate N-oxydiethylene-2-benzothiazole sulfate as a vulcanization accelerator, respectively. Phenamide and tetrabutylthiuram disulfide are shown. Furthermore, in this example, in addition to such a vulcanization accelerator, zinc white (ZnO) and stearic acid were used as vulcanization accelerators. The primary particle size of SAF carbon as carbon black was 19 nm, and the primary particle size of HAF carbon was 30 nm.

Moreover, the characteristic evaluation test with respect to each vulcanized rubber test piece is performed in accordance with a non-resonant method specified in JIS-K-6394-1976, test temperatures: −10 ° C., 20 ° C. and 40 ° C., test frequency: 0. Under the conditions of 5 Hz, average strain (shear): 0%, strain amplitude (shear): 175%, load-deflection curves were obtained, respectively, from which absolute spring constants at each measurement temperature: | K ^* | (- 10 ° C.), | K ^* | (40 ° C.) and sine of the loss angle at 20 ° C .: sin δ was determined, and the attenuation constant and G (temperature dependence) were determined from the following equations.
Attenuation constant = (sin δ) / 2
G (temperature dependence) = | K ^* | (−10 ° C.) / | K ^* | (40 ° C.)

As is clear from the results in Tables 1 to 3, it is recognized that all of the rubber compositions according to Test Examples 1 to 9 are effective in improving the damping characteristics without being affected by the temperature dependence. Among them, in particular, in the rubber compositions of Test Examples 5 to 9 , since a specific natural asphalt and a plasticizer are blended, a dramatic improvement in damping characteristics, It will be appreciated that a very good temperature dependence can be achieved together. Further, from the comparison between Test Example 2 and Comparative Example 3, a favorable result was obtained when SAF carbon having a small primary particle size (19 nm) was blended rather than (30 nm) HAF carbon having a large primary particle size. It is also accepted. On the other hand, in the rubber compositions of Comparative Examples 1 and 2, since no pitch, tar or asphalt is blended, it is recognized that the damping constant is poor and the damping characteristics are not sufficient.

It is a partially cutaway explanatory view showing a typical example of a seismic isolation rubber laminate to which the present invention is applied.

Explanation of symbols

10 Seismic isolation rubber laminate 12 Rubber block 14 Metal plate 16 Rubber layer 18 Upper mounting plate 20 Lower mounting plate

Claims (4)

A seismic isolation rubber laminate comprising a rigid hard plate and a rubber layer alternately laminated, wherein the rubber layer has a softening point of 110 ° C. or more with respect to 100 parts by weight of the rubber material . natural asphalt, it was formulated in proportions of 1 to 50 parts by weight, and with respect to 100 parts by weight of the rubber material, the rubber composition further comprises an SAF carbon black proportion of 10 to 150 parts by weight A seismic isolation rubber laminate characterized in that it is formed by using. The seismic isolation rubber laminate according to claim 1, wherein the rubber material contains natural rubber and / or a diene synthetic rubber as a main component. Wherein the rubber composition, the plasticizer solidifying point of -30 ° C. or less, in the above ratio of 1 to 50 parts by weight per 100 parts by weight of rubber material, further claim 1 or claim being made to blend Item 3. The seismic isolation rubber laminate according to item 2 . The seismic isolation rubber laminate according to any one of claims 1 to 3, which is used for supporting a bridge on a pier.

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