JPH11201231A - Seismic isolation structure and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base isolation structure and a production method therefor that can make a thin rubber layer, which ensures high vertical stiffness, low horizontal stiffness, and good creep-proof characteristics. SOLUTION: 0.1-10 vol.% of short fiber and 1-50 wt.pts. of carbon black with respect to 100 wt.pts. of rubber are blended in a rubber layer 2 of the base isolation structure 1 comprising a laminated body 4 composed of rubber layers 2 and metal plates 3. Accordingly, swelling of a rubber composition after passed nipping at a sheeting process can be suppressed, and a thickness of the rubber layer 2 can be made thin. Therefore, the vertical stiffness of the base isolation structure 1 can be raised, and its creep-proof characteristic is also raised. A short fiber of 0.1 mm-5 mm in length, and of 0.3-50 deniers in thickness is desirable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation structure in which the period of vibration transmitted to a building during an earthquake is made longer than the period of the earthquake, and a method of manufacturing the same. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation structure having a stacked body and a method of manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, seismic isolation structures have been used to prevent damage to buildings, bridges, and other structures during an earthquake. This seismic isolation structure includes a laminate in which thin rubber layers and hard layers are alternately laminated and bonded. By adopting the laminated structure, the circumferential movement of rubber against vertical compressive load is restrained, the bulging of rubber in the circumferential direction is suppressed, the compressive deformation of the seismic isolation structure is reduced, and On the other hand, high rigidity can be obtained. On the other hand, since the adhesion between the rubber layer and the hard layer is not a constraint for a load in the horizontal direction, the rigidity of the seismic isolation structure in the horizontal direction can be reduced. Therefore, this seismic isolation structure can support a structure with a large load and exhibit the function of extending the period of vibration transmitted to the structure due to deformation of the laminate during an earthquake (so-called seismic isolation function). Is done.

[0003] However, the seismic isolation function of the conventional seismic isolation structure cannot be said to be sufficient. In particular, the seismic isolation structure having a further enhanced seismic isolation function has recently been developed along with the increasing tendency to prevent damage from the great earthquake. What is being desired is the reality. The seismic isolation function can be enhanced by using a low-hardness rubber layer to reduce the horizontal rigidity of the seismic isolation structure.However, using a low-hardness rubber layer reduces the vertical rigidity of the seismic isolation structure. This causes a disadvantage that the building becomes unable to support a heavy-load building. In addition, since the seismic isolation structure continues to support the structure for a period equivalent to the durability of the structure (for example, several decades), the creep distortion of the rubber layer increases when a rubber layer having a low hardness is used, There is also the disadvantage that the construct cannot be supported uniformly.

[0004]

If the thickness of the rubber layer is further reduced, the ratio of the thickness of the rubber layer to the horizontal cross-sectional area is reduced, and the number of the rubber layers and the hard layers to be laminated is increased, the low hardness of the rubber layer is reduced. Even if the rubber layer is used, the vertical rigidity of the seismic isolation structure can be maintained, and the creep resistance can be maintained. In order to form such a thin rubber layer, for example, when a calender roll is used, it is necessary to narrow the nip between the rolls, and when an extruder is used, it is necessary to narrow the die nip. However, if the nip between the rolls and the die nip are too narrow, the sheet may be perforated or a sheet having a uniform thickness may not be stably obtained. Even if the nip between the rolls or the base nip is narrowed to the limit where a sheet having a uniform thickness can be obtained stably, the rubber expands in the thickness direction after passing through the nip, so that a sufficiently thin rubber layer cannot be obtained. .

[0005] The present invention has been made in view of these problems, the thickness of the rubber layer can be reduced, and therefore sufficiently high vertical rigidity, sufficiently low horizontal rigidity, and sufficiently good creep resistance It is an object of the present invention to provide a seismic isolation structure that can exhibit characteristics and a method of manufacturing the same.

[0006]

Means for Solving the Problems The invention made to achieve the above-mentioned object is a seismic isolation structure provided with a laminate in which a rubber layer and a hard layer are laminated, and the rubber layer has 0.
1% by volume or more and 10% by volume or less of short fiber and rubber content of 100
A seismic isolation structure characterized in that 1 to 50 parts by weight of carbon black is blended with respect to parts by weight (claim 1).

Another object of the present invention is to provide a method of manufacturing a seismic isolation structure having a laminated body in which a rubber layer and a hard layer are laminated, wherein the method comprises the steps of: % By weight of a rubber composition in which a short fiber of 10% by volume or more and carbon black of 1 part by weight to less than 50 parts by weight with respect to 100 parts by weight of rubber are sheeted. And vulcanizing and adhering to form a laminate (claim 5).

According to these inventions, since short fibers are compounded in the rubber layer, the expansion after passing through the nip during sheeting can be greatly reduced. For this reason, a thin rubber layer can be obtained even if sheeting is performed by using a roll nip or a die nip equivalent to the conventional one. Also,
Since it is not necessary to forcibly reduce the nip interval, a hole is not generated in the sheet, and a sheet having a uniform thickness cannot be stably obtained.

Further, in these inventions, the rubber component 1
Improves rubber properties such as creep resistance, heat aging resistance, tensile strength, compressive strength, and tear strength of the rubber layer because 1 to 50 parts by weight of carbon black is blended with respect to 00 parts by weight. Can be done.

In the seismic isolation structure using the thin rubber layer thus obtained, higher vertical rigidity and better creep resistance can be obtained while maintaining low horizontal rigidity. Further, by making the rubber layer thin, a rubber having low hardness can be used for the rubber layer, and lower horizontal rigidity can be obtained while maintaining high vertical rigidity and good creep resistance.

In the present invention, it is preferable to use short fibers having a length of 0.1 mm or more and 5 mm or less in order not to reduce the durability of the seismic isolation structure while reducing the thickness of the rubber layer. Item 2).

In these inventions, in order to improve the durability of the seismic isolation structure, it is preferable to use short fibers having a thickness of 0.3 denier to 50 denier (claim 3).

In these inventions, in order to obtain sufficiently high vertical rigidity, sufficiently low horizontal rigidity, and sufficiently good creep resistance, it is preferable that the thickness of the rubber layer is 1.7 mm or less. Item 4).

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view of a base isolation structure 1 according to an embodiment of the present invention. This seismic isolation structure 1
Includes a laminate 4 in which a plurality of rubber layers 2 and metal plates 3 as hard layers are alternately laminated. The rubber layer 2 and the metal plate 3 are bonded by vulcanization. The planar shape of the rubber layer 2 and the metal plate 3 is circular. The center of the laminate 4 is hollow, and the center is filled with a columnar lead 7 for damping vibration. The laminate 4 has a skin rubber 5 on its outer periphery. The rubber layer 2 and the skin rubber 5 are integrated by rubber flow when the laminate 4 is vulcanized. Although various metal materials can be applied to the metal plate 3, steel is generally used. Metal flanges 6a and 6b made of steel or the like are provided above and below the laminate 4. The metal flange portions 6a and 6b and the rubber layer 2 that abuts on the metal flange portions 6a and 6b are vulcanized and bonded. The lower metal flange 6a is connected to the foundation ground by a suitable connecting means (not shown), and the upper metal flange 6b is connected to a building, a bridge or the like by a suitable connecting means (not shown). Is done.

For the rubber layer 2, a rubber composition using a natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, chloroprene rubber, acrylonitrile butadiene rubber, ethylene propylene rubber, EPDM, a mixture thereof or the like as a base rubber is used. Can be The rubber composition includes a vulcanizing agent, a vulcanization accelerator, a vulcanization retarder, a vulcanization acceleration aid,
Various chemicals such as an antioxidant, a reinforcing agent, a softener, and a filler are appropriately compounded.

The thickness of the rubber layer 2 is 1.7 mm or less, and is thin. Thereby, the ratio of the thickness to the horizontal cross-sectional area of the rubber layer 2 is reduced. Therefore, the circumferential movement of the rubber with respect to the vertical compressive load is restrained, the bulging of the rubber in the circumferential direction is suppressed, the compressive deformation of the seismic isolation structure is reduced, and the ratio of the vertical rigidity to the horizontal rigidity is increased. Have been. Therefore,
When the hardness of the rubber layer 2 is made equal to that of the conventional rubber layer, the vertical rigidity can be further increased while maintaining the low horizontal rigidity. Further, even when the rubber layer 2 has a lower hardness than the conventional one and the horizontal rigidity is further suppressed, a high vertical rigidity can be maintained. Furthermore, by making the rubber layer 2 thin,
The creep resistance of the rubber layer 2 can be improved.
In this respect, the thickness of the rubber layer 2 is more preferably equal to or less than 1.3 mm, and particularly preferably equal to or less than 1.0 mm. In addition, although the lower limit of the thickness of the rubber layer 2 is not particularly limited in the present invention because the thickness of the rubber layer 2 is preferably smaller, the thickness of the rubber layer 2 is generally considered in consideration of workability. 0.3 mm or more is preferred.

The rubber layer 2 is formed by sheeting the rubber composition with a calender roll, an extruder or the like to form a rubber sheet, cutting this rubber sheet into appropriate dimensions, and further laminating it with a metal plate 3 to be vulcanized. It is formed by doing. Since short fibers are compounded in the rubber layer 2, expansion after passing through the nip during sheeting can be greatly reduced. For this reason, a thin rubber layer 2 can be obtained even if sheeting is performed using a nip between rolls or a base nip that is equivalent to a conventional one. In addition, since it is not necessary to forcibly reduce the nip interval, a hole is not formed in the rubber sheet, and it is not possible to stably obtain a rubber sheet having a uniform thickness.

The compounding amount of the short fibers in the rubber layer 2 is 0.1.
It is set to 1% by volume or more and 10% by volume or less. If the compounding amount is less than 0.1% by volume, the coefficient of expansion of the thickness after the rubber composition has passed through the nip becomes large, and it becomes impossible to obtain a sufficiently thin rubber layer 2. Conversely, if the compounding amount exceeds 10% by volume, the hardness of the rubber layer 2 increases,
The horizontal rigidity of the seismic isolation structure 1 is increased.

The short fibers used in the present invention are fibers having a length of 0.05 mm or more and 200 mm or less. The length of the short fiber is preferably 0.1 mm or more and 5 mm or less, particularly preferably 1 mm or more and 5 mm or less. If the length of the short fibers is less than the above range, the expansion rate of the thickness of the rubber composition after passing through the nip becomes large, and it may not be possible to obtain a sufficiently thin rubber layer 2. Conversely, if the length of the short fibers exceeds the above range, the short fibers are entangled with each other and exist as foreign matter in the rubber layer 2, and when the rubber layer 2 is deformed by an earthquake, a crack is generated from the foreign matter. As a result, the durability of the seismic isolation structure 1 may be reduced.

The thickness of the short fiber is 0.3 denier or more and 50
Denier or less is preferable, and 0.6 to 50 denier is particularly preferable. If the thickness of the short fibers is less than the above range, the short fibers are entangled with each other and exist as foreign matter in the rubber layer 2. The durability of the seismic structure 1 may be reduced. Conversely, if the thickness of the short fiber exceeds the above range, the short fiber itself becomes a foreign substance in the rubber layer 2, and when the rubber layer 2 is deformed by an earthquake, a crack is generated from the short fiber and the seismic isolation structure is formed. The durability of the body 1 may be reduced.

The short fibers used may be synthetic fibers, inorganic fibers or metal fibers. Examples of the material of the synthetic fiber used include nylon, polyester, polypropylene, rayon, polyvinyl chloride, polyethylene, and acrylonitrile. Examples of the inorganic fiber used include glass fiber and carbon fiber. As the material of the metal fiber used,
For example, copper, aluminum, steel and the like can be mentioned.

The rubber layer 2 contains 1 to 50 parts by weight of carbon black per 100 parts by weight of rubber. If the compounding amount of the carbon black is less than 1 part by weight, rubber properties such as creep resistance, heat aging resistance, tensile strength, compressive strength, and tear strength of the rubber layer 2 are reduced. On the other hand, if the compounding amount of carbon black is 50 parts by weight or more, the seismic isolation function of the seismic isolation structure becomes insufficient. From this viewpoint, a particularly preferable blending amount of carbon black is 1 part by weight or more and less than 20 parts by weight based on 100 parts by weight of the rubber component.

The present invention is not limited to a seismic isolation structure 1 filled with a lead 7 as shown in FIG. 1, but also a type in which unvulcanized rubber is filled instead of the lead 7 as vibration damping means. Also applicable to As shown in FIG. 2, a seismic isolation structure 11 of a type in which a rubber plate 12 and a metal plate 13 are simply laminated to form a laminate 14 and the rubber plate 12 has a high damping characteristic. Can also be used.

In the present invention, various specifications can be changed, for example, a short fiber is blended into only a part of the rubber layer constituting the laminate.

[0026]

Hereinafter, the present invention will be described in detail with reference to Examples.
Of course, the present invention is not construed as being limited based on these examples.

[Experiment 1] Experiments in which the blending amount of short fibers was varied [Example 1] 100 parts by weight of natural rubber (SMR CV-60) was put into a 1.5 liter BR type Banbury and masticated. In addition, 0.1 part by weight of nylon 6 short fibers having a thickness of 6 denier and a length of 1 mm, 1.5 parts by weight of sulfur, and N-cyclohexyl-2-benzo as a vulcanization accelerator were added. 1. Thiazole sulfenamide (trade name “Noxeller CZ” manufactured by Ouchi Shinko Chemical Co., Ltd.)
0 parts by weight, zinc oxide 5 parts by weight, stearic acid 1 part by weight, FEF carbon black 19 parts by weight, naphthene-based process oil 30 parts by weight, and N as an antioxidant
1 part by weight of -phenyl-N-isopropyl-p-phenylenediamine, 1 part by weight of a polymer of 2,2,4-trimethyl-1,2 dihydroquinoline as another antioxidant, and 2 parts by weight of paraffin wax. , And 5 parts by weight of a black sub, kneaded for 5 minutes, and discharged. The discharged rubber composition was kneaded with an open roll and sheeted with the nip between the rolls closed. The thickness of the rubber sheet thus obtained is shown in Table 1 below.

By laminating the rubber sheet and the metal plate,
As shown in FIG. 1, a seismic isolation structure of Example 1 having a lead body in the center was prepared. The laminated body of this seismic isolation structure has a diameter of 600 mm, the height of the laminated body is 300 mm, and the diameter of the lead body is 100 mm.

Example 2, Example 3, Comparative Example 1, and Comparative Example 2 The procedure of Example 1 was repeated, except that the blending amount of the short fibers was varied as shown in Table 1 below. 2, seismic isolation structures of Example 3 and Comparative Example 2 were obtained. Comparative Example 1 was performed in the same manner as in Example 1 except that no short fibers were blended.
The seismic isolation structure was obtained.

[Evaluation of Seismic Isolation Structures] The seismic isolation structures of Examples 1 to 3 and Comparative Examples 1 and 2 were subjected to the following evaluations.

[Shear breaking strain] 50 kgf for each seismic isolation structure
While applying a vertical load of / cm ² , the upper metal flange portion 6b was fixed, and the lower metal flange portion 6a was displaced in the horizontal direction until the seismic isolation structure was broken. A value (percentage) obtained by dividing the displacement at the time of rupture by the height of the laminate was obtained and defined as a shear fracture strain. These results are shown in Table 1 below.

[Shear modulus] 50 kgf for each seismic isolation structure
/ Cm ² while applying a vertical load, fixing the upper metal flange 6b and displacing the lower metal flange 6a in the horizontal direction until the displacement becomes 50% of the height of the laminate. Was. The shear strain and stress of the rubber layer were calculated from the displacement-load curve at this time, and defined as the shear modulus. These results
This is shown in Table 1 below.

[Vertical rigidity] 50 kgf /
The rate of change in the thickness of the rubber layer when a vertical load of cm ² was applied was measured, and the vertical rigidity was calculated. These results
This is shown in Table 1 below.

[Creep rate] 85% Celsius
2 by applying a vertical load of 70kgf / cm ² under every environment
Left for 0 days. The amount of elastic deformation in the vertical direction before and after standing was measured, and the ratio of the amount of deformation after standing to the initial deformation was defined as the creep rate. These results are shown in Table 1 below.

[0035]

[Table 1]

In Table 1, the seismic isolation structures of Examples 1 to 3 in which the short fiber content is 0.1% by volume or more and 10% by volume or less are the seismic isolation structures of Comparative Example 1 in which no short fiber is incorporated. The rubber sheet is thinner than the body. this is,
This is because the expansion of the rubber composition after passing through the nip between the rolls was suppressed by the short fiber blending. And as a result of having made the rubber sheet thickness thin, the vertical rigidity is high and the creep rate is low.

On the other hand, in the seismic isolation structure of Comparative Example 2 in which short fibers were blended in 20% by volume, although the thickness of the rubber sheet could be reduced, the shear fracture strain was extremely low, and the shear modulus increased. I have. This is because too much short fibers were blended.

From these results, in order to obtain a base-isolated structure having sufficiently high vertical rigidity, sufficiently low horizontal rigidity (shear modulus), and sufficiently good creep resistance, it is necessary to use short fibers. It is understood that the blending amount needs to be 0.1% by volume or more and 10% by volume or less.

[Experiment 2 Experiments in which the thickness of the short fibers was changed] [Examples 4 to 6] The short fibers used were nylon 0.6 short fibers having a thickness of 0.6 denier and a length of 1 mm. The seismic isolation structure of Example 4 was obtained in the same manner as Example 2 except for the above.

The seismic isolation structure of the fifth embodiment is the same as that of the second embodiment except that the short fiber used is a short fiber made of nylon-6 having a thickness of 50 denier and a length of 1 mm. Obtained.

Further, the seismic isolation structure of Example 6 was replaced with the seismic isolation structure of Example 6 except that the short fibers used were short fibers made of nylon-6 having a thickness of 100 denier and a length of 1 mm. Obtained.

With respect to these seismic isolation structures, the above-mentioned rubber sheet thickness, shear fracture strain, shear modulus, vertical rigidity and creep rate were measured. These results are shown in Table 2 below together with the results of the seismic isolation structure of Example 2.

[0043]

[Table 2]

In Table 2, the thicker the short fiber, the more difficult it is to make the rubber sheet thinner, the lower the shear fracture strain, the lower the vertical rigidity, and the higher the creep rate. This indicates that the thickness of the short fiber is preferably 50 denier or less.

[Experiment 3 Experiments with different lengths of short fibers] [Examples 7 to 9] The short fibers used were nylon 6 short fibers having a thickness of 6 denier and a length of 0.05 mm. The seismic isolation structure of Example 7 was obtained in the same manner as Example 2 except for the above.

Further, the seismic isolation structure of Example 8 was replaced with the seismic isolation structure of Example 8 except that the short fibers used were nylon 6 short fibers having a thickness of 6 denier and a length of 5 mm. Obtained.

Further, the seismic isolation structure of the ninth embodiment was replaced with the seismic isolation structure of the ninth embodiment in the same manner as in the second embodiment except that the short fibers used were nylon 6 short fibers having a thickness of 6 denier and a length of 10 mm. Obtained.

With respect to these seismic isolation structures, the above-mentioned rubber sheet thickness, shear fracture strain, shear modulus, vertical rigidity and creep rate were measured. These results are shown in Table 3 below together with the results of the seismic isolation structure of Example 2.

[0049]

[Table 3]

In Table 3, in the seismic isolation structure of Example 7 in which the short fiber length is as short as 0.05 mm, the sheet thickness cannot be reduced, and therefore the vertical rigidity is not sufficiently high, and the creep rate is low. Is not small enough. This is because the effect of blending short fibers is not sufficiently exhibited.

On the other hand, in the seismic isolation structure of Example 9 in which the short fiber length is as long as 10 mm, the shear fracture strain is not sufficiently high. This is because the short fibers are entangled and exist as foreign matter in the rubber layer.

From this, it is understood that the length of the short fiber to be blended is preferably 0.1 mm or more and 5 mm or less, and particularly preferably 1 mm or more and 5 mm or less.

[Experiment 4 Experiments in which the amount of carbon black was varied] [Examples 10 and 11] Example 2 was repeated except that the amount of carbon black was varied as shown in Table 4 below.
In the same manner as in the above, seismic isolation structures of Examples 10 and 11 were obtained.

With respect to these seismic isolation structures, the above-described rubber sheet thickness, shear fracture strain, shear modulus, vertical rigidity, and creep rate were measured. These results are shown in Table 4 below together with the results of the seismic isolation structure of Example 2.

[0055]

[Table 4]

Table 4 shows that the seismic isolation structure of any of the examples has sufficient characteristics as a seismic isolation structure in terms of shear fracture strain, shear modulus, vertical rigidity, and creep rate.

From the above experimental results, the superiority of the present invention was proved.

[0058]

As described above, according to the present invention,
The thickness of the rubber layer can be reduced, so that the vertical rigidity,
A seismic isolation structure excellent in balance between horizontal rigidity, strength and creep resistance and a method for manufacturing the same can be provided.

According to the method of manufacturing a seismic isolation structure of the present invention, expansion of the rubber composition after passing through the nip can be suppressed, and therefore, a rubber layer having a designed thickness can be easily produced. Can be. In addition, since it is not necessary to make the nip interval extremely narrow, it is possible to suppress the occurrence of perforations in the rubber sheet and the unevenness of the thickness of the rubber sheet.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a seismic isolation structure according to one embodiment of the present invention.

FIG. 2 is a sectional view showing a seismic isolation structure according to another embodiment of the present invention.

[Explanation of symbols]

 1, 11 ... seismic isolation structure 2, 12 ... rubber layer 3, 13 ... metal plate 4, 14 ... laminated body 5 ... skin rubber 6a, 6b ... metal flange 7 ... Lead body

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 21/00 C08L 21/00 E04H 9/02 331 E04H 9/02 331A F16F 15/04 F16F 15/04 A

Claims (5)

[Claims] 1. A seismic isolation structure comprising a laminate in which a rubber layer and a hard layer are laminated, wherein the rubber layer has 0.1% by volume or more and 10% by volume or less of short fibers and a rubber component. A seismic isolation structure comprising 100 parts by weight and 1 to 50 parts by weight of carbon black. 2. The seismic isolation structure according to claim 1, wherein the short fibers have a length of 0.1 mm or more and 5 mm or less. 3. The seismic isolation structure according to claim 1, wherein the thickness of the short fibers is not less than 0.3 denier and not more than 50 denier. 4. The seismic isolation structure according to claim 1, wherein a rubber layer having a thickness of 1.7 mm or less is used for the laminate. 5. A method for producing a seismic isolation structure having a laminated body in which a rubber layer and a hard layer are laminated, comprising: 0.1% by volume to 10% by volume of short fibers;
A rubber composition in which 1 part by weight or more and less than 50 parts by weight of carbon black are blended with respect to 00 parts by weight, and the obtained rubber sheet and a hard layer are laminated and vulcanized and bonded to form a laminate. A method for manufacturing a seismic isolation structure, comprising: