JP5714828B2 - Rubber composition for high damping bearing and high damping bearing - Google Patents

Description

  The present invention relates to a rubber composition for high damping bearing and a high damping bearing body that can be suitably used for bridge bearings and the like.

  Rubber bearings and other supports are used for structural support such as bridges and elevated roads, and for basic seismic isolation of buildings. The rubber bearing is a laminated body in which a plurality of hard plates such as steel plates and a rubber composition made of a rubber material having viscoelastic properties are alternately laminated. A rubber bearing is a member installed at the contact point between an upper structure (for example, main girder and main structure) and a lower structure (for example, an abutment or a pier), and the load on the upper structure of a building such as a building or a bridge. And the structure can follow the displacement of the upper structure and the lower structure caused by the vibration caused by an earthquake or the like. Rubber bearings are made by alternately laminating hard plates and rubber compositions and firmly bonding them together to improve the load resistance of the superstructure of the building and to generate horizontal forces caused by vibrations such as earthquakes. Dispersed by the elasticity of rubber.

  For rubber bearings, a rubber composition for seismic isolation having a damping performance in which vibration energy such as earthquake is absorbed by rubber is used. A rubber composition used as a rubber bearing for seismic isolation is required to have a high damping property (a vibration energy is attenuated by converting vibration into more heat).

As a rubber composition used for such a seismic isolation rubber bearing, 100 parts by mass of a diene rubber, a nitrogen adsorption specific surface area (N ₂ SA) of 150 to 300 m ² / g, and a DBP absorption amount of 115 cm ³ / 100g or less, and the rubber composition containing the carbon black 50-90 mass part whose difference of a nitrogen adsorption specific surface area and a CTAB adsorption specific surface area is 5-34 m < ² > / g is proposed. According to this rubber composition, the damping property is high, and stable characteristics can be exhibited over a long period of time (for example, see Patent Document 1).

Further, the main component is natural rubber, the nitrogen adsorption specific surface area (N ₂ SA) is 100 to 140 m ² / g, the CTAB adsorption specific surface area is 100 to 130 m ² / g, the DBP absorption is 90 to 120 ml / 100 g, ΔDBP ( to 24M4DBP oil absorption -DBP oil absorption) of 100 parts by mass of the rubber component of carbon black 10 to 30 cm ^3/100 g, a rubber composition prepared by adding 30 to 80 parts by weight has been proposed. According to this rubber composition, even if it is natural rubber, it exhibits excellent damping properties, and can stably exhibit excellent damping properties without depending on temperature (for example, see Patent Document 2).

JP 2007-246655 A JP 2008-222874 A

  Here, rubber bearings used for vibration isolation, vibration isolation and seismic isolation need to be able to withstand long-term use, and improvement of fatigue resistance is particularly important. Carbon black with a small particle size is used to improve damping, and carbon black with a large particle size and high structure is used to improve fatigue resistance, so damping and fatigue resistance are a trade-off. There is a relationship. For this reason, the conventional rubber compositions described in Patent Documents 1 and 2 have improved damping properties, but there is a problem that further improvement in fatigue resistance is desired.

  In order to be able to withstand long-term use as a rubber bearing, a rubber composition having improved fatigue resistance while maintaining high damping properties is required.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rubber composition for a high damping bearing and a high damping bearing body that have improved fatigue resistance while maintaining high damping.

The present invention includes the following (1) to (5).
(1) a nitrogen adsorption specific surface area (N ₂ SA) is at 150 meters ² / g or more 250 meters ² / g or less, dibutyl phthalate (DBP) oil absorption of not more than 80 cm ^3/100 g or more 115cm ^3/100 g, and, DBP oil absorption amount and the compression DBP absorption difference between (24M4DBP oil absorption) (ΔDBP) is containing carbon black is not more than 10cm ³ / 100g, JIS was measured according to JIS K6253 a hardness (Hs) of 85 or less Shear modulus (Geq) is 0.87 or more, shear rate before and after a shear test in which 70% strain was applied 5000 times under the conditions of a deformation frequency of 0.5 Hz and a measurement temperature of 23 ° C. or less. (GEQ) rate of change is less than 1.04, high damping support for a rubber composition, wherein the rate of change of the equivalent attenuation constant (Heq) is 0.87 or more
(2) containing natural rubber and at least one diene rubber other than the natural rubber;
The content of the carbon black is 50 parts by mass or more and 95 parts by mass or less with respect to 100 parts by mass of the total rubber of the natural rubber and at least one diene rubber other than the natural rubber. The rubber composition for high damping bearings according to (1) above.
(3) The rubber composition for high damping bearings according to (1) or (2), further comprising a petroleum resin.
(4) The rubber composition for a high attenuation bearing according to (3), wherein the content of the petroleum resin is 5 parts by mass or more and 45 parts by mass or less with respect to 100 parts by mass of the rubber.
(5) A high plate formed by alternately laminating soft plates made of the rubber composition for high damping bearings according to any one of (1) to (4) and rigid hard plates. Damping bearing body.

According to the present invention, N ₂ SA of the carbon black is not more than 150 meters ² / g or more 250m ² / g, DBP oil absorption amount is not more than 80 cm ^3/100 g or more 115cm ³ / 100g, compression DBP oil absorption and DBP oil absorption the difference between the amount of (ΔDBP) with 10 cm ^3/100 g or less, it is possible to provide a high while maintaining damping, high damping support for a rubber composition having improved fatigue resistance.

FIG. 1 is a schematic cross-sectional view schematically showing an example of the high-damping support body of the present invention. FIG. 2 is a side view schematically showing a sample for a lap shear type shear test. FIG. 3 is a graph showing an example of a hysteresis curve obtained by a lap shear type shear test.

  The present invention will be described in detail below. The present invention is not limited to the embodiments and examples. In addition, constituent elements in the following embodiments and examples include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[Embodiment]
The rubber composition for high damping bearings of the present invention (hereinafter also referred to as “the composition of the present invention”) has a nitrogen adsorption specific surface area (N ₂ SA) of 150 m ² / g or more and 250 m ² / g or less. dibutyl (DBP) oil absorption of not more than 80 cm ^3/100 g or more 115cm ^3/100 g, and the difference between the DBP absorption and the compressed DBP absorption (24M4DBP oil absorption) (ΔDBP) is at most 10 cm ^3/100 g A rubber composition for high damping bearings containing carbon black. Hereinafter, each component used for the composition of this invention is demonstrated.

<Carbon black>
As described above, the carbon black used in the composition of the present invention has a nitrogen adsorption specific surface area (N ₂ SA) of 150 m ² / g or more and 250 m ² / g or less, and a dibutyl phthalate (DBP) oil absorption of 80 cm. ^3/100 g or more 115cm and a ^3/100 g or less, and the difference between the DBP absorption and the compressed DBP absorption (24M4DBP oil absorption) (ΔDBP) is less carbon black 10 cm ^3/100 g.

(Nitrogen adsorption specific surface area)
The nitrogen adsorption specific surface area (N ₂ SA) refers to the specific surface area by the nitrogen adsorption method, and the nitrogen adsorption specific surface area (N ₂ SA) is a method for measuring the total specific surface area of powder particles such as carbon black. Usually, the larger the value of the nitrogen adsorption specific surface area (N ₂ SA), the smaller the particle size of the carbon black. The nitrogen adsorption specific surface area (N ₂ SA) is measured according to “Nitrogen adsorption method—single point method” described in JIS K6217-2-2001.

In the present invention, the nitrogen adsorption specific surface area (N ₂ SA) is at 150 meters ² / g or more 250 meters ² / g or less, 175 m ² / g or more 225m is preferably from ² / g, 185m ² / g or more 215m ² / g or less is more preferable. When the nitrogen adsorption specific surface area (N ₂ SA) is in the above range, the balance between the processability of the rubber composition for a high damping bearing of the present invention and the damping performance of the high damping bearing of the present invention described later is good. .

(DBP oil absorption)
Dibutyl phthalate (DBP) oil absorption is a measure of the ability of carbon black to absorb dibutyl phthalate (DBP), and DBP oil absorption is an indicator of the degree of development of the structure between carbon black constituent unit particles. It will be. If carbon black has the same particle size, the structure of carbon black tends to be smaller as the DBP oil absorption value is smaller. The DBP oil absorption is measured according to “How to Obtain Oil Absorption” described in JIS K6217-4-2008.

In the present invention, DBP oil absorption is at 80 cm ^3/100 g or more 115cm ^3/100 g or less, 95cm ^3/100 g or more 113cm ^3/100 g or less, more preferably not more than 99cm ^3/100 g or more 110 cm ^3/100 g. Generally it by a higher structure of capable of improving the dispersibility in the rubber matrix, reduced elongation characteristics DBP oil absorption amount is one of important properties as rubber bearings exceeds 115cm ^3/100 g Or workability during kneading may be reduced. Further, the DBP oil absorption is reduced when less than 80 cm ^3/100 g modulus, since the spring characteristics may become insufficient.

(ΔDBP)
ΔDBP is a value indicating the difference (ΔDBP = DBP oil absorption−24M4DBP oil absorption) between the DBP oil absorption and the compressed DBP oil absorption (24M4DBP oil absorption) measured for a sample compressed four times at 24,000 psi. ΔDBP serves as an index for evaluating the structure characteristics of carbon black after kneading with rubber. The 24M4DBP oil absorption indicates the DBP oil absorption after the structure is destroyed (after kneading with rubber), and the compressed DBP oil absorption may be expressed as 24M4DBP oil absorption.

In the present invention, DerutaDBP is, 0 cm ³ / is the larger 10 cm ^3/100 g or less than 100 g, preferably 3 cm ^3/100 g or more 9cm ^3/100 g or less, more preferably 5 cm ^3/100 g or more 9cm ^3/100 g. When ΔDBP exceeds 10 cm ^3/100 g, the proportion of fragile structures structure is increased, structure is destroyed during kneading of the rubber, and there is a fear that it is impossible to obtain a sufficient strength. A rubber composition obtained by blending carbon black whose ΔDBP is controlled within the above range can improve fatigue resistance while maintaining high damping properties.

(Ratio between half-value width of aggregate distribution and Stokes diameter)
The ratio (D50 / Dst) between the half-value width (D50) of the aggregate distribution and the Stokes diameter (Dst) represents the degree of distribution of the produced carbon black, and the smaller this value, the sharper the aggregate distribution. The Stokes diameter (Dst) is the Stokes equivalent diameter of the maximum frequency in the distribution curve of the Stokes equivalent diameter of the aggregate obtained by centrifugal sedimentation of carbon black. The half width (D50) refers to the width of the distribution curve at a position where 50% of the maximum Stokes equivalent diameter maximum frequency is obtained. In the present invention, measurement is performed as follows. First, carbon black is added to water to adjust the carbon black concentration to 0.05% by mass, and then a sample solution that is sufficiently dispersed by ultrasonic waves is prepared. Next, 10 mL of spin solution (distilled water) is added to a rotating disk (rotation speed: 8000 rpm), then 0.2 ml of the sample solution is injected, centrifugal sedimentation is started, and absorbance is measured by photoelectric precipitation. From the result, an aggregate distribution curve is created, and the half width (D1 / 2) and Stokes diameter (Dst) of the aggregate distribution are calculated. For measurement of absorbance, a Disk Centrifuge Photo sedimentometer (manufactured by Joyice Loebl) is used.

  In the present invention, the ratio (D50 / Dst) of the half-value width (D50) of the aggregate distribution to the Stokes diameter (Dst) is preferably 0.78 or less, and is 0.65 or more and 0.78 or less. Is more preferably 0.68 or more and 0.78 or less. When the ratio (D50 / Dst) of the half-value width (D50) of the aggregate distribution to the Stokes diameter (Dst) is within the above range, the aggregate distribution is sharpened, thereby improving the dispersibility of the carbon black. The processability of the inventive composition is also good.

  The content of carbon black used in the composition of the present invention is 50 parts by mass with respect to 100 parts by mass of a total rubber of natural rubber (NR) and at least one diene rubber other than natural rubber (NR) described later. It is preferably not less than 55 parts by mass and not more than 90 parts by mass, more preferably not less than 60 parts by mass and not more than 85 parts by mass. The composition of the present invention is processed by mixing it with a rubber component composed of at least one diene rubber other than natural rubber (NR) and natural rubber (NR), which will be described later, with the carbon black content in the above range. Thus, fatigue resistance can be improved while maintaining high damping and maintaining high damping.

(Production method)
The method for producing the carbon black of the present invention is not particularly limited, and can be produced by appropriately controlling combustion conditions, high-temperature combustion gas flow rate, feedstock introduction conditions, reaction stop time, and the like. Specifically, for example, in a reaction zone where raw material hydrocarbons are converted to carbon black, a method in which the calcination gas is made uniform and subjected to a thermal decomposition reaction at a high temperature (1600 ° C. or higher) and in a short time (within 100 msec), etc. It is done.

<Diene rubber>
The diene rubber used in the composition of the present invention is not particularly limited. For example, natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile. -Butadiene copolymer rubber (NBR), butyl rubber (IIR), halogenated butyl rubber (Br-IIR, Cl-IIR), chloroprene rubber (CR) and the like. The average molecular weight, monomer composition molar ratio, halogenation rate, and the like of these diene rubbers are not particularly limited, and can be arbitrarily set depending on the intended use.

Among these, it is preferable to use natural rubber (NR) as a rubber component because the processability of the composition of the present invention is good and the high damping support of the present invention is also good.
Further, since the temperature dependence of the damping property and shear modulus of the high damping bearing of the present invention described later can be reduced, butadiene rubber (BR) is used as a rubber component in addition to natural rubber (NR). preferable.

  In the present invention, in addition to the natural rubber (NR), at least one diene rubber other than the natural rubber (NR) is preferably used in combination. As a suitable combination when the NR and two or more diene rubbers other than the NR are used in combination, the rubber components have excellent compatibility, workability, green strength, and vulcanized physical properties. What can ensure the temperature dependence and damping property of the high damping bearing using the rubber composition for high damping bearing of the present invention is preferable. For example, a combined system of natural rubber (NR) and butadiene rubber (BR) and a combined system of natural rubber (NR), isoprene rubber (IR) and butadiene rubber (BR) are preferable. Among these, a combination system of natural rubber (NR) and butadiene rubber (BR) is more preferable in that this characteristic is more excellent. These mixing ratios are not particularly limited. In addition, a combined system of isoprene rubber (IR) and butadiene rubber (BR) is preferably used instead of natural rubber (NR).

<Petroleum resin>
The composition of the present invention preferably further contains a petroleum resin. As the petroleum resin, conventionally known ones can be used, for example, C5 aliphatic unsaturated hydrocarbon polymer, C9 aromatic unsaturated hydrocarbon polymer, C5 aliphatic. Copolymers of unsaturated hydrocarbons and C9 aromatic unsaturated hydrocarbons can be used. By containing such a petroleum resin, physical properties such as tensile strength after vulcanization and elongation at break are improved, and the damping property of the high-damping support of the present invention described later is further enhanced. Such a petroleum resin can stably exhibit high damping properties and excellent shear modulus when used in combination with an aggregate of quartz and kaolinite described later.

  Specific examples of the C5 aliphatic unsaturated hydrocarbon include, for example, 1-pentene, 2-pentene, 2-methyl-1-butene contained in a C5 fraction obtained by thermal decomposition of naphtha, Olefinic hydrocarbons such as 3-methyl-1-butene and 2-methyl-2-butene; 2-methyl-1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene, 3-methyl-1 , 2-olefin hydrocarbons such as 2-butadiene; These can be polymerized or copolymerized in the presence of a suitable catalyst. Here, the C5 aliphatic unsaturated hydrocarbon polymer is a co-polymer of a single C5 aliphatic unsaturated hydrocarbon homopolymer and two or more C5 aliphatic unsaturated hydrocarbons. It refers to any polymer.

  Specific examples of the C9 aromatic unsaturated hydrocarbon include, for example, α-methylstyrene, o-vinyltoluene, m-vinyltoluene, p contained in a C9 fraction obtained by thermal decomposition of naphtha. -Vinyl-substituted aromatic hydrocarbons such as vinyltoluene. These can be polymerized or copolymerized in the presence of a suitable catalyst. Here, the C9 aromatic unsaturated hydrocarbon polymer is a co-polymer of a single C9 aromatic unsaturated hydrocarbon homopolymer and two or more C9 aromatic unsaturated hydrocarbons. It refers to any polymer.

  In addition, a copolymer of a C5 aliphatic unsaturated hydrocarbon and a C9 aromatic unsaturated hydrocarbon is a C9 aromatic unsaturated hydrocarbon in that the softening point of the copolymer is high. What a unit is 60 mol% or more is preferable, and what is 90 mol% or more is more preferable. A copolymer of a C5 aliphatic unsaturated hydrocarbon and a C9 aromatic unsaturated hydrocarbon can be copolymerized in the presence of a suitable catalyst.

  In the present invention, the petroleum resin preferably has a softening point (JIS K2207) of 100 ° C. or higher because the molecular weight and the reactivity of the double bond affect the physical properties of the diene rubber. The above is more preferable.

  In the present invention, the content of the petroleum resin is 5 masses with respect to 100 mass parts of a total rubber of natural rubber (NR) and at least one diene rubber other than natural rubber (NR). It is preferably no less than 45 parts by mass and more preferably no less than 10 parts by mass and no greater than 45 parts by mass. When the content of the petroleum resin is within the above range, a high-damping support body that is balanced and does not deteriorate the stability against repeated shear deformation for a long time while maintaining a high damping property is obtained. be able to.

  Furthermore, in the present invention, the mass ratio (inorganic filler / petroleum resin) between the inorganic filler and the petroleum resin described later is 1 / 0.2 or more and 1 in the range of the petroleum resin content in the mass part. It is preferably /3.5 or less, more preferably 1/1 or more and 1 / 3.0 or less, and still more preferably 1/1 or more and 1 / 2.5 or less. When the mass ratio between the inorganic filler and the petroleum resin is within the above range, a high attenuation support having high attenuation and excellent stability against repeated shear deformation can be obtained.

<Silica>
It is one of the preferred embodiments that the composition of the present invention further contains silica. As the silica, conventionally known ones can be used, and specific examples thereof include fumed silica, calcined silica, precipitated silica, pulverized silica, fused silica, colloidal silica, etc., and these can be used alone. Or two or more of them may be used in combination. Silica preferably has an average agglomerated particle size of 5 μm to 50 μm, and more preferably 5 μm to 30 μm.

  In the present invention, the content of the silica is preferably 5 parts by mass or more and 35 parts by mass or less, and more preferably 10 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the diene rubber. preferable. When the silica content is in the above range, a highly damped support body excellent in damping property and shear modulus can be obtained.

<Inorganic filler>
It is one of the preferred embodiments that the composition of the present invention further contains an inorganic filler. The inorganic filler does not include the above-described carbon black and silica. Examples of the inorganic filler used include soft clays such as T-clay, kaolin clay, wax stone clay, sericite clay, and calcined clay; diatomaceous earth; heavy calcium carbonate, magnesium carbonate, aluminum hydroxide, sulfuric acid And agglomerates of barium, talc, quartz and kaolinite. Among these, from the viewpoint that the high damping bearing of the present invention, which will be described later, and the stability of physical properties against repeated shear deformation can be kept particularly high, the coagulation of T-clay, kaolin clay, quartz and kaolinite. Aggregation is preferred.

  Here, conventionally known aggregates of quartz and kaolinite can be used. Especially, it is preferable that it is a natural coupling | bonding material of block quartz and plate-shaped kaolinite. Suitable examples of commercially available products include siritin (Siritin Z86, Siritin V85, Siritin N82, Siritin 85, Siritin N87 (all manufactured by Hoffman Mineral Co., Ltd.)). In addition, what has the same structure manufactured artificially can also be used.

  As described above, when the composition of the present invention contains an aggregate of quartz and kaolinite, it is particularly excellent in the effect of improving the stability of damping property and shear modulus, and when used in combination with the petroleum resin, Damping and shear modulus can be exhibited more stably.

  Further, the mass ratio of quartz and kaolinite constituting the aggregate of quartz and kaolinite (quartz / kaolinite) is not particularly limited. The reason why the mass ratio of quartz and kaolinite is preferably 12/1 or more and 1/1 or less is preferable because it is possible to stably exhibit higher damping properties and superior shear modulus. More preferably, it is 1 or less.

  Further, the aggregate of quartz and kaolinite can contain, for example, iron oxide, phosphorus component, and sulfur component in addition to quartz and kaolinite. Such an aggregate may be used independently and may use 2 or more types together.

  In the present invention, the content of the inorganic filler is preferably 5 parts by mass or more and 55 parts by mass or less, more preferably 10 parts by mass or more and 50 parts by mass or less, with respect to 100 parts by mass of the diene rubber. More preferably, it is more than 40 parts by weight. When the content of the inorganic filler is in the above range, it is possible to obtain a highly-damped support body that is stable in terms of damping properties and shear modulus against long-term repeated shear deformation while maintaining high damping properties.

  Moreover, in this invention, it is preferable that the total amount of the said silica and the said inorganic filler is 20 to 75 mass parts with respect to 100 mass parts of said diene rubbers, and is 30 to 65 mass parts. It is more preferable that the amount is not more than part by mass. When the total amount of silica and inorganic filler is in such a range, the damping is higher, the damping against long-term repeated shear deformation and the shear modulus are more stable, and the balance is high. A damping bearing is obtained.

  Furthermore, in the present invention, the mass ratio between the silica and the inorganic filler is preferably from 1/1 to 1 / 2.5, more preferably from 1/1 to 1 / 2.0. preferable. When the mass ratio of silica to the inorganic filler is within this range, the processability of the composition of the present invention becomes better.

<Additives>
The composition of the present invention can contain other additives as necessary within a range not impairing the object of the present invention. Examples of the additive include a vulcanizing agent, a vulcanization accelerator, an anti-aging agent, a plasticizer, a softening agent, a vulcanization aid, a flame retardant, a weathering agent, and a heat resistance agent. Specific examples of the vulcanizing agent include sulfur; organic sulfur-containing compounds such as TMTD; organic peroxides such as dicumyl peroxide; and the like. Specific examples of the vulcanization accelerator include sulfenamides such as N-cyclohexyl-2-benzothiazole sulfenamide (CBS); thiazoles such as mercaptobenzothiazole; tetramethylthiuram monosulfide and the like. Thiurams; stearic acid; and the like. Specific examples of the antiaging agent include ketone / amine condensates such as TMDQ; amines such as DNPD; monophenols such as styrenated phenol; and the like. Specific examples of the plasticizer include phthalic acid derivatives (for example, DBP, DOP and the like), sebacic acid derivatives (for example, DBS and the like) monoesters, and the like. Specific examples of the softening agent include paraffinic oil (process oil).

  Although the manufacturing method of the composition of this invention is not specifically limited, For example, a well-known method and apparatus (for example, a Banbury mixer, a kneader, a roll, etc.) are used for the unvulcanized rubber composition which mix | blended each component mentioned above. And can be prepared by kneading.

Thus, the compositions of the present invention, the nitrogen adsorption specific surface area (N ₂ SA) of not more than 150 meters ² / g or more 250 meters ² / g, a dibutylphthalate (DBP) oil absorption of 80 cm ^3/100 g or more 115cm ³ / 100g or less, and the difference (DerutaDBP) is 10 cm ³ / 100g high damping support for a rubber composition containing at which carbon black following the DBP absorption and the compressed DBP absorption (24M4DBP oil absorption). By controlling ΔDBP within the above range and suppressing it, it is possible to obtain a high-damping bearing rubber composition with improved fatigue resistance while maintaining high damping.

<High damping bearing>
Hereinafter, the high damping bearing body of the present invention will be described. The high-damping bearing body of the present invention is a high-damping bearing body obtained by alternately laminating the soft plate made of the composition of the present invention and the rigid hard plate, and the high-damping bearing body of the present invention. The body is a structure used for bridge support, building base isolation, etc.

  FIG. 1 is a schematic cross-sectional view schematically showing an example of the high-damping support body of the present invention. As shown in FIG. 1, a high-damping bearing body (base-isolated laminate) 10 includes a flexible plate 11-1 to 11-6 made of a rubber composition for a high-damping bearing body (the composition of the present invention) and rigidity. The hard plates 12-1 to 12-7 that are included are alternately laminated. The soft plates 11-1 to 11-6 are made of the composition of the present invention and are rubber-like elastic plates, and thus function as a vibration absorbing layer. The hard plates 12-1 to 12-7 are reinforcing rigid plates, and the hard plates 12-1 to 12-7 are not particularly limited. For example, general structural steel plates and cold rolled steel plates Various materials such as reinforced plastics such as steel plates, ceramics, plastics, fiber reinforced plastics (FRP), polyurethane, wood, etc., metals and non-metals are used.

  The high-damping support 10 may be configured by providing an adhesive layer between the soft plates 11-1 to 11-6 and the hard plates 12-1 to 12-7, or without providing an adhesive layer. It may be configured by directly vulcanizing.

  Moreover, although the high attenuation | damping support body 10 has laminated | stacked the soft board 11-1 to 11-6 and the hard board 12-1 to 12-7 alternately, the soft board 11-1 to 11-6 is each respectively. Two or more layers may be laminated.

  The high-damping support body 10 is composed of 13 layers consisting of 6 layers composed of soft plates 11-1 to 11-6 and 7 layers composed of hard plates 12-1 to 12-7. The invention is not limited to this. The number of layers of the soft plates 11-1 to 11-6 and the hard plates 12-1 to 12-7 constituting the high-damping support body 10 can be arbitrarily set according to the intended use, required characteristics, and the like. .

  Further, the size, the overall thickness, the thickness of the soft plates 11-1 to 11-6, the thickness of the hard plates 12-1 to 12-7, etc. are also used. It can be arbitrarily set according to required characteristics.

  In order to manufacture the high-damping support body 10, the composition of the present invention is formed into a sheet and then vulcanized to form sheet-shaped soft plates 11-1 to 11-6 made of the rubber composition of the present invention. Then, a layer containing an adhesive may be provided and alternately laminated with the hard plates 12-1 to 12-7. Alternatively, the composition of the present invention that has not been vulcanized in advance is formed into a sheet shape, and alternately laminated with the hard plates 12-1 to 12-7, and then heated to vulcanize the composition of the present invention. You may make it adhere | attach the soft board 11-1 to 11-6 and the hard board 12-1 to 12-7 simultaneously with forming 11-1 to 11-6.

The high-damping support body 10 uses the above-described composition of the present invention as a material constituting the soft plates 11-1 to 11-6, and thus improves fatigue resistance while maintaining high damping performance. It has the effect of being excellent. In Specifically, indicators become shear modulus of the damping performance measured by lap shear Shear test described below (GEQ) is preferably at 0.87N / mm ² or more, 0.90 N / mm ² or more More preferably. Further, the equivalent attenuation constant (Heq) measured in the same manner is preferably 0.18% or more, more preferably 0.19% or more, and further preferably 0.20% or more.

  In the high damping bearing of the present invention, the shear modulus (Geq) and equivalent damping constant (Heq) required for each product are satisfied, and the Geq change rate and Heq change rate required by the method described below are as follows. A range is preferred. The Geq change rate in the high damping bearing of the present invention is preferably 0.90 or more and 1.15 or less, preferably 0.90 or more and 1.10 or less, from the viewpoint that the increase in Geq is small (the increase in shear rigidity is small). Is more preferably 0.90 or more and 1.05 or less. Further, the Heq change rate in the high damping bearing of the present invention is preferably 0.82 or more and 0.90 or less from the viewpoint that the decrease in Heq is small with respect to repeated shear deformation (the decrease in damping property is small). 0.84 or more and 0.90 or less are more preferable, and 0.87 or more and 0.90 or less are still more preferable.

(Heq and Geq)
The equivalent damping constant (Heq) and shear modulus (Geq) are measured by a lap shear type shear test. FIG. 2 is a side view schematically showing a sample for a lap shear type shear test. As shown in FIG. 2, the lap shear type shear test sample 20 is obtained by placing (lamination) a rolled unvulcanized rubber composition 21 and a steel plate 22 and then press vulcanizing at 130 ° C. for 120 minutes. . The unvulcanized rubber composition 21 is an unvulcanized rubber composition of the composition of the present invention that has been rolled to a size of 25 mm wide × 25 mm long × 5 mm thick. The steel plate 22 is a steel plate (width 25 mm × length 100 mm × thickness 20 mm) having a surface sandblasted and coated with a metal adhesive.

The lap shear type shear test is performed under the following conditions using a vibrator (manufactured by Saginamiya), an input signal oscillator, and an output signal processor. Using the sample 20 for lap shear type shear test produced as described above, 1 each when 175% strain was applied 11 times at a deformation frequency of 0.5 Hz and a measurement temperature of 23 ° C. by a biaxial shear tester. The average (n = 10) (Geq, Heq) of the shear characteristic values of the times is obtained. Geq and Heq are calculated according to the following formulas (1) and (2) from the hysteresis loop obtained by the lap shear type shear test. Further, using this high-damping support, 70% strain is applied 5000 times under the same conditions, and then the average shear characteristic values (Geq ₅₀₀₀ and Heq ₅₀₀₀ ) are obtained again under the same conditions as the above-mentioned shear characteristic values.

(Geq change rate and Heq change rate)
Next, determine the Heq change rate obtained by dividing the GEQ change rate and Heq ₅₀₀₀ divided by the GEQ ₅₀₀₀ in GEQ in Heq. Based on the Geq change rate and Heq change rate, changes in physical properties when the support body is repeatedly subjected to shear deformation can be evaluated.

  FIG. 3 is a graph showing an example of a hysteresis curve of a support body. A shear strain is periodically applied to the support body from one direction, and the stress of the support body caused by the shear strain is distorted on the horizontal axis. (%), The vertical axis represents stress. The equivalent damping constant (Heq) and shear modulus (Geq) of the support are expressed by the following formulas (1) and (2), respectively. The equivalent damping constant (Heq) of the support body is calculated according to the following formula (1) using Xmax and Qmax shown in the hysteresis curve shown in FIG. 3 obtained in the lap shear type shear test. The shear modulus (Geq) is calculated by the following formula (2).

  In equation (1), ΔW is the area of the hysteresis loop (the shaded area in FIG. 3). In the formula (2), Keq is represented by the following formula (3), H represents the total thickness of the rubber layer laminated in the high-damping support, and A is the cross-sectional area of the rubber layer.

  If the high-damping support body 10 of the present invention is used as a vibration energy absorbing device such as a vibration isolator, a vibration isolator, a seismic isolation device or the like, its use and the like are not particularly limited. In particular, since the high-damping support body 10 of the present invention has excellent characteristics as described above, for example, support for structures such as bridges and elevated roads, bridges, basic isolation of buildings, and isolation of buildings. It is suitably used as a device for absorbing vibration energy for various types of seismic isolation, vibration isolation, vibration isolation, etc.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

<Preparation of carbon black 1-6>
Using carbon black manufacturing plant, the nitrogen adsorption specific surface area ^{_{(N 2 SA) [m 2}} / g], DBP oil absorption [cm ³ / 100g], 24M4DBP oil absorption [cm ³ / 100g] and DBP oil absorption amount and the compression DBP absorption the amount and the difference between (24M4DBP oil ^{absorption) (ΔDBP) [cm 3 /} 100g] However, to produce carbon black 1~6 (CB1~6) so that each becomes a value shown in table 1 below. The nitrogen adsorption specific surface area was measured according to JIS K6217-2-2001, and the DBP oil absorption was measured according to JIS K6217-4-2001. Also, CB1, 3, 4 and 6 can be obtained by requesting production from Shin Nikka Carbon Co., Ltd., and CB2 is “Nitelon # 415UD” and CB5 made by Nikka Chemical Co., Ltd. Is available under the trade name “Niteron # 410” manufactured by Nippon Kayaku Carbon.

<Examples 1 to 4, Reference Examples 1 and 2 , Comparative Examples 1 to 14>
[Preparation of unvulcanized rubber composition]
Each component was blended so as to have the composition shown in Table 2 below (unit: part by mass), and kneaded for 5 minutes with a B-type Banbury mixer to prepare an unvulcanized rubber composition.

[Preparation of sample for lap shear type shear test]
The prepared unvulcanized rubber composition was rolled into a size of 25 mm width × 25 mm length × 5 mm thickness. An unvulcanized rubber composition after rolling (reference numeral 21 in FIG. 2) and a steel plate sand-blasted and coated with a metal adhesive (width 25 mm × length 100 mm × thickness 20 mm, reference numeral 22 in FIG. 2) Was placed (laminated) as in the lap shear type shear test sample 20 shown in FIG. 2 and then press vulcanized at 130 ° C. for 120 minutes to prepare a lap shear type shear test sample.

The unvulcanized physical properties, normal physical properties, and dynamic properties of the unvulcanized rubber composition prepared as described above were measured.
The dynamic characteristics include an average shear characteristic value (Geq, Heq), a Geq change rate (Geq ₅₀₀₀ / Geq) obtained by dividing Geq ₅₀₀₀ by Geq, and a Heq change rate (Heq) obtained by dividing Heq ₅₀₀₀ by Heq. ₅₀₀₀ / Heq). In Comparative Examples 13 and 14, estimated values were obtained when the blending amounts of CB1 in Reference Example 1 and Examples 1 and 2 were 45 parts by mass and 100 parts by mass.

[Unvulcanized properties]
The unvulcanized physical property is obtained by measuring the minimum viscosity (Vm) of Mooney viscosity of an unvulcanized rubber composition. About the obtained unvulcanized rubber composition, in accordance with JIS K6300-1-2001, an L-shaped rotor is used, the preheating time is 1 minute, and the test temperature is 125 ° C. The minimum viscosity (Vm) of Mooney viscosity Was measured. The results are shown in Table 2. Further, the minimum viscosity (Vm) of Mooney viscosity at 125 ° C. can be judged to be excellent in workability if it is 100 or less, but is preferably 90 or less from the viewpoint of workability during mass production.

[Normal physical properties]
The normal state physical properties are measured by measuring the tensile strength (T _B ) [MPa], elongation at break (E _B ) [%] and JIS A hardness (Hs) of an unvulcanized rubber composition. The JIS A hardness (Hs) was measured according to JIS K6253. The obtained unvulcanized rubber composition was vulcanized for 45 minutes under a pressure of 3.0 MPa using a press molding machine at 148 ° C. to prepare a vulcanized sheet having a thickness of 2 mm. A JIS No. 3 dumbbell-shaped test piece was punched from this sheet, and a tensile test at a tensile speed of 500 mm / min was conducted in accordance with JIS K6251-2004. Tensile strength (T _B ) [MPa], elongation at break (E _B ) [%] And hardness Hs (JIS A) were measured at room temperature. The results are shown in Table 2.

[Dynamic characteristics]
The dynamic characteristics are obtained by measuring an average shear characteristic value (Geq, Heq), a Geq change rate, and a Heq change rate.
(Average shear characteristic value (Geq, Heq))
A lap shear type shear test was performed on the lap shear type shear test sample using a vibrator (manufactured by Saginomiya), an input signal oscillator, and an output signal processor. The number of lap shear type shear test samples used in each example , each reference example, and each comparative example was ten. The above lap shear type shear test sample was subjected to a lap shear type shear test by applying 175% strain 11 times at a deformation frequency of 0.5 Hz with a biaxial shear tester at a measurement temperature of 23 ° C. The average of the characteristic values was obtained. Using Xmax and Qmax indicated by the hysteresis curve obtained by this lap shear type shear test, average shear characteristic values (Geq, Heq) were determined according to the above formulas (1) and (2). The results are shown in Table 2. Here, the shear modulus (Geq) is desirably a high value, but is preferably 0.87 or more, and more preferably 0.90 or more. The equivalent attenuation constant (Heq) is desirably a high value, but is preferably 0.19 or more, and more preferably 0.20 or more.

Subsequently, using the sample, a lap shear type shear test was performed again using a shear tester similar to the above, with a deformation frequency of 0.5 Hz, a measurement temperature of 23 ° C., and 70% strain applied 5000 times. Similarly to the above, average shear characteristic values (Heq ₅₀₀₀ , Geq ₅₀₀₀ ) were determined.

(Geq change rate and Heq change rate)
Geq ₅₀₀₀ was divided by Geq to obtain a Geq change rate (Geq ₅₀₀₀ / Geq). When the value of the Geq change rate (Geq ₅₀₀₀ / Geq) is smaller than 1.04, it is preferable because there is little change in characteristics of the shear elastic modulus. Further, Heq ₅₀₀₀ was divided by Heq to obtain a Heq change rate (Heq ₅₀₀₀ / Heq). When the value of the Heq change rate (Heq ₅₀₀₀ / Heq) is 0.87 or more, it is suitable as a rubber composition for a high damping bearing having a high shear modulus, which is preferable. The results are shown in Table 2.

The following components were used for each component in Table 2 other than CB1 to 6 described above.
・ Natural rubber: STR20, manufactured by SIAM INDO RUBBER ・ Butadiene rubber: NipolBR1220, manufactured by Nippon Zeon ・ Silica: Nipseal AQ, manufactured by Tosoh Silica ・ Clay: SUPREX PLAY, manufactured by Kentucky Tennessee Clay Company ・ Zinc oxide: Zinc No. 3, manufactured by Shodo Chemical Industry Co., Ltd. ・ Stearic acid: Bead stearic acid YR, manufactured by NOF Corporation ・ Petroleum resin: High Resin # 120S (softening point 120 ° C.), manufactured by Toho Chemical Co., Ltd. ・ Anti-aging agent: 6C, Seiko Chemical・ Wax: Sunnock, manufactured by Ouchi Shinsei Chemical Co., Ltd. ・ Oil: Aroma oil (AO-MIX, manufactured by Sankyo Oil Chemical Co., Ltd.)
・ Sulfur: Sulfur powder, manufactured by Hosoi Chemical Co., Ltd. ・ Vulcanization accelerator: Noxeller CZ, manufactured by Ouchi Shinsei Chemical Co., Ltd.

As is apparent from Tables 1 and 2, when a rubber composition prepared using CB5 whose DBP oil absorption is not within a predetermined range is used, the minimum Mooney viscosity (Vm ) Was high, and it was found that the processability was poor (see Comparative Examples 7 to 9). Moreover, when using CB3-6 in which the difference ((DELTA) DBP) of DBP oil absorption amount and 24M4DBP oil absorption amount is not in a predetermined range, it is the compounding quantity from a viewpoint of improving fatigue resistance, maintaining a high damping property. It was found that when the ratio is increased, the rate of change in Geq is increased or the rate of change in Heq is decreased and fatigue resistance is inferior (see Comparative Examples 1 to 14). On the other hand, rubbers prepared using CB1 and CB2 adjusted so that the nitrogen adsorption specific surface area (N ₂ SA), DBP oil absorption amount, difference between DBP oil absorption amount and 24M4 DBP oil absorption amount (ΔDBP) is within a predetermined range. Compared to rubber compositions prepared using CB3-6, the composition has a low Geq change rate, can maintain a high Heq change rate, has excellent workability, and maintains high damping properties while improving fatigue resistance. It was found that it was excellent in making (see Example 1, Reference Example 1 ).

  As described above, the high damping bearing rubber composition and the high damping bearing body according to the present invention can improve fatigue resistance while maintaining high damping performance. It can be suitably used for basic seismic isolation.

10 High damping bearing body (Seismic isolation laminate)
11-1 to 11-6 Soft plate 12-1 to 12-7 Hard plate 20 Sample for lap shear type shear test 21 Rolled unvulcanized rubber composition 22 Steel plate

Claims (5)

Nitrogen adsorption specific surface area (N ₂ SA) of not more than 150 meters ² / g or more 250m ² / g, a dibutylphthalate (DBP) oil absorption of not more than 80 cm ^3/100 g or more 115cm ³ / 100g, and, DBP oil absorption amount a compression DBP oil absorption difference between (24M4DBP oil absorption) (ΔDBP) is containing carbon black is less than 10 cm ^3/100 g, and the JIS a hardness was measured in accordance with JIS K6253 (Hs) is 85 or less, Shear modulus (Geq) before and after a shear test in which a shear modulus (Geq) is 0.87 or more, a deformation frequency of 0.5 Hz, and a measurement temperature of 23 ° C. or less and 70% strain is applied 5000 times. The rubber composition for high damping bearings is characterized in that the rate of change of A is less than 1.04 and the rate of change of equivalent damping constant (Heq) is 0.87 or more . Containing natural rubber and at least one diene rubber other than the natural rubber,
The content of the carbon black is 50 parts by mass or more and 95 parts by mass or less with respect to 100 parts by mass of the total rubber of the natural rubber and at least one diene rubber other than the natural rubber. The rubber composition for high damping bearings according to claim 1.   The rubber composition for high damping bearings according to claim 1 or 2, further comprising petroleum resin.   The rubber composition for a high damping bearing according to claim 3, wherein the content of the petroleum resin is 5 parts by mass or more and 45 parts by mass or less with respect to 100 parts by mass of the rubber.   A high-damping support body comprising a soft plate made of the rubber composition for high-damping support according to any one of claims 1 to 4 and a rigid hard plate alternately laminated.

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