JP2009149856A - Rubber composition for high-damping laminate, and high-damping laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition for a high-damping laminate of high damping performance, excellent in a modulus of shearing elasticity, and capable of obtaining a laminate having low temperature-dependency about the damping performance and the modulus of shearing elasticity even in a very cold district where the minimum air temperature reaches about -30°C in a winter. <P>SOLUTION: This rubber composition for the high-damping laminate contains 100 pts.mass of a diene rubber, 40-75 pts.mass of carbon black, 5-35 pts.mass of silica, 5-55 pts.mass of an inorganic filler and 5-50 pts.mass of a petroleum resin, and the diene rubber contains 80 mass% or more of vinyl-cis-butadiene rubber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rubber composition for a high attenuation laminate and a high attenuation laminate.

  In recent years, seismic isolation devices, seismic isolation devices, seismic isolation devices and the like are rapidly spreading as vibration energy absorbing devices. In such an apparatus, a rubber composition having vibration energy damping performance is used.

  For example, laminated rubber for seismic isolation used in bridge bearings and building seismic isolation devices has high damping (attenuates vibration energy by converting vibration into more heat) and the desired shear elasticity The rate is required to develop.

  As a rubber composition used for such a seismic isolation laminated rubber, the present applicant described in Patent Document 1 “100 parts by mass of a diene rubber, 40 to 75 parts by mass of carbon black, and 5 to 35 parts by mass of silica. , A rubber composition for a high attenuation laminate comprising 5 to 55 parts by mass of an inorganic filler and 5 to 50 parts by mass of a petroleum resin.

JP 2006-143849 A

However, the rubber composition for a high-damping laminate described in Patent Document 1 has high damping properties and excellent shear modulus, but in extremely cold regions where the minimum winter temperature reaches about minus 30 ° C, the damping properties and It became clear that the temperature dependence of the shear modulus may increase.
Therefore, the present invention realizes a laminate having high damping properties, excellent shear modulus, and low damping and temperature dependence of shear modulus even in extremely cold regions where the minimum winter temperature reaches about minus 30 ° C. An object of the present invention is to provide a rubber composition for a high attenuation laminate.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that carbon black, silica, an inorganic filler, and a petroleum resin are added to a diene rubber containing a specific amount of vinyl-cisbutadiene rubber. When using a rubber composition blended at a specific ratio, it has high damping properties, excellent shear modulus, and temperature dependence of damping properties and shear modulus even in extremely cold regions where the minimum winter temperature is about minus 30 ° C. The present invention has been completed by finding that a laminate having a small thickness can be obtained.
That is, the present invention provides the following (1) to (4).

(1) 100 parts by weight of diene rubber, 40 to 75 parts by weight of carbon black, 5 to 30 parts by weight of silica, 5 to 55 parts by weight of inorganic filler, and 5 to 50 parts by weight of petroleum resin,
A rubber composition for a high-damping laminate, wherein the diene rubber contains 80% by mass or more of vinyl-cisbutadiene rubber.

(2) The total content of the silica and the inorganic filler is 20 to 75 parts by mass with respect to 100 parts by mass of the diene rubber,
The rubber composition for a high attenuation laminate according to (1), wherein a mass ratio of the silica and the inorganic filler (silica / inorganic filler) is 1/1 to 1 / 2.5.

  (3) The high ratio according to (1) or (2) above, wherein the mass ratio of the inorganic filler to the petroleum resin (inorganic filler / petroleum resin) is from 1 / 0.2 to 1 / 3.5. Rubber composition for damping laminate.

  (4) A high attenuation laminate obtained by alternately laminating the rubber composition for a high attenuation laminate according to any one of (1) to (3) and a hard plate.

  As will be described below, according to the present invention, damping properties and shear modulus are high, and the temperature dependence of damping properties and shear modulus even in extremely cold regions where the minimum winter temperature reaches about minus 30 ° C. It is possible to provide a rubber composition for a high attenuation laminate that can realize a laminate having a small thickness.

The present invention is described in detail below.
The rubber composition for highly attenuated laminates of the present invention (hereinafter, also simply referred to as “the rubber composition of the present invention”) comprises 100 parts by mass of a diene rubber, 40 to 75 parts by mass of carbon black, and 5 to 30 parts of silica. A rubber for a high damping laminate comprising 5 parts by mass, 5 to 55 parts by mass of an inorganic filler, and 5 to 50 parts by mass of a petroleum resin, and the diene rubber contains 80% by mass or more of vinyl-cisbutadiene rubber. It is a composition.
Next, the diene rubber, carbon black, silica, inorganic filler and petroleum resin contained in the rubber composition of the present invention will be described in detail.

<Diene rubber>
The diene rubber contained in the rubber composition of the present invention is not particularly limited as long as it contains 80% by mass or more of vinyl-cis butadiene rubber, and contains 100% by mass of vinyl-cis butadiene rubber. -It may consist only of cis-butadiene rubber.

Here, vinyl - and cis-butadiene rubber, in an inert organic solvent mainly composed of C ₄ fraction, polybutadiene rubber composite comprising the cis-1,4 polymerization and syndiotactic-1,2 polymerization (Hereinafter also referred to as “VCR”).
Specific examples of the vinyl-cis butadiene rubber include, for example, 97 to 80% by mass of cis-1,4-polybutadiene rubber having a cis 1,4-bond content of 90% or more, and syndiotactic-1,2-polybutadiene. Examples include composites composed of 3 to 20% by mass.

  In the present invention, as such a vinyl-cis butadiene rubber, for example, a commercially available product such as UBEPOL-VCR manufactured by Ube Industries, Ltd. can be used.

By using a diene rubber containing 80% by mass or more of such vinyl-cis butadiene rubber, the high attenuation laminate of the present invention obtained by alternately laminating the rubber composition of the present invention and a hard plate obtained. (Hereinafter, also referred to as “the laminate of the present invention”) can be highly attenuated, and even in extremely cold regions where the minimum temperature in winter reaches about minus 30 ° C., the temperature dependence of the attenuation and shear modulus. Can be reduced.
Specifically, an equivalent damping constant (Heq) that is an index of damping performance measured by a lap shear shear test described later can be 0.20 or more. Further, the equivalent attenuation constant at minus 30 ° C. measured by lap shear shear test described below the ratio of the equivalent attenuation constant in (Heq ^{-30 ° C.)} and ^{23 ℃ (Heq 23 ℃) (} Heq -30 ℃ / Heq 23 ℃) can be less than 1.10, the shear modulus at minus 30 ° C. to similarly measured (GEQ ^{-30 ° C.)} and shear modulus at ^{23 ℃} (Geq 23 ℃) ratio of (Geq ^{-30 ℃} / Geq ^{23 ° C} ) can be less than 1.40.

The reason why the damping property can be increased and the temperature dependence of damping property and shear modulus can be reduced even in extremely cold regions where the minimum temperature in winter reaches about -30 ° C is clear in detail. However, considering that the glass transition point of VCR is −107 ° C. and equal to the glass transition point of general-purpose butadiene rubber (BR), the rubber composition mainly composed of VCR is also composed mainly of BR. It is thought that it is for exhibiting the outstanding low temperature characteristic like the rubber composition to do.
However, as can be seen from the results of Comparative Examples 3 and 5 which will be described later, this is the case when a diene rubber containing 70% by mass or more of a general-purpose polybutadiene rubber (BR) is used. This is a surprising effect in view of the inferiority. This is considered to be because the syndiotactic-1,2 polymerization portion acts as a resin component in the structure of the VCR.

The diene rubber contained in the rubber composition of the present invention contains vinyl-cis butadiene rubber in an amount of 80% by mass or more, and if the content is less than 100% by mass, other diene rubber is contained. Will do.
Other diene rubbers are 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.
Among these, it is preferable to use NR together for the reason that the balance between physical properties such as modulus, tensile strength, elongation at break and workability is good, and it further reduces the temperature dependence of the damping property and shear modulus. For the reason, it is preferable to use BR together.

<Carbon black>
Conventionally known carbon black can be used as the carbon black contained in the rubber composition of the present invention.

In the present invention, carbon black having a CTAB adsorption specific surface area of 100 m ² / g or more is preferably used, and carbon black of 110 to 370 m ² / g is more preferably used.
When the CTAB adsorption specific surface area is in the range of 100 m ² / g or more, the damping property of the obtained laminate of the present invention can be maintained higher.
Here, the CTAB adsorption specific surface area is a value obtained by measuring the surface area that carbon black can be used for adsorption with rubber molecules by adsorption of CTAB (cetyltrimethylammonium bromide).
Examples of such carbon black include SAF, ISAF, and HAF. The CATB adsorption specific surface area can be measured by the method described in ASTM D3765-80.

In this invention, content of carbon black is 40-75 mass parts with respect to 100 mass parts of diene rubbers, and it is preferable that it is 50-75 mass parts.
When the content of carbon black is within this range, the resulting laminate of the present invention has high damping properties and good shear modulus.

<Silica>
A conventionally well-known thing can be used for the silica contained in the rubber composition of this invention.
Specific examples of silica include fumed silica, calcined silica, precipitated silica, pulverized silica, and fused silica.
Silica preferably has an average aggregate particle diameter of 5 to 50 μm, more preferably 5 to 30 μm.

In this invention, content of a silica is 5-30 mass parts with respect to 100 mass parts of diene rubbers, and it is preferable that it is 10-30 mass parts.
When the content of silica is within this range, the resulting laminate of the present invention has high damping properties and good shear modulus.

<Inorganic filler>
As the inorganic filler contained in the rubber composition of the present invention, conventionally known fillers other than the above-described carbon black and silica can be used.
Specific examples of such inorganic fillers 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, barium sulfate, talc, aggregates of quartz and kaolinite, and the like.
Among these, T-clay, kaolin clay, and an aggregate of quartz and kaolinite are preferable from the viewpoint that damping property and stability against long-term shear deformation can be kept particularly high.

A conventionally well-known thing can be used for the aggregate of said quartz and kaolinite. Among them, it is preferable to use a natural combination of massive quartz and plate-shaped kaolinite.
As such an aggregate, for example, commercially available products such as siritin (Siritin Z86, Siritin V85, Siritin N82, Siritin 85, Siritin N87 (all manufactured by Hoffman Mineral Co., Ltd.)) can be used. In addition, what has the same structure manufactured artificially can also be used.
By containing such an agglomerate as an inorganic filler, the rubber composition of the present invention has particularly improved damping properties and stability of shear modulus. Properties and shear modulus can be exhibited stably.

  Moreover, the mass ratio (quartz / kaolinite) of quartz and kaolinite constituting the aggregate of quartz and kaolinite is not particularly limited. Even when the high damping laminate of the present invention obtained by alternately laminating a rubber composition containing such an aggregate and a hard plate is repeatedly subjected to shear deformation, it has higher damping properties and superior shear modulus. For the reason that it can be stably exhibited, the mass ratio of quartz and kaolinite is preferably 12/1 to 1/1, and more preferably 9/1 to 2/1.

  Furthermore, the aggregate of quartz and kaolinite can contain, for example, iron oxide, a phosphorus component, and a sulfur component in addition to quartz and kaolinite. Such aggregates can be used alone or in combination of two or more.

In this invention, content of an inorganic filler is 5-55 mass parts with respect to 100 mass parts of diene rubbers, It is preferable that it is 10-50 mass parts, It is 15-40 mass parts. Is more preferable.
When the content of the inorganic filler is within this range, the resulting laminate of the present invention has high damping properties and good shear modulus.

  In the present invention, the total content of the silica and the inorganic filler is preferably 20 to 75 parts by mass, and 30 to 65 parts by mass with respect to 100 parts by mass of the diene rubber. Is more preferable. When the total content of silica and the inorganic filler is within this range, the resulting laminate of the present invention has a higher damping property, and has a more stable damping property and shear modulus against long-term repeated shear deformation. It becomes.

  In the present invention, the mass ratio (silica / inorganic filler) between the silica and the inorganic filler is preferably 1/1 to 1/2. More preferably 0. When the mass ratio of silica to the inorganic filler is within this range, the processability of the resulting rubber composition of the present invention is good.

<Petroleum resin>
A conventionally well-known thing can be used for the petroleum resin contained in the rubber composition of this invention.
Examples of petroleum resins include C5 aliphatic unsaturated hydrocarbon polymers, C9 aromatic unsaturated hydrocarbon polymers, C5 aliphatic unsaturated hydrocarbons and C9 aromatic unsaturated polymers. Examples thereof include a copolymer with a hydrocarbon.

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.

  The above petroleum resin has a molecular weight and a double bond reactivity that affect the physical properties of the diene rubber, so that the softening point (JIS K2207) is preferably 100 ° C. or higher, more preferably 120 ° C. or higher. preferable.

In this invention, content of petroleum resin is 5-50 mass parts with respect to 100 mass parts of diene rubbers, and it is preferable that it is 10-45 mass parts.
When the content of the petroleum resin is within this range, the obtained laminate of the present invention maintains high damping properties, has low temperature dependence, and is stable in damping properties and shear modulus against long-term repeated shear deformation. It will be a thing. Further, as described above, when used in combination with an aggregate of quartz and kaolinite, high damping properties and excellent shear modulus can be stably exhibited.

  In the present invention, the mass ratio of the inorganic filler to the petroleum resin (inorganic filler / petroleum resin) is preferably 1 / 0.2 to 1 / 3.5, and 1/1 to 1/3. 0.0 is more preferable, and 1/1 to 1 / 2.5 is still more preferable. When the mass ratio of the inorganic filler and the petroleum resin is within this range, the obtained laminate of the present invention is stable in damping property and shear modulus against long-term repeated shear deformation while maintaining high damping property. It becomes.

<Other additives>
The rubber 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 and zinc oxide; 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 rubber composition of this invention is not specifically limited, For example, the unvulcanized rubber composition which mix | blended each component mentioned above can be prepared by kneading | mixing etc. using a well-known method and apparatus.

  The laminate of the present invention is a high-attenuation laminate obtained by alternately laminating the rubber composition of the present invention and the hard plate described above, and is a structure used for bridge support, building base isolation, etc. is there.

  In FIG. 1, the cross-sectional schematic of the high attenuation | damping laminated body showing an example of the embodiment of the laminated body of this invention is shown. In FIG. 1, the code | symbol 1 represents a high attenuation | damping laminated body (seismic isolation laminated body), the code | symbol 2 represents a hard board, and the code | symbol 3 represents the rubber composition for high attenuation | damping laminated bodies of this invention.

As shown in FIG. 1 as an example, the high attenuation laminate 1 of the present invention includes a rubber composition 3 for a high attenuation laminate of the present invention and a hard plate 2 (for example, a general structural steel plate, a cold rolled steel plate, etc.). Are alternately stacked.
The high attenuation laminate 1 may be configured by providing an adhesive layer between the rubber composition 3 for the high attenuation laminate of the present invention and the hard plate 2, or directly without providing the adhesive layer. It may be configured by vulcanization.

In FIG. 1, the high attenuation laminate 1 of the present invention is shown in a state where the rubber composition 3 for the high attenuation laminate of the present invention and the hard plate 2 are alternately laminated. The body rubber composition 3 may have a structure in which two or more layers are laminated.
Moreover, in FIG. 1, although the example of a total of 13 layers of 6 layers about the rubber composition 3 for high attenuation laminated bodies of this invention and 7 layers about the hard board 2 is shown, the high attenuation laminated body 1 of this invention is shown. The number of laminated layers of the rubber composition 3 for a highly attenuated laminate of the present invention and the hard plate 2 is not limited to this, and can be arbitrarily set according to the intended use, required characteristics, and the like.
Furthermore, the size of the high attenuation structure 1 of the present invention, the overall thickness, the layer thickness of the rubber composition 3 for the high attenuation laminate of the present invention, the thickness of the hard plate, etc. It can be set arbitrarily according to the required characteristics.

  In order to produce the laminate of the present invention, the rubber composition for a highly attenuated laminate of the present invention is molded into a sheet and then vulcanized to obtain a sheet-like rubber composition, and then a layer containing an adhesive May be laminated alternately with the hard plate, or the rubber composition for the highly damped laminate of the present invention that has not been vulcanized in advance is formed into a sheet shape and laminated alternately with the hard plate, and then heated. Thus, vulcanization and adhesion may be performed simultaneously.

Since the laminated body of the present invention uses the above-described rubber composition of the present invention, it has a high damping property, an excellent shear modulus, and a damping property even in extremely cold regions where the minimum winter temperature reaches about -30 ° C. Further, it has an excellent effect that the temperature dependence of the shear modulus is small.
Specifically, the equivalent damping constant (Heq), which is an index of damping performance measured by a lap shear shear test described later, is 0.20 or more, and the shear modulus (Geq) measured in the same manner is 0.57-0. 96.
Further, the equivalent attenuation constant at minus 30 ° C. measured by lap shear shear test described below the ratio of the equivalent attenuation constant in (Heq ^{-30 ° C.)} and ^{23 ℃ (Heq 23 ℃) (} Heq -30 ℃ / Heq 23 ℃) and becomes less than 1.10, the shear modulus at minus 30 ° C. to measure similarly the (GEQ ^{-30 ° C.)} and 23 shear modulus at ° C. (GEQ ^{23 ° C.)} ratio of ^{(Geq -30 ℃ / Geq 23 ℃} ) 1 Less than 40.

The equivalent damping constant (Heq) and shear modulus (Geq) are measured by a lap shear shear test.
FIG. 2 is a schematic side view of a sample for a lap shear type shear test. In FIG. 2, the code | symbol 4 represents the sample for a lap shear type shear test, the code | symbol 5 represents the rolled unvulcanized rubber composition, and the code | symbol 6 represents a steel plate.
The unvulcanized rubber composition 5 is an unvulcanized rubber composition of the rubber 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 6 is a steel plate (width 25 mm × length 100 mm × thickness 20 mm) having a surface sandblasted and coated with a metal adhesive.
The sample 4 for lap shear type shear test is obtained by placing (stacking) the unvulcanized rubber composition 5 and the steel plate 6 as shown in FIG. 2 and then press vulcanizing at 130 ° C. for 120 minutes.

The lap shear shear test is performed under the following conditions using a vibrator (manufactured by Saginomiya), an input signal oscillator, and an output signal processor.
Using the lap shear type shear test sample prepared as described above, each time when a 175% strain was applied 10 times at a deformation frequency of 0.5 Hz by a biaxial shear tester at a measurement temperature of 23 ° C. Obtain the average shear characteristic value.
Specifically, using the Xmax and Qmax indicated by the hysteresis curve obtained in the lap shear type shear test, the equivalent damping constant (Heq) and shear modulus (Geq) are determined according to the following formulas (1) and (2). calculate. FIG. 3 shows an example of a hysteresis curve obtained by a lap shear type shear test.

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 attenuation laminate, and A is the cross-sectional area of the rubber layer.

  As long as the high-damping laminate is used as a vibration energy absorber, its use, application conditions, and the like are not particularly limited. Among these, since it has the above-described excellent characteristics, it is preferably used as a vibration energy absorbing device for buildings. For example, a vibration energy absorbing device for various types of seismic isolation, vibration isolation and vibration isolation (more specifically, Is suitably used for, for example, support of road bridges, bridges, building base isolation, and detached base isolation).

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely according to an Example, this invention is not limited to the following Example.

(Examples 1-6, Comparative Examples 1-5: Preparation of samples for lap shear type shear test)
First, each compound was blended so as to have the composition shown in Table 1 below (unit: parts by mass) and kneaded for 5 minutes with a B-type Banbury mixer to prepare an unvulcanized rubber composition.
Next, the prepared unvulcanized rubber composition was rolled into a size of width 25 mm × length 25 mm × thickness 5 mm.
An unvulcanized rubber composition after rolling (5 in FIG. 2) and a steel plate (25 mm wide × 100 mm long × 20 mm thick, 6 in FIG. 2) coated with a metal adhesive by sandblasting the surface. 2 was placed (laminated) as shown in the side view of the lap shear type shear test sample 4 in FIG. 2, and then press vulcanized at 130 ° C. for 120 minutes to prepare a lap shear type shear test sample.

<Tensile properties>
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 ) [%], 100% modulus (M ₁₀₀ ) [MPa] and 300% modulus (M ₃₀₀ ) [MPa] were measured at room temperature. The results are shown in Table 1.

<Lap shear test>
A lap shear 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 was ten.
Specifically, the shear characteristics of each time when 175% strain was applied 10 times at a deformation frequency of 0.5 Hz by a biaxial shear tester and a measurement temperature of 23 ° C. with respect to the lap shear type shear test sample. The average of the values was obtained.
Using Xmax and Qmax indicated by the hysteresis curve obtained by this lap shear shear test, average shear characteristic values (Geq, Heq) were determined according to the above formulas (1) and (2). The results are shown in Table 1.

<Evaluation of temperature dependence>
Using the lap shear type shear test sample prepared as described above, each time when a 175% strain was applied 10 times at a deformation frequency of 0.5 Hz by a biaxial shear tester at a measurement temperature of 23 ° C. The average shear characteristic value (n = 10) (Geq ^{23 ° C.} , Heq ^{23 ° C.} ) was determined.
Next, in the same manner as when the measurement temperature was room temperature (23 ° C.) except that the measurement temperature was changed to ^{−30 ° C.} , the average shear characteristic value at ^{−30 ° C.} (n = 10) (Geq ^{−30 ° C.} , Heq- ^{30 ° C} ) was determined.
Then, as the GEQ temperature dependence (in Table 1 in "- 30 ° C. / room temperature" described as) Geq ^{-30 ℃} / Geq ^{23 ℃} were calculated. The Heq temperature dependence was similarly performed. The results are shown in Table 1.

<Mixing / rolling workability>
The mixing / rolling workability is determined when the above-mentioned unvulcanized rubber composition is rolled and the state of the rubber when kneaded for 5 minutes with a B-type Banbury mixer in the preparation of the lap shear type shear test sample described above. The roll workability was evaluated.
As a result, it was evaluated as `` ◎ '' if both the state of rubber and the roll workability were extremely good, and evaluated as `` ○ '' if both the state of rubber and roll workability were good, Although the rubber was not well-organized, it was evaluated as “△” if the roll work could be done, and “x” if the rubber was not collected.

The following were used for each component in Table 1.
・ Natural rubber: STR20, manufactured by TECK BEE HANG ・ Vinyl-cis butadiene rubber: UBEPOL-VCR, manufactured by Ube Industries ・ Butadiene rubber: Nipol BR1220, manufactured by Nippon Zeon ・ Carbon black: Diamond Black I, manufactured by Mitsubishi Chemical Corporation ・ Silica : Nip seal VN3, manufactured by Tosoh Silica Co., Ltd. Inorganic filler: Clay (SUPREX PLAY, manufactured by Kentucky Tennessee Clay Company)
Petroleum resin: High Resin # 120 (softening point 120 ° C, manufactured by Toho Chemical Co., Ltd.)
・ Sulfur: powder sulfur, manufactured by Hosoi Chemical Co., Ltd. ・ Vulcanization accelerator: Noxeller CZ, manufactured by Ouchi Shinsei Chemical Co., Ltd.

As is apparent from Table 1, the laminates obtained from the rubber compositions for highly attenuated laminates prepared in Comparative Examples 1 to 4 are extremely cold regions where the attenuation and the minimum winter temperature reach about minus 30 ° C. The temperature dependence of the shear modulus was not satisfactory.
In contrast, the laminates obtained from the rubber compositions for highly attenuated laminates prepared in Examples 1 to 6 all have high damping properties, excellent shear modulus, and a minimum winter temperature of minus 30 ° C. It was found that the temperature dependence of damping and shear modulus was small even in extremely cold regions.
In addition, it turned out that the comparative example 5 which contains 90 mass% of general purpose butadiene rubbers as diene rubber is inferior to mixing / rolling workability.

FIG. 1 is a schematic cross-sectional view of a highly attenuated laminate that represents an example of an embodiment of the laminate of the present invention. FIG. 2 is a schematic side view of 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.

Explanation of symbols

1 High attenuation laminate (Seismic isolation laminate)
2 Hard plate 3 Rubber composition for high attenuation laminate of the present invention 4 Sample for lap shear type shear test 5 Rolled unvulcanized rubber composition 6 Steel plate

Claims (4)

Containing 100 parts by weight of a diene rubber, 40 to 75 parts by weight of carbon black, 5 to 30 parts by weight of silica, 5 to 55 parts by weight of an inorganic filler, and 5 to 50 parts by weight of a petroleum resin,
A rubber composition for a high attenuation laminate, wherein the diene rubber contains 80% by mass or more of vinyl-cis butadiene rubber. The total content of the silica and the inorganic filler is 20 to 75 parts by mass with respect to 100 parts by mass of the diene rubber,
The rubber composition for a high attenuation laminate according to claim 1, wherein a mass ratio of the silica and the inorganic filler (silica / inorganic filler) is 1/1 to 1 / 2.5.   The rubber composition for a high attenuation laminate according to claim 1 or 2, wherein a mass ratio of the inorganic filler and the petroleum resin (inorganic filler / petroleum resin) is 1 / 0.2 to 1 / 3.5. object.   A high attenuation laminate obtained by alternately laminating the rubber composition for a high attenuation laminate according to any one of claims 1 to 3 and a hard plate.

Images