JP2011126992A - Highly damping composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly damping composition solving a problem of temperature dependency by the use of a base polymer having no polar group and forming a highly damping member having more excellent damping performance than that of an existing one while keeping good processability. <P>SOLUTION: The highly damping composition uses (1) natural rubber, (2) a non-oil-extended styrene-butadiene rubber and at least one kind selected from a group comprising butadiene rubber having Mooney viscosity of ≤50 ML(1+4)100°C as the base polymers in combination. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a highly damped composition that is a source of a highly damped member that relaxes or absorbs transmission of vibration energy.

For example, in a wide range of fields such as buildings and bridges, industrial machinery, aircraft, automobiles, railway vehicles, computers and peripheral equipment, household electrical equipment, and automobile tires, vibration energy transmission is alleviated. In order to absorb or absorb, that is, to perform seismic isolation, vibration control, vibration control, vibration isolation, etc., a high damping member containing rubber or the like as a base polymer is used.
The high damping member includes the base polymer in order to increase the hysteresis loss when vibration is applied to improve damping performance, i.e., to efficiently and quickly attenuate the energy of the vibration. In general, it is formed by a high attenuation composition adjusted so that the peak of tan δ falls within the operating temperature range of the high attenuation member.

That is, the high attenuation composition is formed into a predetermined three-dimensional shape, and when the base polymer is rubber, the high attenuation composition is formed by vulcanization.
Examples of the highly attenuating composition include a base polymer containing silica as an attenuating agent (Patent Document 1), or a base polymer having a polar side chain having two or more polar groups. A material containing a phenolic damping agent or the like (Patent Document 2) is known.

  However, base polymers having polar groups in the molecule, such as those having polar side chains described in Patent Document 2 among the above, generally have a glass transition temperature Tg of around room temperature (3-35 ° C.). Therefore, the high attenuation member formed using the high attenuation composition containing the base polymer tends to increase the temperature dependency of characteristics such as rigidity in the vicinity of the room temperature which is the most general use temperature range. . For this reason, there is a problem that it is difficult to system design a high damping member while incorporating such characteristics.

On the other hand, in the highly attenuating composition of Patent Document 1, if the base polymer having no polar group is selected and used, the temperature-dependent problem can be solved. That is, it is possible to reduce the temperature dependence of characteristics such as rigidity near room temperature, and to form a high damping member that exhibits stable damping performance over a wide temperature range.
However, since a base polymer having no polar group usually has almost no damping performance as a simple substance, for example, in order to provide silica with high damping performance as a damping imparting agent, The content must be increased significantly.

  And as the content ratio of silica is increased, the workability of the high attenuation composition is lowered, and there is a problem that it is difficult to mass-produce a high attenuation member having a desired three-dimensional shape, particularly at a factory level. In addition, it is possible to form a small number of high-attenuation members at the laboratory level. However, since the formed high-attenuation members are hard and difficult to deform, there is a problem that they are easily broken particularly during large deformation.

Therefore, among the base polymer having no polar group, silica, a rosin derivative having two or more hydroxyl groups, an xylene resin, and a phenolic anti-aging agent having two or more hydroxyl groups as an organic damping agent. A highly attenuated composition containing at least one kind has been proposed (Patent Document 3).
According to the high attenuation composition, the temperature dependency problem can be solved by using the base polymer having no polar group. Further, by using silica and an organic damping agent in combination, it is possible to reduce the silica content and improve the processability of the high damping composition. In addition, it is possible to impart good damping performance to the high damping member by using both silica and an organic damping agent.

JP 7-41603 A JP 2000-44813 A JP 2009-138053 A

However, as described in Patent Document 3, there is a limit to the effect of improving attenuation performance by using silica and an organic attenuation imparting agent in combination. The use of two or more organic damping agents has also been studied, but that alone is not sufficient, and some new measures need to be taken to improve damping performance from the present situation.
The purpose of the present invention is to form a high-damping member that has better damping performance than the current one while eliminating the problem of temperature dependence by using a base polymer that does not have a polar group and maintaining good processability. It is to provide a highly attenuated composition.

The present invention provides a base polymer
(1) natural rubber,
(2) at least one selected from the group consisting of a non-oil extended styrene butadiene rubber and a butadiene rubber having a Mooney viscosity of 50 ML (1 + 4) 100 ° C. or less;
Is a highly attenuated composition characterized in that

  According to the present invention, as described above, by using a natural rubber, which is a diene polymer that does not have a polar group, and a non-oil-extended styrene butadiene rubber and / or a butadiene rubber, as described above, It is possible to reduce the temperature dependency of the characteristics of the high damping member near room temperature and solve the temperature dependency problem. Therefore, it is possible to form a high damping member that exhibits stable damping performance over a wide temperature range.

Further, according to the present invention, the combined use can further improve the damping performance of the high damping member from the present state as is apparent from the results of Examples and Comparative Examples described later.
That is, by using two or more kinds of rubbers together as the base polymer, it is possible to cause a deviation between different types of rubber molecules when the high damping member is deformed greatly, and this deviation causes a new damping effect. be able to. Therefore, the damping performance of the high damping member can be improved as compared with the case where the base polymer is a single body.

Further, as the base polymer, the two or more kinds of rubbers, both of which are diene polymers, are selected and used, so that, for example, a high-damping composition can be used as a predetermined high-damping member as compared with other rubbers. It is also possible to improve the adhesion to the metal fittings and the like when vulcanized and bonded to a fitting for mounting at the same time as the three-dimensional shape is formed and vulcanized.
Therefore, the amount of deformation of the high attenuation member that can be deformed without peeling from the metal fittings can be made larger than before. This is also one of the reasons that the damping performance of the high damping member can be improved.

Moreover, according to the present invention, as described above, the damping performance is excellent, and a high damping member that exhibits stable damping performance over a wide temperature range can be formed. The processability of the highly attenuated composition can be improved.
Therefore, according to the high attenuation composition of the present invention, the high attenuation which is more excellent in the attenuation performance than the current situation while eliminating the temperature dependency problem and maintaining good processability by the synergistic effect of these phenomena. A member can be formed.

Therefore, for example, when forming the damping damper for a building as a high damping member using the high damping composition of the present invention as a forming material, the quantity of the damping damper incorporated in one building Can be reduced. In addition, since the temperature dependency is small, for example, the damping damper can be installed near the outer wall of a building having a large temperature difference.
The proportion of the natural rubber in the total amount of the base polymer is preferably 40% by mass or more, and preferably 90% by mass or less. Non-oil-extended styrene-butadiene rubber and diene-based polymer having no polar group are particularly low in temperature dependence, and the content ratio of natural rubber capable of high filling with a filler such as silica is within the above range. By using butadiene rubber together, the damping performance of the high damping member can be further improved by the mechanism described above.

The high attenuation composition of the present invention preferably also contains 100 parts by mass or more and 180 parts by mass or less of silica per 100 parts by mass of the base polymer. Since the silica functions as an attenuation imparting agent as described above, the attenuation performance of the high attenuation member can be further improved.
Moreover, it is preferable that the high attenuation | damping composition of this invention also contains 10 mass parts or more and 20 mass parts or less of silane compounds per 100 mass parts of said silica. The silane compound functions as a dispersant for improving the affinity and compatibility of the silica with organic components such as a base polymer. Therefore, silica can be made to function more satisfactorily as an attenuating agent in the high attenuation member, and the attenuation performance of the high attenuation member can be further improved.

  According to the present invention, it is possible to provide a highly attenuating composition that can form a highly attenuating member that is more excellent in attenuating performance than the current state while eliminating the problem of temperature dependence and maintaining good workability. it can.

It is a disassembled perspective view which decomposes | disassembles and shows the test body as a model of the said high attenuation member produced in order to evaluate the attenuation performance of the high attenuation member which consists of the high attenuation composition of the Example of this invention, and a comparative example. FIGS. 4A and 4B are diagrams for explaining the outline of a testing machine for displacing the test body and obtaining the relationship between the displacement and the load. It is a graph which shows an example of the hysteresis loop which shows the relationship between the displacement amount and a load calculated | required by displacing a test body using the said testing machine.

The high damping composition of the present invention is used as a base polymer,
(1) natural rubber,
(2) at least one selected from the group consisting of a non-oil extended styrene butadiene rubber and a butadiene rubber having a Mooney viscosity of 50 ML (1 + 4) 100 ° C. or less;
It is characterized by using together.

As the styrene-butadiene rubber (SBR), non-oil-extended SBR that has not been extended with extension oil is used among various copolymers obtained by copolymerizing styrene and butadiene by emulsion polymerization, solution polymerization, etc. Is possible.
SBR is limited to non-oil-extended ones, even if oil-extended SBR is used in combination with natural rubber, not only the effect of improving the damping performance of the high-damping member described above is obtained, but also, for example, large This is because the high damping member is easily damaged during deformation.

Non-oil-extended SBR by the emulsion polymerization method includes, for example, JSR (registered trademark) 1500, JSR1502, JSR1507, JSR0202, JSR1503 manufactured by JSR Corporation, Nipol (registered trademark) 1500, Nipol 1502 manufactured by Nippon Zeon Co., Ltd., etc. Is mentioned.
Examples of the non-oil-extended SBR by the solution polymerization method include JSR SL552, JSR SL556, JSR SL574 manufactured by JSR Corporation, Nipol NS112, Nipol NS116 manufactured by Nippon Zeon Corporation, and the like.

As the SBR, those exemplified above may be used singly or in combination of two or more.
As the butadiene rubber (BR), any of various polymers having a polybutadiene structure and having a Mooney viscosity of 50 ML (1 + 4) 100 ° C. or less can be used.
The reason why the Mooney viscosity of BR is limited to 50 ML (1 + 4) 100 ° C. or less is that, even when BR with Mooney viscosity exceeding the above range is used in combination with natural rubber, the effect of improving the damping performance of the high damping member described above is achieved. This is because cannot be obtained. The Mooney viscosity of BR is preferably 25 ML (1 + 4) 100 ° C. or higher even within the above range.

Note that the Mooney viscosity [ML (1 + 4) 100 ° C.] of BR is determined according to the present invention in accordance with Japanese Industrial Standard JIS K6301-1: 2001 “Unvulcanized Rubber—Physical Properties—Part 1: Mooney Viscometer Viscosity and Scorch Time It shall be expressed as a value measured by the measuring method described in “How to obtain”.
Examples of BR satisfying the Mooney viscosity range include UBEPOL (registered trademark) BR130B [29 ML (1 + 4) 100 ° C.], BR133P [35 ML (1 + 4) 100 ° C.], BR700 [37 ML (1 + 4) manufactured by Ube Industries, Ltd. ) 100 ° C], BR230 [38ML (1 + 4) 100 ° C], BR150B [40ML (1 + 4) 100 ° C], BR150 [43ML (1 + 4) 100 ° C], BR150L [43ML (1 + 4) 100 ° C], Nippon Zeon Co., Ltd. Nipol BR1220 [43 ML (1 + 4) 100 ° C.], Nipol BR1220L [29 ML (1 + 4) 100 ° C.], JSR BR01 [45 ML (1 + 4) 100 ° C.], JSR BR51 [38 ML (1 + 4) 100 ° C. ] 1 type, or 2 or more types.

  The proportion of natural rubber in the total amount of the base polymer is preferably 40% by mass or more, and preferably 90% by mass or less. Non-oil-extended SBR and / or BR so that the content ratio of natural rubber that has a particularly low temperature dependency among diene polymers not having a polar group and can be highly filled with a filler such as silica is within the above range. By using together, the damping performance of the high damping member can be further improved by the mechanism described above.

In consideration of further improving the damping performance of the high damping member, the ratio of the natural rubber to the total amount of the base polymer is 70% by mass or less, particularly 50% by mass or less even within the above range. preferable.
The high attenuation composition of the present invention may contain 100 parts by mass or more and 180 parts by mass or less of silica per 100 parts by mass of the base polymer.

As the silica, any one of wet process silica and dry process silica classified by the production method may be used.
The silica, considering that to better achieving the good functioning effect of improving the damping performance of the high damping member as damping-imparting agent, the BET specific surface area of 100 m 2 / ^g or more, particularly 200 meters ² / g or more, preferably 400 m ² / g or less, particularly preferably 250 m ² / g or less. The BET specific surface area is represented by a value measured by a gas phase adsorption method using, for example, a rapid surface area measuring device SA-1000 manufactured by Shibata Chemical Machinery Co., Ltd. and using nitrogen gas as an adsorbed gas.

Examples of the silica include Nipsil (registered trademark) KQ manufactured by Tosoh Silica Corporation.
The content of silica is preferably 100 parts by mass or more, particularly 125 parts by mass or more, and preferably 180 parts by mass or less, particularly 145 parts by mass or less, per 100 parts by mass of the base polymer.

If the content ratio is less than the above range, the effect of improving the attenuation performance of the high attenuation member due to the inclusion of the silica as an attenuation imparting agent may not be sufficiently obtained.
If the above range is exceeded, the processability of the high-attenuating composition is lowered as described above, and it is not easy to mass-produce a high-attenuating member having a desired three-dimensional shape, particularly at the factory level. There is. In addition, a small number of high attenuation members can be formed at the laboratory level, but the formed high attenuation members are hard and difficult to deform.

  The highly attenuating composition of the present invention may further contain a silane compound. Since the silane compound functions as a dispersant for improving the affinity and compatibility of silica with organic components such as a base polymer, the silica is contained in the high attenuation member by containing the silane compound. The damping performance of the high damping member can be further improved by further functioning as a damping property imparting agent.

  Examples of the silane compound include the formula (a):

[Wherein, at least one of R ¹ , R ² , R ³ , and R ⁴ represents an alkoxy group. However, R ¹ , R ² , R ³ , and R ⁴ are not simultaneously an alkoxy group, and represent a cross-linked alkyl group or an aryl group. ]
And various silane compounds that can function as a silica dispersant, such as a silane coupling agent and a silylating agent. In particular, one or more of alkoxysilanes such as hexyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, and diphenyldimethoxysilane are preferable.

The content of the silane compound is preferably 10 parts by mass or more and 20 parts by mass or less per 100 parts by mass of silica.
If the content ratio is less than the above range, the effect of improving the damping performance of the high attenuation member by sufficiently allowing silica to function as an attenuation imparting agent in the high attenuation member by including the silane compound is sufficient. May not be obtained.

Moreover, even if the content ratio exceeds the above range, not only the effect is not obtained, but also foaming or the like may occur during vulcanization molding.
The high attenuation composition of the present invention may contain a softening agent. Examples of the softening agent include oils, plasticizers, and liquid rubber. Liquid rubber is particularly preferable. Examples of the liquid rubber include liquid isoprene rubber and liquid styrene-isoprene rubber. What is necessary is just to set suitably the content rate of the said liquid rubber according to the attenuation | damping characteristic of a high attenuation | damping member.

The highly attenuating composition of the present invention may further contain an attenuating agent other than silica, such as petroleum resin and coumarone resin. What is necessary is just to set suitably the content rate of the said other attenuation | damping property imparting agent according to the attenuation | damping characteristic of a high attenuation | damping member.
Further, the high damping composition of the present invention contains additives for vulcanizing diene base polymers such as vulcanizing agents, vulcanization accelerators, vulcanization accelerating aids and anti-aging agents in appropriate proportions. May be.

Further, the high attenuation composition of the present invention may contain a filler such as carbon black and calcium carbonate in an appropriate ratio.
The high attenuation composition of the present invention is obtained by kneading the above components using an arbitrary kneading machine, and molding the high attenuation composition into a predetermined three-dimensional shape and vulcanizing it to achieve predetermined attenuation characteristics. A high damping member having

  As the high damping member that can be formed using the high damping composition of the present invention, for example, a seismic isolation damper that is incorporated into the foundation of a building such as a building, and a damping damper that is incorporated into the structure of a building. Damping members for cables such as suspension bridges and cable-stayed bridges, anti-vibration members for industrial machines, aircraft, automobiles, railway vehicles, etc., anti-vibration members for computers and their peripheral devices, household electric appliances, etc. Examples include treads for automobile tires.

According to the present invention, by appropriately adjusting the type and content ratio of the diene base polymer, the type and content ratio of the liquid copolymer, silica, silane compound, and other additives with respect to the diene base polymer, the respective uses It is possible to obtain a high damping member having excellent damping performance suitable for the above.
In particular, when the damping damper incorporated in the structure of a building is formed using the high damping composition of the present invention, the damping damper is excellent in damping performance, so that the damping damper incorporated in one building is used. The quantity of seismic dampers can be reduced. In addition, since the temperature dependency is small, for example, the damping damper can be installed near the outer wall of a building having a large temperature difference.

The preparation and testing of the high attenuation compositions in the following examples and comparative examples were carried out in an environment with a temperature of 20 ± 1 ° C. and a relative humidity of 55 ± 1 ° C. unless otherwise specified.
<Example 1>
Natural rubber [SMR (Standard Malaysian Rubber) -CV60] 50 parts by mass as a base polymer, and non-oil-extended SBR [JSR1502 made by JSR Corporation, the above-mentioned, styrene: 23.5%, Mooney viscosity: 52ML ( 1 + 4) 100 ° C., molecular weight: 450,000] 50 parts by mass, liquid isoprene rubber [Claprene LIR-50 made by Kuraray Co., Ltd.] 35 parts by mass, silica [made by Tosoh Silica Co., Ltd. Nipsil KQ] 135 parts by mass, phenyl triethoxysilane (KBE-103 manufactured by Shin-Etsu Chemical Co., Ltd.) 23 parts by mass as a silane compound, and the components shown in Table 1 below were blended, and a closed kneader Was used for kneading to prepare a highly attenuated composition. The content ratio of phenyltriethoxysilane per 100 parts by mass of silica was 17 parts by mass.

Each component in Table 1 is as follows.
Dicyclopentadiene-based petroleum resin: softening point 105 ° C., Marukaretsu (registered trademark) M-890A manufactured by Maruzen Petrochemical Co., Ltd.
Coumarone resin: softening point 90 ° C., Nikko Chemical Co., Ltd. Escron (registered trademark) G-90
Benzimidazole anti-aging agent: 2-mercaptobenzimidazole, NOCRACK MB manufactured by Ouchi Shinsei Chemical Co., Ltd.
Quinone anti-aging agent: Antigen FR manufactured by Maruishi Chemical Co., Ltd.
5% oil-treated powder sulfur: vulcanizing agent, manufactured by Tsurumi Chemical Industry Co., Ltd. Sulfenamide vulcanization accelerator: N-tert-butyl-2-benzothiazolylsulfenamide, manufactured by Ouchi Shinsei Chemical Co., Ltd. Noxeller (registered trademark) NS
Thiuram-based vulcanization accelerator: Noxeller TBT-N manufactured by Ouchi Shinsei Chemical Co., Ltd.
2 types of zinc oxide: Vulcanization accelerating agent, manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: Vulcanization accelerating agent, "Tsubaki" manufactured by NOF Corporation
Carbon Black: Filler, Dia Black (registered trademark) G manufactured by Mitsubishi Chemical Corporation
<Example 2>
As non-oil-extended SBR, the same amount of JSR0202 [manufactured by JSR Corporation, bound styrene: 46%, Mooney viscosity: 45 ML (1 + 4) 100 ° C., molecular weight: 450,000] was used in the same manner as in Example 1. A highly attenuated composition was prepared.

<Comparative example 1>
Instead of non-oil-extended SBR, the same amount of oil-extended SBR [JSR6529 manufactured by JSR Corporation, bound styrene: 31.1%, Mooney viscosity: 52 ML (1 + 4) 100 ° C., molecular weight: 1 million, extended oil amount: 44%] was used in the same manner as in Example 1 to prepare a highly attenuated composition.
<Comparative example 2>
Instead of non-oil-extended SBR, the same amount of oil-extended SBR [JSR0372 manufactured by JSR Corporation, bound styrene: 38.8%, Mooney viscosity: 52 ML (1 + 4) 100 ° C., molecular weight: 700,000 to 800,000, extension A high damping composition was prepared in the same manner as in Example 1 except that the oil amount was 20%.

<Conventional example 1>
A highly attenuated composition was prepared in the same manner as in Example 1 except that the non-oil-extended SBR was not blended and the amount of natural rubber was 100 parts by mass.
<Example 3>
A highly attenuated composition was prepared in the same manner as in Example 1 except that the amount of natural rubber was 90 parts by mass and the amount of non-oil-extended SBR was 10 parts by mass.

<Example 4>
A highly attenuated composition was prepared in the same manner as in Example 1 except that the amount of natural rubber was 70 parts by mass and the amount of non-oil-extended SBR was 30 parts by mass.
<Example 5>
A highly attenuated composition was prepared in the same manner as in Example 1 except that the amount of natural rubber was 40 parts by mass and the amount of non-oil-extended SBR was 60 parts by mass.

<Example 6>
A highly attenuated composition was prepared in the same manner as in Example 1 except that the amount of silica was 100 parts by mass and the amount of phenyltriethoxysilane was 17 parts by mass. The content ratio of phenyltriethoxysilane per 100 parts by mass of silica was 17 parts by mass.
<Example 7>
A highly attenuated composition was prepared in the same manner as in Example 1 except that the amount of silica was 180 parts by mass and the amount of phenyltriethoxysilane was 30.7 parts by mass. The content ratio of phenyltriethoxysilane per 100 parts by mass of silica was 17 parts by mass.

<Damping characteristic evaluation>
(Preparation of test specimen)
The high attenuation compositions prepared in Examples, Comparative Examples, and Conventional Examples are extruded into a sheet shape and then punched to produce a disk 1 (thickness 5 mm × diameter 25 mm) as shown in FIG. The disk 1 is formed by superimposing a rectangular plate-shaped steel plate 2 of thickness 6 mm × length 44 mm × width 44 mm on both the front and back surfaces of the steel sheet and heating to 150 ° C. while pressing in the laminating direction. While the damping composition was vulcanized, the disk 1 was vulcanized and bonded to the two steel plates 2 to produce a specimen 3 for evaluating damping characteristics as a model of a high damping member.

(Displacement test)
As shown in FIG. 2 (a), two test specimens 3 are prepared, and the two test specimens 3 are fixed to one central fixing jig 4 via one steel plate 2, respectively. One left and right fixing jig 5 was fixed to the other steel plate 2 of the test body 3. Then, the central fixing jig 4 is fixed to a fixing arm 6 arranged on the upper side of the testing machine via a joint 7, and two left and right fixing jigs 5 are arranged on the lower side of the testing machine. The movable platen 8 was fixed via a joint 9. A bolt (not shown) was used for each fixation.

  Next, from the above state (initial state), the movable platen 8 is displaced so as to be pushed up in the direction of the fixed arm 6 as indicated by the white arrow in the drawing, and the disc 1 of the test body 3 is moved to the position shown in FIG. As shown in (b), a deformed state in which the specimen 3 is strained and deformed in a direction orthogonal to the stacking direction is obtained, and then from this deformed state, the movable platen 8 is fixed arm 6 as indicated by a white arrow in the figure. The disc 1 was repeatedly deformed, that is, oscillated by repeating the operation for 3 cycles by displacing it so as to be pulled down in the direction opposite to the direction and returning it to the initial state shown in FIG.

The hysteresis loop shown in FIG. 3 shows the relationship between the displacement (mm) and the load (N) of the disc 1 in the direction orthogonal to the stacking direction of the test body 3 when the strain deformation of the third cycle is performed. Asked.
The maximum amount of displacement was set such that the amount of deviation of the two steel plates 2 sandwiching the disc 1 in the direction perpendicular to the stacking direction was 200% of the thickness of the disc 1.

Then, connecting the maximum displacement point and the minimum displacement point of the hysteresis loop H in FIG. 3 as determined by the measurement, said lines L ₁ slope Keq with obtaining the straight line L ₁ shown by a thick solid line in FIG. (N / mm), and from the inclination Keq, the thickness T (mm) of the disc 1, and the cross-sectional area A (mm ² ) of the disc 1 in the direction orthogonal to the stacking direction, the formula (i):

The equivalent shear modulus Geq (N / mm ² ) was determined by
Further, it grated perpendicular L ₂ from the intersection of the hysteresis loop H to the horizontal axis of the graph. Then, the absorbed energy amount ΔW represented by the total surface area of the hysteresis loop H shown with diagonal lines in FIG. 3 and the straight line L ₁ and the perpendicular line L ₂ shown with halftone lines in FIG. And the elastic strain energy W expressed by the surface area of the right triangle region surrounded by the horizontal axis of the graph, the formula (ii):

Thus, an equivalent damping constant Heq was obtained.
It can be determined that the greater the equivalent attenuation constant Heq, the better the specimen 3 is in attenuation performance. In the present example, comparative example, and conventional example, when the equivalent attenuation constant Heq is 0.35 or more, the attenuation performance is good (◯), and when the equivalent attenuation constant Heq is less than 0.35, the attenuation performance is poor (×). Judged. The results are shown in Tables 2 and 3.

When Examples 1 to 7 in Table 2 and Table 3, Comparative Examples 1 and 2, and Conventional Example 1 are compared, the highly attenuated compositions of Examples 1 to 7 using natural rubber and non-oil-extended SBR are used. Thus, it was found that a high attenuation member having excellent attenuation characteristics as compared with the conventional case can be formed.
Moreover, when Example 1 of Table 2 and Examples 3-5 of Table 3 are compared, it turns out that it is preferable that the ratio for which natural rubber accounts to the total amount of a base polymer is 40 to 90 mass%. It was.

Furthermore, when Example 1 of Table 2 and Examples 6 and 7 of Table 3 were compared, it was found that the silica content was preferably 100 parts by mass or more and 180 parts by mass or less per 100 parts by mass of the base polymer. .
<Example 8>
70 parts by mass of natural rubber (the above-mentioned SMR (Standard Malaysian Rubber) -CV60) as a base polymer, and BR (UBEPOL BR130B manufactured by Ube Industries, Ltd., Mooney viscosity: 29 ML (1 + 4) 100 ° C., molecular weight 410,000] 30 parts by mass, liquid isoprene rubber [Claprene LIR-50 made by Kuraray Co., Ltd.] 35 parts by mass, silica [Nippil KQ made by Tosoh Silica Co., Ltd.] 135 parts by mass, And 23 parts by mass of phenyltriethoxysilane (KBE-103 manufactured by Shin-Etsu Chemical Co., Ltd.) as described above and each component shown in Table 1 above, and kneading using a closed kneader. Thus, a highly attenuated composition was prepared. The content ratio of phenyltriethoxysilane per 100 parts by mass of silica was 17 parts by mass.

<Example 9>
A highly attenuated composition was prepared in the same manner as in Example 8 except that the same amount of UBEPOL BR150B (manufactured by Ube Industries, Mooney viscosity: 40 ML (1 + 4) 100 ° C., molecular weight 500,000) was used as BR. .
<Example 10>
A highly attenuated composition was prepared in the same manner as in Example 8 except that the same amount of UBEPOL BR150L (manufactured by Ube Industries, Ltd., Mooney viscosity: 43 ML (1 + 4) 100 ° C., molecular weight 520,000) was used as BR. .

<Comparative Example 3>
A highly attenuating composition was prepared in the same manner as in Example 8 except that the same amount of UBEPOL BR360L (manufactured by Ube Industries, Mooney viscosity: 51 ML (1 + 4) 100 ° C., molecular weight 570,000) was used as BR. .
<Example 11>
A highly attenuated composition was prepared in the same manner as in Example 8 except that the amount of natural rubber was 90 parts by mass and the amount of BR was 10 parts by mass.

<Example 12>
A highly attenuated composition was prepared in the same manner as in Example 8 except that the amount of natural rubber was 50 parts by mass and the amount of BR was 50 parts by mass.
<Example 13>
A highly attenuated composition was prepared in the same manner as in Example 8 except that the amount of natural rubber was 40 parts by mass and the amount of BR was 60 parts by mass.

  The previous attenuation characteristics were evaluated for the examples and comparative examples. The results are shown in Tables 4 and 5.

When Examples 8 to 11 and Comparative Example 3 in Tables 4 and 5 are compared, the highly attenuated compositions of Examples 8 to 11 using natural rubber and BR having a Mooney viscosity of 50 ML (1 + 4) 100 ° C. or less. It was found that a high attenuation member having excellent attenuation characteristics can be formed by using.
Moreover, when Example 8 of Table 4 and Examples 11-13 of Table 5 are compared, it turns out that it is preferable that the ratio for which natural rubber occupies in the total amount of a base polymer is 40 to 90 mass%. It was.

DESCRIPTION OF SYMBOLS 1 Disc 2 Steel plate 3 Test body 4 Center fixing jig 5 Left and right fixing jig 6 Fixed arm 7 Joint 8 Movable platen 9 Joint

Claims (5)

As a base polymer,
(1) natural rubber,
(2) at least one selected from the group consisting of a non-oil extended styrene butadiene rubber and a butadiene rubber having a Mooney viscosity of 50 ML (1 + 4) 100 ° C. or less;
A high-damping composition characterized by being used in combination.   The high damping composition according to claim 1, wherein a ratio of the natural rubber in the total amount of the base polymer is 40% by mass or more and 90% by mass or less.   The high attenuation composition according to claim 1 or 2, further comprising 100 parts by mass or more and 180 parts by mass or less of silica per 100 parts by mass of the base polymer.   The high attenuation | damping composition of Claim 3 which also contains 10 mass parts or more and 20 mass parts or less of silane compounds per 100 mass parts of said silica.   The high-damping composition according to any one of claims 1 to 4, which is used as a material for forming a damping damper for a building.

Images