JP2017082171A - High attenuation rubber composition and viscoelastic damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel high attenuation rubber composition having good processability and capable of forming a viscoelastic body more excellent in attenuation performance than conventional ones and small in reduction of attenuation performance when added large deformation repeatedly.SOLUTION: A high attenuation rubber composition is manufactured by blending silica, alkoxysilane represented by the formula (1), where Rrepresents an alkyl group or a phenyl group having 1 to 10 carbon atoms, Rrepresents an alkyl group having 1 to 3 carbon atoms and n represents the number of 1 to 3, and silicone oligomer with a diene rubber. A viscoelastic damper has a viscoelastic body consisting of such high attenuation rubber composition.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a highly damped rubber composition that is a basis of a viscoelastic body that relaxes or absorbs transmission of vibration energy, and a viscoelastic damper that includes a viscoelastic body made of the highly damped rubber composition. It is.

For example, viscoelastic materials are used in a wide range of fields such as buildings such as buildings and bridges, industrial machines, airplanes, automobiles, railway vehicles, computers and peripheral equipment, household electrical equipment, and automobile tires. By using a viscoelastic body, transmission of vibration energy can be relaxed or absorbed, that is, seismic isolation, vibration control, vibration control, vibration isolation, and the like can be performed.
The viscoelastic body is formed by a high damping rubber composition mainly containing a diene rubber such as natural rubber.

In order to increase the hysteresis loss when vibration is applied to the highly damped rubber composition and to attenuate the energy of the vibration efficiently and quickly, that is, to increase the damping performance, inorganic materials such as carbon black and silica are used. In general, a filler or a tackifier such as rosin or petroleum resin is blended (see, for example, Patent Documents 1 to 3).
In order to further improve the damping performance of the viscoelastic body with these conventional configurations, it is conceivable to increase the blending ratio of an inorganic filler, a tackifier, and the like.

However, a highly damped rubber composition containing a large amount of an inorganic filler increases Mooney viscosity and makes kneading difficult, and a highly damped rubber composition containing a large amount of tackifier has a tackiness during kneading. Since it becomes too high, all have a problem that workability is lowered and it is not easy to knead or form a viscoelastic body having a desired three-dimensional shape.
In particular, when mass-producing viscoelastic bodies at the factory level, the low processability is not desirable because it greatly reduces the productivity, increases the energy required for production, and further increases the production cost.

In Patent Document 4, in order to improve the damping performance of the viscoelastic body, silica, a tackifier having two or more polar groups, and the like are blended with a diene rubber having no polar side chain such as natural rubber. It is being considered.
However, when the blending ratio of the specific tackifier is increased in order to further improve the damping performance than the current situation, the tackifier blooms on the surface of the viscoelastic body and the viscoelasticity is increased. There is a concern that adhesion failure between the body and metal or the like may occur.

In Patent Document 5, it is studied to further improve the damping performance by using a rosin derivative having a specific softening point as a tackifier.
However, when the blending ratio of the rosin derivative is increased in order to further improve the damping performance as compared with the current situation, there is a problem that the adhesiveness at the time of kneading becomes too high and the workability is lowered.

In Patent Document 6, it is studied to further improve the attenuation performance by blending imidazole and a hindered phenol compound as an attenuation imparting agent.
Further, in Patent Document 7, silica, an alkoxysilane that functions as a silylating agent that improves the affinity and dispersibility of the silica for the diene rubber, and a specific reactive component are added to the diene rubber. It has been studied to achieve both high rigidity and good damping performance of the viscoelastic body and good workability of the high damping rubber composition.

However, even in these configurations, the current situation is that the recent demand for higher attenuation cannot be fully met.
In addition, viscoelastic bodies formed using conventional high-damping rubber compositions such as those described in Patent Documents 1 to 7 have a significant decrease in damping performance when large deformations are repeatedly applied, particularly due to earthquakes. However, if the desired performance is to be secured while taking into account such a decrease in damping performance, there is also a problem that the design as a product such as a viscoelastic damper becomes complicated.

Japanese Patent No. 3523613 JP 2007-63425 A Japanese Patent No. 2796044 JP 2009-138053 A JP 2010-189604 A Japanese Patent No. 5086386 JP2013-53251A

An object of the present invention is a novel high-damping rubber that has excellent workability and that can form a viscoelastic body that has excellent damping performance than the current situation and that has a small decrease in damping performance when repeatedly subjected to large deformation. It is to provide a composition.
Moreover, since this invention is provided with the viscoelastic body which consists of the said high attenuation | damping rubber composition, it is providing the viscoelastic damper of buildings etc. which does not have a possibility that the design as a product may become complicated.

  The present invention relates to a diene rubber, silica, formula (1):

Wherein, ^{R 1} represents an alkyl group or phenyl group having 1 to 10 carbon atoms, ^{R 2} represents an alkyl group having 1 to 3 carbon atoms, n is a number of 1-3. ]
A high-damping rubber composition comprising an alkoxysilane represented by the formula (II) and a silicone oligomer.
Moreover, this invention is a viscoelastic damper provided with the viscoelastic body which consists of a high damping rubber composition of the said invention.

According to the present invention, a novel high-damping rubber that has excellent workability and is capable of forming a viscoelastic body that is superior in current damping performance and has a small decrease in damping performance when repeatedly subjected to large deformation. A composition can be provided.
Moreover, according to this invention, since the viscoelastic body which consists of the said high attenuation | damping rubber composition is provided, viscoelastic dampers, such as a building which does not have a possibility that the design as a product may become complicated, can be provided.

It is a disassembled perspective view which decomposes | disassembles and shows the test body as a model of the said viscoelastic body produced in order to evaluate the damping performance of the viscoelastic body which consists of the high damping rubber composition of the Example of this invention, and a comparative example. . FIGS. 9A and 9B are diagrams for explaining the outline of a testing machine for displacing the test body and obtaining the relationship between the displacement amount 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.

<< High damping rubber composition >>
According to the inventors' investigation, when the silicone oligomer is used in combination with the alkoxysilane represented by the formula (1) that functions as a silylating agent that improves the affinity and dispersibility of silica for the diene rubber, the silicone oligomer is By assisting the function of the alkoxysilane, the affinity and dispersibility of the silica for the diene rubber can be further improved as compared with the case where the alkoxysilane is used alone.

Therefore, the damping performance of the viscoelastic body can be further improved without increasing the blending ratio of silica, which may reduce the processability of the high damping rubber composition, and large deformation is repeatedly added to the viscoelastic body. It is also possible to prevent the attenuation performance from being deteriorated.
Moreover, when the silicone oligomer is used in combination, the processability of the high-damping rubber composition can be further improved as compared with the case where the alkoxysilane is used alone.

Therefore, according to the present invention, a highly damped rubber composition that can form a viscoelastic body that has good workability, is excellent in damping performance than the current state, and has a small decrease in damping performance when repeatedly subjected to large deformation. Can provide.
<Diene rubber>
Examples of the diene rubber include at least one selected from the group consisting of natural rubber, isoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), and chloroprene rubber (CR).

  These diene rubbers are excellent in silica affinity for the diene rubber and reactivity with alkoxysilanes blended to improve dispersibility, and have a glass transition temperature of around room temperature (2-35 ° C). Therefore, it is possible to form a viscoelastic body that exhibits stable damping performance over a wide temperature range by reducing the temperature dependence of properties such as rigidity in the vicinity of room temperature, which is the most common operating temperature range. There is.

Among them, the crosslinked structure of rubber molecules in a crosslinked state is gradual, a viscoelastic body excellent in damping performance can be formed, and it is easy to obtain and has an advantage that a highly damped rubber composition can be produced at low cost. Natural rubber is preferably used in that respect.
Examples of the natural rubber include one or more of natural rubbers of various grades such as SMR (Standard Malaysian Rubber) -CV60, and various deproteinized natural rubbers.

In addition, when SBR is used in combination with natural rubber, it is possible to suppress the vulcanization return of natural rubber and the accompanying decrease in damping performance.
As the SBR, any of various SBRs synthesized by copolymerizing styrene and 1,3-butadiene by various polymerization methods such as an emulsion polymerization method and a solution polymerization method can be used.
As the SBR, any of high styrene type, medium styrene type, and low styrene type SBR classified by styrene content can be used.

Furthermore, SBR includes an oil-extended type in which flexibility is adjusted by adding an extending oil, and a non-oil-extended type in which flexibility is not added. In the present invention, any type of SBR can be used.
One or more of these SBRs can be used.
When natural rubber and SBR are used in combination, the blending ratio of SBR is preferably 5 parts by mass or more and preferably 40 parts by mass or less in a total amount of 100 parts by mass of both diene rubbers.

When the blending ratio of SBR is less than this range, there is a possibility that the effect of suppressing the above-described reversion of natural rubber and the accompanying decrease in damping performance due to the combined use of the SBR may not be sufficiently obtained.
On the other hand, when the blending ratio of SBR exceeds the above range, the ratio of natural rubber is relatively reduced, so that the damping performance of the viscoelastic body by the natural rubber is improved, or the viscoelastic body is cost-effective. There is a possibility that the effect of manufacturing at low cost cannot be obtained sufficiently.

On the other hand, by making the blending ratio of SBR within the above range, while maintaining the above-mentioned effects by using mainly natural rubber, the vulcanization return of natural rubber and the accompanying decrease in damping performance are achieved. Etc. can be suppressed satisfactorily.
In consideration of further improving the effect, the blending ratio of SBR is preferably 10 parts by mass or more in the total amount of 100 parts by mass of both diene rubbers in the above range, and 30 parts by mass or less. Is preferred.

<silica>
Silica functions in order to improve the rigidity and damping performance of the viscoelastic body by being dispersed in the diene rubber by the function of alkoxysilane and silicone oligomer.
As such silica, either wet method silica or dry method silica classified according to its production method may be used.

In consideration of further improving the effect of improving the damping performance of the viscoelastic body, silica having a BET specific surface area of 100 to 400 m ² / g, particularly 200 to 280 m ² / g is preferably used. . The BET specific surface area is expressed by a value measured by a gas phase adsorption method using nitrogen gas as an adsorbed gas, for example, using a rapid surface area measuring device SA-1000 manufactured by Shibata Chemical Instruments Co., Ltd.

Specific examples of the silica include NipSil (registered trademark) KQ [wet process silica, BET specific surface area: 240 m ² / g] manufactured by Tosoh Silica Co., Ltd.
The blending ratio of silica is preferably 100 parts by mass or more and preferably 150 parts by mass or less per 100 parts by mass of the total amount of diene rubber.
If the blending ratio of silica is less than this range, there is a possibility that good damping performance cannot be imparted to the viscoelastic body.

In addition, when the blending ratio of silica exceeds the above range, the processability of the high-damping rubber composition is lowered, or the durability when a large deformation is repeatedly applied to the viscoelastic body is lowered, and the viscosity is reduced. There is a risk that the elastic body may be damaged.
On the other hand, by making the blending ratio of silica in the above range, the processability of the highly damped rubber composition can be improved or the durability when large deformation is repeatedly applied to the viscoelastic body can be improved. However, it is possible to give the viscoelastic body as good damping performance and high rigidity as possible.

In consideration of further improving this effect, the blending ratio of silica is preferably 120 parts by mass or more and 100 parts by mass or less per 100 parts by mass of the total amount of the diene rubber even in the above range. Is preferred.
<Alkoxysilane>
As the alkoxysilane, the formula (1):

Wherein, ^{R 1} represents an alkyl group or phenyl group having 1 to 10 carbon atoms, ^{R 2} represents an alkyl group having 1 to 3 carbon atoms, n is a number of 1-3. ]
Various alkoxysilanes represented by the formula can be used.
Examples of the alkoxysilane include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, One type or two or more types of hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane and the like can be mentioned.

In particular, R ¹ in formula (1) is a phenyl group, and R ² is a methyl group, which improves the affinity and dispersibility of silica for diene rubber and is also excellent in the damping performance and rigidity of the viscoelastic body. And at least one kind such as phenyltrimethoxysilane in which n is 1 and phenyltriethoxysilane in which R ¹ is a phenyl group, R ² is an ethyl group and n is 1 are preferable.
<Silicone oligomer>
The silicone oligomer includes monofunctional M represented by the following formula (2), bifunctional D represented by the formula (3), trifunctional T represented by the formula (4), and a formula Of the silicone resin that is an arbitrary copolymer of each tetrafunctional Q repeating unit represented by (5), the dimer, trimer or more of any one of the above repeating units, Various silicone oligomers having a molecular weight of 1000 or less can be used.

  As such a silicone oligomer, for example, various silicone oligomers manufactured by Shin-Etsu Chemical Co., Ltd. can be used, and in particular, at both ends and side chains of the main chain, an alkoxy group such as a methoxy group, a methyl group, and a phenyl group And various non-reactive groups (corresponding to R) such as epoxy groups, mercapto groups, acrylic groups, methacrylic groups, vinyl groups and the like, and various silicone oligomers classified as type A Are preferably used.

Further, as a type A silicone oligomer, for example, X-40-9246 manufactured by the same company [nonreactive group: methyl group, alkoxy group: methoxy group, viscosity at 25 ° C .: 80 mm ² / s, amount of alkoxy group: 12 mass %], X-40-9250 [non-reactive group: methyl group, alkoxy group: methoxy group, viscosity at 25 ° C .: 160 mm ² / s, amount of alkoxy group: 25% by mass], X-40-9227 [none] Reactive group: methyl group and phenyl group, alkoxy group: methoxy group, viscosity at 25 ° C .: 15 mm ² / s, alkoxy group amount: 15% by mass] and the like.

These silicone oligomers function to assist the action of alkoxysilane, as described above, and are also excellent in improving the workability of high-damping rubber compositions and increasing the flexibility of viscoelastic bodies. Yes.
In view of this effect, X-40-9227 is particularly preferable as the silicone oligomer.

<Mass ratio, blending ratio>
The alkoxysilane and the silicone oligomer can be used in any ratio, but they are used in the range of 10/90 or more and 70/30 or less in terms of the mass ratio O / A of the alkoxysilane (A) and the silicone oligomer (O). Is preferred.
When the proportion of silicone oligomer is less than this range, the effect of assisting the action of alkoxysilane by using the silicone oligomer together cannot be obtained sufficiently. There is a possibility that the decrease in the temperature cannot be sufficiently suppressed. In addition, the processability of the highly damped rubber composition may be reduced.

On the other hand, when the proportion of silicone oligomer is larger than the above range, the proportion of alkoxysilane is relatively reduced. Therefore, the affinity and dispersibility of silica with respect to the diene rubber by the alkoxysilane are improved, and the viscosity is increased. There is a possibility that the effect of improving the damping performance of the elastic body cannot be obtained sufficiently.
On the other hand, the combined use of alkoxysilane and silicone oligomer in the above range further improves the damping performance of the viscoelastic body while maintaining good processability of the highly attenuated rubber composition. It is possible to further reduce a decrease in attenuation performance when large deformation is repeatedly applied.

In consideration of further improving this effect, the mass ratio O / A is preferably 20/80 or more, and preferably 40/60 or less, even in the above range.
Further, the total blending ratio of alkoxysilane and silicone oligomer is preferably 10 parts by mass or more and preferably 40 parts by mass or less per 100 parts by mass of the total amount of diene rubber.

When the total blending ratio is less than this range, the damping performance of the viscoelastic body is improved while maintaining good processability of the high damping rubber composition, and the viscoelastic body is repeatedly subjected to large deformation. There is a possibility that the effect of reducing the decrease in the attenuation performance cannot be obtained sufficiently.
On the other hand, when the total blending ratio exceeds the above range, the damping performance and rigidity of the viscoelastic body may be lowered, and the workability of the high damping rubber composition may be lowered.

On the other hand, by making the total blending ratio of alkoxysilane and silicone oligomer in the above range, while further improving the damping performance of the viscoelastic body while maintaining good processability of the high damping rubber composition, It is possible to further reduce the decrease in damping performance when large deformation is repeatedly applied to the viscoelastic body.
In consideration of further improving this effect, the total blending ratio of alkoxysilane and silicone oligomer is preferably 15 parts by mass or more, and preferably 30 parts by mass or less, even in the above range. .

<Crosslinking component>
The high damping rubber composition of the present invention contains a crosslinking component for crosslinking the diene rubber.
Examples of the crosslinking component include a crosslinking agent and an accelerator.
Of the crosslinking components, a sulfur crosslinking agent is particularly preferred as the crosslinking agent.

Examples of the sulfur-based crosslinking agent include sulfur such as powdered sulfur, oil-treated powdered sulfur, precipitated sulfur, colloidal sulfur, and dispersible sulfur, or organic sulfur-containing compounds such as tetramethylthiuram disulfide and N, N-dithiobismorpholine. In particular, sulfur is preferable.
The blending ratio of sulfur is preferably 0.5 parts by mass or more and preferably 3 parts by mass or less per 100 parts by mass of the total amount of diene rubber.

For example, when oil-treated powder sulfur, dispersible sulfur, or the like is used as sulfur, the blending ratio is the ratio of sulfur itself as an active ingredient contained therein.
Examples of the accelerator include sulfenamide accelerators and thiuram accelerators. It is preferable to use two or more kinds of accelerators in combination because the mechanism for promoting crosslinking varies depending on the kind.

Among these, examples of the sulfenamide-based accelerator include Noxeller (registered trademark) NS [N-tert-butyl-2-benzothiazolylsulfenamide] manufactured by Ouchi Shinko Chemical Industry Co., Ltd.
The blending ratio of the sulfenamide-based accelerator is preferably 0.5 parts by mass or more and preferably 3 parts by mass or less per 100 parts by mass of the total amount of the diene rubber.

Examples of the thiuram accelerator include Noxeller TBT [tetrabutylthiuram disulfide] manufactured by Ouchi Shinsei Chemical Co., Ltd.
The mixing ratio of the thiuram accelerator is preferably 0.5 parts by mass or more and preferably 3 parts by mass or less per 100 parts by mass of the total amount of the diene rubber.
<Other ingredients>
In addition to the above-described components, the high-damping rubber composition of the present invention further contains other inorganic fillers other than silica, crosslinking aids, softeners, tackifiers, anti-aging agents, and the like in appropriate proportions. You may mix | blend.

(Inorganic filler)
Examples of inorganic fillers other than silica include carbon black.
As the carbon black, one or more carbon blacks that can function as a filler can be used among various carbon blacks classified according to the production method thereof.

The blending ratio of carbon black is preferably 1 part by mass or more and preferably 5 parts by mass or less per 100 parts by mass of the total amount of diene rubber.
(Crosslinking aid)
Examples of the crosslinking aid include metal compounds such as zinc oxide; fatty acids such as stearic acid, oleic acid, and cottonseed fatty acid, and one or more conventionally known crosslinking aids. In particular, it is preferable to use zinc oxide and stearic acid in combination.

Among these, the blending ratio of zinc oxide is preferably 1 part by mass or more and preferably 5 parts by mass or less per 100 parts by mass of the total amount of the diene rubber.
Further, the mixing ratio of stearic acid is preferably 1 part by mass or more and preferably 3 parts by mass or less per 100 parts by mass of the total amount of the diene rubber.
(Softener)
The softening agent is a component for further improving the processability of the high-damping rubber composition, and examples of the softening agent include liquid rubber that exhibits a liquid state at room temperature (2 to 35 ° C.). Examples of the liquid rubber include one or more of liquid polyisoprene rubber, liquid nitrile rubber (liquid NBR), liquid styrene butadiene rubber (liquid SBR), and the like.

Of these, liquid polyisoprene rubber is preferred. Examples of the liquid polyisoprene rubber include Kuraray (trademark) LIR-30 (number average molecular weight: 28000) and LIR-50 (number average molecular weight: 54000) manufactured by Kuraray Co., Ltd.
The blending ratio of the liquid polyisoprene rubber is preferably 5 parts by mass or more and preferably 50 parts by mass or less per 100 parts by mass of the total amount of diene rubber.

Examples of other softeners include coumarone / indene resin.
Examples of the coumarone-indene resin include various coumarone-indene resins which are mainly composed of a polymer of coumarone and indene, have a relatively low molecular weight of about 1000 or less in average molecular weight, and can function as a softening agent.
As the coumarone-indene resin, for example, Knit Resin (registered trademark) Coumarone G-90 manufactured by Nikkiso Chemical Co., Ltd. [average molecular weight: 770, softening point: 90 ° C., acid value: 1.0 KOHmg / g or less, hydroxyl value] : 25KOHmg / g, bromine number 9g / 100g], G-100N [average molecular weight: 730, softening point: 100 ° C, acid value: 1.0KOHmg / g or less, hydroxyl value: 25KOHmg / g, bromine number 11g / 100g] V-120 [average molecular weight: 960, softening point: 120 ° C., acid value: 1.0 KOH mg / g or less, hydroxyl value: 30 KOH mg / g, bromine value 6 g / 100 g], V-120S [average molecular weight: 950, softening Point: 120 ° C., acid value: 1.0 KOH mg / g or less, hydroxyl value: 30 KOH mg / g, bromine value 7 g / 100 g] and the like.

The blending ratio of the coumarone / indene resin is preferably 3 parts by mass or more and preferably 20 parts by mass or less per 100 parts by mass of the total amount of the diene rubber.
(Tackifier)
Examples of the tackifier include petroleum resins. As the petroleum resin, for example, Marcaretz (registered trademark) M890A [dicyclopentadiene-based petroleum resin, softening point: 105 ° C.] manufactured by Maruzen Petrochemical Co., Ltd. is preferable.

The blending ratio of the petroleum resin is preferably 3 parts by mass or more per 100 parts by mass of the total amount of the diene rubber, and is preferably 30 parts by mass or less.
(Anti-aging agent)
As an anti-aging agent, 1 type, or 2 or more types of various anti-aging agents, such as a benzimidazole type, a quinone type, a polyphenol type, and an amine type, are mentioned, for example. In particular, it is preferable to use a benzimidazole antioxidant and a quinone antioxidant together.

Among them, examples of the benzimidazole-based anti-aging agent include NOCRACK (registered trademark) MB [2-mercaptobenzimidazole] manufactured by Ouchi Shinko Chemical Industry Co., Ltd.
The blending ratio of the benzimidazole anti-aging agent is preferably 0.5 parts by mass or more per 100 parts by mass of the total amount of the diene rubber, and is preferably 5 parts by mass or less.
Examples of the quinone anti-aging agent include Antigen FR [aromatic ketone-amine condensate] manufactured by Cobblestone Chemical Co., Ltd.

The blending ratio of the quinone antioxidant is preferably 0.5 parts by mass or more and preferably 5 parts by mass or less per 100 parts by mass of the total amount of the diene rubber.
<High damping rubber composition>
According to the high-damping rubber composition of the present invention including the above-described components, for example, a viscoelastic bearing for seismic isolation incorporated in the foundation of a building such as a building, or a vibration control (damping control) incorporated in the structure of a building. A viscoelastic body constituting a viscoelastic damper for vibration) can be formed.

Further, according to the high damping rubber composition of the present invention, for example, a vibration damping member for a cable such as a suspension bridge or a cable-stayed bridge, a vibration damping member for an industrial machine, an aircraft, an automobile, a railway vehicle, etc., a computer, its peripheral devices, or a household Various viscoelastic bodies used as vibration isolating members for electric appliances for automobiles, treads for automobile tires, and the like can also be formed.
And according to the present invention, by adjusting diene rubber, silica, alkoxysilane, silicone oligomer, cross-linking component and other various component types and their combination and blending ratio, each viscoelastic body can be used for each application. It can have a suitable and excellent damping performance.

《Viscoelastic damper》
In particular, when the viscoelastic body of a viscoelastic damper incorporated in the structure of a building is formed using the high damping rubber composition of the present invention as a forming material, the viscoelastic body has high damping performance. Even if the damping performance of individual viscoelastic dampers including such viscoelastic bodies is improved and the whole is downsized or the number incorporated in one building is reduced, the same damping performance as before can be secured. be able to.

In addition, it is possible to suppress a decrease in attenuation performance when large deformation is repeatedly applied due to the occurrence of an earthquake, etc., and it is not necessary to secure the expected performance after taking into account the decrease in the attenuation performance. It is also possible to suppress the complicated design of the elastic damper as a product.
In addition, the diene rubber can reduce the temperature dependence of the damping performance and physical properties of the viscoelastic body as described above. For example, a viscoelastic damper can be installed near the outer wall of a building with a large temperature difference. It is also possible to expand the degree of freedom in designing the vibration control performance of objects with viscoelastic dampers.

<Example 1>
100 parts by mass of natural rubber [SMR-CV60] as a diene rubber, 125 parts by mass of silica [NipSil KQ manufactured by Tosoh Silica Co., Ltd.], phenyltriethoxysilane as an alkoxysilane represented by the formula (1) [KBE-103 manufactured by Shin-Etsu Chemical Co., Ltd.] 20 parts by mass and silicone oligomer [X-40-9227 manufactured by Shin-Etsu Chemical Co., Ltd., non-reactive groups: methyl group and phenyl group, alkoxy group: methoxy Viscosity at 25 ° C .: 15 mm ² / s, alkoxy group amount: 15% by mass] 8 parts by mass and each component other than the crosslinking component among the components shown in Table 1 below, are mixed in a closed kneader. After kneading, a high-damping rubber composition was prepared by further adding a crosslinking component and kneading.

The mass ratio O / A was 28.6 / 71.4, and the total blending ratio of alkoxysilane and silicone oligomer was 28 parts by mass per 100 parts by mass of natural rubber as a diene rubber.
The kneading was easy and the processability was evaluated as good (◯).

Each component in the table is as follows. Moreover, the mass part in a table | surface is a mass part per 100 mass parts of natural rubber, respectively.
Liquid polyisoprene rubber: LIR-50 manufactured by Kuraray Co., Ltd., number average molecular weight: 54000
Carbon Black: FEF, Toast Carbon Co., Ltd. Seast 3
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.
Two types of zinc oxide: manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: "Tsubaki" manufactured by NOF Corporation
Coumarone-indene resin: 90 ° C. softening point, Knit Resin (registered trademark) Coumaron G-90 manufactured by Nikko Chemical Co., Ltd.
Dicyclopentadiene-based petroleum resin: softening point 105 ° C., Marukaretsu (registered trademark) M890A manufactured by Maruzen Petrochemical Co., Ltd.
5% oil-treated powder sulfur: vulcanizing agent, manufactured by Tsurumi Chemical Industry Co., Ltd. Sulfenamide accelerator: N-tert-butyl-2-benzothiazolylsulfenamide, manufactured by Ouchi Shinsei Chemical Industry Co., Ltd. Noxeller (registered trademark) NS
Thiuram accelerator: Tetrabutylthiuram disulfide, Noxeller TBT-p manufactured by Ouchi Shinsei Chemical Co., Ltd.
<Example 2>
As diene rubber, 80 parts by mass of natural rubber and 20 parts by mass of SBR [Sumitomo SBR1502 manufactured by Sumitomo Chemical Co., Ltd.] are used in combination, and the above-mentioned components are the same for 100 parts by mass of the total amount of both diene rubbers. A highly attenuated rubber composition was prepared in the same manner as in Example 1 except that the amount was blended.

The mass ratio O / A was 28.6 / 71.4, and the total blending ratio of alkoxysilane and silicone oligomer was 28 parts by mass per 100 parts by mass of the total amount of natural rubber + SBR as the diene rubber.
The kneading was easy and the processability was evaluated as good (◯).
<Example 3>
A highly attenuated rubber composition was prepared in the same manner as in Example 2, except that the blending ratio of the silicone oligomer per 100 parts by mass of the natural rubber + SBR as the diene rubber was 2.5 parts by mass.

The mass ratio O / A was 11.1 / 88.9, and the total blending ratio of alkoxysilane and silicone oligomer was 22.5 parts by mass per 100 parts by mass of the natural rubber + SBR as the diene rubber.
The kneading was easy and the processability was evaluated as good (◯).
<Example 4>
High attenuation in the same manner as in Example 2, except that the blending ratio of alkoxysilane and the blending ratio of silicone oligomer was 13 parts by weight per 100 parts by weight of the natural rubber + SBR as the diene rubber. A rubber composition was prepared.

The mass ratio O / A was 68.4 / 31.6, and the total blending ratio of alkoxysilane and silicone oligomer was 19 parts by mass per 100 parts by mass of the total amount of natural rubber + SBR as the diene rubber.
The kneading was easy and the processability was evaluated as good (◯).
<Comparative example 1>
A highly attenuated rubber composition was prepared in the same manner as in Example 2, except that the silicone oligomer was not compounded with a blending ratio of alkoxysilane of 28 parts by mass per 100 parts by mass of the natural rubber + SBR as the diene rubber. Prepared.

Since the kneading took a longer time than Examples 1 to 6, the workability was evaluated as poor (x).
<Comparative example 2>
A highly attenuated rubber composition was prepared in the same manner as in Example 2 except that alkoxysilane was not compounded with a blending ratio of silicone oligomer of 28 parts by mass per 100 parts by mass of natural rubber + SBR as diene rubber. Prepared.

Kneading was easy and the processability was evaluated as good (◯).
<Attenuation characteristic test>
(Preparation of test specimen)
The high damping rubber compositions prepared in Examples and Comparative Examples are extruded into a sheet and then punched to produce the disc 1 (thickness 5 mm × diameter 25 mm) shown in FIG. A high-attenuation rubber composition for forming a circular plate 1 by heating a rectangular flat steel plate 2 having a thickness of 6 mm, a length of 44 mm and a width of 44 mm through a vulcanized adhesive and heating to 150 ° C. while pressing in the laminating direction. While the product was vulcanized, the disk 1 was vulcanized and bonded to the two steel plates 2 to prepare a test body 3 for evaluating damping characteristics as a model of a viscoelastic body.

(Displacement test)
As shown in FIG. 2 (a), two test bodies 3 are prepared, and the two test bodies 3 are fixed to one central fixing jig 4 with bolts through one steel plate 2, respectively. At the same time, one left and right fixing jig 5 was fixed to the other steel plate 2 of both test bodies 3 with bolts. The center fixing jig 4 is fixed to the upper fixing arm 6 of the testing machine (not shown) with a bolt via a joint 7, and the two left and right fixing jigs 5 are moved to the lower movable plate of the testing machine. 8 was fixed with bolts through a joint 9.

  Next, in this state, the movable platen 8 is displaced so as to be pushed up in the direction of the fixed arm 6 as shown by the white arrow in FIG. 2 (a), so that the disk 1 is shown in FIG. 2 (b). Next, from this state, the movable platen 8 is pulled down in the direction opposite to the direction of the fixed arm 6 as shown by the white arrow in FIG. 2 (b). The operation of displacing the disk 1 and returning it to the state shown in FIG. 2A is one cycle, and the amount of displacement (mm) in the thickness direction of the disk 1 when the disk 1 is repeatedly deformed, that is, vibrated. A hysteresis loop H (see FIG. 3) showing the relationship with the load (N) was obtained.

In the measurement, the above operation was carried out for 3 cycles under an environment of a temperature of 20 ° C., and a third value was obtained. The maximum amount of displacement was set so that the deviation of the two steel plates 2 sandwiching the disc 1 in the direction perpendicular to the thickness direction of the disc 1 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 shown in FIG. 3 obtained by the above measurement, determine the slope Keq (N / mm) of the straight line L ₁ shown by a thick solid line in the figure, From the inclination Keq (N / mm), the thickness T (mm) of the disc 1, and the cross-sectional area A (mm ² ) of the disc 1, the formula (a):

The equivalent shear modulus Geq (N / mm ² ) was determined by
Then, when the equivalent shear elastic modulus Geq (N / mm ² ) in Example 1 is set to 100, the relative value of the equivalent shear elastic modulus Geq (N / mm ² ) of each Example and Comparative Example is obtained, and the relative value is obtained. Of 90 or more were evaluated as good (◯), and those of less than 90 were evaluated as poor (×).
Also, the absorbed energy amount ΔW represented by the total surface area of the hysteresis loop H shown with diagonal lines in FIG. 3, the straight line L ₁ shown with a mesh line in FIG. a shaft, and a straight line L ₁ and the hysteresis loop H elastic strain energy W represented by the surface area of the region surrounded by the perpendicular L ₂ grated in the horizontal axis from the intersection of the formula (b):

Thus, an equivalent damping constant Heq was obtained.
Then, when the equivalent attenuation constant Heq in Example 1 is set to 100, the relative value of the equivalent attenuation constant Heq of each Example and Comparative Example is obtained, and those having a relative value of 99 or more are good (O), less than 99. The thing was evaluated as bad (x).
(Evaluation of damping performance when repeated large deformation is applied)
Displacement shear elasticity modulus Geq ₍₁₎ (N / mm ² ) at the first displacement and transmission shear elasticity at the sixth displacement when the displacement is repeated six times under the same conditions as in the displacement test in an environment of 20 ° C. The ratio Geq ₍₁₎ / Geq ₍₆₎ to the rate Geq ₍₆₎ (N / mm ² ₎ was determined.

Then, when the ratio Geq ₍₁₎ / Geq ₍₆₎ in Example 1 is set to 100, the relative value of the ratio Geq ₍₁₎ / Geq ₍₆₎ of each Example and Comparative Example is obtained, and the relative value is 104. The following were evaluated as good (◯) and those exceeding 104 were evaluated as poor (×).
The results are shown in Table 2.

From the results of Examples 1 to 4 and Comparative Examples 1 and 2 in Table 2, the good processability of the highly attenuated rubber composition is maintained by using the silicone oligomer together with the alkoxysilane represented by the formula (1). However, it has been found that the damping performance of the viscoelastic body can be improved and the decrease in the damping performance when large deformation is repeatedly applied to the viscoelastic body can be reduced.
Moreover, considering that the above effects are further improved from the results of Examples 1 to 4, the mass ratio O / A of alkoxysilane (A) to silicone oligomer (O) is 10/90 or more, particularly 20/80 or more. It has been found that it is preferably 70/30 or less, particularly 40/60 or less.

In consideration of further improving the above effects from the results of Examples 1 to 4, the total compounding ratio of alkoxysilane and silicone oligomer is 10 parts by mass or more, particularly 15 parts per 100 parts by mass of the total amount of diene rubber. It has also been found that the amount is preferably not less than part by mass, preferably not more than 40 parts by mass, particularly preferably not more than 30 parts by mass.
In particular, from the results of Examples 1 and 2, when SBR is used in combination with natural rubber as the diene rubber, the vulcanization return of the natural rubber and the accompanying decrease in attenuation performance are suppressed, thereby further improving the attenuation performance. I found that I can do it.

DESCRIPTION OF SYMBOLS 1 Disc 2 Steel plate 3 Specimen 4 Center fixed jig 5 Left and right fixed jig 6 Fixed arm 7 Joint 8 Movable platen 9 Joint H Hysteresis loop L ₁ Straight line L ₂ perpendicular W Energy ΔW Absorbed energy amount

Claims (6)

Diene rubber, silica, formula (1):

Wherein, ^{R 1} represents an alkyl group or phenyl group having 1 to 10 carbon atoms, ^{R 2} represents an alkyl group having 1 to 3 carbon atoms, n is a number of 1-3. ]
A high-damping rubber composition comprising an alkoxysilane represented by the formula: and a silicone oligomer.   2. The high-damping rubber composition according to claim 1, wherein the diene rubber is at least one selected from the group consisting of natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, and chloroprene rubber.   The high damping rubber composition according to claim 1 or 2, wherein a mass ratio O / A of the alkoxysilane (A) and the silicone oligomer (O) is 10/90 or more and 70/30 or less.   4. The high damping rubber according to claim 1, wherein a total blending ratio of the alkoxysilane and the silicone oligomer is 10 parts by mass or more and 40 parts by mass or less per 100 parts by mass of the total amount of the diene rubber. Composition.   The high-attenuation rubber composition according to any one of claims 1 to 4, wherein a blending ratio of the silica is 100 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the total amount of the diene rubber.   A viscoelastic damper provided with the viscoelastic body which consists of a high attenuation | damping rubber composition of any one of the said Claims 1 thru | or 5.

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