TWI546342B - Highly damping composition and viscoelastic damper - Google Patents

Description

High attenuation composition and viscoelastic damper

The present invention relates to a high attenuation composition which is a raw material for a high attenuation member for mitigating or absorbing the transmission of vibration energy, and a viscoelastic damper comprising a viscoelastic body as a high attenuation member. The viscoelastic body comprises the high attenuation composition.

For example, high-attenuation members are used in a wide range of fields such as buildings such as high-rise buildings or bridges, industrial machinery, aircraft, automobiles, rail vehicles, computers or peripheral devices, household appliances, and even automobile tires. By using the high attenuation member, the transmission of vibration energy can be alleviated or absorbed, that is, vibration-free, vibration-proof, vibration-proof, vibration-proof, and the like.

The high attenuation member is formed of a high attenuation composition mainly comprising natural rubber or the like as a base polymer. The high-attenuation composition is generally formulated with carbon black and cerium oxide in order to increase the hysteresis loss when vibration is applied and to improve the performance of the vibration energy efficiently and rapidly, that is, the attenuation performance. An inorganic filler, an adhesive such as rosin or petroleum resin, or the like (for example, refer to Patent Document 1 to Patent Document 3).

However, the attenuation properties of the high attenuation members cannot be sufficiently improved by using these previously high attenuation compositions. In order to further improve the attenuation performance of the high-attenuation member, it is considered to further increase the blending ratio of the inorganic filler or the adhesive or the like.

However, the high-attenuation composition in which a large amount of inorganic filler or tackifier is formulated has the following problems: increased viscosity, reduced workability, in order to manufacture It is not easy to knead and shape the high-attenuation composition into a three-dimensional shape with a high-attenuation member having a desired three-dimensional shape.

In particular, in the case where a high-attenuation member is mass-produced at the factory level, the decrease in the workability is such that the productivity of the high-attenuation member is largely lowered, the energy required for production is increased, and the production cost is increased. The reason is therefore not ideal.

Therefore, in order to improve the attenuation performance without lowering the workability, Patent Document 4 has studied a method of formulating cerium oxide and a binder having two or more polar groups.

However, the glass transition temperature Tg of the polymer having a polar side chain equal to the base polymer having a polar group in the molecule is generally present in the vicinity of room temperature (3 ° C to 35 ° C), and thus the use of the base polymer is used. The high-attenuation member formed by the high-attenuation composition tends to have a temperature dependency of characteristics such as rigidity in the vicinity of the room temperature which is the most general use temperature region.

Patent Document 5 discloses a method of formulating cerium oxide and a binder having two or more polar groups in a base polymer having no polar side chain such as natural rubber. With this configuration, it is possible to maintain good attenuation performance by using cerium oxide in combination; and by using a polymer having no polar group as a base polymer, the temperature dependency of properties near room temperature is reduced.

However, in the case where the ratio of the viscosity of the adhesion agent is increased in order to further improve the attenuation performance over the present state, it is feared that the adhesion agent is frosted on the surface of the high attenuation member, and the high attenuation member and the metal are generated. Then bad and so on.

Further, the adhesion at the time of kneading becomes too high, and the workability is lowered.

In Patent Document 6, it has been studied to further improve the attenuation performance by using a rosin derivative having a specific softening point as a tackifier.

However, in the case where the blending ratio of the rosin derivative is increased in order to further improve the damping performance, the adhesiveness at the time of kneading is excessively high, and the workability is lowered.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3523613

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2007-63425

[Patent Document 3] Japanese Patent No. 2790044

[Patent Document 4] Japanese Patent No. 3664211

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2009-138053

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2010-189604

The high-attenuation composition described in Patent Literatures 1 to 6 has various problems as described above. However, by appropriately adjusting the blending ratio of each component, etc., it is possible to achieve a certain degree at the same time. High attenuation performance and good processability.

In particular, the crosslinked structure of the rubber molecules in a state of being crosslinked by the crosslinking agent component is loose, and a high-attenuation member excellent in attenuation performance can be formed, and it is easy to obtain, and the high-attenuation composition can be manufactured at low cost. Therefore, a highly attenuating composition using natural rubber as a base polymer can be widely used as a forming material of a high attenuation member.

However, the high-attenuation member formed using the high-attenuation composition has a tendency to greatly reduce the attenuation performance when a large degree of deformation is repeatedly applied.

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-attenuation composition which can form a high-attenuation member which is excellent in attenuation performance and which has a small decrease in attenuation performance when a large degree of deformation is repeatedly applied; and a viscoelastic damping of a building or the like A viscoelastic body comprising a high attenuation member, the viscoelastic body comprising the high attenuation composition.

According to the study by the inventors, the ratio of the isoprene rubber (also referred to as synthetic natural rubber) as the synthetic rubber or the total amount of the isoprene rubber to the two types of rubber is 55 mass% or more. By using the two rubbers of the isoprene rubber and the natural rubber in combination with the natural rubber which was mainly used as the base polymer of the high-attenuation composition, the attenuation property is excellent and the application is repeated. Attenuation performance at the time of deformation is reduced by a small high attenuation member. The inventors speculated that the reason is as follows.

That is, in the high attenuation member (the high attenuation member is a crosslinked product of a high attenuation composition using natural rubber as a base polymer), a plurality of natural rubber molecules are crosslinked by a crosslinking agent component, and The phospholipid or protein present at the end of the molecular chain of each natural rubber molecule is bonded to each other by a relatively weak bond such as a hydrogen bond or an ionic bond, thereby generating a bond point constituting the branched structure, by which the bond point and The total attenuation point of the crosslinking agent component imparts a desired attenuation property to the high attenuation member.

However, the natural rubber molecules at the bond sites are bonded to each other, which is weaker than the cross-linking (molecular bond) of the cross-linking component, especially in the case of high The attenuating member is easily separated when a large degree of deformation is applied.

If a large degree of deformation is released, although one of the separated keys is partially reproduced, or a new key is generated, the remaining keys remain separated and are not regenerated. Therefore, as a large degree of deformation is repeated, the bonding point is gradually reduced, and the attenuation performance of the high attenuation member is lowered.

On the other hand, the isoprene rubber which is a synthetic rubber synthesized by polymerization of isoprene does not have a phospholipid or a protein constituting the bond point at the end of the molecular chain.

Therefore, the bonding point does not exist in the high-attenuating member formed by using the isoprene rubber alone as the base polymer, and becomes not easily separated even by applying a large degree of deformation. The crosslinking point of the crosslinking agent component imparts attenuation properties to the high attenuation member.

In the case where two kinds of rubbers of isoprene rubber and natural rubber are used in combination, when the ratio of the isoprene rubber to the total amount of the two rubbers is 55 mass% or more Although the bond point of the natural rubber is generated in the high-attenuation member as the cross-linking material, when the number of the bond points is greatly reduced and a large degree of deformation is applied, the bond point can be reduced as much as possible. The impact of separation. Therefore, it is possible to suppress as much as possible the reduction in the attenuation performance when a large degree of deformation is repeatedly applied.

Moreover, the isoprene rubber is looser than the other synthetic rubbers such as acrylonitrile-butadiene rubber (NBR), and the crosslinked structure of the rubber molecules at the crosslinking point is loose, forming a crosslink close to the natural rubber. The structure can thus form a high attenuation member having excellent attenuation performance equivalent to or higher than that of natural rubber. Moreover, the isoprene rubber is transferred to the same glass as the natural rubber. The temperature does not exist near room temperature, and therefore has an advantage of reducing the temperature dependency of the rigidity of the high-attenuation member near the room temperature in the most general use temperature region, and forming it in a wide temperature range. A high attenuation member exhibiting stable characteristics.

Therefore, it is possible to provide two kinds of resins, such as cerium oxide, which is a component for improving the attenuation performance of the high-attenuating member, and a benzofuran-anthracene resin and a dicyclopentadiene-based petroleum resin, by the present invention. A high-attenuation member having a property of being excellent in attenuation performance and having a small decrease in attenuation performance when a large degree of deformation is repeatedly applied repeatedly.

That is, the present invention is a high-attenuation composition which is a high-attenuation composition in which a cerium oxide and a resin are formulated in a base polymer, characterized in that as the base polymer, it is used alone as a synthetic rubber. The isoprene rubber is used in such a manner that the ratio of the isoprene rubber to the total amount of the two rubbers is 55% by mass or more, and the two rubbers of the isoprene rubber and the natural rubber are used in combination. Further, two kinds of resins, a benzofuran-anthracene resin and a dicyclopentadiene-based petroleum resin, were used as the resin.

The improvement of the two kinds of resins is particularly excellent in the effect of using the isoprene rubber as the attenuation property of the high-attenuation member of the base polymer.

The total blending ratio of the two kinds of resins is preferably 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of the base polymer.

If the blending ratio does not reach the above range, there is an effect that the damping property of the high-attenuating member is improved by insufficiently obtaining the blending resin. Hey. On the other hand, when the range is exceeded, there is a case where the decrease in the attenuation performance when a large degree of deformation is applied repeatedly becomes large.

Further, the proportion of the cerium oxide is preferably 80 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the base polymer.

When the blending ratio does not reach the above range, there is a possibility that the effect of improving the damping performance of the high-attenuation member due to the insufficient preparation of the cerium oxide can be obtained. On the other hand, when the range is exceeded, there is a case where the decrease in the attenuation performance when a large degree of deformation is applied repeatedly becomes large.

The viscoelastic damper of the present invention is characterized by comprising a viscoelastic body comprising the high attenuation composition of the present invention.

The viscoelastic damper has excellent attenuation performance as described above, and thus can be miniaturized or reduced in the number of built-in one building, and even if a large degree of deformation is repeatedly applied due to an earthquake, the attenuation performance is not comparable. It is greatly reduced, so that the energy of the earthquake or the aftershock generated after it can be surely prevented from being transmitted to the building.

According to the present invention, it is possible to provide a high-attenuation composition which can form a high-attenuation member which is excellent in attenuation performance and which has a small decrease in attenuation performance when a large degree of deformation is repeatedly applied; and a viscoelastic damper of a building or the like It comprises a viscoelastic body as a high attenuation member, said viscoelastic body comprising said high attenuation composition.

<High attenuation composition>

The high-attenuation composition of the present invention is a high-attenuation composition in which a cerium oxide and a resin are formulated in a base polymer, characterized in that: a base polymer, an isoprene rubber as a synthetic rubber alone, or an isoprene rubber of the two rubbers of the isoprene rubber and the natural rubber in the total amount of the two rubbers The ratio of the ratio is 55% by mass or more, and two kinds of resins, a benzofuran-anthracene resin and a dicyclopentadiene-based petroleum resin, are used as the resin.

(base polymer)

As described above, as the base polymer, isoprene rubber alone or two kinds of rubbers of the isoprene rubber and the natural rubber are made of isoprene rubber in the total amount of the two rubbers. The ratio is 55% by mass or more.

Here, as the isoprene rubber, for example, any of the following isoprene rubbers can be used: a mixture of isoprene by a solution polymerization method using a Zeegler catalyst or a lithium catalyst. Isoprene rubber, etc.

The isoprene rubber is not limited thereto, and for example, NIPOL (registered trademark) IR 2200 manufactured by ZEON Co., Ltd. [specific gravity: 0.91, Mooney Visicosity (center value)) is 82], at least one of IR2200L [specific gravity: 0.91, Mooney viscosity (center value) of 70].

Further, as the natural rubber, a usual natural rubber or deproteinized natural rubber or the like can be used.

In the case where the isoprene rubber is used alone as the base polymer, the easily separated bonding points derived from the natural rubber are not formed at all in the high-attenuating member as the cross-linking material, so that the above-mentioned The high attenuation member repeatedly reduces the attenuation performance when a large degree of deformation is applied.

Therefore, in terms of the effect, it is preferred to use isoprene rubber as the base polymer alone.

However, even in the case of using a system in which two rubbers of isoprene rubber and natural rubber are used as a base polymer, the proportion of isoprene rubber in the total amount of the two rubbers can be used as described above. It is limited to 55 mass% or more, and the number of generations of the bond points is reduced, and a reduction in attenuation performance when a large degree of deformation is applied to the high attenuation member is reduced.

Further, by using natural rubber (excellent in the ease of obtaining the material of the natural rubber) as described above, it is also possible to produce a high-attenuation member such as a highly attenuating member or a viscoelastic member such as a viscoelastic damper. Increased sex, which reduces manufacturing costs.

Further, in the combined system, it is considered that the effect of reducing the number of generation of the bond points and reducing the decrease in the attenuation performance when the high-attenuation member is repeatedly subjected to a large degree of deformation is further improved, and the isoprene rubber is further improved. The proportion of the total amount of the two types of rubber is preferably 50% by mass or more, and more preferably 60% by mass or more, in the range.

Further, when the effect of improving the productivity of the high-attenuation composition or the like and the reduction of the manufacturing cost by the use of the natural rubber is further improved, the ratio of the isoprene rubber is preferably 90 in the range. The mass% or less is more preferably 80% by mass or less.

(cerium oxide)

As the cerium oxide, any of the wet type cerium oxide and the dry type cerium oxide classified according to the production method thereof can be used. Further, as the cerium oxide, in consideration of further improving the effect of improving the attenuation performance of the high-attenuation member, it is preferred to use a BET specific surface area of 100 m ² /g to 400 m ² /g, particularly preferably 200 m ² /g. 250 m ² /g of cerium oxide. The BET specific surface area is represented by a value measured by a vapor phase adsorption method using, for example, a rapid surface area measuring device SA-1000 manufactured by Shibata Chemical Instruments Industrial Co., Ltd., or the like, using nitrogen as an adsorption gas.

Examples of the cerium oxide include NipSil (registered trademark) KQ manufactured by Tosoh Silica Corporation.

The blending ratio of the cerium oxide is preferably 80 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the base polymer.

When the blending ratio does not reach the above range, there is a possibility that the effect of improving the damping performance of the high-attenuation member due to the insufficient preparation of the cerium oxide can be obtained. On the other hand, when the range is exceeded, there is a case where the decrease in the attenuation performance when a large degree of deformation is applied repeatedly becomes large.

On the other hand, by setting the blending ratio of the cerium oxide within the above range, it is possible to suppress as much as possible the reduction in the attenuation performance when the high-attenuating member is repeatedly applied with a large degree of deformation, and the height can be high. The attenuating member imparts good attenuation properties.

(resin)

The resin may be a combination of a benzofuran-anthracene resin and a dicyclopentadiene-based petroleum resin.

Among them, examples of the benzofuran-ruthenium-based resin include various polymers which mainly contain a polymer of benzofuran and hydrazine, a relatively low molecular weight having an average molecular weight of about 1,000 or less, and a function as a softening agent.

The benzofuran-anthraquinone resin may, for example, be listed as a daily chemical company. Nitto Resin (registered trademark) benzofuran G-90 manufactured by the company [average molecular weight of 770, softening point of 90 ° C, acid value of 1.0 mg KOH / g or less, hydroxyl value of 25 mg KOH / g, bromine number of 9 g / 100 g ], G-100N [average molecular weight is 730, softening point is 100 ° C, acid value is 1.0 mgKOH/g or less, hydroxyl value is 25 mgKOH/g, bromine value is 11 g/100 g], V-120 [average molecular weight is 960, The softening point is 120 ° C, the acid value is 1.0 mgKOH/g or less, the hydroxyl value is 30 mgKOH/g, the bromine value is 6 g/100 g], V-120S [the average molecular weight is 950, the softening point is 120 ° C, and the acid value is 1.0 mgKOH). One or more of /g or less, a hydroxyl value of 30 mgKOH/g, and a bromine number of 7 g/100 g].

In addition, the dicyclopentadiene-based petroleum resin is a biscyclopentadiene-based petroleum resin which is an alicyclic hydrocarbon resin synthesized by using dicyclopentadiene contained in a C5 fraction of petroleum as a main raw material.

The dicyclopentadiene-based petroleum resin is, for example, Maruka Rez (registered trademark) M-890A manufactured by Maruzen Petrochemical Co., Ltd. [softening point: 105 ° C, specific gravity 1.1, iodine value: 190 g/100 g, acid value) 1 or 2 or more types of M-845A [softening point: 145 ° C, specific gravity 1.1, iodine value: 190 g/100 g, acid value: 0.1 mgKOH/g or less].

The total blending ratio of the two resins is preferably 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of the base polymer.

When the blending ratio is less than the above range, there is a possibility that the effect of improving the damping performance of the high-attenuating member due to the inability to sufficiently obtain the blending resin is obtained. On the other hand, when the range is exceeded, there is repeated application The decrease in attenuation performance at a large degree of deformation becomes large.

On the other hand, when the total blending ratio of the two kinds of resins is within the above range, it is possible to suppress as much as possible the reduction in the attenuation performance when the high-attenuating member is repeatedly applied with a large degree of deformation, and the High attenuation components impart good attenuation properties.

Further, in the case where the resin is used in combination with the two resins of the benzofuran-anthraquinone-based resin and the dicyclopentadiene-based petroleum resin, it is preferred to set the total blending ratio of the two resins to the above range. Inside.

(other ingredients)

In the highly attenuating composition of the present invention, other inorganic fillers other than the cerium oxide or a crosslinking agent component for crosslinking the base polymer may be blended in an appropriate ratio.

Examples of the other inorganic fillers include carbon black or calcium carbonate.

In addition, one type or two or more types of carbon black which can function as a filler in various carbon blacks classified according to the production method and the like can be used.

The blending ratio of the carbon black is not particularly limited, and is preferably 1 part by mass or more and 5 parts by mass or less per 100 parts by mass of the base polymer.

In addition, as the calcium carbonate, powdery calcium carbonate which functions as a filler in synthetic calcium carbonate, heavy calcium carbonate or the like classified according to the production method or the like can be used arbitrarily. Further, as the calcium carbonate, calcium carbonate which has been subjected to surface treatment in order to improve affinity, dispersibility, and the like with respect to the base polymer or the like can be used.

As the crosslinking component, various crosslinking components capable of crosslinking the base polymer can be used. It is particularly preferred to use a sulfur vulcanization crosslinking component. Sulfur sulfur The chemical crosslinking component may be a combination of a vulcanizing agent, a vulcanization accelerator, and a vulcanization accelerating aid. It is particularly preferable to combine a vulcanizing agent, a vulcanization accelerator, and a vulcanization accelerating aid which are difficult to cause a problem that the rubber elasticity of the high-attenuating member is excessively increased to cause a decrease in the damping performance.

Examples of the vulcanizing agent include sulfur or a sulfur-containing organic compound. Particularly good is sulfur.

Examples of the vulcanization accelerator include a sulfinamide-based vulcanization accelerator and a thiuram-based vulcanization accelerator. Since the vulcanization accelerator has a different mechanism for promoting vulcanization depending on the type, it is preferred to use two or more kinds in combination.

In the sulfinamide-based vulcanization accelerator, for example, Nocceler (registered trademark) NS [N-t-butyl-2-benzothiazolylsulfinamide] manufactured by Ouchi Shinko Chemical Co., Ltd., and the like can be cited. Further, examples of the thiuram vulcanization accelerator include Nocceler TBT (tetrabutyl thiuram disulfide) manufactured by Ouchi Shinko Chemical Industry Co., Ltd., and the like.

Examples of the vulcanization accelerating aid include zinc white, stearic acid, and the like. It is generally preferred to use both as a vulcanization accelerating aid.

The blending ratio of the vulcanizing agent, the vulcanization accelerator, and the vulcanization accelerating aid may be appropriately adjusted depending on characteristics such as attenuation performance or rigidity which are different depending on the use of the high-attenuating member or the like.

In the high-attenuation composition of the present invention, various additives such as a decane compound, a softener, and an anti-aging agent may be further blended in an appropriate ratio as needed.

In addition, the decane compound is represented by the formula (a), and can be used as a decane compound which functions as a dispersing agent of cerium oxide, such as a decane coupling agent or a decylating agent.

[wherein, at least one of R ¹ , R ² , R ³ and R ⁴ represents an alkoxy group. Wherein R ¹ , R ² , R ³ and R ⁴ are not simultaneously alkoxy groups, and the others represent an alkyl group or an aryl group].

Particularly preferred are alkoxydecanes such as hexyltrimethoxydecane, phenyltrimethoxydecane, phenyltriethoxydecane, and diphenyldimethoxydecane.

Examples of the decane compound include KBE-103 (phenyltriethoxydecane) manufactured by Shin-Etsu Chemical Co., Ltd., and the like.

The blending ratio of the decane compound is not particularly limited, but is preferably 5 parts by mass or more and 25 parts by mass or less per 100 parts by mass of the cerium oxide.

The softener is a component for further improving the processability of the high-attenuation composition, and the softener is, for example, a liquid rubber which is liquid at room temperature (2 ° C to 35 ° C). The liquid rubber may, for example, be one or more selected from the group consisting of liquid polyisoprene rubber, liquid nitrile rubber (liquid NBR), and liquid styrene butadiene rubber (liquid SBR).

Among them, preferred is a liquid polyisoprene rubber. The liquid polyisoprene rubber may, for example, be Kuraplen (manufactured by Kuraray Co., Ltd.). , registered trademark) LIR-30 (number average molecular weight is 28,000), LIR-50 (number average molecular weight is 54000), and the like.

The blending ratio of the liquid polyisoprene rubber is preferably 5 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the base polymer.

If the blending ratio does not reach the above range, there is a possibility that the effect of lowering the rigidity of the high-attenuating member due to the liquid polyisoprene rubber can not be sufficiently obtained. On the other hand, when it exceeds the above range, there is a fear that the attenuation performance of the high attenuation member is lowered.

The anti-aging agent may, for example, be one or more of various anti-aging agents such as benzimidazole-based, anthraquinone-based, polyphenol-based, and amine-based. It is particularly preferred to use a benzimidazole-based anti-aging agent in combination with a lanthanide anti-aging agent.

Among them, the benzimidazole-based anti-aging agent is, for example, Nocrac (registered trademark) MB [2-mercaptobenzimidazole] manufactured by Ouchi Shinko Chemical Co., Ltd., and the like. Further, examples of the lanthanide anti-aging agent include Antigen FR [aromatic ketone-amine condensate] manufactured by Maruishi Chemicals Co., Ltd., and the like.

The blending ratio of the two anti-aging agents is not particularly limited, and it is preferred that the benzimidazole-based anti-aging agent is 0.5 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the base polymer. Further, it is preferred that the lanthanoid anti-aging agent is 0.5 parts by mass or more and 5 parts by mass or less per 100 parts by mass of the base polymer.

Further, as other additives, for example, a rosin derivative of a resin containing rosin as a constituent component such as an ester of rosin and a polyol or a rosin-modified maleic acid resin is known.

However, in the case of formulating a rosin derivative, as described above, although the attenuation performance of the high-attenuation member can be improved, the attenuation characteristic of the high-attenuation member is greatly reduced when a large degree of deformation is repeatedly applied. problem. Therefore, the highly attenuating composition of the present invention is preferably free of rosin derivatives (except rosin derivatives).

Further, it is known that an imidazole-based compound other than a compound which functions as a benzimidazole-based anti-aging agent described in the above-described compound having an imidazole ring in the molecule can improve the attenuation property of the high-attenuation member. .

Examples of the imidazole-based compound include imidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-phenylimidazole. , 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenylimidazole, and 2-phenyl-4-methylimidazole.

However, when the imidazole-based compound is blended, there is a problem that the high-attenuation member is largely degraded when a large degree of deformation is repeatedly applied. Therefore, the highly attenuating composition of the present invention preferably contains no imidazole-based compound other than the compound which functions as a benzimidazole-based anti-aging agent (except for the imidazole-based compound).

Examples of the high-attenuation member which can be produced by using the high-attenuation composition of the present invention include a vibration-damping damper incorporated in a foundation of a building such as a high-rise building, and a shock-proof built in a structure of a building. (Vibration) Vibration-damping members for cables such as viscoelastic dampers, suspension bridges or diagonal bridges, anti-vibration members for industrial machinery or aircraft, automobiles, rail vehicles, etc., computers or peripheral devices, or household appliances Anti-vibration members, and tire wheels for automobiles Tread and so on.

According to the present invention, a high attenuation member having excellent attenuation properties suitable for the respective uses can be obtained by adjusting the kinds of the base polymer, cerium oxide, resin, and other various components, and combinations thereof, and blending ratios.

<Viscoelastic Damper>

Particularly in the case of using the high-attenuation composition of the present invention as a material for forming a viscoelastic body of a viscoelastic damper of a building as a high-attenuation member, the viscoelastic body has high attenuation property, and thus includes the The viscous performance of the viscoelastic damper of the viscoelastic body is improved, and even if it is miniaturized and the number of interiors installed in one building is reduced, the shock absorbing performance equivalent to or higher than the previous one can be obtained.

Moreover, even if a large degree of deformation is repeatedly applied due to the occurrence of an earthquake, the attenuation performance is not largely reduced, so that the energy of the aftershock generated after the earthquake or thereafter can be surely prevented from being transmitted to the building.

[Example] <Example 1>

(modulation of high attenuation composition)

40 parts by mass of natural rubber (SMR (Standard Malaysian Rubber)-CV60] as a base polymer, and isoprene rubber [NIPOL (registered trademark) IR2200 manufactured by ZEON Co., Ltd. ] 60 parts by mass of cerium oxide [NipSil (registered trademark) KQ manufactured by Tosoh Silica Corporation] 120 parts by mass, benzofuran-indene resin [daily coating 10 parts by mass of Nitto Resin (registered trademark) benzofuran G-90], and dicyclopentadiene petroleum resin [Maruka Rez (registered trademark) M-890A manufactured by Maruzen Petrochemical Co., Ltd.] 10 parts by mass of each component shown in the following Table 1 was kneaded using a closed kneader to prepare a highly attenuating composition. Further, the parts by mass in Table 1 are parts by mass per 100 parts by mass of the total amount of the natural rubber and the isoprene rubber as the base polymer, respectively.

The components in the table are as follows.

Decane compound: phenyl triethoxy decane, KBE-103 manufactured by Shin-Etsu Chemical Co., Ltd.

Liquid polyisoprene rubber: LIR-50 manufactured by Kuraray Co., Ltd., with a number average molecular weight of 54,000

Carbon Black: Diablack (registered trademark) G manufactured by Mitsubishi Chemical Corporation

Benzimidazole-based anti-aging agent: 2-mercaptobenzimidazole, Nocrac MB manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

Anti-aging agent: Antigen FR manufactured by Maruishi Chemical Co., Ltd.

2 kinds of zinc oxide: manufactured by Mitsui Metal Mining Co., Ltd.

Stearic acid: "Tsubaki" manufactured by Nippon Oil Co., Ltd.

5% oil treated powder sulfur: vulcanizing agent, manufactured by Tsurumi Chemical Industry Co., Ltd.

Vulcanization accelerator NS: N-tert-butyl-2-benzothiazolylsulfinamide, Nocceler (registered trademark) NS manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

Vulcanization accelerator TBT: tetrabutyl thiuram disulfide, Nocceler TBT-N manufactured by Ouchi Shinko Chemical Industry Co., Ltd.

<Example 2>

The blending ratio of the natural rubber is set to 20 parts by mass, the blending ratio of the isoprene rubber is set to 80 parts by mass, and the blending ratio of the vulcanization accelerator NS is set to 1.16 parts by mass, and the proportion of the vulcanization accelerator TBT is adjusted. The high-attenuation composition was prepared in the same manner as in Example 1 except that the amount was 1.16 parts by mass.

<Example 3>

The natural rubber is not prepared, and the blending ratio of the isoprene rubber is set to 100 parts by mass, and the blending ratio of the vulcanization accelerator NS is set to 1.2 parts by mass, and the blending ratio of the vulcanization accelerator TBT is set to 1.2 parts by mass. Other than this, the high attenuation composition was prepared in the same manner as in Example 1.

<Comparative Example 1>

The isoprene rubber is not prepared, and the blending ratio of the natural rubber is set to 100 parts by mass, and the blending ratio of the vulcanization accelerator NS is set to 1 part by mass, and the blending ratio of the vulcanization accelerator TBT is set to 1 part by mass. Other than this, the high attenuation composition was prepared in the same manner as in Example 1.

<Comparative Example 2>

The blending ratio of the natural rubber is 70 parts by mass, the blending ratio of the isoprene rubber is 30 parts by mass, and the blending ratio of the vulcanization accelerator NS is set to 1.06 parts by mass, and the proportion of the vulcanization accelerator TBT is adjusted. A high attenuation composition was prepared in the same manner as in Example 1 except that the amount was 1.06 parts by mass.

<Comparative Example 3>

The blending ratio of the natural rubber is 60 parts by mass, the blending ratio of the isoprene rubber is 40 parts by mass, and the blending ratio of the vulcanization accelerator NS is set to 1.08 parts by mass, and the proportion of the vulcanization accelerator TBT is adjusted. A high attenuation composition was prepared in the same manner as in Example 1 except that the amount was 1.08 parts by mass.

<Comparative Example 4>

A high-attenuation composition was prepared in the same manner as in Example 1 except that 40 parts by mass of the natural rubber and 60 parts by mass of the styrene-butadiene rubber were used as the base polymer.

<Comparative Example 5>

In the same manner as in Example 1, except that 40 parts by mass of the natural rubber and 60 parts by mass of the butadiene rubber were used as the base polymer, the preparation was high. Attenuate the composition.

<Attenuation characteristic test>

(production of test body)

The high-attenuation composition prepared in the examples and the comparative examples was extruded into a thin plate shape and then pressed, and as shown in FIG. 1, a circular plate 1 (thickness: 5 mm × diameter: 25 mm) was produced, and the disk 1 was formed. A rectangular flat plate-shaped steel sheet 2 having a thickness of 6 mm, a length of 44 mm, and a width of 44 mm is laminated on both sides of the back by a vulcanizing adhesive, and heated to 150 ° C while being pressurized in the lamination direction to form a high attenuation of the disc 1 . The composition was vulcanized, and the disk 1 and the two steel sheets 2 were vulcanized, and a test body 3 for evaluation of attenuation characteristics as a model of a high attenuation member was produced.

(displacement test)

Two test bodies 3 were prepared as shown in Fig. 2 (a), and the two test bodies 3 were fixed to one central fixing jig 4 by bolts via one of the steel plates 2, and One of the left and right fixing jigs 5 is fixed to the other steel plate 2 of each of the test bodies 3 by bolts. Then, the center fixing jig 4 is bolted to the upper fixing arm 6 of the testing machine (not shown) via the joint 7, and the two left and right fixing jigs 5 are bolted to the above via the joint 9. The movable plate 8 on the lower side of the test machine.

Next, in this state, as shown by the hollow arrow in the figure, the movable disk 8 is displaced and lifted in the direction of the fixed arm 6, and as shown in Fig. 2(b), the circular plate 1 in the test body 3 is set. a state of strain deformation in a direction orthogonal to the lamination direction of the test body 3, and secondly from the state, as shown in the figure As shown by the hollow arrow in the middle, the movable disk 8 is displaced and lowered in the direction opposite to the direction of the fixed arm 6, and returned to the state shown in Fig. 2(a), and the above operation is determined as one cycle. The disc 1 in the test body 3 is reversely strain-deformed, and even if it vibrates, the hysteresis loop H (refer to FIG. 3), the hysteresis loop H indicates that the disc 1 is orthogonal to the lamination direction of the test body 3. The relationship between the amount of displacement (mm) and the load (N).

The measurement was carried out in an environment of a temperature of 20 ° C, and the operation of the three cycles was carried out to obtain the third value. In addition, the maximum displacement amount is set so that the amount of shift of the two steel sheets 2 that sandwich the disc 1 in the direction orthogonal to the lamination direction is 100% of the thickness of the disc 1.

Next, the maximum displacement point in the hysteresis loop H shown in Fig. 3 obtained by the above measurement is connected to the minimum displacement point, and the slope Keq of the straight line L ₁ indicated by the thick solid line in the figure is obtained. (N/mm), from the slope Keq (N/mm), the thickness T (mm) of the disc 1, and the cross-sectional area A (mm ² ) of the disc 1, according to the formula (1):

The equivalent shear elastic modulus Geq (N/mm ² ) was obtained. Further, the relative value of the equivalent shear elastic modulus Geq (N/mm ² ) of each of the examples and the comparative examples when the equivalent shear elastic modulus Geq (N/mm ² ) in Comparative Example 1 was set to 100 was determined. value.

Moreover, the amount of absorbed energy ΔW (indicated by the total surface area of the hysteresis loop H) indicated by the oblique line in Fig. 3, and the elastic strain energy W represented by the square grid line in Fig. 3 The straight line L ₁ , the horizontal axis of the graph, and the surface area of the region surrounded by the perpendicular line L ₂ perpendicular to the horizontal axis from the intersection of the straight line L ₁ and the hysteresis loop H are expressed by the formula (2):

The equivalent decay constant Heq is obtained. The larger the equivalent decay constant Heq, the more excellent the attenuation performance of the test body 3 can be determined. Therefore, the relative value of the equivalent decay constant Heq of each of the examples and the comparative examples when the equivalent decay constant Heq in Comparative Example 1 is set to 100 is obtained.

(Evaluation of attenuation performance when a large degree of deformation is applied repeatedly)

The maximum displacement amount is set such that the amount of shift of the two steel sheets 2 that sandwich the circular plate 1 in the direction orthogonal to the laminated direction is 200% of the thickness of the circular plate 1, and the displacement is The test was carried out in the same manner, and the equivalent shear elastic modulus Geq ₍₃₎ (N/mm ² ) and the 30th displacement of the third displacement when the displacement was repeated 30 times in an environment of a temperature of 20 ° C were obtained. The ratio of the equivalent shear modulus of elasticity Geq ₍₃₀₎ (N/mm ² ) is Geq ₍₃₀₎ /Geq ₍₃₎ .

The closer the ratio is to 1, the smaller the decrease in the attenuation performance when the test body 3 is subjected to a large degree of deformation. Therefore, the case where the ratio is 0.81 or more is regarded as acceptable, and the attenuation performance when the large deformation is repeatedly performed is evaluated. Reduced.

The above results are shown in Table 2.

According to the results of Examples 1 to 3 and Comparative Examples 1 to 5 of Table 2, it is understood that as the base polymer, isoprene rubber alone or the isoprene rubber and natural rubber are used. The rubber is used in such a manner that the proportion of the isoprene rubber in the total amount of the two types of rubber is 55% by mass or more, whereby the good attenuation property of the high attenuation member can be maintained and can be reduced as much as possible. The reduction in the attenuation performance when a small degree of deformation is applied to a small degree of reversal.

Further, according to the results of Examples 1 to 3, it is understood that in terms of reducing the effect of the decrease in the attenuation property, it is preferred to use isoprene rubber alone as a base polymer, in the same In the combination of the two rubbers of the olefin rubber and the natural rubber, it is preferred that the proportion of the isoprene rubber in the total amount of the two rubbers is as much as possible within the range of 55 mass% or more. Big.

<Example 4, Example 5>

In the same manner as in Example 2, the preparation ratio was as high as 80 parts by mass (Example 4) and 150 parts by mass (Example 5) per 100 parts by mass of the total amount of the base polymer. Attenuate the composition.

<Example 6~Example 8>

The blending ratio of the benzofuran-fluorene-based resin and the dicyclopentadiene-based petroleum resin was set to 1 part by mass (Example 6) and 5 parts by mass (Example 7) per 100 parts by mass of the total amount of the base polymer. A high-attenuation composition was prepared in the same manner as in Example 2 except that 15 parts by mass (Example 8) was used.

Each of the foregoing tests was carried out on the highly attenuating composition prepared in each of the examples. The results are shown together with the results of Example 2 in Table 3.

According to the results of Example 2, Example 4, and Example 5 of Table 3, it is understood that the proportion of the cerium oxide is preferably 80 parts by mass or more and 150 parts by mass or less per 100 parts by mass of the total amount of the base polymer. And, according to the example 2. The results of the examples 6 to 8 show that the total ratio of the benzofuran-indene resin to the dicyclopentadiene petroleum resin is preferably 1 mass per 100 parts by mass of the base polymer. More than 30 parts by weight.

1‧‧‧ round plate

2‧‧‧ steel plate

3‧‧‧Test body

4‧‧‧Central Fixture

Fixed fixture around 5‧‧

6‧‧‧Fixed Arm

7, 9‧‧‧ joints

8‧‧‧ movable plate

H‧‧‧ Hysteresis loop

Keq‧‧‧ slope

L ₁ ‧‧‧ Straight line

L ₂ ‧‧‧ vertical line

W‧‧‧Energy

△W‧‧‧Amount of absorbed energy

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded perspective view showing, in an exploded manner, a test body which is produced as a high attenuation member model for evaluating the attenuation performance of a high attenuation member including a high attenuation composition of an example of the present invention.

2(a) and 2(b) are diagrams illustrating the outline of a testing machine for determining the relationship between the displacement amount and the load by displacing the test body.

3 is a graph showing an example of a hysteresis loop showing the relationship between the displacement amount and the load, which is obtained by displacing the test body using the test machine.

H‧‧‧ Hysteresis loop

Keq‧‧‧ slope

L ₁ ‧‧‧ Straight line

L ₂ ‧‧‧ vertical line

W‧‧‧Energy

△W‧‧‧Amount of absorbed energy

Claims (4)

A highly attenuating composition which is a high-attenuation composition in which a cerium oxide and a resin are formulated in a base polymer, characterized in that as the base polymer, an isoprene rubber as a synthetic rubber is used alone. Alternatively, the two rubbers of the isoprene rubber and the natural rubber are used in such a manner that the ratio of the isoprene rubber to the total amount of the two rubbers is 55% by mass or more, and benzene is used. Two kinds of resins, furan-anthracene resin and dicyclopentadiene-based petroleum resin, are used as the resin, and the high-attenuation composition does not contain a rosin derivative. The high-attenuation composition according to the first aspect of the invention, wherein the total blending ratio of the two resins is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of the base polymer. The high-attenuation composition according to any one of the preceding claims, wherein the cerium oxide is formulated in an amount of 80 parts by mass or more per 100 parts by mass of the base polymer, 150 parts by mass or less. A viscoelastic damper comprising a viscoelastic body, the viscoelastic body comprising the high-attenuation composition according to any one of claims 1 to 3.