JP2009030016A - High damping rubber composition and damping member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high damping rubber composition that does not use an aromatic oil which may contain a polycyclic aromatic hydrocarbon, thereby, reduces environmental burden, that shows less temperature dependence of the elastic modulus and that can develop high damping performance even in large deformation, and to provide a damping member comprising the high damping rubber composition. <P>SOLUTION: The high damping rubber composition is prepared by compounding, with respect to 100 parts by mass of a base rubber, 10 to 30 parts by mass of one or more kinds of softening agent selected from a group consisting of liquid rubber, paraffin oil and naphthene oil, 5 to less than 30 parts by mass of carbon black, and 100 to 180 parts by mass of silica, and 5 to 25 parts by mass of a silane compound with respect to 100 parts by mass of the silica, but not compounding an oil containing a polycyclic aromatic hydrocarbon. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a high-damping rubber composition and a vibration damping member comprising the high-damping rubber composition, and in particular, to improve the environmental dependency of vibration damping performance and elastic modulus at the time of large deformation of a building or the like, and reduce the environmental load. To do.

  2. Description of the Related Art Conventionally, devices (vibration control devices) that absorb vibration energy generated by earthquakes, traffic vibrations, wind vibrations, and the like have been used in buildings such as houses and buildings, bridges, and the like. Among damping devices, damping devices that use high-damping rubber as damping members are relatively inexpensive and have a damping effect even for minute vibrations such as wind vibration while having excellent vibration damping performance. Since it has the advantage of being able to be demonstrated, it is widely used.

However, viscoelastic materials such as rubber have high rigidity at low temperatures but low rigidity at high temperatures, and there is a problem that rigidity and elastic modulus change according to the temperature, making it difficult to obtain stable vibration control performance. .
Therefore, the present applicant added 30 to 200 parts by weight of silica to 100 parts by weight of a base rubber having a C—C bond in the main chain in Japanese Patent Application Laid-Open No. 7-41603 (Patent Document 1), A silica-containing highly attenuated rubber composition in which 5 to 50% by weight of a silane compound is added to silica and kneaded is provided. From the rubber composition, it is possible to obtain a highly damped rubber exhibiting a high damping property and having a low elastic modulus temperature dependency.
Furthermore, the present applicant provides a damping member obtained by vulcanizing and molding a rubber composition containing a predetermined amount of silica and a silane compound with respect to a base rubber in Japanese Patent Laid-Open No. 10-81787 (Patent Document 2). is doing. The vibration damping member exhibits sufficient vibration damping performance even in a long and long bridge with a long cable length and has a characteristic of low temperature dependence.

JP 7-41603 A JP-A-10-81787

  The vibration damping members of Patent Literature 1 and Patent Literature 2 have low temperature dependence of the elastic modulus, and are excellent in vibration damping performance. However, in the event of a large earthquake that can be subjected to a large shear deformation that exceeds twice the thickness of the high-damping rubber, wind fluctuations during strong winds such as typhoons, and high-rise building vibration control devices that are prone to high vibration on high floors When it is used, the damping performance and elastic modulus are not sufficient and there is room for improvement.

In addition, the aromatic oils used in the production of the vibration damping rubber composition, including Patent Document 1 and Patent Document 2, contain polycyclic aromatic hydrocarbons (PAH) in the human body and In recent years, it has been recognized that there is a risk of adverse effects on the environment. For this reason, in Europe, a rule has been established to completely stop the use of harmful plasticizers including PAH, and voluntary regulations to reduce the use of aroma-based oils are being promoted in tires and the like.
However, when a large amount of a reinforcing agent such as silica or carbon black is blended, it is conventionally essential to add an aromatic oil that has a high effect of improving kneadability as a softening agent. It is used. Although studies have been made to remove polycyclic aromatic hydrocarbons by distilling aromatic oils, it is necessary to carry out multiple distillations, which increases costs and is not practical.
Thus, there is a need for a highly damped rubber composition that can provide good kneadability and high vibration damping performance without blending aroma oils.

  The present invention has been made in view of the above problems, and does not use an aromatic oil that may contain polycyclic aromatic hydrocarbons, while reducing the environmental load, while the temperature dependence of the elastic modulus is small, It is an object of the present invention to provide a high damping rubber composition that can exhibit high damping performance even when large deformation occurs during an earthquake or typhoon, and a damping member made of the high damping rubber composition.

  In order to solve the above-mentioned problem, as a first invention, 10 parts by mass or more of 30 or more kinds of softening agents selected from the group consisting of liquid rubber, paraffin oil and naphthenic oil with respect to 100 parts by mass of the base rubber. Parts by mass, carbon black is 5 parts by mass or more and less than 30 parts by mass, silica is 100 parts by mass or more and 180 parts by mass or less, and silane compound is compounded by 5 parts by mass or more and 25 parts by mass or less with respect to 100 parts by mass of silica. And the high damping rubber composition characterized by not containing the oil containing a polycyclic aromatic hydrocarbon is provided.

In the present invention, at least one selected from the group consisting of liquid rubber, paraffin oil and naphthenic oil is used as a softening agent as an alternative to the aroma oil containing PAH. Therefore, it is possible to reduce or eliminate adverse effects on the human body and the environment, which are problematic when using an aroma oil as a softening agent.
Further, by blending the softener, carbon black, silica and silane compound in the blending ratio with respect to the base rubber, at the time of kneading the high damping rubber composition, the adhesiveness is lowered to the base rubber. The kneadability is improved, the obtained kneaded product is easily taken out from the closed kneader, and the processability is improved.
Furthermore, the vibration damping member made of the high damping rubber manufactured from the high damping rubber composition has a small temperature dependency of the elastic modulus, has an excellent elastic modulus at the time of large shear deformation, and greatly reduces the bleed of the softening agent. It can suppress and can reduce the physical property change in durable use.
Hereinafter, each component will be described in detail.

As the base rubber, natural rubber and various synthetic rubbers can be used.
As synthetic rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, norbornene rubber, ethylene propylene rubber, butyl rubber, halogenated butyl rubber, chloroprene rubber, acrylonitrile butadiene rubber, epichlorohydrin rubber, chlorosulfonated polyethylene, polysulfide rubber, etc. are used. be able to.
These may be used alone or in combination of two or more.
Of these, natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, and acrylonitrile butadiene rubber are preferably used.

As the softening agent, at least one selected from the group consisting of liquid rubber, paraffin oil and naphthenic oil is used. The softening agent is preferably liquid rubber or paraffin oil, and most preferably liquid rubber.
The liquid rubber is classified from the base rubber in that the raw rubber is classified according to the shape at room temperature and is liquid and fluid. The liquid rubber undergoes chain extension and crosslinking by a chemical reaction, and can be a high molecular weight crosslinked rubber.
As the liquid rubber, it is preferable to use a liquid diene rubber that can be cured to become a rubber component integrated with the base rubber.
Examples of the liquid diene rubber include liquid isoprene rubber, liquid styrene isoprene rubber, liquid styrene butadiene rubber, liquid acrylonitrile butadiene rubber, liquid butadiene rubber, and liquid chloroprene rubber. These may be used alone or in combination of two or more.

Among these, it is preferable to use at least one liquid diene rubber selected from liquid isoprene rubber, liquid styrene isoprene rubber, liquid butadiene rubber, liquid styrene butadiene rubber and liquid acrylonitrile butadiene rubber. It is preferably used with one or more base rubbers selected from the group consisting of rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber and acrylonitrile butadiene rubber.
When the base rubber and the liquid rubber are used in such a combination, the compatibility between the base rubber and the liquid rubber is good, and since they are uniformly kneaded, the kneadability and workability can be greatly improved. In addition, since the liquid rubber is easily cross-linked with the base rubber in the obtained highly-damped rubber, it also functions as a rubber component, so that the bleeding of the softening agent can be greatly reduced.
In particular, it is preferable to use natural rubber having a large molecular weight as the base rubber and liquid isoprene rubber as the liquid rubber because the temperature dependence of the damping performance at low temperatures can be extremely reduced.

A known paraffinic process oil can be used as the paraffin oil. For example, Idemitsu Kosan Co., Ltd. Diana Process Oil PW, Diana Fresia P, W, K, S series can be mentioned.
A known naphthenic oil can be used as the naphthenic oil. For example, Diana Process Oil NS, NR, NM, Diana Fresia G, F, NR, N, U series manufactured by Idemitsu Kosan Co., Ltd. can be mentioned.
In addition, a mixed oil of paraffin oil and naphthenic oil can be used. An example is Diana Process Oil NP manufactured by Idemitsu Kosan Co., Ltd.

  One or more softeners selected from the group consisting of the liquid rubber, paraffin oil, and naphthenic oil are blended at a ratio of 10 parts by mass to 30 parts by mass with respect to 100 parts by mass of the base rubber. When the amount is less than 10 parts by weight with respect to 100 parts by weight of the base rubber, kneading is difficult and processability is reduced. When the amount exceeds 30 parts by weight, the amount of the softening agent is excessive, and the rigidity of the resulting high damping rubber is high. This is because the vibration damping performance is lowered and the vibration damping performance is lowered.

In addition, carbon black is blended at a ratio of 5 parts by mass or more and less than 30 parts by mass with respect to 100 parts by mass of the base rubber.
This is because if the carbon black is less than 5 parts by mass, it is difficult to obtain a sufficient reinforcing effect, and if it is 30 parts by mass or more, the kneadability and molding processability are reduced.
The carbon black is more preferably 15 parts by mass or more and less than 30 parts by mass with respect to 100 parts by mass of the base rubber.

  As the carbon black, high-activity carbon black can be used in addition to general carbon black such as FEF carbon, ISAF carbon, SAF carbon, and HAF carbon.

The silica can increase the damping property and reduce the temperature dependence of the elastic modulus.
Silica is blended at a ratio of 100 parts by mass or more and 180 parts by mass or less with respect to 100 parts by mass of the base rubber. Preferably, it is 120 to 150 mass parts. This is because if the amount is less than 100 parts by mass, the damping performance and the temperature dependence of the elastic modulus when large shear deformation is applied deteriorate, and if it exceeds 180 parts by mass, kneading into rubber becomes difficult.

The silica used in the present invention may be either hydrous or anhydrous silica, but hydrous silica is preferably used. The specific surface area of the silica may have a range of 100m ² / g~400m ² / g, preferably in the range of 150m ² / g~300m ² / g.
The specific surface area of silica is measured by a gas phase adsorption method using nitrogen gas as an adsorbed gas (for example, a rapid surface area measuring apparatus SA-1000 manufactured by Shibata Chemical Instruments Co., Ltd.). When the specific surface area is less than 100 m ² / g, the effect of imparting attenuation decreases, and when the specific surface area exceeds 400 m ² / g, there is a problem in kneadability, which is not preferable in terms of cost.

Furthermore, 5 mass parts or more and 25 mass parts or less of silane compounds are mix | blended with respect to 100 mass parts of said silica.
The silane compound has an effect of improving kneadability, but when it is less than 5 parts by mass with respect to 100 parts by mass of silica, the reaction amount with respect to silica is small, and there is no effect of improving kneadability and workability. When the amount of the silane compound exceeds 25 parts by mass, the blending amount becomes excessive and the effect of adding is reduced. When the blending ratio is used, the compatibility with the base rubber and silica is excellent.
The amount of the silane compound is preferably 15 to 20 parts by mass with respect to 100 parts by mass of silica.

（式中、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４のうちの少なくとも１つはアルコキシ基、またはハロゲン原子を示し、他は同一または異なって水素原子、アルキル基またはアリール基を示す。） As said silane compound, what is represented by following General formula (1) can be used.

(In the formula, at least one of R ¹ , R ² , R ³ and R ⁴ represents an alkoxy group or a halogen atom, and the other represents the same or different and represents a hydrogen atom, an alkyl group or an aryl group.)

In the silane compound represented by the general formula (1), examples of the alkoxy group corresponding to R ^{1 to} R ⁴ include those having various carbon numbers represented by C _n H _{2n + 1} O. Of these, a methoxy group or an ethoxy group having 1 to 2 carbon atoms is preferable. Examples of the halogen atom include fluorine, chlorine, bromine and the like.

Examples of the alkyl group include those having various carbon numbers represented by C _n H _{2n + 1} , and those having about 1 to 20 carbon atoms are preferable. Examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a secondary butyl group, a tertiary butyl group, a pentyl group, a hexyl group, and a heptyl group. Octyl group, nonyl group, decyl group, undecyl group, dodecyl group and the like.
Examples of the aryl group include a phenyl group, a tolyl group, a xylyl group, a biphenylyl group, an o-terphenyl group, a naphthyl group, an anthryl group, and a phenanthryl group.

  Specific examples of the silane compound represented by the general formula (1) include, but are not limited to, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, dimethyldimethoxysilane, trimethylethoxysilane, and trimethylmethoxy. Silane, isobutyltrimethoxysilane, n-decyltrimethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, hexyltrimethoxysilane, octadecylmethyldimethoxysilane, octadecyltrimethoxysilane, methyltri Chlorosilane, dimethyldichlorosilane, triphenylchlorosilane, heptadecafluorodecylmethyldichlorosilane, heptadecafluorodecyltrichlorosilane And triethylchlorosilane.

The highly attenuated rubber composition of the present invention preferably contains no polycyclic aromatic hydrocarbons in other components.
The polycyclic aromatic hydrocarbon is a general term for compounds having two or more hexagonal benzene rings, and representative examples thereof include naphthalene composed of two benzene rings, three anthracenes, four benzopyrenes, and the like.

  The high damping rubber composition of the present invention includes a vulcanizing agent, a vulcanization accelerator, a vulcanization acceleration aid, a vulcanization retarder, a reinforcing agent / filler other than silica and carbon black, as described above. Various additives such as other softeners, plasticizers, and tackifiers may be added. In addition, in order to improve the dispersibility at the time of kneading, a dispersant, a solvent, and the like may be appropriately blended.

  Examples of the vulcanizing agent include sulfur, organic sulfur-containing compounds, and organic peroxides. Examples of the vulcanizing accelerator include thiuram vulcanization accelerators such as tetramethylthiuram disulfide and tetramethylthiuram monosulfide; Dithiocarbamates such as zinc dibutyldithiocarbamate, zinc diethyldithiocarbamate, sodium dimethyldithiocarbamate, and tellurium diethyldithiocarbamate; 2-mercaptobenzothiazole, N-cyclohexyl-2-benzothiazolesulfenamide, etc. Thiazoles; organic accelerators such as thioureas such as trimethylthiourea and N, N′-diethylthiourea; and inorganic accelerators such as slaked lime, magnesium oxide, titanium oxide, and resurge (PbO).

Examples of the vulcanization acceleration aid include fatty acids such as stearic acid, oleic acid, and cottonseed fatty acid, and metal oxides such as zinc white. Examples of the vulcanization retarder include aromatic organic acids such as salicylic acid, phthalic anhydride, and benzoic acid; N-nitrosodiphenylamine, N-nitroso-2,2,4-trimethyl-1,2-dihydroquinone, N-nitroso Examples thereof include nitroso compounds such as phenyl-β-naphthylamine.
The total amount of the vulcanizing agent, vulcanization accelerator, vulcanization acceleration aid and vulcanization retarder is preferably about 4 to 15 parts by mass with respect to 100 parts by mass of the base rubber.

The anti-aging agent is not particularly limited, but imidazoles such as 2-mercaptobenzimidazole; phenyl-α-naphthylamine, N, N′-di-β-naphthyl-p-phenylenediamine, N-phenyl-N ′. Examples include amines such as isopropyl-p-phenylenediamine; phenols such as di-t-butyl-p-cresol and styrenated phenol.
The blending amount of the antioxidant is preferably about 1.5 to 5 parts by mass with respect to 100 parts by mass of the base rubber.

As fillers other than silica and carbon black, inorganic reinforcing agents such as zinc white, surface treated precipitated calcium carbonate, magnesium carbonate, talc, clay, or coumarone indene resin, phenol resin, xylene resin, high styrene resin An organic reinforcing agent such as (a styrene-butadiene copolymer having a high styrene content) can be used.
Examples of the filler include calcium carbonate, clay, barium sulfate, and diatomaceous earth.
When a reinforcing agent and / or a filler other than silica and carbon black is included, the blending amount is preferably about 1 to 30 parts by mass with respect to 100 parts by mass of the base rubber.

When blending other softeners other than the liquid rubber, naphthenic oil and paraffin oil, those not containing polycyclic aromatic hydrocarbons are used, for example, fatty acids such as stearic acid and lauric acid, cottonseed oil, Examples include various softeners such as tall oil, asphalt substances, and paraffin waxes such as vegetable oils, mineral oils, and synthetics.
When a softener other than the liquid rubber is included, the blending amount is preferably about 10 to 30 parts by mass with respect to 100 parts by mass of the base rubber.

It is preferable to use a tackifier that does not contain polycyclic aromatic hydrocarbons. Petroleum resins such as cyclopentadiene resins, coumarone / indene resins, rosin resins, etc. are used alone or in combination of two or more. Can be used. Among these, it is preferable to use a coumarone-indene resin or a cyclopentadiene resin.
The compounding amount of the tackifier is preferably 5 to 50 parts by mass and more preferably 5 to 40 parts by mass with respect to 100 parts by mass of the base rubber.

  The high damping rubber composition described above is prepared by kneading each component using a closed kneader and the like, then taking it out of the kneader, putting it into an extruder, extruding it, cutting it into a required shape, and preforming it. A damping member made of high-damping rubber is manufactured by filling in a mold molding machine, heating at a required temperature, and vulcanizing and molding.

As a second invention, it comprises a vibration damping member obtained by vulcanization molding of the above-described highly attenuated rubber composition,
In the dynamic viscoelasticity test at measurement temperatures of 0 ° C. and 20 ° C., the equivalent shear modulus (Geq 50%) at 50% shear deformation of the thickness is 0.7 N / mm ² or more, and the equivalent viscous damping constant (heq 50%) is 0.25 or more, equivalent shear modulus (Geq 300%) at 300% thickness shear deformation is 0.3 N / mm ² or more, and equivalent viscosity damping constant (heq 300%) is 0.20 or more. The vibration damping member characterized by the above is provided.

The damping performance imparted to the building or the like by the damping member is roughly the rigidity of the damping member (here, equivalent shear modulus (Geq)) and damping constant (here, equivalent viscous damping constant (equivalent damping constant) (heq)). ) And the product. Therefore, it is preferable that the equivalent shear modulus (Geq) and the equivalent viscous damping constant (equivalent damping constant) (heq) are both large.
The vibration damping member of the present invention having an equivalent shear modulus (Geq) and an equivalent viscous damping constant (heq) in the above-mentioned range at both 0 ° C. and 20 ° C. has a small environmental dependency and is effective in damping performance. Are better. Further, the vibration damping performance can be exhibited not only at the time of shear deformation of 50% of the thickness but also at the time of shear deformation of 300%, and good vibration damping performance can be obtained.

In the dynamic viscoelasticity test, the equivalent viscous damping constant (equivalent damping constant) (heq) and the equivalent shear modulus (Geq = Keq / (S / D)) are the sinusoidal addition that causes shear deformation of the viscoelastic material. The hysteresis loop (hysteresis curve) at that time is measured and calculated based on the result.
Describing based on FIG. 1, heq is a numerical value calculated by the following equation (Equation 1).
heq = ΔW / 2πW (Equation 1)
W: elastic energy of shear deformation (area of two triangles shown in FIG. 1; unit is N · mm)
ΔW: Total energy absorbed by shear deformation (area surrounded by hysteresis curve shown in FIG. 1, unit is N · mm)

Geq is a numerical value calculated by the following formula (Formula 2).
Geq = Keq / (S / D) = F / U _Be / (S / D) (Equation 2)
F: Load when giving maximum displacement (unit: N)
U _Be : Maximum displacement (unit: mm)
S / D: Shape factor of test sample (shear area of sample / shear gap of sample, unit is mm)

  If the use environment of the damping member is 0 ° C. to 20 ° C., the equivalent shear elastic modulus Geq (t = 0 ° C.) at 0 ° C. and the equivalent shear elasticity at 20 ° C. at 50% shear deformation. It is preferable that the ratio of the ratio Geq (t = 20 ° C.), Geq (t = 0 ° C.) / Geq (t = 20 ° C.) ≦ 2.2. In addition, at the time of 300% shear deformation, the ratio of the equivalent shear modulus Geq (t = 0 ° C.) at 0 ° C. to the equivalent shear modulus Geq (t = 20 ° C.) at 20 ° C., Geq (t = 0 ° C.) / Geq (t = 20 ° C.) ≦ 1.6.

The vibration damping member has a rectangular parallelepiped shape with a length of 10 to 500 mm, a width of 10 to 500 mm, and a thickness of 3 to 60 mm, or a cylindrical shape with a diameter of 10 to 300 mm and a thickness of 3 to 60 mm. And is suitably used for a vibration control device for a bridge girder.
The opposing surface of the damping member made of the high-damping rubber having the rectangular parallelepiped shape or the cylindrical shape is used as a damping unit in which the metal plate is bonded and fixed to the metal plate, and the metal plate is fixed to a fixed member of a building or a bridge girder. Is preferred.
A damping unit having a damping member made of high damping rubber sandwiched between the metal plates can be mass-produced by a factory, and can be used as a component of various types of damping devices.

From the viewpoint of reliability in bonding, it is preferable to manufacture the vibration damping unit by vulcanizing and bonding to the metal plate simultaneously with vulcanization of the high damping rubber composition.
For example, it can be manufactured by the following manufacturing method.
(1) The unvulcanized high damping rubber composition is extruded so as to have a predetermined shape, then cut, preliminarily molded, heated in a predetermined mold and vulcanized and molded. At the same time as vulcanization, it is vulcanized and bonded to a metal plate for attachment to the vibration damping device.
(2) The unvulcanized high-damping rubber composition is press vulcanized using a predetermined mold and, at the same time as the press vulcanization, is vulcanized and bonded to a plate for attachment to a vibration damping device.

Note that, regardless of indoor or outdoor use, the outer peripheral surface of the high-damping rubber may be coated with a coating layer having excellent weather resistance in order to prevent the weather-resistant deterioration of the high-damping rubber.
Examples of the material excellent in weather resistance constituting the coating layer include brominated products of paramethylstyrene-isobutylene copolymer, butyl rubber, and ethylene-propylene copolymer rubber.
The coating layer is formed by winding an unvulcanized sheet for the coating layer made of the above material around the outer peripheral surface of an unvulcanized preform, and simultaneously vulcanizing and vulcanizing and bonding the sheet itself. It may be formed by performing.

  As described above, the high-damping rubber composition of the present invention comprises a base rubber having at least one softener selected from the group consisting of a predetermined amount of liquid rubber, paraffin oil and naphthenic oil, carbon black, silica, Since the silane compound is blended, a damping member made of a highly damped rubber can be obtained from the composition, which has a low temperature dependence of the elastic modulus and exhibits high damping performance even during large deformation.

  In addition, since the blending amount of the softening agent is small, bleeding of the softening agent can be suppressed. In particular, when liquid rubber is used as the softening agent, the liquid rubber is cross-linked with the base rubber, so that bleeding of the softening agent can be significantly suppressed. Furthermore, since the conventional aroma-based oil that may contain polycyclic aromatic hydrocarbons is not used, the load on the environment and the human body can be reduced.

Embodiments of the present invention will be described below.
In the vibration damping member of this embodiment, one or more softening agents selected from the group consisting of liquid rubber, paraffin oil, and naphthenic oil, carbon black, silica, and a silane compound are blended in the base rubber. It is obtained from a highly attenuated rubber composition obtained by vulcanization.

Next, the components of the high damping rubber composition will be described.
One or more softeners selected from the group consisting of liquid rubber, paraffin oil and naphthenic oil are blended at a ratio of 10 to 30 parts by mass with respect to 100 parts by mass of the base rubber. Diene rubber is used as the base rubber, and in this embodiment, any of natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, and acrylonitrile butadiene rubber is used.
As the liquid rubber, a liquid diene rubber made of any of liquid isoprene rubber, liquid styrene isoprene rubber, liquid butadiene rubber, liquid styrene butadiene rubber, or liquid acrylonitrile butadiene rubber is used.
As the paraffin oil, paraffinic process oil is used.
As naphthenic oil, naphthenic process oil is used.
In the highly attenuated rubber composition of this embodiment, no aromatic oil is used as a softening agent, and the softening agent does not contain a polycyclic aromatic hydrocarbon.

Carbon black is blended at a ratio of 5 parts by mass or more and less than 30 parts by mass with respect to 100 parts by mass of the base rubber.
As the carbon black, HAF carbon having a nitrogen adsorption specific surface area of about 79 m ² / g and a DBP oil absorption of about 101 ml / 100 g is used.

Further, 100 parts by mass or more and 180 parts by mass or less of silica and 5 to 25 parts by mass of a silane compound are blended with respect to 100 parts by mass of the silica with respect to 100 parts by mass of the base rubber.
Silica having a BET specific surface area of 100 to 400 m ² / g is used, and phenyltriethoxysilane is used as the silane compound.

  Furthermore, 10-40 mass parts of petroleum resin is mix | blended as a tackifier with respect to 100 mass parts of base rubber. As a petroleum resin, a coumarone resin and a dicyclopentadiene petroleum resin are used in combination, and used in a mass ratio of (coumarone resin: dicyclopentadiene petroleum resin) = (1: 5) to (5: 1). ing.

Powder sulfur is used as the vulcanizing agent, and 0.5 to 5 parts by mass is blended with 100 parts by mass of the base rubber.
As a vulcanization accelerator, N-tert-butyl-2-benzothiazolylsulfenamide and tetrabutylthiuram disulfide are used in combination, each at a ratio of 0.5 to 5 parts by mass with respect to 100 parts by mass of the base rubber. It is blended.
As a vulcanization acceleration aid, zinc oxide is blended at a ratio of 0.5 to 5 parts by mass with respect to 100 parts by mass of the base rubber, and stearic acid is 0.3 with respect to 100 parts by mass of the base rubber. It mix | blends in the ratio of -5 mass parts.
2-mercaptoben ヅ imidazole and polymerized 2,2,4-trimethyl-1,2-dihydroquinoline as anti-aging agents are blended at a ratio of 0.5 to 5 parts by mass with respect to 100 parts by mass of the base rubber. ing.
The high-damping rubber composition is produced using not only a softening agent but also other components to be blended that do not contain a polycyclic aromatic hydrocarbon that is suspected to be carcinogenic or endocrine disrupting.

The high damping rubber composition containing the above components is manufactured as a vibration damping member made of a high damping rubber member by the following method.
First, using a kneading device such as a closed kneader such as a kneader or Banbury mixer, a single screw extruder, a 1.5 screw extruder, a twin screw extruder, an open roll, or a hot roll, a base rubber, a softener, carbon Black, silica, a silica compound, and other compounding agents are kneaded in advance, and a vulcanizing agent is added to the obtained kneaded material and kneaded.

The kneaded product is press vulcanized at 120 to 180 ° C. for a predetermined time (10 minutes or more and less than 3 hours), and molding and vulcanization are simultaneously performed to obtain a vibration damping member made of high damping rubber.
The damping member has a rectangular parallelepiped shape with a length of 10 to 500 mm, a width of 10 to 500 mm, and a thickness of 3 to 60 mm. Alternatively, it has a cylindrical shape with a diameter of 10 to 300 mm and a thickness of 3 to 60 mm.
The damping member made of the high damping rubber is bonded to the metal plate using an adhesive.
Alternatively, the kneaded material is sandwiched between two metal plates such as aluminum, iron, and stainless steel that have been subjected to a surface treatment such as blasting in advance, and vulcanized and bonded together with press vulcanization. Manufactured as a metal plate attached.

The vibration damping member made of the high damping rubber has an equivalent shear modulus (Geq 50%) at 50% shear deformation of the thickness of 0.7 N / mm in a dynamic viscoelasticity test at measurement temperatures of 0 ° C. and 20 ° C. ² or more, the equivalent viscosity damping constant (heq 50%) is 0.25 or more, and the equivalent shear elastic modulus (Geq 300%) at 300% shear deformation of the thickness is 0.3 N / mm ² or more. The damping constant (heq 300%) is 0.20 or more, the temperature dependency is small, and the elastic modulus at the time of large shear deformation is extremely excellent.
The measurement of the dynamic viscoelasticity test is performed by the method described in the examples described later.

  Hereinafter, although the Example and comparative example of this invention are shown, this invention is not limited to these.

(Examples 1-21, Comparative Examples 1-14)
35 parts by mass of the following petroleum resin, 1.5 parts by mass of the vulcanizing agent, and vulcanization accelerator with respect to 100 parts by mass of the components shown in Tables 1 and 2 and natural rubber or isoprene rubber 1 part by weight, 1 part by weight of vulcanization accelerator 2, 0.7 part by weight of zinc oxide, 4 parts by weight of zinc white, and 1 part by weight of stearic acid were weighed and put into a closed kneader while heating to 70 to 200 ° C. Kneading for 10 minutes to 1 hour.

Details of each component and specific product names are as follows.
・ Natural rubber; SMR-CV60
-Isoprene rubber; "Nipol IR2200 (trade name)" manufactured by Nippon Zeon Co., Ltd.
・ Silica: “Nipsil KQ (trade name)” manufactured by Nippon Silica Co., Ltd. (BET specific surface area 236 m ² / g)
Silane compound: Phenyltriethoxysilane “KBE103 (trade name)” manufactured by Shin-Etsu Chemical Co., Ltd.
Carbon black 1; FEF carbon “Seast SO (trade name)” manufactured by Tokai Carbon Co., Ltd. (nitrogen adsorption specific surface area 42 m ² / g, DBP absorption 115 ml / 100 g)
Carbon black 2; HAF carbon “Seast 3 (trade name)” manufactured by Tokai Carbon Co., Ltd. (nitrogen adsorption specific surface area 79 m ² / g, DBP absorption 101 ml / 100 g)
Liquid isoprene rubber 1; “Kuraprene LIR50 (trade name)” manufactured by Kuraray Co., Ltd. (glass transition temperature −63 ° C., molecular weight 47,000)
Liquid isoprene rubber 2; “Kuraprene LIR30 (trade name)” manufactured by Kuraray Co., Ltd. (glass transition temperature −63 ° C., molecular weight 29,000)
Liquid styrene isoprene rubber: “Kuraprene LIR310 (trade name)” manufactured by Kuraray Co., Ltd. (glass transition temperature −63 ° C., molecular weight 31,000)
Liquid BR (liquid butadiene rubber); “Kuraprene LIR300 (trade name)” manufactured by Kuraray Co., Ltd. (glass transition temperature −95 ° C., molecular weight 45,000)
Liquid NBR (liquid acrylonitrile butadiene rubber); “Nipol 1312 (trade name)” manufactured by Nippon Zeon Co., Ltd. (glass transition temperature −40 ° C. (estimated from acrylonitrile amount))
・ Liquid SBR (liquid styrene butadiene rubber); manufactured by Sartomer ・ Petroleum resin: Maruzen Chemical Co., Ltd. dicyclopentadiene-based petroleum resin “Marcaretz M809A (trade name)” (petroleum resin 1) and Nippon Steel Chemical Co., Ltd. Coumarone resin “Escron G-90 (trade name)” (petroleum resin 2) used at a mass ratio (petroleum resin 1: petroleum resin 2) = (10:25) • Paraffin oil 1; manufactured by Idemitsu Kosan Co., Ltd. "Diana Process Oil PW-90 (trade name)"
Paraffin oil 2; “Diana Process Oil PW-380 (trade name)” manufactured by Idemitsu Kosan Co., Ltd.
・ Naphthenic oil 1; “Diana Fresia N-90 (trade name)” manufactured by Idemitsu Kosan Co., Ltd.
・ Naphthenic oil 2; “Diana Fresia N-430 (trade name)” manufactured by Idemitsu Kosan Co., Ltd.
・ Aroma oil: “Diana Process Oil AH-16 (trade name)” manufactured by Idemitsu Kosan Co., Ltd.
・ Vulcanizing agent: 5% oil-treated powdered sulfur from Tsurumi Chemical Co., Ltd. ・ Vulcanization accelerator 1: N-tert-butyl-2-benzothiazolylsulfenamide “Noxeller” from Ouchi Shinsei Chemical Co., Ltd. NS (Product Name) "
・ Vulcanization accelerator 2; Tetrabutylthiuram disulfide “Noxeller TBT (trade name)” manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
・ Zinc flower: “Zinc oxide 2 types (trade name)” manufactured by Mitsui Mining & Smelting Co., Ltd.
・ Stearic acid; Tsubaki (trade name) manufactured by NOF Corporation
Anti-aging agent 1: 2-mercaptoben ヅ imidazole “NOCRACK MB (trade name)” manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Anti-aging agent 2; Polymerized 2,2,4-trimethyl-1,2-dihydroquinoline “Antioxidant FR (trade name)” manufactured by Matsubara Sangyo Co., Ltd.

The obtained kneaded material was press vulcanized at 130 ° C. to 180 ° C. for 10 minutes or more and less than 3 hours to obtain a vibration damping member made of high damping rubber. The vibration damping member had a diameter of 25 mm and a thickness of 5 mm.
The damping member 110 was bonded to the two metal plates 111 and 112 to obtain a damping unit 113 shown in FIG.

As shown in FIG. 2 (B), two sets of vibration damping units 113 are installed in a measuring device (Shimadzu Corporation, EHF-EV020K2-040-1 A-type servo pulser durability tester), and 0 ° C. Then, a dynamic viscoelasticity evaluation test at 20 ° C. was performed to determine an equivalent shear modulus (Geq) and an equivalent viscous damping constant (heq).
Specifically, vibration was performed in the direction of the arrow at a frequency of 2 Hz, and the equivalent shear modulus (Geq) and the equivalent viscosity damping constant (heq) were obtained from the load value and strain of the load-strain loop curve shown in FIG.
The test was performed under the conditions of 0 ° C. and 20 ° C., and the shear strain was ± 50% and ± 300% of the sample thickness.

  The measurement results are shown in Tables 1 to 4 together with the difference in the composition of each component.

In Comparative Example 1 using aroma oil as a softening agent, Geq 300% at 20 ° C. was less than 0.3 N / mm ² and lacked the elastic modulus at the time of large deformation. Moreover, since the aroma oil which may contain a polycyclic aromatic hydrocarbon is used, there was a concern about the influence on the environment and the human body.
In Comparative Example 2 in which the blending amount of silica was less than 100 parts by mass with respect to 100 parts by mass of the base rubber, Geq 300% at 20 ° C. was less than 0.3 N / mm ² and lacked the elastic modulus at the time of large deformation. .
On the other hand, Comparative Example 3 in which the compounding amount of silica is more than 180 parts by mass with respect to 100 parts by mass of the base rubber has poor processability, and silica, carbon black, etc. cannot be uniformly kneaded into the base rubber. It was.

In Comparative Examples 4 and 5 containing more than 30 parts by weight of paraffin oil, Geq 300% at 20 ° C. was less than 0.3 N / mm ² and lacked the elastic modulus at the time of large deformation.
Comparative Example 6 in which none of liquid rubber, paraffin oil, or naphthenic oil was blended as a softening agent, and Comparative Example 7 in which the blending amount of the softening agent was less than 10 parts by weight with respect to 100 parts by weight of the base rubber was processed. The properties were poor and could not be uniformly kneaded into the base rubber. Comparative Example 8 in which the blending amount of the liquid rubber is more than 30 parts by mass with respect to 100 parts by mass of the base rubber is such that Geq 300% at 20 ° C. is less than 0.3 N / mm ² and elastic modulus at the time of large deformation near normal temperature Was lacking.
Further, in Comparative Examples 9 and 14 in which the blending amount of carbon black is less than 5 parts by mass with respect to 100 parts by mass of the base rubber, Geq 300% at 20 ° C. is less than 0.3 N / mm ² and large deformation near normal temperature The elastic modulus at the time was lacking. Comparative Example 10 in which the blending amount of carbon black was 30 parts by mass or more with respect to 100 parts by mass of the base rubber was poor in workability and became too hard to be uniformly kneaded into the base rubber.
Comparative Example 11 in which no silane compound was blended, Comparative Example 12 in which the blending amount of the silane compound was less than 5 parts by mass with respect to 100 parts by mass of silica, and the blending amount of the silane compound was 25 masses with respect to 100 parts by mass of silica. In Comparative Example 13, which had more parts than the part, both had poor processability and could not be uniformly kneaded into the base rubber. In particular, Comparative Examples 12 and 13 could not be kneaded with rubber, and were in a rough state.

On the other hand, 10 parts by mass or more and 30 parts by mass or less of one or more softeners selected from the group consisting of liquid rubber, paraffin oil and naphthenic oil, and 5 parts by mass of carbon black with respect to 100 parts by mass of the base rubber. More than 30 parts by weight, 100 parts by weight or more and 180 parts by weight or less of silica, and Examples 1 to 21 prepared from high-damping rubber compositions containing 5 to 25 parts by weight of a silane compound with respect to 100 parts by weight of silica. The damping member made of high-damping rubber has an equivalent shear modulus (Geq 50%) at 50% thickness shear deformation of 0.7 N / mm ² or more at any temperature condition of 0 ° C. and 20 ° C. viscous damping constant (heq50%) is 0.25 or more, and, at 300% shear deformation at an equivalent shear modulus of the thickness (Geq300%) is 0.3 N / mm ² or more, the equivalent viscous damping constant (h Q300%) is at least 0.20, it has a high equivalent shear modulus and equivalent viscous damping constant, very good damping performance, temperature dependence of the damping characteristics is small, was excellent.
In addition, the high damping rubber composition of the present invention is excellent in processability, can uniformly knead the base rubber and other compounding agents, and does not contain polycyclic aromatic hydrocarbons as a softening agent. It is also excellent in that no load is applied.

  The vibration damping member comprising the high damping rubber composition of the present invention can be applied to various vibration damping devices. For example, damping walls for high-rise buildings such as detached houses, condominiums, and buildings, connection-type and brace-type building damping materials, bridge damping devices, and floating breakwaters with damping functions And cabinets equipped with vibration control devices, vibration control systems for TV antennas, and the like.

It is a figure which shows the method of calculating an equivalent viscous damping constant (heq) from a hysteresis curve measurement result. (A) It is a perspective view which shows the damping member of an Example, (B) is a figure explaining the method of the dynamic viscoelasticity test using (A).

Explanation of symbols

110 Damping member 113 Damping unit

Claims (4)

  One or more softening agents selected from the group consisting of liquid rubber, paraffin oil, and naphthenic oil are used in an amount of 10 to 30 parts by mass, and carbon black is 5 to 30 parts by mass with respect to 100 parts by mass of the base rubber. Less than 100 parts by weight, 100 parts by weight or more and 180 parts by weight or less of silica, and 100 parts by weight of silica containing 5 parts by weight or more and 25 parts by weight or less of a silane compound, and an oil containing polycyclic aromatic hydrocarbons A high-damping rubber composition characterized by being not blended.   The high-damping rubber composition according to claim 1, wherein the base rubber is one or more selected from the group consisting of natural rubber, isoprene rubber, butadiene rubber, styrene butadiene rubber, and acrylonitrile butadiene rubber.   2. The softening agent is at least one liquid diene rubber selected from the group consisting of liquid isoprene rubber, liquid styrene isoprene rubber, liquid butadiene rubber, liquid styrene butadiene rubber and liquid acrylonitrile butadiene rubber. 2. The high damping rubber composition according to 2. A vibration damping member produced by vulcanization molding of the high damping rubber composition according to any one of claims 1 to 3,
In the dynamic viscoelasticity test at measurement temperatures of 0 ° C. and 20 ° C., the equivalent shear modulus (Geq 50%) at 50% shear deformation of the thickness is 0.7 N / mm ² or more, and the equivalent viscous damping constant (heq 50%) is 0.25 or more, equivalent shear modulus (Geq 300%) at 300% thickness shear deformation is 0.3 N / mm ² or more, and equivalent viscosity damping constant (heq 300%) is 0.20 or more. A damping member characterized by that.

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