JP5478820B2 - Anti-vibration rubber - Google Patents

Description

The present invention relates to an anti-vibration rubber comprising a highly damped rubber composition, and in particular, does not impair processability while blending a filler, has little temperature dependence, and has high damping performance.

  2. Description of the Related Art Conventionally, high damping rubber has been used in vibration control devices that absorb vibration energy generated by earthquakes, traffic vibrations, wind vibrations, and the like in buildings such as houses and buildings, bridges, and the like. High damping rubber is widely used because it has excellent vibration damping performance, is relatively inexpensive, and has the advantage of exhibiting a damping effect against minute vibrations such as wind fluctuations.

  As a technique for enhancing the vibration damping characteristics (tan δ) of the rubber composition forming such a high-damping rubber, JP 2000-44813 A (Patent Document 1), JP 7-41603 A (Patent Document 2), Japanese Unexamined Patent Application Publication No. 2007-45998 (Patent Document 3) has been proposed.

In Patent Document 1, a high-damping material composition in which a hindered phenol-based damping imparting agent and a damping characteristic peak temperature adjusting agent are blended with a base polymer having a polar base chain is used, and the Tg ( The damping characteristic is enhanced by adjusting the temperature range to the glass transition point.
However, since a polymer having a polar base chain generally has a Tg near room temperature, the rigidity of the vibration-proof rubber molded from the highly-damped material composition is highly temperature-dependent, and the actual vibration damping system It is difficult to incorporate into the design.

In addition, in the Patent Document 2, the present applicant added 30 to 200 parts by weight of silica to 100 parts by weight of the base rubber having a C—C bond in the main chain, and added 5 to 5 silane compounds to the silica. A 50% by weight blended and kneaded product provides a highly damped rubber composition containing silica that exhibits high damping and has little temperature dependence of elastic modulus.
The high-damping rubber composition of Patent Document 2 uses a polymer having a small temperature dependency such as natural rubber, and is excellent in that the temperature dependency is low near normal temperature, but the material itself has almost no damping performance. It is necessary to add a filler. Therefore, in order to obtain even greater damping performance, it is necessary to blend a large amount of filler such as silica or carbon black. However, if a large amount of filler is blended, the workability deteriorates and from the viewpoint of mass productivity at the factory. There is room for improvement.

  Patent Document 3 proposes a highly-damping material composition containing a rubber component and an aromatic oligomer having at least one hydroxyl group at one end, but the use of the aromatic oligomer alone is sufficient. It is difficult to obtain a good attenuation performance.

JP 2000-44813 A JP 7-41603 A Japanese Patent Laid-Open No. 2007-45998

The present invention has been made in view of the above problems, it is excellent in workability, low temperature dependence of the elastic modulus, and provides a high damping rubber composition or Ranaru rubber vibration isolator with superior damping performance It is an issue.

In order to solve the above problems, the present invention provides:
80 to 180 parts by mass of silica, 3 to 50 parts by mass of an attenuating agent having 2 or more polar groups, with respect to 100 parts by mass of rubber that does not have a polar group as a base rubber,
The attenuating agent may be one or more selected from the group consisting of a rosin derivative having two or more hydroxyl groups, an xylene resin having an alkoxy group or / and a hydroxy group, and a phenolic anti-aging agent having two or more hydroxyl groups. molded from Oh Ru high damping rubber composition, heq100% equivalent viscous damping constant at 20 ° C. is providing a rubber cushion, characterized in that there is a 0.25 or more.

As described above, since the rubber having no polar group is used as the base rubber, the temperature dependence of the elastic modulus can be reduced. Further, silica to be blended with the rubber exhibits a high damping property when blended in the rubber composition and has a characteristic that the temperature dependence of the elastic modulus is small. Further, when one or more of a rosin derivative having two or more hydroxyl groups, a xylene resin, and a phenolic anti-aging agent having two or more hydroxyl groups are blended as an attenuating agent having two or more polar groups, the silica and Since the affinity with rubber can be increased and the blending amount is suppressed to 3 to 50 parts by mass, the processability does not deteriorate and the mass production performance can be improved.
In this way, silica with high dispersibility and damping performance is blended with base rubber that does not have a polar group with low temperature dependence, and an attenuating agent that has good affinity for both silica and base rubber. By doing so, a rubber composition having excellent processability and high damping performance can be obtained. Furthermore, when the damping performance of the rubber composition is increased, the damping device necessary for the development of the targeted damping performance is used when the damping rubber molded from the rubber composition is used in the damping device attached to the building. Can be reduced, that is, the cost can be reduced. Further, the space can be effectively used by reducing the number of installed devices. Furthermore, since the temperature dependency is small, it can be arranged near the outer wall of a building having a large temperature difference.

The mixing amount of the attenuating agent is 3 to 50 parts by mass with respect to 100 parts by mass of the rubber having no polar group. If the amount is less than 3 parts by mass, sufficient attenuation performance cannot be obtained. It is because workability will worsen if it exceeds a mass part. And if it is set as the compounding quantity of the said attenuation | damping property imparting agent, it will become a suitable quantity with respect to the compounding quantity 80-180 mass part of the said silica.
The blending amount of the attenuating agent is more preferably 10 to 50 parts by weight, and particularly preferably 10 to 40 parts by weight with respect to 100 parts by weight of rubber not having a polar group.

As described above, as the attenuating agent, one or more of a rosin derivative having two or more hydroxyl groups, a xylene resin, and a phenolic anti-aging agent having two or more hydroxyl groups are used.
Since these attenuating agents have polar groups in the molecule, they are due to intermolecular forces of “attenuating agents”, “attenuating agents and silica”, or “attenuating agents and rubber molecules”. Interaction can be increased. In addition, when there is only one polar group in one molecule, it ends with an interaction between two molecules. However, since the attenuating agent of the present invention has two or more polar groups in one molecule, Group interactions can occur continuously. Therefore, it is considered that a large hysteresis loss occurs.

Examples of the polar group of the attenuating agent include one or more of a hydroxyl group (hydroxyl group), an alkoxy group, a carbonyl group, a carboxyl group, etc. Among them, it is preferable that a hydroxyl group and / or an alkoxy group is included. .
In particular, it is preferable that at least one of the polar groups is a hydroxyl group because it strongly causes an interaction with silica. The number of hydroxyl groups is particularly preferably 2 or more. The hydroxyl group may comprise either a phenolic hydroxyl group or an alcoholic hydroxyl group.

The rosin derivative having two or more hydroxyl groups serving as the attenuating agent is a rosin obtained by removing turpentine by steam distillation of a pine resin (pine pine) and modified by introducing two or more hydroxyl groups. Is preferred.
As the rosin derivative having two or more hydroxyl groups, for example, those having two hydroxyl groups introduced as exemplified in the following chemical formula (1) are preferably used.

  When using the rosin derivative which has a 2 or more hydroxyl group, the compounding quantity of 10-50 mass parts with respect to 100 mass parts of rubber | gum which does not have a polar group, Furthermore, 10-40 mass parts is suitable.

The xylene resin used as the attenuating agent is a resin obtained by reacting xylene (especially m-xylene) with an aldehyde, and has an alkoxy group and / or a hydroxy group as described above.
The xylene resin having an alkoxy group, large methoxy polar as alkoxy groups, in addition to those having an ethoxy group, a hydrocarbon is substituted with an alkoxy group, a compound containing a so-called ether linkage is also preferably used. Such a compound includes a compound in which 1 to 20 polyalkylene oxide units are introduced, and the polyalkylene oxide unit is preferably polyethylene oxide or polypropylene oxide.

Examples of the xylene resin include commercially available products such as “Nikanol (trade name)” series manufactured by Fudou Co., Ltd.
Specifically, “Nikanol G” having a plurality of alkoxy groups as shown in the representative structures of the following chemical formulas (2) to (11), and having four hydroxyl groups as shown in the following chemical formula (12) Nicanol HP100 ”,“ Nicanol K100 ”having two hydroxyl groups and two alkoxy groups as shown in the following chemical formula (13), four hydroxyl groups and three alkoxy groups as shown in the following chemical formula (14) “Nicanol K140” having one hydroxyl group and a plurality of alkoxy groups as shown in the following chemical formula (15), two hydroxyl groups and a plurality of alkoxy as shown in the following chemical formula (16) And “Nicanol K1005” having a group.

  When xylene resin is used, the blending amount is preferably 10 to 50 parts by mass, and more preferably 10 to 40 parts by mass with respect to 100 parts by mass of the rubber having no polar group.

  Examples of the phenol-based anti-aging agent having two or more hydroxyl groups serving as the attenuating agent include bisphenol-based, polyphenol-based, thiobisphenol-based, and hydroquinone-based anti-aging agents.

Examples of the bisphenol-based antioxidant include 1,1-bis (3-hydroxyphenyl) cyclohexane, 2,2′-methylenebis (4-methyl-6-tert-butylphenol) (MBMBP) (the following chemical formula (17)), 2 , 2′-methylenebis (4-ethyl-6-tert-butylphenol), 2,2′-methylenebis [6- (1-methylcyclohexyl)]-p-cresol, 4,4′-butylidenebis (3-methyl-6) -Tert-butylphenol) (BBMTBP), 3,9-bis [2- (3-tert-butyl-4-hydroxy-5-methylphenylpropionyloxy) -1,1-dimethylethyl] -2,4,8, And 10-tetraoxaspiro (5,5) undecane.
Examples of the polyphenol antioxidant include tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane.
Examples of the thiobisphenol antioxidant include 4,4-thiobis (3-methyl-6-tert-butylphenol), 4,4′-bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide, 4,4′-thiobis (6-tert-butyl-o-cresol) and the like.
Examples of the hydroquinone antioxidant include 2,5-di-tert-butylhydroquinone (DBHQ) and 2,5-di-tert-amylhydroquinone.
These may be used alone or in combination of two or more.

Of these, it is preferable to use a bisphenol-based antioxidant, and in addition to 2,2′-methylenebis (4-methyl-6-tert-butylphenol) (MBMBP) represented by the following chemical formula (17), 2,2′- Methylenebis (4-ethyl-6-tert-butylphenol), 2,2′-methylenebis [6- (1-methylcyclohexyl)]-p-cresol, 4,4′-butylidenebis (3-methyl-6-tert-butylphenol) ) (BBMTBP) is preferably used.

  When using the phenol type antioxidant which has a 2 or more hydroxyl group, the compounding quantity of 10-40 mass parts is suitable with respect to 100 mass parts of rubber | gum which does not have the said polar group.

As described above, as the rubber component, rubber having no polar group is used as the base rubber. Since rubbers having no polar group generally have a glass transition temperature (Tg) lower than room temperature, the temperature dependence of rigidity near room temperature, which was a disadvantage of using a polymer having a polar group, is kept low. be able to. As a result, as described above, it is possible to install a damper using a high-damping rubber also in a place with a large temperature difference such as the vicinity of the outer wall of a building.
In the present specification, the “base rubber” refers to a rubber that occupies 80% by mass or more of all rubber components.

Examples of the base rubber having no polar group include crosslinkable rubbers such as natural rubber, isoprene rubber, butadiene rubber, butyl rubber, styrene butadiene rubber, and ethylene propylene rubber. These may be used alone or in combination of two or more.
Especially, since temperature dependence is small, it is preferable to use 1 or more types selected from the group which consists of natural rubber, isoprene rubber, and butadiene rubber. It is particularly preferable to use natural rubber.

As long as the temperature dependence of the physical properties near normal temperature does not decrease, a rubber having another polar group can be blended with the rubber having no polar group, which is a base rubber.
Examples of the rubber having a polar group that can be blended with the rubber having no polar group include cross-linkable rubbers such as norbornene rubber, halogenated butyl rubber, chloroprene rubber, acrylonitrile butadiene rubber, epichlorohydrin rubber, chlorosulfonated polyethylene, and polysulfide rubber. Can be mentioned.
Even in this case, the rubber having a polar group is preferably less than 20% by mass, more preferably less than 10% by mass of the total rubber component.

As described above, the silica can exhibit high damping performance when used together with the damping agent.
Silica is blended at a ratio of 80 parts by mass or more and 180 parts by mass or less with respect to 100 parts by mass of the rubber not having the polar group. Preferably, they are 100 to 180 mass parts. This is because if the amount is less than 80 parts by mass, sufficient damping performance is difficult to obtain, 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, it is preferable that 10-20 mass parts of silane agents are mix | blended with respect to 100 mass parts of said silica.
The silane agent has an effect of improving the kneadability of silica. When the amount is less than 10 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 agent exceeds 20 parts by mass, the blending amount becomes excessive and the effect of adding is reduced. When the blending ratio is used, the compatibility with rubber and silica having no polar group is excellent.
The compounding amount of the silane agent is preferably 15 to 20 parts by mass, more preferably 15 to 17 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 agent, what is represented by following General formula (18) 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 agent represented by the general formula (18), 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 agent represented by the general formula (18) 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.

Moreover, you may mix | blend carbon black with the high attenuation | damping rubber composition used by this invention.
When carbon black is blended, the blending amount depends on the amount of silica, but it is preferably a ratio of 1 part by mass or more and less than 20 parts by mass with respect to 100 parts by mass of rubber having no polar group.
This is because if the carbon black is less than 1 part by mass, it is difficult to obtain a reinforcing effect by blending the carbon black, and if it is 20 parts by mass or more, the kneadability and moldability are reduced. More preferably, they are 1 mass part or more and less than 10 mass parts, Most preferably, they are 1 mass part or more and 5 mass parts or less.

  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.

As other components other than the components described above, a vulcanizing agent, a vulcanization accelerator, an anti-aging agent other than the phenol-based anti-aging agent having two or more hydroxyl groups, a vulcanization accelerating aid, silica, Various additives other than carbon black, such as reinforcing agents and fillers, 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.
These other components are all components that do not correspond to the attenuating agent.

Examples of the vulcanizing agent include sulfur, organic sulfur-containing compounds, and organic peroxides, and it is preferable to use sulfur.
As sulfur, normally recovered sulfur can be pulverized into fine powder. Surface-treated sulfur with improved dispersibility can also be used as appropriate. Insoluble sulfur can also be used to avoid bloom from unvulcanized rubber.
Examples of the organic sulfur-containing compound include N, N′-dithiobismorpholine, diphenyl disulfide, pentabromodisulfide, pentachlorothiophenol, pentachlorothiophenol zinc salt, and the like.
Organic peroxides include benzoyl peroxide, 1,1-di- (tert-butylperoxy) -3,3,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di- (benzoylperoxy). ) Hexane, 2,5-dimethyl-2,5-di- (benzoylperoxy) -3-hexene, 2,5-dimethyl-2,5-di- (tert-butylperoxy) hexane, di-tert- Butyl peroxydiisopropylbenzene, di-tert-butyl peroxide, di-tert-butyl peroxybenzoate, dicumyl peroxide, tert-butyl cumyl peroxide, 2,5-dimethyl-2,5-di- (tert- Butylperoxy) -3-hexene, 1,3-bis (tert-butylperoxyisopropyl) benzene, n- Examples include til-4,4-bis (tert-butylperoxy) valerate, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, tert-butylperoxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and the like. It is done.
Examples of heat-resistant crosslinking agents include 1,3-bis (citraconimidomethyl) benzene, sodium hexamethylene-1,6-bisthiosulfate dihydrate, 1,6-bis (dibenzylthiocarbamoyl disulfide) hexane, and the like. Can be mentioned.
Examples of the resin crosslinking agent include alkylphenol resins or brominated alkylphenol formaldehyde resins such as Tackey Roll 201, Tackey Roll 250-III (manufactured by Taoka Chemical Co., Ltd.), and Hitanol 2501 (manufactured by Hitachi Chemical Co., Ltd.). It is done.
The vulcanizing agent is preferably 0.5 to 5 parts by mass, more preferably 1 to 3 parts by mass with respect to 100 parts by mass of all rubber components.

As the vulcanization accelerator, either an inorganic accelerator or an organic accelerator can be used.
Examples of the inorganic accelerator include slaked lime, magnesium oxide, titanium oxide, or resurge (PbO).
Examples of the organic accelerator include thylliums, thiazoles, thioureas, dithiocarbamates, guanidines, sulfenamides, and the like.
Examples of the thyriums include tetramethyl thylium monosulfide, tetramethyl thyrium disulfide, tetraethyl thyrium disulfide, tetrabutyl tyrium disulfide, dipentamethylene tyrium tetrasulfide, and the like.
Examples of thiazoles include 2-mercaptobenzothiazole, benzothiazyl disulfide, N-cyclohexylbenzothiazole and the like.
Examples of thioureas include N, N′-diethylthiourea, ethylenethiourea, and totimethylthiourea.
Dithiocarbamate salts include: zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, sodium dimethyldithiocarbamate, sodium diethyldithiocarbamate, copper dimethyldithiocarbamate, dimethyldithiothiol Examples thereof include iron (III) carbamate, selenium ethyldithiocarbamate, and tellurium diethyldithiocarbamate.
Examples of the guanidine accelerator include di-o-tolylguanidine, 1,3-diphenylguanidine, 1-o-tolylbiguanide, dicatechol borate di-o-tolylguanidine, and the like.
Examples of the sulfenamides include N-cyclohexyl-2-benzothiazolylsulfenamide, N-oxydiethylene-2-benzothiazolylsulfenamide, N-tert-butyl-2-benzothiazolylsulfenamide, or N , N′-dicyclohexyl-2-benzothiazolylsulfenamide and the like.
The vulcanization accelerator is selected from the range of 0 to 15 parts by mass with respect to 100 parts by mass of the total rubber component in the case of an inorganic accelerator, and is 0.000 with respect to 100 parts by mass of the total rubber component in the case of an organic accelerator. It is preferably selected from the range of 5 to 5 parts by mass.

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.
The said vulcanization | cure acceleration | stimulation adjuvant is selected from the range of 0.5-20 mass parts with respect to 100 mass parts of all the rubber components, Preferably it is 1-10 mass parts.
The total amount of the vulcanizing agent, the vulcanization accelerator, and the vulcanization accelerator auxiliary is preferably about 4 to 15 parts by mass with respect to 100 parts by mass of the total rubber components.

Other anti-aging agents other than the above-described phenol-based anti-aging agents having two or more hydroxyl groups include imidazoles such as 2-mercaptobenzimidazole; phenyl-α-naphthylamine, N, N′-di-β-naphthyl- Amines such as p-phenylenediamine, N-phenyl-N'-isopropyl-p-phenylenediamine, polymerized 2,2,4-trimethyl-1,2-dihydroquinoline; di-t-butyl-p-cresol, styrene Examples thereof include monophenols such as fluorinated phenols.
Especially, it is preferable to use imidazoles and amines which are excellent in the effect of increasing the ozone resistance of the rubber having no polar group.
The blending amount of the other anti-aging agent is preferably 1.5 to 10 parts by mass, preferably 2 to 5 parts by mass with respect to 100 parts by mass of all rubber components.

In addition, the monophenol type antioxidant which has only one hydroxyl group as shown by the following chemical formula (19) does not correspond to the attenuating agent. However, the use with the attenuating agent is not prevented.

As fillers other than silica and carbon black, inorganic reinforcing agents such as calcium carbonate, surface-treated precipitated calcium carbonate, magnesium carbonate, barium sulfate, talc, clay, diatomaceous earth, or phenol resin, high styrene resin (styrene-containing) Organic reinforcing agents such as styrene-butadiene copolymers in large quantities can be used.
When a reinforcing agent and / or 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 all rubber components.

Softeners include fatty acids such as stearic acid and lauric acid, vegetable oils, tall oil, asphalt substances, vegetable oil and mineral oil softeners such as paraffin wax; liquid rubbers such as liquid IR, liquid SIS, liquid SBR, and liquid NBR Various synthetic softeners can be exemplified.
The blending amount of the softener is preferably about 10 to 50 parts by mass with respect to 100 parts by mass of all rubber components.

As the tackifier, those that do not fall under the attenuating agent, such as petroleum resins such as cyclopentadiene resin, coumarone / indene resin, aromatic resin, aromatic / aliphatic mixed resin, rosin These resins can be used alone or in combination of two or more. 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 weight, more preferably 5 to 40 parts by weight with respect to 100 parts by weight of all rubber components.
In addition to the above, a dispersant, a solvent and the like may be appropriately blended.

Proof Fugo beam made of a high damping rubber composition of the present invention were kneaded by using a closed kneading machine each component of the high damping rubber composition, extruding and introducing kneaded product into an extruder, which After being cut into a required shape and preformed, it is filled in a mold molding machine, heated at a required temperature and vulcanized to form a vibration-proof rubber molded into the required shape.
Alternatively, the kneaded product is directly press vulcanized at a required temperature to form a vibration-proof rubber having a required shape.

As described above, the vibration-proof rubber of the present invention is characterized in that the equivalent viscosity damping constant heq 100% at 20 ° C. is 0.25 or more.
The equivalent viscosity damping constant heq100% indicates an equivalent viscosity damping constant at the time of 100% thickness shear deformation, and the larger the value, the better the damping performance .

Moreover, it is preferable that the equivalent shear elastic modulus (Geq100%) which shows the rigidity which the said vibration-proof rubber has is 0.1 N / mm < ² > or more. The upper limit is preferably 1.5 N / mm ² or less.
The equivalent shear elastic modulus Geq100% indicates an equivalent shear elastic modulus at the time of 100% shear deformation of the thickness.

  The equivalent viscosity damping constant (heq) and the equivalent shear modulus (Geq) are calculated by measuring the hysteresis characteristics of the anti-vibration rubber by the following method and obtaining the horizontal characteristic value from the hysteresis loop of FIG. Yes.

Specifically, the hysteresis characteristics are measured using a test body 13 as shown in FIG. 2A in which the vibration-proof rubber 10 and the metal plates 11 and 12 are bonded. As shown in FIG. 2 (B), the two test bodies 13 are fixed to the center fixing jig 14 and the left and right fixing jigs 15 with bolts, respectively, and this is uniaxial shear test as shown in FIG. 2 (C). The lower part of the machine is connected with bolts and the upper part of the shearing tester is connected with bolts via the joint 16, and the upper part of the shearing tester is fixed and the lower part in the vertical direction as shown in FIG. It is installed so that the test body 13 is displaced by being displaced.
Next, repeated loading (sinusoidal vibration) causing shear deformation in the vertical direction at the lower part of the shear tester is performed four times, and the hysteresis characteristics of the third wave are measured.

The history loop of FIG. 1 obtained by measuring the history characteristics defines the following horizontal characteristic values.
W: Strain energy (area of one triangle indicated by the hatched portion in FIG. 1; unit is N · mm)
ΔW: Total absorbed energy (area surrounded by hysteresis loop shown in FIG. 1; unit is N · mm)
Keq: equivalent stiffness (inclination of hysteresis loop at maximum displacement point, unit is N / mm)

From the horizontal characteristic value, heq is a numerical value calculated by the following equation (Equation 1).
heq = (1 / 4π) · (ΔW / W) (Equation 1)
The equivalent shear modulus (Geq) is a numerical value calculated by the following (Equation 2).
Geq = Keq × (d / S) (Equation 2)
d: Rubber height of test specimen (mm)
S: Rubber cross-sectional area of test specimen (mm ² )

The anti-vibration rubber of the present invention may be produced as a vibration damping member by vulcanizing and bonding to a metal plate simultaneously with vulcanization of the high damping rubber composition. By vulcanizing and bonding to a metal plate, the reliability of bonding can be increased.
For example, the vibration damping member can be manufactured by the following manufacturing method.
(A) After extruding the unvulcanized high-damping rubber composition so as to have a predetermined shape, it is cut and heated in a predetermined mold in a pre-formed state and vulcanized and molded. At the same time as vulcanization, it is vulcanized and bonded to a metal plate for attachment to a vibration damping device.
(B) The unvulcanized high-damping rubber composition is press vulcanized using a predetermined mold, and at the same time as the press vulcanization, vulcanized and bonded to a plate for attachment to a vibration damping device.

  The anti-vibration rubber 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 , Cabinets equipped with damping devices, and damping systems for TV antennas. In addition, you may use for vibration isolators, such as precision equipment.

As described above, the anti-vibration rubber composed of the high-damping rubber composition of the present invention contains a predetermined amount of silica and a damping agent having a specific chemical structure in a rubber having no polar group. While having a composition with excellent processability, it is possible to increase the interaction due to the intermolecular force between “attenuating agents”, “attenuating agent and silica”, or “attenuating agent and rubber molecules”. Furthermore, since it has two or more polar groups in one molecule and interaction by the polar groups can be continuously generated, a large hysteresis loss can be generated.
Anti-vibration rubber molded from a rubber composition with high damping performance in this way reduces the number of damping devices required to achieve the desired damping performance when used in a damping device attached to a building. And cost can be reduced. Further, the space can be effectively used by reducing the number of installed devices. Furthermore, since the rubber having no polar group is used as the base rubber, elastic modulus, it is possible to reduce the temperature dependency of physical properties such as rigidity, a large temperature difference, such as near the outer wall of a building It becomes possible to install a damping member at the place.

Embodiments of the present invention will be described below.
In the highly attenuated rubber composition of the present embodiment, silica and an attenuation imparting agent having two or more polar groups are blended with the rubber component of the base material having no polar groups.

As the rubber component serving as the base material, one or more of natural rubber, isoprene rubber, and butadiene rubber, which are rubbers having no polar group, are used. 80 to 180 parts by mass of silica is blended with 100 parts by mass of the rubber not having the polar group. Silica having a BET specific surface area of 100 to 400 m ² / g is used.
Furthermore, in order to improve the kneadability of silica, a silane agent such as phenyltriethoxysilane is blended in an amount of 15 to 20 parts by mass with respect to 100 parts by mass of silica.

The attenuating agent has two or more polar groups, and one or more of a rosin derivative having two or more hydroxyl groups, a xylene resin, and a phenolic anti-aging agent having two or more hydroxyl groups are used. It is blended in an amount of 3 to 50 parts by mass with respect to 100 parts by mass of the rubber having no polar group.
As the rosin derivative having two or more hydroxyl groups, a rosin-containing diol having two or more hydroxyl groups introduced per rosin molecule as shown in the chemical formula (1) is used. As the rosin derivative, one having a hydroxyl value of 100 or more and 150 or less is used.
The xylene resin, the chemical formula (2) to (11), (12), (13), (14), (15), as shown in (16), an alkoxy group and / or hydroxy in the molecule It is used Dressings containing group.
As the phenol-based anti-aging agent having two or more hydroxyl groups, a bisphenol-based anti-aging agent is used, and 2,2-methylenebis (4-methyl-6-tert-butylphenol) is used in this embodiment.

Along with the silica, silane agent and damping agent, the base rubber component is further blended with a tackifier, softener, vulcanizing agent, vulcanization accelerator, anti-aging agent, and carbon black. .
As the tackifier, a petroleum resin is blended in an amount of 20 to 50 parts by mass with respect to 100 parts by mass of rubber having no polar group. 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.
As said softener, 10-50 mass parts with respect to 100 mass parts of rubbers which do not have a polar group as a softener , Preferably 15-35 mass parts is mix | blended.

Powdered sulfur is used as the vulcanizing agent, and 0.5 to 5 parts by mass is blended with 100 parts by mass of rubber having no polar group.
As the vulcanization accelerator, N-tert-butyl-2-benzothiazolylsulfenamide and tetrabutylthiuram disulfide are used in combination, and 0.5 to 5 parts by mass with respect to 100 parts by mass of rubber having no polar group. It is blended in the ratio of.
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 rubber having no polar group, and stearic acid is added to 100 parts by mass of rubber having no polar group. It mix | blends in the ratio of 0.3-5 mass parts with respect to.
2-mercaptobenzimidazole and polymerized 2,2,4-trimethyl-1,2-dihydroquinoline as anti-aging agents not corresponding to the attenuating agent are 0.5 each for 100 parts by mass of rubber having no polar group. It mix | blends in the ratio of -5 mass parts.
Furthermore, carbon black is blended at a ratio of 1 part by mass or more and less than 5 parts by mass with respect to 100 parts by mass of rubber having no polar group. As the carbon black, FEF carbon is used.

Antivibration rubber is molded by the following method using the high damping rubber composition comprising the above-described components.
First, the components are put into a kneader such as a kneader or a Banbury mixer and kneaded.
Next, the kneaded product is extruded using a single-screw extruder, a 1.5-screw extruder, a twin-screw extruder, an open roll, a hot roll, or the like, and this is cut into a required shape and preformed.
Next, the preform is filled in a mold molding machine, heated at a required temperature for a predetermined time, and vulcanized to form a vibration-proof rubber having a desired shape such as a sheet, a rectangular parallelepiped, or a cylinder. .
Alternatively, the kneaded product is press-vulcanized at 120 to 180 ° C. for a predetermined time to form a vibration-proof rubber.

In the step of molding the vibration-proof rubber, 80 to 180 parts by mass of silica and 3 to 50 parts by mass of an attenuating agent are blended with respect to 100 parts by mass of the rubber having no polar group as the base rubber. The filler is not blended, and the damping agent has good affinity with the base rubber and silica, so it is easy to knead, and the silica and damping agent are evenly dispersed in the base rubber and extruded. And is excellent in processability, and therefore, mass productivity is good.
The kneaded material is sandwiched between two metal plates such as aluminum, iron, and stainless steel that have been subjected to surface treatment such as blasting in advance, and vulcanized and bonded together with press vulcanization. It can also be manufactured as a state of a vibration damping member.

  The anti-vibration rubber produced in the above process exhibits high damping performance in which the equivalent viscosity damping constant (heq 100%) at a measurement temperature of 20 ° C. is in the range of 0.25 to 1.0. Further, since rubber having no polar group is used and the temperature dependency of physical properties such as rigidity is small, it is excellent as a high damping rubber for vibration control or vibration isolation.

  Examples of the present invention and comparative examples are shown below.

(Examples 1-17, Comparative Examples 1-11)
After weighing the components in the blending amounts shown in Tables 1 to 4, the mixture was put into a closed kneader and kneaded for 10 minutes to 2 hours while heating to 70 to 200 ° C. to obtain a kneaded product (composition). This was press vulcanized at 130 ° C. to 180 ° C. for 10 minutes or more and less than 3 hours to obtain an anti-vibration rubber comprising a high damping rubber composition. The anti-vibration rubber had a diameter of 25 mm and a thickness of 5 mm.

The details of the chemicals used as the damping agent in the examples are as follows.
Xylene resin 1; “Nikanol G (trade name)” manufactured by Fudou Co., Ltd. (mixed structure of the chemical formulas (2) to (11))
-Xylene resin 2; "Nikanol HP100 (trade name)" manufactured by Fudou Co., Ltd. (the above chemical formula (12))
Xylene resin 3; “Nikanol K100 (trade name)” manufactured by Fudou Co., Ltd. (the above chemical formula (13))
Xylene resin 4; “Nikanol K140 (trade name)” manufactured by Fudou Co., Ltd. (the above chemical formula (14))
Xylene resin 5; “Nikanol L5R (trade name)” manufactured by Fudou Co., Ltd. (the above chemical formula (15))
Xylene resin 6; “Nikanol K1005 (trade name)” manufactured by Fudou Co., Ltd. (the above chemical formula (16))
Rosin derivative 1; rosin-containing diol “Pine Crystal D6011 (trade name)” manufactured by Arakawa Chemical Industries, Ltd. (the above chemical formula (1), hydroxyl value 113 to 126)
Anti-aging agent 1; 2,2-methylenebis (4-methyl-6-tert-butylphenol) “NOCRACK NS-6 (trade name)” manufactured by Ouchi Shinsei Chemical Co., Ltd. (the above chemical formula (17))

The components used in the comparative example as a control substance for the attenuating agent of the above examples are as follows. That is, they do not have two or more polar groups in one molecule.
・ Rosin derivative 2; Rosin ester “Pine Crystal KE-100 (trade name)” manufactured by Arakawa Chemical Industries, Ltd.
・ Rosin derivative 3; Rosin ester “Pine Crystal KE-359 (trade name)” manufactured by Arakawa Chemical Industries, Ltd.
・ Hydrogenated petroleum resin 1; Alicyclic saturated hydrocarbon resin “ALCON P70 (trade name)” manufactured by Arakawa Chemical Industries, Ltd.
・ Hydrogenated petroleum resin 2; Arakawa Chemical Industries, Ltd. alicyclic saturated hydrocarbon resin “ALCON P100 (trade name)”
Anti-aging agent 2; 2,6-di-tert-butyl-4-methylphenol “NOCRACK 200 (trade name)” manufactured by Ouchi Shinsei Chemical Co., Ltd. (the above chemical formula (19))

Details of each component other than those described above and specific product names are as follows.
・ Natural rubber; SMR-CV60
・ Silica 1; “Silica VN3 (trade name)” manufactured by Tosoh Silica Co., Ltd. (BET specific surface area 200 m ² / g)
・ Silica 2; “Nippsil KQ (trade name)” manufactured by Tosoh Silica Co., Ltd. (BET specific surface area 230 m ² / g)
Silane agent: Phenyltriethoxysilane “KBE-103 (trade name)” manufactured by Shin-Etsu Chemical Co., Ltd.
・ Aroma oil (softener); “Diana Process Oil AH-16 (trade name)” manufactured by Idemitsu Kosan Co., Ltd.
・ Carbon black; FEF carbon "Dia Black E (trade name)" manufactured by Mitsubishi Chemical Corporation
Anti-aging agent 3; 2-mercaptobenzimidazole “NOCRACK MB (trade name)” manufactured by Ouchi Shinsei Chemical Co., Ltd.
Anti-aging agent 4: Polymerized 2,2,4-trimethyl-1,2-dihydroquinoline “Antigen FR (trade name)” manufactured by Matsubara Sangyo 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
Petroleum resin 1; dicyclopentadiene-based petroleum resin “Marcaretz M890A (trade name)” manufactured by Maruzen Chemical Co., Ltd.
・ Petroleum resin 2: Coumarone resin "Escron G-90 (trade name)" manufactured by Nippon Steel Chemical Co., Ltd.
・ Vulcanizing agent: 5% oil-treated powder sulfur “MIDAS 105 (trade name)” manufactured by BIGEN CO., LTD.
・ Vulcanization accelerator 1; N-tert-butyl-2-benzothiazolylsulfenamide “Noxeller NS (trade name)” manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
・ Vulcanization accelerator 2; Tetrabutylthiuram disulfide “Noxeller TBT-n (trade name)” manufactured by Ouchi Shinsei Chemical Co., Ltd.

  The obtained anti-vibration rubber was evaluated by the following method.

(Evaluation of equivalent shear elastic modulus (Geq) and equivalent viscous damping constant (heq))
Measurement was performed by the method shown in FIG. As shown in FIG. 2 (A), after obtaining a test body 13 in which two pieces of the obtained anti-vibration rubber 10 are bonded to the metal plates 11 and 12 by vulcanization adhesion, FIGS. ) Is installed in a uniaxial shear tester (A type servo pulsar endurance tester “EHF-EV020K2-040-1” manufactured by Shimadzu Corporation) in the direction of the arrow (vertical direction) in the figure. Repeated loading (sinusoidal vibration) causing shear deformation was performed four times, and the hysteresis characteristics of the third wave were measured.
From the obtained hysteresis loop, horizontal characteristic values ΔW, W, and Keq as shown in FIG. 1 are obtained, and the equivalent viscous damping constant (heq 100%) and equivalent shear of the high-damping rubber are obtained by the formulas (1) and (2). The elastic modulus (Geq 100%) was determined.
The test was performed under the condition of 20 ° C. and shear strain of ± 100% with respect to the sample thickness.
The vibration-proof rubber preferably has an equivalent viscosity damping constant (heq 100%) of 0.25 or more.

(Processability)
The workability when the kneaded product was kneaded to produce a rubber composition was measured according to the following criteria.
“◯”: The kneading apparatus was able to knead uniformly and uniformly without any problem.
“X”: The torque was large and the kneading apparatus could not be sufficiently kneaded.

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

Comparative Examples 1 and 2 in which the compounding amount of silica is less than 80 parts by mass with respect to 100 parts by mass of rubber having no polar group, Comparative Examples in which no damping imparting agent is compounded or the compounding amount is less than 3 parts by mass 4, 5 and Comparative Examples 6 to 10 in which hydrogenated petroleum resin, rosin derivative or anti-aging agent as a reference material not corresponding to the above-described attenuation imparting agent was blended had a heq of 100% of less than 0.25, which was sufficient. The vibration performance could not be obtained. Further, with respect to 100 parts by mass of rubber having no polar group, Comparative Example 3 in which the compounding amount of silica exceeds 180 parts by mass, and Comparative Example 11 in which the compounding amount of the attenuating agent exceeds 50 parts by mass is poor in workability. A uniform composition could not be produced.
On the other hand, 80 to 180 parts by mass of silica and 3 to 50 parts by mass of an attenuating agent having two or more polar groups per 100 parts by mass of rubber having no polar group, the attenuating agent As for high attenuation rubber composition of Examples 1-17 using a rosin derivative which has two or more hydroxyl groups, a xylene resin, or a phenolic anti-aging agent which has two or more hydroxyl groups, heq100% is 0.25 or more all In addition, sufficient vibration damping performance can be obtained with excellent workability.

The high-damping rubber composition of the present invention and the vibration-proof rubber comprising the high-damping rubber composition can be applied to various vibration damping members and 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 a cabinet equipped with a vibration damping device, a vibration damping system for a television antenna, and a vibration damping device such as a precision instrument.

It is a figure which shows the method of calculating a horizontal characteristic value from a history loop. (A)-(D) is a figure explaining the method of measuring a history characteristic.

Explanation of symbols

    10 Anti-vibration rubber

Claims (4)

80 to 180 parts by mass of silica, 3 to 50 parts by mass of an attenuating agent having 2 or more polar groups, with respect to 100 parts by mass of rubber that does not have a polar group as a base rubber,
The attenuating agent may be one or more selected from the group consisting of a rosin derivative having two or more hydroxyl groups, an xylene resin having an alkoxy group or / and a hydroxy group, and a phenolic anti-aging agent having two or more hydroxyl groups. molded from Oh Ru high damping rubber composition, rubber vibration insulator which Heq100% equivalent viscous damping constant at 20 ° C. which is characterized in that there is a 0.25 or more. The anti-vibration rubber according to claim 1, wherein the rubber having no polar group is at least one selected from the group consisting of natural rubber, isoprene rubber and butadiene rubber. Furthermore, the anti-vibration rubber | gum of Claim 1 or Claim 2 containing 10 mass parts or more and 20 mass parts or less of silane agents with respect to 100 mass parts of said silica. Furthermore, 15-35 mass parts with respect to 100 mass parts of said rubber | gum, and 1 mass part or more and 5 mass parts or less of carbon black with respect to 100 mass parts of said rubber | gum are mix | blended. The anti-vibration rubber according to any one of the above .

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