JP2010260933A - Rubber composition for seismic isolation structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rubber composition for a seismic isolation structure having both of a high elastic modulus and a high damping property. <P>SOLUTION: This rubber composition for the seismic isolation structure includes ≥2 and <50 mass% of polybutadiene, in a rubber component, in which a content of a 1,4-trans bond is ≥90%. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rubber composition for seismic isolation structures suitable for bridges and buildings.

Generally, in the formulation of a rubber composition, characteristics such as elastic modulus and hysteresis loss are controlled by adjusting the number of blended parts such as carbon black, oil, and resin.
By the way, since a rubber composition for a base isolation structure, particularly a rubber composition for a base isolation structure, requires both a high elastic modulus and a high damping characteristic, the method of increasing the amount of carbon black or reducing the amount of oil There was a limit. In addition, there is a disadvantage that permanent compression strain increases when the amount of carbon black is increased in order to increase the elastic modulus.
On the other hand, for example, in patent document 1, the high attenuation | damping property is provided by mix | blending liquid polyisoprene rubber.
In Patent Document 2, a high-damping seismic isolation rubber composition is obtained by applying carbon black having specific colloidal characteristics.
However, even with these methods, there is a limit to satisfy both the high elastic modulus and the high damping characteristic, and a new solution is required.

Japanese Patent Laid-Open No. 10-324777 JP 2001-164044 A

  Under such circumstances, an object of the present invention is to provide a rubber composition for a base-isolated structure that has both a high elastic modulus and a high damping characteristic.

The inventors of the present invention have completed the present invention as a result of earnestly studying a new compounding composition of the rubber composition for a seismic isolation structure in order to achieve the above object.
That is, the present invention
(1) A rubber composition for a base-isolated structure comprising 2% by mass or more and less than 50% by mass of polybutadiene having a 1,4-trans bond content of 90% or more in the rubber component;
(2) The rubber composition for a seismic isolation structure according to (1), further comprising a resin, and (3) the resin is a polyester polyol resin, an alicyclic petroleum resin, or a phenol resin. At least selected from the group consisting of xylene resins, aliphatic petroleum resins, aromatic petroleum resins, aliphatic-aromatic copolymer resins, rosin resins, terpene resins, ketone resins, and modified resins of these resins It is 1 type, It is a rubber composition for seismic isolation structures as described in said (2) characterized by the above-mentioned.

  According to the present invention, it is possible to provide a rubber composition for a base-isolated structure that has both a high elastic modulus and a high damping characteristic.

It is the schematic which shows the structure of the sample for a shear elastic modulus measurement of a rubber composition, (A) shows the state which pinches | interposes a rubber sheet, (B) shows the state which adhere | attached the rubber sheet.

The rubber composition for a base-isolated structure of the present invention contains 2% by mass or more of polybutadiene having a 1,4-trans bond content of 90% or more (hereinafter sometimes referred to as “high-trans polybutadiene”) in the rubber component. And less than 50% by mass. If it is less than 2% by mass, it is difficult to obtain the effects of a high elastic modulus and high damping characteristics, and if it is 50% by mass or more, the breaking characteristics of the rubber composition are lowered.
In the present invention, the 1,4-trans bond content is measured according to the Morero method by infrared spectroscopic analysis.

A polybutadiene having a 1,4-trans bond content of 90% or more used in the present invention has been conventionally known. For example, JP-A-9-241428 has a 1,4-trans bond content of 92% and a weight average. A production example of a high trans polybutadiene having a molecular weight of 3.2 × 10 ⁴ and a production example of a high trans polybutadiene having a 1,4-trans bond content of 91% and a weight average molecular weight of 14.8 × 10 ⁴ are disclosed. JP 2002-69237 discloses an example of producing a high trans polybutadiene having a 1,4-trans bond content of 92% and a weight average molecular weight of 6.4 × 10 ⁴ .

In the present invention, natural rubber and / or diene synthetic rubber is suitably used as the rubber component in addition to the above-mentioned high transpolybutadiene. The diene synthetic rubber includes styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR) other than the above, polyisoprene rubber (IR), chloroprene rubber, butyl rubber (IIR), halogenated butyl rubber, ethylene-propylene. -Diene terpolymer rubber (EPDM) etc. are mentioned. Of these, natural rubber, polyisoprene rubber, styrene-butadiene copolymer rubber, and polybutadiene rubber that is not high trans (for example, 1,4-cis bond content) from the viewpoint of mechanical properties and workability of the vulcanized rubber composition. The rubber component preferably contains 30% by mass or more, more preferably more than 50% by mass, of a diene rubber selected from high cis BR).
If necessary, ethylene-propylene rubber (EPR), fluorine rubber, silicone rubber, urethane rubber, or the like may be used as the rubber component.
Two or more kinds of rubbers may be used as rubber components other than the above-mentioned high trans polybutadiene.

  The rubber composition of the present invention preferably contains a resin. By blending the resin, the damping property can be further increased. As the resin, polyester polyol resin, alicyclic petroleum resin, phenol resin, xylene resin, aliphatic petroleum resin, aromatic petroleum resin, aliphatic-aromatic copolymer resin, rosin resin, terpene resin, ketone It is preferably at least one selected from the group consisting of resins and modified resins of these resins.

  The total amount of the above-mentioned resins is preferably 5 to 100 parts by mass, more preferably 5 to 80 parts by mass, and more preferably 5 to 60 parts by mass per 100 parts by mass of the rubber component. More preferably. By containing 5 to 100 parts by mass, the Malins effect (a phenomenon in which the elastic modulus decreases in repeated deformation) can be reduced while maintaining workability and mechanical properties.

As a polyester polyol resin, Nippon Zeon Co., Ltd. product name "Zeofine" is mentioned.
Examples of the alicyclic petroleum resin include cyclopentadiene resin, and particularly preferred is dicyclopentadiene resin. Examples of the dicyclopentadiene resin include those manufactured by Nippon Zeon Co., Ltd., trade names “Quinton 1325” and “Quinton 1700”, manufactured by Maruzen Petrochemical Co., Ltd., and trade names “Marcaretz M M-890A”. Examples of other alicyclic petroleum resins include Arakawa Chemical Industries, Ltd., trade name “Arcon P-90” and the like.

Examples of the phenol resin include phenol / formaldehyde resins such as Arakawa Chemical Industries, trade name “Tamanol 510”, Sumitomo Bakelite Co., Ltd., trade name “Sumilite Resin PR-19900”, and the like. -Tert-butylphenol acetylene resin, for example, BASF Corporation, registered trademark "Cholecin" and the like, terpene phenol resin, for example, Yasuhara Chemical Co., Ltd., trade name "YS Polystar" U series, T-series , Trade name “YS Polystar S145”, manufactured by Arakawa Chemical Industries, Ltd., trade names “Tamanol 803L”, “Tamanol 901”, and the like.
Examples of the xylene resin include xylene / formaldehyde resins such as “Lignol R-70” manufactured by Lignite Co., Ltd.

  Examples of aliphatic petroleum resins include 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, and 2-methyl-, which are contained in the C5 fraction obtained by thermal decomposition of naphtha. Olefin hydrocarbons such as 2-butene, diolefin hydrocarbons such as 2-methyl-1,3-butadiene, 1,2-pentadiene, 1,3-pentadiene, 3-methyl-1,3-butadiene, etc. And a resin obtained by polymerizing. For example, product numbers “1102”, “1202 (U)”, “1205”, “1304”, “1310” manufactured by ExxonMobil Co., Ltd., trade name “Highlets G-” "100X", "Hilets T-100X", "Hilets C-110X", "Hilets R-100X", synthetic polyterpene resin made by Nippon Zeon Co., Ltd., trade names "Quinton A100", "Quinton B170", "Quinton K100 "etc. are mentioned.

As an aromatic petroleum resin, vinyl-substituted aromatic carbonization such as α-methylstyrene, o-vinyltoluene, m-vinyltoluene, p-vinyltoluene and the like obtained by thermal decomposition of naphtha and contained in the C9 fraction. Examples thereof include resins obtained by polymerizing hydrogen or the like. For example, trade name “Nisseki Neopolymer L-90”, “Nisseki Neopolymer 120”, manufactured by Nippon Oil Refining Co., Ltd. and the like can be mentioned.
Examples of the aliphatic-aromatic copolymer resins include ExxonMobil's product names “2101” and “2307”, registered trade names “Escollets”, Mitsui Chemicals, Inc., trade names “Hilets T-480X”, “Hilets” H-180X "etc. are mentioned.

  Examples of rosin resins include gum rosin obtained by steam distillation of raw pine yam to remove the turpentine oil, wood rosin obtained by solvent extraction from pine stumps, and various rosin derivative resins. Is done. Examples of rosin derivative resins include rosin pentaerythritol ester resin, rosin glycerol ester resin, hydrogenated rosin resin, and the like.

As the terpene resin, the product name “YS Resin PX-1250”, “YS Resin TO-125”, “YS Resin TR-105”, manufactured by Yashara Chemical Co., which is a polyterpene resin, “Picolite A115” manufactured by Hercules Corporation, “Picolite S115” and the like.
Examples of the ketone resin include Arakawa Chemical Industries, Ltd., trade name “Ketone Resin K-90”, and the like.

The rubber composition of the present invention preferably contains carbon black as a reinforcing filler. This is to increase the elastic modulus and increase the damping property. Examples of the carbon black used include standard varieties such as SAF, ISAF, HAF, FEF, GPF, SRF (rubber furnace) and MT carbon black (pyrolytic carbon).
The amount is preferably 20 to 120 parts by mass, more preferably 25 to 100 parts by mass, and still more preferably 30 to 100 parts by mass with respect to 100 parts by mass of the rubber component.

  The rubber composition of the present invention may contain a compounding agent that is blended and used in an ordinary rubber composition together with the above components. For example, various fillers other than carbon black (for example, silica, clay, calcium carbonate, etc.), silane coupling agents, sulfur as vulcanizing agents, vulcanization accelerators, vulcanization accelerators, softening of various process oils, etc. Examples of various compounding agents generally blended such as an agent, zinc white, stearic acid, wax, and anti-aging agent.

  Examples of the sulfur vulcanizing agent include powdered sulfur, highly dispersible sulfur, insoluble sulfur and the like. Also, sulfur vulcanization accelerators for rubber include N-cyclohexyl-2-benzothiazolesulfenamide, Nt-butyl-2-benzothiazolesulfenamide, N-oxydiethylene-2-benzo Sulfenamides such as thiazole sulfenamide, N, N-diisopropyl-2-benzothiazole sulfenamide, thiazoles such as 2-mercaptobenzothiazole and dibenzothiazyl disulfide, guanidines such as diphenylguanidine, tetramethylthiuram Disulfides, tetraethylthiuram disulfides, tetrabutylthiuram disulfides, tetramethylthiuram monosulfides, dipentamethylenethiuram tetrasulfides and other thiurams, pentamethylenedithiocarbamic acid piperidine salts, pipecolyl Pipecoline thiocarbamate, zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate, zinc N-ethyl-N-phenyldithiocarbamate, zinc N-pentamethylenedithiocarbamate, zinc dibenzyldithiocarbamate, sodium dimethyldithiocarbamate Dithiocarbamates such as sodium diethyldithiocarbamate, sodium dibutyldithiocarbamate, copper dimethyldithiocarbamate, ferric dimethyldithiocarbamate, tellurium diethyldithiocarbamate, zinc butylxanthate, zinc isopropylxanthate, xanthogens such as sodium isopropylxanthate Examples include acid salts. These can be used in combination. The total use amount of the vulcanization accelerator is preferably 0.3 to 10.0 parts by mass, more preferably 0.5 to 10.0 parts by mass with respect to 100 parts by mass of the rubber component. More preferably, it is 0.5 to 6.0 parts by mass.

  Further, in combination with the above vulcanizing agent and / or vulcanization accelerator, organic peroxide, quinonedioxime, polyfunctional acrylic monomer (for example, trimethylolethane triacrylate (TMETA), trimethylolpropane triacrylate ( TMPTA), dipentaerythritol ether hexaacrylate (DPEHA), pentaerythritol tetraacrylate (DPEHA), dimethylolpropane diacrylate (TMPTA), stearyl acrylate (SA), etc.), and triazine thiol can be used.

  A known anti-aging agent can also be selected and used for the anti-aging agent. For example, N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine (6PPD: 6C), N-phenyl-N′-isopropyl-p-phenylenediamine (IPPD: 3C), 2,2 , 4-trimethyl-1,2-dihydroquinoline polymer (RD) and the like. These can use about 0.5-6 mass parts with respect to 100 mass parts of rubber components.

The rubber composition of the present invention can be molded into various shapes such as a sheet, a rectangular parallelepiped, a rectangle, a polygon, a cylinder, and a sphere. It is also possible to use it by forming it into a sheet and punching it out. Depending on the purpose of use, it may be irregularly shaped. In particular, in the case of a rubber composition for a seismic isolation structure, it is generally in the form of a sheet.
A plurality of rubber compositions (rubber sheets) molded into a sheet shape are laminated to obtain a seismic isolation structure with a rubber laminate.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples.
The rubber composition hardness (Hd), elongation at break (Eb), tensile stress at break (TSb), 100% elongation tensile stress (Md100), 300% elongation tensile stress (Md300), shear modulus (G : Shear rate 100%) and equivalent damping constant (Heq 100%) were measured by the following methods.

(1) Hardness (Hd)
The hardness was determined according to JIS K 6253: 2006.
(2) Elongation at break (Eb), Tensile stress at break (TSb), 100% elongation tensile stress (Md100) and 300% elongation tensile stress (Md300)
In accordance with JIS K 6251: 2004, elongation at break, tensile stress at break, 100% elongation tensile stress and 300% elongation tensile stress were determined.

(3) Shear elastic modulus (G: shear rate 100%) and equivalent damping coefficient (Heq 100%)
[Preparation of shear elastic modulus measurement sample]
One rectangular rubber sheet 1 obtained by punching a rubber sheet into a square of 25 mm × 25 mm was produced, and this was sandwiched between two iron plates 2 of 25 mm × 60 mm × 2.3 mm in thickness. That is, as shown in FIG. The rubber sheet 1 was sandwiched between two iron plates 2 coated with an adhesive so as to have a crank shape in cross section. Thus, vulcanization was performed in a state where the iron plate 2 and the surface of the rubber sheet 1 in contact with the iron plate 2 were bonded, and the iron plate 2 and the surface of the rubber sheet 1 were bonded. As a result, a sample having the shape shown in FIG.
[Measurement of shear modulus]
The sample was placed in a spring stiffness / loss energy measuring device (manufactured by Kakinomiya Seisakusho, model: EFH-26-8-10). The above-mentioned two iron plates (FIG. 1 (B)) were applied to the rubber sheet on the outside and inside with a shearing force having a shear rate of 100% at a frequency of 0.2 Hz, and a shear elastic modulus (G: shear rate of 100). %) And equivalent attenuation coefficient (Heq 100%).

Production Example Production of High Trans Polybutadiene A stainless steel reactor equipped with a thermometer, a stirrer, a vulcanizer, and an injection spout was replaced with nitrogen gas, and 4086 g of a butadiene / hexane solution (23.7% by mass) was replaced with this. Butadiene), 12.0 mL nickel boroacylate dissolved in 25 mL hexane (0.84 mol / L hexane solution: 1.0 mmol phgm: addition amount to 100 g monomer), 49 mL tributylaluminum (0.62 mol / L hexane) Solution: 3.0 mmol phgm), 2.64 mL stock solution of triphenyl phosphite (1.0 mmol phgm) dissolved in 25 mL hexane, 15.6 mL trifluoroacetic acid (20 mmol phgm) dissolved in 25 mL hexane Injected. Thereafter, polymerization was carried out at 80 ° C. for 6 hours, and this solution was poured into a container containing excess isopropanol and an antiaging agent, and the polymerization was stopped and reprecipitated. Furthermore, this was filtered and vacuum-dried at 50 degreeC, and crystalline high trans polybutadiene was obtained. The catalyst molar ratio was (nickel boroacylate / tributylaluminum / triphenyl phosphite / trifluoroacetic acid) = (1/3/1/20). The obtained high trans polybutadiene had a 1,4-trans bond content of 92% and a weight average molecular weight of 3.2 × 10 ⁴ .

Examples 1-5 and Comparative Examples 1-3
The rubber compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were prepared by kneading in a Banbury mixer according to the formulation shown in Table 1 (the unit is “part by mass”). The obtained rubber composition was rolled to a thickness of 2 mm using a roll for rubber rolling to produce a rubber sheet. Using these rubber sheets, hardness (Hd), elongation at break (Eb), tensile stress at break (TSb), 100% elongation tensile stress (Md100), 300% elongation tensile stress (Md300) , Shear modulus (G: shear rate 100%) and equivalent damping constant (Heq 100%) were evaluated. The results are shown in Table 1.

[note]
“Breaking” in Table 1 indicates that the sample broke during measurement of the shear elastic modulus and equivalent damping coefficient and could not be measured.
* 1: Emulsion polymerization SBR: Product name “SBR # 1500” manufactured by JSR Corporation
* 2: High cis BR: Product name “BR 01” manufactured by JSR Corporation
* 3: High trans polybutadiene: High trans polybutadiene obtained in the above production example * 4: N220: Asahi Carbon Co., Ltd., trade name “Asahi # 80”
* 5: Anti-aging agent 6PPD, N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine, manufactured by Ouchi Shinsei Chemical Co., Ltd., trade name “NOCRACK 6C”
* 6: Polyester polyol resin: Product name “Zeofine” manufactured by Nippon Zeon Co., Ltd.
* 7: Dicyclopentadiene resin: Product name “Quinton 1325” manufactured by Nippon Zeon Co., Ltd.
* 8: Xylene resin: Lignite Co., Ltd., trade name “Lignol R-70”
* 9: Vulcanization accelerator DPG: Diphenylguanidine, manufactured by Ouchi Shinsei Chemical Co., Ltd. Product name “Noxeller D”
* 10: Vulcanization accelerator CZ: N-cyclohexyl-2-benzothiazolylsulfenamide, manufactured by Ouchi Shinsei Chemical Co., Ltd., trade name “Noxeller CZ”

  As is clear from Table 1, the rubber compositions of Examples 1 to 5 all have a higher shear elastic modulus and a larger equivalent damping coefficient than the rubber compositions of Comparative Examples 1 to 3, It was possible to achieve both high elastic modulus and high damping characteristics.

  The rubber composition of the present invention and the seismic isolation structure obtained from the rubber composition are effective mainly for support parts such as road bridges and bridges, and seismic isolation structures for buildings such as high-rise buildings and houses. And is also preferably used for applications such as a vibration isolator in an experimental apparatus or the like. Moreover, it is used suitably also for buffer materials, such as a cable-stayed bridge cable.

1 Square rubber sheet 2 Iron plate

Claims (3)

  A rubber composition for a base-isolated structure, comprising a polybutadiene having a 1,4-trans bond content of 90% or more and less than 50% by mass in a rubber component.   The rubber composition for a seismic isolation structure according to claim 1, further comprising a resin.   The resin is polyester polyol resin, alicyclic petroleum resin, phenol resin, xylene resin, aliphatic petroleum resin, aromatic petroleum resin, aliphatic-aromatic copolymer resin, rosin resin, terpene resin, ketone. The rubber composition for a seismic isolation structure according to claim 2, wherein the rubber composition is at least one selected from the group consisting of resins and modified resins of these resins.

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