JP2581670B2 - Rubber composition for seismic isolation - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rubber composition for a seismic isolation rubber of a seismic isolation device.

[Prior Art] Rubber having high loss characteristics is generally used for various devices for mitigating and absorbing vibration energy, but conventionally, rubber compositions used for such applications have high loss characteristics. In order to provide a good carbon content, a large amount of carbon is added, and a softening agent is added and used for the purpose of improving processability and improving elongation characteristics after vulcanization.

[Problems to be Solved by the Invention] However, in a rubber composition to which a softening agent is added, the softening agent itself does not have rubber elasticity and does not react with rubber, so that the physical properties of the vulcanized rubber In many cases.

On the other hand, there is a rubber itself having high loss characteristics at room temperature, such as SBR containing high styrene, but this rubber has a large variation in its elastic modulus and loss characteristics depending on the temperature used. There was a problem that stable performance could not be obtained.

[Means and Actions for Solving the Problems] The rubber composition for seismic isolation of the present invention comprises a cyclopentadiene resin and / or a dicyclopentadiene resin in a proportion of 15 parts by weight based on 100 parts by weight of a rubber mainly composed of natural rubber. The cyclopentadiene resin and / or the dicyclopentadiene resin has a softening point of 50 to 200 ° C and a bromine value of 40 to 150.

According to the present invention, a natural rubber is provided with a high loss property, and its temperature dependency, breaking property, and adhesion are obtained by blending a cyclopentadiene resin and / or a dicyclopentadiene resin having a specific softening point and a bromine value. A rubber for seismic isolation with significantly improved properties and the like is provided.

That is, the present inventors have excellent high loss characteristics,
After extensive studies to obtain a rubber composition having excellent properties such as temperature dependency and fracture properties, adhesive properties, a specific cyclopentadiene resin or dicyclopentadiene resin was
It has been found that the processability of rubber is improved, and a chemical reaction or a physical interaction occurs between the rubber and the rubber during vulcanization, thereby contributing to an improvement in rubber properties. Specifically, cyclopentadiene resin or dicyclopentadiene resin has better workability when compounded with rubber and generates less heat than ordinary process oil.

The deterioration of the fracture characteristics due to the compounding is small.

Those obtained by blending them with natural rubber have low temperature dependency and good rubber-metal adhesion. In addition, migration during long-term use, which is observed in ordinary process oils, was hardly recognized, and it was confirmed that rubber properties were excellent in long-term stability.

 The present invention has been made based on such findings.

 Hereinafter, the present invention will be described in detail.

In the present invention, the cyclopentadiene resin or dicyclopentadiene resin to be blended with the rubber containing natural rubber as a main component is a petroleum resin mainly composed of cyclopentadiene or dicyclopentadiene, and cyclopentadiene or dicyclopentadiene, It refers to a copolymer with olefinic hydrocarbons that can be copolymerized with this, or a polymer of cyclopentadiene and / or dicyclopentadiene. It is necessary that these resins contain at least 30% by weight, preferably at least 50% by weight of the resin weight, based on the weight of cyclopentadiene, dicyclopentadiene or a mixture of cyclopentadiene and dicyclopentadiene. Is done.

The olefin hydrocarbons copolymerizable with cyclopentadiene or dicyclopentadiene include 1-butene, 2-butene, isobutylene, 1-pentene, and 2-olefin.
Pentene, 2-methyl-1-butene, 3-methyl-1-
Olefinic hydrocarbons such as butene and 2-methyl-2-butene; butadiene, isoprene, 3-methylbutadiene
1,2 etc. diolefin hydrocarbons; and styrene, α-
Examples thereof include vinyl-substituted aromatic hydrocarbons such as methylstyrene and vinyltoluene, which can be copolymerized with cyclopentadiene or dicyclopentadiene by a Friedel-Crafts reaction or the like in the presence of a suitable catalyst.

In the present invention, such a cyclopentadiene resin or dicyclopentadiene resin has a softening point (ring-ball type JIS) in consideration of its molecular weight and reactivity of double bond for the effectiveness of the physical properties of the vulcanized rubber. K-5902) is 50 to 200
° C, the bromine number (ASTM D-1158-57T) is in the range of 40-150. The softening point of the cyclopentadiene resin and / or dicyclopentadiene resin is preferably from 80 to 150 ° C, and the preferred bromine number is from 50 to 150.

In the present invention, the compounding amount of these cyclopentadiene resins and / or dicyclopentadiene resins is determined based on 100 parts by weight of a rubber mainly composed of natural rubber, in view of the processability of the obtained rubber composition and the loss characteristics of the rubber. It is necessary to be 15 to 100 parts by weight, preferably 20 to 80 parts by weight.

The rubber component of the rubber composition of the present invention contains natural rubber as a main component, and may contain BR, NBR, butyl rubber, halogenated butyl rubber, chloroprene rubber, or the like, if necessary. In this case, the ratio of the natural rubber in the rubber component is desirably 60% by weight or more.

Such a rubber composition of the present invention may contain, if necessary, various fillers, antioxidants, plasticizers, softeners, oils, and other general additives for rubber materials. By performing vulcanization under the above vulcanization conditions, a high-loss rubber can be obtained.

The rubber obtained by vulcanizing the seismic isolation composition of the present invention has extremely high loss characteristics, and also has good temperature dependency, fracture characteristics, adhesiveness, etc., so that it absorbs vibration energy. It can be effectively applied to seismic isolation devices as a rubber material related to relaxation. When the rubber composition for seismic isolation of the present invention is applied to a seismic isolation device, a product having excellent properties such as elongation characteristics, temperature dependency, rubber-metal adhesion and long-term physical stability is obtained. It is possible to get.

[Examples] Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as the gist is not exceeded.

Examples 1 to 3 and Comparative Examples 1 and 2 The rubber compositions having the compositions shown in Table 1 were vulcanized, and their physical properties were examined. The results are shown in Table 1.

Table 1 shows that the rubber compositions of Comparative Examples 1 and 2 use a large amount of aroma oil, so that the temperature dependency and the elongation at break are extremely low, while the dicyclopentadiene resin is blended. It is apparent that the rubber compositions of Examples 1 to 3 of the present invention have good loss characteristics, temperature dependence, rubber breaking characteristics, and various adhesive properties, and are very well balanced as a whole.

* 1: Dicyclopentadiene polymer. Softening point 116 ° C, bromine number 65.

* 2: h _{100 This} is the hysteresis ratio of the sample when subjected to 100% tensile deformation at 25 ° C, and is a measure of loss characteristics. In addition, pulling speed
At 200 mm / min, h ₁₀₀ is the stress-strain curve in FIG. Given by the area ratio of

* 3: E ' _(-10) / E' ₍₊₃₀₎ The value of the storage modulus E 'at -10 ° C, dynamically measured at 12 Hz and strain of 0.01%, at 30 ° C and E' _(-10).
And the ratio to the value E ′ ₍₊₃₀₎ in the above, and was used as an index of the temperature dependency.

* 4: Tensile test (25 ° C) at an Eb (%) tensile speed of 300 mm / min.
It is the elongation at break due to.

* 5: Md ₁₀₀ (kg / cm ² ) Stress at 100% strain by a tensile test (25 ° C.) at a tensile speed of 300 mm / min. Example 4 A high loss rubber composition of the present invention and a steel sheet shown in Table 2 below Are laminated alternately and vulcanized to produce a seismic isolation rubber with the following structure, and its loss tangent (tanδ) as its structure
I asked.

Configuration of seismic isolation rubber Shape: cylindrical shape Thickness of rubber layer of the present invention: 2 mm Number of rubber layers: 18 layers Thickness of steel plate: 1 mm 〃 Length: 160 mm Number of steel plates: 17 layers The loss tangent (tan δ) as a structure when a shear strain of 100% was applied while applying a surface pressure of 30 kg / cm ² to the rubber was measured. As a result, tanδ is 0.37
(Temperature: 25 ° C., frequency: 0.5 Hz). From this result,
It can be seen that the seismic isolation rubber using the high loss rubber composition of the present invention has a sufficient vibration energy absorption and relaxation effect (seismic isolation effect and damper). The adhesion between the rubber and the steel plate was also good.

[Effects of the Invention] As described in detail above, the high-loss rubber composition of the present invention has excellent loss characteristics and remarkably excellent characteristics such as temperature dependency, fracture characteristics, and adhesiveness. Quake,
It is extremely effective as a rubber material for seismic isolation, vibration proof, and vibration damping devices, and can exhibit its high loss characteristics stably for a long time under any environment.

Such a high-loss rubber composition of the present invention is extremely suitable especially as a rubber material for seismic isolation rubber.

[Brief description of the drawings]

FIG. 1 is a graph showing a stress-strain curve used for measuring a hysteresis ratio in Examples and Comparative Examples.

Claims (1)

(57) [Claims] 1. A rubber comprising a natural rubber as a main component comprising a cyclopentadiene resin and / or a dicyclopentadiene resin.
A rubber composition for seismic isolation prepared by mixing 15 to 100 parts by weight with respect to 0 parts by weight, wherein the cyclopentadiene resin and / or dicyclopentadiene resin has a softening point of 50 to 200 ° C.
And a bromine number of 40 to 150.