JPH0232135A - High damping rubber vibration insulator composition - Google Patents

Abstract

PURPOSE:To obtain a rubber composition effective for vibration release, vibration removal, vibration prevention and absorption of vibration to building structure and floor level having high damping properties comprising polyisoprene rubber having content of 1,2- or 3,4-bond of isoprene in a specific range. CONSTITUTION:The aimed rubber composition comprising polyisoprene rubber having 20-60% total content of 1,2- or 3,4-bond of isoprene.

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention provides a rubber material that has high damping properties and is very effective in absorbing vibrations from buildings or floors, such as seismic isolation, vibration isolation, or vibration isolation. Regarding the composition.

(Prior Art) In recent years, an isolation construction method using seismic isolation rubber laminates has been attracting attention for the purpose of reducing the input acceleration of vibrations generated by strata into buildings. This is done by insulating the ground and the building with a soft layer, reducing the natural frequency of the building compared to the vibration frequency of the ground during an earthquake, thereby reducing the input acceleration of vibration, and This is to minimize damage to people, fi machines, etc.

The seismic isolation rubber laminate used here is a soft layer (rubber).
It is designed to have a spring constant ratio of approximately 1000:1 between fir wood and hard layers (iron plates). In order to soften input acceleration, it is soft in the lateral direction, and has the ability to not break even during large lateral deformations.

However, since the conventionally used seismic isolation rubber composition is soft and has very low hysteresis loss, the seismic isolation rubber laminate using this rubber composition has no ability to damp the vibrations of the superstructure by itself. There is no, therefore,
Vibration damping was measured using various dampers such as viscous dampers. However, this had the disadvantage that the structure of the building would be complicated, and the construction period and cost would be relatively high.

Therefore, in order to simplify the entire seismic isolation construction method, we considered adding a high damping capacity to the conventional seismic isolation rubber laminate itself and eliminating the damper. However, it is extremely difficult to provide high damping properties while satisfying the required properties for seismic isolation rubber compositions: ■low creep properties, ■low temperature dependence, ■fracture resistance, and ■long-term stability of performance. It was difficult.

Conventionally, in order to increase the loss characteristics of a rubber composition,
Countermeasures have been taken by increasing the amount or grade of carbon black, or by adding resins and softeners, but these often result in significantly worse creep properties, as well as temperature dependence and fracture properties.

(Problems to be Solved by the Invention) An object of the present invention is to provide a seismic isolation rubber ffi structure that does not require a gunpah, etc., is advantageous in terms of construction period and cost, and has high damping properties itself. .

(Means for Solving the Problems) The present invention provides a highly attenuated seismic isolation rubber composition containing polyisoprene rubber in which the total content of 1,2- or 3,4-bonds of isoprene is 20% or more and less than 60%. Pertains to.

The rubber composition of the present invention is composed of a blend of the above polyisoprene rubber and other rubber, and the proportion of the above polyisoprene rubber in 100 parts by weight of rubber is preferably about 10 to 60 parts by weight. Examples of the rubber include natural rubber (NR), butadiene rubber (BR), styrene-butanoene rubber (SBR), and polyisoprene rubber (IR) other than those mentioned above.

In the present invention, if the total content of 1,2- or 3,4-bonds in the polyisoprene rubber is less than 20%, good damping properties cannot be obtained, and if it is 60% or more, the fracture properties deteriorate significantly, In addition, the temperature dependence becomes large and it does not function as a seismic isolation rubber.
If it is less than 0 parts by weight, the damping properties will be slightly low, and if it exceeds 60 parts by weight, the temperature dependence, fracture properties, and creep properties will be slightly reduced.
The bond content was measured by spectrophotometry using an A-2 infrared spectrophotometer manufactured by JASCO Corporation. The key band is 840 for cis-1,4-bonds.
The peak at C-1 is 89 for the 3,4-bond.
Select the peak at 0cm1 and the peak at 910C11''1 for the 1.2-bond, and calculate the content from their extinction coefficients.For the trans-1,4-bond, select the peak at 910C11''1. Calculate the total amount by subtracting from 00%.

The rubber composition of the present invention includes known vulcanizing agents, vulcanization accelerators, vulcanization accelerators, vulcanization retarders, organic peroxides, reinforcing agents, fillers, anti-aging agents, tackifiers, and colorants. Of course, agents etc. can be added.

The rubber composition of the present invention can be obtained by kneading the above-mentioned components using a conventional processing device such as a roll, a Banbury mixer, or a Nigu.

(Effects of the Invention) The seismic isolation rubber composition of the present invention does not require gumpar etc.
It is advantageous in terms of construction period and cost, and has high damping properties itself. In addition, the rubber composition of the present invention has low loss properties without substantially deteriorating the properties as a seismic isolation rubber composition other than loss properties, such as low creep properties, low temperature dependence, fracture resistance, and long-term stability of performance. It is possible to significantly increase the characteristics.

(Example) Examples and comparative examples will be described below. Note that parts simply indicate parts by weight.

In addition, the creep property uses JIS compression set as a substitute property,
The test method is based on JIS K 6301-10.

However, the test temperature is room temperature. The goal is for this to be 10 or less.

For the fracture properties, elongation at break is used as a substitute property, and the test method is JI.
Complies with SK 6301-3. The goal is 700 or more.

The loss characteristic is the loss tangent tan, and the test method is a viscoelastic spectrometer manufactured by Oiki Seisakusho.
Tests were conducted using a new model at 0 Hz, 5% strain, and room temperature. The target is 0.25 or more.

For the temperature dependence, the temperature dispersion of Hs is used as a substitute characteristic, and the measurement is performed using J
Complies with ISK 6301-5. Hs(-
10''C)-Hs (40°C) = ΔHs, and ΔHs was expressed in 5 increments from the smallest to ◎, ○, Δ, ×, XX, and ◎ was considered to be good with less temperature dependence.

Examples and Comparative Examples 100 parts of the rubber component listed in Table 1, each part of carbon black, each part of aromatic oil, 3 parts of resin and zinc white, 2 parts of stearic acid, 1 part of wax, 2 parts of anti-aging agent (Santoflex 13) part, 1.5 parts of sulfur g and accelerator (C
BS) was kneaded in a Banbury mixer to obtain a rubber composition. The characteristics of the obtained rubber composition were
Blend Nos. 7 to 10 shown in the table are examples, and the others are comparative examples.

Blend No. 1 had very good creep properties, temperature dependence, fracture properties, etc., but the loss properties were very small and had no damping performance. If an attempt is made to improve the loss characteristics using conventional methods, the results will be such that the properties other than the loss characteristics are inferior, as shown in Blend Nos. 2 to 4. Alternatively, even if vinyl isoprene rubber is used, the use is outside the scope of the claims.

No. 5 has a small damping ability, and No. 6 has a good damping performance but poor creep characteristics and temperature dependence.

On the other hand, in formulation Nos. 7 to 10, the loss characteristics are improved while substantially maintaining the low creep characteristics, fracture resistance characteristics, and low temperature dependence required for a seismic isolation rubber composition.

(that's all) Sender: Toyo Tire & Rubber Industries Co., Ltd. Representative Patent Attorney 1) Iwao Mura

Claims (1)

[Claims] (1) A high-damping seismic isolation rubber composition containing polyisoprene rubber in which the total content of 1,2- or 3,4-bonds of isoprene is 20% or more and less than 60%.