JPH0559219A - Highly damping rubber composition - Google Patents

Abstract

PURPOSE:To provide a rubber composition for, e.g. earthquake-proof rubber, which is highly damping, can dispense with dampers or the like, and is advantageous in the term and cost of working. CONSTITUTION:The title composition comprises 100 pts.wt. rubber component composed of 15-99 pts.wt. polyisoprene rubber and 1-85 pts.wt. other rubber, and 3-80 pts.wt. rosin derivative, and the total content of the 1,2- or 3,4-bond in the rubber component is 10-80%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber composition which has a high damping property and is very effective for absorbing vibration energy such as seismic isolation, vibration isolation or vibration isolation.

[0002]

2. Description of the Related Art In recent years, a seismic isolation construction method using a seismic isolation rubber laminate has been attracting attention for the purpose of reducing the input acceleration of vibrations to a building caused by an earthquake. This isolates the ground from the building with a soft layer and reduces the natural frequency of the building to the frequency of the ground at the time of an earthquake, thereby reducing the input acceleration of vibration, which is contained in the building or in it. It minimizes damage to people and machines.

The seismic isolation rubber laminate used here is a combination of alternating soft layers (rubbers) and hard layers (iron plates, etc.). In order to soften the input acceleration, it is soft in the lateral direction and has the property of not breaking even during large lateral deformation.

However, since the seismic isolation rubber composition used conventionally has a very small hysteresis loss, the seismic isolation rubber laminate using this rubber composition itself has the ability to damp the vibration of the upper structure. There is no
Vibration was measured by various dampers such as viscous dampers. However, this has a drawback that the structure becomes complicated as a building, and the construction period and cost are expensive.

Therefore, in order to simplify the whole seismic isolation construction method, the present applicant proposes that the conventional seismic isolation rubber laminate itself has a high damping capacity and the damper can be removed, 1,2-or 3,4.
Method using polyisoprene having a bond
-32135), but this method still satisfies the required properties for the seismic isolation rubber composition: low creep property, low temperature dependence, fracture resistance, long-term stability of performance, It has been difficult to provide even higher damping.

Conventionally, in order to increase the loss characteristic of a rubber composition, the amount or grade of carbon black has been improved or a resin or a softening agent has been added. In many cases, the stability and long-term stability deteriorate.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a rubber composition which does not require a damper or the like and is advantageous in terms of construction period and cost and which has a high damping property itself such as the above-mentioned seismic isolation rubber. Especially.

[0008]

The present invention provides 1,2- or 3,4-
100 parts by weight of a rubber component consisting of 15 to 99 parts by weight of a polyisoprene rubber having a bond and 1 to 85 parts by weight of another rubber, and 3 to 80 parts by weight of a rosin derivative, and 1,2- or The present invention relates to a rubber composition having a high damping property in which the total content of 3,4-bonds is 10 to 80%.

Incidentally, in JP-A-64-48951, a rubber material in which a rosin derivative is mixed with a cyclopentadiene resin in a rubber component is described in the left upper column to the right lower column on page 6.
This rubber material is a rubber material coated to improve the weather resistance of the soft plate, and is different from the rubber material of the soft layer itself as in the present invention.

The rubber composition of the present invention contains a blend of the above polyisoprene rubber and another rubber, but the proportion of the above polyisoprene rubber in 100 parts by weight of the rubber is preferably 15 to 99 parts by weight. Other rubbers include natural rubber (N
R), styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR) other than the above, and the like, and they are blended in a proportion of 1 to 85 parts by weight.

In the present invention, 1,2-or the above rubber component is used.
The total content of 3,4-bonds is preferably 10 to 80%, 20 to 5
5% is more preferable. If it is less than 10%, good damping properties cannot be obtained, and if it exceeds 80%, the temperature dependence tends to increase. In the present invention, the content of 1,2-bonds and 3,4-bonds was measured by a spectrophotometric method using an A-2 type infrared spectrophotometer manufactured by JASCO Corporation. The key band, the peaks at 840 cm ^-1 for cis-1,4-bond, the peak for the 3,4-bond in 890 cm ^-1, and 1,2 for binding Is calculated by selecting the peak at 910 cm ⁻¹ and calculating the content rate from the extinction coefficient, and for trans-1,4-bonding by subtracting the total amount of the above three kinds of binding from 100%.

In the present invention, 3 to 80 parts by weight of the rosin derivative is added to 100 parts by weight of the rubber component. As the rosin derivative, the main component is a mixture of abietic acid, pimaric acid and a carboxylic acid having a structure similar to these, various rosin-based esters, polymerized rosin, hydrogenated rosin, cured rosin, hyrosin, zinc resinate, modified rosin, etc. Is mentioned. Examples of commercially available products include Pencel KK (Arakawa Chemical Industry) and the like. The rosin derivative is preferably used in the range of 15 to 55 parts by weight based on 100 parts by weight of the rubber component. If it is less than 3 parts by weight, good damping property cannot be obtained, and if it exceeds 80 parts by weight, the creep property is deteriorated.

The rubber composition of the present invention contains known vulcanizing agents, vulcanization accelerators, vulcanization accelerating aids, vulcanization retarders, organic peroxides,
Of course, colorants, reinforcing agents, antiaging agents, fillers, softening agents, plasticizers, tackifiers, lubricants and the like can be added.

Examples of the filler include carbon black, clay, silica, talc, mica, calcium carbonate, magnesium carbonate, barium sulfate, aluminum hydroxide, zinc oxide, and various natural or artificial fibers. 20-200 for 100 parts by weight of rubber
It is preferable to use parts by weight.

Examples of the softening agent include tall oil mainly composed of linoleic acid, oleic acid and abietic acid, pine tar, rapeseed oil, cottonseed oil, peanut oil, castor oil, palm oil,
Plant softeners such as Factis, paraffin oils, naphthenic oils, mineral oil softeners such as aromatic oils, and the like,
The mixing ratio is preferably 1 to 150 parts by weight with respect to 100 parts by weight of rubber.

Examples of the plasticizer include phthalic acid-based, sebacic acid-based, adipic acid-based, phosphoric acid ester-based, epoxy-based, chlorinated paraffin-based, ether-based, thioether-based, polyester-based and polyether-based plasticizers. The compounding ratio is preferably 1 to 150 parts by weight with respect to 100 parts by weight of rubber.

Examples of the tackifier include alkylphenol formaldehyde resin, alkylphenol acetylene resin, coumarone indene resin, xylene formaldehyde resin, polybutene and petroleum resin.
The mixing ratio is preferably 1 to 50 parts by weight with respect to 100 parts by weight of rubber.

Examples of the lubricant include stearic acid, stearic acid metal soap, high melting point wax, low molecular weight polyethylene, polyethylene glycol, octadecylamine and the like, and the mixing ratio thereof is 1 to 100 parts by weight of rubber.
It is preferably 50 parts by weight.

The rubber composition of the present invention can be obtained by kneading the above components with a usual processing device such as a roll, a Banbury mixer or a kneader.

[0020]

EXAMPLES Examples and comparative examples will be described below.
Incidentally, “parts” means “parts by weight”.

The damping property of the rubber composition is as follows: 30 layers of rubber of 135φ × 1 mm and 133φ × made by using the obtained rubber composition.
Equivalent damping constant (heq) of the laminated body in which 29 layers of 1 mm plates are laminated alternately is described in "Life and Reliability Report of Laminated Rubber for Base Isolation Structure" (Layered Rubber Special Committee for Seismic Isolation Structure) It was measured and evaluated by the method. The composition No. 1 was set as 100 and expressed as an index.

The creep characteristics were measured by measuring the amount of subsidence of the laminate when the above-mentioned laminate was loaded with a load of 4 tons in a constant temperature bath set at 80 ° C. and when the actual phase was 60 years. The total rubber thickness of the laminate was evaluated. ○ …… <0.025, △ …… 0.025 to 0.030, × …… 0.030
<

As for the breaking property, the breaking elongation is used as a substitute property, and the JI
It was measured according to SK6301-3.

The static shear modulus (G) was measured by the method described in "Vibration isolating rubber" (Japan Railway Vehicle Manufacturers Association), and the ratio of G at -10 ° C and 40 ° C was obtained to determine the compounding No. .1 to 10
Expressed as 0.

Examples and Comparative Examples 100 parts of the rubber component shown in Table 1, each part of rosin derivative (pentaerythritol ester of polymerized rosin of abietic acid), each part of carbon black, each part of aromatic oil, 3 parts of zinc white, stearin 2 parts acid, 1 wax
Part, anti-aging agent (Santofrex 13) 2 parts, sulfur 1.5
And 0.8 parts of accelerator (CBS) were kneaded with a Banbury mixer to obtain a rubber composition. The respective properties of the obtained rubber composition are shown in Table 1. Formulation Nos. 7 to 12 are examples,
Others are comparative examples.

[0026]

[Table 1]

Formulation Nos. 1 and 2 have good creep characteristics, fracture characteristics, and temperature dependence, but have no damping property. Formulation No. 3 shows that the damping property is insufficient only by adding the rosin derivative to NR. Compound No. 4 is in the rubber component
It indicates that the total content of 1,2- or 3,4-bonds exceeds 80% and the temperature dependence is deteriorated. Compound No. 5 is in the rubber component
The total content of 1,2- or 3,4-bonds is less than 10%,
It is shown that the addition of a rosin derivative does not have sufficient damping properties. Formulation No. 6 shows that the rosin derivative exceeds 80 parts by weight and the creep property is deteriorated.

On the other hand, Formulation Nos. 7 to 12 are good overall, and Formulation Nos. 8 and 9 show that IR can be blended with SBR and BR.

[0029]

The rubber composition of the present invention does not require a damper or the like, is advantageous in terms of construction period and cost, and has a high damping property itself. Further, the rubber composition of the present invention has low creep properties, low temperature dependence, fracture resistance, long-term stability of performance, etc.
The loss characteristics can be remarkably increased without substantially deteriorating the characteristics other than the loss characteristics as the seismic isolation rubber composition.

Claims (1)

[Claims] 1. A rubber component comprising 100 parts by weight of (a) 15 to 99 parts by weight of a polyisoprene rubber having 1,2- or 3,4-bonds and 1 to 85 parts by weight of another rubber, and (b) a rosin. A rubber composition having a high damping property, containing 3 to 80 parts by weight of a derivative, and having a total content of 1,2- or 3,4-bonds in the rubber component (c) of 10 to 80%.