JP2000336207A - High damping rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high damping rubber composition with a small hysteresis dependence. SOLUTION: A high damping rubber composition comprising 100 pts.wt. of a diene rubber, 25-55 pts.wt. of a resin, 0-50 pts.wt. of a softener and 20-150 pts.wt. of a reinforcement, is formed in such a way that the first step in the rubber kneading comprises the preparing of a master batch which, putting the pts.wt. of the diene rubber=A, those of the resin=B, those of the softener= C, and those of the reinforcement=D, satisfies the relationship shown in formula I (wherein, 20<=A<=100; 0<=B<=55; 0<=C<=5; and 0.16<=D<=150, provided D is 80% or more of a blended amount of the whole reinforcers) and that the second and subsequent steps comprises the blending of the obtained master batch, the remaining diene rubber, reinforcements, and the other additives.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-damping rubber composition having a small hysteresis dependency and a seismic isolation bearing using the same.

[0002]

2. Description of the Related Art Conventionally, a high-damping rubber is compounded with a carbon black or the like having a small particle size in order to realize a high damping property. According to such carbon black, a high damping property can be obtained, but the shear modulus of elasticity G at the time of the initial deformation is high, and there is a problem that it becomes softer than the G at the time of the initial deformation.

[0003]

Therefore, in order to solve the above-mentioned problems of the prior art, the present invention uses a method of splitting and mixing a polymer and carbon black in kneading a rubber, so that the history of a high damping rubber can be improved. It is an object of the present invention to provide a high damping rubber composition having reduced dependency.

[0004]

According to the present invention, 100 parts by weight of a diene rubber contains 5 to 55 parts by weight of a resin, 0 to 50 parts by weight of a softener and 20 to 150 parts by weight of a reinforcing agent. In the damping rubber composition, in the first stage of the rubber kneading, the diene rubber A, the resin B, the softener C, and the reinforcing agent D are expressed by the following formula I:

(Equation 2) (Where, 20 ≦ A ≦ 100, 0 ≦ B ≦ 55, 0 ≦ C ≦ 5
0,16 ≦ D ≦ 150, where D is 80% or more of the total amount of the reinforcing agent. ), A masterbatch that satisfies the relationship of
A high damping rubber composition is provided in which the remaining diene rubber, reinforcing agent, and other compounding agents are mixed.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the kneading of rubber, the present inventors, in the first stage of mixing, mix a diene rubber and carbon black, or further a resin and a softener under severe conditions, By mixing and mixing the master batch, the remaining carbon black, and other compounding agents in the mixing after the step, it has been found that a high damping rubber having a small hysteresis dependence can be obtained.

[0006] In order to obtain this high damping rubber composition, in the mixing in the first step, A parts by weight of the diene rubber, B parts by weight of the resin, C parts by weight of the softener, and a reinforcing agent (carbon Black) is D parts by weight, and the following conditional expression is used between the amounts of these components.

(Equation 3) (Where, 20 ≦ A ≦ 100, 0 ≦ B ≦ 55, 0 ≦ C ≦ 5
0,16 ≦ D ≦ 150, where D is 80% or more of the total amount of the reinforcing agent. Experiments have shown that it is necessary to obtain a masterbatch in which the amounts of the respective components in the mixing in the first stage are determined so as to satisfy the condition (1). Therefore, the desired high-attenuation rubber composition according to the present invention cannot be obtained even if any one of the blending amounts of the above-mentioned blending components and their relational expressions in the first-stage mixing is missing.

In the mixing in the second and subsequent steps, in addition to the master batch obtained in the first step, the remaining diene rubber, reinforcing agent and other compounding agents are mixed by a conventional mixing means. Good. In general, vulcanizing compounds such as sulfur and a vulcanization accelerator are compounded in the final mixing step, separately from the compounding ingredients in the second step.

As the diene rubber used in the high damping rubber composition of the present invention, any of the conventional diene rubbers can be applied, for example, natural rubber (NR), various butadiene rubbers (BR), various styrenes -Butadiene copolymer rubber (SBR), polyisoprene rubber (IR), acrylonitrile butadiene rubber, chloroprene rubber, ethylene-propylene copolymer rubber, etc. can be used alone or in combination.

The resin used in the high damping rubber composition of the present invention includes, for example, coumarone plastics obtained by copolymerizing coumarone, indene, styrene and the like contained in solvent naphtha, and steam of petroleum. By cracking, petroleum resins such as resins polymerized without isolating diolefins and monoolefins contained in a cracked oil fraction by-produced from an ethylene plant that produces ethylene, propylene, etc., are used. It is commercially available as Nippon Steel Chemical Co., Ltd., High Resin (Toho Chemical Industry Co., Ltd.), FTR (Mitsui Petrochemical Industry Co., Ltd.), etc., and can be easily obtained.

The high-damping rubber composition of the present invention generally contains a softening agent such as oil, a reinforcing agent such as carbon black and silica, a vulcanizing agent such as sulfur, various vulcanization accelerators, an antiaging agent and the like. The various additives used in the high-attenuation rubber are mixed and used in conventional amounts.

The high damping rubber composition obtained by the present invention has a small hysteresis dependence and good vibration absorption characteristics. Therefore, this rubber composition is used as a vibration absorption layer, and this and a steel sheet are alternately laminated. By using a seismic isolation bearing having the above structure, an extremely useful seismic isolation bearing can be obtained.

[0012]

EXAMPLES The present invention will be further described below with reference to Examples and Comparative Examples, but it goes without saying that the present invention is not limited to the following Examples.

The following commercially available products were used for the components used in the following Examples and Comparative Examples. NR: SIR-20 BR: Nipol 1220 (Nippon Zeon Co., Ltd.) Carbon black 1: Show black N134 (Showa Cabot Corp.), DBP oil absorption: 123 ml / 100 g Carbon black 2: Show black N110 (Showa Cabot Corp.) )), DBP oil absorption: 115 ml / 100 g Zinc flower: Zinc flower No. 3 (Seido Chemical Co., Ltd.) Stearic acid: Lunac YA (Kao Soap Co., Ltd.) Aroma oil: Process oil X-140 (Kyodo Oil Co., Ltd.) )) Resin: High Resin (Toho Chemical Industry Co., Ltd.) Sulfur: Oil-treated sulfur (Karuizawa Smelting Co., Ltd.) Vulcanization accelerator: Noxeller NS (Nt-butyl-2-benzothiazolyl-sulfenamide) ( Ouchi Shinko Chemical Co., Ltd.)

Preparation of Samples (Examples 1 to 6, Comparative Example 1) In the first stage, rubber, resin, carbon black, oil, etc. were mixed in a 1.5 liter closed mixer at a ratio shown in Table 1 to 3 to 5 times. The mixture was kneaded for a minute and released when the temperature reached 165 ± 5 ° C. to obtain a master batch (NP1). Next, in the second stage, the NP1 obtained in the first stage, and / or the remaining rubber,
And carbon black, zinc white, stearic acid, oil and the like were added and kneaded for 3 to 5 minutes, and released when the temperature reached 165 ± 5 ° C. to obtain a master batch (NP2). Finally, in the third stage, the NP2 obtained in the second stage and the vulcanization system component were kneaded with an 8-inch open roll to obtain a rubber composition. Preparation of Samples (Comparative Examples 3 and 4) Rubber, resin, carbon black, zinc white, stearic acid, and oil were kneaded in a 1.5-liter closed mixer for 3 to 5 minutes at the ratios shown in Table 1, and 165 ± Released when the temperature reached 5 ° C., a masterbatch (NP1) was obtained. Then N
P1 and the vulcanization system were kneaded with an 8-inch open roll to obtain a rubber composition.

Method for Measuring Physical Properties of Vulcanized Rubber The physical properties of the present invention were evaluated by producing a seismic isolation laminate (size: 135 mm × 135 mm × 74 mm) shown in FIG. 1 in which rubber and an iron plate were alternately laminated. To produce the seismic isolation laminate, the unvulcanized rubber of the present invention is molded into a sheet, and after obtaining a rubber composition 1, an adhesive is applied to a hard plate 2 made of a steel plate for general structure, a cold-rolled steel plate, or the like. It was obtained by coating and vulcanizing under pressure. 1) Retention of shear modulus for the second time The shear modulus at 0.5 Hz and 100% strain was measured with a biaxial shear tester, and then the same measurement was performed again.
The shear modulus was measured, and was calculated from the retention rate (%) of the second shear modulus = second shear modulus / first shear modulus × 100. 2) Retention of shear modulus after one week The shear modulus at 0.5 Hz and 100% strain was measured with a biaxial shear tester, and after one week, the same measurement was performed again to measure the shear modulus. Then, the retention rate (%) of the shear modulus after one week = shear modulus after one week / first shear modulus × 100. 3) Vibration Absorption Characteristics The vibration absorption characteristics were evaluated by an equivalent viscous damping constant at 0.5 Hz and 150% strain by a two-axis shear tester.

Examples 1 to 6 and Comparative Examples 1 to 4 The results are shown in Table 1 below.

[Table 1]

According to the results shown in Table 1, the seismic isolation laminates of Examples 1 to 6 using the high damping rubber composition of the present invention were compared with Comparative Example 1
It can be seen that, as compared with those of Nos. 1 to 4, the hysteresis dependency is excellent, and the vibration absorption characteristics are also good.

[0018]

The high damping rubber composition of the present invention and the seismic isolation bearing using the same are very useful because they have little hysteresis dependence and good vibration absorption characteristics.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a seismic isolation bearing in which a high-damping rubber composition of the present invention and a steel plate are alternately laminated.

[Explanation of symbols]

 1: Rubber composition 2: Steel plate

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16F 1/36 F16F 1/36 C // (C08L 9/00 45:02) (C08L 9/00 57: 02) F-term (reference) 3J059 BA43 BC02 BC08 BC20 EA04 GA42 4F070 AA05 AA06 AA07 AA08 AA09 AA11 AA18 AC04 AC23 AC94 AE01 AE02 FA03 FB04 FC01 FC03 4F100 AA25 AA37 AB03B AK01A AK28 AC1 AC00 AC08 AC091 AE053 BA012 BB151 BK002 DA036 DJ016 FD016 FD023 FD060 FD140 FD150 GL00

Claims (2)

[Claims] 1. A high-damping rubber composition comprising 5 to 55 parts by weight of a resin, 0 to 50 parts by weight of a softening agent and 20 to 150 parts by weight of a reinforcing agent with respect to 100 parts by weight of a diene rubber.
In the first stage of rubber kneading, diene rubber A weight part, resin B
In parts by weight, softener C parts by weight and reinforcing agent D parts by weight, formula I: (Where, 20 ≦ A ≦ 100, 0 ≦ B ≦ 55, 0 ≦ C ≦ 5
0,16 ≦ D ≦ 150, where D is 80% or more of the total amount of the reinforcing agent. ), A masterbatch that satisfies the relationship of
A high-damping rubber composition comprising the remaining diene rubber, a reinforcing agent, and other compounding agents. 2. A seismic isolation bearing in which rubber layers and steel plates are alternately laminated, wherein the rubber layer is made of the high damping rubber composition according to claim 1.