JP2618760B2 - Anti-vibration rubber composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-vibration rubber composition used for a vibration-proof rubber of a hard disk of a computer and a vibration-proof rubber of a general electric appliance such as a washing machine.

[0002]

2. Description of the Related Art In general, as a vibration isolating rubber for a hard disk of a computer, polynorbornene is a main component, a reinforcing agent such as carbon black, a filler such as calcium carbonate, and a softening agent such as process oil. A low rebound resilient rubber composition is used. Also, a vibration-proof rubber using a low-rebound resilience rubber composition obtained by mixing ethylene-propylene-diene rubber (EPDM) in consideration of weather resistance with the above composition is used. Further, a rubber made of a low-rebound resilience rubber composition containing butyl rubber as a main component is also used as an anti-vibration rubber for general home appliances such as a washing machine. The low resilience rubber composition containing polynorbornene as a main component,
It has a high loss coefficient (tan σ) near room temperature and high attenuation, and exhibits good vibration isolation performance near room temperature.
However, due to its high temperature dependency, high vibration isolation cannot be exhibited in a temperature region other than the room temperature region. Also,
The low resilience rubber composition containing butyl rubber as a main component cannot exhibit sufficient vibration damping properties both at around room temperature and at around high temperature.

[0003] From such a viewpoint, the present inventors have conducted studies and found that butyl rubber is used as a main component and a phenolic resin is added to the butyl rubber to shift the peak of the loss coefficient to around normal temperature, and to increase the room temperature. A low rebound resilient rubber composition capable of exhibiting excellent vibration isolation performance in the above temperature range by increasing the loss coefficient in the vicinity of a high temperature range has been developed (Japanese Patent Application No. 2-46486).

[0004]

However, in the above low rebound resilience rubber composition, by shifting the peak of the loss coefficient to around normal temperature, the loss coefficient in the high temperature region from around normal temperature is increased, and the excellent vibration damping performance is obtained. However, there is a problem that the compression set becomes large and the tensile strength becomes small.

The present invention has been made in view of such circumstances, and provides a vibration-proof rubber composition which is excellent in vibration-proof performance in a wide temperature range from room temperature to high temperature, and has a small compression set and a high tensile strength. With that purpose.

[0006]

Means for Solving the Problems In order to achieve the above-mentioned object, a vibration-proof rubber composition according to the present invention comprises a halogenated butyl rubber as a main component, a phenolic resin and a reinforcing agent. A reactive phenolic resin represented by the following general formula (1) as the phenolic resin, and the reinforcing agent (C) and a reactive phenolic represented by the general formula (1) The mixing ratio of the resins (A) to each other [(C) / (A)] is expressed as a weight ratio of (C) /
(A) = 2 to 25 is set.

[0007]

Embedded image [Wherein, R is an alkyl group. ]

[0008]

The present inventors have conducted a series of studies to obtain a vibration-proof rubber composition which has excellent vibration-proof performance in a wide temperature range and has a small compression set and a high tensile strength. As a result, halogenated butyl rubber is the main component,
The anti-vibration rubber composition containing the reinforcing agent contains the reactive phenolic resin represented by the general formula (1), and the mutual mixing ratio between the reactive phenolic resin and the reinforcing agent is specified. The inventors have found that when the ratio is set within the range, in addition to excellent vibration isolation performance, a small compression set and high tensile strength can be obtained, and the present invention has been achieved.

Next, the present invention will be described in detail.

The anti-vibration rubber composition of the present invention is obtained by using a halogenated butyl rubber as a main component, a reinforcing agent and a reactive phenol resin.

The halogenated butyl rubber is not particularly limited, and a conventionally known one can be used.
Among them, chlorinated butyl rubber is preferably used.

The reinforcing agent used together with the halogenated butyl rubber is used to increase the hardness, tensile strength and the like of the vibration damping rubber, and generally, carbon black is used. However, other than that, white carbon and the like can be mentioned, and they are used alone or in combination. Most preferred is carbon black.

In the vibration-proof rubber composition of the present invention, a reactive phenol resin represented by the following general formula (1) is used together with the above-mentioned raw materials. The reaction type phenol resin is a heat reaction type alkyl phenol formaldehyde resin.

[0014]

Embedded image [Wherein, R is an alkyl group. ]

The reactive phenolic resin represented by the general formula (1), that is, the so-called heat-reactive alkylphenol formaldehyde resin, can be obtained by reacting phenol with formaldehyde. Then, the halogen of the halogenated butyl rubber reacts with the methylol group of the thermal reaction type alkylphenol formaldehyde resin represented by the general formula (1) to form a kind of crosslinked structure. For this reason, the glass transition temperature of the obtained vibration damping rubber composition increases (the peak temperature of the loss coefficient increases), and tackiness is imparted.

It is to be noted that a part of the reactive phenol resin represented by the above general formula (1) may be replaced with a non-reactive phenol resin, and both may be used in combination. Examples of the non-reactive phenol resin include an alkylphenol formaldehyde resin represented by the following general formula (2).

[0017]

Embedded image [Wherein, R is an alkyl group. ]

When the reactive phenolic resin (A) represented by the general formula (1) and the non-reactive phenolic resin (B) are used in combination, the mixing ratio of A / B = 0.08 to
It is preferable to set the ratio to 4.0.

In addition, in addition to the above-mentioned raw materials, fillers, vulcanizing agents, vulcanization accelerators, vulcanization aids, and the like can be appropriately blended with the vibration-proof rubber composition of the present invention, if necessary.

The above-mentioned filler is used for the purpose of improving the workability and the like of the vibration isolating rubber, and includes calcium carbonate and the like.

The anti-vibration rubber composition of the present invention can be produced, for example, as follows using each of the above-mentioned raw materials. That is, it is possible to mix the above-mentioned raw materials at a predetermined ratio and mix them in a mixer to produce the mixture. The low rebound resilience rubber composition thus obtained is in the form of a sheet. By shaping and vulcanizing the composition, a vibration-proof rubber having a predetermined shape can be produced. In this case, the mixing ratios of the respective raw materials are set as follows. The above general formula (1)
Is preferably set in the range of 2 to 25 parts of the reactive phenol resin based on 100 parts of the halogenated butyl rubber. That is, when the mixing ratio of the reactive phenolic resin is less than 2 parts, the tensile strength tends to be small and the compression set tends to be large, and when it exceeds 25 parts, the hardness tends to be too high. In addition, the compounding ratio of the reinforcing agent,
30 to 30 parts of reinforcing agent per 100 parts of halogenated butyl rubber
It is preferable to set the ratio to 80 parts. Further, the mutual mixing ratio [(C) / (A)] of the reinforcing agent (C) and the reactive phenol resin (A) represented by the general formula (1) is expressed by weight ratio of (C) / (A). = 2 to 25.

[0022]

As described above, the anti-vibration rubber composition of the present invention is obtained by adding a reinforcing agent and a reactive type represented by the general formula (1) to a low-rebound elastic rubber composition containing halogenated butyl rubber as a main component. Since the phenol resin and the phenol resin are contained so as to have a specific mixing ratio, a peak of the loss coefficient is formed near room temperature, and the compressive strain is small and the tensile strength is large. As a result, by using this, it is possible not only to exhibit good vibration-proof performance in a wide temperature range from near room temperature to high temperature, but also to manufacture a vibration-proof rubber which is difficult to set. Therefore, this anti-vibration rubber, as a vibration-proof rubber for computer hard disks, does not cause a reduction in vibration-proof performance even when the computer generates heat, and provides almost perfect vibration-proof in a wide temperature range from near room temperature to high temperature. That is, the dimensional change is small even in long-term use. The anti-vibration rubber can also be suitably used as an anti-vibration rubber for general home electric appliances which generate vibration such as a washing machine.

Next, examples will be described together with comparative examples.

[0024]

Examples 1 to 5 The raw materials shown in Table 1 below were blended in the proportions shown in the same table, and mixed in a mixer to obtain a sheet-like low-elasticity rubber composition. Next, this was molded and vulcanized to produce an anti-vibration rubber, and the characteristics of the anti-vibration rubber were measured and shown in Table 1 below.

[0025]

[Table 1]

* 1: Exxon chlorobutyl 106 manufactured by Exxon Chemical
6 was used. * 2: Tatsuki roll 101 manufactured by Taoka Chemical Co., Ltd. was used. * 3: Tatsukiroll 201G manufactured by Taoka Chemical Co., Ltd. was used. * 4: Spectrometer (frequency 1) manufactured by Yokohama System Co., Ltd.
00 Hz).

[0027]

Comparative Examples 1 to 4 Raw materials shown in Table 2 below were blended in the proportions shown in the same table, and mixed in a mixer to obtain a sheet-like low-elasticity rubber composition. Next, this was molded and vulcanized to produce an anti-vibration rubber, and the characteristics of the anti-vibration rubber were measured and are shown in Table 2 below.

[0028]

[Table 2]

* 1: Exxon chlorobutyl 106 manufactured by Exxon Chemical Co., Ltd.
6 was used. * 2: Tatsuki roll 101 manufactured by Taoka Chemical Co., Ltd. was used. * 3: Tatsukiroll 201G manufactured by Taoka Chemical Co., Ltd. was used. * 4: Spectrometer (frequency 1) manufactured by Yokohama System Co., Ltd.
00 Hz).

As is clear from the results shown in Tables 1 and 2, the product of the example has a smaller compression set and a higher tensile strength than the product of the comparative example. Further, the peak temperature of the loss coefficient is also formed near room temperature.

FIGS. 1 and 2 show the relationship between the loss coefficient and the temperature of the vibration isolating rubbers obtained in the above Examples and Comparative Examples.
It was shown to. In FIG. 1, curves A to E correspond to Examples 1 to 5, respectively.
It corresponds to. Also, in FIG.
This corresponds to Comparative Examples 1 to 4. As is clear from the comparison of the curves, in the example product, the peak of the loss coefficient of the temperature-loss coefficient curve is formed in the usable range. However, it can be seen that the peak of the loss coefficient is formed on the low temperature side in the comparative example product, which is not suitable for practical use.

From these facts, it can be seen that the products of the examples exhibit good vibration damping characteristics in a wide temperature range from near room temperature to a high temperature, and have little sag even after long-term use.

[0033]

[Brief description of the drawings]

FIG. 1 is a curve diagram showing a temperature-loss coefficient relationship of a vibration-proof rubber obtained by using the vibration-proof rubber composition of the present invention.

FIG. 2 is a curve diagram showing a relationship between temperature and loss coefficient of a vibration-proof rubber as a comparative example product.

Claims (1)

(57) [Claims] 1. A halogenated butyl rubber as a main component,
An anti-vibration rubber composition comprising a phenolic resin and a reinforcing agent, wherein a reactive phenolic resin represented by the following general formula (1) is blended as the phenolic resin ,
And the reaction represented by the general formula (1) with the reinforcing agent (C)
Mixing ratio of the phenolic resin (A) [(C) /
(A)] is in the range of (C) / (A) = 2 to 25 by weight ratio.
An anti-vibration rubber composition characterized by being set in a box. Embedded image [Wherein, R is an alkyl group. ]