JP2001193775A - Vibration-proof rubber and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration-proof rubber with low dynamic spring property and high deterioration property combined. SOLUTION: An unvulcanized rubber material A for giving a low dynamic spring property and a unvulcanized rubber material B for giving high deterioration property are uniformly kneaded together with vulcanizer capable of vulcanizing only the rubber material B, while the rubber material B heated to be finely diffused into the rubber material A is vulcanized and then the vulcanizer capable of vulcanizing the rubber material A is further incorporated into a desired form, which is heated to vulcanize the rubber material A, whereby the vibration- proof rubber is formed which shows a sea-island structure with the vulcanized rubber material B being finely diffused as an island phase into a matrix of the vulcanized rubber material A.

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 and a method for producing the same, and more particularly, to an anti-vibration rubber realizing both low dynamic spring characteristics and high damping characteristics, and a method for advantageously producing such an anti-vibration rubber. It is about.

[0002]

2. Description of the Related Art As is well known, an anti-vibration rubber which is interposed between two members constituting a vibration transmission system and which connects the two members with vibration isolation has been widely used in various fields. For example, they have been used in automobiles as engine mounts, body mounts, member mounts, suspension bushes, and the like.

[0003] By the way, in the case of the above-mentioned anti-vibration rubber for automobiles, which is used in a transmission system of a plurality of kinds of vibrations having different frequencies or the like, the anti-vibration rubber usually corresponds to each input vibration. To demonstrate the characteristics effectively,
Desired. Specifically, when vibrations in a relatively high frequency range of 100 Hz or more are input to an anti-vibration rubber for an automobile, a low dynamic spring characteristic is generally required, and a low dynamic spring characteristic of about 10 to 20 Hz is required. When frequency vibrations are input, high attenuation characteristics are required.

In order to obtain an anti-vibration rubber having such anti-vibration characteristics as a low dynamic spring and a high damping, conventionally,
For example, a natural rubber (NR) having excellent low dynamic spring characteristics is used as a rubber material constituting a vibration isolating rubber, and carbon black is added thereto to achieve high attenuation.
Various improvement measures on the material side, such as modification of rubber materials and improvement of the compounding method thereof, have been studied, but in any of them, until the characteristic requirements are sufficiently satisfied, It was not at all.

[0005] In other words, the mechanism of manifesting the spring characteristics is the bonding, restraint and entanglement between the polymer molecules constituting the rubber material,
Alternatively, the damping mechanism is based on the bond / restraint between the polymer molecule and the reinforcing agent added to the material, while the mechanism of the attenuation is based on the friction between the polymer molecules or between the polymer molecule and the reinforcing agent. Therefore, when the damping property is increased, the spring characteristic is also increased, and conversely, when the low dynamic spring property is realized, the damping property is also reduced. There is, therefore, no rubber material capable of realizing both such low dynamic spring and high damping contradictory characteristics at present.

[0006] On the other hand, as one approach from a structural aspect, not from such a material aspect, the adoption of a fluid-filled anti-vibration rubber has been studied. Such a fluid-filled anti-vibration rubber is generally provided with a plurality of fluid chambers in an elastic body made of a predetermined rubber material,
It has a structure provided with an orifice flow path (a constricted flow path) that connects these fluid chambers to each other. Based on the resonance action of the fluid flowing through the orifice flow path, the frequency range of the input vibration is reduced. It is configured so that the various anti-vibration performances required can be exhibited effectively.However, such a fluid-filled type anti-vibration rubber requires a complicated structure. In addition, there is an inherent problem that a problem such as a rise in manufacturing cost and a deterioration in manufacturability is caused due to an increase in the number of components constituting the device.

[0007]

The present invention has been made in view of the above circumstances, and an object of the present invention is to achieve both a low dynamic spring characteristic and a high damping characteristic. An object of the present invention is to provide an anti-vibration rubber capable of realizing good cost performance and manufacturability, and a method of advantageously producing such an anti-vibration rubber.

[0008]

According to the present invention, in order to solve such a problem, a vulcanized material having a high damping property is provided in a matrix made of a vulcanized rubber material A having a low dynamic spring property. The rubber material B is finely dispersed as an island phase to provide a vibration-isolating rubber exhibiting a sea-island structure, and the vulcanized rubber material B as the island phase is an unvulcanized rubber material A
While unvulcanized rubber material B is uniformly kneaded and dispersed therein, vulcanization of rubber material B is performed, while the unvulcanized rubber material A is formed.
The gist of the present invention is an anti-vibration rubber characterized by being vulcanized in a dispersed state of such a vulcanized rubber material B.

That is, in the vibration damping rubber according to the present invention, a sea phase made of a vulcanized rubber material A giving low dynamic spring characteristics and an island phase made of a vulcanized rubber material B giving high damping characteristics are provided. And the sea-island structure has a great feature in that it is formed as described above. In the vulcanized rubber material A as a sea phase having a sea-island structure, excellent low dynamic spring characteristics can be exhibited, while the vulcanized rubber material A is uniformly dispersed in a matrix composed of the vulcanized rubber material A in the form of fine particles. Was
The vulcanized rubber material B as an island phase can exhibit high damping characteristics.

In short, the anti-vibration rubber according to the present invention can exhibit a low dynamic spring characteristic and a high damping characteristic in each of the vulcanized rubber material A and the vulcanized rubber material B to a high degree. Unlike conventional rubber materials, it is possible to achieve both of these characteristics.

Therefore, the product of the present invention can be particularly preferably used as an anti-vibration rubber attached to a plurality of types of vibration transmission systems having different frequencies, such as anti-vibration rubber for automobiles.
An effective anti-vibration effect can be exhibited against those vibrations.

In addition, in such a vibration-proof rubber,
Since it does not require a complicated structure as in the case of a fluid-filled anti-vibration rubber or the like, there is an advantage that it can be manufactured at low cost and relatively easily.

According to one preferred embodiment of the vibration damping rubber according to the present invention as described above, the vulcanized rubber material B has an average particle diameter of 0 in the vulcanized rubber material A. It is desirable that the particles are finely dispersed as particles having a size of 0.1 to 100 μm, whereby the desired vibration damping characteristics (low dynamic spring-high damping) can be exhibited more effectively, The physical properties required as a vibration rubber can also be satisfactorily ensured.

According to another preferred embodiment of the present invention, NR or a blend of NR and BR or SBR having excellent low dynamic spring characteristics is employed as the rubber material A. As rubber material B, halogenated IIR having high damping performance, maleic acid-modified EP
Preferably, M, CR, carboxyl-modified NBR, CSM, FR or acrylic rubber is employed. By adopting such a configuration, more effective anti-vibration characteristics can be realized more advantageously.

Further, according to the present invention, a vulcanized rubber material B having a high damping property is finely dispersed as an island phase in a matrix made of a vulcanized rubber material A having a low dynamic spring property. The rubber material A is a natural rubber, the rubber material B is an acrylic rubber, and the rubber material A and the rubber material B are 90/10 in weight ratio. A state in which the vulcanized rubber material B as the island phase is uniformly dispersed in the unvulcanized rubber material A while being mixed at a ratio of about 60/40. Below, by vulcanizing the rubber material B, 0.1 to 100
While being formed as fine particles with a size of μm,
The gist of the present invention is also a vibration-proof rubber characterized in that the unvulcanized rubber material A is vulcanized in a dispersed state of the vulcanized rubber material B.

In the vibration damping rubber according to the present invention, a predetermined amount of a vulcanized acrylic rubber rubber material giving a high damping characteristic is added to a sea phase made of a vulcanized natural rubber material giving a low dynamic spring characteristic. Since the fine particles are uniformly dispersed as fine-grained island phases having a size of 0.1 to 100 μm, the above-described good vibration damping characteristics (low dynamic spring-high damping) can be advantageously exhibited. At the same time, the acrylic rubber as the island phase effectively disperses and alleviates the stress applied to the vibration isolating rubber, thereby achieving excellent durability.

Further, the present invention relates to a vulcanization method which comprises vulcanizing only an unvulcanized rubber material A giving a low dynamic spring characteristic and an unvulcanized rubber material B giving a high damping characteristic. And vulcanizing the rubber material B finely dispersed in the rubber material A while heating and kneading the rubber material B uniformly. And vulcanizing the rubber material A by heating to form a desired shape, and then heating the vulcanized rubber material B in a matrix composed of the vulcanized rubber material A. A method for producing an anti-vibration rubber characterized by obtaining an anti-vibration rubber exhibiting a sea-island structure in which is dispersed finely as an island phase is also the gist of the invention.

According to such a method of manufacturing a vibration-proof rubber according to the present invention, a vulcanized rubber material exhibiting a high damping property in a matrix (sea phase) of a vulcanized rubber material A exhibiting a low dynamic spring characteristic. From the point that the sea-island structure in which B is uniformly dispersed as a fine island phase can be advantageously formed,
It is possible to advantageously produce a vibration-isolating rubber capable of achieving an effective vibration-damping effect by realizing both a low dynamic spring characteristic and a high damping characteristic.

Further, according to the method of the present invention, the advantage that the vibration-proof rubber exhibiting the excellent vibration-proof performance as described above can be produced at a low cost with a relatively simple operation can be enjoyed. You can do it.

In a preferred embodiment of the method for producing a vibration-proof rubber according to the present invention, a vulcanizing agent capable of vulcanizing only the rubber material B is added to the unvulcanized rubber material B. After mixing, uniform kneading with the unvulcanized rubber material A is performed. By employing such a method, the kneading time of the rubber material A, the rubber material B and the vulcanizing agent capable of vulcanizing only the rubber material B can be advantageously shortened. Since the dispersibility of the rubber material B and the vulcanizing agent becomes even more uniform, the production of an anti-vibration rubber having more excellent high-damping characteristics becomes possible.

According to another preferred embodiment of the method of the present invention, the vulcanization of the rubber material A is performed in a sulfur vulcanization system, while the vulcanization of the rubber material B is
It is carried out in a resin vulcanization system, a metal oxide vulcanization system or an amine vulcanization system.
By performing vulcanization in different vulcanization systems, the desired sea-island structure can be realized more advantageously, and a vibration-proof rubber having better vibration-proof properties can be obtained.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The anti-vibration rubber according to the present invention is formed of a rubber material A having a low dynamic spring characteristic and a rubber material B having a high damping characteristic. Specifically, first, the unvulcanized material of the rubber material A is kneaded uniformly with the unvulcanized material of the rubber material A,
In a state where the unvulcanized rubber material B is finely dispersed in the unvulcanized rubber material A, the rubber material B is vulcanized, and thereafter, the unvulcanized rubber material A is vulcanized and molded. As a result, it is formed with a specific structure composed of the vulcanized rubber materials A and B, and there is a major feature of the present invention.

That is, in the vibration-proof rubber formed by the characteristic method of the present invention as described above, the vulcanized rubber material A
And the vulcanized rubber material B are not mutually compatible with each other, but the vulcanized rubber material B is dispersed very uniformly as fine particulate island phases in a matrix (sea phase) of the vulcanized rubber material A. The so-called sea-island structure is adopted. By adopting such a specific sea-island structure, the vulcanized rubber material A, which is the sea phase, can sufficiently exhibit excellent low dynamic spring characteristics. It was possible to obtain high damping characteristics in the vulcanized rubber material B as the island phase while securing the same.

In short, the anti-vibration rubber according to the present invention has a low dynamic spring characteristic and a high damping characteristic in each of the vulcanized rubber material A and the vulcanized rubber material B constituting the same in a functionally separated manner. In other words, it is possible to advantageously achieve both of the low dynamic spring characteristic and the high damping characteristic, which can be expressed to a high degree, in other words, cannot be achieved by the conventional rubber material.

By the way, in such a vibration-proof rubber according to the present invention, as the rubber material A that gives the sea phase, after vulcanization, a low dynamic spring characteristic particularly effective for vibration in a high frequency region is advantageously exhibited. Any material can be used as long as it can be used.Among various known rubber materials having such properties, an appropriate material is selected and used according to required characteristics. Among such rubber materials, natural rubber (NR), NR and butadiene rubber (B
R), or a blend of NR with styrene butadiene rubber (SBR).
(Hereinafter, such a rubber material is referred to as an NR-based material) is suitably adopted, whereby the vulcanized rubber material A has a more excellent low dynamic spring performance. It can be demonstrated.

On the other hand, a rubber material B that provides an island phase of the vibration-isolating rubber
As a characteristic after vulcanization, while exhibiting a high damping effect particularly against low-frequency vibration, the vulcanization can be performed in a vulcanization system different from the rubber material A. Therefore, among various rubber materials conventionally known as high damping materials,
Those satisfying such conditions for the vulcanization system are appropriately selected and used according to the required characteristics. For example, as described above, when an NR-based material is used as the rubber material A, a halogenated butyl rubber such as chlorinated butyl rubber (halogenated IIR), a maleic acid-modified ethylene propylene rubber (maleic acid-modified EP)
The use of M), chloroprene rubber (CR), carboxyl-modified nitrile rubber (carboxyl-modified NBR), chlorosulfonated polyethylene (CSM), fluororubber (FR) or acrylic rubber is particularly recommended.
However, each of the exemplified rubber materials can exhibit an effective high damping effect after vulcanization in any of them, and as described later, a vulcanization material different from the NR material is used. It is needless to say that the system can be adopted, as shown in Table 1 below, each of which has gas resistance, weather resistance, heat resistance, ozone resistance, oil resistance, chemical resistance, etc. This is because various properties can be effectively imparted to the vibration-proof rubber.

[0027]

[Table 1]

When acrylic rubber is used as the rubber material B, if it is a synthetic rubber containing a conventionally known alkyl acrylate as a main component,
Any material can be adopted and will be appropriately selected and used according to the required characteristics. Among them, acrylic rubber, which can be vulcanized by an amine vulcanization system described later, That is, a copolymer of alkyl acrylate and 2-chloroethyl vinyl ether (ACM), a copolymer of alkyl acrylate and acrylonitrile (ANM), a copolymer of alkyl acrylate and ethylene (AEM), etc. It is suitably used, and by adopting such an acrylic rubber, the durability of the vibration damping rubber can be advantageously increased.

Then, in the present invention, an anti-vibration rubber exhibiting a desired specific sea-island structure is formed by using such an unvulcanized rubber material A and rubber material B. First, there is no effect on the rubber material A together with the unvulcanized rubber material A and the unvulcanized rubber material B,
A vulcanizing agent (hereinafter, referred to as a vulcanizing agent B) acting only on the rubber material B and having the function of promoting the vulcanization is heated while uniformly kneading. It is possible to vulcanize the rubber material B in a state where the unvulcanized rubber material B is finely and uniformly dispersed in the unvulcanized rubber material A without vulcanizing the rubber material A. You can.

Here, as described above, the vulcanizing agent B used for vulcanizing the rubber material B may be one that can vulcanize only the rubber material B without vulcanizing the rubber material A. Since it is indispensable, generally, a vulcanizing agent that satisfies such conditions among various known vulcanizing agents is appropriately selected in consideration of the types of the rubber materials A and B, and the like. Will be used. Specifically, for example, when the rubber material A made of the NR-based material is employed as described above, as shown in Table 2 below, as the vulcanizing agent B, an alkylphenol resin that does not act on the NR-based material, a modified resin, From among resins such as alkylphenol resins, metal oxides such as zinc oxide and magnesium oxide, and polyamines such as hexamethylenediamine carbamate, an appropriate one is selected and used according to the type of rubber material B, and used. It is desirable to carry out vulcanization of the rubber material B in a resin vulcanization system, a metal oxide vulcanization system or an amine vulcanization system containing such a vulcanizing agent. In addition, in the following Table 2, when the halogenated IIR, maleic acid-modified EPM, CR, carboxyl-modified NBR, CSM, FR or acrylic rubber exemplified as the preferable material is used as the rubber material B, ,Indicated.

[0031]

[Table 2]

In the present invention, the vulcanizing agent B is combined with a predetermined vulcanization accelerator which does not act on the rubber material A or a vulcanization accelerator, and the rubber material B It is also possible to carry out vulcanization. For example, as shown in Table 2 above, appropriate vulcanization accelerators and vulcanization accelerators are used depending on the types of the rubber material B and the vulcanizing agent B to be employed. By selecting the auxiliaries and combining them with the vulcanizing agent B and kneading the unvulcanized rubber materials A and B, more effective vulcanization can be realized. Also,
When vulcanizing the rubber material B, the rubber material A
It is also possible to knead the rubber materials A and B, the vulcanizing agent B and the like by appropriately using various known rubber compounding agents as long as the rubber is not vulcanized.

In order to heat the unvulcanized rubber materials A and B together with the vulcanizing agent B while uniformly kneading the rubber materials B, the vulcanization reaction in the rubber material B proceeds.
Normally, a known kneading device such as Banbury, which can knead the polymer under heating conditions, is used. Unvulcanized rubber materials A and B, a vulcanizing agent B, etc. are required in such a device. After mixing and introducing as a rubber raw material, a predetermined kneading and heating operation is to be performed. At this time, in the rubber raw material supplied to the kneading apparatus, unvulcanized rubber material A and rubber In the case of the material B, it is preferable that each is used in an appropriate amount so that desired properties or physical properties can be advantageously achieved in the finally obtained anti-vibration rubber. The ratio (rubber material A / rubber material B) is 95/5 to 5
It is used so as to be 30/70. This is because, when the amount of the rubber material B used is too small as compared with the rubber material A, the obtained vulcanized rubber material B cannot sufficiently exhibit the high damping effect. This is because if the amount of the material B is too large as compared with the rubber material A, the physical properties of the vibration-proof rubber, for example, the tensile strength and the hardness are deteriorated. However, in the present invention,
If the amount of the rubber material B used is larger than that of the rubber material A, the physical properties of the vibration-proof rubber may be greatly reduced. Material A and rubber material B were mixed at a weight ratio of 95 /
It is more desirable to use it so as to be 5/50/50. However, when acrylic rubber is used as the rubber material B, the weight ratio (rubber material A / rubber material B)
In this case, it is desirable to mix them so as to be 90/10 to 60/40. However, if the amount of the acrylic rubber used is less than this range, the effects (high attenuation, durability, etc.) of blending the acrylic rubber cannot be sufficiently obtained. If the amount of the rubber material used is larger than the above range, other physical properties such as compression set will be deteriorated.

A vulcanizing agent B introduced into a kneading device as a rubber raw material together with the unvulcanized products of the rubber materials A and B.
And vulcanization accelerators and vulcanization accelerators, respectively, in order to favorably promote the desired vulcanization reaction in rubber material B,
The rubber material B is used in an appropriate amount corresponding to the usage amount.

Further, when the rubber raw materials such as the unvulcanized rubber materials A and B and the vulcanizing agent B are introduced into the kneading apparatus in the amounts described above, the rubber materials A and B and the vulcanizing agent Even if B and the like are supplied to the device at the same time, there is no problem, but in the present invention,
Advantageously, the vulcanizing agent B or the like is previously blended in a predetermined amount with the unvulcanized rubber material B to prepare and prepare a mixture such as a master batch. A method of combining the thus obtained mixture with the rubber material A and the unvulcanized rubber material B contained in the mixture so that the weight ratio thereof becomes a desired value, and supplying the mixture as a rubber raw material to an apparatus. Are preferably used. By employing such a method, not only can the kneading time be shortened advantageously, but also the dispersion state of the rubber material B and the vulcanizing agent B in the unvulcanized rubber material A can be further improved. Since it can be made uniform, the damping characteristics of the vulcanized rubber material B can be greatly improved.

Further, in the kneading operation performed after introducing the predetermined rubber raw material into the kneading apparatus as described above, in the present invention, the rubber material B in the unvulcanized rubber material A is The kneading time is usually set so that the dispersion state of the rubber material B as described above can be advantageously obtained because it is necessary to perform the dispersion until the dispersion is fine and uniform to the extent that the desired properties can be exhibited. In addition to the types and amounts of the materials A and B and the performance of the kneading apparatus, the temperature is appropriately set. A temperature at which the sulfurization reaction can proceed sufficiently is advantageously employed.

Thus, the vulcanized rubber material B obtained by such a kneading and heating operation must be present in the unvulcanized rubber material A in a state of being uniformly dispersed in the form of fine particles. However, the particle size of the vulcanized rubber material B is appropriately adjusted by the above-described kneading operation or the like so that the required high damping characteristics can be favorably exhibited. It is desirable that the vulcanized rubber material B is formed to have an average particle diameter of 0.1 to 100 μm, preferably 0.1 to 30 μm. This means that if the average particle size is too small, the desired damping characteristics cannot be sufficiently realized. Conversely, if the average particle size is too large, it affects the physical properties of the vibration-proof rubber. This is because such a problem as above is caused. The average particle size of the vulcanized rubber material B is determined by various measurement methods,
Advantageously, as the average particle diameter, each particle made of the vulcanized rubber material B is observed with a scanning electron microscope (SEM) or a scanning probe microscope (SPM), and its diameter is measured. What is obtained by calculating the average value of is preferably adopted.

In the present invention, after vulcanization of the rubber material B as described above, the unvulcanized rubber material in a state in which the vulcanized rubber material B is dispersed inside A
After adding and compounding a vulcanizing agent capable of vulcanizing the rubber material A (hereinafter referred to as vulcanizing agent A), the unvulcanized rubber material A is vulcanized and molded. Is formed.

By the way, in the formation of the vibration damping rubber according to the present invention, prior to the vulcanization molding of the unvulcanized rubber material A,
The vulcanizing agent A to be mixed with the rubber material A has no problem as long as the vulcanization reaction in the rubber material A can proceed favorably. Usually, the type of the rubber material A and the required protection are not affected. In consideration of vibration characteristics and the like, an appropriate one is selected from various known vulcanizing agents, and the rubber material A
In particular, as described above, when an NR-based material is used as the rubber material A, sulfur is used as the vulcanizing agent A, and such sulfur vulcanization is performed. It is preferred to carry out the vulcanization of the rubber material A in the system.

In the present invention, a suitable vulcanization accelerator or a vulcanization acceleration aid is added to the rubber material A in a required amount together with the vulcanizing agent A to obtain a vulcanization agent. Even if the system is constituted in an embodiment containing these vulcanization accelerators and vulcanization acceleration aids, there is no problem. Representative examples of such a vulcanization accelerator include, for example, Nt-butyl-2-benzothiazolylsulfenamide (BBS) and N-cyclolhexyl-2-benzothiazylsulfenamide (CBS). ), N-oxydiethylene-2-benzothiazolesulfenamide (OB
S) and the like; sulfenamides such as zinc dimethyldithiocarbamate (ZnMDC) and zinc diethyldithiocarbamate (ZnEDC); tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), and tetrabutylthiuram disulfide (TETD) Thiurams such as TBTD) and the like, and examples of the vulcanization accelerator include zinc oxide and stearic acid.

The rubber material A may further contain, if necessary, a reinforcing agent such as carbon black, a reaction product of acetone and diphenylamine, and a phenylenediamine such as N-phenyl-N'-isopropyl-p-phenylenediamine. It is also possible to incorporate various rubber compounding agents such as anti-aging agents such as waxes and waxes and softening agents such as mineral oils. Needless to say, these compounds do not impair the desired low dynamic spring characteristics, and need to be used in an amount that does not impair the characteristics. For example, when using carbon black, if the amount of use (blending amount) increases,
Since the dynamic spring characteristics of the rubber material A are greatly affected, the amount of carbon black used is 60 parts by weight based on 100 parts by weight of the unvulcanized rubber material A.
An amount which is less than or equal to parts by weight is advantageously employed.

Further, when such a vulcanizing agent A and various additives are blended into the unvulcanized rubber material A containing the vulcanized rubber material B in a dispersed state, the vulcanizing agent A and the various additives are added to the rubber material A. It is preferable that after adding the sulfurizing agent A and the like, the mixture is further kneaded by a kneading operation using a roll machine or the like so as to uniformly mix the rubber material A. By the vulcanization operation, the vulcanization of the rubber material A can be performed uniformly and satisfactorily on the whole. In addition, in such a kneading operation, generally, an appropriate kneading time and an appropriate temperature condition,
Adopted.

Further, after compounding the vulcanizing agent A and the like with the unvulcanized rubber material A, as described above, the rubber material A
The specific method of vulcanization is to mold it by a molding method such as die molding and to heat it at a predetermined temperature while achieving the desired shape. Thus, various known techniques for vulcanizing the rubber material A can be advantageously employed.
Press vulcanization, in which vulcanization is performed simultaneously with molding, is more preferably used. In such vulcanization molding, the vulcanization conditions such as temperature, pressure and time during vulcanization are set so that the rubber material A can be satisfactorily vulcanized. Is appropriately determined in consideration of the above.
Further, in such vulcanization molding of the rubber material A, at the time of vulcanization or after vulcanization, even if a predetermined metal fitting made of iron material or aluminum material is bonded,
There is no hindrance, therefore, the present invention is intended to be applied to the vibration-proof rubber having no metal fittings, as well as the vibration-proof rubber with no metal fittings, Must be understood. Further, as described above, the shape, size, and the like of the vibration-proof rubber obtained by vulcanizing and molding the rubber material A are not particularly limited.
It can be set as appropriate according to the desired degree of vibration damping characteristics and the intended use.

In short, as described above, in the vibration damping rubber formed according to the present invention, the vulcanized rubber material B contains fine particles (generally, (0.1 to 100 μm) as an island phase, which presents a sea-island structure that is present in a uniformly dispersed state. As a result, such a specific sea-island structure provides low dynamic spring characteristics and It can exhibit both high attenuation characteristics. In other words, the anti-vibration rubber according to the present invention can exhibit anti-vibration characteristics of low dynamic spring and high damping by a relatively simple structure composed of specific vulcanized rubber materials A and B. Therefore, it is possible to manufacture easily and at low cost by the method of the present invention as described above.

Therefore, according to the present invention, an anti-vibration characteristic (low dynamic spring or high damping) effective for the intended vibration is exhibited according to the frequency range of the vibration to be anti-vibrated. By selecting the rubber material to be obtained and adopting it as the rubber material A or the rubber material B, it is possible to advantageously form an anti-vibration rubber which can sufficiently cope with a plurality of types of vibrations having different frequencies. ,Therefore,
The product of the present invention thus obtained can be suitably used in a vibration transmission system that requires vibration isolation against a plurality of types of vibrations, such as an automobile, and exhibits an extremely excellent vibration isolation effect. You get.

[0046]

EXAMPLES Hereinafter, some examples of the present invention will be described to clarify the present invention more specifically. However, the present invention imposes some restrictions by the description of such examples. It goes without saying that you don't receive anything. In addition, the present invention, in addition to the following examples, in addition to the above specific description, various modifications based on the knowledge of those skilled in the art, unless departing from the spirit of the present invention,
It should be understood that modifications, improvements and the like can be made.

(1) Dynamic Characteristics Test, Tensile Test, and Hardness Test First, according to the present invention, unvulcanized natural rubber (NR) is prepared as a rubber material A that provides low dynamic spring characteristics.
In the compounding composition shown in Table 3 below, chlorinated butyl rubber (Cl-II) as rubber material B giving high damping characteristics
A master batch was prepared by mixing zinc oxide as a vulcanizing agent B with the unvulcanized product of R). In the preparation of this master batch, zinc diethyldithiocarbamate (ZnEDC) was used as a vulcanization accelerator, while stearic acid was used as a vulcanization accelerator.

[0048]

[Table 3]

Next, using the NR and the masterbatch prepared above, the NR and the Cl-
It is possible to prepare a rubber raw material by combining NR and a master batch so that IIR and the respective weight ratios (NR / Cl-IIR) become the respective blend ratios shown in Table 4 below, and heat-knead the rubber raw material. 5-10
Minutes, while kneading uniformly, by heating at a temperature of 150 to 160 ° C., without vulcanizing the NR,
By vulcanizing only Cl-IIR, preliminary samples of Inventive Examples 1 to 6 were obtained. For each of the obtained preliminary samples, the particle diameter of Cl-IIR dispersed in the sample (NR) was measured, and the average value was determined. , About 0.5 to 5 μm.

Further, by using each of the preliminary samples thus obtained, one of the unvulcanized NRs constituting the preliminary sample was determined.
To 100 parts by weight, various components as shown in Table 4 below, such as sulfur as the vulcanizing agent A, were added in the proportions shown in Table 4 and mixed with a roll machine. After kneading and uniformly compounding, press vulcanizing
The test pieces (Examples 1 to 6 of the present invention) for the dynamic characteristic test, the tensile test, and the hardness test were each produced by vulcanization under the vulcanization conditions of 0 ° C. × 20 minutes.

In the above, N-cyclohexyl-2-benzothiazylsulfenamide (CBS) blended with NR is a vulcanization accelerator, and zinc oxide and stearic acid are vulcanization accelerators. Used as an agent. In this example, N-phenyl-N'-isopropyl-p-phenylenediamine was used as an antioxidant, and carbon black was used as a reinforcing agent, while mineral oil was used as a softening agent. Was.

The test piece for the dynamic characteristic test was prepared by first preparing a cylindrical vulcanized rubber sample having a diameter of 50 mm and a height of 25 mm by the above vulcanization molding. Diameter for upper and lower surfaces of sample:
It was produced by bonding a pair of 60 mm and 6 mm thick iron disk fittings with an adhesive. On the other hand, JIS-K-
A dumbbell-shaped test piece (3) specified in “3. Tensile test” in “Physical test method for vulcanized rubber” of No. 6301-1995.
And a test piece for hardness test is defined in “5. Hardness test” in “Physical test method for vulcanized rubber” in JIS-K-6301-1995.
A test piece having a thickness of 2 mm was prepared.

[0053]

[Table 4]

On the other hand, for comparison, first, rubber raw materials (Comparative Examples 1 and 2) were prepared by compounding only NR (unvulcanized product) as a rubber material in accordance with the respective composition shown in Table 5 below. ,Got ready. Next, vulcanization molding was performed by press vulcanization under the conditions of 160 ° C. × 20 minutes using each of the rubber raw materials, and a dynamic characteristic test was performed in the same manner as the test pieces of Examples 1 to 6 described above. Test pieces (Comparative Examples 1 and 2) for a tensile test and a hardness test were respectively manufactured.

In the preparation of the rubber raw material according to the comparative example, the function or function of each component added to the NR is the same as that of the above-described present invention example. The carbon black used in an appropriate amount also functions as a high attenuation component as in the conventional case.

[0056]

[Table 5]

Using the test pieces according to Examples 1 to 6 of the present invention and Comparative Examples 1 and 2 obtained as described above, the following dynamic characteristics test, tensile test, and hardness test were performed.

-Dynamic characteristic test- Using each test piece for the dynamic characteristic test obtained above,
Apply an axial load to each test piece.
To compress 5.5 mm in the axial direction, and once reduced the load.
Then, by compressing again 5.5 mm,
Measure the load-deflection characteristics during the second loading process and
Based on this, a load-deflection curve is created, and
From the line, the load when the deflection is 1.25mm and 3.75mm
Value: P₁, P _Two(Unit is N)
Therefore, the following equation: Ks = (P_Two−P₁) /2.5
Therefore, the static spring constant: Ks (N / mm) was calculated.
Separately, each test piece is moved in the axial direction by 2.5
mm, the test piece in the compressed state
From the lower part of the
Amplitude: ± 0.05mm constant displacement harmonic compression vibration, frequency
Number: Perform a test at 100 Hz, JIS-
K-6385-1995 "Testing method of anti-vibration rubber"
In accordance with the “non-resonant method (a)”
Dynamic spring constant (storage spring constant): Kd₁₀₀(N / mm)
I asked. And such Kd₁₀₀And the Ks obtained above
From this, the dynamic magnification (= Kd₁₀₀/ Ks) and calculate the result.
The results are shown in Tables 6 and 7 below. In addition,
The small value of the ratio means that the test piece
However, in the dynamic spring characteristic with respect to the vibration of 100 Hz,
It means that it is a good thing.

In the dynamic characteristic test in this embodiment,
Further, with each test piece compressed in the axial direction by 2.5 mm, from below the test piece, a constant displacement harmonic compression vibration having an amplitude: ± 0.5 mm centering on the compression position was applied at a frequency of 15 Hz. Perform additional tests, J
15H in accordance with “Non-resonant method (a)” in “Testing method of anti-vibration rubber” of IS-K-6385-1995.
The loss factor at the time of z: tan δ is determined, and the result is
The results are shown in Tables 6 and 7 below. In addition, it can be understood that a large value of the loss coefficient indicates that the target test piece exhibits a high damping property against a vibration of 15 Hz.

Further, the dynamic magnification: Kd ₁₀₀ / Ks and the loss factor in each test piece obtained as described above:
The relationship with tan δ [15 Hz] is shown graphically in FIG. In FIG. 1, □ indicates the test piece of the present invention, while ● indicates the test piece of the comparative example.

-Tensile test-Using each of the test pieces for tensile test obtained above, according to the test method specified in "3. Tensile test" of JIS-K-6301-1995, a predetermined tensile tester The test piece is tensioned until it breaks, and the tensile stress at 100% elongation (100% modulus) and the maximum stress until fracture (tensile strength: T
b) and elongation at break (elongation at break: Eb) were measured,
The results are shown in Tables 6 and 7 below. For the test pieces according to Examples 1 to 6 of the present invention, the Tb and Eb thus obtained were compared with the blend ratios shown in Table 4 above, and the results were plotted as a bar graph (Tb) and a line graph. FIG. 2 is a graph (Eb). Note that FIG.
2 shows the values of Tb and Eb in the test piece of Comparative Example 1 as values when the blend ratio was 100/0.

-Hardness test- Using each test piece for the hardness test obtained above, a spring-type hardness test is performed in accordance with "5. Hardness test" of JIS-K-6301-1995. Machine: The hardness of the test piece was measured using an A type, and the results are also shown as JIS-A hardness in Tables 6 and 7 below.

[0063]

[Table 6]

[0064]

[Table 7]

As is clear from the results of the dynamic characteristics test shown in Tables 6 and 7 and FIG. 1, the test piece of Comparative Example 1 composed of NR has a low dynamic spring characteristic (dynamic magnification). However, the damping property (loss coefficient) is also low, and a comparison was made using a rubber raw material in which a larger amount of carbon black was added to NR than in Comparative Example 1. In the test piece of Example 2, although the damping property of the carbon black was higher than that of Comparative Example 1, as shown by a solid line in FIG. , It is recognized that it is rising rapidly. Therefore, when a larger amount of carbon black is used, as in the conventional case, in order to realize a higher damping property than that of Comparative Example 2, as shown by the broken line in FIG. The fact that the dynamic spring characteristics cannot be advantageously realized can be easily predicted, and it can be seen that such a conventional method is hardly effective.

On the other hand, in each of the test pieces of Examples 1 to 6 of the present invention, unlike the test piece of Comparative Example 2 described above, while maintaining the dynamic spring characteristics (dynamic magnification) low,
It is recognized that the damping property (loss coefficient) can be effectively enhanced. From this, it can be seen that the present invention can very advantageously realize the anti-vibration characteristics of low dynamic spring and high damping. It is understood that it is.

On the other hand, as is clear from the results of the tensile test and the hardness test shown in Tables 6 and 7 and FIG.
% Modulus, tensile strength (Tb), elongation at break (Eb), and other properties such as hardness and hardness, which are comparable to those of the conventional comparative example, are achieved. Be recognized. In particular, in the present invention,
As shown in FIG. 2, the rubber material B, Cl-IIR,
When used in an amount smaller than the rubber material A, NR,
It can be seen that physical properties such as Tb and Eb can be secured at a sufficiently high level.

(2) Durability Test As in the above-described various tests, first, unvulcanized natural rubber (NR) is prepared as a rubber material A having a low dynamic spring characteristic, and is shown in Table 8 below. Acrylic rubber (AE
M: VAMAC-G: manufactured by Du Pont-Mitsui Polychemicals Co., Ltd.) to prepare a masterbatch (hereinafter referred to as masterbatch AEM) in which hexamethylenediaminecarbamate as vulcanizing agent B is blended. ,
Got ready. In addition, in the preparation of this master batch AEM, while diol tolyl guanidine (DT) was used as a vulcanization accelerator, stearic acid was used as a vulcanization accelerator.

[0069]

[Table 8]

Next, using the NR and the master batch AEM prepared above, the NR and the AEM in the master batch AEM were combined so as to have a compounding ratio shown in Table 9 below to prepare a rubber raw material. Then, the mixture is charged in a Banbury mixer capable of heating and kneading, and then uniformly kneaded at a temperature of 150 to 160 ° C. and a temperature of 5 to 1 ° C.
By heating for 0 minutes, only the acrylic rubber was vulcanized without vulcanizing the NR.
And a preliminary sample of Comparative Example 4 were obtained.

Then, using each of the obtained preliminary samples (uncured NR for Comparative Example 3), the preliminary sample was subjected to various tests, including sulfur, as shown in Table 9 below. Ingredients, zinc oxide + stearic acid, HAF carbon black (ASTM-N330), and a softening agent: an aromatic process oil were added so as to have a ratio shown in Table 9 below, and further kneaded with a roll machine. NR was vulcanized by press-vulcanization molding operation, and then vulcanized to form various test pieces for a durability test and a compression set test (Examples 7 to 7).
9, Comparative Examples 3 and 4) were produced. As the vulcanization conditions, a test piece for a durability test was 160 ° C. × 20 minutes, and a test piece for a compression set was 160 ° C. × 30 minutes. Further, each test piece obtained in this manner (Example 7
To 9), the particle size of the acrylic rubber dispersed in the NR was measured for each.
It was confirmed that the thickness was about 5 to 3 μm.

As a test piece for the durability test, a dumbbell-shaped No. 5 type test piece specified in “Tensile test method for vulcanized rubber” of JIS-K-6251-1993 was prepared. As a test piece for a compression set test, a large test piece for a compression set test specified in JIS-K-6262-1997 "Method for testing permanent set of vulcanized rubber and thermoplastic rubber" was prepared.

[0073]

[Table 9]

Then, Example 7 thus obtained was obtained.
Using each of the test pieces according to ９9 and Comparative Examples 3 and 4,
The following durability test and compression set test were performed.

-Durability Test- Using each of the test pieces for the durability test obtained above, a predetermined tensile tester is used to apply a tensile strain of 0 to 100% to each test piece in the axial direction. To 300
Given repeatedly at a rate of times / minute until it breaks,
The number of times until breakage was measured, and the results are shown in Table 10 below as durability (dumbbell fatigue).

-Compression set test-Using each of the test pieces for compression set test obtained above, according to the test method specified in "5. Compression set test" of JIS-K-6262-1997. After applying a load by a predetermined compression device and compressing at a predetermined ratio and maintaining the state at 100 ° C. × 22 hours, the load is released and then left to cool at room temperature for a predetermined time. The compression set was determined by measuring the thickness at the center of the sample, and the results are shown in Table 10 below.

[0077]

[Table 10]

As is clear from the results shown in Table 10, according to the present invention, natural rubber is used as the rubber material A for providing low dynamic spring characteristics, while acrylic rubber is used for the rubber material B for providing high damping characteristics. It can be seen that in each of the test pieces of Examples 7 to 9, the durability can be effectively increased as compared with that of Comparative Example 3 consisting of only NR. However, even if acrylic rubber is used as the rubber material B that provides high damping characteristics, the durability of the test piece of Comparative Example 4 in which the compounding amount is outside the scope of the present invention is not improved. Although there is
The value of the compression set, which is a physical property required for the vibration-proof rubber, is increased and deteriorates.

[0079]

As is apparent from the above description, the vibration isolating rubber according to the present invention can realize both low dynamic spring characteristics and high damping characteristics, and It can be particularly advantageously applied as a vibration-proof rubber which requires various vibration-proof performances in response to a plurality of types of vibration having different frequencies, such as a vibration-proof rubber for automobiles such as a mount. And, according to the method for producing a vibration-proof rubber according to the present invention, a vibration-proof rubber capable of exhibiting such excellent effects is provided by:
Inexpensive and easy fabrication becomes possible.

[Brief description of the drawings]

FIG. 1 is a graph showing a relationship between a dynamic magnification and a loss coefficient obtained in an example.

FIG. 2 is a graph showing the tensile strength and elongation at break obtained in the examples in comparison with the blend ratio of natural rubber and chlorinated butyl rubber.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 11/00 C08L 11/00 13/00 13/00 23/20 23/20 23/28 23/28 27 / 12 27/12 33/08 33/08 F16F 15/08 F16F 15/08 D // (C08L 7/00 (C08L 7/00 33:08) 33:08) F term (reference) 3J048 AA01 BA01 BA23 BD01 EA01 EA13 3J059 AD04 AD06 BA41 EA06 GA01 GA07 4J002 AC01W AC011 AC03X AC08X AC102 BB212 BB242 BD122 BG042 GM00

Claims (7)

[Claims] 1. A sea-island structure in which a vulcanized rubber material B giving high damping characteristics is finely dispersed as an island phase in a matrix made of vulcanized rubber material A giving low dynamic spring characteristics. The vulcanized rubber material B, which is an island phase, is obtained by uniformly kneading and dispersing the unvulcanized rubber material B in the unvulcanized rubber material A. While the rubber material B is formed by vulcanization, the unvulcanized rubber material A is formed.
Wherein the rubber material B is vulcanized in a dispersed state of the vulcanized rubber material B. 2. The vulcanized rubber material B has an average particle diameter of 0.1 to 100 μm in the vulcanized rubber material A.
2. The rubber cushion according to claim 1, which is finely dispersed as particles having a size of m. 3. The rubber material A is NR or NR and B
R or SBR, wherein the rubber material B is a halogenated IIR, maleic acid-modified EPM, C
The anti-vibration rubber according to claim 1 or 2, which is R, carboxyl-modified NBR, CSM, FR or acrylic rubber. 4. A sea-island structure in which a vulcanized rubber material B giving high damping characteristics is finely dispersed as an island phase in a matrix made of vulcanized rubber material A giving low dynamic spring characteristics. The rubber material A is a natural rubber, the rubber material B is an acrylic rubber, and the rubber material A and the rubber material B are in a weight ratio of 90/10 to 60/40. Under the condition that the vulcanized rubber material B as the island phase is uniformly dispersed in the unvulcanized rubber material A, the rubber material B By performing vulcanization, fine particles having a size of 0.1 to 100 μm are formed, while the unvulcanized rubber material A is in a dispersed state of the vulcanized rubber material B. Under the vulcanized Anti-vibration rubber, characterized in that there. 5. An unvulcanized rubber material A having a low dynamic spring characteristic and an unvulcanized rubber material B having a high damping characteristic are uniformly mixed with a vulcanizing agent capable of vulcanizing only the rubber material B. After kneading, the mixture is heated to vulcanize the rubber material B finely dispersed in the rubber material A. Then, a vulcanizing agent capable of vulcanizing the rubber material A is further compounded. The rubber material A is formed into a desired shape and heated.
To obtain a vibration-isolating rubber exhibiting a sea-island structure in which the vulcanized rubber material B is finely dispersed as an island phase in a matrix composed of the vulcanized rubber material A. A method for producing a vibration-proof rubber, characterized in that: 6. After mixing a vulcanizing agent capable of vulcanizing only the rubber material B with the unvulcanized rubber material B, uniform kneading with the unvulcanized rubber material A is performed. The method for producing an anti-vibration rubber according to claim 5, which is performed. 7. The vulcanization of the rubber material A is carried out in a sulfur vulcanization system, while the vulcanization of the rubber material B is carried out in a resin vulcanization system, a metal oxide vulcanization system or an amine vulcanization system. A method for producing a vibration-proof rubber according to claim 5 or 6.