JPH07330919A - Bonding method of rubber to metal - Google Patents

Abstract

PURPOSE:To provide a method for bonding rubber to various metals easily and satisfactorily without using an adhesive by subjecting the surface of a metal to a specific treatment and bonding a rubber material to the metal surface under vulcanization. CONSTITUTION:After a metal sulfide layer is formed on the surface of a metal, a rubber material is placed on the surface and bonded to it under vulcanization. The sulfide layer is formed e.g. by immersing the metal in a soln. contg. sulfur ions (e.g. a soln. of sodium or potassium sulfide), by exposing the metal to a hydrogen sulfide gas atmosphere, by immersing the metal in a mixture of a soln. contg. metal ions (e.g. an aq. soln. of iron nitrate or sulfate) with a sulfur-contg. soln. (e.g. an aq. thioacetamide or thiourea soln.), or by sputtering. The surface is pref. cleaned before the sulfide layer is formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for adhering rubber and metal which is useful for producing rubber / metal composite products such as anti-vibration rubber and rubber rollers.

[0002]

2. Description of the Related Art Conventionally, as a technique for adhering a rubber and a metal when manufacturing a rubber-metal composite product such as a vibration-proof rubber or a rubber roller, an adhesive is previously applied to the metal side, The so-called vulcanization adhesion method of adhering unvulcanized rubber by vulcanization molding, and the so-called post-adhesion method of adhering pre-vulcanized rubber and metal with an adhesive are known. From this point of view, the vulcanization bonding method is generally used. However, the method using such an adhesive has a problem that the pretreatment of the metal and the step of applying the adhesive are very complicated. That is,
As the metal treatment before applying the adhesive, a cleaning treatment for removing impurities, oils, etc., a blast treatment for enhancing the adhesive strength, or a chemical treatment is indispensable. Also,
Adhesives are usually used for undercoating that has excellent affinity with metals,
Since two types of topcoat adhesives with excellent affinity for rubber are used, it is necessary to apply the adhesive twice. Moreover, if there is coating unevenness, the adhesive force may be significantly reduced, resulting in poor adhesion. Therefore, strict process control is required. The complexity of such a treatment step makes it more difficult to apply when the adhesive is very large or small, or when the shape is complicated.

Further, in the conventional adhesive, an organic solvent is usually used as a solvent or a dispersant for the adhesive component, so that the working environment is bad and special equipment is required to improve the working environment. there were.

Moreover, due to the recent regulation of ozone-depleting substances, the adhesive components and solvents that can be used are limited, and they can be widely applied to various rubbers and metals and can be adhered to them well. It is the actual situation that has not been obtained yet.

Under these circumstances, in recent years, a method of directly bonding metal and rubber without using an adhesive, for example, a method of directly vulcanizing and bonding brass or brass-plated metal and rubber,
Furthermore, a method for directly vulcanizing and adhering a rubber containing a triazine thiol compound and a metal has been developed and attracted attention.

However, the above-mentioned direct adhesion between brass and brass-plated metal and rubber has a problem that the adhesion is influenced by the copper ratio in brass, in addition to the drawback that the metal is limited. In the case of adhesion of brass having a low copper ratio, compounding an organic cobalt salt or the like into rubber improves the initial adhesion but deteriorates the durability. Further, since the brass or brass plating itself has poor storage stability, there are problems that the adhesive force is likely to vary, and so-called masking treatment of the non-adhesive portion is difficult.

Even in the direct bonding method using a triazine thiol compound, good adhesive strength cannot be obtained depending on the type of metal or rubber. In order to obtain good adhesive strength, the vulcanizing agent or vulcanizing agent used is used. As with brass and brass plating, where accelerators and the like must be controlled within a narrow range,
There are many problems to be solved for practical use, such as difficulty in masking a part that does not require adhesion.

[0008]

As described above, in recent years, as a technique for adhering metal and rubber, there has been proposed a method for directly adhering metal and rubber without using an adhesive having various problems in workability and environment. Although developed, it can be widely applied to adhesion of various metals and rubbers, and does not require strict control of compounding agents and vulcanization conditions to obtain good adhesion, and does not require adhesion. Adhesive technology has not been established yet, which allows easy masking of parts.

The present invention has been made in view of the above problems of the prior art, and is capable of adhering various metals and rubber satisfactorily and easily without using an adhesive. It is intended to provide a bonding method with

[0010]

The method for adhering a rubber and a metal according to the present invention comprises the steps of forming a metal sulfide layer on the surface of a metal body,
It is characterized in that a rubber material is placed on it and vulcanized and bonded together.

Here, as a method for forming the metal sulfide layer on the surface of the metal body, a method of immersing the metal body in a solution containing sulfur ions, for example, a sodium sulfide solution, a potassium sulfide solution, or the like, or a hydrogen sulfide of the metal body is used. A method of exposing to a gas atmosphere, a method of immersing a metal body in a metal ion-containing solution such as an aqueous solution of iron nitrate or iron sulfate and a sulfur-containing solution such as an aqueous solution of thioacetamide or an aqueous solution of thiourea, or a sputtering method is used. be able to.

By such a method, a reaction represented by the following formula occurs on the surface of the metal body, and a layer made of metal sulfide is formed. M + S ^{2 −} → MS + 2e ⁻ (M is a metal) Then, when a rubber material is arranged on the metal sulfide layer formed in this way and vulcanization adhesion is performed, M-MS-
Bonds such as R and M-MS-S-R (R is rubber) are generated, and a composite body in which the metal body and the rubber material are firmly bonded is obtained.

The metal body and the rubber material used in the present invention are not particularly limited, and various metal materials and rubber materials can be used. In the present invention, it is preferable to perform a cleaning treatment on the surface of the metal body before forming the metal sulfide layer. Although this increases the number of steps, the adhesive strength can be further increased.

[0014]

As described above, in the method of the present invention, the metal sulfide layer is formed on the surface of the metal body, and the rubber material is placed on the metal sulfide layer and vulcanized and adhered to form a metal sulfide layer at the interface between the metal body and the rubber material. -M
Since a bond such as S-R and M-MS-S-R is generated,
Both are firmly adhered. In such a method, since no adhesive is used, a complicated adhesive application step is not required, workability is excellent, and there is no fear of environmental pollution, so there is no need to take measures against it. . Further, the type of the metal body or the rubber material that is the adherend is not specified, and the present invention can be widely applied to adhesion of various metals and rubber.

[0015]

EXAMPLES Next, examples of the present invention will be described.

Example 1 A cold-rolled steel plate (SPCC steel plate) of 85 mm × 25 mm × 3 mm having its surface washed was dipped in a constant temperature bath of 50 ° C. containing a 10% Na ₂ S solution for 10 minutes. , A sulfide layer was formed on the surface. Next, between two SPCC steel sheets with this sulfide layer formed, a rubber material with a thickness of 3 mm (100 parts by weight of unvulcanized natural rubber, 30 parts by weight of carbon black, an antioxidant [Ouchi Shinko Made by Kagaku, trade name Nocrac 224] 3 parts by weight,
Stearic acid 1.5 parts by weight, zinc white 5 parts by weight, sulfur 2 parts by weight, vulcanization accelerator [Kawaguchi Chemical Co., Ltd., trade name Axel D
M] 1 part by weight was kneaded and extruded into a sheet shape), placed in a mold, and placed under a pressure of 15 MPa at a temperature of 150 ° C for 10
It was heated and vulcanized for minutes to prepare an adhesive test piece having a structure shown in FIG. In FIG. 1, 1 indicates a steel plate and 2 indicates rubber.

Example 2 A washed SPCC steel sheet 1 obtained in the same manner as in Example 1
Is set in a quartz glass tube 3 of a reactor as shown in FIG. 2, the inside of the tube is replaced with H ₂ gas, and then H ₂ gas is added.
_While supplying a mixed gas of ₂ and H ₂ S into the tube, a heat treatment was performed at 300 ° C. for 5 minutes in the electric melting furnace 4 to form a sulfide layer on the surface of the SPCC steel sheet 1. Then, in the same manner as in Example 1, a rubber material having a thickness of 3 mm was placed between two SPCC steel sheets having a sulfide layer formed thereon, and the rubber material was placed in a mold and heat-vulcanized under pressure. I glued them together.

Example 3 A washed SPCC steel sheet 1 obtained in the same manner as in Example 1
Is set in a glass reaction vessel 5 as shown in FIG. 3, and an aqueous iron nitrate solution and an aqueous thioacetamide solution are introduced into the vessel 5 at 70 ° C. for 10 minutes to form a sulfide layer on the surface of the SPCC steel plate 1. Formed. Then, in the same manner as in Example 1, between the two SPCC steel sheets on which the sulfide layer was formed, the thickness was
A 3 mm rubber material was placed, placed in a mold, and heat-vulcanized under pressure to bond them together.

Example 4 A washed SPCC steel sheet 1 obtained in the same manner as in Example 1
Is set in a vacuum chamber 6 of a sputtering apparatus as shown in FIG. 4, and a voltage of 1.5 kV is applied to a SPCC steel plate steel electrode 7 through a capacitor while Ar gas is flowed at a flow pressure of 1 Pa,
A H ₂ S gas was introduced to form a sulfide layer on the surface of the SPCC steel plate 1. The processing time was 10 minutes. In FIG. 4, 8 is a sample stand. After that, in the same manner as in Example 1,
A rubber material having a thickness of 3 mm was placed between two SPCC steel sheets having a sulfide layer formed thereon, and the rubber material was placed in a mold and heated and vulcanized under pressure to bond them together.

Comparative Example The same SPCC steel sheet as that used in Example 1 was washed, blasted and washed in this order, and then a two-component coating type adhesive (low
ChemFlo 205 / Chemloc 252 manufactured by Dofar East Inco-Polled Co., Ltd. was applied. That is, first,
The basecoat adhesive was applied and dried, then the topcoat adhesive was applied and dried. Then, between the two SPCC steel plates having the obtained adhesive layer, in the same manner as in Example 1,
A rubber material having a thickness of 3 mm was arranged, and heated and vulcanized under pressure by a mold to bond them together.

With respect to the adhesive test pieces of the respective Examples and Comparative Examples thus obtained, the initial adhesive force and 100 ° C.
The adhesive strength after 10-day heat aging was measured. The results are shown in Table 1.
The adhesive force was calculated by the following formula.

[0022]

[Table 1] As is clear from Table 1, the example is simpler than the comparative example and the number of steps is significantly reduced, and the adhesive strength is equal to or higher than that of the comparative example both in the initial stage and after heat aging. .

[0023]

As is apparent from the above examples, according to the method of the present invention, a metal sulfide layer is formed on the surface of a metal body, and a rubber material is directly disposed on the metal sulfide layer to integrally perform vulcanization adhesion. Therefore, the number of steps can be significantly reduced as compared with the conventional method using an adhesive, and furthermore, the rubber and the metal can be bonded with a high adhesive force. Moreover, the type, shape, size, etc. of the rubber or metal that is the material to be adhered is not specified, and it can be widely used for adhesion of various rubbers and metals. Therefore, anti-vibration rubber, rubber roller,
It is extremely useful for manufacturing various rubber / metal composite products such as oil seals.

[Brief description of drawings]

FIG. 1 is a perspective view showing an adhesion test piece prepared in one example of the present invention.

FIG. 2 is a diagram schematically showing an example of an apparatus used in the present invention.

FIG. 3 is a diagram schematically showing another example of the apparatus used in the present invention.

FIG. 4 is a diagram schematically showing an example of a sputtering apparatus used in the present invention.

[Explanation of symbols]

 1 ………… SPCC steel plate 2 ………… Rubber 3 ………… Quartz glass tube 4 ………… Electric melting furnace 5 ……… Reaction vessel 6 ……… Vacuum chamber 7 ……… Electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuro Ogo, 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa, Showa Electric Cable Co., Ltd. (72) Kazuhisa Ishikawa, Sakae Oda, Kawasaki-ku, Kawasaki, Kanagawa 1-1-1, Showa Cable Denki Co., Ltd. (72) Inventor Noriei Kyo, 2-1-1, Oda Sakae, Kawasaki-ku, Kawasaki-ku, Kanagawa Prefecture (72) In Showa Cable Denki Co., Ltd. (72) Masahiro Minowa Kawasaki, Kanagawa Prefecture 2-1-1 Oda Sakae, Kawasaki-ku, Ichi, Showa Electric Wire & Cable Co., Ltd.

Claims (2)

[Claims] 1. A method for adhering rubber and metal, comprising forming a metal sulfide layer on the surface of a metal body, arranging a rubber material thereon, and integrally vulcanizing and adhering. 2. The method for adhering a rubber and a metal according to claim 1, wherein the metal sulfide layer is formed by immersing the metal body in a sulfur ion-containing solution or exposing the metal body to a hydrogen sulfide gas atmosphere. A method of immersing a metal body in a solution containing a metal ion and a solution containing sulfur, or a method of adhering a rubber and a metal using a sputtering method.