JP3222958B2 - Metal / rubber composite vibration insulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal / rubber composite vibration isolator in which a metal fitting is adhered to a vibration isolating rubber body exhibiting a vibration isolating effect, and relates to a vibration isolator for an automobile such as a mount for an engine or a bush for a suspension link. Used as a body or as an anti-vibration support for other machinery.

[0002]

2. Description of the Related Art As a metal / rubber composite vibration isolator, a surface of a metal fitting made of aluminum or an alloy thereof is subjected to a chromate treatment to form a chromate film, and the surface of the film is coated with a simultaneous vulcanizing adhesive. It is known that a vibration-proof rubber member is simultaneously vulcanized and bonded (see Japanese Utility Model Publication No. 3-26337).

[0003]

However, in the case of a metal / rubber composite vibration isolator using a metal fitting subjected to the above-described chromate treatment, the chromate treatment is mainly performed for rust prevention of the metal fitting. However, the desired corrosion resistance may not actually be obtained. That is, vulcanization bonding of the vibration-isolating rubber body is performed after the above-mentioned chromate treatment, and heat (100 ° C. or more) at the time of the vulcanization bonding causes fine cracks in the chromate film. It invades and causes corrosion of metal fittings.

[0004] Such a problem does not occur only in the case of the above-mentioned vulcanization bonding, but also in the case where the vulcanized rubber is adhered to the above-mentioned metal fittings by a thermosetting adhesive, the thermosetting of the adhesive does not occur. For this reason, heating is required, which is the same problem as in the case of vulcanization bonding.

[0005] Therefore, the present invention is to improve the adhesion stability between the metal fitting and the vibration-proof rubber body while preventing the above-mentioned chromate film from cracking.

[0006]

SUMMARY OF THE INVENTION The present invention provides
As a result of intensive studies on such problems, they have found that a surface treatment using a silane coupling agent after the above-mentioned chromate treatment can solve the above-mentioned problems, and have completed the present invention.

That is, a means for solving the above-mentioned problem is a metal / rubber composite vibration isolator in which a metal member is adhered to a vibration-proof rubber member exhibiting a vibration-proof action, and a chromate film is formed on the surface of the metal member. An organic silane compound film formed by a silane coupling agent is formed on the chromate film, and a thermosetting adhesive is formed on the surface of the organic silane compound film to be bonded to the vibration-proof rubber body. Is formed by heat-curing, and the surface of the vibration-proof rubber body that has been subjected to the surface activation treatment is bonded to the adhesive-cured layer of the metal fitting by an isocyanate-based adhesive. It is characterized by the following.

In the case of this means, when the organic silane compound film covers the chromate film and the thermosetting adhesive is thermally cured, or when the vibration damping rubber body is bonded by heat curing of the isocyanate-based adhesive. Protects this chromate coating from the heat of
Further, the organic silane compound film reinforces the chromate film and physically suppresses occurrence of cracks. For this reason, the corrosion resistance of the metal fitting is obtained, and the adhesive stability of the adhesive cured layer to the metal fitting (chromate film) is obtained.

That is, the organic silane compound has a hydrolyzable substituent such as an alkoxy group and a halogen, and a group which easily reacts with an organic substance such as a vinyl group, an epoxy group and an amino group. Chemically bond with the chromate film to form the reinforcement. Further, even if cracks occur in the chromate film, the organic silane compound film prevents the background of the metal fitting from being exposed.

The organic silane compound film is bonded to the adhesive layer by a group which easily reacts with the organic substance, thereby improving the adhesion between the adhesive layer and the chromate film and thus the surface of the metal fitting. To increase the adhesive stability of the adhesive layer to the adhesive.

The metal fittings may be made of non-ferrous metal, such as aluminum or aluminum alloy, even if they are made of iron.
It may be made of a magnesium alloy.

As the vibration-proof rubber member, natural rubber (N
R) and synthetic rubber (for example, styrene butadiene rubber (S
(BR) or butadiene rubber (BR), etc., or by blending natural rubber and styrene butadiene rubber (NR / SBR) or blending natural rubber and butadiene rubber (NR / BR). It can also be molded.

The organic silane compound includes XR-
Various silane coupling agents represented by the general formula of Si- (OR ') 3 can be used. In this case, X is a methacryloxy-based, amine-based, epoxy-based, or mercapto-based active group, and R and R 'are alkyl groups. For example,
γ-methacryloxypropyltrimethoxysilane, γ-
It is preferable to use aminopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, or the like.

As the thermosetting adhesive, a two-part curable adhesive such as a phenolic resin-based or chlorinated rubber-based adhesive, or a one-part curable adhesive can be used.

The surface activation treatment of the vibration-proof rubber body is for activating the vulcanized rubber surface with an organic acid, an inorganic acid or a physical treatment, and includes a halogenation treatment, a nitration treatment, and a cyclization treatment. , Methylene iodide treatment or plasma treatment.

In the case of the above-mentioned halogenation treatment, halogenated isocyanuric acid, halogenated succinimide,
Among halogenated isocyanates, N-halogensulfonamides or halogenated hydantoins, etc., a halogenation treating agent such as hydrochloric acid, hypochlorous acid, sodium hypochlorite, iodine chloride or iodine bromide as an inorganic acid. select. Among them, isocyanate iodide, dichloroisocyanuric acid, trichloroisocyanuric acid, N-dichloro-P-toluenesulfonamide and the like are preferable in terms of surface treatment performance, processing safety, treatment speed and the like. The selected halogenating agent is dissolved in a suitable organic solvent and diluted to a concentration of 0.1 to 30%, preferably 1 to 20% to obtain a halogenated solution. As the organic solvent, toluene, xylene, isooctane, dimethyl ether, ethyl acetate, methyl ethyl ketone, carbon tetrachloride, industrial thinner, or the like may be used. Then, after degreased the surface of the vibration-isolating rubber body which is a vulcanized rubber, it is immersed in the halogenated solution or sprayed or coated with the halogenated solution for a relatively short time (for example, a few seconds or more). 3 minutes). In this case, rinsing of the surface is often not necessary.

In the case of the above-mentioned nitration treatment, a nitrating agent is selected from among iodine nitrate, iodine azide, bromine azide, nitric acid and mixed acid. Then, a low-concentration nitrating solution is applied to the surface of the vibration-proof rubber body for a short time, and then the applied surface is sufficiently washed with water. In the case of this nitration treatment, since the reactivity is relatively large, it is necessary to perform the treatment in a sufficient safety facility.

In the case of the above cyclization treatment, a concentrated sulfuric acid solution is used as a cyclization treatment solution, and the surface of the rubber vibration insulator is immersed or coated in the cyclization treatment solution at room temperature for 2 to 20 minutes. The attached concentrated sulfuric acid is washed away with water.

In the case of the above-mentioned methylene iodide treatment, methylene iodide is dissolved in an appropriate solvent to form 0.1 to 10%
To a methylene iodide-treated solution, and this solution is applied to the surface of the rubber vibration insulator.

Further, in the case of the plasma treatment, a low-temperature plasma of 100 to 60,000 Wsec / l is irradiated on the surface of the rubber vibration insulator.

In the production of the above-mentioned metal / rubber composite vibration insulator, for example, after a base treatment (such as alkali degreasing) of a metal fitting is performed, a chromate treatment is performed, an organic silane treatment with a silane coupling agent is performed, and then the organic silane While applying and drying a thermosetting adhesive on the surface of the compound film,
A method in which an activation treatment is performed on the surface of the vibration-proof rubber body, an isocyanate-based adhesive is applied to the activation-treated surface, and a thermosetting adhesive layer of the metal fitting is laminated and adhered to the adhesive layer. Can be implemented.

For the above chromate treatment, a chromic acid method, a chromium phosphate method, or the like can be adopted. For example, a chromate film is formed on the surface of a metal fitting by immersing the metal fitting in an acidic bath of a chromate treatment solution. Can be. In the organic silane treatment, immersion of the metal fitting in a silane coupling agent solution, brush coating or spray application of the same solution to the metal fitting can be employed.

[0023]

Thus, according to the present invention, a chromate film is formed on the surface of a metal fitting, and an organic silane compound film is formed on the chromate film by a silane coupling agent. An adhesive cured layer formed by thermosetting a thermosetting adhesive is formed on the surface of the film to be bonded to the vibration-isolating rubber body, and the adhesive-cured layer is activated by the activation of the vibration-isolating rubber body. Since the bonding surface is bonded by an isocyanate-based adhesive, it is possible to prevent cracking of the chromate film and to make the adhesion of the adhesive layer to the chromate film good, so that it can be used in a corrosive environment. It is possible to maintain strong adhesion between the metal fitting and the vibration-proof rubber body for a long period of time.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A reference example will be described below prior to an embodiment of the present invention.

<Reference Example> FIG. 1 shows a metal / rubber composite vibration isolator (engine mount of an automobile) according to a reference example of the present invention. In FIG. 1, reference numeral 1 denotes a cylindrical anti-vibration rubber body, and reference numerals 2 and 2 denote aluminum alloy fittings bonded to both ends of the anti-vibration rubber body 1. As shown in FIG. 2, the entire surface of the metal fitting 2 has a chromate film 3 and an organic silane compound film 4 formed by a silane coupling agent.
Are formed in order from the bottom, and the vibration-proof rubber body 1 is adhered to the surface of the organosilane compound film 3 of the metal fitting 2 via the lower layer 4 and the upper layer 5 made of a simultaneous vulcanizing adhesive.

The lower layer 5 is made of a phenol resin-based primer adhesive, and the upper layer 6 is made of a chlorinated rubber-based adhesive containing chlorosulfonated polyethylene as a main component.

The metal / rubber composite vibration isolator was manufactured by the following steps.

-Chromate treatment of metal fitting 2- The chromate treatment of metal fitting 2 was performed in the following order.

Alkaline degreasing → water washing → pickling → water washing → smut removal → water washing → formation of chromate film 3 → water washing → hot water washing → drying In the chemical treatment of the chromate film 3, the metal fitting 2 Immersion in acidic chromate treatment solution (normal temperature-50 ° C x 3-
180 seconds). The chromate treatment solution contains chromic acid and hydrogen fluoride as main components and contains a reaction accelerator.

-Organic Silane Treatment- The metal fitting 2 after the above chromate treatment was immersed in a silane coupling agent solution to form an organic silane compound film 4 on the surface of the metal fitting 2. The composition of the silane coupling agent solution is as follows.

Alcohol 1 liter Silane coupling agent 20 ml Water 10 ml The immersion conditions were 30 minutes at room temperature, and the drying conditions after immersion were 100 ° C. × 20 minutes.

-Adhesive application- The phenolic resin-based primer adhesive is applied to the surface of the organic silane compound film 4 to be bonded to the vibration isolating rubber body 1, and after this is dried, the chlorinated rubber-based adhesive is applied. And dried. The drying conditions are all 70 ° C. × 5 minutes.

-Vulcanized Adhesion- The metal fitting 2 coated with the adhesive is placed in a vulcanizing mold, the unvulcanized rubber for the vibration-proof rubber body 1 is injected, and then heated to heat the vibration-proof rubber body 1. Was vulcanized and bonded to the metal fitting 2.

(Test) The following test was performed to confirm the effect of the above-mentioned reference example.

-Specimens-Specimens were prepared for each of Reference Examples a to d and Comparative Examples a and b in accordance with Section 8.3.1 of JIS K6301. The composition of the rubber part corresponding to the vibration-proof rubber body 1 in each test piece is as shown in Table 1.

[0036]

[Table 1]

The material of the metal part corresponding to the metal fitting 2 in each of the test pieces of Reference Examples a to d is aluminum alloy (JIS
A5052, 6063 or 7 in H4000
003), and γAPS is used as the silane coupling agent.
(Γ-aminopropyltriethoxysilane) or γMP
S (γ-methacryloxypropyltrimethoxysilane)
Was used. That is, in Reference Examples a to d, the material of the metal part or the type of the silane coupling agent was different from each other, and these are listed in Table 2. In Comparative Examples a and b, as the surface treatment of the metal part, only the chromate treatment was performed without performing the organic silane treatment. Also in this comparative example, the material of each metal part is listed in Table 2.

For each of the test pieces of the reference example and the comparative example, Chemrock 205 (trade name, manufactured by US Road Co., Ltd.) was used as a phenolic resin-based primer adhesive for the lower layer 4.
As the chlorinated rubber-based adhesive for the upper layer 5, Chemlock 252 (trade name, manufactured by Road Co., USA) was used.

-Contents of Test- Each of the test pieces was subjected to a 90-degree peel test based on Section 8.3 of JIS K6301. The peel test was performed in combination with a salt spray test (SST) according to JISZ2371. That is, the peel test was carried out at the initial stage (without salt spray), 600 hours after salt spray, 720 hours after salt spray, and 1000 hours after the salt spray.

-Test results- The test results are shown in Table 2. In the same table, the meaning of each symbol of R-RC-CP-M in the item of the peeled state is as follows.

R: Breakage of rubber part RC: Breakage between rubber part and adhesive CP: Breakage of adhesive part M: Breakage between metal and adhesive

[0042]

[Table 2]

According to Table 2, Reference Examples a to d and Comparative Examples a and
b, there is almost no difference in the initial stage, but as the salt water spray time becomes longer, the peeling load and the peeling state become different. That is, the peeling load is slightly higher in the reference example, and the ratio of breakage between the metal part and the adhesive increases in the comparative example, whereas it decreases in the reference example. From this, as in the present invention, the metal fitting 2
When the organic silane compound film 4 is formed on the surface of the chromate film 3 by a silane coupling agent, the corrosion resistance and the adhesion stability may be higher than those obtained by performing only the conventional chromate treatment. Understand.

<Example> Next, an example of the present invention will be described.

The metal / rubber composite vibration isolator of this embodiment is a cylindrical bush, which is shown in FIGS. In the figure, reference numeral 21 denotes a cylindrical vibration-proof rubber body, and reference numeral 22 denotes a vibration-proof rubber body 21.
Aluminum alloy inner tube fitting adhered to the inner peripheral surface of the
Reference numeral 23 denotes an aluminum alloy outer metal fitting adhered to the outer peripheral surface of the vibration-proof rubber body 21. The same vulcanization bonding as that of the reference example is employed for bonding the inner cylinder fitting 22 to the vibration-proof rubber body 21.

On the other hand, FIG.
As shown in FIG. 5, a chromate film 24 is formed, and an organic silane compound film 25 by a silane coupling agent is formed on the chromate film 24.
A lower layer 26 and an upper layer 27 formed by thermosetting a thermosetting (simultaneously vulcanizing) adhesive are formed on the surface of the organic silane compound film 25 bonded to the vibration-proof rubber body 21. The outer peripheral surface of the vibration-proof rubber body 21 is subjected to a predetermined surface activation treatment. Then, the outer cylinder fitting 2
The surface of the above-mentioned vibration-proof rubber body 21 on which the adhesive cured layer 27 has been subjected to the surface activation treatment is used to form the isocyanate-based adhesive layer 2.
8 bonded together.

The bonding between the vibration-proof rubber body 21 and the outer sleeve 23 was carried out by the following steps.

—Chromate Treatment and Organosilane Treatment of Outer Tube Fitting 23—Chromate treatment and organic silane treatment of the outer tube fitting 23 were performed in the same manner as in the reference example.

-Formation of Adhesive Cured Layer- The above-mentioned Chemloc 205 is applied as a lower layer 26 on the surface (inner peripheral surface) of the organic silane compound film 24 of the outer tube fitting 23 that adheres to the vibration-proof rubber member 21 and is dried. After, upper layer 2
As No. 7, Chemlock 220 (chlorinated rubber-based adhesive) manufactured by US Road Co., Ltd. was applied and dried. The drying conditions are all 70 ° C. × 5 minutes. Then, these adhesives were thermally cured at 150 ° C. for 20 minutes, thereby forming the cured adhesive layers 26 and 27.

-Surface activation treatment- After the outer peripheral surface of the vibration-isolating rubber body 21 is subjected to a degreasing treatment with a solvent, a 3% solution of trichloroisocyanuric acid (the diluent is an organic solvent) is applied to the outer peripheral surface. Was activated.

-Adhesion- After an isocyanate-based adhesive is applied to the outer peripheral surface of the vibration-proof rubber body 21, the vibration-proof rubber body 21 is pressed into the cylindrical hole of the outer cylindrical fitting 23 and compressed radially inward. The isocyanate-based adhesive was cured under a heating condition of 120 ° C. for 20 minutes while the elastic restoring force of the rubber was applied. As a result, the isocyanate-based adhesive layer 28 was formed, and the vibration-proof rubber body 21 and the outer tube 23 were integrated.

(Test) The following test was performed to confirm the effects of the above-described embodiment.

-Test piece-The test piece is the above-mentioned cylindrical bush, and was prepared for each of Examples e and f and Comparative example c according to the method described above. The rubber composition of the vibration-proof rubber body in each test piece is as shown in Table 1, and the material of the metal fittings 22 and 23 is an aluminum alloy (A5052 in JIS H4000). As for the silane coupling agent, the above-mentioned γAP
S was used, and γMPS was used in Example f. In Comparative Example c, only the chromate treatment was performed as a surface treatment on the metal fittings.

Each of the test pieces of the above Examples and Comparative Examples was provided with the above Chemlock 2 for the adhesive cured layers 26 and 27.
No. 05 and No. 220 were used, and a urethane bond was used as an isocyanate adhesive.

-Contents of Test- For each of the above test pieces, the outer cylinder 23 is held, and an axial load is applied to the anti-vibration rubber body 21 and the inner cylinder 22 to punch them out. The test was performed.
The punching test was also performed in combination with the salt spray test similarly to the test in the reference example.

-Test Results- The test results are shown in Table 3. In the same table, the meaning of each symbol in the item of the peeled state is the same as in the case of Table 2.

[0057]

[Table 3]

According to Table 3, in Examples e and f and Comparative example c, in both the breaking load and the breaking state,
There is almost no difference between the initial period and the short period of salt spraying, but when the period is longer, the breaking load is slightly higher in the example as in the test results of the reference example, and also in the comparative example. In this case, the ratio of breakage between the metal part and the adhesive increases, whereas in the embodiment, the ratio decreases. This supports the improvement of corrosion resistance or adhesion stability.

In particular, instead of directly bonding the vibration-proof rubber body 21 to the surface of the aluminum alloy fitting 23 with an isocyanate-based adhesive, a chromate film 24, an organic silane compound film 25, and a heat-cured adhesive Hardened layer 26,2
7, since the isocyanate-based adhesive is applied after covering the ground, the anti-vibration rubber body 21 which is a vulcanized rubber can be firmly bonded to the metal fitting 23, and the corrosion resistance of the metal fitting can be improved. It can be improved.

In this case, the organic silane compound film 25
Is bonded to the inorganic chromate film 24 and the phenolic adhesive cured layer 26 to bridge the two, and further, the phenolic adhesive cured layer 26 and the chlorinated rubber adhesive cured layer 27 Because strong bonding is obtained between the rubber-based adhesive cured layer 27 and the isocyanate-based adhesive layer 28, and between the isocyanate-based adhesive layer 28 and the activated surface of the vibration-proof rubber body 21, respectively. And consequently the metal fitting 2
It is recognized that 3 and the vibration-proof rubber body 21 are firmly connected.

The method of manufacturing the vibration isolator described in the above embodiment is merely an example, and the conditions of each step can be appropriately changed according to the material of the metal fittings, the type of the adhesive used, and the like. is there.

In the above embodiment, the isocyanate-based adhesive may be applied to the metal fitting, or may be applied to both the metal fitting and the vibration-proof rubber body.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a vibration isolator of a reference example.

FIG. 2 is a cross-sectional view of a bonding portion of a vibration isolator according to a reference example.

FIG. 3 is an exploded sectional view of the vibration isolator of the embodiment.

FIG. 4 is a sectional view of a bonding portion of the vibration isolator according to the embodiment.

[Explanation of symbols]

 1,21 anti-vibration rubber body 2,22,23 metal fittings 3,24 chromate film 4,25 organosilane compound film 5,6 simultaneous vulcanizable adhesive layer 26,27 adhesive cured layer 28 isocyanate adhesive layer

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 C08J 5/12 F16F 15/00-15/36

Claims (1)

(57) [Claims] 1. A metal / rubber composite vibration isolator comprising a metal member bonded to a vibration-isolating rubber member exhibiting a vibration-proof action, wherein a chromate film is formed on a surface of the metal member, Having an organic silane compound film formed by a silane coupling agent formed thereon, and an adhesive obtained by thermosetting a thermosetting adhesive on the surface of the organic silane compound film bonded to the vibration-proof rubber body. A metal / rubber, wherein a cured layer is formed, and an adhesive surface of the vibration-proof rubber body, which has been subjected to a surface activation treatment, is adhered to the adhesive cured layer of the fitting with an isocyanate-based adhesive. Composite vibration insulator.