JP2012072790A - Vibration-proof rubber member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration-proof rubber member having superior adhesion in an interface between a fitting and a rubber material, and also having superior rust prevention.SOLUTION: In the vibration-proof rubber member, a rubber material 1 and a fitting 2 with a chemical conversion coating 4 formed on its surface are integrally formed via an adhesive agent layer (undercoating adhesive agent layer 3a and a topcoating adhesive agent layer 3b) formed on the chemical conversion coating 4, wherein the chemical conversion coating 4 on the surface of the fitting 2 is subjected to sealing processing by electroless nickel plating 5, and the upper part of the chemical conversion coating 4 is not plated and is stuck to the adhesive agent layer.

Description

  The present invention relates to an anti-vibration rubber member that can be widely used for an automotive bush, an engine mount, an industrial machine, and the like.

  In general, a vibration isolating rubber member used for an automobile bush, an engine mount, an industrial machine anti-vibration member, etc. is a rubber member with a metal fitting formed by integrating a metal fitting and a rubber material. It is used as a connecting member for various components such as engines.

  In the anti-vibration rubber member, an adhesive is usually used in order to bond the interface between the metal fitting and the rubber material. Generally, “adhesive one-part coating method” using one adhesive, and “priming two-part coating” where a base coat adhesive is applied as a primer to the surface of the metal fitting and then a top coat adhesive is further applied. However, the two-component coating method is widely used for bonding between general-purpose rubber and metal fittings (see, for example, Patent Documents 1 and 2).

  In addition, before applying an adhesive to the metal fitting, in order to improve adhesion, blasting is performed on the metal fitting surface (adhesion surface), or a chemical conversion film made of zinc phosphate or the like is formed. (For example, see Patent Document 3).

JP-A-7-301278 JP 2001-170944 A JP 2007-118292 A

  For example, FIG. 2 shows an adhesion state between the metal fitting and the rubber material. In the figure, 1 is a rubber material, 2 is a metal fitting, 3a is an undercoat adhesive layer, 3b is an overcoat adhesive layer, and 4 is a chemical conversion film. The chemical conversion film 4 formed on the metal fitting 2 is a crystalline film. When enlarged, the chemical conversion film 4 has a gap (hole) α between the crystals as shown in FIG. Is exposed. In the place not covered with the rubber material 1 (the rubber material non-adhered portion), the exposed metal fitting surface 2 ′ is in contact with the outside air, so that moisture adheres in some cases. When moisture adheres in this way, corrosion of the metal proceeds and rust is generated. Further, due to the capillary phenomenon caused by the blasted surface applied to the surface of the metal fitting 2 and the gap α between the chemical conversion coatings 4 crystals, the metal fitting 2 and the rubber material 1 are separated from the end of the rubber material bonding portion shown in the figure. The water may enter slightly toward the surface. Therefore, also in the rubber material bonding part, when the infiltrated moisture comes into contact with the metal fitting surface 2 ″ exposed from the gap of the chemical conversion film 4, rust may be generated from the starting point. In the rubber material bonding part, The adhesive applied on the chemical conversion film 4 (adhesive constituting the undercoat adhesive layer 3a and the topcoat adhesive layer 3b) can completely block the gaps of the chemical conversion film 4 due to the viscosity of the adhesive. Since it is not possible, it is difficult to eliminate the rust at the rubber material bonding portion as described above.

  In conventional car durability, even if rust is generated on the anti-vibration rubber member as described above, there has been no particular problem. However, now that the durability of the car has increased, and there is a need to cope with various environments by globalization due to globalization, the occurrence of such rust cannot be ignored. For example, in an environment where there is concern about corrosion due to acid rain, snowmelt salt, salt water, etc., corrosion / deterioration is likely to proceed, resulting in peeling of the metal fitting 2 and the rubber material 1 and application to a mating member (bolt, etc.). There is a risk of inducing rust and destruction of members.

  As a method for solving such a problem of corrosion resistance, conventionally, after attaching the metal fitting 2 and the rubber material 1 as shown in FIG. A rust preventive paint is applied to the portion (exposed surface of the metal fitting 2). The masking is performed in order to prevent the paint adhering to the rubber material 1 from peeling off and contaminating the automobile body.

  However, if the anticorrosive coating is applied while masking as described above, the manufacturing process becomes complicated, and further, a drying process is required after the application, and thus the manufacturing time is also increased. Even if the anticorrosive paint is applied in this way, it is difficult to completely prevent the intrusion of moisture due to the capillary action as described above at the rubber material bonding portion.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a vibration-proof rubber member that is excellent in adhesion at the interface between the metal fitting and the rubber material and also excellent in rust prevention.

  In order to achieve the above object, the vibration-insulating rubber member of the present invention comprises a rubber material and a metal fitting having a chemical conversion film formed on the surface thereof, with an adhesive layer formed on the chemical conversion film being integrated. An anti-vibration rubber member formed on the metal film, wherein the chemical conversion film on the surface of the metal fitting is sealed by electroless nickel plating, and the upper part of the chemical conversion film adheres to the adhesive layer without being plated. It takes the composition that it is.

  That is, the present inventors have intensively studied to solve the above problems. In the course of the research, after attaching the metal fitting 2 and the rubber material 1 as in the past, the anti-corrosion paint is not applied to the rubber material non-adhered portion of the metal fitting 2 to obtain the anti-corrosion effect. Before the metal fitting 2 is plated so as to fill the gaps (holes) between the crystals of the chemical conversion film 4 formed on the metal fitting 2 (sealing treatment), the metal fitting 2 is allowed to exhibit a rust prevention effect. I recalled. This sealing treatment needs to be performed with a highly corrosion-resistant material, and the sealing treatment described above is performed so that the adhesion of the chemical conversion film 4 (adhesion between the chemical conversion film 4 and the adhesive layer) is not impaired. Therefore, it is required that the chemical conversion film 4 is not completely covered (the upper portion (convex portion) of the chemical conversion film 4 is not plated). From such a viewpoint, the present inventors repeated various experiments. As a result, when electroless nickel plating is applied to the metal fitting 2 on which the chemical conversion film 4 is formed, only the metal surface, that is, as shown in FIG. It was found that nickel plating having high corrosion resistance (electroless nickel plating 5) can be deposited only on the metal surface 2 'of the metal fitting 2 exposed from the gap (hole) evenly (with no difference in adhesion amount). Furthermore, by controlling the treatment time and treatment temperature of the electroless nickel plating, the upper portion of the chemical conversion film 4 can be satisfactorily performed without being plated, and excessive sealing can be prevented. I found out. Thus, the present inventors have found that the intended purpose can be achieved, and have reached the present invention.

  As described above, the nickel plating is selectively deposited only on the metal surface (including the metal surface of the metal fitting 2 exposed from the gap of the chemical conversion film 4) for the following reason. That is, for example, when the hypophosphite anion in the electroless nickel plating solution comes into contact with the metal surface, the metal surface acts as a catalyst to cause dehydrogenolysis, and the hydrogen atoms generated thereby are It is adsorbed on the surface and activated. When the nickel cation in the electroless nickel plating solution comes into contact with this metal surface, nickel is deposited on the metal surface by a reduction reaction. The activated hydrogen atoms on the metal surface react with a hypophosphite anion in the electroless nickel plating solution to reduce the phosphorus contained therein to form an alloy with nickel. This is the reason why nickel plating is not applied to the surface of the chemical conversion film 4 and nickel plating is applied only to the metal surface of the metal fitting 2 exposed from the gap, which is a characteristic part of the present invention. For this reason, even if the water from the outside permeates into the portion covered with the rubber material 1 by capillary action, the holes of the chemical conversion film 4 are all filled with nickel plating, so that rust hardly occurs. In addition, in the present invention, nickel plating only fills the pores of the chemical conversion film 4 and does not completely cover the upper part of the chemical conversion film 4, so that the adhesion improving effect of the surface of the chemical conversion film 4 itself is impaired. I can't.

  The anti-vibration rubber member of the present invention is formed by integrally forming a rubber material and a metal fitting having a chemical film formed on the surface via an adhesive layer formed on the chemical film. The chemical conversion film on the surface of the metal fitting is sealed by electroless nickel plating, and the upper part of the chemical conversion film is bonded to the adhesive layer without being plated. Therefore, it is excellent in the adhesiveness in the interface of a metal fitting and a rubber material, and excellent in rust prevention. In particular, the anti-vibration rubber member of the present invention is resistant to rust and has a long service life even in environments where rust is likely to occur due to the effects of acid rain, snowmelt salt, salt water, etc. Suitable for use in harsh environments such as mounting. In addition, the vibration-insulating rubber member of the present invention eliminates the need for manufacturing processes such as masking and coating film drying, compared to conventional anti-vibration rubber members to which a rust-proof coating is applied. Can be manufactured in a short time.

  In particular, when the chemical conversion film is made of zinc phosphate, more excellent adhesion and rust prevention can be obtained.

  In addition, when the adhesive layer formed on the chemical conversion film is composed of two layers of an undercoat adhesive layer and an overcoat adhesive layer formed on and in contact with the undercoat adhesive layer, better adhesion can be obtained. Can do.

  In addition, the vibration-proof rubber member of the present invention is a liquid-sealed type (a sealed space in which a part of a rubber material is formed on a chamber wall that deforms in response to vibration input and is composed of the chamber wall and a part of a metal fitting If the liquid is encapsulated, the rust and adhesiveness degradation caused by the intrusion of the liquid between the metal fitting and the rubber material, as seen in conventional liquid encapsulated types, can be eliminated. Therefore, superior durability performance can be exhibited as compared with a conventional liquid-filled vibration-proof rubber member.

It is an expanded sectional view which shows the principal part (adhesion interface of a metal fitting and a rubber material) of the vibration isolator rubber member of this invention. It is an expanded sectional view which shows the principal part (adhesion interface of a metal fitting and a rubber material) of the conventional vibration-proof rubber member. It is sectional drawing which shows the cylindrical bush which is one Embodiment of the vibration isolator rubber member of this invention. It is a scanning electron microscope (SEM) photograph which shows a state when electroless nickel plating is given to the chemical conversion film (zinc phosphate film) on the metal fitting surface for a predetermined time. It is sectional drawing which shows the liquid enclosure vibration proof mount which is other embodiment of the vibration proof rubber member of this invention. It is a front view which shows the test sample used for the adhesive test.

  Next, an embodiment of the present invention will be described.

  FIG. 3 shows an embodiment of the anti-vibration rubber member of the present invention. In this embodiment, a cylindrical bush for an automobile will be described as an example of the vibration-proof rubber member of the present invention. The cylindrical bush has a cylindrical inner cylinder fitting (metal fitting) 22a coaxially bonded and integrated to the inner peripheral surface of a cylindrical vibration-proof rubber (rubber material) 21, and the cylindrical anti-vibration rubber. A cylindrical outer tube fitting (metal fitting) 22 b is coaxially bonded and integrated on the outer peripheral surface of the vibration rubber 21.

  And the interface part between the metal fitting and the rubber material, that is, the interface part between the inner cylinder metal fitting 22a and the vibration isolating rubber 21, and the interface part between the outer cylinder metal fitting 22b and the vibration isolating rubber 21 are schematically represented as follows: For example, as shown in FIG. In the figure, 1 is a rubber material, 2 is a metal fitting, 3a is an undercoat adhesive layer, 3b is a topcoat adhesive layer, 4 is a chemical conversion film, and 5 is an electroless nickel plating (nickel plating). As shown in FIG. 1, an anti-vibration rubber member of the present invention comprises an adhesive layer (undercoat adhesion) in which a rubber material 1 and a metal fitting 2 having a chemical conversion film 4 formed on the surface thereof are formed on the chemical conversion film 4. An anti-vibration rubber member formed integrally through the agent layer 3a and the top coat adhesive layer 3b), wherein the chemical conversion film 4 on the surface of the metal fitting 2 is sealed with an electroless nickel plating 5, and The upper part of the chemical conversion film 4 is bonded to the adhesive layer without being plated, and this is the greatest feature.

  As described above, since the upper part of the chemical conversion film 4 needs to be bonded to the adhesive layer without being plated, it is necessary to prevent the chemical conversion film 4 from being completely covered with the electroless nickel plating 5. At this time, the thickness of the electroless nickel plating 5 is preferably in the range of 10 to 200% of the thickness of the chemical conversion film 4 on the surface of the metal fitting 2, and more preferably in the range of 10 to 90% of the thickness of the chemical conversion film 4. That is, if the thickness of the electroless nickel plating 5 exceeds the above range, the adhesion of the chemical conversion film 4 (adhesion between the chemical conversion film 4 and the adhesive layer) is impaired. It is because favorable rust prevention property cannot be obtained as the thickness of 5 is less than the said range.

  The sealing treatment of the chemical conversion film 4 by the electroless nickel plating 5 is performed by, for example, preparing an electroless nickel plating solution and immersing the metal fitting 2 having the chemical conversion film 4 formed on the surface for a predetermined time. Is called. The electroless nickel plating performed in this manner has the property that only the metal surface is plated, and since it is uniform even in a narrow place, the surface of the metal fitting exposed from the gaps (holes) between the crystals of the chemical conversion film 4 Even 2 'is plated uniformly to every corner, and thus the above-described sealing treatment is favorably performed. And the thickness of the electroless nickel plating 5 to be sealed can be set within a predetermined range as described above by controlling the plating processing time, processing temperature, and the like. In the electroless plating, plating is deposited on the metal surface not by electrons caused by energization but by electrons released by oxidation of the reducing agent contained in the plating solution. In the present invention, sodium hypophosphite is preferably used as the reducing agent contained in the plating solution because it easily reacts with an iron group element typified by iron as a catalyst. In order not to adversely affect (dissolve) the chemical conversion film 4, the pH of the plating solution is preferably 8 to 11, but there is no problem even if the pH is about 6 to 11 depending on the processing temperature and time. Furthermore, as a sealing method for obtaining high corrosion resistance, a reduction in the reaction rate is effective for the refinement of crystal grains for dense sealing. By improving the accelerator, stabilizer, pH, surfactant, etc.) and processing conditions (temperature, liquid agitation, ultrasonic introduction, voltage application at the initial stage of processing, etc.), better sealing properties can be obtained, Corrosion resistance is improved.

  And about the electroless nickel plating 5 for the said sealing process, in order to ensure the adhesiveness of the chemical conversion film 4, it does not completely coat | cover the chemical conversion film 4, but only a metal exposed part (metal fitting surface 2 '). It is necessary to deposit the electroless nickel plating 5. From this viewpoint, the immersion treatment time in the plating solution is preferably 2 to 4 minutes. Thus, since the antirust treatment is performed in a short time, the vibration-insulating rubber member of the present invention is excellent in productivity. In addition, since the metal fitting 2 is rust-prevented before the rubber material 1 is bonded, even if moisture enters between the metal fitting 2 and the rubber material 1 due to capillary action after the bonding, the metal fitting 2 Corrosion can be prevented. For this reason, induction of rust and peeling of the metal fitting 2 and the rubber material 1 due to the induction of rust are eliminated.

  Here, FIG. 4 is a scanning electron microscope (SEM) photograph (reflected electron image) showing a state when electroless nickel plating is applied to the chemical conversion film (zinc phosphate film) on the surface of the metal fitting for a predetermined time. The photo on the right is 2000 times and the photo on the left is 5000 times. Moreover, the dark gray part of a photograph is a zinc phosphate film | membrane, and a white part is electroless nickel plating. From the photograph, it can be confirmed that the electroless nickel plating is performed over time so as to fill the gaps (holes) in the zinc phosphate coating. In this way, the chemical conversion film (zinc phosphate film) is sealed.

  Examples of the chemical conversion film 4 include a chemical conversion film made of a crystalline material such as zinc phosphate, zinc calcium phosphate, manganese phosphate, and tin phosphate. Especially, what consists of zinc phosphate is preferable in order to obtain the more outstanding adhesiveness and rust prevention property in this invention. In addition, the solution used for forming the chemical conversion film 4 is, for example, an aqueous solution having a pH of 2 to 3 containing zinc zinc phosphate and an oxidizing agent such as nitrite when forming a zinc phosphate film. The concentration of zinc phosphate in this zinc phosphate solution is usually set within a range of 10 to 20% by weight.

  And in the present invention, the thickness of the chemical conversion film 4 is preferably in the range of 1 to 10 μm, more preferably in the range of 1 to 5 μm, from the viewpoint of obtaining better adhesion and rust prevention.

  The chemical conversion film 4 has been subjected to a sealing treatment, and is effective as a measure for preventing corrosion of the metal fitting 2 in addition to improving adhesion. Therefore, in the rubber material non-bonding portion in FIG. 1, it is not necessary to apply a rust preventive paint as in the prior art, but a rust preventive paint may be further applied as necessary. Since the chemical conversion film 4 is not completely covered by plating, it can exhibit excellent adhesiveness (adhesion) even for the anticorrosive paint.

  Next, materials for forming the vibration-proof rubber member of the present invention other than the chemical conversion film 4 and the electroless nickel plating 5 will be described in detail with reference to FIG.

  Examples of a material for forming the rubber material 1 shown in FIG. 1 include natural rubber (NR), butadiene rubber (BR), styrene butadiene rubber (SBR), isoprene rubber (IR), acrylonitrile butadiene rubber (NBR), and carboxyl-modified NBR. , Chloroprene rubber (CR), ethylene propylene rubber (EPM, EPDM), maleic acid modified EPM, butyl rubber (IIR), halogenated IIR, chlorosulfonated polyethylene (CSM), fluoro rubber (FKM), acrylic rubber, epichlorohydride Rubber and the like. These may be used alone or in combination of two or more. Of these, natural rubber is preferred from the viewpoint of good vibration resistance. Depending on the required performance, reinforcing agents such as carbon black, vulcanizing agents, vulcanization accelerators, lubricants, auxiliaries, plasticizers, anti-aging agents and the like are appropriately added to the above materials.

  Further, the metal fitting 2 shown in FIG. 1 may be made of metal, and is formed of a conventionally known metal such as iron, copper, aluminum, magnesium, lead, tin, alloys thereof, stainless steel, or the like. Things are used. Note that the inner cylinder fitting 22a and the outer cylinder fitting 22b shown in FIG. 3 may be made of the same type of metal or different types of metal.

  Further, the adhesive layer formed on the chemical conversion film 4 may be either a one-component type or a two-component type. However, as shown in FIG. 1, the undercoat adhesive layer 3a and the undercoat adhesive layer 3a When it consists of two layers of the top coat adhesive layer 3b formed in contact (two-component type), more excellent adhesiveness can be obtained.

  As the material for the adhesive layer, an adhesive containing a halogenated elastomer, a phenol resin, an epoxy resin or the like as a polymer component is particularly useful. Examples of halogenated elastomers include chlorinated rubber, chlorosulfonated polyethylene, brominated chlorinated polybutadiene, and the like. As a phenol resin, a novolak type, a resol type, and various modified phenol resins are included. The polymer component is usually 10 to 70% by weight of the basic component in the adhesive. If it is less than 10% by weight, a sufficient adhesive effect cannot be obtained. Even if it is used in excess of 70% by weight, sufficient action due to cooperation with other components cannot be obtained. Here, the basic component means the entire solid content excluding the solvent component. As the solvent component, water, xylene, ethylbenzene, methyl isobutyl ketone and the like are used.

  The adhesive may contain various subcomponents, fillers, thickeners, crosslinking agents, and other additives / subcomponents. Examples of the filler include calcium carbonate, dikelite, silica, kaolin clay, barium sulfate and the like. Examples of the thickener include polyacrylic acid, silica, bentonite and the like. Examples of the crosslinking agent include polyvalent metal salts, polyisocyanate compounds, polyepoxy compounds, polyamide compounds, nitroso compounds and the like. Examples of subcomponents include metal oxides such as titanium oxide, lead oxide, and zinc oxide, carbon black, polyimide compounds, and isocyanates.

  When the adhesive layer is composed of two layers of an undercoat adhesive layer 3a and an overcoat adhesive layer 3b as shown in FIG. 1, when using a commercial product for the adhesive, the undercoat adhesive is used. For the layer 3a, for example, commercially available products such as Chemlock 205, XPJ-113, XPJ-77, XPJ-106 manufactured by Lord Far East Co., Ltd. can be used. For the topcoat adhesive layer 3b, for example, commercially available products such as Chemlock 6125, XJ-370, XJ-371, XJ-380, and XJ-381 manufactured by Road Far East can be used.

  Here, as described above, the cylindrical bush shown in FIG. 3 shows an embodiment of the vibration-insulating rubber member of the present invention. The cylindrical bush shown in FIG. It has an adhesive structure. The cylindrical bush as described above can be manufactured as follows, for example. In addition, the manufacturing method of the vibration-proof rubber member of this invention is not specifically limited to the procedure as shown below.

That is, first, the inner cylinder fitting 22a and the outer cylinder fitting 22b are prepared, and a roughening process is appropriately performed on the outer circumferential surface of the inner cylinder fitting 22a and the inner circumferential surface of the outer cylinder fitting 22b. Specifically, after masking the inner peripheral surface and both end opening surfaces of the inner cylindrical fitting 22a and the outer peripheral surface and both end opening surfaces of the outer cylindrical fitting 22b, the outer peripheral surface of the inner cylindrical fitting 22a and the inner peripheral surface of the outer cylindrical fitting 22b. Is roughened by sandblasting or the like using an abrasive having a grain size of # 20 to # 70 [ten-point average roughness (Rz) of about 10 to 30 μm. Measured with Surfcom 1400D manufactured by Tokyo Seimitsu Co., Ltd.]. Next, the chemical conversion film 4 (film weight of about 1.5 to 4.0 g / m ² ) is formed on the rough surface portion using a zinc phosphate solution or the like. Thereafter, as described above, the inner cylinder fitting 22a and the outer cylinder fitting 22b on which the chemical conversion film 4 is formed are immersed in an electroless nickel plating solution for a predetermined time to perform an electroless nickel plating treatment. Then, an undercoat adhesive is applied to the outer periphery of the inner cylinder fitting 22a and the inner circumference of the outer cylinder fitting 22b by spraying or the like, and then naturally dried [25 ° C. (room temperature) × about 60 minutes] An adhesive layer 3a (thickness of about 5 to 20 μm) is formed. Subsequently, an overcoat adhesive is applied to the surface of the undercoat adhesive layer 3a by spraying or the like, and then naturally dried [25 ° C. (room temperature) × about 60 minutes] to form an overcoat adhesive layer 3b (thickness of 5 to 20 μm). Degree). And after removing the said masking from these inner cylinder metal fittings 2 and outer cylinder metal fittings 3, these inner cylinder metal fittings 22a and outer cylinder metal fittings 22b are coaxially arranged in a mold for molding, The molding space surrounded by the outer cylinder fitting 22b and the mold is filled with unvulcanized rubber for forming the antivibration rubber 21, and then vulcanized (about 140 to 200 ° C. × 5 to 60 minutes). In this way, the cylindrical bush can be produced.

  The anti-vibration rubber member of the present invention is used other than the above-described cylindrical bush, other than the cylindrical shape, which is used for automobiles and transportation equipment (industrial transportation vehicles such as airplanes, forklifts, excavators, cranes, railway vehicles, etc.). It is suitably used as a vibration isolating member used for various machines such as bushes, engine mounts, motor mounts, and industrial machines. That is, the shape of the metal fitting is not limited to a cylindrical shape, and there are various shapes such as a flat plate shape and a wave shape. In these shapes, a sandwich shape in which a rubber material is sandwiched between upper and lower metal fittings is commonly used, but metal fittings may be provided only on either the upper or lower metal.

  Further, the vibration isolating rubber member of the present invention is a liquid encapsulating type anti-vibration mount or the like (a part of the rubber material is formed on a chamber wall that deforms in response to vibration input, The liquid may be enclosed in a sealed space composed of a portion). That is, the rubber material portion is formed on a chamber wall that deforms in response to vibration input, and has a structure in which liquid is sealed in a sealed space composed of the chamber wall and a part of the metal fitting. It is. In such a liquid-encapsulated type, in the conventional product, due to the structure, the encapsulated liquid easily permeates the adhesive interface between the rubber material and the metal fitting, and rust and adhesive strength are easily reduced. However, since the anti-vibration rubber member of the present invention has an adhesive structure between the rubber material and the metal fitting as shown in FIG. 1, it is possible to eliminate such rust and adhesive force reduction. Therefore, the anti-vibration rubber member of the present invention, which is a liquid-filled type, can exhibit superior durability performance compared to a conventional liquid-filled-type anti-vibration rubber member.

  Here, FIG. 5 is an example in which the present invention is applied to a liquid-filled vibration-proof mount. In the figure, reference numeral 31 denotes a thick cylindrical vibration-proof rubber body (rubber material) in which a main liquid chamber A is formed. A thick metal connecting member (metal fitting) 32 is inserted into the upper opening of the rubber body 31 so as to close it, and the upper end of the rubber body 31 and the outer peripheral surface of the connecting member 32 are connected to each other. These are joined by an adhesive structure of a rubber material and a metal fitting as shown in FIG. Bolts 32a project from the upper surface of the connecting member 32, and are connected to the engine, which is a vibrating body. Further, the outer periphery of the rubber body 31 is also bonded to a cylindrical metal side plate 35 forming a part of a metal connecting member by an adhesive structure of a rubber material and a metal fitting as shown in FIG. . A thin rubber film 33 is disposed below the rubber body 31, and the upper part thereof is a sub liquid chamber B. The sub liquid chamber B and the main liquid chamber A are partitioned by a partition plate 34. . The outer peripheries of the partition plate 34, the rubber film 33, and the metal support plate 36 therebelow are clamped in a lower end portion of the side plate 35 bent in a U shape, and are fixed by caulking them. The side plate 35 and the support plate 36 connected to the side plate 35 constitute a metal connecting member, and are connected to the vehicle body as a base body by a bolt 36a projecting from the lower end of the support plate 36. Filled liquid is sealed in the main liquid chamber A and the sub liquid chamber B. In addition, ethylene glycol, diethylene glycol, water, etc. are used for the said sealing liquid. Further, a liquid channel 41 is formed in the outer peripheral portion of the partition plate 34, and the liquid channel 41 communicates with the main liquid chamber A and the sub liquid chamber B through communication holes 411 and 412. When the rubber body 31 is deformed due to vibration input, the sealed liquid flows through the liquid chambers A and B via the liquid flow path 41, and performs vibration damping.

  Next, examples will be described together with comparative examples. However, the present invention is not limited to these examples.

[Example 1]
[Zinc phosphate coating treatment]
A 25 mm × 60 mm steel plate (thickness: 2 mm) was shot blasted and roughened, and then Chemibonder 5020 (manufactured by Nippon CB Chemical Co., Ltd.) was used in an amount of 60 g / liter. Immersion in a zinc phosphate solution (45 ° C.) mixed with 1.1 g / liter of 1.1 g / liter as a promoter and Axelene 101 (manufactured by Nippon CB Chemical Co., Ltd.) as an accelerator (4 minutes) A zinc phosphate coating (thickness 3 μm) was formed.

[Electroless nickel plating]
The iron plate coated with the zinc phosphate film is placed in a 90 ° C. electroless plating bath [electroless nickel plating solution containing Top Nicolo LPH-SLF (Okuno Pharmaceutical Co., Ltd.) at a rate of 250 ml / liter]. Soaked for 4 minutes. In this way, the zinc phosphate coating was sealed by electroless nickel plating to produce a sample for corrosion resistance evaluation. It was confirmed that the sealing treatment by electroless nickel plating was performed with a thickness (thickness of 1.5 μm) less than the thickness of the zinc phosphate coating. The thickness was measured by cutting the test sample, measuring the cut surface with an electron microscope at 10 arbitrary locations, and taking the average value.

[Preparation of samples for adhesion test]
Prepare two Φ40.5mm steel discs with bolts erected at the center of one side and roughen the surface where the bolts are not erected by shot blasting. ] And [electroless nickel plating treatment] were performed in this order. Applying Chemlock 205 (made by Road Far East) as an undercoat adhesive to the surfaces of the two steel discs obtained in this way, where the bolts are not erected, respectively, and drying and undercoat adhesion An agent layer (thickness 10 μm) was formed. Subsequently, Chemlock 6125 (manufactured by Road Far East Co., Ltd.) was applied as a topcoat adhesive to the surface of the undercoat adhesive layer and dried to form a topcoat adhesive layer (thickness 10 μm). Then, the two iron discs are arranged in the molding die, and further, unvulcanized rubber is filled between the two iron discs, followed by vulcanization (150 ° C. × 20 minutes). The sample for an adhesive test (sample of a vibration-proof rubber member) as shown in FIG. In the figure, 12 is an iron disk, 13 is a bolt erected on the iron disk, and 11 is a rubber material (thickness 15 mm) formed by vulcanization of the unvulcanized rubber. The unvulcanized rubber includes 100 parts by weight of natural rubber, 30 parts by weight of carbon black, 2.5 parts by weight of vulcanizing agent (sulfur), and a vulcanization accelerator (Noxeller CZ, Ouchi Shinsei Chemical Co., Ltd.). 1 part by weight, 5 parts by weight of zinc oxide, 1 part by weight of stearic acid, 4.5 parts by weight of anti-aging agent, and 5 parts by weight of naphthenic mineral oil can be kneaded with a kneader such as a kneader. Used. Further, the thickness of the adhesive layer was obtained by cutting a test sample, measuring the cut surface with an electron microscope at 10 arbitrary positions, and taking the average value.

[Comparative Example 1]
Samples (corrosion resistance evaluation sample and adhesion test sample) were prepared in the same manner as in Example 1 except that the electroless nickel plating treatment was not performed.

[Comparative Example 2]
Samples (corrosion resistance evaluation sample and adhesion test sample) were prepared in the same manner as in Example 1 except that the electroless nickel plating treatment was performed for 20 minutes. In addition, the sealing treatment by the electroless nickel plating was performed with a thickness exceeding the thickness of the zinc phosphate coating (thickness 7 μm), and it was confirmed that the zinc phosphate coating was completely covered by plating. The thickness was measured by cutting the test sample, measuring the cut surface with an electron microscope at 10 arbitrary locations, and taking the average value.

  With respect to the samples of Examples and Comparative Examples thus obtained, each characteristic was evaluated according to the following criteria. The results are also shown in Table 1 below.

[Corrosion depth after spraying with salt water]
The sample for corrosion resistance evaluation is subjected to a salt spray test (35 ° C, 5% aqueous sodium chloride solution continuously sprayed at 98 ± 10 kPa pressure) in accordance with JIS Z 2371. Maximum corrosion due to corrosion after 480 hours The amount of thinning (mm) was measured. The thinning due to corrosion is due to dissolution of iron. Further, iron is dissolved (ionized) by corrosion, and the one combined with oxygen becomes rust (red rust and the like). Therefore, if the amount of thinning is large, the amount of rust generated increases.

(Initial adhesion)
A tensile test was performed on the adhesion test sample by pulling the bolt 13 in the X direction of FIG. The tensile test was performed by pulling at a speed of 100 mm / min using a strograph (manufactured by Toyo Seiki Co., Ltd.), and then measuring the peeling interface. In addition, what did not produce interface peeling and the material failure of the rubber material was confirmed in the whole surface of the peeling interface was evaluated as "100%".

[Rubber peeling rate after spraying with salt water]
The same test as the salt spray test was performed on the adhesion test sample in a state where the bolt 13 was pulled in the X direction of FIG. 6 and the rubber material was stretched 25%. Then, it was further left for 1000 hours in the stretched state. And the rubber peeling rate (%) at this time was measured.

  As is apparent from the results in Table 1 above, in Example 1, the zinc phosphate coating was subjected to a sealing treatment by electroless nickel plating, thereby suppressing the progression of iron corrosion (thinning) due to salt water. Since it is recognized, the sealing treatment applied to the zinc phosphate coating of Example 1 is performed with a thickness less than the thickness of the zinc phosphate coating, leaving the top surface of the convex portion of the zinc phosphate coating. It can be seen that the initial adhesiveness and the long-term adhesiveness after spraying with salt water are stable.

  On the other hand, in Comparative Example 1, since the zinc phosphate coating was not sealed as in the example, the progress of corrosion was noticeable. In Comparative Example 2, the progress of corrosion was suppressed by the sealing treatment by electroless nickel plating, but the sealing treatment was performed at a thickness exceeding the thickness of the zinc phosphate coating, and the zinc phosphate coating was completely covered by plating. As a result, the rubber peeling rate after spraying with salt water was high, resulting in poor adhesion.

DESCRIPTION OF SYMBOLS 1 Rubber material 2 Metal fitting 3a Undercoat adhesive layer 3b Topcoat adhesive layer 4 Chemical conversion film 5 Electroless nickel plating

Claims (4)

  An anti-vibration rubber member in which a rubber material and a metal fitting having a chemical conversion film formed on a surface thereof are integrally formed via an adhesive layer formed on the chemical conversion film, and the chemical conversion of the metal fitting surface is formed. A vibration-insulating rubber member, wherein the film is sealed by electroless nickel plating, and the upper part of the chemical conversion film is adhered to the adhesive layer without being plated.   The vibration-insulating rubber member according to claim 1, wherein the chemical conversion film is made of zinc phosphate.   The vibration-insulating rubber member according to claim 1 or 2, wherein the adhesive layer formed on the chemical conversion film comprises two layers of an undercoat adhesive layer and an overcoat adhesive layer formed in contact with the undercoat adhesive layer. .   A part of the rubber material is formed on a chamber wall that deforms in response to vibration input, and a liquid is sealed in a sealed space constituted by the chamber wall and a part of the metal fitting. The anti-vibration rubber member according to any one of 3.