JPH04312847A - Painted anti-vibration rubber parts - Google Patents

Abstract

PURPOSE:To prevent a coat sticking to the surface of a rubber elastic product as an anti-vibration rubber member from coming off to adhere to a product around the elastic product or viscously settle on the product, and further prevent a product around the elastic product from becoming contaminated and subsequently discolored by an aging inhibitor migrated from the coat. CONSTITUTION:An anti-vibration rubber member obtained by vulcanizing a rubber elastic product to adhere to a metal part in one piece is finish-coated using an epoxy resin paint with a film hardness of H or higher in terms of pencil hardness and Tg of 30 deg.C or higher to obtain a required coated anti- vibration rubber member.

Description

[Detailed description of the invention]

0001

[Technical Field] The present invention provides a method in which a rubber elastic body is vulcanized and bonded to a predetermined metal fitting, and then a finish coating is applied to the metal fitting part.
This invention relates to a painted anti-vibration rubber member.

0002

[Background Art] Conventionally, various anti-vibration rubber members for vehicles such as engine mounts, body mounts, suspension bushes, etc. have been produced by integrally bonding metal fittings and rubber elastic bodies using an alkyd This is done by applying a finishing coat to the metal fittings using a resin paint such as lacquer-based paint or lacquer-based paint. These alkyd-based and lacquer-based paints are advantageously used because they dry well and dry even at room temperature. However, with such a finishing coat, it is inevitable that the paint will adhere to unnecessary rubber surfaces, so whenever the rubber is bent, the paint film attached to the rubber surface will crack and peel. I have a falling problem.

For this reason, in the manufacture of automobiles, etc., after such painted anti-vibration rubber members are assembled into vehicles, when the vehicles are stacked in two tiers and transported by carrier cars, etc., the rubber surface may be damaged due to vibration. The paint film adhering to the vehicle may peel off, allowing paint to adhere to the lower vehicle body surface. When this adhered coating film receives heat and becomes sticky,
It became difficult to remove, making the removal work troublesome.

[0004] Furthermore, the paint film adhering to the body contaminates the painted surface of the body, causing the body color to turn yellow. This is because the anti-aging agent blended into the rubber composition that provides the rubber elastic body of the anti-vibration rubber member blooms on the rubber surface and transfers to the coating film on the rubber surface.
This is then caused by further migration of the contaminating anti-aging agent from the paint film to the painted surface of the body when the paint film cracks and peels off and adheres to the body.

By the way, one possible means of preventing these problems is not to use an anti-aging agent when forming the rubber elastic body of the vibration-proof rubber member, but in this case, the problem of yellowing may occur. Even if this can be prevented, the problem of paint film sticking remains. It is also possible to use urethane-based resin paint for painting.In that case, the paint film will not easily peel off, reducing stickiness and yellowing, but if the paint film peels off, it will damage the body. It sticks and causes yellowing. In addition, urethane resin paints also have the problem of high cost.

[0006]

[Problem to be solved] Against this background, the present invention solves the following problems:
The problem to be solved is as follows.
To prevent a paint film peeled off from a painted anti-vibration rubber member from adhering to and sticking to other products in the vicinity or contaminating the painted surface and causing yellowing.

[0007]

[Solution] In order to solve the above problems, the inventors of the present invention have conducted intensive research and found that when using epoxy resin paint, the anti-pollution agent does not transfer to the painted surface of the car body, etc. He found out. The present invention has been completed based on this knowledge, and provides a vibration-proof rubber member in which a rubber elastic body is integrally provided on a predetermined metal fitting, and has a coating film hardness of H or more in pencil hardness, and Tg
A painted anti-vibration rubber member characterized by being finished with an epoxy resin paint whose temperature is 30°C or higher,
This is the summary.

[0008]

[Specific Structure] In short, the painted anti-vibration rubber member according to the present invention uses an epoxy resin paint in which an epoxy resin is used as a film-forming polymer component for the final coating. As mentioned above, even if this epoxy resin paint adheres to a painted panel such as a car body, the anti-aging agent will not transfer to the painted panel, so it will not contaminate the painted panel and cause yellowing. It is possible to prevent this. The reason for this is not yet clear, but it is presumed that the amine, which is a contaminating anti-aging agent, is trapped within the epoxy.

Therefore, in the present invention, not all epoxy resin paints can be used, but in particular, paints with a pencil hardness of H or higher (see JIS-K-5400 "General Test Methods for Paints") and has a Tg (glass transition point) of 30
An epoxy resin paint with a temperature above ℃ is used. This effectively prevents the paint film that has peeled off from the painted anti-vibration rubber member from adhering to painted panels such as car bodies, and even if it adheres and heat is applied,
It is difficult to soften and prevents sticking.

[0010] That is, the coating hardness of such an epoxy resin paint is related to the adhesion to a painted panel such as a car body, and if this hardness is low, the contact area becomes large and the possibility of sticking increases. Therefore, in the present invention,
Defined as H or higher in terms of pencil hardness. Preferably it is 2H or more. Further, Tg is related to the softening of the coating film, and if Tg is high, softening does not occur and stickiness is reduced. In the present invention, by specifying the temperature to be 30° C. or higher, it is effectively prevented from softening even at high temperatures comparable to the bonnet temperature in summer, and is effectively prevented from sticking to painted panels such as car bodies. Note that preferably Tg
is considered to be 40°C or higher.

[0011] The epoxy resin paint is applied to the vibration-proof rubber member, in which the metal fittings and the vibration-proof rubber are integrally vulcanized and bonded, according to various known coating methods such as spraying or dipping. After that, generally,
It is heated to 80-120°C and dried.

0012

[Examples] Below, typical examples of the present invention will be shown to clarify the present invention more specifically. However, the present invention is not limited in any way by the description of such examples. Needless to say, it is not something that can be accepted. Furthermore, in addition to the following examples, various changes, modifications, improvements, etc. can be made to the present invention based on the knowledge of those skilled in the art, as long as they do not depart from the spirit of the present invention. should be understood.

First, a vulcanized rubber sheet is coated with an epoxy resin paint (film hardness: 2H, Tg: 60°C), a lacquer resin paint, an alkyd resin paint (Tg: 20°C), and a urethane resin paint. was applied and dried. Then, after 3 days, each coating was peeled off and placed on a white panel for car bodies. Thereafter, the panel was heated under various conditions as shown in Table 1 below, and the ease with which the coating film was peeled off from the panel after the heating operation was completed was evaluated. The results are also shown in Table 1. In addition, those that were easy to remove were indicated as ○, those that were somewhat difficult to remove were indicated as △, and those that were stuck and difficult to remove were indicated as ×.

After removing the paint film, the degree of discoloration of that part of the white panel was measured using a color difference meter, and Δ
E(a) was calculated. Furthermore, after exposing the panel for 4 hours using a sunshine carbon weather meter (water was sprayed for 12 minutes per hour), the degree of discoloration was measured again to determine ΔE(b). These results are also shown in Table 1.

[0015]

[Table 1]

As is clear from the results in Table 1, under any heating conditions, the epoxy resin paint did not stick to the panel and could be removed extremely easily. Furthermore, the degree of discoloration was extremely low, showing excellent results. On the other hand, lacquer-based resin paints and alkyd-based resin paints tend to stick after heating, making it difficult to remove them from the panel. In particular, when lacquer-based resin paints were heated to high temperatures, they caused severe sticking. and,
With lacquer-based resin paints and alkyd-based resin paints, the degree of discoloration was extremely high, and yellowing was clearly observed. Furthermore, in the case of urethane-based resin paints, sticking occurred when heated at high temperatures. Moreover, the degree of discoloration was also quite high.

[0017]

[Effects of the Invention] As is clear from the above explanation, since the painted anti-vibration rubber member according to the present invention is coated with a specific epoxy resin paint, it will not peel off from the painted anti-vibration rubber member. The fallen paint film is effectively prevented from adhering to other products in the vicinity or from sticking under heating. In addition, the anti-aging agent that has bloomed from the rubber elastic body of the anti-vibration rubber member can be effectively prevented from transferring from the peeled off coating to other products, thereby preventing discoloration of surrounding products. This can also be effectively prevented.

Claims (1)

[Claims] Claim 1: A vibration-proof rubber member that is formed by integrally providing a rubber elastic body with a predetermined metal fitting, and has a coating film hardness of H in pencil hardness.
A painted anti-vibration rubber member characterized in that it is finished with an epoxy resin paint having a Tg of 30° C. or higher.