JPH06210791A - Resin composite oscillation-damping aluminum sheet with excellent press-formability - Google Patents

Abstract

PURPOSE:To provide a resin compound oscillation-damping aluminum sheet consisting of a skin aluminum sheet and a resin sandwiched between the former and a modulus of resin elasticity limited to a specific range for the deep drawing of an aluminum sheet which is conventionally difficult. CONSTITUTION:The skin aluminum sheet as a skin restricting sheet of a resin compound oscillation-damping aluminum sheet is 0.3mm to 3.0mm thick; the intermediate resin layer is 0.01 to 0.2mm thick. In addition, the modulus of resin elasticity is 3.5X10<6> to 3.5X10<8>dyne/cm<2> at press-molding temperature. Thus this oscillation-damping aluminum sheet has superb press-formability, so that it displays more outstanding press-formability in the form of oscillation- damping sheet compared to an aluminum sheet itself.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration-damping aluminum plate having excellent press formability (the aluminum plate referred to in the present application includes an aluminum alloy plate; hereinafter referred to as an aluminum plate).
It is about. The present invention is a damping aluminum plate,
Materials suitable for use in automobile panels, home appliances, building materials, and other mechanical parts, to minimize the increase in weight, reduce vibration, and suppress noise. Is.

[0002]

2. Description of the Related Art In recent years, there is a strong demand for reduction and suppression of vibration and noise levels as automobiles, home appliances, information communication devices, etc. become more sophisticated and more sophisticated. In addition, noise and vibration tend to be regulated for the purpose of improving indoor and outdoor environments.

In response to such a tendency, a metal material serving as a noise source or a vibration source absorbs vibration damping performance of a member itself which generates noise, that is, converts it into heat energy,
It is required to add a function of reducing the acoustic radiation by attenuating the vibration speed or the vibration amplitude and further improving the function. On the other hand, the movement toward reduction of exhaust gas due to weight reduction of automobiles and miniaturization of home electric appliances and the like tends to increase more and more, and it is also demanded to reduce the weight of material itself. Therefore, there is a demand for providing a material that satisfies both of these requirements and that has excellent vibration damping performance and enables the weight reduction of the product.

In response to such a demand, a composite type vibration damping material having a multilayer structure in which an intermediate layer having viscoelasticity is sandwiched between metal layers has been proposed as a material having excellent vibration damping property. And, this composite type vibration damping material has been studied in members and structural members for which vibrations such as automobile oil pans, engine covers, home appliances, and other mechanical parts should be reduced,
Has been adopted.

Generally, the damping performance of such a composite damping material depends on the performance of the viscoelastic intermediate layer constituting the intermediate layer. When this damping performance is expressed by a loss coefficient, the loss coefficient exhibits a peak characteristic at a certain temperature, and it is most effective to use it near this peak characteristic temperature.
Are known. Therefore, the viscoelastic composition of the intermediate layer is generally selected according to the use environment.

Conventionally, as a viscoelastic composition constituting the viscoelastic intermediate layer of such a composite type vibration damping material, polyester alone (Japanese Patent Laid-Open No. 50-143880) or polyester with a plasticizer added ( Japanese Patent Laid-Open No. 51-937
No. 70) Polyurethane foam alone (Japanese Patent Laid-Open No. 51-
91981) or a simple substance of polyamide (Japanese Patent Laid-Open No. Sho 5).
6-159160), ethylene-vinyl acetate copolymer simple substance (JP-A-57-34949) polyvinyl butyral or a composition of polyvinyl butyral and polyvinyl acetate mixed with a plasticizer and a tackifier (special JP-B-55-27975) Copolymer of isocyanate prepolymer and vinyl monomer (Japanese Patent Publication No. 52-2655)
No. 4), or Japanese Patent Publication No. 39-12451, Japanese Patent Publication No. 45-34703, and Japanese Patent Publication No. 62-74645.
The copolymers and the like disclosed in the publication are known.

On the other hand, regarding the demand for weight reduction of automobiles,
In recent years, application of an aluminum plate to a vehicle body panel has been particularly studied and put to practical use. Therefore, as a lightweight material having vibration damping performance, a resin composite type vibration damping material having an aluminum plate as a skin material is considered promising. However, when an aluminum plate is used as the skin material of the composite type vibration damping material for the purpose of reducing the weight, since the press formability of the aluminum plate is lower than that of the steel plate, the vibration damping produced by the conventional viscoelastic composition described above is used. In the case of an aluminum plate, a reduction in press formability is inevitable compared to the case of a vibration-damping steel plate.

In order to improve the press formability of an aluminum plate, it has been recognized that it is effective to improve the mechanical properties of the aluminum plate such as ductility, r value and n value. However, when an aluminum plate is used as the skin material of the composite type vibration damping material, the elongation is reduced as compared with the case of a single plate, so that the press formability is deteriorated.

[0009]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a damping aluminum plate having a viscoelastic resin composition as an intermediate layer, which can improve press formability without affecting damping properties. Provided is a composite type vibration-damping aluminum plate excellent in press formability using an elastic resin composition.

[0010]

Means for Solving the Problems As a result of intensive investigations by the present inventors, in order to achieve the object of the present invention, the composition of the aluminum plate and the characteristics of the viscoelastic resin composition in the resin composite type vibration damping aluminum plate were investigated. Has reached the present invention.
That is, the gist of the present invention is a resin composite type damping aluminum plate consisting of two aluminum plates and a viscoelastic resin layer in the middle, in which the front and back skin materials are from 0.3 to 3.0 mm thick. The thickness of the intermediate viscoelastic resin layer constrained by the skin aluminum plate is 0.01 to 0.2 mm.
And the elastic modulus of the intermediate viscoelastic resin layer at the press molding temperature is 3.5 × 10 ⁶ to 3.5 × 10 ⁸ dyne.
/ Cm ² is a resin composite type vibration-damping aluminum plate having excellent press formability.

The present invention will be described in detail below. First, the aluminum plate used for the skin, the plate thickness 0.3 ~
Must be in the 3.0 mm range. If the thickness of the skin material is less than 0.3 mm, wrinkles are likely to occur during press molding, which is not preferable. Further, if the thickness of the skin material exceeds 3.0 mm, the rigidity of the aluminum plate becomes too high, and the resin tends to peel off due to residual strain of the skin material during press molding, which is not preferable.

The type of aluminum plate used in the present invention does not matter. The surface of the aluminum plate is
Various surface treatments such as anodic oxidation treatment, chromate treatment, silane coupling agent treatment, and titanate coupling agent treatment may be performed for the purpose of improving the adhesiveness of the resin. The thickness of the intermediate viscoelastic resin used in the present invention is
The range of 0.01 to 0.2 mm is the most preferable. If the thickness of the resin layer deviates from the range of 0.01 to 0.2 mm, the adhesive force will be reduced and peeling may occur during press molding, which is not preferable.

The elastic modulus of the intermediate viscoelastic resin layer during press molding is 3.5 × 10 ^{6 to} 3.5 × 10 ⁸ dyne / cm.
Needs to be in the ² range. When the elastic modulus of the intermediate viscoelastic resin layer is less than 3.5 × 10 ⁶ dyne / cm ² , wrinkles on the flange portion and body portion of the press-formed product increase. The elastic modulus of the intermediate viscoelastic resin layer is 3.5 ×
If it exceeds 10 ⁸ dyne / cm ² , cracks are likely to occur at the punch shoulder of the press-formed product, making it impossible to perform deep drawing.

The intermediate viscoelastic resin layer used in the present invention is preferably amorphous from the viewpoint of improving vibration damping performance. As the resin, for example, amorphous polyester, polyisobutylene, polyurethane, polyurethane urea, polyurea, amorphous polyamide, amorphous polyamideimide,
Examples thereof include polyimide, acrylic resin, epoxy resin, vinyl acetate resin, amorphous polyolefin resin, blends of various resins, and copolymers. The elastic modulus of the resin is 3.5 × 10 ⁶ to 3.5 × 10 ⁸ d
A plasticizer in the resin for the purpose of keeping it within the range of yne / cm ² .
Alternatively, various additives such as an inorganic powder component and a crosslinking agent may be added.

[0015]

The resin composite type vibration-damping aluminum plate of the present invention has not only excellent vibration-damping performance, but also excellent moldability that enables press molding, which has been difficult even with conventional aluminum single plates. I have. The reason why such excellent press moldability is obtained is that the elastic modulus of the resin is made lower than that of a normal resin to cause a shearing direction deviation between the front and back plates, and the stress concentration of the aluminum plate is dispersed and relaxed. This is probably because of this.

If the elastic modulus of the resin is too low, the deviation between the front and back plates becomes too large, and stress is concentrated on one plate due to wrinkles, and it is considered that the resin is broken.

[0017]

EXAMPLES The present invention will be specifically described below with reference to examples. Example 1 The influence of the elastic modulus of the resin on the press moldability was investigated under the following conditions. The test piece was coated with a 1100 series aluminum plate having a thickness of 0.6 mm and a resin solution having a resin solid content of 30 wt% by a bar coater to a thickness of 0.025 mm and dried with hot air at 200 ° C. for 3 minutes. Another aluminum plate coated with the resin and the resin surfaces were bonded together, and hot pressed under the conditions of a pressure of 5 kgf / cm ² and a temperature of 200 ° C.

The prepared damping plate has an outer diameter of 104 mm (drawing ratio 2.08), 105 mm (drawing ratio 2.10), 109 mm
A cylindrical press molding test was performed by punching into a disk shape having a (drawing ratio of 2.18) and 110 mm (drawing ratio of 2.20).
In the press test, the punch diameter is 50 mmφ, the punch shoulder is R4 mm, the die shoulder is R8 mm, and the molding speed is 300 mm / mi.
n, wrinkle pressing pressure was 600 kgf, rust preventive lubricating oil was applied, and the maximum deep drawing forming height was measured. In this test, since a forming height of 40 mm or more results in drawing, it is expressed as “≧ 40” in the table showing the results.

The elastic modulus of resin is room temperature (20 ° C.), 1 Hz
The value obtained by measuring the dynamic elastic modulus in was used. Table 1 shows the press molding test results. As is clear from the table, the one according to the present invention has excellent press molding performance.

[0020]

[Table 1]

Example 2 Next, the influence of the plate thickness of the aluminum plate as the skin material on the press formability was investigated. The method of making the test material and the test evaluation are the same as in Example 1, but the thickness of the aluminum plate as the skin material is 0.01, 0.2, 0.3, 3.0 mm.
I changed it. The resin used was a polyester-epoxy resin having an elastic modulus of 3.1 × 10 ⁸ dyne / cm ² , and the resin thickness was 0.05 mm.

The results of the press-molding test are shown in Table 2, which shows good press-molding performance when the plate thickness of the aluminum plate is 0.3 to 3.0 mm.

[0023]

[Table 2]

Example 3 In the same manner as in Example 1, a polyester-epoxy resin having an elastic modulus of 3.1 × 10 ⁸ dyne / cm ² was used as an intermediate layer constrained by an aluminum plate having a thickness of 0.6 mm. A vibration-damping aluminum plate having a resin thickness varied from 0.005 to 0.22 mm was prepared by using it, and a press test was conducted. The results are shown in Table 3. As is clear from the press molding evaluation results in Table 3, the thickness of the intermediate resin layer is 0.01 to 0.20 mm.
Shows good press molding performance.

[0025]

[Table 3]

Example 4 Press-formability of a single aluminum plate (thickness: 1.0 mm) and two aluminum plates (thickness: 0.6 mm)
Were simply overlapped with each other and the press formability was evaluated under the condition of no constraint. The results are shown in Table 4. As is clear from Table 4, the press forming performance of the aluminum single plate and the unbonded two plates are considerably inferior to the above-mentioned one according to the present invention. In other words, by using the resin composite type aluminum plate having the constitution of the present invention, it is possible to perform deep drawing, which was difficult with the conventional aluminum plate single plate.

[0027]

[Table 4]

[0028]

As is clear from the examples and comparative examples, the elastic modulus of the intermediate resin layer constrained by the aluminum plate, the resin thickness, and the thickness of the aluminum plate serving as the skin material are set within the optimum range. The resin composite-type aluminum plate of the present invention is extremely useful as a lightweight damping material because it is possible to realize extremely excellent press formability.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Noguchi 4-3-18 Nihombashi Muromachi, Chuo-ku, Tokyo Within Sky Aluminum Co., Ltd. (72) Inventor Yuji Abe 4-3-18 Nihonbashi Muromachi, Chuo-ku, Tokyo Within Sky Aluminum Co., Ltd.

Claims (1)

[Claims] 1. A resin composite type vibration damping aluminum plate comprising two aluminum plates and a viscoelastic resin layer in the middle thereof, wherein the front and back skin materials are aluminum plates having a thickness of 0.3 to 3.0 mm. The thickness of the intermediate viscoelastic resin layer constrained by the aluminum plate is 0.01 to 0.2 mm,
Further, the elastic modulus of the intermediate viscoelastic resin layer at the press molding temperature is 3.5 × 10 ⁶ to 3.5 × 10 ⁸ dyne / cm ^2, which is a resin composite mold excellent in press moldability. Swing aluminum plate.