JPS58205759A - Vibration inhibiting material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vibration damping material, and particularly to a vibration damping material for preventing vibrations in a vehicle interior used in a vehicle such as an automobile.

BACKGROUND OF THE INVENTION Conventionally, as an allocation material used in vehicles such as automobiles, there are, for example, those shown in FIG. That is, thickness 5
Applying and pasting a viscoelastic layer 2 such as an acrylic ester adhesive or a butyl rubber adhesive on one side of a restraining layer 1 made of metal foil such as aluminum foil or iron foil with a thickness of approximately 0 μm to 1' mm. A sheet-like damping material 3 with a two-layer structure formed by the above method is known, and it can be attached to a vibration-damping material 4 such as a roof or a door inside a car or the like using the adhesiveness of its viscoelastic layer 2. It is used as. Such a damping material 3 converts the mechanical energy due to vibrations applied to the damping material 4 into heat through shear strain generated in the viscoelastic layer 2 sandwiched between the damping material 4 and the constraining layer 1. It is based on the principle of converting it into energy and damping it.

Therefore, the material for the viscoelastic layer should preferably have a high loss coefficient itself and an optimum storage shear modulus at the operating temperature. Although the optimal storage shear modulus varies depending on the thickness of each layer composing the allocation material, Young's modulus, etc.
It is preferably within the range of 0.003 to 0.01 kg/-.

Viscoelastic materials with such storage shear modulus values are extremely soft and easily deformable, and must also have adhesive properties to facilitate adhesion between the damping material and the damping material. listed as a condition.

However, such conventional vibration damping materials are expensive because they use, for example, butyl rubber-based compositions as soft and adhesive components, and if the use of butyl rubber is increased, the damping properties will be improved. Although this will increase, the price and weight will also rise, and at present it is used as a bookkeeping sheet with a thickness of about 1 to 3 mm. Therefore, there was a problem in that the vibration damping properties in the vehicle interior were insufficient.

The present invention has been made by focusing on these conventional problems, and includes a vibration damping material consisting of a soft and adhesive viscoelastic layer and a metal foil restraining layer. Elastic modulus lo o o kg/c++! As described above, particulate polyurethane having a shore D hardness of 45 or more and an average particle diameter of 3 mm or less is used as a soft adhesive component 10 constituting the viscoelastic layer described in t)fl.
12″0 parts by weight or less per 0 sentinel, preferably 20 to 1
It is a distribution material characterized by blending 20 weight parts.

Hereinafter, the present invention will be explained based on the drawings. FIG. 2 is a diagram showing an embodiment of the present invention. That is, it is a damping material 7 in which a viscoelastic layer 6 made of a soft adhesive component mixed with particulate polyurethane is formed on one side of a restraining layer 5 made of metal foil such as aluminum foil, iron foil, copper foil, etc. This damping material 7 is used by being attached to a damping material 8, which is a vehicle body steel plate such as a door, roof, or floor of a vehicle such as an automobile.

Examples of the soft adhesive component constituting the viscoelastic layer of the damping material according to the present invention include butyl rubber, acrylic rubber, nitrile rubber,
Synthetic rubbers such as ethylene-propylene rubber, chloroprene rubber, silicone rubber, fluoro rubber, ethylene-acrylic rubber, polyester elastomer, epichlorohydrin rubber, liquid rubber, chlorinated polyethylene, isoprene rubber, urethane rubber, styrene-butadiene rubber, and natural rubber. There are also unvulcanized rubber compositions in which a part or mixture of re-vulcanized recycled rubber is blended with an adhesion silicone-imparting agent such as petroleum resin, an inorganic filler, etc., but butyl rubber is preferred.

Butyl rubber is a rubber with extremely low unsaturation that is made by copolymerizing imbutylene and a small amount of isoprene at extremely low temperatures.

The polyurethane used in the present invention is a granular material having a bending elastic modulus of 1 o o, 0 kg/aa or more, a hardness of 45 or more (Shore D hardness), and crushed by a crusher to an average particle size of 3 mm or less. This means that if the soft adhesive component exceeds 3 ml+ as shown in Figure 3,
This is because the vibration damping effect increases little as the thickness increases, and the cost becomes relatively high. Therefore, it is preferable that the viscoelastic layer has a thickness of 3 mm or less, and the average particle size of the particulate polyurethane is also desirably 3 mm or less! l~i. Shore D
If the hardness is less than 45, the difference in hardness from butyl rubber will be small and the effect will be reduced. However, soft adhesive component 1
The blending amount of particulate polyurethane per 00 parts by weight is 1
It is 20 parts by weight or less, preferably 1 to 20 to 120 parts by weight.

In addition, Fig. 3 shows particulate polyurethane obtained by crushing polyurethane with a flexural modulus of elasticity of 1000 kg/cd or more and a shore D hardness of 45 mm or less in a crusher to an average particle size of 3 mm or less, and a butyl rubber (AID + 10, Manufactured by Esso) 100
Parts by weight, polybutene (Nisseki Polybutene I (TJ300,
A predetermined amount was blended with 130 parts by weight (manufactured by Nippon Oil Co., Ltd.), 50 parts by weight of petroleum resin (ys resin, manufactured by Yasushi Oil Co., Ltd.), and 10 parts by weight of carbon black, kneaded with a rubber roller, and pressed to form a sheet. Later, 100μ thick
These are the test results obtained by manufacturing a vibration damping material by pasting it on aluminum foil of 1.5 m, and conducting it based on the test piece manufacturing method and test method described below (resonance frequency quadratic, experimental temperature 23°C).
).

The viscoelastic layer may further contain polybutene, petroleum resin, carbon black, and the like.

To form a viscoelastic layer, a predetermined amount of particulate polyurethane and additives such as polybutene, petroleum resin, carbon black, etc. are added to the soft adhesive component, and the mixture is kneaded using a rubber roller, a Banbury mixer, etc., and then a restraining layer is formed. This can be done by pressing onto a certain metal foil to the above thickness using a roller, press, extruder, etc., or by forming it into a sheet I-shaped object and then sticking it to the metal foil.

The damping material formed in this manner is used by being attached to vehicle body steel plates such as interior doors, roofs, and floors of vehicles such as automobiles.

Next, the present invention will be explained in more detail by giving Examples. In addition, in the following Examples and Comparative Examples, parts are parts by weight unless otherwise specified.

In addition, vibration damping properties were tested using the following method.

Preparation of test piece 1. A mild steel plate of 0111 x 100 m + x x 260 mm was degreased, washed with water, and then coated with anionic electrodeposition paint.
3.1mm x 1 on this painted surface baked at 75℃ for 30 minutes
A dielectric material according to the invention measuring 00×220 mm was applied.

Test Method All samples were measured at 23° C. using the cantilever resonance method, which is the most popular method for measuring the amount of damping and which determines the loss coefficient from the width of the resonance curve.

Example 1 85 parts of polyol (Sannix FA-909, manufactured by Sanyo Chemical Co., Ltd.), 15 parts of ethylene glycol, 5 parts of Freon, 1 part of triethylenediamine, 0.01 part of diptyltin dilauret, diisocyanate (Sumidur P)
C1 (manufactured by Sumitomo Bayer Urethane Co., Ltd.) 90 parts of the raw material was mixed at a mold injection pressure of 50 kg/d and a mold temperature of 75.
A polyurethane injection molded at ℃ with a bending elastic modulus of 1000 kg/d and a shore D hardness of 45 is crushed to obtain a maximum average particle size of 3.
11 m of particulate polyurethane was produced.

The amounts of the particulate polyurethane thus obtained were varied (0 parts, 20 parts, 50 parts, and 120 parts), and 100 parts of butyl rubber (AID+101 manufactured by Esso Corporation) and polybdenum (Nisseki Polybdenum HU300° Nippon Oil Co., Ltd.) were used. The mixture was mixed with 130 parts of petroleum resin (YS Resin, manufactured by Yasushi Oil Co., Ltd.) and 10 parts of carbon black, kneaded with a rubber roller, and formed into a sheet with a press.
A damping material was produced by adhering it to an aluminum foil with a thickness of 100 μm.

The test results are as shown in Table 1 and Figure 4.7- there were.

According to this example, the loss coefficient (damping property) increases as the amount of particulate polyurethane added increases.

The difference between second-order, third-order, and fourth-order frequencies is a difference in vibration frequency, and overall, the larger the loss coefficient, the better the damping performance. In the case where polyurethane was not added, the third-order and fourth-order loss coefficients at the resonant frequency were small, and this affected the overall performance, resulting in poor vibration damping properties. However, in the case of the present invention, the loss coefficient exceeds 0.03 at all secondary, tertiary, and quartic resonance frequencies, and sufficient allocability can be obtained over a wide range of frequencies.

Example 2 In the same method as in Example 1, the bending elastic modulus was 4000 kg/7 s under the same conditions except that 85 parts of Zannix Ti'A, -728 was used as the polyol.
Produce polyurethane with Shore D hardness of 60 and crush it to produce particulate polyurethane with a maximum average particle size of 3.
is.

Experiments were carried out by varying the amount of particulate polyurethane. 8- Test pieces of damping material were manufactured in the same manner as in Example 1 and tested. The results were as shown in Table 1 and Figure 5. there were.

According to this example, the vibration damping properties are increased by increasing the flexural modulus and shore D hardness of the particulate polyurethane.

Example 3 The polyurethane obtained by the method of Example 2 was crushed to obtain particulate polyurethane having a maximum average particle size of 0.5 tnw. Test specimens of vibration damping materials were manufactured and tested in the same manner as in Example 1 with various amounts of this particulate polyurethane, and the results were as shown in Table 1 and FIG. 6.

According to this example, even if the average particle size of the particles is 0.5 mm or less, the effect of improving vibration damping properties can be obtained.
A similar effect will be exhibited if it is less than or equal to M+I+.

Example 4 Hyprox was used as a raw material for polyurethane compounding.
ox) 9/(yl.

Injection molded at mold temperature 75℃, bending elastic modulus 10,000
kg/crl s Polyurethane having a Shore D hardness of 80 was produced and crushed to produce particulate polyurethane having a maximum average particle size of 311+11. Test pieces of vibration damping material were manufactured in the same manner as in Example 1 with various amounts of this particulate polyurethane, and tests were conducted.The results are as shown in Table 1 and Figure 7. Met.

According to this example, it is clear that even if the hardest polyurethane commonly synthesized is used, the effect of adding particulate polyurethane continues.

Comparative Example 1 Elastolan E190FN as polyurethane compounding raw material
Polyurethane with a bending elastic modulus of 900 kg/era and a Shore D hardness of 39 was produced using AT (manufactured by Nippon Elastolan Co., Ltd.), and this was crushed to produce particulate polyurethane with a maximum average particle size of 3. Test pieces of damping material were manufactured in the same manner as in Example 1 with various amounts of this particulate polyurethane, and tested. The results were as shown in Table 1 and Figure 8. .

According to this comparative example, the bending elastic modulus is 900 kl? /i.

Even if polyurethane having a shore D hardness of 39 is used, the damping effect does not increase, but rather tends to decrease.

This is because the effect of the present invention is considered to be a damping effect due to friction between the rigid filler (polyurethane) and the polymer (for example, butyl rubber), so a certain degree of hardness is required.

Comparative Example 2 In the method of Example 2, the particle size of particulate polyurethane was
The same method was carried out except that 11IK was used, but in both cases, a sheet with a thickness of 3 stripes could not be formed, and unevenness occurred.

As is clear from Figure 1, if the thickness of the viscoelastic layer is three or more lines, the damping property improvement rate will decrease and it will be difficult to obtain an effect compared to the increase in cost. Although it is desirable to have a particle size of 3 mm or less, if a particle size of 5 mm is added and pressed to a thickness of 3 mm, the surface becomes uneven, the adhesive property is extremely reduced, and it becomes difficult to stick. Therefore, it is desirable that the average particle diameter of the particulate polyurethane is 3 g++a or less.

Comparative Example 3 In the method of Example 2, the amount of particulate polyurethane was 16
When the same method was carried out except that the amount was 0 parts, the moldability was poor and it was not possible to form a sheet.

In this comparative example, the bonding force of the adhesive butyl rubber, which acts as a bond between polyurethane particles, was significantly reduced, making it easier to cut, resulting in poor molding. Therefore, the amount of particulate polyurethane added is preferably 120 parts or less.

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- As explained above, according to the present invention, in a vibration damping layer whose structure is composed of a viscoelastic layer having a soft and adhesive force and a constraining layer of metal foil, the viscoelastic layer bending modulus of elasticity 100
0kg/7 or more, Shore D hardness 45 or more, average particle size 3
Since the damping material contains 1 ml or less of particulate polyurethane in an amount of 120 parts by weight or less per 100 parts by weight of the soft adhesive component constituting the viscoelastic layer, the damping material is lower than that of a damping material without the addition of particulate polyurethane. Test (temperature: 2
3℃, substrate: 1 * m x 10 ll1 m x 2
60 mtn steel plate, cantilever resonance method, free length: 220
urn) with 120 parts by weight of particulate polyurethane added to 10'0 parts by weight of the soft adhesive component. Indicates the loss factor. Table 2 shows the soft adhesive component 1.
Data is shown in which the loss coefficients when 20 parts by weight, 50 parts by weight, and 120 parts by weight of particulate polyurethane were added to 00 parts by weight, respectively, were compared with those without addition.

Table 2 Note) Amount (PHR) fo: Resonance frequency (Hz) η: Loss coefficient The reason why the vibration damping material according to the present invention exhibits the above effects is because of the poly91 foam blended into the soft adhesive component. Due to the particles, during vibration, a movement of shear occurs between the soft adhesive component and the polyurethane particles or between the polyurethane particles, and this movement has the effect of absorbing vibration energy, and the vibration absorption effect is due to the addition of the hard component. This has an effect that outweighs the reduction in damping properties caused by cracking. However, since the particulate polyurethane is kneaded into the soft adhesive component, the soft adhesive component covers the particulate polyurethane and its adhesiveness is not impaired.

In addition to the above-mentioned common effects, each embodiment has the following effects. That is, the polyurethane used in the present invention is a resin currently used for automobile bumpers, and its use is expected to increase in the future. Although it is difficult to dispose of molded and defective products, it is extremely useful for resource saving and waste disposal because they can be crushed and used.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a conventional damping material, FIG. 2 is a cross-sectional view of an example of a damping material according to the present invention, and FIG. 3 is a graph showing the relationship between the viscoelastic layer thickness and loss coefficient in the damping material. 4 to 8 are graphs showing the relationship between the number of parts of particulate polyurethane added to the distribution material and the loss coefficient. 5... Restriction layer, 6... Viscoelastic layer, 7... Damping material,
8..., damped material. Placement of rice cakes (seeing @ (furnace) Kyou Kaede appetizer @C-2

Claims (3)

[Claims] (1) In a distribution material consisting of a viscoelastic layer that is soft and has adhesive strength and a constraining layer of metal foil, the viscoelastic layer has a bending elastic modulus of 1000 kg/crIll and an average particle size of 3 m111 or more with a Shore D hardness of 45 or more. A vibration damping material characterized in that 120 parts by weight or less of the following particulate polyurethane is blended per 100 parts by weight of the soft adhesive component constituting the viscoelastic layer. (2) The damping material according to claim 1, wherein the soft adhesive component is butyl rubber. (3) The damping material according to claim 1 or 2, wherein the viscoelastic layer has a thickness of 3 mm or less.