JPH068038B2 - Damping material - Google Patents

Description

The present invention relates to a material having excellent workability such as deep drawing and bending and having extremely high vibration damping property.

In recent years, the effects of noise from transportation such as automobiles, railroads, and vehicles, and noise or vibration from factories and construction sites on the surrounding inhabitants have increased daily, and have become a major social problem.

As a means of solving this problem, research and development of vibration absorbing materials such that the materials themselves have a vibration absorbing capacity have been promoted, and vibration damping materials with high vibration absorbing performance suitable for applications such as vehicles, ships, industrial machines and iron bridges have been developed. Used as a structural member.

As a noise source of automobiles, noise from the parts around the engine, especially from the oil pan is large, and it is necessary to reduce the noise.

As such a damping material, conventionally, a vinyl acetate-ethyl acrylate copolymer (Japanese Patent Publication No. 45-35662), a copolymer obtained by grafting a vinyl acetate-ethylene copolymer with a mixture of styrene and acrylonitrile ( Japanese Patent Publication 4
6-17064), a resin composition mainly composed of a carboxylic acid-modified polyolefin resin (Japanese Patent Laid-Open No. 59-80454), and a laminated structure having an intermediate layer or bitumen with a filler such as calcium carbonate. The added materials and the like are known.

However, when these are made into a laminated structure with a metal plate, they have a vibration absorbing ability in a specific temperature range, but the adhesiveness to the metal plate is insufficient, or the elastic modulus of the composition of the intermediate layer is It has a drawback that it is inferior in deep drawing and bending workability due to mechanical press due to its low heat resistance, inferior heat resistance, etc., and as a vibration-damping metal plate, it has a difficulty in secondary workability. Is.

The drawback of the workability of a conventional vibration-damping metal plate by a mechanical press or the like is that, for example, in deep drawing, the metal plate ends are misaligned, or in severe cases, the two upper and lower metal plates are vibration-damped. In addition to the problem that the resin layer deviates from the flexible resin layer to cause a mouth opening, the low elasticity of the resin layer causes waviness on the surface of the molded product and wrinkles on the corner curved surface.

Also, 180 ° bending, which is called hemming, is applied to the end processing of the vibration-damping metal plate. However, in such severe processing, waviness and wrinkling of the metal plate surface become even more severe, and it is put to practical use. It was unbearable.

In view of these problems, the present invention has an object to provide a highly damping material having excellent workability such as deep drawing and bending, and excellent damping performance.

The inventors of the present invention have conducted extensive studies in order to provide such an excellent high vibration damping material, and as a result, a vibration damping layer formed by sandwiching a damping layer made of a thermoplastic resin between two metal plates. As the material, the damping layer has an elongation rate of 5 at a temperature of 20 ° C.
The peak temperature of the loss factor (tan δ) is -5 at 0% or more.
Mainly ethylene-maleic anhydride copolymer and / or ethylene-maleic anhydride-acrylic acid ester terpolymer or ethylene-maleic anhydride-methacrylic acid terpolymer in the range of 0 to 130 ° C. A vibration-damping material consisting of a resin composition contained as a component and having an adhesive strength between the vibration-damping layer and a metal plate of 3 kg / cm or more in a 180 ° peeling test at a temperature of 20 ° C. is processed with excellent vibration-damping properties. The present invention was found to have both heat resistance and heat resistance.

The present invention will be described in detail below.

As the thermoplastic resin which can be used in the control layer of the present invention, an ethylene-maleic anhydride copolymer containing 0.3 to 20% by weight of maleic anhydride and having a melt index of 0.5 to 50 g / 10 minutes, or Ethylene 30-98.7% by weight, maleic anhydride 0.3-20% by weight and 1-50% by weight of a third monomer copolymerizable with these two components.
Examples of the terpolymer include: The method for producing these copolymers is not particularly limited, but a method of radically copolymerizing ethylene and maleic anhydride and, if necessary, an eighth monomer in an autoclave reactor with a stirrer under high pressure. Is exemplified.

Examples of the third monomer include propylene,
Olefins such as isobutene, vinyl acetate, ethyl acrylate, butyl acrylate, ethyl methacrylate, butyl methacrylate, methyl methacrylate, and methyl vinyl ether, vinyl derivatives, acrylic acid derivatives or methacrylic acid derivatives.

The melt index of these copolymers is generally about 0.
It can be adjusted over 1 to 3000 g / 10 minutes, but is preferably about 0.5 to 50 g / 10 minutes.

The thermoplastic resin for the damping layer suitable for the present invention is ethylene 30
~ 98.7% by weight, maleic anhydride 0.3-20% by weight
And a terpolymer consisting of 1 to 50% by weight of at least one ester selected from alkyl acrylate or alkyl methacrylate containing an alkyl group having 1 to 6 carbon atoms. More particularly preferred resins include ethylene copolymers containing 1 to 4% by weight of maleic anhydride and 3 to 40% by weight of ethyl acrylate or butyl acrylate and having a melt index of 1 to 10 g / 10 minutes.

The resin composition containing the above-mentioned copolymer as the main component contains 20% by weight or less of a polymer such as a polyolefin resin, a polyester resin, a polyamide resin, butyl rubber, or a filler such as carbon black or calcium carbonate. Can be added.

In the present invention, the reason why the resin used for the damping layer needs to have an elongation at 20 ° C. of 50% or more is that the damping composite material using a resin having a lower elongation as the damping layer is bent or drawn. This is because a defective phenomenon such as cracking occurs during press working and molding.

The reason for this is that the elongation of the metal plate used for the composite material is generally 50% or less, and the elongation of the damping layer needs to be higher than this.

The resin elongation is 50% before the necking occurs.
%, It is desirable that the obtained composite material has physical properties.

Further, the reason why the peak temperature of the loss coefficient (tan δ) of the resin used for the damping layer needs to be −50 to 130 ° C. is that a composite material using a resin having a peak temperature outside this range is generally used. This is because the vibration damping performance at the operating temperature is poor.

The inventors of the present invention have found that the peak temperature of the loss coefficient (tan δ) of the resin and the peak temperature of the loss coefficient (η) in the mechanical impedance method, which is the standard for the damping property of the composite material using the loss coefficient (tan δ). During the first 10 to 30 ℃ to the temperature of the former
It was found that there is a correlation that the temperature added to the temperature becomes the latter.

For this reason, the peak temperature of the loss coefficient (tan δ) must be -20 to 115 ° C as a material at a general use temperature, that is, an outside air temperature of -10 to 50 ° C and an industrial material use application of 0 to 145 ° C.

Based on this, the above-mentioned tan δ peak temperature range was determined so that the η peak temperature of the composite material overlaps with its operating temperature.

When used as the damping layer of the present invention, from the viewpoint of easy workability in the normal temperature range and high damping property in the applied temperature range,
As a result of the examination, the peak value of the loss coefficient (tan δ) was 0.
It was found that if it is 5 or more, excellent performance that wide high vibration damping can be obtained.

The applicable temperature range referred to here is a temperature range in which vibration damping performance is required, and for example, in the case of automobile engine parts,
It suffices that high vibration damping performance is maintained in a temperature range of 50 to 130 ° C. centered at 80 to 90 ° C. or in a temperature range of 10 to 50 ° C. for an automobile body material.

If the total thickness of the resin layers, that is, the single-layer film thickness is 30 μ or more, the vibration damping performance is good, but in order to have good workability such as bending and drawing, it is preferably 100 μ or less, and most preferably Is preferably 30 μ or more and 60 μ or less.

However, if it is too thin, a jumping phenomenon during resistance welding (a phenomenon that conducts at an unnecessary place and short-circuits at that place and causes a hole in the steel plate), which is thought to be due to conductive foreign matter adhering to the steel plate, occurs. As a preventive measure, it has been found that the film thickness is preferably 50 μm or more, and most preferably 70 μm or more.

Further, for the purpose of achieving both a weight reduction effect and high rigidity and high vibration damping performance, it is desirable that the resin layer be relatively thick as compared with the metal plate, and about 0.3 to 5 mm is preferable. .

The method of practicing the present invention can be carried out by molding the resin composition into a film by a usual molding method such as inflation processing, calendar processing, T-die processing.

The metal plate used in the present invention includes various steel plates, stainless steel, aluminum, copper, titanium, etc., or a plate made of an alloy, or the like, and a metal plate subjected to a surface treatment such as tin plate or galvanized iron. included.

As a method for producing the vibration damping material of the present invention, a normal patch method or a continuous hot pressing method can be applied arbitrarily.

For example, there is a method in which a resin is interposed between the metal plates to heat and pressure bond them.

Bonding is generally performed at 150-260 ° C.

The vibration damping material of the present invention can be used particularly for preventing noise and vibration generated from an automobile.

In this case, the source of the noise and vibration of the automobile is the engine parts, and the main one is the oil pan.

Also, good results are obtained when applied to other covers such as a timing belt cover directly attached to the engine body.

When the material of the present invention was applied to an oil pan for a diesel engine of a medium-duty truck, it was found that a noise low range of 3 dB could be achieved about 1 m away from the engine.

It was also found that the effect of applying noise to vehicle interior parts, especially floor panels or dash panels, was great in preventing noise and vibration.

Moreover, when applied to the outer and inner steel materials for doors as automobile outer plates, favorable results were obtained in that the unpleasant noise at the time of opening and closing the door was reduced.

Next, to prevent noise and vibration at home or office,
It is desirable to apply it to electric parts, and especially to the material of covers for motors or ballasts.

Further, for this purpose, it is desirable to apply it to room partitions or building members such as wall materials or floor materials, and it has been found that it is also useful for preventing noise pollution when applied to rain doors or aluminum sash doors.

Generally, a high noise level includes noise from a road construction engine or a generator, and it is also a preferable application to apply to these members.

Further, in order to prevent noise from automobiles, motorcycles, etc. as general transportation means, good results are obtained when used as a braking brake member or a driving chain member.

In this case, it was found that the unpleasant noise when braking or driving the chain was removed.

Good results have also been obtained as a muffler member.

In addition, using it as a floor material and wall material for railway vehicles as a public transportation means is also highly effective in preventing noise pollution.

As described above, the material of the present invention can be used in various applications. However, in the application of directly controlling vibration, it is desirable that the core thickness is 30 to 100 μ from the viewpoint of press workability. However, in covers or wall materials or floor materials that do not require particularly difficult processing, it is necessary to increase the total thickness in order to obtain the effect of retaining strength,
At that time, by setting the thickness of the internal resin layer to 0.3 to 5 mm, it is possible to obtain the effect of reducing the weight, which is preferable.

Hereinafter, the present invention will be described in detail with reference to Examples, but these are examples and the present invention is not limited thereto.

In the examples, the peak temperature of the loss coefficient (tan δ) of the vibration-damping layer film was measured using Rheovibron (110 Hz) manufactured by Toyo Baldwin, and the elongation was determined at 20 ° C. and a pulling speed of 200 mm / min.

The loss coefficient (η), which represents the vibration absorption capacity of the damping material, is a forced vibration by the mechanical impedance method (central vibration) and the frequency is 10
The measurement was performed at 00 Hz and a temperature of 20 to 130 ° C. The adhesion test between the metal plate and the damping layer was conducted by cold rolling steel plate (0.8 mm) / (50
μ) / Cold rolled steel plate (0.8 mm) composition at 190 ° C, 5
Min, 30Kg / cm ² condition, 180 ° angle, 50m
It was evaluated by a pulling speed of m / min.

Melt index Measured according to JIS K6760.

As the processing method, the molds shown in FIGS. 1 and 2 were used, and bending back and drawability were tested, and slip, peeling, wrinkle and the like were evaluated.

FIG. 1 (a) is a sectional view of a bending-back working test die. In the figure, 1, 2, and 3 are mold members, 4 is a spacer,
5 shows a sample. Moreover, 2R, 5R, etc. show curvature. FIG. 1 (b) is a perspective view of a bending-back processing test molded product. In the same figure, section A, section B, and section C indicate evaluation observation portions, respectively.

FIG. 2 (a) is a sectional view of a drawing workability test die. In the figure, 1, 2, 3, 4, and 5 are mold members, and 6 is a sample. Further, 5R indicates the curvature, and 50φ and 56φ indicate the diameter of the corresponding portion.

FIG. 2 (b) is a perspective view of the drawn workability test molded product. In the figure, 1 is a wrinkle on the A portion, 2 is a wrinkle on the flange, and 3 is an evaluation observation portion of the slip of the plate.

Example 1 An extruder equipped with an extruder for supplying a terpolymer of ethylene-maleic anhydride (2% by weight) -butyl acrylate (30% by weight) having a melt index of 4.5 g / 10 min, and an inflation die (diameter 150 mm). A tubular body using an inflation device having a take-up speed of 7.0 m / min,
The film was taken out under a blow-up ratio of 2.0 and cut open to obtain a film having a folding diameter of 470 mm and a thickness of 50 μm. The physical properties of the resins used are shown in Table 1.

The obtained film was subjected to thermocompression bonding (170 ° C., 5 minutes, 30 Kg / cm ² ) between 0.8 mm-thick cold rolled steel plates, and the adhesiveness, workability and vibration absorption were measured.

The results are shown in Tables 2 to 3 and FIG.

FIG. 3 is a temperature-loss coefficient (η) relationship diagram of the damping material.

Comparative Example 1 A side-itch steel plate was prepared as follows using the resin composition mainly composed of the carboxylic acid-modified polyolefin resin disclosed in Example 4 of JP-A-59-80454.

0.7% by weight of maleic anhydride in linear low density polyethylene (made by CdF Chimie) with a melt index of 4 g / 10 min
And 0.1% by weight of t-butyl peroxylaurate were added and mixed for 2 minutes with a Henschel mixer,
The mixture was kneaded with an extruder having a diameter of 30 mm and set at 190 ° C., and then pelletized.

100 parts by weight of this modified polyethylene and a linear low density polyethylene (CdF Chimie) with a melt index of 4 g / 10 min.
125 parts by weight and methyl methacrylate polymer 2
5 parts by weight were mixed and the mixture was set at 190 ° C. 3
The mixture was kneaded with a 0 mmφ extruder and then pelletized.

A film obtained by forming a film using this material in the same manner as in Example 1 was subjected to thermocompression bonding (170 ° C., 5 minutes, 30 Kg / cm ² ) between 0.8 mm-thick cold-rolled steel plates for adhesion. The workability, processability and vibration absorption were measured.

The results are shown in Tables 2 to 3 and FIG.

FIG. 3 is a temperature-loss coefficient (η) relationship diagram of the damping material.

[Brief description of drawings]

FIG. 1 (a) is a sectional view of a bending-back working test die. FIG. 1 (b) is a perspective view of a bending-back processing test molded product. FIG. 2 (a) is a sectional view of a drawing workability test die. FIG. 2 (b) is a perspective view of the drawn workability test molded product. FIG. 3 is a temperature-loss coefficient (η) relationship diagram of the damping material.

Claims (9)

[Claims] 1. A vibration-damping material comprising a vibration-damping layer made of a thermoplastic resin sandwiched between two metal plates, the vibration-damping layer having an elongation at a temperature of 20 ° C. of 50% or more. Containing 0.3 to 20% by weight of maleic anhydride having a loss factor (tan δ) peak temperature in the range of −50 to 130 ° C.
Melt index 0.5 to 50 g / 10 min ethylene-maleic anhydride copolymer and / or ethylene 30
~ 98.7% by weight, maleic anhydride 0.3-20% by weight
And a resin composition containing, as a main component, a terpolymer containing 1 to 50% by weight of at least one ester selected from alkyl acrylate or alkyl methacrylate containing an alkyl group having 1 to 6 carbon atoms. And the adhesive strength between the damping layer and the metal plate is 180 ° at a temperature of 20 ° C.
A vibration damping material characterized by a peeling test of 3 kg / cm or more. 2. The control according to claim 1, wherein the loss coefficient (tan δ) of the resin composition has a peak temperature in the range of −20 to 115 ° C. and a peak value of 0.5 or more. Vibratory material. 3. The vibration damping material according to claim 1, wherein the thickness of the vibration damping layer is 30 μm or more and 100 μm or less. 4. The material according to claim 1, wherein the damping layer has a thickness of 0.3 to 5 mm. 5. A damping material comprising a damping layer made of a thermoplastic resin sandwiched between two metal plates, wherein the damping layer has an elongation at a temperature of 20 ° C. of 50% or more. Containing 0.3 to 20% by weight of maleic anhydride having a loss factor (tan δ) peak temperature in the range of −50 to 130 ° C.
Melt index 0.5 to 50 g / 10 min ethylene-maleic anhydride copolymer and / or ethylene 30
~ 98.7% by weight, maleic anhydride 0.3-20% by weight
And a resin composition containing, as a main component, a terpolymer containing 1 to 50% by weight of at least one ester selected from alkyl acrylate or alkyl methacrylate containing an alkyl group having 1 to 6 carbon atoms. And the adhesive strength between the damping layer and the metal plate is 180 ° at a temperature of 20 ° C.
Automotive parts with excellent vibration control using a vibration control material characterized by a peeling test of 3 kg / cm or more. 6. A component according to claim 5, wherein the automobile component is an engine component. 7. The component according to claim 6, wherein the engine component is an oil pan. 8. The component according to claim 5, wherein the automobile component is an automobile body component. 9. The component according to claim 8, wherein the automobile body component is a floor panel, a dash panel or a door.