JPS6246638A - Vibration-damping 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 material that is excellent in processability such as deep drawing and bending, and has extremely high vibration damping properties.

In recent years, the impact of noise from transportation such as automobiles, trains, and other vehicles, as well as noise and vibration from factories and construction sites, on surrounding residents is increasing day by day, and has become a major social problem.

As a means of solving this problem, research and development is progressing on vibration-absorbing materials that have vibration-absorbing ability themselves. It is used as a structural member.

Furthermore, noise from parts around the engine, particularly the oil pan, is a major source of noise in automobiles, and it has become necessary to reduce this noise.

As such a damping material, vinyl acetate-ethyl acrylate copolymer (Japanese Patent Publication No. 45-85662
), a copolymer obtained by grafting a mixture of styrene and acrylonitrile onto a vinyl acetate-ethylene copolymer (Japanese Patent Publication No. 46-17064), and a resin composition based on a carboxylic acid-modified polyolefin resin (Japanese Patent Publication No. 17064/1989) 59-
Laminated structures with a composition such as No. 80454) as an intermediate layer, and materials in which filler such as calcium carbonate is added to bitumen are known.

However, when these are made into a laminated structure with a metal plate, although they have vibration absorption ability in a specific temperature range, the adhesion with the metal plate is insufficient, and the elastic modulus of the intermediate layer composition is insufficient. The fact is that it has disadvantages such as poor deep drawing and bending workability with mechanical presses due to low heat resistance, and poor heat resistance, so it has difficulties in secondary workability as a vibration damping metal plate. It is.

The disadvantages of the workability of conventional vibration-damping metal plates using mechanical presses, etc. include, for example, during deep drawing, the edge of the metal plate may shift, or in severe cases, two laminated earthwork metal plates may become vibration-damping. In addition to the problem of separation from the elastic resin layer and opening, the low elasticity of the resin layer also causes waving on the surface of the molded product and wrinkles on the curved corner surfaces.

In addition, a 180° bending process known as hemi-jig process is carried out to process the edges of vibration-damping metal plates, but such severe process causes the metal plate surface to become even more wavy and wrinkled, making it difficult to put it into practical use. It had become unbearable.

SUMMARY OF THE INVENTION In view of these problems, the present invention aims to provide a highly damping material that has excellent workability in deep drawing, bending, etc., and has excellent damping performance.

The Ministry of the Invention and others have proposed a damping material composed of such an excellent daytime damping material, in which the damping layer has a loss coefficient (tan a) of 50% or more at a temperature of 20°C. Ethylene-maleic anhydride copolymer and/or ethylene-maleic anhydride-acrylic ester terpolymer or ethylene-maleic anhydride-methacrylic ester having a peak temperature in the range of -50 to 180°C. It is made of a resin composition containing a terpolymer as a main component, and the adhesive strength between the damping layer and the gold coin plate is 1 at a temperature of 20°C.
The present invention was achieved by discovering that a damping material having a resistance of 8 K4I/erg or more in an 80° peeling test has excellent damping properties as well as workability and heat resistance.

The present invention will be explained in detail below.

The damping layer of the present invention (thermoplastic resins that can be used include:
Ethylene-maleic anhydride copolymer containing 0.3 to 20% by weight of anhydrous 71/inic acid and having a melt index of 0.5 to 50 f/10 min, or ethylene 30 to 9
8.77aQ:%, maleic anhydride 08-20% by weight and an eighth monomer that can be copolymerized with these two components.
Examples include terpolymer containing 50% by weight. The method for producing these copolymers is not particularly limited, but an example is a method of radically copolymerizing ethylene, maleic anhydride, and, if necessary, the weight of Flute 3 under high pressure in an autoclave reactor equipped with a stirrer. be done.

For example, olefins such as propylene, isobutyne, vinyl acetate, ethyl acrylate, butyl acrylate, ethyl methacrylate, butyl methacrylate, methyl methacrylate-1, methyl vinyl ether, vinyl -ol derivatives, acrylic acid derivatives or methacrylic acid derivatives.

The melt index of these copolymers is generally about 0.
．． Although it can be adjusted over 1 to 8000 g/10 minutes, it is preferably about 0.5 to 5 ON/10 minutes.

The thermoplastic resin suitable for the damping layer in the present invention is ethylene 30
~98.7% by weight, 08-20% maleic anhydride, and 1-50% by weight of at least one ester selected from alkyl acrylates or alkyl methacrylates containing an alkyl group having 1 to 6 carbon atoms. A terpolymer consisting of % is exemplified. Furthermore, as a particularly preferable resin,
An ethylene copolymer having a melt index of 1 to 10 I710 minutes and containing 1 to 4% by weight of maleic anhydride and 8 to 40 it% of ethyl acrylate or butyl acrylate can be mentioned.

The resin composition mainly composed of the above copolymer may contain up to 20% by weight of polyolefin resin, polyester resin, polyamide fruit tree [IL butyl rubber or other polymers or fillers such as carbon black or calcium carbonate]. can be added.

In the present invention, the reason why the elongation rate at 20°C of the resin used for the damping layer is required to be 50% or more is that the damping composite material using a resin with a lower elongation rate as the damping layer cannot be bent or drawn. The probability of defective phenomena such as cracking occurring during press forming is 50% or less, and the elongation rate of the vibration damping layer needs to be higher than this.

The elongation rate of the resin is 5 before the occurrence of Ne Soking.
It is desirable for the content to exceed 0% in terms of the physical properties of the resulting composite material.

Also, fi' used for h1th F-da! 4 The reason why the peak temperature of the finger loss coefficient (tan/l) is required to be between 150 and 130°C is that composite materials using Higuchi: 7, whose peak temperature is outside this range, cannot reach the general use temperature. This is because the vibration damping performance is reduced.
Temperature and control of the composite material used for the η-pjll and Iq layers: Mechanical and impedance method (L1 failure) During the peak temperature, add 10-30℃ to the former temperature and the two
Since there is a correlation between the 4 types of changes, the loss coefficient ( It is necessary that the peak temperature of tan δ) is between 120 and 115°C.

This, 1. Based on this, the above-mentioned tan δ beer temperature 1 was determined so that the peak temperature of η of the composite material overlaps with its use temperature.

In addition, when used as the damping layer of the present invention, from the viewpoint of easy processability in the room temperature range and high vibration damping property in the applicable temperature range,
When the peak value of the loss coefficient (tan δ) was 0.
If it is 5 or more, excellent performance such as widely high vibration damping can be obtained (1).

The applicable temperature range here refers to the temperature range in which vibration damping performance is required; for example, in the case of engine parts for automobiles, the temperature range is 50 to 130 degrees Celsius, centered around 80 to 90 degrees Celsius, or the temperature range for automobile body parts. The material may be one that maintains good vibration damping performance in a temperature range of 10 to 50°C.

That's the total thickness of the shrine! -11! The ta film thickness is
It is preferably 1004 or less, most preferably '
Lt 30 a Ull: It is desirable that it is 60μ or less.

However, if the metal plate is too thin, there will be a problem of bleed-out during resistance welding, which is thought to be due to conductive foreign matter adhering to the steel plate. Therefore, as a preventive measure, it is desirable to make the film thickness 50μ or more, and most preferably 70μ or more, in order to achieve both performance, the resin layer is relatively thin compared to the metal plate. It is desirable that the thickness be as thick as possible, and a thickness of about 0.8 to 5 is good.

The method of carrying out the present invention is to process the tree composition by, for example, inflating, calendaring, T-die processing, etc.
This is possible by forming it into a film using the 7 [g processing method].

The gold 1D plate used in the present invention is a single piece or an alloy plate made of various steel plates, stainless steel, aluminum, steel, titanium, etc., and some of these metals have been subjected to surface treatment such as yellowtail or galvanized iron. Also includes boards.

As a method for producing the 1.1III material of the present invention, any method such as a normal batch method or continuous heat press method can be applied.

For example, there is a method of interposing a resin between two metal plates and bonding them under heat and pressure.

, 兦 7. is generally carried out at 150 to 260°C.

The vibration damping material of the present invention can be particularly used to prevent noise and vibration generated from automobiles.

In this case, the sources of noise and vibration in automobiles are engine parts, of which the oil pan is the main source.

Good results can also be obtained when applied to other covers that are attached directly to the engine body, such as timing belt covers.

When the material of the present invention was applied to an oil pan for a diesel engine of a medium-sized truck, it was found that noise could be reduced by 8 dB at a location approximately 1 m away from the engine.

It has also been found that application to vehicle body parts, particularly floor panels or dash panels, is highly effective in preventing noise and vibrations entering the vehicle interior.

In addition, when applied to outer and inner door steel materials for automobile exterior panels, favorable results were obtained in that unpleasant noises when opening and closing doors were reduced.

Next, to prevent noise and vibration in homes or offices,
It is desirable to apply the present invention to electrical parts, and in particular to covers for motors or ballasts.

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

In addition, the noise level generally includes the noise from road construction engines or generators, and it is also preferable to apply it to these parts.

In addition, in order to prevent noise from bicycles, motorcycles, etc. as a means of general transportation, brake parts for braking or [
Good results can be obtained when used as a dynamic chain member.

It has been found that in this case, unpleasant noises during brake braking or chain drive can be eliminated.

Good results have also been obtained as a muffler member.

It is also effective in preventing noise pollution when used as flooring and wall materials for railway vehicles as a means of public transportation.

As described above, the material of the present invention can be used for various purposes, but in applications that directly control vibration, it is preferable from the viewpoint of press workability that the core thickness be 30 to 100 μm as described above. However, for covers, wall materials, or floor materials that do not require particularly difficult processing, it is necessary to increase the overall thickness in order to maintain strength.
At this time, by setting the thickness of the internal resin layer to 0.8 to 5, a 6fi effect can also be obtained, which is a favorable property.

EXAMPLES The present invention will be specifically explained below with reference to Examples, but these are merely illustrative and the present invention is not limited thereto.

In the examples, the peak temperature of the loss coefficient (tan δ) of the damping layer film was determined by the Toyo Baldwin fissure rheopyron (1
10Hz), and the elongation rate was measured at 20℃ and 200m.
It was determined at a tensile speed of /min.

The loss coefficient (η) representing the vibration absorption ability of the Htll vibration material was measured by forced vibration using the mechanical impedance method (central vibration) at a frequency of 1000 Hz and a temperature of 20 to 130°C. The adhesion test between the metal plate and the damping JU was conducted using cold rolled A plate ((
18m) / (50a, ) / cold rolled copper plate (0
, 8 gardens)! The tube was extubated under the conditions of 190°C, 5 minutes, and 30 Kf/cd using a J-type machine, and evaluated at an angle of 180' and a tensile rate of 50'5/min.

Melt index was measured according to JIS K6760.

For workability, the molds shown in FIGS. 1 and 2 were used to test bending back and drawing workability, respectively, and evaluate slippage, peeling, wrinkles, etc.

FIG. 1(a) is a cross-sectional view of the bending test mold.

In the figure, 1.2.3 indicates a mold member, 4 indicates a spacer, and 5 indicates a sample. 2R again.

5R etc. indicate curvature. Figure 1 (b) shows the bending process.

, Figure 12 (a) is a folded view of the cross processing (raw test case type). In the same figure, 1.2.3, 4.5 are mold members,
6 indicates a sample. Further, 5R indicates the curvature, and L 50φ, 5G, and I indicate the μ of the corresponding portion.

FIG. 2 (1)) is a perspective view of a test molded product subjected to exhaust modification. In the same figure, 1 indicates the 1st part of the A section, 2 indicates the flange wrinkle, and 8 indicates the provisional slippage.

Example 1 Equipped with an extruder that supplies an ethylene-maleic anhydride ff (double Ti, %)-butyl acrylate (80 wt U%) ternary co-monomer with a melt index of 4.59/i4 Inflation die (diameter 150 m)
The tubular body was taken up and cut using an inflation weight having a take-up speed of 7.0=/min and a blower/tube size of 2.0 to give a fold diameter of 470=+11. Thickness 50μ
A film was obtained. Table 1 shows the physical properties of the vB fingers used.

Using the obtained film, heat pressure MC1ro℃, 5 minutes, 80Kf/clI was applied between 0.8 wm thick cold rolled steel plates.
l) l, adhesion, processability and vibration absorption were measured.

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

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

Comparative Example 1 A Santoi "t" plate was prepared as follows using a resin composition mainly composed of a carboxylic acid-modified polyolefin resin disclosed in Example 4 of JP-A-59-80454.

Maleic anhydride 0,
7% by weight and t-butyl peroxylaurate 0612
% by weight was added and mixed for 2 minutes using a Henschel mixer, which was then kneaded by extrusion at 80 vmψ set at 190°C and pelletized.

100 parts by weight of this modified polyethylene and a linear low-density ribbon with a melt index of 4 g/10 minutes (
125 parts by weight (manufactured by CdF Ch 1m1e) and 25 parts of methyl methacrylate polymer were mixed, and the mixture was kneaded in an 80wφ extruder set at 190°C, and then pelletized.

This material was formed into a film in the same manner as in Example 1, and the resulting film was heat-pressed (170°C, 5 minutes, 80 to 4/i) between 0.8 m thick cold rolled steel plates. Adhesion and workability Figure 8 shows the temperature-loss coefficient (η
).

Table 1 Table 2 Easy unprinting of 10 drawings FIG. 1(a) is a cross-sectional view of the bending test mold.

FIG. 1(b) is a perspective view of a molded product tested by bending back.

FIG. 2(a) is a sectional view of a drawing test mold.

FIG. 2(b) is a perspective view of a molded product tested for drawability.

FIG. 8 is a diagram showing the relationship between temperature and loss coefficient (η) of the damping material.

Claims (9)

[Claims] (1) A damping material composed of a damping layer made of thermoplastic resin sandwiched between two metal plates, the damping layer comprising:
The elongation rate at a temperature of 20°C is 50% or more, and the loss factor (
An ethylene-maleic anhydride copolymer containing 0.3 to 20% by weight of maleic anhydride with a peak temperature of tan δ) in the range of -50 to 130°C, and a melt index of 0.5 to 50 g/10 min. or ethylene 30-98
．． 7% by weight, 0.3-20% by weight of maleic anhydride, and 1-50% by weight of at least one ester selected from alkyl acrylates or alkyl methacrylates containing an alkyl group having 1 to 6 carbon atoms. It is characterized by being made of a resin composition containing a terpolymer as a main component, and having an adhesive strength between the damping layer and a metal plate of 3 kg/cm or more in a 180° peeling test at a temperature of 20°C. vibration damping material. (2) The peak temperature of the loss coefficient (tan δ) of the resin composition is in the range of -20 to 115°C, and the peak value is 0.
．． 5 or more, the damping material according to claim 1. (3) The damping material according to claim 1, wherein the damping layer has a thickness of 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 constructed by sandwiching a damping layer made of thermoplastic resin between two metal plates, the damping layer comprising:
The elongation rate at a temperature of 20°C is 50% or more, and the loss factor (
An ethylene-maleic anhydride copolymer containing 0.3 to 20% by weight of maleic anhydride with a peak temperature of tan δ) in the range of -50 to 130°C, and a melt index of 0.5 to 50 g/10 min. or ethylene 30-98
．． 7% by weight, 0.3-20% by weight of maleic anhydride, and 1-50% by weight of at least one ester selected from alkyl acrylates or alkyl methacrylates containing an alkyl group having 1 to 6 carbon atoms. It is made of a resin composition containing a terpolymer as a main component, and the adhesive strength between the damping layer and the metal plate is 3 kg/cm or more in a 180° peeling test at a temperature of 20°C. Automotive parts with excellent vibration damping properties using characteristic vibration damping materials. (6) The part according to claim 5, wherein the automobile part is an engine part. (7) The component according to claim 6, wherein the engine component is an oil pan. (8) The part according to claim 5, wherein the automobile part is an automobile body part. (9) The part according to claim 8, wherein the automobile body part is a floor panel, a dash panel, or a door.