JPH068039B2 - Damping composite 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, vinyl acetate-ethyl acrylate copolymer (Japanese Patent Publication No. 35662/1985),
A copolymer obtained by grafting a mixture of styrene and acrylonitrile onto a vinyl acetate-ethylene copolymer (Japanese Patent Publication No. 4617064), and a resin composition mainly composed of a carboxylic acid-modified polyolefin resin (JP-A-59-80454). No.), a laminated structure having a composition as an intermediate layer, a material in which a filler such as calcium carbonate is added to bitumen, 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 adhesion control with 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.

In addition, 180 ° bending, which is called hemming, is applied to the edge processing of the vibration-damping metal plate. However, in such severe processing, the wavy and wrinkled surface of the metal plate becomes even more severe, and it is practically used. It was unbearable.

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

The inventors of the present invention have conducted extensive studies to provide such an excellent vibration damping material, and as a result, a vibration damping material formed by sandwiching a damping layer made of a thermoplastic resin between two metal plates is used. The damping layer is composed of at least two multilayers, and at least one of them has an elongation of 50 at a temperature of 20 ° C.
% Or more, the loss factor (tan δ) peak temperature is -50 to
It contains 0.3 to 20% by weight of maleic anhydride in the range of 130 ° C. and has a melt index of 0.5 to 50 g / 10.
Minutes ethylene-maleic anhydride copolymer and / or ethylene 30-98.7% by weight, maleic anhydride 0.3
To 20 wt% and 1 to 50 wt% of at least one ester selected from alkyl acrylate or alkyl methacrylate containing an alkyl group having 1 to 6 carbon atoms as a main component Which is composed of a multi-layer of a vibration-damping layer made of the resin composition or a multi-layer of the vibration-damping layer and a layer of another resin, and the adhesion strength between the metal plate and the layer in contact with the metal plate is 180 ° at a temperature of 20 ° C. In the peeling test, they have found that the vibration-damping composite material having a vibration damping property of 3 kg / cm or more has excellent vibration-damping properties as well as processing control and heat resistance, and thus reached the present invention.

The present invention will be described in detail below.

The thermoplastic resin that can be used in the damping layer of the present invention includes 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, Alternatively, ethylene 30 to 98.7% by weight, maleic anhydride 0.3 to 20% by weight, and 1 to 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, a third 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.

The damping layer of the present invention includes a multilayer damping layer made of the same or different resin composition according to the present invention.

When the damping layer is a multi-layer composed of at least one kind of the resin composition layer according to the present invention and another resin layer, examples of the other resin layer include a polyolefin resin layer and a polyester resin layer.

The polyolefin resin is mainly polyethylene or polypropylene, and for example, ethylene-vinyl acetate copolymer, ionomer resin or α-olefin-glycidyl methacrylate-vinyl acetate copolymer or other olefin-polar vinyl compound copolymer, Alternatively, a resin containing a carboxylic acid-modified resin such as a maleic anhydride-modified polyolefin may be used.

Among these, the addition of carboxylic acid modified resin
It is desirable because it has excellent adhesion to steel plates.

The polyester resin comprises a dicarboxylic acid component such as terephthalic acid and a diol component, and the dicarboxylic acid component other than terephthalic acid has 2 carbon atoms such as azelaic acid, sebacic acid, adipic acid and dodecanedicarboxylic acid.
To 20 fatty acid dicarboxylic acids, isophthalic acid, naphthalenedicarboxylic acid and other aromatic dicarboxylic acids, or cyclohexanedicarboxylic acid and other alicyclic dicarboxylic acids, alone or as a mixture, as the diol component, ethylene glycol, 1,3-propanediol, Aliphatics such as 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, neopentyl glycol, 1,4-cyclohexanediol, 2-ethyl-2-butyl-1,3-propanediol A resin obtained by polymerizing a glycol or an alicyclic glycol alone or in a mixture.

To this polyester resin, a resin having an epoxy group, such as an epoxy resin, is added to prevent deterioration and improve adhesive strength.
It is possible to mix less than or equal to wt%.

20% by weight or less of an amorphous polymer or a filler can be added to the resin composition, the polyolefin resin, and the polyester resin according to the present invention.

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 sheet used for the composite material is generally 50% 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 from the physical properties of the obtained composite material.

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 the composite material using the resin whose peak temperature is outside this range is generally used. This is because the vibration damping capability at temperature is poor.

The present inventors have found that the peak temperature of the loss factor (tan δ) of the resin and the peak temperature of the loss factor (η) in the mechanical impedance method, which is the standard of the damping property of the composite material using it as the damping layer. In the meantime, the former temperature is 10 ~ 30 ℃
It was found that there is a correlation that the temperature added to the temperature becomes the latter.

Therefore, as a material at a general use temperature, that is, an outside air temperature of -10 to 50 ° C and an industrial material use temperature of 0 to 145 ° C,
It was found that the peak temperature of the loss coefficient (tan δ) needs to be -20 to 115 ° C.

Based on this, the above-mentioned peak temperature range of tan δ was determined so that the peak temperature of η of the composite material overlaps with its use 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 examination, the peak value of the loss coefficient (tan δ) is 0.5.
As described above, at least one layer is the resin composition of the present invention, and when the resin layers having different peak temperatures of 5 to 20 ° C. are combined, excellent performance that extremely wide vibration damping is obtained can be obtained. I understood.

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 is sufficient that high vibration damping performance is maintained in a temperature range of 50 to 130 ° C. around 80 to 90 ° C. and in a temperature range of 10 to 50 ° C. for automobile body materials.

For this application, the glass transition temperature (Tg) is 45-60 ° C.
It has been found that it is most preferable to use a multilayer film having a three-layer structure composed of the resin layer of 1), the resin layer of 60 to 75 ° C and the resin layer of 75 to 90 ° C.

If the total thickness of the resin layers, that is, the composite film thickness, is 30 μ or more, the vibration damping performance is good, but in order to have good workability such as bending drawing, it is preferably 100 μ or less, and most preferably 30 μ. It is desirable that it is not less than 60 μm.

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.

In the method for carrying out the present invention, one kind of resin is formed into a film by a usual forming method such as inflation processing, calendering, T-die processing, etc., and layers of other resins are provided on the inner and outer surfaces of this film. . As the method, if existing techniques such as a method of forming each film by dry lamination, a method of forming a laminated film by a heat lamination method, a method of extrusion laminating, a method of simultaneously forming a laminated film by a multilayer extrusion method are used. Of these, the method of molding by the multi-layer extrusion method is particularly preferable in terms of easiness of molding, interlayer adhesion of the obtained film, and cost.

As a multilayer molding method, up to 3 types and 3 layers are generally used in terms of cost, easiness of forming, etc.
It was found that the vibration damping performance was further improved when the layer-processed films were stacked to form 5 to 6 layers.

In this case, it is costly and easy to bond the steel sheet to a five-layer structure by supplying the inflation-processed film of type 2/3 layer or film of type 3/3 layer after pinch roll in a tube shape. It turned out to be preferable.

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, an ordinary batch method or a continuous hot pressing method can be arbitrarily applied.

For example, there is a method in which a resin is interposed between a metal plate and a metal plate, and thermocompression bonding is performed.

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 noise reduction of 3 dB could be achieved at a place about 1 m away from the engine.

It was also found that the effect of applying noise to vehicle interior materials, especially floor panels or dash panels, is 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 a bicycle, a motorcycle or the like as a general transportation means, good results can be obtained when it is 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 is the Toyo Baldwin Rheovibron (110).
Hz) and the elongation was determined at 20 ° C. and a pulling speed of 200 mm / min.

The loss factor (η), which represents the vibration absorption capacity of the damping material, is the forced vibration by the mechanical impedance method (central vibration) and the frequency is
The measurement was performed at 1000 Hz and a temperature of 20 to 130 ° C. Adhesion test between metal plate and damping layer is cold rolled steel plate (0.8mm) /
(50μ) / 190 with cold rolled steel plate (0.8mm)
Bonding was carried out under the conditions of 30 ° C./cm ² for 5 minutes at a temperature of 180 ° and a pulling speed of 50 mm / min.

The melt index was measured according to JIS K6760. As for workability, the molds shown in FIGS. 1 and 2 were used, and bending back and drawing workability 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 Linear low-density polyethylene with a melt index of 4 g / 10 min (Sumikasen LGA401 manufactured by Sumitomo Chemical Co., Ltd.)
0.7% by weight of maleic anhydride and 0.1% by weight of t-butylperoxylaurate were added to and mixed with a Henschel mixer for 2 minutes.
The mixture was kneaded with a φ extruder and then pelletized.

100 parts by weight of this modified polyethylene, 125 parts by weight of linear low-density polyethylene (Sumikasen LGA 401 manufactured by Sumitomo Chemical Co., Ltd.) with a melt index of 4 g / 10 min, and a methyl methacrylate polymer (SUMIPEX B manufactured by Sumitomo Chemical Co., Ltd.) -LO) (25 parts by weight) was mixed, and the mixture was kneaded by an extruder having a diameter of 30 mm and set at 190 ° C, and then pelletized. An extruder for supplying the pellets as the inner and outer layers and an ethylene-maleic anhydride (2% by weight) -butyl acrylate (30% by weight) terpolymer as the intermediate layer for 4.5 g / 10 minutes of melt idenx Using an inflation device with a multi-layer inflation die (caliber 150 mm) equipped with an extruder to
The film was taken out under conditions of a take-up speed of 7.0 m / min and 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 resin of the intermediate layer 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. Figure 3 shows
It is a temperature-loss coefficient ((eta)) relationship figure of a damping material.

Example 2 Similar to Example 1, the melt index was 2.0 g / 1.
An extruder supplying 0-minute ethylene-maleic anhydride (2% by weight) -butyl acrylate (5% by weight) terpolymer as inner and outer layers, and a melt index of 4.5 g / 10
Equipped with an extruder that supplies the terpolymer of ethylene-maleic anhydride (2 wt%)-butyl acrylate (30 wt%) as an intermediate layer, and an inflator with a multi-layer inflation die (diameter 150 mm) is used. Take up the tubular body at a take-up speed of 7.0 m / min and a blow-up ratio of 2.0.
Under the above conditions, it is folded and folded, and the diameter is 470mm and the thickness is 100μ.
I got a film that is Table 1 shows the physical property values of the resin for the inner and outer layers and the intermediate layer.

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 relationship diagram of the temperature-loss coefficient (η) of the vibration damping material.

Comparative Example 1 A sandwich steel sheet 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.

This modified polyethylene and melt index 4g / 10
Minute linear low-density polyethylene (manufactured by CdF Chimie) and methyl methacrylate polymer were mixed in the same proportion as in Example 1, and the mixture was kneaded by an extruder of 30 mmφ set at 190 ° C. and then pelletized.

A film obtained by forming a film using this material in the same manner as in Examples 1 and 2 was subjected to thermocompression bonding (230 ° C., 5 minutes, 30 kg / cm ² ) between 0.8 mm thick cold rolled steel plates. The adhesiveness, processability and vibration absorption were measured.

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

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

Claims (9)

[Claims] 1. A vibration-damping composite material constituted by sandwiching a sex-vibration layer made of a thermoplastic resin between two metal plates, wherein the vibration-damping layer is constituted by a multilayer of at least two layers. At least one layer of which has an elongation of 50% or more at a temperature of 20 ° C. and a peak temperature of a loss coefficient (tan δ) of −50 to 13
An ethylene-maleic anhydride copolymer containing 0.3 to 20% by weight of maleic anhydride in the range of 0 ° C. and a melt index of 0.5 to 50 g / 10 min and / or 30 to 98.7% by weight of ethylene, anhydrous Terpolymer of 1 to 50% by weight of at least one ester selected from alkyl acrylate or alkyl methacrylate containing an alkyl group of 1 to 6 carbon atoms and 0.3 to 20% by weight of maleic acid. A vibration-damping composite comprising a resin composition containing as a main component, and having an adhesive strength between the vibration-damping layer and the metal plate of 3 kg / cm or more in a 180 ° peeling test at a temperature of 20 ° C. material. 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 composite material. 3. The vibration-damping composite 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 damping composite material according to claim 1, wherein the damping layer has a thickness of 0.3 to 5 mm. 5. A vibration-damping composite material, which is formed by sandwiching a vibration-damping layer made of a thermoplastic resin between two metal plates, wherein the vibration-damping layer is composed of a multilayer of at least two layers. At least one layer of which has an elongation of 50% or more at a temperature of 20 ° C. and a peak temperature of a loss coefficient (tan δ) of −50 to 13
An ethylene-maleic anhydride copolymer containing 0.3 to 20% by weight of maleic anhydride in the range of 0 ° C. and a melt index of 0.5 to 50 g / 10 min and / or 30 to 98.7% by weight of ethylene. , Maleic anhydride 0.3-20
Resin containing, as a main component, 1% to 50% by weight of at least one ester selected from alkyl acrylate or alkyl methacrylate containing 1% to 6% alkyl groups. The adhesive strength between the vibration damping layer and the metal plate is 18 at a temperature of 20 ° C.
Automotive parts with excellent vibration damping using a vibration damping composite material characterized by having a peeling test at 0 ° C 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. A component according to claim 8, wherein the automobile body component is a floor panel, a dash panel or a door.