JPS62248634A - Vibration-damping sound-insulating sheet for car - 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] <Industrial Application Field> The present invention relates to a plate-shaped damping layer that is adhered to a vehicle panel surface, and a soundproof porous structure made of a foamed rubber compound formed on the damping layer. Conventionally, the above-mentioned vibration-damping and sound-insulating structures have been made using rubber layers, as shown in Fig. 3. A damping layer forming material in the form of a sheet made of an adhesive compound is set on the vehicle floor surface, and then heated and softened in a drying oven or the like to blend into the vehicle floor surface (vehicle panel) l to form the damping layer 2. A soundproof layer 3 is formed by cutting and pasting a soundproof layer forming material made of felt (poor followability) or the like on the damping layer 2. A mat layer 5 is formed on the soundproof layer 3 by adhering a mat layer forming material (usually a backed carpet). Note that felt herein refers to natural fibers, synthetic fibers, recycled fibers, etc., impregnated with synthetic resins such as phenol resins and vinyl acetate resins, and then hardened into a plate shape.

This vibration damping and soundproofing structure had the following problems.

(A) Formation of the damping layer and the soundproofing layer are separate processes, and the soundproofing layer is formed by cutting and pasting, so the total number of construction steps increases.

(b) Due to the cutting and pasting of felt, there are parts where the soundproof layer is not formed as shown in the example.

Soundproofing effect is not good.

Therefore, in order to solve the above-mentioned problems, the inventors of the present application first created a damping layer forming material made of a rubber-based adhesive compound;
Patent application No. 59-22705 for a vibration-damping and sound-insulating sheet for vehicles having a laminated structure with a sound-insulating layer forming material made of a foamed rubber compound.
The construction of this anti-vibration sheet is proposed in the specification attached to the patent application No. 9 (unpublished).
Place it on the vehicle panel surface and dry it in a drying oven (heating temperature usually 1.
40 to 160° C.), the damping layer forming material 7 in the state shown in FIG. 4 is heated and softened to form the vehicle panel surface 1.
The soundproof layer forming material 8 is foamed to form a porous soundproof layer 12 and a porous soundproof layer 13, respectively (see FIG. 5).

Furthermore, in FIG. 5, the porous soundproof layer 13 is
The inventors of the present invention have proposed a soundproofing layer forming material that is flat at the interface (Patent Application No. 60-27)
(See No. 0101 (unpublished)).

<Problems to be Solved by the Invention> This vibration-damping and sound-insulating sheet can solve the above-mentioned problems. However, since the porous soundproofing layer 13 is formed on the interior side of the vehicle, the pores of the porous soundproofing layer 13 have a soundproofing effect on the sound from the outside of the vehicle. When the air enters the hole, there is a problem in that the air vibration is attenuated by the resistance of the peripheral wall of the hole, and the conversion into thermal energy is not performed effectively.

Therefore, in order to improve sound insulation, the thickness of the porous sound insulation layer must be increased, but this is not desirable as it increases weight and material cost (see comparative example in Table 2).
.

Means for Solving the Problems〉 In view of the problems mentioned above, the inventors of the present invention have conducted extensive studies, and as a result, they have placed a plate on top of the porous soundproof layer, and created a structure that combines the plate and vibration damping layer. We noticed that if the porous sound insulation layer is sandwiched between the two layers, the vibration damping and sound insulation sheet will have a typical sound absorbing board structure, and we came up with the idea of a vibration damping and sound insulation sheet for vehicles with the following structure.

That is, to form a vibration-damping and sound-insulating structure comprising a plate-shaped damping layer that is adhered to the vehicle panel surface and a porous sound-insulating layer made of a foamed rubber compound formed on the damping layer. 4Stl refers to a vibration-damping and sound-insulating sheet used in a porous sound-insulating layer in which a resonance absorbing plate is formed.

Detailed Description of Means> The configuration of each of the above means will be explained in detail with reference to an example in FIG. FIG. 1 is a cross-sectional view of the vibration-damping and sound-insulating sheet for a vehicle according to the present invention, and FIG. 2 is a cross-sectional view showing a construction mode thereof.

(a) Damping layer The material for forming the damping layer forming material 7 is not particularly limited, but is generally a rubber-based adhesive compound (rubber component).

A mixture of bituminous components, filler components, softener components, etc.) is used. In order to maintain the desired vibration damping performance even in high-temperature ranges, there are some rubber-based viscous compounds described in (h) mixed with a cross-linked thermosetting resin that can co-cross-link with the rubber component (in this application). See Japanese Patent Application No. 60-158796 (unpublished) by the inventors.

Some damping layer forming materials have a two-layer structure of (a) adhesive layer forming material and (b) constraining layer forming material. Here, (a) the adhesive layer forming material can generally be the above-mentioned rubber-based adhesive compound or one in which a crosslinkable thermosetting resin capable of co-crosslinking with the rubber component is mixed therein ( (See Japanese Patent Application No. 60-158798 (unpublished) by the present inventors, etc.).

(i) For the constrained layer forming material, a thermosetting resin that can be co-crosslinked with the rubber component of the adhesive layer forming material (a) can be used. These include unsaturated polyester resin, silicone capped phenolic resin, epoxy resin, urea resin, etc. This thermosetting resin is kept in a semi-hardened state before installing the vibration damping and sound insulating sheet so that it will fluidize and become familiar with the vehicle panel surface 1 at the beginning of heating (see prior art) and then harden. It is desirable to mix various reinforcing agents, fillers, etc. into the width of the curable resin.

(a) As a constraining layer forming material, it is also possible to use a material in which a quality component is mixed into the above-mentioned thermosetting resin. Furthermore, a rubber component can also be mixed.

Furthermore, (a) as the constrained layer forming material, a rubber component mixed with a Koga component, an inorganic filler, a fibrous filler, etc. can also be used.

For the above, please refer to Japanese Patent Application No. 60-158797 filed by the present inventors.

(b) Porous soundproofing layer The material 8 for forming the porous soundproofing layer includes conventional rubber polymers such as carpon black, zinc white, inorganic fillers, softeners, tackifiers, vulcanizing agents, and vulcanization accelerators. A foamed rubber compound is used, which is obtained by adding and kneading a foaming agent to the rubber compound. The rubber-based polymer is selected from gutter rubbers such as NBR, IIR, EPDM, SBR, and natural rubber, and their recycled rubbers. ! Alternatively, a mixture of two or more types can be exemplified.

Here, if the above-mentioned rubber-based polymer consists of 15 to 85 wt% of l,2-polybutadiene and the remainder of rubber, the material for forming the porous soundproof layer will be slightly absorbed during the heating process during construction. The fluidity of the floor surface appears, and the surface becomes flat regardless of the uneven shape of the vehicle's grooves.This is suitable because it can meet the demand for flat floor surfaces, which has been increasing in demand from users in recent years. (See Japanese Patent Application No. 60-270101 filed by the present inventors).

Incidentally, various compounding agents and blowing agents are added to the rubber-based polymer so that open cells are formed in the porous soundproof layer. If each bubble is independent, a resonance transmission phenomenon will occur, and the sound insulation performance against sounds outside the vehicle will deteriorate, which is not preferable.

(C) Resonance absorbing plate material 9 After the construction described in (e) below, the forming material 9 of the resonance absorbing plate material 9 becomes a plate shape (resonance absorbing plate material 24), and the damping layer 1
The material is not particularly limited, as long as it can form a typical sound-absorbing plate structure of one plate and one porous layer by sandwiching the porous sound-insulating fi 23 between them. The material 7 can be used as it is as the forming material 9 of the resonance absorbing plate calendar. In addition, vinyl chloride resin, ETA
, PMMA, PE, PP, various synthetic resins such as vinyl acetate resin, and various elastomers can also be used.

Furthermore, when using a specific foamed rubber compound containing 1,2-polybutadiene as the forming material 8 of the porous soundproofing layer, the upper surface of the porous soundproofing layer 23 (the surface in contact with the resonance absorbing plate) is flat. Therefore, a plate material (metal, synthetic resin, ceramic, etc.) can be used as the resonance absorbing plate 24 as is. In addition, the lining part of the mat layer 5 is formed with high density to have a substantially plate shape, and the lining part of the mat layer 5 is formed into a substantially plate shape, and the lining part of the mat layer 5 is formed into a substantially plate shape.
It is also possible to do this.

In addition, this resonance absorption plate W! If 24 is too heavy, the rubber compound forming the porous soundproof layer may not be sufficiently foamed or the porous soundproof layer 23 may sag, which is not desirable.

(d) Formation of vibration-damping and sound-insulating sheet Each of the above-mentioned compositions of (a) vibration-damping layer, (b) porous sound-insulating layer, and (C) resonance absorbing plate is mixed in a kneader, panburi mixer, etc., and then rolled. Separated or extruded sheet-shaped damping layer forming material 7 (usually 0.2 to 5 mm), porous soundproofing layer forming material 8 (usually 1 to 5 mm), resonance absorbing plate forming material 9
(usually 0.5 to 31 cm), and then laminated with each molding material to form the vibration damping and soundproofing sheet of the present invention (see Figure 1). Keep it as a separate long object.

After cutting each piece to a predetermined size, it can be laminated or rolled out or extruded at the same time.

Incidentally, when the resonance absorbing plate 24 is a portion lined with a plate material such as metal or a mat layer with high density.

The damping layer forming material 7 and the porous sound insulating layer forming material 8 are formed in the same manner as described above, and are pasted in F7m layers. Then, the plate material or the mat layer is formed into a predetermined shape so that it can be attached to the porous soundproof layer.

(e) Construction of vibration-damping and sound-insulating sheet When the vibration-damping and sound-insulating sheet thus obtained is a triple 81-layer structure consisting of a damping layer molded material 7, a porous sound insulation layer molded material 8, and a resonance absorbing plate molded material 9. To do this, the vibration-damping and sound-insulating sheet is set on the vehicle panel surface 1 and passed through a drying oven (heating temperature is usually 140-160°C). The damping layer 12 roars as it adjusts due to its own weight.

The porous soundproofing layer forming material 8 is foamed to form the porous soundproofing layer 24. Here, the rubber polymer component of the material 8 for forming the porous soundproof layer is 1.2-polybutadiene...15 to 85 wt.
%, rubber content...remaining part, then during heating, the porous soundproofing layer forming material 8 exhibits some fluidity, and the interface with the resonance absorbing plate 24 becomes flat.

The material 9 for forming the resonance absorbing plate 24 also becomes the resonance absorbing plate 24 by the heating.

In addition, when using a plate material such as a metal or a part lined with a high density Yat layer as the resonance absorbing plate 24, a granular layer of the vibration damping layer forming material 7 and the porous sound insulating layer forming material 8 is used in advance. is placed on the vehicle panel surface 1 and heated in the same manner as above to form the damping layer 1.
2 and a porous soundproof layer 23 are formed. Then, the plate material or mat layer is attached to L of the porous soundproof layer 23.

<Operations and Effects of the Invention> The vibration damping and sound insulating sheet for vehicles of the present invention comprises a plate-shaped damping layer that is adhered to the vehicle panel surface as described above, and a foam rubber compound formed on the damping layer. This vibration-damping and sound-insulating sheet is used to form a vibration-damping and sound-insulating structure comprising a porous sound-insulating layer, and has a structure in which resonance absorbing plates are formed on the porous sound-insulating layer.

Such a vibration damping and sound insulating sheet has a typical sound absorbing plate structure of plate (vibration damping layer) - porous layer (porous sound insulating layer) - plate (resonance absorbing plate calendar), and its resonance absorption effect reduces external noise from the vehicle. to ensure quietness in the vehicle interior.

Therefore, in order to improve the soundproofing effect of the vibration damping and sound insulating sheet for vehicles, there is no need to make the thickness particularly thick as in the vibration damping and sound insulating sheet for vehicles of the prior application (see comparative example in Table 2). According to the invention, it is possible to improve the soundproofing performance of a vibration-damping and sound-insulating sheet for a vehicle without particularly increasing the weight or material cost of the sheet.

<Example> (1) The damping layer molded material 7 was formed by kneading a rubber-based adhesive compound of the following composition in a kneader and extruding it to a thickness of one layer.

Damping layer compound (Unit: parts by weight) Straight asphalt (80/100) 30 Bronze asphalt (10/20) 40 Recycled SBR30 Petroleum resin (softening point 100°C) 10 Process oil 5 Talc
100 mica
10 asbestos
30(2) Forming material 8 of the porous soundproof layer was formed by kneading a foamed rubber compound of the following composition in a kneader and dispensing it to a predetermined thickness such that the thickness after one foaming was 10s layer.

Foamed rubber compound (unit double placement) 1.2-polybutadiene 50 natural rubber
50 zinc white
5 stearic acid 2 calcium carbonate 150 process oil 50 carbon black
20 sulfur
1.5 Vulcanization accelerator
2.5 Foaming agent 10
Foaming aid 10(3) The molding material 9 of the resonance absorbing plate calendar is a rubber compound (
A-C) were kneaded in a kneader and extruded to the thickness of two intestines.

The thus obtained forming materials for each layer were pasted together in 81 layers to obtain vibration damping and sound insulating sheets of Examples (1 to 3) shown in Table 2.

In addition, when the molding material 9 of the resonance absorbing plate is a resin-based compound (d, e in Table 1), it is difficult to apply it to the molding material 8 of the porous soundproofing layer molded previously when it is in a liquid state. ) or sprinkled on it (when in powder form) and heat-treated to a semi-cured state to form vibration-damping and sound-insulating sheets of each example (4°5).

The height is 2mm.

In the case of f (steel plate) in Table 1, the damping layer forming material 7 and the porous soundproofing layer forming material 8 are pasted, set on the panel surface 1 of the vehicle and heated, respectively. After forming the porous sound insulating layer 23, a resonance absorbing plate made of a steel plate having a thickness of 0.8 mm was adhered to the porous sound insulating layer 23 to obtain the vibration damping and sound insulating sheet of Example 6.

(4) Regarding each of the above Examples, tests were conducted for each item shown below. The test results are shown in Table 2.

Test item - Expansion ratio of porous soundproof layer... Place the unfoamed molding material 8 on release paper and heat and foam in a constant temperature bath at 150°C for 30 minutes. It was determined from the rate of change in thickness before and after foaming.

■Water absorption rate of porous soundproofing layer (evaluation of bubble continuity) -20
mmX 20m5c7) Unfoamed sheet at 150℃ x 30
Heat and foam the mixture under 40°C water 111,
It was determined from the weight change rate after being immersed for 1 hour under a reduced pressure of 130 mmHl.

■Sound insulation property: Vibration and sound insulation sheet is made of iron plate (240■IX1
50mmX0.8sst) After human set, 150
The test was performed on a test piece obtained by heat treatment under the conditions of 30 minutes at °C.

In general, the sample was attached to the opening at the boundary between the sound source chamber and the sound source chamber, and while the 71 waves under test were being oscillated steadily from the speaker in the sound source chamber, each of the sound source chamber and the sound receiving chamber was The sound pressure level was measured using a 1/3 octave analyzer via a microphone, and was determined as the difference between the sound pressure levels in both chambers.

■Vibration damping properties: Test pieces obtained in the same manner as in the sound insulation test were judged based on the loss coefficient calculated from the measurement results by the damping method in an atmosphere of 20°C.

■Followability/Surface flatness...The vibration control 11 sheet (approximately 700m x 400mm) of each example fist comparison example was set on a corrugated iron plate (corrugated shape: R15m5. depth 15mm) l, The heat treatment was carried out under the following conditions, and the followability and surface flatness were evaluated using n-vision, where 0: good, X: bad.

The thickness of the resonance absorbing plate f is 0.8 mm.

From the results in Table 2, it can be seen that the vibration damping and sound insulating sheet for vehicles of the present invention has approximately half the wall thickness as that of the prior application and has the same sound insulating effect.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a vibration-damping and sound-insulating sheet for a vehicle as an example of the present invention, Fig. 2 is a cross-sectional view showing a construction mode thereof, and Fig. 3 is a cross-sectional view showing a construction mode of a conventional vibration-damping and sound-damping sheet for a vehicle. 4 is a sectional view of a vibration damping and sound insulating sheet for a vehicle according to the prior application, and FIG. 5 is a sectional view showing a similar construction mode. 1...Vehicle panel surface. 5... Sheet. 7... Vibration damping layer forming material, 8... Porous sound insulating layer forming material, 9... Resonance absorbing plate formation material, 12... Vibration damping layer, 23... Porous sound insulating layer . 24... Resonant absorption board calendar. Figure 1 Figure 2

Claims (1)

[Scope of Claims] A vibration damping and sound insulating structure comprising a plate-shaped damping layer attached to a vehicle panel surface and a porous sound insulating layer made of a foamed rubber compound formed on the damping layer. 1. A vibration-damping and sound-insulating sheet for a vehicle, characterized in that a resonance absorbing plate is formed on the porous sound-insulating layer.