JPH0820873B2 - Lightweight soundproof material that can be deep-drawn - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightweight soundproofing material, and more particularly to a lightweight soundproofing material which is excellent in deep drawability and which can reduce the weight of the soundproofing material itself and can follow severe irregularities.

[0002]

2. Description of the Related Art Conventionally, for example, as a ceiling material for automobiles, a molded ceiling material obtained by pressure-molding felt alone or integrally with a non-woven fabric skin material has been used. In addition, recently, a molded ceiling material has been manufactured in which the honeycomb plate 1 is placed with the felt 4 and is integrated with the non-woven fabric skin material 6 to be heat-pressed.

However, although the molded ceiling material made of only felt is excellent in deep-drawing formability, satisfactory performance in sound absorption and rigidity cannot be obtained. Further, the molded ceiling material in which the honeycomb plate 1 is sandwiched by the felt 4 and integrated with the non-woven fabric skin material 6 has a drawback that the soundproof material itself increases in weight although it has excellent sound absorption and rigidity.

[0004]

SUMMARY OF THE INVENTION The object of the present invention is to reduce the weight of a soundproofing material in order to further reduce the weight of an automobile, and at the same time, the soundproofing material is excellent in sound absorption and rigidity. The point is to achieve deep drawability.

[0005]

As a solution to this problem, the inventors of the present invention have conducted intensive studies and found that one side of the felt 4 on which the honeycomb plate 1 is placed is replaced with a resin cotton 2 and a skin layer 3. Therefore, the gist of the present invention lies in the following items.

After the resin cotton 2 and the skin layer 3 are integrated, they are impregnated in a thermosetting resin, dried and then integrated on one surface of the honeycomb plate 1, and the other surface is integrated with the felt 4. A lightweight soundproof material that can be deep-drawn because it is made into a material.

[0007]

A light-weight soundproof material capable of deep drawing, characterized in that paper, glass mat, or glass paper is used as the skin layer 3.

A lightweight soundproof material capable of deep drawing, characterized in that an adhesive 5 is applied in advance on at least one surface of a honeycomb plate 1.

The resin cotton 2 which is an essential constituent of the present invention is a resin fiber which is lightly compression molded, and examples thereof include polyester fiber, polyamide fiber, polyvinyl alcohol fiber and polyvinyl chloride fiber.

As the skin layer 3, it is indispensable that the weight can be reduced as compared with the case where the felt is used.
It is preferable that it also has a surface reinforcing function, and examples thereof include glass paper, glass mat, and paper.

It is essential that the resin cotton 2 and the skin layer 3 are previously impregnated with a thermosetting resin. The thermosetting resin is a phenol resin, a polyelter resin, a urethane resin, a melamine resin, a paraffin resin or the like, and the impregnation method is preferably dipping or coating. The amount of the thermosetting resin impregnated in the resin cotton 2 is required to ensure the adhesion with the honeycomb plate 1, and is preferably about 1 to 100% of the weight of the resin cotton. The amount of impregnation may be selected depending on whether or not the adhesive is applied.

The honeycomb plate 1 is preferably made of a paper material such as kraft paper, K-liner paper, cardboard or the like or a plastic material having a honeycomb structure in terms of formability.

The felt 4 integrated with one surface of the honeycomb plate 1 is mainly composed of one or more discontinuous fiber materials of animal, vegetable and synthetic resin and a binder such as thermosetting resin. It will be.

It is preferable to place a sound absorbing layer between the resin cotton 2 and the honeycomb plate 1 from the viewpoint of improving the sound absorbing performance, and one having a thickness about half that of the conventionally used felt 4 or polystyrene, polypropylene, A foam material such as polyurethane is used.

The surface densities of the constituent materials are 30 to 150 g / m ² for the skin layer 3 and ^{2 for} the resin cotton 2 when the thermosetting resin is impregnated.
Is about 30 to 100 g / m ² , and the felt 4 used conventionally is about 350 to 1000 g / m ² .

Honeycomb plate 1 and resin cotton 2 or felt 4
The adhesion with the adhesive may be performed only by heating and pressing without applying an adhesive, but using hot melt or the application adhesive 5 in the cells of the honeycomb plate 1 in advance makes the adhesion stronger. Is preferred.

As a method of integrally molding the respective constituent materials, for example, in the case where the honeycomb plate 1 is placed with the felt 4 and the resin cotton 2 integrated with the felt 4,
30 seconds to 2 minutes at 0 to 250 ° C, 1 to 200 kg / cm
The condition of ² is preferable.

[0019]

EXAMPLES The following examples are provided for a more detailed understanding of the present invention. Naturally, the invention is not limited to the following examples.

[0020]

Example 1 A resin cotton made of polyester fibers and a skin layer made of glass paper were integrated, impregnated in a phenol resin, and then dried to form an integrated product. After providing a bulky non-woven fabric of 500 g / m ² on one side of a cardboard honeycomb plate and an integrated body of resin cotton and a skin layer on the other side, at 200 ° C. for 45 seconds, 5 kg / cm ² Sound-proofing material 1 was obtained by pressure molding under the conditions and integrating them.

[0021]

Example 2 A resin cotton made of polyvinyl chloride fiber and a skin layer made of glass mat were integrated, impregnated in a melamine resin and then dried to form an integrated product. After providing a bulky non-woven fabric of 500 g / m ² on one side of a plastic honeycomb plate, and an integrated body of resin cotton and a skin layer on the other side, 200 ° C. for 45 seconds, 5 kg / cm ² condition Was pressure-molded and integrated to obtain a soundproof material 2.

[0022]

Comparative Example A soundproof material 3 was obtained by press-molding bulky felt on both sides of a cardboard honeycomb plate at 200 ° C. for 1 minute under the condition of 5 kg / cm ² and integrating them.

[0023]

[Test method] The weight per 1 m ^{2 of the} soundproof material 1 to the soundproof material 3 was measured, and the sound absorption coefficient was measured by the reverberation chamber method.

[0024]

Results: The soundproof material 1 had a weight of 1040 g / m ² and a sound absorption coefficient of 0.5 (250 Hz). The weight of the soundproofing material 2 is 1045 g / m ² , and the sound absorption coefficient is 0.5 (250H
z). The weight of the soundproofing material 3 is 1200 g / m ²
The sound absorption coefficient was 0.5 (250 Hz).

[0025]

EFFECTS OF THE INVENTION The soundproof material according to the present invention can achieve a light weight while maintaining a satisfactory soundproof effect.

[0026]

[Brief description of drawings]

FIG. 1 is a sectional view of a soundproof material according to the present invention.

FIG. 2 is a cross-sectional view of a conventional soundproof material.

[Explanation of symbols] 1 honeycomb plate 2 resin cotton 3 skin layer 4 felt 5 adhesive 6 non-woven fabric skin material

Claims (3)

[Claims] 1. A resin cotton and a skin layer are integrated, impregnated in a thermosetting resin, dried and then integrated on one surface of a honeycomb plate, and the other surface is integrated with felt. A lightweight soundproof material that can be deep-drawn. 2. The light-weight soundproofing material capable of deep drawing according to claim 1, wherein paper, glass mat or glass paper is used as the skin layer. 3. A deep-drawable lightweight soundproofing material according to claim 1, wherein an adhesive is applied in advance on at least one surface of the honeycomb plate.