JPH074897B2 - Molded soundproofing material for automobiles - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded soundproofing material for an automobile, which comprises a sound-absorbing material and a sound-insulating sheet integrated with each other. More specifically, it is a soundproofing material in which the fiber component of the sound-absorbing material is specified. The present invention relates to a molded soundproof material for automobiles, which is mounted on a dash panel that separates a vehicle interior from an engine room, to prevent engine noise.

[0002]

2. Description of the Related Art Conventionally, for example, in a dash panel or the like that separates an engine room and a vehicle interior of an automobile, a sound absorbing material formed by forming a bulk material of a fiber material or forming a foam material has been used. A sound-insulating sheet is used as a unit.

However, there is a long-awaited demand for the development of a molded soundproofing material having a further excellent soundproofing effect due to the demand for even quieter passenger compartments. In order to achieve such an object, the weight of the sound absorbing material is increased. Although the method of forming a bulky material improves the soundproofing effect, it is not preferable because the soundproofing material itself significantly increases in weight in proportion to the improvement of the soundproofing effect.

[0004]

SUMMARY OF THE INVENTION Therefore, according to the present invention, the weight per unit area of the sound absorbing material and the sound insulating material is not increased at all.
The purpose is to develop a molded soundproofing material that satisfies the required soundproofing effect in all frequency ranges.

[0005]

[Means for Solving the Problems] As a solution to the above problems, the inventors of the present invention have conducted intensive studies and as a result, by limiting a certain proportion of the fiber components constituting the sound absorbing material to a specific fiber raw material, the whole frequency range is reduced. The present invention has revealed that an excellent soundproofing effect can be realized, and the gist of the present invention lies below.

As a sound absorbing material made of fiber, 80 of the used fibers are used.
A molded soundproofing material for automobiles, characterized in that a sound absorbing material made of fiber, which is made of cotton by weight% or more, and a sound insulating sheet are integrated.

In the fiber sound absorbing material used in the present invention, it is essential that 80% by weight or more of the used fiber is cotton,
Other than less than 20% by weight is glass wool, hemp, wool, polyester fiber, nylon fiber, rayon, acrylic fiber,
It is possible to use organic or inorganic natural or synthetic fibers such as polypropylene fiber, polyethylene fiber, carbon fiber, kinol, and various metal fibers. If the amount of cotton used is less than 80% by weight, there is a possibility that a certain level or more of excellent sound absorbing performance may not be manifested in all frequency regions, which is not preferable.

[0008] The so-called fluff, which is formed by defibrating the woven cloth used for clothing and the like used in the conventional sound absorbing material made of fibers, has a cotton content of 30 to 40% by weight, It is necessary to mix cotton with a weight about three times as much as the used amount of the unwoven wool and to use it as a total amount of used cotton of 80% by weight or more.

Among the molded soundproofing materials of the present invention, a conventionally known manufacturing method can be used as a method for manufacturing the fiber sound absorbing material. That is, a fibrous raw material is mixed with a thermosetting resin such as phenol resin or a thermoplastic resin such as polyester or polypropylene to form a fleece, which is then heated to produce a semi-cured bulky fabric. A fibrous sound absorbing material is obtained by cutting this into an appropriate size, placing it on a molding die for molding into an arbitrary shape, and performing pressure molding or heat pressure molding.

When pressure molding or the like, rubber such as synthetic rubber, natural rubber or recycled rubber, binder such as bituminous material or synthetic resin, if necessary, is mixed with filler such as extender pigment and additive, and kneaded. It is also possible to form a soundproof material having excellent sound absorption performance and sound insulation performance by laminating it on a sound insulation material having excellent sound insulation performance that has been rolled and formed into a sheet and molding at the same time.

[0011]

EXAMPLES In order to understand the present invention, examples will be described below. Needless to say, the present invention is not limited to the examples below.

[0012]

Example 1 A raw material of a sound absorbing material made of fibers was manufactured by mixing a fiber raw material of 100% by weight of cotton with a phenol resin to form a fleece, heating it into a semi-cure state, and cutting it into an appropriate size. The raw material of the fiber sound absorbing material is placed on a lower mold heated to 200 ° C. and the upper mold is lowered to 100 kg.
Heat / press molding for 1 minute at a surface weight of 1000 / cm ² .
A molded product of a fiber sound absorbing material having a weight of g / m ² was prepared. Kneaded 40 parts by weight of butyl rubber, 5 parts by weight of blown asphalt, 50 parts by weight of calcium carbonate and 5 parts by weight of talc, and 3 mm
It was extruded to a thick thickness to form a sound insulating sheet. The sound insulation sheet was preheated at 100 ° C. for 1 minute, placed on a lower mold cooled to 5 ° C., and vacuum formed. The above-mentioned molded product of the sound absorbing material made of fiber is placed on the vacuum molded product of the sound insulation sheet via an adhesive, and the upper mold is lowered to 100 kg / cm ^2.
Was pressure-molded for 30 seconds to obtain an automobile molded soundproofing material 1 having a surface weight of 5500 g / m ² .

[0013]

Example 2 A phenolic resin was mixed with a mixed fiber raw material consisting of 80% by weight of cotton and 20% by weight of polyester fiber to form a fleece, which was then heated to a semi-cure state and cut into an appropriate size to absorb the sound of the fiber. A raw material was manufactured.
The raw material of the fiber sound absorbing material is preheated at 180 ° C. for 1 minute, then placed on the lower mold cooled to 5 ° C. to lower the upper mold, and cooled at 100 kg / cm ^{2 for} 1 minute. Pressure molding was performed to prepare a molded product of a fiber sound absorbing material having a surface weight of 1000 g / m ² . 40 parts by weight of butyl rubber, 5 parts by weight of blown asphalt, 50 parts by weight of calcium carbonate and 5 parts by weight of talc were kneaded and extruded to a thickness of 3 mm to obtain a sound insulating sheet. The sound insulation sheet was preheated at 100 ° C. for 1 minute, placed on a lower mold cooled to 5 ° C., and vacuum formed. Place the above-mentioned molded product of the sound absorbing material made of fiber through the adhesive on the vacuum molded product of the sound insulation sheet, lower the upper mold, and press-mold at 100 kg / cm ^{2 for} 30 seconds to obtain a surface weight. A molded soundproofing material 2 for automobile having a weight of 5500 g / m ² was obtained.

[0014]

Example 3 A phenolic resin was mixed with a mixed fiber raw material consisting of 85% by weight of cotton, 5% by weight of wool, 5% by weight of glass wool and 5% by weight of polyester fiber to form a fleece, which was then heated to a semi-cured state. A fiber sound absorbing material was produced by cutting it into a suitable size. The raw material of the sound absorbing material made of fiber is placed on a lower mold heated to 200 ° C. to lower the upper mold, and heated and pressed at 100 kg / cm ^{2 for} 1 minute to obtain a surface weight of 1000 g / m 2. A molded article of the fiber sound absorbing material of ² was prepared. Butyl rubber 40 parts by weight, blown asphalt 5 parts by weight, calcium carbonate 50 parts by weight and talc 5
A part by weight was kneaded and extruded to a thickness of 3 mm to form a sound insulating sheet. The sound insulation sheet was preheated at 100 ° C. for 1 minute, placed on a lower mold cooled to 5 ° C., and vacuum formed. Place the above-mentioned molded product of the sound absorbing material made of fiber through the adhesive on the vacuum molded product of the sound insulation sheet, lower the upper mold, and press-mold at 100 kg / cm ^{2 for} 30 seconds to obtain a surface weight. A molded soundproofing material 3 for automobile of 5500 g / m ² was obtained.

[0015]

Example 4 Phenolic resin was mixed with a mixed fiber raw material consisting of 80% by weight of cotton, 5% by weight of wool, 5% by weight of glass wool and 10% by weight of polyester fiber to form a fleece, which was then heated to a semi-cured state. A fiber sound absorbing material was produced by cutting it into a suitable size. The raw material of the sound absorbing material made of fiber is placed on a lower mold heated to 200 ° C. to lower the upper mold, and heated and pressed at 100 kg / cm ^{2 for} 1 minute to obtain a surface weight of 1000 g / m 2. A molded article of the fiber sound absorbing material of ² was prepared. 40 parts by weight of butyl rubber, 5 parts by weight of blown asphalt, 50 parts by weight of calcium carbonate and 5 parts by weight of talc were kneaded and extruded to a thickness of 3 mm to obtain a sound insulating sheet. The sound insulation sheet was preheated at 100 ° C. for 1 minute, placed on a lower mold cooled to 5 ° C., and vacuum formed. Place the above-mentioned molded product of the sound absorbing material made of fiber through the adhesive on the vacuum molded product of the sound insulation sheet, lower the upper mold, and press-mold at 100 kg / cm ^{2 for} 30 seconds to obtain a surface weight. 5500 g / m ² of molded automobile soundproofing material 4 was obtained.

[0016]

[Comparative Example 1] A phenolic resin was mixed with a mixed fiber raw material consisting of 60% by weight of cotton and 40% by weight of polyester fiber to form a fleece, which was then heated to a semi-cure state and cut into an appropriate size to absorb the sound of the fiber. A raw material was manufactured.
The raw material of the sound absorbing material made of fiber is placed on a lower mold heated to 200 ° C. to lower the upper mold, and heated and pressed at 100 kg / cm ^{2 for} 1 minute to obtain a surface weight of 1000 g / m 2. A molded article of the fiber sound absorbing material of ² was prepared. Butyl rubber 40 parts by weight, blown asphalt 5 parts by weight, calcium carbonate 50
Parts by weight and 5 parts by weight of talc were kneaded and extruded to a thickness of 3 mm to obtain a sound insulating sheet. 10 sound-insulating sheets
After preheating at 0 ° C. for 1 minute, it was placed on a lower mold cooled to 5 ° C. and vacuum formed. Place the above-mentioned molded product of the sound absorbing material made of fiber through the adhesive on the vacuum molded product of the sound insulation sheet, lower the upper mold, and press-mold at 100 kg / cm ^{2 for} 30 seconds to obtain a surface weight. A molded soundproofing material 5 for automobile having a weight of 5500 g / m ² was obtained.

[0017]

Comparative Example 2 Phenolic resin is mixed with a mixed fiber raw material composed of 40% by weight of cotton, 10% by weight of glass wool and 50% by weight of polyester fiber to form a fleece, which is then heated to a semi-cure state and made into an appropriate size. The raw material of the sound absorbing material made of fiber was manufactured by cutting. 18 sheets of the fiber sound absorbing material
After preheating at 0 ° C for 1 minute, it was placed on the lower mold cooled to 5 ° C and the upper mold was lowered to 100 kg / cm ^2.
At room temperature for 1 minute, cooling and pressure molding, surface weight 1000g / m ²
A molded article of the sound absorbing material made of fiber was produced. Butyl rubber 40 parts by weight, blown asphalt 5 parts by weight, calcium carbonate 5
0 parts by weight and 5 parts by weight of talc were kneaded and extruded to a thickness of 3 mm to obtain a sound insulating sheet. 1 sound insulation sheet
After preheating at 00 ° C. for 1 minute, it was placed on a lower mold cooled to 5 ° C. and vacuum formed. On the vacuum molded product of the sound insulation sheet, the molded product of the sound absorbing material made of fiber is placed via an adhesive, and the upper mold is lowered to 30 at 100 kg / cm ² .
The molded soundproofing material 6 for automobiles having a surface weight of 5500 g / m ² was obtained by pressure molding for ² seconds.

[0018]

[Test method] The soundproofing effect at each frequency of the molded soundproofing materials for automobiles 1 to 6 was measured.

[0019]

[Result 1] The test results are shown in Table 1. The unit in the table is dB. The larger the number, the higher the soundproofing effect.

[Table 1]

[0021]

EFFECTS OF THE INVENTION It has been clarified that the molded soundproofing material according to the present invention satisfies the soundproofing effect required in all frequency regions.

Claims (1)

[Claims] 1. As a sound absorbing material made of fiber, 8 of the used fibers are used.
A molded soundproofing material for automobiles, characterized in that a sound absorbing material made of fiber made of 0% by weight or more of cotton and a sound insulating sheet are integrated.