JPH11293019A - Soundproof material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an improved soundproof effect by using a porous material having a specific Poisson's ratio to give excellent vibrational properties and effective sound energy absorbing properties to a soundproof material. SOLUTION: A resin composition is obtained by blending 100 parts by weight of a rubber component consisting of an EPDM having a Mooney viscosity ML1+2 (100 deg.C) of 30-100 comprising 45-70 mol.% of ethylene, 5-20 mol.% of an α-olefin and 50-10 mol.% of a polyene with not more than 150, preferably 5-50, parts by weight of a foaming agent, 1-30 parts by weight of a vulcanizing agent, 30-300 parts by weight of a filler, a foaming assistant, a vulcanizing assistant, a softener, a reinforcer, a lubricant, a stabilizer and the like. This composition is extended on an interliner to have a thickness of 0.5-50 mm and is heated to 100-200 deg.C for 10-60 min to be foamed and vulcanized such that the foaming magnitude be not more than 50 times, preferably 5-40 times, further preferably 8-30 times, to obtain a soundproof material consisting of a porous material having an apparent thickness of not more than 100 mm, preferably 0.5-70 mm and a Poisson's ratio of not more than 0.3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproofing material suitable for soundproofing various articles such as automobiles, buildings, housing equipment and electric and electronic equipment.

[0002]

2. Description of the Related Art Hitherto, as a soundproofing material, a foam or a fiber composite formed of a material having a high value based on tan δ which is an index indicating internal loss has been known. However, there is a problem that the sound absorption effect as expected as predicted from the above-mentioned tan δ is not achieved, and the desired soundproof performance cannot be obtained in many cases.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to develop a soundproofing material which is excellent in sound absorbing effect and exhibits high soundproofing effect.

[0004]

SUMMARY OF THE INVENTION The present invention provides a soundproofing material comprising a porous member having a Poisson's ratio of 0.3 or less.

[0005]

The soundproofing effect of the soundproofing material made of a porous member is achieved by converting sound energy consisting of air vibration into heat energy by viscous frictional resistance of internal air when passing through the soundproofing material, The main mechanism is a mechanism in which the soundproofing material absorbs energy and vibrates itself, thereby converting sound energy into heat energy and consuming it.In the present invention, the soundproofing material itself is based on the above Poisson's ratio. It excels in vibration and absorbs sound energy efficiently, and exhibits an excellent soundproofing effect.

The above is based on the finding that the required characteristics are not sufficient in the conventional design of a soundproofing material based on tan δ. In other words, the internal loss of absorbing and consuming sound energy as vibration energy can be increased by setting the material based on tan δ, but this is premised on vibration of the soundproofing material due to absorption of sound energy. Therefore, even if a material having a high internal loss is used, the soundproofing effect is difficult to be exerted when the soundproofing material has poor vibration properties.

The present invention is based on the Poisson's ratio, which is an index of the easiness of deformation as a volume, and conditions it to a small numerical value to make the soundproofing material easy to vibrate as a whole. As a result, the vibration of the soundproofing material is guaranteed, and the efficient soundproofing effect is achieved.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The soundproofing material of the present invention comprises a porous member having a Poisson's ratio of 0.3 or less.

[0009] The porous member used may be one having a Poisson's ratio of 0.3 or less. Accordingly, as the porous member, for example, foams made of various polymers such as olefin-based, urethane-based, acrylic-based, vinyl chloride-based, SBR-based, NR-based, NBR-based and blends thereof, natural and synthetic organic and Any suitable fiber aggregate, such as a non-woven fabric formed of suitable inorganic fibers, may be used.

Therefore, any of the materials used for manufacturing a conventional porous member for forming a soundproofing material can be used.
A preferred porous member is a tan according to the intended use of the soundproofing material.
It is formed of a material having a high internal loss based on δ. The soundproofing material may have an appropriate layer form, and may be formed, for example, as a laminate, a mixture, or a composite of two or more types of porous members.

The foam may have an appropriate cell structure such as a closed cell structure, an open cell structure, or a cell structure in which these are mixed. Foams that can be preferably used include those made of appropriate thermoplastic resins such as polyurethane, polyethylene, and polyvinyl chloride, and appropriate rubber-based polymers such as butyl rubber and isoprene rubber, particularly EPDM and rubber-based polymers using them in combination. It is.

Specific examples of the EPDM foam include:
Copolymers containing as components ethylene-, olefins such as propylene and butene-1, and cyclic or non-cyclic polyenes having a non-conjugated double bond such as dicyclopentadiene or ethylidene norbornene, preferably 45 to 70 moles of ethylene %, Α-olefin 5-20 mol%, polyene 50-
10 mol%, especially Mooney viscosity ML _{1 + 2} (100
(C) of 30 to 110, and EPDM as a component.

As the rubber component other than EPDM in the rubber foam using EPDM in combination, suitable rubber components such as natural rubber, butyl rubber, chloroprene rubber, acrylic rubber, styrene / butadiene rubber and nitrile / butadiene rubber can be used. Can be used. The amount of EPDM used is preferably 20% by weight or more of the total rubber component from the viewpoints of weather resistance and durability.

The above-mentioned foam having an open-cell structure is obtained by, for example, forming a mixture of a polymer component and an appropriate additive such as a foaming agent or a vulcanizing agent into a sheet or the like and subjecting it to foam vulcanization treatment.
The cell can be manufactured by a method of subjecting a part or all of the cell to physical property adjustment processing such as foam breaking by an appropriate means such as compression processing.

Examples of the foaming agent include azo-based compounds such as azodicarbonamide, dinitrosopentamethylenetetramine, sodium hydrogencarbonate and 4,4'-oxybis (benzenesulfonylsemicarbazide), N-nitroso-based compounds, inorganic compounds and semicarbazides. And hydrazine-based and triazole-based ones. The amount of the foaming agent to be used is preferably 150 parts by weight or less, more preferably 100 parts by weight or less, particularly preferably 5 to 50 parts by weight, per 100 parts by weight of the rubber component, in view of the expansion ratio for obtaining the desired physical properties.

Examples of the vulcanizing agent include sulfur, P-quinone dioxime, P, P'-dibenzoylquinone dioxime, 4,4'-dithiodimorpholine, P-dinitrosobenzine, ammonium benzoate, N, Appropriate materials such as N'-m-phenylenedimaleimide can be used. The amount of the vulcanizing agent to be used is preferably 1 to 30 parts by weight per 100 parts by weight of the rubber component from the viewpoint of obtaining desired physical properties while preventing foaming inhibition such as insufficient vulcanization and outgassing.

In preparing the above-mentioned admixture, suitable foaming aids such as urea-based, salicylic-acid-based and benzoic acid-based, aldehyde ammonia-based, aldehydeamine-based, thiourea-based and guanidine-based, thiazole-based and sulfenamide-based compounds can be used. A suitable vulcanization aid such as a thiuram-based, dithiocarbamate-based, or xanthate-based can be used as necessary.

Also, for example, fillers composed of calcium carbonate, talc, clay, mica powder, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, metal oxides such as aluminum oxide and zinc oxide, paraffinic and naphthenic Additives such as a softening agent such as a system, an aroma system or an asphalt system, a reinforcing agent such as carbon black, a lubricant such as stearic acid, and a stabilizer such as zinc white can also be added as needed in the preparation of the admixture. .

In the above, the amount of the filler used is 3 parts per 100 parts by weight of the rubber component from the viewpoint of controlling physical properties such as strength.
0 to 300 parts by weight is preferred. The amount of softener used is
10 to 100 parts by weight of the rubber component from the viewpoint of adjusting the viscosity of the admixture related to foaming properties and preventing blooming.
300 parts by weight are preferred.

From the viewpoint of attainment of the above Poisson's ratio, as a foam, for example, 0.5 to 5
It is developed at a thickness of 0 mm and heat-treated at a temperature of 100 to 200 ° C. for 10 to 60 minutes so that the expansion ratio becomes 50 times or less, particularly 5 to 40 times, particularly 8 to 30 times. Those subjected to foam vulcanization can be preferably used. The porous member may be one obtained by impregnating an open-cell foam with an appropriate resin such as an acrylic resin, a polybutyral resin, or a polyester resin.

On the other hand, as a fiber assembly, suitable natural or synthetic organic or inorganic fibers such as glass wool, rock wool, and various synthetic fibers are resin-bonded or heat-bonded, needle-punched or spun-lace, spun-bonded or stitch-bonded. And those formed into a nonwoven fabric or the like by an appropriate method such as powder adhesion or solvent adhesion can be preferably used. A fiber assembly formed by extruding the above-described composition for forming a foam into a non-woven fabric or the like by extrusion melt blowing or the like can also be preferably used. The fiber assembly may be one in which fibers are partially adhered or cross-linked.

The Poisson's ratio of the porous member is adjusted, for example, by controlling the type of the formed polymer and the expansion ratio as described above in the case of the foam, and by controlling the type and the state of the fibers used in the fiber assembly. Can be performed.

The form of the soundproofing material can be appropriately determined according to the purpose of use, such as the place of application, and the thickness thereof is also arbitrary. Generally, based on the apparent thickness, no more than 100 mm, especially 0.1 mm.
The thickness is 5 to 70 mm, especially 1 to 40 mm. Note that the soundproofing material does not need to have a uniform thickness, and may have partially different thicknesses.

A soundproofing material having a partially different wall thickness is obtained by filling a chip formed by, for example, crushing a porous member into flakes into a predetermined mold by applying an adhesive to the surface thereof. It can be formed efficiently by a method such as compression molding.

The soundproofing material according to the present invention can be used for soundproofing of an appropriate place according to the prior art, such as an automobile, a building, a dwelling equipment and an electric / electronic equipment. In that case,
For example, a method of forming in a predetermined form in advance and interposing between various members, or a method of attaching a tape-shaped or sheet-shaped material to a target member by an appropriate method such as a winding method or a sticking method, etc. The soundproofing process can be performed by an appropriate method according to the related art.

[0026]

EXAMPLES Example 1 EP rubber polymer (EPT402 manufactured by Mitsui Petrochemical Co., Ltd.)
1, the same applies hereinafter) 100 parts (parts by weight, the same applies hereinafter), heavy calcium carbonate 120 parts, asphalt softener 100
Parts, carbon black 15 parts, zinc white 5 parts, stearic acid 1 part, foaming agent (Vinifol AC, manufactured by Eiwa Chemical Industry Co., Ltd.)
#LQ, the same applies hereinafter) 25 parts, sulfur 1.5 parts and vulcanization accelerator (Nouchira EZ, manufactured by Ouchi Shinko Chemical Co., Ltd .; the same applies hereinafter) 4
Part was kneaded with a pressure kneader, and it was extruded to a thickness of 10
The resulting sheet was molded into a sheet having a thickness of 0.1 mm, heated in an oven at 160 ° C. for 30 minutes, and foamed and vulcanized to obtain a soundproofing material made of a foam having a foaming ratio of 9 and a Poisson's ratio of 0.25.

Example 2 70 parts of EP rubber-based polymer, 30 parts of low density polyethylene (Misolan, manufactured by Mitsui Petrochemical Co., Ltd.), 20 parts of heavy calcium carbonate, 20 parts of asphalt-based softener, 10 parts of carbon black, and 5 parts of zinc white Part, stearic acid 1 part, foaming agent 30
Parts, 1.5 parts of sulfur and 3 parts of a vulcanization accelerator are kneaded with a pressure kneader, formed into a sheet having a thickness of 10 mm by an extruder, and heated in an oven at 160 ° C. for 30 minutes to foam. By vulcanizing, a soundproofing material consisting of a foam having a foaming ratio of 25 and a Poisson's ratio of 0.21 was obtained.

Example 3 Rubber-based polymer (Kuraray Co., Ltd., Kraton G1657)
100 parts, resin (Clearon P-12, manufactured by Yasuhara Chemical Co., Ltd.)
5) 50 parts and 2 parts of an anti-aging agent (Irganox B612, manufactured by Ciba Geigy) are kneaded with a mixing roll, and the mixture is extruded at a head temperature of 230 with a melt blow apparatus.
° C., basis weight 0.25 g / cm ² was deposited nonwoven fabric while molding the fibrous under the conditions of hot air temperature 260 ° C., to obtain a soundproofing material consisting of fiber assembly of Poisson's ratio 0.09.

Comparative Example The expansion ratio was the same as in Example 1 except that the blending amount of the asphalt softening agent was 80 parts, the blending amount of the blowing agent was 15 parts, and the blending amount of the vulcanization accelerator was 5 parts. Was obtained, and a soundproofing material comprising a foam having a Poisson's ratio of 0.40 was obtained.

Evaluation Test Sound Absorption Coefficient The sound absorption coefficient of the soundproofing materials obtained in Examples and Comparative Examples was measured according to JIS A1.
405 was measured by a vertical incidence sound absorption coefficient measuring device. The results for 1 kHz, 2 kHz and 4 kHz are shown in the following table.

[0031]

Claims (1)

[Claims] 1. A soundproofing material comprising a porous member having a Poisson's ratio of 0.3 or less.