JP6594644B2 - Glass fiber insulation sound absorber and method of using the same - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a heat insulating sound absorber made of glass fiber, and more specifically to a glass fiber heat insulating sound absorber for mainly suppressing transmission of vehicle tire vibration noise into a vehicle interior and a method of using the same.

  Since automobiles emit various noises, various measures are taken to prevent such noises. For example, a glass fiber heat insulating sound absorber is used in an engine room of an automobile for the purpose of reducing noise and the like and insulating heat generated from the engine section. This glass fiber heat-absorbing sound absorber is formed by press-molding a mat-like glass fiber assembly to which an uncured thermosetting resin is adhered.

For example, Patent Document 1 discloses a relatively bulky soundproof portion having a density of substantially 8.0 to 80.0 kg / m ³ and a relatively integrated soundproof portion provided along at least one face thereof. An insulator-type liner comprising a fibrous material pad having a dense skin layer and a crimped edge having a thickness of about 0.5 to 3.0 mm, wherein the skin layer has a thickness of substantially An insulator-type liner is disclosed, characterized in that it has a density of 0.25 to 10.0 mm and a density of substantially 32.0 to 1600.0 kg / m ³ .

  On the other hand, in order to suppress tire vibration noise, the vehicle compartment is entirely covered with a sound absorber separately from the sound absorption of engine sound. If the entire vehicle compartment is covered with a sound absorber for absorbing engine sound as in Patent Document 1, the density is high due to its high density, which is not preferable from the viewpoint of reducing the weight of an automobile. In addition, since the engine sound and tire sound have different sound frequencies (engine sound is 1000 Hz to 4000 Hz, tire sound is 500 Hz to 2000 Hz), it is necessary to construct a sound absorber suitable for each sound, Therefore, it is not possible to use the heat insulating sound absorber for glass fiber as it is as a sound absorber for tire sound.

  Conventionally, in order to suppress tire vibration noise, it has been the mainstream to form a sound absorber using organic fibers from the viewpoint of weight reduction of the vehicle body. Such an organic fiber sound absorber is attached to a ceiling, a door, a dashboard, a floor or the like in order to cover the entire area of the vehicle body.

Patent No. 4129427

  However, since development of automobiles equipped with a heat source such as a fuel cell has been progressing in recent years, an organic fiber sound absorber may be burned by this heat. Further, in the mechanism of the sound absorber that converts sound vibration energy into heat energy, in order to efficiently convert the energy, it is necessary to propagate the sound vibration energy to the inside of the sound absorber and perform the entire sound absorber. Since organic fibers have low conversion efficiency per fiber, it is necessary to increase the number of fibers per unit volume in order to absorb sound, air is blocked, and sound propagation does not reach the entire sound absorber. For this reason, there exists a problem that the sound absorption body of an organic fiber is inferior in sound absorption performance compared with a glass fiber sound absorption body. In the passenger compartment, tire noise with a low frequency is particularly worrisome, and it is desired to suppress this noise.

  The present invention is based on the above-described conventional technology, and can achieve weight reduction even when a sound absorbing body is formed using glass fiber, and heat insulating sound absorbing glass fiber suitable for absorbing tire noise having a frequency of 500 Hz to 2000 Hz. The object is to provide a body and a method of use thereof.

In order to achieve the above object, the present invention includes a sound absorbing layer and a sound insulating layer, which are glass fiber molded articles, and the sound absorbing layer has a thickness of 10 mm to 30 mm and a glass fiber having a diameter of 3 μm to 5 μm by 50 kg / a density of ^{m 3} ~100kg / m ^3, the sound insulation layer has a density of 60kg ^{/ m 3} ~120kg ^/ m 3 and a diameter having a thickness of 5mm~10mm is the glass fiber 5μm~7μm A glass fiber heat-absorbing sound absorber is provided.

  Preferably, the density of the sound insulation layer is higher than the density of the sound absorption layer, and the sound insulation layer, the sound absorption layer, and the resin resin film are in contact with each other and overlap each other.

Preferably, the sound insulation layer has a compression rate of 10% or less when a load of 4 kPa is applied.

Preferably, the sound absorbing layer and the sound insulating layer are formed by using a thermosetting resin containing no formaldehyde as a binder.

  The present invention also provides a method for using a glass fiber heat-absorbing sound absorber, characterized in that the sound insulation layer is disposed on the outer side and the sound absorption layer is disposed on the inner side of a vehicle cabin.

According to the present invention, since glass fibers having a diameter of 5 μm to 7 μm are used for the sound insulation layer, the elastic modulus of the surface of the sound insulation layer is improved, and low frequency tire noise can be easily reflected. The density of the sound insulation layer since it is ^{60kg / m 3 ~120kg / m 3} , a sound which has not been reflected is propagated within the sound absorbing layer through the air in the sound insulation layer. Here, since glass fibers having a diameter of 3 μm to 5 μm are used for the sound absorbing layer, the number of glass fibers per unit volume is increased, and the number of cells formed by crossing glass fibers is increased. For this reason, the convection of the air in a sound absorption layer can be suppressed. In addition, an increase in the number of glass fibers per unit volume increases the glass surface area, and the viscous resistance generated between the fibers and the air makes it easier to absorb sound vibration energy. This improves the efficiency of conversion into sound and can contribute to the improvement of sound absorption.

  Further, according to a preferred aspect of the present invention, the density of the sound insulation layer is higher than the density of the sound absorption layer, and the sound insulation layer, the sound absorption layer, and the resin film are in contact with each other and overlap each other, thereby causing tire noise. Without propagating to the passenger compartment side of the automobile, reflection by the sound insulation layer and the resin film is repeated and attenuated in the sound absorption layer, and further improvement in sound absorption can be realized.

  Further, when the load of 4 kPa is applied to the sound insulation layer, the compression rate is set to 10% or less, whereby the elasticity of the sound insulation layer surface is increased and the surface reflectivity of the tire noise is improved.

  Further, by forming the sound absorbing layer and the sound insulating layer by using a thermosetting resin containing no formaldehyde as a binder, formaldehyde, which is a harmful substance, is not generated. Therefore, it can be safely used even around the passenger compartment, which is a space where people exist.

  In addition, by arranging a sound insulation layer on the outside and a sound absorption layer on the inside of the vehicle cabin, the sound insulation layer harder than the sound absorption layer is on the sound transmission source side (tire noise transmission side). Will be arranged. It has been found that by arranging the sound insulation layer having the fiber diameter, density and thickness as described above on the tire noise transmission source side, relatively low frequency tire noise can be reflected. Furthermore, since the sound insulation layer has the fiber diameter, density, and thickness as described above, a part of the tire noise passes through the sound insulation layer and can be efficiently absorbed by the sound absorption layer to further suppress the tire noise.

It is the schematic of the glass fiber heat insulation sound absorber which concerns on this invention. It is the schematic which shows the preferable Example of the glass fiber heat insulation sound absorber which concerns on this invention. It is the graph which compared the sound absorption rate of an Example and a comparative example.

  As shown in FIG. 1, a glass fiber heat insulating sound absorber 1 according to the present invention includes a sound absorbing layer 2 and a sound insulating layer 3 which are glass fiber molded products. The sound absorbing layer 2 and the sound insulating layer 3 are obtained by pressure-heating molding a mat-like glass fiber assembly (hereinafter referred to as an intermediate) to which an uncured thermosetting binder is attached.

  Although there are many types of glass fibers, there is no particular limitation on the glass composition of the glass fibers used in the present invention, but a soda lime glass used for glass wool insulation or a glass composition called A glass is preferred. . If it is the said glass composition, it is excellent in economical efficiency at the point that mass production is possible by using a centrifugal method at a comparatively low melting temperature.

Here, the sound absorption layer 2, and diameter has a thickness of 10mm~30mm has a density of 50kg ^{/ m 3} ~100kg ^/ m 3 by glass fibers 3Myuemu～5myuemu.
The diameter of the glass fiber used for the sound absorbing layer 2 is 3 μm to 5 μm. If the diameter of a glass fiber exists in said range, the number of the glass fibers per unit volume will increase, and the number of cells which glass fibers will cross | intersect will increase. For this reason, the convection of the air in the sound absorption layer 2 can be suppressed. In addition, an increase in the number of glass fibers per unit volume increases the glass surface area, and the viscous resistance generated between the fibers and air makes it easier to absorb the vibration energy of sound. This improves the efficiency of conversion into sound and can contribute to the improvement of sound absorption.

The density of the sound absorption layer 2 ^{is 50kg / m 3 ~100kg / m 3} , is preferably ^{60kg / m 3 ~80kg / m 3} . By setting the density of the sound absorbing layer 2 to 50 kg / m ³ or more, the tire noise transmitted through the sound absorbing layer 2 is reduced, and the sound absorption rate is improved. On the other hand, by setting the density of the sound absorbing layer to 100 kg / m ³ or less, reflection of sound due to an increase in the density of the sound absorbing layer 2 is suppressed, and the sound absorption rate is improved.

  The thickness of the sound absorbing layer 2 is 10 mm to 30 mm, preferably 15 mm to 30 mm, and more preferably 20 mm to 30 mm. If the thickness of the sound-absorbing layer 2 is in the above range, tire noise will not pass and sufficient sound-absorbing properties can be realized, such as ceilings, doors, floors and dashboards around the passenger compartment. It can be installed even in a narrow space.

Sound insulation layer 3 of the glass fiber insulation sound absorber of the invention, and a diameter having a thickness of 5mm~10mm has a density of 60kg ^{/ m 3} ~120kg ^/ m 3 by glass fibers 5Myuemu～7myuemu.

  Since glass fibers having a diameter of 5 μm to 7 μm are used for the sound insulating layer 3, the elastic modulus of the surface of the sound insulating layer 3 is improved, and the tire noise can be easily reflected on the surface. If the density of the sound insulation layer 3 is in the above range, the sound that has not been reflected is propagated into the sound absorption layer 2 through the air in the sound insulation layer 3.

The density of the sound insulation layer 3 is ^{60kg / m 3 ~120kg / m 3} , preferably from ^{80kg / m 3 ~120kg / m 3} . If the density of the sound insulation layer 3 is 60 kg / m ³ or more, a hardness sufficient to reflect the surface of tire noise can be obtained. If the density of the sound insulation layer 3 is 120 kg / m ³ or less, it is possible to suppress a decrease in sound absorption performance due to excessive reflection of tire noise.

  The thickness of the sound insulation layer 3 is 5 mm to 10 mm, and preferably 7 mm to 10 mm. However, the thickness is appropriately set in consideration of optimizing the weight and rigidity of the glass fiber heat-absorbing sound absorber 1. If the thickness of the sound insulation layer 3 is 5 mm or more, a sound insulation layer that reflects the surface of tire noise can be formed, and the handleability of the sound absorber 1 as a whole is improved. If thickness is 10 mm or less, the mass increase as the sound-absorbing body 1 whole can be suppressed.

  The sound insulation layer 3 of the glass fiber heat insulating sound absorber of the present invention preferably has a compressibility of 10% or less when a load of 4 kPa is applied. This is because if the compression ratio of the sound insulation layer is 10% or less, the elasticity of the sound insulation layer becomes high and the surface reflectivity of tire noise is improved.

  The glass fiber heat insulating sound absorber of the present invention has a density of the sound insulating layer 3 higher than that of the sound absorbing layer 2, and a resin film 4 is provided on the surface of the sound absorbing layer 2 opposite to the surface on which the sound insulating layer 3 is in contact. Are preferably arranged in contact with each other. That is, it is preferable that the glass fiber heat-absorbing sound absorber 1 is in contact with each other in the order of the sound insulating layer 3, the sound absorbing layer 2, and the resin plate 4.

  By disposing the resin film inside the sound absorbing layer, even if tire noise passes through the sound absorbing layer, it can be reflected by the resin film and further absorbed by the sound absorbing layer. Even at this stage, even if the tire noise passes through the sound absorbing layer, the tire noise is further reflected by the sound insulating layer and again absorbed by the sound absorbing layer. Therefore, the tire noise is reflected between the resin plate and the sound insulation layer, and is absorbed while being repeatedly attenuated by the sound absorption layer therebetween. For this reason, more reliable sound absorption becomes possible.

And density of the sound insulation layer is not particularly limited to density ratio of the backing layer, the density of the sound insulation layer is preferably higher ^5kg / ^{m 3 ~30kg} / m 3 than the density of the sound absorbing layer, and further, 10 kg / m More preferably, it is ^{3 to} 20 kg / m ³ higher.

  Although there is no limitation in particular in the kind, thickness, etc. of a resin film, it is preferable to make it adhere simultaneously when heat-press-molding a glass fiber heat-absorbing sound-absorbing body, and 200 to 250 degreeC which is the molding temperature of a glass fiber heat-absorbing sound-absorbing body. It is preferable that no dissolution or large shrinkage occurs.

  Examples of the resin film include high-density polyethylene, polypropylene, polyethylene terephthalate, and polyamide. These resin films may be single-layered or laminated, or aluminum or silica may be deposited.

  Furthermore, as an aspect of the resin film, a film obtained by laminating a high-density polyethylene film of 10 μm to 15 μm and a polyamide film of 10 μm to 15 μm as an adhesive layer with the sound absorber is more preferable in terms of adhesion and heat resistance.

  It is preferable that the sound absorbing layer 2 and the sound insulating layer 3 of the glass fiber heat insulating sound absorber of the present invention are formed by using a thermosetting resin not containing formaldehyde as a binder. Thereby, formaldehyde which is a harmful substance is not generated. Therefore, it can be safely used even around the passenger compartment, which is a space where people exist.

  Examples of the type of thermosetting resin that does not contain formaldehyde include thermosetting resins that cure by any one of amidation reaction, imidation reaction, esterification reaction, and transesterification reaction. For example, a resin composition containing a polycarboxylic acid obtained by polymerizing an ethylenically unsaturated monomer and a crosslinking agent containing an alcohol having an amino group or an imino group can be used.

  As the polycarboxylic acid, for example, one or more monomers selected from ethylenically unsaturated carboxylic acid monomers may be used alone, or an ethylenically unsaturated monomer containing no carboxyl group. You may use what is obtained by superposing | polymerizing using a body together.

  Examples of the ethylenically unsaturated monomer containing no carboxyl group include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, and t-butyl (meth). Acrylate, 2-ethylhexyl (meth) acrylate, cetyl (meth) acrylate, n-stearyl (meth) acrylate, diethylene glycol ethoxy (meth) acrylate, methyl-3-methoxy (meth) acrylate, ethyl-3-methoxy (meth) acrylate , Butyl-3-methoxy (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, tetrahydrofurfuryl acrylate, 2-hydroxyethyl acrylate 2-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, mono (meth) acrylate of trihydric or higher polyol, aminoalkyl (meth) acrylate, N-alkylaminoalkyl (meth) acrylate, N, N-dialkylaminoalkyl ( Acrylic monomers such as (meth) acrylate, vinyl alkyl ether, N-alkyl vinyl amine, N, N-dialkyl vinyl amine, N-vinyl pyridine, N-vinyl imidazole, N- (alkyl) aminoalkyl vinyl amine, etc. Vinyl monomers, (meth) acrylamide, N-alkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide, N, N-dialkylaminoalkyl (meth) acrylamide, diacetone (meth) acrylamide, N-bi Amide monomers such as formamide, N-vinylacetamide, N-vinylpyrrolidone, aliphatic unsaturated hydrocarbons such as ethylene, propylene, isobutylene, isoprene, butadiene, styrene, α-methylstyrene, p-methoxystyrene, Styrene monomers such as vinyl toluene, p-hydroxystyrene, p-acetoxystyrene, vinyl ester monomers such as vinyl acetate and vinyl propionate; acrylonitrile, glycidyl (meth) acrylate and the like. Moreover, these may use together 1 type, or 2 or more types.

  Examples of the ethylenically unsaturated carboxylic acid monomer include acrylic acid, methacrylic acid, crotonic acid, fumaric acid, maleic acid, 2-methylmaleic acid, itaconic acid, 2-methylitaconic acid, α-β-methylene. Glutaric acid, monoalkyl maleate, monoalkyl fumarate, maleic anhydride, acrylic anhydride, β- (meth) acryloyloxyethylene hydrogen phthalate, β- (meth) acryloyloxyethylene hydrogen maleate, β- (meta ) Acrylyloxyethylene hydrogen succinate and the like.

  The crosslinking agent contained in the thermosetting resin contains an alcohol having an amino group and / or an imino group. Examples of such alcohols include alkanolamines such as ethanolamine, isopropanolamine, diethanolamine, diisopropanolamine, and aliphatic polyamines (eg, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 1, 2-diaminopropane, 1,3-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 3,3′-iminobis (propylamine), 3- (methylamino) propylamine, 3- (dimethyl Amino) propylamine, 3- (ethylamino) propylamine, 3- (butylamino) propylamine, N-methyl-3,3′-iminobis (propylamine), polyethyleneimine, etc.), aromatic poly (For example, phenylenediamine, o-tolidine, m-toluylenediamine, m-xylylenediamine, dianisidine, diaminodiphenyl ether, 1,4-diaminoanthraquinone, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4′-diaminobenzanilide, 4,4′-diamino-3,3′-diethyldiphenylmethane, etc.), heterocyclic amines (eg piperazine, 2-methylpiperazine, 1- (2-aminoethyl) piperazine, 2 , 5-dimethylpiperazine, cis-2,6-dimethylpiperazine, bis (aminopropyl) piperazine, 1,3-di (4-piperidyl) propane, 3-amino-1,2,4-triazole, 1-aminoethyl Amines such as -2-methylimidazole), ethylene oxide, or Polyamine polyol obtained by adding B pyrene oxide.

  Further, the thermosetting resin may further contain a polyol other than the alcohol as a crosslinking agent. Such a polyol is preferably a water-soluble polyol. Specifically, 1,2-ethanediol (ethylene glycol) and its dimer or trimer, 1,2-propanediol (propylene) Glycol) and dimers or trimers thereof, 1,3-propanediol, 2,2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,3 -Butanediol, 1,4-butanediol, 2-methyl-2,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol 1,6-hexanediol, 1,4-cyclohexanediol, 2-ethyl-1,3-hexanediol, 2-hydroxymethyl-2-methyl-1,3 Propanediol, 2-ethyl-2-hydroxymethyl-2-methyl-1,3-propanediol, 1,2,6-hexanetriol, 2,2-bis (hydroxymethyl) -2,3-propanediol, etc. Aliphatic polyols, trialkanolamines such as triethanolamine and triisopropanolamine, sugars such as glucose, fructose, mannitol, sorbitol and maltitol, and the above polyols and polyester polyols such as phthalic acid, adipic acid and azelaic acid, polyethylene glycol , Polypropylene glycol, acrylic resin polyol and the like. These can use together 1 type (s) or 2 or more types. Among them, trialkanolamine is preferable because it has a high boiling point and is difficult to volatilize.

  In addition to the main thermosetting resin, the thermosetting binder used in the present invention contains a pH adjuster, a curing accelerator, a silane coupling agent, a colorant, a dustproof agent, and an alkali component eluted from inorganic fibers. If necessary, additives such as a neutralizing agent may be added. The binder is adjusted to a predetermined concentration by mixing the above components according to a conventional method and adding water.

  Regarding the molding of the glass fiber heat-absorbing sound absorber of the present invention, a mold having a desired shape is obtained by adhering the aqueous binder made of the thermosetting resin to a mat-like glass fiber assembly (intermediate body) in an uncured state. Heat-press molding inside.

  There is no particular limitation on the production method of the intermediate body to which the uncured thermosetting resin is adhered, but preferably, immediately after the molten glass is fiberized by a centrifugal method, the aqueous binder of the thermosetting resin is glass by spraying. It is formed by applying to fibers and collecting cotton by suction or the like.

  Furthermore, in the intermediate used for forming the sound absorbing layer, the adhesion amount of the uncured thermosetting resin binder is preferably 5% by mass to 15% by mass. If the adhesion amount of the uncured thermosetting resin binder is within the above range, the requirements regarding the density of the sound absorbing layer of the present invention can be satisfied.

If the adhesion amount of the uncured thermosetting binder is less than 5% by mass, the density of the sound absorbing layer 2 after molding may not exceed 50 kg / m ^3. If the adhesion amount exceeds 15% by mass, the sound absorbing layer The density of 2 may exceed 100 kg / m ³ , both of which reduce the sound absorption of the sound absorbing layer.

  On the other hand, in the intermediate used for forming the sound insulation layer 3, the adhesion amount of the uncured thermosetting binder is preferably 8% by mass to 20% by mass. If the adhesion amount of the uncured thermosetting binder is within the above range, the density of the sound insulation layer 3 intended by the present invention can be reached. If the adhesion amount of the uncured thermosetting binder is less than 8% by mass, the density and compression rate of the sound insulation layer after molding may not be in the desired ranges. If the adhesion amount exceeds 20% by mass, the sound insulation layer The density and the compression ratio of the film are not improved any more, which is uneconomical.

There is no particular limitation on the method for molding a glass fiber heat-absorbing sound absorber of the present invention, but the sound insulating layer 3 and the sound absorbing layer 2 are preferably integrally formed. For example, when producing a molded body of 25 m64K (weight per unit area: 1600 g / m ² ), it is set in a mold set at 200 to 250 ° C. on both sides so that the sound insulation layer 3 side has a fiber diameter of 7 μm and the sound absorption layer 2 side has a fiber diameter of 4 μm. Heat for 5-10 minutes.

  When the sound insulating layer 3 and the sound absorbing layer 2 are separately formed, when the sound insulating layer 3 is manufactured, a mold having a gap that matches the size of the sound insulating layer 3 is used. An intermediate of the mass calculated from the desired density and dimensions as the sound insulation layer 3 is placed in a mold and cured at a pressure of 8 TPa to 12 TPa and a temperature of 200 ° C. to 250 ° C. for 5 minutes to 10 minutes, and the sound insulation layer 3 is molded. Next, the sound absorbing layer 2 is formed on the sound insulating layer 3. At this time, the mold to be used has a gap having a dimension obtained by adding the dimension of the sound absorbing layer 2 to the dimension of the glass fiber heat insulating sound absorber 1, that is, the dimension of the sound insulating layer 3. The previously formed sound insulation layer 3 is placed in a mold, and an intermediate body having a mass calculated from the desired density and dimensions of the sound absorption layer 2 is placed in the mold, and pressure 8 TPa to 12 TPa, temperature The sound absorber 1 is molded by curing at 200 to 250 ° C. for 5 to 10 minutes.

  The sound insulating layer and the sound absorbing layer are bonded together by an uncured thermosetting binder contained in the intermediate when the sound absorbing layer is formed (at the time of manufacturing the intermediate). If it is said molding conditions, adhesion of a sound insulation layer and a sound absorption layer is enough. Thereafter, the resin film 4 is bonded to the surface of the sound absorbing layer 2 opposite to the surface where the sound insulating layer 3 is in contact. The sound insulating layer 3 and the sound absorbing layer 2 may be laminated at the time of molding, and may be bonded simultaneously with molding and curing, or may be bonded after being molded.

  As described above, it is possible to suppress the tire noise when the glass fiber heat insulating sound absorber 1 is used in such a manner that the sound insulating layer 3 is disposed outside and the sound absorbing layer 2 is disposed inside the vehicle cabin. Most preferable from the viewpoint. By using in this way, the sound insulation layer 3 that is harder than the sound absorbing layer 2 is disposed on the sound transmission source side (tire noise transmission source side). It has been found that by arranging the sound insulation layer 3 having the fiber diameter, density, and thickness as described above on the tire noise transmission source side, tire noise at a relatively low frequency can be reflected first. Furthermore, since the sound insulation layer 3 has the fiber diameter, density, and thickness as described above, part of the tire noise passes through the sound insulation layer 3 and is efficiently absorbed by the sound absorption layer 2 to further suppress the tire noise. it can.

  In addition, as shown in FIG. 2, when a resin resin film 4 is arranged inside the sound absorbing layer 2, even if tire noise passes through the sound absorbing layer 2, this sound is reflected by the resin film 4. Returning to the sound absorbing layer 2 again, the sound absorbing layer 2 can absorb the sound. Even at this stage, even if the tire noise passes through the sound absorbing layer 2, the tire noise is further reflected by the sound insulating layer 3 and again absorbed by the sound absorbing layer 2. Therefore, the tire noise is reflected between the resin film 4 and the sound insulation layer 3 and is absorbed by the sound absorption layer 2 between them while being repeatedly attenuated. For this reason, more reliable sound absorption can be realized.

Example 1
As Example 1, the following glass fiber heat insulating sound absorber was obtained. First, melted glass was made into glass fibers having an average fiber diameter of 4 μm by a centrifugal method, and immediately after that, an aqueous thermosetting binder composed of polyacrylic acid and diethanolamine was sprayed. The adhesion amount of the aqueous curable binder was set to 5% by mass to obtain an intermediate A. Separately, the molten glass was made into glass fibers having an average fiber diameter of 7 μm by a centrifugal method, and immediately after that, an aqueous thermosetting binder composed of polyacrylic acid and diethanolamine was sprayed. The adhesion amount of the aqueous curable binder was set to 8% by mass to obtain an intermediate B.

The intermediate B is cut to a mass of 160 g, placed in a mold having a 500 mm square and a depth of 8 mm, and heated at a mold temperature of 240 ° C. and a molding pressure of 10 TPa for a molding time of 7 minutes. Pressure cured. As a result, a sound insulating layer having a 500 mm square, a thickness of 8 mm, and a density of 80 kg / m ³ was obtained. On the other hand, this sound insulation layer is installed in a mold having a gap of 25 mm and a depth of 500 mm, and the intermediate A is cut so as to have a mass of 255 g and laminated with the sound insulation layer to obtain a mold temperature of 240. The composition was cured by heating and pressing at a molding temperature of 10 ° C. and a molding pressure of 10 TPa for 10 minutes. Thereby, the glass fiber heat-insulating sound absorber of Example 1 was molded. In addition, the part laminated | stacked on the sound-insulating layer is a sound-absorbing layer, and this sound-absorbing layer part has a thickness of 17 mm and a density of 60 kg / m ³ , and a glass fiber heat insulating sound absorber has a thickness of 25 mm and a density of 66.4 kg. / M ³ .

(Example 2)
As Example 2, the following glass fiber heat-absorbing sound absorber was obtained. In the same manner as in Example 1, Intermediate A and Intermediate B were obtained.

Intermediate B is cut to have a mass of 160 g, placed in a mold having a gap of 25 mm in depth of 500 mm square, and further, Intermediate A is cut to have a mass of 255 g. And then cured by heating and pressing at a mold temperature of 240 ° C. and a molding pressure of 10 TPa for a molding time of 7 minutes. In this way, the glass fiber heat insulating sound absorber of Example 2 was molded. The sound insulation layer formed with the intermediate B is a thickness of 8 mm, a density of 60 kg / m ³ , and a sound absorption layer formed of the intermediate A, and the sound absorption layer has a thickness of 17 mm and a density of 60 kg / m ³ . In addition, the heat insulating sound absorber for glass fiber had a thickness of 25 mm and a density of 66.4 kg / m ³ .

(Example 3)
As Example 3, the following glass fiber heat-absorbing sound absorber was obtained. In the same manner as in Example 1, Intermediate A and Intermediate B were obtained.

The intermediate B is cut to a mass of 240 g, placed in a mold having a 500 mm square and a depth of 8 mm, and heated at a mold temperature of 240 ° C. and a molding pressure of 10 TPa for a molding time of 7 minutes. Pressure cured. As a result, a sound insulating layer having a 500 mm square, a thickness of 8 mm, and a density of 120 kg / m ³ was obtained. On the other hand, this sound insulation layer is installed in a mold having a gap of 25 mm and a depth of 500 mm, and the intermediate A is cut so as to have a mass of 425 g and laminated with the sound insulation layer to obtain a mold temperature of 240. The composition was cured by heating and pressing at a molding temperature of 10 ° C. and a molding pressure of 10 TPa for 10 minutes. Thus, the glass fiber heat-absorbing sound absorber of Example 3 was molded. In addition, the part laminated | stacked on the sound-insulating layer is a sound-absorbing layer, and this sound-absorbing layer part has a thickness of 17 mm and a density of 100 kg / m ³ , and the glass fiber heat insulating sound absorber has a thickness of 25 mm and a density of 106.4 kg. / M ³ .

(Comparative Example 1)
As Comparative Example 1, the following glass fiber heat insulating sound absorber was obtained. First, melted glass was made into glass fibers having an average fiber diameter of 5.5 μm by a centrifugal method, and immediately after that, an aqueous thermosetting binder composed of polyacrylic acid and diethanolamine was sprayed. The adhesion amount of the aqueous curable binder was set to 8% by mass to obtain an intermediate C. This intermediate C was cut to a mass of 415 g and placed in a mold having a 500 mm square and a 25 mm deep gap, and heated at a mold temperature of 240 ° C. and a molding pressure of 10 TPa for a molding time of 7 minutes. Pressure cured. Thereby, the glass fiber heat-insulated sound absorber of Comparative Example 1 having a thickness of 25 mm and a density of 22 kg / m ³ was molded.

(Comparative Example 2)
As Comparative Example 2, the following glass fiber heat insulating sound absorber was obtained. Intermediate A was obtained in the same manner as Example 1.

This intermediate A was cut to a mass of 415 g and placed in a mold having a 500 mm square and a 25 mm deep gap, and heated at a mold temperature of 240 ° C. and a molding pressure of 10 TPa for a molding time of 7 minutes. Pressure cured. Thereby, the glass fiber heat-insulated sound absorber of Comparative Example 2 having a thickness of 25 mm and a density of 66.4 kg / m ³ was molded.

(Comparative Example 3)
As Comparative Example 3, the following glass fiber heat-absorbing sound absorber was obtained. Intermediate A was obtained in the same manner as Example 1.

This intermediate A was cut to a mass of 665 g and placed in a mold having a 500 mm square and a 25 mm deep gap, and heated at a mold temperature of 240 ° C. and a molding pressure of 10 TPa for a molding time of 7 minutes. Pressure cured. Thereby, the glass fiber heat-insulated sound absorber of Comparative Example 4 having a thickness of 25 mm and a density of 106.4 kg / m ³ was molded.

  About the said Examples 1-3 and Comparative Examples 1-3, the (normal incidence) sound absorption rate was measured for every predetermined frequency. The measurement was performed according to JIS A-1405-2. It can be seen that Examples 1 to 3 have a higher sound absorption rate at any frequency than Comparative Examples 1 to 3, and have excellent sound absorption performance.

1: Glass fiber heat insulating sound absorber, 2: Sound absorbing layer, 3: Sound insulating layer, 4: Resin film

Claims (5)

It has a sound absorbing layer and a sound insulating layer that are glass fiber molded products,
The sound absorption layer has a density of 50kg ^{/ m 3} ~100kg ^/ m 3 and a diameter having a thickness of 10mm~30mm is a glass fiber 3Myuemu～5myuemu,
The sound insulation layer has a glass fiber insulation sound absorbing body characterized by having a density of 60kg ^{/ m 3} ~120kg ^/ m 3 by and diameter 7 [mu] m glass fiber has a thickness of 5 mm to 10 mm. The density of the sound insulation layer is higher than the density of the sound absorption layer,
2. The glass fiber heat-absorbing sound absorber according to claim 1, wherein the sound insulating layer, the sound absorbing layer, and a resin resin film are in contact with each other and overlap each other.   3. The glass fiber heat-absorbing sound absorber according to claim 1, wherein the sound insulation layer has a compression rate of 10% or less when a load of 4 kPa is applied.   The said sound absorption layer and the said sound insulation layer are formed by using the thermosetting resin which does not contain formaldehyde as a binder, The glass fiber heat insulation sound absorber of Claims 1-3 characterized by the above-mentioned.   The method for using a glass fiber heat-absorbing sound absorber according to any one of claims 1 to 4, wherein the sound insulation layer is arranged on the outside and the sound absorption layer is arranged on the inside of a vehicle compartment.

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