JP2005249902A - Acoustic material and waterproof acoustic material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the flexibility of a product form, by effectively absorbing wide-band noise of not only a low-frequency region of 150 Hz or lower, but also a high-frequency region exceeding 150 Hz. <P>SOLUTION: The acoustic material comprises a foaming body layer 1 arranged at a sound source side, a first porous body layer 2 laminated on the sound source side of the foaming body layer 1, and a second porous body layer 4 laminated on the side of a rigid wall 3 of the foaming body layer 1. The foaming body layer 1 is formed of: a first diol of 500-5,000 of a molecular weight; a second diol of 500 or lower for the molecular weight, an inorganic filler; water as a foaming agent; and a foaming body regarding each component of isocyanate as the raw material component. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a sound-absorbing material and a water-resistant sound-absorbing material, and in particular, can effectively absorb broadband noise not only in a low frequency region of 150 Hz or less but also in a high frequency region exceeding 150 Hz, and can improve the degree of freedom of the product form. The present invention relates to a sound absorbing material and a water-resistant sound absorbing material.

  Conventionally, as this kind of sound absorbing material, (a) one using a porous body layer made of glass wool, rock wool or the like, (b) one provided with an air layer on the sound source side, (c) the sound source side of the sound absorbing material And (d) a structure in which at least two layers of high-density and low-density fiber assemblies having different air permeability of 5 to 100 times are laminated (for example, patent documents) 1).

  However, in the sound-absorbing material (a) and (b), in order to exert a required sound-absorbing effect against noise whose frequency band exceeds 500 Hz or noise of 500 Hz or less, the thickness of the porous body layer The thickness has to be increased, and as a result, the weight of the sound absorbing material is increased as a whole. In addition, in the sound absorbing material (c), since an air layer is present on the sound source side of the sound absorbing material, there is a problem that the weight of the sound absorbing material becomes heavy and a large space must be taken. On the other hand, the sound-absorbing material (d) uses a viscous resistance of air, and by laminating fiber assemblies having different densities on a porous sound-absorbing structure that absorbs sound by converting sound wave energy into heat energy, The high-density part is an additional mass, and the low-density part plays the role of a spring, so that a so-called dynamic vibration absorber is constructed to improve the sound absorption coefficient particularly in the low frequency band. In particular, in a so-called low frequency band of 100 Hz or less, there is a problem that a sufficient sound absorption effect cannot be obtained. In addition, sound and vibration in the low frequency band generate not only air propagation sound but also rattling of buildings and windows, so it is necessary to take measures against solid propagation sound and vibration prevention at the same time. The countermeasure was difficult.

  For this reason, the present applicant firstly uses a viscous resistance of air to convert sound wave energy into thermal energy and absorbs sound, and then a sound absorbing material in which fiber assemblies having different densities are laminated. Has been developed and applied (Japanese Patent Laid-Open No. 2003-316364).

  The sound absorbing material includes a foam layer disposed on the sound source side and a porous body layer laminated on the rigid wall side of the foam layer. Here, the foam layer is formed of a foam containing a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate. Moreover, the porous body layer is formed of general-purpose glass wool.

  According to the sound absorbing material having such a configuration, a so-called dynamic vibration absorber, in which the high density portion plays the role of additional mass and the low density portion plays the role of spring, can improve the sound absorption coefficient particularly in the low frequency band. .

  However, the sound absorbing material having such a configuration has the following drawbacks.

  1stly, the glass wool which comprises a porous body layer had the difficulty that the sound absorption effect became weak in the high frequency area | region of 150 Hz or more, or the low frequency area | region of 150 Hz or less.

  Secondly, the foam layer and the porous body layer are integrally molded, and a surface film is formed on the sound source side of the foam layer during the integral molding, so that the degree of freedom of the product cannot be improved. there were. In other words, since the surface film is formed at the same time when the foam layer and the porous body layer are integrally formed, in order to exhibit the required sound absorption characteristics, the sound source side of the foam layer and the rigidity of the porous body layer are required. There was the difficulty that the wall side had to be changed.

  Thirdly, since the glass wool constituting the porous body layer is exposed, there is a problem that the sound absorption characteristics, particularly the sound absorption characteristics in a low frequency region, are lowered when the glass wool gets wet with water.

JP-A-8-152890 JP 2003-316364 A

  The present invention provides a sound-absorbing material and a water-absorbing sound-absorbing material that can effectively absorb wide-band noise in a high-frequency region exceeding 150 Hz as well as a low-frequency region of 150 Hz or less and improve the degree of freedom of the product form. It is aimed.

  The sound absorbing material according to the first aspect of the present invention includes a foam layer disposed on the sound source side, a first porous body layer laminated on the sound source side of the foam layer, and a rigid wall side of the foam layer. A foam layer comprising a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and Each component of isocyanate is used as a raw material component.

  The sound absorbing material according to the second aspect of the present invention includes a foam layer disposed on the sound source side, a second porous body layer laminated on the rigid wall side of the foam layer, and a sound source side surface of the foam layer. The foam layer is formed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, and an inorganic layer. Each component of the filler, water as a foaming agent, and isocyanate is used as a raw material component.

  The sound absorbing material according to the third aspect of the present invention includes a foam layer disposed on the sound source side, a second porous body layer stacked on the rigid wall side of the foam layer, and a sound source side surface of the foam layer. And the foam layer is formed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, and an inorganic filling. The material, water as a foaming agent, and each component of isocyanate are used as raw material components.

  The sound absorbing material according to the fourth aspect of the present invention includes a foam layer disposed on the sound source side, a second porous body layer laminated on the rigid wall side of the foam layer, and the sound source side of the foam layer. A foam layer comprising: a first diol having a molecular weight of 500 to 5000; a second diol having a molecular weight of 500 or less; an inorganic filler; water as a blowing agent; and an isocyanate component. Is a raw material component.

  The sound absorbing material according to the fifth aspect of the present invention includes a foam layer disposed on the sound source side, a second porous body layer laminated on the rigid wall side of the foam layer, and the sound source side of the foam layer A foam layer comprising a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a blowing agent, and isocyanate. A component is a raw material component.

  The sound absorbing material according to the sixth aspect of the present invention includes a foam layer disposed on the sound source side, a first porous body layer laminated on the sound source side of the foam layer, and a rigid wall side of the foam layer. And a damping material layer disposed on the rigid wall side of the second porous body layer, the foam layer being a first diol having a molecular weight of 500 to 5000 The second diol having a molecular weight of 500 or less, the inorganic filler, water as a foaming agent, and isocyanate components are used as raw material components.

  The sound absorbing material according to the seventh aspect of the present invention includes a foam layer disposed on the sound source side, a first porous body layer laminated on the sound source side of the foam layer, and a rigid wall side of the foam layer A second porous body layer that is laminated to the second porous body layer, a damping material layer that is disposed on the rigid wall side of the second porous body layer, and a second porous body layer that is disposed between the damping material layer and the second porous body layer. The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a blowing agent, and isocyanate components. It is what.

  According to an eighth aspect of the present invention, in the sound absorbing material according to any one of the first to seventh aspects, the density of the foam is 50 to 500 kg / m 3.

  According to a ninth aspect of the present invention, in the sound absorbing material according to any one of the first to eighth aspects, the ratio of the hydroxyl group content contained in the first diol and the hydroxyl group content contained in the second diol is: 1: 0.3-2.5.

  According to a tenth aspect of the present invention, in the sound absorbing material according to any one of the first to ninth aspects, the content of the inorganic filler is 10 to 200 parts by weight with respect to 100 parts by weight of the first diol. Has been.

  According to an eleventh aspect of the present invention, in the sound absorbing material according to any one of the first to tenth aspects, the content of water as a foaming agent is 2 to 5 parts by weight with respect to 100 parts by weight of the first diol. It is said that.

  According to a twelfth aspect of the present invention, in the sound absorbing material according to any one of the first to eleventh aspects, the total of the hydroxyl content of the first and second diols and water as the blowing agent and the isocyanate of the isocyanate The isocyanate index (NCO / OH), which is a ratio to the content, is in the range of 0.5 to 1.0.

  According to a thirteenth aspect of the present invention, in the sound absorbing material according to any one of the first to twelfth aspects, the isocyanate index is in the range of 0.6 to 0.9.

  According to a fourteenth aspect of the present invention, in the sound absorbing material according to any one of the first to thirteenth aspects, the first diol is a polyester polyol, a polyether polyol, a polybutadiene polyol, a polyisoprene polyol, a polyolefin polyol, a poly The diol is any diol selected from acrylic ester polyols and polycarbonate polyols.

  According to a fifteenth aspect of the present invention, in the sound absorbing material according to any one of the first to fourteenth aspects, the second diol is ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol, or the like. It is assumed that the diol is any one selected from the group consisting of aliphatic groups and aromatic groups such as N, N-bis (2-hydroxypropyl) aniline.

  A sixteenth aspect of the present invention is the sound absorbing material according to any one of the first to fifteenth aspects, wherein the inorganic filler is carbon black, silica, calcium carbonate, mica, talc, magnesium oxide, aluminum oxide, The inorganic filler is any one selected from magnesium hydroxide and aluminum hydroxide.

  According to a seventeenth aspect of the present invention, in the sound absorbing material according to any one of the first aspect to the first aspect, the isocyanate is 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4 ′ diphenylmethane diisocyanate. , Carbodiimide-modified diphenylmethane diisocyanate, crude tolylene diisocyanate, crude diphenylmethane diisocyanate, p-phenylene diisocyanate, p-xylene diisocyanate, tetramethylene-1,4-diisocyanate. .

  According to an eighteenth aspect of the present invention, in the sound absorbing material according to any one of the first to seventeenth aspects, the porous body layer includes coarse hair felt, vegetable fiber felt, animal fiber felt, and synthetic fiber felt. Or a mixture thereof.

  According to a nineteenth aspect of the present invention, in the sound absorbing material according to any one of the first to eighteenth aspects, the constraining material layer is made of a member having a large Young's modulus.

  According to a twentieth aspect of the present invention, in the sound absorbing material according to any one of the seventh to nineteenth aspects, the constraining material layer is made of a metal material.

  According to a twenty-first aspect of the present invention, in the sound absorbing material according to any one of the seventh to twentieth aspects, the thickness of the constraining material layer is 0.1 to 2 mm.

  A water-resistant sound absorbing material according to a twenty-second aspect of the present invention includes the sound absorbing material according to any one of the first to twenty-first aspects and a water resistant layer provided on the outer surface of the sound absorbing material.

  According to a twenty-third aspect of the present invention, in the water-resistant sound absorbing material according to the twenty-second aspect, the water-resistant layer is composed of a resin film having a thickness of about 100 μm.

  According to a twenty-fourth aspect of the present invention, in the water-resistant sound absorbing material according to the twenty-second aspect, the water-resistant layer is made of a water-repellent cloth.

  According to the sound absorbing material and the water-resistant sound absorbing material of the first aspect to the twenty-third aspect of the present invention, the following effects are obtained.

  First, by providing a porous body layer on both sides of the foam layer, the sound absorption characteristics in a high frequency region of 150 Hz or higher can be improved, and as a result, a sound absorbing material that can be used in a wide frequency range can be provided.

  Second, by providing a hole or the like with a needle-like member in the surface film of the sound absorbing material, the air permeability of the foam layer can be improved, and as a result, the sound absorbing characteristics in the low frequency region can be improved.

  3rdly, the freedom degree of a product form can be improved by making the film | membrane layer formed by the different body adhere | attach and contact on the sound source side of a foam layer.

  Fourthly, by providing a water-resistant layer on the outer surface of the sound-absorbing material composed of the laminate, it is possible to maintain sound-absorbing characteristics in the low-frequency region.

Embodiments to which the sound absorbing material of the present invention is applied will be described below with reference to the drawings.
[First Embodiment]
FIG. 1 is a cross-sectional view showing a first embodiment of a sound absorbing material in the present invention.

  In the figure, a sound absorbing material 1 includes a foam layer 1 disposed on the sound source side, a first porous body layer 2 laminated on the sound source side of the foam layer 1, and a rigid wall 3 of the foam layer 1. And a second porous body layer 4 laminated on the side. Here, as the foam layer 1, a foam having open-cell foaming is used. This is because when the sound wave enters the foam layer 1, the air in the gap portion vibrates, the sound wave energy is converted into heat energy by the viscous resistance of the air, and the sound absorption is performed. This is because the foam layer 1 itself vibrates and the sound wave energy is converted into heat energy by the viscous resistance at this time, and sound absorption is performed. Also, the first and second porous body layers 2 and 4 are laminated on both surfaces of the foam layer 1 because the foam layer 1 part acts as an additional mass, that is, a weight, This is because the portion functions as a spring, that is, an air spring, and performs sound absorption by membrane vibration.

  The foam layer 1 in the present invention is formed of the following foam.

  First, the foam is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and an isocyanate component. By making the first diol, which is the main polymer, a diol having a molecular weight of 500 to 5000, and preferably a molecular weight of 1000 to 2000, it is possible to obtain a foam with added vibration damping properties. Here, when the main polymer is composed of a diol having a molecular weight of less than 500, a hard foam is obtained and vibration damping properties cannot be obtained. On the other hand, when the molecular weight is composed of a diol having a molecular weight exceeding 5000, the initial viscosity is increased and the required foaming is achieved. The body cannot be obtained. When a polyol other than triol or the diol used in the present invention is used as the main polymer, it is difficult to obtain vibration damping properties.

  Second, the density of the foam is preferably in the range of 50 to 500 kg / m3. If the density is less than 50 kg / m3, the air permeability becomes too good and the sound absorption efficiency in the low frequency region is deteriorated. If the density exceeds 500 kg / m3, the air permeability becomes too bad, and the sound is reflected and the sound absorption becomes difficult. Because.

  Thirdly, as the first diol constituting the foam, polyester polyol, polyether polyol, polybutadiene polyol, polyisoprene polyol, polyolefin polyol, polyacrylic ester polyol, polycarbonate polyol and the like are suitable.

  Fourth, the second diol constituting the foam is used as a chain extender of the foam layer 1 of the present invention and plays a role of reinforcement. Here, the reason why the molecular weight is 500 or less is that if the molecular weight exceeds 500, the reinforcing effect cannot be obtained. Further, when this component is a polyol other than triol or diol used in the present invention, the reinforcing effect becomes too great and the vibration damping property is impaired.

  Fifth, the second diol constituting the foam may be an aliphatic group such as ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol, or N, N-bis (2-hydroxypropyl). Aromatic diols such as aniline are preferred.

  Here, the ratio of the hydroxyl group content contained in the first diol used in the foam and the hydroxyl group content contained in the second diol is preferably 1: 0.3 to 2.5. This is because if the ratio of the hydroxyl group content of the second diol is less than 0.3, the reinforcing effect becomes insufficient, and even if the ratio of the hydroxyl group content exceeds 2.5, no difference in effect is observed.

  Sixth, the inorganic filler constituting the foam is used for the purpose of reinforcing the foam layer and adding damping properties. This inorganic filler is preferably blended in an amount of 10 to 200 parts by weight per 100 parts by weight of the first diol having a molecular weight of 500 to 5000. If the amount is less than 10 parts by weight, the effect of adding sufficient reinforcement and vibration damping is small, and if it exceeds 200 parts by weight, the viscosity of the composition before molding becomes high and molding becomes difficult.

  Seventh, as the inorganic filler constituting the foam, carbon black, silica, calcium carbonate, mica, talc, magnesium oxide, aluminum oxide, magnesium hydroxide, aluminum hydroxide and the like are suitable.

  Eighth, water constituting the foam is used as a foaming agent. Although the addition amount of a foaming agent should just be the quantity from which a foam is obtained, 2-5 weight part is suitable with respect to 100 weight part of 1st diols with a molecular weight of 500-5000. This is because if the amount is less than 2 parts by weight, sufficient foaming is not performed, and if the amount exceeds 5 parts by weight, no significant difference in effect is observed.

  Ninthly, as the isocyanate constituting the foam, basically those used for the production of urethane foam can be used, and in particular, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude tolylene diisocyanate, crude diphenylmethane diisocyanate, p-phenylene diisocyanate, p-xylene diisocyanate, tetramethylene-1,4-diisocyanate, and the like are suitable. Can be used as a mixture.

  Tenth, in order to impart moderate rigidity and vibration damping to the foam, the ratio of the total hydroxyl group content of the first diol, the second diol, and water as the blowing agent to the isocyanate content of the isocyanate It is desirable that the isocyanate index (NCO / OH) is in the range of 0.5 to 1.0, preferably 0.6 to 0.9. This is because if the isocyanate index is less than 0.5, the degree of cross-linking decreases and rigidity decreases, and if it exceeds 1.0, moderate rigidity is obtained, but vibration damping performance decreases.

  11thly, you may add suitably the catalyst used for manufacture of a normal urethane foam layer, a foaming agent, a flame retardant, a plasticizer, a coloring agent, etc. to said foam according to the objective.

  Next, the 1st, 2nd porous body layers 2 and 4 in this invention are set as the respectively same structure, The following are formed, respectively.

  First, the first and second porous body layers 2 and 4 are formed of either glass wool or rock wool, or a combination thereof. Specifically, it is formed by laminating glass wool or rock wool of the same type or different types.

Second, the first and second porous body layers 2 and 4 have a loss coefficient η of 0.05 or more, an air permeability of 0.1 dm ³ / s or more, a thickness of 1 to 50 mm, preferably 10 to 10 mm. It is made of 25 mm. The first and second porous body layers 2 and 4 having such a configuration have excellent sound absorption characteristics over a wide range from a low frequency region to a high frequency region, and also reduce solid-borne sound and vibration. Also demonstrates effective vibration damping.

  Thirdly, the first and second porous body layers 2 and 4 are formed with a thermal conductivity of 0.1 to 0.5 W / mK. Moreover, the 1st, 2nd porous body layers 2 and 4 are formed with what mix | blended the thermal conductivity imparting material with the base material the urethane foam or the urethane foam base material. Here, as the thermal conductivity imparting material, one selected from those composed of ceramics or metal materials, silicon carbide powder, alumina powder, aluminum powder, graphite, copper powder, stainless steel powder, or 2 of these. A mixture of at least seeds or graphite (the amount of graphite added is 10 to 150 parts by weight with respect to 100 parts by weight of the polyol forming the urethane foam) is used.

  The first and second porous body layers 2 and 4 having such a configuration are attached to a sound source such as an engine, and are effective in reducing air-borne sound, solid-borne sound, and vibration generated from the engine. Even if the temperature of the room or the soundproof box rises due to the operation of the engine, the temperature rise of the porous body can be suppressed, the deterioration is not promoted, and the life is prolonged.

FIG. 2 shows the sound absorption characteristics of the sound absorbing material in the first embodiment. Here, in the figure, the thick line L1 is the sound absorption characteristic of the conventional sound absorbing material in which the thickness of the porous body layer is 100 mm, and the thin line L2 is the thickness of the first porous body layer 1 of 25 mm, the second The sound absorption characteristics of the sound absorbing material of the present invention in which the thickness of the porous body layer 4 is 75 mm, the dotted line L3 indicates the sound absorption characteristics of a conventional sound absorbing material in which the porous body layer is made of glass wool and the thickness is 100 mm. ing. From the figure, it can be seen that the sound absorbing material (thin line L2) of the present invention exhibits excellent sound absorbing characteristics not only in a low frequency region of 150 Hz or less but also in a high frequency region of 150 Hz or more. Therefore, if the sound absorbing material in the first embodiment is used, it is possible to provide a sound absorbing material that can cope with a wide frequency range.
[Second Embodiment]
FIG. 3 is a cross-sectional view showing a second embodiment of the sound-absorbing material in the present invention. In the figure, parts common to those in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted.

  In FIG. 2, the sound absorbing material 1 includes a foam layer 1 disposed on the sound source side, a second porous body layer 4 laminated on the rigid wall 3 side of the foam layer 1, and a sound source of the foam layer 1. And a coating surface 5 formed on the side surface.

  Here, a large number of holes (not shown) are provided on the sound source side of the coating surface 5 in a direction perpendicular to the coating surface 5 by a needle-like member.

  By forming such holes in the coating surface 5, the air permeability of the coating surface 5 is improved, and as a result, the peak frequency of the sound absorption coefficient can be moved to the low frequency side.

FIG. 4 shows the sound absorption characteristics of the sound absorbing material in the second embodiment. Here, in the figure, the thin line L4 is a sound absorption characteristic of a conventional sound absorbing material having no holes on the coating surface 5, and the dotted line L5 is a hole on the sound source side of the coating surface 5 with 50 holes per cm ² by a needle-like member. The sound absorption characteristic of the formed first sound absorbing material of the present invention, the thick line L6, is the sound absorption of the second sound absorbing material of the present invention in which 200 holes per 1 cm ² are formed on the sound source side of the coating surface 5 by a needle-like member. The characteristics are shown. From the figure, it can be seen that the peak frequency of the sound absorption rate in the first and second sound absorbing materials of the present invention is shifted to the low frequency side. Therefore, if the sound absorbing material in the second embodiment is used, it is possible to provide a sound absorbing material that can cope with a low frequency region of 150 Hz or less. In addition, it replaces with formation of the hole by such a needle-shaped member, and there exists an effect similar to the above-mentioned sound-absorbing material, even if a coating process is given to the coating surface 5 with a grinder and the said surface is roughened.
[Third Embodiment]
FIG. 5 is a cross-sectional view showing a third embodiment of the sound-absorbing material in the present invention. In the figure, parts common to those in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted.

  In FIG. 5, the sound absorbing material 1 includes a foam layer 1 disposed on the sound source side, a second porous body layer 4 laminated on the rigid wall side of the foam layer 1, and a sound source side of the foam layer 1. And a coating layer 6 adhered to the substrate.

  Here, the coating layer 6 is formed separately from the integral molding of the foam layer 1 and the second porous body layer 4. This is to improve the degree of freedom of the product form.

FIG. 6 shows the sound absorption characteristics of the sound absorbing material in the third embodiment. Here, the thick line L7 in the figure represents the sound absorption of the conventional first sound absorbing material in which the porous body layer 4 made of glass wool has a thickness of 50 mm and the coating layer is integrally formed on the sound source side of the foam layer 1. Characteristics, one-dot chain line L8 is a sound absorption characteristic of a conventional second sound-absorbing material in which the thickness of the porous body layer 4 made of glass wool is 100 mm, and a coating layer is integrally formed on the sound source side of the foam layer 1, a dotted line L9 is a sound absorption characteristic of the first sound-absorbing material of the present invention in which the thickness of the porous body layer 4 made of glass wool is 50 mm, and a separate coating layer 6 is bonded to the sound source side of the foam layer 1; L10 represents the sound absorption characteristics of the second sound absorbing material of the present invention in which the porous layer 4 made of glass wool has a thickness of 50 mm and a separate coating layer 6 is bonded to the sound source side of the foam layer 1. ing. From the figure, it can be seen that the first and second sound absorbing materials of the present invention exhibit the same sound absorbing characteristics as the conventional first and second sound absorbing materials. Therefore, if the sound absorbing material in the third embodiment is used, a separate coating layer 6 is bonded and applied to the sound source side or rigid wall side of the foam layer 1 in accordance with the required sound absorbing characteristics and construction method. This can be dealt with by contact (contact), and thus the degree of freedom of the product form can be improved. In addition, the coating layer 6 is not limited to what was adhere | attached on the foam layer 1, You may make the coating layer 6 contact | abut (contact) the foam layer 1. FIG.
[Fourth Embodiment]
FIG. 7 is a cross-sectional view showing a fourth embodiment of the sound-absorbing material in the present invention. In the figure, parts common to those in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted.

  In FIG. 7, the sound absorbing material 1 includes a foam layer 1 disposed on the sound source side, a first porous body layer 2 laminated on the sound source side of the foam layer 1, and a rigid wall 4 of the foam layer 1. A second porous body layer 4 laminated on the side, and a damping material layer 7 disposed on the rigid wall side of the second porous body layer 4 are provided.

  The damping material layer 7 in the present invention is not particularly limited as long as the object can be achieved. For example, the damping material layer 7 is a foam made of a viscoelastic body having open cells inside, and the viscoelastic foam is a sound source. The one in which the foam density distribution is adjusted so that the foam density increases or decreases as it approaches the side is used. Here, as the viscoelastic foam, a plurality of viscoelastic foams, each having a different foam density, are laminated so that the foam density is larger or smaller as the sound source side is approached, In addition, as the foaming density of the viscoelastic foam, it is a high density or low density on the sound source side, and thirdly, a laminate of a damping sheet made of a viscoelastic body on the sound source side of the viscoelastic foam, Fourthly, a laminate of closed cell foam made of viscoelastic material on the sound source side of the viscoelastic foam, fifth, a laminate of metal thin film layer on the sound source side of the viscoelastic foam, sixth, What laminated | stacked the damping sheet | seat which consists of a viscoelastic body on the rigid wall side of a viscoelastic foam is used.

When the damping material layer 7 having such a configuration is arranged, the effect of further reducing vibration and solid-propagating sound is increased.
[Fifth Embodiment]
FIG. 8 is a cross-sectional view showing a fifth embodiment of the sound-absorbing material in the present invention. In the figure, parts common to those in FIGS. 1 and 7 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In FIG. 8, the sound absorbing material 1 includes a foam layer 1 disposed on the sound source side, a first porous body layer 2 laminated on the sound source side of the foam layer 1, and a rigid wall 3 of the foam layer 1. The second porous body layer 4 laminated on the side, the damping material layer 7 disposed on the rigid wall 4 side of the second porous body layer 4, the second porous body layer 4 and the damping And a constraining material layer 8 disposed between the material layers 7.

  The constraining material layer 8 in the present invention is composed of the following.

  First, it is preferable to use a material having a Young's modulus larger than that of the damping material layer 7 as the restraining material layer 8.

  Secondly, a material made effective of the sound absorption effect of the foam layer 1 and suitable for the purpose as the constraining material layer 8 is a metal material, specifically, a punching metal made of aluminum or stainless steel. Or the nonwoven fabric etc. which consist of aluminum fibers are suitable.

  Third, the thickness of the constraining material layer is preferably 0.1 to 2 mm. This is because if the thickness is less than 0.1 mm, the intended effect cannot be obtained, and even if the thickness exceeds 2 mm, no difference is seen in the effect. Note that the foam layer 2 on the sound source side also has the coating surface 6 in the present embodiment.

If the sound absorbing material having such a configuration is used, the vibration damping effect can be further improved.
[Sixth Embodiment]
FIG. 9 is a cross-sectional view showing a sixth embodiment of the water-resistant and sound-absorbing material in the present invention. In the figure, the same reference numerals are given to the same parts as those in FIGS. 1, 7, and 8, and detailed description thereof is omitted.

  In FIG. 9, the water-absorbing sound-absorbing material 1 includes any one of the aforementioned sound-absorbing materials, for example, the sound-absorbing material shown in FIG. 1 and a water-resistant layer 9 provided on the outer surface of the sound-absorbing material.

  Here, as the water resistant layer 9, a resin film having a thickness of about 100 μm is used.

  If the sound absorbing material is covered with such a resin film or a water-repellent cloth, the glass wool constituting the first and second porous bodies 2 and 4 is not likely to get wet with water. Can be maintained. Note that the same effect can be obtained by wrapping with a water-repellent cloth instead of the resin film.

  In the first to sixth embodiments described above, the foam layer 1 is described as a single foam layer having a uniform foam density. First, a foam having open cells inside, in which a thin film layer is integrally formed with the foam on the surface on the sound source side, and second, a thin film layer having a thickness of 1 mm or less, for example, One that is integrally molded with the foam on both the side and the rigid wall side, third, the foam density of the open-cell foam is different in the thickness direction, and fourth, the plurality of different foams The open cell foam is laminated so that the foam density is inclined, fifth, the foam density of the open cell foam is high on the sound source side, sixth, You may use what consists of a viscoelastic body as an open-cell foam.

  Further, instead of the above-described vibration damping material layer, the following configuration, for example, a viscoelastic body coated fiber is applied to the surface of each fiber to form a viscoelastic body coated fiber, and each viscoelastic body coated fiber is assembled. A fibrous aggregate having a sound-absorbing effect may be used. Here, the fibrous aggregate is one in which the fiber density distribution is adjusted so that the fiber density increases or decreases with increasing distance from the brother 1 toward the sound source side, and secondly, a plurality of fibers each having a different fiber density. The fibrous aggregate is laminated so that the fiber density is increased or decreased as it approaches the sound source side. Third, the fiber density of the fibrous assembly is high or low on the sound source side. Fourthly, a laminate of a vibration damping sheet made of a viscoelastic material on the sound source side of the fibrous assembly, and fifth, a closed cell foam made of a viscoelastic material on the sound source side of the fibrous assembly. A laminated body, sixth a laminated metal thin film layer on the sound source side of the fibrous aggregate, and seventh a laminated damping sheet made of a viscoelastic body on the rigid wall side of the fibrous aggregate. Things may be used.

Sectional drawing which shows 1st Embodiment of the sound-absorbing material in this invention. Explanatory drawing which shows the sound-absorption characteristic of the sound-absorbing material which concerns on the 1st Embodiment of this invention. Sectional drawing which shows 2nd Embodiment of the sound-absorbing material in this invention. Explanatory drawing which shows the sound absorption characteristic of the sound-absorbing material which concerns on the 2nd Embodiment of this invention. Sectional drawing which shows 3rd Embodiment of the sound-absorbing material in this invention. Explanatory drawing which shows the sound-absorption characteristic of the sound-absorbing material which concerns on the 3rd Embodiment of this invention. Sectional drawing which shows 4th Embodiment of the sound-absorbing material in this invention. Sectional drawing which shows 5th Embodiment of the sound-absorbing material in this invention. Sectional drawing which shows 6th Embodiment of the sound-absorbing material in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Sound absorption material 1 ... Foam layer 2 ... 1st porous body layer 3 ... Rigid wall 4 ... 2nd porous body layer 5 ... Coating surface 6 ... -Coating layer 7 ... Damping material layer 8 ... Restraining material layer

Claims (24)

A foam layer disposed on the sound source side, a first porous body layer laminated on the sound source side of the foam layer, and a second porous body layer laminated on the rigid wall side of the foam layer And
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. Sound absorbing material. A foam layer disposed on the sound source side, a second porous body layer laminated on the rigid wall side of the foam layer, and formed on the sound source side surface of the foam layer, A coating surface provided with holes,
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. Sound absorbing material. Formed on the sound source side of the foam layer, the second porous body layer laminated on the rigid wall side of the foam layer, and the sound source side surface of the foam layer, and the own sound source side is friction processed And a coating surface roughened by
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. Sound absorbing material. A foam layer disposed on the sound source side, a second porous body layer laminated on the rigid wall side of the foam layer, and a coating layer bonded to the sound source side of the foam layer,
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. Sound absorbing material. A foam layer disposed on the sound source side, a second porous body layer laminated on the rigid wall side of the foam layer, and a coating layer in contact with the sound source side of the foam layer,
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. Sound absorbing material. A foam layer disposed on the sound source side, a first porous body layer laminated on the sound source side of the foam layer, and a second porous body layer laminated on the rigid wall side of the foam layer And a damping material layer disposed on the rigid wall side of the second porous body layer,
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. Sound absorbing material. A foam layer disposed on the sound source side, a first porous body layer laminated on the sound source side of the foam layer, and a second porous body layer laminated on the rigid wall side of the foam layer And a damping material layer disposed on the rigid wall side of the second porous body layer, and a constraining material layer disposed between the second porous body layer and the damping material layer,
The foam layer is composed of a first diol having a molecular weight of 500 to 5000, a second diol having a molecular weight of 500 or less, an inorganic filler, water as a foaming agent, and isocyanate components as raw material components. Sound absorbing material.   The sound absorbing material according to any one of claims 1 to 7, wherein the foam has a density of 50 to 500 kg / m3.   9. The ratio of the hydroxyl group content contained in the first diol and the hydroxyl group content contained in the second diol is 1: 0.3 to 2.5. The sound absorbing material according to any one of claims.   The sound absorbing material according to any one of claims 1 to 9, wherein the content of the inorganic filler is 10 to 200 parts by weight with respect to 100 parts by weight of the first diol.   11. The sound absorbing material according to claim 1, wherein a content of water as the foaming agent is 2 to 5 parts by weight with respect to 100 parts by weight of the first diol.   The isocyanate index (NCO / OH), which is the ratio of the total hydroxyl content of the first and second diols and water as a blowing agent to the isocyanate content of the isocyanate, is in the range of 0.5 to 1.0. The sound-absorbing material according to any one of claims 1 to 11, wherein the sound-absorbing material is in the form.   The sound absorbing material according to any one of claims 1 to 12, wherein the isocyanate index is in a range of 0.6 to 0.9.   The first diol is any diol selected from polyester polyol, polyether polyol, polybutadiene polyol, polyisoprene polyol, polyolefin polyol, polyacrylate polyol, and polycarbonate polyol. The sound-absorbing material according to any one of claims 1 to 13.   The second diol is selected from aliphatic systems such as ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol and decanediol, or aromatic systems such as N, N-bis (2-hydroxypropyl) aniline. The sound-absorbing material according to claim 1, which is any selected diol.   The inorganic filler is any inorganic filler selected from carbon black, silica, calcium carbonate, mica, talc, magnesium oxide, aluminum oxide, magnesium hydroxide, and aluminum hydroxide. The sound-absorbing material according to any one of claims 1 to 15.   The isocyanate is 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4 ′ diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate, crude tolylene diisocyanate, crude diphenylmethane diisocyanate, p-phenylene diisocyanate, p-xylene diisocyanate. The sound-absorbing material according to any one of claims 1 to 16, wherein the sound-absorbing material is any isocyanate selected from tetramethylene-1,4-diisocyanate.   The porous body layer is made of any one of a coarse felt, a vegetable fiber felt, an animal fiber felt, a synthetic fiber felt, or a mixture thereof. The sound-absorbing material according to item.   The sound absorbing material according to any one of claims 7 to 18, wherein the constraining material layer is formed of a member having a large Young's modulus.   The sound absorbing material according to claim 7, wherein the constraining material layer is made of a metal material.   21. The sound absorbing material according to claim 7, wherein a thickness of the constraining material layer is 0.1 to 2 mm.   A sound-absorbing material comprising the sound-absorbing material according to any one of claims 1 to 21 and a water-resistant layer provided on an outer surface of the sound-absorbing material.   The water-resistant and sound-absorbing material according to claim 22, wherein the water-resistant layer is a resin film having a thickness of about 100 µm. The water-resistant and sound-absorbing material according to claim 22, wherein the water-resistant layer is a water-repellent cloth.

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