JP2015052074A - Sound insulation material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide sound insulation material composed of resin foam, which is lightweight and has excellent sound insulation effect without secondary processing such as covering of an internal surface or an external surface with a resin film.SOLUTION: Sound insulation material is composed of polyurethane resin foam, a permeability of the polyurethane resin foam measured in accordance with JIS-L1096 is 0.05 to 20 cm/cm/sec, and an average value of a ratio of the long diameter/short diameter of a cell constituting the polyurethane resin foam is 1.5 or more. It is preferable that the resin foam is arranged so that sound enters in a long diameter direction of the cell, permeability is secured while sound collides with a cell membrane, thereby obtaining excellent sound insulation performance.

Description

  The present invention relates to a sound insulating material composed of a resin foam.

  Conventionally, a flexible material such as flexible urethane foam or glass wool has been widely used as a wall member and a ceiling member of a building, or as a sound absorbing material for an automobile interior.

  The sound absorbing material absorbs energy in the air layer (in the cell in the case of a resin foam), and the greater the thickness of the same material, the greater the sound absorbing effect. On the other hand, the sound insulation effect increases as the surface density (mass per unit volume) of the sound insulation material increases.

  As a sound-absorbing / sound-insulating material for noise countermeasures, the following Patent Document 1 enables control of air permeability of a base material made of a melamine resin foam and a desired position on the inner or outer surface or outer surface of the base material. A sound-absorbing and sound-insulating material composed of a ventilation control layer to be covered is described.

  Patent Document 2 below describes a sound absorbing material / sound insulating material having a resin layer having a breathability of 1/2 to 1/50 of the foamed resin base material on the surface of the foamable resin base material having continuous breathability. Has been.

JP 2002-287769 A JP 2007-30268 A

  However, in the technique described in the above-mentioned patent document, the resin foam only has a sound absorption effect, and the sound insulation effect is mainly contributed by the air flow control layer or the resin layer laminated on the resin foam. The fact is that there is nothing that has a sound insulation effect only with the body.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resin foam that is lightweight and has an excellent sound insulation effect without secondary processing such as coating the inner surface or outer surface with a resin film. It is in providing the sound-insulating material comprised by this.

The above object can be achieved by the present invention as described below. That is, the present invention is a sound insulating material composed of a resin foam, and the resin foam has an air permeability measured in accordance with JIS-L1096 of 0.05 to 20 cm ³ / cm ² / sec. And the average value of the major axis / minor axis ratio of the cells constituting the resin foam is 1.5 or more. In the sound insulating material according to the present invention, the resin foam is preferably a polyurethane resin foam.

When the air permeability measured in accordance with JIS-L1096 of the resin foam constituting the sound insulating material, particularly the polyurethane resin foam, is 0.05 to 20 cm ³ / cm ² / sec, the foam is closed Although the rate is low and the cells in the foam are almost in communication with each other, there is a tendency that many cell films constituting the cells in the resin foam remain. When a large amount of cell membrane remains in the foam cell, when sound enters the foam, the incident sound collides with the cell membrane and penetrates while being attenuated. There is an effect.

  In general, a cell of a resin foam, particularly a polyurethane resin foam is often substantially spherical, but in the present invention, the ratio of the major axis / minor axis ratio of the cell constituting the resin foam, particularly the polyurethane resin foam, is used. The feature is that the average value is 1.5 or more. In the present invention, the resin foam, in particular, the average value of the major axis / minor axis ratio of the cells of the polyurethane resin foam is 1.5 or more, and the major axis direction of the cells is aligned in one direction. In particular, the polyurethane resin foam has anisotropy. In this case, if the polyurethane resin foam is arranged so that the sound is incident in the major axis direction of the cell, the sound insulation performance is particularly excellent because the air permeability is secured while the sound collides with the cell membrane. become.

The resin foam constituting the sound insulating material according to the present invention preferably has a density of 15 kg / m ³ or less. As described above, the sound insulation effect of the sound insulation material tends to hold the mass rule that the sound insulation effect increases as the surface density increases. When the density of the body is 15 kg / m ³ or less, an excellent sound insulating effect is achieved while being lightweight.

It is a figure which shows an example of the cell structure of the polyurethane resin foam which comprises the sound insulating material which concerns on this invention. It is a figure which shows an example of the sound insulation evaluation method of the sound insulation material which concerns on this invention.

As the resin foam constituting the sound insulating material according to the present invention, the air permeability measured according to JIS-L1096 is 0.05 to 20 cm ³ / cm ² / sec, and the cell constituting the resin foam Any resin foam having an average value of the major axis / minor axis ratio of 1.5 or more can be used. Specifically, a phenol resin foam or a polyurethane resin foam is mentioned, for example. The low-density resin foam includes, for example, a melamine resin foam. However, since the melamine resin foam has a non-film structure (a structure having only a cell skeleton) with almost no cell film of cells in the foam, it will be described later. As the experimental results show, the air permeability is very high. For this reason, a melamine resin foam is excluded as a resin foam which comprises the sound insulating material which concerns on this invention.

  The low-density phenolic resin foam is prepared by a known method described by those skilled in the art, such as phenol resin initial condensate, decomposable foaming agent, surfactant and solvent as described in JP-A-63-46238. It is obtained by filling into a mold, heating to a temperature equal to or higher than the foam curing temperature, and foaming at a foaming ratio of 70 to 200 times.

The sound insulating material according to the present invention is preferably composed of a polyurethane resin foam having an air permeability measured in accordance with JIS-L1096 of 0.05 to 20 cm ³ / cm ² / sec. As a method of adjusting the air permeability of the polyurethane resin foam within such a numerical range, for example, a method of reducing the density of the polyurethane resin foam can be mentioned. When the density of the polyurethane resin foam is lowered, the air permeability tends to decrease, and the cell tends to be stretched in the foaming direction at the time of foaming as the foaming ratio increases. Since the cells are elongated in the foaming direction and have an elliptical shape in a cross-sectional view, in the present invention, the average value of the major axis / minor axis ratio of the cells constituting the polyurethane resin foam can be 1.5 or more. .

In order to reduce the density of the polyurethane resin foam, it is necessary to increase as much as possible the ratio of the blowing agent component such as water contained in the polyol composition to be reacted with the polyisocyanate component. However, as the amount of the foaming agent component increases, the resin strength becomes insufficient at the foaming stage of the foam, so that a lot of foam gas escapes in the foam, and the foam tends to shrink. For this reason, even if it increases the ratio of foaming agent components, such as water, contained in a polyol composition, the density reduction of a foam may become inadequate after all. Hereinafter, an example of a polyurethane resin foam having a low density and an air permeability measured in accordance with JIS-L1096 of 0.05 to 20 cm ³ / cm ² / sec will be described. However, the polyurethane resin foam according to the present invention is not limited to those exemplified below.

  As a polyol composition which is one of the raw materials of the polyurethane resin foam, for example, a polyol compound having a mean number of functional groups of 2 to 4, a weight average molecular weight of 3000 to 8000, and a polymer of an alkylene oxide. The thing containing ether polyol (A) and short glycol (B) whose molecular weight is less than 250 can be illustrated.

  The polyether polyol (A) is a polyoxyalkylene polyol obtained by ring-opening addition polymerization of alkylene oxide to an initiator having 2 to 4 active hydrogen atoms. Specific examples of the initiator include aliphatic polyhydric alcohols (for example, ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,6-hexane. Diols, neopentyl glycol, cyclohexylene glycol, glycols such as cyclohexanedimethanol, triols such as trimethylolpropane and glycerin, tetrafunctional alcohols such as pentaerythritol, aliphatic amines (for example, ethylenediamine, propylenediamine, butylenediamine) , Alkylene diamines such as hexamethylene diamine and neopentyl diamine, alkanol amines such as monoethanolamine and diethanolamine), aromatic amines (for example, 2, -Toluenediamine, 2,6-toluenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylmethane, p-phenylenediamine, o-phenylenediamine, naphthalenediamine, etc.), each of which is used alone. However, it is preferable to use an aliphatic alcohol as the initiator, more preferably a triol, more preferably glycerin, and the polyether polyol (A) may be used in combination. The average functional group number is 2 to 4, more preferably 2.5 to 3.5, and the polyether polyol (A) more preferably has a weight average molecular weight of 3000 to 5000.

  Examples of the alkylene oxide include ethylene oxide, propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, styrene oxide, and cyclohexene oxide. Among these, it is preferable to use ethylene oxide and propylene oxide in combination to cause ring-opening addition polymerization to the initiator. At that time, the ratio of ethylene oxide ((ethylene oxide) / (ethylene oxide + propylene oxide)) is preferably 5% to 30%.

  The hydroxyl value of the polyether polyol (A) is preferably 20 to 100 mgKOH / g, and more preferably 30 to 60 mgKOH / g. When the hydroxyl value is less than 20 mg KOH / g, the viscosity ratio of the polyol composition to the polyisocyanate component increases, leading to poor stirring during mixing. On the other hand, when it exceeds 100 mgKOH / g, it becomes difficult to impart appropriate toughness to the obtained polyurethane foam. The hydroxyl value is a value measured according to JIS K1557-1: 2007.

  Short glycol (B) having a molecular weight of less than 250 includes, for example, ethylene glycol (molecular weight 62), propylene glycol (molecular weight 76), diethylene glycol (molecular weight 106), dipropylene glycol (molecular weight 134), 1,4-butanediol (molecular weight). 90), 1,3-butanediol (molecular weight 90), 1,6-hexanediol (molecular weight 118), glycerin (molecular weight 92), tripropylene glycol (molecular weight 192), and the like. Among these, diethylene glycol, dipropylene glycol and glycerin are preferable and diethylene glycol is particularly preferable in order to increase the resin strength of the foam more reliably. The molecular weight of the short glycol (B) is preferably 62 to 200 mgKOH / g, more preferably 90 to 150 mgKOH / g.

  In the polyol composition, it is preferable that the polyol compound further contains a polyether polyol (C) which has an average functional group number of 2 to 4 and a weight average molecular weight of 3000 to 5000 and is a propylene oxide polymer. . The polyether polyol (C) is a polyoxyalkylene polyol obtained by ring-opening addition polymerization of propylene oxide alone to an initiator having 2 to 4 active hydrogen atoms. Examples of the initiator include the aliphatic polyhydric alcohols, aliphatic amines, and aromatic amines described above, and are not particularly limited. As the initiator, glycerol is particularly preferable.

  In order to lower the density of the polyurethane resin foam and ensure the air permeability within a desired range, the polyol composition contains 10 to 80 parts by weight of the polyether polyol (A) in 100 parts by weight of the polyol compound. It is preferable to contain 10-60 parts by weight of the short glycol (B), 15-70 parts by weight of the polyether polyol (A), and 10-50 parts by weight of the short glycol (B). preferable. When the polyether polyol (C) is contained, the polyether polyol (A) is contained in an amount of 10 to 30 parts by weight, the short glycol (B) is contained in an amount of 10 to 60 parts by weight, and the polyether polyol (C) 30. ~ 70 parts by weight, preferably 15 to 25 parts by weight of polyether polyol (A), 10 to 50 parts by weight of short glycol (B), and 40 to 60 parts by weight of polyether polyol (C) It is more preferable to contain part.

  A foaming agent known to those skilled in the art can be added to the polyol composition, but water can be preferably used. The blowing agent is preferably water alone, and the blending amount thereof is preferably 20 to 100 parts by weight, more preferably 30 to 90 parts by weight, still more preferably 40 parts by weight based on 100 parts by weight of the polyol compound. ~ 80 parts by weight. Thus, the density of a polyurethane resin foam can be reduced by blending a large amount of water.

The density of polyurethane foam is preferably in the 15 kg / ^{m 3} or less, more preferably to 8~12kg / ^{m 3,} it is particularly preferable that the 9~11kg / ^{m 3.} Such density can be set within the above range by adjusting the amount of water as a foaming agent to 20 to 100 parts by weight (vs. 100 parts by weight of the polyol compound), for example. Here, the foam density is a value measured according to JIS K7222. Further, air permeability of the polyurethane foam ^is a 0.05~20cm ^{3 /} cm 2 ^{/ sec,} is preferably ^{0.1~15cm 3 / cm 2 / sec,} 0.1~10cm 3 / cm More preferably, it is ² / sec. Here, the air permeability of the polyurethane resin foam is a value measured according to JIS-L1096.

  Usually, a flame retardant, a catalyst, and a foam stabilizer are further blended in the polyol composition. Moreover, you may further mix | blend the various additives mix | blended with the polyol composition for polyurethane foams, such as a coloring agent and antioxidant.

  Examples of the flame retardant include metal compounds such as organophosphates, halogen-containing compounds, and aluminum hydroxide. Particularly, organophosphates are preferable because they have an effect of reducing the viscosity of the polyol composition. Examples of the organic phosphate ester include halogenated alkyl ester of phosphoric acid, alkyl phosphate ester, aryl phosphate ester, and phosphonate ester. Specific examples include tris (chloropropyl) phosphate (TMCPP, manufactured by Daihachi Chemical), tributoxyethyl phosphate (TBEP), tributyl phosphate, triethyl phosphate, trimethyl phosphate, cresyl phenyl phosphate, and the like. It is preferable that the compounding quantity of a flame retardant is 10-50 weight part with respect to 100 weight part of polyol compounds, More preferably, it is 15-40 weight part. In particular, when the polyol composition contains 20 parts by weight or more of a flame retardant with respect to 100 parts by weight of the polyol compound, in addition to the polyether polyol (A) and the short glycol (B), deterioration of foam brittleness is prevented. This is preferable.

  As the catalyst, a tertiary amine catalyst having a resinizing activity stronger than the foaming activity can be suitably used. As such a tertiary amine catalyst, N, N, N ′, N ′ can be used. -Tetramethylethylenediamine, N, N, N ', N'-tetramethylhexamethylenediamine, diazabicycloundecene, N, N-dimethylcyclohexylamine, triethylenediamine and the like.

  It is preferable that the compounding quantity of a catalyst is 0.1-10 weight part with respect to 100 weight part of polyol compounds, More preferably, it is 1-6 weight part.

  Examples of the foam stabilizer include, among known foam stabilizers for polyurethane foams, a graft copolymer of polyoxyalkylene glycol, which is a polymer of ethylene oxide or propylene oxide, and polydimethylsiloxane. Silicone foam stabilizers having an oxyethylene group content of 70 to 100 mol% in oxyalkylene are preferably used. Specifically, SH-193, SF-2937F, SF-2938F (manufactured by Toray Dow Corning Silicone), B-8465, B-8467, B-8481 (made by Evonik Degussa Japan), L-6900 (made by Momentive) etc. are mentioned. The blending amount of the foam stabilizer is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the polyol compound.

  Various polyisocyanate compounds such as aromatic, alicyclic and aliphatic polyisocyanates having two or more isocyanate groups are used as the polyisocyanate component which is mixed and reacted with the polyol composition to form a polyurethane resin foam. be able to. Preferably, liquid diphenylmethane diisocyanate (MDI) is used because it is easy to handle, fast in reaction, excellent in physical properties of the resulting polyurethane foam, and low in cost. As liquid MDI, crude MDI (c-MDI) (44V-10, 44V-20, etc. (manufactured by Sumika Bayer Urethane Co., Ltd.), Millionate MR-200 (Nippon Polyurethane Industry)), uretonimine-containing MDI (Millionate MTL; Nippon Polyurethane) Industrial)). In addition to liquid MDI, other polyisocyanate compounds may be used in combination. As the polyisocyanate compound to be used in combination, a polyisocyanate compound known in the technical field of polyurethane can be used without limitation.

The polyurethane resin foam constituting the sound insulating material according to the present invention is, for example, the following production method;
A process for producing a polyurethane resin foam obtained by using a polyol compound, a foam composition containing water as a foaming agent, and a foamed stock solution composition containing a polyisocyanate component, wherein the polyol compound has an average number of functional groups. 2 to 4, a weight average molecular weight of 3000 to 8000, a polyether polyol (A) which is a polymer of alkylene oxide, and a short glycol (B) having a molecular weight of less than 250, and a polyol compound 100 It can be produced by a method for producing a polyurethane resin foam containing 20 to 100 parts by weight of water with respect to parts by weight and mixing and reacting a polyol composition and a polyisocyanate component. According to this production method, it is possible to produce a polyurethane resin foam having a low air permeability, cells extending in the foaming direction of the foam, and an average value of the major axis / minor axis ratio of the cell of 1.5 or more. it can.

  The cells of the polyurethane resin foam constituting the sound insulating material according to the present invention may be substantially spherical, but may be elliptical having a major axis and a minor axis. When the cells of the polyurethane resin foam have an elliptical shape and the major axis direction of the cells is aligned in one direction, the polyurethane resin foam has anisotropy, as shown in FIG. In FIG. 1, the cell film interval is longer in the major axis direction of the cell (direction A in FIG. 1), and more cell film remains in the minor axis direction of the cell. When the cells of the polyurethane resin foam are elongated in the foaming direction (major axis direction) to become an elliptical shape, as shown in FIG. 1, the cell membrane portion (the minor axis direction side cell membrane portion) having a high degree of elongation at the time of foaming is formed. It is easy to tear and communicate. When the sound enters from the major axis direction of the cell (foaming direction of foam (direction A in FIG. 1)) and goes out in the major axis direction, the sound advances in the major axis direction along the cell film, After passing through the communicating portion to the minor axis direction side, the sound needs to travel in the major axis direction along the cell membrane again. That is, when the sound travels in the major axis direction of the cell, the sound travels along a complicated path along the cell film. Therefore, when the cells of the polyurethane resin foam constituting the sound insulating material according to the present invention have an elliptical shape and the major axis direction of the cells is aligned in one direction, the sound insulation performance is particularly excellent in the major axis direction (foaming direction) of the cell. It becomes. For this reason, the sound insulation performance of the sound insulation material can be particularly enhanced by devising the arrangement so that sound is incident in the major axis direction of the cell (foaming direction of the foam (direction A in FIG. 1)).

  In the present invention, the average value of the major axis / minor axis ratio of the cells constituting the polyurethane resin foam is 1.5 or more, more preferably 2 or more, and particularly preferably 3 or more.

  The average value of the major axis / minor axis ratio of the cells constituting the polyurethane resin foam is obtained by cutting the polyurethane resin foam in the foaming direction, photographing the cross section with an electron microscope at an arbitrary measurement position, and measuring at each measurement position. It can be calculated by measuring the average value of the major axis / minor axis ratios of the cells and averaging them.

  The polyurethane resin foam preferably has a closed cell ratio of 15% or less, more preferably 0 to 10%. By increasing the communication rate in this way, it is possible to ensure excellent dimensional stability as a polyurethane foam. Here, the closed cell ratio is a value measured according to ASTM D2856.

  The polyurethane resin foam constituting the sound insulating material according to the present invention exhibits not only a sound insulating effect but also a sufficient heat insulating performance when the thermal conductivity λ is λ ≦ 0.04 W / m · K. Can do. Here, the thermal conductivity is a value measured according to JIS-A1412-2.

  Since the sound insulating material according to the present invention is lightweight and can exhibit a sound insulating effect with the resin foam alone, secondary processing such as covering the inner surface or outer surface of the resin foam with a resin film is basically used. unnecessary. Therefore, it is applicable to many uses, for example, can be used suitably as a sound insulation material for automobiles.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Examples 1-2
(Preparation of polyol composition)
A polyurethane resin foam having an air permeability measured in accordance with JIS-L1096 of 0.05 to 20 cm ³ / cm ² / sec and an average value of the major axis / minor axis ratio of the cell of 1.5 or more. In order to manufacture, the polyol composition was prepared by the mixing | blending described in following Table 1 as an example. The details of each component in Table 1 are as follows.

(1) Polyol compound Polyether polyol (A); trade name “EX-230” (manufactured by Asahi Glass Co., Ltd.), polyether polyol (weight average) obtained by addition polymerization of ethylene oxide and propylene oxide using glycerol as an initiator Molecular weight 3000, hydroxyl value (OHV) = 56 mgKOH / g)
Short glycol (B); diethylene glycol (DEG) (molecular weight 106, hydroxyl value (OHV) = 1058 mg KOH / g, manufactured by Nacalai Tesque)
Polyether polyol (C); trade name “T-3000S” (manufactured by Mitsui Chemicals), polyether polyol obtained by addition polymerization of only propylene oxide using glycerol as an initiator (weight average molecular weight 3000, hydroxyl value = 56mgKOH / g)

(2) Flame retardant: Trade name “TMCPP” (manufactured by Daihachi Chemical Co., Ltd.)
(3) Foam stabilizer: silicone-based nonionic surfactant, trade name “SF-2938F” (manufactured by Toray Dow Corning Silicone)
(4) Catalyst: N, N-dimethylaminoethoxyethanol, trade name “Kao No. 26” (manufactured by Kao Corporation)

  Using a polyol composition and a polyisocyanate component (c-MDI (“Sumijoule 44V-10” manufactured by Sumika Bayer Urethane Co., Ltd., NCO%: 31%) adjusted with the formulation shown in Table 1), an isocyanate index (NCO Index) Is injected from a mixing head into a mold (longitudinal direction a length 1.82 m, width direction b length 0.4 m, thickness direction c length 0.5 m). did. Thereafter, the foaming stock solution composition is reacted to have a shape substantially the same as the space in the mold, and the thickness direction (the minor axis direction of the cell, the B direction in FIG. 1) and the foaming direction of the foam cell (the major axis direction of the cell, A polyurethane resin foam panel in which A direction in FIG. 1 is substantially vertical (90 °) is manufactured, and a predetermined sample shape (length: 150 mm width: 150 mm thickness: 10 mm) is cut out from the polyurethane foam panel, Evaluation was performed. In Example 1, the evaluation of air permeability and sound insulation was performed by making air or sound incident in the B direction, and in Example 2, it was made by making air or sound incident in the A direction. The measurement results are shown in Table 2.

Comparative Examples 1-5
Conventional PE (polyethylene) fiber bodies, melamine resin foam bodies, and soft polyurethane foam bodies having the density and air permeability shown in Table 2 were used. The measurement results are shown in Table 2.

  Each physical property described in Table 2 was measured by the following method.

[Resin foam density]
About the resin foam density, it calculated | required based on JIS-K7222.

[Air permeability]
It calculated | required based on JIS-L1096 (Breathability A method fragile meter method).

[Sound insulation]
As shown in FIG. 2, the jig 1 is set and the speaker 2 continuously emits sound from 100 to 5000 Hz, and the sound pressure is measured by the microphone 3 installed every 50 Hz. The sound pressure difference with or without the measurement sample 4 set was calculated, and the sound insulation was evaluated. The sound pressure difference was calculated as an average value between 100 and 800 Hz, between 800 and 2000 Hz, and between 2000 and 5000 Hz.

  From the results shown in Table 2, the polyurethane resin foam having a low density and low air permeability exhibits excellent sound insulation, and in Example 2 in which sound is incident in the major axis direction of the elliptical cell, the sound insulation is particularly excellent. I understand. On the other hand, since the melamine resin foam according to Comparative Example 2 has a filmless structure (structure having only a cell skeleton) in which there is almost no cell membrane of cells in the foam, the air permeability is very high. For this reason, the sound insulation performance was significantly reduced as compared with the polyurethane resin foam. In the flexible polyurethane resin foam according to Comparative Example 3-5, when the air permeability was lowered, the sound insulation performance was increased, but the density tended to increase.

Claims (3)

A sound insulating material composed of resin foam,
The resin foam has an air permeability measured in accordance with JIS-L1096 of 0.05 to 20 cm ³ / cm ² / sec, and an average of the major axis / minor axis ratio of the cells constituting the resin foam. A sound insulating material having a value of 1.5 or more.   The sound insulating material according to claim 1, wherein the resin foam is a polyurethane resin foam. The sound insulating material according to claim 1, wherein the resin foam has a density of 15 kg / m ³ or less.

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