JPH1088688A - Civil engineering building sound absorbing member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a civil engineering building sound absorbing member compatible with high damping efficiency and high sound absorbing efficiency. SOLUTION: A civil engineering buiding sound absorbing member is formed of a rigid member 2 and a foam 3 formed by reacting a mixture constituted of polyolefin-polyol having a saturated hydrocarbon resin build and water as a foaming agent and organic polyisocyanate making fatty acid ester having hydroxide group in a chain as a basic build uner the existence of a surface-active agent substituting at least part of hydroxide group for hydrophilic-group and laminated on the surface of the rigid member 2. By the constitution, since the foam 3 dispeses water uniformly, an uniform cell is formed, and high damping efficiency and high sound absorbing efficiency are ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sound absorbing member used in the field of civil engineering and construction. Since the sound absorbing member of the present invention has a low water absorption, it can be used for outdoor use such as a sound absorbing panel on a highway.

[0002]

2. Description of the Related Art Noise from roads caused by traveling vehicles is as follows.
As a means for preventing the signal from being further amplified by being reflected on the wall surface of an elevated road or a building near the road, it has been proposed to attach a sound absorbing plate to the lower surface of the elevated road or the wall of the building. As this sound absorbing plate, glass wool, urethane foam, foamed rubber and the like are generally used.

Further, in order to prevent the sound of a piano at home from leaking to the outside, the walls of the room are also formed from soundproof panels. As the soundproofing panel, a soundproofing material such as glass wool or urethane foam laminated on the back side of a wall material such as plywood is used. In this case, it is necessary to have a vibration damping property for suppressing vibration of the wall material due to sound, and a material having both a vibration damping property and a sound absorbing property is selected.

By the way, materials having high vibration damping properties include:
It is conventionally known that rubber or resin having high viscoelasticity is preferable, and a foam is preferable for obtaining high sound absorbing properties. Therefore, a vibration damping / absorbing member made of foamed rubber or urethane is used, but it has been difficult to achieve both vibration damping and sound absorbing properties. In addition, foamed urethane and glass wool using conventional polyether polyols have high water absorption, so if they are used in areas where water comes in contact with rain, etc., the weight will increase significantly due to water absorption, and once water is absorbed, the water will be released easily. Not done. Therefore, there is a problem that the sound absorbing member falls off from the wall surface and mold is generated, and when the sound absorbing member is in contact with a metal component, rust is generated. Therefore, the sound absorbing member cannot be used outdoors where it is exposed to rain.

A foam made by impregnating and adhering a water-repellent material such as asphalt to foamed urethane, a foam made by reacting and foaming polybutadiene and an organic isocyanate, or a foam made by reacting castor oil, a dimer acid-modified polyol and an organic isocyanate. Foams are known. Although these foams have a low water absorption rate, foams obtained by impregnating and adhering a water-repellent material such as asphalt to urethane foam are thinned during curing, and foams obtained by reacting and foaming polybutadiene and an organic isocyanate, or A foam obtained by reacting and casting castor oil, a dimer acid-modified polyol and an organic isocyanate has a defect that it has poor weather resistance because it has a double bond.

Japanese Unexamined Patent Publication (Kokai) No. 2-298574 discloses a foam sealing material obtained by reacting a polyol having a saturated hydrocarbon resin skeleton with an organic isocyanate in the presence of a reactive silicone oil. This foamed sealing material shows a good water-stopping property, has no thinning phenomenon, and is excellent in weather resistance.

[0007]

However, when a foam is formed by the method disclosed in the above publication, there is a problem that the dispersibility of water as a blowing agent is extremely poor and a uniform foam cannot be formed. Was. Even though the dispersion can be temporarily and uniformly dispersed by a disper or the like, separation starts at the time of injection into the mold or immediately after the injection, and the obtained foam becomes inhomogeneous.

[0008] The present invention has been made in view of such circumstances, and forms a homogeneous foam that can ensure high vibration damping, high sound absorption, and low water absorption, and uses the foam to control the foam. An object of the present invention is to provide a sound-absorbing member for civil engineering construction which is excellent in vibration and sound-absorbing properties, and is also excellent in waterproofness.

[0009]

According to the first aspect of the present invention, there is provided a sound-absorbing member for civil engineering and construction, which comprises a rigid member, a polyolefin polyol having a saturated hydrocarbon resin skeleton, water and an organic compound as a foaming agent. And a foam formed by reacting a mixture comprising polyisocyanate with a surfactant having a fatty acid ester having a hydrophilic group in the chain as a basic skeleton and laminated on the surface of the rigid member. .

The feature of the sound absorbing member for civil engineering construction according to claim 2 is that, in the sound absorbing member according to claim 1, the polyolefin polyol has a side chain and has a reactive primary hydroxyl group at a molecular terminal. Features.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Rigid members include wood, resin,
A material formed from a rigid material such as FRP or metal can be used. In addition, in the case of absorbing the radiated sound of the traveling sound of a car, a concrete wall such as a highway, a floor wall facing the ground of an elevated road, a wall of a building facing the road, and the like may be used as the rigid member. In the case of a sound-absorbing member for a building, decorative plywood, a ceiling material, a floor material and the like are exemplified as the rigid member.

The greatest feature of the present invention resides in the foam laminated on the surface of the rigid member. The conventional foamed polyurethane uses polyether polyol, so that it can foam uniformly and obtain high sound absorbing properties, but has a drawback that the water absorption is large. Therefore, it was conceived to use a polyolefin polyol having a low affinity for water.However, polyolefin polyol is poorly compatible with water as a foaming agent, and a problem that a uniform foam cannot be obtained due to cell collapse when foam molding is performed. It became clear that there was.

The inventors of the present application have conducted intensive studies,
The present inventors have found that it is possible to form a homogeneous foam of a polyolefin polyol by using a special composition, and have found that the obtained foam has both high vibration damping properties and sound absorbing properties, thereby completing the present invention. Things. The polyolefin polyol having a saturated hydrocarbon resin skeleton refers to, for example, an atactic butadiene oligomer as described in Chemical Formula 1 or a hydrogenated polybutadiene.
This polyolefin polyol can be produced, for example, by subjecting butadiene to anionic living polymerization.

[0014]

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The polyolefin polyol preferably has a side chain and a reactive primary hydroxyl group at a molecular terminal. By having a side chain, the foamed body to be formed is further improved in vibration damping properties. The polyolefin polyol preferably has a number average molecular weight in the range of 1,000 to 9000. If the number average molecular weight is less than 1000, the foam becomes hard and brittle, and if it exceeds 9000, the viscosity becomes too high and foam molding may be difficult. Particularly desirable is a range of 1500 to 3000. In order to make the number average molecular weight in the range of 1,000 to 9000, the hydroxyl value is preferably 10 to 140.

As the organic polyisocyanate, those used for urethane foams using ordinary polyether polyols can be used as they are. Examples of such organic polyisocyanates include MDI, TDI
System, XDI system, HMDI system, IPDI system and the like. The present inventors conducted experiments using various surfactants to uniformly disperse water in the polyolefin polyol. As a result, they have found that a surfactant having a fatty acid ester having a hydrophilic group in a chain as a basic skeleton gives particularly preferable results. The surfactant preferably has an HLB value of 10 or more.

In order to introduce a hydrophilic group into the chain of a fatty acid ester, it is necessary to use a fatty acid ester having a hydroxyl group or a double bond and to substitute or add a hydrophilic group to the hydroxyl group or the double bond. it can. A typical example of such a fatty acid ester is castor oil, but not limited to castor oil, and fatty acid esters such as peanut oil, olive oil, fish oil, and whale oil can also be used.

In particular, when a hydrophilic group is introduced using a fatty acid ester having a hydroxyl group in the chain, the replacement of the hydrophilic group is facilitated and uniform dispersion of water becomes possible. Also, even if a hydroxyl group that has not been substituted with a hydrophilic group remains, because it is integrated as a part of the foam by reaction with the isocyanate,
The foam becomes more hydrophobic and the water absorption can be greatly reduced.

The polyolefin polyol, the surfactant and the organic isocyanate have an NCO / OH of 60 to 150.
It is desirable that they are mixed in the range described below. When NCO / OH is less than 60, the crosslink density is reduced, and the obtained sound absorbing member has reduced vibration damping and sound absorbing properties. NCO / OH is 1
If it exceeds 50, a problem that the foam becomes brittle occurs. A particularly desirable range is an NCO / OH of 80 to 120.

Further, it is desirable to add the surfactant in an amount of 20 to 200 parts by weight with respect to 100 parts by weight of water used. If the amount of the surfactant is less than 20 parts by weight, the mixing of water becomes uneven and uniform foam molding becomes difficult.
If the amount exceeds 200 parts by weight, the characteristics of the sound absorbing member deteriorate. When foam molding is difficult due to high viscosity of the polyolefin polyol, it is preferable to add a plasticizer. The viscosity of the system can be reduced by the plasticizer, and foam molding at normal temperature can be performed.
As the plasticizer, a known plasticizer such as a phthalate ester type or a phosphoric acid type can be used. In addition to the components described above, a foam stabilizer, a flame retardant, and the like can be used.

In the production of the sound absorbing member of the present invention, the above components are mixed to react with the polyolefin polyol and the organic isocyanate, and the reaction between water and the organic isocyanate generates carbon dioxide and foams. Ordinary foam molding methods can be used. That is, by performing this reaction in the mold, a foam filled in the cavity is formed. This reaction needs to be performed in a liquid state.If the viscosity of the polyolefin polyol is high, the reaction may be performed by lowering the viscosity by heating, or the reaction may be performed by lowering the viscosity with a plasticizer as described above. Can also.

In order to form the sound-absorbing member of the present invention, the foam thus obtained may be laminated on a rigid member by bonding it with an adhesive or the like, or the rigid member may be arranged in a mold. It can also be formed by integrally molding a foam. In the sound absorbing member of the present invention thus manufactured,
Since the foam cells are fine and the airflow resistance increases, high sound absorption characteristics can be obtained from relatively low frequency sounds to high frequency sounds. In addition, since it is hydrophobic due to the polyolefin polyol, the water absorption is small. When compared at the same foaming density, tan δ and loss coefficient are large and excellent in vibration damping properties and heat resistance as compared with urethane foam using polyether polyol.

In the sound-absorbing member of the present invention, it is desirable that the above-mentioned mixture is foamed at a foaming ratio of 2 to 30 times. If the foaming ratio is lower than 2 times, almost no sound absorbing properties can be obtained, and if the foaming ratio is higher than 30 times, the vibration damping properties rapidly decrease.

[0024]

The present invention will be specifically described below with reference to Test Examples, Examples and Comparative Examples. (Test example)

[0025]

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100 parts by weight of a saturated hydrocarbon polyolefin polyol having a side chain (having a hydroxyl value of 48 and a number average molecular weight of 2,000) represented by the chemical formula 2 and 3.5 parts by weight of water are mixed to make the hydroxyl group of castor oil hydrophilic. A surfactant (manufactured by Ito Oil Co., Ltd.) substituted with a sulfuric acid ester sodium salt (SO ₄ Na) group as a functional group, and a silicone oil-based foam stabilizer (“S
Z-1313 "(manufactured by Nippon Unicar Co., Ltd.) were mixed with 3.5 parts by weight of each of the surfactants.

The sample after stirring and mixing is left for a predetermined time, and thereafter, an organic isocyanate (Pure / Crud = 80/2)
0, NCO% = 32.2, Sumitomo Bayer Urethane Co., Ltd.
NCO index (100 × NCO equivalent / OH)
(Equivalent) was 100, and a cup foaming test was performed. Then, the cell state and foamability were evaluated, and the results are shown in Table 1.

[0028]

[Table 1]

[0029] Table 1 shows that the castor oil-modified surfactant has a particularly stable cell state and is excellent in foam stability.

(Embodiment 1) FIGS. 1 and 2 show a sound absorbing member according to an embodiment of the present invention. This sound-absorbing member is formed by attaching a foam 3 to a wall 20 of a building 2 facing a road, a floor wall of an elevated road, or a wall and a ceiling of a semi-underground road. Hereinafter, the foam 3 will be described in detail.

100 parts by weight of a saturated hydrocarbon polyolefin polyol having a side chain (having a hydroxyl value of 48 and a number average molecular weight of 2000) represented by the above formula (2) and sulfuric acid having a hydrophilic group as a fatty acid ester in castor oil. 2. a surfactant substituted with an ester sodium salt (SO ₄ Na) group;
5 parts by weight, 3.5 parts by weight of water and 40 plasticizers (DUP)
Parts by weight and 20 parts by weight of a flame retardant or the like are mixed with stirring, and an organic isocyanate (Pure / Crud = 80 /
20, NCO% = 32.2, and Sumitomo Bayer Urethane Co., Ltd.) were mixed such that the NCO index (100 × NCO equivalent / OH equivalent) became 100.

Then, a predetermined amount of the mixture was immediately poured into a predetermined mold, and the foam 3 was foam-molded. Further, a test piece having a predetermined shape was produced by foam molding using another mold. The foam density of the obtained foam and test piece is 0.1
2. About the obtained test piece, the tensile strength and the breaking elongation were measured by the usual method. In addition, the test piece was kept at 175 ° C for 24 hours.
After heating for hours, similarly measure the tensile strength and elongation at break,
The tensile strength after heat deterioration and elongation at break were taken as the values.

Further, the test piece was immersed in water at room temperature for 24 hours, and the water absorption was determined from the increased weight. In addition, thickness 30
mm absorption test method (JISA1)
405), 500 Hz, 1000 Hz, 200 Hz
The sound absorption of the sound waves of 0 Hz and 5000 Hz was measured.

Further, a strip-shaped steel plate having a thickness of 10
mm test piece was attached and held in a cantilever shape to determine the loss factor. Further, tan δ at 25 ° C. was determined by a viscoelastic spectrometer (“Rheospectra DVE4” manufactured by Rheology). Table 2 summarizes the results of these measurements. (Example 2) Test pieces were prepared in the same manner as in Example 1 except that the amount of the surfactant added was 0.5 part by weight, and various physical properties were measured in the same manner. Table 2 shows the results.

Example 3 Example 1 was used as a polyol.
The same saturated hydrocarbon polyolefin polyol as in 7
0 parts by weight and a fatty acid ester-based polyol (having a hydroxyl value of 5
3, a test piece was prepared in the same manner as in Example 1 except that 30 parts by weight of a number average molecular weight of 2,000, manufactured by Toa Gosei Co., Ltd. were used, and various physical properties were measured in the same manner. .

Example 4 A test piece was prepared in the same manner as in Example 1 except that the plasticizer was used in an amount of 20 parts by weight, the surfactant was used in an amount of 2.5 parts by weight, and water was used in an amount of 2.5 parts by weight. Table 2 shows the results of measuring various physical properties in the same manner. (Example 5) A test piece was prepared in the same manner as in Example 1 except that the mixture was heated to 60 ° C and injected into a mold without using a plasticizer, and the results of similarly measuring various physical properties were shown in the table. It is shown in FIG.

Example 6 A hydrogenated polybutadiene (having a hydroxyl value of 4) was used in place of the saturated hydrocarbon polyolefin polyol.
7, number average molecular weight 2100, manufactured by Nippon Soda Co., Ltd.)
A test piece was prepared in the same manner as in Example 1 except that 0 part by weight was used, and various physical properties were measured in the same manner.

(Comparative Example 1) Instead of a saturated hydrocarbon polyolefin polyol, a polyether polyol (having a hydroxyl value of 28, a number average molecular weight of 6000, "Sumiphen 306"
3) 100 parts by weight of Sumitomo Bayer Urethane Co., Ltd., and a silicone oil-based foam stabilizer (“S
A test piece was prepared in the same manner as in Example 1 except that 0.5 parts by weight of Z-1313 (manufactured by Nippon Unicar Co., Ltd.) and 2.0 parts by weight of water were used without using a plasticizer. Table 2 shows the results obtained by measuring various physical properties.

Comparative Example 2 In place of the saturated hydrocarbon-based polyolefin polyol, an unsaturated hydrocarbon-based polyolefin polyol (having a hydroxyl value of 47, a number average molecular weight of 2,800,
A test piece was prepared in the same manner as in Example 1 except that 100 parts by weight of Idemitsu Petrochemical Co., Ltd.) was used, and the results of similarly measuring various physical properties are shown in Table 2.

(Comparative Example 3) Test pieces were prepared in the same manner as in Example 1 except that no surfactant was used, and various physical properties were measured in the same manner. Table 2 shows the results. (Comparative Example 4) In the same manner as in Example 1 except that 3 parts by weight of a silicone oil-based foam stabilizer ("SZ-1313" manufactured by Nippon Unicar Co., Ltd.) was used instead of the castor oil-based surfactant. Table 2 shows the results of measurement of various physical properties in the same manner.

(Evaluation)

[0042]

[Table 2]

From Table 2, it can be seen that Comparative Example 1, which is a conventional urethane foam, exhibits a certain degree of vibration damping properties, but is not used in a portion having a high water absorption and coming into contact with water. It can also be seen that the high frequency sound has a high sound absorption coefficient, but the low frequency sound has a low sound absorption coefficient.

In Comparative Example 2 using an unsaturated hydrocarbon-based polyolefin polyol, the water absorption was low, but the heat resistance was poor and the tan δ was low. In Comparative Example 3 in which no surfactant was used and in Comparative Example 4 in which the surfactant was a silicone-based surfactant, cells were disintegrated because water was not uniformly dispersed, and it was difficult to form a foam. On the other hand, the test piece of each example, which is a foam used for the sound absorbing member of the present invention, has low water absorption and excellent heat resistance, and shows a stable sound absorption coefficient from low to high frequencies. Therefore, the floor wall 10 of the elevated road 1 and the wall 2 of the building 2 facing the elevated road 1
By laminating it to zero, noise from a running car can be absorbed and noise can be effectively reduced. And since the water absorption is low, the increase in weight due to rain is prevented, and since it has excellent weather resistance, it can sufficiently withstand outdoor use.

Example 7 The foams of the above examples have a large tan δ and excellent vibration damping properties. Therefore, if it is used for a sound absorbing member for buildings, such as a wall material of a soundproof room, a sound absorbing member having both sound absorbing properties and vibration damping properties can be obtained.
FIG. 3 is a sectional view of the sound absorbing member of the present embodiment. This sound absorbing member is composed of a decorative panel 4 and a foam 5 integrally laminated on the back side of the decorative panel 4.
Are formed with a plurality of through holes 40. The decorative panel 4 is made of veneer plywood, and the foam 5 is the same foam as in the first embodiment.

This sound absorbing member is used as an indoor soundproof panel. The sound in the room enters through the through hole 40 and is absorbed by the foam 5. Further, the vibration of the decorative panel panel 4 due to the sound is suppressed by the foam 5. Therefore, leakage of room sound to the outside is reliably suppressed, and an excellent soundproof panel is obtained.

[0047]

According to the sound-absorbing member of the present invention, the water-absorbing rate is low, the weather resistance is excellent, and the sound-absorbing and vibration-damping properties are excellent. it can.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a state in which a sound absorbing member according to one embodiment of the present invention is used.

FIG. 2 is an explanatory view showing a state in which the sound absorbing member of one embodiment of the present invention is used.

FIG. 3 is a sectional view of a sound absorbing member according to another embodiment of the present invention.

[Explanation of symbols]

2: Building 3: Foam 4: Decorative panel 5: Foam 40: Through hole

Continuing from the front page (72) Inventor Shinsuke Koyamauchi 3600, Gezu, Kita-gaiyama, Komaki-shi, Aichi Prefecture Inside of Tokai Rubber Industries Co., Ltd. (1) Inside the Tokai Chemical Industry Co., Ltd. (72) Inventor Yutaka Ando In the Tokai Chemical Industry Company, Ltd.

Claims (2)

[Claims] 1. A surfactant comprising a mixture of a rigid member, a polyolefin polyol having a saturated hydrocarbon resin skeleton, water as a foaming agent and an organic polyisocyanate, and a fatty acid ester having a hydrophilic group in the chain as a basic skeleton. And a foam formed by reacting in the presence of an agent and laminated on the surface of the rigid member. 2. The sound-absorbing member for civil engineering and construction according to claim 1, wherein the polyolefin polyol has a side chain and has a reactive primary hydroxyl group at a molecular terminal.