JP2023050609A - Soundproof material and manufacturing method therefor - Google Patents

Abstract

To provide a light-weight soundproof material which is composed of a polyurethane foam and offers high soundproofing capability.SOLUTION: A soundproof material composed of a polyurethane foam having a coating layer on a surface thereof is provided. The coating layer exhibits a breathability (as per JIS K6400-7:2012A) of 10 L/min or less and a portion on the inner side the coating layer exhibits a breathability (as per JIS K6400-7:2012A) of 15 L/min or greater. The polyurethane foam has density (as per JIS K7222:2005) that is less than 130 kg/m3.SELECTED DRAWING: Figure 1

Description

The present invention relates to a soundproofing material and its manufacturing method.

2. Description of the Related Art Conventionally, in automobiles, soundproofing materials are arranged in gaps in sound transmission paths around fenders, instrument panels, cowls, etc. to suppress transmission of noise into the interior of the vehicle.

Since it is difficult to achieve both sound insulation and sound absorption with conventional soundproofing materials using a single material, an integrated product consisting of a sound insulation sheet with a high specific gravity to ensure sound insulation and polyurethane foam to ensure sound absorption. (Patent Document 1).

JP-A-02-151899

However, the sound insulating material consisting of the sound insulating sheet and the polyurethane foam has a problem of being heavy. In addition, when the surface on which the soundproofing material is installed is uneven, the shape followability of the soundproofing material deteriorates due to the presence of the soundproofing sheet, and a gap is generated between the soundproofing material installation surface and the soundproofing material. sound insulation may not be obtained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a soundproofing material that is lightweight and has high soundproofing properties.

A first aspect of the invention is a soundproofing material composed of polyurethane foam, wherein the polyurethane foam has a coating layer on its surface, and the breathability of the coating layer (JIS K6400-7: 2012A method) is 10 L / min. The air permeability (JIS K6400-7: 2012A method) on the inner side of the coating layer is 15 L / min or more, and the density (JIS K7222: 2005) is less than 130 kg / m ³ . do.

A second aspect of the invention is a method for producing a soundproofing material composed of polyurethane foam, wherein a release agent having two melting peaks of 70 to 90°C and 100 to 130°C is applied to the inner surface of a foaming mold. A soundproofing material composed of a polyurethane foam having a coating layer on its surface is produced by applying a polyurethane foam raw material into the foaming mold and foaming to form a polyurethane foam having a coating layer on the surface. characterized by

A third aspect of the invention is the second aspect of the invention, wherein the release agent having two melting peaks is a mixture containing a wax component having a weight average molecular weight of 1000 or more and a wax component having a weight average molecular weight of 600 or less. It is characterized by being a release agent.

A fourth aspect of the invention is the second or third aspect of the invention, wherein the polyurethane foam having a coating layer on the surface thereof has an air permeability (JIS K6400-7:2012A method) of 10 L/min or less. The air permeability (JIS K6400-7: 2012A method) on the inner side than the coating layer is 15 L / min or more, and the density (JIS K7222: 2005) is less than 130 kg / m ³ . .

ADVANTAGE OF THE INVENTION According to this invention, the sound-insulating material which is lightweight and has high sound-insulating property is obtained.

It is a table|surface which shows the result of the density, air permeability, and sound insulation of each Example and each comparative example. 4 is a table showing the composition of polyurethane foam raw materials used in each example and each comparative example. 5 is a graph showing transmission loss measurement results for some examples and some comparative examples.

Embodiments of the present invention will be described below. The soundproof material of the present invention is composed of polyurethane foam.

The polyurethane foam constituting the soundproof material has a coating layer on the surface, and the breathability of the coating layer (JIS K6400-7: 2012A method) is 10 L / min or less, preferably 8 L / min or less, more preferably 5 L / min. The air permeability (JIS K6400-7:2012A method) on the inner side of the surface coating layer is 15 L/min or more, preferably 18 L/min or more, and more preferably 20 L/min or more.

The coating layer on the surface is a portion of the surface in which the polyurethane foam cells are compressed and is composed of a denser layer than the portion on the inner side (center side) of the polyurethane foam. The thickness of the coating layer is usually about 0.001 to 3 mm.
In the present invention, the inner side of the surface coating layer is the inner (central side) portion away from the surface coating layer, specifically, the portion 3 mm or more away from the surface of the polyurethane foam.

By setting the air permeability of the surface coating layer and the air permeability of the inner side of the polyurethane foam within the above ranges and making the air permeability of the surface coating layer lower than the air permeability of the inner side, good sound insulation can be obtained. .
Also, the difference between the air permeability of the surface coating layer and the air permeability of the inner side is preferably 10 L/min or more, more preferably 15 L/min or more, and still more preferably 20 L/min or more.

The density (JIS K7222:2005) of the polyurethane foam constituting the soundproof material is less than 130 kg/m ³ , preferably less than 100 kg/m ³ , more preferably 80-40 kg/m ³ . The density range of the polyurethane foam can be varied by varying the blending of the polyurethane foam raw material (mainly the blending amount of the blowing agent) and the injection amount of the polyurethane foam raw material into the foam mold.
By setting the density of the polyurethane foam forming the soundproof material within the above range, the weight of the soundproof material can be reduced.

The soundproofing material of the present invention is produced by molding in which a polyurethane foam raw material is injected into a foaming mold and foamed. Molding is a method that is often used as a molding method for polyurethane foam, and it is possible to obtain a polyurethane foam in a desired product shape without post-processing by preforming the product shape on the inner surface of the foaming mold. can.

Polyurethane foam raw materials include polyols, catalysts, cross-linking agents, blowing agents, and polyisocyanates.
Polyol is a compound having two or more hydroxyl groups in one molecule, and is produced by addition polymerization of alcohol (polyhydric alcohol) having two or more functional groups, or ethylene oxide or propylene oxide using these as initiators. It is a thing.
Polyols may be polyether polyols, polyester polyols or polymer polyols. Further, the polyol is not limited to one type, and may be composed of a plurality of types.
The polyol preferably has 2 to 4 functional groups and a molecular weight of 3,000 to 7,000.

Examples of catalysts include amine-based catalysts and metal catalysts used for polyurethane foams. As the amine catalyst, N,N-dimethylcyclohexylamine, N,N-dimethylbenzylamine, N,N-dimethylaminoethanol, N,N',N'-trimethylaminoethylpiperazine, triethylenediamine and the like are used. Examples of metal catalysts include tin catalysts such as stass octoate and dibutyltin dilaurate, phenylmercuric propionate, and lead octenate. The amount of catalyst is preferably about 0.1 to 8.0 parts by weight with respect to 100 parts by weight of polyol.

Examples of cross-linking agents include polyhydric alcohols such as ethylene glycol, diethylene glycol, glycerin, butanetetraol, and polyoxypropylene glycol, diethanolamine, and polyamines. The cross-linking agent is not limited to one type, and multiple types may be used in combination. The amount of the cross-linking agent is preferably about 0.3 to 5 parts by weight with respect to 100 parts by weight of the polyol. If the amount of the cross-linking agent is less than the above range, the film-forming effect tends to be reduced, and if it is greater, the polyurethane foam tends to be too hard.

Examples of foaming agents include water, hydrocarbons, halogen compounds, and the like, and one or more of these may be used. Examples of hydrocarbons include cyclopentane, isopentane, normal pentane, and the like. Halogen compounds include methylene chloride, trichlorofluoromethane, dichlorodifluoromethane, nonafluorobutylmethylether, nonafluorobutylethylether, pentafluoroethylmethylether, heptafluoroisopropylmethylether and the like. Among these, water is particularly suitable as the foaming agent. The amount of water as a foaming agent is preferably about 1 to 10 parts by weight, more preferably about 1 to 7 parts by weight, based on 100 parts by weight of the polyol.

Polyisocyanate is not particularly limited as long as it is a compound having two or more isocyanate groups, and those for polyurethane foam can be used. The polyisocyanate may be used in combination of not only one kind but also two or more kinds. Examples of polyisocyanates include aromatic, aliphatic, and alicyclic isocyanate compounds, and modified products thereof.

Examples of aromatic isocyanate compounds include diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate, tolylene diisocyanate (TDI), naphthalene diisocyanate (NDI), p-phenylene diisocyanate (PPDI), xylene diisocyanate (XDI), tetramethylxylene diisocyanate dianate (TMXDI), tolidine isocyanate (TODI) and the like. Examples of aliphatic isocyanate compounds include hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), lysine triisocyanate (LTI) and the like. Alicyclic isocyanate compounds include isophorone diisocyanate (IPDI), cyclohexyl diisocyanate (CHDI), hydrogenated XDI (H ₆ XDI), hydrogenated MDI (H ₁₂ MDI) and the like. Modified isocyanate compounds include urethane modified isocyanate compounds, dimers, trimers, carbodiimide modified products, allophanate modified products, buret modified products, urea modified products, isocyanurate modified products, oxazolidone modified products, isocyanate group-terminated prepolymers. A polymer etc. are mentioned.

The amount of polyisocyanate to be blended is preferably such that the isocyanate index is 70-110. If the isocyanate index is less than 70, the strength of the polyurethane foam becomes too low, resulting in poor durability, or shrinkage due to difficulty in gas release, resulting in poor molding condition. On the other hand, if the isocyanate index exceeds 110, the polyurethane foam will have a high hardness, and the soundproofing material will be difficult to deform into the shape of the mating surface. The isocyanate index is a value that indicates the equivalent ratio of the isocyanate groups of the polyisocyanate to the total of active hydrogen groups (for example, hydroxyl groups of polyols, active hydrogen groups of water used as a blowing agent, etc.) in the polyurethane foam raw material, expressed as a percentage. , a measure used in the field of polyurethane foams.

In addition, additives are appropriately added to the polyurethane foam raw material. Additives that are appropriately blended include foam stabilizers, foam breakers, flame retardants, colorants, and the like.

The foam stabilizer may be one used for polyurethane foams, and examples include silicone foam stabilizers, fluorine-containing compound foam stabilizers, and known surfactants.

The foam breaker has the effect of destroying bubbles (cells) during foaming of polyurethane foam. Types of foam breaking agents include hydrocarbon, ester, silicone, and polyol types, and are not limited to one type, and two or more types may be used.
Hydrocarbon-based foam breakers include oils such as polybutene. Examples of ester-based foam breakers include dimer acid diesters. Cyclopentasiloxane etc. can be mentioned as a silicone type foam breaker. Examples of polyols include polyether polyols having a high ethylene oxide addition amount (EO rate of 50% or more, preferably EO rate of 60 to 100%).

The amount of the defoaming agent to be added is preferably about 0.01 to 15 parts by weight with respect to 100 parts by weight of the polyol. If the amount of the foam breaker is too large, it becomes difficult to foam the polyurethane foam well.

Flame retardants include powder flame retardants such as phosphorous and ammonium polyphosphate, and liquid flame retardants such as phosphate ester flame retardants, and either one or both of them may be used in combination.
As the coloring agent, one can be used according to the place where the soundproofing material is used.

When molding the soundproof material, first, a release agent is applied to the inner surface of the foam mold. The foaming mold is composed of a split mold that can be separated into upper and lower molds, etc., and the inner surface of the mold has the same shape as the outer shape of the soundproof material. Further, the foaming mold is embedded with heating means such as an electric heater and a heat medium circulation pipe, so that the mold temperature can be adjusted to a predetermined mold temperature by hot water, heating oil, etc. flowing through the electric heater and the heat medium circulation pipe. The mold temperature is preferably about 50 to 70°C. When the mold temperature is lower than 50°C, the curability deteriorates, resulting in poor productivity. On the other hand, when the mold temperature is higher than 70°C, the reactivity of the polyurethane foam raw material becomes too high, and the polyurethane foam raw material flows. There is a risk that the properties will be deteriorated, lack of meat, and the appearance surface will be rough.

As the release agent, one containing a solid content (wax component) having two melting peaks, a melting peak at 70 to 90°C and a melting peak at 100 to 130°C, is used. A melting peak is a value measured by a differential scanning calorimeter (DSC) for the solid content remaining after evaporation of the liquid component of the mold release agent. A release agent having two melting peaks, one at 70 to 90° C. and the other at 100 to 130° C., provides a polyurethane foam with a good surface coating layer.

The release agent having two melting peaks, a melting peak at 70-90° C. and a melting peak at 100-130° C., preferably contains a branched wax-based releasing agent. As the branched wax-based release agent, a branched wax such as modified polyethylene wax, microcrystalline wax, or hydrocarbon wax is used as the main component, and this is dissolved in an organic solvent, or an emulsifier is used to add moisture. and those dispersed in The branched wax-based release agent facilitates the formation of a coating layer on the surface of the polyurethane foam.

A release agent having two melting peaks, a melting peak at 70 to 90°C and a melting peak at 100 to 130°C, contains a wax component with a weight average molecular weight of 1000 or more and a wax component with a weight average molecular weight of 600 or less. Mixed release agents are preferred.

The release agent can be applied to the inner surface of the foaming mold with a brush, spray, or the like. The coating amount of the release agent is preferably 10 to 100 g/m ² .

After the release agent is applied to the inner surface of the foaming mold, the polyurethane foam raw material is mixed and injected into the foaming mold, and the foaming mold is closed. The amount of the polyurethane foam raw material injected into the foam mold is such that the resulting polyurethane foam has a density (JIS K7222:2005) of less than 130 kg/m ³ (0.13 g/cm ³ ).

After foaming the polyurethane foam raw material, the foaming mold is opened and the soundproofing material made of polyurethane foam is removed from the mold. The polyurethane foam constituting the resulting soundproof material has a film layer on its surface and has the physical properties described above.

On the mold inner surfaces of a foaming mold with an inner dimension of 500 x 500 x 20 mm (internal volume of 5000 cm ³ ) and a foaming mold with an inner dimension of 500 x 250 x 40 mm (internal volume of 5000 cm ³ ), the inner shape of the mold is a rectangular parallelepiped, A release agent selected from ^the following release agents A, B, and C according to each implementation and each comparative example shown in FIG. Polyurethane foam raw materials composed of the formulation shown in FIG. 2 are mixed, injected into a foaming mold in an amount that gives the density set for each example and each comparative example, and foamed while maintaining the mold temperature at 60 ° C. let me After that, the mold was demoulded to obtain soundproofing materials of each example and each comparative example made of polyurethane foam.

・ Release agent A: branched wax-based release agent, first melting peak 81.0 ° C., second melting peak 110.2 ° C., product name: FRX-C8, manufactured by Neos Co., Ltd. ・ Release agent B: branched wax-based Release agent, melting peak 106.9°C, product name: M975, manufactured by Chukyo Yushi Co., Ltd. Release agent C: linear wax-based release agent, first melting peak 93.2°C, second melting peak 108.3 ° C., product name; T-626, manufactured by Chukyo Yushi Co., Ltd. Polyol A; polyether polyol, molecular weight 7000, functional group number 3, EO content 14%, product name; KC-737, manufactured by Sanyo Chemical Industries Co., Ltd. Polyol B; Polyether polyol, molecular weight 5000, functional group number 3, EO content 14%, product name; FA-703, manufactured by Sanyo Chemical Industries Co., Ltd. Polyol C; polymer polyol, molecular weight 5000, functional group number 3, product name; Kasei Kogyo Co., Ltd. Catalyst A; amine catalyst, product name: DABCO BL-11, manufactured by Evonik Catalyst B; amine catalyst, product name: DABCO 33LSI, manufactured by Evonik Catalyst C; amine catalyst, product name: TOYOCAT D-60 , manufactured by Tosoh Corporation ・Crosslinking agent; diethanolamine ・Foam stabilizer; silicone foam stabilizer, product name: B8738LF2, manufactured by Evonik ・Foam breaking agent: polyether polyol, molecular weight 4800, number of functional groups 3, PO/EO = 30/70 ( EO ratio 70%), product name: CP1421, manufactured by Dow Chemical Co., Ltd. Blowing agent: water, polyisocyanate: polymeric MDI, NCO%;

Regarding the polyurethane foam (soundproof material) of each example and each comparative example, the density (JIS JIS K7222: 2005), the air permeability of the surface coating layer (JIS K6400-7: 2012A method) and the air permeability of the inner side (JIS K6400 -7: 2012A method) was measured.

The air permeability of the coating layer was measured by cutting a 10 mm portion from the surface of a polyurethane foam molded with dimensions of 500 x 250 x 40 mm to obtain a test piece for measuring the coating layer with dimensions of 51 x 51 x 10 mm. The air permeability of the internal side was measured by cutting the center portion of the molded polyurethane foam in the thickness direction (10 to 20 mm away from the surface) and measuring the internal side with the same dimensions (51 x 51 x 10 mm). Strips were prepared and used for measurements.

When the air permeability of the coating layer is 5 L/min or less, the coating layer is evaluated for breathability "◎". In the case of large, the air permeability of the coating layer was evaluated as "▴".
When the difference in breathability between the coating layer and the inner side is 20 L/min or more, the difference in breathability is evaluated as "◎". /min, the air permeability was evaluated as “▴”.
Based on the air permeability evaluation and the air permeability difference evaluation of the coating layer, a comprehensive evaluation of air permeability was performed based on the following criteria. If both the air permeability evaluation and the air permeability difference evaluation of the coating layer are "◎", the overall air permeability judgment is "◎". ” or both are “〇”, the overall breathability judgment is “〇”, and when one or both of the breathability evaluation and the breathability difference evaluation of the coating layer is “▲”, the breathability comprehensive judgment is made “▲”. .

In addition, the sound insulating properties of the sound insulating materials of Example 1, Comparative Example 1 and Comparative Example 5 having a density of 50 kg/m ³ and Comparative Example 9 having a density of 150 kg/m ³ were evaluated.
Sound insulation is determined by measuring the sound transmission loss (JIS A1441-1: 2007/ISO 15186-1: 2000) in the 1/3 octave band, and averaging the sound transmission loss at frequencies of 400Hz-4kHz (average transmission loss). asked for This average transmission loss is preferably 12 dB or more, more preferably 14 dB or more, and even more preferably 16 dB or more.
If the average transmission loss (average transmission loss) of 400Hz-4kHz is 16dB or more, "◎", if it is 12dB or more and less than 16dB, it is "○", if it is 8dB or more and less than 12dB, it is "△", if it is less than 8dB was marked with an “X”. It should be noted that it is preferable to judge the sound insulation by comparing the same density.
The transmission loss was measured using a sound source reverberation chamber of 36 m ³ , a sound receiving anechoic chamber of 20 m ³ , and a measurement area of 400×400 mm (0.16 m ² ). A 500 mm square×20 mm thick polyurethane foam soundproofing material (with a film layer on the surface) was surrounded by a 50 mm wide frame, and the gap was further sealed with clay. Sound is incident from the reverberation chamber, which is the sound source side, and the numerical value at 250Hz-10kHz is measured at 25 locations (80mm pitch) at 215mm away from the surface of the soundproof material from the sound receiving anechoic chamber, which is the non-sound source side. An average value of 4 kHz was calculated. The measurement results are shown in FIG.

Examples 1 and 2 are examples in which the release agent A was used, the isocyanate index was set to 80, and the density of the polyurethane foam was changed to 50 kg/m ³ (Example 1) and 70 kg/m ³ (Example 2). be.

In Example 1 (density: 50 kg/m ³ ), the air permeability of the inner side was 56.6 L/min, the air permeability of the surface coating layer was 3.0 L/min, the evaluation was "⊚", and the surface coating layer and the inner side The air permeability difference was 53.6 L/min, the evaluation was "⊚", the air permeability comprehensive judgment was "⊚", the average transmission loss at 400 Hz-4 kHz was 14.3 dB, and the sound insulation was judged as "⊚". In addition, Example 1 had a higher sound insulation than the average transmission loss of 10.9 dB at 400 Hz-4 kHz in Comparative Example 1 having the same density, and was evaluated as "Good" for sound insulation.

In Example 2 (density 70 kg/m ³ ), the air permeability of the inner side is 22.0 L/min, the air permeability of the surface coating layer is 3.5 L/min, the evaluation is "⊚", the surface coating layer and the inner side was 18.5 L/min, the evaluation was "◯", and the air permeability comprehensive judgment was "◯".

Examples 3 and 4 are examples in which the release agent A was used, the isocyanate index was set to 100, and the density of the polyurethane foam was changed to 50 kg/m ³ (Example 3) and 70 kg/m ³ (Example 4). be.

In Example 3 (density: 50 kg/m ³ ), the air permeability of the inner side was 55.0 L/min, the air permeability of the surface coating layer was 3.7 L/min, the evaluation was "⊚", and the surface coating layer and the inner side was 51.2 L/min.

In Example 4 (density 70 kg/m ³ ), the air permeability of the inner side was 24.1 L/min, the air permeability of the surface coating layer was 3.9 L/min, the evaluation was "⊚", and the surface coating layer and the inner side was 20.3 L/min.

Comparative Examples 1 and 2 are examples in which release agent B was used, the isocyanate index was set to 80, and the density of the polyurethane foam was changed to 50 kg/m ³ (Comparative Example 1) and 70 kg/m ³ (Comparative Example 2). be.

In Comparative Example 1 (density 50 kg/m ³ ), the air permeability of the inner side is 58.6 L/min, the air permeability of the surface coating layer is 26.9 L/min, the evaluation is “▴”, the surface coating layer and the inner side 31.7 L / min, the air permeability difference is 31.7 L / min, the evaluation is “◎”, the air permeability comprehensive judgment is “▲”, the average transmission loss at 400 Hz-4 kHz is 10.9 dB, and the sound insulation is lower than that of Example 1 with the same density. , and the sound insulation was judged to be "Δ".

In Comparative Example 2 (density 70 kg/m ³ ), the air permeability of the inner side was 22.1 L/min, the air permeability of the surface coating layer was 9.2 L/min, the evaluation was "◯", and the surface coating layer and the inner side was 12.9 L/lmin, the evaluation was "▴", and the air permeability comprehensive judgment was "▴".

Comparative Examples 3 and 4 are examples in which release agent B was used, the isocyanate index was 100, and the density of the polyurethane foam was changed to 50 kg/m ³ (Comparative Example 3) and 70 kg/m ³ (Comparative Example 4). be.

In Comparative Example 3 (density 50 kg/m ³ ), the air permeability of the inner side is 68.6 L/min, the air permeability of the surface coating layer is 14.0 L/min, the evaluation is "▴", the surface coating layer and the inner side was 54.6 L/min.

In Comparative Example 4 (density 70 kg/m ³ ), the air permeability of the inner side is 35.1 L/min, the air permeability of the surface coating layer is 14.7 L/min, the evaluation is “▴”, the surface coating layer and the inner side was 20.5 L/min.

Comparative Examples 5 and 6 are examples in which release agent C was used, the isocyanate index was 80, and the density of the polyurethane foam was changed to 50 kg/m ³ (Comparative Example 5) and 70 kg/m ³ (Comparative Example 6). be.

In Comparative Example 5 (density 50 kg/m ³ ), the air permeability of the inner side is 47.3 L/min, the air permeability of the surface coating layer is 14.7 L/min, the evaluation is "▴", the surface coating layer and the inner side The difference in air permeability from 32.6 L / min, the evaluation "◎", the overall air permeability evaluation "▲", the average transmission loss at 400 Hz-4 kHz is 7.5 dB, which is higher than Example 1 and Comparative Example 1 with the same density The sound insulation property was low, and the judgment of the sound insulation property was "x".

In Comparative Example 6 (density 70 kg/m ³ ), the air permeability of the inner side is 21.3 L/min, the air permeability of the surface coating layer is 7.3 L/min, the evaluation is “◯”, the surface coating layer and the inner side was 14.0 L/min, the evaluation was "▴", and the overall air permeability was "▴".

Comparative Examples 7 and 8 are examples in which release agent C was used, the isocyanate index was 100, and the density of the polyurethane foam was changed to 50 kg/m ³ (Comparative Example 7) and 70 kg/m ³ (Comparative Example 8). be.

In Comparative Example 7 (density 50 kg/m ³ ), the air permeability of the inner side is 54.4 L/min, the air permeability of the surface coating layer is 18.9 L/min, the evaluation is "▴", the surface coating layer and the inner side was 35.5 L/min.

In Comparative Example 8 (density 70 kg/m ³ ), the air permeability of the inner side is 26.1 L/min, the air permeability of the surface coating layer is 11.5 L/min, the evaluation is “▴”, the surface coating layer and the inner side was 14.6 L/min.

Comparative Example 9 is an example in which release agent B is used, the isocyanate index is 100, and the density of the polyurethane foam is 150 kg/m ³ .
In Comparative Example 9, the air permeability of the inner side was 24.8 L/min, the air permeability of the surface coating layer was 7.8 L/min, the evaluation was "◯", and the difference in air permeability between the surface coating layer and the inner side was 17.8 L/min. 0 L/min, evaluation “◯”, air permeability comprehensive judgment “◯”, average transmission loss at 400 Hz-4 kHz was 15.8 dB, and since the release agent B different from the release agent of the present invention was used, the same density The sound insulation was lower than that of Example 5, and the sound insulation was judged to be "◯".
Comparative Example 9 had a high density of 150 kg/m ³ , so it had good sound insulation, but it was heavy.

Comparative Example 10 is an example in which release agent C is used, the isocyanate index is 100, and the density of the polyurethane foam is 150 kg/m ³ .
In Comparative Example 10, the air permeability of the inner side was 31.8 L/min, the air permeability of the surface coating layer was 30.2 L/min, the evaluation was "▴", and the difference in air permeability between the surface coating layer and the inner side was 1. It was 6 L/min, the evaluation was "▴", and the air permeability comprehensive judgment was "▴".

Thus, according to the present invention, it is possible to obtain a soundproofing material that is lightweight and has high soundproofing properties. It should be noted that the present invention is not limited to the embodiments, and can be modified without departing from the gist of the invention.

Claims (4)

In the soundproofing material composed of polyurethane foam,
The polyurethane foam has a coating layer on the surface, the breathability of the coating layer (JIS K6400-7: 2012A method) is 10 L / min or less, and the air permeability on the inner side of the coating layer (JIS K6400- 7:2012A method) is 15 L/min or more, and the density (JIS K7222:2005) is less than 130 kg/m ³ . In a method for manufacturing a soundproofing material composed of polyurethane foam,
A release agent having two melting peaks of 70 to 90° C. and 100 to 130° C. is applied to the inner surface of the foam mold, and a polyurethane foam raw material is injected into the foam mold and foamed to coat the surface. 1. A method for producing a soundproofing material, comprising: producing a soundproofing material comprising a polyurethane foam having a film layer on the surface thereof by molding a polyurethane foam having a layer. 3. The release agent according to claim 2, wherein the release agent having two melting peaks is a mixed release agent containing a wax component having a weight average molecular weight of 1000 or more and a wax component having a weight average molecular weight of 600 or less. A method of manufacturing a soundproofing material. The polyurethane foam having a coating layer on the surface has an air permeability of the coating layer (JIS K6400-7: 2012A method) of 10 L / min or less, and the air permeability of the inner side of the coating layer (JIS K6400-7: 2012A method) is 15 L/min or more, and the density (JIS K7222:2005) is less than 130 kg/m ³ .

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