JP2022044071A - Soundproof material and method for producing soundproof material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soundproof material capable of improving soundproof performance and a method for manufacturing the same.
SOLUTION: The soundproofing material 10 includes a polyurethane foam 11 for sound absorption. The soundproofing material 10 is made of polyurethane by integrating a breathable skin material on the surface of the polyurethane foam and blowing a compressed gas from the surface of the foam-molded polyurethane foam 11 into the inside through the skin material. It is manufactured by additionally machining a break hole 32Y in the cell film 31 of the plurality of foam cells 30 included in the foam 11.
[Selection diagram] FIG. 17

Description

The present disclosure relates to a soundproofing material containing a foam and a method for producing the same.

Patent Document 1 describes a soundproofing material containing a polyurethane foam having open cells.

Jitsuzensho 49-081516 (page 2 of the specification)

It is desired to improve the soundproofing performance as compared with the conventional soundproofing material described above.

The first aspect of the invention made to solve the above problems is a method for manufacturing a soundproof material containing polyurethane foam, wherein the polyurethane foam is sandwiched between a pair of breathable skin materials. The polyurethane foam and the pair of skin materials are integrated, and a blow treatment is performed in which compressed gas is blown into the inside of the foam-molded polyurethane foam through the skin material to obtain a plurality of foam cells contained in the polyurethane foam. This is a method for manufacturing a soundproof material in which a break hole is additionally machined in the cell film.

A second aspect of the invention is the method for manufacturing a soundproof material according to the first aspect, wherein the blow treatment is performed by bringing the tip surface of a nozzle for ejecting the compressed gas into contact with or close to the surface of the skin material. ..

A third aspect of the invention is the method for producing a soundproofing material according to the second aspect, wherein the dynamic pressure of the compressed gas is 0.1 to 1 MPa.

A fourth aspect of the invention is any one of the first to third aspects, wherein the piercing treatment of piercing the surface of the polyurethane foam with the tips of a plurality of needles or blades through the skin material is performed before the blow treatment. Is the method for manufacturing a soundproof material according to the above embodiment.

A fifth aspect of the invention is a soundproofing material containing polyurethane foam, wherein the polyurethane foam and the pair of skin materials are integrated so that the polyurethane foam is sandwiched between a pair of breathable skin materials. The polyurethane foam has break holes formed in the cell membranes of the plurality of foam cells, and the number of closed cells among the foam cells is closer to the surface on which the skin material is integrated than from the inside of the polyurethane foam. It is a soundproofing material that is not so small.

A sixth aspect of the present invention is a soundproofing material containing polyurethane foam, in which the polyurethane foam and the pair of skin materials are integrated so that the polyurethane foam is sandwiched between a pair of breathable skin materials. The polyurethane foam is provided with break holes formed in the cell membranes of the plurality of foam cells contained in the polyurethane foam, and the air permeability of the polyurethane foam is larger as it is closer to the surface on which the skin material is integrated than from the inside of the polyurethane foam. It is a soundproof material.

A seventh aspect of the invention is that the polyurethane foam has a flat shape, the skin material is integrated on both the front and back surfaces thereof, and the number of closed cells per unit cross-sectional area in the central portion of the polyurethane foam in the thickness direction is defined. The soundproofing according to the fifth or sixth aspect, wherein the ratio of the number of the closed cells per unit cross-sectional area in the surface layer portion from both the front and back surfaces of the polyurethane foam to a depth of 3 mm is 0.7 or less. It is a material.

In the eighth aspect of the invention, the ratio of the number of open cells to the total number of foamed cells is larger from the inside of the polyurethane foam closer to the surface on which the skin material is integrated, from the fifth aspect to the seventh aspect. The soundproofing material according to any one of the embodiments.

A ninth aspect of the invention is any one of the fifth to eighth aspects, wherein the break hole breaks the cell membrane by the wind pressure of the compressed gas blown into the inside of the polyurethane foam through the skin material. The soundproofing material according to the first aspect.

A tenth aspect of the invention is described in any one of the fifth to ninth aspects, wherein the polyurethane foam has a 50% compressive hardness of 500N to 3000N based on the method E of JISK6400-2: 2012. It is a soundproof material.

In the first aspect of the invention, the polyurethane foam and the pair of skin materials are integrated so as to sandwich the polyurethane foam with a pair of breathable skin materials. Then, a blow process of blowing the compressed gas into the polyurethane foam is performed through the skin material, and break holes are additionally machined in the cell membranes of the plurality of foam cells. As a result, the foam cells on the surface side of the polyurethane foam, in which the skin material is integrated, can easily communicate with each other, and sound (air) can easily enter the inside of the polyurethane foam. This makes it possible to improve the sound absorbing performance of the polyurethane foam while protecting the polyurethane foam with the skin material, and it is possible to improve the soundproofing performance of the soundproof material.

In the second aspect of the invention, the blow treatment is performed so that the tip surface of the nozzle for ejecting the compressed gas is in contact with or close to the surface of the skin material. Therefore, it becomes easy to blow the compressed gas into the polyurethane foam, and it is possible to suppress the variation in the amount of the compressed gas blown. In this case, by setting the dynamic pressure of the compressed gas to 0.1 to 1 MPa (the third aspect of the invention), it becomes easy to form break holes up to the inside of the polyurethane foam.

In the fourth aspect of the invention, the tip of the needle or the blade is pierced into the surface of the polyurethane foam through the skin material before the blow treatment, so that the compressed gas can be easily blown into the inner side of the polyurethane foam through the puncture mark. ..

In the soundproofing material of the fifth aspect of the present invention, the polyurethane foam and the pair of skin materials are integrated so that the polyurethane foam is sandwiched between the pair of breathable skin materials. Further, it is provided with foam holes formed in the cell membrane during foam molding of the polyurethane foam, and the number of closed cells among the foam cells is smaller as the number of closed cells is closer to the surface where the skin material is integrated than the inside of the polyurethane foam. This makes it possible to increase the number of open cells that communicate with each other through break holes or the like as they are closer to the surface than the inside of the polyurethane foam. Further, in the soundproofing material of the sixth aspect of the invention, the air permeability of the polyurethane foam is larger as it is closer to the surface where the skin material is integrated than the inside of the polyurethane foam. According to these configurations, it is possible to enhance the air permeability of the surface side portion of the polyurethane foam, and it is possible to enhance the sound absorption performance of the polyurethane foam with respect to the sound from the surface side, and as a result, the soundproofing material is soundproofed. It is possible to improve the performance.

In the seventh aspect of the invention, the polyurethane foam has a flat shape and the skin material is integrated on both the front and back surfaces thereof, and the front and back surfaces of the polyurethane foam are relative to the number of closed cells per unit cross-sectional area in the central portion in the thickness direction of the polyurethane foam. The ratio of the number of closed cells per unit cross-sectional area in the surface layer portion from both sides to a depth of 3 mm is 0.7 or less. According to this configuration, it is possible to particularly improve the sound absorption performance of the polyurethane foam.

In the eighth aspect of the invention, the ratio of the number of open cells to the total number of foamed cells is larger as it is closer to the surface where the skin material is integrated than the inside of the polyurethane foam. According to this configuration, the air permeability on the surface side of the polyurethane foam is enhanced to facilitate ventilation to the inside of the polyurethane foam, and the sound absorption performance of the polyurethane foam can be further improved.

As in the ninth aspect of the invention, the break hole of the polyurethane foam can be easily formed by breaking the cell membrane by the wind pressure of the compressed gas blown into the inside of the polyurethane foam through the skin material.

In the tenth aspect of the invention, since the 50% compressive hardness of the polyurethane foam is 500 to 3000 N, it is possible to secure the rigidity. This makes it possible to stabilize the shape of the polyurethane foam. In polyurethane foams with a 50% compression hardness in the above range, for example, if break holes are formed in the cell membrane by roll crushing, the dimensional accuracy is lowered because they are not crushed and restored, and the appearance tends to be deteriorated due to wrinkles. However, since the configuration of the present invention eliminates the need for roll crushing, it is possible to suppress deterioration of the dimensional accuracy and appearance of the polyurethane foam.

Side sectional view of the soundproof material according to the first embodiment Enlarged side sectional view of polyurethane foam for soundproofing material Enlarged side cross section of polyurethane foam foam cell Side sectional view of the soundproofing material that has been blown Side sectional view showing an example of using a soundproof material Side sectional view of the soundproof material according to the second embodiment Enlarged side sectional view of polyurethane foam for soundproofing material Enlarged side cross section of polyurethane foam foam cell (A) Side cross-sectional view of the mold and the skin material fixed to the mold open state, (B) Side cross-sectional view of the mold and the skin material when the raw material is injected in the mold open state. (A) Side cross-sectional view of the mold and the skin material when the mold is closed and the raw material starts foaming, (B) Side cross-sectional view of the polyurethane foam and the skin material foam-molded in the mold. Side sectional view of the soundproofing material blown from the surface of the polyurethane foam Side cross-sectional view of the soundproofing material that has been blown from the skin material side Side sectional view showing an example of using a soundproof material Side sectional view of the soundproof material according to the third embodiment (A) Side cross-sectional view of the mold and the skin material fixed to the mold open state, (B) Side cross-sectional view of the mold and the skin material when the raw material is injected in the mold open state. (A) Side cross-sectional view of the mold and the skin material when the mold is closed and the raw material starts foaming, (B) Side cross-sectional view of the polyurethane foam and the skin material foam-molded in the mold. Side cross-sectional view of the soundproofing material that has been blown from the skin material side Side sectional view showing an example of using a soundproof material Perspective view of the soundproofing material according to the fourth embodiment (A) side sectional view, (B) bottom view of the soundproofing material according to the fifth embodiment. Side cross-sectional view of polyurethane foam that is pierced from the exposed surface side Side cross-sectional view of polyurethane foam that is pierced from the skin material side Enlarged image of foam cells on the outer peripheral surface of polyurethane foam Table showing examples and comparative examples

[First Embodiment]
As shown in FIG. 1, the soundproofing material 10 according to the first embodiment is made of polyurethane foam 11. In the present embodiment, the polyurethane foam 11 has a flat shape, has open cells, and has sound absorption. Examples of the flat shape include a plate shape and other flat shapes, and the flat shape also includes a shape in which irregularities are formed on the front surface or the back surface. In this embodiment, the polyurethane foam 11 has a flat plate shape.

The polyurethane foam 11 is preferably a semi-rigid polyurethane foam. Since the flexible polyurethane foam is soft and has low rigidity, and the rigid polyurethane foam has high hardness and too high rigidity, a semi-rigid polyurethane foam having appropriate rigidity is more preferable. As the semi-rigid polyurethane foam, for example, those having a 50% compression hardness based on the E method of JIS K6400-2: 2012 of 500 to 3000 N are preferable.

The apparent density of the polyurethane foam 11 (based on JIS K7222: 2005) is preferably 30 to 90 kg / m ³ . When the apparent density is 40 kg / m ³ or more, the sound insulation of the polyurethane foam 11 is particularly improved, and when the apparent density is 60 kg / m ³ or less, the weight of the polyurethane foam 11 is particularly preferable. The thickness of the polyurethane foam 11 is, for example, 1 to 50 mm.

As shown in FIG. 3, in the polyurethane foam 11, the foam cells 30 are densely packed. As the foam cell 30, an open cell 30A and a closed cell 30B are provided. The open cells 30A are communication with each other through cell holes 32 penetrating the cell membrane 31 that separates the foam cells 30. The closed cell 30B is surrounded by a cell membrane 31 in which the cell hole 32 is not provided, and does not communicate with other foam cells 30. Here, in the present disclosure, in an image in which the polyurethane foam 11 is magnified 35 times with a microscope (for example, SEM or the like), the presence or absence of the cell hole 32 is determined, and the cell hole 32 is not visually recognized in the cell film 31 surrounding the foamed cell 30. In this case, the foamed cell 30 is a closed cell 30B. For example, the polyurethane foam 11 contains 20 to 150 foam cells / 25 mm.

As shown in FIGS. 1 and 2, the polyurethane foam 11 has a sound absorbing surface 11M that allows sound (air) to enter the polyurethane foam 11, and a sound absorbing path 33 that communicates from the sound absorbing surface 11M to the inside of the polyurethane foam 11. Has a sound absorbing structure 40 provided with. Specifically, as shown in FIG. 3, the sound absorbing surface 11M is a surface of the surface of the polyurethane foam 11 in which the open cell 30A of the foam cell 30 is opened. Further, the sound absorbing path 33 is composed of a plurality of open cells 30A communicating from the sound absorbing surface 11M toward the inside of the polyurethane foam 11. The sound absorbing surface 11M of the polyurethane foam 11 may not have a skin layer formed on it, or may have a breathable skin layer formed on it. Here, in the present disclosure, the skin layer is a surface layer having an apparent density higher than that of the inner portion of the polyurethane foam 11, and is, for example, 0. Depth from the surface of the polyurethane foam 11. It is a part up to 5 to 1 mm. For example, in FIG. 23, the surface of the polyurethane foam 11 is shown on the upper side and the skin layer is shown by reference numeral 16.

Here, as the cell hole 32 described above, a foam hole 32X formed during foam molding of the polyurethane foam 11 and a break hole 32Y formed by breaking the cell film 31 after foam molding are provided. .. Specifically, as will be described later, the break hole 32Y is formed by breaking the cell film 31 by the wind pressure of the compressed gas blown into the inside from the surface (sound absorbing surface 11M) of the polyurethane foam 11. For example, the broken cell film 31 may be attached to the opening edge of the broken hole 32Y.

In the present embodiment, the sound absorbing structure 40 of the polyurethane foam 11 has a structure in which the total opening area of the cell holes 32 including the foam holes 32X and the breaking holes Y becomes larger as it is closer to the sound absorbing surface 11M than the inside of the polyurethane foam. ing. Further, in the sound absorbing structure 40, the air permeability of the polyurethane foam 11 is larger as it is closer to the sound absorbing surface 11M than the inside of the polyurethane foam 11. According to these configurations, the air permeability of the portion of the polyurethane foam 11 on the sound absorbing surface 11M side is enhanced, and the sound absorbing performance of the polyurethane foam 11 (that is, the soundproofing material 10) with respect to the sound from the sound absorbing surface 11M side is improved. Is possible. Further, since the air permeability of the polyurethane foam 11 is lower in the interior than in the portion on the sound absorbing surface 11M side, it is possible to improve the sound insulation of the polyurethane foam 11. In the above comparison of the total opening area, for example, the area of the cell hole 32 shown in the enlarged image of the predetermined region (for example, the surface side region S and the central region D shown in FIG. 2) of the cut surface of the polyurethane foam 11 is used. It can be calculated by area calculation software or the like and compared at different depths from the sound absorbing surface 11M. Specifically, since the directions in which the cell holes 32 are open are random and isotropic as a whole, the total planar area of the cell holes 32 in a predetermined region of the cut surface in any direction is measured and the cells are calculated. Comparisons can be made at different depths. The air volume of the polyurethane foam 11 is, for example, divided into three equal parts in the thickness direction, and the air volume between the central portion in the thickness direction and the portion on the sound absorbing surface 11M side (JIS K6400-7 B method: 2012). It can be compared by measuring (based on).

Further, in the sound absorbing structure 40 of the polyurethane foam 11, the number of closed cells 30B is smaller as it is closer to the sound absorbing surface 11M than the inside of the polyurethane foam 11. Specifically, the number of closed cells 30B per unit cross-sectional area in the surface layer portion 10S from the sound absorbing surface 11M to the depth 3 mm with respect to the number of closed cells 30B per unit cross-sectional area in the central portion of the polyurethane foam 11 in the thickness direction. The closed cell ratio, which is the ratio of numbers, is preferably 0.7 or less. Here, the central portion of the polyurethane foam 11 in the thickness direction is arranged inside the surface layer portion 10S and is located at the center position 10D of the polyurethane foam 11 in the thickness direction (in the example of the present embodiment, the depth from the sound absorbing surface 11M is It is a region (for example, the central region D shown in FIG. 2) including a region (position of 10 mm). According to the configuration in which the closed cell ratio is 0.7 or less, the sound absorption performance of the polyurethane foam 11 can be particularly improved. The closed cell ratio is more preferably 0.65 or less, and even more preferably 0.6 or less. Further, in the present embodiment, in the sound absorbing structure 40, the ratio of the number of open cells 30A to the total number of foaming cells 30 increases as it is closer to the sound absorbing surface 11M than the inside of the polyurethane foam 11. Also with this configuration, the air permeability of the portion of the polyurethane foam 11 on the sound absorbing surface 11M side is enhanced to facilitate ventilation to the inside of the polyurethane foam 11, and the sound absorbing performance of the polyurethane foam can be further improved. The number of closed cells 30B and open cells 30A is, for example, the surface side region S of a predetermined area included in the surface layer portion 10S of the cut surface of the polyurethane foam 11 and the central region D of a predetermined area including the central position 10D ( It can be obtained by counting the number of closed cells 30B and open cells 30A shown in the enlarged image (for example, SEM image or the like) of FIG. 2). Then, if the numbers are compared between the regions of the polyurethane foam 11 having different depths from the sound absorbing surface 11M, a closed cell ratio or the like can be obtained.

Further, in the polyurethane foam 11 of the soundproofing material 10, the ratio of the major axis to the minor axis (major axis / minor axis ratio) of the cell shape of the foam cell 30 in the central portion (central region D) in the thickness direction is 1 to 1.5. It is preferable to have. The major axis is the length of the longest portion of the foam cell 30, and the minor axis is the length of the smallest portion of the foam cell 30. The directions of the major axis and the minor axis are different for each foam cell 30, but the major axis direction is substantially orthogonal to the thickness direction, and the minor axis direction is substantially the same as the thickness direction. The major axis / minor axis ratio is, for example, the largest foam cell 30, the smallest foam cell 30, and any other three of the foam cells 30 shown in the enlarged image of the central region D (see FIG. 2). It can be calculated from the ratio of the average major axis and the average minor axis of the foam cells 30 and the total of five foam cells.

In the present embodiment, both the front and back surfaces of the polyurethane foam 11 have sound absorbing surfaces 11M, and the sound absorbing structures 40 are provided on both sides of the front and back surfaces. The sound absorbing surface 11M may be arranged on the entire outer surface of the polyurethane foam 11, or may be arranged only on one side of the front and back surfaces.

Further, in the present embodiment, the outer peripheral surface 11E of the polyurethane foam 11 is a cut surface on which the skin layer is not formed. On the outer peripheral surface 11E, the portion of the cell film 31 where the cell hole 32 is not open reflects light and is easy to shine. That is, when there are many closed cells 30B, there are many parts that are easily shined. On the other hand, the portion of the cell film 31 in which the total opening area of the cell holes 32 is large is difficult to shine. Therefore, looking at the outer peripheral surface 11E of the polyurethane foam 11 of the present embodiment, the light becomes more difficult as it approaches the sound absorbing surfaces 11M on the front and back surfaces from the central portion in the thickness direction. In the present embodiment, the surface layer portion 10S constituting the sound absorbing surfaces 11M on the front and back sides is a layered region in which it is harder to shine than a deeper portion, and break holes 32Y are unevenly distributed in this layered region. There is.

The soundproofing material 10 is manufactured, for example, as follows. In order to manufacture the soundproof material 10, the polyurethane foam 11 is first obtained by foam molding in a molding die (that is, obtained by molding). The polyurethane foam 11 may be formed by slab molding.

When foam-molding the polyurethane foam 11, it is preferable to use, for example, a linear hydrocarbon wax as a mold release agent. This makes it easy to form an open cell surface 11MA (that is, a surface for ventilating) in which the foam cell 30 including the open cell 30A is opened on the surface of the polyurethane foam 11. Specifically, among the molding dies for foam molding, a linear hydrocarbon wax is applied to the molding surface for molding the open cell surface 11MA, then a polyurethane raw material is injected into the molding dies, and the polyurethane raw material is foam-cured. The polyurethane foam 11 may be formed by forming the polyurethane foam 11.

Examples of the above-mentioned linear hydrocarbon wax include paraffin wax, Fishertroph wax, sazole wax and the like, and a solvent-based mold release agent dispersed in an organic solvent and an aqueous-based wax dispersed in water using an emulsifier. A mold release agent or the like can be used. Examples of the branched chain hydrocarbon wax include microcrystalline wax, modified polyethylene wax and the like, and a solvent-based mold release agent, a water-based mold release agent and the like can be used.

The polyurethane foam 11 is appropriately cut after molding, and then blow-treated as shown in FIG. In the blow process, a compressed gas is blown into the polyurethane foam 11 to break the cell film 31 of the foam cell 30 of the polyurethane foam 11 to form a break hole 32Y.

Specifically, in the blow treatment, compressed gas (for example, air) is blown from the open cell surfaces 11MA on the front and back surfaces of the polyurethane foam 11. Specifically, as shown in FIG. 4, the blow process applies the tip surface of the nozzle N, which ejects the compressed gas (that is, the opening edge of the ejection port) of the blow gun, to the open cell surface 11MA of the polyurethane foam 11. It is done in contact. The blow process may be performed so that the nozzle N is close to the open cell surface 11MA (for example, separated by a distance of 2 mm or less). According to these methods, it becomes easy to blow the compressed gas into the polyurethane foam 11, and it is possible to suppress the variation in the amount of the compressed gas blown. Further, in this case, it is preferable that the dynamic pressure of the compressed gas blown into the polyurethane foam 11 is 0.1 to 1.0 MPa. This facilitates the formation of a sound absorbing path to the inside of the polyurethane foam 11. The compressed gas used in the blow treatment may be, for example, an inert gas such as nitrogen or argon, in addition to air.

When the blow treatment is performed, the total opening area of the foam holes 32X formed at the time of foam molding becomes large, and the break holes 32Y are formed in the polyurethane foam 11, especially in the portion of the polyurethane foam 11 near the open cell surface 11MA. The sound absorbing path 33 is added. As a result, the sound absorbing structure 40 is formed. At this time, the sound absorbing surface 11M is formed from the open cell surface 11MA.

In the present embodiment, the blow treatment is performed over the entire front and back surfaces of the polyurethane foam 11, but it may be performed only on a part of the polyurethane foam 11, for example, it may be performed on only one of the front and back surfaces, or the front and back surfaces. It may be done only on a part of at least one side of the. Further, for example, if the nozzle N of the blow gun used in the blow process is shaped like a T, the blow process can be efficiently performed by widening the ejection port of the compressed gas in the nozzle N. The blow treatment may be performed while feeding the polyurethane foam 11. In this case, it is preferable to perform the blow treatment in a state where the nozzle N is not in contact with the polyurethane foam 11 but is in close proximity to the polyurethane foam 11. Further, in this case, the blow process can be efficiently performed by using the T-shaped nozzle N which is wider than the polyurethane foam 11.

Before the blow treatment, the open cell surface 11MA of the polyurethane foam 11 may be pierced by piercing the tips of a plurality of needles or blades. This makes it possible to easily blow the compressed gas into the inner side of the polyurethane foam 11 through the perforations formed by the piercing process. Further, before the blow process, a notch process for making a notch in the sound absorbing surface 11M with a cutter may be performed. By performing this treatment as well, it becomes possible to easily blow the compressed gas from the notch to the inner side of the polyurethane foam 11. These piercing treatments and cutting treatments are particularly effective when the surface of the polyurethane foam 11 on which the skin layer is formed is blown. In this case, by forming the perforations and cuts at a depth that does not penetrate the polyurethane foam 11 and deeper than the skin layer, it is possible to facilitate blowing the compressed gas into the polyurethane foam 11. When the perforations and cuts are formed on both the front and back surfaces of the polyurethane foam 11, it is preferable to form the perforations and cuts at positions where they do not overlap when viewed from the thickness direction. By doing so, it is possible to suppress a decrease in the rigidity of the polyurethane foam 11.

When the above blow process is completed, the soundproofing material 10 shown in FIG. 1 is completed. As described above, in the present embodiment, the surface of the polyurethane foam 11 is blown, and the foam cells 30 are communicated with each other through the break holes 32Y. It is possible to provide a sound absorbing structure having a large total opening area of 32.

The details of the raw material of the polyurethane foam 11 are as follows.

As the polyol component, known ether-based polyols, ester-based polyols, ether ester-based polyols, polymer polyols and the like used in the production of polyurethane foam can be used alone or in combination of two or more. Examples of the ether-based polyol include polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin and trimethylolpropane, or polyether polyols obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to the polyhydric alcohols. The ester-based polyol is polycondensed from an aliphatic carboxylic acid such as malonic acid, succinic acid and adipic acid, an aromatic carboxylic acid such as phthalic acid, and an aliphatic glycol such as ethylene glycol, diethylene glycol and propylene glycol. The polyester polyol thus obtained can be mentioned. Further, an ether ester-based polyol containing both an ether group and an ester group in the polyol, or a polymer polyol obtained by polymerizing an ethylenically unsaturated compound or the like in the ether-based polyol can also be used.

The polyisocyanate component may be aromatic, alicyclic, or aliphatic, and may be a bifunctional isocyanate having two isocyanate groups in one molecule, or three in one molecule. It may be a trifunctional or higher-functional isocyanate having more than one isocyanate group, or a modified product thereof (for example, one having various modifications such as urethane modification, allophanate modification, and burette modification). It can be used alone or in combination. Bifunctional isocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane dianate, 2, Aromatic ones such as 2'-diphenylmethane diisocyanate, alicyclic ones such as cyclohexane-1,4-diisocyanate and isophorone diisocyanate, and aliphatic ones such as butane-1,4-diisocyanate, hexamethylene diisocyanate and lysine isocyanate. The system can be mentioned. Examples of trifunctional or higher functional isocyanates include 1-methylbenzol-2,4,6-triisocyanate, 1,3,5-trimethylbenzol-2,4,6-triisocyanate, and polypeptide MDI (polymethylenepolyphenylpoly). Isocyanate) and the like.

The foaming agent is not particularly limited, but water is preferable. Further, carbon dioxide gas, pentane, hydrofluoroolefin (HFO) or the like may be used in combination with water as a foaming agent as a foaming aid.

As the catalyst, known catalysts used for producing polyurethane foam can be used. For example, amine catalysts such as diethanolamine, triethylenediamine, bis (2-dimethylaminoethyl) ether, N, N, N', N ″, N ″ -pentamethyldiethylenetriamine, tetramethylguanidine, imidazole compounds, and Stanasoct. Examples thereof include a tin catalyst such as ate and a metal catalyst such as phenylmercury propionate or lead octate (also referred to as an organic metal catalyst). A plurality of catalysts may be used in combination.

The raw material of the polyurethane foam 11 may contain a foam stabilizer. As the defoaming agent, known ones used for producing polyurethane foam can be used, and examples thereof include silicone-based defoaming agents and non-silicone-based surfactants.

The raw material of the polyurethane foam 11 is prepared separately as a liquid A containing a polyol component, a foaming agent, a catalyst and the like, and a liquid B containing a polyisocyanate component. When the raw material of the polyurethane foam 11 contains a defoaming agent, these are blended in the liquid A.

In the method for manufacturing the soundproofing material 10 of the present embodiment, a blow treatment is performed in which compressed gas is blown into the inside from the open cell surface 11MA of the polyurethane foam 11, and break holes 32Y are added to the cell membranes 31 of the plurality of foam cells 30. , A sound absorbing path 33 communicating from the sound absorbing surface 11M of the polyurethane foam 11 to the inside is added. Therefore, the sound absorbing performance of the polyurethane foam 11 can be improved, and the sound absorbing performance of the soundproofing material 10 can be improved.

In the present embodiment, the break hole 32Y of the polyurethane foam 11 can be easily formed by breaking the cell membrane with the wind pressure of the compressed gas by the blow treatment.

In the soundproofing material 10 of the present embodiment, the total opening area of the cell hole 32 including the foam hole 32X formed in the cell film 31 during foam molding of the polyurethane foam 11 and the break hole 32Y is the surface of the polyurethane foam 11 from the inside. The closer it is to (sound absorbing surface 11M), the larger it is. Further, the air volume of the polyurethane foam 11 is larger as it is closer to the sound absorbing surface 11M than the inside of the polyurethane foam 11. According to these configurations, it is possible to enhance the air permeability of the portion of the polyurethane foam 11 on the sound absorbing surface 11M side, and it is possible to enhance the sound absorbing performance for the sound from the sound absorbing surface 11M side of the polyurethane foam 11, as a result. , It is possible to improve the soundproofing performance of the soundproofing material 10. Further, since the air permeability can be lowered inside the polyurethane foam as compared with the portion on the sound absorbing surface 11M side, the sound insulation of the polyurethane foam 11 can be improved. Moreover, by making it easier for the sound (air) to enter the inside of the polyurethane foam 11, it is possible to suppress the sound incident on the sound absorbing surface 11M from being reflected to the outside. These make it possible to improve the soundproofing property of the soundproofing material 10.

Further, in the polyurethane foam 11, the number of closed cells 30B having no cell hole 32 in the cell film 31 is smaller as it is closer to the sound absorbing surface 11M than the inside of the polyurethane foam 11. Therefore, among the foam cells 30, it is possible to increase the number of open cells 30A communicated through the cell holes 32, and it is possible to increase the air permeability as the sound absorbing surface 11M is closer to the inside of the polyurethane foam 11. This makes it possible to further improve the sound absorption performance of the polyurethane foam 11.

Further, the ratio of the number of closed cells per unit cross-sectional area in the surface layer portion 10S from the sound absorbing surface 11M to the depth of 3 mm to the number of closed cells 30B per unit cross-sectional area in the central portion of the polyurethane foam 11 in the thickness direction is determined. When it is 0.7 or less, it is possible to particularly improve the sound absorption performance of the polyurethane foam 11.

Further, by setting the 50% compression hardness of the polyurethane foam to 500 to 3000 N, it is possible to secure the rigidity of the polyurethane foam 11 and to stabilize the shape of the polyurethane foam 11. In the polyurethane foam 11 having a 50% compressive hardness in the above range, for example, when a break hole 32Y is formed in the cell film 31 by roll crushing, the dimensional accuracy is lowered or the appearance is wrinkled because it is not crushed and restored. However, according to the present embodiment, since the roll crushing is not required, it is possible to suppress deterioration of the dimensional accuracy and appearance of the polyurethane foam 11.

In the soundproofing material 10 of the present embodiment, the sound absorbing surface 11M and the sound absorbing path 33 are arranged on both sides of the flat polyurethane foam 11 in the thickness direction, so that the sound absorbing performance from both sides is improved. Can be done.

FIG. 5 shows an example of using the soundproofing material 10 of the present embodiment. In this example, the soundproof material 10 is provided in the soundproof structure of a building or a vehicle. Specifically, in this soundproof structure, the soundproof material 10 is sandwiched between a pair of plate-shaped soundproof materials 71 and 72 in close contact with each other or separated from each other. In the case of the close contact state, the soundproofing material 10 may be brought into close contact with, for example, the sound insulating materials 71 and 72 in a non-adhesive state. The sound insulating materials 71 and 72 are made of, for example, iron plates, gypsum boards, concrete, etc., which have sound insulating properties, and include double floors, double walls, double ceilings, etc. of buildings, and body panels of vehicles such as vehicles. A sound insulation mat that can be layered on it, etc. can be mentioned. As described above, according to the soundproof structure in which the soundproof material 10 of the present embodiment is arranged between the pair of soundproof materials 71 and 72, it is possible to improve the sound absorption performance and the sound insulation performance.

[Second Embodiment]
As shown in FIG. 6, in the soundproofing material 10V according to the second embodiment, the skin material 20 is integrated with a part of the surface of the polyurethane foam 11. In the soundproofing material 10V of the present embodiment, the polyurethane foam 11 has a flat shape, and the skin material 20 is integrated only on one surface of the front and back surfaces thereof. Examples of the flat shape include a plate shape and other flat shapes, and the flat shape also includes a shape in which irregularities are formed on the front surface or the back surface. In this embodiment, the polyurethane foam 11 has a flat plate shape.

In this embodiment, the skin material 20 has breathability. Specifically, the skin material 20 is made of a fiber sheet 21, and the skin material 20 is formed with an impregnated layer 22 formed by impregnating and curing the raw material 11G of polyurethane foam 11 on the fiber sheet 21, and the impregnated layer 22 is formed. The skin material 20 containing the above has breathability. The air volume of the skin material 20 including the impregnated layer 22 based on JIS K6400-7 B method: 2012 is preferably 3 to 90 ml / cm ² / s, and more preferably 5 to 80 ml / cm ² / s. preferable. The skin material 20 may be non-breathable, and may be, for example, a non-breathable material obtained by impregnating the fiber sheet 21 with the impregnation layer 22, or a resin film or the like.

Specifically, the skin material 20 of the present embodiment is composed of two layers of fiber sheets 21 and 21. The impregnated layer 22 is formed to have substantially the same thickness as the inner fiber sheet 21A arranged on the polyurethane foam 11 side. Further, in the present embodiment, the outer fiber sheet 21B has a larger fiber diameter and basis weight than the inner fiber sheet 21A. For example, the inner fiber sheet 21A and the outer fiber sheet 21B are integrated by a needle punch.

The polyurethane foam 11 of the soundproofing material 10V of the present embodiment has a foam structure having a sound absorbing surface 11M and a sound absorbing path 33 similar to the polyurethane foam 11 of the soundproofing material 10 of the first embodiment. Specifically, this foam structure is provided on both the front and back surfaces of the skin material 20 of the polyurethane foam 11, and both sides have a sound absorbing surface 11M. Here, the foam structure having the sound absorbing surface 11M on the opposite side (lower side of FIG. 6) of the polyurethane foam 11 has the same closed cell ratio as that of the first embodiment, but the skin material. Even in a foam structure having a sound absorbing surface 11M covered with 20, the closed cell ratio is preferably 0.7 or less. In the present embodiment, since the Claude cell ratio is 0.7 or less even on the sound absorbing surface 11M on the skin material 20 side, it is possible to particularly improve the sound absorbing performance of the polyurethane foam 11 with respect to the sound from the skin material 20 side. Become. Here, the closed cell ratio is the central portion of the polyurethane foam 11 in the thickness direction (that is, the portion including the central position 10D (FIG. 7) having a depth of 10 mm from the sound absorbing surface 11M covered with the skin material 20). It is the ratio of the number of closed cells 30B per unit cross-sectional area in the surface layer portion 10S (FIG. 7) from the sound absorbing surface 11M to the depth 3 mm to the number of closed cells 30B per unit cross-sectional area in FIG. .. The closed cell ratio is more preferably 0.65 or less, and further preferably 0.60 or less, from the viewpoint of improving the sound absorption performance with respect to the sound on the skin material 20 side.

The details of the skin material 20 are as follows. The fibers constituting the fiber sheet 21 include polyethylene terephthalate (PET) fiber, polyester fiber, polypropylene fiber, polyamide fiber, acrylic fiber, vinylon fiber, polyurethane fiber (spandex), glass fiber, carbon fiber, and natural fiber (for example, wool). , Cotton, cellulose nanofibers, etc.), Zylon (registered trademark), etc. In addition, examples of the form of the fiber sheet 21 include non-woven fabric, woven fabric, and knitting. Examples of the non-woven fabric include spunlace non-woven fabric, spunbond non-woven fabric, needle punch non-woven fabric and the like.

The fiber diameter of the fiber sheet 21 is preferably 2 to 10 denier (d), and more preferably 2 to 8 denier. The basis weight of the fiber sheet 21 is preferably 70 to 500 g / m ² , more preferably 90 to 500 g / m ² . When the fiber sheet 21 is composed of fibers having a fine fiber diameter in this way, the fibers can be brought into a dense state by shortening the distance between the fine fibers. Therefore, the raw material 11G of the polyurethane foam 11 is the fiber sheet 21 (skin). It can be made difficult to seep out from the material 20).

A resin other than the polyurethane resin, such as an acrylic acid ester resin such as ethyl acrylate and a rubber resin such as styrene-butadiene rubber (SBR), may be attached to the fiber sheet 21 at 35 to 100 g / m ² . preferable. When a resin other than the polyurethane resin adheres to the fiber sheet 21, a resin other than the polyurethane resin intervenes between the fibers, making it difficult for the raw material 11G of the polyurethane foam 11 to pass through the fiber sheet 21 (skin material 20). The raw material 11G can be made more difficult to seep out. The resin other than the polyurethane-based resin may be attached to the surface of the fiber sheet 21 or may be attached to the fibers inside the fiber sheet 21. For example, in the latter case, the polyurethane-based resin constituting the impregnated layer 22 may cover a resin other than the polyurethane-based resin adhering to the fiber. In order to attach a resin other than the polyurethane resin to the fiber sheet 21, the emulsion is applied to the surface of the fiber sheet 21, the fiber sheet 21 is impregnated with the emulsion, or the powder is sprayed on the surface of the fiber sheet 21. It may be done by applying a hot roller or hot air.

The skin material 20 has the air permeability of the impregnated layer 22 by adjusting the type of fiber constituting the fiber sheet 21, the fiber diameter, the basis weight, the amount of adhesion of a resin other than the polyurethane resin such as the acrylic acid ester resin, and the like. Can be adjusted.

Since the inner fiber sheet 21A is densely packed with fine fibers and is impregnated with an acrylic acid ester resin, the amount of impregnation (penetration) of the raw material 11G can be limited. Thereby, the air permeability of the skin material 20 can be ensured. On the other hand, the outer fiber sheet 21B has a larger fiber diameter than the inner fiber sheet 21A, for example, 5 denier or more, so that the wear resistance of the soundproof material 10V can be improved. In FIG. 6 and the like, the impregnated layer 22 is shown in gray.

Next, a method of manufacturing the soundproof material 10V of the present embodiment will be described. In order to manufacture the soundproof material 10V, first, the raw material 11G of the polyurethane foam 11 (see FIG. 9B) and the skin material 20 are prepared. Specifically, as the raw material 11G of the polyurethane foam 11, a material containing a polyol component, a polyisocyanate component, a foaming agent, a catalyst and the like is prepared, and each skin material 20 (fiber sheets 21A and 21B are needle punched). To be integrated.) Is prepared.

As the raw material 11G of the polyurethane foam 11, the same material as that exemplified as the raw material of the polyurethane foam 11 of the soundproofing material 10 of the first embodiment can be used.

The raw material 11G of the polyurethane foam 11 is prepared separately as a liquid A containing a polyol component, a foaming agent, a catalyst and the like, and a liquid B containing a polyisocyanate component. When the raw material 11G contains a defoaming agent, these are blended in the liquid A.

As shown in FIG. 9A, the molding die 50 for molding the soundproofing material 10 includes a lower die 51 and an upper die 52 facing each other with the cavity interposed therebetween. Then, for example, the skin material 20 is fixed to the molding surface 52M of the upper mold 52. Specifically, at this time, the fiber sheet 21 to be the inner fiber sheet 21A is arranged so as to face the cavity side. Further, for example, the acrylic acid ester resin is impregnated in advance only on the inner fiber sheet 21A.

Next, as shown in FIG. 9B, the raw material 11G in which the liquid A and the liquid B are mixed is injected into the molding recess 51U of the lower mold 51, and then the molding mold 50 is closed (FIG. 9). 10 (A)), the raw material 11G is foamed and cured to form the polyurethane foam 11 (see FIG. 10B). At this time, the raw material 11G is impregnated into the skin material 20 (specifically, the inner fiber sheet 21A) and cured to form the impregnated layer 22, and the polyurethane foam 11 and the skin material 20 are adhered and integrated. Will be done.

The molding die 50 is opened, and the integrated polyurethane foam 11 and the skin material 20 are removed from the molding die 50.

Next, the polyurethane foam 11 is appropriately cut, and then, as shown in FIG. 11, a blow treatment is performed from the open cell surface 11MA of the polyurethane foam 11 in the same manner as in the first embodiment. As a result, the cell film 31 of the polyurethane foam 11 is broken to form a breaking hole 32Y, and the sound absorbing structure 40 is formed.

As shown in FIG. 12, in the present embodiment, the blow treatment is also performed from the skin material 20 side integrated with the polyurethane foam 11. That is, the compressed gas is blown into the polyurethane foam 11 from the outside of the skin material 20, the cell film 31 is broken, the break hole 32Y is formed, the sound absorbing path 33 is added, and the sound absorbing structure 40 is formed. Further, as shown in FIG. 12, this blow process is also performed by bringing the tip surface of the nozzle N for ejecting the compressed gas (that is, the opening edge of the ejection port) of the blow gun into contact with the skin material 20. The blow process may be performed by moving the nozzle N closer to the skin material 20 (for example, separating them within a distance of 2 mm). According to these methods, it becomes easy to blow the compressed gas into the polyurethane foam 11, and it is possible to suppress the variation in the amount of the compressed gas blown. Further, in this case, it is preferable that the dynamic pressure of the compressed gas to be blown is 0.1 to 1.0 MPa. This facilitates the formation of a sound absorbing path to the inside of the polyurethane foam 11. The blow treatment from the skin material 20 side is also performed over the entire skin material 20, but may be performed only on a part of the skin material 20.

When the blow process is completed, the soundproofing material 10V shown in FIG. 6 is completed.

Even with the soundproofing material 10V of the present embodiment, the same effect as that of the soundproofing material 10 of the first embodiment can be obtained. Further, in the present embodiment, since one side of the polyurethane foam 11 is covered with the skin material 20, the soundproofing performance of the soundproofing material 10V can be improved by the sound insulating effect or the sound absorbing effect of the skin material 20. Further, by providing the impregnation layer on the skin material 20, it is possible to improve the sound insulation performance of the soundproof material 10V and also to improve the rigidity of the soundproof material 10V. Further, since the sound absorbing structure 40 is provided on both the side of the polyurethane foam 11 facing the skin material 20 and the side opposite to the skin material 20, it is possible to improve the sound absorbing performance for the sound from both the front and back surfaces of the polyurethane foam 11. Become.

Further, as shown in FIG. 13, the soundproof material 10V of the present embodiment can also be used for a soundproof structure of a building or a vehicle. Examples thereof include a structure in which a soundproofing material 10V is sandwiched between a pair of soundproofing materials 71 and 72 in a state of being in close contact with or separated from each other. As described above, according to the soundproof structure in which the soundproof material 10V is arranged between the pair of sound insulation materials 71 and 72, it is possible to improve the sound absorption performance and the sound insulation performance.

[Third Embodiment]
As shown in FIG. 14, the soundproofing material 10W according to the second embodiment has a configuration in which the polyurethane foam 11 is sandwiched between a pair of skin materials 20. Specifically, the skin material 20 is integrated on both the front and back surfaces of the polyurethane foam 11.

In the present embodiment, the polyurethane foam 11 is provided with the same sound absorbing structure 40 as the skin material 20 side in the second embodiment on both the front and back sides. Further, the front and back skin materials 20 have an impregnated layer 22 and are breathable. As the polyurethane foam 11 and the skin material 20, those made of the same materials as those exemplified in the first embodiment and the second embodiment and those having the same characteristics can be used. In this embodiment, the pair of skin materials 20 have the same configuration, but they may be different. In this case, for example, the impregnating layer 22 may be provided only on one of the skin materials 20. Further, the impregnated layer 22 may not be provided on any of the skin materials 20.

The soundproofing material 10W of the present embodiment is manufactured, for example, as follows. First, as shown in FIGS. 15 and 16, the polyurethane foam 11 is formed in the same manner as in the second embodiment. In the present embodiment, the skin material 20 is set on the molding surfaces of both the upper mold 52 and the lower mold 51. At this time, the fiber sheets 21A inside the pair of skin materials 20 are arranged so as to face each other facing the cavity side (FIG. 15A).

Next, after the raw material 11G in which the liquid A and the liquid B are mixed is injected into the molding recess 51U of the lower mold 51 (15 (B)), the molding mold 50 is closed (FIG. 16 (A)). , Raw material 11G is foamed and cured to form polyurethane foam 11 (see FIG. 16B). At this time, the raw material 11G is impregnated into the pair of skin materials 20 (specifically, the inner fiber sheet 21A) and cured to form the impregnated layer 22, and the polyurethane foam 11 and the pair of skin materials are paired. 20 is bonded and integrated.

Next, when the integrated polyurethane foam 11 and the skin material 20 are removed from the molding die 50, a blow process is performed. Specifically, in the present embodiment, the polyurethane foam 11 is blown through the skin material 20 in the same manner as in the second embodiment, and the blow treatment is performed from the front and back of the polyurethane foam 11. As a result, break holes 32Y are formed on the front and back surfaces of the polyurethane foam 11, a sound absorbing path 33 is added, and a sound absorbing structure 40 is formed. At this time, as shown in FIG. 17, in the same manner as in the second embodiment, in this blow process as well, the tip surface of the nozzle N for ejecting the compressed gas of the blow gun is brought into contact with the skin material 20. Will be done. The blow process may be performed so that the tip surface of the nozzle N is close to the skin material 20 as in the second embodiment.

In the soundproofing material 10W of the present embodiment, the sound absorbing structure 40 on the front and back of the polyurethane foam 11 makes it possible to improve the sound absorbing performance of the polyurethane foam 11, and it is possible to improve the soundproofing performance of the soundproofing material 10W. Further, in the soundproof material 10W, since the skin material 20 having the impregnated layer 22 is arranged on both the front and back surfaces of the polyurethane foam 11, the soundproof material 10 can be made difficult to warp.

In this embodiment, the sound absorbing structure 40 may be provided only on one side of the front and back surfaces of the polyurethane foam 11. Further, only one of the pair of skin materials 20 may have breathability. In this case, the other skin material 20 may be a fiber sheet that is non-breathable by the impregnated layer 22, or may be a non-breathable resin film.

Further, as shown in FIG. 18, the soundproofing material 10W of the present embodiment can also be used for a soundproofing structure of a building or a vehicle. Examples thereof include a structure in which a soundproofing material 10W is sandwiched between a pair of soundproofing materials 71 and 72 in a state of being in close contact with or separated from each other. As described above, according to the soundproof structure in which the soundproof material 10W is arranged between the pair of soundproof materials 71 and 72, it is possible to improve the sound absorption performance and the sound insulation performance.

[Fourth Embodiment]
As shown in FIG. 19, in the soundproofing material 10X according to the fourth embodiment, a notch is formed on one of the front and back surfaces (open cell surface 11MA) of the polyurethane foam 11 having a flat shape. Specifically, a plurality of linear notches 15 are formed on one surface of the polyurethane foam 11, and the parallel linear notches 14 composed of these linear notches 15 are orthogonal to each other to form a grid-like notch 13. Is forming. In this embodiment, each linear notch 15 is arranged parallel to one side of the polyurethane foam 11 and extends from one end to the other of the polyurethane foam 11. Further, the grid-like notches 13 extend over the entire one surface of the polyurethane foam 11.

The notch depth of the linear notch 15 (that is, the grid-like notch 13) may be up to the center in the thickness direction of the polyurethane foam 11, and the position of the front and back sides of the polyurethane foam 11 near one side or the other side. It may be up to. For example, in the present embodiment, the skin material 20 is integrated with the other surface of the polyurethane foam 11. In this case, the depth of cut may be as deep as the boundary between the polyurethane foam 11 and the skin material 20. Further, for example, when the polyurethane foam 11 is molded by molding, a skin layer is likely to be formed on the surface of the polyurethane foam 11. In this case, it is preferable that the depth of cut is deeper than that of the skin layer of polyurethane foam 11. As a result, it is possible to easily ventilate the polyurethane foam 11 to a position deeper than the skin layer. The skin layer of the polyurethane foam 11 is preferably breathable, that is, the open cell 30A is open to the surface, and such a skin layer is as described in the first embodiment. By using a linear hydrocarbon wax as a release agent at the time of foam molding of the polyurethane foam 11, it becomes possible to facilitate the formation.

The soundproofing material 10X of the present embodiment is manufactured, for example, as follows. First, in the same manner as in the second embodiment, the skin material 20 is integrally formed on the other side of the front and back of the flat polyurethane foam 11. Next, a grid-like notch 13 is made in one of the front and back surfaces (exposed surface) of the polyurethane foam 11. Specifically, the surface of the polyurethane foam 11 opposite to the skin material 20 is arranged on the upper side, and a stamp having a grid-like cutter is pressed against the surface from the upper side. As a result, a grid-like notch 13 is formed in the polyurethane foam 11.

Next, a blow process is performed in which a compressed gas is blown from the exposed surface of the polyurethane foam 11. Here, since the notch 13 is formed on the exposed surface of the polyurethane foam 11 as described above, it becomes easy to blow the compressed gas from the blow gun into the inside of the polyurethane foam 11 through the notch 13, and a break hole 32Y is formed. It becomes easier to do. Since the polyurethane foam 11 (particularly the flexible polyurethane foam) has high resilience, the notch 13 may be closed after the notch 13 is formed as described above, but even in this case, the notch 13 is made with compressed gas. It can be opened to facilitate blowing compressed gas from the notch 13 into the polyurethane foam 11.

From the above, the soundproof material 10X can be obtained. In addition, in this embodiment, it is not necessary to perform the blow process. Further, the soundproofing material 10X may be composed only of the polyurethane foam 11 without providing the skin material 20.

In the present embodiment, the formation of the notch 13 in the polyurethane foam 11 makes it easier for sound (air) to enter the inside of the polyurethane foam 11, and it is possible to improve the sound absorption property in the inner portion of the polyurethane foam 11. , It is possible to improve the soundproofing property of the soundproofing material 10X. Further, by providing the notch 13 in the polyurethane foam 11, the compressed gas can be blown into the inside of the polyurethane foam 11 through the notch 13. This facilitates the formation of the break hole 32Y and can further improve the sound absorption property of the polyurethane foam 11. Further, by making such a notch deeper than the skin layer in the polyurethane foam 11, it is possible to easily ventilate the polyurethane foam 11 to a deeper position than the skin layer, and it is possible to improve the sound absorption property of the polyurethane foam 11. It will be possible.

[Fifth Embodiment]
As shown in FIGS. 20A and 20B, in the soundproofing material 10Y according to the fifth embodiment, a plurality of puncture marks 18 formed by piercing the tip of a needle or a blade into the polyurethane foam 11 are formed. ing. Specifically, the polyurethane foam 11 has a flat shape, and puncture marks 18 extend from one of the front and back surfaces (open cell surface 11MA) to the middle of the polyurethane foam 11, and these puncture marks 18 are predetermined. They are arranged in a grid pattern with intervals (for example, a square grid pattern or a staggered arrangement). The plurality of stab marks 18 may be arranged randomly.

In the example of the soundproofing material 10Y of the present embodiment, one surface of the polyurethane foam 11 on which the puncture mark 18 is formed is exposed, and the skin material 20 is integrated with the other surface, but the stab is stabbed. The mark 18 may be formed on the other surface side and extend halfway through the polyurethane foam 11 through the skin material 20. Further, the soundproofing material 10Y may be composed of only the polyurethane foam 11, or the soundproofing material 10Y may be configured such that the skin material 20 is integrated on both the front and back surfaces of the polyurethane foam 11. In these cases, the stab marks 18 may be formed only on one side of the polyurethane foam 11 or on both sides. When the puncture marks 18 are formed on both sides of the front and back surfaces of the polyurethane foam 11, the puncture marks 18 of the needles on the front and back surfaces of the polyurethane foam 11 are arranged so as not to overlap each other in the thickness direction of the polyurethane foam 11. Is preferable. This makes it possible to suppress a decrease in the rigidity of the polyurethane foam 11.

The depth of the stab mark 18 may be up to the center of the polyurethane foam 11 in the thickness direction, or may be up to one side of the front and back of the polyurethane foam 11 or the position of the other side. Further, for example, when the polyurethane foam 11 is molded by molding, a skin layer is likely to be formed on the surface of the polyurethane foam 11. In this case, it is preferable that the depth of the puncture mark 18 is deeper than the skin layer of the polyurethane foam 11. As a result, it is possible to easily ventilate the polyurethane foam 11 to a position deeper than the skin layer. The skin layer of the polyurethane foam 11 is preferably one having breathability, that is, one in which the open cell 30A is open to the surface, and such a skin layer is as described in the first embodiment. By using a linear hydrocarbon wax as a release agent at the time of foam molding of the polyurethane foam 11, it becomes possible to facilitate the formation.

In the present embodiment, the width of the puncture mark 18 (specifically, the maximum size when viewed in the piercing direction) is the cell diameter of the foam cell 30 (specifically, the major axis which is the length of the longest portion). That is all. The thickness of the stab mark 18 may be larger or smaller than the cell diameter of the foam cell 30.

The soundproofing material 10Y of the present embodiment is manufactured, for example, as follows. First, in the same manner as in the first embodiment, the polyurethane foam 11 having a flat shape and having the skin material 20 integrated on one surface is obtained. Next, as shown in FIG. 21, a plurality of needle puncture marks 18 are formed on one of the front and back surfaces (exposed surface) of the polyurethane foam 11. Specifically, the surface of the polyurethane foam 11 opposite to the skin material 20 is arranged on the upper side, and a plurality of needles 58 (for example, in a grid pattern) are projected on the lower surface of the pressing die 57. (For example, it may be a sword mountain, etc.) is pressed from above. In this way, a piercing process in which the needle 58 is pierced halfway into the polyurethane foam 11 (specifically, a piercing process in which the needle 58 is pierced and then pulled out) is performed, and puncture marks 18 of the needles arranged in a grid pattern are formed. To. Here, since the polyurethane foam 11 (particularly, the soft polyurethane foam) has high resilience, the puncture mark 18 may close when the stamp 57 is returned. Even in this case, for example, the polyurethane foam may be closed. The puncture mark 18 can be confirmed by magnifying the cut surface of 11 with a microscope or the like.

In the example of this embodiment, the needle 58 of the push die 57 is, for example, as follows. The needle 58 is formed of a cylindrical body portion on the base end side and a triangular pyramid-shaped tip portion. The diameter of the body portion of the needle 58 is 1.35 mm, and the axial length of the body portion is 9 mm. The axial length of the tip of the needle 58 is 4 mm. Further, the needles 58 are arranged in a square grid pattern, and the grid spacing (distance between the central axes of adjacent needles 58) is 3.65 mm. Further, in the present embodiment, for example, the pressing of the push die 57 is set so that only the tip portion of the needle 58 pierces the polyurethane foam 11. The shape and arrangement of the needle 58 are not limited to this example. Further, instead of using the push die 57 provided with the plurality of needles 58, the same needle 58 may be pierced into a plurality of places to perform the piercing process.

When the piercing treatment is completed, next, the same blow treatment as in the first embodiment is performed from the surface of the polyurethane foam 11 on which the piercing mark 18 is formed. In the present embodiment, since the compressed gas can be blown into the inside of the polyurethane foam 11 in the blow treatment through the puncture mark 18, the compressed gas can be easily blown into the inside of the polyurethane foam 11. In addition, in this embodiment, it is not necessary to perform the blow process.

The stab mark 18 may penetrate the skin material 20 integrated with the polyurethane foam 11. In this case, the skin material 20 may be integrated with the other surface of the polyurethane foam 11, and the needle 58 may be pierced from the other surface to form a puncture mark 18 (see FIG. 22). In this case, the puncture mark 18 may or may not be provided on one surface (exposed surface) side of the front and back surfaces of the polyurethane foam 11.

Further, when the piercing process for forming the needle puncture mark 18 is performed from one side of the front and back surfaces of the polyurethane foam 11, the notch process for making the same notch 13 as in the fourth embodiment is performed on the front and back surfaces of the polyurethane foam 11. It may be done from the other side of the. In this case, the notches may be linear, parallel, or grid-like, and are preferably arranged so as not to overlap the puncture marks 18 when viewed from the thickness direction of the polyurethane foam 11. This makes it possible to suppress a decrease in the rigidity of the polyurethane foam 11.

In the present embodiment, the formation of the needle puncture mark 18 on the polyurethane foam 11 facilitates the entry of sound (air) into the inside of the polyurethane foam 11 and improves the sound absorption property in the inner portion of the polyurethane foam 11. This makes it possible to improve the soundproofing property of the soundproofing material 10Y. Further, by providing the piercing mark 18 in the polyurethane foam 11, the compressed gas can be blown into the inside of the polyurethane foam 11 through the piercing mark 18. This facilitates the formation of the break hole 32Y and can further improve the sound absorption property of the polyurethane foam 11. Further, by forming such a puncture mark 18 to a position deeper than the skin layer in the polyurethane foam 11, it is possible to easily ventilate the polyurethane foam 11 to a position deeper than the skin layer, and the sound absorption property of the polyurethane foam 11 is improved. It is possible to make it. The stab mark 18 may be formed by piercing the tip of the blade halfway through the polyurethane foam 11. The soundproofing material 10Y having such a piercing mark 18 can also improve the sound absorbing property.

[Other embodiments]
(1) The polyurethane foam 11 has a flat shape, but is not limited to this, and may have a block shape such as a cube shape, for example.

(2) In the above embodiment, the skin material 20 is integrated with the polyurethane foam 11 by foam molding of the polyurethane foam 11, but the skin material 20 may be laminated later on the foam-molded polyurethane foam 11. .. In this case, the skin material 20 may be laminated on the surface of the polyurethane foam 11 that has been blown.

(3) The soundproofing material 10W of the third embodiment may be manufactured by the following production line. Specifically, this production line is provided with a transport means (for example, a conveyor) for transporting the long skin materials 20 in the longitudinal direction in a state of being vertically opposed to each other. Then, while transporting the skin material 20, the raw material 11G of the polyurethane foam 11 is discharged between the skin materials 20 to foam and cure the raw material 11G to form the polyurethane foam 11. At this time, the raw material 11G of the polyurethane foam 11 impregnates the pair of skin materials 20, and the impregnated layer 22 is formed on each skin material 20. After that, the skin material 20 is cut to a predetermined length together with the polyurethane foam 11 by a cutter to obtain a soundproof material 10W. If the polyurethane foam 11 protrudes from the skin material 20 at the end portion of the soundproof material 10W in the width direction, the protruding portion is appropriately trimmed. Further, if a heating furnace is provided in the middle of the transport path of the transport means, foam hardening of the raw material 11G of the polyurethane foam 11 is promoted, and the moldability of the soundproof material 10 can be improved.

(4) The soundproofing material 10V of the second embodiment may be manufactured on the production line of the other embodiment (3). In this case, of the pair of long skin materials 20 to be transported in the production line of the other embodiment (3), only the lower skin material 20 is transported in the present embodiment, and the lower surface material 20 thereof is to be transported. The raw material 11G of the polyurethane foam 11 may be discharged onto the skin material 20 to be foamed and cured.

(5) In the second and third embodiments, when the skin material 20 is composed of the fiber sheet 21, the skin material 20 may be composed of one fiber sheet 21 or three or more fiber sheets. It may consist of 21.

(6) In the second and third embodiments, the breathable skin material 20 may be a net-like material or a material through which a large number of holes have penetrated.

(7) In the fourth embodiment, the piercing process may also be performed. When the blow treatment is performed, the piercing treatment is preferably performed before the blow treatment. Further, in the fifth embodiment, the cutting process may also be performed. When the blow treatment is performed, the cut treatment is preferably performed before the blow treatment.

Hereinafter, the above embodiment will be described in more detail with reference to Examples and Comparative Examples, but the soundproofing material of the present invention is not limited to the following Examples.

1. 1. Configuration and manufacturing method of soundproofing material

In Examples 1 to 4 and Comparative Examples 1 and 2, polyurethane foam 11 (semi-rigid polyurethane foam) is foam-molded by reacting the raw material 11G, which is a mixture of liquid A and liquid B, as in the production method of the above-described embodiment. By integrating the skin material 20 only on both sides of the polyurethane foam 11, a soundproof material having a size of 500 mm × 500 mm × 20 mm (thickness) was obtained. Then, in Examples 1 to 4 and Comparative Example 2, additional work described later was performed on the soundproofing material of that size. In Examples 1 to 4 and Comparative Examples 1 and 2 in which the thickness of the polyurethane foam 11 is 16 mm and the thickness of each skin material 20 is 2 mm, the presence or absence of additional machining or the type of additional machining with respect to the polyurethane foam 11 is different from each other. The raw material 11G and the skin material 20 of the polyurethane foam 11 are the same.

In Examples 1 to 4 and Comparative Examples 1 and 2, a linear hydrocarbon wax "URM-520" manufactured by Konishi Co., Ltd. was used as a mold release agent during foam molding.

1) Polyurethane foam In each example and each comparative example, the raw material 11G of the polyurethane foam 11 is the same. The details of the composition of the raw material 11G are as follows.

<Liquid A>
Polyol 1; Polyether polyol (30 parts by weight, number average molecular weight: 5500, number of functional groups: 3.6, hydroxyl value: 31.5 mgKOH / g)
Polyol 2; Polymer polyol (70 parts by weight, number average molecular weight: 5000, number of functional groups: 3, hydroxyl value 25 mgKOH / g, solid content concentration: 30%)
Foaming agent; water (4.35 parts by weight)
Amine catalyst 1; "Diethanolamine" manufactured by Showa Kagaku Co., Ltd. (2.50 parts by weight)
Amine catalyst 2; "DABCO BL-11" manufactured by Evonik Japan Co., Ltd. (0.37 parts by weight)
Defoaming agent; "TEGOSTAB B8715LF2" manufactured by Evonik Japan Co., Ltd. (0.50 parts by weight)
Additives: Polyether polyol (1.85 parts by weight, number average molecular weight: 5000, number of functional groups: 3, hydroxyl value 34 mgKOH / g)
<Liquid B>
Polyisocyanate; Polymeric MDI (NCO value 31.5%)

The isocyanate index was 105. The isocyanate index is a value obtained by dividing the number of moles of isocyanate groups of polyisocyanate by the number of moles of total active hydrogen groups such as polyol and foaming agent (water) multiplied by 100.

2) Skin material In Examples 4, Comparative Examples 3 and 4, the skin material 20 was composed of two fiber sheets 21 and 21 (inner fiber sheet 21A and outer fiber sheet 21B). The inner fiber sheet 21A is made of PET fiber having a fiber diameter of 3 denier and has a basis weight of 100 g / m ² . The outer fiber sheet 21B is made of PET fiber having a fiber diameter of 6 denier and has a basis weight of 150 g / m ² . In the skin material 20, only the inner fiber sheet 21A is impregnated with the acrylic acid ester resin, and the impregnation amount is 50 g / m ² .

3) Types of additional machining The details of the additional machining performed when manufacturing the soundproofing materials of the examples and comparative examples are as follows.

(1) Blow treatment In the blow treatment, compressed air was blown in a state where the tip surface of the nozzle N of the blow gun was in contact with the surface of the soundproof material. This blow treatment was performed on at least one of the front and back surfaces of the soundproofing material, and the entire surface was subjected to the blow treatment (hereinafter, the surface to which the blow treatment was appropriately performed is referred to as a blow treatment surface). The diameter of the outlet of the compressed air in the nozzle N of the blow gun used is 1.6 mm, and the dynamic pressure of the compressed air blown into the soundproof material is 0.6 MPa.

(2) Puncture processing In the piercing treatment, the needle 58 was pierced into a plurality of locations of the soundproof material to form a plurality of piercing marks 18 extending halfway in the polyurethane foam 11 in the thickness direction, as in the fifth embodiment. Specifically, the needle 58 includes a body portion having a cylindrical shape and a base end side, and a tip portion having a triangular pyramid shape. The diameter of the body portion of the needle 58 is 1.35 mm, and the axial length of the body portion is 9 mm. The axial length of the tip of the needle 58 is 4 mm. Further, the puncture marks 18 of the needle 58 are arranged in a square grid pattern, and the grid spacing (distance between the central axes of adjacent needles 58) is 3.65 mm. Further, the piercing depth of the needle 58 into the soundproof material is 4.0 mm.

(4) Roll crushing In roll crushing, the polyurethane foam 11 was conveyed and passed between a pair of rotating rolls, and the entire polyurethane foam 11 was crushed. The axial length of the rotating rolls is longer than 500 mm, the diameter of the rotating rolls is 200 mm, the clearance between the pair of rotating rolls is 9 mm, and the transfer speed of the polyurethane foam 11 is 70.5 mm / sec. .. Further, in Comparative Examples 2 and 4, roll crushing was performed 8 times (that is, polyurethane foam 11 was passed 8 times between a pair of rotating rolls). Specifically, roll crushing is performed once for each of the four arrangements in which each side of the polyurethane foam 11 is parallel to the rotating roller and is at the beginning of the transport direction (that is, in an arrangement rotated by 90 degrees). I went 4 times. Further, after the polyurethane foam 11 was turned over, the same roll crushing was performed a total of 4 times.

4) Details of additional work of each example and each comparative example Details of additional work of each example and each comparative example are as follows. In the following and FIG. 24, either one of the front and back surfaces of the soundproofing material is referred to as a first surface, and the other surface is appropriately referred to as a second surface.

<Example 1>
Only blow treatment was performed on both the first surface and the second surface (both front and back surfaces).
<Example 2>
Only the blow treatment was performed on the first surface, and only the piercing treatment was performed on the second surface.
<Example 3>
Only blow processing was performed on the first surface, and no additional processing was performed on the second surface.
<Example 4>
Only the blow treatment was performed on the first surface, and the piercing treatment was performed on the second surface and then the blow treatment was performed.
<Example 5>
Only the piercing process was performed on the first surface, and the piercing process was performed on the second surface, and then the blow process was performed.
<Example 6>
No additional work was performed on the first surface, and the second surface was pierced and then blown.
<Example 7>
Both the first surface and the second surface were pierced and then blown.
<Comparative Example 1>
No additional work has been done on the soundproof material. Therefore, the break hole 32Y is not formed.
<Comparative Example 2>
Only roll crushing was done.

2. 2. Evaluation For each Example and each Comparative Example, the appearance, closed cell ratio, hardness, reverberation room method sound absorption coefficient, transmission loss, etc. were evaluated. The measurement method of the measurement items is as follows.

<Measurement method>
(1) Density The apparent density of polyurethane foam 11 was measured based on JIS K7222: 2005. Specifically, a test piece having a size of 500 mm × 500 mm × 20 mm (thickness) was cut into 100 mm × 100 mm × 20 mm (thickness) for measurement.

(2) Air volume The air volume was measured based on JIS K6400-7 B method: 2012. Specifically, three slice samples (100 mm square) obtained by slicing the soundproof material so as to divide the polyurethane foam 11 in the thickness direction were measured by passing air from the lower surface to the upper surface. Specifically, the portion of the polyurethane foam 11 having a thickness of 4 mm in the center in the thickness direction (central slice sample), the skin material 20 on the first surface side, and the skin material 20 on the second surface side were used as slice samples. .. Then, the central slice sample (polyurethane foam 11) is ventilated from the second surface side (the second surface side is arranged on the lower side), and the latter two slice samples (skin material 20) are impregnated with the impregnated layer 22. The measurement was performed by ventilating from the side (the impregnated layer 22 side was placed on the lower side).

(3) Closed cell ratio With a scanning electron microscope (SEM: manufactured by JEOL Ltd.), a region of a predetermined area in the central portion and the surface layer portion 10S of the outer peripheral surface 11E of the polyurethane foam 11 (central region D in FIG. 2). The surface side region S) was observed, and the number of closed cells 30B in the region of the predetermined area was counted. Then, the ratio of the number of closed cells 30B in the surface side region S to the closed cell ratio was defined as the closed cell ratio. The central region D is determined so that the central position of the polyurethane foam 11 in the thickness direction is the center of the central region D, and the surface side region S is a range from the surface to a depth of 3 mm in the thickness direction of the polyurethane foam 11. I decided to fit inside. Further, the predetermined area observed by SEM in the central region D and the surface region S is 2.5 mm × 2.5 mm. The low closed cell ratio means that the number of closed cells on the surface side is smaller than that on the inside of the polyurethane foam 11. The magnification of the SEM was set to 35 times.

The closed cell ratio was evaluated as ⊚ when it was 0.7 or less, ◯ when it was larger than 0.7 and 1.0 or less, and × when it was larger than 1.0.

(4) Cell diameter A scanning electron microscope (SEM: manufactured by JEOL Ltd.) captured an enlarged image of the central portion (central region D (see FIG. 2)) in the thickness direction on the outer peripheral surface 11E of the polyurethane foam 11. From the average major axis and the average minor axis of a total of five foam cells, the largest foam cell 30, the smallest foam cell 30, and any other three foam cells 30, among the foam cells 30, their average. The ratio of the major axis to the average minor axis (major axis / minor axis) was calculated. The major axis of the foam cell 30 is the length of the longest portion in each foam cell 30 confirmed by SEM, and the minor axis of the foam cell 30 is the shortest in each foam cell 30 confirmed by SEM. It is the length of the part that has become. The magnification of the SEM was set to 35 times.

The above-mentioned major axis / minor axis values of the foam cell 30 were evaluated as ⊚ when it was 1 or more and 1.5 or less, and × when it was larger than 1.5.

(5) Deformation due to additional machining Deformation of the soundproof material before and after the additional machining was confirmed. Specifically, the thickness of the test piece before and after the additional machining was measured, and the change was confirmed. The thickness of the test piece was measured at three locations (both ends and central portion) for each of the four sides of the test piece, and the average value of the thicknesses at these 12 locations was used.

The thickness of the soundproofing material after the additional machining was evaluated as ⊚ when it was 19 mm or more, ◯ when it was 18 mm or more and less than 19 mm, and × when it was less than 18 mm. As described above, the thickness of the soundproofing material before the additional machining is 20 mm.

(6) Hardness The hardness of the polyurethane foam 11 was measured based on JIS K6400-2 E method: 2012. Specifically, a test piece of 500 mm × 500 mm × 20 mm is cut into 200 mm × 200 mm × 20 mm, and a compression jig (the pressing surface is a circle with a diameter of 80 mm) is used to compress from above at a compression speed of 50 mm / min. The test piece was compressed until the amount of deformation in the thickness direction became 80% of the original thickness of the test piece, and the load at the time of 50% compression (50% compression hardness) was measured. The soundproof material was arranged so that the first surface faced upward.

The 50% compression hardness was evaluated as ⊚ when it was 500 N or more, and × when it was less than 500 N.

(7) Transmission loss The transmission loss was measured based on JIS A1441-1: 2007. Specifically, a measurement sample is obtained by stacking a test piece on an iron plate (500 mm × 500 mm × 0.8 mm (thickness)) and further stacking a rubber plate (500 mm × 500 mm × 1.0 mm (thickness)) on it. The soundproofing material was arranged so that the first surface faced upward.

The transmission loss was evaluated as ⊚ when it was 50 dB or more, ◯ when it was 48 dB or more and less than 50 dB, and × when it was less than 48 dB.

(8) Reverberation room method sound absorption coefficient Based on JIS A1409: 1998, the reverberation room method sound absorption coefficient of the test piece of the soundproof material was measured. Specifically, four test pieces with a size of 500 mm x 500 mm x 20 mm (thickness) spread on the floor of the reverberation room are used as measurement samples with a size of 1 m x 1 m x 20 mm in the reverberation room at each frequency. The method sound absorption coefficient was measured. At this time, the outer circumference of the measurement sample was covered with an aluminum fixing tool, and the gaps between the test pieces and the test piece and the fixing tool were sealed with aluminum tape. Then, the sound absorption coefficient at frequencies 500, 630, 800, 1000, 1250, 1600, 2000, 2500, 3150, 4000, 5000, and 6300 Hz is arranged with the first surface facing up and the second surface facing up. Both were measured, and the average value of all the measured values was taken as the reverberation room method sound absorption coefficient of the test piece.

The reverberation room method sound absorption coefficient was evaluated as ⊚ when it was 0.50 or more, ◯ when it was 0.45 or more and less than 0.50, and × when it was less than 0.45.

When all of the above evaluation items were ◎, the overall evaluation was “◎”, when there was ○ but no ×, the overall evaluation was “○”, and when there was even one ×, the overall evaluation was “×”.

<Evaluation result>
As shown in FIG. 24, in Examples 1 to 7 in which the blow treatment is performed as additional processing, the reverberation room method sound absorption coefficient is significantly improved as compared with Comparative Examples 1 and 3 in which no additional processing is performed. It was confirmed (evaluation ◎). In Examples 1 to 7, the transmission loss is also better than that of Comparative Examples 1 and 3 (evaluation ○ or higher). Further, as can be seen from the comparison between Example 1 and Example 3, it was found that the improvement of the reverberation room method sound absorption coefficient is greater when the blow treatment is performed from both sides of the soundproofing material than from only one side. Further, as can be seen from the comparison between Example 1 and Example 4 and the comparison between Example 1 and Example 7, as an additional work, the blow treatment is performed after the piercing treatment rather than the case where only the blow treatment is performed. It can be seen that the reverberation room method sound absorption coefficient is larger in this case.

Further, in Comparative Example 2 in which roll crushing was performed as additional machining, the reverberation room sound absorption coefficient and transmission loss were improved as compared with Comparative Example 1 in which no additional machining was performed, but the polyurethane foam by roll crushing was performed. The deformation of 11 was large. Specifically, the polyurethane foam 11 was crushed by roll crushing, and the thickness of the polyurethane foam 11 became thinner (see the thickness after additional machining). Further, in Comparative Example 2, as can be seen from the comparison of the 50% compression hardness with Comparative Example 1, the hardness is increased. Therefore, it can be seen that when roll crushing is performed, the soundproofing material is difficult to restore and the dimensional accuracy is lowered. As can be seen from the major axis / minor axis ratio of the cell diameter, in Comparative Example 2, the foam cell 30 is longer than in Examples 1 to 7 and Comparative Example 1. It is considered that this is because the foam cell 30 was crushed by the roll crushing.

On the other hand, in Examples 1 to 7 in which the blow treatment was performed without performing roll crushing, the deformation of the polyurethane foam 11 was not confirmed even in Comparative Example 1 in which no additional processing was performed, and polyurethane. The hardness of the foam 11 was almost the same (thickness after additional machining, 50% compression hardness, both evaluated ◎). As described above, it was found that the soundproofing materials of Examples 1 to 7 can improve the sound absorbing property while preventing the deterioration of the dimensional accuracy due to the additional machining.

As described above, it can be confirmed that the soundproofing materials of Examples 1 to 7 subjected to the blow treatment can improve the sound absorption property while preventing the deterioration of the dimensional accuracy as compared with the soundproofing materials of Comparative Examples 1 and 2. (Comprehensive evaluation is ○ or higher).

10 Soundproofing material 11 Polyurethane foam 13 Notch 18 Stab mark 30 Foam cell 30A Open cell 30B Closed cell 31 Cell membrane 32 Cell hole 32X Foam hole 32Y Break hole 33 Sound absorption path

Claims (10)

A method for manufacturing soundproofing materials including polyurethane foam.
The polyurethane foam and the pair of skin materials are integrated so that the polyurethane foam is sandwiched between a pair of breathable skin materials.
A method for producing a soundproofing material, in which a blow process is performed in which a compressed gas is blown into the foam-molded polyurethane foam through the skin material to add break holes to the cell membranes of a plurality of foam cells contained in the polyurethane foam. .. The method for producing a soundproof material according to claim 1, wherein the blow treatment is performed by bringing the tip surface of a nozzle for ejecting the compressed gas into contact with or close to the surface of the skin material. The method for producing a soundproof material according to claim 2, wherein the dynamic pressure of the compressed gas is 0.1 to 1 MPa. The soundproofing material according to any one of claims 1 to 3, wherein a piercing treatment is performed in which the tips of a plurality of needles or blades are pierced into the surface of the polyurethane foam through the skin material before the blow treatment. Production method. Soundproofing material containing polyurethane foam
The polyurethane foam and the pair of skin materials are integrated so that the polyurethane foam is sandwiched between a pair of breathable skin materials.
It has break holes formed in the cell membranes of the plurality of foam cells contained in the polyurethane foam.
A soundproofing material in which the number of closed cells among the foamed cells is smaller as the number of closed cells is closer to the surface where the skin material is integrated than the inside of the polyurethane foam. Soundproofing material containing polyurethane foam
The polyurethane foam and the pair of skin materials are integrated so that the polyurethane foam is sandwiched between a pair of breathable skin materials.
It has break holes formed in the cell membranes of the plurality of foam cells contained in the polyurethane foam.
A soundproofing material in which the air permeability of the polyurethane foam is larger as the air permeability of the polyurethane foam is closer to the surface on which the skin material is integrated than the inside of the polyurethane foam. The polyurethane foam has a flat shape, and the skin material is integrated on both the front and back surfaces thereof.
The ratio of the number of closed cells per unit cross-sectional area in the surface layer portion from both the front and back surfaces of the polyurethane foam to a depth of 3 mm to the number of closed cells per unit cross-sectional area in the central portion in the thickness direction of the polyurethane foam. The soundproofing material according to claim 5 or 6, wherein the amount is 0.7 or less. 15. The soundproofing material described. The soundproofing material according to any one of claims 5 to 8, wherein the breaking hole breaks the cell membrane by the wind pressure of a compressed gas blown into the inside of the polyurethane foam through the skin material. .. The soundproofing material according to any one of claims 5 to 9, wherein the polyurethane foam has a 50% compressive hardness of 500N to 3000N based on the method E of JIS K6400-2: 2012.

Images