JP2013043798A - Double glazing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double glazing having improved sound insulation performance regardless of the size of the double glazing without damaging its appearance.SOLUTION: In this double glazing 100, a sealed hollow layer 1 is formed between each glass plate G1, 2 by spacing apart a plurality of glass plates G1, 2 through a spacer 4, and a member 9 for resonance is arranged on a position at a prescribed interval from the spacer 4 approximately in parallel therewith in the hollow layer 1, and a hollow part partitioned by the member 9 for resonance, the spacer 4 and the glass plates G1, 2 is formed. In the double glazing, the member 9 for resonance communicates the hollow layer 1 with the hollow part 2, and a meandering communication passage 10 having a prescribed width is formed therein, and further the communication passage 10 is formed continuously along the longitudinal direction of the spacer 4, and a resonator is formed by the member 9 for resonance and the hollow part 2.

Description

  The present invention relates to a multilayer glass provided with a resonance member that improves sound insulation in a low frequency region.

  Multi-layer glass generally has a configuration in which a plurality of glass plates are spaced apart by a spacer, and a hollow layer that is a sealed space is formed by the glass plate and the spacer, and multi-layer glass has a hollow layer. As a result, heat insulation performance is enhanced, and there are advantages such as prevention of dew condensation and reduction of the load of air-conditioning on the indoor side.

Although the double-glazed glass has a hollow layer, it has excellent heat insulation performance. However, the presence of this hollow layer results in low sound insulation performance compared to a glass plate having the same thickness including the hollow layer. This is because the higher the density of the object, the more easily the sound is absorbed and attenuated, and it is harder to vibrate due to the solid resistance. . In particular, double glazing has come to be used as a door or window material, and is required to have sufficient heat insulation performance as well as heat insulation performance.

  Several factors are known for reducing the sound insulation performance of double-glazed glass. To improve the sound insulation performance of double-glazed glass, it is mainly necessary to suppress two phenomena: the coincidence effect and the resonance transmission phenomenon. Is known to be important.

  The coincidence effect is a phenomenon in which transmission loss decreases at a specific frequency in a plate-like material, in other words, sound insulation performance decreases. Specifically, when sound is incident obliquely on the plate surface, there is a phase difference in the sound pressure depending on the position on the plate surface, so that inherent bending forced vibration occurs along the plate surface, and sound is transmitted at a certain frequency. This is a phenomenon in which the sound insulation performance deteriorates due to an increase in the noise.

  The resonance transmission phenomenon means that in a double-layer glass, a pair of glasses resonate with a hollow layer as a spring, and the system on the right side and the system on the left side are the same with a hollow layer part (mechanical equilibrium point) as a boundary. It is a phenomenon that vibrates at a frequency. The two systems are equivalent in terms of energy and resonate with each other, and the sound insulation performance of the double-glazed glass deteriorates at this frequency.

  Conventionally, in order to improve the sound insulation of the multilayer glass, a multilayer glass in which a Helmholtz resonator using a sound absorption effect that converts acoustic energy into thermal energy is interposed between plate glasses has been studied.

  For example, in Patent Document 1, a rod-shaped resonance member having a small hole penetrating at a predetermined interval is arranged at the peripheral portion of a plate glass, and a sound absorbing part having an air layer portion is arranged between the resonance member and the spacer. A multilayer glass having a sound insulation structure for forming a Helmholtz resonator using a sound absorption effect for converting acoustic energy into thermal energy is disclosed.

JP 2003-063844 A

  As shown in FIG. 6, the double-glazed glass provided with the conventional resonance member disclosed in Patent Document 1 has two glass plates G1 and G2 spaced apart via a spacer 4, and the two glasses A hollow layer 1 that is a space sealed by G1, G2 and the spacer 4 is formed. Further, in the hollow layer 1, a resonance member 7 having a rod shape and a thickness L is disposed in parallel with the spacer 4 at a predetermined distance H from the spacer 4, and the resonance member 7 and two glass plates are disposed. The cavity 2 is formed by G1 and G2.

  Further, as shown in FIG. 7, the resonance member 7 is provided with a plurality of through holes 8 having a diameter d communicating with the hollow layer 1 and the cavity 2 with a predetermined pitch interval P. The resonance member 7 and the cavity 2 form a Helmholtz resonator.

  The conventional configuration described in Patent Document 1 is considered to be equivalent to a configuration in which the through holes 8 are continuously provided in the resonance member 7 at every predetermined pitch interval P and the Helmholtz resonators are continuously arranged. In this conventional configuration, the greater the number of through-holes 8 in the resonance member 7, the greater the number of resonators and the greater the sound absorption effect.

  However, the double-glazed glass described in Patent Document 1 has a limitation on the interval between the through holes 8 (a predetermined interval is necessary) in order to obtain a sufficient sound absorption effect, and is applied to openings such as small windows. In this case, since each side of the multilayer glass becomes short, a sufficient number of through holes 8 cannot be physically provided in the resonance member 7.

  Therefore, in the configuration of the Helmholtz resonator described in Patent Document 1, when applied to a small-sized double-layer glass, a sufficient number of through-holes 8 cannot be provided in the short-side resonance member 7, and the Helmholtz resonance is performed. There is a problem that it is difficult to fully exhibit the effect of the vessel and to exhibit excellent sound insulation characteristics. That is, in the resonance member provided with the conventional through-hole, it becomes difficult to increase the number of resonators that exhibit the sound absorption effect when the size of the multilayer glass is reduced. In addition, the individual resonators located at the end of the double-glazed glass cannot obtain the sound absorption effect at the designed frequency due to size limitations.

  The present invention has been made in view of the above-mentioned problems, and in a multilayer glass provided with a resonance member, the multilayer glass having a wide range from a small size to a large size opening without impairing the appearance. An object of the present invention is to provide a double-glazed glass that can be adapted to the size and has a sufficient sound insulation performance.

  In order to solve the above problems, the inventors of the present invention have formed a meandering communication path that connects the hollow layer and the cavity portion in the resonance member, thereby expressing the sound absorption effect in the low frequency region. By continuously forming the passage along the longitudinal direction of the spacer, the sound absorption effect of the Helmholtz resonator can be expressed without being affected by the size (length and shape of each side) of the multilayer glass. The headline, the present invention has been reached.

  That is, the present invention forms a sealed hollow layer between the glass plates by separating a plurality of glass plates via a spacer, and the hollow layer is substantially parallel to the spacer. A resonance member is disposed at a predetermined interval, and is a multi-layer glass in which a cavity portion defined by the resonance member, the spacer, and the glass plate is formed, and the resonance member is the hollow layer A meandering communication path having a predetermined width is formed, and the communication path is formed continuously along the longitudinal direction of the spacer, and the resonance member A multilayer glass comprising a resonator formed by the cavity.

  Further, the resonance member may be composed of at least two substantially U-shaped cross-section members or substantially Y-shaped cross-section members arranged to face each other at a predetermined interval.

  According to this configuration, since the meandering communication path can be easily formed by facing at least two substantially U-shaped members or substantially Y-shaped members in cross section, a special member is used for the resonance member. There is no need to perform complicated operations such as drilling, which is advantageous from the viewpoint of manufacturing.

  According to the present invention, since the meandering communication path that connects the hollow layer and the cavity is formed in the resonance member, the communication path corresponding to the opening of the Helmholtz resonator can be lengthened. The sound absorption effect can be sufficiently exhibited. In addition, since this communication passage is formed continuously along the longitudinal direction of the spacer, it is not affected by the shape of the glass, and even if the length of each side such as a small-sized multi-layer glass is small, it is as designed. A Helmholtz resonator can be formed. Therefore, the sound absorption effect of the Helmholtz resonator can be sufficiently exhibited without being affected by the size of the multilayer glass.

It is a partial expanded sectional view which shows an example of the multilayer glass concerning this invention. FIG. 2 is an enlarged view of the vicinity of a resonance member in FIG. 1. It is a perspective view of the multilayer glass which concerns on this invention. It is a sound-insulation performance curve graph (Example 1) of the multilayer glass which concerns on this invention. It is a sound-insulation performance curve graph (Example 2) of the multilayer glass which concerns on this invention. It is a partial expanded sectional view which shows an example of the conventional multilayer glass. It is a perspective view of the multilayer glass provided with the conventional member for resonance.

  Hereinafter, the multilayer glass 100 according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a partially enlarged cross-sectional view showing an example of a multilayer glass according to the present invention. FIG. 3 is a perspective view of the multilayer glass according to the present invention. FIG. 6 is a partially enlarged cross-sectional view showing an example of a multilayer glass provided with a conventional resonance member. In addition, in FIG. 6, the same code | symbol was attached | subjected about the part which has the same structure and effect | action as the multilayer glass of this invention of FIG.

  As shown in FIG. 1, the double-glazed glass 100 of the present invention is a space in which two glass plates G 1 and G 2 are separated by a spacer 4 and sealed with two glasses G 1 and G 2 and a spacer 4. A hollow layer 1 is formed.

  A primary sealing material 5 such as a butyl rubber adhesive is adhered to both sides of the spacer 4, and the two glasses G 1 and G 2 are bonded and integrated with the primary sealing material 5, and the two glasses G 1 and G 2 are separated and sealed. The hollow layer 1 thus formed is formed. The spacer 4 is filled with a desiccant such as zeolite. The secondary seal portion 6 having a concave shape surrounded by the two glasses G1 and G2 and the spacer 4 is filled with a silicone sealant, a polysulfide sealant, or the like so that moisture does not enter.

  In the hollow layer 1, a slit-type resonance member 9 is disposed in parallel to the spacer 4 and spaced apart from the spacer 4 by a predetermined distance. Hereinafter, the resonance member according to the present invention will be described as a slit-type resonance member 9. A cavity 2 defined by the slit-type resonance member 9, the spacer 4, and the two glasses G1 and G2 is formed. Further, the slit-type resonance member 9 has a meandering communication passage 10 having a predetermined width communicating with the hollow layer 1 and the cavity portion 2, and further, as shown in the perspective view of FIG. The communication passage 10 is formed continuously along the longitudinal direction of the spacer 4. The slit-type resonance member 9 and the cavity 2 form a Helmholtz resonator that exhibits a sound absorption effect.

  In the Helmholtz resonator in the double-glazed glass 100 of the present invention, the method of forming the serpentine communication passage 10 in the resonance member is a special method of forming the serpentine communication passage 10 in a conventional resonance member such as acrylic or metal member. It may be formed by performing hole processing, and is not particularly limited. For example, from the viewpoint of cost and manufacturing, an inexpensive metal cross-sectionally U-shaped member such as aluminum or a substantially cross-sectionally U-shaped member (slit-type resonance member 9) is used. A meandering communication passage 10 is formed in the resonance member by using at least two members or at least two members having a substantially Y-shaped cross section and opposing each other at a predetermined interval in the space of the hollow layer 1. Also good.

  Hereinafter, the principle of the Helmholtz resonator applied to the multilayer glass 100 of the present invention and the calculation of the resonance frequency (fr) will be described in detail.

The resonance frequency (fr) of the Helmholtz resonator in the present invention can be calculated using the following mathematical formula 1 in the configuration of the double-glazed glass 100 shown in FIGS. In the following Equation 1, C is the velocity of sound of gas, L is the length of the communication passage 10, b is the width of the communication passage 10, H is the height of the air layer from the spacer 4 to the slit-type resonance member 9, W Is the width of the hollow layer 1, and K is the tube end correction coefficient. As shown in FIG. 2, the length L of the communication passage 10 is from the opening A on the cavity 2 side of the communication passage 10 provided in the slit-type resonance member 9 to the opening B on the hollow layer 1 side. The distance is calculated by measuring the length with reference to the center point of the width b of the communication passage 10.
Further, K shown in Formula 1 is a coefficient when the slit-type resonance member 9 of the present invention is used in the Helmholtz resonator, and represents an opening end correction value as Kb. The tube end correction coefficient K can be calculated by the following formula 2. In Equation 2, P is the slit opening ratio (P = b / W), where b is the width of the communication passage 10 and W is the width of the hollow layer 1.

In addition, the width of b represents an average value from the opening A on the cavity 2 side to the opening B on the hollow layer 1 side of the cavity 2, and the width of several arbitrarily in the communication passage 10. b is measured and calculated as an average.
From Equation 1 above, it is possible to appropriately design the resonance frequency (fr) of the Helmholtz resonator formed in the multilayer glass 100. In the double-glazed glass 100 of the present invention, the slit-type resonance member 9 is formed, and the communication path 10 that communicates the hollow layer 1 and the cavity 2 is made to meander, so that the length L of the communication path 10 is sufficiently increased. The resonance frequency (fr) can be designed in a sufficiently low frequency region.

As a specific shape in the present invention, the length L of the communication passage 10 is 10 mm or more and 160 mm or less, and the width b of the communication passage is 0.1 mm or more and 3.0 mm or less, and further 0.3 mm or more. 2.0 mm or less is particularly preferable. Further, the cross-sectional area (H × W) of the cavity 2 constituted by the spacer 4 and the slit-type resonance member 9 is 30 mm ² or more and 1080 mm ² or less, and the thickness of the glass plates G1 and G2 is 2.7 mm or more. It is preferable that the width W of the hollow layer 1 is 6.0 mm or more and 12.0 mm or less. By making it into the above numerical range, it is possible to improve the sound insulation performance in the low frequency region by resonance transmission without impairing the appearance of the multilayer glass.

  In the present invention, the resonance frequency of the resonator is preferably designed to be 150 to 650 Hz. In general double-glazed glass, resonance occurs in the sound range of 200 to 1000 Hz (especially 200 to 500 Hz) due to limitations such as the size of the hollow layer, the type of gas enclosed in the hollow layer, and the thickness of the plate glass. The problem of a decrease in sound insulation performance due to the transmission phenomenon is likely to occur, and the decrease in the sound insulation performance in this frequency region tends to affect the sound insulation grade. Therefore, if the resonance frequency of the resonator is 150 to 650 Hz, the sound insulation performance in the low frequency region is improved by avoiding a decrease in the sound insulation performance due to the resonance transmission phenomenon in the sound region of 200 to 1000 Hz as much as possible. -2, T-3, etc., can be provided.

  The slit-type resonance member 9 may be provided along the entire circumference of the four sides of the multilayer glass 100, or may be provided along only one side or along two sides. Further, a plurality of slit-type resonance members 9 may be provided continuously toward the center side of the multilayer glass 100.

  The method for fixing the slit-type resonance member 9 to the glass plates G1 and G2 is not particularly limited. For example, a method of sticking with a double-sided adhesive tape having excellent weather resistance and durability, and the like, similar weather resistance Alternatively, an adhesive that exhibits an adhesive force with excellent durability may be used.

  Various materials can be used as the material of the slit-type resonance member 9, for example, a hard resin such as acrylic, a metal material such as rubber, aluminum, and the like. A smooth finish may be used.

    Moreover, according to the above embodiment, there exists the effect shown below.

  The slit-type resonance member 9 according to the present invention is provided with a meandering communication path 10 that communicates the hollow layer 1 and the cavity 2, and the communication path 10 is continuous along the longitudinal direction of the spacer 4. Therefore, the passage for communicating the hollow layer 1 and the cavity 2 is larger than the conventional multilayer glass provided with a through hole. Therefore, the dehumidifying effect of the desiccant 3 works sufficiently for the hollow layer 1 in a short time, and it is possible to more completely prevent the occurrence of condensation in the double-glazed glass.

  Further, since the serpentine communication passage 10 having a sufficient space is formed in the slit-type resonance member 9, the resonance is compared with the multilayer glass provided with the conventional resonance member 9 as in Patent Document 1. The communication member 10 has a sufficient communication path 10 and the influence of heat transfer from the outside via the resonance member 9 is small. That is, in this invention, compared with the prior art example shown in FIG.6 and FIG.7, it can prevent that the heat insulation fall by the transmission of the heat | fever through the member for resonance arises.

  In addition, since the communication path 10 is formed continuously in the slit type resonance member 9 along the longitudinal direction of the spacer 4, the size of the multilayer glass is larger than that of the conventional example shown in FIGS. 6 and 7. There is also an advantage that the appearance of the appearance is not impaired by the variation in the position of the through hole due to.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  In the multilayer glass according to the present invention, when at least two members having a substantially U-shaped cross section or a substantially Y-shaped cross section are used as the resonance member, a combination of the substantially U-shaped cross section or the substantially Y-shaped cross section member, respectively. It is also possible to use different materials.

  The multi-layer glass according to the present invention is applied to various multi-layer glasses in which a plurality of glass plates are spaced apart by using a spacer, and a hollow layer that is a sealed space is formed by the glass plate and the spacer. be able to. For example, the present invention can be applied not only to a single hollow layer but also to a multi-layer glass in which three or more opposing glass plates are used to form two or more hollow layers.

  The glass plates G1 and G2 applied to the multilayer glass 100 of the present invention are manufactured by a float method or the like, and then are raw glass (single plate glass) that has not been subjected to any post-treatment, and after manufacturing, air cooling strengthening or chemical strengthening. It is possible to use tempered glass subjected to tempering treatment such as laminated glass, laminated glass bonded through a resin intermediate film such as polyvinyl butyral film, and glass with mesh. Of course, it is also possible to use Low-E glass in which at least one of the two glass plates constituting the multilayer glass of the present invention is coated with a low radiation film that suppresses heat transfer.

  Further, the type of gas enclosed in the multilayer glass is not particularly limited. For example, a gas such as argon, krypton, xenon, helium, neon, sulfur hexafluoride, etc., generally enclosed in a known multilayer glass. Can be mentioned. The multilayer glass of the present invention can of course be applied to a multilayer glass in which a single component gas or a gas obtained by mixing at least two single component gases is enclosed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to the Example which concerns. The sound insulation performance of the multilayer glass according to the present invention was evaluated by the following sound insulation performance test.

  Specifically, the effects of the sound insulation performance by installing the slit-type resonance member according to the present invention were evaluated by Examples 1 and 2 in which the resonance member was provided and Comparative Example 1 in which the resonance member was not provided.

<Evaluation of sound insulation performance>
The sound insulation performance test was performed based on “Sash” JIS A4706: 2000 and “Method for measuring sound transmission loss in a laboratory” JIS A1416. At that time, the sound transmission loss at the center frequency of 1/3 octave was measured based on the JIS. In the measurement, the sound source was placed on the glass plate G1 side, and the measuring instrument was placed on the glass plate G2 side.

  Specifically, the type I test chamber (reverberation chamber) described in JIS A1416: 2000 is used, and the test specimen is fixed and installed using two wooden pressing edges (25 mm × 25 mm). JIS A1416: 2000 The sound transmission loss was measured by the method described in 1. The measurement value of sound transmission loss is judged according to JIS A4706: 2000, “a) The sound transmission loss at 16 points from 125 Hz to 4000 Hz all exceeds the corresponding sound insulation grade line. If the sum of the values below the corresponding sound insulation grade line is 3 dB or less, the sound insulation grade is assumed.b) Sound transmission loss is converted in all frequency bands, and the converted value (6 points) corresponds to the sound insulation grade line. On the other hand, regarding the sound insulation grade, if any of the criteria a) and b) is satisfied, each sound insulation grade is passed.

[Example 1]
In the multi-layer glass as shown in FIG. 1, a float single plate glass (FL8) having a total thickness of 22.4 mm and a glass plate G1, G2 having a plate thickness of 7.7 mm and a 4.7 mm float glass (FL5). The slit-type resonance member 9 was installed, and the sound insulation performance was measured using a double-layer glass (FL8 + Re10 + FL5) composed of the hollow layer 1 (Re10) having a thickness of 10 mm. In addition, the measured size of the double-layer glass was 1230 mm × 1480 mm.

  As the slit-type resonance member 9, a plurality of substantially U-shaped members made of aluminum having a shape as shown in FIG. By arranging the concave portions formed on one surface side of the substantially U-shaped member in a non-contact state to face each other, a meandering communication path was formed and adjusted to have a predetermined width (b). In addition, the glass plate G1, G2 side was stuck on the other surface side of the substantially U-shaped member in cross section with a commercially available double-sided adhesive tape, respectively.

  The slit-type resonance member 9 was installed in parallel to each spacer, and was arranged at a total of four locations, the long side left and right and the short side up and down. On the long side (1480 mm) inside the multi-layer glass, the length (L) of the communication passage 10 is 140 mm, the width (b) of the communication passage 10 is 1 mm, the air layer height (H) is 20 mm, and the air layer width (W). A slit-type resonance member 9 having a resonance frequency of 325 Hz was set to 10 mm.

  Further, on the short side (1230 mm), the length (L) of the communication passage 10 is 64 mm, the width (b) of the communication passage 10 is 1 mm, the air layer height (H) is 20 mm, and the air layer width (W) is 10 mm. A slit-type resonance member 9 having a resonance frequency of 479 Hz was installed. In addition, the length (L) of the communication path 10 on the long side and the short side was adjusted by arranging a plurality of slit-type resonance members 9 continuously as necessary.

[Example 2]
In the same structure (FL8 + Re10 + FL5) as in Example 1, the length (L) of the communication passage 10 (L) is 26 mm on the long side (1480 mm) and the short side (1230 mm) inside the multilayer glass. A slit-type resonance member 9 having a width (b) of 10 mm, an air layer height (H) of 80 mm, an air layer width (W) of 10 mm, and a resonance frequency of 371 Hz was installed. In addition, the length (L) of the communication path 10 on the long side and the short side was adjusted as necessary by arranging a plurality of slit-type resonance members 9 continuously.

[Comparative Example 1]
Float single plate glass (FL8) having a total thickness of 22.4 mm and having glass plates G1 and G2 of 7.7 mm as a double-layer glass without the resonance member according to the present invention. Sound insulation performance was measured using a multi-layer glass (FL8 + Air10 + FL5) composed of the hollow layer 1 (Air10) which is a plate glass (FL5) and the thickness of the hollow layer 1 is 10 mm. In addition, the measured size of the double-layer glass was 1230 mm × 1480 mm.

  From the sound insulation performance curve graph of the multilayer glass in the present invention of FIGS. 4 and 5, the multilayer glass of Examples 1 and 2 provided with the resonance member of the present invention is compared with Comparative Example 1 in which the resonance member is not provided. Thus, it can be seen that the sound insulation performance in the frequency region of 200 to 1000 Hz is greatly improved, and that the sound insulation characteristics are improved by the resonance member of the present invention.

  Further, the multilayer glass of the present invention from Examples 1 and 2 is a multilayer glass having an excellent sound insulation performance satisfying the sound insulation class T-3 with a total thickness of 22.4 mm and a limited thickness. I understand that. The multilayer glass of the present invention can be applied with a conventional multilayer sash frame without increasing the thickness of the glass plate more than necessary in order to obtain sufficient sound insulation performance. This is advantageous in terms of cost.

  According to the double-glazed glass according to the present invention, not only buildings and vehicles, but also windows and door members used for openings in condominiums, etc. adjacent to main roads, trains, and aircraft, where noise from outside is a concern. Can be applied to.

DESCRIPTION OF SYMBOLS 100 Multi-layer glass G1, G2 Glass plate 1 Hollow layer 2 Hollow part 3 Desiccant 4 Spacer 5 Primary sealing material 6 Secondary sealing material 7 Resonance member (conventional example)
8 Through-hole 9 Slit-type resonance member (member with substantially U-shaped cross section)
10 Communication passage

Claims (7)

By separating a plurality of glass plates through a spacer, a sealed hollow layer is formed between the glass plates, and the hollow layer is substantially parallel to the spacer and resonates at a predetermined interval. A multi-layer glass in which a cavity member is formed, and a cavity section defined by the resonance member, the spacer and the glass plate is formed;
The resonance member includes a meandering communication passage having a predetermined width that communicates the hollow layer and the hollow portion, and the communication passage is formed continuously along the longitudinal direction of the spacer. A multilayer glass comprising a resonator formed by the resonance member and the cavity.   The multilayer glass according to claim 1, wherein the resonance member is composed of at least two substantially U-shaped members or substantially Y-shaped members arranged to face each other at a predetermined interval. The length of the meandering communication path communicating the hollow layer and the cavity is 10 mm or more and 160 mm or less, and the cross-sectional area of the cavity formed of the spacer and the resonance member is 30 mm ² or more and 1080 mm ^2. The multilayer glass according to claim 1 or 2, wherein the predetermined width of the communication passage is 0.1 mm or more and 3.0 mm or less.   The multilayer glass according to any one of claims 1 to 3, wherein a resonance frequency of the resonator is 150 Hz or more and 650 Hz or less.   The multilayer glass according to any one of claims 1 to 4, wherein when it is made a sash, it passes a sound insulation class T-3 according to JIS A4706: 2000.   A window comprising the multi-layer glass according to any one of claims 1 to 5. A door to which the multilayer glass according to any one of claims 1 to 5 is attached.