WO2014126251A1

WO2014126251A1 - Laminated glass, and structure having same mounted thereto

Info

Publication number: WO2014126251A1
Application number: PCT/JP2014/053698
Authority: WO
Inventors: 神吉　哲; 貴弘浅井
Original assignee: 日本板硝子株式会社
Priority date: 2013-02-18
Filing date: 2014-02-18
Publication date: 2014-08-21
Also published as: JP6629809B2; JP6223314B2; CN104136391A; JPWO2014126251A1; JP2018002592A; JP5647380B1; JP2015051919A

Abstract

[Problem] To provide laminated glass which can improve sound insulation properties, can provide infrared transmittance to a prescribed range, and is formed from sheets of glass having different thicknesses. [Solution] This laminated glass has: an outer glass sheet; an inner glass sheet which is arranged to face the outer glass sheet, and which is thinner than the outer glass sheet; and an intermediate film which is sandwiched between the outer glass sheet and the inner glass sheet. The transmittance of the laminated glass for light having a wavelength of 870-940nm is 30-80%. The thickness of the outer glass sheet is 1.8-2.3mm. The thickness of the inner glass sheet is 0.6-2.0mm. The intermediate film is formed from a plurality of layers including at least a core layer, and the Young's modulus of the core layer at a frequency of 100Hz and a temperature of 20°C is 1-20MPa, and lower than the Young's modulus of the other layers.

Description

Laminated glass and mounting structure to which the glass is mounted

The present invention relates to a laminated glass used for a windshield of an automobile and a mounting structure to which the glass is mounted.

In recent years, from the viewpoint of improving the fuel efficiency of automobiles, it has been required to reduce the weight of glass such as windshields to be mounted, and accordingly, development of glass with a small thickness has been promoted. However, if the thickness is reduced, the sound insulation performance is lowered, so that there is a problem that sound outside the vehicle flows into the vehicle interior and the vehicle interior environment deteriorates. In order to solve this problem, for example, Patent Document 1 describes a laminated glass for automobiles that maintains the sound insulation performance at a predetermined frequency while reducing the surface density. This laminated glass has a resin intermediate film disposed between a pair of glass plates.

JP 2002-326847 A

By the way, in laminated glass like patent document 1, although the fall of sound insulation performance can be prevented to some extent by making thickness small, since the thickness of the glass of the vehicle outside also becomes small, the glass cracking by the external force of the vehicle outside There is a problem that is likely to occur. In order to solve this, a method of reducing the surface density as a whole by reducing the thickness of the glass on the outside of the vehicle while reducing the thickness of only the glass plate on the inside of the vehicle is conceivable. In this regard, the present inventor examined as follows.

First, when the thicknesses of the glass inside and outside the vehicle are different, the present inventors have a frequency range of 2000 to 5000 Hz that is easy for humans to hear, as shown in FIG. It was found that the sound insulation performance deteriorates. The figure is a graph showing the result of simulating the relationship between frequency and sound transmission loss (STL). This graph is composed of laminated glass (hereinafter referred to as first laminated glass) composed of two glass plates having a thickness of 1.5 mm and different glass plates having thicknesses of 2.0 mm and 1.0 mm. Laminated glass (hereinafter referred to as second laminated glass) is displayed. In any laminated glass, a resin intermediate film is disposed between two glass plates. According to this graph, it can be seen that the sound transmission loss of the second laminated glass is lower than that of the first laminated glass in the frequency range of 3000 to 5000 Hz. That is, it was found that the use of glass plates having different thicknesses reduces the sound insulation performance in the frequency range of 2000 to 5000 Hz that is easy for humans to hear.

As described above, when glass with different thicknesses are combined, although the weight can be reduced, there is a problem that sound transmission loss is reduced. In particular, the sound insulation performance in the frequency range of 2000 to 5000 Hz, which is easy for humans to hear, is deteriorated, resulting in a problem that the in-vehicle environment is deteriorated. Such a problem is a problem that can occur not only in automobile glass but also in laminated glass that requires weight reduction and sound insulation.

The present invention has been made to solve the above problems, and provides a laminated glass composed of glass plates having different thicknesses, which achieves both weight reduction and sound insulation, and a mounting structure to which the laminated glass is attached. With the goal.

The laminated glass according to the present invention includes an outer glass plate, an inner glass plate disposed opposite to the outer glass plate and having a smaller thickness than the outer glass plate, and an intermediate film sandwiched between the outer glass plate and the inner glass plate. The inner glass plate has a thickness of 0.6 to 1.8 mm, and the intermediate film is composed of a plurality of layers including at least a core layer, and the Young's modulus of the core layer is 100 Hz. , At 20 ° C., 1 to 20 MPa, which is lower than the Young's modulus of the other layers.

In the laminated glass described above, the inner glass plate can have a thickness of 0.8 to 1.6 mm.

In the laminated glass described above, the inner glass plate can have a thickness of 1.0 to 1.4 mm.

In the laminated glass described above, the inner glass plate can have a thickness of 0.8 to 1.3 mm.

In the laminated glass described above, the thickness of the core layer can be 0.1 to 2.0 mm.

In the laminated glass described above, the thickness of the outer glass plate can be 1.8 to 5.0 mm.

In the laminated glass described above, the Young's modulus of the core layer can be 1 to 16 MPa at a frequency of 100 Hz and a temperature of 20 ° C.

In the laminated glass described above, the tan δ of the interlayer film can be set to 0.5 to 3.0 at a frequency of 100 Hz and a temperature of 20 ° C.

Moreover, the laminated glass attachment structure according to the present invention includes any one of the laminated glasses described above and an attachment portion for attaching the laminated glass to a vertical attachment angle of 45 degrees or less. Such an attachment structure is, for example, an automobile or a building, and the attachment portion is a frame or the like for attaching laminated glass. Moreover, a laminated glass can be attached with a well-known method with respect to an attaching part.

According to the present invention, it is possible to provide a laminated glass made of glass having different thicknesses, which achieves both weight reduction and sound insulation, and a mounting structure on which the glass is mounted.

It is sectional drawing which shows one Embodiment of the laminated glass which concerns on this invention. It is the front view (a) and sectional view (b) which show the amount of doubles of a curved laminated glass. It is a graph which shows the relationship between the general frequency and sound transmission loss of a curved glass plate and a planar glass plate. It is a schematic plan view which shows the measurement position of the thickness of a laminated glass. It is an example of the image used for the measurement of a core layer. It is the schematic which shows the attachment method of a laminated glass. It is a graph which shows the relationship between the frequency when changing the thickness of a single plate glass, and sound transmission loss. It is a graph which shows the result of evaluation of an outside glass board. It is a model figure of the simulation for outputting sound transmission loss. It is a graph which shows the result of evaluation about the Young's modulus of a core layer. It is a graph which shows the result of evaluation about the thickness of a core layer. It is a graph which shows the result of evaluation about the attachment angle of a laminated glass. It is a graph which shows the result of evaluation about the Young's modulus of an outer layer. It is a graph which shows the result of evaluation about the Young's modulus of an outer layer. It is a graph which shows the relationship between the frequency and sound transmission loss in the conventional laminated glass.

DESCRIPTION OF SYMBOLS 1 Outer glass plate 2 Inner glass plate 3 Intermediate film 31 Core layer 32 Outer layer

Hereinafter, an embodiment of a laminated glass according to the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a laminated glass according to the present embodiment. As shown in the figure, the laminated glass according to this embodiment includes an outer glass plate 1, an inner glass plate 2, and an intermediate film 3 sandwiched between these glasses. The outer glass 1 is a glass plate disposed on the side susceptible to disturbance, and the inner glass 2 is a glass plate disposed on the opposite side. Therefore, for example, when this laminated glass is used as a window glass of an automobile, the glass plate on the outside of the vehicle becomes an outer glass plate, and when used as a building material, the side facing outward becomes an outer glass plate. However, depending on the disturbance that can be received, the arrangement may be opposite. Hereinafter, each member will be described.

<1. Outer glass plate and inner glass plate>
As the outer glass plate 1 and the inner glass plate 2, known glass plates can be used, and they can be formed of heat ray absorbing glass, general clear glass, green glass, or UV green glass. However, when this laminated glass is used for a window glass of an automobile, it is necessary to realize visible light transmittance in accordance with the safety standard of the country where the automobile is used. For example, the required solar radiation absorption rate can be secured by the outer glass plate 1, and the visible light transmittance can be adjusted by the inner glass plate 2 so as to satisfy the safety standard. Below, an example of a composition of clear glass and an example of a heat ray absorption glass composition are shown.

(Clear glass)
SiO ₂ : 70 to 73% by mass
Al ₂ O ₃ : 0.6 to 2.4% by mass
CaO: 7 to 12% by mass
MgO: 1.0 to 4.5% by mass
R ₂ O: 13 to 15% by mass (R is an alkali metal)
Total iron oxide converted to Fe ₂ O ₃ (T-Fe ₂ O ₃ ): 0.08 to 0.14% by mass

(Heat ray absorbing glass)
The composition of the heat-absorbing glass, for example, based on the composition of the clear glass, the proportion of the total iron oxide in terms of _{_{Fe 2 O 3 (T-Fe}} 2 O 3) and 0.4 to 1.3 wt%, CeO The ratio of ₂ is 0 to 2% by mass, the ratio of TiO ₂ is 0 to 0.5% by mass, and the glass skeleton components (mainly SiO ₂ and Al ₂ O ₃ ) are T-Fe ₂ O ₃ , CeO. _The composition can be reduced by an increase of ₂ and TiO ₂ .

The outer glass plate 1 mainly needs durability and impact resistance against external obstacles. For example, when this laminated glass is used as a windshield of an automobile, the outer glass plate 1 has impact resistance performance against flying objects such as pebbles. is necessary. From this viewpoint, the thickness of the outer glass plate 1 is preferably 1.8 mm or more, 1.9 mm or more, 2.0 mm or more, 2.1 mm or more, or 2.2 mm or more. On the other hand, the upper limit of the thickness of the outer glass is preferably 5.0 mm or less, 4.0 mm or less, 3.1 mm or less, 2.5 mm or less, 2.4 mm or less. Among them, it is preferably larger than 2.1 mm and 2.5 mm or less, particularly preferably 2.2 mm or more and 2.4 mm or less.

On the other hand, the inner glass plate 2 needs to be thinner than the outer glass plate 1 in order to reduce the weight of the laminated glass. Specifically, as will be described later, it is preferably in the range of 1.2 mm ± 0.6 mm, which is easily affected by the frequency range of 2000 to 5000 Hz that is easy for humans to hear. Specifically, the thickness of the inner glass plate 2 is preferably 0.6 mm or more, 0.8 mm or more, 1.0 mm or more, and 1.3 mm or more. On the other hand, the upper limit of the thickness of the inner glass plate 2 is preferable in the order of 1.8 mm or less, 1.6 mm or less, 1.4 mm or less, 1.3 mm or less, and less than 1.1 mm. Among these, for example, 0.6 mm or more and less than 1.1 mm is preferable.

Further, the shape of the outer glass plate 1 and the inner glass plate 2 according to the present embodiment may be either a planar shape or a curved shape. However, since the curved shape of the STL is lowered, the curved glass particularly requires an acoustic measure. The reason why the STL value is lower in the curved shape than in the planar shape is that the curved shape is more influenced by the resonance mode.

Furthermore, when the glass has a curved shape, the sound insulation performance decreases as the amount of double increases. The double amount is an amount indicating the bending of the glass plate. For example, when a straight line L connecting the center of the upper side and the center of the lower side is set as shown in FIG. The largest distance between and is defined as the amount of double.

FIG. 3 is a graph showing a result of simulating a general frequency and STL relationship between a curved glass plate and a planar glass plate. According to FIG. 3, the curved glass plate has no significant difference in STL in the range of the doubly amount of 30 to 38 mm, but the STL decreases in a frequency range of 4000 Hz or less compared to the planar glass plate. I understand that Therefore, when producing a curved glass plate, the amount of double is better, but for example, when the amount of double exceeds 30 mm, the Young's modulus of the core layer of the intermediate film is 20 MPa (frequency) as will be described later. 100 Hz, temperature 20 ° C.) or less.

Here, an example of a method for measuring the thickness when the glass plate is curved will be described. First, about a measurement position, as shown in FIG. 4, it is two places up and down on the center line S extended in the up-down direction at the center of the left-right direction of a glass plate. The measuring instrument is not particularly limited, and for example, a thickness gauge such as SM-112 manufactured by Teclock Co., Ltd. can be used. At the time of measurement, it is arranged so that the curved surface of the glass plate is placed on a flat surface, and the end of the glass plate is sandwiched by the thickness gauge and measured. Even when the glass plate is flat, it can be measured in the same manner as when the glass plate is curved.

<2. Interlayer>
The intermediate film 3 is formed of a plurality of layers, and as an example, as shown in FIG. 1, a soft core layer 31 can be configured by three layers sandwiched by a harder outer layer 32. . However, it is not limited to this configuration, and it may be formed of a plurality of layers having the soft core layer 31. For example, two layers including the core layer 31 (one core layer and one outer layer), or an odd number of five or more layers arranged around the core layer 31 (one core layer and one outer layer) 4 layers), or an even number of layers including the core layer 31 inside (the core layer is one layer and the other layers are outer layers).

The core layer 31 is softer than the outer layer 32, but in this respect, the material can be selected based on the Young's modulus. Specifically, it is preferably 1 to 20 MPa, more preferably 1 to 16 MPa at a frequency of 100 Hz and a temperature of 20 degrees. Further, it is preferably 1 to 10 MPa. As a measuring method, for example, frequency dispersion measurement can be performed with a strain amount of 0.05% using a solid viscoelasticity measuring device DMA-50 manufactured by Metravib. Hereinafter, unless otherwise specified, in this specification, the Young's modulus is a value measured by the above method. However, the measurement when the frequency is 200 Hz or less uses an actual measurement value. When the frequency is higher than 200 Hz, a calculation value based on the actual measurement value is used. The calculated value is based on a master curve calculated by using the WLF method from the actually measured value.

On the other hand, the Young's modulus of the outer layer 32 is not particularly limited as long as it is larger than the core layer. For example, it is preferable in the order of 560 MPa or more, 650 MPa or more, 1300 MPa or more, 1764 MPa or more at a frequency of 100 Hz and a temperature of 20 degrees. On the other hand, the upper limit of the Young's modulus of the outer layer 32 is not particularly limited, but can be set from the viewpoint of workability, for example. For example, it is empirically known that when it becomes 1750 MPa or more, workability, particularly cutting becomes difficult. Moreover, when providing a pair of outer layer 32 which pinches | interposes the core layer 31, it is preferable to make the Young's modulus of the outer layer 32 by the side of the outer side glass plate 1 larger than the Young's modulus of the outer layer 32 by the side of the inner side glass plate 2. Thereby, the damage resistance performance with respect to the external force from the outside of a vehicle or the outdoors improves.

The tan δ of the core layer 31 of the intermediate film 3 is preferably 0.5 to 3.0, more preferably 0.7 to 2.0, and more preferably 1.0 to 1.0 at a frequency of 100 Hz and a temperature of 20 degrees. A ratio of 1.5 is particularly preferred. When tan δ is in the above range, sound is easily absorbed, and sound insulation performance is improved. However, if it exceeds 3.0, the intermediate film 3 becomes too soft and difficult to handle, which is not preferable. On the other hand, if it is less than 0.5, the impact resistance is lowered, which is not preferable.

On the other hand, tan δ of the outer layer may be a value smaller than that of the core layer 31, and can be determined between 0.1 and 3.0 at a frequency of 100 Hz and a temperature of 20 degrees, for example.

Further, the material constituting each of the

layers

31 and 32 is not particularly limited, but it is necessary that the material has at least a Young's modulus in the above range. For example, the outer layer 32 can be comprised by polyvinyl butyral resin (PVB). Polyvinyl butyral resin is preferable because it is excellent in adhesiveness and penetration resistance with each glass plate. On the other hand, the core layer 31 can be made of an ethylene vinyl acetate resin (EVA) or a polyvinyl acetal resin softer than the polyvinyl butyral resin constituting the outer layer. By sandwiching the soft core layer between them, the sound insulation performance can be greatly improved while maintaining the same adhesion and penetration resistance as the single-layer resin intermediate film.

In general, the hardness of the polyvinyl acetal resin is controlled by (a) the degree of polymerization of the starting polyvinyl alcohol, (b) the degree of acetalization, (c) the type of plasticizer, (d) the addition ratio of the plasticizer, etc. Can do. Therefore, by appropriately adjusting at least one selected from these conditions, even with the same polyvinyl butyral resin, a hard polyvinyl butyral resin used for the outer layer and a soft polyvinyl butyral resin used for the core layer It can be made separately. Furthermore, the hardness of the polyvinyl acetal resin can also be controlled by the type of aldehyde used for acetalization, coacetalization with a plurality of aldehydes or pure acetalization with a single aldehyde. Although it cannot generally be said, the polyvinyl acetal resin obtained by using an aldehyde having a large number of carbon atoms tends to be softer. Therefore, for example, when the outer layer is made of polyvinyl butyral resin, the core layer has an aldehyde having 5 or more carbon atoms (for example, n-hexylaldehyde, 2-ethylbutyraldehyde, n-heptylaldehyde, n- Octyl aldehyde) can be used as a polyvinyl acetal resin obtained by acetalization with polyvinyl alcohol. In addition, when a predetermined Young's modulus is obtained, it is not limited to the said resin.

The total thickness of the intermediate film 3 is not particularly limited, but is preferably 0.3 to 6.0 mm, more preferably 0.5 to 4.0 mm, and 0.6 to 2.0 mm. It is particularly preferred. On the other hand, the thickness of the core layer 31 is preferably 0.1 to 2.0 mm, and more preferably 0.1 to 0.6 mm. This is because if the thickness is smaller than 0.1 mm, the influence of the soft core layer 31 is difficult to reach, and if the thickness is larger than 2.0 mm or 0.6 mm, the total thickness increases and the cost is increased. On the other hand, the thickness of the outer layer 32 is not particularly limited, but is preferably 0.1 to 2.0 mm, and more preferably 0.1 to 1.0 mm. In addition, the total thickness of the intermediate film 3 can be made constant, and the thickness of the core layer 31 can be adjusted therein.

The thickness of the core layer 31 can be measured as follows, for example. First, the cross section of the laminated glass is enlarged and displayed by 175 times using a microscope (for example, VH-5500 manufactured by Keyence Corporation). And the thickness of the core layer 31 is specified visually, and this is measured. At this time, in order to eliminate visual variation, the number of measurements is set to 5 times, and the average value is set as the thickness of the core layer 31. For example, an enlarged photograph of a laminated glass as shown in FIG. 5 is taken, and the core layer is specified in this and the thickness is measured.

Note that the thickness of the intermediate film 3 does not have to be constant over the entire surface, and may be a wedge shape for laminated glass used for a head-up display, for example. In this case, the thickness of the intermediate film 3 is measured at a portion having the smallest thickness, that is, the lowermost side portion of the laminated glass. When the intermediate film 3 is wedge-shaped, the outer glass plate 1 and the inner glass plate 2 are not arranged in parallel. Such an arrangement is also included in the “opposing arrangement” between the outer glass plate and the inner glass plate in the present invention. And That is, the “opposing arrangement” of the present invention includes an arrangement of the outer glass plate 1 and the inner glass plate 2 when the intermediate film 3 whose thickness is increased at a change rate of 3 mm or less per 1 m, for example.

Although the manufacturing method of the intermediate film 3 is not particularly limited, for example, after blending resin components such as the above-mentioned polyvinyl acetal resin, a plasticizer, and other additives as necessary, and uniformly kneading, each layer is collectively And a method of laminating two or more resin films prepared by this method by a pressing method, a laminating method or the like. The resin film before lamination used in a method of laminating by a press method, a laminating method or the like may have a single layer structure or a multilayer structure.

<3. Manufacturing method of laminated glass>
The manufacturing method of the laminated glass which concerns on this embodiment is not specifically limited, The manufacturing method of a conventionally well-known laminated glass can be employ | adopted. For example, first, the intermediate film 3 is sandwiched between the outer glass plate 1 and the inner glass plate 2, placed in a rubber bag, and pre-bonded at about 70 to 110 ° C. while sucking under reduced pressure. Other methods can be used for the preliminary adhesion. For example, the intermediate film 3 is sandwiched between the outer glass plate 1 and the inner glass plate 2 and heated at 45 to 65 ° C. in an oven. Subsequently, this laminated glass is pressed by a roll at 0.45 to 0.55 MPa. Next, the laminated glass is again heated at 80 to 105 ° C. in an oven and then pressed again with a roll at 0.45 to 0.55 MPa. Thus, preliminary adhesion is completed.

Next, this bonding is performed. The pre-bonded laminated glass is subjected to main bonding by an autoclave at 8 to 15 atm and 100 to 150 ° C. Specifically, the main bonding can be performed under the conditions of 14 atm and 145 ° C. Thus, the laminated glass according to the present embodiment is manufactured.

<6. Laminated glass mounting structure>
The laminated glass mentioned above can be attached to attachment structures, such as a car and a building, for example. At this time, the laminated glass is attached to the attachment structure via the attachment portion. The attachment portion corresponds to, for example, a frame such as a urethane frame for attachment to an automobile, an adhesive, a clamp, or the like. As an example of attachment to an automobile, as shown in FIG. 6A, first, pins 50 are attached to both ends of the laminated glass 10, and the adhesive 60 is applied to the automobile frame 70 to be attached. . A through hole 80 into which a pin is inserted is formed in the frame. And the laminated glass 10 is attached to the flame | frame 70 as shown in FIG.6 (b). First, the pin 50 is inserted into the through hole 80 and the laminated glass 10 is temporarily fixed to the frame 70. At this time, since a step is formed in the pin 50, the pin 50 is inserted only halfway through the through-hole 80, whereby a gap is generated between the frame 70 and the laminated glass 10. And since the adhesive material 60 mentioned above is apply | coated to this clearance gap, the laminated glass 10 and the flame | frame 70 are fixed via the adhesive material 60 with progress of time.

In the attachment of the laminated glass to the attachment structure, the attachment angle of the laminated glass 10 is preferably 45 degrees or less from the vertical N as shown in FIG.

<6. Features>
According to the present embodiment, the following effects can be obtained by setting the Young's modulus of the core layer 31 constituting a part of the intermediate film 3 to a small value of 1 to 20 MPa at a frequency of 100 Hz and a temperature of 20 degrees. . First, when the Young's modulus of the intermediate film is large, even a laminated glass has a strong property as a single plate. Moreover, as shown in the following formula, the coincidence frequency generally shifts to a higher frequency side as the thickness and Young's modulus of glass become smaller.

Considering these, for example, when the Young's modulus of the intermediate film 3 is large, even if the total thickness is 4 mm, the coincidence frequency is 3 to 4 kHz as in the case of a single plate having a thickness of 4 mm. The performance drops in a frequency band that is easy to hear. On the other hand, if the Young's modulus decreases, the performance of the laminated glass is the sum of the two glass plates. For example, if it is a laminated glass consisting of a 2 mm glass plate and a 1 mm glass plate, its performance tends to be the sum of the performances of the two glass plates. That is, since the thickness of each glass plate shown in FIG. 7 is smaller than 4 mm, the coincidence frequency shifts to the high frequency side, and the 2 mm glass plate has a coincidence frequency around 5000 Hz, and the 1 mm glass plate has a coincidence at 8000 Hz. There is a frequency. And since the performance of the laminated glass of these 1 mm and 2 mm thick glass plates is the sum of them, the coincidence frequency exists between 5000 and 8000 Hz. In addition, FIG. 7 is a graph which shows the result of having simulated the relationship between the frequency and STL of the single plate which is not a laminated glass.

Therefore, in this embodiment, the Young's modulus of the core layer 31 constituting a part of the intermediate film 3 is 1 to 20 MPa at a frequency of 100 Hz and a temperature of 20 degrees. The total is added to the glass plate 2. As a result, even if the thickness of the inner glass plate 2 is reduced to 0.4 to 2.0 mm, the sound insulation performance does not deteriorate at a frequency that is easy for humans to hear. That is, the coincidence frequency is shifted to the high frequency side by reducing the thickness of the inner glass plate 2. Therefore, as described above, it is possible to increase the sound transmission loss that is reduced in the frequency region of 2000 to 5000 Hz due to the thinning of the inner glass plate 2. As a result, it is possible to improve the sound insulation performance in the frequency range of 2000 to 5000 Hz that is easy for humans to hear, as well as reducing the weight of the laminated glass.

Further, the present inventor has found that when the Young's modulus of the outer layer 32 of the intermediate film 3 is improved, the sound insulation performance in a frequency range of about 4000 Hz or more is improved. For example, when the outer layer 32 having a Young's modulus of 560 MPa (20 ° C., 100 Hz) is used for the outer layer having a Young's modulus of 441 MPa (20 ° C., 100 Hz), the STL is 0.3 dB at a frequency of 6300 Hz. I found it to improve. In general, since it is assumed that a human can recognize a change in sound of 0.3 dB or more, by increasing the Young's modulus, a sound insulation effect that can be recognized by a human can be obtained in a high frequency range. Further, it has been found that the higher the Young's modulus of the outer layer 32, the higher the sound insulation performance. For example, when the Young's modulus is 880 MPa (20 ° C., 100 Hz) or higher, the STL is 1.0 dB or higher at a frequency of 6300 Hz. It has been found that STL is further improved when the pressure is 1300 MPa (20 ° C., 100 Hz) or higher.

On the other hand, in the low frequency range of 1000 to 3500 Hz, it is known that the STL decreases when the Young's modulus of the outer layer is improved. However, it has also been found that the decrease is small.

Hereinafter, examples of the present invention will be described. However, the present invention is not limited to the following examples.

<1. Evaluation of thickness of outer glass plate>
First, the thickness of the outer glass plate was evaluated. Here, the following seven laminated glasses were prepared. Each laminated glass includes an outer glass plate, an inner glass plate, and an intermediate film sandwiched between them. In the intermediate film, the thicknesses of the core layer and the outer layer were 0.1 mm and 0.33 mm, respectively, and the Young's modulus was 10 MPa and 441 MPa (20 ° C., 100 Hz), respectively.

The above laminated glasses were arranged at an angle of 60 degrees from the vertical, and granite having an average particle diameter of about 5 to 20 mm was collided with each laminated glass at a speed of 64 km / h. Thirty granites collided with each laminated glass, and the occurrence rate of cracks was calculated. The result is as shown in FIG. As shown in the figure, in the laminated glasses 1 to 4 having an outer glass plate thickness of 2.0 mm, the occurrence rate of cracks was 5% or less regardless of the thickness of the inner glass plate. On the other hand, in the laminated glasses 5 and 6 in which the thickness of the outer glass plate was 1.8 mm or less, the occurrence rate of cracks was 8% regardless of the thickness of the inner glass. Therefore, from the viewpoint of impact resistance against flying objects, the thickness of the outer glass plate is preferably 1.8 mm or more as described above. More preferably, it is 2.0 mm or more.

<2. Evaluation of Young's modulus of core layer>
The laminated glass which concerns on an Example and a comparative example was prepared as follows.

Each glass plate was formed of the above-described clear glass. Moreover, the intermediate film was comprised with the core layer and a pair of outer layer which clamps this. The thickness of the intermediate film was 0.76 mm, the thickness of the core layer was 0.1 mm, and the thicknesses of both outer layers were 0.33 mm. The Young's modulus of both outer layers was adjusted to 441 MPa (20 ° C., 100 Hz).

The sound transmission loss was evaluated by simulation for the above examples and comparative examples. The simulation conditions are as follows.

First, the simulation was performed using acoustic analysis software (ACTRAN, manufactured by Free Field technology). In this software, the sound transmission loss (transmitted sound pressure level / incident sound pressure level) of the laminated glass can be calculated by solving the following wave equation using the finite element method.

Next, calculation conditions will be described.
(1) Model setting Figure 9 shows the model of laminated glass used in this simulation. In this model, a laminated glass is defined in which an outer glass plate, an intermediate film, an inner glass plate, and a urethane frame are laminated in this order from the sound source side. Here, the reason why the urethane frame is added to the model is that there is a considerable influence on the calculation result of sound transmission loss due to the presence or absence of the urethane frame, and between the laminated glass and the vehicle windshield. This is because it is generally considered that a urethane frame is used and bonded.
(2) Input condition 1 (dimensions, etc.)

Note that the size of the glass plate, 800 × 500 mm, is smaller than the size used in an actual vehicle. As the glass size increases, the STL value tends to worsen because the larger the size, the larger the constrained portion and the greater the resonance mode. However, even if the glass size is different, the tendency of the relative value for each frequency, that is, the laminated glass made of glass plates with different thicknesses becomes worse in a predetermined frequency band than the laminated glass made of glass plates with the same thickness. The trend is the same.

Further, the random diffuse sound wave in Table 3 is a sound wave having a sound wave of a predetermined frequency transmitted with an incident angle in any direction with respect to the outer glass plate, and a sound source in a reverberation chamber for measuring sound transmission loss. Is assumed.
(3) Input condition 2 (property value)

[About Young's modulus and loss factor of core layer and both outer layers]
Different values were used for each main frequency. This is because the Young's modulus is strongly frequency dependent due to the viscous effect because the core layer and both outer layers are viscoelastic bodies. In addition, although the temperature dependence is large, the physical property value which assumed temperature constant (20 degreeC) was used this time.

The above simulation method is the same in the following

items

3, 4, and 5.

The results are as shown in the graph of FIG. According to this result, the STL value due to the different thickness can be suppressed by setting the Young's modulus of the core layer to 20 MPa (20 ° C., 100 Hz) or less as in Examples 1 to 4. Further, as in Examples 2 to 4, by setting the Young's modulus of the core layer to 16 MPa (20 ° C., 100 Hz) or less, compared with Comparative Example 1 in which both glasses have the same thickness, in a frequency region of 2000 to 5000 Hz. Sound transmission loss is high. Further, as in Examples 3 and 4, by setting the Young's modulus of the core layer to 10 MPa (20 ° C., 100 Hz) or less, compared with Comparative Example 1 in which both glasses have the same thickness, in a frequency region of 2000 to 5000 Hz. The sound transmission loss is clearly high. Therefore, it has been found that by making the inner glass plate thinner than the outer glass plate and setting the Young's modulus of the core layer to 20 MPa or less, the sound insulation performance in a frequency range of 2000 to 5000 Hz that is easy for humans to hear is improved.

<3. Evaluation of core layer thickness>
The laminated glass which concerns on an Example and a comparative example was prepared as follows. Here, the thickness of the core layer was changed and the sound transmission loss was calculated by the simulation method. The intermediate film was composed of three layers, and the thickness of the core layer and the outer layer was changed without changing the total thickness. The Young's modulus of the core layer was 10 MPa (20 ° C., 100 Hz), and the Young's modulus of the outer layer was 441 Mpa (20 ° C., 100 Hz). The thicknesses of the outer glass plate and the inner glass plate were 2.0 mm and 1.0 mm, respectively.

The sound transmission loss was evaluated by simulation for the above examples and comparative examples. The results are as shown in FIG. According to the figure, it can be seen that when the thickness of the core layer is smaller than 0.1 mm, the sound transmission loss is reduced in the frequency range of 2000 to 5000 Hz. Therefore, in order to increase the sound insulation performance in the frequency range of 2000 to 5000 Hz that is easy for humans to hear, the thickness of the core layer is preferably set to 0.1 mm or more.

<4. Evaluation of the mounting angle of laminated glass>
Subsequently, the mounting angle of the laminated glass was evaluated by a simulation in which the incident angle of sound was changed. Here, the sound transmission loss was calculated by changing the angle from the vertical to 0 to 75 degrees. Each glass plate was formed of the above-described clear glass. Moreover, the intermediate film was comprised with the core layer and a pair of outer layer which clamps this. The thickness of the intermediate film was 0.76 mm, the thickness of the core layer was 0.1 mm, and the thicknesses of both outer layers were 0.33 mm. The Young's modulus of the core layer was 10 MPa (20 ° C., 100 Hz), and the Young's modulus of both outer layers was 441 MPa (20 ° C., 100 Hz). Moreover, the thickness of the glass plate was 2.0 mm and 1.0 mm.

For the above examples and comparative examples, sound transmission loss was evaluated by the above simulation method. However, a simulation was performed by adding a laminated glass mounting angle as an input condition. The results are as shown in FIG. According to the figure, it can be seen that when the mounting angle exceeds 60 degrees, the sound transmission loss sharply decreases at a frequency near 3000 Hz. Therefore, it has been found that in order to increase the sound insulation performance in the frequency range of 2000 to 5000 Hz that is easy for humans to hear, it is preferable that the mounting angle of the laminated glass from the vertical is 45 degrees or less. Moreover, if it is 60 degrees or less, sound insulation performance can be improved, and sound insulation performance can be improved by setting it as 75 degrees or less depending on the case.

<5. Evaluation of Young's modulus of outer layer>
In order to evaluate the Young's modulus of the outer layer, laminated glasses according to Examples and Comparative Examples were prepared as follows. Here, the thickness of the outer glass and the inner glass was made constant, the Young's modulus of the outer layer and the core layer of the intermediate film was changed, and the sound transmission loss was calculated by the simulation method. Each glass plate was formed of the above-described clear glass, and the intermediate film was composed of a core layer and a pair of outer layers sandwiching the core layer. The thickness of the intermediate film was 0.76 mm, the thickness of the core layer was 0.1 mm, and the thicknesses of both outer layers were 0.33 mm.

The results are as follows. First, the results of Examples 13 and 14 are shown in FIG. In the evaluation of the Young's modulus of the core layer described above, it was found that when the Young's modulus is 20 MPa or less, the sound transmission loss is increased in a frequency range of 2000 to 5000 Hz that is easy for humans to hear. On the other hand, in Examples 13 and 14, the Young's modulus of the outer layer was changed while keeping the Young's modulus of the core layer constant. As a result, as shown in FIG. 13, in Example 14 where the Young's modulus of the outer layer was high, it was found that the sound transmission loss was high in a high frequency region of 5000 Hz or higher.

In Examples 15 to 18, the Young's modulus of the core layer is further lowered and the Young's modulus of the outer layer is increased. As shown in FIG. 14, in these examples, the sound transmission loss in the frequency region of 2000 to 5000 Hz is higher than those in Examples 13 and 14, but in Examples 13 and 14, the frequency is higher than 5000 Hz. The sound transmission loss in the frequency domain is not high. In particular, when the Young's modulus of the outer layer exceeds 1764 MPa, the sound transmission loss in a high frequency region of 5000 Hz or higher hardly increases.

Claims

An outer glass plate,
An inner glass plate disposed opposite to the outer glass plate and having a smaller thickness than the outer glass plate,
An intermediate film sandwiched between the outer glass plate and the inner glass plate;
With
The inner glass plate has a thickness of 0.6 to 1.8 mm;
The intermediate film is composed of a plurality of layers including at least a core layer,
The laminated glass having a Young's modulus of the core layer of 1 to 20 MPa at a frequency of 100 Hz and a temperature of 20 ° C., which is lower than the Young's modulus of the other layers.
The laminated glass according to claim 1, wherein the inner glass plate has a thickness of 0.8 to 1.6 mm.
The laminated glass according to claim 1, wherein the inner glass plate has a thickness of 1.0 to 1.4 mm.
The laminated glass according to claim 1, wherein the inner glass plate has a thickness of 0.8 to 1.3 mm.
The laminated glass according to any one of claims 1 to 4, wherein the core layer has a thickness of 0.1 to 2.0 mm.
The laminated glass according to any one of claims 1 to 5, wherein the outer glass plate has a thickness of 1.8 to 5.0 mm.
The laminated glass according to any one of claims 1 to 6, wherein the Young's modulus of the core layer is 1 to 16 MPa at a frequency of 100 Hz and a temperature of 20 ° C.
The laminated glass according to any one of claims 1 to 7, wherein the intermediate film is in contact with the core layer and has at least one outer layer of 560 MPa or more at a frequency of 100 Hz and a temperature of 20 ° C.
The laminated glass according to any one of claims 1 to 7,
An attachment structure for laminated glass, comprising: an attachment portion for attaching the laminated glass to a vertical attachment angle of 45 degrees or less.