Interlayer film for laminated glass and laminated glass

Abstract

The present invention provides an interlayer film for laminated glass that can suppress the occurrence of blisters at the ends of the laminated glass and improve the transparency of the laminated glass even without high-temperature and high-pressure treatment in an autoclave. The interlayer film for laminated glass of the present invention is an interlayer film for laminated glass having a structure of one layer or a structure of two or more layers. Among them, the interlayer film has a first layer. When a specific compression creep test is performed on test sample A with a diameter of 8 mm and a thickness of 0.8 mm obtained by cutting the first layer, the change in the thickness of test sample A before and after the compression creep test is 50 μm or more and 325 μm or less.

Description

Technical Field

[0001] The present invention relates to an interlayer film for laminated glass for obtaining laminated glass. Further, the present invention relates to laminated glass using the interlayer film for laminated glass. Background Art

[0002] Even when laminated glass is broken by an external impact, the amount of scattered glass fragments is small, and the safety performance is excellent. Therefore, the laminated glass is widely used in vehicles, railway vehicles, spacecraft, ships, buildings, and the like.

[0003] The laminated glass is generally manufactured by the following method: after sandwiching an interlayer film for laminated glass between two glass plates, high-temperature and high-pressure treatment using an autoclave is performed to press-bond the interlayer film and the glass plates (for example, Patent Document 1).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2009-190947 Summary of the Invention

[0007] Technical Problem to be Solved by the Invention

[0008] The high-temperature and high-pressure treatment using an autoclave during the manufacture of laminated glass is performed, for example, under conditions of 130°C or higher and 1 MPa or higher. However, the high-temperature and high-pressure treatment using an autoclave is a process that requires a large amount of equipment investment and is a process with a large amount of carbon dioxide emissions.

[0009] In addition, in an interlayer film having a functional film such as a light control film, when high-temperature and high-pressure treatment using an autoclave is performed, there is a case where the functional film deteriorates.

[0010] On the other hand, when manufacturing laminated glass without performing high-temperature and high-pressure treatment using an autoclave using a conventional interlayer film, there is a case where blisters occur at the ends of the laminated glass or the transparency of the laminated glass decreases.

[0011] An object of the present invention is to provide an interlayer film for laminated glass that can suppress the occurrence of blisters at the ends of the laminated glass and can improve the transparency of the laminated glass even without performing high-temperature and high-pressure treatment using an autoclave. Further, an object of the present invention is to provide laminated glass using the interlayer film for laminated glass.

[0012] Technical Means for Solving the Problem

[0013] According to a broad aspect of the present invention, there is provided an interlayer film for laminated glass, which is an interlayer film for laminated glass having a structure of one layer or a structure of two or more layers. Among them, the interlayer film has a first layer. When performing the following compression creep test on test sample A obtained by cutting the first layer, with a diameter of 8 mm and a thickness of 0.8 mm, the change amount of the thickness of test sample A before and after the compression creep test is 50 μm or more and 325 μm or less (in this specification, the "interlayer film for laminated glass" is sometimes abbreviated as "interlayer film").

[0014] Compression creep test: In a state where a load of 410 g is applied to test sample A, the temperature is raised from 30 °C to 90 °C at a rate of 6 °C per minute and held at 90 °C for 5 minutes. The absolute value of the difference between the thickness of test sample A at 30 °C just after holding for 5 minutes before starting the compression creep test and the thickness of test sample A at 90 °C just after holding for 5 minutes at the end of the compression creep test is set as the change amount of the thickness of test sample A before and after the compression creep test.

[0015] According to a broad aspect of the present invention, there is provided an interlayer film for laminated glass, which is an interlayer film for laminated glass having a structure of one layer or a structure of two or more layers. Among them, the interlayer film has a first layer with a thickness of 200 μm or more and 900 μm or less. Let the thickness of the first layer be T B μm. When performing the following compression creep test on test sample B obtained by cutting the first layer, with a diameter of 8 mm and a thickness of T B μm, the change amount of the thickness of test sample B before and after the compression creep test is 50 μm or more and 325 μm or less (in this specification, the "interlayer film for laminated glass" is sometimes abbreviated as "interlayer film").

[0016] Compression creep test: In a state where a load of 410 g is applied to test sample B, the temperature is raised from 30 °C to 90 °C at a rate of 6 °C per minute and held at 90 °C for 5 minutes. The absolute value of the difference between the thickness of test sample B at 30 °C just after holding for 30 minutes before starting the compression creep test and the thickness of test sample B at 90 °C just after holding for 5 minutes at the end of the compression creep test is set as the change amount of the thickness of test sample B before and after the compression creep test.

[0017] According to a broad aspect of the present invention, there is provided an interlayer film for laminated glass, which is an interlayer film for laminated glass having a structure of one layer or a structure of two or more layers. Among them, the interlayer film has a first layer. The thickness of the interlayer film is 80 μm or more and 1600 μm or less. Let the thickness of the interlayer film be T C μm. For test sample obtained by cutting the interlayer film, with a diameter of 8 mm and a thickness of T CWhen a test sample C with a thickness of [[μm]] is subjected to the following compression creep test, the change in the thickness of the test sample C before and after the compression creep test is 50 [[μm]] or more and 325 [[μm]] or less (in this specification, the "interlayer film for laminated glass" may sometimes be abbreviated as the "interlayer film").

[0018] Compression creep test: In a state where a load of 410 g is applied to the test sample C, the temperature is raised from 30 °C to 90 °C at a rate of 6 °C per minute, and held at 90 °C for 5 minutes. The absolute value of the difference between the thickness of the test sample C at 30 °C at the start of the compression creep test and the thickness of the test sample C just after holding at 90 °C for 5 minutes at the end of the compression creep test is defined as the change in the thickness of the test sample C before and after the compression creep test.

[0019] In a specific embodiment of the interlayer film of the present invention, the first layer contains a thermoplastic resin and a plasticizer.

[0020] In a specific embodiment of the interlayer film of the present invention, the thermoplastic resin contained in the first layer is a polyvinyl acetal resin.

[0021] In a specific embodiment of the interlayer film of the present invention, the interlayer film has a structure of two or more layers, and the interlayer film further includes a second layer, and the second layer is disposed on the first surface side of the first layer.

[0022] In a specific embodiment of the interlayer film of the present invention, the first layer is the surface layer of the interlayer film.

[0023] According to a broad embodiment of the present invention, there is provided a laminated glass including a first laminated glass component, a second laminated glass component, and the interlayer film for laminated glass, and the interlayer film for laminated glass is disposed between the first laminated glass component and the second laminated glass component.

[0024] Effects of the Invention

[0025] The interlayer film of the present invention has a structure of one layer or two or more layers. The interlayer film of the present invention includes a first layer. In the interlayer film of the present invention, when the test sample A with a diameter of 8 mm and a thickness of 0.8 mm obtained by cutting the first layer is subjected to the above compression creep test, the change in the thickness of the test sample A before and after the compression creep test is 50 [[μm]] or more and 325 [[μm]] or less. In the interlayer film of the present invention, due to the above configuration, even without high-temperature and high-pressure treatment using an autoclave, the occurrence of blisters at the ends of the laminated glass can be suppressed, and the transparency of the laminated glass can be improved.

[0026] The interlayer film of the present invention has a structure of 1 layer or a structure of 2 or more layers. The interlayer film of the present invention has a first layer with a thickness of 200 μm or more and 900 μm or less. In the interlayer film of the present invention, the thickness of the first layer is set to T B μm. For the test sample B with a diameter of 8 mm and a thickness of T B μm obtained by cutting the first layer, when the above-mentioned compression creep test is performed, the change amount of the thickness of the test sample B before and after the compression creep test is 50 μm or more and 325 μm or less. In the interlayer film of the present invention, due to the above-mentioned constitution, even without the high-temperature and high-pressure treatment based on an autoclave, the occurrence of blisters at the end of the laminated glass can be suppressed, and the transparency of the laminated glass can be improved.

[0027] The interlayer film of the present invention has a structure of 1 layer or a structure of 2 or more layers. The interlayer film of the present invention has a first layer. In the interlayer film of the present invention, the thickness of the interlayer film is 80 μm or more and 1600 μm or less. In the interlayer film of the present invention, the thickness of the interlayer film is set to T C μm. For the test sample C with a diameter of 8 mm and a thickness of T C μm obtained by cutting the interlayer film, when the above-mentioned compression creep test is performed, the change amount of the thickness of the test sample C before and after the compression creep test is 50 μm or more and 325 μm or less. In the interlayer film of the present invention, due to the above-mentioned constitution, even without the high-temperature and high-pressure treatment based on an autoclave, the occurrence of blisters at the end of the laminated glass can be suppressed, and the transparency of the laminated glass can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Figure 1 is a cross-sectional view schematically showing the interlayer film for laminated glass according to the first embodiment of the present invention.

[0029] Figure 2 Figure 2 is a cross-sectional view schematically showing the interlayer film for laminated glass according to the second embodiment of the present invention.

[0030] Figure 3 Figure 3 is a cross-sectional view schematically showing the interlayer film for laminated glass according to the third embodiment of the present invention.

[0031] Figure 4 Figure 4 is schematically showing an example of a cross-sectional view of a laminated glass using the Figure 1 interlayer film for laminated glass shown.

[0032] Figure 5 Figure 5 ​​​​​​​​​​(a) to (e) are examples of photographed images for evaluating blisters in the end portion of laminated glass.

[0033] Figure 6 Figure 5 (a) to (e) are examples of photographed images for evaluating the transparency of laminated glass. Detailed implementation mode

[0034] Hereinafter, the detailed content of the present invention will be described.

[0035] (Interlayer film for laminated glass)

[0036] The interlayer film for laminated glass of the present invention (hereinafter sometimes simply referred to as "interlayer film") has a structure of 1 layer or a structure of 2 or more layers. The interlayer film of the present invention includes a first layer. In the interlayer film of the present invention, when a compression creep test is performed on test sample A having a diameter of 8 mm and a thickness of 0.8 mm obtained by cutting the first layer, the change amount of the thickness of test sample A before and after the compression creep test is 50 μm or more and 325 μm or less.

[0037] Compression creep test: In a state where a load of 410 g is applied to test sample A, the temperature is raised from 30 °C to 90 °C at 6 °C per minute, held at 90 °C for 5 minutes, and the absolute value of the difference between the thickness of test sample A at 30 °C just after holding for 5 minutes at 30 °C before starting the compression creep test and the thickness of test sample A at 90 °C just after holding for 5 minutes at 90 °C at the end of the compression creep test is defined as the change amount of the thickness of test sample A before and after the compression creep test.

[0038] Specifically, in an environment of 30 °C, a load of 410 g is applied to test sample A, and in a state where this load is applied, it is held at 30 °C for 5 minutes, and the thickness of test sample A at 30 °C just after holding for 5 minutes at 30 °C is measured. In addition, in an environment of 30 °C, a load of 410 g is applied to test sample A, and in a state where this load is applied, it is held at 30 °C for 5 minutes, then the temperature is raised from 30 °C to 90 °C at 6 °C per minute, and then held at 90 °C for 5 minutes, and the thickness of test sample A at 90 °C just after holding for 5 minutes at 90 °C is measured. A load of 410 g is applied to test sample A, and the thickness is measured in a state where the load is applied until the thickness of test sample A at 90 °C just after holding for 5 minutes at 90 °C is measured.

[0039] The interlayer film for laminated glass of the present invention (hereinafter sometimes simply referred to as "interlayer film") has a structure of 1 layer or a structure of 2 or more layers. The first layer of the interlayer film of the present invention has a thickness of 200 μm or more and 900 μm or less. In the interlayer film of the present invention, the thickness of the first layer is set as T B ​​μm, for a test sample B with a diameter of 8 mm and a thickness of T obtained by cutting the first layer B μm, when the following compression creep test is performed on the test sample B, the change in the thickness of the test sample B before and after the compression creep test is 50 μm or more and 325 μm or less.

[0040] Compression creep test: In a state where a load of 410 g is applied to the test sample B, the temperature is raised from 30°C to 90°C at 6°C / minute, held at 90°C for 5 minutes, and the absolute value of the difference between the thickness of the test sample B at 30°C just after holding for 30 minutes before the start of the compression creep test and the thickness of the test sample B at 90°C just after holding for 5 minutes at the end of the compression creep test is defined as the change in the thickness of the test sample B before and after the compression creep test.

[0041] Specifically, in an environment of 30°C, a load of 410 g is applied to the test sample B, and in the state where this load is applied, it is held at 30°C for 30 minutes, and the thickness of the test sample B at 30°C just after holding for 30 minutes is measured. In addition, in an environment of 30°C, a load of 410 g is applied to the test sample B, and in the state where this load is applied, it is held at 30°C for 30 minutes, then the temperature is raised from 30°C to 90°C at 6°C / minute, and then held at 90°C for 5 minutes, and the thickness of the test sample B at 90°C just after holding for 5 minutes is measured. A load of 410 g is applied to the test sample B, and the thickness is measured in the state where the load is applied until the thickness of the test sample B at 90°C just after holding for 5 minutes is measured.

[0042] The interlayer film for laminated glass of the present invention (hereinafter, sometimes simply referred to as "interlayer film") has a structure of 1 layer or a structure of 2 or more layers. The interlayer film of the present invention includes a first layer. In the interlayer film of the present invention, the thickness of the interlayer film is 80 μm or more and 1600 μm or less. In the interlayer film of the present invention, the thickness of the interlayer film is set to T C μm, for a test sample C with a diameter of 8 mm and a thickness of T obtained by cutting the interlayer film C μm, when the following compression creep test is performed on the test sample C, the change in the thickness of the test sample C before and after the compression creep test is 50 μm or more and 325 μm or less.

[0043] Compression creep test: In a state where a load of 410 g is applied to the test sample C, the temperature is raised from 30°C to 90°C at 6°C / minute, held at 90°C for 5 minutes, and the absolute value of the difference between the thickness of the test sample C at 30°C at the start of the compression creep test and the thickness of the test sample C at 90°C just after holding for 5 minutes at the end of the compression creep test is defined as the change in the thickness of the test sample C before and after the compression creep test.

[0044] Specifically, a load of 410 g was applied to test sample C in an environment of 30°C, and the thickness of test sample C at 30°C just after applying this load was measured. In addition, a load of 410 g was applied to test sample C in an environment of 30°C. In the state where this load was applied, immediately after applying the load, the temperature was raised from 30°C to 90°C at 6°C per minute, and then held at 90°C for 5 minutes. The thickness of test sample C at 90°C just after holding for 5 minutes at 90°C was measured. A load of 410 g was applied to test sample C, and the thickness was measured in the state where the load was applied until the thickness of test sample C at 90°C just after holding for 5 minutes at 90°C was measured.

[0045] In the interlayer film of the present invention, due to having the above-described configuration, even without performing high-temperature and high-pressure treatment using an autoclave, the occurrence of blisters at the ends of laminated glass can be suppressed, and the transparency of laminated glass can be improved.

[0046] In the interlayer film of the present invention, compared with high-temperature and high-pressure treatment using an autoclave, laminated glass can be manufactured under conditions of low temperature and low pressure (for example, 100°C or lower and 0.5 MPa or lower). Therefore, laminated glass can be manufactured without a large amount of equipment investment in equipment such as autoclaves, and the amount of carbon dioxide emissions during the manufacture of laminated glass can be reduced. In addition, the production capacity based on the conventional method for manufacturing laminated glass by performing autoclave treatment can be maintained.

[0047] In addition, in the case of the interlayer film of the present invention, the penetration resistance of laminated glass can be improved.

[0048] The interlayer film of the present invention has a structure of one layer or a structure of two or more layers. The interlayer film of the present invention may have a structure of one layer, may have a structure of two layers, may have a structure of two or more layers, may have a structure of three layers, may have a structure of three or more layers, may have a structure of four or more layers. The interlayer film of the present invention has a first layer. The interlayer film of the present invention may be a single-layer interlayer film having only the first layer, or may be a multi-layer interlayer film having the first layer and other layers.

[0049] The interlayer film may have a structure of two or more layers, and may have a second layer in addition to the first layer. In the case where the interlayer film has the second layer, the second layer is disposed on the first surface side of the first layer.

[0050] In the case where the interlayer film is a multi-layer interlayer film having a structure of two or more layers, the interlayer film has a first surface layer and a second surface layer.

[0051] In the intermediate film, it is preferable to have the first layer as the surface layer in the intermediate film. The first layer is preferably the surface layer of the intermediate film. In the intermediate film, it is preferable to have the first layer as the first surface layer, and more preferably to have the first layer as the first surface layer and the second surface layer. In this case, the effects of the present invention can be further effectively exerted. It should be noted that in the case where the intermediate film is a single-layer intermediate film having only the first layer, the first layer is the surface layer.

[0052] The intermediate film may have a structure of three or more layers, and a third layer may be provided in addition to the first layer and the second layer. When the intermediate film has the third layer, the third layer is disposed on the surface side of the second layer opposite to the first layer.

[0053] Hereinafter, the compression creep test performed in the present invention will be described in more detail.

[0054] Test sample A is a test sample having a diameter of 8 mm and a thickness of 0.8 mm obtained by cutting the first layer. The test sample A can be prepared by the following method: after peeling the layer to be measured (the first layer) from the intermediate film, it is compression molded at 150 °C. The test sample A is prepared for the compression creep test.

[0055] Test sample B is prepared using the first layer having a thickness of 200 μm or more and 900 μm or less. When the thickness of the first layer is set to T B μm, test sample B is a test sample having a diameter of 8 mm and a thickness of T B μm obtained by cutting the first layer. Therefore, the thickness of the first layer is the same as the thickness of the test sample B.

[0056] Test sample C is prepared using an intermediate film having a thickness of 80 μm or more and 1600 μm or less. When the thickness of the intermediate film is set to T C μm, test sample C is a test sample having a diameter of 8 mm and a thickness of T C μm obtained by cutting the intermediate film. Therefore, the thickness of the intermediate film is the same as the thickness of the test sample C.

[0057] In the compression creep test, test samples A, B, and C are arranged between a first jig having a circular surface with a diameter of 8 mm and a second jig having a circular surface with a diameter of 8 mm. While applying a load of 410 g in the thickness direction of test samples A, B, and C, the temperature is raised from 30°C to 90°C at a rate of 6°C per minute, held at 90°C for 5 minutes, and the absolute value of the difference between the thicknesses of test samples A, B, and C at 30°C, which had been held at 30°C for 5 minutes or 30 minutes immediately before the start of the compression creep test, and the thicknesses of test samples A, B, and C at 90°C, which had been held at 90°C for 5 minutes immediately after the end of the compression creep test, is defined as the change in the thicknesses of test samples A, B, and C before and after the compression creep test. It should be noted that generally, the thicknesses of test samples A, B, and C after the compression creep test are less than the thicknesses of test samples A, B, and C before the compression creep test.

[0058] As a device that can be used in the compression creep test, for example, a viscoelasticity measuring device (such as "RSA-G2" manufactured by T·A·INSTRUMENTS) can be cited. In addition, the thicknesses of test samples A, B, and C before and after the compression test can be measured by monitoring the gap between the compression measurement jigs of the viscoelasticity measuring device. When using RSA-G2, the measurement can be carried out by setting the sensor mode to a spring.

[0059] In the intermediate film, when the compression creep test is performed on test sample A, the change in the thickness of test sample A before and after the compression creep test is 50 μm or more and 325 μm or less. When the change amount is less than 50 μm, the transparency of the laminated glass tends to decrease. When the change amount exceeds 325 μm, bubbles are likely to occur at the ends of the laminated glass.

[0060] The change in the thickness of test sample A before and after the compression creep test is preferably 75 μm or more, more preferably 100 μm or more, preferably 300 μm or less, and more preferably 250 μm or less. When the change amount is above the lower limit, the transparency of the laminated glass can be further improved. When the change amount is below the upper limit, the occurrence of bubbles at the ends of the laminated glass can be further effectively suppressed.

[0061] In the intermediate film, when the compression creep test is performed on test sample B, the change in the thickness of test sample B before and after the compression creep test is 50 μm or more and 325 μm or less. When the change amount is less than 50 μm, the transparency of the laminated glass tends to decrease. When the change amount exceeds 325 μm, bubbles are likely to occur at the ends of the laminated glass.

[0062] The change in the thickness of test sample B before and after the compression creep test is preferably 75 μm or more, more preferably 100 μm or more, preferably 300 μm or less, and more preferably 250 μm or less. When the change is above the lower limit, the transparency of the laminated glass can be further improved. When the change is below the upper limit, the occurrence of blisters at the ends of the laminated glass can be further effectively suppressed.

[0063] In the interlayer film, when the compression creep test is performed on test sample C, the change in the thickness of test sample C before and after the compression creep test is 50 μm or more and 325 μm or less. When the change is less than 50 μm, the transparency of the laminated glass tends to decrease. When the change exceeds 325 μm, blisters tend to occur at the ends of the laminated glass.

[0064] The change in the thickness of test sample C before and after the compression creep test is preferably 75 μm or more, more preferably 100 μm or more, preferably 300 μm or less, and more preferably 250 μm or less. When the change is above the lower limit, the transparency of the laminated glass can be further improved. When the change is below the upper limit, the occurrence of blisters at the ends of the laminated glass can be further effectively suppressed.

[0065] It should be noted that as a method for controlling the change in the thickness of test samples A, B, and C before and after the compression creep test within the preferred range, the following methods can be cited. (1) When the average degree of polymerization of the thermoplastic resin contained in the first layer or the interlayer film increases, the change becomes smaller. (2) When the content of the plasticizer contained in the first layer or the interlayer film increases, the change becomes larger. (3) When the hydrogen bond force of the resin contained in the first layer or the interlayer film becomes stronger, the change becomes smaller. By appropriately combining these methods, the change can be controlled within the preferred range.

[0066] Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0067] Figure 1 It is a cross-sectional view schematically showing the interlayer film for laminated glass according to the first embodiment of the present invention.

[0068] Figure 1The intermediate film 11 shown is a multilayer intermediate film having a structure of two or more layers. The intermediate film 11 is used to obtain laminated glass. The intermediate film 11 is an intermediate film for laminated glass. The intermediate film 11 includes a first surface layer 1, an intermediate layer 3, and a second surface layer 2. The intermediate film 11 has a three-layer structure. The intermediate layer 3 is disposed and laminated on the first surface 1a of the first surface layer 1. The intermediate layer 3 is disposed and laminated on the first surface 2a of the second surface layer 2. The first surface layer 1 and the second surface layer 2 are each the first layer. The second layer, which is the intermediate layer 3, is disposed on the first surface side of the first layer, which is the surface layer. The intermediate layer 3 is disposed and sandwiched between the first surface layer 1 and the second surface layer 2. Therefore, the intermediate film 11 has a multilayer structure (first layer / second layer / first layer) formed by laminating the first layer, the second layer, and the first layer in this order. In this case, the two first layers can be distinguished and referred to as the first layer A and the first layer B.

[0069] Figure 2 It is a cross-sectional view schematically showing the intermediate film for laminated glass according to the second embodiment of the present invention.

[0070] Figure 2 The intermediate film 11A shown is a single-layer intermediate film having a one-layer structure. The intermediate film 11A is the first layer. The intermediate film 11A is used to obtain laminated glass. The intermediate film 11A is an intermediate film for laminated glass.

[0071] Figure 3 It is a cross-sectional view schematically showing the intermediate film for laminated glass according to the third embodiment of the present invention.

[0072] Figure 3The intermediate film 11B shown is a multilayer intermediate film having a structure of two or more layers. The intermediate film 11B is used to obtain laminated glass. The intermediate film 11B is an intermediate film for laminated glass. The intermediate film 11B includes a first surface layer 1B, a second intermediate layer 4B, a first intermediate layer 3B, a third intermediate layer 5B, and a second surface layer 2B. The intermediate film 11B has a five-layer structure. The second intermediate layer 4B is disposed and laminated on the first surface 1Ba of the first surface layer 1B. The third intermediate layer 5B is disposed and laminated on the first surface 2Ba of the second surface layer 2B. The first surface layer 1B and the second surface layer 2B are each the first layer. A second layer, which is the second intermediate layer 4B, is disposed on the first surface 1Ba side of the first layer, which is the first surface layer 1B. A third layer, which is the third intermediate layer 5B, is disposed on the first surface 2Ba side of the first layer, which is the second surface layer 2B. A functional film, which is a light control film in the present embodiment, is disposed and sandwiched between the second intermediate layer 4B and the third intermediate layer 5B. Therefore, the intermediate film 11B has a multilayer structure (first layer / second layer / functional film / third layer / first layer) formed by laminating the first layer, the second layer, the functional film, the third layer, and the first layer in this order. In this case, the two first layers can be distinguished and referred to as the first layer A and the first layer B.

[0073] The glass transition temperature of the first layer or the surface layer is preferably 20°C or higher, more preferably 25°C or higher, further preferably 30°C or higher, preferably 45°C or lower, more preferably 40°C or lower, and further preferably 35°C or lower. When the glass transition temperature of the first layer or the surface layer is above the lower limit and below the upper limit, the effects of the present invention can be further effectively exerted. In addition, when the glass transition temperature of the first layer or the surface layer is below the upper limit, the penetration resistance of the laminated glass can be further improved.

[0074] The softening point of the first layer or the surface layer is preferably 45°C or higher, more preferably 50°C or higher, preferably 70°C or lower, and more preferably 65°C or lower. When the softening point of the first layer or the surface layer is above the lower limit and below the upper limit, the effects of the present invention can be further effectively exerted. In addition, when the softening point of the first layer or the surface layer is below the upper limit, the penetration resistance of the laminated glass can be further improved.

[0075] The glass transition temperature and the softening point can be obtained by viscoelasticity measurement. The viscoelasticity measurement is specifically carried out in the following manner.

[0076] The test piece was stored for 12 hours in an environment of 23 ± 2°C at room temperature and 25 ± 5% humidity. Then, using a viscoelasticity measuring device "ARES-G2" manufactured by TA INSTRUMENTS, the viscoelasticity was measured. A parallel plate with a diameter of 8 mm was used as the fixture, and the measurement was carried out in shear mode under the conditions of a temperature decrease rate of 3°C / minute from 100°C to -20°C and conditions of a frequency of 1 Hz and a strain of 1%. In the obtained measurement results, the peak temperature of the loss tangent was set as the glass transition temperature Tg (°C). The temperature at which the value of the loss tangent becomes the minimum in the temperature region between Tg (°C) and 100°C was set as the softening point.

[0077] The viscoelasticity can be measured using the intermediate film itself. In this case, the peak of tanδ derived from the first layer can be read according to the measurement results. For an intermediate film having a structure of two or more layers, the layers can be peeled off from each other, and the glass transition temperature of the layer to be measured can be measured. In addition, in the case of laminated glass, after cooling the laminated glass with liquid nitrogen or the like, the laminated glass component can be peeled off from the intermediate film, and the viscoelasticity can be measured using the peeled intermediate film.

[0078] Hereinafter, the intermediate film, the first layer, the second layer, the third layer of the present invention, and the details of each component used in the intermediate film will be described in detail.

[0079] (Thermoplastic resin)

[0080] The intermediate film preferably contains a thermoplastic resin (hereinafter, sometimes referred to as thermoplastic resin (0)). Examples of the thermoplastic resin include polyvinyl acetate resin, polyester resin, polyvinyl acetal resin, vinyl acetate resin, polystyrene resin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic copolymer resin, polyurethane resin, ionomer resin, polyvinyl alcohol resin, polyolefin resins such as aliphatic polyolefins, and (meth)acrylic resins (polymers having a (meth)acryloyl group). It should be noted that polyoxymethylene (or polyacetal) resin is included in polyvinyl acetal resin. As the thermoplastic resin, thermoplastic resins other than these can be used. The thermoplastic resin can be a thermoplastic elastomer.

[0081] The intermediate film preferably contains a polyvinyl acetal resin (hereinafter sometimes referred to as polyvinyl acetal resin (0)) as the thermoplastic resin (0). The thermoplastic resin (0) contained in the intermediate film is preferably a polyvinyl acetal resin (0). The first layer (including a single-layer intermediate film) preferably contains a thermoplastic resin (hereinafter sometimes referred to as thermoplastic resin (1)). In the first layer, as the thermoplastic resin (1), a polyvinyl acetal resin (hereinafter sometimes referred to as polyvinyl acetal resin (1)) is preferably contained. The thermoplastic resin (1) contained in the first layer is preferably a polyvinyl acetal resin (1). In the second layer, a thermoplastic resin (hereinafter sometimes referred to as thermoplastic resin (2)) is preferably contained. In the second layer, as the thermoplastic resin (2), a polyvinyl acetal resin (hereinafter sometimes referred to as polyvinyl acetal resin (2)) or a polyester resin is preferably contained. The thermoplastic resin (2) contained in the second layer is preferably a polyvinyl acetal resin (2) or a polyester resin. In the third layer, a thermoplastic resin (hereinafter sometimes referred to as thermoplastic resin (3)) or a polyester resin is preferably contained. In the third layer, as the thermoplastic resin (3), a polyvinyl acetal resin (hereinafter sometimes referred to as polyvinyl acetal resin (3)) or a polyester resin is preferably contained. The thermoplastic resin (3) contained in the third layer is preferably a polyvinyl acetal resin (3) or a polyester resin. The thermoplastic resin (1), the thermoplastic resin (2), and the thermoplastic resin (3) may be the same or different. From the viewpoint of further improving the sound insulation property, the thermoplastic resin (1) is preferably different from the thermoplastic resin (2) and the thermoplastic resin (3). The polyvinyl acetal resin (1), the polyvinyl acetal resin (2), and the polyvinyl acetal resin (3) may be the same or different. From the viewpoint of further improving the sound insulation property, the polyvinyl acetal resin (1) is preferably different from the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3). Each of the thermoplastic resin (0), the thermoplastic resin (1), the thermoplastic resin (2), and the thermoplastic resin (3) may be used alone or two or more thereof may be used in combination. Each of the polyvinyl acetal resin (0), the polyvinyl acetal resin (1), the polyvinyl acetal resin (2), and the polyvinyl acetal resin (3) may be used alone or two or more thereof may be used in combination.

[0082] The polyvinyl acetal resin can be produced, for example, by acetalizing polyvinyl alcohol (PVA) with an aldehyde. The polyvinyl acetal resin is preferably an acetalized product of polyvinyl alcohol. The polyvinyl alcohol is obtained, for example, by saponifying polyvinyl acetate. The saponification degree of the polyvinyl alcohol is generally in the range of 70 mol% to 99.9 mol%.

[0083] The average degree of polymerization of the polyvinyl alcohol (PVA) is preferably 200 or more, more preferably 500 or more, further preferably 1500 or more, further preferably 1600 or more, particularly preferably 2600 or more, most preferably 2700 or more, and preferably 5000 or less, more preferably 4000 or less, further preferably 3500 or less. When the average degree of polymerization is at or above the lower limit, the penetration resistance of the laminated glass is further improved. When the average degree of polymerization is at or below the upper limit, the molding of the interlayer film becomes easier.

[0084] The average degree of polymerization of the polyvinyl alcohol is determined by the method based on JIS K6726 "Test Methods for Polyvinyl Alcohol".

[0085] The polyvinyl acetal resin (1) may be a mixture of two or more polyvinyl acetal resins having different average degrees of polymerization of polyvinyl alcohol. In this case, the polyvinyl acetal resin (1) is preferably a mixture of a first polyvinyl acetal resin (1A) having an average degree of polymerization of polyvinyl alcohol of 1500 or more and a second polyvinyl acetal resin (1B) having an average degree of polymerization of polyvinyl alcohol of 1000 or less.

[0086] The average degree of polymerization of the polyvinyl alcohol of the polyvinyl acetal resin (1) is preferably 900 or more, more preferably 1000 or more, preferably 1400 or less, more preferably 1300 or less.

[0087] The average degree of polymerization of the polyvinyl alcohol of the first polyvinyl acetal resin (1A) is preferably 1500 or more, more preferably 1600 or more, preferably 2000 or less, more preferably 1800 or less.

[0088] The average degree of polymerization of the polyvinyl alcohol of the second polyvinyl acetal resin (1B) is preferably 400 or more, more preferably 500 or more, preferably 1000 or less, more preferably 900 or less.

[0089] When using a mixture of two or more polyvinyl acetal resins (1A) and (1B) having different average degrees of polymerization of polyvinyl alcohol, the absolute value of the difference in the average degree of polymerization is preferably 500 or more, more preferably 600 or more, preferably 1200 or less, more preferably 1100 or less.

[0090] In 100% by weight in total of the first polyvinyl acetal resin (1A) and the second polyvinyl acetal resin (1B), the content of the second polyvinyl acetal resin (1B) is preferably 20% by weight or more, more preferably 25% by weight or more, preferably 80% by weight or less, and more preferably 75% by weight or less. When the content of the second polyvinyl acetal resin (1B) is within the above lower limit and the above upper limit, the effects of the present invention can be further effectively exerted.

[0091] The number of carbon atoms of the acetal group contained in the polyvinyl acetal resin is not particularly limited. The aldehyde used in the production of the polyvinyl acetal resin is not particularly limited. The number of carbon atoms of the acetal group in the polyvinyl acetal resin is preferably 3 to 5, and more preferably 3 or 4. When the number of carbon atoms of the acetal group in the polyvinyl acetal resin is 3 or more, the glass transition temperature of the intermediate film becomes sufficiently low. The number of carbon atoms of the acetal group in the polyvinyl acetal resin may be 4 or 5.

[0092] The aldehyde is not particularly limited. Generally, an aldehyde having 1 to 10 carbon atoms is preferably used. Examples of the aldehyde having 1 to 10 carbon atoms include propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexanal, n-octanal, n-nonanal, n-decanal, formaldehyde, acetaldehyde, and benzaldehyde. The aldehyde is preferably propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-hexanal or n-valeraldehyde, more preferably propionaldehyde, n-butyraldehyde or isobutyraldehyde, and further preferably n-butyraldehyde. The aldehyde may be used alone or in combination of two or more.

[0093] In the interlayer film, it is preferable to contain polyvinyl butyral resin as a thermoplastic resin (0). In the interlayer film, it is preferable to contain polyvinyl butyral resin as a polyvinyl acetal resin (0). The thermoplastic resin (0) contained in the interlayer film is preferably polyvinyl butyral resin. In the first layer, it is preferable to contain polyvinyl butyral resin as a thermoplastic resin (1). In the first layer, it is preferable to contain polyvinyl butyral resin as a polyvinyl acetal resin (1). The thermoplastic resin (1) contained in the first layer is preferably polyvinyl butyral resin. In the second layer, it is preferable to contain polyvinyl butyral resin as a thermoplastic resin (2). In the second layer, it is preferable to contain polyvinyl butyral resin as a polyvinyl acetal resin (2). The thermoplastic resin (2) contained in the second layer is preferably polyvinyl butyral resin. In the third layer, it is preferable to contain polyvinyl butyral resin as a thermoplastic resin (3). In the third layer, it is preferable to contain polyvinyl butyral resin as a polyvinyl acetal resin (3). The thermoplastic resin (3) contained in the third layer is preferably polyvinyl butyral resin. The polyvinyl butyral resins contained in the interlayer film, the first layer, the second layer, and the third layer may each use only one type, or two or more types may be used in combination.

[0094] The hydroxyl group content (hydroxyl amount) of the polyvinyl acetal resin (0) is preferably 15 mol% or more, more preferably 18 mol% or more, preferably 40 mol% or less, and more preferably 35 mol% or less. When the hydroxyl group content is at least the lower limit, the adhesion of the interlayer film is further improved. In addition, when the hydroxyl group content is at most the upper limit, the interlayer film has higher flexibility and the operation of the interlayer film becomes easier.

[0095] The hydroxyl group content (hydroxyl amount) of the polyvinyl acetal resin (1) is preferably 25 mol% or more, more preferably 28 mol% or more, more preferably 30 mol% or more, further preferably 31.5 mol% or more, further preferably 32 mol% or more, and particularly preferably 33 mol% or more. The hydroxyl group content (hydroxyl amount) of the polyvinyl acetal resin (1) is preferably 38 mol% or less, more preferably 37 mol% or less, further preferably 36.5 mol% or less, and particularly preferably 36 mol% or less. When the hydroxyl group content is at least the lower limit, the adhesion of the interlayer film is further improved. In addition, when the hydroxyl group content is at most the upper limit, the interlayer film has higher flexibility and the operation of the interlayer film becomes easier.

[0096] The content ratio of each of the hydroxyl groups of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) is preferably 10 mol% or more, more preferably 15 mol% or more, still more preferably 17 mol% or more, preferably 25 mol% or less, more preferably 20 mol% or less, still more preferably 19 mol% or less, and particularly preferably 18 mol% or less. When the content ratio of the hydroxyl group is at least the lower limit, the mechanical strength of the interlayer film is further improved. In particular, when the content ratio of the hydroxyl groups of the polyvinyl acetal resins (2) and (3) is 15 mol% or more, the reaction efficiency is high and the productivity is excellent. In addition, when it is 25 mol% or less, the sound insulation of the laminated glass is further improved. Further, when the content ratio of the hydroxyl group is at most the upper limit, the flexibility of the interlayer film is high and the handling of the interlayer film becomes easy.

[0097] From the viewpoint of further improving the sound insulation, the content ratio of the hydroxyl group of the polyvinyl acetal resin (1) is preferably higher than the content ratio of the hydroxyl group of the polyvinyl acetal resin (2). From the viewpoint of further improving the sound insulation, the content ratio of the hydroxyl group of the polyvinyl acetal resin (1) is preferably higher than the content ratio of the hydroxyl group of the polyvinyl acetal resin (3). From the viewpoint of further improving the sound insulation, the absolute value of the difference between the content ratio of the hydroxyl group of the polyvinyl acetal resin (1) and the content ratio of the hydroxyl group of the polyvinyl acetal resin (2) is preferably 1 mol% or more, more preferably 5 mol% or more, still more preferably 9 mol% or more, particularly preferably 10 mol% or more, and most preferably 12 mol% or more. From the viewpoint of further improving the sound insulation, the absolute value of the difference between the content ratio of the hydroxyl group of the polyvinyl acetal resin (1) and the content ratio of the hydroxyl group of the polyvinyl acetal resin (3) is preferably 1 mol% or more, more preferably 5 mol% or more, still more preferably 9 mol% or more, particularly preferably 10 mol% or more, and most preferably 12 mol% or more. The absolute value of the difference between the content ratio of the hydroxyl group of the polyvinyl acetal resin (1) and the content ratio of the hydroxyl group of the polyvinyl acetal resin (2) and the absolute value of the difference between the content ratio of the hydroxyl group of the polyvinyl acetal resin (1) and the content ratio of the hydroxyl group of the polyvinyl acetal resin (3) are preferably 20 mol% or less.

[0098] The content ratio of the hydroxyl group of the polyvinyl acetal resin is a value expressed as a percentage of the mole fraction obtained by dividing the amount of ethylene groups bonded to the hydroxyl group by the total amount of ethylene groups in the main chain. The amount of ethylene groups bonded to the hydroxyl group can be measured, for example, based on JIS K6728 "Test Methods for Polyvinyl Butyral".

[0099] The acetylation degree (acetyl group content) of the polyvinyl acetal resin (0) is preferably 0.1 mol% or more, more preferably 0.3 mol% or more, further preferably 0.5 mol% or more, preferably 30 mol% or less, more preferably 25 mol% or less, and further preferably 20 mol% or less. When the acetylation degree is above the lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer is improved. When the acetylation degree is below the upper limit, the moisture resistance of the interlayer film and the laminated glass is improved.

[0100] The acetylation degree (acetyl group content) of the polyvinyl acetal resin (1) is preferably 0.01 mol% or more, more preferably 0.5 mol% or more, preferably 10 mol% or less, and more preferably 2 mol% or less. When the acetylation degree is above the lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer is relatively high. When the acetylation degree is below the upper limit, the moisture resistance of the interlayer film and the laminated glass is relatively high.

[0101] The acetylation degrees of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) are each preferably 0.01 mol% or more, more preferably 0.1 mol% or more, further preferably 7 mol% or more, further preferably 9 mol% or more, preferably 30 mol% or less, more preferably 25 mol% or less, further preferably 24 mol% or less, and particularly preferably 20 mol% or less. When the acetylation degree is above the lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer is relatively high. When the acetylation degree is below the upper limit, the moisture resistance of the interlayer film and the laminated glass is relatively high. In particular, when the acetylation degrees of the polyvinyl acetal resins (2) and (3) are 0.1 mol% or more and 25 mol% or less, the puncture resistance is excellent.

[0102] The acetylation degree is a value expressed as a percentage of the mole fraction obtained by dividing the amount of ethylene groups bonded to the acetyl groups by the total amount of ethylene groups in the main chain. The amount of ethylene groups bonded to the acetyl groups can be measured, for example, based on JIS K6728 "Test Methods for Polyvinyl Butyral".

[0103] The acetalization degree (in the case of polyvinyl butyral resin, it is the butyralization degree) of the polyvinyl acetal resin (0) is preferably 60 mol% or more, more preferably 63 mol% or more, preferably 85 mol% or less, more preferably 75 mol% or less, and further preferably 70 mol% or less. When the acetalization degree is above the lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer is improved. When the acetalization degree is below the upper limit, the reaction time required for manufacturing the polyvinyl acetal resin becomes shorter.

[0104] The acetalization degree (butyralization degree in the case of polyvinyl butyral resin) of the polyvinyl acetal resin (1) is preferably 55 mol% or more, more preferably 60 mol% or more, preferably 75 mol% or less, and more preferably 71 mol% or less. When the acetalization degree is at or above the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is high. When the acetalization degree is at or below the upper limit, the reaction time required for manufacturing the polyvinyl acetal resin is shortened.

[0105] The acetalization degrees (butyralization degrees in the case of polyvinyl butyral resin) of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) are preferably 47 mol% or more, more preferably 60 mol% or more, preferably 85 mol% or less, more preferably 80 mol% or less, and further preferably 75 mol% or less. When the acetalization degree is at or above the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is high. When the acetalization degree is at or below the upper limit, the reaction time required for manufacturing the polyvinyl acetal resin is shortened.

[0106] The acetalization degree is determined as follows. First, a value is obtained by subtracting the amount of ethylene groups bonded to hydroxyl groups and the amount of ethylene groups bonded to acetyl groups from the total amount of ethylene groups in the main chain. The mole fraction is obtained by dividing the obtained value by the total amount of ethylene groups in the main chain. The value represented by this mole fraction as a percentage is the acetalization degree.

[0107] It should be noted that the hydroxyl group content (amount of hydroxyl groups), acetalization degree (butyralization degree), and acetylation degree are preferably calculated based on the results measured by the method based on JIS K6728 "Test Methods for Polyvinyl Butyral". However, the measurement based on ASTM D1396-92 can be used. In the case where the polyvinyl acetal resin is polyvinyl butyral resin, the hydroxyl group content (amount of hydroxyl groups), the acetalization degree (butyralization degree), and the acetylation degree are calculated based on the results measured by the method based on JIS K6728 "Test Methods for Polyvinyl Butyral".

[0108] In 100% by weight of the thermoplastic resin contained in the intermediate film, the content of the polyvinyl acetal resin is preferably 10% by weight or more, more preferably 30% by weight or more, further preferably 50% by weight or more, further preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. In 100% by weight of the thermoplastic resin contained in the intermediate film, the content of the polyvinyl acetal resin is preferably 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin of the intermediate film is preferably the polyvinyl acetal resin.

[0109] In 100% by weight of the thermoplastic resin contained in the first layer, the content of the polyvinyl acetal resin is preferably 10% by weight or more, more preferably 30% by weight or more, still more preferably 50% by weight or more, still more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. In 100% by weight of the thermoplastic resin contained in the first layer, the content of the polyvinyl acetal resin is preferably 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin in the first layer is preferably a polyvinyl acetal resin.

[0110] (Plasticizer)

[0111] The interlayer film preferably contains a plasticizer. The first layer (including a single-layer interlayer film) preferably contains a plasticizer (hereinafter sometimes referred to as plasticizer (1)). The second layer preferably contains a plasticizer (hereinafter sometimes referred to as plasticizer (2)). The third layer preferably contains a plasticizer (hereinafter sometimes referred to as plasticizer (3)). By using a plasticizer or by using a combination of a polyvinyl acetal resin and a plasticizer, the impact resistance and penetration resistance are made more excellent, and the adhesion of the layer containing a polyvinyl acetal resin and a plasticizer to the laminated glass member or other layers is suitably improved. The plasticizer is not particularly limited. The plasticizer (1), the plasticizer (2), and the plasticizer (3) may be the same or different. The plasticizer (1), the plasticizer (2), and the plasticizer (3) may each use only one kind, or two or more kinds may be used in combination.

[0112] Examples of the plasticizer include organic ester plasticizers such as mono-carboxylic acid esters and poly-carboxylic acid esters, and organic phosphoric acid plasticizers such as organic phosphoric acid plasticizers and organic phosphorous acid plasticizers. The plasticizer is preferably an organic ester plasticizer. The plasticizer is preferably a liquid plasticizer.

[0113] Examples of the mono-carboxylic acid ester include glycol esters obtained by reacting a glycol with a mono-carboxylic acid. Examples of the glycol include triethylene glycol, tetraethylene glycol, and tripropylene glycol. Examples of the mono-carboxylic acid include butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptanoic acid, n-octanoic acid, 2-ethylhexanoic acid, n-nonanoic acid, decanoic acid, and benzoic acid.

[0114] Examples of the poly-carboxylic acid ester include ester compounds of a poly-carboxylic acid and an alcohol having a linear or branched structure with 4 to 8 carbon atoms. Examples of the poly-carboxylic acid include adipic acid, sebacic acid, and azelaic acid.

[0115] Examples of the organic ester plasticizer include: triethylene glycol bis(2-ethylpropionate), triethylene glycol bis(2-ethylbutyrate), triethylene glycol bis(2-ethylhexanoate), triethylene glycol dioctanoate, triethylene glycol bis(n-octanoate), triethylene glycol bis(n-heptanoate), tetraethylene glycol bis(n-heptanoate), dibutyl sebacate, dioctyl azelate, dibutyl carbitol oxalate, ethylene glycol bis(2-ethylbutyrate), 1,3-propanediol bis(2-ethylbutyrate), 1,4-butanediol bis(2-ethylbutyrate), diethylene glycol bis(2-ethylbutyrate), diethylene glycol bis(2-ethylhexanoate), dipropylene glycol bis(2-ethylbutyrate), triethylene glycol bis(2-ethylvalerate), tetraethylene glycol bis(2-ethylbutyrate), diethylene glycol dioctanoate, diethylene glycol dibenzoate, dipropylene glycol dibenzoate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, a mixture of heptyl and nonyl adipates, diisononyl adipate, diisodecyl adipate, heptyl nonyl adipate, dibutyl sebacate, an oil-modified sebacic alkyd, and a mixture of a phosphate ester and an adipate ester. Organic ester plasticizers other than these can be used. Other adipate esters other than the above-mentioned adipate esters can also be used.

[0116] Examples of the organic phosphoric acid plasticizer include: tributoxyethyl phosphate, isodecyl phenyl phosphate, and triisopropyl phosphate.

[0117] The plasticizer is preferably a diester plasticizer represented by the following formula (1).

[0118] [Chemical formula 1]

[0119]

[0120] In the formula (1), R1 and R2 each represent an organic group having 2 to 10 carbon atoms, R3 represents an ethylene group, an isopropylidene group, or a n-propylene group, and p represents an integer of 3 to 10. R1 and R2 in the formula (1) are each preferably an organic group having 5 to 10 carbon atoms, more preferably an organic group having 6 to 10 carbon atoms.

[0121] The plasticizer preferably contains triethylene glycol bis(2-ethylhexanoate) (3GO), triethylene glycol bis(2-ethylbutyrate) (3GH), or triethylene glycol bis(2-ethylpropionate). The plasticizer more preferably contains triethylene glycol bis(2-ethylhexanoate) (3GO) or triethylene glycol bis(2-ethylbutyrate) (3GH), and even more preferably contains triethylene glycol bis(2-ethylhexanoate).

[0122] In the first layer, with respect to 100 parts by weight of the thermoplastic resin (1) (100 parts by weight of the polyvinyl acetal resin (1) when the thermoplastic resin (1) is the polyvinyl acetal resin (1)), the content of the plasticizer (1) is defined as content (1). The content (1) is preferably 20 parts by weight or more, more preferably 25 parts by weight or more, still more preferably 28 parts by weight or more, preferably 40 parts by weight or less, more preferably 38 parts by weight or less, still more preferably 35 parts by weight or less, and particularly preferably 33 parts by weight or less. When the content (1) is at or above the lower limit, the flexibility of the interlayer film is relatively high and the handling of the interlayer film becomes easier. When the content (1) is at or above the lower limit, the flexibility of the interlayer film is relatively high and the handling of the interlayer film becomes easier. When the content (1) is at or below the upper limit, the flexural rigidity is further improved. When the content (1) is at or above the lower limit and at or below the upper limit, the effects of the present invention can be further effectively exerted.

[0123] In the second layer, with respect to 100 parts by weight of the thermoplastic resin (2) (100 parts by weight of the polyvinyl acetal resin (2) when the thermoplastic resin (2) is the polyvinyl acetal resin (2)), the content of the plasticizer (2) is defined as content (2). The content (2) is preferably 50 parts by weight or more, more preferably 55 parts by weight or more, still more preferably 60 parts by weight or more, preferably 100 parts by weight or less, more preferably 90 parts by weight or less, still more preferably 85 parts by weight or less, and particularly preferably 80 parts by weight or less. When the content (2) is at or above the lower limit, the flexibility of the interlayer film is relatively high and the handling of the interlayer film becomes easier. When the content (2) is at or below the upper limit, the penetration resistance of the laminated glass is further improved.

[0124] In the third layer, with respect to 100 parts by weight of the thermoplastic resin (3) (100 parts by weight of the polyvinyl acetal resin (3) when the thermoplastic resin (3) is the polyvinyl acetal resin (3)), the content of the plasticizer (3) is defined as content (3). The content (3) is preferably 50 parts by weight or more, more preferably 55 parts by weight or more, still more preferably 60 parts by weight or more, preferably 100 parts by weight or less, more preferably 90 parts by weight or less, still more preferably 85 parts by weight or less, and particularly preferably 80 parts by weight or less. When the content (3) is at or above the lower limit, the flexibility of the interlayer film is relatively high and the handling of the interlayer film becomes easier. When the content (3) is at or below the upper limit, the penetration resistance of the laminated glass is further improved.

[0125] The content (1) and the content (2) may be the same or different. The content (1) and the content (3) may be the same or different. From the viewpoint of improving the sound insulation of the laminated glass, it is preferable that the content (1) and the content (2) are the same, or the content (1) is lower than the content (2), and more preferably the content (1) is lower than the content (2). From the viewpoint of improving the sound insulation of the laminated glass, it is preferable that the content (1) and the content (3) are the same, or the content (1) is lower than the content (3), and more preferably the content (1) is lower than the content (3).

[0126] From the viewpoint of further improving the sound insulation of the laminated glass, the absolute value of the difference between the content (2) and the content (1), and the absolute value of the difference between the content (3) and the content (1) are each preferably 10 parts by weight or more, more preferably 15 parts by weight or more, and still more preferably 20 parts by weight or more. The absolute value of the difference between the content (2) and the content (1), and the absolute value of the difference between the content (3) and the content (1) are each preferably 80 parts by weight or less, more preferably 75 parts by weight or less, and still more preferably 70 parts by weight or less.

[0127] (Heat insulation substance)

[0128] The interlayer film preferably contains a heat insulation substance. The first layer (including a single-layer interlayer film) preferably contains a heat insulation substance. The second layer preferably contains a heat insulation substance. The third layer preferably contains a heat insulation substance. Only one kind of the heat insulation substance may be used, or two or more kinds may be used in combination.

[0129] The heat insulation substance preferably contains component X or heat insulation particles, and the component X is at least one of a phthalocyanine compound, a naphthalocyanine compound, and an anthracene phthalocyanine compound. In this case, both the component X and the heat insulation particles may be included.

[0130] Component X:

[0131] The interlayer film preferably contains component X, and the component X is at least one of a phthalocyanine compound, a naphthalocyanine compound, and an anthracene phthalocyanine compound. The first layer preferably contains the component X. The second layer preferably contains the component X. The third layer preferably contains the component X. The component X is a heat insulation substance. Only one kind of the component X may be used, or two or more kinds may be used in combination.

[0132] The component X is not particularly limited. As the component X, conventionally known phthalocyanine compounds, naphthalocyanine compounds, and anthracene phthalocyanine compounds can be used.

[0133] Examples of the component X include phthalocyanine, derivatives of phthalocyanine, naphthalocyanine, derivatives of naphthalocyanine, anthracene phthalocyanine, and derivatives of anthracene phthalocyanine. The phthalocyanine compound and the derivative of phthalocyanine preferably each have a phthalocyanine skeleton. The naphthalocyanine compound and the derivative of naphthalocyanine preferably each have a naphthalocyanine skeleton. The anthracene phthalocyanine compound and the derivative of anthracene phthalocyanine preferably each have an anthracene phthalocyanine skeleton.

[0134] From the viewpoint of further improving the heat insulation properties of the intermediate film and the laminated glass, the component X is preferably at least one selected from phthalocyanine, derivatives of phthalocyanine, naphthalocyanine, and derivatives of naphthalocyanine, and more preferably at least one of phthalocyanine and derivatives of phthalocyanine.

[0135] From the viewpoint of effectively improving the heat insulation properties and maintaining the visible light transmittance at a higher level for a long time, the component X preferably contains a vanadium atom or a copper atom. The component X preferably contains a vanadium atom and also preferably contains a copper atom. The component X is more preferably at least one of phthalocyanine containing a vanadium atom or a copper atom and derivatives of phthalocyanine containing a vanadium atom or a copper atom. From the viewpoint of further improving the heat insulation properties of the intermediate film and the laminated glass, the component X preferably has a structural unit in which an oxygen atom is bonded to a vanadium atom.

[0136] In 100% by weight of the intermediate film or in 100% by weight of the layer (the first layer, the second layer, or the third layer) containing the component X, the content of the component X is preferably 0.001% by weight or more, more preferably 0.005% by weight or more, further preferably 0.01% by weight or more, and particularly preferably 0.02% by weight or more. In 100% by weight of the intermediate film or in 100% by weight of the layer (the first layer, the second layer, or the third layer) containing the component X, the content of the component X is preferably 0.2% by weight or less, more preferably 0.1% by weight or less, further preferably 0.05% by weight or less, and particularly preferably 0.04% by weight or less. When the content of the component X is above the lower limit and below the upper limit, the heat insulation properties are sufficiently improved and the visible light transmittance is sufficiently improved. For example, the visible light transmittance can reach 70% or more.

[0137] Heat insulating particles:

[0138] The intermediate film preferably contains heat insulating particles. The first layer preferably contains the heat insulating particles. The second layer preferably contains the heat insulating particles. The third layer preferably contains the heat insulating particles. The heat insulating particles are heat insulating substances. By using the heat insulating particles, infrared rays (heat rays) can be effectively blocked. The heat insulating particles can be used alone or in combination of two or more.

[0139] From the viewpoint of further improving the heat insulation property of the laminated glass, the heat insulating particles are more preferably metal oxide particles. The heat insulating particles are preferably particles formed of an oxide of a metal (metal oxide particles).

[0140] Infrared rays with a wavelength longer than visible light and above 780 nm have less energy compared to ultraviolet rays. However, the thermal effect of infrared rays is greater, and when infrared rays are absorbed by a substance, they are released in the form of heat. Therefore, infrared rays are generally referred to as heat rays. By using the heat insulating particles, infrared rays (heat rays) can be effectively blocked. It should be noted that heat insulating particles refer to particles that can absorb infrared rays.

[0141] Specific examples of the heat insulating particles include: aluminum-doped tin oxide particles, indium-doped tin oxide particles, antimony-doped tin oxide particles (ATO particles), gallium-doped zinc oxide particles (GZO particles), indium-doped zinc oxide particles (IZO particles), aluminum-doped zinc oxide particles (AZO particles), niobium-doped titanium oxide particles, sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles, thallium-doped tungsten oxide particles, rubidium-doped tungsten oxide particles, tin-doped indium oxide particles (ITO particles), tin-doped zinc oxide particles, silicon-doped zinc oxide particles and other metal oxide particles, lanthanum hexaboride (LaB6) particles, etc. Heat insulating particles other than these can be used. Since the heat ray shielding function is high, metal oxide particles are preferred, and ATO particles, GZO particles, IZO particles, ITO particles or tungsten oxide particles are more preferred, and ITO particles or tungsten oxide particles are particularly preferred. In particular, since the heat ray shielding function is high and it is easy to obtain, tin-doped indium oxide particles (ITO particles) are preferred, and tungsten oxide particles are also preferred.

[0142] From the viewpoint of further improving the heat insulation property of the interlayer film and the laminated glass, the tungsten oxide particles are preferably metal-doped tungsten oxide particles. The "tungsten oxide particles" include metal-doped tungsten oxide particles. Specific examples of the metal-doped tungsten oxide particles include: sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles, thallium-doped tungsten oxide particles, rubidium-doped tungsten oxide particles, etc.

[0143] From the viewpoint of further improving the heat insulation property of the interlayer film and the laminated glass, cesium-doped tungsten oxide particles are particularly preferred. From the viewpoint of further improving the heat insulation property of the interlayer film and the laminated glass, the cesium-doped tungsten oxide particles are preferably tungsten oxide particles represented by the chemical formula: Cs 0.33 WO3.

[0144] The average particle diameter of the heat insulating particles is preferably 0.01 μm or more, more preferably 0.02 μm or more, preferably 0.1 μm or less, and more preferably 0.05 μm or less. When the average particle diameter is at least the lower limit, the shielding property of the heat rays is sufficiently improved. When the average particle diameter is at most the upper limit, the dispersibility of the heat insulating particles is improved.

[0145] The "average particle diameter" means the volume average particle diameter. The average particle diameter can be measured using a particle size distribution measuring device (such as "UPA-EX150" manufactured by Nikkiso Co., Ltd.).

[0146] In 100% by weight of the intermediate film or in 100% by weight of the layer (the first layer, the second layer or the third layer) containing the heat insulating particles, the content of each of the heat insulating particles (especially the content of tungsten oxide particles) is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, further preferably 1% by weight or more, and particularly preferably 1.5% by weight or more. In 100% by weight of the intermediate film or in 100% by weight of the layer (the first layer, the second layer or the third layer) containing the heat insulating particles, the content of each of the heat insulating particles (especially the content of tungsten oxide particles) is preferably 6% by weight or less, more preferably 5.5% by weight or less, further preferably 4% by weight or less, particularly preferably 3.5% by weight or less, and most preferably 3% by weight or less. When the content of the heat insulating particles is at least the lower limit and at most the upper limit, the heat insulation property is sufficiently improved and the visible light transmittance is sufficiently improved.

[0147] (metal salt)

[0148] The intermediate film preferably contains at least one metal salt (hereinafter sometimes referred to as metal salt M) selected from alkaline earth metal salts other than alkali metal salts and magnesium salts and magnesium salts. In addition, since magnesium is an alkaline earth metal, the intermediate film preferably contains at least one metal salt M selected from alkali metal salts and alkaline earth metal salts. The first layer preferably contains the metal salt M. The second layer preferably contains the metal salt M. The third layer preferably contains the metal salt M. It should be noted that alkaline earth metals refer to 6 metals: Be, Mg, Ca, Sr, Ba, and Ra. By using the metal salt M, it becomes easy to control the adhesiveness between the intermediate film and laminated glass components such as glass plates or the adhesiveness between the layers in the intermediate film. The metal salt M can be used alone or in combination of two or more.

[0149] The metal salt M preferably contains at least one metal selected from Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba. The metal salt contained in the intermediate film preferably contains at least one metal selected from K and Mg.

[0150] In addition, the metal salt M is more preferably an alkaline earth metal salt of an organic acid having 2 to 16 carbon atoms other than an alkali metal salt of an organic acid having 2 to 16 carbon atoms or a magnesium salt of an organic acid having 2 to 16 carbon atoms, or a magnesium salt of an organic acid having 2 to 16 carbon atoms. In addition, since magnesium is an alkaline earth metal, the metal salt M is preferably an alkali metal salt of an organic acid having 2 to 16 carbon atoms or an alkaline earth metal salt of an organic acid having 2 to 16 carbon atoms. The metal salt M is more preferably a magnesium carboxylate salt having 2 to 16 carbon atoms or a potassium carboxylate salt having 2 to 16 carbon atoms.

[0151] Examples of the magnesium carboxylate salt having 2 to 16 carbon atoms and the potassium carboxylate salt having 2 to 16 carbon atoms include magnesium acetate, potassium acetate, magnesium propionate, potassium propionate, magnesium 2-ethylbutyrate, potassium 2-ethylbutyrate, magnesium 2-ethylhexanoate, and potassium 2-ethylhexanoate.

[0152] The total content of Mg and K in the intermediate film containing the metal salt M or the layer (the first layer, the second layer, or the third layer) containing the metal salt M is preferably 5 ppm or more, more preferably 10 ppm or more, still more preferably 20 ppm or more, preferably 300 ppm or less, more preferably 250 ppm or less, and still more preferably 200 ppm or less. When the total content of Mg and K is above the lower limit and below the upper limit, the adhesiveness between the intermediate film and the laminated glass member (such as a glass plate) or the adhesiveness between the layers in the intermediate film can be further improved.

[0153] (Ultraviolet ray shielding agent)

[0154] The intermediate film preferably contains an ultraviolet ray shielding agent. The first layer preferably contains an ultraviolet ray shielding agent. The second layer preferably contains an ultraviolet ray shielding agent. The third layer preferably contains an ultraviolet ray shielding agent. By using an ultraviolet ray shielding agent, the visible light transmittance is less likely to decrease even when the intermediate film and the laminated glass are used for a long time. The ultraviolet ray shielding agent can be used alone or in combination of two or more.

[0155] The ultraviolet ray shielding agent contains an ultraviolet absorber. The ultraviolet ray shielding agent is preferably an ultraviolet absorber.

[0156] Examples of the ultraviolet ray shielding agent include an ultraviolet ray shielding agent containing a metal atom, an ultraviolet ray shielding agent containing a metal oxide, an ultraviolet ray shielding agent having a benzotriazole structure (benzotriazole compound), an ultraviolet ray shielding agent having a benzophenone structure (benzophenone compound), an ultraviolet ray shielding agent having a triazine structure (triazine compound), an ultraviolet ray shielding agent having a malonic ester structure (malonic ester compound), an ultraviolet ray shielding agent having an oxanilide structure (oxanilide compound), and an ultraviolet ray shielding agent having a benzoate structure (benzoate compound).

[0157] Examples of the ultraviolet ray shielding agent containing a metal atom include platinum particles, particles in which the surface of platinum particles is coated with silica, palladium particles, and particles in which the surface of palladium particles is coated with silica. The ultraviolet ray shielding agent is preferably not a heat insulating particle.

[0158] The ultraviolet ray shielding agent is preferably an ultraviolet ray shielding agent having a benzotriazole structure, an ultraviolet ray shielding agent having a benzophenone structure, an ultraviolet ray shielding agent having a triazine structure, or an ultraviolet ray shielding agent having a benzoate structure. The ultraviolet ray shielding agent is more preferably an ultraviolet ray shielding agent having a benzotriazole structure or an ultraviolet ray shielding agent having a benzophenone structure, and further preferably an ultraviolet ray shielding agent having a benzotriazole structure.

[0159] Examples of the ultraviolet ray shielding agent containing a metal oxide include zinc oxide, titanium oxide, and cerium oxide. In addition, the surface of the ultraviolet ray shielding agent containing a metal oxide can be coated. Examples of the coating material for the surface of the ultraviolet ray shielding agent containing a metal oxide include insulating metal oxides, hydrolyzable organosilicon compounds, and polysiloxane compounds.

[0160] Examples of the insulating metal oxide include silica, alumina, and zirconia. The insulating metal oxide has a band gap energy of 5.0 eV or more, for example.

[0161] Examples of the ultraviolet ray shielding agent having a benzotriazole structure include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole ("Tinuvin P" manufactured by BASF), 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole ("Tinuvin 320" manufactured by BASF), 2-(2'-hydroxy-3'-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole ("Tinuvin 326" manufactured by BASF), and 2-(2'-hydroxy-3',5'-di-pentylphenyl)benzotriazole ("Tinuvin 328" manufactured by BASF). From the viewpoint of excellent ultraviolet ray shielding performance, the ultraviolet ray shielding agent is preferably an ultraviolet ray shielding agent having a benzotriazole structure containing a halogen atom, and more preferably an ultraviolet ray shielding agent having a benzotriazole structure containing a chlorine atom.

[0162] Examples of the ultraviolet ray shielding agent having a benzophenone structure include OCTABENZONE ("Chimassorb 81" manufactured by BASF).

[0163] Examples of the ultraviolet light screening agent having a triazine structure include "LA-F70" manufactured by ADEKA Corporation and 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol ("Tinuvin1577FF" manufactured by BASF Corporation).

[0164] Examples of the ultraviolet light screening agent having a malonic ester structure include dimethyl 2-(p-methoxybenzylidene)malonate, tetraethyl 2,2-(1,4-phenylenedimethylene)bis(malonate), 2-(p-methoxybenzylidene)-bis(1,2,2,6,6-pentamethyl-4-piperidyl)malonate, etc.

[0165] Examples of commercially available products of the ultraviolet light screening agent having a malonic ester structure include Hostavin B-CAP, Hostavin PR-25, and Hostavin PR-31 (all manufactured by CLARIANT Corporation).

[0166] Examples of the ultraviolet light screening agent having an oxanilide structure include oxalic acid diamides such as N-(2-ethylphenyl)-N'-(2-ethoxy-5-tert-butylphenyl)oxamide, N-(2-ethylphenyl)-N'-(2-ethoxyphenyl)oxamide, and 2-ethyl-2'-ethoxy-oxanilide ("Sanduvor VSU" manufactured by CLARIANT Corporation), which have an aryl group substituted on the nitrogen atom.

[0167] Examples of the ultraviolet light screening agent having a benzoate structure include 2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate ("Tinuvin120" manufactured by BASF Corporation), etc.

[0168] In 100% by weight of the intermediate film or in 100% by weight of the layer (the first layer, the second layer or the third layer) containing the ultraviolet light shielding agent, the content of the ultraviolet light shielding agent and the content of the benzotriazole compound are preferably 0.1% by weight or more, more preferably 0.2% by weight or more, further preferably 0.3% by weight or more, and particularly preferably 0.5% by weight or more. In 100% by weight of the intermediate film or in 100% by weight of the layer (the first layer, the second layer or the third layer) containing the ultraviolet light shielding agent, the content of the ultraviolet light shielding agent and the content of the benzotriazole compound are preferably 2.5% by weight or less, more preferably 2% by weight or less, further preferably 1% by weight or less, and particularly preferably 0.8% by weight or less. When the content of the ultraviolet light shielding agent is above the lower limit and below the upper limit, the decrease in visible light transmittance after a certain period of time can be further suppressed. In particular, in 100% by weight of the layer containing the ultraviolet light shielding agent, by making the content of the ultraviolet light shielding agent 0.2% by weight or more, the decrease in visible light transmittance of the intermediate film and the laminated glass after a certain period of time can be significantly suppressed.

[0169] (Antioxidant)

[0170] The intermediate film preferably contains an antioxidant. The first layer preferably contains an antioxidant. The second layer preferably contains an antioxidant. The third layer preferably contains an antioxidant. Only one kind of antioxidant may be used, or two or more kinds may be used in combination.

[0171] Examples of the antioxidant include phenolic antioxidants, sulfur antioxidants, and phosphorus antioxidants. The phenolic antioxidant is an antioxidant having a phenolic skeleton. The sulfur antioxidant is an antioxidant containing a sulfur atom. The phosphorus antioxidant is an antioxidant containing a phosphorus atom.

[0172] The antioxidant is preferably a phenolic antioxidant or a phosphorus antioxidant.

[0173] Examples of the phenolic antioxidant include: 2,6-di-tert-butyl-p-cresol (BHT), butylated hydroxyanisole (BHA), 2,6-di-tert-butyl-4-ethylphenol, stearyl β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis-(4-methyl-6-butylphenol), 2,2'-methylenebis-(4-ethyl-6-tert-butylphenol), 4,4'-butylidene-bis-(3-methyl-6-tert-butylphenol), 1,1,3-tris-(2-methyl-hydroxy-5-tert-butylphenyl) butane, tetrakis [methylene-3-(3',5'-tert-butyl-4-hydroxyphenyl) propionate] methane, 1,3,3-tris-(2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl) benzene, bis(3,3'-tert-butylphenol) ethylene glycol butyrate, and bis(3-tert-butyl-4-hydroxy-5-methylphenyl) ethylene bis(oxyethylene), etc. It is preferable to use one or more of these antioxidants.

[0174] Examples of the phosphorus antioxidant include: tridecyl phosphite, tris(tridecyl) phosphite, triphenyl phosphite, tris(nonylphenyl) phosphite, bis(tridecyl) pentaerythritol diphosphite, bis(decyl) pentaerythritol diphosphite, tris(2,4-di-tert-butylphenyl) phosphite, bis(2,4-di-tert-butyl-6-methylphenyl) ethyl phosphite, and 2,2'-methylenebis(4,6-di-tert-butyl-1-phenoxy)(2-ethylhexoxy) phosphorus, etc. It is preferable to use one or more of these antioxidants.

[0175] Examples of the commercially available products of the antioxidant include: "IRGANOX 245" manufactured by BASF, "IRGAFOS 168" manufactured by BASF, "IRGAFOS 38" manufactured by BASF, "SUMILIZER BHT" manufactured by Sumitomo Chemical Co., Ltd., "H-BHT" manufactured by Sakai Chemical Industry Co., Ltd., and "IRGANOX 1010" manufactured by BASF, etc.

[0176] In order to maintain a high visible light transmittance of the interlayer film and the laminated glass for a long time, in 100% by weight of the interlayer film or in 100% by weight of the layer (the first layer, the second layer or the third layer) containing the antioxidant, the content of the antioxidant is preferably 0.1% by weight or more. In addition, since the addition effect of the antioxidant is saturated, in 100% by weight of the interlayer film or in 100% by weight of the layer containing the antioxidant, the content of the antioxidant is preferably 2% by weight or less.

[0177] (Other components)

[0178] The intermediate film, the first layer, the second layer, and the third layer may each contain additives such as coupling agents, dispersants, surfactants, flame retardants, antistatic agents, pigments, dyes, adhesion modifiers other than metal salts, moisture-proof agents, fluorescent brighteners, and infrared absorbers as needed. These additives may be used alone or in combination of two or more.

[0179] (Functional film)

[0180] The intermediate film may have a functional film in order to exhibit specific functions. Examples of the functional film include a light control film, an infrared reflection film, a colored film, and a film printed with a pattern design.

[0181] Examples of the light control film include a film having an electrochromic layer and an electrolyte layer. The electrochromic layer is a layer containing an electrochromic compound (a compound having electrochromic properties). It should be noted that having electrochromic properties means having the property of changing the light transmittance by applying a voltage.

[0182] Examples of the infrared reflection film include a resin film with a metal foil, a multilayer film having a metal layer and a dielectric layer formed on a resin film, a multilayer resin film, and a liquid crystal film. These films have the property of reflecting infrared rays.

[0183] The resin film with a metal foil includes: a resin film and a metal foil laminated on the outer surface of the resin film. Examples of the material of the resin film include polyethylene terephthalate resin, polyethylene naphthalate resin, polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic acid copolymer resin, polyurethane resin, polyvinyl alcohol resin, polyolefin resin, polyvinyl chloride resin, and polyimide resin. Examples of the material of the metal foil include aluminum, copper, silver, gold, palladium, and alloys containing these.

[0184] The multilayer film having a metal layer and a dielectric layer formed on the resin film is a multilayer film obtained by alternately laminating the metal layer and the dielectric layer on the resin film in any number of layers. It should be noted that in the multilayer film having a metal layer and a dielectric layer formed on the resin layer, it is preferable that all of the metal layer and the dielectric layer are alternately laminated, but it may also be a structure in which a part is not alternately laminated, such as metal layer / dielectric layer / metal layer / dielectric layer / metal layer / metal layer / dielectric layer / metal layer.

[0185] Examples of the material for the resin film in the multilayer laminate film include polyethylene, polypropylene, polylactic acid, poly(4-methylpentene-1), polyvinylidene fluoride, cyclic polyolefin, polymethyl methacrylate, polyvinyl chloride, polyvinyl alcohol, polyamides such as nylon 6, 11, 12, 66, polystyrene, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyester, polyphenylene sulfide, and polyetherimide. Examples of the material for the metal layer in the multilayer laminate film include the same materials as those for the metal foil in the resin film with a metal foil. A coating of a metal or a mixed oxide of a metal can be provided on both sides or one side of the metal layer. Examples of the material for the coating include ZnO, Al2O3, Ga2O3, InO3, MgO, Ti, NiCr, and Cu. In addition, examples of the material for the dielectric layer in the multilayer laminate film include indium oxide, etc.

[0186] The multilayer resin film is a laminate film formed by laminating a plurality of resin films. Examples of the material for the multilayer resin film include the same materials as those for the resin film in the multilayer laminate film. The number of resin films laminated in the multilayer resin film is 2 or more, can be 3 or more, and can be 5 or more. The number of resin films laminated in the multilayer resin film can be 1000 or less, can be 100 or less, and can be 50 or less.

[0187] The multilayer resin film can be a multilayer resin film formed by alternately or randomly laminating two or more thermoplastic resin layers having different optical properties (refractive indices) in any number of layers. Such a multilayer resin film is configured to obtain desired infrared reflection performance.

[0188] Examples of the liquid crystal film include a film formed by laminating cholesteric liquid crystal layers that reflect light of any wavelength in any number of layers. Such a liquid crystal film is configured to obtain desired infrared reflection performance.

[0189] The infrared reflection film may contain infrared reflective particles. The infrared reflective particles are particles having infrared reflection performance, and examples include plate particles having a thickness of 1 nm or more and 1000 μm or less. For example, in a resin film in which silver nanoplates are dispersed, an infrared reflection film having infrared reflection performance can be obtained by adjusting the thickness, surface area, and arrangement state of the silver nanoplates.

[0190] From the viewpoint of excellent infrared reflection performance, the functional film preferably has a property that the infrared transmittance is 40% or less at at least one wavelength in the range of 800 nm to 2000 nm. In the range of 800 nm to 2000 nm, the infrared transmittance is more preferably 30% or less, and further preferably 20% or less.

[0191] The transmittance of each wavelength in the range of 800 nm to 2000 nm of the functional film can be measured specifically by the following method. Prepare a single functional film. Using a spectrophotometer ("U-4100" manufactured by HITACHI HIGH-TECH), the spectral transmittance of each wavelength in the range of 800 nm to 2000 nm of the functional film is obtained based on JIS R3106:1998.

[0192] (Other details of the interlayer film for laminated glass)

[0193] The interlayer film is suitable for obtaining laminated glass without autoclave treatment. However, the interlayer film can also be used to obtain laminated glass by autoclave treatment.

[0194] The thickness of the interlayer film is not particularly limited. From the viewpoint of practical use and the viewpoint of sufficiently improving the penetration resistance and bending rigidity of the laminated glass, the thickness of the interlayer film is preferably 0.1 mm or more, more preferably 0.25 mm or more, preferably 3 mm or less, and more preferably 1.5 mm or less. When the thickness of the interlayer film is above the lower limit, the penetration resistance and bending rigidity of the laminated glass are further improved. When the thickness of the interlayer film is below the upper limit, the transparency of the interlayer film and the laminated glass is further improved.

[0195] Let the thickness of the interlayer film be T. The thicknesses of the first layer, the first surface layer, and the second surface layer are each preferably 0.005T or more, more preferably 0.01T or more, further preferably 0.02T or more, preferably 0.17T or less, more preferably 0.15T or less, more preferably 0.13T or less, more preferably 0.1T or less, and further preferably 0.09T or less. When the thickness is above the lower limit and below the upper limit, the sound insulation is further improved in a wide temperature range.

[0196] The interlayer film can be an interlayer film with a uniform thickness or an interlayer film with a variable thickness. The cross-sectional shape of the interlayer film can be rectangular or wedge-shaped.

[0197] The interlayer film can be wound into a roll of the interlayer film. The roll can include a core and the interlayer film wound around the outer periphery of the core.

[0198] The distance between one end and the other end of the intermediate film is preferably 3 m or less, more preferably 2 m or less, particularly preferably 1.5 m or less, preferably 0.5 m or more, more preferably 0.8 m or more, and particularly preferably 1 m or more. When the intermediate film has a length direction and a width direction, the distance between one end and the other end is the distance in the length direction of the intermediate film. When the intermediate film has a square planar shape, the distance between one end and the other end is the distance between the opposite one end and the other end.

[0199] The method for manufacturing the intermediate film of the present invention is not particularly limited. As the method for manufacturing the intermediate film of the present invention, in the case of a single-layer intermediate film, examples thereof include a method of extruding a resin composition using an extruder and a method of performing hot press molding. As the method for manufacturing the intermediate film of the present invention, in the case of a multi-layer intermediate film, for example, a method of forming each layer using each resin composition for forming each layer and then laminating the obtained layers; and a method of laminating each layer by co-extruding each resin composition for forming each layer using an extruder, etc.

[0200] From the viewpoint of excellent manufacturing efficiency of the intermediate film, it is preferable that the same polyvinyl acetal resin is contained in the first surface layer and the second surface layer. From the viewpoint of excellent manufacturing efficiency of the intermediate film, it is more preferable that the same polyvinyl acetal resin and the same plasticizer are contained in the first surface layer and the second surface layer. From the viewpoint of excellent manufacturing efficiency of the intermediate film, it is further preferable that the first surface layer and the second surface layer are formed of the same resin composition.

[0201] The intermediate film preferably has an uneven shape on at least one of the two side surfaces. The intermediate film more preferably has an uneven shape on both side surfaces. As the method for forming the uneven shape, there is no particular limitation, and examples thereof include a lip embossing method, an embossing roll method, a calender roll method, and a profile extrusion method. From the viewpoint of being able to quantitatively form a constant uneven pattern, that is, embossing of a plurality of uneven shapes, the embossing roll method is preferable.

[0202] (Laminated glass)

[0203] The laminated glass of the present invention includes: a first laminated glass member, a second laminated glass member, and the intermediate film for laminated glass. In the laminated glass of the present invention, the intermediate film for laminated glass is disposed between the first laminated glass member and the second laminated glass member.

[0204] Figure 4 is schematically showing the use of Figure 1 A cross-sectional view of an example of a laminated glass using the intermediate film for laminated glass shown.

[0205] Figure 4The laminated glass 31 shown includes a first laminated glass component 21, a second laminated glass component 22, and an interlayer film 11. The interlayer film 11 is disposed and sandwiched between the first laminated glass component 21 and the second laminated glass component 22.

[0206] The first laminated glass component 21 is laminated on the first surface 11a of the interlayer film 11. The second laminated glass component 22 is laminated on the second surface 11b of the interlayer film 11, which is opposite to the first surface 11a.

[0207] Thus, the laminated glass of the present invention includes a first laminated glass component, a second laminated glass component, and an interlayer film, and this interlayer film is an interlayer film for the laminated glass of the present invention. In the laminated glass of the present invention, the interlayer film is disposed between the first laminated glass component and the second laminated glass component.

[0208] The first laminated glass component is preferably a first glass plate. The second laminated glass component is preferably a second glass plate.

[0209] Examples of the first and second laminated glass components include a glass plate and a PET (polyethylene terephthalate) film. The laminated glass includes not only the laminated glass in which an interlayer film is sandwiched between two glass plates, but also the laminated glass in which an interlayer film is sandwiched between a glass plate and a PET film or the like. The laminated glass is a laminate including a glass plate, and it is preferable to use at least one glass plate. The first laminated glass component and the second laminated glass component are each a glass plate or a PET film, and it is preferable that the laminated glass includes a glass plate as at least one of the first laminated glass component and the second laminated glass component. It is particularly preferable that both the first and second laminated glass components are glass plates.

[0210] Examples of the glass plate include inorganic glass and organic glass. Examples of the inorganic glass include float plate glass, heat ray absorbing plate glass, heat ray reflecting plate glass, polished plate glass, embossed plate glass, wired glass, and green glass. The organic glass is a synthetic resin glass used in place of inorganic glass. Examples of the organic glass include polycarbonate plates and poly(meth)acrylic resin plates. Examples of the poly(meth)acrylic resin plates include poly(methyl methacrylate) plates.

[0211] The thicknesses of the first laminated glass component and the second laminated glass component are each preferably 1 mm or more, preferably 5 mm or less, and more preferably 3 mm or less. In addition, when the laminated glass component is a glass plate, the thickness of the glass plate is preferably 0.5 mm or more, more preferably 0.7 mm or more, preferably 5 mm or less, and more preferably 3 mm or less. When the laminated glass component is a PET film, the thickness of the PET film is preferably 0.03 mm or more and preferably 0.5 mm or less.

[0212] The method for manufacturing the laminated glass preferably includes: a step of obtaining a laminate by disposing an interlayer film between the first laminated glass component and the second laminated glass component and then bonding the first and second laminated glass components to the interlayer film. It should be noted that in this step, it is preferable to degas the air remaining between the first laminated glass component, the second laminated glass component, and the interlayer film by pressing rollers or by placing them in a rubber bag and performing reduced-pressure suction. In addition, the temperature during bonding is, for example, 70°C to 100°C.

[0213] The interlayer film and the laminated glass can be used in automobiles, railway vehicles, airplanes, ships, buildings, etc. The interlayer film and the laminated glass can be used for other purposes. The interlayer film and the laminated glass are preferably an interlayer film and laminated glass for construction or vehicles, and more preferably an interlayer film and laminated glass for vehicles. The interlayer film and the laminated glass can be used for the windshield, side glass, rear glass, or skylight glass of an automobile, etc. The interlayer film and the laminated glass are suitable for automobiles. The interlayer film is suitable for obtaining the laminated glass of an automobile.

[0214] Examples and comparative examples are given below to explain the present invention in more detail. The examples used in the present invention are not limited.

[0215] In the polyvinyl acetal resin used, n-butyraldehyde having 4 carbon atoms is used for acetalization. For the polyvinyl acetal resin, the degree of acetalization (degree of butyral acetalization), degree of acetylation, and hydroxyl group content are measured by the method according to JIS K 6728 "Test Method for Polyvinyl Butyral". It should be noted that when measured by ASTM D1396-92, the same values as those obtained by the method based on JIS K6728 "Test Method for Polyvinyl Butyral" are shown.

[0216] Prepare the following materials.

[0217] (Polyvinyl acetal resin)

[0218] Polyvinyl acetal resin (polyvinyl butyral resin (PVB1), average degree of polymerization 1700, hydroxyl group content 30.4 mol%, acetylation degree 1.0 mol%, acetalization degree (butyralization degree) 68.6 mol%)

[0219] Polyvinyl acetal resin (polyvinyl butyral resin (PVB2), average degree of polymerization 850, hydroxyl group content 31.0 mol%, acetylation degree 1.0 mol%, acetalization degree (butyralization degree) 68.0 mol%)

[0220] Polyvinyl acetal resin (polyvinyl butyral resin (PVB3), average degree of polymerization 1500, hydroxyl group content 30.8 mol%, acetylation degree 0.5 mol%, acetalization degree (butyralization degree) 68.7 mol%)

[0221] (Plasticizer)

[0222] Triethylene glycol di-2-ethylhexanoate (3GO)

[0223] (Metal salt M)

[0224] Mg mixture (50:50 (weight ratio) mixture of magnesium 2-ethylbutyrate and magnesium acetate)

[0225] (UV screening agent)

[0226] Tinuvin326 (2-(2’-hydroxy-3’-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, “Tinuvin326” manufactured by BASF)

[0227] (Antioxidant)

[0228] BHT (2,6-di-tert-butyl-p-cresol)

[0229] (Example 1)

[0230] Preparation of the composition for forming the intermediate film (first layer):

[0231] Mix the following components and knead well with a mixing roll to obtain the composition for forming the intermediate film (first layer).

[0232] 37.5 parts by weight of polyvinyl butyral resin (PVB1)

[0233] 62.5 parts by weight of polyvinyl butyral resin (PVB2)

[0234] 30 parts by weight of triethylene glycol di-2-ethylhexanoate (3GO)

[0235] The metal salt M (Mg mixture) in an amount of 70 ppm in the obtained intermediate film

[0236] The ultraviolet light screening agent (Tinuvin 326) in an amount of 0.2% by weight in the obtained intermediate film

[0237] The antioxidant (BHT) in an amount of 0.2% by weight in the obtained intermediate film

[0238] Preparation of the intermediate film:

[0239] The composition for forming the intermediate film (the first layer) was heated and compression molded to prepare a single-layer intermediate film (thickness 0.8 mm) having only the first layer.

[0240] (Examples 2 to 5 and Comparative Examples 1 to 4)

[0241] The type and content of the resin and the content of the plasticizer were changed as shown in Tables 1 and 2. Except for this, a single-layer intermediate film (thickness 0.8 mm) was prepared in the same manner as in Example 1.

[0242] (Evaluation)

[0243] (1) Glass transition temperature and softening point of the first layer

[0244] The obtained first layer was stored in an environment of room temperature 23 ± 2°C and humidity 25 ± 5% for 12 hours. Then, using a viscoelasticity measuring device “ARES-G2” manufactured by TA INSTRUMENTS, the viscoelasticity was measured. A parallel plate with a diameter of 8 mm was used as the jig, and the measurement was carried out in a shear mode under the conditions of a temperature decrease rate of 3°C / minute from 100°C to -20°C and a frequency of 1 Hz and a strain of 1%. In the obtained measurement results, the peak temperature of the loss tangent was set as the glass transition temperature Tg (°C). The temperature at which the value of the loss tangent in the temperature range between Tg (°C) and 100°C became the minimum was set as the softening point.

[0245] (2) Weight average molecular weight and number average molecular weight of the resin contained in the first layer

[0246] The obtained first layer was dissolved in N-methylpyrrolidone to prepare a 0.2 wt% solution, and the solution was filtered through a 0.45 μm filter. For the N-methylpyrrolidone, a sample in which lithium bromide was dissolved at a concentration of 10 mmol / ml was used. Subsequently, a gel permeation chromatography apparatus ("Shodex GPC-101", detector: RI-71S, autoinjector: AS101, guard column: KF-G, column: two LF-804 in series) was used to measure the number average molecular weight and weight average molecular weight of the polyvinyl acetal resin in terms of polystyrene. The measurement was carried out under the conditions of a flow rate of 0.5 ml / min and a column temperature of 40 °C. It should be noted that as standard samples ("Shodex Standard SM-105"), 10 samples with the following weight average molecular weights were used. The sample numbers (weight average molecular weights) are as follows: S-1.3 (1270), S-3.2 (3180), S-6.9 (6940), S-22 (21800), S-53 (52500), S-139 (139000), S-333 (333000), S-609 (609000), S-1345 (1350000), S-2704 (2700000). The molecular weight was plotted against the elution time at the peak top of each standard sample peak, and the obtained approximate straight line was used as a calibration curve.

[0247] (3) Compression creep test

[0248] The obtained first layer (intermediate film) was cut into a diameter of 8 mm to obtain test samples. Using the obtained test samples, a compression creep test was carried out by the above method. It should be noted that the thickness of the first layer (intermediate film) was 0.8 mm, and the test samples thus obtained belonged to test samples A, B, and C. In addition, the thickness of the test samples after the compression creep test was less than the thickness of the test samples before the compression creep test.

[0249] (4) Falling ball test (penetration resistance)

[0250] Two glass plates (clear float glass) with a length of 30 cm × a width of 30 cm × a thickness of 2.5 mm were prepared. The obtained intermediate film was sandwiched between the two glass plates to obtain a laminate. The obtained laminate was placed in a rubber bag and degassed at a vacuum degree of 2660 Pa (20 torr) for 20 minutes. Subsequently, in the degassed state, the laminate was heated at a heating rate of 4 °C / min to 90 °C, held at 90 °C for 5 minutes, and then cooled to 30 °C. Then, the normal pressure was restored. Thus, laminated glass was obtained.

[0251] For the obtained laminated glass, an iron ball with a diameter of 82 mm and a weight of 2260 g was dropped from a height of 4 m at a position 150 mm inward from the end of the laminated glass.

[0252] [Judgment Criteria for Drop Ball Test (Penetration Resistance)]

[0253] Pass: After the drop ball test, the iron ball remains on the laminated glass

[0254] Fail: After the drop ball test, the iron ball penetrates the laminated glass and falls

[0255] (5) Blistering in the End of Laminated Glass (Blistering in the Edge Part)

[0256] Prepare two glass plates (clear float glass) with a length of 10 cm × width of 10 cm × thickness of 2.5 mm. Sandwich the obtained intermediate film between the two glass plates to obtain a laminate. Place the obtained laminate in a rubber bag and degas it at a vacuum of 2660 Pa (20 torr) for 20 minutes. Then, heat the laminate at a heating rate of 4 °C / minute to 90 °C in the degassed state, hold it at 90 °C for 5 minutes, and then cool it to 30 °C. Next, return to normal pressure. Thus, laminated glass is obtained.

[0257] Place the obtained laminated glass on a black curtain and visually observe the end of the laminated glass, and evaluate the proportion of blistering on a 5-point scale from level 1 to level 5. No blistering is observed at all in level 1, and the part where blistering is observed develops towards level 5.

[0258] It should be noted that an example of the captured image judged as level 1 is Figure 5 as shown in (a), an example of the captured image judged as level 2 is Figure 5 as shown in (b), an example of the captured image judged as level 3 is Figure 5 as shown in (c), an example of the captured image judged as level 4 is Figure 5 as shown in (d), an example of the captured image judged as level 5 is Figure 5 as shown in (e).

[0259] (6) Transparency of Laminated Glass

[0260] Prepare two glass plates (clear float glass) with a length of 30 cm × width of 30 cm × thickness of 2.5 mm. Sandwich the obtained intermediate film between the two glass plates to obtain a laminate. Place the obtained laminate in a rubber bag and degas it at a vacuum of 2660 Pa (20 torr) for 20 minutes. Then, heat the laminate at a heating rate of 6 °C / minute to 95 °C in the degassed state, hold it at 95 °C for 20 minutes, and then cool it to 30 °C. Next, return to normal pressure. Thus, laminated glass is obtained.

[0261] The obtained laminated glass is left standing on a black curtain, and the transparency of the laminated glass is observed with the naked eye, and the transparency level is evaluated in 5 stages from 1 to 5. In level 1, the entire surface is completely transparent, and as it progresses to level 5, parts with lower transparency are observed.

[0262] It should be noted that an example of a captured image determined to be level 1 is Figure 6 as shown in (a), an example of a captured image determined to be level 2 is Figure 6 as shown in (b), an example of a captured image determined to be level 3 is Figure 6 as shown in (c), an example of a captured image determined to be level 4 is Figure 6 as shown in (d), an example of a captured image determined to be level 5 is Figure 6 as shown in (e).

[0263] The detailed content and results are shown in Tables 1 and 2 below. It should be noted that the descriptions of the metal salt M, the ultraviolet light shielding agent, and the antioxidant are omitted in the tables.

[0264]

[0265]

[0266] Symbol Explanation

[0267] 1, 1B... The first surface layer

[0268] 2, 2B... The second surface layer

[0269] 3... The intermediate layer

[0270] 3B... The first intermediate layer

[0271] 4B... The second intermediate layer

[0272] 5B... The third intermediate layer

[0273] 1a, 1Ba, 2a, 2Ba... The first surface

[0274] 11, 11B... The intermediate film

[0275] 11A... The intermediate film (the first layer)

[0276] 11a... The first surface

[0277] 11b... The second surface

[0278] 21... The first laminated glass component

[0279] 22... The second laminated glass component

[0280] 31... Laminated glass

Claims

1. An interlayer film for laminated glass, which is an interlayer film for laminated glass having a structure of 1 layer or a structure of 2 or more layers, wherein, The intermediate film has a first layer, The glass transition temperature of the first layer is 20°C or higher and 45°C or lower, The first layer contains a polyvinyl acetal resin and a plasticizer, In the first layer, the hydroxyl group content of the polyvinyl acetal resin contained is 25 mol% or more and 38 mol% or less, and the degree of acetalization of the polyvinyl acetal resin contained in the first layer is 55 mol% or more and 75 mol% or less, The hydroxyl group content of the polyvinyl acetal resin is the value expressed as a percentage of the mole fraction obtained by dividing the amount of ethylene groups bonded to hydroxyl groups by the total amount of ethylene groups in the main chain, The degree of acetalization is obtained as follows. First, obtain the value obtained by subtracting the amount of ethylene groups bonded to hydroxyl groups and the amount of ethylene groups bonded to acetyl groups from the total amount of ethylene groups in the main chain, divide the obtained value by the total amount of ethylene groups in the main chain to obtain a mole fraction, and the value expressed as a percentage of this mole fraction is the degree of acetalization, In the first layer, relative to 100 parts by weight of the polyvinyl acetal resin, the content of the plasticizer is 30 parts by weight or more and 40 parts by weight or less, The polyvinyl acetal resin contained in the first layer is a mixture of a first polyvinyl acetal resin 1A with an average degree of polymerization of polyvinyl alcohol of 1500 or more and a second polyvinyl acetal resin 1B with an average degree of polymerization of polyvinyl alcohol of 1000 or less, In a total of 100% by weight of the first polyvinyl acetal resin 1A and the second polyvinyl acetal resin 1B, the content of the second polyvinyl acetal resin 1B is 50% by weight or more and 80% by weight or less, When performing the following compression creep test on test sample A obtained by cutting the first layer with a diameter of 8 mm and a thickness of 0.8 mm, the change amount of the thickness of test sample A before and after the compression creep test is 50 μm or more and 325 μm or less, Compression creep test: In a state where a load of 410 g is applied to test sample A, heat from 30°C to 90°C at 6°C per minute and hold at 90°C for 5 minutes. The absolute value of the difference between the thickness of test sample A at 30°C just kept for 5 minutes before starting the compression creep test and the thickness of test sample A at 90°C just kept for 5 minutes at the end of the compression creep test is set as the change amount of the thickness of test sample A before and after the compression creep test.

2. An interlayer film for laminated glass, which is an interlayer film for laminated glass having a structure of 1 layer or a structure of 2 or more layers, wherein, The intermediate film has a first layer with a thickness of 200 μm or more and 900 μm or less, The glass transition temperature of the first layer is 20°C or higher and 45°C or lower, The first layer contains a polyvinyl acetal resin and a plasticizer, In the first layer, the hydroxyl group content of the polyvinyl acetal resin contained is 25 mol% or more and 38 mol% or less, and the degree of acetalization of the polyvinyl acetal resin contained in the first layer is 55 mol% or more and 75 mol% or less, The hydroxyl group content of the polyvinyl acetal resin is the value expressed as a percentage of the mole fraction obtained by dividing the amount of ethylene groups bonded to hydroxyl groups by the total amount of ethylene groups in the main chain, The degree of acetalization is determined as follows. First, a value obtained by subtracting the amount of ethylene groups bonded to hydroxyl groups and the amount of ethylene groups bonded to acetyl groups from the total amount of ethylene groups in the main chain is calculated. Then, the molar fraction is obtained by dividing the calculated value by the total amount of ethylene groups in the main chain, and the value expressed as a percentage of this molar fraction is the degree of acetalization. In the first layer, the content of the plasticizer is 30 parts by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the polyvinyl alcohol acetal resin. The polyvinyl alcohol acetal resin contained in the first layer is a mixture of a first polyvinyl alcohol acetal resin 1A having an average degree of polymerization of polyvinyl alcohol of 1500 or more and a second polyvinyl alcohol acetal resin 1B having an average degree of polymerization of polyvinyl alcohol of 1000 or less. In a total of 100% by weight of the first polyvinyl alcohol acetal resin 1A and the second polyvinyl alcohol acetal resin 1B, the content of the second polyvinyl alcohol acetal resin 1B is 50% by weight or more and 80% by weight or less. The thickness of the first layer is set as T B μm, for the diameter 8 mm and thickness T obtained by cutting the first layer B When the test sample B with a thickness of 200 μm is subjected to the following compression creep test, the change in thickness of the test sample B before and after the compression creep test is 50 μm or more and 325 μm or less. Compression creep test: In a state where a load of 410 g is applied to test sample B, the temperature is raised from 30 °C to 90 °C at a rate of 6 °C per minute and held at 90 °C for 5 minutes. The absolute value of the difference between the thickness of test sample B at 30 °C just after holding for 30 minutes before starting the compression creep test and the thickness of test sample B at 90 °C just after holding for 5 minutes at the end of the compression creep test is defined as the change in the thickness of test sample B before and after the compression creep test.

3. An interlayer film for laminated glass, which is an interlayer film for laminated glass having a structure of 1 layer or a structure of 2 or more layers, wherein, The intermediate film has a first layer. The glass transition temperature of the first layer is 20 °C or more and 45 °C or less. The thickness of the intermediate film is 80 μm or more and 1600 μm or less. The first layer contains a polyvinyl alcohol acetal resin and a plasticizer. The hydroxyl group content of the polyvinyl alcohol acetal resin contained in the first layer is 25 mol% or more and 38 mol% or less, and the degree of acetalization of the polyvinyl alcohol acetal resin contained in the first layer is 55 mol% or more and 75 mol% or less. The hydroxyl group content of the polyvinyl alcohol acetal resin is the value expressed as a percentage of the molar fraction obtained by dividing the amount of ethylene groups bonded to hydroxyl groups by the total amount of ethylene groups in the main chain. The degree of acetalization is determined as follows. First, a value obtained by subtracting the amount of ethylene groups bonded to hydroxyl groups and the amount of ethylene groups bonded to acetyl groups from the total amount of ethylene groups in the main chain is calculated. Then, the molar fraction is obtained by dividing the calculated value by the total amount of ethylene groups in the main chain, and the value expressed as a percentage of this molar fraction is the degree of acetalization. In the first layer, the content of the plasticizer is 30 parts by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the polyvinyl alcohol acetal resin. The polyvinyl alcohol acetal resin contained in the first layer is a mixture of a first polyvinyl alcohol acetal resin 1A having an average degree of polymerization of polyvinyl alcohol of 1500 or more and a second polyvinyl alcohol acetal resin 1B having an average degree of polymerization of polyvinyl alcohol of 1000 or less. In a total of 100% by weight of the first polyvinyl alcohol acetal resin 1A and the second polyvinyl alcohol acetal resin 1B, the content of the second polyvinyl alcohol acetal resin 1B is 50% by weight or more and 80% by weight or less. Set the thickness of the intermediate film to T C μm. For test sample C with a diameter of 8 mm and a thickness of T C μm obtained by cutting the intermediate film, when performing the following compression creep test, the change amount of the thickness of test sample C before and after the compression creep test is 50 μm or more and 325 μm or less. Compression creep test: While a load of 410 g is applied to test sample C, the temperature is raised from 30°C to 90°C at a rate of 6°C per minute, held at 90°C for 5 minutes, and the absolute value of the difference between the thickness of test sample C at 30°C at the start of the compression creep test and the thickness of test sample C just after holding for 5 minutes at 90°C at the end of the compression creep test is defined as the change in the thickness of test sample C before and after the compression creep test.

4. The interlayer film for laminated glass according to any one of claims 1 to 3, wherein, The degree of acetylation of the polyvinyl acetal resin contained in the first layer is 0.01 mol% or more and 10 mol% or less.

5. The interlayer film for laminated glass according to any one of claims 1 to 3, wherein, The intermediate film has a structure of two or more layers. The intermediate film further includes a second layer. The second layer is disposed on the first surface side of the first layer.

6. The interlayer film for laminated glass according to any one of claims 1 to 3, wherein, The first layer is the surface layer of the intermediate film.

7. The interlayer film for laminated glass according to claim 6, wherein, The softening point of the first layer is 45°C or more and 70°C or less.

8. The interlayer film for laminated glass according to claim 1, wherein, The thickness of the intermediate film is 80 μm or more and 1600 μm or less.

9. A laminated glass, comprising: a first laminated glass component, a second laminated glass component, and the interlayer film for laminated glass according to any one of claims 1 to 8, wherein the interlayer film for laminated glass is disposed between the first laminated glass component and the second laminated glass component.

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