Interlayer film for laminated glass and laminated glass

Abstract

Provided is an intermediate film for laminated glass that can heighten sound insulation in a low-frequency region while maintaining high sound insulation in a high-frequency region.　An intermediate film for laminated glass according to the present invention is an intermediate film for laminated glass, having a structure of two or more layers, wherein: the intermediate film has one end and another end on the opposite side from the one end; each layer included in the intermediate film has one end and another end on the opposite side of the one end; the one end of each of the layers is positioned on the one end side of the intermediate film in a direction connecting the one end and the other end of the intermediate film; the other end of each of the layers is positioned on the other end side of the intermediate film in a direction connecting the one end and the other end of the intermediate film; in the intermediate film, the thickness of the other end is thicker than the thickness of the one end; and in at least one layer included in the intermediate film, the thickness at the other end is thinner than the thickness at the one end.

Description

[Technical Field]

[0001] The present invention relates to an interlayer film for laminated glass used to obtain laminated glass. The present invention also relates to laminated glass using the interlayer film for laminated glass. [Background technology]

[0002] Laminated glass is excellent in safety because it generates only a small amount of glass fragments even when broken by external impact. For this reason, laminated glass is widely used in automobiles, railway vehicles, aircraft, ships, buildings, etc. Laminated glass is manufactured by sandwiching an interlayer film between a pair of glass sheets.

[0003] Head-up displays (HUDs) are also known as laminated glass for use in automobiles. HUDs can display measurement information, such as speed, which is driving data for the automobile, on the windshield, allowing the driver to perceive the display as if it were projected on the windshield in front of them.

[0004] The above HUD has the problem that measurement information, etc. appears double.

[0005] In order to suppress ghosting, a wedge-shaped interlayer film is used, one end of which is thinner than the other end (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] WO2018 / 070461A1 Summary of the Invention [Problem to be solved by the invention]

[0007] When laminated glass with a conventional wedge-shaped interlayer is used in automobiles and the like, it can improve sound insulation in the high frequency range of about 4000 Hz to 5000 Hz, such as wind noise.

[0008] However, with conventional wedge-shaped interlayer films, it is difficult to adjust the natural frequency, and therefore it can be difficult to improve sound insulation in the low frequency range while maintaining high sound insulation in the high frequency range. For example, with conventional wedge-shaped interlayer films, it can be difficult to improve sound insulation in the low frequency range, such as muffled noise, while maintaining high sound insulation in the high frequency range, such as wind noise.

[0009] An object of the present invention is to provide an interlayer film for laminated glass that can enhance sound insulation in the low-frequency range while maintaining high sound insulation in the high-frequency range. Another object of the present invention is to provide laminated glass using the interlayer film for laminated glass. [Means for solving the problem]

[0010] According to a broad aspect of the present invention, there is provided an interlayer film for laminated glass having a structure of two or more layers, the interlayer film having one end and another end opposite the one end, each layer included in the interlayer film having one end and another end opposite the one end, the one end of each layer being located on the one end side of the interlayer film in a direction connecting the one end and the other end of the interlayer film, and the other end of each layer being located on the other end side of the interlayer film in a direction connecting the one end and the other end of the interlayer film, the thickness of the other end of the interlayer film being thicker than the thickness of the one end, and at least one layer included in the interlayer film having a thickness at the other end that is thinner than the thickness at the one end (in this specification, "interlayer film for laminated glass" may be abbreviated as "interlayer film").

[0011] In a specific aspect of the interlayer film according to the present invention, the interlayer film is an interlayer film for laminated glass having a structure of three or more layers, and includes a first layer, a second layer, and a third layer, the first layer being disposed on a first surface side of the second layer, and the third layer being disposed on a second surface side of the second layer opposite the first surface.

[0012] In a specific aspect of the interlayer film according to the present invention, the thickness of the first layer at the other end is smaller than the thickness at the one end.

[0013] In a specific aspect of the interlayer film according to the present invention, the third layer has a thickness at the other end greater than a thickness at the one end.

[0014] In a specific aspect of the interlayer film according to the present invention, the ratio of the average thickness of the first layer to the average thickness of the interlayer film is smaller than the ratio of the average thickness of the third layer to the average thickness of the interlayer film, and the ten-point average roughness Rz of the surface of the first layer opposite to the second layer is 9 μm or more.

[0015] In a specific aspect of the interlayer film according to the present invention, the third layer has a thickness at the other end that is smaller than the thickness at the one end.

[0016] In a specific aspect of the interlayer film according to the present invention, the ratio of the average thickness of the third layer to the average thickness of the interlayer film is smaller than the ratio of the average thickness of the first layer to the average thickness of the interlayer film, and the ten-point average roughness Rz of the surface of the third layer opposite to the second layer is 9 μm or more.

[0017] In a specific aspect of the interlayer film according to the present invention, the first layer contains a thermoplastic resin and a plasticizer, the second layer contains a thermoplastic resin and a plasticizer, and the third layer contains a thermoplastic resin and a plasticizer.

[0018] In a specific aspect of the interlayer film according to the present invention, the content of the plasticizer in the second layer per 100 parts by weight of the thermoplastic resin in the second layer is greater than the content of the plasticizer in the first layer per 100 parts by weight of the thermoplastic resin in the first layer, and the content of the plasticizer in the second layer per 100 parts by weight of the thermoplastic resin in the second layer is greater than the content of the plasticizer in the third layer per 100 parts by weight of the thermoplastic resin in the third layer.

[0019] In a specific aspect of the interlayer film according to the present invention, the thickness of the interlayer film at the one end is 300 μm or more.

[0020] According to a broad aspect of the present invention, there is provided laminated glass comprising a first laminated glass element, a second laminated glass element, and the above-described interlayer film for laminated glass, with the interlayer film for laminated glass disposed between the first laminated glass element and the second laminated glass element. [Effects of the Invention]

[0021] The interlayer film according to the present invention has a structure of two or more layers. The interlayer film according to the present invention has one end and another end opposite the one end. Each layer included in the interlayer film according to the present invention has one end and another end opposite the one end. In the interlayer film according to the present invention, the one end of each layer is located on the one end side of the interlayer film in a direction connecting the one end and the other end of the interlayer film, and the other end of each layer is located on the other end side of the interlayer film in a direction connecting the one end and the other end of the interlayer film. In the interlayer film according to the present invention, the thickness of the other end is thicker than the thickness of the one end. In at least one layer included in the interlayer film according to the present invention, the thickness of the other end is thinner than the thickness of the one end. The interlayer film for laminated glass according to the present invention has the above configuration, and can improve sound insulation in the low frequency range while maintaining high sound insulation in the high frequency range. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a cross-sectional view schematically illustrating an interlayer film for laminated glass according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a third embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fourth embodiment of the present invention. [Figure 5] FIG. 5 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fifth embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a sixth embodiment of the present invention. [Figure 7] FIG. 7 is a cross-sectional view that schematically shows an example of laminated glass that uses the interlayer film for laminated glass shown in FIG. [Figure 8] FIG. 8 is a plan view schematically showing an optical distortion inspection device used to measure optical distortion in the examples and comparative examples. [Figure 9] FIG. 9 is a front view schematically showing an optical distortion inspection device used to measure optical distortion in the examples and comparative examples. [Figure 10] 10(a) and (b) are diagrams for explaining the processing operations in the image processing unit. DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention will be described in detail below.

[0024] The interlayer film for laminated glass according to the present invention (sometimes abbreviated as "interlayer film" in this specification) is used in laminated glass.

[0025] The interlayer film has a structure of two or more layers. Therefore, the interlayer film includes at least a first layer and a second layer. In the interlayer film, the first layer is disposed on the first surface side of the second layer.

[0026] The interlayer film may have a three-layer structure, a three or more layer structure, a four or more layer structure, a five or more layer structure, or a six or more layer structure. An interlayer film having a three or more layer structure includes at least a first layer, a second layer, and a third layer. In an interlayer film having a three or more layer structure, the first layer is disposed on a first surface side of the second layer, and the third layer is disposed on a second surface side of the second layer opposite to the first surface. In an interlayer film having a three or more layer structure, the first layer, the second layer, and the third layer are disposed in this order, aligned in the thickness direction of the interlayer film.

[0027] The structure of the interlayer film may differ partially. For example, the interlayer film of the present invention may have a portion having a single-layer structure and a portion having a two or more-layer structure. In the present invention, when the interlayer film has a portion having a two or more-layer structure, the interlayer film is considered to have a two or more-layer structure. The interlayer film of the present invention may have a portion having a single-layer structure and a portion having a three or more-layer structure. The interlayer film of the present invention may have a portion having a two-layer structure and a portion having a three or more-layer structure. In the present invention, when the interlayer film has a portion having a three or more-layer structure, the interlayer film is considered to have a three or more-layer structure.

[0028] The interlayer film has one end and the other end opposite the one end. The one end and the other end of the interlayer film are opposite ends of the interlayer film.

[0029] Each layer included in the interlayer film has one end and the other end opposite the one end. The one end and the other end of each layer are opposite ends of the layer. The one end of each layer is located on the one end side of the interlayer film in a direction connecting the one end and the other end of the interlayer film, and the other end of each layer is located on the other end side of the interlayer film in a direction connecting the one end and the other end of the interlayer film.

[0030] In the present invention, the thickness of the other end of the intermediate film is greater than the thickness of the one end.

[0031] In the present invention, in at least one layer included in the interlayer film, the thickness at the other end is thinner than the thickness at the one end. That is, in the interlayer film, the thickness at the other end of at least one layer is thinner than the thickness at the one end of the layer. The interlayer film has at least one layer whose thickness at the other end is thinner than the thickness at the one end.

[0032] The interlayer film according to the present invention has the above-described configuration, and therefore can maintain high sound insulation in the high frequency range while improving sound insulation in the low frequency range.

[0033] In the interlayer film according to the present invention, the natural frequency can be easily adjusted by, for example, controlling the thickness ratio of each layer included in the interlayer film, which makes it possible to improve sound insulation in the low frequency range, such as against booming noise, while maintaining high sound insulation in the high frequency range, such as against wind noise.

[0034] Furthermore, in the interlayer film according to the present invention, the occurrence of optical distortion can be suppressed by adjusting the shape of each layer.

[0035] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[0036] FIG. 1 is a cross-sectional view schematically illustrating an interlayer film for laminated glass according to a first embodiment of the present invention.

[0037] The interlayer film 11 shown in Fig. 1 is used to obtain laminated glass. The interlayer film 11 is an interlayer film for laminated glass.

[0038] The intermediate film 11 has one end 11a and the other end 11b. The thickness of the intermediate film 11 at the other end 11b is greater than the thickness of the one end 11a. The thickness of the intermediate film 11 increases uniformly from the one end 11a side to the other end 11b side.

[0039] The interlayer film 11 includes a first layer 1, a second layer 2, and a third layer 3. The interlayer film 11 has a three-layer structure. The second layer 2 has a first surface 2a and a second surface 2b. The first surface 2a and the second surface 2b are surfaces that face each other. The first layer 1 is disposed on the first surface 2a side of the second layer 2 and stacked thereon. The third layer 3 is disposed on the second surface 2b side of the second layer 2 and stacked thereon. The first layer 1 and the second layer 2 are in contact with each other. The second layer 2 and the third layer 3 are in contact with each other. The second layer 2 is disposed between the first layer 1 and the third layer 3 and sandwiched therebetween. The first layer 1, the second layer 2, and the third layer 3 each have one end and the other end. One ends of these layers are located on the one end 11a side of the intermediate film 11 in the direction connecting one end 11a and the other end 11b of the intermediate film 11. The other ends of these layers are located on the other end 11b side of the intermediate film 11 in the direction connecting one end 11a and the other end 11b of the intermediate film 11. One ends of the first layer 1, the second layer 2, and the third layer 3 correspond to one end 11a of the intermediate film 11. The other ends of the first layer 1, the second layer 2, and the third layer 3 correspond to the other end 11b of the intermediate film 11. The end face on the one end 11a side of the intermediate film 11 is made up of the end faces on one end sides of the first layer 1, the second layer 2, and the third layer 3. The end face on the other end 11b side of the intermediate film 11 is made up of the end faces on the other end sides of the first layer 1, the second layer 2, and the third layer 3.

[0040] The thickness of the first layer 1 at the other end thereof is thinner than the thickness of the first layer 1 at one end thereof. The cross-sectional shape of the first layer 1 in the thickness direction has a rectangular portion and a wedge-shaped portion. The cross-sectional shape of the first layer 1 in the thickness direction has a rectangular portion on one end 11a side and a wedge-shaped portion on the other end 11b side. The first layer 1 has a region where the thickness decreases from one end side to the other end side. The first layer 1 has a portion where the amount of thickness decrease is greater within the region where the thickness decreases from one end side to the other end side.

[0041] The thickness of the second layer 2 at the other end thereof is greater than the thickness of the second layer 2 at one end thereof. The cross-sectional shape of the second layer 2 in the thickness direction has a rectangular portion and a wedge-shaped portion. The cross-sectional shape of the second layer 2 in the thickness direction has a rectangular portion on one end side and a wedge-shaped portion on the other end side. The second layer 2 has a region where the thickness increases from one end side to the other end side.

[0042] The thickness of the third layer 3 at the other end is greater than the thickness of the third layer 3 at one end. The thickness of the third layer 3 increases from one end to the other end. The third layer 3 has a portion where the amount of increase in thickness is greater within the region where the thickness increases from one end to the other end.

[0043] FIG. 2 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a second embodiment of the present invention.

[0044] The interlayer film 11A shown in Fig. 2 is used to obtain laminated glass. The interlayer film 11A is an interlayer film for laminated glass.

[0045] The intermediate film 11A has one end 11a and the other end 11b. The thickness of the intermediate film 11A at the other end 11b is greater than the thickness of the one end 11a. The thickness of the intermediate film 11A increases uniformly from the one end 11a to the other end 11b.

[0046] The interlayer film 11A includes a first layer 1A, a second layer 2A, and a third layer 3A. The interlayer film 11A has a three-layer structure. The second layer 2A has a first surface 2Aa and a second surface 2Ab. The first surface 2Aa and the second surface 2Ab are surfaces that face each other. The first layer 1A is disposed on the first surface 2Aa side of the second layer 2A and stacked thereon. The third layer 3A is disposed on the second surface 2Ab side of the second layer 2A and stacked thereon. The first layer 1A and the second layer 2A are in contact with each other. The second layer 2A and the third layer 3A are in contact with each other. The second layer 2A is disposed between the first layer 1A and the third layer 3A and is sandwiched therebetween. The first layer 1A, the second layer 2A, and the third layer 3A each have one end and the other end. One ends of these layers are located on the one end 11a side of the intermediate film 11A in the direction connecting one end 11a and the other end 11b of the intermediate film 11A. The other ends of these layers are located on the other end 11b side of the intermediate film 11A in the direction connecting one end 11a and the other end 11b of the intermediate film 11A. One ends of the first layer 1A, the second layer 2A, and the third layer 3A correspond to one end 11a of the intermediate film 11A. The other ends of the first layer 1A, the second layer 2A, and the third layer 3A correspond to the other end 11b of the intermediate film 11A. The end face on the one end 11a side of the intermediate film 11A is made up of the end faces on the one end sides of the first layer 1A, the second layer 2A, and the third layer 3A. The end face on the other end 11b side of the intermediate film 11A is made up of the end faces on the other end sides of the first layer 1A, the second layer 2A, and the third layer 3A.

[0047] The thickness of the first layer 1A at the other end is thinner than the thickness of the first layer 1A at one end. The cross-sectional shape of the first layer 1A in the thickness direction has a rectangular portion and a wedge-shaped portion. The cross-sectional shape of the first layer 1A in the thickness direction has a rectangular portion at one end and a wedge-shaped portion at the other end. The first layer 1A has a region where the thickness decreases from one end to the other end. The first layer 1A has a portion where the amount of thickness decrease is greater within the region where the thickness decreases from one end to the other end.

[0048] The thickness of the second layer 2A at the other end is greater than the thickness of the second layer 2A at one end. The thickness of the second layer 2A increases from one end to the other end. The second layer 2A has a portion where the amount of increase in thickness is greater within the region where the thickness increases from one end to the other end.

[0049] The thickness of the third layer 3A at the other end is thinner than the thickness of the third layer 3A at one end. The thickness of the third layer 3A decreases from one end to the other end. The third layer 3A has a portion where the amount of thickness reduction is greater within the region where the thickness decreases from one end to the other end.

[0050] FIG. 3 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a third embodiment of the present invention.

[0051] The interlayer film 11B shown in Fig. 3 is used to obtain laminated glass. The interlayer film 11B is an interlayer film for laminated glass.

[0052] The intermediate film 11B has one end 11a and the other end 11b. The thickness of the intermediate film 11B at the other end 11b is greater than the thickness of the one end 11a. The thickness of the intermediate film 11B increases uniformly from the one end 11a side to the other end 11b side.

[0053] The interlayer film 11B includes a first layer 1B, a second layer 2B, and a third layer 3B. The interlayer film 11B has a three-layer structure. The second layer 2B has a first surface 2Ba and a second surface 2Bb. The first surface 2Ba and the second surface 2Bb are surfaces that face each other. The first layer 1B is disposed on the first surface 2Ba side of the second layer 2B and stacked thereon. The third layer 3B is disposed on the second surface 2Bb side of the second layer 2B and stacked thereon. The first layer 1B and the second layer 2B are in contact with each other. The second layer 2B and the third layer 3B are in contact with each other. The second layer 2B is disposed between the first layer 1B and the third layer 3B and is sandwiched therebetween. The first layer 1B, the second layer 2B, and the third layer 3B each have one end and the other end. One ends of these layers are located on the one end 11a side of the intermediate film 11B in the direction connecting one end 11a and the other end 11b of the intermediate film 11B. The other ends of these layers are located on the other end 11b side of the intermediate film 11B in the direction connecting one end 11a and the other end 11b of the intermediate film 11B. One ends of the first layer 1B, the second layer 2B, and the third layer 3B correspond to one end 11a of the intermediate film 11B. The other ends of the first layer 1B, the second layer 2B, and the third layer 3B correspond to the other end 11b of the intermediate film 11B. The end face on the one end 11a side of the intermediate film 11B is made up of the end faces on one end sides of the first layer 1B, the second layer 2B, and the third layer 3B. The end face on the other end 11b side of the intermediate film 11B is made up of the end faces on the other end sides of the first layer 1B, the second layer 2B, and the third layer 3B.

[0054] The thickness of the first layer 1B at the other end is greater than the thickness of the first layer 1B at one end. The thickness of the first layer 1B increases from one end to the other end. The increase in thickness of the first layer 1B is uniform from one end to the other end.

[0055] The thickness of the second layer 2B at the other end is thinner than the thickness of the second layer 2B at one end. The thickness of the second layer 2B decreases from one end to the other end. The amount of decrease in thickness of the second layer 2B is uniform from one end to the other end.

[0056] The thickness of the third layer 3B at the other end is greater than the thickness of the third layer 3B at one end. The thickness of the third layer 3B increases from one end to the other end. The amount of increase in thickness of the third layer 3B from one end to the other end is uniform.

[0057] FIG. 4 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fourth embodiment of the present invention.

[0058] The interlayer film 11C shown in Fig. 4 is used to obtain laminated glass. The interlayer film 11C is an interlayer film for laminated glass.

[0059] The intermediate film 11C has one end 11a and the other end 11b. The thickness of the intermediate film 11C at the other end 11b is greater than the thickness of the one end 11a. The thickness of the intermediate film 11C increases uniformly from the one end 11a side to the other end 11b side.

[0060] The interlayer film 11C includes a first layer 1C, a second layer 2C, and a third layer 3C. The interlayer film 11C has a three-layer structure. The second layer 2C has a first surface 2Ca and a second surface 2Cb. The first surface 2Ca and the second surface 2Cb are surfaces that face each other. The first layer 1C is disposed on the first surface 2Ca side of the second layer 2C, and stacked thereon. The third layer 3C is disposed on the second surface 2Cb side of the second layer 2C, and stacked thereon. The first layer 1C and the second layer 2C are in contact with each other. The second layer 2C and the third layer 3C are in contact with each other. The second layer 2C is disposed between the first layer 1C and the third layer 3C, and is sandwiched therebetween. The first layer 1C, the second layer 2C, and the third layer 3C each have one end and the other end. One end of each of these layers is located on the side of one end 11a of the intermediate film 11C in the direction connecting one end 11a and the other end 11b of the intermediate film 11C. The other end of each of these layers is located on the side of the other end 11b of the intermediate film 11C in the direction connecting one end 11a and the other end 11b of the intermediate film 11C. One ends of the first layer 1C, the second layer 2C, and the third layer 3C correspond to one end 11a of the intermediate film 11C. The other ends of the first layer 1C, the second layer 2C, and the third layer 3C correspond to the other end 11b of the intermediate film 11C. The end face on the side of one end 11a of the intermediate film 11C is made up of the end faces on one end of the first layer 1C, the second layer 2C, and the third layer 3C. The end face on the side of the other end 11b of the intermediate film 11C is made up of the end faces on the other end of the first layer 1C, the second layer 2C, and the third layer 3C.

[0061] The thickness of the first layer 1C at the other end is thinner than the thickness of the first layer 1C at one end. The thickness of the first layer 1C decreases from one end to the other end. The amount of decrease in thickness of the first layer 1C is uniform from one end to the other end.

[0062] The thickness of the second layer 2C at the other end is the same as the thickness at one end of the second layer 2C. The thickness of the second layer 2C is uniform from one end to the other end.

[0063] The thickness of the third layer 3C at the other end is greater than the thickness of the third layer 3C at one end. The thickness of the third layer 3C increases from one end to the other end. The increase in thickness of the third layer 3C is uniform from one end to the other end.

[0064] FIG. 5 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fifth embodiment of the present invention.

[0065] The interlayer film 11D shown in Fig. 5 is used to obtain laminated glass. The interlayer film 11D is an interlayer film for laminated glass.

[0066] The intermediate film 11D has one end 11a and the other end 11b. The thickness of the other end 11b of the intermediate film 11D is greater than the thickness of the one end 11a. The cross-sectional shape of the intermediate film 11D in the thickness direction has a wedge-shaped portion 11Da and a rectangular portion 11Db. The intermediate film 11D has the wedge-shaped portion 11Da on the one end 11a side and the rectangular portion 11Db on the other end 11b side. In the wedge-shaped portion 11Da of the cross-sectional shape of the intermediate film 11D in the thickness direction, the increase in thickness is uniform from the one end 11a side to the other end 11b side.

[0067] The interlayer 11D includes a first layer 1D, a second layer 2D, and a third layer 3D. The first layer 1D is disposed on the first surface 2Da side of the second layer 2D, and they are stacked. The third layer 3D is disposed on the second surface 2Db side of the second layer 2D, and they are stacked. The first layer 1D, the second layer 2D, and the third layer 3D each have one end and the other end. One end of each of these layers is located on the one end 11a side of the interlayer 11D in the direction connecting the one end 11a and the other end 11b of the interlayer 11D. The other end of each of these layers is located on the other end 11b side of the interlayer 11D in the direction connecting the one end 11a and the other end 11b of the interlayer 11D. One end of each of the first layer 1D, the second layer 2D, and the third layer 3D corresponds to the one end 11a of the interlayer 11D. The other ends of the first layer 1D, the second layer 2D, and the third layer 3D correspond to the other end 11b of the intermediate film 11D. The end face on one end 11a of the intermediate film 11D is made up of the end faces on one end of the first layer 1D, the second layer 2D, and the third layer 3D. The end face on the other end 11b of the intermediate film 11D is made up of the end faces on the other end of the first layer 1D, the second layer 2D, and the third layer 3D.

[0068] The thickness of the first layer 1D at the other end is thinner than the thickness of the first layer 1D at one end. The cross-sectional shape of the first layer 1D in the thickness direction has a rectangular portion and a wedge-shaped portion. The cross-sectional shape of the first layer 1D in the thickness direction has a rectangular portion at one end and a wedge-shaped portion at the other end. The first layer 1D has a region where the thickness decreases from one end to the other end. The first layer 1D has a portion where the amount of thickness decrease is greater within the region where the thickness decreases from one end to the other end.

[0069] The thickness of the second layer 2D at the other end is greater than the thickness of the second layer 2D at one end. The cross-sectional shape of the second layer 2D in the thickness direction has a rectangular portion and a wedge-shaped portion. The cross-sectional shape of the second layer 2D in the thickness direction has a rectangular portion on one end side and a wedge-shaped portion on the other end side. The second layer 2D has a region whose thickness increases from one end side to the other end side.

[0070] The thickness of the third layer 3D at the other end is greater than the thickness of the third layer 3D at one end. The cross-sectional shape of the third layer 3D in the thickness direction has a wedge-shaped portion. The third layer 3D has a region where the thickness increases from one end to the other end. The third layer 3D has a portion where the amount of increase in thickness is greater within the region where the thickness increases from one end to the other end.

[0071] FIG. 6 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a sixth embodiment of the present invention.

[0072] The interlayer film 11E shown in Fig. 6 is used to obtain laminated glass. The interlayer film 11E is an interlayer film for laminated glass.

[0073] The intermediate film 11E has one end 11a and the other end 11b. The thickness of the other end 11b of the intermediate film 11E is greater than the thickness of the one end 11a. The intermediate film 11E has a region where the thickness increases from the one end 11a side to the other end 11b side. The region where the thickness increases includes a first portion 11Ea where the thickness increase is constant, and a second portion 11Eb where the thickness increase is constant. The thickness increase in the first portion 11Ea is different from the thickness increase in the second portion 11Eb. The thickness increase in the first portion 11Ea is greater than the thickness increase in the second portion 11Eb.

[0074] The interlayer 11E includes a first layer 1E, a second layer 2E, and a third layer 3E. The first layer 1E is disposed on the first surface 2Ea side of the second layer 2E, and they are stacked. The third layer 3E is disposed on the second surface 2Eb side of the second layer 2E, and they are stacked. The first layer 1E, the second layer 2E, and the third layer 3E each have one end and the other end. One end of each of these layers is located on the one end 11a side of the interlayer 11E in the direction connecting the one end 11a and the other end 11b of the interlayer 11E. The other end of each of these layers is located on the other end 11b side of the interlayer 11E in the direction connecting the one end 11a and the other end 11b of the interlayer 11E. One end of each of the first layer 1E, the second layer 2E, and the third layer 3E corresponds to the one end 11a of the interlayer 11E. The other ends of the first layer 1E, the second layer 2E, and the third layer 3E correspond to the other end 11b of the intermediate film 11E. The end face on one end 11a of the intermediate film 11E is made up of the end faces on one end of the first layer 1E, the second layer 2E, and the third layer 3E. The end face on the other end 11b of the intermediate film 11E is made up of the end faces on the other end of the first layer 1E, the second layer 2E, and the third layer 3E.

[0075] The thickness of the first layer 1E at the other end is thinner than the thickness of the first layer 1E at one end. The cross-sectional shape of the first layer 1E in the thickness direction has a rectangular portion and a wedge-shaped portion. The cross-sectional shape of the first layer 1E in the thickness direction has a rectangular portion on one end and a wedge-shaped portion on the other end. The first layer 1E has a region where the thickness decreases from one end to the other end. The first layer 1E has a portion where the amount of thickness decrease is greater in the region where the thickness decreases from one end to the other end.

[0076] The thickness of the second layer 2E at the other end is greater than the thickness of the second layer 2E at one end. The cross-sectional shape of the second layer 2E in the thickness direction has a rectangular portion and a wedge-shaped portion. The cross-sectional shape of the second layer 2E in the thickness direction has a rectangular portion on one end side and a wedge-shaped portion on the other end side. The second layer 2E has a region whose thickness increases from one end side to the other end side.

[0077] The thickness of the third layer 3E at the other end is greater than the thickness of the third layer 3E at one end. The cross-sectional shape of the third layer 3E in the thickness direction has a wedge-shaped portion. The third layer 3E has a region where the thickness increases from one end to the other end. The third layer 3E has a portion where the amount of increase in thickness is greater within the region where the thickness increases from one end to the other end.

[0078] In the interlayer film according to the present invention, another layer may be disposed between the first layer and the second layer, and between the second layer and the third layer, although it is preferable that the first layer and the second layer are directly laminated, and it is preferable that the second layer and the third layer are directly laminated.

[0079] The first layer is preferably a surface layer of an interlayer film. The third layer is preferably a surface layer of an interlayer film. When the interlayer film has a structure of three or more layers, the second layer is a middle layer of the interlayer film.

[0080] In the interlayer film of the present invention, at least one layer has a thickness that is thinner at the other end than at one end. In the interlayer film of the present invention, the thickness at the other end of one layer may be thinner than at the one end, or the thickness at the other end of two layers may be thinner than at the one end. Furthermore, when the interlayer film of the present invention has a structure of four or more layers, the thickness at the other end of three or more layers in the interlayer film may be thinner than at the one end. The layer that is thinner at the other end than at the one end may be the first layer, the second layer, or the third layer.

[0081] In the interlayer film of the present invention, the thickness at the other end is greater than the thickness at the one end, and in at least one layer included in the interlayer film of the present invention, the thickness at the other end is less than the thickness at the one end. Thus, in the interlayer film of the present invention, the thickness at the other end of at least one layer is greater than the thickness at the one end. In the interlayer film of the present invention, the thickness at the other end of one layer may be greater than the thickness at the one end, and in two layers, the thickness at the other end may be greater than the thickness at the one end. Furthermore, when the interlayer film of the present invention has a structure of four or more layers, the thickness at the other end of three or more layers in the interlayer film may be greater than the thickness at the one end. The layer whose thickness at the other end is greater than the thickness at the one end may be the first layer, the second layer, or the third layer.

[0082] In order to more effectively exert the effects of the present invention, it is preferable that the thickness of the first layer at the other end is thinner than the thickness of the first end.

[0083] From the viewpoint of more effectively suppressing the occurrence of optical distortion, it is preferable that the thickness of the first layer at the other end is thinner than the thickness at one end, and that the thickness of the third layer at the other end is thicker than the thickness at one end.

[0084] From the viewpoint of further improving sound insulation, it is preferable that the thickness of the first layer at the other end is thinner than the thickness at one end, and that the thickness of the third layer at the other end is the same as or thinner than the thickness at the one end.From the viewpoint of further improving sound insulation, it is preferable that the thickness of the first layer at the other end is thinner than the thickness at one end, and that the thickness of the third layer at the other end is thinner than the thickness at one end.

[0085] From the viewpoint of more effectively suppressing the occurrence of optical distortion, it is preferable that the layer having a thickness at the other end that is thinner than the thickness at the one end has a cross-sectional shape in the thickness direction that is rectangular and a wedge-shaped portion, and in this case, it is preferable that the rectangular portion is located at the one end and the wedge-shaped portion is located at the other end.

[0086] In a cross section of the interlayer film in the thickness direction, it is preferable that the area (cross-sectional area) of the first layer or the third layer is larger than that of the second layer, and it is more preferable that the area (cross-sectional area) of the first layer and the third layer is larger than that of the second layer, respectively. In this case, optical distortion can be more effectively suppressed.

[0087] In a cross section of the interlayer film in the thickness direction, it is preferable that there is a portion where the area (cross-sectional area) of the second layer is larger than the area (cross-sectional area) of the first layer or the third layer, and it is more preferable that there is a portion where the area (cross-sectional area) is larger than the area (cross-sectional area) of the first layer and the area (cross-sectional area) of the third layer. In this case, sound insulation can be further improved.

[0088] The interlayer film may have a uniform thickness region. The uniform thickness region refers to a region in which the thickness does not change by more than 10 μm over a distance of 10 cm in the direction connecting one end of the interlayer film to the other end. Accordingly, the uniform thickness region refers to a region in which the thickness does not change by more than 10 μm over a distance of 10 cm in the direction connecting one end of the interlayer film to the other end. Specifically, the uniform thickness region refers to a region in which the thickness does not change at all over a distance of 10 cm in the direction connecting one end of the interlayer film to the other end, or a region in which the thickness changes by 10 μm or less over a distance of 10 cm in the direction connecting one end of the interlayer film to the other end.

[0089] The uniform thickness portion is preferably located closer to the one end of the intermediate film than the center between the one end and the other end.

[0090] The distance of the interlayer film in the direction connecting one end to the other end thereof is defined as distance L. The distance of the first layer in the direction connecting one end to the other end thereof is defined as distance L1. The distance of the second layer in the direction connecting one end to the other end thereof is defined as distance L2. The distance of the third layer in the direction connecting one end to the other end thereof is defined as distance L3. The distance of a layer whose thickness at the other end is thinner than the thickness at the one end thereof in the direction connecting one end to the other end thereof is defined as distance L4.

[0091] The interlayer preferably has a minimum thickness in a region from 0L to 0.5L from one end to the other end, and a maximum thickness in a region from 0L to 0.5L from the other end to the one end. It is more preferable that the interlayer has a minimum thickness in a region from 0L to 0.2L from one end to the other end, and a maximum thickness in a region from 0L to 0.2L from the other end to the one end. It is even more preferable that the interlayer has a minimum thickness at one end and a maximum thickness at the other end. In these cases, the minimum thickness and the maximum thickness may be present in a portion of each region, or in the entirety of each region.

[0092] The distance L between one end and the other end of the interlayer film is preferably 0.5 m or more, more preferably 0.8 m or more, and even more preferably 1 m or more, and is preferably 3 m or less, more preferably 2 m or less, and even more preferably 1.5 m or less.

[0093] The distance L1 between one end and the other end of the first layer is preferably 0.5 m or more, more preferably 0.8 m or more, even more preferably 1 m or more, and is preferably 3 m or less, more preferably 2 m or less, even more preferably 1.5 m or less.

[0094] The distance L2 between one end and the other end of the second layer is preferably 0.5 m or more, more preferably 0.8 m or more, even more preferably 1 m or more, and is preferably 3 m or less, more preferably 2 m or less, even more preferably 1.5 m or less.

[0095] The distance L3 between one end and the other end of the third layer is preferably 0.5 m or more, more preferably 0.8 m or more, even more preferably 1 m or more, and is preferably 3 m or less, more preferably 2 m or less, even more preferably 1.5 m or less.

[0096] The distance L4 between one end and the other end of the layer whose thickness at the other end is thinner than that at the one end is preferably 0.5 m or more, more preferably 0.8 m or more, even more preferably 1 m or more, and is preferably 3 m or less, more preferably 2 m or less, even more preferably 1.5 m or less.

[0097] The ratio of the distance L1 to the distance L (distance L1 / distance L) is preferably 0.3 or more, more preferably 0.5 or more, even more preferably 0.7 or more, and most preferably 1. The ratio (distance L1 / distance L) may be 1 or less, or may be 0.95 or less.

[0098] The ratio of the distance L2 to the distance L (distance L2 / distance L) is preferably 0.3 or more, more preferably 0.5 or more, even more preferably 0.7 or more, and most preferably 1. The ratio (distance L2 / distance L) may be 1 or less, or may be 0.95 or less.

[0099] The ratio of the distance L3 to the distance L (distance L3 / distance L) is preferably 0.3 or more, more preferably 0.5 or more, even more preferably 0.7 or more, and most preferably 1. The ratio (distance L3 / distance L) may be 1 or less, or may be 0.95 or less.

[0100] The ratio of the distance L4 to the distance L (distance L4 / distance L) is preferably 0.3 or more, more preferably 0.5 or more, even more preferably 0.7 or more, and most preferably 1. The ratio (distance L4 / distance L) may be 1 or less, or may be 0.95 or less.

[0101] The thickness of one end of the interlayer film is preferably 300 μm or more, more preferably 500 μm or more, even more preferably 700 μm or more, and preferably 1600 μm or less, more preferably 1400 μm or less, even more preferably 1200 μm or less. If the thickness of one end of the interlayer film is at least the above lower limit, the penetration resistance and bending rigidity of the laminated glass will be further improved. If the thickness of one end of the interlayer film is not more than the above upper limit, the transparency of the interlayer film and the laminated glass will be further improved.

[0102] The maximum thickness of the interlayer film is preferably 400 μm or more, more preferably 600 μm or more, even more preferably 800 μm or more, and particularly preferably 1000 μm or more, and is preferably 3.5 mm or less, more preferably 2.9 mm or less. When the maximum thickness of the interlayer film is at least the above lower limit, the penetration resistance and bending rigidity of the laminated glass are further improved. When the thickness of the interlayer film is not more than the above upper limit, the transparency of the interlayer film and the laminated glass is further improved.

[0103] The average thickness of the first layer is preferably 100 μm or more, more preferably 200 μm or more, even more preferably 300 μm or more, and is preferably 1100 μm or less, more preferably 950 μm or less, even more preferably 800 μm or less. When the average thickness of the first layer is equal to or greater than the above lower limit and equal to or less than the above upper limit, the effects of the present invention can be more effectively exhibited.

[0104] The average thickness of the second layer is preferably 50 μm or more, more preferably 60 μm or more, even more preferably 80 μm or more, and is preferably 1200 μm or less, more preferably 1000 μm or less, even more preferably 800 μm or less. When the average thickness of the second layer is not less than the above lower limit and not more than the above upper limit, the effects of the present invention can be more effectively exhibited.

[0105] The average thickness of the third layer is preferably 100 μm or more, more preferably 200 μm or more, even more preferably 300 μm or more, and is preferably 1100 μm or less, more preferably 950 μm or less, even more preferably 800 μm or less. When the average thickness of the third layer is not less than the above lower limit and not more than the above upper limit, the effects of the present invention can be more effectively exhibited.

[0106] In a layer having a thickness thinner at the other end than at the one end, the absolute value of the difference between the thickness of the layer at the one end and the thickness of the layer at the other end is preferably 1 μm or more, more preferably 5 μm or more, even more preferably 10 μm or more, and preferably 600 μm or less, more preferably 500 μm or less, even more preferably 400 μm or less. When the absolute value of the difference is equal to or greater than the above lower limit and equal to or less than the above upper limit, the effects of the present invention can be more effectively exhibited. The interlayer film preferably has at least one layer (a layer having a thickness thinner at the other end than the thickness at the one end) that satisfies the preferred upper or lower limit of the absolute value of the difference.

[0107] The thickness of the intermediate film at a predetermined position is T μm, the thickness of the first layer at the same position as the predetermined position is T1 μm, and the thickness of the third layer at the same position as the predetermined position is T3 μm.

[0108] When the thickness of the interlayer film is measured from one end to the other, the absolute value of the difference between the maximum value of T1 / T and the minimum value of T1 / T is preferably 0.03 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and preferably 0.7 or less, more preferably 0.5 or less, even more preferably 0.4 or less. When the absolute value of the difference is equal to or greater than the above lower limit and equal to or less than the above upper limit, the effects of the present invention can be more effectively exhibited. T1 / T is the ratio of T1 to T.

[0109] When the thickness of the interlayer film is measured from one end to the other, the absolute value of the difference between the maximum value of T3 / T and the minimum value of T3 / T is preferably 0.03 or more, more preferably 0.05 or more, even more preferably 0.1 or more, and preferably 0.7 or less, more preferably 0.5 or less, even more preferably 0.4 or less. When the absolute value of the difference is equal to or greater than the above lower limit and equal to or less than the above upper limit, the effects of the present invention can be more effectively exhibited. T3 / T is the ratio of T3 to T.

[0110] The interlayer film has a region where the thickness increases from one end to the other end. The interlayer film may be an interlayer film where the increase in thickness is uniform from one end to the other end of the interlayer film, or may be an interlayer film where the increase in thickness is not uniform. The interlayer film may have a portion where the increase in thickness is uniform within the region where the thickness increases from one end to the other end. The interlayer film may have a portion where the increase in thickness is large within the region where the thickness increases from one end to the other end. The interlayer film may have a portion where the increase in thickness is small within the region where the thickness increases from one end to the other end. The interlayer film may have a region where the thickness is uniform.

[0111] The first layer may have a region where the thickness increases from one end to the other end. The first layer may have a portion where the amount of increase in thickness is uniform within the region where the thickness increases from one end to the other end. The first layer may have a portion where the amount of increase in thickness is large within the region where the thickness increases from one end to the other end. The first layer may have a portion where the amount of increase in thickness is small within the region where the thickness increases from one end to the other end. The first layer may have a region where the thickness decreases from one end to the other end. The first layer may have a portion where the amount of decrease in thickness is uniform within the region where the thickness decreases from one end to the other end. The first layer may have a portion where the amount of decrease in thickness is large within the region where the thickness decreases from one end to the other end. The first layer may have a portion where the amount of decrease in thickness is small within the region where the thickness decreases from one end to the other end. The first layer may have a region where the thickness is uniform.

[0112] The second layer may have a region where the thickness increases from one end to the other end. The second layer may have a portion where the amount of increase in thickness is uniform within the region where the thickness increases from one end to the other end. The second layer may have a portion where the amount of increase in thickness is large within the region where the thickness increases from one end to the other end. The second layer may have a portion where the amount of increase in thickness is small within the region where the thickness increases from one end to the other end. The second layer may have a region where the thickness decreases from one end to the other end. The second layer may have a portion where the amount of decrease in thickness is uniform within the region where the thickness decreases from one end to the other end. The second layer may have a portion where the amount of decrease in thickness is large within the region where the thickness decreases from one end to the other end. The second layer may have a portion where the amount of decrease in thickness is small within the region where the thickness decreases from one end to the other end. The second layer may have a region where the thickness is uniform.

[0113] The third layer may have a region where the thickness increases from one end to the other end. The third layer may have a portion where the amount of increase in thickness is uniform within the region where the thickness increases from one end to the other end. The third layer may have a portion where the amount of increase in thickness is large within the region where the thickness increases from one end to the other end. The third layer may have a portion where the amount of increase in thickness is small within the region where the thickness increases from one end to the other end. The third layer may have a region where the thickness decreases from one end to the other end. The third layer may have a portion where the amount of decrease in thickness is uniform within the region where the thickness decreases from one end to the other end. The third layer may have a portion where the amount of decrease in thickness is large within the region where the thickness decreases from one end to the other end. The third layer may have a portion where the amount of decrease in thickness is small within the region where the thickness decreases from one end to the other end. The third layer may have a region where the thickness is uniform.

[0114] To prevent double images, the wedge angle (θ) of the interlayer can be appropriately set according to the installation angle of the laminated glass. The wedge angle (θ) is the wedge angle of the entire interlayer.

[0115] To further suppress ghosting, the wedge angle (θ) of the interlayer film is preferably 0.1 mrad (0.00575 degrees) or more, more preferably 0.2 mrad (0.0115 degrees) or more, and preferably 2 mrad (0.1146 degrees) or less, more preferably 0.7 mrad (0.0401 degrees) or less. When the wedge angle (θ) is equal to or greater than the lower limit, laminated glass suitable for vehicles with a large windshield installation angle, such as trucks and buses, can be obtained. When the wedge angle (θ) is equal to or less than the upper limit, laminated glass suitable for vehicles with a small windshield installation angle, such as sports cars, can be obtained.

[0116] The wedge angle (θ) of the interlayer film is the interior angle at the intersection of a line connecting the surface portion (first surface portion) on one side of the interlayer film between the maximum and minimum thickness portions of the interlayer film and a line connecting the surface portion (second surface portion) on the other side of the interlayer film between the maximum and minimum thickness portions of the interlayer film. When the portion of the interlayer film whose cross-sectional shape in the thickness direction is rectangular is the thickest portion of the interlayer film, the line is drawn so that the wedge angle (θ) is maximized. When the portion of the interlayer film whose cross-sectional shape in the thickness direction is rectangular is the thinnest portion of the interlayer film, the line is drawn so that the wedge angle (θ) is maximized. The wedge angle (θ) of the interlayer film can be approximately calculated as follows: The thickness of the interlayer film is measured at both the maximum and minimum thickness portions. The wedge angle (θ) of the interlayer film is approximately calculated based on the result of (the absolute value (μm) of the difference between the thickness at the thickest part of the interlayer film and the thickness at the thinnest part of the interlayer film ÷ the distance (mm) between the thickest part and the thinnest part of the interlayer film).

[0117] The wedge angle θ of the interlayer and the thickness of the interlayer may be measured by a measuring device such as a contact type thickness measuring device "TOF-4R" (manufactured by Yamabun Denki Co., Ltd.).

[0118] The thickness is measured using the above-mentioned measuring device at a membrane transport speed of 2.15 mm / min to 2.25 mm / min from one end to the other end over the shortest distance.

[0119] The wedge angle (θ) and thickness of the interlayer film after it has been formed into laminated glass can be measured using a measuring device such as the non-contact multilayer film thickness measuring device "OPTIGAUGE" (manufactured by Lumetrics). By using this measuring device, the thickness of the interlayer film can be measured in the laminated glass state.

[0120] The interlayer film is suitable for use in laminated glass for a head-up display (HUD). The interlayer film is preferably an interlayer film for a HUD. The interlayer film preferably has a display corresponding area corresponding to the display area of ​​the HUD.

[0121] From the viewpoint of suppressing double images more effectively, it is preferable that the intermediate film has the display corresponding area in the region from a position 6 cm from one end of the intermediate film toward the other end to a position 63.8 cm from the one end toward the other end.

[0122] From the viewpoint of suppressing double images more effectively, it is more preferable that the intermediate film has the display corresponding area in the region from a position 8 cm from one end of the intermediate film toward the other end to a position 61.8 cm from the one end toward the other end.

[0123] From the viewpoint of suppressing double images even more effectively, it is even more preferable that the intermediate film has the display corresponding area in a region from a position 9 cm from one end of the intermediate film toward the other end to a position 60.8 cm from the one end toward the other end.

[0124] From the viewpoint of suppressing double images more effectively, it is particularly preferable that the intermediate film has the display corresponding area in the region from a position 9.5 cm from one end of the intermediate film toward the other end to a position 60.3 cm from the one end toward the other end.

[0125] From the viewpoint of suppressing double images more effectively, it is most preferable that the intermediate film have the display corresponding area in the region from a position 10 cm from one end of the intermediate film toward the other end to a position 59.8 cm from the one end toward the other end.

[0126] The display-corresponding area may be present in a part or the entire area from the one end of the interlayer film to the position (for example, 63.8 cm) from the one end to the other end. The display-corresponding area may be approximately 30 cm in size in the direction connecting the one end and the other end.

[0127] From the viewpoint of effectively suppressing double images, it is preferable that the intermediate film has a portion whose cross-sectional shape in the thickness direction is wedge-shaped in the region from a position 6 cm from one end of the intermediate film toward the other end to a position 63.8 cm from the one end toward the other end.

[0128] From the viewpoint of effectively suppressing double images, it is more preferable that the intermediate film has a portion whose cross-sectional shape in the thickness direction is wedge-shaped in the region from a position 8 cm from one end of the intermediate film toward the other end to a position 61.8 cm from the one end toward the other end.

[0129] From the viewpoint of effectively suppressing double images, it is further preferable that the intermediate film has a portion whose cross-sectional shape in the thickness direction is wedge-shaped in the region from a position 9 cm from one end of the intermediate film toward the other end to a position 60.8 cm from the one end toward the other end.

[0130] From the viewpoint of effectively suppressing double images, it is particularly preferable that the intermediate film has a portion whose cross-sectional shape in the thickness direction is wedge-shaped in the region from a position 9.5 cm from one end of the intermediate film toward the other end to a position 60.3 cm from the one end toward the other end.

[0131] From the viewpoint of effectively suppressing double images, it is most preferable that the intermediate film has a portion whose cross-sectional shape in the thickness direction is wedge-shaped in the region from a position 10 cm from one end of the intermediate film toward the other end to a position 59.8 cm from the one end toward the other end.

[0132] The portion having a wedge-shaped cross section in the thickness direction may be present in part or the entire area from the one end to the other end to the position (e.g., 63.8 cm). The portion having a wedge-shaped cross section in the thickness direction may be present over a length of about 30 cm in the direction connecting the one end and the other end.

[0133] The interlayer film may have a shade area. The shade area may be separated from the display-corresponding area. The shade area is provided, for example, for the purpose of preventing the driver from feeling dazzled by sunlight or outdoor lighting while driving. The shade area may also be provided to provide heat insulation. The shade area is preferably located at the edge of the interlayer film. The shade area is preferably strip-shaped.

[0134] In the shaded region, a colorant or filler may be used to change the color and visible light transmittance. The colorant or filler may be contained in only a portion of the interlayer film thickness, or may be contained in the entire interlayer film thickness.

[0135] From the viewpoint of improving the display quality and widening the field of view, the visible light transmittance of the display-corresponding area is preferably 70% or more, more preferably 80% or more, even more preferably 88% or more, and particularly preferably 90% or more. The visible light transmittance of the display-corresponding area is preferably higher than that of the shade area. The visible light transmittance of the display-corresponding area may be lower than that of the shade area. The visible light transmittance of the display-corresponding area is preferably 50% or more higher, more preferably 60% or more higher than that of the shade area.

[0136] For example, when the visible light transmittance varies between the display corresponding area and the shade area of ​​the interlayer film, the visible light transmittance is measured at the center position of the display corresponding area and the center position of the shade area.

[0137] The visible light transmittance of the obtained laminated glass at a wavelength of 380 nm to 780 nm can be measured using a spectrophotometer (Hitachi High-Technologies Corporation's "U-4100") in accordance with JIS R3211: 1998. It is preferable to use clear glass with a thickness of 2 mm as the glass plate.

[0138] The display-corresponding region preferably has a length direction and a width direction. Because the interlayer film has excellent versatility, the width direction of the display-corresponding region is preferably a direction connecting the one end and the other end. The display-corresponding region is preferably strip-shaped.

[0139] The interlayer film preferably has an MD direction and a TD direction. The interlayer film is obtained, for example, by melt extrusion molding. The MD direction is the flow direction of the interlayer film during production. The TD direction is a direction perpendicular to the flow direction of the interlayer film during production and perpendicular to the thickness direction of the interlayer film. The one end and the other end are preferably located on opposite sides of the TD direction.

[0140] Hereinafter, each material that can be used for the interlayer film according to the present invention will be described in detail.

[0141] (thermoplastic resin) The interlayer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (0)). The interlayer preferably contains a polyvinyl acetal resin (hereinafter may be referred to as polyvinyl acetal resin (0)) as the thermoplastic resin (0). The first layer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (1)). The first layer preferably contains a polyvinyl acetal resin (hereinafter may be referred to as polyvinyl acetal resin (1)) as the thermoplastic resin (1). The second layer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (2)). The second layer preferably contains a polyvinyl acetal resin (hereinafter may be referred to as polyvinyl acetal resin (2)) as the thermoplastic resin (2). The third layer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (3)). The third layer preferably contains a polyvinyl acetal resin (hereinafter, may be referred to as polyvinyl acetal resin (3)) as the thermoplastic resin (3). The thermoplastic resin (1), the thermoplastic resin (2), and the thermoplastic resin (3) may be the same or different. In order to further improve sound insulation, the thermoplastic resin (2) is preferably different from the thermoplastic resin (1) 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. In order to further improve sound insulation, the polyvinyl acetal resin (2) is preferably different from the polyvinyl acetal resin (1) 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 in combination of two or more. The polyvinyl acetal resin (0), the polyvinyl acetal resin (1), the polyvinyl acetal resin (2), and the polyvinyl acetal resin (3) may each be used alone or in combination of two or more.

[0142] Examples of the thermoplastic resin include polyvinyl acetal resin, polyvinyl acetate, ethylene-vinyl acetate copolymer resin, ethylene-acrylic acid copolymer resin, polyurethane resin, ionomer resin, polyvinyl alcohol resin, etc. Thermoplastic resins other than these may also be used.

[0143] 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 can be obtained, for example, by saponifying polyvinyl acetate. The degree of saponification of the polyvinyl alcohol is generally within the range of 70 mol% to 99.9 mol%.

[0144] The average degree of polymerization of the polyvinyl alcohol (PVA) is preferably 200 or more, more preferably 500 or more, even more preferably 1500 or more, even more preferably 1600 or more, particularly preferably 2600 or more, and most preferably 2700 or more, and is preferably 5000 or less, more preferably 4000 or less, and even more preferably 3500 or less. When the average degree of polymerization is at least the lower limit, the penetration resistance of the laminated glass is further improved. When the average degree of polymerization is at most the upper limit, the interlayer film can be easily formed.

[0145] The average degree of polymerization of the polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Testing method for polyvinyl alcohol."

[0146] The number of carbon atoms in the acetal group contained in the polyvinyl acetal resin is not particularly limited. The aldehyde used in producing the polyvinyl acetal resin is not particularly limited. The number of carbon atoms in 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 in the acetal group in the polyvinyl acetal resin is 3 or more, the glass transition temperature of the interlayer film becomes sufficiently low. The number of carbon atoms in the acetal group in the polyvinyl acetal resin may be 4 or 5.

[0147] The aldehyde is not particularly limited. Generally, an aldehyde having 1 to 10 carbon atoms is suitably used. Examples of the aldehyde having 1 to 10 carbon atoms include propionaldehyde, n-butylaldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexylaldehyde, n-octylaldehyde, n-nonylaldehyde, n-decylaldehyde, formaldehyde, acetaldehyde, and benzaldehyde. The aldehyde is preferably propionaldehyde, n-butylaldehyde, isobutyraldehyde, n-hexylaldehyde, or n-valeraldehyde, more preferably propionaldehyde, n-butylaldehyde, or isobutyraldehyde, and even more preferably n-butylaldehyde. The above aldehydes may be used alone or in combination of two or more.

[0148] The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin (0) is preferably 15 mol% or more, more preferably 18 mol% or more, and preferably 40 mol% or less, more preferably 35 mol% or less. When the hydroxyl group content is equal to or greater than the lower limit, the adhesive strength of the interlayer film is further increased. When the hydroxyl group content is equal to or less than the upper limit, the flexibility of the interlayer film is increased, making it easier to handle.

[0149] The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin (2) is preferably 17 mol% or more, more preferably 20 mol% or more, even more preferably 22 mol% or more, and preferably 28 mol% or less, more preferably 27 mol% or less, even more preferably 25 mol% or less, and particularly preferably 24 mol% or less. When the hydroxyl group content is at least the lower limit, the mechanical strength of the interlayer film is further increased. In particular, when the hydroxyl group content of the polyvinyl acetal resin (2) is 20 mol% or more, the reaction efficiency is high and productivity is excellent, and when it is 28 mol% or less, the sound insulation of the laminated glass is further improved. Furthermore, when the hydroxyl group content is at most the upper limit, the flexibility of the interlayer film is high, making it easier to handle.

[0150] The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin (1) and the polyvinyl acetal resin (3) is preferably 25 mol% or more, more preferably 28 mol% or more, more preferably 30 mol% or more, even more preferably 31.5 mol% or more, even more preferably 32 mol% or more, and particularly preferably 33 mol% or more. The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin (1) and the polyvinyl acetal resin (3) is preferably 38 mol% or less, more preferably 37 mol% or less, even more preferably 36.5 mol% or less, and particularly preferably 36 mol% or less. When the hydroxyl group content is above the lower limit, the adhesive strength of the interlayer film is further increased. On the other hand, when the hydroxyl group content is below the upper limit, the flexibility of the interlayer film is increased, making the interlayer film easier to handle.

[0151] From the viewpoint of further improving sound insulation, the hydroxyl group content of the polyvinyl acetal resin (2) is preferably lower than the hydroxyl group content of the polyvinyl acetal resin (1). From the viewpoint of further improving sound insulation, the hydroxyl group content of the polyvinyl acetal resin (2) is preferably lower than the hydroxyl group content of the polyvinyl acetal resin (3). The absolute value of the difference between the hydroxyl group content of the polyvinyl acetal resin (2) and the hydroxyl group content of the polyvinyl acetal resin (1) is defined as absolute value A, and the absolute value of the difference between the hydroxyl group content of the polyvinyl acetal resin (2) and the hydroxyl group content of the polyvinyl acetal resin (3) is defined as absolute value B. From the viewpoint of further improving sound insulation, the absolute values ​​A and B are each preferably 1 mol % or more, more preferably 5 mol % or more, even more preferably 9 mol % or more, particularly preferably 10 mol % or more, and most preferably 12 mol % or more. The absolute value A and the absolute value B are each preferably 20 mol % or less.

[0152] The hydroxyl group content of the polyvinyl acetal resin is the molar fraction calculated by dividing the number of ethylene groups having hydroxyl groups by the total number of ethylene groups in the main chain, and is expressed as a percentage. The number of ethylene groups having hydroxyl groups can be measured, for example, in accordance with JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0153] The degree of acetylation (amount of acetyl groups) of the polyvinyl acetal resin (0) is preferably 0.1 mol% or more, more preferably 0.3 mol% or more, even more preferably 0.5 mol% or more, and preferably 30 mol% or less, more preferably 25 mol% or less, even more preferably 20 mol% or less. When the degree of acetylation is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is improved. When the degree of acetylation is equal to or less than the upper limit, the moisture resistance of the interlayer film and laminated glass is improved.

[0154] The degree of acetylation (amount of acetyl groups) of the polyvinyl acetal resin (2) is preferably 0.01 mol% or more, more preferably 0.1 mol% or more, even more preferably 7 mol% or more, even more preferably 9 mol% or more, and is preferably 30 mol% or less, more preferably 25 mol% or less, even more preferably 24 mol% or less, and particularly preferably 20 mol% or less. When the degree of acetylation is at least the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is improved. When the degree of acetylation is at most the upper limit, the moisture resistance of the interlayer film and laminated glass is improved. In particular, when the degree of acetylation of the polyvinyl acetal resin (2) is 0.1 mol% or more and 25 mol% or less, excellent penetration resistance is achieved.

[0155] The degree of acetylation (acetyl group amount) of each of the polyvinyl acetal resin (1) and the polyvinyl acetal resin (3) is preferably 0.01 mol% or more, more preferably 0.5 mol% or more, and preferably 10 mol% or less, more preferably 2 mol% or less. When the degree of acetylation is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is improved. When the degree of acetylation is equal to or less than the upper limit, the moisture resistance of the interlayer film and laminated glass is improved.

[0156] The degree of acetylation is a molar fraction calculated by dividing the amount of ethylene groups having acetyl groups by the total amount of ethylene groups in the main chain, and is expressed as a percentage. The amount of ethylene groups having acetyl groups can be measured, for example, in accordance with JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0157] The degree of acetalization of the polyvinyl acetal resin (0) (the degree of butyralization in the case of a polyvinyl butyral resin) is preferably 60 mol% or more, more preferably 63 mol% or more, and preferably 85 mol% or less, more preferably 75 mol% or less, and even more preferably 70 mol% or less. When the degree of acetalization is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is increased. When the degree of acetalization is equal to or less than the upper limit, the reaction time required to produce the polyvinyl acetal resin is shortened.

[0158] The degree of acetalization of the polyvinyl acetal resin (2) (the degree of butyralization in the case of a polyvinyl butyral resin) is preferably 47 mol% or more, more preferably 60 mol% or more, and preferably 85 mol% or less, more preferably 80 mol% or less, and even more preferably 75 mol% or less. When the degree of acetalization is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is increased. When the degree of acetalization is equal to or less than the upper limit, the reaction time required to produce the polyvinyl acetal resin is shortened.

[0159] The degree of acetalization of the polyvinyl acetal resin (1) and the polyvinyl acetal resin (3) (the degree of butyralization in the case of a polyvinyl butyral resin) is preferably 55 mol% or more, more preferably 60 mol% or more, and preferably 75 mol% or less, more preferably 71 mol% or less. When the degree of acetalization is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is increased. When the degree of acetalization is equal to or less than the upper limit, the reaction time required to produce the polyvinyl acetal resin is shortened.

[0160] The degree of acetalization is determined as follows. First, the amount of ethylene groups to which hydroxyl groups are bonded and the amount of ethylene groups to which acetyl groups are bonded are subtracted from the total amount of ethylene groups in the main chain to determine the value. The obtained value is divided by the total amount of ethylene groups in the main chain to determine the molar fraction. The value expressed as a percentage of this molar fraction is the degree of acetalization.

[0161] The hydroxyl group content (hydroxyl group amount), acetalization degree (butyralization degree), and acetylation degree are preferably calculated from the results of measurements performed according to JIS K6728 "Testing Methods for Polyvinyl Butyral." However, measurements according to ASTM D1396-92 may also be used. When the polyvinyl acetal resin is a polyvinyl butyral resin, the hydroxyl group content (hydroxyl group amount), acetalization degree (butyralization degree), and acetylation degree can be calculated from the results of measurements performed according to JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0162] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the interlayer film is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the interlayer film may be 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin in the interlayer film is preferably polyvinyl acetal resin.

[0163] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the first layer is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the first layer may be 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin of the first layer is preferably polyvinyl acetal resin.

[0164] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the second layer is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the second layer may be 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin in the second layer is preferably polyvinyl acetal resin.

[0165] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the third layer is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the third layer may be 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin in the third layer is preferably polyvinyl acetal resin.

[0166] (plasticizer) From the viewpoint of further increasing the adhesive strength of the interlayer film, the interlayer film according to the present invention preferably contains a plasticizer (hereinafter, sometimes referred to as plasticizer (0)). The first layer 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)). When the thermoplastic resin contained in the interlayer film is a polyvinyl acetal resin, it is particularly preferable that the interlayer film (each layer) contains a plasticizer. The layer containing the polyvinyl acetal resin preferably contains a plasticizer.

[0167] The plasticizer is not particularly limited. Conventionally known plasticizers can be used as the plasticizer. Only one type of plasticizer can be used, or two or more types can be used in combination.

[0168] Examples of the plasticizer include organic ester plasticizers such as monobasic organic acid esters and polybasic organic 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.

[0169] Examples of the monobasic organic acid ester include glycol esters obtained by reacting glycol with a monobasic organic acid. Examples of the glycol include triethylene glycol, tetraethylene glycol, and tripropylene glycol. Examples of the monobasic organic acid include butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, n-nonylic acid, decylic acid, and benzoic acid.

[0170] Examples of the polybasic organic acid ester include ester compounds of a polybasic organic acid and an alcohol having a linear or branched structure and having 4 to 8 carbon atoms. Examples of the polybasic organic acid include adipic acid, sebacic acid, and azelaic acid.

[0171] Examples of the organic ester plasticizer include triethylene glycol di-2-ethylpropanoate, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, and diethylene glycol di-2-ethylbutylene. Examples of suitable organic ester plasticizers include diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprylate, diethylene glycol dibenzoate, dipropylene glycol dibenzoate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, a mixture of heptyl adipate and nonyl adipate, diisononyl adipate, diisodecyl adipate, heptylnonyl adipate, dibutyl sebacate, oil-modified alkyd sebacate, and a mixture of a phosphate ester and an adipate. Organic ester plasticizers other than those listed above may also be used as the organic ester plasticizer. Furthermore, adipic acid esters other than the above-mentioned adipic acid esters may also be used as the adipic acid ester.

[0172] Examples of the organic phosphoric acid plasticizer include tributoxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate.

[0173] The plasticizer is preferably a diester plasticizer represented by the following formula (1):

[0174] [ka]

[0175] In the above formula (1), R1 and R2 each represent an organic group having 2 to 10 carbon atoms, R3 represents an ethylene group, an isopropylene group, or an n-propylene group, and p represents an integer of 3 to 10. In the above formula (1), R1 and R2 each preferably represent an organic group having 5 to 10 carbon atoms, and more preferably represent an organic group having 6 to 10 carbon atoms.

[0176] The plasticizer preferably includes triethylene glycol di-2-ethylhexanoate (3GO), triethylene glycol di-2-ethylbutyrate (3GH), or triethylene glycol di-2-ethylpropanoate, more preferably triethylene glycol di-2-ethylhexanoate (3GO) or triethylene glycol di-2-ethylbutyrate (3GH), and even more preferably triethylene glycol di-2-ethylhexanoate (3GO).

[0177] The content of the plasticizer (0) relative to 100 parts by weight of the thermoplastic resin (0) in the interlayer film is defined as the content (0). The content (0) is preferably 5 parts by weight or more, more preferably 25 parts by weight or more, even more preferably 30 parts by weight or more, and preferably 100 parts by weight or less, more preferably 60 parts by weight or less, even more preferably 50 parts by weight or less. When the content (0) is at least the lower limit, the penetration resistance of the laminated glass is further improved. When the content (0) is at most the upper limit, the transparency of the interlayer film is further improved.

[0178] In the second layer, the content of the plasticizer (2) relative to 100 parts by weight of the thermoplastic resin (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, and even more preferably 60 parts by weight or more. The content (2) is preferably 100 parts by weight or less, more preferably 90 parts by weight or less, even more preferably 85 parts by weight or less, and particularly preferably 80 parts by weight or less. When the content (2) is at least the lower limit, the flexibility of the interlayer film is increased, making it easier to handle. When the content (2) is at most the upper limit, the penetration resistance of the laminated glass is further improved.

[0179] In the first layer, the content of the plasticizer (1) relative to 100 parts by weight of the thermoplastic resin (1) is defined as content (1). In the third layer, the content of the plasticizer (3) relative to 100 parts by weight of the thermoplastic resin (3) is defined as content (3). The contents (1) and (3) are each preferably 5 parts by weight or more, more preferably 10 parts by weight or more, even more preferably 15 parts by weight or more, even more preferably 20 parts by weight or more, particularly preferably 24 parts by weight or more, and most preferably 25 parts by weight or more. The contents (1) and (3) are each preferably 45 parts by weight or less, more preferably 40 parts by weight or less, even more preferably 35 parts by weight or less, particularly preferably 32 parts by weight or less, and most preferably 30 parts by weight or less. When the contents (1) and (3) are equal to or greater than the lower limits, the flexibility of the interlayer film is increased, making the interlayer film easier to handle. When the content (1) and the content (3) are equal to or less than the upper limit, the penetration resistance of the laminated glass is further improved.

[0180] In order to improve the sound insulation of the laminated glass, the content (2) is preferably greater than the content (1), and the content (2) is preferably greater than the content (3).

[0181] 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 (2) and the content (3) are each preferably 10 parts by weight or more, more preferably 15 parts by weight or more, and even 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 (2) and the content (3) are each preferably 80 parts by weight or less, more preferably 75 parts by weight or less, and even more preferably 70 parts by weight or less.

[0182] (heat-shielding material) The intermediate film preferably contains a heat-shielding material. The first layer preferably contains a heat-shielding material. The second layer preferably contains a heat-shielding material. The third layer preferably contains a heat-shielding material. Only one type of heat-shielding material may be used, or two or more types may be used in combination.

[0183] The heat-shielding material preferably contains at least one component X selected from a phthalocyanine compound, a naphthalocyanine compound, and an anthracyanine compound, or contains heat-shielding particles. In this case, the heat-shielding material may contain both the component X and the heat-shielding particles.

[0184] Ingredient X: The interlayer film preferably contains at least one component X selected from a phthalocyanine compound, a naphthalocyanine compound, and an anthracyanine 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. Only one component X may be used, or two or more components X may be used in combination.

[0185] There are no particular restrictions on the component X. As the component X, conventionally known phthalocyanine compounds, naphthalocyanine compounds, and anthracyanine compounds can be used.

[0186] Examples of the component X include phthalocyanine, phthalocyanine derivatives, naphthalocyanine, naphthalocyanine derivatives, anthracyanine, and anthracyanine derivatives. The phthalocyanine compound and the phthalocyanine derivative each preferably have a phthalocyanine skeleton. The naphthalocyanine compound and the naphthalocyanine derivative each preferably have a naphthalocyanine skeleton. The anthracyanine compound and the anthracyanine derivative each preferably have an anthracyanine skeleton.

[0187] From the viewpoint of further improving the heat-shielding properties of the interlayer film and laminated glass, the above-mentioned component X is preferably at least one selected from the group consisting of phthalocyanine, phthalocyanine derivatives, naphthalocyanine, and naphthalocyanine derivatives, and more preferably at least one of phthalocyanine and phthalocyanine derivatives.

[0188] From the viewpoint of effectively improving the heat-shielding properties and maintaining a higher visible light transmittance for a long period of time, the above-mentioned component X preferably contains a vanadium atom or a copper atom. The above-mentioned component X preferably contains a vanadium atom, and also preferably contains a copper atom. The above-mentioned component X is more preferably at least one of a phthalocyanine containing a vanadium atom or a copper atom, and a derivative of a phthalocyanine containing a vanadium atom or a copper atom. From the viewpoint of further improving the heat-shielding properties of the interlayer film and laminated glass, the above-mentioned component X preferably has a structural unit in which an oxygen atom is bonded to a vanadium atom.

[0189] The content of component X in 100 wt% of the interlayer film or in 100 wt% of the layer containing component X (the first, second, or third layer) is preferably 0.001 wt% or more, more preferably 0.005 wt% or more, even more preferably 0.01 wt% or more, and particularly preferably 0.02 wt% or more. The content of component X in 100 wt% of the interlayer film or in 100 wt% of the layer containing component X (the first, second, or third layer) is preferably 0.2 wt% or less, more preferably 0.1 wt% or less, even more preferably 0.05 wt% or less, and particularly preferably 0.04 wt% or less. When the content of component X is equal to or greater than the above-mentioned lower limit and equal to or less than the above-mentioned upper limit, the heat-shielding properties and visible light transmittance are sufficiently high. For example, a visible light transmittance of 70% or more is possible.

[0190] Heat-shielding particles: The interlayer film preferably contains heat-shielding particles. The first layer preferably contains heat-shielding particles. The second layer preferably contains heat-shielding particles. The third layer preferably contains heat-shielding particles. The heat-shielding particles are a heat-shielding material. Use of the heat-shielding particles can effectively block infrared rays (heat rays). Only one type of the heat-shielding particles may be used, or two or more types may be used in combination.

[0191] From the viewpoint of further enhancing the heat-shielding properties of the laminated glass, the heat-shielding particles are more preferably metal oxide particles. The heat-shielding particles are preferably particles formed from a metal oxide (metal oxide particles).

[0192] Infrared rays, which have wavelengths longer than visible light (780 nm or longer), have a smaller amount of energy than ultraviolet rays. However, infrared rays have a large thermal effect, and when infrared rays are absorbed by a substance, they are released as heat. For this reason, infrared rays are generally called heat rays. By using the above-mentioned heat-shielding particles, infrared rays (heat rays) can be effectively blocked. Heat-shielding particles refer to particles that can absorb infrared rays.

[0193] Examples of the heat-shielding particles include metal oxide particles such as 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, tungsten oxide particles, tin-doped indium oxide particles (ITO particles), tin-doped zinc oxide particles, and silicon-doped zinc oxide particles, as well as lanthanum hexaboride (LaB6) particles. Heat-shielding particles other than these may also be used. Due to their high heat-shielding function, the heat-shielding particles are preferably metal oxide particles, more preferably ATO particles, GZO particles, IZO particles, ITO particles, or tungsten oxide particles, and particularly preferably ITO particles or tungsten oxide particles. The heat-shielding particles are preferably tin-doped indium oxide particles (ITO particles), and also preferably tungsten oxide particles, because they have a high heat-ray shielding function and are easily available.

[0194] From the viewpoint of further improving the heat-shielding properties of the interlayer film and laminated glass, the tungsten oxide particles are preferably metal-doped tungsten oxide particles. The "tungsten oxide particles" include metal-doped tungsten oxide particles. Examples of the metal-doped tungsten oxide particles include sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles, thallium-doped tungsten oxide particles, and rubidium-doped tungsten oxide particles.

[0195] From the viewpoint of further improving the heat-shielding properties of the interlayer film and laminated glass, cesium-doped tungsten oxide particles are particularly preferred. From the viewpoint of further improving the heat-shielding properties of the interlayer film and laminated glass, the cesium-doped tungsten oxide particles are represented by the formula: Cs 0.33 Tungsten oxide particles represented by WO3 are preferred.

[0196] The average particle size of the heat-shielding particles is preferably 0.01 μm or more, more preferably 0.02 μm or more, and preferably 0.1 μm or less, more preferably 0.05 μm or less. When the average particle size is equal to or greater than the lower limit, the heat ray shielding property is sufficiently high. When the average particle size is equal to or less than the upper limit, the dispersibility of the heat-shielding particles is high.

[0197] The "average particle size" refers to the volume-average particle size. The average particle size can be measured using a particle size distribution analyzer ("UPA-EX150" manufactured by Nikkiso Co., Ltd.) or the like.

[0198] The content of the heat-shielding particles (particularly the content of tungsten oxide particles) in 100 weight % of the interlayer film or 100 weight % of the layer containing the heat-shielding particles (first layer, second layer, or third layer) is preferably 0.01 weight % or more, more preferably 0.1 weight % or more, even more preferably 1 weight % or more, and particularly preferably 1.5 weight % or more. The content of the heat-shielding particles (particularly the content of tungsten oxide particles) in 100 weight % of the interlayer film or 100 weight % of the layer containing the heat-shielding particles (first layer, second layer, or third layer) is preferably 6 weight % or less, more preferably 5.5 weight % or less, even more preferably 4 weight % or less, particularly preferably 3.5 weight % or less, and most preferably 3 weight % or less. When the content of the heat-shielding particles is at least the above lower limit and at most the above upper limit, the heat shielding property is sufficiently high and the visible light transmittance is sufficiently high.

[0199] (metal salts) The interlayer film preferably contains at least one metal salt (hereinafter sometimes referred to as 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. Alkaline earth metals refer to six metals: Be, Mg, Ca, Sr, Ba, and Ra. The use of the metal salt M makes it easy to control the adhesion between the interlayer film and a laminated glass member such as a glass plate, or the adhesion between each layer in the interlayer film. Only one type of the metal salt M may be used, or two or more types may be used in combination.

[0200] The metal salt M preferably contains at least one metal selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba. The metal salt contained in the interlayer film preferably contains at least one metal selected from the group consisting of K and Mg.

[0201] Furthermore, alkali metal salts of organic acids having 2 to 16 carbon atoms and alkaline earth metal salts of organic acids having 2 to 16 carbon atoms can be used as the metal salt M. The metal salt M may include a magnesium salt of a carboxylic acid having 2 to 16 carbon atoms or a potassium salt of a carboxylic acid having 2 to 16 carbon atoms.

[0202] Examples of the magnesium salts of carboxylic acids having 2 to 16 carbon atoms and the potassium salts of carboxylic acids having 2 to 16 carbon atoms include magnesium acetate, potassium acetate, magnesium propionate, potassium propionate, magnesium 2-ethylbutyrate, potassium 2-ethylbutanoate, magnesium 2-ethylhexanoate, and potassium 2-ethylhexanoate.

[0203] The total content of Mg and K in the interlayer film containing the metal salt M or in the layer (first layer, second layer, or third layer) containing the metal salt M is preferably 5 ppm or more, more preferably 10 ppm or more, and even more preferably 20 ppm or more, and is preferably 300 ppm or less, more preferably 250 ppm or less, and even more preferably 200 ppm or less. When the total content of Mg and K is at least the above lower limit and at most the above upper limit, the adhesion between the interlayer film and a laminated glass member such as a glass plate, or the adhesion between the layers in the interlayer film, can be more effectively controlled.

[0204] (UV screening agent) The interlayer film preferably contains an ultraviolet blocking agent. The first layer preferably contains an ultraviolet blocking agent. The second layer preferably contains an ultraviolet blocking agent. The third layer preferably contains an ultraviolet blocking agent. By using an ultraviolet blocking agent, the visible light transmittance of the interlayer film and laminated glass is more unlikely to decrease even after long-term use. Only one type of ultraviolet blocking agent may be used, or two or more types may be used in combination.

[0205] The ultraviolet screening agent includes an ultraviolet absorbing agent, and the ultraviolet screening agent is preferably an ultraviolet absorbing agent.

[0206] Examples of the ultraviolet screening agent include ultraviolet screening agents containing metal atoms, ultraviolet screening agents containing metal oxides, ultraviolet screening agents having a benzotriazole structure (benzotriazole compounds), ultraviolet screening agents having a benzophenone structure (benzophenone compounds), ultraviolet screening agents having a triazine structure (triazine compounds), ultraviolet screening agents having a malonic acid ester structure (malonic acid ester compounds), ultraviolet screening agents having an oxalic acid anilide structure (oxalic acid anilide compounds), and ultraviolet screening agents having a benzoate structure (benzoate compounds).

[0207] Examples of the ultraviolet shielding agent containing the metal atom include platinum particles, platinum particles whose surfaces are coated with silica, palladium particles, and palladium particles whose surfaces are coated with silica. The ultraviolet shielding agent is preferably not a heat-shielding particle.

[0208] The ultraviolet screening agent is preferably an ultraviolet screening agent having a benzotriazole structure, an ultraviolet screening agent having a benzophenone structure, an ultraviolet screening agent having a triazine structure, or an ultraviolet screening agent having a benzoate structure, more preferably an ultraviolet screening agent having a benzotriazole structure or an ultraviolet screening agent having a benzophenone structure, and even more preferably an ultraviolet screening agent having a benzotriazole structure.

[0209] Examples of the ultraviolet screening agent containing a metal oxide include zinc oxide, titanium oxide, and cerium oxide. Furthermore, the surface of the ultraviolet screening agent containing a metal oxide may be coated. Examples of the coating material for the surface of the ultraviolet screening agent containing a metal oxide include insulating metal oxides, hydrolyzable organosilicon compounds, and silicone compounds.

[0210] Examples of the insulating metal oxide include silica, alumina, zirconia, etc. The insulating metal oxide has a band gap energy of, for example, 5.0 eV or more.

[0211] Examples of the ultraviolet screening agent having a benzotriazole structure include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole ("Tinuvin P" manufactured by BASF), 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole ("Tinuvin 320" manufactured by BASF), 2-(2'-hydroxy-3'-t-butyl-5-methylphenyl)-5-chlorobenzotriazole ("Tinuvin 326" manufactured by BASF), and 2-(2'-hydroxy-3',5'-di-amylphenyl)benzotriazole ("Tinuvin 328" manufactured by BASF). Because of their excellent ultraviolet screening performance, the ultraviolet screening agent is preferably an ultraviolet screening agent having a benzotriazole structure containing a halogen atom, and more preferably an ultraviolet screening agent having a benzotriazole structure containing a chlorine atom.

[0212] Examples of the ultraviolet screening agent having a benzophenone structure include octabenzone ("Chimassorb 81" manufactured by BASF).

[0213] Examples of the ultraviolet 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 ("Tinuvin 1577FF" manufactured by BASF).

[0214] Examples of the ultraviolet screening agent having a malonic acid ester structure include dimethyl 2-(p-methoxybenzylidene)malonate, tetraethyl-2,2-(1,4-phenylenedimethylidene)bismalonate, and 2-(p-methoxybenzylidene)-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)malonate.

[0215] Commercially available UV screening agents having the malonic acid ester structure include Hostavin B-CAP, Hostavin PR-25, and Hostavin PR-31 (all manufactured by Clariant).

[0216] Examples of the ultraviolet screening agent having the oxalic acid anilide structure include oxalic acid diamides having an aryl group substituted on the nitrogen atom, such as N-(2-ethylphenyl)-N'-(2-ethoxy-5-t-butylphenyl)oxalic acid diamide, N-(2-ethylphenyl)-N'-(2-ethoxy-phenyl)oxalic acid diamide, and 2-ethyl-2'-ethoxy-oxalanilide ("Sanduvor VSU" manufactured by Clariant).

[0217] Examples of the ultraviolet screening agent having a benzoate structure include 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate ("Tinuvin 120" manufactured by BASF).

[0218] The content of the ultraviolet screening agent and the content of the benzotriazole compound in 100% by weight of the interlayer film or 100% by weight of the layer containing the ultraviolet screening agent (first layer, second layer, or third layer) is preferably 0.1% by weight or more, more preferably 0.2% by weight or more, even more preferably 0.3% by weight or more, and particularly preferably 0.5% by weight or more. In this case, even after long-term use of the interlayer film and laminated glass, the visible light transmittance is even less likely to decrease. The content of the ultraviolet screening agent and the content of the benzotriazole compound in 100% by weight of the interlayer film or 100% by weight of the layer containing the ultraviolet screening agent (first layer, second layer, or third layer) is preferably 2.5% by weight or less, more preferably 2% by weight or less, even more preferably 1% by weight or less, and particularly preferably 0.8% by weight or less. In particular, by ensuring that the content of the ultraviolet ray blocking agent is 0.2% by weight or more relative to 100% by weight of the layer containing the ultraviolet ray blocking agent, the visible light transmittance is even less likely to decrease even after long-term use of the interlayer film and laminated glass.

[0219] (antioxidant) The interlayer 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 type of antioxidant may be used, or two or more types may be used in combination.

[0220] Examples of the antioxidant include phenol-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants. The phenol-based antioxidants are antioxidants having a phenol skeleton. The sulfur-based antioxidants are antioxidants containing sulfur atoms. The phosphorus-based antioxidants are antioxidants containing phosphorus atoms.

[0221] The antioxidant is preferably a phenol-based antioxidant or a phosphorus-based antioxidant.

[0222] Examples of the phenolic antioxidant include 2,6-di-t-butyl-p-cresol (BHT), butylhydroxyanisole (BHA), 2,6-di-t-butyl-4-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis-(4-methyl-6-butylphenol), 2,2'-methylenebis-(4-ethyl-6-t-butylphenol), 4,4'-butylidene-bis-(3-methyl-6-t-butylphenol), 1,1,3-tris-(2-methyl-hydroxy-5- t-butylphenyl)butane, tetrakis[methylene-3-(3',5'-butyl-4-hydroxyphenyl)propionate]methane, 1,3,3-tris-(2-methyl-4-hydroxy-5-t-butylphenol)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis(3,3'-t-butylphenol)butyric acid glycol ester, and bis(3-t-butyl-4-hydroxy-5-methylbenzenepropanoate)ethylenebis(oxyethylene). One or more of these antioxidants are preferably used.

[0223] Examples of the phosphorus-based antioxidant include tridecyl phosphite, tris(tridecyl)phosphite, triphenyl phosphite, trinonylphenyl phosphite, bis(tridecyl)pentaerythritol diphosphite, bis(decyl)pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)phosphite, bis(2,4-di-t-butyl-6-methylphenyl)ethyl ester phosphorous acid, and 2,2'-methylenebis(4,6-di-t-butyl-1-phenyloxy)(2-ethylhexyloxy)phosphorus, etc. One or more of these antioxidants are preferably used.

[0224] Commercially available antioxidants include, for example, "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.

[0225] In order to maintain high visible light transmittance of the interlayer film and laminated glass for a long period of time, the content of the antioxidant in 100% by weight of the interlayer film or 100% by weight of the layer containing the antioxidant (first layer, second layer, or third layer) is preferably 0.03% by weight or more, and more preferably 0.1% by weight or more. Furthermore, since the effect of adding the antioxidant becomes saturated, the content of the antioxidant in 100% by weight of the interlayer film or 100% by weight of the layer containing the antioxidant is preferably 2% by weight or less.

[0226] (Other ingredients) The interlayer film, the first layer, the second layer, and the third layer may each contain, as necessary, additives such as a colorant, a coupling agent, a dispersant, a surfactant, a flame retardant, an antistatic agent, an adhesion modifier other than a metal salt, a moisture-resistant agent, a fluorescent brightening agent, an infrared absorbing agent, etc. These additives may be used alone or in combination of two or more.

[0227] (Other details of interlayer film for laminated glass) The interlayer film may be wound into a roll of the interlayer film. The roll may include a winding core and the interlayer film wound around the outer periphery of the winding core.

[0228] The method for producing the interlayer film is not particularly limited.

[0229] In view of excellent production efficiency of the interlayer film, it is preferable that the first layer and the third layer contain the same polyvinyl acetal resin. In view of excellent production efficiency of the interlayer film, it is more preferable that the first layer and the third layer contain the same polyvinyl acetal resin and the same plasticizer. In view of excellent production efficiency of the interlayer film, it is even more preferable that the first layer and the third layer are formed from the same resin composition.

[0230] The interlayer film preferably has an uneven shape on at least one of its two surfaces. The interlayer film more preferably has an uneven shape on both surfaces. The method for forming the uneven shape is not particularly limited, and examples thereof include lip embossing (melt fracture), embossing roll, calender roll, and profile extrusion.

[0231] The ratio of the average thickness of the first layer to the average thickness of the interlayer (average thickness of the first layer / average thickness of the interlayer) is defined as ratio (1). The ratio of the average thickness of the third layer to the average thickness of the interlayer (average thickness of the third layer / average thickness of the interlayer) is defined as ratio (3).

[0232] When ratio (1) is smaller than ratio (3), the ten-point average roughness Rz of the surface of the first layer opposite the second layer is preferably 9 μm or more, more preferably 12 μm or more, even more preferably 15 μm or more, particularly preferably 18 μm or more, and most preferably 20 μm or more. When ratio (1) is smaller than ratio (3), the ten-point average roughness Rz of the surface of the first layer opposite the second layer is preferably 100 μm or less, more preferably 90 μm or less, even more preferably 80 μm or less, particularly preferably 70 μm or less, and most preferably 60 μm or less. When the ten-point average roughness Rz is equal to or greater than the above lower limit and equal to or less than the above upper limit, self-adhesion between interlayer films can be suppressed during production of the interlayer film, during storage of the interlayer film, and during production of laminated glass using the interlayer film.

[0233] When ratio (3) is smaller than ratio (1), the ten-point average roughness Rz of the surface of the third layer opposite the second layer is preferably 9 μm or more, more preferably 12 μm or more, even more preferably 15 μm or more, particularly preferably 18 μm or more, and most preferably 20 μm or more. When ratio (3) is smaller than ratio (1), the ten-point average roughness Rz of the surface of the first layer opposite the second layer is preferably 100 μm or less, more preferably 90 μm or less, even more preferably 80 μm or less, particularly preferably 70 μm or less, and most preferably 60 μm or less. When the ten-point average roughness Rz is equal to or greater than the above lower limit and equal to or less than the above upper limit, self-adhesion between interlayer films can be suppressed during production of the interlayer film, during storage of the interlayer film, and during production of laminated glass using the interlayer film.

[0234] When ratio (1) is the same as ratio (3), the ten-point average roughness Rz of the surface of the first layer opposite to the second layer and the ten-point average roughness Rz of the surface of the third layer opposite to the second layer are each preferably 9 μm or more, more preferably 12 μm or more, even more preferably 15 μm or more, particularly preferably 18 μm or more, and most preferably 20 μm or more. When ratio (1) is the same as ratio (3), the ten-point average roughness Rz of the surface of the first layer opposite to the second layer and the ten-point average roughness Rz of the surface of the third layer opposite to the second layer are each preferably 100 μm or less, more preferably 90 μm or less, even more preferably 80 μm or less, particularly preferably 70 μm or less, and most preferably 60 μm or less. When the ten-point average roughness Rz is equal to or greater than the lower limit and equal to or less than the upper limit, self-adhesion between interlayer films can be suppressed during production of the interlayer film, during storage of the interlayer film, and during production of laminated glass using the interlayer film.

[0235] The ten-point average roughness Rz is measured in accordance with JIS B0601: 1994. As a measuring device for measuring the ten-point average roughness Rz, for example, "Surfcorder SE300" manufactured by Kosaka Laboratory Co., Ltd. can be used.

[0236] (Laminated glass) The laminated glass of the present invention includes a first laminated glass member, a second laminated glass member, and the above-described interlayer film for laminated glass. In the laminated glass of the present invention, the above-described interlayer film for laminated glass is disposed between the first laminated glass member and the second laminated glass member.

[0237] FIG. 7 is a cross-sectional view that schematically shows an example of laminated glass that uses the interlayer film for laminated glass shown in FIG.

[0238] The laminated glass 31 shown in FIG. 7 comprises a first laminated glass member 21, a second laminated glass member 22, and an interlayer film 11. The interlayer film 11 is disposed and sandwiched between the first laminated glass member 21 and the second laminated glass member 22. The first laminated glass member 21 is laminated on a first surface (one surface) of the interlayer film 11. The second laminated glass member 22 is laminated on a second surface (the other surface) opposite the first surface of the interlayer film 11. The first laminated glass member 21 is laminated on the outer surface of the first layer 1 of the interlayer film 11. The second laminated glass member 22 is laminated on the outer surface of the third layer 3 of the interlayer film 1.

[0239] The first laminated glass member is preferably a first glass plate, and the second laminated glass member is preferably a second glass plate.

[0240] Examples of the first and second laminated glass members include glass plates and PET (polyethylene terephthalate) films. The laminated glass includes not only laminated glass in which an interlayer film is sandwiched between two glass plates, but also 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 glass plates, and preferably includes at least one glass plate. It is preferable that the first laminated glass member and the second laminated glass member are each a glass plate or a PET film, and that the laminated glass includes a glass plate as at least one of the first laminated glass member and the second laminated glass member. It is particularly preferable that both the first and second laminated glass members are glass plates.

[0241] Examples of the glass plate include inorganic glass and organic glass. Examples of the inorganic glass include float glass, heat-absorbing glass, heat-reflecting glass, polished glass, patterned glass, lined glass, and green glass. The organic glass is a synthetic resin glass that replaces 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 polymethyl(meth)acrylate plates.

[0242] The thickness of each of the first laminated glass member and the second laminated glass member is preferably 1 mm or more, preferably 5 mm or less, more preferably 3 mm or less. When the laminated glass member is a glass plate, the thickness of the glass plate is preferably 0.5 mm or more, more preferably 0.7 mm or more, and preferably 5 mm or less, more preferably 3 mm or less. When the laminated glass member is a PET film, the thickness of the PET film is preferably 0.03 mm or more, and preferably 0.5 mm or less.

[0243] The method for producing the laminated glass is not particularly limited. First, an interlayer film is sandwiched between the first laminated glass member and the second laminated glass member to obtain a laminate. Next, the air remaining between the first laminated glass member, the second laminated glass member, and the interlayer film is removed, for example, by passing the obtained laminate through a pressure roll or placing it in a rubber bag and suctioning it under reduced pressure. Thereafter, a pre-bonded laminate is obtained by pre-bonding at about 70°C to 110°C. Next, the pre-bonded laminate is placed in an autoclave or pressed at about 120°C to 150°C and a pressure of 1 MPa to 1.5 MPa to be bonded. In this manner, a laminated glass can be obtained.

[0244] The interlayer film and the laminated glass can be used in automobiles, railway vehicles, aircraft, ships, buildings, etc. The interlayer film and the laminated glass can also be used for applications other than these. The interlayer film and the laminated glass are preferably interlayer films and laminated glass for vehicles or buildings, and more preferably interlayer films and laminated glass for vehicles. The interlayer film and the laminated glass can be used for automobile windshields, side windows, rear windows, roof glass, backlight glass, etc. The interlayer film and the laminated glass are preferably used in automobiles. The interlayer film is preferably used to obtain laminated glass for automobiles.

[0245] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0246] The polyvinyl acetal resin used was acetalized using n-butylaldehyde, which has four carbon atoms. The degree of acetalization (degree of butyralization), degree of acetylation, and hydroxyl group content of the polyvinyl acetal resin were measured according to JIS K6728 "Testing Methods for Polyvinyl Butyral." Note that when measured according to ASTM D1396-92, the values ​​were similar to those obtained by the method according to JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0247] The Tinuvin 326 used in the examples and comparative examples was 2-(2'-hydroxy-3'-t-butyl-5-methylphenyl)-5-chlorobenzotriazole ("Tinuvin 326" manufactured by BASF), and the BHT used in the examples and comparative examples was 2,6-di-t-butyl-p-cresol.

[0248] Example 1 Preparation of resin composition for forming second layer: The following components were blended and thoroughly kneaded with a mixing roll to obtain a resin composition for forming the second layer.

[0249] Polyvinyl acetal resin (average polymerization degree 3000, hydroxyl group content 22 mol%, acetylation degree 13 mol%, acetalization degree 65 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 68.8 parts by weight Tinuvin 326 in an amount to provide 0.2% by weight in the resulting second layer BHT in an amount to give 0.2% by weight in the resulting second layer

[0250] Preparation of resin compositions for forming the first layer and the third layer: The following components were blended and thoroughly kneaded with a mixing roll to obtain a resin composition for forming the first layer and the third layer.

[0251] Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 30.5 mol%, acetylation degree 1 mol%, acetalization degree 68.5 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 38.6 parts by weight Tinuvin 326 in an amount of 0.2% by weight in the resulting first and third layers BHT in an amount to give 0.2% by weight in the resulting first and third layers

[0252] Preparation of interlayer: The resin composition for forming the second layer and the resin compositions for forming the first and third layers were co-extruded using a co-extruder. The pressure distribution when the resin compositions were joined was adjusted. In this way, an interlayer film having a three-layer structure (first layer / second layer / third layer) and a thickness at one end greater than that at the other end (interlayer film having the shape shown in Table 4) was obtained.

[0253] Examples 2 to 12 Except for changing the configuration of the interlayer film as shown in Tables 4 to 7, an interlayer film having a three-layer structure (first layer / second layer / third layer) and in which the thickness at the other end was greater than the thickness at one end was obtained in the same manner as in Example 1.

[0254] Example 13 (Synthesis of Polyvinyl Acetate (1)) A glass polymerization vessel equipped with a reflux condenser, dropping funnel, thermometer, and nitrogen inlet was prepared. 100 parts by weight of vinyl acetate monomer, 1.0 part by weight of 3-methyl-3-buten-1-ol, and 3.8 parts by weight of methanol were placed in the polymerization vessel, and the contents were heated and stirred to replace the atmosphere in the polymerization vessel with nitrogen. Next, the temperature inside the polymerization vessel was raised to 60°C, and 0.02 parts by weight of the polymerization initiator tert-butyl peroxyneodecanate, 150 parts by weight of vinyl acetate monomer, and 1.5 parts by weight of 3-methyl-3-buten-1-ol were added dropwise over 4 hours. After the completion of the addition, polymerization was allowed to proceed for 2 hours, yielding a solution containing polyvinyl acetate. This solution was dried in an oven at 110°C for 3 hours to obtain polyvinyl acetate (1).

[0255] Preparation of resin composition for forming second layer: The following components were blended and thoroughly kneaded with a mixing roll to obtain a resin composition for forming the second layer.

[0256] Polyvinyl acetate (1) 100 parts by weight Plasticizer (bis(2-butoxyethyl) adipate (D931)) 80 parts by weight Tinuvin 326 in an amount to provide 0.2% by weight in the resulting second layer BHT in an amount to give 0.2% by weight in the resulting second layer

[0257] Preparation of resin compositions for forming the first layer and the third layer: The following components were blended and thoroughly kneaded with a mixing roll to obtain a resin composition for forming the first layer and the third layer.

[0258] Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 31 mol%, butyralization degree 68 mol%, acetylation degree 1 mol%) 100 parts by weight Plasticizer (bis(2-butoxyethyl) adipate (D931)) 35 parts by weight Metal salt M (Mg mixture) in an amount such that the Mg content in the resulting first layer and third layer is 70 ppm Tinuvin 326 in an amount of 0.2% by weight in the resulting first and third layers BHT in an amount to give 0.2% by weight in the resulting first and third layers

[0259] Preparation of interlayer: The resin composition for forming the second layer and the resin compositions for forming the first and third layers were co-extruded using a co-extruder. The pressure distribution when the resin compositions were joined was adjusted. In this way, an interlayer film having a three-layer structure (first layer / second layer / third layer) and a thickness at one end greater than that at the other end (interlayer film having the shape shown in Table 7) was obtained.

[0260] (Comparative Example 1) The following components were blended and thoroughly kneaded with a mixing roll to obtain a resin composition for forming the first layer.

[0261] Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 30.5 mol%, acetylation degree 1 mol%, acetalization degree 68.5 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 40 parts by weight Tinuvin 326 in an amount to provide 0.2% by weight in the resulting first layer BHT in an amount to give 0.2% by weight in the resulting first layer

[0262] Preparation of interlayer: The resin composition for forming the first layer was extruded using an extruder to obtain an interlayer film having a single layer structure and a thickness at one end that is thicker at the other end than at the other end (an interlayer film having the shape shown in Table 1).

[0263] (Comparative Example 2) Except for changing the configuration of the interlayer film as shown in Table 1, an interlayer film having a single layer structure and a greater thickness at one end than at the other end was obtained in the same manner as in Comparative Example 1.

[0264] (Comparative Examples 3 to 9) Interlayer films having a three-layer structure (first layer / second layer / third layer) and having a thickness at one end greater than that at the other end were obtained in the same manner as in Example 1, except that the configuration of the interlayer film was changed as shown in Tables 2 and 3. Note that the interlayer films obtained in Comparative Examples 3 to 9 do not have a layer whose thickness at the other end is thinner than that at the one end.

[0265] (Comparative Example 10) Preparation of resin composition for forming second layer: The following components were blended and thoroughly kneaded with a mixing roll to obtain a resin composition for forming the second layer.

[0266] Polyvinyl acetate (1) 100 parts by weight Plasticizer (bis(2-butoxyethyl) adipate (D931)) 80 parts by weight Tinuvin 326 in an amount to provide 0.2% by weight in the resulting second layer BHT in an amount to give 0.2% by weight in the resulting second layer

[0267] Preparation of resin compositions for forming the first layer and the third layer: The following components were blended and thoroughly kneaded with a mixing roll to obtain a resin composition for forming the first layer and the third layer.

[0268] Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 31 mol%, butyralization degree 68 mol%, acetylation degree 1 mol%) 100 parts by weight Plasticizer (bis(2-butoxyethyl) adipate (D931)) 35 parts by weight Metal salt M (Mg mixture) in an amount such that the Mg content in the resulting first layer and third layer is 70 ppm Tinuvin 326 in an amount of 0.2% by weight in the resulting first and third layers BHT in an amount to give 0.2% by weight in the resulting first and third layers

[0269] Preparation of interlayer: The resin composition for forming the second layer and the resin compositions for forming the first and third layers were co-extruded using a co-extruder to obtain an interlayer film having a three-layer structure (first layer / second layer / third layer) and a thickness at one end that is thicker at the other end. Note that the interlayer film obtained in Comparative Example 10 does not have a layer whose thickness at the other end is thinner than that at the one end.

[0270] (evaluation) (1) Thickness of the interlayer and the layers that make up the interlayer The thickness of the obtained interlayer film and the layers constituting the interlayer film were measured using a contact-type thickness measuring instrument "TOF-4R" (manufactured by Yamabun Denki Co., Ltd.) The thickness measurement was carried out at a film conveying speed of 2.15 mm / min to 2.25 mm / min from one end to the other over the shortest distance.

[0271] In addition, the absolute values ​​of the following differences were calculated from the measurement results.

[0272] Absolute value of the difference between the maximum value of T1 / T and the minimum value of T1 / T Absolute value of the difference between the maximum value of T3 / T and the minimum value of T3 / T

[0273] Here, T is the thickness of the intermediate film at a predetermined position, and T1 and T3 are the thicknesses of the first layer and the third layer at the same positions as the above-mentioned predetermined position.

[0274] (2) Ten-point average roughness Rz The ratio (1) of the average thickness of the first layer to the average thickness of the interlayer film (average thickness of the first layer / average thickness of the interlayer film) and the ratio (3) of the average thickness of the third layer to the average thickness of the interlayer film (average thickness of the third layer / average thickness of the interlayer film) were calculated. The ten-point average roughness Rz of the surface of the first or third layer, whichever had the smaller thickness ratio to the interlayer film, on the side opposite the second layer was measured in accordance with JIS B0601:1994. The measuring instrument used was a "Surfcorder SE300" manufactured by Kosaka Laboratory Co., Ltd.

[0275] (3) Optical distortion (3-1) Preparation of laminated glass The resulting interlayer was sandwiched between two sheets of clear glass measuring 15 cm in length, 30 cm in width, and 2.5 mm in thickness conforming to JIS R3202:1996 to obtain a laminate. The resulting laminate was placed in a rubber bag, which was then connected to a suction vacuum. The laminate was heated to 70°C and simultaneously held under a reduced pressure of 16 kPa for 10 minutes to pre-pressure-bond the laminate. After returning to atmospheric pressure, the pre-pressure-bonded laminate was pressurized in an autoclave at 140°C and a pressure of 1300 kPa for 10 minutes. After pressing, the temperature was returned to 50°C and atmospheric pressure to obtain laminated glass.

[0276] (3-2) Measurement of optical distortion An optical distortion inspection device shown in Figures 8 and 9 was prepared. Figure 8 is a plan view that schematically shows the optical distortion inspection device used to measure the optical distortion. Figure 9 is a front view that schematically shows the optical distortion inspection device used to measure the optical distortion. Figures 10(a) and 10(b) are diagrams for explaining the processing operations in the image processing unit.

[0277] The optical distortion inspection device 41 is a device for measuring the optical distortion value of a measurement object W. The optical distortion inspection device 41 includes a light source unit 42, a slit section 43, a measurement object placement section 44, a projection surface 45, an image input section 46, an image processing section 47, a stand 48, and an evaluation section 49. In FIGS. 8 and 9, the measurement object W is placed on the measurement object placement section 44.

[0278] The light source unit 42 includes a light emitting section 421, an optical fiber 422, and an irradiation port 423. Irradiation light emitted by the light emitting section 421 passes through the optical fiber 422 and is irradiated from the irradiation port 423 toward the slit section 43. A halogen lamp ("EYEDICHRO-COOLHALOGEN (15V100W)" manufactured by Iwasaki Electric Co., Ltd.) was used as the light emitting section 421.

[0279] The stand 48 includes a stand main body 481 and an arm 482. The image input unit 46 is placed on the arm 482.

[0280] The irradiation port 423, the slit section 43, the measurement object placement section 44, and the projection surface 45 are movable in the direction of the optical axis A on the stand 48.

[0281] The slit section 43 has a slit in the center. The light emitted from the light source unit 42 passes through the slit of the slit section 43 and reaches the object W to be measured.

[0282] The irradiated light transmitted through the measurement object W is projected onto a projection surface 45. The projection surface 45 can be installed at an angle θ with respect to the optical axis A. A white sheet of paper was used as the projection surface 45.

[0283] The image input unit 46 captures an image of the projection surface 45, converts the brightness of the captured image into signals, and generates a grayscale image. A CCD camera ("XC-ST70" manufactured by Sony Corporation) was used as the image input unit.

[0284] The image processing unit 47 detects the optical distortion of the measurement object W based on the degree of variation in the grayscale of the grayscale image. The image processing unit 47 outputs the variance value of the density values ​​between each pixel of the grayscale image. The evaluation unit 49 compares the variance value calculated by the image processing unit 47 with a variance value within a predetermined allowable range, and evaluates the optical distortion of the measurement object W.

[0285] The image processing unit 47 converts each pixel of the grayscale image into a pixel value between 0 and 255 according to the grayscale of the grayscale image. As shown in Fig. 10(a), a 400 pixel x 400 pixel area formed by connecting four points, namely, pixel coordinates (120, 40), (520, 40), (120, 440), and (520, 440), was divided into a total of 16 windows (windows W1 to W16), each of 100 pixel x 100 pixel. The 16 windows were divided without overlapping with each other.

[0286] In Figure 10(b), only one window is shown enlarged. The "variance of pixel values" was calculated for 100 pixels in the same column of one window (indicated by the dashed arrow in Figure 10(b)). The "variance of pixel values" was calculated for each of columns 1 to 100 of the window. The variance of pixel values ​​V1 was calculated for the first column of the window. The variance of pixel values ​​V2 was calculated for the second column of the window. Similarly, the variances of pixel values ​​V3 to V100 were calculated. One hundred "variances of pixel values" (variances V1 to V100) are obtained per window. The average of these 100 "variances of pixel values" was taken as the "optical distortion of the window."

[0287] The "optical distortion of the window" was calculated for each of the 16 windows. The average value of the 16 "optical distortion of the window" was taken as the "optical distortion of the measurement object."

[0288] Two measurement objects were used as the measurement object W: the obtained laminated glass and a calibration laminated glass. The calibration laminated glass was obtained by placing a calibration single-layer interlayer film with a visible light transmittance of 88% between two sheets of clear float glass with a thickness of 2.5 mm. The visible light transmittance of the calibration single-layer interlayer film was measured at wavelengths of 380 nm to 780 nm in accordance with JIS R3211:1998 using a spectrophotometer (for example, the "U-4100" manufactured by Hitachi High-Technologies Corporation).

[0289] The above-mentioned calibration laminated glass was prepared using the above-mentioned calibration single-layer interlayer film in the following manner.

[0290] The above-mentioned calibration monolayer interlayer film was sandwiched between two sheets of clear glass measuring 15 cm in length, 30 cm in width, and 2.5 mm in thickness conforming to JIS R3202:1996 to obtain a laminate. The obtained laminate was placed in a rubber bag, and the rubber bag was connected to a suction vacuum. The laminate was heated to a temperature of 70°C and simultaneously held under a reduced pressure of 16 kPa for 10 minutes to pre-pressure-bond the laminate. After returning to atmospheric pressure, the pre-pressure-bonded laminate was pressurized in an autoclave at 140°C and a pressure of 1300 kPa for 10 minutes. After pressing, the conditions were returned to 50°C and atmospheric pressure to obtain the above-mentioned calibration laminated glass.

[0291] The positions of the irradiation port, slit section, measurement object placement section, projection surface, image input section, etc., the shape and size of the slit, the illuminance of the light source, the angle θ between the optical axis and the projection surface, etc. were adjusted so that the optical distortion value without the measurement object placed would be 1.30 and the optical distortion value of the calibration laminated glass would be 1.14. The state without the measurement object placed means a state where no object is placed on the measurement object placement section. The optical distortion value of the obtained laminated glass was measured using an optical distortion inspection device adjusted so that the optical distortion value without the measurement object placed would be 1.30 and the optical distortion value of the calibration laminated glass would be 1.14.

[0292] [Optical distortion criteria] ○: Optical distortion value is 1.9 or less △: Optical distortion value is over 1.9 and 3 or less ×: Optical distortion value exceeds 3

[0293] (4) Sound insulation (4-1) Preparation of laminated glass The resulting interlayer was sandwiched between two 2 mm thick clear glass sheets conforming to JIS R3202:1996 to obtain a laminate. The resulting laminate was placed in a rubber bag and degassed at a vacuum of 2.6 kPa for 20 minutes. It was then transferred to an oven in the degassed state and held at 90°C for 30 minutes for vacuum pressing to pre-bond the laminate. The pre-bonded laminate was then compressed in an autoclave for 20 minutes at 135°C and a pressure of 1.2 MPa to obtain a laminated glass measuring 950 mm long and 1500 mm wide.

[0294] (4-2) Natural frequency (sound insulation in the low frequency range) 3D geometry data of the obtained laminated glass was created using an optical 3D digitizer (Boulder Innovation Group's "FP7000") and analysis software (Spectris's "BKConnect"). The first surface of the laminated glass was divided into regions of 5 cm or less in length and 5 cm or less in width in the directions corresponding to the vertical and horizontal directions of the laminated glass in the 3D geometry data. The vertical and horizontal directions of the regions correspond to the vertical and horizontal directions of the laminated glass.

[0295] The first surface of the laminated glass has a plurality of the above-mentioned regions (regions each having a length of 5 cm or less and a width of 5 cm or less). Since the laminated glass has a length of 950 mm and a width of 1500 mm, for example, if it is divided so that each region has a length of 5 cm and a width of 5 cm, 570 regions are obtained.

[0296] An accelerometer (PCB PIEZOTRONICS "352C68") was prepared. On the first surface of the laminated glass, the vertical length of the laminated glass was L1 and the horizontal length was L2, and one of the four vertices of the first surface was designated vertex O. On the first surface of the laminated glass, accelerometers were installed at three positions: 0.3L1 vertically and 0.3L2 horizontally from the vertex O; 0.7L1 vertically and 0.5L2 horizontally from the vertex O; and 0.6L1 horizontally and 0.8L2 from the vertex O. Since the laminated glass measured 950 mm vertically and 1500 mm horizontally, accelerometers were installed at three positions: 285 mm vertically and 450 mm horizontally from the vertex O; 665 mm vertically and 750 mm horizontally from the vertex O; and 570 mm horizontally and 1200 mm from the vertex O. The laminated glass with the accelerometer installed was placed in a free-free state. Methods for placing the laminated glass with the accelerometer installed in a free-free state include suspending the laminated glass with soft rubber and placing it on a soft cushion. In this example, the laminated glass was placed in a free-free state by suspending it with soft rubber. In each of the above regions, vibration was applied with an impact hammer to the center positions in the vertical and horizontal directions of the divided regions on the first surface of the laminated glass, and the transfer function (response (m / s) to excitation (F)) was calculated. 2 ) were calculated. The natural frequencies were measured by experimental modal analysis. The obtained transfer functions were curve-fitted using the Polynomial-Z method to calculate each natural frequency Xn (Hz). n represents the order of the vibration mode. For example, X1 represents the natural frequency of the first vibration mode. For the natural frequencies X1 to X10 corresponding to the first to tenth vibration modes, a comparative example having the same wedge angle (θ) was used as a reference, and the absolute values ​​Y1 to Y10 of the differences in the natural frequencies between the comparative example and the example were calculated. For example, the absolute value Y1 is the absolute value of the difference between the natural frequency X1 of the comparative example and the natural frequency X1 of the example.

[0297] The sound insulation in the low frequency range was judged based on the following criteria.

[0298] [Criteria for determining natural frequency (sound insulation in the low frequency range)] ○: At least one of absolute values ​​Y1 to Y10 exceeds 2 Hz ×: All absolute values ​​Y1 to Y10 are 2 Hz or less

[0299] (4-3) STL (sound insulation in the high frequency range) The resulting laminated glass was evaluated for STL (sound insulation in the high frequency range) in accordance with JISA1441-1. The sound pressure of the sound incident on the sample during measurement was the average sound pressure measured by five microphones installed in a reverberation chamber. The sound transmitted through the sample was measured as an average sound intensity in a semi-anechoic chamber on the sound receiving side, with the measurement plane being a distance of 130 mm from the sample surface. The sound intensity was evaluated by scanning using an intensity probe microphone. The sound insulation in the high frequency range was evaluated based on the STL values ​​at four 1 / 3 octave band frequencies: 2500 Hz, 3150 Hz, 4000 Hz, and 5000 Hz, according to the following criteria.

[0300] [STL (high frequency sound insulation) criteria] ○: All four STL values ​​are 32 dB or higher ×: At least one of the four STL values ​​is less than 32 dB

[0301] The configurations of the interlayer films and the results are shown in Tables 1 to 7 below.

[0302] In Tables 1 to 7, *1, *2, and *3 have the following meanings: *1: (T: thickness of the interlayer film at a specified position, T1: thickness of the first layer at the same position as the specified position) *2: (T: thickness of the interlayer film at a specified position, T3: thickness of the third layer at the same position as the specified position) *3: (ten-point average roughness Rz (μm) of the surface opposite the second layer of the layer with the smaller thickness ratio to the interlayer film between the first and third layers)

[0303] [Table 1]

[0304] [Table 2]

[0305] [Table 3]

[0306] [Table 4]

[0307] [Table 5]

[0308] [Table 6]

[0309] [Table 7] [Explanation of symbols]

[0310] 1, 1A, 1B, 1C, 1D, 1E...First layer 2, 2A, 2B, 2C, 2D, 2E...Second layer 2a, 2Aa, 2Ba, 2Ca, 2Da, 2Ea...first surface 2b, 2Ab, 2Bb, 2Cb, 2Db, 2Eb...Second surface 3,3A,3B,3C,3D,3E…Third layer 11,11A,11B,11C,11D,11E...intermediate film 11a…one end 11b...other end 11Da...Wedge-shaped part 11Db...rectangular part 11Ea...First portion with constant thickness increase 11Eb...Second portion with constant thickness increase 21...First laminated glass member 22...Second laminated glass member 31...Laminated glass 41...Optical distortion inspection device 42...Light source unit 43...Slit section 44...Measurement object placement section 45...Projection surface 46...Image input unit 47...Image processing unit 48...Trestle 49...Evaluation Department 421...Light emitting part 422...Optical fiber 423...Irradiation port 481... Stand body 482...Arm A...Optical axis W: Measurement object

Claims

1. An interlayer film for laminated glass having a structure of two or more layers, the intermediate film has one end and another end opposite to the one end, Each layer included in the intermediate film has one end and another end opposite to the one end, the one end of each layer is located on the one end side of the intermediate film in a direction connecting the one end and the other end of the intermediate film, and the other end of each layer is located on the other end side of the intermediate film in a direction connecting the one end and the other end of the intermediate film, In the intermediate film, the thickness of the other end is greater than the thickness of the one end, At least one layer included in the intermediate film has a thickness at the other end that is smaller than a thickness at the one end, the layer having a thickness at the other end smaller than that at the one end contains a polyvinyl acetal resin.

2. An interlayer film for laminated glass having a structure of three or more layers, a first layer, a second layer, and a third layer; the first layer is disposed on a first surface side of the second layer, The interlayer film for laminated glass according to claim 1 , wherein the third layer is disposed on a second surface side of the second layer opposite the first surface.

3. An intermediate film for laminated glass as described in Claim 2, wherein the thickness of the second layer at the other end is thinner than the thickness at the one end.

4. The interlayer film for laminated glass according to claim 2 or 3, wherein the thickness of the first layer at the other end is smaller than the thickness of the first layer at the one end.

5. The interlayer film for laminated glass according to claim 4 , wherein the thickness of the third layer at the other end is greater than the thickness of the third layer at the one end.

6. a ratio of the average thickness of the first layer to the average thickness of the interlayer is smaller than a ratio of the average thickness of the third layer to the average thickness of the interlayer; 6. The interlayer film for laminated glass according to claim 4, wherein the surface of the first layer opposite to the second layer has a ten-point average roughness Rz of 9 μm or more.

7. The interlayer film for laminated glass according to claim 4 , wherein the thickness of the third layer at the other end is smaller than the thickness of the third layer at the one end.

8. a ratio of the average thickness of the third layer to the average thickness of the intermediate film is smaller than a ratio of the average thickness of the first layer to the average thickness of the intermediate film; 8. The interlayer film for laminated glass according to claim 7, wherein the surface of the third layer opposite to the second layer has a ten-point average roughness Rz of 9 μm or more.

9. the first layer includes a thermoplastic resin and a plasticizer; the second layer includes a thermoplastic resin and a plasticizer; The interlayer film for laminated glass according to any one of claims 2 to 8, wherein the third layer comprises a thermoplastic resin and a plasticizer.

10. a content of the plasticizer in the second layer relative to 100 parts by weight of the thermoplastic resin in the second layer is greater than a content of the plasticizer in the first layer relative to 100 parts by weight of the thermoplastic resin in the first layer; 10. The interlayer film for laminated glass according to claim 9, wherein a content of the plasticizer in the second layer per 100 parts by weight of the thermoplastic resin in the second layer is greater than a content of the plasticizer in the third layer per 100 parts by weight of the thermoplastic resin in the third layer.

11. The interlayer film for laminated glass according to any one of claims 1 to 10, wherein the thickness of the interlayer film at the one end is 300 µm or more.

12. a first laminated glass member; and a second laminated glass member; and and the interlayer film for laminated glass according to any one of claims 1 to 11, The laminated glass, wherein the interlayer film for laminated glass is disposed between the first laminated glass member and the second laminated glass member.

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