Interlayer film for laminated glass and laminated glass

Abstract

The present invention provides an interlayer film for laminated glass that can suppress ghosting and appearance unevenness when light is irradiated. The interlayer film for laminated glass (11) of the present invention includes a first layer (1) containing a thermoplastic resin and a plasticizer, and a second layer (2) containing a thermoplastic resin and a plasticizer, the minimum thickness of the first layer (1) is 20 μm or more, when the ratio of the thickness of the first layer (1) at one end (11a) of the interlayer film to the thickness of the interlayer film at the one end (11a) is set as ratio A, and the ratio of the thickness of the first layer (1) at the other end (11b) of the interlayer film to the thickness of the interlayer film at the other end (11b) is set as ratio B, in the case where the wedge angle is 0.1 mrad or more and 0.5 mrad or less, the ratio B is 1.1 times or more and 1.7 times or less of the ratio A, in the case where the wedge angle exceeds 0.5 mrad, the ratio B is 0.8 times or more and 1.1 times or less of the ratio A, and the content of the plasticizer in the first layer (1) is more than the content of the plasticizer in the second layer (2).

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 Art

[0002] Even if laminated glass breaks due to external impact, the amount of scattered glass fragments is small, making it highly safe. Therefore, such laminated glass is widely used in automobiles, railway vehicles, aircraft, ships, buildings, and the like. Laminated glass is manufactured by sandwiching an interlayer film for laminated glass between a pair of glass sheets.

[0003] As the laminated glass for automobiles, a head-up display (HUD) is known. Through the HUD, the driving data of the automobile, i.e., measurement information such as speed, can be displayed on the windshield of the automobile.

[0004] The above-mentioned HUD has a problem in that the measurement information displayed on the windshield appears as a double image.

[0005] Patent Document 1 below discloses laminated glass that can suppress ghosting, using a wedge-shaped interlayer film with a specific wedge angle sandwiched between a pair of glass sheets. By adjusting the wedge angle of the interlayer film, this laminated glass can connect the measurement information reflected from one glass sheet and the measurement information reflected from the other glass sheet to a single point in the driver's field of view. This reduces the risk of ghosting and obstruction of the driver's field of view.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application No. 4-502525 Summary of the Invention

[0009] Problems solved by the invention

[0010] To impart sound insulation and other functions to an interlayer film, a multilayer interlayer film structure is sometimes used, for example, where a sound-insulating interlayer film is sandwiched between conventional interlayer films. Laminated glass using conventional multilayer wedge-shaped interlayer films may exhibit visible linear or dotted irregularities in appearance when exposed to light. This irregularity is sometimes referred to as "distortion."

[0011] An object of the present invention is to provide an interlayer film for laminated glass that can suppress ghosting in laminated glass and reduce visible unevenness in the laminated glass when exposed to light. Another object of the present invention is to provide laminated glass using the interlayer film for laminated glass.

[0012] A limited object of the present invention is to provide an interlayer film for laminated glass that suppresses ghosting in laminated glass, minimizes visible unevenness in the laminated glass's appearance when illuminated by light, and exhibits excellent sound insulation. A further object of the present invention is to provide laminated glass using the interlayer film for laminated glass.

[0013] Technical means to solve the problem

[0014] According to a broad aspect of the present invention, there is provided an interlayer film for laminated glass (occasionally referred to as "interlayer film" in this specification), which is an interlayer film for laminated glass and includes: a first layer containing a thermoplastic resin and a plasticizer; and a second layer containing a thermoplastic resin and a plasticizer, the second layer being disposed on a first surface side of the first layer, the interlayer film for laminated glass having one end and another end opposite the one end, the other end having a thickness greater than that of the one end, the first layer having a minimum thickness of 20 μm or greater and a wedge angle of 0.1 mrad or greater, and the thickness of the first layer at the one end being adjusted relative to the thickness of the interlayer film at the one end. When the ratio of the thickness of the first layer at the other end to the thickness of the interlayer film at the other end is denoted as ratio A, and the ratio of the thickness of the first layer at the other end to the thickness of the interlayer film at the other end is denoted as ratio B, when the wedge angle is 0.1 mrad or more and 0.5 mrad or less, the ratio B is 1.1 times or more and 1.7 times or less of the ratio A, and when the wedge angle exceeds 0.5 mrad, the ratio B is 0.8 times or more and 1.1 times or less of the ratio A, and the content of the plasticizer in the first layer relative to 100 parts by weight of the thermoplastic resin in the first layer is greater than the content of the plasticizer in the second layer relative to 100 parts by weight of the thermoplastic resin in the second layer.

[0015] According to a specific embodiment of the interlayer film of the present invention, the wedge angle is 0.5 mrad or less.

[0016] According to a specific embodiment of the interlayer film of the present invention, the wedge angle is 0.47 mrad or less.

[0017] According to a specific embodiment of the intermediate film of the present invention, the wedge angle exceeds 0.5 mrad.

[0018] According to a specific embodiment of the interlayer film of the present invention, the minimum thickness of the second layer is 270 μm or more.

[0019] According to a specific embodiment of the interlayer film of the present invention, the interlayer film includes a portion having a wedge-shaped cross-section in the thickness direction.

[0020] According to a specific embodiment of the interlayer film of the present invention, the thermoplastic resin in the first layer is a polyvinyl acetal resin, and the thermoplastic resin in the second layer is a polyvinyl acetal resin.

[0021] According to a specific embodiment of the interlayer film of the present invention, the hydroxyl group content of the polyvinyl acetal resin in the first layer is lower than the hydroxyl group content of the polyvinyl acetal resin in the second layer.

[0022] According to a specific embodiment of the interlayer film of the present invention, the interlayer film includes a third layer containing a thermoplastic resin, and the third layer is disposed on a second surface side of the first layer opposite to the first surface side.

[0023] According to a specific embodiment of the interlayer film of the present invention, the thermoplastic resin in the first layer is a polyvinyl acetal resin, the thermoplastic resin in the third layer is a polyvinyl acetal resin, the third layer contains a plasticizer, the hydroxyl content of the polyvinyl acetal resin in the first layer is lower than the hydroxyl content of the polyvinyl acetal resin in the third layer, and the content of the plasticizer in the first layer relative to 100 parts by weight of the polyvinyl acetal resin in the first layer is greater than the content of the plasticizer in the third layer relative to 100 parts by weight of the polyvinyl acetal resin in the third layer.

[0024] According to a specific embodiment of the interlayer film of the present invention, the minimum combined thickness of the second and third layers is 540 μm or more.

[0025] According to a specific embodiment of the interlayer film of the present invention, the interlayer film is used as laminated glass for a head-up display.

[0026] According to a broad aspect of the present invention, there is provided a laminated glass comprising a first laminated glass component, a second laminated glass component, and the interlayer film for laminated glass, wherein the interlayer film for laminated glass is disposed between the first laminated glass component and the second laminated glass component.

[0027] Effects of the Invention

[0028] The interlayer film for laminated glass of the present invention comprises a first layer containing a thermoplastic resin and a plasticizer, and a second layer containing a thermoplastic resin and a plasticizer, wherein the second layer is disposed on the first surface side of the first layer. The interlayer film for laminated glass of the present invention has one end and another end located opposite the one end, wherein the thickness of the other end is greater than the thickness of the one end. In the interlayer film for laminated glass of the present invention, the minimum thickness of the first layer is 20 μm or greater, and the wedge angle is 0.1 mrad or greater. In the interlayer film for laminated glass of the present invention, the ratio of the thickness of the first layer at the one end to the thickness of the interlayer film at the one end is defined as ratio A, and the ratio of the thickness of the first layer at the other end to the thickness of the interlayer film at the other end is defined as ratio B. In the interlayer film for laminated glass of the present invention, when the wedge angle is 0.1 mrad or more and 0.5 mrad or less, the ratio B is 1.1 to 1.7 times the ratio A. When the wedge angle exceeds 0.5 mrad, the ratio B is 0.8 to 1.1 times the ratio A. In the interlayer film for laminated glass of the present invention, the content of the plasticizer in the first layer relative to 100 parts by weight of the thermoplastic resin in the first layer is greater than the content of the plasticizer in the second layer relative to 100 parts by weight of the thermoplastic resin in the second layer. The interlayer film for laminated glass of the present invention, having the above-described configuration, can suppress ghosting in laminated glass and reduce the appearance of unevenness in the laminated glass when illuminated by light. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 (a) and (b) are a cross-sectional view and a front view schematically showing an interlayer film for laminated glass according to a first embodiment of the present invention.

[0030] Figure 2 (a) and (b) are a cross-sectional view and a front view schematically showing an interlayer film for laminated glass according to a second embodiment of the present invention.

[0031] Figure 3 To express the use Figure 1 A cross-sectional view of an example of laminated glass including an interlayer film for laminated glass is shown. DETAILED DESCRIPTION

[0032] Hereinafter, the present invention will be described in detail.

[0033] The interlayer film for laminated glass of the present invention (sometimes simply referred to as "interlayer film" in this specification) is used for laminated glass.

[0034] The interlayer film of the present invention has a structure of two or more layers. The interlayer film of the present invention may have a structure of two layers or a structure of three or more layers. The interlayer film of the present invention is a multilayer interlayer film.

[0035] The interlayer film of the present invention comprises a first layer and a second layer. The interlayer film of the present invention preferably comprises a third layer. In the interlayer film of the present invention, the second layer is disposed on the first surface side of the first layer. When the interlayer film of the present invention comprises a third layer, the third layer is preferably disposed on the second surface side of the first layer, opposite to the first surface side.

[0036] In the interlayer film of the present invention, the first layer contains a thermoplastic resin and a plasticizer, and the second layer contains a thermoplastic resin and a plasticizer. When the interlayer film of the present invention includes a third layer, the third layer preferably contains a thermoplastic resin and a plasticizer.

[0037] The interlayer film of the present invention has one end and another end located opposite the one end. The one end and the other end are opposite ends of the interlayer film. In the interlayer film of the present invention, the other end is thicker than the one end.

[0038] The minimum thickness of the first layer of the interlayer film of the present invention is 20 μm or more.

[0039] In the interlayer film of the present invention, the wedge angle is 0.1 mrad or more.

[0040] In the interlayer film of the present invention, the ratio of the thickness (a1) of the first layer at one end to the thickness (a) of the interlayer film at one end is defined as ratio A ((a1) / (a)). Ratio A is an indicator of the proportion of the thickness occupied by the first layer at one end of the interlayer film.

[0041] In the interlayer film of the present invention, the ratio of the thickness (bl) of the first layer at the other end to the thickness (b) of the interlayer film at the other end is defined as ratio B ((bl) / (b)). Ratio B is an indicator of the proportion of the thickness occupied by the first layer at the other end of the interlayer film.

[0042] In the interlayer film of the present invention, when the wedge angle is 0.1 mrad to 0.5 mrad, the ratio B is 1.1 to 1.7 times the ratio A. That is, the ratio B / ratio A is 1.1 to 1.7.

[0043] In the interlayer film of the present invention, when the wedge angle exceeds 0.5 mrad, the ratio B is 0.8 to 1.1 times the ratio A. That is, the value of ratio B / ratio A is 0.8 to 1.1.

[0044] In the interlayer film of the present invention, the content of the plasticizer in the first layer relative to 100 parts by weight of the thermoplastic resin in the first layer is greater than the content of the plasticizer in the second layer relative to 100 parts by weight of the thermoplastic resin in the second layer.

[0045] Conventional interlayer films may exhibit linear or dot-shaped appearance unevenness when exposed to light. This appearance unevenness is sometimes referred to as "distortion."

[0046] Since the present invention has the above-mentioned configuration, ghosting in the laminated glass can be suppressed, and uneven appearance of the laminated glass can be less easily seen when the laminated glass is irradiated with light.

[0047] In the present invention, when display information is reflected from the display unit to the laminated glass, the occurrence of ghosting can be suppressed. In the present invention, uneven appearance called "distortion" can be suppressed.

[0048] Conventional multilayer interlayer films with a wedge angle of 0.1 mrad or greater easily cause uneven appearance of laminated glass when exposed to light. The interlayer film of the present invention can significantly reduce the appearance of uneven appearance of laminated glass when exposed to light. The interlayer film of the present invention can significantly reduce the appearance of uneven appearance of laminated glass when exposed to light even when the wedge angle is 0.1 mrad or greater and 0.5 mrad or less, and can significantly reduce the appearance of uneven appearance of laminated glass when exposed to light even when the wedge angle exceeds 0.5 mrad.

[0049] Furthermore, the present invention, due to the aforementioned configuration, can improve sound insulation. Since the content of the plasticizer in the first layer relative to 100 parts by weight of the thermoplastic resin in the first layer is greater than the content of the plasticizer in the second layer relative to 100 parts by weight of the thermoplastic resin in the second layer, sound insulation is effectively improved. In the laminated glass with improved sound insulation of the present invention, ghosting can be suppressed, and uneven appearance of the laminated glass can be less noticeable when illuminated by light.

[0050] Furthermore, conventional interlayer films with a wedge angle of 0.1 mrad to 0.5 mrad tend to make the laminated glass appear uneven when exposed to light. Conventional interlayer films with a wedge angle of 0.1 mrad to 0.47 mrad tend to make the laminated glass appear even more uneven when exposed to light. The interlayer film of the present invention, even with a wedge angle of 0.1 mrad to 0.5 mrad, and even with a wedge angle of 0.47 mrad or less, can sufficiently reduce the appearance of the laminated glass from being uneven when exposed to light. It should be noted that the interlayer film of the present invention may also have a wedge angle exceeding 0.5 mrad.

[0051] From the perspective of effectively suppressing ghosting and making uneven appearance of the laminated glass less noticeable when irradiated with light, when the wedge angle is 0.1 mrad or more and 0.5 mrad or less, the ratio B / ratio A is preferably 1.6 or less, more preferably 1.5 or less, and even more preferably 1.4 or less.

[0052] From the perspective of effectively suppressing ghosting and making uneven appearance of the laminated glass less noticeable when irradiated with light, when the wedge angle is 0.1 mrad to 0.5 mrad, the ratio B / ratio A is preferably 1.2 or more, more preferably 1.3 or more.

[0053] From the perspective of effectively suppressing ghosting and making uneven appearance of the laminated glass less noticeable when irradiated with light, when the wedge angle exceeds 0.5 mrad, the ratio B / ratio A is preferably 1.0 or less, more preferably 0.95 or less.

[0054] From the perspective of effectively suppressing ghosting and making uneven appearance of the laminated glass less noticeable when irradiated with light, when the wedge angle exceeds 0.5 mrad, the ratio B / ratio A is preferably 0.85 or greater, more preferably 0.9 or greater.

[0055] The interlayer film of the present invention is suitably used as a laminated glass for a head-up display (HUD). The interlayer film of the present invention is preferably an interlayer film for a HUD.

[0056] The interlayer film of the present invention preferably has a display-compatible region corresponding to the display area of ​​the HUD. This display-compatible region is an area capable of displaying information well. The interlayer film of the present invention preferably includes the display-compatible region in the region extending from a position 10 cm from the one end toward the other end to a position 59.8 cm from the one end toward the other end. The display-compatible region may exist in a portion of the region extending from a position 10 cm from the one end toward the other end to a position 59.8 cm from the one end toward the other end, or may exist throughout the region.

[0057] From the perspective of effectively suppressing ghosting, the interlayer film preferably has a portion having a wedge-shaped cross-sectional shape in the thickness direction in the region extending from a position 10 cm from the one end toward the other end to a position 59.8 cm from the one end toward the other end. The wedge-shaped cross-sectional shape in the thickness direction may exist in a portion of the region extending from a position 10 cm from the one end toward the other end to a position 59.8 cm from the one end toward the other end, or may exist throughout the region.

[0058] The interlayer film of the present invention may also have a shaded area. The shaded area may be separate from the display-corresponding area. The shaded area is provided, for example, to prevent glare from sunlight or outdoor lighting while driving. The shaded area may also be provided to provide thermal insulation. The shaded area is preferably located at the edge of the interlayer film. The shaded area is preferably strip-shaped.

[0059] In the shaded area, a colorant or filler may be used to change the color and visible light transmittance. The colorant or filler may be contained only in a portion of the interlayer film in the thickness direction or in the entire interlayer film in the thickness direction.

[0060] From the perspective of further improving the display and further expanding the field of view, the visible light transmittance of the display-corresponding area is preferably 80% or greater, more preferably 88% or greater, and even more preferably 90% or greater. The visible light transmittance of the display-corresponding area is preferably higher than that of the shadow area. The visible light transmittance of the display-corresponding area may also be lower than that of the shadow area. The visible light transmittance of the display-corresponding area is preferably 50% or greater, more preferably 60% or greater, higher than that of the shadow area.

[0061] For example, when the visible light transmittance of the interlayer film in the display corresponding region and the shaded region changes, the visible light transmittance is measured at the center position of the display corresponding region and the center position of the shaded region.

[0062] The visible light transmittance of the obtained laminated glass at a wavelength of 380 to 780 nm can be measured using a spectrophotometer ("U-4100" manufactured by Hitachi High-Technologies Corporation) in accordance with JIS R3211 (1998). It is preferred to use a 2 mm thick clear glass as the glass plate.

[0063] The display corresponding region preferably has a length direction and a width direction. Due to the excellent versatility of the intermediate film, 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.

[0064] The interlayer film preferably has an MD direction and a TD direction. The interlayer film is obtained, for example, by melt extrusion. The MD direction is the direction in which the interlayer film is produced. The TD direction is perpendicular to the direction in which the interlayer film is produced and perpendicular to the thickness direction of the interlayer film. Preferably, the one end and the other end are located on opposite sides of the TD direction.

[0065] From the viewpoint of achieving a better display, the interlayer film preferably has a portion having a wedge-shaped cross-section in the thickness direction. The display-corresponding region preferably has a wedge-shaped cross-section in the thickness direction.

[0066] The interlayer film may be wound into a roll to form an interlayer film roll. The roll may include a core and the interlayer film. The interlayer film may be wound around the outer circumference of the core.

[0067] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[0068] Figure 1 (a) and (b) schematically show the interlayer film for laminated glass according to the first embodiment of the present invention in a cross-sectional view and a front view. Figure 1 (a) is along Figure 1 (b) is a cross-sectional view of line II. It should be noted that for the convenience of illustration, Figure 1 The sizes and dimensions of the interlayer films in the drawings described below are appropriately changed according to the actual sizes and shapes.

[0069] Figure 1 (a) shows a cross section in the thickness direction of the interlayer 11. Figure 1 In (a) and the figures described later, for the sake of convenience, the thickness of the interlayer film and each layer constituting the interlayer film, and the wedge angle θ are shown differently from the actual thickness and wedge angle.

[0070] Figure 1 The interlayer film 11 shown in (a) and (b) includes a first layer 1 (interlayer), a second layer 2 (surface layer), and a third layer 3 (surface layer). The second layer 2 is disposed and laminated on the first surface side of the first layer 1. The third layer 3 is disposed and laminated on the second surface side of the first layer 1 opposite the first surface. The first layer 1 is disposed and sandwiched between the second layer 2 and the third layer 3. The interlayer film 11 is used to obtain laminated glass. The interlayer film 11 is an interlayer film for laminated glass. The interlayer film 11 is a multilayer interlayer film.

[0071] The intermediate film 11 has one end 11a and another end 11b opposite the one end 11a. The one end 11a and the other end 11b are opposite ends. The first layer 1, the second layer 2, and the third layer 3 have a wedge-shaped cross-section in the thickness direction. The thickness of the second layer 2 and the third layer 3 is greater on the other end 11b side than on the one end 11a side. Therefore, the thickness of the intermediate film 11 is greater at the other end 11b than at the one end 11a. Consequently, the intermediate film 11 has both thinner and thicker regions.

[0072] The interlayer film 11 has a display-corresponding region R1 corresponding to the display area of ​​the head-up display. The interlayer film 11 has a peripheral region R2 adjacent to the display-corresponding region R1. In this embodiment, the display-corresponding region R1 extends from a position 10 cm from one end 11a toward the other end l1b to a position 59.8 cm from one end 11a toward the other end l1b.

[0073] The intermediate film 11 has a shaded area R3 separated from the display corresponding area R1 . The shaded area R3 is located at the edge of the intermediate film 11 .

[0074] exist Figure 2 (a) and (b) schematically show an interlayer film for laminated glass according to a second embodiment of the present invention in a cross-sectional view and a front view. Figure 2 (a) is along Figure 2 (b) Cross-sectional view along line II. Figure 2 (a) shows a cross section in the thickness direction of the intermediate film 11A.

[0075] Figure 2 The interlayer film 11A shown in (a) and (b) includes a first layer 1A (interlayer), a second layer 2A (surface layer), and a third layer 3A (surface layer). The second layer 2A is disposed and laminated on the first surface side of the first layer 1A. The third layer 3A is disposed and laminated on the second surface side of the first layer 1A, opposite to the first surface. The first layer 1A is disposed and sandwiched between the second layer 2A and the third layer 3A. The interlayer film 11A is used to produce laminated glass. The interlayer film 11A is an interlayer film for laminated glass. The interlayer film 11A is a multilayer interlayer film.

[0076] The intermediate film 11A has one end 11a and another end 11b opposite the one end 11a. The one end 11a and the other end 11b are opposite ends. The first layer 1A and the second layer 2A have rectangular cross-sectional shapes in the thickness direction. The thickness of the third layer 3A is greater on the other end 11b side than on the one end 11a side. The third layer 3A has a rectangular cross-sectional portion in the thickness direction and a wedge-shaped cross-sectional portion in the thickness direction. The thickness of the other end 11b of the intermediate film 11A is greater than that of the one end 11a. Therefore, the intermediate film 11A has thinner regions and thicker regions.

[0077] The intermediate film 11A includes a portion 11Aa having a rectangular cross-sectional shape in the thickness direction and a portion 11Ab having a wedge-shaped cross-sectional shape in the thickness direction.

[0078] The intermediate film 11A has a display-corresponding region R1 corresponding to the display area of ​​the head-up display, and has a peripheral region R2 adjacent to the display-corresponding region R1.

[0079] The intermediate film 11A has a shaded area R3 separated from the display corresponding area R1. The shaded area R3 is located at the edge of the intermediate film 11A.

[0080] The interlayer film preferably has a portion having a wedge-shaped cross-section in the thickness direction. The interlayer film preferably has a portion whose thickness gradually increases from one end toward the other end. The interlayer film preferably has a wedge-shaped cross-section in the thickness direction. Examples of the interlayer film's cross-section in the thickness direction include a trapezoid, a triangle, and a pentagon.

[0081] To suppress ghosting, the wedge angle θ of the interlayer film can be appropriately set according to the installation angle of the laminated glass. To further suppress ghosting, the wedge angle θ of the interlayer film is preferably 0.2 mrad (0.0115 degrees) or greater. Furthermore, if the wedge angle θ is above the lower limit, laminated glass suitable for vehicles such as trucks and buses, which have windshields with large installation angles, can be obtained.

[0082] From the perspective of further suppressing ghosting, the wedge angle θ of the interlayer film is preferably 2 mrad (0.1146 degrees) or less, more preferably 0.7 mrad (0.0401 degrees) or less, even more preferably 0.5 mrad (0.0288 degrees) or less, and particularly preferably 0.47 mrad (0.027 degrees) or less. Furthermore, when the wedge angle θ is below the upper limit, laminated glass suitable for vehicles with narrow windshield mounting angles, such as sports cars, can be obtained.

[0083] The wedge angle θ of the interlayer film is defined as the internal angle at the intersection of a straight line connecting the first surface (one surface) of the interlayer film at its maximum and minimum thickness portions, and a straight line connecting the second surface (the other surface) of the interlayer film at its maximum and minimum thickness portions. It should be noted that if there are multiple maximum and minimum thickness portions, or if the maximum and minimum thickness portions exist in a certain region, the maximum and minimum thickness portions used to determine the wedge angle θ are selected so as to maximize the obtained wedge angle θ.

[0084] From the viewpoint of further suppressing ghosting, further improving the handleability of the interlayer film, and making it less likely to produce poor appearance of the laminated glass, the ratio of the thickness of the interlayer film at the one end to the thickness of the interlayer film at the other end is preferably 1.05 or more, more preferably 1.1 or more, and is preferably 1.8 or less, more preferably 1.7 or less.

[0085] The thickness of the interlayer is not particularly limited. The thickness of the interlayer represents the total thickness of the layers constituting the interlayer. Therefore, in the case of a multilayer interlayer 11, the thickness of the interlayer represents the total thickness of the first layer 1, the second layer 2, and the third layer 3.

[0086] The minimum thickness of the intermediate film is preferably 0.1 mm or more, more preferably 0.25 mm or more, further preferably 0.5 mm or more, further preferably 0.65 mm or more, particularly preferably 0.7 mm or more, most preferably 0.725 mm or more, and is preferably 3 mm or less, more preferably 2 mm or less, further preferably 1.5 mm or less.

[0087] The maximum thickness of the interlayer is preferably 0.1 mm or more, more preferably 0.25 mm or more, further preferably 0.5 mm or more, further preferably 0.8 mm or more, particularly preferably 0.9 mm or more, and preferably 3 mm or less, more preferably 2 mm or less, further preferably 1.5 mm or less.

[0088] The distance X between one end and the other end of the intermediate film is preferably 3 m or less, more preferably 2 m or less, particularly preferably 1.5 m or less, and is preferably 0.5 m or more, more preferably 0.8 m or more, particularly preferably 1 m or more.

[0089] Let the distance between one end and the other end be X. The intermediate film preferably has a minimum thickness in a region with a distance of 0X to 0.2X from one end toward the inside, and has a maximum thickness in a region with a distance of 0X to 0.2X from the other end toward the inside. The intermediate film more preferably has a minimum thickness in a region with a distance of 0X to 0.1X from one end toward the inside, and has a maximum thickness in a region with a distance of 0X to 0.1X from the other end toward the inside. Preferably, the intermediate film has a minimum thickness at one end and a maximum thickness at the other end. The intermediate film 11, 11A has a maximum thickness at the other end 11b and a minimum thickness at the one end 11a.

[0090] The interlayer film may have a portion with uniform thickness. The uniform thickness portion refers to a portion whose thickness varies by no more than 10 μm per 10 cm distance in the direction connecting the one end and the other end of the interlayer film. Therefore, the uniform thickness portion refers to a portion whose thickness varies by no more than 10 μm per 10 cm distance in the direction connecting the one end and the other end of the interlayer film. Specifically, the uniform thickness portion refers to a portion whose thickness does not vary at all in the direction connecting the one end and the other end of the interlayer film, or a portion whose thickness varies by no more than 10 μm per 10 cm distance in the direction connecting the one end and the other end of the interlayer film.

[0091] From the perspectives of sufficiently improving adhesion and penetration resistance, minimizing appearance defects in the laminated glass, and improving sound insulation, the minimum thickness of each of the second and third layers is preferably 0.02 mm or greater, more preferably 0.1 mm or greater, even more preferably 0.2 mm or greater, particularly preferably 0.27 mm or greater, and most preferably 0.3 mm or greater. From the perspectives of minimizing appearance defects in the laminated glass and practicality, the minimum thickness of each of the second and third layers is preferably 1 mm or less, more preferably 0.8 mm or less, and even more preferably 0.5 mm or less.

[0092] The maximum thickness of each of the second and third layers is preferably 0.05 mm or greater, more preferably 0.1 mm or greater, even more preferably 0.2 mm or greater, even more preferably 0.3 mm or greater, particularly preferably 0.35 mm or greater, even more particularly preferably 0.45 mm or greater, and most preferably 0.55 mm or greater. When the maximum thickness of each of the second and third layers is above the lower limit and below the upper limit, the adhesive strength and penetration resistance can be sufficiently improved, the appearance of the laminated glass can be further reduced, and the sound insulation can be improved. From a practical perspective, the maximum thickness of each of the second and third layers is preferably 1 mm or less, and more preferably 0.8 mm or less.

[0093] From the perspectives of sufficiently improving adhesion and penetration resistance, minimizing appearance defects in laminated glass, and improving sound insulation, the combined minimum thickness of the second and third layers is preferably 0.04 mm or greater, more preferably 0.2 mm or greater, even more preferably 0.4 mm or greater, particularly preferably 0.54 mm or greater, and most preferably 0.6 mm or greater. From the perspectives of minimizing appearance defects in laminated glass and practicality, the combined minimum thickness of the second and third layers is preferably 2 mm or less, more preferably 1.6 mm or less, and even more preferably 1 mm or less.

[0094] The combined maximum thickness of the second and third layers is preferably 0.1 mm or greater, more preferably 0.2 mm or greater, even more preferably 0.4 mm or greater, even more preferably 0.6 mm or greater, particularly preferably 0.7 mm or greater, even more particularly preferably 0.9 mm or greater, and most preferably 1.1 mm or greater. When the combined maximum thickness of the second and third layers is above the lower limit and below the upper limit, adhesion and penetration resistance are sufficiently enhanced, the appearance of the laminated glass is less likely to be impaired, and sound insulation can be improved. From a practical perspective, the combined maximum thickness of the second and third layers is preferably 2 mm or less, and more preferably 1.6 mm or less.

[0095] From the perspective of reducing the appearance defects of the laminated glass and improving the sound insulation, the minimum thickness of the first layer is preferably 0.05 mm or more, more preferably 0.06 mm or more, and even more preferably 0.07 mm or more. From the perspective of reducing the appearance defects of the laminated glass, the minimum thickness of the first layer is preferably 0.8 mm or less, more preferably 0.6 mm or less, even more preferably 0.3 mm or less, and particularly preferably 0.2 mm or less.

[0096] From the perspective of reducing the appearance defects of the laminated glass and improving the sound insulation, the maximum thickness of the first layer is preferably 0.05 mm or more, more preferably 0.1 mm or more, even more preferably 0.125 mm or more, particularly preferably 0.15 mm or more, and most preferably 0.2 mm or more. From the perspective of reducing the appearance defects of the laminated glass, the minimum thickness of the first layer is preferably 0.8 mm or less, more preferably 0.6 mm or less, and even more preferably 0.3 mm or less.

[0097] The following describes in detail the materials of each layer constituting the multilayer interlayer film.

[0098] (Thermoplastic resin)

[0099] The intermediate film (each layer) contains a thermoplastic resin (hereinafter sometimes described as thermoplastic resin (0)). The intermediate film (each layer) preferably contains a polyvinyl acetal resin (hereinafter sometimes described as polyvinyl acetal resin (0)) as the thermoplastic resin (0). The above-mentioned first layer contains a thermoplastic resin (hereinafter sometimes described as thermoplastic resin (1)), and preferably contains a polyvinyl acetal resin (hereinafter sometimes described as polyvinyl acetal resin (1)) as the thermoplastic resin (1). The above-mentioned second layer contains a thermoplastic resin (hereinafter sometimes described as thermoplastic resin (2)), and preferably contains a polyvinyl acetal resin (hereinafter sometimes described as polyvinyl acetal resin (2)) as the thermoplastic resin (2). The above-mentioned third layer preferably contains a thermoplastic resin (hereinafter sometimes described as thermoplastic resin (3)), and preferably contains a polyvinyl acetal resin (hereinafter sometimes described as polyvinyl acetal resin (3)) as the thermoplastic resin (3).

[0100] The thermoplastic resin (1), the thermoplastic resin (2), and the thermoplastic resin (3) may be the same or different. In order to further improve the sound insulation, the thermoplastic resin (1) is preferably different from the thermoplastic resin (2) and the thermoplastic resin (3). The polyvinyl acetal resin (1), the polyvinyl acetal resin (2), and the polyvinyl acetal resin (3) may be the same or different. In order to further improve the sound insulation, the polyvinyl acetal resin (1) is preferably different from the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3). 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 be used alone or in combination of two or more.

[0101] Examples of the thermoplastic resin include polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic acid copolymer resin, polyurethane resin, polyvinyl alcohol resin, polyolefin resin, polyvinyl acetate resin, and polystyrene resin. Other thermoplastic resins may also be used.

[0102] The thermoplastic resin is preferably a polyvinyl acetal resin. The combination of the polyvinyl acetal resin and a plasticizer further enhances the adhesion of the interlayer film of the present invention to laminated glass components or other interlayer films.

[0103] The polyvinyl acetal resin is obtained, for example, by acetalizing polyvinyl alcohol (PVA) with an aldehyde. The polyvinyl acetal resin is preferably an acetalized product of polyvinyl alcohol. The polyvinyl alcohol is obtained, for example, by saponifying polyvinyl acetate. The degree of saponification of the polyvinyl alcohol is generally in the range of 70 to 99.9 mol%.

[0104] The average degree of polymerization of the polyvinyl alcohol (PVA) is preferably 200 or higher, more preferably 500 or higher, even more preferably 1500 or higher, even more preferably 1600 or higher, particularly preferably 2600 or higher, and most preferably 2700 or higher. It is preferably 5000 or lower, more preferably 4000 or lower, and even more preferably 3500 or lower. If the average degree of polymerization is above the lower limit, the penetration resistance of the laminated glass is further improved. If the average degree of polymerization is below the upper limit, the interlayer film can be easily formed.

[0105] The average degree of polymerization of the polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Testing methods for polyvinyl alcohol".

[0106] The number of carbon atoms of the acetal group contained in the above polyvinyl acetal resin is not particularly limited. The aldehyde used in the production of the above polyvinyl acetal resin is not particularly limited. The number of carbon atoms of the acetal group in the above polyvinyl acetal resin is preferably 3 to 5, more preferably 3 or 4. If the number of carbon atoms of the acetal group in the above polyvinyl acetal resin is 3 or more, the glass transition temperature of the interlayer film is sufficiently reduced.

[0107] The above aldehyde is not particularly limited. In general, an aldehyde having 1 to 10 carbon atoms is suitably used. As the above aldehyde having 1 to 10 carbon atoms, for example, formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-pentanal, 2-ethylbutyraldehyde, n-hexanal, n-octanal, n-nonyl aldehyde, n-decanal, and benzaldehyde, etc. can be given. Propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-hexanal, or n-pentanal is preferred, more preferably propionaldehyde, n-butyraldehyde, or isobutyraldehyde, and further preferably n-butyraldehyde. The above aldehyde can be used alone or in combination of two or more.

[0108] The hydroxyl group content (hydroxyl group amount) of the above polyvinyl acetal resin (1) is preferably 17 mol% or more, more preferably 20 mol% or more, further preferably 22 mol% or more, and is preferably 28 mol% or less, more preferably 27 mol% or less, further preferably 25 mol% or less, and particularly preferably 24 mol% or less. When the above hydroxyl group content is the above lower limit or more, the mechanical strength of the interlayer film is further increased. In particular, when the hydroxyl group content of the above polyvinyl acetal resin (1) is 20 mol% or more, the reaction efficiency is high and the productivity is excellent, and in addition, if it is 28 mol% or less, the sound insulation of the laminated glass is further increased. In addition, when the above hydroxyl group content is the above upper limit or less, the softness of the interlayer film is increased, and the handling of the interlayer film becomes easy.

[0109] The respective contents of the hydroxyl groups of the above polyvinyl acetal resin (2) and the above polyvinyl acetal resin (3) are preferably 25 mol% or more, more preferably 28 mol% or more, more preferably 30 mol% or more, further preferably 31.5 mol% or more, further preferably 32 mol% or more, and particularly preferably 33 mol% or more. The respective contents of the hydroxyl groups of the above polyvinyl acetal resin (2) and the above polyvinyl acetal resin (3) are preferably 38 mol% or less, more preferably 37 mol% or less, further preferably 36.5 mol% or less, and particularly preferably 36 mol% or less. When the above hydroxyl group content is the above lower limit or more, the adhesion of the interlayer film is further increased. In addition, when the above hydroxyl group content is the above upper limit or less, the softness of the interlayer film is increased, and the handling of the interlayer film becomes easy.

[0110] From the viewpoint of further improving the sound insulation performance, the hydroxyl content of the polyvinyl acetal resin (1) is preferably lower than the hydroxyl content of the polyvinyl acetal resin (2). From the viewpoint of further improving the sound insulation performance, the hydroxyl content of the polyvinyl acetal resin (1) is preferably lower than the hydroxyl content of the polyvinyl acetal resin (3). From the viewpoint of further improving the sound insulation performance, the absolute value of the difference between the hydroxyl content of the polyvinyl acetal resin (1) and the hydroxyl content of the polyvinyl acetal resin (2) is preferably 1 mol% or more, more preferably 5 mol% or more, further preferably 9 mol% or more, particularly preferably 10 mol% or more, and most preferably 12 mol% or more. From the viewpoint of further improving the sound insulation performance, the absolute value of the difference between the hydroxyl content of the polyvinyl acetal resin (1) and the hydroxyl content of the polyvinyl acetal resin (3) is preferably 1 mol% or more, more preferably 5 mol% or more, further preferably 9 mol% or more, particularly preferably 10 mol% or more, and most preferably 12 mol% or more. The absolute value of the difference between the hydroxyl content of the polyvinyl acetal resin (1) and the hydroxyl content of the polyvinyl acetal resin (2), and the absolute value of the difference between the hydroxyl content of the polyvinyl acetal resin (1) and the hydroxyl content of the polyvinyl acetal resin (3) are preferably 20 mol% or less.

[0111] The hydroxyl content of the polyvinyl acetal resin is a molar fraction calculated by dividing the amount of ethylene groups bonded with hydroxyl groups by the total amount of ethylene groups in the main chain, expressed as a percentage. The amount of ethylene groups bonded with hydroxyl groups can be measured, for example, in accordance with JIS K6728 "Testing methods for polyvinyl butyral."

[0112] The degree of acetylation (amount of acetyl groups) of the polyvinyl acetal resin (1) 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 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 (1) is at least 0.1 mol% and at most 25 mol%, excellent penetration resistance is achieved.

[0113] The degree of acetylation of each of the polyvinyl acetal resin (2) 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 above the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is improved. When the degree of acetylation is below the upper limit, the moisture resistance of the interlayer film and the laminated glass is improved.

[0114] The degree of acetylation is the molar fraction calculated by dividing the amount of ethylene groups bonded to acetyl groups by the total amount of ethylene groups in the main chain and expressed as a percentage. The amount of ethylene groups bonded to acetyl groups can be measured, for example, in accordance with JIS K6728 "Testing methods for polyvinyl butyral."

[0115] The degree of acetalization of the polyvinyl acetal resin (1) (in the case of a polyvinyl butyral resin, the degree of butyralization) 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. If the degree of acetalization is at least the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is improved. If the degree of acetalization is at most the upper limit, the reaction time required to produce the polyvinyl acetal resin is shortened.

[0116] The degree of acetalization of each of the polyvinyl acetal resin (2) 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 above the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is improved. When the degree of acetalization is below the upper limit, the reaction time required to produce the polyvinyl acetal resin is shortened.

[0117] The degree of acetalization is a value expressed as a percentage and is the molar fraction obtained by subtracting the amount of ethylene groups bonded to hydroxyl groups and the amount of ethylene groups bonded to acetyl groups from the total amount of ethylene groups in the main chain and dividing the result by the total amount of ethylene groups in the main chain.

[0118] The degree of acetalization can be calculated by a method in accordance with JIS K6728 "Testing methods for polyvinyl butyral" or a method in accordance with ASTM D1396-92.

[0119] It should be noted that the hydroxyl content (hydroxyl amount), acetalization degree (butyralization degree), and acetylation degree are preferably calculated based on the results of measurements performed in accordance with JIS K6728 "Testing methods for polyvinyl butyral." However, measurements performed in accordance with ASTM D1396-92 may also be used. When the polyvinyl acetal resin is a polyvinyl butyral resin, the hydroxyl content (hydroxyl amount), acetalization degree (butyralization degree), and acetylation degree can be calculated based on the results of measurements performed in accordance with JIS K6728 "Testing methods for polyvinyl butyral."

[0120] (Plasticizer)

[0121] From the viewpoint of further improving the adhesive strength of the interlayer film, the interlayer film of the present invention contains a plasticizer (hereinafter sometimes referred to as plasticizer (0)). The above-mentioned first layer contains a plasticizer (hereinafter sometimes referred to as plasticizer (1)). The above-mentioned second layer contains a plasticizer (hereinafter sometimes referred to as plasticizer (2)). The above-mentioned 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, the interlayer film (each layer) particularly preferably contains a plasticizer. The layer containing the polyvinyl acetal resin preferably contains a plasticizer.

[0122] The plasticizer is not particularly limited. As the plasticizer, conventionally known plasticizers can be used. The plasticizers may be used alone or in combination of two or more.

[0123] Examples of the plasticizer include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, and organic phosphate plasticizers such as organic phosphate plasticizers and organic phosphite plasticizers. Organic ester plasticizers are preferred. The plasticizer is preferably a liquid plasticizer.

[0124] The monobasic organic acid ester is not particularly limited, and examples thereof include glycol esters obtained by reacting a 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, hexanoic acid, 2-ethylbutyric acid, heptanoic acid, n-octanoic acid, 2-ethylhexanoic acid, n-nonanoic acid, and decanoic acid.

[0125] The polybasic organic acid ester is not particularly limited, and examples thereof include ester compounds formed between a polybasic organic acid and a diol having a linear or branched structure of 4 to 8 carbon atoms. Examples of the polybasic organic acid include adipic acid, sebacic acid, and azelaic acid.

[0126] The organic ester plasticizer is not particularly limited, and examples thereof include triethylene glycol di-2-ethylpropionate, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dioctanoate, 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, and 1,4-butanediol di-2-ethylbutyrate. , diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylvalerate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprylate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, the mixture of heptyl adipate and nonyl adipate, diisononyl adipate, diisodecyl adipate, heptylnonyl adipate, dibutyl sebacate, oil-modified sebacic acid alcohol acid, and the mixture of phosphoric acid ester and adipic acid ester etc.Also can use the organic ester plasticizer except these.Also can use other adipic acid ester except above-mentioned adipic acid ester.

[0127] The organic phosphoric acid plasticizer is not particularly limited, and examples thereof include tributoxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate.

[0128] The plasticizer is preferably a diester plasticizer represented by the following formula (1).

[0129] [Chemical Formula 1]

[0130]

[0131] In the above formula (1), R1 and R2 each represent an organic group having 5 to 10 carbon atoms, R3 represents an ethylene group, an isopropylene group, or an n-propylene group, and p represents an integer from 3 to 10. In the above formula (1), R1 and R2 each represent an organic group having 6 to 10 carbon atoms.

[0132] The plasticizer preferably includes triethylene glycol di-2-ethylhexanoate (3GO) or triethylene glycol di-2-ethylbutyrate (3GH), and more preferably includes triethylene glycol di-2-ethylhexanoate.

[0133] In the interlayer film, the content of the plasticizer (0) relative to 100 parts by weight of the thermoplastic resin (0) is referred to as content (0). The content (0) is preferably 25 parts by weight or more, more preferably 30 parts by weight or more, and preferably 100 parts by weight or less, more preferably 60 parts by weight or less, and 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 enhanced. When the content (0) is at most the upper limit, the transparency of the interlayer film is further enhanced.

[0134] In the first layer, the content of the plasticizer (1) relative to 100 parts by weight of the thermoplastic resin (1) is referred to as content (1). The content (1) 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, and 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 (1) is at least the lower limit, the flexibility of the interlayer film increases, making it easier to handle the interlayer film. When the content (1) is at most the upper limit, the penetration resistance of the laminated glass is further improved.

[0135] In the second layer, the content of the plasticizer (2) relative to 100 parts by weight of the thermoplastic resin (2) is referred to as content (2). In the third layer, the content of the plasticizer (3) relative to 100 parts by weight of the thermoplastic resin (3) is referred to as content (3). The content (2) and the content (3) are each preferably 10 parts by weight or more, more preferably 15 parts by weight or more, further preferably 20 parts by weight or more, particularly preferably 24 parts by weight or more, and preferably 40 parts by weight or less, more preferably 35 parts by weight or less, further preferably 32 parts by weight or less, particularly preferably 30 parts by weight or less. When the content (2) and the content (3) are at least the lower limit, the softness of the interlayer film increases, and the handling of the interlayer film becomes easier. When the content (2) and the content (3) are at most the upper limit, the penetration resistance of the laminated glass is further improved.

[0136] In order to improve the sound insulation of laminated glass, the content (1) is preferably greater than the content (2). In order to further improve the sound insulation of laminated glass, the content (1) is preferably greater than the content (3).

[0137] From the viewpoint of further improving the sound insulation of laminated glass, the absolute value of the difference between the content (2) and the content (1), and the absolute value of the difference between the content (3) and the content (1), are each preferably 5 parts by weight or more, more preferably 8 parts by weight or more, further preferably 10 parts by weight or more, particularly preferably 15 parts by weight or more, and most preferably 20 parts by weight or more. The absolute value of the difference between the content (2) and the content (1), and the absolute value of the difference between the content (3) and the content (1), are each preferably 80 parts by weight or less, more preferably 75 parts by weight or less, and further preferably 70 parts by weight or less.

[0138] (Thermal insulation compound)

[0139] The interlayer film preferably contains a heat-shielding compound. The first layer preferably contains a heat-shielding compound. The second layer preferably contains a heat-shielding compound. The third layer preferably contains a heat-shielding compound. The heat-shielding compounds may be used alone or in combination of two or more.

[0140] The heat shielding compound preferably contains at least one component X selected from the group consisting of phthalocyanine compounds, naphthalocyanine compounds, and anthracyanine compounds, or contains heat shielding particles. In this case, it preferably contains both the component X and the heat shielding particles.

[0141] Ingredient X:

[0142] The interlayer film preferably contains a phthalocyanine compound, a naphthalocyanine compound, or an anthracenephthalocyanine compound (hereinafter, the phthalocyanine compound, the naphthalocyanine compound, and the anthracenephthalocyanine compound may be referred to as component X). The first layer preferably contains component X. The second layer preferably contains component X. The third layer preferably contains component X. Component X is a heat-insulating compound. Component X may be used alone or in combination of two or more.

[0143] There is no particular limitation on the component X. As the component X, conventionally known phthalocyanine compounds, naphthalocyanine compounds, and anthraphthalocyanine compounds can be used.

[0144] Examples of the component X include phthalocyanine, phthalocyanine derivatives, naphthalocyanine, naphthalocyanine derivatives, anthraphthalocyanine, and anthraphthalocyanine derivatives. The phthalocyanine compounds and phthalocyanine derivatives preferably each have a phthalocyanine skeleton. The naphthalocyanine compounds and naphthalocyanine derivatives preferably each have a naphthalocyanine skeleton. The anthraphthalocyanine compounds and anthraphthalocyanine derivatives preferably each have an anthraphthalocyanine skeleton.

[0145] From the viewpoint of further improving the heat shielding properties of the interlayer film and laminated glass, the component X is preferably phthalocyanine, a phthalocyanine derivative, naphthalocyanine, or a naphthalocyanine derivative, and more preferably phthalocyanine or a phthalocyanine derivative.

[0146] From the perspective of effectively improving thermal insulation and maintaining visible light transmittance at a higher level for a long period of time, the component X preferably contains a vanadium atom or a copper atom. The component X preferably contains a vanadium atom, and also preferably contains a copper atom. The component X is more preferably a phthalocyanine containing a vanadium atom or a copper atom, or a derivative of a phthalocyanine containing a vanadium atom or a copper atom. From the perspective of further improving the thermal insulation of the interlayer film and laminated glass, the component X preferably has a structural unit in which an oxygen atom is bonded to a vanadium atom.

[0147] The content of Component X in 100% by weight of the interlayer film or in 100% by weight of the layer containing Component X (the first, second, or third layer) is preferably 0.001% by weight or more, more preferably 0.005% by weight or more, even more preferably 0.01% by weight or more, and particularly preferably 0.02% by weight or more. The content of Component X in 100% by weight of the interlayer film or in 100% by weight of the layer containing Component X (the first, second, or third layer) is preferably 0.2% by weight or less, more preferably 0.1% by weight or less, even more preferably 0.05% by weight or less, and particularly preferably 0.04% by weight or less. When the content of Component X is above the lower limit and below the upper limit, thermal insulation properties are sufficiently enhanced, and visible light transmittance is sufficiently enhanced. For example, visible light transmittance can be 70% or more.

[0148] Thermal insulation particles:

[0149] The intermediate film preferably contains thermal insulation particles. The first layer preferably contains the thermal insulation particles. The second layer preferably contains the thermal insulation particles. The third layer preferably contains the thermal insulation particles. The thermal insulation particles are thermal insulation compounds. By using thermal insulation particles, infrared rays (heat rays) can be effectively blocked. The thermal insulation particles may be used alone or in combination of two or more.

[0150] From the viewpoint of further improving the heat shielding properties of laminated glass, the heat shielding particles are more preferably metal oxide particles. The heat shielding particles are preferably particles formed of a metal oxide (metal oxide particles).

[0151] Infrared light, with wavelengths longer than visible light and exceeding 780nm, has less energy than ultraviolet light. However, infrared light has a significant thermal effect. When absorbed by matter, it is released as heat. Therefore, infrared light is often referred to as heat radiation. The use of the aforementioned thermal insulation particles can effectively block infrared radiation (heat radiation). It should be noted that the so-called thermal insulation particles refer to particles that can absorb infrared radiation.

[0152] Specific examples of the above-mentioned heat-shielding particles include: aluminum-doped tin oxide particles, indium-doped tin oxide particles, antimony-doped tin oxide particles (ATO particles), gallium-doped zinc oxide particles (GZO particles), indium-doped zinc oxide particles (IZO particles), aluminum-doped zinc oxide particles (AZO particles), niobium-doped titanium oxide particles, sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles, thallium-doped tungsten oxide particles, rubidium-doped tungsten oxide particles, tin-doped indium oxide particles (ITO particles), tin-doped zinc oxide particles, silicon-doped zinc oxide particles and other metal oxide particles, or lanthanum hexaboride (LaB6) particles. Heat-shielding particles other than these can also be used. In terms of having a higher shielding function for heat rays, metal oxide particles are preferred, and ATO particles, GZO particles, IZO particles, ITO particles or tungsten oxide particles are more preferred, and ITO particles or tungsten oxide particles are particularly preferred. In particular, in terms of having a higher shielding function for heat rays and being easily available, tin-doped indium oxide particles (ITO particles) are preferred, and tungsten oxide particles are also preferred.

[0153] From the perspective of further improving the thermal insulation properties of the interlayer film and laminated glass, the tungsten oxide particles are preferably metal-doped tungsten oxide particles. The "tungsten oxide particles" mentioned above include metal-doped tungsten oxide particles. Specific examples of such 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.

[0154] From the perspective of further improving the heat shielding properties of the interlayer film and the laminated glass, the doped cesium tungsten oxide particles are particularly preferred. From the perspective of further improving the heat shielding properties of the interlayer film and the laminated glass, the doped cesium tungsten oxide particles are preferably of the formula: Cs 0.33 Tungsten oxide particles represented by WO3.

[0155] The average particle size of the heat shielding particles is preferably 0.01 μm or greater, more preferably 0.02 μm or greater, and preferably 0.1 μm or less, more preferably 0.05 μm or less. When the average particle size is above the lower limit, the heat shielding properties are sufficiently enhanced. When the average particle size is below the upper limit, the dispersibility of the heat shielding particles is enhanced.

[0156] The above-mentioned “average particle size” refers to a 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.

[0157] The content of the thermal shielding particles (particularly the content of tungsten oxide particles) in 100% by weight of the interlayer film or in 100% by weight of the layer containing the thermal shielding particles (the first, second, or third layer) is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, even more preferably 1% by weight or more, and particularly preferably 1.5% by weight or more. The content of the thermal shielding particles (particularly the content of tungsten oxide particles) in 100% by weight of the interlayer film or in 100% by weight of the layer containing the thermal shielding particles (the first, second, or third layer) is preferably 6% by weight or less, more preferably 5.5% by weight or less, even more preferably 4% by weight or less, particularly preferably 3.5% by weight or less, and most preferably 3% by weight or less. When the content of the thermal shielding particles is above the lower limit and below the upper limit, the thermal insulation properties are sufficiently high, and the visible light transmittance is sufficiently high.

[0158] (Metal Salt)

[0159] The above-mentioned intermediate film preferably contains an alkali metal salt, an alkaline earth metal salt, or a magnesium salt (hereinafter sometimes referred to as metal salt M). The above-mentioned intermediate film preferably contains an alkali metal and is derived from the above-mentioned metal salt M. The above-mentioned intermediate film preferably contains an alkaline earth metal and is derived from the above-mentioned metal salt M. The above-mentioned intermediate film preferably contains magnesium and is derived from the above-mentioned metal salt M. The above-mentioned first layer preferably contains the above-mentioned metal salt M. The above-mentioned second layer preferably contains the above-mentioned metal salt M. The above-mentioned third layer preferably contains the above-mentioned metal salt M. By using the above-mentioned metal salt M, it becomes easy to control the adhesion between the intermediate film and laminated glass components such as glass plates, or the adhesion between the layers in the intermediate film. The above-mentioned metal salt M may be used alone or in combination of two or more.

[0160] The metal salt M preferably contains Li, Na, K, Rb, Cs, Mg, Ca, Sr, or Ba. The metal salt contained in the interlayer film preferably contains K or Mg.

[0161] Furthermore, the metal salt M is more preferably an alkali metal salt of an organic acid having 2 to 16 carbon atoms, an alkaline earth metal salt of an organic acid having 2 to 16 carbon atoms, or a magnesium salt of an organic acid having 2 to 16 carbon atoms, and is further preferably a magnesium salt of a carboxylate having 2 to 16 carbon atoms or a potassium salt of a carboxylate having 2 to 16 carbon atoms.

[0162] The magnesium salt of a carboxylate having 2 to 16 carbon atoms and the potassium salt of a carboxylate having 2 to 16 carbon atoms are not particularly limited. Examples of these metal salts include magnesium acetate, potassium acetate, magnesium propionate, potassium propionate, magnesium 2-ethylbutyrate, potassium 2-ethylbutyrate, magnesium 2-ethylhexanoate, and potassium 2-ethylhexanoate.

[0163] 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 above the lower limit and below the upper limit, the adhesion between the interlayer film and the glass sheet, or the adhesion between the layers in the interlayer film, can be further well controlled.

[0164] (UV shielding agent)

[0165] The interlayer film preferably contains a UV shielding agent. The first layer preferably contains a UV shielding agent. The second layer preferably contains a UV shielding agent. The third layer preferably contains a UV shielding agent. The use of a UV shielding agent prevents the visible light transmittance from decreasing even after prolonged use of the interlayer film and laminated glass. The UV shielding agents may be used singly or in combination.

[0166] The ultraviolet shielding agent includes an ultraviolet absorber. The ultraviolet shielding agent is preferably an ultraviolet absorber.

[0167] As the above-mentioned ultraviolet shielding agent, for example, there can be mentioned: an ultraviolet shielding agent containing a metal atom, an ultraviolet shielding agent containing a metal oxide, an ultraviolet shielding agent having a benzotriazole structure (benzotriazole compound), an ultraviolet shielding agent having a benzophenone structure (benzophenone compound), an ultraviolet shielding agent having a triazine structure (triazine compound), an ultraviolet shielding agent having a malonate structure (malonate compound), an ultraviolet shielding agent having an oxalylanilide structure (oxalylanilide compound), and an ultraviolet shielding agent having a benzoate structure (benzoate compound), etc.

[0168] Examples of the metal atom-containing UV shielding agent include platinum particles, particles obtained by coating the surface of platinum particles with silicon dioxide, palladium particles, and particles obtained by coating the surface of palladium particles with silicon dioxide.

[0169] The above-mentioned ultraviolet shielding agent is preferably an ultraviolet shielding agent with a benzotriazole structure, an ultraviolet shielding agent with a benzophenone structure, an ultraviolet shielding agent with a triazine structure, or an ultraviolet shielding agent with a benzoate structure. The above-mentioned ultraviolet shielding agent is more preferably an ultraviolet shielding agent with a benzotriazole structure or an ultraviolet shielding agent with a benzophenone structure, and further preferably an ultraviolet shielding agent with a benzotriazole structure.

[0170] Examples of the ultraviolet light shielding agent containing a metal oxide include zinc oxide, titanium oxide, and cerium oxide. Furthermore, the surface of the ultraviolet light shielding agent containing a metal oxide may be coated. Examples of the coating material on the surface of the ultraviolet light shielding agent containing a metal oxide include insulating metal oxides, hydrolyzable organosilicon compounds, and polysiloxane compounds.

[0171] Examples of the insulating metal oxide include silicon dioxide, aluminum oxide, and zirconium oxide. The insulating metal oxide has a band gap energy of, for example, 5.0 eV or more.

[0172] Examples of the ultraviolet shielding agent having a benzotriazole structure include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole ("Tinuvin P" manufactured by BASF Corporation), 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole ("Tinuvin 320" manufactured by BASF Corporation), 2-(2'-hydroxy-3'-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole ("Tinuvin 326" manufactured by BASF Corporation), and 2-(2'-hydroxy-3',5'-di-pentylphenyl)benzotriazole ("Tinuvin 328" manufactured by BASF Corporation). The ultraviolet shielding agent preferably has a benzotriazole structure containing a halogen atom, and more preferably has a benzotriazole structure containing a chlorine atom, in terms of excellent ultraviolet absorption performance.

[0173] Examples of the ultraviolet shielding agent having a benzophenone structure include octoxynone ("Chimassorb 81" manufactured by BASF Corporation).

[0174] Examples of the ultraviolet shielding 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 Corporation).

[0175] Examples of the ultraviolet shielding agent having a malonate structure include dimethyl 2-(p-methoxybenzylidene)malonate, tetraethyl 2,2-(1,4-phenylenedimethylene)bismalonate, and 2-(p-methoxybenzylidene)-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)malonate.

[0176] Examples of commercially available products of the ultraviolet shielding agent having a malonate structure include Hostavin B-CAP, Hostavin PR-25, and Hostavin PR-31 (all manufactured by Clariant Corporation).

[0177] Examples of the ultraviolet shielding agent having an oxalic acid anilide structure include oxalic acid diamides having an aromatic group substituted on a nitrogen atom, such as N-(2-ethylphenyl)-N'-(2-ethoxy-5-tert-butylphenyl) oxalic acid diamide, N-(2-ethylphenyl)-N'-(2-ethoxyphenyl) oxalic acid diamide, and 2-ethyl-2'-ethoxy-oxanilide ("Sanduvor VSU" manufactured by Clariant Co., Ltd.).

[0178] Examples of the ultraviolet shielding agent having a benzoate structure include 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate ("Tinuvin 120" manufactured by BASF Corporation).

[0179] The content of the UV shielding agent and the benzotriazole compound in 100% by weight of the interlayer film or 100% by weight of the layer containing the UV shielding agent (the first layer, the second layer, or the 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. The content of the UV shielding agent and the benzotriazole compound in 100% by weight of the interlayer film or 100% by weight of the layer containing the UV shielding agent (the first layer, the second layer, or the 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. If the content of the UV shielding agent and the benzotriazole compound is above the lower limit and below the upper limit, the decrease in visible light transmittance over time can be further suppressed. In particular, by setting the content of the ultraviolet shielding agent to 0.2 wt% or more in 100 wt% of the layer containing the ultraviolet shielding agent, a decrease in the visible light transmittance of the interlayer film and the laminated glass over time can be significantly suppressed.

[0180] (Antioxidant)

[0181] The interlayer film preferably contains an antioxidant. The first layer preferably contains an antioxidant. The second layer preferably contains an antioxidant. The third layer preferably contains an antioxidant. The antioxidants may be used alone or in combination of two or more.

[0182] As the above-mentioned antioxidant, a phenol-based antioxidant, a sulfur-based antioxidant, and a phosphorus-based antioxidant, etc. can be given. The above-mentioned phenol-based antioxidant is an antioxidant having a phenol skeleton. The above-mentioned sulfur-based antioxidant is an antioxidant containing a sulfur atom. The above-mentioned phosphorus-based antioxidant is an antioxidant containing a phosphorus atom.

[0183] The above-mentioned antioxidant is preferably a phenol-based antioxidant or a phosphorus-based antioxidant.

[0184] As the above-mentioned phenol-based antioxidant, 2, 6-di-tert-butyl-p-cresol (BHT), butylated hydroxyanisole (BHA), 2, 6-di-tert-butyl-4-ethylphenol, β-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid stearyl ester, 2, 2'-methylenebis-(4-methyl-6- butylphenol), 2, 2'-methylenebis-(4-ethyl-6-tert-butylphenol), 4, 4'-butylidene-bis-(3-methyl-6-tert-butylphenol), 1, 1, 3-tris-(2-methyl-hydroxy-5-tert-butylphenyl) butane, tetrakis [methylene-3-(3', 5'-butyl-4-hydroxyphenyl) propionate] methane, 1, 3, 3-tris-(2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1, 3, 5-trimethyl-2, 4, 6-tris(3, 5-di-tert-butyl-4-hydroxybenzyl) benzene, ethylene glycol bis(3, 3'-tert-butylphenol) butyrate, and ethylene glycol bis(oxyethylene) bis(3-tert-butyl-4-hydroxy-5-methylbenzyl) phosphite, etc. can be given. One or two or more of these antioxidants are suitably used.

[0185] As the above-mentioned phosphorus-based antioxidant, tridecyl phosphite, tris (tridecyl) phosphite, triphenyl phosphite, tris (nonylphenyl) phosphite, bis (tridecyl) pentaerythritol diphosphite, bis (decyl) pentaerythritol diphosphite, tris (2, 4-di-tert-butylphenyl) phosphite, bis (2, 4-di-tert-butyl-6-methylphenyl) ethyl phosphite, and 2, 2'-methylenebis (4, 6-di-tert-butyl-1-phenyloxy) (2-ethylhexyloxy) phosphorus, etc. can be given. One or two or more of these antioxidants are suitably used.

[0186] As a commercial product of the above-mentioned antioxidant, for example, "IRGANOX 245" manufactured by BASF Corporation, "IRGAFOS 168" manufactured by BASF Corporation, "IRGAFOS 38" manufactured by BASF Corporation, "Sumilizer BHT" manufactured by Sumitomo Chemical Industry Co., Ltd., "H-BHT" manufactured by Sakai Chemical Industry Co., Ltd., and "IRGANOX 1010" manufactured by BASF Corporation, etc. can be given.

[0187] In order to maintain high visible light transmittance of the interlayer film and laminated glass over a long period of time, the antioxidant content is preferably 0.1% by weight or greater based on 100% by weight of the interlayer film or 100% by weight of the layer containing the antioxidant (first layer, second layer, or third layer). Furthermore, since the effect of the antioxidant becomes saturated upon addition, the antioxidant content is preferably 2% by weight or less based on 100% by weight of the interlayer film or 100% by weight of the layer containing the antioxidant.

[0188] (Other ingredients)

[0189] The interlayer film, the first layer, the second layer, and the third layer may each contain additives such as a coupling agent, a dispersant, a surfactant, a flame retardant, an antistatic agent, a pigment, a dye, an adhesion modifier other than a metal salt, a moisture resistance agent, a fluorescent brightener, and an infrared absorber, as needed. These additives may be used alone or in combination of two or more.

[0190] (laminated glass)

[0191] Figure 3 To express the use Figure 1 A cross-sectional view of an example of laminated glass including an interlayer film for laminated glass is shown.

[0192] Figure 3 The laminated glass 21 shown includes an interlayer film 11, a first laminated glass component 22, and a second laminated glass component 23. The interlayer film 11 is disposed and sandwiched between the first laminated glass component 22 and the second laminated glass component 23. The first laminated glass component 22 is disposed on a first surface of the interlayer film 11. The second laminated glass component 23 is disposed on a second surface of the interlayer film 11, opposite to the first surface.

[0193] Examples of the laminated glass components include glass sheets and PET (polyethylene terephthalate) films. Laminated glass includes not only laminated glass with an interlayer film sandwiched between two glass sheets, but also laminated glass with an interlayer film sandwiched between a glass sheet and a PET film, etc. Laminated glass is a laminated structure comprising glass sheets, preferably at least one glass sheet. The first and second laminated glass components are each a glass sheet or a PET (polyethylene terephthalate) film, and the interlayer film preferably includes at least one glass sheet as the first and second laminated glass components. It is particularly preferred that both the first and second laminated glass components are glass sheets.

[0194] Examples of the glass plate include inorganic glass and organic glass. Examples of the inorganic glass include float glass, heat-absorbing plate glass, heat-reflecting plate glass, polished plate glass, patterned plate glass, wired plate glass, and green glass. Organic glass is a synthetic resin glass used as an alternative to 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.

[0195] The thickness of each of the first and second laminated glass components is not particularly limited, but is preferably 1 mm or greater and preferably 5 mm or less. When the laminated glass component is a glass sheet, the thickness of the glass sheet is preferably 1 mm or greater and preferably 5 mm or less. When the laminated glass component is a PET film, the thickness of the PET film is preferably 0.03 mm or greater and preferably 0.5 mm or less.

[0196] The method for manufacturing the laminated glass is not particularly limited. For example, the interlayer film is sandwiched between the first and second laminated glass components and then passed through a pressing roller or placed in a rubber bag for vacuum extraction. This allows air remaining between the first laminated glass component and the interlayer film, and between the second laminated glass component and the interlayer film, to be expelled. Subsequently, the laminate is pre-bonded at approximately 70-110°C to produce a laminate. The laminate is then placed in an autoclave or pressed at approximately 120-150°C and a pressure of 1-1.5 MPa to produce laminated glass.

[0197] The laminated glass can be used in automobiles, railway vehicles, aircraft, ships, buildings, and the like. It is preferably laminated glass for construction or vehicles, and more preferably laminated glass for vehicles. It can also be used for applications other than these. It can be used in automobile windshields, side windows, rear windows, or sunroofs. Due to its high thermal insulation and visible light transmittance, it is suitable for automobiles.

[0198] The laminated glass described above is designed for use as a head-up display (HUD). This laminated glass allows measurement information, such as speed, sent from a control unit to be displayed on the windshield via the instrument panel's display unit. This allows the driver to visually confirm both the forward field of view and the measurement information without compromising their field of vision.

[0199] The present invention will be described in more detail below with reference to the following examples, but the present invention is not limited to these examples.

[0200] Prepare the following materials.

[0201] (Thermoplastic resin)

[0202] PVB (1) (polyvinyl acetal resin, average degree of polymerization 1700, hydroxyl content 30.5 mol%, acetylation degree 1 mol%, acetalization degree 68.5 mol%)

[0203] PVB (2) (polyvinyl acetal resin, average degree of polymerization 2300, hydroxyl content 22 mol%, acetylation degree 13 mol%, acetalization degree 65 mol%)

[0204] PVB (3) (polyvinyl acetal resin, hydroxyl content 17 mol%, acetylation degree 7 mol%, acetalization degree 76 mol%)

[0205] PVB (4) (polyvinyl acetal resin, hydroxyl content 23 mol%, acetylation degree 8 mol%, acetalization degree 69 mol%)

[0206] PVB (5) (polyvinyl acetal resin, hydroxyl content 19 mol%, acetylation degree 1 mol%, acetalization degree 80 mol%)

[0207] The polyvinyl acetal resin used was acetalized using n-butyraldehyde having 4 carbon atoms. The degree of acetalization (butyralization), degree of acetylation, and hydroxyl content of the polyvinyl acetal resin were measured using methods in accordance with JIS K6728, "Testing methods for polyvinyl butyral." Measurements using ASTM D1396-92 also yielded the same values ​​as those obtained using the method in accordance with JIS K6728, "Testing methods for polyvinyl butyral."

[0208] (Plasticizer)

[0209] 3GO (Triethylene glycol di-2-ethylhexanoate)

[0210] (UV shielding agent)

[0211] Tinuvin 326 (2-(2'-hydroxy-3'-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, manufactured by BASF Corporation)

[0212] (Antioxidant)

[0213] BHT (2,6-di-tert-butyl-p-cresol)

[0214] (Thermal insulation compound)

[0215] ITO (ITO particles, tin-doped indium oxide particles)

[0216] CWO (CWO particles, doped cesium tungsten oxide (Cs 0.33 WO3) particles)

[0217] (Example 1)

[0218] Preparation of the composition for forming the first layer:

[0219] 60 parts by weight of 3GO, 0.2 parts by weight of Tinuvin 326, and 0.2 parts by weight of BHT were added to 100 parts by weight of PVB (2), and the mixture was fully kneaded using a mixing roll to obtain a composition for forming the first layer.

[0220] Preparation of the composition for forming the second layer and the third layer:

[0221] To 100 parts by weight of PVB (1), 38 parts by weight of 3GO, 0.2 parts by weight of Tinuvin 326, and 0.2 parts by weight of BHT were added and fully kneaded using a mixing roll to obtain a composition for forming the second and third layers.

[0222] Preparation of intermediate film:

[0223] A coextruder was used to coextrude the composition for forming the first layer with the compositions for forming the second and third layers. A wedge-shaped interlayer film having a laminated structure of second layer / first layer / third layer was produced. The resulting interlayer film had a minimum thickness at one end and a maximum thickness at the other end, with no uniform thickness portion. The distance X between one end and the other end of the resulting interlayer film was approximately 1 meter. When the average thickness of the interlayer film was defined as T, the average thickness of the first layer was 0.12T, and the average thickness of the second layer plus the average thickness of the third layer was 0.88T. The average thickness of the second layer was the same as that of the third layer.

[0224] (Examples 2 to 7 and Comparative Examples 1 to 3)

[0225] A wedge-shaped multilayer interlayer film was prepared in the same manner as in Example 1 except that the wedge angle and thickness were set as shown in Table 1 below.

[0226] (Example 8)

[0227] Preparation of the composition for forming the first layer:

[0228] 60 parts by weight of 3GO, 0.2 parts by weight of Tinuvin 326, and 0.2 parts by weight of BHT were added to 100 parts by weight of PVB (2), and the mixture was fully kneaded using a mixing roll to obtain a composition for forming the first layer.

[0229] Preparation of the composition for forming the second layer and the third layer:

[0230] To 100 parts by weight of PVB (1), 38 parts by weight of 3GO, 0.162% by weight of ITO in the second and third layers obtained, 0.2 parts by weight of Tinuvin 326, and 0.2 parts by weight of BHT were added, and the mixture was fully kneaded using a mixing roller to obtain a composition for forming the second and third layers.

[0231] Preparation of intermediate film:

[0232] A coextruder was used to coextrude the composition for forming the first layer with the compositions for forming the second and third layers. A wedge-shaped interlayer film having a laminated structure of second layer / first layer / third layer was produced. The resulting interlayer film had a minimum thickness at one end and a maximum thickness at the other end, with no uniform thickness portion. The distance X between one end and the other end of the resulting interlayer film was approximately 1 meter. When the average thickness of the interlayer film was defined as T, the average thickness of the first layer was 0.12T, and the average thickness of the second layer plus the average thickness of the third layer was 0.88T. The average thickness of the second layer was the same as that of the third layer.

[0233] (Examples 9 to 15, Comparative Examples 4 to 6)

[0234] A wedge-shaped multilayer interlayer film was prepared in the same manner as in Example 8, except that the type of polyvinyl acetal resin, the type and content of the heat-shielding compound, the wedge angle, and the thickness of the first layer were set as shown in Table 2 below.

[0235] (Example 16)

[0236] Prepare the same composition for forming the first layer as in Example 8, and the same composition for forming the second layer and the third layer as in Example 8. Coextrude these compositions using a coextruder. Prepare a wedge-shaped intermediate film having a laminated structure of second layer / first layer / third layer. The intermediate film obtained has a minimum thickness at one end and a maximum thickness at the other end. The intermediate film obtained has a uniform thickness portion with a constant thickness within a distance of 100 mm from the other end toward one end, and the length of the uniform thickness portion is 100 mm. In the intermediate film obtained, the distance X between one end and the other end is approximately 1 m. When the average thickness of the intermediate film is set to T, the average thickness of the first layer is 0.12T, and the total of the average thickness of the second layer and the average thickness of the third layer is 0.88T. The average thickness of the second layer is the same as the average thickness of the third layer.

[0237] (Examples 17 to 24)

[0238] A wedge-shaped multilayer interlayer film was prepared in the same manner as in Example 16, except that the type of polyvinyl acetal resin, the type and content of the heat-shielding compound, the length of the uniform thickness portion, the wedge angle, and the thickness of the first layer were set as shown in Table 3 below.

[0239] (evaluate)

[0240] (1) Ghosting

[0241] Prepare a pair of glass plates (transparent glass, 510 mm × the distance from one end to the other end of the intermediate film X mm, thickness 2.0 mm). Between the pair of glass plates, an intermediate film of a size corresponding to the size of the glass plates is sandwiched to obtain a laminate. The obtained laminate is loaded into an EPDM rubber tube (frame member). The width of the rubber tube is 15 mm. Then, the laminate loaded into the EPDM rubber tube is pre-pressed by a vacuum bag method. The pre-pressed laminate is pressed at 150°C and a pressure of 1.2 MPa using an autoclave to obtain laminated glass.

[0242] The resulting laminated glass was placed in the windshield position with one end of the interlayer facing downward. Display information was reflected from a display unit located below the laminated glass onto the laminated glass. The presence of ghosting was visually observed at a specific location. Ghosting was determined based on the following criteria.

[0243] [Criteria for judging ghosting]

[0244] ○: No ghosting was detected

[0245] ×: Ghosting confirmed

[0246] (2) Uneven appearance when exposed to light

[0247] The laminated glass obtained in the evaluation of ghosting (1) above was irradiated with an ultrahigh-pressure mercury lamp at a distance of 1.5 m from the glass at an angle of 15 degrees below the glass relative to a plane horizontal to the glass surface. Whether linear or dot-shaped distortions were observed was evaluated.

[0248] [Uneven appearance when exposed to light]

[0249] ○○: No linear or dot-shaped unevenness in appearance was observed

[0250] ○: Linear or dot-shaped unevenness in appearance is very slightly visible, but it is not noticeable in actual use.

[0251] ×: Linear or dot-like unevenness is observed, and the degree is noticeable in actual use.

[0252] The details of the interlayer film and the results are shown in Tables 1 to 3 below.

[0253]

[0254]

[0255]

[0256] Explanation of symbols

[0257] 1,1A…first floor

[0258] 2,2A…Second floor

[0259] 3,3A…the third floor

[0260] 11,11A…interlayer

[0261] 11a…one end

[0262] 11b…the other end

[0263] 11Aa… The portion having a rectangular cross-sectional shape in the thickness direction

[0264] 11Ab… The portion with a wedge-shaped cross section in the thickness direction

[0265] 21…Laminated glass

[0266] 22…First laminated glass component

[0267] 23…Second laminated glass component

[0268] R1…Display the corresponding area

[0269] R2…Surrounding area

[0270] R3…Shaded area

Claims

1. An interlayer film for laminated glass, comprising: a first layer comprising a thermoplastic resin and a plasticizer; as well as The second layer contains a thermoplastic resin and a plasticizer, The second layer is arranged on the first surface side of the first layer, The interlayer film for laminated glass has one end and another end opposite to the one end, the thickness of the other end is greater than the thickness of the one end, and the minimum thickness of the first layer is greater than 20 μm. The wedge angle of the interlayer film for laminated glass is 0.1 mrad or more and 0.5 mrad or less. When the ratio of the thickness of the first layer at one end to the thickness of the intermediate film at the one end is defined as ratio A, and the ratio of the thickness of the first layer at the other end to the thickness of the intermediate film at the other end is defined as ratio B, the ratio B is 1.1 times or more and 1.7 times or less of the ratio A. The content of the plasticizer in the first layer relative to 100 parts by weight of the thermoplastic resin in the first layer is greater than the content of the plasticizer in the second layer relative to 100 parts by weight of the thermoplastic resin in the second layer. 2 . The interlayer film for laminated glass according to claim 1 , wherein the wedge angle is 0.47 mrad or less.

3. The interlayer film for laminated glass according to claim 1 or 2, wherein The minimum thickness of the second layer is greater than 270 μm. The interlayer film for laminated glass according to claim 1 or 2, comprising a portion having a wedge-shaped cross-section in the thickness direction.

5. The interlayer film for laminated glass according to claim 1 or 2, wherein The thermoplastic resin in the first layer is polyvinyl acetal resin, The thermoplastic resin in the second layer is polyvinyl acetal resin.

6. The interlayer film for laminated glass according to claim 5, wherein The hydroxyl group content of the polyvinyl acetal resin in the first layer is lower than the hydroxyl group content of the polyvinyl acetal resin in the second layer.

7. The interlayer film for laminated glass according to claim 1 or 2, comprising a third layer containing a thermoplastic resin. The third layer is disposed on a second surface side of the first layer opposite to the first surface side.

8. The interlayer film for laminated glass according to claim 7, wherein The thermoplastic resin in the first layer is polyvinyl acetal resin, The thermoplastic resin in the third layer is polyvinyl acetal resin, The third layer contains a plasticizer, The hydroxyl content of the polyvinyl acetal resin in the first layer is lower than the hydroxyl content of the polyvinyl acetal resin in the third layer. The content of the plasticizer in the first layer relative to 100 parts by weight of the polyvinyl acetal resin in the first layer is greater than the content of the plasticizer in the third layer relative to 100 parts by weight of the polyvinyl acetal resin in the third layer.

9. The interlayer film for laminated glass according to claim 7, wherein The total minimum thickness of the second and third layers is 540 μm or more. 10 . The interlayer film for laminated glass according to claim 1 or 2 , which is used for laminated glass for a head-up display.

11. A laminated glass comprising: The first laminated glass component, a second laminated glass component, and The interlayer film for laminated glass according to any one of claims 1 to 10, The interlayer film for laminated glass is arranged between the first laminated glass component and the second laminated glass component.

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