Intermediate film for laminated glass, and laminated glass

Abstract

Provided is an intermediate film for laminated glass, which is capable of suppressing ghosting and unevenness in appearance when irradiated with light. An intermediate film (11) for laminated glass according to the present invention is provided with 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) being 20 [mu] m or more, and when the ratio of the thickness of the first layer (1) at one end (11a) of the intermediate film to the thickness of the intermediate film at the one end (11a) is set as ratio A, the thickness of the first layer (1) at the other end (11a) of the intermediate film is not less than 20 [mu] m. If the ratio of the thickness of the first layer (1) at the other end (11b) of the intermediate film to the thickness of the intermediate film at the other end (11b) is defined as ratio B, the ratio B is 1.1-1.7 times the ratio A when the wedge angle is 0.1-0.5 mrad, and the ratio B is 0.8-1.1 times the ratio A when the wedge angle exceeds 0.5 mrad, and the thickness of the first layer (1) at the other end (11b) of the intermediate film is 0.8-1.1 times the thickness of the intermediate film when the wedge angle exceeds 0.5 mrad. The content of the plasticizer in the first layer (1) is greater than the content of the plasticizer in the second layer (2).

Description

[0001] This application is a divisional application of Chinese patent application No. 201780035607.5, entitled "Intermediate Film for Laminated Glass and Laminated Glass", filed on October 12, 2017. Technical Field

[0002] This invention relates to an interlayer for obtaining laminated glass. Furthermore, this invention relates to a laminated glass using the aforementioned interlayer for laminated glass. Background Technology

[0003] Even if laminated glass breaks due to external impact, the number of glass fragments scattered is relatively small, resulting in excellent safety. Therefore, laminated glass is widely used in automobiles, railway vehicles, aircraft, ships, and buildings. This type of laminated glass is manufactured by sandwiching an interlayer film between a pair of glass sheets.

[0004] As a type of laminated glass used in automobiles, a head-up display (HUD) is known. A HUD allows the windshield of a car to display the vehicle's driving data, such as speed and other measurement information.

[0005] The aforementioned HUD has a problem where the measurement information displayed on the windshield appears as a ghost image.

[0006] As a type of laminated glass that can suppress ghosting, Patent Document 1 discloses a laminated glass formed by sandwiching a wedge-shaped interlayer with a specific wedge angle between a pair of glass plates. With this laminated glass, by adjusting the wedge angle of the interlayer, the display of measurement information reflected by one glass plate and the display of measurement information reflected by the other glass plate can be connected to a single point in the driver's field of vision. Therefore, the display of measurement information is less prone to ghosting and less likely to obstruct the driver's field of vision.

[0007] Prior art literature

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Publication No. 4-502525 Summary of the Invention

[0010] Problems solved by the invention

[0011] To impart sound insulation and other functions to the interlayer, there are cases where the interlayer is configured as follows: a multilayer interlayer is formed by sandwiching a sound-insulating interlayer between ordinary interlayers. Regarding laminated glass using existing multilayer wedge-shaped interlayers, when illuminated, linear or dot-like unevenness in appearance can be seen. This unevenness is sometimes referred to as "distortion."

[0012] The object of this invention is to provide an interlayer film for laminated glass that can suppress ghosting in laminated glass and make unevenness less noticeable when the laminated glass is illuminated. Furthermore, the object of this invention is also to provide laminated glass using the aforementioned interlayer film.

[0013] The limiting objective of this invention is to provide an interlayer film for laminated glass that can suppress ghosting in laminated glass, makes unevenness less noticeable when the laminated glass is illuminated, and also has excellent sound insulation properties. Furthermore, an objective of this invention is also to provide laminated glass using the aforementioned interlayer film for laminated glass.

[0014] Technical means to solve the problem

[0015] According to a broad aspect of the present invention, an interlayer for laminated glass (sometimes simply referred to as "interlayer") is provided. This interlayer for laminated glass 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 a first surface side of the first layer. The interlayer for laminated glass has one end and another end located opposite to the first end, the thickness of the other end being greater than the thickness of the first end. The minimum thickness of the first layer is 20 μm or more, and the wedge angle is 0.1 mrad or more. The thickness of the first layer at one end is relative to the thickness of the interlayer at the other end. When 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 set 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 set 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 than 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 than 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.

[0016] According to a particular embodiment of the intermediate membrane of the present invention, the wedge angle is less than 0.5 mrad.

[0017] According to a particular embodiment of the intermediate membrane of the present invention, the wedge angle is less than 0.47 mrad.

[0018] According to a particular embodiment of the intermediate membrane of the present invention, the wedge angle exceeds 0.5 mrad.

[0019] According to a specific embodiment of the intermediate film of the present invention, the minimum thickness of the second layer is 270 μm or more.

[0020] According to a particular embodiment of the intermediate film of the present invention, the intermediate film has a portion with a wedge-shaped cross-sectional shape in the thickness direction.

[0021] According to a specific embodiment of the interlayer film of the present invention, the thermoplastic resin in the first layer is polyvinyl acetal resin, and the thermoplastic resin in the second layer is polyvinyl acetal resin.

[0022] According to a specific embodiment of the intermediate film of the present invention, 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 second layer.

[0023] According to a particular embodiment of the interlayer film of the present invention, the interlayer film comprises 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.

[0024] According to a specific embodiment of the interlayer film of the present invention, 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, 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.

[0025] According to a specific embodiment of the intermediate film of the present invention, the combined minimum thickness of the second and third layers is 540 μm or more.

[0026] According to a particular embodiment of the interlayer film of the present invention, the interlayer film is used as laminated glass for a head-up display.

[0027] According to a wide range of embodiments of the present invention, a laminated glass is provided, comprising a first laminated glass component, a second laminated glass component, and an interlayer film for the laminated glass, wherein the interlayer film for the laminated glass is disposed between the first laminated glass component and the second laminated glass component.

[0028] Invention Effects

[0029] The interlayer 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 for laminated glass of the present invention has one end and another end located opposite to the first end, wherein the thickness of the other end is greater than the thickness of the first end. In the interlayer for laminated glass of the present invention, the minimum thickness of the first layer is 20 μm or more, and the wedge angle is 0.1 mrad or more. In the interlayer for laminated glass of the present invention, the ratio of the thickness of the first layer at one end to the thickness of the interlayer at that 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 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 times or more and 1.7 times or less of the ratio A; 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. 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. Because the interlayer film for laminated glass of the present invention has the above-described structure, it can suppress ghosting in laminated glass and make uneven appearance less noticeable when the laminated glass is irradiated with light. Attached Figure Description

[0030] Figure 1 (a) and (b) are schematic cross-sectional and front views illustrating the interlayer film for laminated glass according to the first embodiment of the present invention.

[0031] Figure 2 (a) and (b) are schematic cross-sectional and front views illustrating the interlayer film for laminated glass according to the second embodiment of the present invention.

[0032] Figure 3 To indicate the use Figure 1 The image shows a cross-sectional view of an example of laminated glass with an interlayer. Detailed Implementation

[0033] The present invention will now be described in detail.

[0034] The interlayer film for laminated glass (sometimes referred to simply as "interlayer film" in this specification) of the present invention is used in laminated glass.

[0035] The intermediate membrane of the present invention has a structure with two or more layers. The intermediate membrane of the present invention may have a structure with two layers, or it may have a structure with three or more layers. The intermediate membrane of the present invention is a multilayer intermediate membrane.

[0036] The intermediate film of the present invention comprises a first layer and a second layer. Preferably, the intermediate film of the present invention comprises a third layer. In the intermediate film of the present invention, the second layer is disposed on the first surface side of the first layer. When the intermediate 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.

[0037] In the intermediate 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 intermediate film of the present invention includes a third layer, the third layer preferably contains a thermoplastic resin and preferably contains a plasticizer.

[0038] The intermediate film of the present invention has one end and another end located on the opposite side of the first end. The first end and the other end are opposite ends of the intermediate film. In the intermediate film of the present invention, the thickness of the other end is greater than the thickness of the first end.

[0039] The minimum thickness of the first layer of the intermediate film of the present invention is 20 μm or more.

[0040] In the intermediate membrane of the present invention, the wedge angle is 0.1 mrad or more.

[0041] In the intermediate film of the present invention, the ratio of the thickness (al) of the first layer at one end to the thickness (a) of the intermediate film at one end is set as ratio A((al) / (a)). Ratio A is an indicator of the proportion of the thickness of the first layer at one end of the intermediate film.

[0042] In the intermediate 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 intermediate film at the other end is set as ratio B ((bl) / (b)). Ratio B is an indicator of the proportion of the thickness of the first layer at the other end of the intermediate film.

[0043] In the intermediate film 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 times or more and 1.7 times or less of the ratio A. That is, the value of ratio B / ratio A is 1.1 times or more and 1.7 times or less.

[0044] In the intermediate film of the present invention, 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. That is, the value of ratio B / ratio A is 0.8 or more and 1.1 or less.

[0045] In the intermediate 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.

[0046] In existing intermediate films, when exposed to light, linear or dot-like unevenness can be observed. This unevenness is sometimes referred to as "distortion".

[0047] Because of the above-described structure, the present invention can suppress ghosting in laminated glass and make it less likely for uneven appearance to be seen when the laminated glass is irradiated with light.

[0048] In this invention, ghosting can be suppressed when display information is reflected from the display unit to the laminated glass. This invention also suppresses appearance unevenness, a phenomenon known as "distortion."

[0049] In existing multilayer interlayer films with a wedge angle of 0.1 mrad or more, uneven appearance is easily visible when the laminated glass is illuminated. In the interlayer film of the present invention, uneven appearance is sufficiently difficult to see when the laminated glass is illuminated. Even with a wedge angle of 0.1 mrad or more and 0.5 mrad or less, uneven appearance is sufficiently difficult to see when the laminated glass is illuminated; even with a wedge angle exceeding 0.5 mrad, uneven appearance is sufficiently difficult to see when the laminated glass is illuminated.

[0050] Furthermore, the present invention improves sound insulation due to the aforementioned configuration. 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 sound-insulating laminated glass of the present invention, ghosting in the laminated glass can be suppressed, and unevenness in appearance is less noticeable when the laminated glass is illuminated.

[0051] Furthermore, in existing interlayer films with a wedge angle of 0.1 mrad or more and 0.5 mrad or less, there is a tendency for uneven appearance to be more easily seen when the laminated glass is illuminated. In existing interlayer films with a wedge angle of 0.1 mrad or more and 0.47 mrad or less, there is an even greater tendency for uneven appearance to be easily seen when the laminated glass is illuminated. In the interlayer film of the present invention, even with a wedge angle of 0.1 mrad or more and 0.5 mrad or less, and even with a wedge angle of 0.47 mrad or less, it is sufficiently easy to make uneven appearance less easily seen when the laminated glass is illuminated. It should be noted that the wedge angle of the interlayer film of the present invention may also exceed 0.5 mrad.

[0052] From the viewpoint of effectively suppressing ghosting and making it difficult to see appearance unevenness when the laminated glass is irradiated by light, when the wedge angle is 0.1 mrad or more and 0.5 mrad or less, the ratio of B to A is preferably 1.6 or less, more preferably 1.5 or less, and even more preferably 1.4 or less.

[0053] From the viewpoint of effectively suppressing ghosting and making it less likely for uneven appearance to be seen when the laminated glass is illuminated, when the wedge angle is 0.1 mrad or more and 0.5 mrad or less, the ratio of B to A is preferably 1.2 or more, and more preferably 1.3 or more.

[0054] From the viewpoint of effectively suppressing ghosting and making it less likely for uneven appearance to be seen when the laminated glass is illuminated, when the wedge angle exceeds 0.5 mrad, the ratio of B to A is preferably 1.0 or less, more preferably 0.95 or less.

[0055] From the viewpoint of effectively suppressing ghosting and making it less likely for uneven appearance to be seen when the laminated glass is illuminated, when the wedge angle exceeds 0.5 mrad, the ratio of B to A is preferably 0.85 or more, and more preferably 0.9 or more.

[0056] The interlayer film of the present invention is suitable for use as laminated glass in head-up displays (HUDs). The interlayer film of the present invention is preferably an interlayer film for HUDs.

[0057] The intermediate film of the present invention preferably has a display corresponding area that corresponds to the display area of ​​the HUD. This display corresponding area is an area where information can be displayed well. Preferably, the intermediate film of the present invention has the display corresponding area in a region extending from 10 cm from one end toward the other end to 59.8 cm from one end toward the other end. The display corresponding area may exist in a portion of the region extending from 10 cm from one end to the other end to 59.8 cm from one end to the other end, or it may exist throughout the entire region.

[0058] From the viewpoint of effectively suppressing ghosting, the intermediate film preferably has a wedge-shaped portion in the thickness direction in the region extending from 10 cm from one end to the other end to 59.8 cm from one end to the other end. This wedge-shaped portion in the thickness direction may exist in a portion of the region extending from 10 cm from one end to the other end to 59.8 cm from one end to the other end, or it may exist throughout the entire region.

[0059] The interlayer of the present invention may also have a shaded area. This shaded area may also be separate from the display 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 heat insulation. The shaded area is preferably located at the edge of the interlayer. The shaded area is preferably in the form of a strip.

[0060] In shaded areas, colorants or fillers may be used to alter color and visible light transmittance. Colorants or fillers may be present only in a portion of the thickness direction of the intermediate film, or they may be present throughout the entire thickness direction of the intermediate film.

[0061] From the viewpoint of further improving the display and further expanding the field of view, the visible light transmittance of the aforementioned display area is preferably 80% or more, more preferably 88% or more, and even more preferably 90% or more. The visible light transmittance of the aforementioned display area is preferably higher than that of the aforementioned shadow area. The visible light transmittance of the aforementioned display area may also be lower than that of the aforementioned shadow area. The visible light transmittance of the aforementioned display area is preferably 50% or more higher than that of the aforementioned shadow area, more preferably 60% or more higher.

[0062] It should be noted that, for example, in the intermediate film displaying the corresponding area and the shadow area, the visible light transmittance is measured at the center position of the displaying corresponding area and the center position of the shadow area when the visible light transmittance changes.

[0063] The transmittance of the laminated glass at wavelengths of 380–780 nm can be measured using a spectrophotometer (Hitachi High Technology Co., Ltd., “U-4100”) according to JIS R3211 (1998). It should be noted that a 2 mm thick transparent glass is preferably used as the glass plate.

[0064] The aforementioned display area preferably has both a length direction and a width direction. Due to the excellent versatility of the intermediate film, the width direction of the aforementioned display area is preferably the direction connecting one end to the other end. The aforementioned display area is preferably strip-shaped.

[0065] The aforementioned intermediate film preferably has an MD direction and a TD direction. The intermediate film is obtained, for example, by melt extrusion molding. The MD direction is the direction in which the intermediate film travels during manufacturing. The TD direction is a direction perpendicular to the direction in which the intermediate film travels during manufacturing, and is also perpendicular to the thickness direction of the intermediate film. Preferably, one end and the other end are located on opposite sides of the TD direction.

[0066] For the purpose of displaying a further good viewpoint, the intermediate film preferably has a wedge-shaped portion in the thickness direction. It is preferable that the thickness direction cross-sectional shape of the corresponding region is wedge-shaped.

[0067] The aforementioned intermediate film can also be wound into a roll to form an intermediate film roll. The roll may have a core and an intermediate film. The intermediate film may be wound around the outer periphery of the core.

[0068] The following description will refer to the drawings and describe specific embodiments of the present invention.

[0069] Figure 1 (a) and (b) schematically show the interlayer film for laminated glass according to the first embodiment of the present invention in cross-sectional and front views. Figure 1 (a) is along Figure 1 (b) is a sectional view along line II. It should be noted that, for ease of illustration, Figure 1 The size and dimensions of the intermediate membrane in the following figures shall be appropriately changed according to the actual size and shape.

[0070] Figure 1 (a) shows a cross-section along the thickness direction of the intermediate film 11. It should be noted that... Figure 1 In (a) and the figures described below, for ease of illustration, the thickness of the intermediate film and the layers constituting the intermediate film, as well as the wedge angle θ, are shown in a manner different from the actual thickness and wedge angle.

[0071] Figure 1 The interlayer 11 shown in (a) and (b) comprises a first layer 1 (intermediate layer), a second layer 2 (surface layer), and a third layer 3 (surface layer). The second layer 2 is disposed and stacked on the first surface side of the first layer 1. The third layer 3 is disposed and stacked on the second surface side of the first layer 1 opposite to the first surface. The first layer 1 is disposed and sandwiched between the second layer 2 and the third layer 3. The interlayer 11 is used to obtain laminated glass. The interlayer 11 is an interlayer for laminated glass. The interlayer 11 is a multilayer interlayer.

[0072] The intermediate membrane 11 has one end 11a and another end 11b located on the opposite side of one end 11a. One end 11a and the other end 11b are opposite ends. The cross-sectional shape of the first layer 1, the second layer 2, and the third layer 3 in the thickness direction is wedge-shaped. Regarding the thickness of the second layer 2 and the third layer 3, the thickness of the other end 11b side is greater than that of the one end 11a side. Therefore, the thickness of the intermediate membrane 11 at the other end 11b is greater than the thickness of the one end 11a. Therefore, the intermediate membrane 11 has a thinner region and a thicker region.

[0073] The intermediate film 11 has a display corresponding area R1 that corresponds to the display area of ​​the head-up display. The intermediate film 11 has a peripheral area R2 next to the display corresponding area R1. In this embodiment, the display corresponding area R1 is the area 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.

[0074] The intermediate film 11 has a shaded area R3 that is separated from the display corresponding area R1. The shaded area R3 is located at the edge of the intermediate film 11.

[0075] exist Figure 2 In (a) and (b), the interlayer film for laminated glass according to the second embodiment of the present invention is schematically shown in cross-sectional and front views. Figure 2 (a) is along Figure 2 (b) is a sectional view of line II. Figure 2 (a) A cross-section showing the thickness direction of the intermediate film 11A.

[0076] Figure 2 The interlayer film 11A shown in (a) and (b) comprises a first layer 1A (intermediate layer), a second layer 2A (surface layer), and a third layer 3A (surface layer). The second layer 2A is disposed and stacked on the first surface side of the first layer 1A. The third layer 3A is disposed and stacked 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 obtain laminated glass. The interlayer film 11A is an interlayer film for laminated glass. The interlayer film 11A is a multilayer interlayer film.

[0077] The intermediate membrane 11A has one end 11a and another end 11b located opposite to one end 11a. One end 11a and the other end 11b are opposite ends. The cross-sectional shape of the first layer 1A and the second layer 2A in the thickness direction is rectangular. Regarding the thickness of the third layer 3A, the thickness at the other end 11b is greater than that at one end 11a. The third layer 3A has a portion with a rectangular cross-sectional shape in the thickness direction and a portion with a wedge-shaped cross-sectional shape in the thickness direction. The thickness at the other end 11b of the intermediate membrane 11A is greater than the thickness at one end 11a. Therefore, the intermediate membrane 11A has a thinner region and a thicker region.

[0078] The intermediate membrane 11A has a rectangular cross-sectional shape 11Aa in the thickness direction and a wedge-shaped cross-sectional shape 11Ab in the thickness direction.

[0079] The intermediate film 11A has a display corresponding area R1 that corresponds to the display area of ​​the head-up display. The intermediate film 11A has a peripheral area R2 next to the display corresponding area R1.

[0080] The intermediate film 11A has a shaded area R3 that is separated from the display corresponding area R1. The shaded area R3 is located at the edge of the intermediate film 11A.

[0081] The aforementioned intermediate film preferably has a wedge-shaped portion in the thickness direction. The intermediate film preferably has a portion where the thickness gradually increases from one end to the other. The cross-sectional shape of the intermediate film in the thickness direction is preferably wedge-shaped. Examples of cross-sectional shapes in the thickness direction of the intermediate film include trapezoids, triangles, and pentagons.

[0082] To suppress ghosting, the wedge angle θ of the interlayer film can be appropriately set according to the installation angle of the laminated glass. From the viewpoint of further suppressing ghosting, the wedge angle θ of the interlayer film is preferably 0.2 mrad (0.0115 degrees) or higher. Furthermore, if the above-mentioned wedge angle θ is above the lower limit, laminated glass suitable for vehicles with large installation angles, such as trucks or buses, can be obtained.

[0083] From the viewpoint of further suppressing ghosting, the wedge angle θ of the interlayer 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, if the wedge angle θ is below the aforementioned upper limit, laminated glass suitable for vehicles with small installation angles, such as sports cars, can be obtained.

[0084] The wedge angle θ of the aforementioned intermediate membrane is the interior angle at the intersection of the straight line connecting the first surface (one surface) of the intermediate membrane (the part with the maximum thickness) and the straight line connecting the second surface (another surface) of the intermediate membrane (the part with the maximum thickness) and the minimum thickness. It should be noted that if there are multiple maximum thickness portions and multiple minimum thickness portions, and if either the maximum or minimum thickness portion exists within a certain region, the maximum and minimum thickness portions used to determine the wedge angle θ are selected in a manner that maximizes the calculated wedge angle θ.

[0085] From the viewpoint of further suppressing ghosting, further improving the processability of the interlayer film, and making it less likely to produce appearance defects in laminated glass, the ratio of the thickness of the interlayer film at 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 preferably 1.8 or less, more preferably 1.7 or less.

[0086] The thickness of the aforementioned intermediate film is not particularly limited. The thickness of the aforementioned intermediate film represents the total thickness of all layers constituting the intermediate film. Therefore, in the case of a multilayer intermediate film 11, the thickness of the intermediate film represents the total thickness of the first layer 1, the second layer 2, and the third layer 3.

[0087] The minimum thickness of the interlayer is preferably 0.1 mm or more, more preferably 0.25 mm or more, even more preferably 0.5 mm or more, even more preferably 0.65 mm or more, particularly preferably 0.7 mm or more, most preferably 0.725 mm or more, and preferably 3 mm or less, more preferably 2 mm or less, and even more preferably 1.5 mm or less.

[0088] The maximum thickness of the interlayer is preferably 0.1 mm or more, more preferably 0.25 mm or more, even more preferably 0.5 mm or more, even more 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, and even more preferably 1.5 mm or less.

[0089] The distance X between one end of the aforementioned intermediate membrane and the other end is preferably 3m or less, more preferably 2m or less, particularly preferably 1.5m or less, and preferably 0.5m or more, more preferably 0.8m or more, and particularly preferably 1m or more.

[0090] Let X be the distance between one end and the other end. The intermediate film preferably has a minimum thickness in a region extending from one end inward at a distance of 0X to 0.2X, and a maximum thickness in a region extending from the other end inward at a distance of 0X to 0.2X. More preferably, the intermediate film has a minimum thickness in a region extending from one end inward at a distance of 0X to 0.1X, and a maximum thickness in a region extending from the other end inward at a distance of 0X to 0.1X. Preferably, the intermediate film has a minimum thickness at one end and a maximum thickness at the other end. Intermediate films 11 and 11A have a maximum thickness at the other end 11b and a minimum thickness at one end 11a.

[0091] The aforementioned intermediate film may have a portion with uniform thickness. This uniform thickness portion refers to a portion where the thickness variation does not exceed 10 μm within every 10 cm distance along the direction connecting one end and the other end of the intermediate film. Therefore, the aforementioned uniform thickness portion refers to a portion where the thickness variation does not exceed 10 μm within every 10 cm distance along the direction connecting one end and the other end of the intermediate film. Specifically, the aforementioned uniform thickness portion refers to a portion where the thickness remains completely unchanged in the direction connecting one end and the other end of the intermediate film, or where the thickness variation is less than 10 μm within every 10 cm distance along the direction connecting one end and the other end of the intermediate film.

[0092] From the viewpoint of significantly improving adhesion and penetration resistance, reducing the likelihood of appearance defects in laminated glass, and improving sound insulation, the minimum thickness of each of the second and third layers is preferably 0.02 mm or more, more preferably 0.1 mm or more, further preferably 0.2 mm or more, particularly preferably 0.27 mm or more, and most preferably 0.3 mm or more. From the viewpoint of further reducing the likelihood of appearance defects in 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 further preferably 0.5 mm or less.

[0093] The maximum thickness of each of the second and third layers is preferably 0.05 mm or more, more preferably 0.1 mm or more, further preferably 0.2 mm or more, even more preferably 0.3 mm or more, particularly preferably 0.35 mm or more, even more preferably 0.45 mm or more, and most preferably 0.55 mm or more. When the maximum thickness of each of the second and third layers is above the lower limit and below the upper limit mentioned above, the adhesion and penetration resistance can be sufficiently improved, and the appearance defects of the laminated glass are less likely to occur, thereby improving the sound insulation. From a practical point of view, the maximum thickness of each of the second and third layers is preferably 1 mm or less, more preferably 0.8 mm or less.

[0094] From the viewpoint of significantly improving adhesion and penetration resistance, reducing the likelihood of appearance defects in laminated glass, and improving sound insulation, the minimum combined thickness of the second and third layers is preferably 0.04 mm or more, more preferably 0.2 mm or more, further preferably 0.4 mm or more, particularly preferably 0.54 mm or more, and most preferably 0.6 mm or more. From the viewpoint of further reducing the likelihood of appearance defects in laminated glass and improving practicality, the minimum combined thickness of the second and third layers is preferably 2 mm or less, more preferably 1.6 mm or less, and further preferably 1 mm or less.

[0095] The combined maximum thickness of the second and third layers is preferably 0.1 mm or more, more preferably 0.2 mm or more, further preferably 0.4 mm or more, even more preferably 0.6 mm or more, particularly preferably 0.7 mm or more, even more preferably 0.9 mm or more, and most preferably 1.1 mm or more. When the combined maximum thickness of the second and third layers is above the lower limit and below the upper limit mentioned above, the adhesion and penetration resistance can be sufficiently improved, and the appearance defects of the laminated glass are less likely to occur, thereby improving sound insulation. From a practical point of view, the combined maximum thickness of the second and third layers is preferably 2 mm or less, more preferably 1.6 mm or less.

[0096] From the viewpoint of reducing the likelihood of appearance defects in laminated glass and improving 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 viewpoint of reducing the likelihood of appearance defects in 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.

[0097] From the viewpoint of reducing the likelihood of appearance defects in laminated glass and improving sound insulation, the maximum thickness of the first layer is preferably 0.05 mm or more, more preferably 0.1 mm or more, further preferably 0.125 mm or more, particularly preferably 0.15 mm or more, and most preferably 0.2 mm or more. From the viewpoint of reducing the likelihood of appearance defects in laminated glass, the minimum thickness of the first layer is preferably 0.8 mm or less, more preferably 0.6 mm or less, and further preferably 0.3 mm or less.

[0098] The following is a detailed description of the materials of each interlayer that constitute the multilayer interlayer membrane.

[0099] (Thermoplastic resin)

[0100] The interlayer (each layer) contains a thermoplastic resin (hereinafter sometimes referred to as thermoplastic resin (0)). The interlayer (each layer) preferably contains polyvinyl acetal resin (hereinafter sometimes referred to as polyvinyl acetal resin (0)) as the thermoplastic resin (0). The first layer contains a thermoplastic resin (hereinafter sometimes referred to as thermoplastic resin (1)), and preferably contains polyvinyl acetal resin (hereinafter sometimes referred to as polyvinyl acetal resin (1)) as the thermoplastic resin (1). The second layer contains a thermoplastic resin (hereinafter sometimes referred to as thermoplastic resin (2)), and preferably contains polyvinyl acetal resin (hereinafter sometimes referred to as polyvinyl acetal resin (2)) as the thermoplastic resin (2). The third layer preferably contains a thermoplastic resin (hereinafter sometimes referred to as thermoplastic resin (3)), and preferably contains polyvinyl acetal resin (hereinafter sometimes referred to as polyvinyl acetal resin (3)) as the thermoplastic resin (3).

[0101] The thermoplastic resins (1), (2), and (3) described above may be the same or different. For further improvement of sound insulation, the thermoplastic resin (1) is preferably different from the thermoplastic resins (2) and (3). The polyvinyl acetal resins (1), (2), and (3) described above may be the same or different. For further improvement of sound insulation, the polyvinyl acetal resin (1) is preferably different from the polyvinyl acetal resins (2) and (3). Only one type of each of the thermoplastic resins (0), (1), (2), and (3) may be used, or two or more types may be used in combination. Only one type of each of the polyvinyl acetal resins (0), (1), (2), and (3) may be used, or two or more types may be used in combination.

[0102] Examples of the aforementioned thermoplastic resins include: polyvinyl alcohol 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.

[0103] The thermoplastic resin described above is preferably polyvinyl acetal resin. By combining polyvinyl acetal resin with a plasticizer, the adhesion of the interlayer film of the present invention to laminated glass components or other interlayer films is further improved.

[0104] The aforementioned polyvinyl alcohol acetal resin is obtained, for example, by acetalizing polyvinyl alcohol (PVA) with an aldehyde. Preferably, the aforementioned polyvinyl alcohol acetal resin is an acetalized form of polyvinyl alcohol. The aforementioned polyvinyl alcohol is obtained, for example, by saponifying polyvinyl acetate. The degree of saponification of the aforementioned polyvinyl alcohol is generally in the range of 70 to 99.9 mol%.

[0105] The average degree of polymerization of the aforementioned polyvinyl alcohol (PVA) is preferably 200 or more, more preferably 500 or more, further preferably 1500 or more, even more preferably 1600 or more, particularly preferably 2600 or more, most preferably 2700 or more, and preferably 5000 or less, more preferably 4000 or less, and even more preferably 3500 or less. If the aforementioned average degree of polymerization is above the lower limit, the penetration resistance of the laminated glass is further improved. If the aforementioned average degree of polymerization is below the upper limit, the formation of the interlayer becomes easier.

[0106] The average degree of polymerization of the above-mentioned polyvinyl alcohol was determined according to the method of JIS K6726 "Test Method for Polyvinyl Alcohol".

[0107] The number of carbon atoms in the acetal group of the above-mentioned polyvinyl acetal resin is not particularly limited. The aldehyde used in manufacturing the above-mentioned polyvinyl acetal resin is not particularly limited. The number of carbon atoms in the acetal group of the above-mentioned polyvinyl acetal resin is preferably 3 to 5, more preferably 3 or 4. If the number of carbon atoms in the acetal group of the above-mentioned polyvinyl acetal resin is 3 or more, the glass transition temperature of the intermediate film is sufficiently reduced.

[0108] There are no particular limitations on the aldehydes mentioned above. Generally, aldehydes with 1 to 10 carbon atoms are suitable. Examples of aldehydes with 1 to 10 carbon atoms include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-pentanaldehyde, 2-ethylbutyraldehyde, n-hexanaldehyde, n-octanaldehyde, n-nonanaldehyde, n-decanaldehyde, and benzaldehyde. Propionaldehyde, n-butyraldehyde, isobutyraldehyde, n-hexanaldehyde, or n-pentanaldehyde are preferred, propionaldehyde, n-butyraldehyde, or isobutyraldehyde are more preferred, and n-butyraldehyde is even more preferred. Only one of the above aldehydes may be used, or two or more may be used in combination.

[0109] The hydroxyl content (hydroxyl amount) of the polyvinyl acetal resin (1) is preferably 17 mol% or more, more preferably 20 mol% or more, even more preferably 22 mol% or more, and preferably 28 mol% or less, more preferably 27 mol% or less, even more preferably 25 mol% or less, and particularly preferably 24 mol% or less. When the hydroxyl content is above the lower limit, the mechanical strength of the interlayer is further increased. In particular, when the hydroxyl content of the polyvinyl acetal resin (1) is 20 mol% or more, the reaction efficiency is high and the productivity is excellent. Furthermore, if it is 28 mol% or less, the sound insulation of the laminated glass is further improved. In addition, when the hydroxyl content is below the upper limit, the flexibility of the interlayer is increased, and the processing of the interlayer becomes easier.

[0110] The content of hydroxyl groups in the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) is preferably 25 mol% or more, more preferably 28 mol% or more, more preferably 30 mol% or more, even more preferably 31.5 mol% or more, even more preferably 32 mol% or more, and particularly preferably 33 mol% or more. The content of hydroxyl groups in the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) is preferably 38 mol% or less, more preferably 37 mol% or less, even more preferably 36.5 mol% or less, and particularly preferably 36 mol% or less. When the hydroxyl group content is above the lower limit, the adhesive strength of the interlayer is further improved. In addition, when the hydroxyl group content is below the upper limit, the flexibility of the interlayer increases, and the processing of the interlayer becomes easier.

[0111] From the viewpoint of further improving sound insulation, the hydroxyl content of the polyvinyl acetal resin (1) is preferably lower than that of the polyvinyl acetal resin (2). From the viewpoint of further improving sound insulation, the hydroxyl content of the polyvinyl acetal resin (1) is preferably lower than that of the polyvinyl acetal resin (3). From the viewpoint of further improving sound insulation, 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 sound insulation, 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.

[0112] The hydroxyl content of the aforementioned polyvinyl acetal resin is a percentage value obtained by dividing the amount of hydroxyl-bonded ethylene by the total amount of ethylene in the main chain. The amount of hydroxyl-bonded ethylene can be determined, for example, according to JIS K6728 "Test Method for Polyvinyl Butyral".

[0113] The degree of acetylation (acetyl group content) of the above-mentioned 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 above or below the lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer becomes higher. When the degree of acetylation is below or above the upper limit, the moisture resistance of the interlayer and the laminated glass becomes higher. In particular, if the degree of acetylation of the above-mentioned polyvinyl acetal resin (1) is 0.1 mol% or more and 25 mol% or less, the penetration resistance is excellent.

[0114] The degree of acetylation 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 or below the lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer is improved. When the degree of acetylation is below or below the upper limit, the moisture resistance of the interlayer and the laminated glass is improved.

[0115] The degree of acetylation mentioned above is a percentage value calculated by dividing the amount of acetyl-bonded ethylene by the total amount of ethylene in the main chain. The amount of acetyl-bonded ethylene can be determined, for example, according to JIS K6728 "Test Method for Polyvinyl Butyral".

[0116] The degree of acetalization (in the case of polyvinyl butyral resin) of the above-mentioned polyvinyl acetal resin (1) 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 above or below the lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer becomes higher. If the degree of acetalization is below or below the upper limit, the reaction time required to manufacture the polyvinyl acetal resin becomes shorter.

[0117] The degree of acetalization (or butyralization in the case of polyvinyl butyral resin) of the above-mentioned polyvinyl acetal resin (2) and polyvinyl acetal resin (3) 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 or below the lower limit, the compatibility between the polyvinyl acetal resin and the plasticizer becomes higher. When the degree of acetalization is below or below the upper limit, the reaction time required to manufacture the polyvinyl acetal resin becomes shorter.

[0118] The aforementioned degree of acetalization is the mole fraction expressed as a percentage, obtained by subtracting the amount of hydroxyl-bonded ethylene and acetyl-bonded ethylene from the total amount of ethylene in the main chain, and dividing the result by the total amount of ethylene in the main chain.

[0119] The degree of acetalization mentioned above can be calculated according to the method of JIS K6728 "Test method for polyvinyl butyral" or according to the method of ASTM D1396-92.

[0120] It should be noted that the hydroxyl content (hydroxyl amount), degree of acetalization (degree of butyralization), and degree of acetylation mentioned above are preferably calculated based on the results obtained by means of the method according to JIS K6728 "Test Method for Polyvinyl Butyral". However, the determination according to ASTM D1396-92 may also be used. When the polyvinyl acetal resin is polyvinyl butyral resin, the hydroxyl content (hydroxyl amount), degree of acetalization (degree of butyralization), and degree of acetylation mentioned above can be calculated based on the results obtained by means of the method according to JIS K6728 "Test Method for Polyvinyl Butyral".

[0121] (Plasticizer)

[0122] From the viewpoint of further improving the adhesive strength of the interlayer, the interlayer of the present invention contains a plasticizer (hereinafter sometimes referred to as plasticizer (0)). The first layer contains a plasticizer (hereinafter sometimes referred to as plasticizer (1)). The second layer contains a plasticizer (hereinafter sometimes referred to as plasticizer (2)). The third layer preferably contains a plasticizer (hereinafter sometimes referred to as plasticizer (3)). When the thermoplastic resin contained in the interlayer is polyvinyl acetal resin, the interlayer (each layer) particularly preferably contains a plasticizer. Layers containing polyvinyl acetal resin preferably contain a plasticizer.

[0123] There are no particular limitations on the plasticizers mentioned above. Existing and known plasticizers may be used as plasticizers. Only one type of plasticizer may be used, or two or more may be used in combination.

[0124] Examples of plasticizers include: organic ester plasticizers such as monobasic and polybasic organic esters, and organic phosphoric acid plasticizers such as organic phosphoric acid plasticizers and organic phosphorous acid plasticizers. Organic ester plasticizers are preferred. Liquid plasticizers are more preferably the above-mentioned plasticizers.

[0125] There are no particular limitations on the aforementioned monobasic organic acid esters; examples include diol esters obtained by reacting a diol with a monobasic organic acid. Examples of diols include triethylene glycol, tetraethylene glycol, and tripropylene glycol. Examples of monobasic organic acids include butyric acid, isobutyric acid, hexanoic acid, 2-ethylbutyric acid, heptanoic acid, octanoic acid, 2-ethylhexanoic acid, nonanoic acid, and decanoic acid.

[0126] There are no particular limitations on the aforementioned polybasic organic acid esters; examples include ester compounds formed by polybasic organic acids and diols with straight or branched structures having 4 to 8 carbon atoms. Examples of such polybasic organic acids include adipic acid, sebacic acid, and azelaic acid.

[0127] There are no particular limitations on the aforementioned organic ester plasticizers, but examples 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-propanediol di-2-ethylbutyrate, and 1,4-butanediol di-2-ethylbutyrate. Examples of suitable plasticizers include 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 dioctyl ester, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, mixtures of heptyl adipate and nonyl adipate, diisononyl adipate, diisodecyl adipate, heptylnonyl adipate, dibutyl sebacate, oil-modified sebacate, and mixtures of phosphate esters and adipates. Other organic ester plasticizers besides these can also be used. Other adipates besides those listed above can also be used.

[0128] There are no particular limitations on the aforementioned organophosphate plasticizers; for example, tributoxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate can be cited.

[0129] The plasticizer described above is preferably a diester plasticizer represented by the following formula (1).

[0130] [Chemical Formula 1]

[0131]

[0132] In the above formula (1), R1 and R2 represent organic groups with 5 to 10 carbon atoms, R3 represents ethylene, isopropylene, or n-propylene, and p represents an integer from 3 to 10. R1 and R2 in the above formula (1) are preferably organic groups with 6 to 10 carbon atoms.

[0133] The plasticizers mentioned above preferably contain triethylene glycol di-2-ethylhexanoate (3GO) or triethylene glycol di-2-ethylbutyrate (3GH), and more preferably contain triethylene glycol di-2-ethylhexanoate.

[0134] In the aforementioned interlayer, the content of the plasticizer (0) relative to 100 parts by weight of the thermoplastic resin (0) is defined 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 or above the lower limit, the penetration resistance of the laminated glass is further increased. When the content (0) is at or below the upper limit, the transparency of the interlayer is further increased.

[0135] In the first layer described above, the content of the plasticizer (1) relative to 100 parts by weight of the thermoplastic resin (1) is defined as content (1). The content (1) is preferably 50 parts by weight or more, more preferably 55 parts by weight or more, even more preferably 60 parts by weight or more, and 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 or above the lower limit, the flexibility of the interlayer increases, and the processing of the interlayer becomes easier. When the content (1) is at or below the upper limit, the penetration resistance of the laminated glass is further improved.

[0136] In the second layer, the content of the plasticizer (2) relative to 100 parts by weight of the thermoplastic resin (2) is defined as content (2). In the third layer, the content of the plasticizer (3) relative to 100 parts by weight of the thermoplastic resin (3) is defined as content (3). The contents (2) and (3) are 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, and particularly preferably 30 parts by weight or less. When the contents (2) and (3) are at or above the lower limit, the flexibility of the interlayer increases, and the processing of the interlayer becomes easier. When the contents (2) and (3) are at or below the upper limit, the penetration resistance of the laminated glass is further improved.

[0137] To improve the sound insulation of the laminated glass, the content (1) is greater than the content (2). Furthermore, to further improve the sound insulation of the laminated glass, the content (1) is preferably greater than the content (3).

[0138] 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 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 preferably 80 parts by weight or less, more preferably 75 parts by weight or less, and further preferably 70 parts by weight or less.

[0139] (Insulating compounds)

[0140] The aforementioned intermediate film preferably contains a heat-insulating compound. The aforementioned first layer preferably contains a heat-insulating compound. The aforementioned second layer preferably contains a heat-insulating compound. The aforementioned third layer preferably contains a heat-insulating compound. Only one type of heat-insulating compound may be used, or two or more types may be used in combination.

[0141] The aforementioned heat-insulating compound preferably contains at least one component X selected from phthalocyanine compounds, naphthalene phthalocyanine compounds, and anthracene phthalocyanine compounds, or contains heat-insulating particles. In this case, it is preferable to contain both the aforementioned component X and the aforementioned heat-insulating particles.

[0142] Ingredient X:

[0143] The aforementioned intermediate membrane preferably contains a phthalocyanine compound, a naphthyl phthalocyanine compound, or anthracene phthalocyanine compound (hereinafter, phthalocyanine compound, naphthyl phthalocyanine compound, and anthracene phthalocyanine compound are sometimes referred to as component X). The aforementioned first layer preferably contains component X. The aforementioned second layer preferably contains component X. The aforementioned third layer preferably contains component X. Component X is a heat-insulating compound. Only one type of component X may be used, or two or more types may be used in combination.

[0144] The above-mentioned ingredient X is not particularly limited. As ingredient X, existing and well-known phthalocyanine compounds, naphthalene phthalocyanine compounds, and anthracene phthalocyanine compounds may be used.

[0145] Examples of the aforementioned component X include: phthalocyanines, phthalocyanine derivatives, naphthylphthalocyanines, naphthylphthalocyanine derivatives, anthracene phthalocyanines, and anthracene phthalocyanine derivatives. The aforementioned phthalocyanine compounds and their derivatives preferably have a phthalocyanine skeleton. The aforementioned naphthylphthalocyanine compounds and their derivatives preferably have a naphthylphthalocyanine skeleton. The aforementioned anthracene phthalocyanine compounds and their derivatives preferably have an anthracene phthalocyanine skeleton.

[0146] From the viewpoint of further improving the thermal insulation of the interlayer and laminated glass, the above-mentioned component X is preferably phthalocyanine, a derivative of phthalocyanine, naphthalocyanine or a derivative of naphthalocyanine, and more preferably phthalocyanine or a derivative of phthalocyanine.

[0147] From the viewpoint of effectively improving thermal insulation and maintaining a higher level of visible light transmittance over a long period of time, the aforementioned component X preferably contains vanadium atoms or copper atoms. The aforementioned component X preferably contains vanadium atoms, and even more preferably contains copper atoms. The aforementioned component X is more preferably a phthalocyanine containing vanadium atoms or copper atoms, or a derivative of a phthalocyanine containing vanadium atoms or copper atoms. From the viewpoint of further improving the thermal insulation of the interlayer and the laminated glass, the aforementioned component X preferably has structural units in which oxygen atoms are bonded to vanadium atoms.

[0148] In the aforementioned 100% by weight of the interlayer film or 100% by weight of the layer (first layer, second layer, or third layer) containing the aforementioned component X, the content of component X is preferably 0.001% by weight or more, more preferably 0.005% by weight or more, further preferably 0.01% by weight or more, and particularly preferably 0.02% by weight or more. In the aforementioned 100% by weight of the interlayer film or 100% by weight of the layer (first layer, second layer, or third layer) containing the aforementioned component X, the content of component X is preferably 0.2% by weight or less, more preferably 0.1% by weight or less, further preferably 0.05% by weight or less, and particularly preferably 0.04% by weight or less. When the content of component X is above the aforementioned lower limit and below the aforementioned upper limit, the heat insulation performance is sufficiently high, and the visible light transmittance is sufficiently high. For example, the visible light transmittance can be 70% or more.

[0149] Insulating particles:

[0150] The aforementioned intermediate film preferably contains heat-insulating particles. The aforementioned first layer preferably contains the aforementioned heat-insulating particles. The aforementioned second layer preferably contains the aforementioned heat-insulating particles. The aforementioned third layer preferably contains the aforementioned heat-insulating particles. The aforementioned heat-insulating particles are heat-insulating compounds. By using the heat-insulating particles, infrared rays (heat rays) can be effectively blocked. The aforementioned heat-insulating particles may be used alone or in combination of two or more types.

[0151] From the viewpoint of further improving the thermal insulation performance of laminated glass, the aforementioned thermal insulation particles are more preferably metal oxide particles. The aforementioned thermal insulation particles are preferably particles formed from metal oxides (metal oxide particles).

[0152] Infrared radiation, with wavelengths longer than visible light (above 780 nm), has less energy than ultraviolet light. However, infrared radiation has a significant thermal effect; when absorbed by matter, it is released as heat. Therefore, infrared radiation is generally referred to as heat radiation. By using the aforementioned heat-insulating particles, infrared radiation (heat radiation) can be effectively blocked. It should be noted that heat-insulating particles refer to particles capable of absorbing infrared radiation.

[0153] Specific examples of the aforementioned heat-insulating particles include: aluminum-doped tin oxide particles, indium-doped tin oxide particles, antimony-doped tin oxide particles (ATO particles), gallium-doped zinc oxide particles (GZO particles), indium-doped zinc oxide particles (IZO particles), aluminum-doped zinc oxide particles (AZO particles), niobium-doped titanium oxide particles, sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles, thallium-doped tungsten oxide particles, rubidium-doped tungsten oxide particles, indium tin oxide particles (ITO particles), tin-doped zinc oxide particles, silicon-doped zinc oxide particles, and other metal oxide particles, or lanthanum hexaboride (LaB6) particles, etc. Other heat-insulating particles may also be used. For higher shielding performance of the heat wire, metal oxide particles are preferred, more preferably ATO particles, GZO particles, IZO particles, ITO particles, or tungsten oxide particles, and particularly preferably ITO particles or tungsten oxide particles. In particular, for higher shielding performance of the heat wire and ease of availability, indium tin oxide particles (ITO particles) are preferred, and tungsten oxide particles are also preferred.

[0154] From the viewpoint of further improving the thermal insulation properties of the interlayer and laminated glass, tungsten oxide particles are preferably metal-doped tungsten oxide particles. The term "tungsten oxide particles" includes metal-doped tungsten oxide particles. Specifically, 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.

[0155] From the viewpoint of further improving the thermal insulation properties of the interlayer and the laminated glass, doped cesium tungsten oxide particles are particularly preferred. From the viewpoint of further improving the thermal insulation properties of the interlayer and the laminated glass, the doped cesium tungsten oxide particles are preferably of the formula: Cs 0.33 WO3 represents tungsten oxide particles.

[0156] The average particle size of the aforementioned heat-insulating particles is preferably 0.01 μm or more, more preferably 0.02 μm or more, and preferably 0.1 μm or less, more preferably 0.05 μm or less. When the average particle size is above the aforementioned lower limit, the shielding performance of the heat wire is sufficiently high. When the average particle size is below the aforementioned upper limit, the dispersibility of the heat-insulating particles is high.

[0157] The "average particle size" mentioned above refers to the volume average particle size. The average particle size can be measured using a particle size distribution measuring device (such as the "UPA-EX150" manufactured by Nikkiso Corporation).

[0158] In the aforementioned 100% by weight of the interlayer film or in the 100% by weight of the layers (first layer, second layer, or third layer) containing the aforementioned heat-insulating particles, the content of the aforementioned heat-insulating particles (especially the content of tungsten oxide particles) is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, further preferably 1% by weight or more, and particularly preferably 1.5% by weight or more. In the aforementioned 100% by weight of the interlayer film or in the 100% by weight of the layers (first layer, second layer, or third layer) containing the aforementioned heat-insulating particles, the content of the aforementioned heat-insulating particles (especially the content of tungsten oxide particles) is preferably 6% by weight or less, more preferably 5.5% by weight or less, further preferably 4% by weight or less, particularly preferably 3.5% by weight or less, and most preferably 3% by weight or less. When the content of the aforementioned heat-insulating particles is above the aforementioned lower limit and below the aforementioned upper limit, the heat insulation performance is sufficiently high, and the visible light transmittance is sufficiently high.

[0159] (metal salt)

[0160] The aforementioned interlayer preferably contains an alkali metal salt, an alkaline earth metal salt, or a magnesium salt (hereinafter sometimes referred to as metal salt M). The aforementioned interlayer preferably contains an alkali metal and is derived from the aforementioned metal salt M. The aforementioned interlayer preferably contains an alkaline earth metal and is derived from the aforementioned metal salt M. The aforementioned interlayer preferably contains magnesium and is derived from the aforementioned metal salt M. The aforementioned first layer preferably contains the aforementioned metal salt M. The aforementioned second layer preferably contains the aforementioned metal salt M. The aforementioned third layer preferably contains the aforementioned metal salt M. By using the aforementioned metal salt M, it becomes easier to control the adhesion between the interlayer and laminated glass components such as glass plates, or the adhesion between the layers within the interlayer. Only one type of metal salt M may be used, or two or more may be used in combination.

[0161] The metal salt M preferably contains Li, Na, K, Rb, Cs, Mg, Ca, Sr, or Ba. The metal salt contained in the intermediate film preferably contains K or Mg.

[0162] 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 even more 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.

[0163] There are no particular limitations on the magnesium carboxylate salts with 2 to 16 carbon atoms and the potassium carboxylate salts with 2 to 16 carbon atoms mentioned above. 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.

[0164] The total content of Mg and K in the intermediate film containing the aforementioned metal salt M, or in the layers (first layer, second layer, or third layer) containing the aforementioned metal salt M, is preferably 5 ppm or more, more preferably 10 ppm or more, even more preferably 20 ppm or more, and 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 aforementioned lower limit and below the aforementioned upper limit, the adhesion between the intermediate film and the glass plate, or the adhesion between the layers in the intermediate film, can be further well controlled.

[0165] (UV shielding agent)

[0166] The aforementioned interlayer preferably contains an ultraviolet (UV) shielding agent. The aforementioned first layer preferably contains an UV shielding agent. The aforementioned second layer preferably contains an UV shielding agent. The aforementioned third layer preferably contains an UV shielding agent. By using UV shielding agents, even with prolonged use of the interlayer and laminated glass, the visible light transmittance is unlikely to decrease further. Only one type of UV shielding agent may be used, or two or more may be used in combination.

[0167] The aforementioned ultraviolet shielding agent contains an ultraviolet absorber. Preferably, the ultraviolet shielding agent is an ultraviolet absorber.

[0168] Examples of ultraviolet shielding agents include: ultraviolet shielding agents containing metal atoms, ultraviolet shielding agents containing metal oxides, ultraviolet shielding agents with a benzotriazole structure (benzotriazole compounds), ultraviolet shielding agents with a benzophenone structure (benzophenone compounds), ultraviolet shielding agents with a triazine structure (triazine compounds), ultraviolet shielding agents with a malonic acid ester structure (malonic acid ester compounds), ultraviolet shielding agents with an oxaloaniline structure (oxaloaniline compounds), and ultraviolet shielding agents with a benzoic acid ester structure (benzoic acid ester compounds).

[0169] Examples of ultraviolet shielding agents containing metal atoms include platinum particles, particles formed by coating the surface of platinum particles with silica, palladium particles, and particles formed by coating the surface of palladium particles with silica. Ultraviolet shielding agents are preferably not heat-insulating particles.

[0170] The aforementioned ultraviolet (UV) shielding agent is preferably an UV shielding agent having a benzotriazole structure, an UV shielding agent having a benzophenone structure, an UV shielding agent having a triazine structure, or an UV shielding agent having a benzoic acid ester structure. More preferably, the aforementioned UV shielding agent is an UV shielding agent having a benzotriazole structure or an UV shielding agent having a benzophenone structure, and even more preferably, an UV shielding agent having a benzotriazole structure.

[0171] Examples of ultraviolet shielding agents containing metal oxides include zinc oxide, titanium oxide, and cerium oxide. Furthermore, the surface of these ultraviolet shielding agents containing metal oxides can also be coated. Examples of coating materials for the surface of these ultraviolet shielding agents containing metal oxides include insulating metal oxides, hydrolyzable organosilicon compounds, and polysiloxane compounds.

[0172] Examples of insulating metal oxides include silicon dioxide, aluminum oxide, and zirconium oxide. These insulating metal oxides, for example, possess a band gap energy of 5.0 eV or higher.

[0173] Examples of ultraviolet shielding agents 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). In terms of superior ultraviolet absorption performance, the aforementioned ultraviolet shielding agents are preferably ultraviolet shielding agents having a benzotriazole structure containing halogen atoms, and more preferably ultraviolet shielding agents having a benzotriazole structure containing chlorine atoms.

[0174] Examples of ultraviolet shielding agents with the aforementioned benzophenone structure include octanophenone ("Chimassorb81" manufactured by BASF Corporation).

[0175] Examples of ultraviolet shielding agents with 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 ("Tinuvinl577FF" manufactured by BASF Corporation).

[0176] Examples of ultraviolet shielding agents with malonic acid ester structures include: dimethyl 2-(p-methoxybenzyl)malonate, tetraethyl 2,2-(1,4-phenylenedimethyl)bis(malonate), and 2-(p-methoxybenzyl)-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)malonate.

[0177] Commercially available products that are UV shielding agents with the aforementioned malonic acid ester structure include: Hostavin B-CAP, Hostavin PR-25, and Hostavin PR-31 (all manufactured by Clariant Co., Ltd.).

[0178] Examples of ultraviolet shielding agents with the oxaloylaniline structure include 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-oxyaniline (Sanduvor VSU manufactured by Clariant Co., Ltd.), which are oxalic acid diamides having aryl groups substituted on the nitrogen atom.

[0179] Examples of ultraviolet shielding agents having the aforementioned benzoic acid ester structure include 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoic acid ester ("Tinuvin l20" manufactured by BASF Corporation).

[0180] In the aforementioned 100% by weight of the intermediate film or in the aforementioned 100% by weight of the layer (first layer, second layer, or third layer) containing the aforementioned ultraviolet shielding agent, the content of the ultraviolet shielding agent and the content of the benzotriazole compound are preferably 0.1% by weight or more, more preferably 0.2% by weight or more, further preferably 0.3% by weight or more, and particularly preferably 0.5% by weight or more. In the aforementioned 100% by weight of the intermediate film or in the aforementioned 100% by weight of the layer (first layer, second layer, or third layer) containing the aforementioned ultraviolet shielding agent, the content of the ultraviolet shielding agent and the content of the benzotriazole compound are preferably 2.5% by weight or less, more preferably 2% by weight or less, further preferably 1% by weight or less, and particularly preferably 0.8% by weight or less. If the content of the ultraviolet shielding agent and the content of the benzotriazole compound are above the aforementioned lower limit and below the aforementioned upper limit, the decrease in visible light transmittance over time can be further suppressed. In particular, by making the content of the ultraviolet shielding agent 0.2% by weight or more in 100% of the layer containing the ultraviolet shielding agent, the decrease in visible light transmittance of the interlayer and laminated glass over time can be significantly suppressed.

[0181] (Antioxidants)

[0182] The aforementioned intermediate membrane preferably contains an antioxidant. The aforementioned first layer preferably contains an antioxidant. The aforementioned second layer preferably contains an antioxidant. The aforementioned third layer preferably contains an antioxidant. Only one type of antioxidant may be used, or two or more types may be used in combination.

[0183] Examples of antioxidants include phenolic antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants. Phenolic antioxidants are antioxidants with a phenolic skeleton. Sulfur-based antioxidants are antioxidants containing sulfur atoms. Phosphorus-based antioxidants are antioxidants containing phosphorus atoms.

[0184] The antioxidants mentioned above are preferably phenolic antioxidants or phosphorus antioxidants.

[0185] Examples of phenolic antioxidants include: 2,6-di-tert-butyl-p-cresol (BHT), butylated hydroxyanisole (BHA), 2,6-di-tert-butyl-4-ethylphenol, stearate β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis-(4-methyl-6-butylphenol), 2,2'-methylenebis-(4-ethyl-6-tert-butylphenol), 4,4'-butylenebis-(3-methyl-6-tert-butylphenol), and 1,1,3-tri-(2 (Methyl-hydroxy-5-tert-butylphenyl)butane, tetra[methylene-3-(3',5'-butyl-4-hydroxyphenyl)propionate]methane, 1,3,3-tris-(2-methyl-4-hydroxy-5-tert-butylphenol)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 bis(3-tert-butyl-4-hydroxy-5-methylphenylpropionate) ethylene bis(oxyethylene) ester, etc. One or more of these antioxidants are suitable.

[0186] Examples of phosphorus-based antioxidants include: tridecyl phosphite, tri(tetranyl) phosphite, triphenyl phosphite, trinonylphenyl phosphite, bis(tetranyl)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)phosphite. It is suitable to use one or more of these antioxidants.

[0187] Commercially available examples of the aforementioned antioxidants include: BASF Corporation's "IRGANOX 245", BASF Corporation's "IRGAFOS 168", BASF Corporation's "IRGAFOS 38", Sumitomo Chemical Industries, Ltd.'s "SumilizerBHT", Sakai Chemical Industries, Ltd.'s "H-BHT", and BASF Corporation's "IRGANOX 1010".

[0188] In order to maintain a high visible light transmittance of the interlayer and the laminated glass over a long period of time, the content of the antioxidant in 100% by weight of the interlayer or in 100% by weight of the layer containing the antioxidant (first layer, second layer, or third layer) is preferably 0.1% by weight or more. Furthermore, since the effect of adding antioxidants can become saturated, the content of the antioxidant in 100% by weight of the interlayer or in 100% by weight of the layer containing the antioxidant is preferably 2% by weight or less.

[0189] (Other ingredients)

[0190] The aforementioned intermediate film, first layer, second layer, and third layer may also contain, as needed, additives such as coupling agents, dispersants, surfactants, flame retardants, antistatic agents, pigments, dyes, adhesion modifiers (excluding metal salts), moisture-resistant agents, fluorescent whitening agents, and infrared absorbers. Only one of these additives may be used, or two or more may be used in combination.

[0191] (Laminated glass)

[0192] Figure 3 To indicate the use Figure 1 The image shows a cross-sectional view of an example of laminated glass with an interlayer.

[0193] Figure 3 The laminated glass 21 shown includes an interlayer 11, a first laminated glass component 22, and a second laminated glass component 23. The interlayer 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 11. The second laminated glass component 23 is disposed on a second surface of the interlayer 11 opposite to the first surface.

[0194] Examples of laminated glass components include glass sheets and PET (polyethylene terephthalate) films. The laminated glass includes not only laminated glass with an interlayer sandwiched between two glass sheets, but also laminated glass with an interlayer sandwiched between a glass sheet and a PET film, etc. The laminated glass is a laminate containing glass sheets, and preferably uses at least one glass sheet. The first and second laminated glass components are respectively a glass sheet or a PET (polyethylene terephthalate) film, and the interlayer film preferably includes at least one glass sheet as both the first and second laminated glass components. It is particularly preferred that both the first and second laminated glass components are glass sheets.

[0195] Examples of the aforementioned glass sheets include inorganic glass and plexiglass. Examples of inorganic glass include float glass, heat-absorbing glass, heat-reflecting glass, polished glass, patterned glass, wire-reinforced glass, and green glass. Plexiglass is a synthetic resin glass used as a substitute for inorganic glass. Examples of plexiglass include polycarbonate sheets and poly(meth)acrylic resin sheets. Examples of poly(meth)acrylic resin sheets include polymethyl methacrylate sheets.

[0196] The thickness of the first and second laminated glass components described above is not particularly limited, but is preferably 1 mm or more, and more 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 more, and more 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 more, and more preferably 0.5 mm or less.

[0197] The manufacturing method of the aforementioned laminated glass is not particularly limited. For example, the interlayer film is sandwiched between the first and second laminated glass components, and depressurization is performed by pressing rollers or by placing it in a rubber bag. This removes the air remaining between the first laminated glass component and the interlayer film, and between the second laminated glass component and the interlayer film. Then, pre-bonding is performed at approximately 70-110°C to obtain 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. This yields laminated glass.

[0198] The aforementioned laminated glass can be used in automobiles, railway vehicles, aircraft, ships, and buildings. Preferably, it is laminated glass for architectural or vehicle applications, more preferably for vehicle applications. It can also be used for other purposes. Specifically, it can be used for automobile windshields, side windows, rear windows, or sunroofs. Due to its high heat insulation and high visible light transmittance, it is suitable for use in automobiles.

[0199] The aforementioned laminated glass serves as a head-up display (HUD). Within this laminated glass, measurement information such as speed, transmitted from the control unit, can be displayed on the windshield from the instrument panel's display unit. Therefore, the driver's field of vision is not reduced, and they can simultaneously visually confirm the forward view and measurement information.

[0200] The present invention will be described in more detail below with reference to specific embodiments. The present invention is not limited to these embodiments.

[0201] Prepare the following materials.

[0202] (Thermoplastic resin)

[0203] PVB(1) (polyvinyl alcohol acetal resin, average degree of polymerization 1700, hydroxyl content 30.5 mol%, degree of acetylation 1 mol%, degree of acetalization 68.5 mol%)

[0204] PVB(2) (Polyvinyl alcohol acetal resin, average degree of polymerization 2300, hydroxyl content 22 mol%, degree of acetylation 13 mol%, degree of acetalization 65 mol%)

[0205] PVB(3) (polyvinyl alcohol acetal resin, hydroxyl content 17 mol%, acetylation degree 7 mol%, acetalization degree 76 mol%)

[0206] PVB(4) (polyvinyl alcohol acetal resin, hydroxyl content 23 mol%, acetylation degree 8 mol%, acetalization degree 69 mol%)

[0207] PVB(5) (Polyvinyl alcohol acetal resin, hydroxyl content 19 mol%, acetylation degree 1 mol%, acetalization degree 80 mol%)

[0208] Regarding the polyvinyl acetal resin used, butyraldehyde with 4 carbon atoms was used during acetalization. The degree of acetalization (degree of butyraldehyde), degree of acetylation, and hydroxyl content of the polyvinyl acetal resin were determined according to JIS K6728 "Test Method for Polyvinyl Butyraldehyde". It should be noted that when measured according to ASTM D1396-92, the same values ​​as those obtained according to JIS K6728 "Test Method for Polyvinyl Butyraldehyde" were also observed.

[0209] (Plasticizer)

[0210] 3GO (triethylene glycol di-2-ethylhexanoate)

[0211] (UV shielding agent)

[0212] Tinuvin326 (2-(2'-hydroxy-3'-tert-butyl-5-methylphenyl)-5-chlorobenzotriazole, manufactured by BASF Corporation)

[0213] (Antioxidants)

[0214] BHT (2,6-di-tert-butyl-p-cresol)

[0215] (Insulating compounds)

[0216] ITO (Indium Tin Oxide Particles)

[0217] CWO (CWO particles, doped with cesium tungsten oxide (Cs)) 0.33 WO3) particles)

[0218] (Example 1)

[0219] Preparation of the composition used to form the first layer:

[0220] Compared to 100 parts by weight of PVB(2), 60 parts by weight of 3GO, 0.2 parts by weight of Tinuvin 326 and 0.2 parts by weight of BHT were added, and the mixture was thoroughly kneaded using a mixing roller to obtain a composition for forming the first layer.

[0221] Preparation of the composition used to form the second and third layers:

[0222] Compared 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 the mixture was thoroughly kneaded using a mixing roller to obtain a composition for forming the second and third layers.

[0223] Preparation of the intermediate membrane:

[0224] The composition used to form the first layer is co-extruded with the compositions used to form the second and third layers using a co-extruder. A wedge-shaped intermediate film having a stacked structure of second / first / third layers is prepared. The resulting intermediate film has a minimum thickness at one end and a maximum thickness at the other end, without any uniform thickness portions. In the resulting intermediate film, the distance X between one end and the other end is approximately 1 m. When the average thickness of the intermediate film is set as T, the average thickness of the first layer is 0.12T, and the sum 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.

[0225] (Examples 2-7 and Comparative Examples 1-3)

[0226] Except for setting the wedge angle and thickness as shown in Table 1 below, the wedge-shaped multilayer intermediate film was prepared in the same manner as in Example 1.

[0227] (Example 8)

[0228] Preparation of the composition used to form the first layer:

[0229] Relative to 100 parts by weight of PVB(2), 60 parts by weight of 3GO, 0.2 parts by weight of Tinuvin326, and 0.2 parts by weight of BHT were added, and the mixture was thoroughly kneaded using a mixing roller to obtain a composition for forming the first layer.

[0230] Preparation of the composition used to form the second and third layers:

[0231] Relative to 100 parts by weight of PVB(1), 38 parts by weight of 3GO, 0.162% by weight of ITO in the resulting second and third layers, 0.2 parts by weight of Tinuvin 326, and 0.2 parts by weight of BHT were added, and the mixture was thoroughly kneaded using a mixing roller to obtain a composition for forming the second and third layers.

[0232] Preparation of the intermediate membrane:

[0233] The composition used to form the first layer is co-extruded with the compositions used to form the second and third layers using a co-extruder. A wedge-shaped intermediate film having a stacked structure of second / first / third layers is prepared. The resulting intermediate film has a minimum thickness at one end and a maximum thickness at the other end, without any uniform thickness portions. In the resulting intermediate film, the distance X between one end and the other end is approximately 1 m. When the average thickness of the intermediate film is set as T, the average thickness of the first layer is 0.12T, and the sum 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.

[0234] (Examples 9-15, Comparative Examples 4-6)

[0235] Except for setting the type of polyvinyl acetal resin, the type and content of the heat-insulating compound, the wedge angle and the thickness of the first layer as shown in Table 2 below, the wedge-shaped multilayer intermediate film was prepared in the same manner as in Example 8.

[0236] (Example 16)

[0237] Prepare the same composition as in Example 8 for forming the first layer, and the same composition as in Example 8 for forming the second and third layers. Co-extrude these compositions using a co-extruder. Prepare a wedge-shaped intermediate film having a stacked structure of second / first / third layers. The resulting intermediate film has a minimum thickness at one end and a maximum thickness at the other end. The resulting intermediate film has a uniform thickness portion with a certain thickness within a distance of 100 mm from the other end to the first end, and the length of the uniform thickness portion is 100 mm. In the resulting intermediate film, the distance X between one end and the other end is approximately 1 m. When the average thickness of the intermediate film is set as T, the average thickness of the first layer is 0.12T, and the sum 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.

[0238] (Examples 17-24)

[0239] Except for setting the type of polyvinyl acetal resin, the type and content of the insulating compound, the length of the uniform thickness portion, the wedge angle and the thickness of the first layer as shown in Table 3 below, the wedge-shaped multilayer intermediate film was prepared in the same manner as in Example 16.

[0240] (evaluate)

[0241] (1) Double image

[0242] Prepare a pair of glass plates (transparent glass, 510mm x distance from one end of the interlayer to the other x mm, thickness 2.0mm). Insert an interlayer of the corresponding size between the glass plates to obtain a laminate. Place the resulting laminate into an EPDM rubber tube (frame component). The rubber tube is 15mm wide. Then, pre-press the laminate into the EPDM rubber tube using a vacuum bag method. Press the pre-pressed laminate into an autoclave at 150°C and 1.2MPa to obtain laminated glass.

[0243] The resulting laminated glass is positioned at the windshield location with one end of the interlayer film facing downwards. Display information is reflected from the display unit located below the laminated glass and examined visually at a specific location to check for ghosting. Ghosting is determined based on the following criteria.

[0244] [Criteria for determining ghosting]

[0245] ○: No double image detected

[0246] ×: Double image detected

[0247] (2) Uneven appearance when exposed to light

[0248] For the laminated glass obtained in the evaluation of ghosting in (1) above, an ultra-high pressure mercury lamp was placed 1.5m away from the glass and irradiated at an angle of 15 degrees downward relative to the plane horizontal to the glass. At this time, it was evaluated whether linear or dot-like distortions were observed.

[0249] [Uneven appearance after exposure to light]

[0250] ○○: No linear or dot-like unevenness was observed.

[0251] ○: Very slight linear or dot-like unevenness in appearance, but it is to a degree that is completely imperceptible in actual use.

[0252] ×: Noticeable linear or dot-like unevenness in appearance, and to a degree that would be noticeable during actual use.

[0253] The details and results of the intermediate membrane are shown in Tables 1-3 below.

[0254]

[0255]

[0256]

[0257] Symbol Explanation

[0258] 1,1A…First Layer

[0259] 2,2A…Second Layer

[0260] 3,3A…Third Floor

[0261] 11,11A…intermediate membrane

[0262] 11a…one end

[0263] 11b…the other end

[0264] 11Aa…The portion with a rectangular cross-sectional shape in the thickness direction.

[0265] 11Ab… The section with a wedge-shaped cross-section in the thickness direction.

[0266] 21…Laminated glass

[0267] 22…First laminated glass component

[0268] 23…Second laminated glass component

[0269] R1… displays the corresponding area.

[0270] R2…surrounding area

[0271] R3…Shadow Area

Claims

1. An interlayer for laminated glass, comprising: The first layer contains thermoplastic resin and plasticizer; as well as The second layer contains thermoplastic resin and plasticizer. The second layer is disposed on the first surface side of the first layer. The interlayer for the laminated glass has one end and another end located opposite to the first end, the thickness of the other end being greater than the thickness of the first end, and the minimum thickness of the first layer being 20 μm or more. The wedge angle of the interlayer film used in the laminated glass exceeds 0.5 mrad. When the ratio of the thickness of the first layer at one end to the thickness of the intermediate film at the same end is set 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 set as ratio B, then ratio B is more than 0.8 times and less than 1.1 times 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 minimum thickness of the second layer is 270 μm or more.

3. The interlayer film for laminated glass according to claim 1 or 2, having a wedge-shaped portion in the thickness direction.

4. 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.

5. The interlayer film for laminated glass according to claim 4, wherein, The hydroxyl content of the polyvinyl acetal resin in the first layer is lower than that of the polyvinyl acetal resin in the second layer.

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

7. The interlayer film for laminated glass according to claim 6, 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 that 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.

8. The interlayer for laminated glass according to claim 6, wherein, The combined minimum thickness of the second and third layers is 540 μm or more.

9. The interlayer film for laminated glass according to claim 1 or 2, used as laminated glass for head-up displays.

10. A laminated glass comprising: First laminated glass component The second laminated glass component, and Interlayer for laminated glass according to any one of claims 1 to 9 An interlayer film for the laminated glass is disposed between the first laminated glass component and the second laminated glass component.

Images