Interlayer film for laminated glass and laminated glass

Abstract

Provided is an interlayer film that is for a laminated glass and that, when being formed into a roll, can prevent a winding core from slipping out.　The interlayer film for a laminated glass according to the present invention is provided with: a first resin layer that has one end and the other end on the opposite side of said one end, that has a thickness of 1.05 mm or less at said one end, and that has a glass transition temperature lower than 15℃; and a second resin layer that has a glass transition temperature not lower than 15°C. The interlayer film has a region where there are a total of five or more layers of the first resin layer and the second resin layer lamination stacked in the thickness direction thereof. In the region where there are five or more layers, when the thickness of the surface layer by itself is defined as Y1µm, and the thickness of a layer adjacent to the surface layer is defined as Z µm, Y1 / Z is 1.01 or more.

Description

[Technical Field]

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

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

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

[0004] As an example of the laminated glass, Patent Document 1 below discloses a laminated glass for vehicles in which two curved glass sheets and a multilayer resin interlayer film are laminated together. The resin interlayer film is provided between the glass sheets. In the laminated glass for vehicles, the resin interlayer film has a wedge-shaped cross section in which the thickness of the upper edge side is thicker than the lower edge side when the laminated glass is installed in a vehicle, and is a multilayer film including at least a first resin layer and a second resin layer having a lower hardness than the first resin layer. In the laminated glass for vehicles, the thickness of the first resin layer is 0.3 mm or more in a region 400 mm or less from the lower edge. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-223883 Summary of the Invention [Problem to be solved by the invention]

[0006] The interlayer film is stored in the form of a roll wound around the outer periphery of a winding core. When the interlayer film roll is stored vertically, the winding core may come off from the roll. In particular, if the tension applied when winding the interlayer film around the outer periphery of the winding core is insufficient and the interlayer film does not have a large shrinkage rate, the winding core may come off from the roll when the interlayer film roll is stored vertically.

[0007] Furthermore, when an interlayer film having a larger thickness at one end than at the other end (a so-called wedge-shaped interlayer film) is stored in a roll with the other end facing down and the one end facing up, the difference in tension between the one end and the other end can cause the thinner end to buckle and wrinkle. When a wedge-shaped interlayer film is cut out from the roll and placed on a flat surface, the wrinkles caused by the buckling are likely to remain.

[0008] An object of the present invention is to provide an interlayer film for laminated glass that can prevent the core from coming off when rolled into a roll. Another object of the present invention is to provide an interlayer film for laminated glass that can prevent wrinkles from remaining in a wedge-shaped interlayer film. Another object of the present invention is to provide laminated glass using the interlayer film for laminated glass. [Means for solving the problem]

[0009] According to a broad aspect of the present invention, there is provided an interlayer film for laminated glass (in this specification, "interlayer film for laminated glass" may be abbreviated as "interlayer film") having one end and another end opposite the one end, wherein the thickness of the one end is 1.05 mm or less, and the interlayer film comprises a first resin layer having a glass transition temperature of less than 15°C and a second resin layer having a glass transition temperature of 15°C or higher, and has a region where the total number of layers stacked in the thickness direction of the first resin layer and the second resin layer is 5 or more, and in the region of 5 or more layers, where Y1 μm is the thickness of one surface layer and Z μm is the thickness of one layer adjacent to the surface layer, Y1 / Z is 1.01 or more.

[0010] In a specific aspect of the interlayer film according to the present invention, the thickness of the other end is greater than the thickness of the one end.

[0011] In a specific aspect of the interlayer film according to the present invention, the interlayer film has a region in which the first resin layers and the second resin layers are alternately stacked in the thickness direction.

[0012] In a specific aspect of the interlayer film according to the present invention, the surface layer is the second resin layer.

[0013] In a specific aspect of the interlayer film according to the present invention, when the thickness of the interlayer film is X μm and the thickness of one surface layer is Y2 μm, the interlayer film has a region where Y2 / X is 0.3 or less.

[0014] In a specific aspect of the interlayer film according to the present invention, the average thickness of the surface layer in the region extending from the one end toward the other end at positions 100 mm to 400 mm is less than 300 μm.

[0015] In a specific aspect of the interlayer film according to the present invention, when the average thickness of the surface layer in a region extending from the one end to the other end at a position 50 mm to 150 mm away is Y3 μm and the average thickness of the surface layer in a region extending from the other end to the one end at a position 50 mm to 150 mm away is Y4 μm, Y4 / Y3 is 2.5 or less.

[0016] In a specific aspect of the interlayer film according to the present invention, when the average thickness of the layers other than the surface layer in the region from the one end to the other end, which is from 50 mm to 150 mm, is Y5 μm, and the average thickness of the layers other than the surface layer in the region from the other end to the one end, which is from 50 mm to 150 mm, is Y6 μm, Y6 / Y5 is 2.5 or less.

[0017] In a specific aspect of the interlayer film according to the present invention, the interlayer film has a display corresponding area corresponding to the display area of ​​a head-up display, and the average thickness of the surface layer in each of the display corresponding areas is less than 300 μm.

[0018] In a specific aspect of the interlayer film according to the present invention, when the total thickness of the first resin layers is T1 μm and the total thickness of the second resin layers is T2 μm, the interlayer film has a region in which T2 / T1 is 1 or more.

[0019] According to a broad aspect of the present invention, there is provided laminated glass comprising a first laminated glass element, a second laminated glass element, and the above-described interlayer film for laminated glass, with the interlayer film for laminated glass disposed between the first laminated glass element and the second laminated glass element. [Effects of the Invention]

[0020] The interlayer film of the present invention has one end and another end opposite the one end, and the thickness of the one end is 1.05 mm or less. The interlayer film of the present invention includes a first resin layer having a glass transition temperature of less than 15°C and a second resin layer having a glass transition temperature of 15°C or higher, and has a region where the total number of layers of the first resin layer and the second resin layer stacked in the thickness direction is 5 or more. In the interlayer film of the present invention, in the region where there are 5 or more layers, Y1 / Z is 1.01 or more, where Y1 μm is the thickness of one surface layer and Z μm is the thickness of one layer adjacent to the surface layer. Because the interlayer film of the present invention has the above configuration, it can prevent the winding core from coming off when rolled. [Brief explanation of the drawings]

[0021] [Figure 1] 1(a) and 1(b) are a cross-sectional view and a front view schematically showing an interlayer film for laminated glass according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a third embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fourth embodiment of the present invention. [Figure 5] FIG. 5 is a cross-sectional view that schematically shows an example of laminated glass that uses the interlayer film for laminated glass shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will be described in detail below.

[0023] The interlayer film for laminated glass according to the present invention (sometimes abbreviated as "interlayer film" in this specification) is used in laminated glass.

[0024] The interlayer film has one end and another end opposite the one end. The one end and the other end are opposite ends of the interlayer film. The thickness of the one end of the interlayer film is 1.05 mm or less.

[0025] The interlayer film comprises a first resin layer having a glass transition temperature of less than 15°C and a second resin layer having a glass transition temperature of 15°C or higher, and has a region in which the total number of layers of the first resin layer and the second resin layer stacked in the thickness direction is 5 or more.

[0026] In the region of five or more layers, the interlayer film has a Y1 / Z ratio of 1.01 or more, where Y1 μm is the thickness of one surface layer and Z μm is the thickness of one layer adjacent to the surface layer.

[0027] The interlayer film according to the present invention has the above-described configuration, and therefore, when rolled, it is possible to prevent the core from coming off. Furthermore, when the interlayer film according to the present invention is a wedge-shaped interlayer film in which the thickness at the other end is greater than the thickness at the one end, in addition to the above-described effect, it is possible to prevent wrinkles from remaining. Since the thickness at one end of the interlayer film according to the present invention is 1.05 mm or less, the thickness of each of the first resin layer and each of the second resin layers is relatively thin. Therefore, the flexibility of the interlayer film according to the present invention can be increased, and the interlayer film can be wound with high tension when producing a roll. Therefore, it is possible to prevent the core from coming off the roll. Furthermore, when the interlayer film according to the present invention is a wedge-shaped interlayer film, even if wrinkles due to buckling occur when the interlayer film is stored in a roll state with the other end facing down and the one end facing up, the height of the wrinkles can be reduced by cutting the interlayer film from the roll and placing the interlayer film on a flat surface.

[0028] Furthermore, in conventional wedge-shaped interlayer films in which the thickness at the other end is greater than the thickness at the one end, the shrinkage rate can differ significantly between one end and the other end, and when rolled, the winding length can differ between one end and the other end. Therefore, with conventional wedge-shaped interlayer films, when the interlayer film is unwound from the roll, the thicker other end does not fit the roll, and the interlayer film cannot be heated uniformly in the direction connecting one end and the other end. In contrast, the interlayer film of the present invention can have a small shrinkage rate, so when rolled, the difference in winding length between one end and the other end can be kept small, and as a result, the interlayer film can be heated uniformly.

[0029] Furthermore, the interlayer film according to the present invention includes the first resin layer having a glass transition temperature of less than 15°C, and therefore can effectively improve sound insulation.

[0030] The interlayer film has a region where the total number of layers of the first resin layer and the second resin layer stacked in the thickness direction is 5 or more. In the region, the total number of layers of the first resin layer and the second resin layer stacked in the thickness direction may be 5, 6 or more, 7 or more, 8 or more, 9 or more, or 10 or more. In the region, the total number of layers of the first resin layer and the second resin layer stacked in the thickness direction may be 20 or less, 15 or less, 10 or less, 9 or less, 8 or less, or 6 or less. In the region, the total number of layers of the first resin layer and the second resin layer stacked in the thickness direction is preferably 5, 7, or 11, more preferably 5 or 7, and even more preferably 5. In this case, the occurrence of flow marks can be effectively suppressed. In particular, when the total number of layers of the first resin layer and the second resin layer stacked in the thickness direction is five, the occurrence of flow marks can be more effectively suppressed.

[0031] The interlayer film may have a region in which the total number of layers of the first resin layer and the second resin layer in the thickness direction is 5 or more, either in a part of the interlayer film or throughout the interlayer film. The structure of the interlayer film may be partially different.

[0032] Of 100% of the planar area of ​​the interlayer film, the area of ​​the region where the total number of layers of the first resin layer and the second resin layer stacked in the thickness direction is 5 or more is preferably 1% or more, more preferably 2% or more, even more preferably 3% or more, and particularly preferably 5% or more. Of 100% of the planar area of ​​the interlayer film, the area of ​​the region where the total number of layers of the first resin layer and the second resin layer stacked in the thickness direction is 5 or more may be 50% or more, 60% or more, 70% or more, or even 80% or more. Of 100% of the planar area of ​​the interlayer film, the area of ​​the region where the total number of layers of the first resin layer and the second resin layer stacked in the thickness direction is 5 or more is 100% or less.

[0033] The interlayer film includes at least one first resin layer having a glass transition temperature of less than 15° C. The interlayer film may include only one, two, two or more, or three or more first resin layers.

[0034] The interlayer film includes at least one second resin layer having a glass transition temperature of 15° C. or higher. The interlayer film may include only one second resin layer, two second resin layers, two or more second resin layers, or three or more second resin layers.

[0035] The glass transition temperature of the first resin layer is lower than 15° C. The glass transition temperature of the first resin layer is preferably −20° C. or higher, more preferably −15° C. or higher, even more preferably −10° C. or higher, and preferably 10° C. or lower, more preferably 5° C. or lower, and even more preferably 0° C. or lower. When the glass transition temperature is equal to or higher than the above lower limit and equal to or lower than the above upper limit, the sound insulation of the laminated glass can be further improved.

[0036] The second resin layer has a glass transition temperature of 15° C. or higher. The second resin layer has a glass transition temperature of preferably 20° C. or higher, more preferably 25° C. or higher, even more preferably 30° C. or higher, and preferably 50° C. or lower, more preferably 45° C. or lower, and even more preferably 40° C. or lower. When the glass transition temperature is equal to or higher than the above lower limit and equal to or lower than the above upper limit, the sound insulation of the laminated glass can be further improved, and the interlayer film can be used without impairing the handleability of the interlayer film.

[0037] The absolute value of the difference between the glass transition temperature of the first resin layer and the glass transition temperature of the second resin layer is preferably at least 10° C., more preferably at least 15° C., and is preferably at most 70° C., more preferably at most 65° C. When the absolute value of the difference is at least the above lower limit and at most the above upper limit, the sound insulation of the laminated glass can be further improved.

[0038] The glass transition temperature is determined by viscoelasticity measurement, which is specifically carried out as follows.

[0039] The test specimens are stored for 12 hours at room temperature (23±2°C) and humidity (25±5%). Viscoelasticity is then measured using a TA Instruments ARES-G2 viscoelasticity measuring device. Using parallel plates with a diameter of 8 mm, measurements are performed in shear mode, with the temperature lowered from 100°C to -20°C at a rate of 3°C / min, at a frequency of 1 Hz, and with a strain of 1%. The peak temperature of the loss tangent in the measurement results is taken as the glass transition temperature (Tg) (°C).

[0040] Viscoelasticity measurements may be performed using the interlayer film itself. In this case, the peaks of tan δ derived from each layer may be read from the measurement results. Alternatively, the layers of the interlayer film may be peeled apart to measure the glass transition temperature of the layer to be measured. In the case of laminated glass, the laminated glass may be cooled with liquid nitrogen or the like, and then the laminated glass member and the interlayer film may be peeled off, and the viscoelasticity measurements may be performed using the peeled interlayer film.

[0041] As long as the first resin layer has the specific glass transition temperature, the multiple first resin layers in the interlayer film do not have to have the same glass transition temperature. Also, as long as the second resin layer has the specific glass transition temperature, the multiple second resin layers in the interlayer film do not have to have the same glass transition temperature.

[0042] From the viewpoint of more effectively achieving the effects of the present invention, it is preferable that the first resin layer and the second resin layer have a region where they are alternately laminated in the thickness direction. From the viewpoint of even more effectively achieving the effects of the present invention, it is preferable that the first resin layer and the second resin layer are alternately laminated in the thickness direction.

[0043] The number of the first resin layers and the number of the second resin layers may be the same or different, but from the viewpoint of more effectively achieving the effects of the present invention, it is preferable that the number of the first resin layers is smaller than the number of the second resin layers.

[0044] Since the interlayer film has a structure of five or more layers, the interlayer film has two surface layers (a first surface layer and a second surface layer).

[0045] The interlayer film may include the first resin layer and the second resin layer as the surface layer. The interlayer film may include the first resin layer as the first surface layer and the second resin layer as the second surface layer.

[0046] The surface layer is preferably the second resin layer. In this case, the effects of the present invention can be more effectively exhibited, the sound insulation and penetration resistance of the laminated glass can be further improved, and optical distortion can be effectively suppressed. In addition, degassing properties during production of the laminated glass can be improved.

[0047] In the region of the interlayer having five or more layers, the thickness of one surface layer is defined as Y1 μm, and the thickness of one layer adjacent to the surface layer is defined as Z μm, where Y1 is the thickness of one surface layer at the predetermined position in the region of five or more layers, and Z is the thickness of one layer adjacent to the surface layer at the same position as the predetermined position.

[0048] In the interlayer film, Y1 / Z is 1.01 or more, preferably 1.1 or more, more preferably 1.2 or more, and preferably 15 or less, more preferably 14 or less. When Y1 / Z is equal to or greater than the lower limit and equal to or less than the upper limit, core loss of the roll body can be prevented. The above relationship of Y1 / Z is satisfied in at least one of the first surface layer and the second surface layer, and preferably in both. Note that each of the preferred embodiments of the surface layer described in this specification is satisfied in at least one of the first surface layer and the second surface layer, and preferably in both.

[0049] The thickness of the interlayer is X μm, and the thickness of one surface layer is Y2 μm. X is the thickness of the interlayer at a predetermined position, and Y2 is the thickness of one surface layer at the same position as the predetermined position. Note that Y1 and Y2 may be the same or different.

[0050] The interlayer film preferably has a region (hereinafter sometimes referred to as Region A) where the value of Y2 / X is 0.3 or less. That is, the interlayer film preferably has a region (Region A) where the ratio of the thickness (Y2) of one surface layer to the thickness (X) of the interlayer film is 0.3 or less. The above relationship of Y2 / X is preferably satisfied in at least one of the first surface layer and the second surface layer, and more preferably satisfied in both.

[0051] In the region A, the value of Y2 / X is preferably 0.01 or more, more preferably 0.05 or more, and preferably 0.29 or less, more preferably 0.28 or less. When the value of Y2 / X is equal to or greater than the lower limit, the sound insulation of the laminated glass can be further improved. When the value of Y2 / X is equal to or less than the upper limit, the penetration resistance of the laminated glass can be further improved and optical distortion can be effectively suppressed. When the value of Y2 / X is equal to or greater than the lower limit and equal to or less than the upper limit, the effects of the present invention can be more effectively exhibited. The above relationship of Y2 / X is preferably satisfied in at least one of the first surface layer and the second surface layer, and more preferably satisfied in both.

[0052] Region A is preferably present between 0 mm and 1000 mm from one end to the other end, and more preferably between 50 mm and 950 mm from one end to the other end (in this case, region A may also be present at other positions). In this case, the effects of the present invention can be more effectively exhibited, the sound insulation and penetration resistance of the laminated glass can be further improved, and optical distortion can be effectively suppressed.

[0053] The distance between one end and the other end of the interlayer film is designated as L. Region A preferably exists from 0L to 1.0L from one end to the other end. Region A more preferably exists from 0L to 0.99L from one end to the other end, and even more preferably exists from 0L to 0.95L from one end to the other end (in this case, region A may also be located at other positions). In this case, the effects of the present invention can be more effectively exhibited, the sound insulation and penetration resistance of the laminated glass can be further improved, and optical distortion can be effectively suppressed.

[0054] The average thickness of the surface layer in the region from 50 mm to 150 mm from the one end toward the other end is Y3 μm, and the average thickness of the surface layer in the region from 50 mm to 150 mm from the other end toward the one end is Y4 μm. Note that Y3 may be the same as or different from Y1. Also, Y3 may be the same as or different from Y2.

[0055] From the viewpoint of more effectively exerting the effects of the present invention, the Y4 / Y3 ratio in the interlayer film is preferably 0.3 or more, more preferably 0.5 or more, even more preferably 0.7 or more, and even more preferably 0.9 or more. From the viewpoint of more effectively exerting the effects of the present invention, the Y4 / Y3 ratio in the interlayer film is preferably 2.5 or less, more preferably 2.3 or less, even more preferably 2.0 or less, even more preferably 1.7 or less, even more preferably 1.5 or less, particularly preferably 1.3 or less, and most preferably 1.1 or less. The above relationship of Y4 / Y3 is preferably satisfied in at least one of the first surface layer and the second surface layer, and more preferably in both.

[0056] The average thickness of layers other than the surface layer in the region from 50 mm to 150 mm from the one end toward the other end is Y5 μm, and the average thickness of layers other than the surface layer in the region from 50 mm to 150 mm from the other end toward the one end is Y6 μm.

[0057] From the viewpoint of more effectively exerting the effects of the present invention, the Y6 / Y5 ratio in the interlayer film is preferably 0.3 or more, more preferably 0.5 or more, even more preferably 0.7 or more, and even more preferably 0.9 or more. From the viewpoint of more effectively exerting the effects of the present invention, the Y6 / Y5 ratio in the interlayer film is preferably 2.5 or less, more preferably 2.3 or less, even more preferably 2.0 or less, even more preferably 1.7 or less, even more preferably 1.5 or less, particularly preferably 1.3 or less, and most preferably 1.1 or less. The above Y6 / Y5 relationship is preferably satisfied in at least one of the layers other than the surface layer, and more preferably in all of the layers other than the surface layer.

[0058] From the viewpoint of more effectively exerting the effects of the present invention, it is particularly preferable that the interlayer film has Y4 / Y3 of 2.5 or less and Y6 / Y5 of 2.5 or less.

[0059] The interlayer film is used, for example, in laminated glass for a head-up display. When the interlayer film is used in laminated glass for a head-up display, the interlayer film has a display-corresponding area that corresponds to the display area of ​​the head-up display. The display-corresponding area is an area in which information can be displayed satisfactorily.

[0060] In the interlayer film, the average thickness of the surface layer in the region extending from 100 mm to 400 mm from the one end toward the other end (hereinafter sometimes referred to as Region B) is preferably less than 300 μm. In the interlayer film, the average thickness of the surface layer in the display-corresponding region is preferably less than 300 μm. In this case, the effects of the present invention can be more effectively exhibited, the sound insulation and penetration resistance of the laminated glass can be further improved, and optical distortion can be effectively suppressed. The above value for the average thickness of the surface layer in the display-corresponding region is preferably satisfied in at least one of the first surface layer and the second surface layer, and more preferably satisfied in both.

[0061] The average thickness of the surface layer in region B or the display-corresponding region is preferably 10 μm or more, more preferably 20 μm or more, even more preferably 100 μm or more, and even more preferably 180 μm or more, and is preferably 350 μm or less, more preferably 295 μm or less, and even more preferably 290 μm or less. When the average thickness of the surface layer is equal to or greater than the above-mentioned lower limit and equal to or less than the above-mentioned upper limit, the effects of the present invention can be more effectively exhibited, the sound insulation and penetration resistance of the laminated glass can be further improved, and optical distortion can be effectively suppressed. The above value of the average thickness of the surface layer is preferably satisfied in at least one of the first surface layer and the second surface layer, and more preferably satisfied in both.

[0062] The total thickness of the first resin layer is T1 μm, and the total thickness of the second resin layer is T2 μm, where T1 is the thickness of the first resin layer at a predetermined position, and T2 is the thickness of the second resin layer at the same position as the predetermined position.

[0063] The interlayer film preferably has a region (hereinafter sometimes referred to as region C) where the value of T2 / T1 is 1 or greater. That is, the interlayer film preferably has a region (region C) where the ratio of the total thickness (T2) of the second resin layers to the total thickness (T1) of the first resin layers is 1 or greater.

[0064] In region C, the T2 / T1 value is preferably 1.01 or more, more preferably 1.02 or more, and preferably 40 or less, more preferably 38 or less. When the T2 / T1 value is equal to or greater than the lower limit, the sound insulation of the laminated glass can be further improved. When the T2 / T1 value is equal to or less than the upper limit, the penetration resistance of the laminated glass can be further improved and optical distortion can be effectively suppressed. When the T2 / T1 value is equal to or greater than the lower limit and equal to or less than the upper limit, the effects of the present invention can be more effectively exhibited.

[0065] Region C is preferably present at least between 50 mm and 1000 mm from one end to the other end, and more preferably between 50 mm and 950 mm from one end to the other end. In this case, the effects of the present invention can be more effectively exhibited, the sound insulation and penetration resistance of the laminated glass can be further improved, and optical distortion can be effectively suppressed.

[0066] The distance between one end and the other end of the interlayer film is designated as L. Region C preferably exists at least between 0L and 0.99L from one end to the other end, and more preferably between 0L and 0.95L from one end to the other end. In this case, the effects of the present invention can be more effectively exerted, the sound insulation and penetration resistance of the laminated glass can be further improved, and optical distortion can be effectively suppressed.

[0067] The thickness of one end of the interlayer film is 1.05 mm or less. The thickness of one end of the interlayer film is preferably 0.1 mm or more, more preferably 0.2 mm or more, even more preferably 0.3 mm or more, particularly preferably 0.4 mm or more, and is preferably 1.04 mm or less, more preferably 1.03 mm or less, and even more preferably 1.0 mm or less. When the thickness of one end is not less than the above lower limit and not more than the above upper limit, the effects of the present invention can be more effectively exhibited.

[0068] The thickness of the other end of the interlayer film is preferably greater than the thickness of the one end, more preferably at least 0.01 mm, even more preferably at least 0.05 mm, and particularly preferably at least 0.1 mm. The thickness of the other end of the interlayer film is preferably greater than the thickness of the one end by at most 5 mm, more preferably at most 4.8 mm, and even more preferably at most 4.6 mm. When the thickness of the other end is greater than or equal to the lower limit and less than or equal to the upper limit, the effects of the present invention can be more effectively achieved.

[0069] The maximum thickness of the interlayer is preferably 0.15 mm or more, more preferably 0.25 mm or more, even more preferably 0.5 mm or more, particularly preferably 0.8 mm or more, and is preferably 4 mm or less, more preferably 3.8 mm or less, even more preferably 3.6 mm or less.

[0070] The distance between one end and the other end of the interlayer film is defined as L. The interlayer film preferably has a minimum thickness in a region from 0L to 0.2L from the one end to the other end, and a maximum thickness in a region from 0L to 0.2L from the other end to the one end. It is more preferable that the interlayer film has a minimum thickness in a region from 0L to 0.1L from the one end to the other end, and a maximum thickness in a region from 0L to 0.1L from the other end to the one end. It is preferable that the interlayer film has a minimum thickness at one end and a maximum thickness at the other end. The maximum thickness is the thickness of the portion where the thickness is greatest. The minimum thickness is the thickness of the portion where the thickness is smallest.

[0071] The interlayer film may have a uniform thickness region. The uniform thickness region refers to a region in which the thickness does not vary by more than 10 μm over a distance of 10 cm in the direction connecting one end of the interlayer film to the other end. Accordingly, the uniform thickness region refers to a region in which the thickness does not vary by more than 10 μm over a distance of 10 cm in the direction connecting one end of the interlayer film to the other end. Specifically, the uniform thickness region refers to a region in which the thickness does not vary at all over a distance of 10 cm in the direction connecting one end of the interlayer film to the other end, or a region in which the thickness varies by 10 μm or less over a distance of 10 cm in the direction connecting one end of the interlayer film to the other end.

[0072] From the viewpoint of practical use and of sufficiently increasing adhesive strength and penetration resistance, the maximum thickness of the surface layer in the interlayer film is preferably 20 μm or more, more preferably 25 μm or more, and even more preferably 50 μm or more, and is preferably 2000 μm or less, and more preferably 1800 μm or less.

[0073] From the viewpoint of practicality and of sufficiently increasing penetration resistance, the maximum thickness of the layer (intermediate layer) disposed between the two surface layers in the interlayer film is preferably 60 μm or more, more preferably 80 μm or more, and is preferably 4980 μm or less, more preferably 4800 μm or less.

[0074] The distance L between one end and the other end of the interlayer is preferably 3 m or less, more preferably 2 m or less, particularly preferably 1.5 m or less, and is preferably 0.5 m or more, more preferably 0.8 m or more, particularly preferably 1 m or more.

[0075] From the viewpoint of improving the display, it is preferable that the interlayer film has a portion whose cross section in the thickness direction is wedge-shaped. It is preferable that the cross section in the thickness direction of the display-corresponding region is wedge-shaped.

[0076] To prevent double images, the wedge angle θ of the interlayer film can be appropriately set according to the installation angle of the laminated glass. The wedge angle θ is the wedge angle of the entire interlayer film.

[0077] The wedge angle θ of the interlayer film is the interior angle at the intersection of a line connecting the surface portion (first surface portion) on one side of the interlayer film between the maximum and minimum thickness portions of the interlayer film and a line connecting the surface portion (second surface portion) on the other side of the interlayer film between the maximum and minimum thickness portions of the interlayer film.

[0078] In addition, if there are multiple maximum thickness portions, multiple minimum thickness portions, the maximum thickness portion is in a fixed region, or the minimum thickness portion is in a fixed region, the maximum thickness portion and the minimum thickness portion for determining the wedge angle θ are selected so that the wedge angle θ to be determined is largest.

[0079] To more effectively suppress ghosting, the wedge angle θ of the interlayer film is preferably 0.05 mrad or greater, more preferably 0.1 mrad (0.00575 degrees) or greater, and even more preferably 0.2 mrad (0.0115 degrees) or greater. Furthermore, when the wedge angle θ is equal to or greater than the lower limit, a laminated glass suitable for vehicles with a large windshield installation angle, such as trucks and buses, can be obtained.

[0080] To more effectively suppress ghosting, the wedge angle θ of the interlayer film is preferably 2 mrad (0.1146 degrees) or less, and more preferably 0.7 mrad (0.0401 degrees) or less. Furthermore, when the wedge angle θ is equal to or less than the upper limit, a laminated glass suitable for vehicles with a small windshield installation angle, such as sports cars, can be obtained.

[0081] The wedge angle (θ) of the interlayer film and the thickness of the interlayer film can be measured using a contact thickness measuring instrument "TOF-4R" (manufactured by Yamabun Denki Co., Ltd.).

[0082] The thickness of the interlayer film is measured using the above-mentioned measuring device at a film conveying speed of 2.15 mm / min to 2.25 mm / min from one end to the other end over the shortest distance.

[0083] The thickness of each layer of the interlayer may be measured using a measuring device such as "SE-3000" (manufactured by SELMIC).

[0084] The thickness of each layer of the interlayer film can be measured as follows: The interlayer film is cut in the thickness direction at the measurement position using a razor, cutter, etc. The cut surface of the interlayer film is observed using the measuring device described above, and then the thickness of each layer is measured using calculation software included in the accompanying software.

[0085] The wedge angle (θ) of the interlayer film after it has been formed into laminated glass, the thickness of the interlayer film, and the thickness of each layer of the interlayer film can be measured using a non-contact multilayer film thickness measuring device such as "OPTIGAUGE" (manufactured by Lumetrics). When using such a measuring device, the thickness of the interlayer film can be measured in the laminated glass state.

[0086] The interlayer film is suitable for use in laminated glass for a head-up display (HUD). The interlayer film is preferably an interlayer film for a HUD. The interlayer film preferably has a display corresponding area corresponding to the display area of ​​the HUD.

[0087] From the viewpoint of suppressing double images more effectively, it is preferable that the intermediate film has the display corresponding area in the region from a position 6 cm from one end of the intermediate film toward the other end to a position 63.8 cm from the one end toward the other end.

[0088] From the viewpoint of suppressing double images more effectively, it is more preferable that the intermediate film has the display corresponding area in a region from a position 8 cm from one end of the intermediate film toward the other end to a position 61.8 cm from the one end toward the other end.

[0089] From the viewpoint of suppressing double images more effectively, it is even more preferable that the intermediate film has the display corresponding area in the region from a position 9 cm from one end of the intermediate film toward the other end to a position 60.8 cm from the one end toward the other end.

[0090] From the viewpoint of suppressing double images even more effectively, it is even more preferable that the intermediate film has the display corresponding area in a region from a position 9.5 cm from one end of the intermediate film toward the other end to a position 60.3 cm from the one end toward the other end.

[0091] From the viewpoint of suppressing double images more effectively, it is particularly preferable that the intermediate film has the display corresponding area in the region from a position 10 cm from one end of the intermediate film toward the other end to a position 59.8 cm from the one end toward the other end.

[0092] The display-corresponding area may be present in a part or the entire area of ​​the interlayer film from one end to the other end to the position (for example, 63.8 mm). The display-corresponding area may be approximately 30 cm in size in the direction connecting one end and the other end.

[0093] From the viewpoint of effectively suppressing double images, it is preferable that the intermediate film has a portion whose cross-sectional shape in the thickness direction is wedge-shaped in the region from a position 6 cm from one end of the intermediate film toward the other end to a position 63.8 cm from the one end toward the other end.

[0094] From the viewpoint of effectively suppressing double images, it is more preferable that the intermediate film has a portion whose cross-sectional shape in the thickness direction is wedge-shaped in the region from a position 8 cm from one end of the intermediate film toward the other end to a position 61.8 cm from the one end toward the other end.

[0095] From the viewpoint of effectively suppressing double images, it is even more preferable that the intermediate film has a portion whose cross-sectional shape in the thickness direction is wedge-shaped in the region from a position 9 cm from one end of the intermediate film toward the other end to a position 60.8 cm from the one end toward the other end.

[0096] From the viewpoint of effectively suppressing double images, it is further preferable that the intermediate film has a portion whose cross-sectional shape in the thickness direction is wedge-shaped in the region from a position 9.5 cm from the one end toward the other end of the intermediate film to a position 60.3 cm from the one end toward the other end.

[0097] From the viewpoint of effectively suppressing double images, it is particularly preferable that the intermediate film has a portion whose cross-sectional shape in the thickness direction is wedge-shaped in the region from a position 10 cm from one end toward the other end of the intermediate film to a position 59.8 cm from the one end toward the other end.

[0098] The portion having a wedge-shaped cross section in the thickness direction may be present in part or the entire region from the one end to the other end to the position (e.g., 63.8 mm).The portion having a wedge-shaped cross section in the thickness direction may be present over a length of about 30 cm in the direction connecting the one end and the other end.

[0099] The interlayer film may have a shade area. The shade area may be separated from the display-corresponding area. The shade area is provided, for example, for the purpose of preventing the driver from feeling dazzled by sunlight or outdoor lighting while driving. The shade area may also be provided to provide heat insulation. The shade area is preferably located at the edge of the interlayer film. The shade area is preferably strip-shaped.

[0100] In the shade region, a colorant or filler may be used to change the color and visible light transmittance, etc. The colorant or filler may be contained in only a part of the region in the thickness direction of the interlayer film, or may be contained in the entire region in the thickness direction of the interlayer film.

[0101] From the viewpoint of improving the display quality and widening the field of view, the visible light transmittance of the display-corresponding area is preferably 80% or more, more preferably 88% or more, and even more preferably 90% or more. The visible light transmittance of the display-corresponding area is preferably higher than that of the shade area. The visible light transmittance of the display-corresponding area may be lower than that of the shade area. The visible light transmittance of the display-corresponding area is preferably 50% or more higher, more preferably 60% or more higher than that of the shade area.

[0102] For example, when the visible light transmittance varies in the interlayer film in the display corresponding area and the shade area, the visible light transmittance is measured at the center position of the display corresponding area and the center position of the shade area.

[0103] The visible light transmittance of the obtained laminated glass at a wavelength of 380 nm to 780 nm can be measured using a spectrophotometer (Hitachi High-Technologies Corporation's "U-4100") in accordance with JIS R3211: 1998. It is preferable to use clear glass with a thickness of 2 mm as the glass plate.

[0104] The display-corresponding region preferably has a length direction and a width direction. In order to provide excellent versatility for the interlayer film, the width direction of the display-corresponding region is preferably a direction connecting the one end and the other end. The display-corresponding region is preferably strip-shaped.

[0105] The interlayer film preferably has an MD direction and a TD direction. The interlayer film is obtained, for example, by melt extrusion molding. The MD direction is the flow direction of the interlayer film during production. The TD direction is a direction perpendicular to the flow direction of the interlayer film during production and perpendicular to the thickness direction of the interlayer film. The one end and the other end are preferably located on opposite sides of the TD direction.

[0106] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[0107] 1(a) and 1(b) are a cross-sectional view and a front view schematically showing an interlayer film for laminated glass according to a first embodiment of the present invention. Fig. 1(a) is a cross-sectional view taken along line II in Fig. 1(b). Note that the size and dimensions of the interlayer film in Fig. 1 and the figures described below have been appropriately modified from the actual size and shape for the sake of convenience.

[0108] Fig. 1(a) shows a cross section in the thickness direction of the interlayer film 10. Note that in Fig. 1(a) and the figures described below, for convenience of illustration, the thicknesses and wedge angles (θ) of the interlayer film and each layer that constitutes the interlayer film are shown to be different from the actual thicknesses and wedge angles.

[0109] The interlayer film 10 is used to obtain laminated glass. The interlayer film 10 is an interlayer film for laminated glass. The interlayer film 10 includes first resin layers 11 and 12 and second resin layers 21, 22, and 23. The first resin layers 11 and 12 have a glass transition temperature of less than 15°C. The second resin layers 21, 22, and 23 have a glass transition temperature of 15°C or higher. The interlayer film 10 includes two first resin layers and three second resin layers. In the interlayer film 10, the total number of first resin layers and second resin layers stacked in the thickness direction is five. In the interlayer film 10, the first resin layers and second resin layers are stacked alternately in the thickness direction.

[0110] The interlayer film 10 comprises a second resin layer 21 and a second resin layer 23 as surface layers. The interlayer film 10 comprises a first resin layer 11, a second resin layer 22, and a first resin layer 12 as intermediate layers. The first resin layer 11 is disposed and laminated on a first surface side of the second resin layer 22. The first resin layer 12 is disposed and laminated on a second surface side of the second resin layer 22 opposite the first surface. The second resin layer 21 is disposed and laminated on a surface side of the first resin layer 11 opposite the second resin layer 22. The second resin layer 23 is disposed and laminated on a surface side of the first resin layer 12 opposite the second resin layer 22.

[0111] The interlayer film 10 has one end 10a and the other end 10b opposite the one end 10a. The one end 10a and the other end 10b are opposite ends. The cross-sectional shape in the thickness direction of the first resin layers 11, 12 and the second resin layers 21, 22, 23 is wedge-shaped. The thickness of the first resin layers 11, 12 and the second resin layers 21, 22, 23 is greater on the other end 10b side than on the one end 10a side. Therefore, the thickness of the other end 10b of the interlayer film 10 is greater than the thickness of the one end 10a. The interlayer film 10 has a thin region and a thick region.

[0112] The interlayer film 10 has a region where the thickness increases from one end 10a to the other end 10b. In the region where the thickness increases, the amount of increase in thickness is uniform from one end 10a to the other end 10b.

[0113] The interlayer film 10 has a display-corresponding region R1 that corresponds to the display area of ​​the head-up display. The interlayer film 10 has a peripheral region R2 adjacent to the display-corresponding region R1. The interlayer film 10 has a shade region R3 away from the display-corresponding region R1. The shade region R3 is located at the edge of the interlayer film 10.

[0114] The interlayer film may have six or more layers in the shape shown in FIG. 1(a). The interlayer film may have neither a display-corresponding region nor a shade region in the shape shown in FIG. 1(a). The interlayer film may have a portion where the first resin layer and the second resin layer are not alternately laminated in the shape shown in FIG. 1(a). For example, the interlayer film may have a laminated structure of second resin layer / first resin layer / first resin layer / first resin layer / second resin layer. The interlayer film may have the shape shown in FIG. 1(a), with the first resin layer being the surface layer. The interlayer film may have the shape shown in FIG. 1(a), with all of the first resin layers having a rectangular cross-sectional shape in the thickness direction, and all of the second resin layers having a rectangular cross-sectional shape in the thickness direction. The interlayer film may have the shape shown in FIG. 1(a), with at least one of the first resin layers having a rectangular cross-sectional shape in the thickness direction, and at least one of the second resin layers having a rectangular cross-sectional shape in the thickness direction.

[0115] 2 is a cross-sectional view schematically illustrating an interlayer film for laminated glass according to a second embodiment of the present invention, showing a cross section in the thickness direction of an interlayer film 10A.

[0116] The interlayer film 10A shown in Figure 2 includes first resin layers 11A and 12A and second resin layers 21A, 22A, and 23A. The first resin layers 11A and 12A have a glass transition temperature of less than 15°C. The second resin layers 21A, 22A, and 23A have a glass transition temperature of 15°C or higher. The interlayer film 10 and the interlayer film 10A have different amounts of thickness increase in the regions where the thickness increases.

[0117] The intermediate film 10A has one end 10a and the other end 10b opposite the one end 10a. The one end 10a and the other end 10b are opposite ends. The cross-sectional shape in the thickness direction of the first resin layers 11A, 12A and the second resin layers 21A, 22A, 23A is wedge-shaped. The thickness of the first resin layers 11A, 12A and the second resin layers 21A, 22A, 23A is greater on the other end 10b side than on the one end 10a side. Therefore, the thickness of the other end 10b of the intermediate film 10A is greater than the thickness of the one end 10a. The intermediate film 10A has a thin region and a thick region.

[0118] The interlayer film 10A has a region where the thickness increases from one end 10a to the other end 10b. Within the region where the thickness increases, the interlayer film 10A has a portion where the amount of increase in thickness increases from one end 10a to the other end 10b. The interlayer film 10A also has a region where the cross-sectional shape in the thickness direction is wedge-shaped. Within the region where the cross-sectional shape in the thickness direction is wedge-shaped, the interlayer film 10A has a portion where the wedge angle increases from one end to the other end.

[0119] The interlayer film 10A has a display-corresponding region R1 that corresponds to the display area of ​​the head-up display. The interlayer film 10A has a peripheral region R2 adjacent to the display-corresponding region R1. The interlayer film 10A has a shade region R3 away from the display-corresponding region R1. The shade region R3 is located at the edge of the interlayer film 10A.

[0120] The interlayer film may have six or more layers in the shape shown in FIG. 2. The interlayer film may have neither a display-corresponding region nor a shade region in the shape shown in FIG. 2. The interlayer film may have a portion where the first resin layers and the second resin layers are not alternately laminated in the shape shown in FIG. 2. The interlayer film may have the shape shown in FIG. 2, with the first resin layer being the surface layer. The interlayer film may have the shape shown in FIG. 2, with all of the first resin layers having a rectangular cross-sectional shape in the thickness direction, and all of the second resin layers having a rectangular cross-sectional shape in the thickness direction. The interlayer film may have the shape shown in FIG. 2, with at least one of the first resin layers having a rectangular cross-sectional shape in the thickness direction, and at least one of the second resin layers having a rectangular cross-sectional shape in the thickness direction.

[0121] 3 is a cross-sectional view schematically illustrating an interlayer film for laminated glass according to a third embodiment of the present invention, showing a cross section in the thickness direction of an interlayer film 10B.

[0122] The interlayer film 10B shown in Figure 3 includes first resin layers 11B and 12B and second resin layers 21B, 22B, and 23B. The first resin layers 11B and 12B have a glass transition temperature of less than 15°C. The second resin layers 21B, 22B, and 23B have a glass transition temperature of 15°C or higher. The interlayer film 10 and the interlayer film 10B have different thickness increases in the regions where the thickness increases.

[0123] The intermediate film 10B has one end 10a and the other end 10b opposite the one end 10a. The one end 10a and the other end 10b are opposite ends. The cross-sectional shape in the thickness direction of the first resin layers 11B, 12B and the second resin layers 21B, 22B, 23B is wedge-shaped. The thickness of the first resin layers 11B, 12B and the second resin layers 21B, 22B, 23B is greater on the other end 10b side than on the one end 10a side. Therefore, the thickness of the other end 10b of the intermediate film 10B is greater than the thickness of the one end 10a. The intermediate film 10B has a thin region and a thick region.

[0124] The interlayer film 10B has a region where the thickness increases from one end 10a to the other end 10b. Within the region where the thickness increases, the interlayer film 10B has a portion where the amount of increase in thickness decreases from one end 10a to the other end 10b. The interlayer film 10B also has a region where the cross-sectional shape in the thickness direction is wedge-shaped. Within the region where the cross-sectional shape in the thickness direction is wedge-shaped, the interlayer film 10B has a portion where the wedge angle decreases from one end to the other end.

[0125] The interlayer film 10B has a display-corresponding region R1 that corresponds to the display area of ​​the head-up display. The interlayer film 10B has a peripheral region R2 adjacent to the display-corresponding region R1. The interlayer film 10B has a shade region R3 away from the display-corresponding region R1. The shade region R3 is located at the edge of the interlayer film 10B.

[0126] The interlayer film may have six or more layers in the shape shown in FIG. 3. The interlayer film may have neither a display-corresponding region nor a shade region in the shape shown in FIG. 3. The interlayer film may have a portion where the first resin layer and the second resin layer are not alternately laminated in the shape shown in FIG. 3. The interlayer film may have the shape shown in FIG. 3, with the first resin layer being the surface layer. The interlayer film may have the shape shown in FIG. 3, with all of the first resin layers having a rectangular cross-sectional shape in the thickness direction, and all of the second resin layers having a rectangular cross-sectional shape in the thickness direction. The interlayer film may have the shape shown in FIG. 3, with at least one of the first resin layers having a rectangular cross-sectional shape in the thickness direction, and at least one of the second resin layers having a rectangular cross-sectional shape in the thickness direction.

[0127] 4 is a cross-sectional view schematically illustrating an interlayer film for laminated glass according to a fourth embodiment of the present invention, showing a cross section in the thickness direction of an interlayer film 10C.

[0128] The intermediate film 10C has one end 10a and the other end 10b opposite the one end 10a. The one end 10a and the other end 10b are opposite ends. The cross-sectional shape in the thickness direction of the first resin layers 11C, 12C and the second resin layer 22C is wedge-shaped. The thickness of the first resin layers 11C, 12C and the second resin layer 22C is greater on the other end 10b side than on the one end 10a side. The thickness of the other end 10b of the intermediate film 10C is greater than the thickness of the one end 10a. The intermediate film 10C has a thin region and a thick region.

[0129] The interlayer film 10C has a region where the thickness increases from one end 10a to the other end 10b. In the region where the thickness increases, the amount of increase in thickness is uniform from one end 10a to the other end 10b.

[0130] The interlayer film 10C includes first resin layers 11C and 12C and second resin layers 21C, 22C, and 23C. The first resin layers 11C and 12C have a glass transition temperature of less than 15°C. The second resin layers 21C, 22C, and 23C have a glass transition temperature of 15°C or higher. The second resin layer 21C and the second resin layer 23C are integrated at one end 10a and the other end 10b. The first resin layers 11C and 12C and the second resin layer 22C are embedded between the second resin layer 21C and the second resin layer 23C. The interlayer film 10C has a portion having a five-layer structure and a portion having a single-layer structure. The interlayer film 10C has a region in which the first resin layers and the second resin layers are alternately stacked in the thickness direction.

[0131] The interlayer film 10C has a display-corresponding region R1 that corresponds to the display area of ​​the head-up display. The interlayer film 10C has a peripheral region R2 adjacent to the display-corresponding region R1. The interlayer film 10C has a shade region R3 away from the display-corresponding region R1. The shade region R3 is located at the edge of the interlayer film 10C.

[0132] In the display-corresponding region R1, the intermediate film 10C has a five-layer structure. Also, in the region from the one end 10a to the other end 10b, which extends from the position 100 mm to the position 400 mm, the intermediate film 10C has a five-layer structure.

[0133] In the interlayer film, the cross-sectional shape in the thickness direction of the first resin layer may be wedge-shaped or rectangular. The cross-sectional shape in the thickness direction of the first resin layer is preferably wedge-shaped. In the interlayer film, the cross-sectional shape in the thickness direction of the second resin layer may be wedge-shaped or rectangular. The cross-sectional shape in the thickness direction of the second resin layer is preferably wedge-shaped.

[0134] Hereinafter, each material that can be used for the interlayer film according to the present invention will be described in detail.

[0135] (thermoplastic resin) The interlayer film contains a resin (hereinafter may be referred to as resin (0)). The interlayer film preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (0)). The interlayer film preferably contains a polyvinyl acetal resin (hereinafter may be referred to as polyvinyl acetal resin (0)) as the thermoplastic resin (0). The first resin layer preferably contains a resin (hereinafter may be referred to as resin (1)). The first resin layer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (1)). The first resin layer preferably contains a polyvinyl acetal resin (hereinafter may be referred to as polyvinyl acetal resin (1)) as the thermoplastic resin (1). The second resin layer contains a resin (hereinafter may be referred to as resin (2)). The second resin layer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (2)). The second resin layer preferably contains a polyvinyl acetal resin (hereinafter, sometimes referred to as polyvinyl acetal resin (2)) as the thermoplastic resin (2). The resin (1) and the resin (2) may be the same or different. The thermoplastic resin (1) and the thermoplastic resin (2) may be the same or different. The thermoplastic resin (1) and the thermoplastic resin (2) are preferably both polyvinyl acetal resins. The polyvinyl acetal resin (1) and the polyvinyl acetal resin (2) may be the same or different. The thermoplastic resin (0), the thermoplastic resin (1), and the thermoplastic resin (2) may each be used alone or in combination of two or more. The polyvinyl acetal resin (0), the polyvinyl acetal resin (1), and the polyvinyl acetal resin (2) may each be used alone or in combination of two or more.

[0136] Examples of the thermoplastic resin include polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic acid copolymer resin, polyurethane resin, ionomer resin, polyvinyl alcohol resin, etc. Thermoplastic resins other than these may also be used.

[0137] The polyvinyl acetal resin can be produced, for example, by acetalizing polyvinyl alcohol (PVA) with an aldehyde. The polyvinyl acetal resin is preferably an acetalized product of polyvinyl alcohol. The polyvinyl alcohol can be obtained, for example, by saponifying polyvinyl acetate. The degree of saponification of the polyvinyl alcohol is generally within the range of 70 mol% to 99.9 mol%.

[0138] The average degree of polymerization of the polyvinyl alcohol (PVA) is preferably 200 or more, more preferably 500 or more, even more preferably 1500 or more, even more preferably 1600 or more, particularly preferably 2600 or more, and most preferably 2700 or more, and is preferably 5000 or less, more preferably 4000 or less, and even more preferably 3500 or less. When the average degree of polymerization is at least the lower limit, the penetration resistance of the laminated glass is further improved. When the average degree of polymerization is at most the upper limit, the interlayer film can be easily formed.

[0139] The average degree of polymerization of the polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Testing method for polyvinyl alcohol."

[0140] The number of carbon atoms in the acetal group contained in the polyvinyl acetal resin is not particularly limited. The aldehyde used in producing the polyvinyl acetal resin is not particularly limited. The number of carbon atoms in the acetal group in the polyvinyl acetal resin is preferably 3 to 5, and more preferably 3 or 4. When the number of carbon atoms in the acetal group in the polyvinyl acetal resin is 3 or more, the glass transition temperature of the interlayer film becomes sufficiently low. The number of carbon atoms in the acetal group in the polyvinyl acetal resin may be 4 or 5.

[0141] The aldehyde is not particularly limited. Generally, an aldehyde having 1 to 10 carbon atoms is suitably used. Examples of the aldehyde having 1 to 10 carbon atoms include propionaldehyde, n-butylaldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexylaldehyde, n-octylaldehyde, n-nonylaldehyde, n-decylaldehyde, formaldehyde, acetaldehyde, and benzaldehyde. The aldehyde is preferably propionaldehyde, n-butylaldehyde, isobutyraldehyde, n-hexylaldehyde, or n-valeraldehyde, more preferably propionaldehyde, n-butylaldehyde, or isobutyraldehyde, and even more preferably n-butylaldehyde. The above aldehydes may be used alone or in combination of two or more.

[0142] The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin (0) is preferably 15 mol% or more, more preferably 18 mol% or more, and preferably 40 mol% or less, more preferably 35 mol% or less. When the hydroxyl group content is equal to or greater than the lower limit, the adhesive strength of the interlayer film is further increased. When the hydroxyl group content is equal to or less than the upper limit, the flexibility of the interlayer film is increased, making it easier to handle.

[0143] The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin (1) is preferably 17 mol% or more, more preferably 20 mol% or more, and even more preferably 22 mol% or more. The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin (1) is preferably 30 mol% or less, more preferably 28 mol% or less, even more preferably 27 mol% or less, even more preferably 25 mol% or less, particularly preferably less than 25 mol%, and most preferably 24 mol% or less. When the hydroxyl group content is equal to or greater than the lower limit, the mechanical strength of the interlayer film is further increased. In particular, when the hydroxyl group content of the polyvinyl acetal resin (1) is 20 mol% or more, the reaction efficiency is high and productivity is excellent. When the hydroxyl group content is 30 mol% or less, the sound insulation of the laminated glass is further increased, and when it is 28 mol% or less, the sound insulation is further increased. Furthermore, when the hydroxyl group content is equal to or less than the upper limit, the flexibility of the interlayer film is increased, making it easier to handle.

[0144] The hydroxyl group content of the polyvinyl acetal resin (2) is preferably 25 mol% or more, more preferably 28 mol% or more, even more preferably 30 mol% or more, even more preferably more than 31 mol%, even more preferably 31.5 mol% or more, particularly preferably 32 mol% or more, and most preferably 33 mol% or more. The hydroxyl group content of the polyvinyl acetal resin (2) 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 at least the lower limit, the adhesive strength of the interlayer film is further increased. On the other hand, when the hydroxyl group content is at most the upper limit, the flexibility of the interlayer film is increased, making the interlayer film easier to handle.

[0145] From the viewpoint of further improving sound insulation, the hydroxyl group content of the polyvinyl acetal resin (1) is preferably lower than the hydroxyl group content of the polyvinyl acetal resin (2). From the viewpoint of still further improving sound insulation, the absolute value of the difference between the hydroxyl group content of the polyvinyl acetal resin (1) and the hydroxyl group content of the polyvinyl acetal resin (2) is preferably 1 mol% or more, more preferably 5 mol% or more, even more preferably 9 mol% or more, particularly preferably 10 mol% or more, and most preferably 12 mol% or more.

[0146] The hydroxyl group content of the polyvinyl acetal resin is the molar fraction calculated by dividing the number of ethylene groups having hydroxyl groups by the total number of ethylene groups in the main chain, and is expressed as a percentage. The number of ethylene groups having hydroxyl groups can be measured, for example, in accordance with JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0147] The degree of acetylation (amount of acetyl groups) of the polyvinyl acetal resin (0) is preferably 0.1 mol% or more, more preferably 0.3 mol% or more, even more preferably 0.5 mol% or more, and preferably 30 mol% or less, more preferably 25 mol% or less, and even more preferably 20 mol% or less. When the degree of acetylation is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is improved. When the degree of acetylation is equal to or less than the upper limit, the moisture resistance of the interlayer film and laminated glass is improved.

[0148] The degree of acetylation (amount of acetyl groups) of the polyvinyl acetal resin (1) is preferably 0.01 mol% or more, more preferably 0.1 mol% or more, even more preferably 7 mol% or more, even more preferably 9 mol% or more, and is preferably 30 mol% or less, more preferably 25 mol% or less, even more preferably 24 mol% or less, and particularly preferably 20 mol% or less. When the degree of acetylation is at least the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is improved. When the degree of acetylation is at most the upper limit, the moisture resistance of the interlayer film and laminated glass is improved. In particular, when the degree of acetylation of the polyvinyl acetal resin (1) is 0.1 mol% or more and 25 mol% or less, excellent penetration resistance is achieved.

[0149] The degree of acetylation of the polyvinyl acetal resin (2) is preferably 0.01 mol% or more, more preferably 0.5 mol% or more, and preferably 10 mol% or less, more preferably 2 mol% or less. When the degree of acetylation is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is improved. When the degree of acetylation is equal to or less than the upper limit, the moisture resistance of the interlayer film and laminated glass is improved.

[0150] The degree of acetylation is a molar fraction calculated by dividing the amount of ethylene groups having acetyl groups by the total amount of ethylene groups in the main chain, and is expressed as a percentage. The amount of ethylene groups having acetyl groups can be measured, for example, in accordance with JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0151] The degree of acetalization of the polyvinyl acetal resin (0) (the degree of butyralization in the case of a polyvinyl butyral resin) is preferably 60 mol% or more, more preferably 63 mol% or more, and preferably 85 mol% or less, more preferably 75 mol% or less, and even more preferably 70 mol% or less. When the degree of acetalization is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is increased. When the degree of acetalization is equal to or less than the upper limit, the reaction time required to produce the polyvinyl acetal resin is shortened.

[0152] The degree of acetalization of the polyvinyl acetal resin (1) (the degree of butyralization in the case of a polyvinyl butyral resin) is preferably 47 mol% or more, more preferably 60 mol% or more, and preferably 85 mol% or less, more preferably 80 mol% or less, and even more preferably 75 mol% or less. When the degree of acetalization is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is increased. When the degree of acetalization is equal to or less than the upper limit, the reaction time required to produce the polyvinyl acetal resin is shortened.

[0153] The degree of acetalization of the polyvinyl acetal resin (2) (the degree of butyralization in the case of a polyvinyl butyral resin) is preferably 55 mol% or more, more preferably 60 mol% or more, and preferably 75 mol% or less, more preferably 71 mol% or less. When the degree of acetalization is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is increased. When the degree of acetalization is equal to or less than the upper limit, the reaction time required to produce the polyvinyl acetal resin is shortened.

[0154] The degree of acetalization is determined as follows. First, the amount of ethylene groups to which hydroxyl groups are bonded and the amount of ethylene groups to which acetyl groups are bonded are subtracted from the total amount of ethylene groups in the main chain to determine the value. The obtained value is divided by the total amount of ethylene groups in the main chain to determine the molar fraction. The value expressed as a percentage of this molar fraction is the degree of acetalization.

[0155] The hydroxyl group content (hydroxyl group amount), acetalization degree (butyralization degree), and acetylation degree are preferably calculated from the results of measurements performed according to JIS K6728 "Testing Methods for Polyvinyl Butyral." However, measurements according to ASTM D1396-92 may also be used. When the polyvinyl acetal resin is a polyvinyl butyral resin, the hydroxyl group content (hydroxyl group amount), acetalization degree (butyralization degree), and acetylation degree can be calculated from the results of measurements performed according to JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0156] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the interlayer film is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the interlayer film may be 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin in the interlayer film is preferably polyvinyl acetal resin.

[0157] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the first resin layer is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the first resin layer may be 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin of the first resin layer is preferably polyvinyl acetal resin.

[0158] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the second resin layer is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the second resin layer may be 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin of the second resin layer is preferably polyvinyl acetal resin.

[0159] (plasticizer) From the viewpoint of further increasing the adhesive strength of the interlayer film, the interlayer film according to the present invention preferably contains a plasticizer (hereinafter, sometimes referred to as plasticizer (0)). The first resin layer preferably contains a plasticizer (hereinafter, sometimes referred to as plasticizer (1)). The second resin layer preferably contains a plasticizer (hereinafter, sometimes referred to as plasticizer (2)). When the thermoplastic resin contained in the interlayer film is a polyvinyl acetal resin, it is particularly preferable that the interlayer film (each layer) contains a plasticizer. The layer containing the polyvinyl acetal resin preferably contains a plasticizer.

[0160] The plasticizer is not particularly limited. Conventionally known plasticizers can be used as the plasticizer. Only one type of plasticizer can be used, or two or more types can be used in combination.

[0161] Examples of the plasticizer include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, organic phosphate plasticizers, and organic phosphite plasticizers. The plasticizer is preferably an organic ester plasticizer. The plasticizer is preferably a liquid plasticizer.

[0162] Examples of the monobasic organic acid ester include glycol esters obtained by reacting glycol with a monobasic organic acid. Examples of the glycol include triethylene glycol, tetraethylene glycol, and tripropylene glycol. Examples of the monobasic organic acid include butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptyl acid, n-octylic acid, 2-ethylhexyl acid, n-nonylic acid, decylic acid, and benzoic acid.

[0163] Examples of the polybasic organic acid ester include ester compounds of a polybasic organic acid and an alcohol having a linear or branched structure and having 4 to 8 carbon atoms. Examples of the polybasic organic acid include adipic acid, sebacic acid, and azelaic acid.

[0164] Examples of the organic ester plasticizer include triethylene glycol di-2-ethylpropanoate, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, and diethylene glycol di-2-ethylbutylene. Examples of suitable organic ester plasticizers include diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprylate, diethylene glycol dibenzoate, dipropylene glycol dibenzoate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, a mixture of heptyl adipate and nonyl adipate, diisononyl adipate, diisodecyl adipate, heptylnonyl adipate, dibutyl sebacate, oil-modified alkyd sebacate, and a mixture of a phosphate ester and an adipate. Organic ester plasticizers other than those listed above may also be used as the organic ester plasticizer. Furthermore, adipic acid esters other than the above-mentioned adipic acid esters may also be used as the adipic acid ester.

[0165] Examples of the organic phosphoric acid plasticizer include tributoxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate.

[0166] The plasticizer is preferably a diester plasticizer represented by the following formula (1):

[0167] [ka]

[0168] In the above formula (1), R1 and R2 each represent an organic group having 2 to 10 carbon atoms, R3 represents an ethylene group, an isopropylene group, or an n-propylene group, and p represents an integer of 3 to 10. In the above formula (1), R1 and R2 each preferably represent an organic group having 5 to 10 carbon atoms, and more preferably represent an organic group having 6 to 10 carbon atoms.

[0169] The plasticizer preferably includes triethylene glycol di-2-ethylhexanoate (3GO), triethylene glycol di-2-ethylbutyrate (3GH), or triethylene glycol di-2-ethylpropanoate, more preferably triethylene glycol di-2-ethylhexanoate (3GO) or triethylene glycol di-2-ethylbutyrate (3GH), and even more preferably triethylene glycol di-2-ethylhexanoate (3GO).

[0170] The content of the plasticizer (0) relative to 100 parts by weight of the thermoplastic resin (0) in the interlayer film is defined as the content (0). The content (0) is preferably 5 parts by weight or more, more preferably 25 parts by weight or more, even more preferably 30 parts by weight or more, and preferably 100 parts by weight or less, more preferably 60 parts by weight or less, even more preferably 50 parts by weight or less. When the content (0) is at least the lower limit, the penetration resistance of the laminated glass is further improved. When the content (0) is at most the upper limit, the transparency of the interlayer film is further improved.

[0171] In the first resin layer, 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, and even more preferably 60 parts by weight or more. The content (1) is preferably 100 parts by weight or less, more preferably 90 parts by weight or less, even more preferably 85 parts by weight or less, and particularly preferably 80 parts by weight or less. When the content (1) is at least the lower limit, the flexibility of the interlayer film is increased, making the interlayer film easier to handle. When the content (1) is at most the upper limit, the penetration resistance of the laminated glass is further improved.

[0172] In the second resin layer, the content of the plasticizer (2) relative to 100 parts by weight of the thermoplastic resin (2) is defined as content (2). The content (2) is preferably 5 parts by weight or more, more preferably 10 parts by weight or more, even more preferably 15 parts by weight or more, even more preferably 20 parts by weight or more, particularly preferably 24 parts by weight or more, and most preferably 25 parts by weight or more. The content (2) is preferably 45 parts by weight or less, more preferably 40 parts by weight or less, even more preferably 35 parts by weight or less, particularly preferably 32 parts by weight or less, and most preferably 30 parts by weight or less. When the content (2) is at least the lower limit, the flexibility of the interlayer film is increased, making it easier to handle. When the content (2) is at most the upper limit, the penetration resistance of the laminated glass is further improved.

[0173] In order to improve the sound insulation of the laminated glass, the content (1) is preferably greater than the content (2).

[0174] From the viewpoint of further improving the sound insulation of the laminated glass, the absolute value of the difference between the content (2) and the content (1) is preferably at least 10 parts by weight, more preferably at least 15 parts by weight, even more preferably at least 20 parts by weight, and is preferably at most 80 parts by weight, more preferably at most 75 parts by weight, even more preferably at most 70 parts by weight.

[0175] (heat-shielding material) The intermediate film preferably contains a heat-shielding material. The first resin layer preferably contains a heat-shielding material. The second resin layer preferably contains a heat-shielding material. Only one type of heat-shielding material may be used, or two or more types may be used in combination.

[0176] The heat-shielding material preferably contains at least one component X selected from a phthalocyanine compound, a naphthalocyanine compound, and an anthracyanine compound, or contains heat-shielding particles. In this case, the heat-shielding material may contain both the component X and the heat-shielding particles.

[0177] Ingredient X: The interlayer film preferably contains at least one component X selected from a phthalocyanine compound, a naphthalocyanine compound, and an anthracyanine compound. The first resin layer preferably contains the component X. The second resin layer preferably contains the component X. The component X is a heat-shielding material. Only one type of the component X may be used, or two or more types may be used in combination.

[0178] There are no particular restrictions on the component X. As the component X, conventionally known phthalocyanine compounds, naphthalocyanine compounds, and anthracyanine compounds can be used.

[0179] Examples of the component X include phthalocyanine, phthalocyanine derivatives, naphthalocyanine, naphthalocyanine derivatives, anthracyanine, and anthracyanine derivatives. The phthalocyanine compound and the phthalocyanine derivative each preferably have a phthalocyanine skeleton. The naphthalocyanine compound and the naphthalocyanine derivative each preferably have a naphthalocyanine skeleton. The anthracyanine compound and the anthracyanine derivative each preferably have an anthracyanine skeleton.

[0180] From the viewpoint of further improving the heat-shielding properties of the interlayer film and laminated glass, the above-mentioned component X is preferably at least one selected from the group consisting of phthalocyanine, phthalocyanine derivatives, naphthalocyanine, and naphthalocyanine derivatives, and more preferably at least one of phthalocyanine and phthalocyanine derivatives.

[0181] From the viewpoint of effectively improving the heat-shielding properties and maintaining a higher visible light transmittance for a long period of time, the above-mentioned component X preferably contains a vanadium atom or a copper atom. The above-mentioned component X preferably contains a vanadium atom, and also preferably contains a copper atom. The above-mentioned component X is more preferably at least one of a phthalocyanine containing a vanadium atom or a copper atom, and a derivative of a phthalocyanine containing a vanadium atom or a copper atom. From the viewpoint of further improving the heat-shielding properties of the interlayer film and laminated glass, the above-mentioned component X preferably has a structural unit in which an oxygen atom is bonded to a vanadium atom.

[0182] The content of component X in 100 wt% of the interlayer film or 100 wt% of the layer containing component X (first resin layer or second resin layer) is preferably 0.001 wt% or more, more preferably 0.005 wt% or more, even more preferably 0.01 wt% or more, and particularly preferably 0.02 wt% or more. The content of component X in 100 wt% of the interlayer film or 100 wt% of the layer containing component X (first resin layer or second resin layer) is preferably 0.2 wt% or less, more preferably 0.1 wt% or less, even more preferably 0.05 wt% or less, and particularly preferably 0.04 wt% or less. When the content of component X is equal to or greater than the above lower limit and equal to or less than the above upper limit, the heat-shielding properties and visible light transmittance are sufficiently high. For example, a visible light transmittance of 70% or more is possible.

[0183] Heat-shielding particles: The intermediate film preferably contains heat-shielding particles. The first resin layer preferably contains heat-shielding particles. The second resin layer preferably contains heat-shielding particles. The heat-shielding particles are a heat-shielding substance. Use of the heat-shielding particles can effectively block infrared rays (heat rays). Only one type of the heat-shielding particles may be used, or two or more types may be used in combination.

[0184] From the viewpoint of further enhancing the heat-shielding properties of the laminated glass, the heat-shielding particles are more preferably metal oxide particles.The heat-shielding particles are preferably particles formed from a metal oxide (metal oxide particles).

[0185] Infrared rays, which have wavelengths longer than visible light (780 nm or longer), have a smaller amount of energy than ultraviolet rays. However, infrared rays have a large thermal effect, and when infrared rays are absorbed by a substance, they are released as heat. For this reason, infrared rays are generally called heat rays. By using the above-mentioned heat-shielding particles, infrared rays (heat rays) can be effectively blocked. Heat-shielding particles refer to particles that can absorb infrared rays.

[0186] Examples of the heat-shielding particles include metal oxide particles such as aluminum-doped tin oxide particles, indium-doped tin oxide particles, antimony-doped tin oxide particles (ATO particles), gallium-doped zinc oxide particles (GZO particles), indium-doped zinc oxide particles (IZO particles), aluminum-doped zinc oxide particles (AZO particles), niobium-doped titanium oxide particles, tungsten oxide particles, tin-doped indium oxide particles (ITO particles), tin-doped zinc oxide particles, and silicon-doped zinc oxide particles, as well as lanthanum hexaboride (LaB6) particles. Other heat-shielding particles may also be used. The heat-shielding particles are preferably metal oxide particles because of their high heat-shielding function, and more preferably ATO particles, GZO particles, IZO particles, ITO particles, or tungsten oxide particles. In particular, the heat-shielding particles are preferably ITO particles or tungsten oxide particles because of their high heat-shielding function and ease of availability.

[0187] From the viewpoint of further improving the heat-shielding properties of the interlayer film and laminated glass, the tungsten oxide particles are preferably metal-doped tungsten oxide particles. The "tungsten oxide particles" include metal-doped tungsten oxide particles. Examples of the metal-doped tungsten oxide particles include sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles, thallium-doped tungsten oxide particles, and rubidium-doped tungsten oxide particles.

[0188] From the viewpoint of further improving the heat-shielding properties of the interlayer film and laminated glass, cesium-doped tungsten oxide particles are particularly preferred. From the viewpoint of further improving the heat-shielding properties of the interlayer film and laminated glass, the cesium-doped tungsten oxide particles are represented by the formula: Cs 0.33 Tungsten oxide particles represented by WO3 are preferred.

[0189] The average particle size of the heat-shielding particles is preferably 0.01 μm or more, more preferably 0.02 μm or more, and preferably 0.1 μm or less, more preferably 0.05 μm or less. When the average particle size is equal to or greater than the lower limit, the heat ray shielding property is sufficiently high. When the average particle size is equal to or less than the upper limit, the dispersibility of the heat-shielding particles is high.

[0190] The "average particle size" refers to the volume-average particle size. The average particle size can be measured using a particle size distribution analyzer ("UPA-EX150" manufactured by Nikkiso Co., Ltd.) or the like.

[0191] In 100 wt% of the interlayer film or 100 wt% of the layer containing the heat-shielding particles (first resin layer or second resin layer), the content of the heat-shielding particles (particularly the content of tungsten oxide particles) is preferably 0.01 wt% or more, more preferably 0.1 wt% or more, even more preferably 1 wt% or more, and particularly preferably 1.5 wt% or more. In 100 wt% of the interlayer film or 100 wt% of the layer containing the heat-shielding particles (first resin layer or second resin layer), the content of the heat-shielding particles (particularly the content of tungsten oxide particles) is preferably 6 wt% or less, more preferably 5.5 wt% or less, even more preferably 4 wt% or less, particularly preferably 3.5 wt% or less, and most preferably 3 wt% or less. When the content of the heat-shielding particles is at least the above lower limit and at most the above upper limit, the heat shielding properties are sufficiently high and the visible light transmittance is sufficiently high.

[0192] (metal salts) The interlayer film preferably contains at least one metal salt (hereinafter sometimes referred to as metal salt M) selected from alkali metal salts and alkaline earth metal salts. The first resin layer preferably contains the metal salt M. The second resin layer preferably contains the metal salt M. Alkaline earth metals refer to six metals: Be, Mg, Ca, Sr, Ba, and Ra. The use of the metal salt M makes it easy to control the adhesion between the interlayer film and a laminated glass member such as a glass plate, or the adhesion between each layer in the interlayer film. Only one type of the metal salt M may be used, or two or more types may be used in combination.

[0193] The metal salt M preferably contains at least one metal selected from the group consisting of Li, Na, K, Rb, Cs, Mg, Ca, Sr, and Ba. The metal salt contained in the interlayer film preferably contains at least one metal selected from the group consisting of K and Mg.

[0194] Furthermore, alkali metal salts of organic acids having 2 to 16 carbon atoms and alkaline earth metal salts of organic acids having 2 to 16 carbon atoms can be used as the metal salt M. The metal salt M may include a magnesium salt of a carboxylic acid having 2 to 16 carbon atoms or a potassium salt of a carboxylic acid having 2 to 16 carbon atoms.

[0195] Examples of the magnesium salts of carboxylic acids having 2 to 16 carbon atoms and the potassium salts of carboxylic acids having 2 to 16 carbon atoms include magnesium acetate, potassium acetate, magnesium propionate, potassium propionate, magnesium 2-ethylbutyrate, potassium 2-ethylbutanoate, magnesium 2-ethylhexanoate, and potassium 2-ethylhexanoate.

[0196] The total content of Mg and K in the interlayer film containing the metal salt M or the layer containing the metal salt M (first resin layer or second resin layer) is preferably 5 ppm or more, more preferably 10 ppm or more, even more preferably 20 ppm or more, and is preferably 300 ppm or less, more preferably 250 ppm or less, even more preferably 200 ppm or less. When the total content of Mg and K is equal to or more than the above lower limit and equal to or less than the above upper limit, the adhesion between the interlayer film and the glass plate or the adhesion between the layers in the interlayer film can be more effectively controlled.

[0197] (UV screening agent) The interlayer film preferably contains an ultraviolet blocking agent. The first resin layer preferably contains an ultraviolet blocking agent. The second resin layer preferably contains an ultraviolet blocking agent. By using an ultraviolet blocking agent, the visible light transmittance is more unlikely to decrease even when the interlayer film and laminated glass are used for a long period of time. The ultraviolet blocking agents may be used alone or in combination of two or more.

[0198] The ultraviolet screening agent includes an ultraviolet absorbing agent, and the ultraviolet screening agent is preferably an ultraviolet absorbing agent.

[0199] Examples of the ultraviolet screening agent include ultraviolet screening agents containing metal atoms, ultraviolet screening agents containing metal oxides, ultraviolet screening agents having a benzotriazole structure (benzotriazole compounds), ultraviolet screening agents having a benzophenone structure (benzophenone compounds), ultraviolet screening agents having a triazine structure (triazine compounds), ultraviolet screening agents having a malonic acid ester structure (malonic acid ester compounds), ultraviolet screening agents having an oxalic acid anilide structure (oxalic acid anilide compounds), and ultraviolet screening agents having a benzoate structure (benzoate compounds).

[0200] Examples of the ultraviolet shielding agent containing the metal atom include platinum particles, platinum particles whose surfaces are coated with silica, palladium particles, and palladium particles whose surfaces are coated with silica. The ultraviolet shielding agent is preferably not a heat-shielding particle.

[0201] The ultraviolet screening agent is preferably an ultraviolet screening agent having a benzotriazole structure, an ultraviolet screening agent having a benzophenone structure, an ultraviolet screening agent having a triazine structure, or an ultraviolet screening agent having a benzoate structure, more preferably an ultraviolet screening agent having a benzotriazole structure or an ultraviolet screening agent having a benzophenone structure, and even more preferably an ultraviolet screening agent having a benzotriazole structure.

[0202] Examples of the ultraviolet screening agent containing a metal oxide include zinc oxide, titanium oxide, and cerium oxide. Furthermore, the surface of the ultraviolet screening agent containing a metal oxide may be coated. Examples of the coating material for the surface of the ultraviolet screening agent containing a metal oxide include insulating metal oxides, hydrolyzable organosilicon compounds, and silicone compounds.

[0203] Examples of the insulating metal oxide include silica, alumina, zirconia, etc. The insulating metal oxide has a band gap energy of, for example, 5.0 eV or more.

[0204] Examples of the ultraviolet screening agent having a benzotriazole structure include 2-(2'-hydroxy-5'-methylphenyl)benzotriazole ("Tinuvin P" manufactured by BASF), 2-(2'-hydroxy-3',5'-di-t-butylphenyl)benzotriazole ("Tinuvin 320" manufactured by BASF), 2-(2'-hydroxy-3'-t-butyl-5-methylphenyl)-5-chlorobenzotriazole ("Tinuvin 326" manufactured by BASF), and 2-(2'-hydroxy-3',5'-di-amylphenyl)benzotriazole ("Tinuvin 328" manufactured by BASF). Because of their excellent ultraviolet screening performance, the ultraviolet screening agent is preferably an ultraviolet screening agent having a benzotriazole structure containing a halogen atom, and more preferably an ultraviolet screening agent having a benzotriazole structure containing a chlorine atom.

[0205] Examples of the ultraviolet screening agent having a benzophenone structure include octabenzone ("Chimassorb 81" manufactured by BASF).

[0206] Examples of the ultraviolet screening agent having a triazine structure include "LA-F70" manufactured by ADEKA Corporation and 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol ("Tinuvin 1577FF" manufactured by BASF).

[0207] Examples of the ultraviolet screening agent having a malonic acid ester structure include dimethyl 2-(p-methoxybenzylidene)malonate, tetraethyl-2,2-(1,4-phenylenedimethylidene)bismalonate, and 2-(p-methoxybenzylidene)-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)malonate.

[0208] Commercially available UV screening agents having the malonic acid ester structure include Hostavin B-CAP, Hostavin PR-25, and Hostavin PR-31 (all manufactured by Clariant).

[0209] Examples of the ultraviolet screening agent having the oxalic acid anilide structure include oxalic acid diamides having an aryl group or the like substituted on the nitrogen atom, such as N-(2-ethylphenyl)-N'-(2-ethoxy-5-t-butylphenyl) oxalic acid diamide, N-(2-ethylphenyl)-N'-(2-ethoxy-phenyl) oxalic acid diamide, and 2-ethyl-2'-ethoxy-oxalanilide ("Sanduvor VSU" manufactured by Clariant).

[0210] Examples of the ultraviolet screening agent having a benzoate structure include 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate ("Tinuvin 120" manufactured by BASF).

[0211] The content of the ultraviolet screening agent and the content of the benzotriazole compound in 100 wt% of the interlayer film or 100 wt% of the layer containing the ultraviolet screening agent (first resin layer or second resin layer) are preferably 0.1 wt% or more, more preferably 0.2 wt% or more, even more preferably 0.3 wt% or more, and particularly preferably 0.5 wt% or more. In this case, the decrease in visible light transmittance after the lapse of time is further suppressed. The content of the ultraviolet screening agent and the content of the benzotriazole compound in 100 wt% of the interlayer film or 100 wt% of the layer containing the ultraviolet screening agent (first resin layer or second resin layer) are preferably 2.5 wt% or less, more preferably 2 wt% or less, even more preferably 1 wt% or less, and particularly preferably 0.8 wt% or less. In particular, by having the content of the ultraviolet screening agent be 0.2 wt% or more in 100 wt% of the layer containing the ultraviolet screening agent, the decrease in visible light transmittance of the interlayer film and laminated glass after the lapse of time can be significantly suppressed.

[0212] (antioxidant) The interlayer preferably contains an antioxidant. The first resin layer preferably contains an antioxidant. The second resin layer preferably contains an antioxidant. Only one type of antioxidant may be used, or two or more types may be used in combination.

[0213] Examples of the antioxidant include phenol-based antioxidants, sulfur-based antioxidants, and phosphorus-based antioxidants. The phenol-based antioxidants are antioxidants having a phenol skeleton. The sulfur-based antioxidants are antioxidants containing sulfur atoms. The phosphorus-based antioxidants are antioxidants containing phosphorus atoms.

[0214] The antioxidant is preferably a phenol-based antioxidant or a phosphorus-based antioxidant.

[0215] Examples of the phenolic antioxidant include 2,6-di-t-butyl-p-cresol (BHT), butylhydroxyanisole (BHA), 2,6-di-t-butyl-4-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis-(4-methyl-6-butylphenol), 2,2'-methylenebis-(4-ethyl-6-t-butylphenol), 4,4'-butylidene-bis-(3-methyl-6-t-butylphenol), 1,1,3-tris-(2-methyl-hydroxy-5- t-butylphenyl)butane, tetrakis[methylene-3-(3',5'-butyl-4-hydroxyphenyl)propionate]methane, 1,3,3-tris-(2-methyl-4-hydroxy-5-t-butylphenol)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, bis(3,3'-t-butylphenol)butyric acid glycol ester, and bis(3-t-butyl-4-hydroxy-5-methylbenzenepropanoate)ethylenebis(oxyethylene). One or more of these antioxidants are preferably used.

[0216] Examples of the phosphorus-based antioxidant include tridecyl phosphite, tris(tridecyl)phosphite, triphenyl phosphite, trinonylphenyl phosphite, bis(tridecyl)pentaerythritol diphosphite, bis(decyl)pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)phosphite, bis(2,4-di-t-butyl-6-methylphenyl)ethyl ester phosphorous acid, and 2,2'-methylenebis(4,6-di-t-butyl-1-phenyloxy)(2-ethylhexyloxy)phosphorus, etc. One or more of these antioxidants are preferably used.

[0217] Commercially available antioxidants include, for example, "IRGANOX 245" manufactured by BASF, "IRGAFOS 168" manufactured by BASF, "IRGAFOS 38" manufactured by BASF, "Sumilizer BHT" manufactured by Sumitomo Chemical Co., Ltd., "H-BHT" manufactured by Sakai Chemical Industry Co., Ltd., and "IRGANOX 1010" manufactured by BASF.

[0218] In order to maintain high visible light transmittance of the interlayer film and laminated glass for a long period of time, the content of the antioxidant in 100% by weight of the interlayer film or 100% by weight of the layer containing the antioxidant (first resin layer or second resin layer) is preferably 0.03% by weight or more, and more preferably 0.1% by weight or more. Furthermore, since the effect of adding an antioxidant becomes saturated, the content of the antioxidant in 100% by weight of the interlayer film or 100% by weight of the layer containing the antioxidant is preferably 2% by weight or less.

[0219] (Other ingredients) The interlayer film, the first resin layer, and the second resin layer may each contain, as necessary, additives such as a coupling agent, a dispersant, a surfactant, a flame retardant, an antistatic agent, an adhesion modifier other than a metal salt, a moisture-resistant agent, a fluorescent brightener, an infrared absorber, etc. These additives may be used alone or in combination of two or more.

[0220] (Other details of interlayer film for laminated glass) The interlayer film may be wound into a roll of the interlayer film. The roll may include a winding core and the interlayer film wound around the outer periphery of the winding core.

[0221] The interlayer film preferably has an uneven shape on at least one of its two surfaces. The interlayer film more preferably has an uneven shape on both surfaces. The method for forming the uneven shape is not particularly limited, and examples thereof include lip embossing (melt fracture), embossing roll, calender roll, and profile extrusion.

[0222] The interlayer preferably has a surface texture formed by melt fracture or embossing roll, more preferably by melt fracture or embossing roll at a linear pressure of 0.10 kN / cm or less. By using the above methods, a good texture can be imparted to the surface layer even if it is relatively thin, and as a result, optical distortion can be effectively suppressed.

[0223] From the viewpoint of forming a large number of uneven shapes that are quantitatively consistent uneven patterns, the interlayer film preferably has uneven shapes formed on its surface by an embossing roll method.

[0224] (Laminated glass) The laminated glass of the present invention includes a first laminated glass member, a second laminated glass member, and the above-mentioned interlayer film for laminated glass. In the laminated glass of the present invention, the interlayer film for laminated glass is disposed between the first laminated glass member and the second laminated glass member.

[0225] The laminated glass is, for example, a head-up display. When the laminated glass is a head-up display, the laminated glass has a display area for the head-up display. The display area is an area where information can be displayed well.

[0226] The laminated glass is preferably a head-up display (HUD).

[0227] A head-up display system can be obtained using the head-up display. The head-up display system includes the laminated glass and a light source device for irradiating the laminated glass with light for image display. The light source device can be attached to the dashboard of a vehicle, for example. An image can be displayed by irradiating the display area of ​​the laminated glass with light from the light source device.

[0228] figure 5 2 is a cross-sectional view schematically illustrating an example of laminated glass using the interlayer film for laminated glass shown in FIG. 1.

[0229] figure 5 The laminated glass 20 shown in Figure 1 comprises a first laminated glass member 31, a second laminated glass member 32, and an interlayer film 10. The interlayer film 10 is disposed and sandwiched between the first laminated glass member 31 and the second laminated glass member 32. The first laminated glass member 31 is laminated on a first surface (one surface) of the interlayer film 10. The second laminated glass member 32 is laminated on a second surface (the other surface) opposite the first surface of the interlayer film 10. The first laminated glass member 31 is laminated on the outer surface of the second resin layer 21 of the interlayer film 10. The second laminated glass member 32 is laminated on the outer surface of the second resin layer 23 of the interlayer film 10.

[0230] As described above, the laminated glass according to the present invention comprises a first laminated glass member, a second laminated glass member, and an interlayer film, and the interlayer film is the interlayer film for laminated glass according to the present invention.

[0231] The first laminated glass member is preferably a first glass plate, and the second laminated glass member is preferably a second glass plate.

[0232] Examples of the first and second laminated glass members include glass plates and PET (polyethylene terephthalate) films. The laminated glass includes not only laminated glass in which an interlayer film is sandwiched between two glass plates, but also laminated glass in which an interlayer film is sandwiched between a glass plate and a PET film or the like. The laminated glass is a laminate including glass plates, and preferably includes at least one glass plate. It is preferable that the first laminated glass member and the second laminated glass member are each a glass plate or a PET film, and that the laminated glass includes a glass plate as at least one of the first laminated glass member and the second laminated glass member. It is particularly preferable that both the first and second laminated glass members are glass plates.

[0233] Examples of the glass plate include inorganic glass and organic glass. Examples of the inorganic glass include float glass, heat-absorbing glass, heat-reflecting glass, polished glass, patterned glass, lined glass, and green glass. The organic glass is a synthetic resin glass that replaces inorganic glass. Examples of the organic glass include polycarbonate plates and poly(meth)acrylic resin plates. Examples of the poly(meth)acrylic resin plates include polymethyl(meth)acrylate plates.

[0234] The thickness of each of the first laminated glass member and the second laminated glass member is preferably 1 mm or more, preferably 5 mm or less, and more preferably 3 mm or less. When the laminated glass member is a glass plate, the thickness of the glass plate is preferably 0.5 mm or more, more preferably 0.7 mm or more, and preferably 5 mm or less, and more preferably 3 mm or less. When the laminated glass member is a PET film, the thickness of the PET film is preferably 0.03 mm or more, and preferably 0.5 mm or less.

[0235] The method for producing the laminated glass is not particularly limited. First, an interlayer film is sandwiched between the first laminated glass member and the second laminated glass member to obtain a laminate. Next, the air remaining between the first laminated glass member, the second laminated glass member, and the interlayer film is removed, for example, by passing the obtained laminate through a pressure roll or placing it in a rubber bag and suctioning it under reduced pressure. Thereafter, a pre-bonded laminate is obtained by pre-bonding at about 70°C to 110°C. Next, the pre-bonded laminate is placed in an autoclave or pressed at about 120°C to 150°C and a pressure of 1 MPa to 1.5 MPa to be bonded. In this manner, a laminated glass can be obtained.

[0236] The interlayer film and the laminated glass can be used in automobiles, railway vehicles, aircraft, ships, buildings, etc. The interlayer film and the laminated glass can also be used for applications other than these. The interlayer film and the laminated glass are preferably interlayer films and laminated glass for vehicles or buildings, and more preferably interlayer films and laminated glass for vehicles. The interlayer film and the laminated glass can be used for automobile windshields, side windows, rear windows, roof glass, backlight glass, etc. The interlayer film and the laminated glass are preferably used in automobiles. The interlayer film is preferably used to obtain laminated glass for automobiles.

[0237] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0238] The polyvinyl acetal resin used was acetalized using n-butylaldehyde, which has four carbon atoms. The degree of acetalization (degree of butyralization), degree of acetylation, and hydroxyl group content of the polyvinyl acetal resin were measured according to JIS K6728 "Testing Methods for Polyvinyl Butyral." Note that when measured according to ASTM D1396-92, the values ​​were similar to those obtained by the method according to JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0239] The following components were blended and thoroughly kneaded with a mixing roll to prepare compositions A1 to C1 for forming the first resin layer.

[0240] Composition A1 for forming the first resin layer: Polyvinyl acetal resin (average polymerization degree 3000, hydroxyl group content 23.8 mol%, acetylation degree 12.4 mol%, acetalization degree 63.8 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 60 parts by weight Tinuvin 326 (2-(2'-hydroxy-3'-t-butyl-5-methylphenyl)-5-chlorobenzotriazole, "Tinuvin 326" manufactured by BASF) in an amount of 0.2% by weight based on 100% by weight of the resulting first resin layer BHT (2,6-di-t-butyl-p-cresol) in an amount of 0.2% by weight based on 100% by weight of the resulting first resin layer

[0241] Composition B1 for forming the first resin layer: Polyvinyl acetal resin (average polymerization degree 2300, hydroxyl group content 22.9 mol%, acetylation degree 12.1 mol%, acetalization degree 65 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 60 parts by weight Tinuvin 326 (2-(2'-hydroxy-3'-t-butyl-5-methylphenyl)-5-chlorobenzotriazole, "Tinuvin 326" manufactured by BASF) in an amount of 0.2% by weight based on 100% by weight of the resulting first resin layer BHT (2,6-di-t-butyl-p-cresol) in an amount of 0.2% by weight based on 100% by weight of the resulting first resin layer

[0242] Composition C1 for forming the first resin layer: Polyvinyl acetal resin (average polymerization degree 3000, hydroxyl group content 26.5 mol%, acetylation degree 1 mol%, acetalization degree 72.5 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 40 parts by weight Tinuvin 326 (2-(2'-hydroxy-3'-t-butyl-5-methylphenyl)-5-chlorobenzotriazole, "Tinuvin 326" manufactured by BASF) in an amount of 0.2% by weight based on 100% by weight of the resulting first resin layer BHT (2,6-di-t-butyl-p-cresol) in an amount of 0.2% by weight based on 100% by weight of the resulting first resin layer

[0243] The following components were blended and thoroughly kneaded with a mixing roll to prepare compositions A2 to C2 for forming the second resin layer.

[0244] Composition A2 for forming the second resin layer: Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 30.3 mol%, acetylation degree 0.9 mol%, acetalization degree 68.8 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 40 parts by weight Tinuvin 326 (2-(2'-hydroxy-3'-t-butyl-5-methylphenyl)-5-chlorobenzotriazole, "Tinuvin 326" manufactured by BASF) in an amount of 0.2% by weight based on 100% by weight of the resulting second resin layer BHT (2,6-di-t-butyl-p-cresol) in an amount of 0.2% by weight based on 100% by weight of the resulting second resin layer

[0245] Composition B2 for forming the second resin layer: Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 24.7 mol%, acetylation degree 0.9 mol%, acetalization degree 74.4 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 45 parts by weight Tinuvin 326 (2-(2'-hydroxy-3'-t-butyl-5-methylphenyl)-5-chlorobenzotriazole, "Tinuvin 326" manufactured by BASF) in an amount of 0.2% by weight based on 100% by weight of the resulting second resin layer BHT (2,6-di-t-butyl-p-cresol) in an amount of 0.2% by weight based on 100% by weight of the resulting second resin layer

[0246] Composition C2 for forming the second resin layer: Polyvinyl acetal resin (average polymerization degree 2300, hydroxyl group content 24.2 mol%, acetylation degree 12.2 mol%, acetalization degree 63.6 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 45 parts by weight Tinuvin 326 (2-(2'-hydroxy-3'-t-butyl-5-methylphenyl)-5-chlorobenzotriazole, "Tinuvin 326" manufactured by BASF) in an amount of 0.2% by weight based on 100% by weight of the resulting second resin layer BHT (2,6-di-t-butyl-p-cresol) in an amount of 0.2% by weight based on 100% by weight of the resulting second resin layer

[0247] (Comparative Example 1) Preparation of interlayer: Composition A1 for forming the first resin layer and composition A2 for forming the second resin layer were co-extruded using a co-extruder, and the interlayer film was wound up to obtain a roll. In this way, a wedge-shaped interlayer film (outline shown in Figure 1) having a three-layer laminate structure of second resin layer / first resin layer / second resin layer was produced.

[0248] Example 1 Preparation of interlayer: Composition B1 for forming the first resin layer and composition B2 for forming the second resin layer were co-extruded using a co-extruder, and the interlayer film was wound up to obtain a roll. In this way, a wedge-shaped interlayer film (outline shown in Figure 1) with a five-layer laminate structure of second resin layer / first resin layer / second resin layer / first resin layer / second resin layer was produced.

[0249] (Examples 2 and 3 and Comparative Examples 2 and 3) The type of composition for forming the first resin layer, the type of composition for forming the second resin layer, and the wedge angle and thickness of the interlayer film were changed as shown in Tables 1 and 2. Other than these, a wedge-shaped interlayer film (outline shown in FIG. 1) having a five-layer laminate structure of second resin layer / first resin layer / second resin layer / first resin layer / second resin layer was produced in the same manner as in Example 1.

[0250] Example 4 A wedge-shaped interlayer film (outline shown in Figure 1) having a five-layer laminate structure of first resin layer / second resin layer / first resin layer / second resin layer / first resin layer was produced in the same manner as in Example 1, except that the lamination order of the first resin layer and the second resin layer was changed.

[0251] Comparative Example 4 A wedge-shaped interlayer film (outline shown in Figure 1) having five second resin layers was produced in the same manner as in Example 1, except that compositions A2 and B2 for forming the second resin layer were co-extruded using a co-extruder and the interlayer film was wound up to obtain a roll body.

[0252] Example 5 Composition B1 for forming the first resin layer and composition B2 for forming the second resin layer were co-extruded using a co-extruder, and the interlayer film was wound up to obtain a roll. In this way, a wedge-shaped interlayer film (outline shown in Figure 1, surface layer is the second resin layer) with a seven-layer laminate structure in which the first resin layer and the second resin layer are alternately laminated in the thickness direction was produced.

[0253] Example 6 The type of composition for forming the first resin layer, the type of composition for forming the second resin layer, the lamination order of the first and second resin layers, and the wedge angle and thickness of the interlayer film were changed as shown in Tables 3 and 4. Except for these, the same procedure as in Example 5 was used to produce a wedge-shaped interlayer film having a seven-layer laminate structure in which the first resin layers and the second resin layers were alternately laminated in the thickness direction (outline shown in FIG. 1, surface layer is the first resin layer).

[0254] (Examples 7 and 8) The type of composition for forming the first resin layer, the type of composition for forming the second resin layer, and the wedge angle and thickness of the interlayer film were changed as shown in Tables 3 and 4. Except for these, the same procedure as in Example 5 was used to produce a wedge-shaped interlayer film having a seven-layer laminate structure in which first resin layers and second resin layers were alternately laminated in the thickness direction (outline shown in Figure 1, surface layer is the second resin layer).

[0255] Example 9 Composition B1 for forming the first resin layer and composition B2 for forming the second resin layer were co-extruded using a co-extruder, and the interlayer film was wound up to obtain a roll. In this way, a wedge-shaped interlayer film (outline shown in Figure 1, surface layer is the second resin layer) with a nine-layer laminate structure in which the first resin layer and the second resin layer are alternately laminated in the thickness direction was produced.

[0256] Example 10 The type of composition for forming the first resin layer, the type of composition for forming the second resin layer, the lamination order of the first and second resin layers, and the wedge angle and thickness of the interlayer film were changed as shown in Tables 5 and 6. Except for these, a wedge-shaped interlayer film (outline shown in FIG. 1, surface layer is the first resin layer) having a nine-layer laminate structure in which the first resin layers and the second resin layers were alternately laminated in the thickness direction was produced in the same manner as in Example 9.

[0257] Example 11 The type of composition for forming the first resin layer, the type of composition for forming the second resin layer, and the wedge angle and thickness of the interlayer film were changed as shown in Tables 5 and 6. Except for these, the same procedure as in Example 9 was used to produce a wedge-shaped interlayer film having a nine-layer laminate structure in which first resin layers and second resin layers were alternately laminated in the thickness direction (outline shown in Figure 1, surface layer is the second resin layer).

[0258] Example 12 Composition B1 for forming the first resin layer and composition B2 for forming the second resin layer were co-extruded using a co-extruder, and the interlayer film was wound up to obtain a roll. In this way, a wedge-shaped interlayer film (outline shown in Figure 1, surface layer is the second resin layer) with an 11-layer laminate structure in which the first resin layer and the second resin layer are alternately laminated in the thickness direction was produced.

[0259] Example 13 The type of composition for forming the first resin layer, the type of composition for forming the second resin layer, the lamination order of the first and second resin layers, and the wedge angle and thickness of the interlayer film were changed as shown in Tables 5 and 6. Except for these, the same procedure as in Example 12 was used to produce a wedge-shaped interlayer film having an 11-layer laminate structure in which the first resin layers and the second resin layers were alternately laminated in the thickness direction (outline shown in Figure 1, surface layer is the first resin layer).

[0260] (Examples 14 and 15) The type of composition for forming the first resin layer, the type of composition for forming the second resin layer, and the wedge angle and thickness of the interlayer film were changed as shown in Tables 7 and 8. Except for these, the same procedure as in Example 12 was used to produce a wedge-shaped interlayer film having an 11-layer laminate structure in which first resin layers and second resin layers were alternately laminated in the thickness direction (outline shown in Figure 1, surface layer is the second resin layer).

[0261] (Examples 16 to 18) The wedge angle and thickness of the interlayer film were changed as shown in Tables 7 and 8. Other than these, wedge-shaped interlayer films (the surface layer was the second resin layer) with a five-layer laminate structure in which first resin layers and second resin layers were alternately laminated in the thickness direction were fabricated in the same manner as in Example 3. In Examples 16 and 17, the layer structure was such that the direction of increase in thickness of the surface layers (layers 1 and 5) was opposite to the direction of increase in thickness of the entire interlayer film. In Example 8, the layer structure was such that the direction of increase in thickness of the surface layers (layers 1 and 5) and core layer (layer 3) was opposite to the direction of increase in thickness of the entire interlayer film.

[0262] (evaluation) (1) Glass transition temperature Tg The interlayer film was stored for 12 hours at a room temperature of 23±2°C and a humidity of 25±5%. The viscoelasticity was then measured using a TA Instruments ARES-G2 viscoelasticity measuring device. Using a parallel plate with a diameter of 8 mm as the jig, measurements were performed in shear mode, with the temperature decreasing from 100°C to -20°C at a rate of 3°C / min, at a frequency of 1 Hz, and at a strain of 1%. The peak temperature of the loss tangent in the measurement results was taken as the glass transition temperature Tg (°C). The glass transition temperatures of the first resin layer and the second resin layer in the resulting interlayer film were determined in this manner.

[0263] (2) Wedge angle and thickness of the interlayer The thickness and wedge angle of the interlayer were measured using a contact-type thickness measuring instrument "TOF-4R" (manufactured by Yamabun Denki Co., Ltd.) according to the method described above. The thicknesses of the first and second resin layers were also measured using a microscope "SE-3000" (manufactured by SELMIC Co., Ltd.) according to the method described above. Furthermore, Y1 / Z, Y2 / X, Y4 / Y3, Y6 / Y5, and T2 / T1 were measured according to the method described above, and the presence or absence of a region where Y2 / X was 0.3 or less (region A) and a region where T2 / T1 was 1 or more (region C) was investigated. The average thickness of each surface layer was also calculated in a region (region B) extending from 100 mm to 400 mm from one end of the interlayer to the other.

[0264] (3) Core coming out The obtained interlayer film was wound around the outside of the winding core so that one end of the interlayer film was 10 mm from the end of the winding core to obtain a roll. The obtained interlayer film was placed vertically on a floor at room temperature of 15°C with the other end facing up, and a load of 70 kg was applied to the top of the roll to observe whether one end of the interlayer film came into contact with the floor, and the winding core was judged to have come off.

[0265] [Criteria for determining whether the core has come loose] ○: One end of the roll body does not contact the floor ×: One end of the roll body comes into contact with the floor

[0266] (4) Maximum wrinkle height An interlayer film measuring 100 cm long x 100 cm wide (roll width) was cut out from the obtained roll. The cut interlayer film was left standing on a flat surface in an environment of 15°C. 24 hours after leaving it standing, the maximum height of wrinkles occurring at the edge of the interlayer film was measured.

[0267] [Criteria for determining maximum wrinkle height] ○: Maximum wrinkle height is less than 4cm ×: Maximum height of wrinkles is 4cm or more

[0268] The configurations of the interlayer films and the results are shown in Tables 1 to 8 below.

[0269] The meanings of Y3, Y4, Y5, and Y6 in the table and the relationships below are as explained below. Y1 / Z: Y1 / Z when the thickness of one surface layer is Y1 μm and the thickness of one layer adjacent to the surface layer is Z μm Y2 / X: When the thickness of the intermediate film is X μm and the thickness of one surface layer is Y2 μm, Y2 / X Y4 / Y3: Y4 / Y3 when the average thickness of the surface layer in the region from 50 mm to 150 mm from one end to the other end is Y3 μm, and the average thickness of the surface layer in the region from 50 mm to 150 mm from the other end to the one end is Y4 μm Y6 / Y5: Y6 / Y5 when the average thickness of layers other than the surface layer in the region from 50 mm to 150 mm from one end toward the other end is Y5 μm, and the average thickness of layers other than the surface layer in the region from 50 mm to 150 mm from the other end toward the one end is Y6 μm T2 / T1: T2 / T1 when the total thickness of the first resin layer is T1 μm and the total thickness of the second resin layer is T2 μm

[0270] [Table 1]

[0271] [Table 2]

[0272]

Table 3

[0273]

Table 4

[0274]

Table 5

[0275]

Table 6

[0276]

Table 7

[0277]

Table 8

[0278] When laminated glass was produced using the interlayer films obtained in Examples 1 to 15, Examples 1 to 3, in which the surface layer was the second resin layer, had better degassing properties when producing laminated glass than Example 4, in which the surface layer was the first resin layer. Furthermore, Examples 5, 7, and 8, in which the surface layer was the second resin layer, had better degassing properties when producing laminated glass than Example 6, in which the surface layer was the first resin layer. Furthermore, Examples 9 and 11, in which the surface layer was the second resin layer, had better degassing properties when producing laminated glass than Example 10, in which the surface layer was the first resin layer. Furthermore, Examples 12, 14, and 15, in which the surface layer was the second resin layer, had better degassing properties when producing laminated glass than Example 13, in which the surface layer was the first resin layer. Furthermore, the laminated glass produced using the interlayer films of Examples 1 to 3, 5, 7 to 9, 11, 12, 14, and 15, in which the surface layer was the second resin layer, had reduced optical distortion compared to the laminated glass produced using the interlayer films of Examples 4, 6, 10, and 13, in which the surface layer was the first resin layer. [Explanation of symbols]

[0279] 10,10A,10B,10C…intermediate film 10a…one end 10b...other end 11, 11A, 11B, 11C, 12, 12A, 12B, 12C...first resin layer 20...Laminated glass 21, 21A, 21B, 21C, 22, 22A, 22B, 22C, 23, 23A, 23B, 23C...second resin layer 31...First laminated glass member 32...Second laminated glass member

Claims

1. a first end and a second end opposite the first end; The thickness of the other end is greater than the thickness of the one end, The thickness of the one end is 1.05 mm or less, a first resin layer having a glass transition temperature of less than 15°C and a second resin layer having a glass transition temperature of 15°C or higher; a region in which the total number of layers of the first resin layer and the second resin layer in the thickness direction is 5 or more; In the region having five or more layers, the thickness of one surface layer is Y １ When the thickness of one layer adjacent to the surface layer is Z μm, Y １ / Z is 1.01 or more, An interlayer film for laminated glass, comprising a region in which the first resin layers and the second resin layers are alternately laminated in the thickness direction.

2. A device having one end and another end opposite the one end, The thickness of the other end is greater than the thickness of the one end, The thickness of the one end is 1.05 mm or less, a first resin layer having a glass transition temperature of less than 15°C and a second resin layer having a glass transition temperature of 15°C or higher; a region in which the total number of layers of the first resin layer and the second resin layer in the thickness direction is 5 or more; In the region of five or more layers, when the thickness of one surface layer is Y 1 μm and the thickness of one layer adjacent to the surface layer is Z μm, Y 1 / Z is 1.01 or more; An interlayer film for laminated glass, having a region where Y 2 / X is 0.3 or less, where X μm is the thickness of the interlayer film and Y 2 μm is the thickness of one surface layer.

3. A device having one end and another end opposite the one end, The thickness of the other end is greater than the thickness of the one end, The thickness of the one end is 1.05 mm or less, a first resin layer having a glass transition temperature of less than 15°C and a second resin layer having a glass transition temperature of 15°C or higher; a region in which the total number of layers of the first resin layer and the second resin layer in the thickness direction is 5 or more; In the region of five or more layers, when the thickness of one surface layer is Y 1 μm and the thickness of one layer adjacent to the surface layer is Z μm, Y 1 / Z is 1.01 or more; an interlayer film for laminated glass, wherein the average thickness of the surface layer in each region extending from a position 100 mm to a position 400 mm from the one end toward the other end is less than 300 μm.

4. The interlayer film for laminated glass according to any one of claims 1 to 3, wherein the surface layer is the second resin layer.

5. The average thickness of the surface layer in the region from the position of 50 mm to the position of 150 mm from the one end toward the other end is defined as Y ３ μm, and the average thickness of the surface layer in the region from the position of 50 mm to the position of 150 mm from the other end toward the one end is Y ４ When μm is used, Y ４ / Y ３ The interlayer film for laminated glass according to any one of claims 1 to 4, wherein the modulus of elasticity is 2.5 or less.

6. The average thickness of the layers other than the surface layer in the region from the position of 50 mm to the position of 150 mm from the one end toward the other end is defined as Y ５ μm, and the average thickness of the layers other than the surface layer in the region from the position of 50 mm to the position of 150 mm from the other end toward the one end is Y ６ When μm is used, Y ６ / Y ５ The interlayer film for laminated glass according to any one of claims 1 to 5, wherein the modulus of elasticity is 2.5 or less.

7. a display corresponding area corresponding to a display area of ​​a head-up display; The interlayer film for laminated glass according to any one of claims 1 to 6, wherein the average thickness of the surface layer in the display-corresponding region is less than 300 µm.

8. The total thickness of the first resin layer is T １ μm, and the total thickness of the second resin layer is T ２ When μm, T ２ / T １ The interlayer film for laminated glass according to any one of claims 1 to 7, having a region in which

9. a first laminated glass member; and a second laminated glass member; and and the interlayer film for laminated glass according to any one of claims 1 to 8, The laminated glass, wherein the interlayer film for laminated glass is disposed between the first laminated glass member and the second laminated glass member.

Images