Interlayer film for laminated glass and laminated glass

Abstract

Provided is a laminated glass interlayer film in which a deep color part having uniform parallel light transmittance exists in a shade area and which can thus suppress irregular color in the shade area.　A laminated glass interlayer film according to the present invention has one end and the other end opposite to the one end. The thickness of the other end is larger than the thickness of the one end. The interlayer film is disposed between two sheets of clear glass conforming to JIS R3202: 1996 to obtain a laminated glass X. When a specific parallel light transmittance for the obtained laminated glass X is measured, the interlayer film includes: a gradation part in which the parallel light transmittance is continuously reduced from one end side to the other end side and an absolute value of a change rate of the parallel light transmittance exceeds 0.3% / mm; a transparent part that is located on one end side from the gradation part and has a parallel light transmittance of 60% or more; and a deep color part that is located on the other end side from the gradation part and includes one or more points A where the absolute value of the change rate of the parallel light transmittance is 0.3% / mm or less.

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 even if it is broken by an external impact, the amount of glass fragments that fly off is small. For this reason, the laminated glass is widely used in automobiles, railway vehicles, aircraft, ships, buildings, etc. The laminated glass is manufactured by sandwiching an interlayer film between a pair of glass sheets. The interlayer film is manufactured by, for example, the method described in Patent Document 1 below (the conduit method) or the method described in Patent Document 2 below (the feed block method).

[0003] Furthermore, a head-up display (HUD) is known as an example of the laminated glass used in automobiles. HUDs can display measurement information, such as speed, which is the vehicle's driving data, on the windshield of the automobile, allowing the driver to perceive the display as if it were projected on the windshield in front of them.

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

[0005] In order to suppress double images, a wedge-shaped interlayer film is used. Furthermore, as described in Patent Document 3, a shade area may be provided in the wedge-shaped interlayer film from the viewpoints of design and light blocking properties. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-231521 [Patent Document 2] WO2009 / 001856A1 [Patent Document 3] Japanese Patent Application Publication No. 11-130481 Summary of the Invention [Problem to be solved by the invention]

[0007] In the shade region, a colorant is generally used to change the color and visible light transmittance. However, in a conventional wedge-shaped interlayer film, the thickness of the colored layer containing the colorant changes as the thickness of the interlayer film changes. Therefore, in a conventional wedge-shaped interlayer film, there is no region in the shade region where the parallel light transmittance is uniform, and color unevenness is likely to occur in the thick part of the colored layer.

[0008] In particular, in an interlayer film having a large width, such as an interlayer film used in a roof-integrated windshield, color unevenness is likely to occur in the shade area.

[0009] An object of the present invention is to provide an interlayer film for laminated glass and laminated glass that has a dark color portion with uniform parallel light transmittance in the shade region, thereby suppressing color unevenness in the shade region. [Means for solving the problem]

[0010] According to a broad aspect of the present invention, there is provided an interlayer film for laminated glass (herein, "interlayer film for laminated glass" may be abbreviated as "interlayer film"), which has one end and another end opposite the one end, the thickness of the other end being greater than the thickness of the one end, and which is disposed between two pieces of clear glass conforming to JIS R3202:1996 to obtain laminated glass X, and when the resulting laminated glass X is measured for parallel light transmittance as described below, the interlayer film has: a gradation section in which the parallel light transmittance continuously decreases from the one end side to the other end side and the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm; a transparent section that is located closer to the one end than the gradation section and has a parallel light transmittance of 60% or more; and a dark section that is located closer to the other end than the gradation section and includes one or more points A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less.

[0011] Measurement of parallel light transmittance: Starting from a position 2 cm from the one end toward the other end, multiple points A are selected at 1 cm intervals from the starting point toward the other end. The parallel light transmittance of laminated glass X is measured at each point A. The x-axis direction is defined as "distance from the one end" and the y-axis direction is defined as "parallel light transmittance." An approximate line is created in a 2 cm area from three points: one point A and two points 1 cm away on either side of point A in the direction connecting the one end and the other end. The absolute value of the rate of change in parallel light transmittance obtained from the approximate line is defined as the "absolute value of the rate of change in parallel light transmittance" at one point A. The "absolute value of the rate of change in parallel light transmittance" is determined for each point A.

[0012] In a specific aspect of the interlayer film according to the present invention, the ratio of the distance of the dark color portion in the direction connecting the one end and the other end to the distance of the interlayer film in the direction connecting the one end and the other end is 0.05 or more.

[0013] In a specific aspect of the interlayer film according to the present invention, the distance of the dark color portion in the direction connecting the one end and the other end is 50 mm or more.

[0014] In a specific aspect of the interlayer film according to the present invention, the interlayer film has a uniform thickness portion whose thickness does not change by more than 10 μm within a distance range of 10 cm in a direction connecting the one end and the other end, and the uniform thickness portion is located closer to the other end than a midpoint between the one end and the other end.

[0015] In a specific aspect of the interlayer film according to the present invention, the gradation portion and the dark color portion each have a colored layer containing a colorant, and the shortest distance between the surface of the interlayer film in the thickness direction and the surface of the colored layer in the thickness direction is 10 μm or more.

[0016] 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.

[0017] According to a broad aspect of the present invention, there is provided laminated glass having one end and another end opposite the one end, the thickness of the other end being greater than the thickness of the one end, the laminated glass comprising a first laminated glass element, a second laminated glass element, and an interlayer film, the interlayer film being disposed between the first laminated glass element and the second laminated glass element, and when the parallel light transmittance of the laminated glass is measured as described below, the laminated glass has a gradation portion in which the parallel light transmittance continuously decreases from the one end side to the other end side and the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm, a transparent portion located closer to the one end than the gradation portion and having a parallel light transmittance of 60% or more, and a dark portion located closer to the other end than the gradation portion and including one or more points A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less.

[0018] Measurement of parallel light transmittance: Starting from a position 2 cm from the one end toward the other end, multiple points A are selected at 1 cm intervals from the starting point toward the other end. The parallel light transmittance of the laminated glass is measured at each point A. The x-axis direction is defined as the "distance from the one end" and the y-axis direction is defined as the "parallel light transmittance." An approximate straight line is created in a 2 cm area from three points: one point A and two points 1 cm away on either side of point A in the direction connecting the one end and the other end. The absolute value of the rate of change in parallel light transmittance obtained from the approximate straight line is defined as the "absolute value of the rate of change in parallel light transmittance" at the one point A. The "absolute value of the rate of change in parallel light transmittance" is determined for each point A. [Effects of the Invention]

[0019] The interlayer film of the present invention has one end and another end opposite the one end, and the thickness of the other end is greater than the thickness of the one end. The interlayer film of the present invention is placed between two sheets of clear glass conforming to JIS R3202:1996 to obtain laminated glass X, and the parallel light transmittance of the obtained laminated glass X is measured. The interlayer film of the present invention has the following portions (1) to (3): (1) a gradation portion in which the parallel light transmittance continuously decreases from the one end side to the other end side, and the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm; (2) a transparent portion located closer to the one end than the gradation portion, and having a parallel light transmittance of 60% or more; (3) a dark portion located closer to the other end than the gradation portion, and including one or more points A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less. The interlayer film for laminated glass according to the present invention has the above-described configuration, and therefore has a dark color portion with a uniform parallel light transmittance in the shade region, thereby making it possible to suppress color unevenness in the shade region.

[0020] The laminated glass according to the present invention has one end and another end opposite to the one end, and the thickness of the other end is greater than the thickness of the one end. The laminated glass according to the present invention includes a first laminated glass member, a second laminated glass member, and an interlayer film, with the interlayer film disposed between the first laminated glass member and the second laminated glass member. When the parallel light transmittance of the laminated glass according to the present invention is measured, the laminated glass has the following portions (1) to (3): (1) a gradation portion in which the parallel light transmittance continuously decreases from the one end side to the other end side, and the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm; (2) a transparent portion located closer to the one end than the gradation portion, and having a parallel light transmittance of 60% or more; (3) a dark portion located closer to the other end than the gradation portion, and including one or more points A at which the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less. The laminated glass according to the present invention has the above-described configuration, and therefore has a dark color portion in the shade region where the parallel light transmittance is uniform, thereby making it possible to suppress color unevenness in the shade region. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a cross-sectional view schematically illustrating an interlayer film for laminated glass according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a second embodiment of the present invention. [Figure 3] FIG. 3 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a third embodiment of the present invention. [Figure 4] FIG. 4 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fourth embodiment of the present invention. [Figure 5] FIG. 5 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fifth embodiment of the present invention. [Figure 6] FIG. 6 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a sixth embodiment of the present invention. [Figure 7]FIG. 7 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a seventh embodiment of the present invention. [Figure 8] FIG. 8 is a cross-sectional view schematically showing an interlayer film for laminated glass according to an eighth embodiment of the present invention. [Figure 9] FIG. 9 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a ninth embodiment of the present invention. [Figure 10] FIG. 10 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a tenth embodiment of the present invention. [Figure 11] FIG. 11 is a cross-sectional view schematically showing an interlayer film for laminated glass according to an eleventh embodiment of the present invention. [Figure 12] FIG. 12 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a twelfth embodiment of the present invention. [Figure 13] FIG. 13 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a thirteenth embodiment of the present invention. [Figure 14] FIG. 14 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fourteenth embodiment of the present invention. [Figure 15] FIG. 15 is a cross-sectional view that schematically shows an example of laminated glass that uses the interlayer film for laminated glass shown in FIG. [Figure 16] 16(a) to 16(c) are cross-sectional views that schematically show a conventional wedge-shaped interlayer film having a shade region. [Figure 17] 17(a) and (b) are cross-sectional views that schematically show a conventional wedge-shaped interlayer film having a shaded area. [Figure 18] 18(a) and (b) are cross-sectional views that schematically show a conventional wedge-shaped interlayer film having a shaded area. 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 a single-layer structure or a two or more-layer structure. The interlayer film may have a single-layer structure or a two or more-layer structure. The interlayer film may have a two-layer structure, a three-layer structure, a three or more-layer structure, a four or more-layer structure, or a four or more-layer structure. Furthermore, the interlayer film may have a five-layer structure, a five or more-layer structure, a six-layer structure, or a six or more-layer structure. The interlayer film may be a single-layer interlayer film having only a first layer (single-layer interlayer film), or may be an interlayer film having a two or more-layer structure having a first layer and another layer (multilayer interlayer film). The interlayer film may have these structures in part of the interlayer film, or throughout the entire interlayer film. The structure of the interlayer film may be partially different.

[0025] The interlayer film according to the present invention has one end and another end opposite the one end. The one end and the other end are opposite ends of the interlayer film. In the interlayer film according to the present invention, the thickness of the other end is greater than the thickness of the one end.

[0026] In the present invention, the interlayer film is disposed between two sheets of clear glass conforming to JIS R3202:1996 to obtain laminated glass X. The laminated glass X is preferably produced as follows.

[0027] A laminate is obtained by sandwiching an interlayer between two 2mm-thick clear glass sheets conforming to JIS R3202:1996. The resulting laminate is placed in a rubber bag and degassed at a vacuum of 2.6 kPa for 20 minutes. The degassed laminate is then transferred to an oven and held at 90°C for 30 minutes for vacuum pressing to pre-bond the laminate. The pre-bonded laminate is then compressed in an autoclave for 20 minutes at 135°C and a pressure of 1.2 MPa to obtain laminated glass X.

[0028] In the present invention, the obtained laminated glass X is subjected to the following parallel light transmittance measurement. One end of the interlayer film corresponds to one end of the laminated glass X. The other end of the interlayer film corresponds to the other end of the laminated glass X. It is preferable that one end of the interlayer film is located at one end of the laminated glass X, and that the other end of the interlayer film is located at the other end of the laminated glass X.

[0029] Measurement of parallel light transmittance: (1) Starting from a position 2 cm from the one end toward the other end, multiple points A are selected at 1 cm intervals from the starting point toward the other end. (2) The parallel light transmittance of the laminated glass X is measured at each point A. (3) The x-axis direction is defined as the "distance from the one end" and the y-axis direction is defined as the "parallel light transmittance." An approximate line is created in a 2 cm area from three points: one point A and two points 1 cm away from the point A on either side of the direction connecting the one end and the other end. The absolute value of the change rate in parallel light transmittance obtained from the approximate line is defined as the "absolute value of the change rate in parallel light transmittance" at the one point A. The "absolute value of the change rate in parallel light transmittance" is determined for each point A.

[0030] In the above (1), points A are set at 1 cm intervals. Points are selected from one end of the interlayer film to the other end so that points can be selected at 1 cm intervals (positions where the interval is not less than 1 cm and the distance between point A and the other end is not less than 2 cm). The point A closest to the one end of the interlayer film is point A1, which is 2 cm from the one end of the interlayer film toward the other end, and the next point A is point A2, which is 3 cm from the one end of the interlayer film toward the other end. The next point A is point A3, which is 4 cm from the one end of the interlayer film toward the other end. Point An is located (n+1) cm (n is a natural number) from the one end of the interlayer film toward the other end. Point A1, point A2, and point A3 are each included in the points A set at 1 cm intervals in the above (1). For convenience, the point 1 cm from the one end of the interlayer film toward the other end is designated as point A0. Note that point A0 is not included in points A that are set at intervals of 1 cm in the above (1).

[0031] In the above (2), the parallel light transmittance of the laminated glass X is measured at each position A. Therefore, the number of parallel light transmittance values ​​obtained is equal to the number of positions A. The parallel light transmittance of the laminated glass X is measured in accordance with JIS R3106:1998. Specifically, it is measured as follows.

[0032] Using a spectrophotometer, the laminated glass X was placed on the optical path between the light source and the integrating sphere, parallel to the normal to the optical axis and 13 cm away from the integrating sphere, so that only transmitted parallel light was received by the integrating sphere. The parallel light transmittance refers to the visible light transmittance calculated from the spectral transmittance measured in this state. Examples of the spectrophotometer include the "U-4100" manufactured by Hitachi High-Technologies Corporation.

[0033] In (3) above, the "three points, namely, point A1 closest to the one end of the interlayer film and two points 1 cm away from point A1 on either side of the one end in the direction connecting the one end and the other end" refer to the following three points: a point 1 cm, a point 2 cm, and a point 3 cm from the one end of the interlayer film toward the other end. In other words, points A0, A1, and A2. From the parallel light transmittances at points A0, A1, and A2, an approximate line is created with the x-axis direction defined as "distance from the one end" and the y-axis direction defined as "parallel light transmittance." The absolute value of the rate of change in parallel light transmittance calculated from the obtained approximate line is defined as "the absolute value of the rate of change in parallel light transmittance at point A1."

[0034] In (3) above, the "three points, namely, point A2, which is second closest to the one end of the interlayer film, and two points 1 cm away from point A2 on either side of the one end in the direction connecting the one end and the other end" refer to the following three points: points 2 cm, 3 cm, and 4 cm from the one end of the interlayer film toward the other end. In other words, points A1, A2, and A3. From the parallel light transmittances at points A1, A2, and A3, an approximate line is created with the x-axis direction defined as "distance from the one end" and the y-axis direction defined as "parallel light transmittance." The absolute value of the rate of change in parallel light transmittance calculated from the approximate line thus obtained is defined as the "absolute value of the rate of change in parallel light transmittance at point A2."

[0035] In the present invention, the "change rate of parallel light transmittance at point A3" and the "change rate of parallel light transmittance at point A(n-1)" are calculated in a similar manner. Since point A is selected as described above, the three points used to create the approximation curve do not lie in an area less than 1 cm from one end to the other end, and do not lie in an area less than 1 cm from the other end to the one end.

[0036] When the parallel light transmittance of the laminated glass X is measured, the interlayer film has the following portions (1) to (3): In the present invention, the gradation portion is determined, and then the transparent portion and the dark portion are determined.

[0037] (1) A gradation portion in which the parallel light transmittance decreases continuously from the one end side to the other end side, and the absolute value of the rate of change in the parallel light transmittance exceeds 0.3% / mm.

[0038] (2) A transparent portion located closer to the one end than the gradation portion and having a parallel light transmittance of 60% or more.

[0039] (3) A dark color portion that is located closer to the other end than the gradation portion and includes one or more points A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less.

[0040] Therefore, the interlayer film of the present invention has, from one end to the other end, a transparent portion, a gradation portion, and a dark portion in this order. The gradation portion and the dark portion form a shade region. Note that the interlayer film of the present invention may also have a portion that does not correspond to any of the three portions: the transparent portion, the gradation portion, and the dark portion.

[0041] The interlayer film according to the present invention has the above-described configuration, and therefore has a dark portion in the shade region with a uniform parallel light transmittance, thereby suppressing color unevenness in the shade region. The interlayer film according to the present invention has a dark portion in the shade region with a uniform parallel light transmittance, even though the thickness of the other end is greater than the thickness of the one end, and therefore suppresses color unevenness in the shade region.

[0042] The dark color portion may include a point A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less, and a point A where the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm. Of the multiple points A, a point A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less is referred to as point Aa. Of the multiple points A, a point A where the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm is referred to as point Ab. In this case, the dark color portion may include one or more points Aa. The dark color portion may include one or more points Ab in addition to point Aa. Furthermore, "(3) a dark color portion located on the other end side of the gradation portion and including one or more points A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less" means "(3) a dark color portion located on the other end side of the gradation portion and including one or more points Aa where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less."

[0043] Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[0044] First, a conventional wedge-shaped interlayer having a shaded area will be described.

[0045] 16(a) to (c), 17(a) and (b), and 18(a) and (b) are cross-sectional views that schematically show conventional wedge-shaped interlayer films having shade regions.

[0046] The interlayer film 100 shown in FIG. 16(a) has one end 100a and the other end 100b. The thickness of the other end 100b is greater than the thickness of the one end 100a. The interlayer film 100 includes a first layer 101 and a colored layer 104. The colored layer 104 is embedded in the first layer 101. The interlayer film 100 has a shaded region R4. The shaded region R4 corresponds to the region where the colored layer 104 is present.

[0047] The interlayer film 100A shown in FIG. 16(b) has one end 100Aa and the other end 100Ab. The thickness of the other end 100Ab is greater than the thickness of the one end 100Aa. The interlayer film 100A includes a first layer 101A, a second layer 102A, a third layer 103A, and a colored layer 104A. The colored layer 104A is embedded in the second layer 102A. The interlayer film 100A has a shaded region R4. The shaded region R4 corresponds to the region where the colored layer 104A is present.

[0048] The interlayer film 100B shown in FIG. 16(c) has one end 100Ba and the other end 100Bb. The thickness of the other end 100Bb is greater than the thickness of the one end 100Ba. The interlayer film 100B includes a first layer 101B, a second layer 102B, a third layer 103B, and a colored layer 104B. The colored layer 104B is embedded between the first layer 101B and the second layer 102B. The interlayer film 100B has a shaded region R4. The shaded region R4 corresponds to the region where the colored layer 104B is present.

[0049] The interlayer film 100C shown in FIG. 17(a) has one end 100Ca and the other end 100Cb. The thickness of the other end 100Cb is greater than the thickness of the first end 100Ca. The interlayer film 100C does not increase in thickness uniformly from the first end 100Ca to the other end 100Cb. The interlayer film 100C has a region where the thickness increases from the first end 100Ca to the other end 100Cb. Within the region where the thickness increases, the interlayer film 100C has a portion where the increase in thickness decreases from the first end 100Ca to the other end 100Cb. The interlayer film 100C includes a first layer 101C, a second layer 102C, a third layer 103C, and a colored layer 104C. The colored layer 104C is embedded in the second layer 102C. The interlayer film 100C has a shade region R4. Shaded region R4 corresponds to the region where colored layer 104C is present.

[0050] The interlayer film 100D shown in FIG. 17(b) has one end 100Da and the other end 100Db. The thickness at the other end 100Db is greater than the thickness at the one end 100Da. The interlayer film 100D does not increase in thickness uniformly from the one end 100Da side to the other end 100Db side. The outer shape of the interlayer film 100D is similar to that of the interlayer film 100C. The interlayer film 100D includes a first layer 101D, a second layer 102D, a third layer 103D, and a colored layer 104D. The colored layer 104D is embedded between the first layer 101D and the second layer 102D. The interlayer film 100D has a shaded region R4. The shaded region R4 corresponds to the region where the colored layer 104D is present.

[0051] The interlayer film 100E shown in FIG. 18(a) has one end 100Ea and the other end 100Eb. The thickness of the other end 100Eb is greater than the thickness of the one end 100Ea. The interlayer film 100E includes a first layer 101E, a second layer 102E, a third layer 103E, and a colored layer 104E. The colored layer 104E is embedded in the second layer 102E. The cross-sectional shapes in the thickness direction of the first layer 101E and the third layer 103E include a wedge-shaped portion and a rectangular portion. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 102E and the colored layer 104E includes a wedge-shaped portion and a rectangular portion. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 102E and the colored layer 104E where the colored layer 104E is not present is wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 102E and the colored layer 104E where the colored layer 104E is present is rectangular. The interlayer 100E has a shaded region R4. The shaded region R4 corresponds to the region where the colored layer 104E is present.

[0052] The interlayer film 100F shown in FIG. 18(b) has one end 100Fa and the other end 100Fb. The thickness of the other end 100Fb is greater than the thickness of the one end 100Fa. The outer shape of the interlayer film 100F is similar to that of the interlayer film 100E. The interlayer film 100F includes a first layer 101F, a second layer 102F, a third layer 103F, and a colored layer 104F. The colored layer 104F is embedded between the first layer 101F and the second layer 102F. The interlayer film 100F has a shaded region R4. The shaded region R4 corresponds to the region where the colored layer 104F is present.

[0053] In the interlayer films 100, 100A-100F, the thickness of the colored layers 104, 104A-104F also changes as the thickness of the interlayer film changes. Therefore, in the interlayer films 100, 100A-100F, there is no region in the shade region R4 where the parallel light transmittance is uniform. In the interlayer films 100, 100A-100F, the parallel light transmittance continuously decreases in the shade region R4 from one end 100a, 100Aa-100Fa toward the other end 100b, 100Ab-100Fb.

[0054] Next, an interlayer film having a shaded area according to a specific embodiment of the present invention will be described. In the following embodiments, different parts can be interchanged.

[0055] FIG. 1 is a cross-sectional view schematically illustrating an interlayer film for laminated glass according to a first embodiment of the present invention.

[0056] The interlayer film 1 shown in Figure 1 is used to obtain laminated glass. The interlayer film 1 is an interlayer film for laminated glass.

[0057] The interlayer film 1 has a length direction and a width direction. The left-right direction in FIG. 1 is the width direction, and the front-to-back direction is the length direction.

[0058] The interlayer film 1 comprises a first layer 11, a second layer 12, a third layer 13, and a colored layer 14. The second layer 12 is disposed on a first surface (one surface) of the first layer 11. The second layer 12 is laminated on the first surface of the first layer 11. The first layer 11 and the second layer 12 are in contact with each other. The third layer 13 is disposed on a second surface (other surface) of the first layer 11 opposite the first surface. The third layer 13 is laminated on the second surface of the first layer 11. The first layer 11 and the third layer 13 are in contact with each other. The first layer 11 is disposed between the second layer 12 and the third layer 13, and is sandwiched therebetween.

[0059] The colored layer 14 is embedded in the second layer 12. On the other end 1b side of the interlayer 1, the colored layer 14 is embedded in the second layer 12. On the other end 1b side of the interlayer 1 in the width direction, the colored layer 14 is embedded in the second layer 12. The colored layer 14 and the first layer 11 are not in contact with each other.

[0060] The cross-sectional shape in the thickness direction of the first layer 11 and the third layer 13 is wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12 and the colored layer 14 is also wedge-shaped. The thickness of the first layer 11 and the third layer 13 is greater on the other end 1b side than on the one end 1a side.

[0061] The thickness of the interlayer 1 at the other end 1b is greater than the thickness of the one end 1a. The thickness of the interlayer 1 increases uniformly from the one end 1a side to the other end 1b side.

[0062] The interlayer film 1 has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1a of the interlayer film 1, the dark portion R3 is located at the other end 1b of the interlayer film 1, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous with each other.

[0063] The transparent portion R1 is composed of a first layer 11, a second layer 12, and a third layer 13. The gradation portion R2 and the dark color portion R3 are composed of the first layer 11, the second layer 12, the third layer 13, and a colored layer 14. The gradation portion R2 and the dark color portion R3 form a shade region R4.

[0064] In the gradation portion R2, the thickness of the colored layer 14 increases continuously from one end 1a toward the other end 1b, whereas in the dark color portion R3, the thickness of the colored layer 14 is uniform.

[0065] FIG. 2 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a second embodiment of the present invention.

[0066] The interlayer film 1A shown in Figure 2 is used to obtain laminated glass. The interlayer film 1A is an interlayer film for laminated glass.

[0067] The interlayer film 1A has a length direction and a width direction. The left-right direction in Figure 2 is the width direction, and the front-to-back direction is the length direction.

[0068] The interlayer film 1A includes a first layer 11A, a second layer 12A, a third layer 13A, and a colored layer 14A. The second layer 12A is disposed on a first surface (one surface) of the first layer 11A. The second layer 12A is laminated on the first surface of the first layer 11A. The first layer 11A and the second layer 12A are in contact with each other. The third layer 13A is disposed on a second surface of the first layer 11A opposite to the first surface. The third layer 13A is laminated on the second surface of the first layer 11A. The first layer 11A and the third layer 13A are in contact with each other. The first layer 11A is disposed between the second layer 12A and the third layer 13A, and is sandwiched therebetween.

[0069] The colored layer 14A is embedded between the first layer 11A and the second layer 12A. At the other end 1Ab of the interlayer 1A, the colored layer 14A is embedded between the first layer 11A and the second layer 12A. At the other end 1Ab in the width direction of the interlayer 1A, the colored layer 14A is embedded between the first layer 11A and the second layer 12A. The colored layer 14A is in contact with the first layer 11A and the second layer 12A.

[0070] The cross-sectional shape in the thickness direction of the first layer 11A and the third layer 13A is wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12A and the colored layer 14A is also wedge-shaped. The thickness of the first layer 11A and the third layer 13A is greater on the other end 1Ab side than on the one end 1Aa side.

[0071] The thickness of the interlayer 1A at the other end 1Ab is greater than the thickness of the one end 1Aa, and the increase in thickness of the interlayer 1A is uniform from the one end 1Aa side to the other end 1Ab side.

[0072] The interlayer film 1A has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Aa of the interlayer film 1A, the dark portion R3 is located at the other end 1Ab of the interlayer film 1A, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous with each other.

[0073] The transparent portion R1 is composed of a first layer 11A, a second layer 12A, and a third layer 13A. The gradation portion R2 and the dark color portion R3 are composed of a first layer 11A, a second layer 12A, a third layer 13A, and a colored layer 14A. The gradation portion R2 and the dark color portion R3 form a shade region R4.

[0074] In the gradation portion R2, the thickness of the colored layer 14A increases continuously from one end 1Aa toward the other end 1Ab, whereas in the dark color portion R3, the thickness of the colored layer 14A is uniform.

[0075] FIG. 3 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a third embodiment of the present invention.

[0076] The interlayer film 1B shown in Figure 3 is used to obtain laminated glass. The interlayer film 1B is an interlayer film for laminated glass.

[0077] The intermediate film 1B has a length direction and a width direction. The left-right direction in Fig. 3 is the width direction, and the front-to-back direction is the length direction.

[0078] The interlayer film 1B includes a first layer 11B, a second layer 12B, a third layer 13B, and a colored layer 14B. The second layer 12B is disposed on a first surface (one surface) of the first layer 11B. The second layer 12B is laminated on the first surface of the first layer 11B. The first layer 11B and the second layer 12B are in contact with each other. The third layer 13B is disposed on a second surface of the first layer 11B opposite the first surface. The third layer 13B is laminated on the second surface of the first layer 11B. The first layer 11B and the third layer 13B are in contact with each other. The first layer 11B is disposed between the second layer 12B and the third layer 13B, sandwiching them.

[0079] The colored layer 14B is embedded in the second layer 12B. At the other end 1Bb side of the interlayer 1B, the colored layer 14B is embedded in the second layer 12B. At the other end 1Bb side in the width direction of the interlayer 1B, the colored layer 14B is embedded in the second layer 12B. The colored layer 14B and the first layer 11B are not in contact with each other.

[0080] The cross-sectional shapes in the thickness direction of the first layer 11B and the third layer 13B have wedge-shaped portions and rectangular portions. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12B and the colored layer 14B has wedge-shaped portions and rectangular portions. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12B and the colored layer 14B where the colored layer 14B is not present is wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12B and the colored layer 14B where the colored layer 14B is present is rectangular. The thicknesses of the first layer 11B and the third layer 13B are greater on the other end 1Bb side than on the one end 1Ba side.

[0081] The thickness of the interlayer film 1B at the other end 1Bb is greater than the thickness of the one end 1Ba. The cross-sectional shape of the interlayer film 1B in the thickness direction has a wedge-shaped portion and a rectangular portion. In the wedge-shaped portion of the interlayer film 1B in the thickness direction, the increase in thickness is uniform from the one end 1Ba side to the other end 1Bb side.

[0082] The interlayer film 1B has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Ba of the interlayer film 1B, the dark portion R3 is located at the other end 1Bb of the interlayer film 1B, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous. The cross-sectional shape of the transparent portion R1 in the thickness direction is wedge-shaped. The cross-sectional shapes of the gradation portion R2 and the dark portion R3 in the thickness direction are rectangular.

[0083] The transparent portion R1 is composed of a first layer 11B, a second layer 12B, and a third layer 13B. The gradation portion R2 and the dark color portion R3 are composed of a first layer 11B, a second layer 12B, a third layer 13B, and a colored layer 14B. The gradation portion R2 and the dark color portion R3 form a shade region R4. The cross-sectional shape of the shade region R4 in the thickness direction is rectangular.

[0084] In the gradation portion R2, the thickness of the colored layer 14B increases continuously from one end 1Ba toward the other end 1Bb, whereas in the dark color portion R3, the thickness of the colored layer 14B is uniform.

[0085] FIG. 4 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fourth embodiment of the present invention.

[0086] The interlayer film 1C shown in Fig. 4 is used to obtain laminated glass. The interlayer film 1C is an interlayer film for laminated glass.

[0087] The intermediate film 1C has a length direction and a width direction. The left-right direction in Figure 4 is the width direction, and the front-to-back direction is the length direction.

[0088] The interlayer film 1C includes a first layer 11C, a second layer 12C, a third layer 13C, and a colored layer 14C. The second layer 12C is disposed on a first surface (one surface) of the first layer 11C. The second layer 12C is laminated on the first surface of the first layer 11C. The first layer 11C and the second layer 12C are in contact with each other. The third layer 13C is disposed on a second surface of the first layer 11C opposite the first surface. The third layer 13C is laminated on the second surface of the first layer 11C. The first layer 11C and the third layer 13C are in contact with each other. The first layer 11C is disposed between the second layer 12C and the third layer 13C, sandwiching them.

[0089] The colored layer 14C is embedded between the first layer 11C and the second layer 12C. At the other end 1Cb side of the interlayer 1C, the colored layer 14C is embedded between the first layer 11C and the second layer 12C. At the other end 1Cb side of the interlayer 1C in the width direction, the colored layer 14C is embedded between the first layer 11C and the second layer 12C. The colored layer 14C is in contact with the first layer 11C and the second layer 12C.

[0090] The cross-sectional shapes in the thickness direction of the first layer 11C and the third layer 13C have wedge-shaped portions and rectangular portions. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12C and the colored layer 14C has wedge-shaped portions and rectangular portions. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12C and the colored layer 14C where the colored layer 14C is not present is wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12C and the colored layer 14C where the colored layer 14C is present is rectangular. The thicknesses of the first layer 11C and the third layer 13C are greater on the other end 1Cb side than on the one end 1Ca side.

[0091] The thickness of the interlayer film 1C at the other end 1Cb is greater than the thickness of the one end 1Ca. The cross-sectional shape of the interlayer film 1C in the thickness direction has a wedge-shaped portion and a rectangular portion. In the wedge-shaped portion of the interlayer film 1C in the thickness direction, the increase in thickness is uniform from the one end 1Ca side to the other end 1Cb side.

[0092] The interlayer film 1C has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Ca of the interlayer film 1C, the dark portion R3 is located at the other end 1Cb of the interlayer film 1C, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous. The cross-sectional shape of the transparent portion R1 in the thickness direction is wedge-shaped. The cross-sectional shapes of the gradation portion R2 and the dark portion R3 in the thickness direction are rectangular.

[0093] The transparent portion R1 is composed of a first layer 11C, a second layer 12C, and a third layer 13C. The gradation portion R2 and the dark color portion R3 are composed of a first layer 11C, a second layer 12C, a third layer 13C, and a colored layer 14C. The gradation portion R2 and the dark color portion R3 form a shade region R4. The cross-sectional shape of the shade region R4 in the thickness direction is rectangular.

[0094] In the gradation portion R2, the thickness of the colored layer 14C increases continuously from one end 1Ca toward the other end 1Cb, whereas in the dark color portion R3, the thickness of the colored layer 14C is uniform.

[0095] FIG. 5 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fifth embodiment of the present invention.

[0096] The interlayer film 1D shown in Fig. 5 is used to obtain laminated glass. The interlayer film 1D is an interlayer film for laminated glass.

[0097] The intermediate film 1D has a length direction and a width direction. The left-right direction in Fig. 5 is the width direction, and the front-to-back direction is the length direction.

[0098] The interlayer film 1D includes a first layer 11D, a second layer 12D, a third layer 13D, and a colored layer 14D. The second layer 12D is disposed on a first surface (one surface) of the first layer 11D. The second layer 12D is laminated on the first surface of the first layer 11D. The first layer 11D and the second layer 12D are in contact with each other. The third layer 13D is disposed on a second surface of the first layer 11D opposite the first surface. The third layer 13D is laminated on the second surface of the first layer 11D. The first layer 11D and the third layer 13D are in contact with each other. The first layer 11D is disposed and sandwiched between the second layer 12D and the third layer 13D.

[0099] The colored layer 14D is embedded in the second layer 12D. At the other end 1Db side of the interlayer 1D, the colored layer 14D is embedded in the second layer 12D. At the other end 1Db side in the width direction of the interlayer 1D, the colored layer 14D is embedded in the second layer 12D. The colored layer 14D and the first layer 11D are not in contact with each other.

[0100] The cross-sectional shapes in the thickness direction of the first layer 11D and the third layer 13D are wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12D and the colored layer 14D is also wedge-shaped. The thicknesses of the first layer 11D and the third layer 13D are greater on the other end 1Db side than on the one end 1Da side.

[0101] In the interlayer film 1D, the thickness at the other end 1Db is greater than the thickness at the one end 1Da. In the interlayer film 1D, the increase in thickness from the one end 1Da side to the other end 1Db side is not uniform.

[0102] The interlayer film 1D has a region where the thickness increases from one end 1Da to the other end 1Db. Within the region where the thickness increases, the interlayer film 1D has a portion where the increase in thickness decreases from one end 1Da to the other end 1Db. The interlayer film 1D 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 1D has a portion where the wedge angle decreases from one end 1Da to the other end 1Db.

[0103] The interlayer film 1D has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Da of the interlayer film 1D, the dark portion R3 is located at the other end 1Db of the interlayer film 1D, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous with each other.

[0104] The transparent portion R1 is composed of a first layer 11D, a second layer 12D, and a third layer 13D. The gradation portion R2 and the dark color portion R3 are composed of a first layer 11D, a second layer 12D, a third layer 13D, and a colored layer 14D. The gradation portion R2 and the dark color portion R3 form a shade region R4.

[0105] In the gradation portion R2, the thickness of the colored layer 14D increases continuously from one end 1Da toward the other end 1Db, whereas in the dark color portion R3, the thickness of the colored layer 14D is uniform.

[0106] FIG. 6 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a sixth embodiment of the present invention.

[0107] The interlayer film 1E shown in Fig. 6 is used to obtain laminated glass. The interlayer film 1E is an interlayer film for laminated glass.

[0108] The intermediate film 1E has a length direction and a width direction. The left-right direction in Fig. 6 is the width direction, and the front-to-back direction is the length direction.

[0109] The interlayer film 1E includes a first layer 11E, a second layer 12E, a third layer 13E, and a colored layer 14E. The second layer 12E is disposed on a first surface (one surface) of the first layer 11E. The second layer 12E is laminated on the first surface of the first layer 11E. The first layer 11E and the second layer 12E are in contact with each other. The third layer 13E is disposed on a second surface of the first layer 11E opposite the first surface. The third layer 13E is laminated on the second surface of the first layer 11E. The first layer 11E and the third layer 13E are in contact with each other. The first layer 11E is disposed between the second layer 12E and the third layer 13E, sandwiching them.

[0110] The colored layer 14E is embedded between the first layer 11E and the second layer 12E. At the other end 1Eb side of the interlayer 1E, the colored layer 14E is embedded between the first layer 11E and the second layer 12E. At the other end 1Eb side of the interlayer 1E in the width direction, the colored layer 14E is embedded between the first layer 11E and the second layer 12E. The colored layer 14E is in contact with the first layer 11E and the second layer 12E.

[0111] The cross-sectional shapes in the thickness direction of the first layer 11E and the third layer 13E are wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12E and the colored layer 14E is also wedge-shaped. The thicknesses of the first layer 11E and the third layer 13E are greater on the other end 1Eb side than on the one end 1Ea side.

[0112] In the interlayer film 1E, the thickness at the other end 1Eb is greater than the thickness at one end 1Ea, and the increase in thickness from the one end 1Ea side to the other end 1Eb side is not uniform.

[0113] The interlayer film 1E has a region where the thickness increases from one end 1Ea to the other end 1Eb. Within the region where the thickness increases, the interlayer film 1E has a portion where the amount of increase in thickness decreases from one end 1Ea to the other end 1Eb. The interlayer film 1E 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 1E has a portion where the wedge angle decreases from one end 1Ea to the other end 1Eb.

[0114] The interlayer film 1E has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Ea of the interlayer film 1E, the dark portion R3 is located at the other end 1Eb of the interlayer film 1E, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous with each other.

[0115] The transparent portion R1 is composed of a first layer 11E, a second layer 12E, and a third layer 13E. The gradation portion R2 and the dark color portion R3 are composed of a first layer 11E, a second layer 12E, a third layer 13E, and a colored layer 14E. The gradation portion R2 and the dark color portion R3 form a shade region R4.

[0116] In the gradation portion R2, the thickness of the colored layer 14E increases continuously from one end 1Ea toward the other end 1Eb, whereas in the dark color portion R3, the thickness of the colored layer 14E is uniform.

[0117] FIG. 7 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a seventh embodiment of the present invention.

[0118] The interlayer film 1F shown in Figure 7 is used to obtain laminated glass. The interlayer film 1F is an interlayer film for laminated glass.

[0119] The intermediate film 1F has a length direction and a width direction. The left-right direction in Fig. 7 is the width direction, and the front-to-back direction is the length direction.

[0120] The interlayer film 1F includes an infrared reflective layer 15F, a second layer 12F, a third layer 13F, and a colored layer 14F. The second layer 12F is disposed on a first surface (one surface) of the infrared reflective layer 15F. The second layer 12F is laminated on the first surface of the infrared reflective layer 15F. The infrared reflective layer 15F and the second layer 12F are in contact with each other. The third layer 13F is disposed on a second surface of the infrared reflective layer 15F opposite the first surface. The third layer 13F is laminated on the second surface of the infrared reflective layer 15F. The infrared reflective layer 15F and the third layer 13F are in contact with each other. The infrared reflective layer 15F is disposed and sandwiched between the second layer 12F and the third layer 13F.

[0121] The colored layer 14F is embedded in the second layer 12F. At the other end 1Fb side of the interlayer 1F, the colored layer 14F is embedded in the second layer 12F. At the other end 1Fb side in the width direction of the interlayer 1F, the colored layer 14F is embedded in the second layer 12F. The colored layer 14F and the infrared reflective layer 15F are not in contact with each other.

[0122] The cross-sectional shape in the thickness direction of the infrared reflecting layer 15F is rectangular. The cross-sectional shape in the thickness direction of the third layer 13F is wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12F and the colored layer 14F is rectangular. The thickness of the third layer 13F is greater on the other end 1Fb side than on the one end 1Fa side.

[0123] In the intermediate film 1F, the thickness at the other end 1Fb is greater than the thickness at the one end 1Fa, and the increase in thickness of the intermediate film 1F is uniform from the one end 1Fa side to the other end 1Fb side.

[0124] The interlayer film 1F has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Fa of the interlayer film 1F, the dark portion R3 is located at the other end 1Fb of the interlayer film 1F, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous with each other.

[0125] The transparent portion R1 is composed of an infrared reflective layer 15F, a second layer 12F, and a third layer 13F. The gradation portion R2 and the dark color portion R3 are composed of an infrared reflective layer 15F, a second layer 12F, a third layer 13F, and a colored layer 14F. The gradation portion R2 and the dark color portion R3 form a shade region R4.

[0126] In the gradation portion R2, the thickness of the colored layer 14F increases continuously from one end 1Fa toward the other end 1Fb, whereas in the dark color portion R3, the thickness of the colored layer 14F is uniform.

[0127] FIG. 8 is a cross-sectional view schematically showing an interlayer film for laminated glass according to an eighth embodiment of the present invention.

[0128] The interlayer film 1G shown in Fig. 8 is used to obtain laminated glass. The interlayer film 1G is an interlayer film for laminated glass.

[0129] The intermediate film 1G has a length direction and a width direction. The left-right direction in Fig. 8 is the width direction, and the front-to-back direction is the length direction.

[0130] The interlayer film 1G includes an infrared reflective layer 15G, a second layer 12G, a third layer 13G, and a colored layer 14G. The second layer 12G is disposed on a first surface (one surface) of the infrared reflective layer 15G. The second layer 12G is laminated on the first surface of the infrared reflective layer 15G. The infrared reflective layer 15G and the second layer 12G are in contact with each other. The third layer 13G is disposed on a second surface of the infrared reflective layer 15G opposite the first surface. The third layer 13G is laminated on the second surface of the infrared reflective layer 15G. The infrared reflective layer 15G and the third layer 13G are in contact with each other. The infrared reflective layer 15G is disposed between the second layer 12G and the third layer 13G, sandwiching them.

[0131] The colored layer 14G is embedded between the infrared reflective layer 15G and the second layer 12G. At the other end 1Gb side of the interlayer 1G, the colored layer 14G is embedded between the infrared reflective layer 15G and the second layer 12G. At the other end 1Gb side of the interlayer 1G in the width direction, the colored layer 14G is embedded between the infrared reflective layer 15G and the second layer 12G. The colored layer 14G is in contact with the infrared reflective layer 15G and the second layer 12G.

[0132] The cross-sectional shape in the thickness direction of the infrared reflecting layer 15G is rectangular. The cross-sectional shape in the thickness direction of the third layer 13G is wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12G and the colored layer 14G is rectangular. The thickness of the third layer 13G is greater on the other end 1Gb side than on the one end 1Ga side.

[0133] In the intermediate film 1G, the thickness at the other end 1Gb is greater than the thickness at one end 1Ga. In the intermediate film 1G, the increase in thickness is uniform from the one end 1Ga side to the other end 1Gb side.

[0134] The interlayer film 1G has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Ga of the interlayer film 1G, the dark portion R3 is located at the other end 1Gb of the interlayer film 1G, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous with each other.

[0135] The transparent portion R1 is composed of an infrared reflective layer 15G, a second layer 12G, and a third layer 13G. The gradation portion R2 and the dark color portion R3 are composed of an infrared reflective layer 15G, a second layer 12G, a third layer 13G, and a colored layer 14G. The gradation portion R2 and the dark color portion R3 form a shade region R4.

[0136] In the gradation portion R2, the thickness of the colored layer 14G increases continuously from one end 1Ga toward the other end 1Gb, whereas in the dark color portion R3, the thickness of the colored layer 14G is uniform.

[0137] FIG. 9 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a ninth embodiment of the present invention.

[0138] The interlayer film 1H shown in Fig. 9 is used to obtain laminated glass. The interlayer film 1H is an interlayer film for laminated glass.

[0139] The intermediate film 1H has a length direction and a width direction. The left-right direction in FIG. 9 is the width direction, and the front-to-back direction is the length direction.

[0140] The interlayer film 1H includes an infrared reflective layer 15H, a second layer 12H, a third layer 13H, and a colored layer 14H. The second layer 12H is disposed on a first surface (one surface) of the infrared reflective layer 15H. The second layer 12H is laminated on the first surface of the infrared reflective layer 15H. The infrared reflective layer 15H and the second layer 12H are in contact with each other. The third layer 13H is disposed on a second surface of the infrared reflective layer 15H opposite the first surface. The third layer 13H is laminated on the second surface of the infrared reflective layer 15H. The infrared reflective layer 15H and the third layer 13H are in contact with each other. The infrared reflective layer 15H is disposed between the second layer 12H and the third layer 13H, sandwiching them.

[0141] The colored layer 14H is embedded in the second layer 12H. At the other end 1Hb side of the interlayer 1H, the colored layer 14H is embedded in the second layer 12H. At the other end 1Hb side in the width direction of the interlayer 1H, the colored layer 14H is embedded in the second layer 12H. The colored layer 14H and the infrared reflective layer 15H are not in contact with each other.

[0142] The cross-sectional shape in the thickness direction of the infrared reflecting layer 15H is rectangular. The cross-sectional shape in the thickness direction of the third layer 13H is wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12H and the colored layer 14H is rectangular. The thickness of the third layer 13H is greater on the other end 1Hb side than on the one end 1Ha side.

[0143] In the interlayer film 1H, the thickness at the other end 1Hb is greater than the thickness at one end 1Ha. In the interlayer film 1H, the increase in thickness from the one end 1Ha side to the other end 1Hb side is not uniform.

[0144] The interlayer film 1H has a region where the thickness increases from one end 1Ha to the other end 1Hb. Within the region where the thickness increases, the interlayer film 1H has a portion where the increase in thickness decreases from one end 1Ha to the other end 1Hb. The interlayer film 1H 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 1H has a portion where the wedge angle decreases from one end 1Ha to the other end 1Hb.

[0145] The interlayer film 1H has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Ha of the interlayer film 1H, the dark portion R3 is located at the other end 1Hb of the interlayer film 1H, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous with each other.

[0146] The transparent portion R1 is composed of an infrared reflective layer 15H, a second layer 12H, and a third layer 13H. The gradation portion R2 and the dark color portion R3 are composed of an infrared reflective layer 15H, a second layer 12H, a third layer 13H, and a colored layer 14H. The gradation portion R2 and the dark color portion R3 form a shade region R4.

[0147] In the gradation portion R2, the thickness of the colored layer 14H increases continuously from the one end 1Ha side toward the other end 1Hb side, whereas in the dark color portion R3, the thickness of the colored layer 14H is uniform.

[0148] FIG. 10 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a tenth embodiment of the present invention.

[0149] The interlayer film 1I shown in Fig. 10 is used to obtain laminated glass. The interlayer film 1I is an interlayer film for laminated glass.

[0150] The intermediate film 1I has a length direction and a width direction. The left-right direction in Fig. 10 is the width direction, and the front-to-back direction is the length direction.

[0151] The interlayer film 1I includes an infrared reflective layer 15I, a second layer 12I, a third layer 13I, and a colored layer 14I. The second layer 12I is disposed on a first surface (one surface) of the infrared reflective layer 15I. The second layer 12I is laminated on the first surface of the infrared reflective layer 15I. The infrared reflective layer 15I and the second layer 12I are in contact with each other. The third layer 13I is disposed on a second surface of the infrared reflective layer 15I opposite the first surface. The third layer 13I is laminated on the second surface of the infrared reflective layer 15I. The infrared reflective layer 15I and the third layer 13I are in contact with each other. The infrared reflective layer 15I is disposed and sandwiched between the second layer 12I and the third layer 13I.

[0152] The colored layer 14I is embedded between the infrared reflective layer 15I and the second layer 12I. At the other end 1Ib side of the interlayer 1I, the colored layer 14I is embedded between the infrared reflective layer 15I and the second layer 12I. At the other end 1Ib side of the interlayer 1I in the width direction, the colored layer 14I is embedded between the infrared reflective layer 15I and the second layer 12I. The colored layer 14I is in contact with the infrared reflective layer 15I and the second layer 12I.

[0153] The cross-sectional shape in the thickness direction of the infrared reflecting layer 15I is rectangular. The cross-sectional shape in the thickness direction of the third layer 13I is wedge-shaped. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12I and the colored layer 14I is rectangular. The thickness of the third layer 13I is greater on the other end 1Ib side than on the one end 1Ia side.

[0154] The thickness of the intermediate film 1I at the other end 1Ib is greater than the thickness of the one end 1Ia. The increase in thickness of the intermediate film 1I from the one end 1Ia side to the other end 1Ib side is not uniform.

[0155] The interlayer film 1I has a region where the thickness increases from one end 1Ia to the other end 1Ib. Within the region where the thickness increases, the interlayer film 1I has a portion where the increase in thickness decreases from one end 1Ia to the other end 1Ib. The interlayer film 1I 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 1I has a portion where the wedge angle decreases from one end 1Ia to the other end 1Ib.

[0156] The interlayer film 1I has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Ia of the interlayer film 1I, the dark portion R3 is located at the other end 1Ib of the interlayer film 1I, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous with each other.

[0157] The transparent portion R1 is composed of an infrared reflective layer 15I, a second layer 12I, and a third layer 13I. The gradation portion R2 and the dark color portion R3 are composed of an infrared reflective layer 15I, a second layer 12I, a third layer 13I, and a colored layer 14I. The gradation portion R2 and the dark color portion R3 form a shade region R4.

[0158] In the gradation portion R2, the thickness of the colored layer 14I increases continuously from one end 1Ia toward the other end 1Ib. In the dark color portion R3, the thickness of the colored layer 14I is uniform.

[0159] FIG. 11 is a cross-sectional view schematically showing an interlayer film for laminated glass according to an eleventh embodiment of the present invention.

[0160] The interlayer film 1J shown in Fig. 11 is used to obtain laminated glass. The interlayer film 1J is an interlayer film for laminated glass.

[0161] The intermediate film 1J has a length direction and a width direction. The left-right direction in FIG. 11 is the width direction, and the front-to-back direction is the length direction.

[0162] The interlayer film 1J includes an infrared reflective layer 15J, a second layer 12J, a third layer 13J, and a colored layer 14J. The second layer 12J is disposed on a first surface (one surface) of the infrared reflective layer 15J. The second layer 12J is laminated on the first surface of the infrared reflective layer 15J. The infrared reflective layer 15J and the second layer 12J are in contact with each other. The third layer 13J is disposed on a second surface of the infrared reflective layer 15J opposite the first surface. The third layer 13J is laminated on the second surface of the infrared reflective layer 15J. The infrared reflective layer 15J and the third layer 13J are in contact with each other. The infrared reflective layer 15J is disposed between the second layer 12J and the third layer 13J, being sandwiched therebetween.

[0163] The colored layer 14J is embedded in the second layer 12J. At the other end 1Jb side of the interlayer 1J, the colored layer 14J is embedded in the second layer 12J. At the other end 1Jb side in the width direction of the interlayer 1J, the colored layer 14J is embedded in the second layer 12J. The colored layer 14J and the infrared reflective layer 15J are not in contact with each other.

[0164] The cross-sectional shape in the thickness direction of the infrared reflecting layer 15J is rectangular. The cross-sectional shape in the thickness direction of the third layer 13J has a wedge-shaped portion and a rectangular portion. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12J and the colored layer 14J is rectangular. The thickness of the third layer 13J is greater on the other end 1Jb side than on the one end 1Ja side.

[0165] The thickness of the interlayer 1J at the other end 1Jb is greater than the thickness of the one end 1Ja. The cross-sectional shape of the interlayer 1J in the thickness direction has a wedge-shaped portion and a rectangular portion. In the wedge-shaped portion of the interlayer 1J in the thickness direction, the increase in thickness is uniform from the one end 1Ja side to the other end 1Jb side.

[0166] The interlayer film 1J has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Ja of the interlayer film 1J, the dark portion R3 is located at the other end 1Jb of the interlayer film 1J, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous. The cross-sectional shape of the transparent portion R1 in the thickness direction is wedge-shaped. The cross-sectional shapes of the gradation portion R2 and the dark portion R3 in the thickness direction are rectangular.

[0167] The transparent portion R1 is composed of an infrared reflective layer 15J, a second layer 12J, and a third layer 13J. The gradation portion R2 and the dark color portion R3 are composed of an infrared reflective layer 15J, a second layer 12J, a third layer 13J, and a colored layer 14J. The gradation portion R2 and the dark color portion R3 form a shade region R4. The cross-sectional shape of the shade region R4 in the thickness direction is rectangular.

[0168] In the gradation portion R2, the thickness of the colored layer 14J increases continuously from one end 1Ja toward the other end 1Jb. In the dark color portion R3, the thickness of the colored layer 14J is uniform.

[0169] FIG. 12 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a twelfth embodiment of the present invention.

[0170] The interlayer film 1K shown in Fig. 12 is used to obtain laminated glass. The interlayer film 1K is an interlayer film for laminated glass.

[0171] The intermediate film 1K has a length direction and a width direction. The left-right direction in FIG. 12 is the width direction, and the front-to-back direction is the length direction.

[0172] The interlayer film 1K includes an infrared reflective layer 15K, a second layer 12K, a third layer 13K, and a colored layer 14K. The second layer 12K is disposed on a first surface (one surface) of the infrared reflective layer 15K. The second layer 12K is laminated on the first surface of the infrared reflective layer 15K. The infrared reflective layer 15K and the second layer 12K are in contact with each other. The third layer 13K is disposed on a second surface of the infrared reflective layer 15K opposite the first surface. The third layer 13K is laminated on the second surface of the infrared reflective layer 15K. The infrared reflective layer 15K and the third layer 13K are in contact with each other. The infrared reflective layer 15K is disposed between the second layer 12K and the third layer 13K, being sandwiched therebetween.

[0173] The colored layer 14K is embedded between the infrared reflective layer 15K and the second layer 12K. At the other end 1Kb side of the interlayer 1K, the colored layer 14K is embedded between the infrared reflective layer 15K and the second layer 12K. At the other end 1Kb side of the interlayer 1K in the width direction, the colored layer 14K is embedded between the infrared reflective layer 15K and the second layer 12K. The colored layer 14K is in contact with the infrared reflective layer 15K and the second layer 12K.

[0174] The cross-sectional shape in the thickness direction of the infrared reflecting layer 15K is rectangular. The cross-sectional shape in the thickness direction of the third layer 13K has a wedge-shaped portion and a rectangular portion. The cross-sectional shape in the thickness direction of the layer formed by combining the second layer 12K and the colored layer 14K is rectangular. The thickness of the third layer 13K is greater on the other end 1Kb side than on one end 1Ka side.

[0175] The thickness of the interlayer film 1K at the other end 1Kb is greater than the thickness of the one end 1Ka. The cross-sectional shape of the interlayer film 1K in the thickness direction has a wedge-shaped portion and a rectangular portion. In the wedge-shaped portion of the interlayer film 1K in the thickness direction, the increase in thickness is uniform from the one end 1Ka side to the other end 1Kb side.

[0176] The interlayer film 1K has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Ka of the interlayer film 1K, the dark portion R3 is located at the other end 1Kb of the interlayer film 1K, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous. The cross-sectional shape of the transparent portion R1 in the thickness direction is wedge-shaped. The cross-sectional shapes of the gradation portion R2 and the dark portion R3 in the thickness direction are rectangular.

[0177] The transparent portion R1 is composed of an infrared reflective layer 15K, a second layer 12K, and a third layer 13K. The gradation portion R2 and the dark color portion R3 are composed of an infrared reflective layer 15K, a second layer 12K, a third layer 13K, and a colored layer 14K. The gradation portion R2 and the dark color portion R3 form a shade region R4. The cross-sectional shape of the shade region R4 in the thickness direction is rectangular.

[0178] In the gradation portion R2, the thickness of the colored layer 14K increases continuously from one end 1Ka side toward the other end 1Kb side. In the dark color portion R3, the thickness of the colored layer 14K is uniform.

[0179] FIG. 13 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a thirteenth embodiment of the present invention.

[0180] The interlayer film 1L shown in Figure 13 is used to obtain laminated glass. The interlayer film 1L is an interlayer film for laminated glass.

[0181] The intermediate film 1L has a length direction and a width direction. The left-right direction in FIG. 13 is the width direction, and the front-to-back direction is the length direction.

[0182] The interlayer 1L includes a first layer 11L and a colored layer 14L.

[0183] The colored layer 14L is embedded in the first layer 11L. On the other end 1Lb side of the interlayer 1L, the colored layer 14L is embedded in the first layer 11L. On the other end 1Lb side of the interlayer 1L in the width direction, the colored layer 14L is embedded in the first layer 11L.

[0184] The thickness of the interlayer 1L at the other end 1Lb is greater than the thickness of the one end 1La. The cross-sectional shape of the interlayer 1L in the thickness direction is wedge-shaped. The cross-sectional shape of the layer formed by combining the first layer 11L and the colored layer 14L in the thickness direction is also wedge-shaped. The interlayer 1L has a uniform increase in thickness from the one end 1La side to the other end 1Lb side.

[0185] The interlayer film 1L has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1La of the interlayer film 1L, the dark portion R3 is located at the other end 1Lb of the interlayer film 1L, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous with each other.

[0186] The transparent portion R1 is formed by the first layer 11L. The gradation portion R2 and the dark color portion R3 are formed by the first layer 11L and the colored layer 14L. The gradation portion R2 and the dark color portion R3 form a shade region R4.

[0187] In the gradation portion R2, the thickness of the colored layer 14L increases continuously from one end 1La toward the other end 1Lb, whereas in the dark color portion R3, the thickness of the colored layer 14L is uniform.

[0188] The interlayer film 1L shown in Fig. 13 is an interlayer film that includes a first layer and a colored layer and has the outer shape shown in Fig. 1. The interlayer film may also be an interlayer film that includes a first layer and a colored layer and has the outer shape shown in Figs. 3 and 5.

[0189] FIG. 14 is a cross-sectional view schematically showing an interlayer film for laminated glass according to a fourteenth embodiment of the present invention.

[0190] The interlayer film 1M shown in Fig. 14 is used to obtain laminated glass. The interlayer film 1M is an interlayer film for laminated glass.

[0191] The intermediate film 1M has a length direction and a width direction. The left-right direction in FIG. 14 is the width direction, and the front-to-back direction is the length direction.

[0192] The intermediate film 1M includes a first layer 11M and a colored layer 14M.

[0193] The colored layer 14M is embedded in the first layer 11M. On the other end 1Mb side of the intermediate film 1M, the colored layer 14M is embedded in the first layer 11M. On the other end 1Mb side of the intermediate film 1M in the width direction, the colored layer 14M is embedded in the first layer 11M.

[0194] In the interlayer film 1M, the thickness at the other end 1Mb is greater than the thickness at one end 1Ma. The cross-sectional shape in the thickness direction of the interlayer film 1M has a wedge-shaped portion and a rectangular portion. The cross-sectional shape in the thickness direction of the layer formed by combining the first layer 11M and the colored layer 14M has a wedge-shaped portion and a rectangular portion. In the interlayer film 1M, the amount of increase in thickness in the portion where the thickness increases from the one end 1Ma side to the other end 1Mb side is uniform.

[0195] The interlayer film 1M has a transparent portion R1, a gradation portion R2, and a dark portion R3. The transparent portion R1 is located at one end 1Ma of the interlayer film 1M, the dark portion R3 is located at the other end 1Mb of the interlayer film 1M, and the gradation portion R2 is located between the transparent portion R1 and the dark portion R3. The transparent portion R1, the gradation portion R2, and the dark portion R3 are continuous. The cross-sectional shape of the transparent portion R1 and the gradation portion R2 in the thickness direction is wedge-shaped. The cross-sectional shape of the dark portion R3 in the thickness direction is rectangular.

[0196] The transparent portion R1 is composed of a first layer 11M. The gradation portion R2 and the dark color portion R3 are composed of the first layer 11M and a colored layer 14M. The gradation portion R2 and the dark color portion R3 form a shade region R4. The cross-sectional shape of the shade region R4 in the thickness direction has a wedge-shaped portion and a rectangular portion.

[0197] In the gradation portion R2, the thickness of the colored layer 14M increases continuously from one end 1Ma toward the other end 1Mb, whereas in the dark color portion R3, the thickness of the colored layer 14M is uniform.

[0198] In the interlayer films 1, 1A to 1M shown in Figures 1 to 14, the gradation portion is formed by changing the thickness of the colored layer. In the interlayer film according to the present invention, the gradation portion may be formed by changing the concentration of the colorant contained in the colored layer. For example, in the interlayer film, the gradation portion may be formed by increasing the concentration of the colorant contained in the colored layer from one end to the other end.

[0199] In the interlayer films 1B, 1C, 1J, and 1K shown in Figures 3, 4, 11, and 12, the transparent portion is composed of a portion having a wedge-shaped cross section in the thickness direction of the interlayer film, and the gradation portion and dark portion are composed of a portion having a rectangular cross section in the thickness direction of the interlayer film. In the interlayer film 1M shown in Figure 14, the transparent portion and gradation portion are composed of a portion having a wedge-shaped cross section in the thickness direction of the interlayer film, and the dark portion are composed of a portion having a rectangular cross section in the thickness direction of the interlayer film. In the present invention, as in the interlayer film having the shape shown in Figure 14, the transparent portion may have a portion having a rectangular cross section in the thickness direction of the interlayer film, and the gradation portion and dark portion may have a portion having a wedge-shaped cross section in the thickness direction of the interlayer film.

[0200] The interlayer film may have, within the region of increasing thickness, a portion where the amount of increase in thickness increases from one end side to the other end side.The interlayer film may have, within the region having a wedge-shaped cross section in the thickness direction, a portion where the wedge angle increases from one end side to the other end side.

[0201] The gradation portion is a region where, when the parallel light transmittance of the laminated glass X is measured, the parallel light transmittance continuously decreases from one end to the other end, and the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm. The gradation portion may include a portion where the parallel light transmittance is 60% or more. The gradation portion includes one or more points A where the rate of change in parallel light transmittance exceeds 0.3% / mm. The number of points A included in the gradation portion where the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, particularly preferably 4 or more, and most preferably 5 or more. The number of points A included in the gradation portion where the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm may be 1,500 or less, or may be 1,450 or less.

[0202] The transparent portion is a region located closer to the one end than the gradation portion and having a parallel light transmittance of 60% or more when the parallel light transmittance of the laminated glass X is measured. The parallel light transmittance of the transparent portion is preferably 61% or more, and more preferably 62% or more.

[0203] The dark color portion is a region that is located closer to the other end than the gradation portion when the parallel light transmittance of the laminated glass X is measured, and that includes one or more points A at which the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less. From the viewpoint of further suppressing color unevenness in the shade region, the absolute value of the rate of change in parallel light transmittance at point A at which the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less is preferably 0.29% / mm or less, more preferably 0.28% / mm or less. From the viewpoint of further suppressing color unevenness in the shade region, the dark color portion preferably includes a point at which the absolute value of the rate of change in parallel light transmittance is 0.29% / mm or less, and more preferably includes a point at which the absolute value of the rate of change in parallel light transmittance is 0.28% / mm or less. From the viewpoint of further suppressing color unevenness in the shade region, it is preferable that the dark color portion includes a point where the absolute value of the rate of change in parallel light transmittance is 0.27% / mm or less, and it is more preferable that the dark color portion includes a point where the absolute value of the rate of change in parallel light transmittance is 0.26% / mm or less.

[0204] The interlayer film has a dark color portion including one or more points A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less. The number of points A included in the dark color portion where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less is preferably 2 or more, more preferably 3 or more, even more preferably 4 or more, particularly preferably 5 or more, and most preferably 6 or more. The greater the number of points A included in the dark color portion where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less, the more effectively color unevenness in the shade region is suppressed. The number of points A included in the dark color portion where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less may be 300 or less, or may be 299 or less.

[0205] 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 the one end and the other end of the interlayer film. 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 the one end and the other end of the interlayer film. 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 the one end and the other end of the interlayer film, or a region in which the thickness varies by 10 μm or less over a distance of 10 cm in the direction connecting the one end and the other end of the interlayer film.

[0206] The uniform thickness region is preferably located closer to the one end than the center position between the one end and the other end of the interlayer film. The center position of the uniform thickness region is preferably located closer to the other end than the center position between the one end and the other end of the interlayer film. The distance between the center position of the uniform thickness region and the other end is preferably shorter than the distance between the center position of the uniform thickness region and the one end. The uniform thickness region is preferably located in the dark color region. The center position of the uniform thickness region is preferably located in the dark color region. In these cases, the absolute value of the "change rate of parallel light transmittance at point A" can be adjusted more easily.

[0207] The distance of the transparent portion in the direction connecting the one end and the other end of the interlayer film is defined as distance L1. The distance of the gradation portion in the direction connecting the one end and the other end of the interlayer film is defined as distance L2. The distance of the dark color portion in the direction connecting the one end and the other end of the interlayer film is defined as distance L3. Distances L1, L2, and L3 are the distances shown in Figures 1 to 14. Furthermore, if the interlayer film has a uniform thickness portion, the distance of the uniform thickness portion in the direction connecting the one end and the other end of the interlayer film is defined as distance L4.

[0208] The distance L1 is preferably 10 mm or more, more preferably 20 mm or more, and is preferably 3000 mm or less, more preferably 2990 mm or less.

[0209] The distance L2 is preferably 10 mm or more, more preferably 20 mm or more, and is preferably 3000 mm or less, more preferably 2990 mm or less.

[0210] The distance L3 is preferably 50 mm or more, more preferably 60 mm or more, and is preferably 3000 mm or less, more preferably 2990 mm or less.

[0211] The distance L4 is preferably 10 mm or more, more preferably 20 mm or more, and is preferably 3000 mm or less, more preferably 2990 mm or less.

[0212] The distance of the intermediate film in the direction connecting the one end and the other end of the intermediate film is defined as a distance L.

[0213] The ratio of the distance L1 to the distance L (distance L1 / distance L) is preferably 0.02 or more, more preferably 0.03 or more, and is preferably 0.98 or less, more preferably 0.97 or less.

[0214] The ratio of the distance L2 to the distance L (distance L2 / distance L) is preferably 0.02 or more, more preferably 0.03 or more, and is preferably 0.98 or less, more preferably 0.97 or less.

[0215] The ratio of the distance L3 to the distance L (distance L3 / distance L) is preferably 0.05 or more, more preferably 0.051 or more, and is preferably 0.98 or less, more preferably 0.97 or less.

[0216] The ratio of the distance L4 to the distance L (distance L3 / distance L) is preferably 0.02 or more, more preferably 0.03 or more, and is preferably 0.98 or less, more preferably 0.97 or less.

[0217] The interlayer preferably has a minimum thickness in a region of 0L to 0.2L from one end to the other end, and a maximum thickness in a region of 0L to 0.2L from the other end to the one end. In this case, the minimum thickness and the maximum thickness may be located anywhere in the region of 0L to 0.2L. It is more preferable that the interlayer has a minimum thickness in a region of 0L to 0.1L from one end to the other end, and a maximum thickness in a region of 0L to 0.1L from the other end to the one end. It is preferable that the interlayer has a minimum thickness at one end and a maximum thickness at the other end.

[0218] The interlayer film preferably has a uniform thickness region in a region from the other end to the one end at a distance of 0L to 0.98L. In this case, the uniform thickness region may be located anywhere in the region at a distance of 0L to 0.98L.

[0219] The maximum thickness of the interlayer film is preferably 0.1 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 3 mm or less, more preferably 2.9 mm or less. When the thickness of the interlayer film is at least the above lower limit, the penetration resistance and bending rigidity of the laminated glass are further improved. When the thickness of the interlayer film is not more than the above upper limit, the transparency of the interlayer film and the laminated glass is further improved.

[0220] The average thickness of the interlayer is T.

[0221] In the multilayer interlayer film, the average thickness of the first layer is preferably 0.035 T or more, more preferably 0.0625 T or more, even more preferably 0.1 T or more, and is preferably 0.4 T or less, more preferably 0.375 T or less, even more preferably 0.25 T or less, and particularly preferably 0.15 T or less. When the average thickness of the first layer is 0.4 T or less, the bending rigidity becomes even better.

[0222] The average thickness of the infrared reflective layer is preferably 0.035T or more, more preferably 0.0625T or more, even more preferably 0.1T or more, and is preferably 0.4T or less, more preferably 0.375T or less, even more preferably 0.25T or less, particularly preferably 0.15T or less.

[0223] The average thickness of the colored layer is preferably 0.01 T or more, more preferably 0.02 T or more, even more preferably 0.03 T or more, and is preferably 0.04 T or less, more preferably 0.99 T or less, even more preferably 0.98 T or less, and particularly preferably 0.97 T or less. The average thickness of the colored layer may be 0.9 T or less, 0.8 T or less, 0.7 T or less, 0.6 T or less, 0.5 T or less, 0.4 T or less, 0.3 T or less, or 0.2 T or less.

[0224] The average thickness of each of the second layer and the third layer is preferably 0.3T or more, more preferably 0.3125T or more, even more preferably 0.375T or more, and is preferably 0.97T or less, more preferably 0.9375T or less, even more preferably 0.9T or less. The average thickness of each of the second layer and the third layer may be 0.46875T or less, or may be 0.45T or less. Furthermore, when the average thickness of each of the second layer and the third layer is not less than the above lower limit and not more than the above upper limit, the rigidity and sound insulation of the laminated glass are further improved.

[0225] The total average thickness of the second layer and the third layer is preferably at least 0.625 T, more preferably at least 0.75 T, even more preferably at least 0.85 T, and is preferably at most 0.97 T, more preferably at most 0.9375 T, and even more preferably at most 0.9 T. When the total average thickness of the second layer and the third layer is at least the above-mentioned lower limit and at most the above-mentioned upper limit, the rigidity and sound insulation of the laminated glass are further improved.

[0226] The total average thickness of the colored layer, second layer, and third layer is preferably at least 0.625 T, more preferably at least 0.75 T, even more preferably at least 0.85 T, and is preferably at most 0.97 T, more preferably at most 0.9375 T, and even more preferably at most 0.9 T. When the total average thickness of the second layer and the third layer is at least the above-mentioned lower limit and at most the above-mentioned upper limit, the rigidity and sound insulation of the laminated glass are further improved.

[0227] To prevent double images, the wedge angle (θ) of the interlayer can be set appropriately depending on the installation angle of the laminated glass. The wedge angle (θ) is the wedge angle of the entire interlayer.

[0228] To further suppress ghosting, the wedge angle (θ) of the interlayer film is preferably 0.1 mrad (0.00575 degrees) or more, more preferably 0.2 mrad (0.0115 degrees) or more, and preferably 2 mrad (0.1146 degrees) or less, more preferably 0.7 mrad (0.0401 degrees) or less. When the wedge angle (θ) is equal to or greater than the lower limit, laminated glass suitable for vehicles with a large windshield installation angle, such as trucks and buses, can be obtained. When the wedge angle (θ) is equal to or less than the upper limit, laminated glass suitable for vehicles with a small windshield installation angle, such as sports cars, can be obtained.

[0229] 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. The wedge angle (θ) of the interlayer film can be approximately calculated as follows: The thickness of the interlayer film is measured at each of the maximum and minimum thickness portions. The wedge angle (θ) of the interlayer film is approximately calculated based on the result of (the absolute value (μm) of the difference between the thickness at the maximum thickness portion of the interlayer film and the thickness at the minimum thickness portion of the interlayer film ÷ the distance (mm) between the maximum thickness portion and the minimum thickness portion of the interlayer film).

[0230] The wedge angle θ of the interlayer and the thickness of the interlayer may be measured by a measuring device such as a contact type thickness measuring device "TOF-4R" (manufactured by Yamabun Denki Co., Ltd.).

[0231] The thickness is measured using the above-mentioned measuring device at a membrane transport speed of 2.15 mm / min to 2.25 mm / min from one end to the other end over the shortest distance.

[0232] The wedge angle (θ) and thickness of the interlayer film after it has been formed into laminated glass can be measured using a measuring device such as the non-contact multilayer film thickness measuring device "OPTIGAUGE" (manufactured by Lumetrics). By using this measuring device, the thickness of the interlayer film can be measured in the laminated glass state.

[0233] The shortest distance between the surface of the interlayer film in the thickness direction and the surface of the colored layer in the thickness direction is preferably 10 μm or more, more preferably 20 μm or more, and is preferably 3000 μm or less, more preferably 2990 μm or less. When the shortest distance is equal to or greater than the above lower limit and equal to or less than the above upper limit, color transfer can be effectively suppressed.

[0234] Hereinafter, each material that can be used for the interlayer film according to the present invention will be described in detail.

[0235] (thermoplastic resin) The interlayer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (0)). The interlayer preferably contains a polyvinyl acetal resin (hereinafter may be referred to as polyvinyl acetal resin (0)) as the thermoplastic resin (0). The first layer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (1)). The first layer preferably contains a polyvinyl acetal resin (hereinafter may be referred to as polyvinyl acetal resin (1)) as the thermoplastic resin (1). The second layer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (2)). The second layer preferably contains a polyvinyl acetal resin (hereinafter may be referred to as polyvinyl acetal resin (2)) as the thermoplastic resin (2). The third layer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (3)). The third layer preferably contains a polyvinyl acetal resin (hereinafter may be referred to as polyvinyl acetal resin (3)) as the thermoplastic resin (3). The colored layer preferably contains a thermoplastic resin (hereinafter may be referred to as thermoplastic resin (4)). The colored layer preferably contains a polyvinyl acetal resin (hereinafter may be referred to as polyvinyl acetal resin (4)) as the thermoplastic resin (4). The thermoplastic resin (1), the thermoplastic resin (2), the thermoplastic resin (3), and the thermoplastic resin (4) may be the same or different. Since sound insulation is further improved, the thermoplastic resin (1) is preferably different from the thermoplastic resin (2) and the thermoplastic resin (3). The polyvinyl acetal resin (1), the polyvinyl acetal resin (2), the polyvinyl acetal resin (3), and the polyvinyl acetal resin (4) may be the same or different. The polyvinyl acetal resin (1) is preferably different from the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3), since this further improves the sound insulation.The thermoplastic resin (0), the thermoplastic resin (1), the thermoplastic resin (2), the thermoplastic resin (3), and the thermoplastic resin (4) may each be used alone or in combination of two or more thereof. The polyvinyl acetal resin (0), the polyvinyl acetal resin (1), the polyvinyl acetal resin (2), the polyvinyl acetal resin (3), and the polyvinyl acetal resin (4) may each be used alone or in combination of two or more thereof.

[0236] 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.

[0237] 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%.

[0238] 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.

[0239] The average degree of polymerization of the polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Testing method for polyvinyl alcohol."

[0240] 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.

[0241] 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.

[0242] 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.

[0243] 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, even more preferably 22 mol% or more, and preferably 28 mol% or less, more preferably 27 mol% or less, even more preferably 25 mol% or less, and particularly preferably 24 mol% or less. When the hydroxyl group content is at least the lower limit, the mechanical strength of the interlayer film is further increased. In particular, when the hydroxyl group content of the polyvinyl acetal resin (1) is 20 mol% or more, the reaction efficiency is high and productivity is excellent, and when it is 28 mol% or less, the sound insulation of the laminated glass is further improved. Furthermore, when the hydroxyl group content is at most the upper limit, the flexibility of the interlayer film is high, making it easier to handle.

[0244] When the colored layer is embedded in the first layer, the preferred range of the hydroxyl group content of the polyvinyl acetal resin (4) is the same as the preferred range of the hydroxyl group content of the polyvinyl acetal resin (1). When the colored layer is not embedded in the second layer or the third layer and is not a surface layer of an interlayer film, the preferred range of the hydroxyl group content of the polyvinyl acetal resin (4) is the same as the preferred range of the hydroxyl group content of the polyvinyl acetal resin (1).

[0245] The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) is preferably 25 mol% or more, more preferably 28 mol% or more, more preferably 30 mol% or more, even more preferably 31.5 mol% or more, even more preferably 32 mol% or more, and particularly preferably 33 mol% or more. The hydroxyl group content (hydroxyl group amount) of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) is preferably 38 mol% or less, more preferably 37 mol% or less, even more preferably 36.5 mol% or less, and particularly preferably 36 mol% or less. When the hydroxyl group content is above the lower limit, the adhesive strength of the interlayer film is further increased. On the other hand, when the hydroxyl group content is below the upper limit, the flexibility of the interlayer film is increased, making the interlayer film easier to handle.

[0246] When the colored layer is embedded in the second layer or the third layer, the preferred range of the hydroxyl group content of the polyvinyl acetal resin (4) is the same as the preferred range of the hydroxyl group content of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3). When the colored layer is a surface layer of an interlayer film, the preferred range of the hydroxyl group content of the polyvinyl acetal resin (4) is the same as the preferred range of the hydroxyl group content of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3).

[0247] 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 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 (3). 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 defined as absolute value A, and 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 (3) is defined as absolute value B. From the viewpoint of further improving sound insulation, the absolute values ​​A and B are each preferably 1 mol % or more, more preferably 5 mol % or more, even more preferably 9 mol % or more, particularly preferably 10 mol % or more, and most preferably 12 mol % or more. The absolute value A and the absolute value B are each preferably 20 mol % or less.

[0248] There are cases where the colored layer is embedded in the first layer, and cases where the colored layer is not embedded in the second layer and the third layer and is not a surface layer of the interlayer film. In these cases, from the viewpoint of further improving sound insulation, the hydroxyl group content of the polyvinyl acetal resin (4) is preferably lower than the hydroxyl group content of the polyvinyl acetal resin (2). From the viewpoint of further improving sound insulation, the hydroxyl group content of the polyvinyl acetal resin (4) is preferably lower than the hydroxyl group content of the polyvinyl acetal resin (3). The absolute value of the difference between the hydroxyl group content of the polyvinyl acetal resin (4) and the hydroxyl group content of the polyvinyl acetal resin (2) is defined as absolute value C, and the absolute value of the difference between the hydroxyl group content of the polyvinyl acetal resin (4) and the hydroxyl group content of the polyvinyl acetal resin (3) is defined as absolute value D. From the viewpoint of further improving sound insulation, the absolute value C and the absolute value D are each preferably 1 mol % or more, more preferably 5 mol % or more, even more preferably 9 mol % or more, particularly preferably 10 mol % or more, and most preferably 12 mol % or more. The absolute value C and the absolute value D are each preferably 20 mol % or less.

[0249] The colored layer may be embedded in the second layer or the third layer, or may be a surface layer of an interlayer film. In these cases, 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 (4). From the viewpoint of 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 (4) 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. 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 (4) is preferably 20 mol% or less.

[0250] 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."

[0251] The degree of acetylation (amount of acetyl groups) of the polyvinyl acetal resin (0) is preferably 0.1 mol% or more, more preferably 0.3 mol% or more, even more preferably 0.5 mol% or more, and preferably 30 mol% or less, more preferably 25 mol% or less, even more preferably 20 mol% or less. When the degree of acetylation is equal to or greater than the lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer is improved. When the degree of acetylation is equal to or less than the upper limit, the moisture resistance of the interlayer film and laminated glass is improved.

[0252] 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.

[0253] When the colored layer is embedded in the first layer, the preferred range of the acetylation degree of the polyvinyl acetal resin (4) is the same as the preferred range of the acetylation degree of the polyvinyl acetal resin (1). When the colored layer is not embedded in the second layer or the third layer and is not a surface layer of an interlayer film, the preferred range of the acetylation degree of the polyvinyl acetal resin (4) is the same as the preferred range of the acetylation degree of the polyvinyl acetal resin (1).

[0254] The degree of acetylation (acetyl group amount) of each of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) is preferably 0.01 mol% or more, more preferably 0.5 mol% or more, and preferably 10 mol% or less, more preferably 2 mol% or less. When the degree of acetylation is 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.

[0255] When the colored layer is embedded in the second layer or the third layer, the preferred range of the acetylation degree of the polyvinyl acetal resin (4) is the same as the preferred range of the acetylation degree of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3). When the colored layer is a surface layer of an interlayer film, the preferred range of the acetylation degree of the polyvinyl acetal resin (4) is the same as the preferred range of the acetylation degree of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3).

[0256] 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."

[0257] 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.

[0258] 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.

[0259] When the colored layer is embedded in the first layer, the preferred range of the acetalization degree of the polyvinyl acetal resin (4) is the same as the preferred range of the acetalization degree of the polyvinyl acetal resin (1). When the colored layer is not embedded in the second layer or the third layer and is not a surface layer of an interlayer film, the preferred range of the acetalization degree of the polyvinyl acetal resin (4) is the same as the preferred range of the acetalization degree of the polyvinyl acetal resin (1).

[0260] The degree of acetalization of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3) (the degree of butyralization in the case of a polyvinyl butyral resin) is preferably 55 mol% or more, more preferably 60 mol% or more, and preferably 75 mol% or less, more preferably 71 mol% or less. When the degree of acetalization is 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.

[0261] When the colored layer is embedded in the second layer or the third layer, the preferred range of the acetalization degree of the polyvinyl acetal resin (4) is the same as the preferred range of the acetalization degree of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3). When the colored layer is a surface layer of an interlayer film, the preferred range of the acetalization degree of the polyvinyl acetal resin (4) is the same as the preferred range of the acetalization degree of the polyvinyl acetal resin (2) and the polyvinyl acetal resin (3).

[0262] 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.

[0263] 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."

[0264] 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 is preferably 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.

[0265] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the first layer is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the first layer is preferably 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin in the first layer is preferably polyvinyl acetal resin.

[0266] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the second layer is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the second layer is preferably 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin in the second layer is preferably polyvinyl acetal resin.

[0267] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the third layer is preferably 10% by weight or more, more preferably 30% by weight or more, even more preferably 50% by weight or more, even more preferably 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the third layer is preferably 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin in the third layer is preferably polyvinyl acetal resin.

[0268] The content of polyvinyl acetal resin in 100% by weight of the thermoplastic resin contained in the colored 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 colored layer is preferably 100% by weight or less. The main component (50% by weight or more) of the thermoplastic resin in the colored layer is preferably polyvinyl acetal resin.

[0269] (plasticizer) From the viewpoint of further increasing the adhesive strength of the interlayer film, the interlayer film according to the present invention preferably contains a plasticizer (hereinafter, sometimes referred to as plasticizer (0)). The first layer preferably contains a plasticizer (hereinafter, sometimes referred to as plasticizer (1)). The second layer preferably contains a plasticizer (hereinafter, sometimes referred to as plasticizer (2)). The third layer preferably contains a plasticizer (hereinafter, sometimes referred to as plasticizer (3)). The colored layer preferably contains a plasticizer (hereinafter, sometimes referred to as plasticizer (4)). 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 a polyvinyl acetal resin preferably contains a plasticizer.

[0270] 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.

[0271] Examples of the plasticizer include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, and organic phosphoric acid plasticizers such as organic phosphoric acid plasticizers and organic phosphorous acid plasticizers. The plasticizer is preferably an organic ester plasticizer. The plasticizer is preferably a liquid plasticizer.

[0272] 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.

[0273] 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.

[0274] 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. Adipate esters other than the above-mentioned adipates may also be used.

[0275] Examples of the organic phosphoric acid plasticizer include tributoxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate.

[0276] The plasticizer is preferably a diester plasticizer represented by the following formula (1):

[0277] [ka]

[0278] 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.

[0279] 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.

[0280] 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.

[0281] In the first layer, the content of the plasticizer (1) relative to 100 parts by weight of the thermoplastic resin (1) is defined as content (1). 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.

[0282] When the colored layer is embedded in the first layer, the preferred range of the content of the plasticizer (4) (hereinafter sometimes referred to as content (4)) relative to 100 parts by weight of the thermoplastic resin (4) in the colored layer is the same as the preferred range of content (1). When the colored layer is not embedded in the second layer or the third layer and is not a surface layer of an interlayer film, the preferred range of the content of the plasticizer (4) (hereinafter sometimes referred to as content (4)) relative to 100 parts by weight of the thermoplastic resin (4) in the colored layer is the same as the preferred range of content (1).

[0283] In the second layer, the content of the plasticizer (2) relative to 100 parts by weight of the thermoplastic resin (2) is defined as content (2). In the third layer, the content of the plasticizer (3) relative to 100 parts by weight of the thermoplastic resin (3) is defined as content (3). The contents (2) and (3) are each preferably 5 parts by weight or more, more preferably 10 parts by weight or more, even more preferably 15 parts by weight or more, even more preferably 20 parts by weight or more, particularly preferably 24 parts by weight or more, and most preferably 25 parts by weight or more. The contents (2) and (3) are each preferably 45 parts by weight or less, more preferably 40 parts by weight or less, even more preferably 35 parts by weight or less, particularly preferably 32 parts by weight or less, and most preferably 30 parts by weight or less. When the contents (2) and (3) are equal to or greater than the lower limits, the flexibility of the interlayer film is increased, making the interlayer film easier to handle. When the content (2) and the content (3) are equal to or less than the upper limit, the penetration resistance of the laminated glass is further improved.

[0284] When the colored layer is embedded in the second layer or the third layer, the preferred range of the content of the plasticizer (4) (hereinafter sometimes referred to as content (4)) relative to 100 parts by weight of the thermoplastic resin (4) is the same as the preferred ranges of content (2) and content (3). When the colored layer is a surface layer of an interlayer film, the preferred range of the content of the plasticizer (4) (hereinafter sometimes referred to as content (4)) relative to 100 parts by weight of the thermoplastic resin (4) is the same as the preferred ranges of content (2) and content (3).

[0285] In order to improve the sound insulation of the laminated glass, the content (1) is preferably greater than the content (2), and the content (1) is preferably greater than the content (3).

[0286] When the colored layer is embedded in the first layer and when the colored layer is not a surface layer of an interlayer film, the content (4) is preferably greater than the content (2), and the content (4) is preferably greater than the content (3), in order to improve the sound insulation of the laminated glass.

[0287] When the colored layer is embedded in the second layer or the third layer, or when the colored layer is a surface layer of an interlayer film, the content (1) is preferably greater than the content (4) in order to improve the sound insulation of the laminated glass.

[0288] From the viewpoint of further improving the sound insulation of the laminated glass, the absolute value of the difference between the content (2) and the content (1) and the absolute value of the difference between the content (3) and the content (1) are each preferably 10 parts by weight or more, more preferably 15 parts by weight or more, and even more preferably 20 parts by weight or more. The absolute value of the difference between the content (2) and the content (1) and the absolute value of the difference between the content (3) and the content (1) are each preferably 80 parts by weight or less, more preferably 75 parts by weight or less, and even more preferably 70 parts by weight or less.

[0289] There are cases where the colored layer is embedded in the first layer, and cases where the colored layer is not embedded in the second layer and the third layer and is not a surface layer of an interlayer film. In these cases, 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 (4) and the absolute value of the difference between the content (3) and the content (4) are each preferably 10 parts by weight or more, more preferably 15 parts by weight or more, and even more preferably 20 parts by weight or more. The absolute value of the difference between the content (2) and the content (4) and the absolute value of the difference between the content (3) and the content (4) are each preferably 80 parts by weight or less, more preferably 75 parts by weight or less, and even more preferably 70 parts by weight or less.

[0290] When the colored layer is embedded in the second layer or the third layer, or when the colored layer is a surface layer of an interlayer film, from the viewpoint of further improving the sound insulation of the laminated glass, the absolute value of the difference between the content (4) and the content (1) is preferably 10 parts by weight or more, more preferably 15 parts by weight or more, and even more preferably 20 parts by weight or more. The absolute value of the difference between the content (4) and the content (1) is preferably 80 parts by weight or less, more preferably 75 parts by weight or less, and even more preferably 70 parts by weight or less.

[0291] (coloring agent) The intermediate film preferably contains a colorant. The colored layer preferably contains a colorant. Examples of the colorant include inorganic particles, pigments, and dyes.

[0292] Examples of the inorganic particles include carbon black particles, carbon nanotube particles, graphene particles, iron oxide particles, zinc oxide particles, calcium carbonate particles, alumina particles, kaolin clay particles, calcium silicate particles, magnesium oxide particles, magnesium hydroxide particles, aluminum hydroxide particles, magnesium carbonate particles, talc particles, feldspar powder particles, mica particles, baryte particles, barium carbonate particles, titanium oxide particles, silica particles, and glass beads. Only one type of the inorganic particles may be used, or two or more types may be used in combination.

[0293] The inorganic particles preferably include carbon black particles, carbon nanotube particles, graphene particles, calcium carbonate particles, titanium oxide particles, or silica particles, and more preferably calcium carbonate particles. Use of these preferred inorganic particles reduces unevenness in appearance when light passes through, thereby providing laminated glass with even more excellent appearance design.

[0294] The average particle size of the inorganic particles is preferably 0.01 μm or more, more preferably 0.5 μm or more, and preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 10 μm or less. The average particle size indicates the weight-average particle size. The average particle size can be measured by dynamic light scattering using a light scattering measurement device with a laser as a light source. An example of the light scattering measurement device is the "DLS-6000AL" manufactured by Otsuka Electronics Co., Ltd.

[0295] Examples of the dye include pyrene-based dyes, aminoketone-based dyes, anthraquinone-based dyes, azo-based dyes, etc. The dyes may be used alone or in combination of two or more.

[0296] Examples of the pyrene dye include Solvent Green 5 (CAS79869-59-3) and Solvent Green 7 (CAS6358-69-6).

[0297] Examples of the aminoketone dyes include Solvent Yellow 98 (CAS12671-74-8), Solvent Yellow 85 (CAS12271-01-1), Solvent Red 179 (CAS8910-94-5), and Solvent Red 135 (CAS71902-17-5).

[0298] Examples of the anthraquinone dyes include Solvent Yellow 163 (CAS13676091-0), Solvent Red 207 (CAS15958-69-6), Disperse Red 92 (CAS12236-11-2), Solvent Violet 13 (CAS81-48-1), Disperse Violet 31 (CAS6408-72-6), Solvent Blue 97 (CAS61969-44-6), Solvent Blue 45 (CAS37229-23-5), Solvent Blue 104 (CAS116-75-6), and Disperse Blue 214 (CAS104491-84-1).

[0299] Examples of the azo dyes include Solvent Yellow 30 (CAS 3321-10-4), Solvent Red 164 (CAS 70956-30-8), and Disperse Blue 146 (CAS 88650-91-3).

[0300] The pigment may be an organic pigment or an inorganic pigment. The organic pigment may be an organic pigment having a metal atom or an organic pigment not having a metal atom. Only one type of the pigment may be used, or two or more types may be used in combination.

[0301] Examples of the organic pigment include phthalocyanine compounds, quinacridone compounds, azo compounds, pentaphene compounds, perylene compounds, indole compounds, and dioxazine compounds.

[0302] Other examples of colorants include dark reddish-brown mixed pigments that are a mixture of black pigment (carbon black), red pigment (CI Pigment red), blue pigment (CI Pigment blue), and yellow pigment (CI Pigment yellow).

[0303] (heat-shielding material) The intermediate film preferably contains a heat-shielding material. The first layer preferably contains a heat-shielding material. The second layer preferably contains a heat-shielding material. The third layer preferably contains a heat-shielding material. The colored 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.

[0304] 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. The heat-shielding material may also correspond to the colorant.

[0305] Ingredient X: The interlayer film preferably contains at least one component X selected from a phthalocyanine compound, a naphthalocyanine compound, and an anthracyanine compound. The first layer preferably contains the component X. The second layer preferably contains the component X. The third layer preferably contains the component X. The colored layer preferably contains the component X. The component X is a heat-shielding material. Only one type of component X may be used, or two or more types may be used in combination.

[0306] 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.

[0307] 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.

[0308] 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.

[0309] From the viewpoint of effectively improving the heat-shielding properties and maintaining a higher visible light transmittance for a long period of time, the component X preferably contains a vanadium atom or a copper atom. The component X preferably contains a vanadium atom, and also preferably contains a copper atom. The component X is more preferably 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 component X preferably has a structural unit in which an oxygen atom is bonded to a vanadium atom.

[0310] The content of component X in 100 wt% of the interlayer film or in 100 wt% of the layer containing component X (first layer, second layer, third layer, or colored layer) is preferably 0.001 wt% or more, more preferably 0.005 wt% or more, even more preferably 0.01 wt% or more, and particularly preferably 0.02 wt% or more. The content of component X in 100 wt% of the interlayer film or in 100 wt% of the layer containing component X (first layer, second layer, third layer, or colored 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 at least the above lower limit and at most 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.

[0311] Heat-shielding particles: The interlayer film preferably contains heat-shielding particles. The first layer preferably contains heat-shielding particles. The second layer preferably contains heat-shielding particles. The third layer preferably contains heat-shielding particles. The colored layer preferably contains heat-shielding particles. The heat-shielding particles are a heat-shielding material. The use of heat-shielding particles can effectively block infrared rays (heat rays). Only one type of heat-shielding particle may be used, or two or more types may be used in combination.

[0312] 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).

[0313] Infrared rays, which have wavelengths of 780 nm or more, which are longer than visible light, 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.

[0314] Specific 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, sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles, thallium-doped tungsten oxide particles, rubidium-doped tungsten oxide particles, tin-doped indium oxide particles (ITO particles), tin-doped zinc oxide particles, and silicon-doped zinc oxide particles, as well as lanthanum hexaboride (LaB6) particles. Other heat-shielding particles may also be used. Metal oxide particles are preferred due to their high heat-shielding function, with ATO particles, GZO particles, IZO particles, ITO particles, or tungsten oxide particles being more preferred, and ITO particles or tungsten oxide particles being particularly preferred. In particular, tin-doped indium oxide particles (ITO particles) are preferred because they have a high heat ray shielding function and are easily available, and tungsten oxide particles are also preferred.

[0315] 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. Specific examples of the metal-doped tungsten oxide particles include sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles, thallium-doped tungsten oxide particles, and rubidium-doped tungsten oxide particles.

[0316] 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.

[0317] 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.

[0318] 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.

[0319] The content of the heat-shielding particles (particularly the content of tungsten oxide particles) in 100 weight % of the interlayer film or 100 weight % of the layer containing the heat-shielding particles (first layer, second layer, third layer, or colored layer) is preferably 0.01 weight % or more, more preferably 0.1 weight % or more, even more preferably 1 weight % or more, and particularly preferably 1.5 weight % or more. The content of the heat-shielding particles (particularly the content of tungsten oxide particles) in 100 weight % of the interlayer film or 100 weight % of the layer containing the heat-shielding particles (first layer, second layer, third layer, or colored layer) is preferably 6 weight % or less, more preferably 5.5 weight % or less, even more preferably 4 weight % or less, particularly preferably 3.5 weight % or less, and most preferably 3 weight % or less. When the content of the heat-shielding particles is at least the above lower limit and at most the above upper limit, the heat shielding property is sufficiently high and the visible light transmittance is sufficiently high.

[0320] (metal salts) The interlayer film preferably contains at least one metal salt (hereinafter sometimes referred to as metal salt M) selected from alkali metal salts and alkaline earth metal salts. The first layer preferably contains the metal salt M. The second layer preferably contains the metal salt M. The third layer preferably contains the metal salt M. The colored 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.

[0321] 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.

[0322] 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.

[0323] 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.

[0324] The total content of Mg and K in the interlayer film containing the metal salt M or in the layer (first layer, second layer, third layer, or colored layer) containing the metal salt M is preferably 5 ppm or more, more preferably 10 ppm or more, and even more preferably 20 ppm or more, and is preferably 300 ppm or less, more preferably 250 ppm or less, and even more preferably 200 ppm or less. When the total content of Mg and K is 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 laminated glass member (such as glass plates) or the adhesion between the layers in the interlayer film can be more effectively controlled.

[0325] (UV screening agent) The interlayer film preferably contains an ultraviolet blocking agent. The first layer preferably contains an ultraviolet blocking agent. The second layer preferably contains an ultraviolet blocking agent. The third layer preferably contains an ultraviolet blocking agent. The colored layer preferably contains an ultraviolet blocking agent. By using an ultraviolet blocking agent, the visible light transmittance of the interlayer film and laminated glass is more unlikely to decrease even after long-term use. The ultraviolet blocking agents may be used alone or in combination of two or more.

[0326] The ultraviolet screening agent includes an ultraviolet absorbing agent, and the ultraviolet screening agent is preferably an ultraviolet absorbing agent.

[0327] 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).

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 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.

[0332] 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.

[0333] Examples of the ultraviolet screening agent having a benzophenone structure include octabenzone ("Chimassorb 81" manufactured by BASF).

[0334] 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).

[0335] 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.

[0336] 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).

[0337] Examples of the ultraviolet screening agent having the oxalic acid anilide structure include oxalic acid diamides having an aryl group substituted on the nitrogen atom, such as N-(2-ethylphenyl)-N'-(2-ethoxy-5-t-butylphenyl)oxalic acid diamide, N-(2-ethylphenyl)-N'-(2-ethoxy-phenyl)oxalic acid diamide, and 2-ethyl-2'-ethoxy-oxalanilide ("Sanduvor VSU" manufactured by Clariant).

[0338] 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).

[0339] The content of the ultraviolet screening agent and the content of the benzotriazole compound in 100% by weight of the interlayer film or 100% by weight of the layer containing the ultraviolet screening agent (first layer, second layer, third layer, or colored layer) is preferably 0.1% by weight or more, more preferably 0.2% by weight or more, even more preferably 0.3% by weight or more, and particularly preferably 0.5% by weight or more. In this case, the decrease in visible light transmittance over time is further suppressed. The content of the ultraviolet screening agent and the content of the benzotriazole compound in 100% by weight of the interlayer film or 100% by weight of the layer containing the ultraviolet screening agent (first layer, second layer, third layer, or colored layer) is preferably 2.5% by weight or less, more preferably 2% by weight or less, even more preferably 1% by weight or less, and particularly preferably 0.8% by weight or less. In particular, by making the content of the ultraviolet ray blocking agent 0.2% by weight or more in 100% by weight of the layer containing the ultraviolet ray blocking agent, it is possible to significantly suppress the decrease in visible light transmittance of the interlayer film and laminated glass over time.

[0340] (antioxidant) The interlayer film preferably contains an antioxidant. The first layer preferably contains an antioxidant. The second layer preferably contains an antioxidant. The third layer preferably contains an antioxidant. The colored layer preferably contains an antioxidant. Only one type of antioxidant may be used, or two or more types may be used in combination.

[0341] 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.

[0342] The antioxidant is preferably a phenol-based antioxidant or a phosphorus-based antioxidant.

[0343] 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.

[0344] 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.

[0345] 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.

[0346] In order to maintain high visible light transmittance of the interlayer film and laminated glass for a long period of time, the content of the antioxidant in 100% by weight of the interlayer film or 100% by weight of the layer containing the antioxidant (first layer, second layer, third layer, or colored layer) is preferably 0.03% by weight or more, and more preferably 0.1% by weight or more. Furthermore, since the effect of adding the antioxidant becomes saturated, the content of the antioxidant in 100% by weight of the interlayer film or 100% by weight of the layer containing the antioxidant is preferably 2% by weight or less.

[0347] (Other ingredients) The intermediate film, the first layer, the second layer, the third layer, and the colored 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.

[0348] (Infrared reflective layer) The intermediate film may have an infrared reflective layer. The infrared reflective layer reflects infrared rays. The infrared reflective layer is not particularly limited as long as it has the ability to reflect infrared rays.

[0349] Examples of the infrared reflective layer include a resin film with a metal foil, a multilayer laminate film in which a metal layer and a dielectric layer are formed on a resin layer, a multilayer resin film, a liquid crystal film, etc. These films have the ability to reflect infrared rays.

[0350] The infrared reflective layer is particularly preferably a metal foil-coated resin film, a multilayer resin film, or a liquid crystal film. These films have excellent infrared reflective properties. Therefore, the use of these films can provide laminated glass with even higher heat shielding properties and capable of maintaining high visible light transmittance for an even longer period of time.

[0351] The metal foil-coated resin film includes a resin film and a metal foil laminated on the outer surface of the resin film. Examples of materials for the resin film include polyethylene terephthalate resin, polyethylene naphthalate resin, polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ethylene-acrylic acid copolymer resin, polyurethane resin, polyvinyl alcohol resin, polyolefin resin, polyvinyl chloride resin, and polyimide resin. Examples of materials for the metal foil include aluminum, copper, silver, gold, palladium, and alloys containing these.

[0352] The multilayer laminate film in which a metal layer and a dielectric layer are formed on the resin layer is a multilayer laminate film in which any number of metal layers and dielectric layers are alternately laminated on a resin layer (resin film). In the multilayer laminate film in which a metal layer and a dielectric layer are formed on the resin layer, it is preferable that all of the metal layers and dielectric layers are alternately laminated, but there may be a structural portion in which some of the layers are not alternately laminated, such as metal layer / dielectric layer / metal layer / dielectric layer / metal layer / metal layer / dielectric layer / metal layer.

[0353] Materials for the resin layer (resin film) in the multilayer laminate film include the same materials as those for the resin film in the metal foil-attached resin film. Materials for the resin layer (resin film) in the multilayer laminate film include polyethylene, polypropylene, polylactic acid, poly(4-methylpentene-1), polyvinylidene fluoride, cyclic polyolefins, polymethyl methacrylate, polyvinyl chloride, polyvinyl alcohol, polyamides such as nylon 6, 11, 12, and 66, polystyrene, polycarbonate, polyethylene terephthalate, polyethylene naphthalate, polyester, polyphenylene sulfide, and polyetherimide. Materials for the metal layer in the multilayer laminate film include the same materials as those for the metal foil in the metal foil-attached resin film. A coating layer of metal or a mixed oxide of metals can be applied to both or one side of the metal layer. Materials for the coating layer include ZnO, Al2O3, Ga2O3, InO3, MgO, Ti, NiCr, and Cu.

[0354] Examples of materials for the dielectric layers in the multilayer laminated film include indium oxide.

[0355] The multilayer resin film is a laminate film in which a plurality of resin films are laminated. Examples of materials for the multilayer resin film include the same materials as those for the resin layers (resin films) in the multilayer laminate film. The number of resin films laminated in the multilayer resin film is 2 or more, or may be 3 or more, or may be 5 or more. The number of resin films laminated in the multilayer resin film may be 1000 or less, or may be 100 or less, or may be 50 or less.

[0356] The multilayer resin film may be a multilayer resin film in which two or more types of thermoplastic resin layers having different optical properties (refractive indexes) are alternately or randomly laminated in any number of layers, and is configured to obtain the desired infrared reflectivity.

[0357] The liquid crystal film may be a film formed by laminating any number of cholesteric liquid crystal layers that reflect light of any wavelength, and is configured to provide the desired infrared reflectivity.

[0358] In order to achieve excellent infrared reflection performance, the infrared reflective layer preferably has an infrared transmittance of 40% or less at at least one wavelength in the range of 800 nm to 2000 nm, more preferably 30% or less, and even more preferably 20% or less at at least one wavelength in the range of 800 nm to 2000 nm.

[0359] Specifically, the transmittance of the infrared reflective layer at each wavelength in the range of 800 nm to 2000 nm is measured as follows: A single infrared reflective layer is prepared. Using a spectrophotometer (Hitachi High-Technologies Corporation's "U-4100"), the spectral transmittance of the infrared reflective layer at each wavelength in the range of 800 nm to 2000 nm is measured in accordance with JIS R3106:1998.

[0360] (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.

[0361] The interlayer film can be produced, for example, by the method described in JP 2006-231521 A (Method 1, conduit method) or the method described in WO 2009 / 001856 A1 (Method 2, Feed Block method (FB method)). Method 1 (conduit method) can satisfactorily produce interlayer films having the colored layer shapes shown in Figures 1, 3, 5, 7, 9, 11, 13, and 14. Method 2 (FB method) can satisfactorily produce interlayer films having the colored layer shapes shown in Figures 2, 4, 6, 8, 10, and 12.

[0362] More specifically, the interlayer film can be produced as follows.

[0363] (1) In the conduit method, by adjusting the slit shape of the conduit, it is possible to satisfactorily obtain the gradation portion, the transparent portion, and the dark portion, in which the parallel light transmittance and the rate of change in the parallel light transmittance satisfy specific ranges. In particular, it is possible to satisfactorily obtain a wedge-shaped interlayer film with a uniform thickness in the dark portion. (2) In the FB method, by adjusting the slit shape in the FB, it is possible to satisfactorily obtain the gradation portion, the transparent portion, and the dark portion, in which the parallel light transmittance and the rate of change in the parallel light transmittance satisfy specific ranges. In particular, it is possible to satisfactorily obtain a wedge-shaped interlayer film with a uniform thickness in the dark portion. (3) By adjusting the shape of the mold outlet, it is possible to make the thickness on the other end side uniform, and it is possible to satisfactorily obtain the gradation portion, the transparent portion, and the dark portion, in which the parallel light transmittance and the rate of change in the parallel light transmittance satisfy specific ranges. In particular, it is possible to satisfactorily obtain a wedge-shaped interlayer film with a uniform thickness in the dark portion. (4) After a uniformly thick dark-colored portion (rectangular intermediate layer) is extruded using a conventional method, a wedge-shaped layer is laminated onto the rectangular intermediate layer. This method allows for easy lamination of a high-performance layer, such as an infrared reflective layer, between the rectangular intermediate layer and the wedge-shaped layer.

[0364] In view of excellent production efficiency of the interlayer film, it is preferable that the second layer and the third layer contain the same polyvinyl acetal resin. In view of excellent production efficiency of the interlayer film, it is more preferable that the second layer and the third layer contain the same polyvinyl acetal resin and the same plasticizer. In view of excellent production efficiency of the interlayer film, it is even more preferable that the second layer and the third layer are formed from the same resin composition.

[0365] The interlayer film preferably has an uneven shape on at least one of its two surfaces. It is more preferable that the interlayer film has an uneven shape on both surfaces. The method for forming the uneven shape is not particularly limited, and examples thereof include lip embossing, embossing roll, calendar roll, and profile extrusion. The embossing roll method is preferred because it can quantitatively form a large number of uneven embossments with a consistent uneven pattern.

[0366] (Laminated glass) The laminated glass of the present invention includes a first laminated glass member, a second laminated glass member, and the above-described interlayer film for laminated glass. In the laminated glass of the present invention, the above-described interlayer film for laminated glass is disposed between the first laminated glass member and the second laminated glass member.

[0367] The laminated glass according to the present invention has one end and another end opposite the one end. The one end and the other end are opposite ends of the laminated glass. In the laminated glass according to the present invention, the thickness of the other end is greater than the thickness of the one end.

[0368] The above laminated glass was measured for parallel light transmittance as follows.

[0369] Measurement of parallel light transmittance: (1) Starting from a position 2 cm from the one end toward the other end, multiple points A are selected at 1 cm intervals from the starting point toward the other end. (2) The parallel light transmittance of the laminated glass is measured at each point A. (3) The x-axis direction is defined as the "distance from the one end" and the y-axis direction is defined as the "parallel light transmittance," and an approximate line is created in a 2 cm area from three points: one point A and two points 1 cm away from point A on both sides of the direction connecting the one end and the other end. The absolute value of the parallel light transmittance ratio calculated from the approximate line is defined as the "absolute value of the change ratio of parallel light transmittance" at the one point A. The "absolute value of the change ratio of parallel light transmittance" is calculated for each point A.

[0370] In the above (1), points A are set at 1 cm intervals. Points are selected from one end of the laminated glass to the other end so that points can be selected at 1 cm intervals (positions where the interval is not less than 1 cm and the distance between point A and the other end is not less than 2 cm). The point A closest to the one end of the laminated glass is point A1, which is 2 cm from the one end toward the other end of the laminated glass, and the next point A is point A2, which is 3 cm from the one end toward the other end of the laminated glass. The next point A is point A3, which is 4 cm from the one end toward the other end of the laminated glass. Point An is located (n+1) cm from the one end toward the other end of the laminated glass (n is a natural number). Point A1, point A2, and point A3 are each included in the points A set at 1 cm intervals in the above (1). For convenience, the point 1 cm from the one end toward the other end of the laminated glass is referred to as point A0. Note that point A0 is not included in points A that are set at intervals of 1 cm in the above (1).

[0371] In the above (2), the parallel light transmittance of the laminated glass is measured at each position A. Therefore, the number of parallel light transmittance values ​​obtained is equal to the number of positions A. The parallel light transmittance of the laminated glass is measured in accordance with JIS R3106:1998. Specifically, it is measured as follows.

[0372] Using a spectrophotometer, the laminated glass was placed parallel to the normal to the optical axis on the optical path between the light source and the integrating sphere, at a distance of 13 cm from the integrating sphere, so that only the transmitted parallel light was received by the integrating sphere. The parallel light transmittance refers to the visible light transmittance calculated from the spectral transmittance measured in this state. Examples of the spectrophotometer include the "U-4100" manufactured by Hitachi High-Technologies Corporation.

[0373] In (3) above, the "three points, namely, point A1 closest to the one end of the laminated glass and two points 1 cm away from point A1 on either side of the one end in the direction connecting the one end and the other end" refer to the following three points: points 1 cm, 2 cm, and 3 cm from the one end of the laminated glass toward the other end. In other words, points A0, A1, and A2. From the parallel light transmittances at points A0, A1, and A2, an approximation line is created with the x-axis direction defined as the "distance from the one end" and the y-axis direction defined as the "parallel light transmittance." The absolute value of the rate of change in parallel light transmittance calculated from the resulting approximation line is defined as the "absolute value of the rate of change in parallel light transmittance at point A1."

[0374] In (3) above, the "three points, namely, point A2, which is the second closest to the one end of the laminated glass, and two points 1 cm away from point A2 on either side of the one end in the direction connecting the one end and the other end" refer to the following three points: points 2 cm, 3 cm, and 4 cm from the one end of the laminated glass toward the other end. In other words, points A1, A2, and A3. From the parallel light transmittances at points A1, A2, and A3, an approximation line is created with the x-axis direction defined as the "distance from the one end" and the y-axis direction defined as the "parallel light transmittance." The absolute value of the rate of change in parallel light transmittance calculated from the resulting approximation line is defined as the "absolute value of the rate of change in parallel light transmittance at point A2."

[0375] In the present invention, the "change rate of parallel light transmittance at point A3" and the "change rate of parallel light transmittance at point A(n-1)" are calculated in a similar manner. Since point A is selected as described above, the three points used to create the approximation curve do not lie in an area less than 1 cm from one end to the other end, and do not lie in an area less than 1 cm from the other end to the one end.

[0376] When the parallel light transmittance of the laminated glass is measured, the laminated glass has the following parts (1) to (3): In the present invention, the gradation part is determined, and then the transparent part and the dark part are determined.

[0377] (1) A gradation portion in which the parallel light transmittance decreases continuously from the one end side to the other end side, and the absolute value of the rate of change in the parallel light transmittance exceeds 0.3% / mm.

[0378] (2) A transparent portion located closer to the one end than the gradation portion and having a parallel light transmittance of 60% or more.

[0379] (3) A dark color portion that is located closer to the other end than the gradation portion and includes one or more points A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less.

[0380] Therefore, the laminated glass according to the present invention has, from one end to the other end, a transparent portion, a gradation portion, and a dark portion. The gradation portion and the dark portion form a shade region.

[0381] The laminated glass according to the present invention has the above-described configuration, and therefore has a dark portion in the shade region with a uniform parallel light transmittance, thereby making it possible to suppress color unevenness in the shade region. The laminated glass according to the present invention has a dark portion in the shade region with a uniform parallel light transmittance, even though the thickness of the other end is greater than the thickness of the one end, and therefore makes it possible to suppress color unevenness in the shade region.

[0382] The dark color portion may include a point A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less, and a point A where the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm. Of the multiple points A, a point A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less is referred to as point Aa. Of the multiple points A, a point A where the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm is referred to as point Ab. In this case, the dark color portion may include one or more points Aa. The dark color portion may include one or more points Ab in addition to point Aa. Furthermore, "(3) a dark color portion located on the other end side of the gradation portion and including one or more points A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less" means "(3) a dark color portion located on the other end side of the gradation portion and including one or more points Aa where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less."

[0383] FIG. 15 is a cross-sectional view that schematically shows an example of laminated glass that uses the interlayer film for laminated glass shown in FIG.

[0384] The laminated glass 21 shown in FIG. 15 comprises a first laminated glass member 31, a second laminated glass member 32, and an interlayer film 1. The interlayer film 1 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 1. The second laminated glass member 32 is laminated on a second surface (the other surface) opposite the first surface of the interlayer film 1. The first laminated glass member 31 is laminated on the outer surface of the second layer 12 of the interlayer film 1. The second laminated glass member 32 is laminated on the outer surface of the third layer 13 of the interlayer film 1.

[0385] As described above, the laminated glass according to the present invention includes 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. In the laminated glass according to the present invention, the interlayer film is disposed between the first laminated glass member and the second laminated glass member.

[0386] The gradation portion is a region where, when the parallel light transmittance of the laminated glass is measured, the parallel light transmittance continuously decreases from one end to the other end, and the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm. The gradation portion may include a portion where the parallel light transmittance exceeds 60%. The gradation portion includes one or more points A where the rate of change in parallel light transmittance exceeds 0.3% / mm. The number of points A included in the gradation portion where the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm is preferably 1 or more, more preferably 2 or more, even more preferably 3 or more, particularly preferably 4 or more, and most preferably 5 or more. The number of points A included in the gradation portion where the absolute value of the rate of change in parallel light transmittance exceeds 0.3% / mm may be 1,500 or less, or may be 1,450 or less.

[0387] The transparent portion is a region located closer to the one end than the gradation portion and having a parallel light transmittance of 60% or more when the parallel light transmittance of the laminated glass is measured. The parallel light transmittance of the transparent portion is preferably 61% or more, more preferably 62% or more.

[0388] The dark color portion is a region located closer to the other end than the gradation portion when the parallel light transmittance of the laminated glass is measured, and includes point A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less. From the viewpoint of further suppressing color unevenness in the shade region, the absolute value of the rate of change in parallel light transmittance at point A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less is preferably 0.29% / mm or less, more preferably 0.28% / mm or less. From the viewpoint of further suppressing color unevenness in the shade region, the dark color portion preferably includes a point where the absolute value of the rate of change in parallel light transmittance is 0.29% / mm or less, and more preferably includes a point where the absolute value of the rate of change in parallel light transmittance is 0.28% / mm or less. From the viewpoint of further suppressing color unevenness in the shade region, it is preferable that the dark color portion includes a point where the absolute value of the rate of change in parallel light transmittance is 0.27% / mm or less, and it is more preferable that the dark color portion includes a point where the absolute value of the rate of change in parallel light transmittance is 0.26% / mm or less.

[0389] The laminated glass has a dark color portion including one or more points A where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less. The number of points A included in the dark color portion where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less is preferably 2 or more, more preferably 3 or more, even more preferably 4 or more, particularly preferably 5 or more, and most preferably 6 or more. The greater the number of points A included in the dark color portion where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less, the more effectively color unevenness in the shade region is suppressed. The number of points A included in the dark color portion where the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less may be 300 or less, or may be 299 or less.

[0390] The distance of the transparent portion in the direction connecting the one end and the other end of the laminated glass is defined as distance L1. The distance of the gradation portion in the direction connecting the one end and the other end of the laminated glass is defined as distance L2. The distance of the dark portion in the direction connecting the one end and the other end of the laminated glass is defined as distance L3. Distances L1, L2, and L3 are the distances shown in Figure 15.

[0391] The distance L1 is preferably 10 mm or more, more preferably 20 mm or more, and is preferably 3000 mm or less, more preferably 2990 mm or less.

[0392] The distance L2 is preferably 10 mm or more, more preferably 20 mm or more, and is preferably 3000 mm or less, more preferably 2990 mm or less.

[0393] The distance L3 is preferably 50 mm or more, more preferably 60 mm or more, and is preferably 3000 mm or less, more preferably 2990 mm or less.

[0394] The distance between the interlayer films in the direction connecting the one end and the other end of the laminated glass is defined as distance L.

[0395] The ratio of the distance L1 to the distance L (distance L1 / distance L) is preferably 0.02 or more, more preferably 0.03 or more, and is preferably 0.98 or less, more preferably 0.97 or less.

[0396] The ratio of the distance L2 to the distance L (distance L2 / distance L) is preferably 0.02 or more, more preferably 0.03 or more, and is preferably 0.98 or less, more preferably 0.97 or less.

[0397] The ratio of the distance L3 to the distance L (distance L3 / distance L) is preferably 0.05 or more, more preferably 0.051 or more, and is preferably 0.98 or less, more preferably 0.97 or less.

[0398] The first laminated glass member is preferably a first glass plate, and the second laminated glass member is preferably a second glass plate.

[0399] 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.

[0400] 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.

[0401] The thickness of each of the first laminated glass member and the second laminated glass member is preferably 1 mm or more, preferably 5 mm or less, more preferably 3 mm or less. When the laminated glass member is a glass plate, the thickness of the glass plate is preferably 0.5 mm or more, more preferably 0.7 mm or more, and preferably 5 mm or less, more preferably 3 mm or less. When the laminated glass member is a PET film, the thickness of the PET film is preferably 0.03 mm or more, and preferably 0.5 mm or less.

[0402] 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 obtain a laminated glass.

[0403] 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.

[0404] 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.

[0405] 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."

[0406] Example 1 Preparation of the composition for forming the first layer: The following components were blended and thoroughly kneaded with a mixing roll to obtain a composition for forming the first layer.

[0407] Polyvinyl acetal resin (average polymerization degree 3000, hydroxyl group content 22 mol%, acetylation degree 13 mol%, acetalization degree 65 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 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 in the resulting first layer BHT (2,6-di-t-butyl-p-cresol) in an amount to give 0.2% by weight in the resulting first layer

[0408] Preparation of compositions for forming the second and third layers: The following components were blended and thoroughly kneaded with a mixing roll to obtain compositions for forming the second and third layers.

[0409] Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 30.5 mol%, acetylation degree 1 mol%, acetalization degree 68.5 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 38 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 in the resulting second and third layers. BHT (2,6-di-t-butyl-p-cresol) in an amount to provide 0.2% by weight in the resulting second and third layers

[0410] Preparation of the composition for forming the color layer: The following components were blended and thoroughly kneaded with a mixing roll to obtain a composition for forming a colored layer.

[0411] Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 30.5 mol%, acetylation degree 1 mol%, acetalization degree 68.5 mol%) 100 parts by weight Triethylene glycol-di-2-ethylhexanoate (3GO) 40 parts by weight Calcium carbonate particles (inorganic particles, weight average particle diameter 5.0 μm) in an amount of 5.9% by weight in 100% by weight of the composition for forming the resulting colored layer (and in the resulting colored layer)

[0412] Preparation of interlayer: An interlayer film was produced using the FB method by adjusting the slit shape within the FB to ensure a uniform flow rate of the composition for forming the colored layer in the dark color area. The composition for forming the first layer, the compositions for forming the second and third layers, and the composition for forming the colored layer were co-extruded using an extruder, and the interlayer film was wound up to obtain a roll. In this way, a wedge-shaped interlayer film was produced. The obtained interlayer film had a minimum thickness at one end and a maximum thickness at the other end. The structure of the obtained interlayer film is shown in Table 2.

[0413] Laminated glass production: An interlayer film was sandwiched between two 2 mm thick clear glass sheets conforming to JIS R3202:1996 to obtain a laminate. The obtained laminate was placed in a rubber bag and degassed at a vacuum of 2.6 kPa for 20 minutes. The degassed laminate was then transferred to an oven and held at 90°C for a further 30 minutes for vacuum pressing to pre-bond the laminate. The pre-bonded laminate was then pressed in an autoclave for 20 minutes under conditions of 135°C and a pressure of 1.2 MPa to obtain a laminated glass. The obtained laminated glass corresponds to the above-mentioned laminated glass X.

[0414] (Example 3,4,6,7,9,11, Reference example 2,5,8,10, 12 and Comparative Examples 1 to 6) Except for changing the configuration of the interlayer film as shown in Tables 1 to 5, the interlayer film and laminated glass were produced by the FB method or the conduit method in the same manner as in Example 1.

[0415] ( reference Example 13) The following components were blended and thoroughly kneaded with a mixing roll to obtain compositions for forming the second and third layers.

[0416] Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 30.5 mol%, acetylation degree 1 mol%, acetalization degree 68.5 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 38 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 in the resulting second and third layers. BHT (2,6-di-t-butyl-p-cresol) in an amount to provide 0.2% by weight in the resulting second and third layers

[0417] Preparation of the composition for forming the color layer: The following components were blended and thoroughly kneaded with a mixing roll to obtain a composition for forming a colored layer.

[0418] Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 30.5 mol%, acetylation degree 1 mol%, acetalization degree 68.5 mol%) 100 parts by weight Triethylene glycol-di-2-ethylhexanoate (3GO) 40 parts by weight Calcium carbonate particles (inorganic particles, weight average particle diameter 5.0 μm) in an amount of 5.9% by weight in 100% by weight of the composition for forming the resulting colored layer (and in the resulting colored layer)

[0419] A coextrusion of the second layer and the colored layer, and a third layer were produced using the conduit method as follows. The resulting second layer and colored layer were coextruded using an extruder to obtain a coextrusion of the second layer and the colored layer. The composition for forming the third layer was extruded using an extruder to obtain the third layer. The coextrusion of the second layer and the colored layer had a rectangular shape, and the third layer had a minimum thickness at one end and a maximum thickness at the other end. The slit shape of the conduit was also adjusted to ensure a uniform flow rate of the composition for forming the colored layer in the dark colored portion.

[0420] Infrared reflective layer: The following infrared reflective layers were prepared:

[0421] XIR-75 (metal foil-coated resin film, "XIR-75" manufactured by Southwall Technologies)

[0422] The metal foil in XIR-75 has a five-layer structure of In2O3 / Ag / In2O3 / Ag / In2O3.

[0423] Laminated glass production: A laminate was obtained by sandwiching a co-extrusion of the second layer and the colored layer, an infrared reflective layer, and a third layer, in that order, between two 2mm-thick clear glass sheets conforming to JIS R3202:1996. The resulting laminate was placed in a rubber bag and degassed at a vacuum of 2.6 kPa for 20 minutes. The degassed laminate was then transferred to an oven and held at 90°C for 30 minutes for vacuum pressing to pre-bond the laminate. The pre-bonded laminate was then pressure-bonded in an autoclave for 20 minutes at 135°C and a pressure of 1.2 MPa to obtain a laminated glass. The resulting laminated glass corresponds to the laminated glass X described above.

[0424] (Example 16 ~18 and Reference Examples 14 and 15 ) Except for the changes in the interlayer structure and infrared reflective layer as shown in Tables 5 and 6, reference In the same manner as in Example 13, an interlayer film and a laminated glass were produced by the FB method or the conduit method.

[0425] The infrared reflective layer Nano90S in the table refers to the "Multi-Layer Nano 90S" manufactured by Sumitomo 3M.

[0426] ( reference Example 19) The following components were blended and thoroughly kneaded in a mixing roll to obtain a composition for forming the first layer.

[0427] Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 30.5 mol%, acetylation degree 1 mol%, acetalization degree 68.5 mol%) 100 parts by weight Triethylene glycol di-2-ethylhexanoate (3GO) 38 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 in the resulting second and third layers. BHT (2,6-di-t-butyl-p-cresol) in an amount to provide 0.2% by weight in the resulting second and third layers

[0428] Preparation of the composition for forming the color layer: The following components were blended and thoroughly kneaded with a mixing roll to obtain a composition for forming a colored layer.

[0429] Polyvinyl acetal resin (average polymerization degree 1700, hydroxyl group content 30.5 mol%, acetylation degree 1 mol%, acetalization degree 68.5 mol%) 100 parts by weight Triethylene glycol-di-2-ethylhexanoate (3GO) 40 parts by weight Calcium carbonate particles (inorganic particles, weight average particle diameter 5.0 μm) in an amount of 5.9% by weight in 100% by weight of the composition for forming the resulting colored layer (and in the resulting colored layer)

[0430] Preparation of interlayer: The interlayer film was produced using the FB method by adjusting the slit shape within the FB to ensure a uniform flow rate of the composition for forming the colored layer in the dark color area. The composition for forming the first layer and the composition for forming the colored layer were co-extruded using an extruder, and the interlayer film was wound up to obtain a roll. In this way, a wedge-shaped interlayer film was produced. The obtained interlayer film had a minimum thickness at one end and a maximum thickness at the other end. The structure of the obtained interlayer film is shown in Table 7.

[0431] Laminated glass production: An interlayer film was sandwiched between two 2 mm thick clear glass sheets conforming to JIS R3202:1996 to obtain a laminate. The obtained laminate was placed in a rubber bag and degassed at a vacuum of 2.6 kPa for 20 minutes. The degassed laminate was then transferred to an oven and held at 90°C for a further 30 minutes for vacuum pressing to pre-bond the laminate. The pre-bonded laminate was then pressed in an autoclave for 20 minutes under conditions of 135°C and a pressure of 1.2 MPa to obtain a laminated glass. The obtained laminated glass corresponds to the above-mentioned laminated glass X.

[0432] ( reference Example 20 and Comparative Examples 7 and 8) Except for the change in the interlayer structure as shown in Table 7, reference In the same manner as in Example 19, an interlayer film and a laminated glass were produced by the FB method or the conduit method.

[0433] (evaluation) (1) Measurement of parallel light transmittance The parallel light transmittance of the obtained laminated glass was measured in accordance with JIS R3106: 1998. Specifically, the measurement was carried out as follows.

[0434] Using a spectrophotometer (Hitachi High-Technologies Corporation's "U-4100"), the laminated glass was placed on the optical path between the light source and the integrating sphere, parallel to the normal to the optical axis and 13 cm away from the integrating sphere, so that only transmitted parallel light was received by the integrating sphere. The parallel light transmittance refers to the visible light transmittance calculated from the spectral transmittance measured in this state.

[0435] Example 1 ,3,4,6,7,9,11,16 ~18 and reference examples 2,5,8,10,12~15, The interlayer films and laminated glasses obtained in Examples 19 and 20 had a transparent portion, a gradation portion, and a dark portion from one end to the other. On the other hand, the interlayer films and laminated glasses obtained in Comparative Examples 1 to 8 did not have a dark portion.

[0436] (2) Color unevenness in the shaded area (visual inspection) The resulting laminated glass was placed on a light table, and the colored pattern in the shaded area of ​​the laminated glass was visually observed from the side opposite the light source while a fluorescent lamp on the light table was irradiated. Ten people observed the resulting laminated glass using the above observation method, and the visual color unevenness in the shaded area was judged according to the following criteria. Furthermore, a white film printed with a 1 cm square grid pattern was placed between the laminated glass and the light table, and the laminated glass was placed parallel to the film, 1.5 cm away from it in the thickness direction of the laminated glass. The colored pattern was observed while a fluorescent lamp was irradiated from above the laminated glass.

[0437] [Criteria for judging color unevenness (visual) in shaded areas] ○: Color unevenness cannot be identified △: Slightly discernible color unevenness ×: Color unevenness is clearly discernible

[0438] (3) Color unevenness in the shade area (parallel light transmittance) The proportion (%) of the dark colored area in the shaded area was calculated using the formula: distance L3 / (distance L2+distance L3)×100, based on the distance of the shaded area in the direction connecting one end to the other end (distance L2+distance L3) and the distance of the dark colored area in the direction connecting one end to the other end (distance L3).

[0439] [Criteria for judging color unevenness in shaded areas (parallel light transmittance)] ○: The ratio of dark areas to the shaded area is 1% or more ×: The ratio of dark areas to the shaded area is less than 1%

[0440] The configurations of the interlayer films and the results are shown in Tables 1 to 7 below.

[0441] [Table 1]

[0442] [Table 2]

[0443] [Table 3]

[0444] [Table 4]

[0445] [Table 5]

[0446] [Table 6]

[0447] [Table 7] [Explanation of symbols]

[0448] 1,1A,1B,1C,1D,1E,1F,1G,1H,1I,1J,1K,1L,1M...intermediate film 1a,1Aa,1Ba,1Ca,1Da,1Ea,1Fa,1Ga,1Ha,1Ia,1Ja,1Ka,1La,1Ma...One end 1b, 1Ab, 1Bb, 1Cb, 1Db, 1Eb, 1Fb, 1Gb, 1Hb, 1Ib, 1Jb, 1Kb, 1Lb, 1Mb... other end 11, 11A, 11B, 11C, 11D, 11E, 11L, 11M...First layer 12, 12A, 12B, 12C, 12D, 12E, 12F, 12G, 12H, 12I, 12J, 12K...Second layer 13, 13A, 13B, 13C, 13D, 13E, 13F, 13G, 13H, 13I, 13J, 13K...Third layer 14,14A,14B,14C,14D,14E,14F,14G,14H,14I,14J,14K,14L,14M……Colored layer 15F,15G,15H,15I,15J,15K...Infrared reflective layer 21...Laminated glass 21a…one end 21b...other end 31...First laminated glass member 32...Second laminated glass member R1…transparent part R2...Gradient section R3...Dark color part R4: Shade area

Claims

1. The intermediate film has 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 interlayer film comprises a first layer or an infrared reflective layer, a second layer, a third layer, and a colored layer; the second layer is disposed on a first surface side of the first layer or the infrared reflective layer, the third layer is disposed on a second surface side of the first layer or the infrared reflective layer opposite to the first surface, and the colored layer is embedded between the first layer or the infrared reflective layer and the second layer; the first layer, the second layer, and the third layer each contain a thermoplastic resin; the thermoplastic resin in the first layer comprises a polyvinyl acetal resin; the thermoplastic resin in the second layer comprises a polyvinyl acetal resin; the polyvinyl acetal resin in the first layer is different from the polyvinyl acetal resin in the second layer; The interlayer film was placed between two sheets of clear glass conforming to JIS R3202:1996 to obtain laminated glass X. When the parallel light transmittance of the obtained laminated glass X was measured as follows, it was found that the interlayer film a gradation portion in which the parallel light transmittance continuously decreases from the one end side to the other end side, and the absolute value of the rate of change in the parallel light transmittance exceeds 0.3% / mm; a transparent portion located closer to the one end than the gradation portion and having a parallel light transmittance of 60% or more; a dark color portion located closer to the other end than the gradation portion and including one or more points A at which the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less. Measurement of parallel light transmittance: Starting from a position 2 cm from the one end toward the other end, multiple points A are selected at 1 cm intervals from the starting point toward the other end. The parallel light transmittance of the laminated glass X is measured at each point A. The x-axis direction is defined as "distance from the one end" and the y-axis direction is defined as "parallel light transmittance." An approximate straight line is created in a 2 cm region from three points: one point A and two points 1 cm away from the point A on both sides in the direction connecting the one end and the other end. The absolute value of the rate of change in parallel light transmittance obtained from the approximate straight line is defined as the "absolute value of the rate of change in parallel light transmittance" at the one point A. The "absolute value of the rate of change in parallel light transmittance" is determined for each point A.

2. 2. The interlayer film for laminated glass according to claim 1, wherein a ratio of a distance of the dark color portion in a direction connecting the one end and the other end to a distance of the interlayer film in the direction connecting the one end and the other end is 0.05 or more.

3. The interlayer film for laminated glass according to claim 1 or 2, wherein a distance between the dark color portions in a direction connecting the one end and the other end is 50 mm or more.

4. the intermediate film has a uniform thickness portion whose thickness does not change by more than 10 μm within a distance range of 10 cm in a direction connecting the one end and the other end, The interlayer film for laminated glass according to any one of claims 1 to 3, wherein the uniform thickness portion is located closer to the one end than a center position between the one end and the other end.

5. the gradation portion and the dark color portion each have a colored layer containing a colorant, The interlayer film for laminated glass according to any one of claims 1 to 4, wherein the shortest distance between the surface of the interlayer film in the thickness direction and the surface of the colored layer in the thickness direction is 10 µm or more.

6. The interlayer film for laminated glass according to any one of claims 1 to 5, wherein a cross-sectional shape in the thickness direction of the layer formed by combining the second layer and the colored layer is wedge-shaped or has a wedge-shaped portion and a rectangular portion.

7. The interlayer film for laminated glass according to any one of claims 1 to 5, wherein a cross-sectional shape in the thickness direction of the layer formed by combining the second layer and the colored layer is rectangular or has a wedge-shaped portion and a rectangular portion.

8. The interlayer film for laminated glass according to any one of claims 1 to 7, wherein the gradation portion and the dark color portion have a portion whose cross section in the thickness direction of the interlayer film is wedge-shaped.

9. The first layer is provided, the first layer is a layer formed using a composition for forming a first layer, the second layer is a layer formed using a composition for forming a second layer, The interlayer film for laminated glass according to any one of claims 1 to 8, wherein a composition for forming the first layer and a composition for forming the second layer are different.

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

11. The laminated glass has 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 laminated glass comprises a first laminated glass member, a second laminated glass member, and an interlayer film; the interlayer film is disposed between the first laminated glass member and the second laminated glass member; the interlayer film comprises a first layer or an infrared reflective layer, a second layer, a third layer, and a colored layer; the second layer is disposed on a first surface side of the first layer or the infrared reflective layer, the third layer is disposed on a second surface side of the first layer or the infrared reflective layer opposite to the first surface, and the colored layer is embedded between the first layer or the infrared reflective layer and the second layer; the first layer, the second layer, and the third layer each contain a thermoplastic resin; the thermoplastic resin in the first layer comprises a polyvinyl acetal resin; the thermoplastic resin in the second layer comprises a polyvinyl acetal resin; the polyvinyl acetal resin in the first layer is different from the polyvinyl acetal resin in the second layer; When the parallel light transmittance of the laminated glass was measured, the laminated glass was a gradation portion in which the parallel light transmittance continuously decreases from the one end side to the other end side, and the absolute value of the rate of change in the parallel light transmittance exceeds 0.3% / mm; a transparent portion located closer to the one end than the gradation portion and having a parallel light transmittance of 60% or more; and a dark-colored portion located closer to the other end than the gradation portion and including one or more points A at which the absolute value of the rate of change in parallel light transmittance is 0.3% / mm or less. Measurement of parallel light transmittance: Starting from a position 2 cm from the one end toward the other end, multiple points A are selected at 1 cm intervals from the starting point toward the other end. The parallel light transmittance of the laminated glass is measured at each point A. The x-axis direction is defined as "distance from the one end" and the y-axis direction is defined as "parallel light transmittance." An approximate straight line is created in a 2 cm region from three points: one point A and two points 1 cm away from the point A on both sides in the direction connecting the one end and the other end. The absolute value of the rate of change in parallel light transmittance obtained from the approximate straight line is defined as the "absolute value of the rate of change in parallel light transmittance" at the one point A. The "absolute value of the rate of change in parallel light transmittance" is determined for each point A.

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