Intermediate film for laminated glass, and laminated glass

Abstract

This intermediate film for laminated glass has a first resin layer, wherein the first resin layer includes at least two kinds of filler (A), the haze is 2.0%-13.0%, and the reflectance is flat in a spectral reflectance curve in a wavelength range of 400-700 nm.

Description

Interlayer film for laminated glass, and laminated glass

[0001] The present invention relates to an interlayer film for laminated glass and laminated glass having the interlayer film for laminated glass.

[0002] Laminated glass is safe because it shatters little if it is broken by an external impact, and is therefore widely used as window glass for various vehicles such as automobiles and for windows in buildings, etc. A widely known type of laminated glass is one in which a pair of panes of glass are integrated together by sandwiching an interlayer film for laminated glass containing a resin component such as a polyvinyl acetal resin between them.

[0003] In recent years, interlayer films for laminated glass have often been required to have a design feature, and they are sometimes colored by incorporating a colorant into the interlayer film for laminated glass. It is also known that metal particles are incorporated into interlayer films for laminated glass for coloring purposes. For example, Patent Document 1 discloses that a metal pigment is incorporated into an interlayer film for laminated glass, which comprises polyvinyl butyral and a plasticizer. Patent Document 1 also discloses that the interlayer film for laminated glass may further contain a coloring material such as a pigment or dye in a resin composition containing the metal pigment. An example of the metal pigment is a plate-like mica pigment coated with a metal oxide.

[0004] International Publication No. 2016 / 028963

[0005] In recent years, the designs of window glass for automobiles and buildings have become increasingly diverse, and there is a demand for a variety of expressions in automobiles, for example. However, conventional interlayer films for laminated glass containing pigments or dyes only color the window glass and are unable to sufficiently enhance the design. Furthermore, as shown in Patent Document 1, it is possible to create a glossy appearance by incorporating metallic pigments, but interlayer films for laminated glass containing metallic pigments generally tend to have reduced transparency.

[0006] Therefore, an object of the present invention is to provide an interlayer film for laminated glass that has excellent transparency while providing a metallic look and enhancing design.

[0007] As a result of extensive investigation, the present inventors have found that the above-mentioned problems can be solved by using two or more types of fillers, setting the haze within a certain range, and flattening the reflectance in a spectral reflectance curve with a wavelength of 400 to 700 nm, and have completed the present invention as described below. That is, the present invention provides the following [1] to

[15] . [1] An interlayer film for laminated glass, comprising a first resin layer, the first resin layer containing at least two or more types of filler (A), having a haze of 2.0% or more and 13.0% or less, and having a flat reflectance in a spectral reflectance curve with a wavelength of 400 to 700 nm. [2] The interlayer film for laminated glass according to above [1], wherein the ratio of the maximum value to the minimum value of the reflectance in the spectral reflectance curve with a wavelength of 400 to 700 nm is 1.0 or more and 1.4 or less. [3] The interlayer film for laminated glass according to [1] or [2] above, wherein the filler (A) has a* of reflected light in the range of -9.0 or more and 7.0 or less, and b* of reflected light in the range of -8.5 or more and 8.5 or less. [4] The interlayer film for laminated glass according to any of [1] to [3] above, wherein the filler (A) includes two or more fillers whose colors are complementary to each other. [5] The interlayer film for laminated glass according to any of [1] to [4] above, wherein the filler (A) has, for any two fillers, an absolute value of the sum of the a* of reflected light (|Ra*(F1) + Ra*(F2)|) in the range of 0 or more and 3.0 or less, and an absolute value of the sum of the b* of reflected light (|Rb*(F1) + Rb*(F2)|) in the range of 0 or more and 7.0 or less. (wherein the a* and b* of the first filler are Ra*(F1) and Rb*(F1), and the a* and b* of the second filler are Ra*(F2) and Rb*(F2).) [6] The interlayer film for laminated glass according to any one of [1] to [5] above, wherein the at least two or more fillers (A) each contain a metal oxide. [7] The interlayer film for laminated glass according to any one of [1] to [6] above, wherein the first resin layer has a chroma Rc* of reflected light in the visible light region of 0 or more and 5.5 or less. [8] The interlayer film for laminated glass according to any one of [1] to [7] above, wherein the first resin layer has a chroma Tc* of transmitted light in the visible light region of 0 or more and 5.5 or less. [9] The interlayer film for laminated glass according to any one of [1] to [8] above, wherein the first resin layer satisfies at least one of the following requirements (1) to (3):(1) The chroma Rc* of reflected light in the visible light region is 0 or more and 4.0 or less. (2) The chroma Tc* of transmitted light in the visible light region is 0 or more and 4.0 or less. (3) The haze is 3.0% or more and 10.0% or less.

[10] The interlayer film for laminated glass according to any one of [1] to [9] above, wherein the first resin layer further contains a colorant.

[11] The interlayer film for laminated glass according to any one of [1] to

[10] above, further comprising a second resin layer.

[12] The interlayer film for laminated glass according to

[11] above, wherein the second resin layer contains a colorant.

[13] The interlayer film for laminated glass according to

[12] above, wherein the ratio of the maximum value to the minimum value of reflectance is 1.0 or more and 1.6 or less in a spectral reflectance curve of a wavelength of 400 to 700 nm measured from the first resin layer side.

[14] The interlayer film for laminated glass according to any one of [1] to

[13] above, which satisfies at least one of the following requirements (4) and (5): (4) The chroma Rc* of reflected light of the interlayer film for laminated glass is 0 or more and 7.0 or less. (5) The chroma Tc* of transmitted light of the interlayer film for laminated glass is 0 or more and 7.0 or less.

[15] Laminated glass, comprising: a first laminated glass member; a second laminated glass member; and the interlayer film for laminated glass according to any one of [1] to

[14] above, wherein the interlayer film is disposed between the first laminated glass member and the second laminated glass member.

[0008] According to the present invention, it is possible to provide an interlayer film for laminated glass that has excellent transparency while providing a metallic appearance and enhancing design.

[0009] 1 is a schematic diagram showing that reflectance is flat in a spectral reflectance curve; FIG. 2 is a schematic cross-sectional view showing a flat-plate-shaped filler (A) having a laminated structure; FIG. 3 is a schematic cross-sectional view showing an example of an interlayer film for laminated glass; FIG. 4 is a spectral reflectance curve of Example 1; FIG. 5 is a spectral reflectance curve of Comparative Example 1.

[0010] The present invention will be described in more detail below. The interlayer film for laminated glass of the present invention (hereinafter sometimes simply referred to as "interlayer film") has a first resin layer, and the first resin layer contains at least two types of filler. The interlayer film of the present invention also has a haze of 2.0% or more and 13.0% or less, and exhibits a flat reflectance in the spectral reflectance curve for wavelengths of 400 to 700 nm. By having the above configuration, the interlayer film can impart a luxurious metallic feel, improving design while also providing good see-through properties. The interlayer film of the present invention will be described in detail below.

[0011] (Haze) The interlayer film of the present invention has a haze of 2.0% or more and 13.0% or less. If the haze exceeds 13.0%, light scattering cannot be suppressed, causing cloudiness and making it difficult to improve transparency. If the haze is less than 2.0%, it becomes difficult to impart a luxurious, heavy metallic feel with the filler (A). From the above viewpoints, the haze of the interlayer film is preferably 12.0% or less, more preferably 10.0% or less, and even more preferably 9.5% or less, and preferably 3.0% or more, more preferably 4.0% or more, and even more preferably 4.5% or more. The haze of the interlayer film can be adjusted by the type and content of the filler, etc.

[0012] The haze of the interlayer film was measured from either side of a laminated glass produced by bonding two standard clear glass sheets together via an interlayer film. Therefore, it is not necessary for both values ​​(Haze 1, Haze 2) measured from both sides to be within the above range. However, as described below, when a second resin layer, which is a colored layer, is provided in addition to the first resin layer, the haze of the interlayer film should preferably be the value (Haze 1) measured from the second resin layer side. The laminated glass produced under the conditions described in the Examples should preferably be used when measuring the haze.

[0013] (Spectral Reflectance) The interlayer film of the present invention has a flat reflectance in the spectral reflectance curve for wavelengths of 400 to 700 nm. In the present invention, the flat reflectance can create a luxurious metallic feel with a strong gray color impression, enhancing the design. Here, flat reflectance means that when a spectral reflectance curve for wavelengths of 400 to 700 nm is plotted with the horizontal axis representing wavelength and the vertical axis representing reflectance, as shown in FIG. 1 , the spectral reflectance curve is generally flat, and there is substantially no wavelength dependency of the reflectance in the wavelength range of 400 to 700 nm.

[0014] In the spectral reflectance curve for wavelengths of 400 to 700 nm, Rmax / Rmin, which is the ratio of the maximum to minimum reflectance, is preferably 1.6 or less. When Rmax / Rmin is 1.6 or less, the spectral reflectance curve becomes generally flat, making it easier to achieve a luxurious metallic look. Rmax / Rmin is more preferably 1.5 or less, even more preferably 1.4 or less, and even more preferably 1.35 or less. The lower the Rmax / Rmin, the better, and it is sufficient that it is 1.0 or more. When a second resin layer serving as a colored layer is provided as described below, Rmax / Rmin becomes relatively large, preferably 1.6 or less, more preferably 1.5 or less, and even more preferably 1.4 or less. On the other hand, when a second resin layer serving as a colored layer is not provided, Rmax / Rmin becomes relatively small, preferably 1.4 or less, more preferably 1.35 or less, and even more preferably 1.3 or less. In the spectral reflectance curve for wavelengths of 400 to 700 nm, the reflectance at the wavelength at which the reflectance is maximum is Rmax (maximum value), and the reflectance at the wavelength at which the reflectance is minimum is Rmin (minimum value).

[0015] Rmin in the spectral reflectance curve for the wavelength range of 400 to 700 nm is preferably 4% or more, more preferably 6% or more, even more preferably 7% or more, and even more preferably 9% or more. An Rmin of 4% or more allows for a sufficient metallic appearance. Furthermore, Rmin is preferably 50% or less, more preferably 40% or less, even more preferably 25% or less, and even more preferably 18% or less. Setting Rmin to 50% or less prevents unnecessary reflection and an unnecessary decrease in transparency. The spectral reflectance can be adjusted by the type and content of the filler. Furthermore, by using two or more types of filler and adjusting the type and content of the filler, it is possible to lower Rmax / Rmin or flatten the reflectance.

[0016] The spectral reflectance curve was obtained by measuring the spectral reflectance from either side of a laminated glass prepared by bonding two reference clear glass sheets together via an interlayer film. The laminated glass used may be prepared under the conditions described in the Examples. However, as described below, when a second resin layer, which is a colored layer, is provided in addition to the first resin layer, the spectral reflectance curve should be prepared using the spectral reflectance measured from the first resin layer side. That is, the spectral reflectance should be determined from the side opposite to the side on which the haze was measured.

[0017] (Filler (A)) In the present invention, the first resin layer contains two or more types of fillers (A). By containing two or more types of fillers (A), the first resin layer can flatten the reflectance in the spectral reflectance curve in the wavelength range of 400 to 700 nm while maintaining a low haze, and can impart a luxurious metallic feel.

[0018] Each of the two or more fillers (A) may be a filler containing any one of a metal, a metal oxide, and a non-metallic material. In the first resin layer, the filler (A) may be dispersed in the resin constituting the first resin layer. Each of the two or more fillers (A) preferably contains at least any one of a metal oxide and a non-metallic material, and more preferably contains a metal oxide. Furthermore, the two or more fillers (A) may be a filler having visible light reflecting properties. The filler (A) is formed from a specific material, and by having visible light reflecting properties, it is easier to create a metallic look.

[0019] Examples of metals in the filler (A) include aluminum, silver, copper, platinum, gold, titanium, nickel, tin, tin-cobalt alloy, indium, and chromium. Examples of metal oxides include titanium oxide, silicon oxide, indium oxide, niobium oxide, zinc oxide, antimony oxide, and tungsten oxide. Examples of non-metallic materials include inorganic compounds other than metals and metal oxides, such as glass and mica.

[0020] The fillers (A) containing metal oxides are preferably fillers containing two or more compounds in each particle, and are preferably fillers containing two or more metal oxides in each particle, or fillers containing a metal oxide and a non-metallic material such as mica or glass in each particle. Among these, the fillers (A) are more preferably fillers containing two or more metal oxides in each particle.

[0021] In each particle, the filler containing two or more compounds preferably has a multilayer structure. Specific examples include fillers having a multilayer structure of two or more metal oxides, fillers having a multilayer structure of a metal oxide and mica, and fillers having a multilayer structure of a metal oxide and glass. When the filler (A) has the multilayer structure described above, the first resin layer can easily adjust the a* and b* values ​​of the reflected light of the filler (A), as described below, and can easily achieve a flat reflectance in the spectral reflectance curve at wavelengths of 400 to 700 nm. Among the above, it is more preferable that each filler (A) has a multilayer structure of two or more metal oxides. When the filler (A) has a multilayer structure of two or more metal oxides, it can easily impart a metallic feel to the reflected light. Furthermore, it is easier to ensure the light transmittance of the first resin layer, making it easier to improve see-through properties.

[0022] In the metal oxide multilayer structure, it is preferable that the refractive indexes of two or more metal oxides are different from each other. By forming layers with different refractive indexes using metal oxides with different refractive indexes, it is easier to ensure a moderate metallic effect due to reflection between the layers, and it is also easier to adjust the a* and b* values ​​of the reflected light of the filler (A) described below. Furthermore, in a filler having a metal oxide multilayer structure, it is preferable that the layers formed by metal oxides with different refractive indexes are adjacent to each other. From the viewpoint of improving see-through visibility and metallic effect, the refractive index difference between the metal oxides with different refractive indexes is preferably 0.1 or more and 1.2 or less. The refractive index difference is more preferably 0.3 or more and 1.1 or less, and even more preferably 0.6 or more and 1.05 or less.

[0023] In filler (A) having a multilayer structure of two or more metal oxides, the thickness ratio between layers formed by different metal oxides is preferably 1:2 to 1:15. Filler (A) having such a thickness ratio facilitates the creation of a metallic appearance. The thickness ratio is more preferably 1:3 to 1:13, and even more preferably 1:4 to 1:11. Furthermore, by controlling the thickness ratio, filler (A) can also change the hue (a*, b*) of reflected light. The thickness ratio is the average value of values ​​measured by observing 50 random particles using a scanning electron microscope (SEM) or the like.

[0024] The two or more metal oxides are preferably selected from the group consisting of titanium oxide, silicon oxide, indium oxide, niobium oxide, zinc oxide, antimony oxide, and tungsten oxide, and among these, titanium oxide and silicon oxide are preferred. Titanium oxide is titanium dioxide (TiO ２ ), and may be of the rutile type, the anatase type, or the brookite type. Silicon oxide is silicon dioxide (SiO ２ ). The filler (A) more preferably contains both titanium oxide and silicon oxide, and further preferably has a multilayer structure of a titanium oxide layer and a silicon oxide layer. As described above, the filler (A) is preferably a metal oxide particle having a multilayer structure formed from two or more types of metal oxides, and is preferably a particle in which a metal oxide particle (a middle layer described later) made of at least one type of metal oxide is coated with at least one type of metal oxide of a different kind.

[0025] The filler (A) having a multilayer structure of metal oxide and glass is preferably formed from glass and a metal oxide selected from the group consisting of titanium oxide, silicon oxide, indium oxide, niobium oxide, zinc oxide, antimony oxide, and tungsten oxide. Among these, the metal oxide is preferably titanium oxide, silicon oxide, or both. The filler (A) having a multilayer structure of metal oxide and glass more preferably has a multilayer structure of a glass layer and a metal oxide layer, and in particular, it is preferred that the middle layer constituting the glass layer is a particle coated with a metal oxide (preferably titanium oxide, silicon oxide, or both).

[0026] The filler (A) having a multilayer structure of a metal oxide and mica is preferably formed from mica and a metal oxide selected from the group consisting of titanium oxide, silicon oxide, indium oxide, niobium oxide, zinc oxide, antimony oxide, and tungsten oxide, and among these, titanium oxide is preferred as the metal oxide.The filler (A) having a multilayer structure of a metal oxide and mica more preferably has a multilayer structure of a mica layer and a metal oxide layer, and in particular, it is preferred that the middle layer constituting the mica layer is a particle coated with a metal oxide (preferably titanium oxide).

[0027] The shape of the filler (A) may be any of a polygonal shape such as a sphere or a quadrangular prism, a polygonal pyramid shape such as a triangular pyramid or a quadrangular pyramid, a cylindrical shape, a cone shape, an irregular shape, a needle shape, a fiber shape, a flat shape, etc., but a flat shape is preferable. When the filler (A) has a flat shape, it can be oriented along the surface direction of the interlayer film as described below, which makes it easier to reflect a certain amount of incident visible light while improving the transparency of the interlayer film. In addition, the regular reflection makes it less likely for light scattering to occur, making it easier to reduce the haze of the laminated glass.

[0028] When the flat-plate-shaped filler (A) has the above-mentioned multilayer structure, it is preferable that multiple layers are provided along the thickness direction, and preferably 2 to 5 layers, more preferably 2 to 4 layers, and even more preferably 3 layers are provided along the thickness direction. A multilayer-structured filler emits various colors due to interference of reflected light generated by reflection at the interfaces between the layers and on the filler surface, and the color of the reflected light of each filler (i.e., the values ​​of a* and b*) can be changed, for example, by changing the thickness of the layer on the surface side of the multilayer structure (e.g., coating layer 11 described below).

[0029] A specific example of a flat-plate-shaped filler (A) having a three-layer structure is shown in FIG. 2. When the filler (A) has a three-layer structure, as shown in FIG. 2, it is preferable that the filler (A) has an intermediate layer 10 and coating layers 11 and 12 provided on both sides of the intermediate layer 10. The filler shown in FIG. 2 preferably has a multilayer structure of metal oxides, and the metal oxides forming the coating layers 11 and 12 are preferably different from the metal oxide forming the intermediate layer 10. The metal oxides forming the coating layers 11 and 12 are preferably the same. The refractive index of the metal oxides forming the coating layers 11 and 12 is preferably higher than the refractive index of the intermediate layer 10. By relatively increasing the refractive index of the coating layers 11 and 12, light is transmitted while being appropriately reflected, which makes it easier to improve both the transparency and metallic feel of the interlayer film. Furthermore, because the three-layer structure has a higher refractive index of the metal oxides in the coating layers 11 and 12 than that of the middle layer 10, light incident from either of the two surfaces is appropriately reflected, thereby more effectively ensuring transparency and creating a metallic appearance. The preferred value for the difference in refractive index between the coating layers 11 and 12 and the middle layer 10 is as described above. The thickness of each of the coating layers 11 and 12 is preferably smaller than that of the middle layer 10. The preferred specific thickness ratio (each coating layer:middle layer) is as shown in the thickness ratio between the layers.

[0030] In the plate-shaped filler (A) having a multilayer structure of metal oxides, it is particularly preferred that the coating layers 11 and 12 are both titanium oxide layers and the middle layer 10 is a silicon oxide layer. The plate-shaped filler (A) is not limited to the above-mentioned three-layer structure, and may have a two-layer structure, in which case one of the coating layers 11 and 12 may be omitted. It may also have a multilayer structure of four or more layers.

[0031] The average particle size (D50) of each filler (A) is, for example, 1 μm or more and 100 μm or less, preferably 3 μm or more and 90 μm or less, and more preferably 5 μm or more and 80 μm or less. Furthermore, from the viewpoint of achieving both transparency and a metallic finish while easily suppressing light scattering in the interlayer film, the average particle size of the filler (A) having a multilayer structure of metal oxide is preferably 1 μm or more and 20 μm or less, more preferably 3 μm or more and 18 μm or less, and more preferably 5 μm or more and 16 μm or less. The average particle size (D50) is a value measured using a laser diffraction / scattering particle size distribution analyzer, and the value (D50) at which the cumulative volume is 50% is defined as the average particle size.

[0032] The thickness of the filler (A) is preferably 0.01 μm or more and 4 μm or less, more preferably 0.1 μm or more and 3.5 μm or less, and even more preferably 0.2 μm or more and 3 μm or less, from the viewpoint of easily ensuring transparency and easily producing a metallic feel. The thickness of the filler (A) is the average value of values ​​measured by observing 50 random particles using a scanning electron microscope (SEM) or the like. The thickness of the filler (A) may be the length in the direction perpendicular to the longitudinal direction of the filler, in which the maximum length is the shortest, and the thickness of the plate-shaped filler (A) is the length in the vertical direction in FIG. 2.

[0033] The aspect ratio of the filler (A) is preferably 1 or more, more preferably 1.1 or more, even more preferably 1.2 or more, and preferably 50 or less, more preferably 30 or less, even more preferably 15 or less, and even more preferably 10 or less. The above aspect ratios facilitate a metallic appearance while improving transparency. Furthermore, as described below, by orienting the filler (A) along the surface direction of the interlayer film, it is possible to reflect a certain amount of incident visible light while further improving the transparency of the interlayer film. Furthermore, by setting the aspect ratio to 50 or less, it is possible to prevent the average particle size (D50) of the filler (A) from becoming unnecessarily large. The aspect ratio of the filler (A) is the ratio of the length of the major axis to the length of the minor axis of the filler (A) observed with a scanning electron microscope. The major axis and minor axis refer to the major axis and minor axis of the filler (A) when viewed in a planar view along the thickness direction. For a flat-shaped filler, these refer to the longitudinal direction and the direction perpendicular to the surface direction.

[0034] When the filler (A) has orientable anisotropy, such as when it has a flat plate shape, it is preferable that its longitudinal direction be oriented along the plane direction of the interlayer film. Furthermore, when it has a flat plate shape, it is preferable that the plane direction of the filler (A) be oriented along the plane direction of the interlayer film. That is, the flat-shaped filler (A) is preferably oriented so that the thickness direction of the filler (A) is oriented along the thickness direction of the interlayer film. A filler (A) having the above orientation appropriately reflects light traveling along the thickness direction of the interlayer film while partially transmitting the light, and can also suppress light scattering caused by the filler (A). This makes it easier to reduce haze and improve transparency. In the first resin layer, two or more types of fillers (A) may be used in combination, and two or more types of fillers (A) may be used in combination.

[0035] The method for producing the filler (A) is not particularly limited, and for example, a filler (A) having a multilayer structure may be produced by coating particles formed from a metal oxide with another metal oxide, or by coating particles formed from mica or glass with a metal oxide. Alternatively, a sheet formed from a metal oxide may be coated with another metal oxide and then crushed to form a flat-plate-shaped filler (A). A commercially available product may be used as the filler (A).

[0036] For each of the two or more fillers (A), it is preferable that the a* of the reflected light is -11.0 or more and 9.0 or less, and the b* of the reflected light is -10 or more and 10 or less, and it is more preferable that the a* of the reflected light is -9.0 or more and 7.0 or less, and the b* of the reflected light is -8.5 or more and 8.5 or less. When the a* and b* of the two or more fillers (A) are within the above ranges, it becomes easier to obtain a luxurious metallic feel. The a* and b* of the reflected light of each filler can be adjusted by the material, structure, size, etc. of the filler. For example, in a multilayered filler, as described above, the thickness of each layer, such as a coating layer, can be appropriately adjusted to obtain a filler having the desired a* and b* of reflected light.

[0037] For the sake of simplicity, the a* and b* of the reflected light of multiple fillers may be described below by referring to the first filler (also referred to as the first filler) as Ra*(F1) and Rb*(F1), and the second filler (also referred to as the second filler) as Ra*(F2) and Rb*(F2). The a* and b* of the reflected light of each filler are measured on a laminated glass prepared by preparing an interlayer film containing 0.05% by mass of the filler and bonding two reference glass sheets together via the interlayer film. The laminated glass and interlayer film may be prepared by the method described in the Examples. In this specification, a* and b* refer to the chromaticity a* and b* in the L*a*b* color space.

[0038] The two or more fillers (A) preferably include two or more types that reflect light of different colors, and preferably include at least two fillers that are complementary in color. By including multiple fillers of different colors, particularly complementary in color, in the first resin layer, the colors of the fillers tend to cancel each other out, resulting in a high-quality metallic appearance with a strong gray color. Furthermore, this facilitates flattening the reflectance in the spectral reflectance curve at wavelengths of 400 to 700 nm, and also facilitates lowering the Rmax / Rmin ratio.

[0039] Here, the two types of fillers (first and second fillers) whose colors are complementary to each other do not need to be in a strict complementary color relationship, as long as the mixed use of the two fillers results in a lower saturation than the saturation of either filler. Furthermore, the two types of fillers (first and second fillers) whose colors are complementary to each other may have opposite signs (+, -) for both the a* and b* of the reflected light. That is, for the complementary color fillers, if the a* of the reflected light of one filler is +, the a* of the reflected light of the other filler is -, and if the b* of the reflected light of one filler is +, the b* of the reflected light of the other filler is -.

[0040] Furthermore, it is preferable that any two types of fillers (first and second fillers) have an absolute value (|Ra*(F1) + Ra*(F2)|) of 0 or more and 5.0 or less when the a* of the reflected light is added, and an absolute value (|Rb*(F1) + Rb*(F2)|) of 0 or more and 9.0 or less when the b* of the reflected light is added. Two types of fillers having the above relationship have complementary colors and cancel each other out, or even if they are not complementary colors, the filler is less likely to impart color. Therefore, filler (A) makes it easier to create a high-quality metallic feel with a strong gray color. Furthermore, it makes it easier to flatten the reflectance in the spectral reflectance curve at wavelengths of 400 to 700 nm. Here, it is more preferable that |Ra*(F1)+Ra*(F2)| is 0 or more and 3.0 or less, and |Rb*(F1)+Rb*(F2)| is 0 or more and 7.0 or less, and it is even more preferable that |Ra*(F1)+Ra*(F2)| is 0 or more and 3.0 or less, and |Rb*(F1)+Rb*(F2)| is 0 or more and 3.0 or less. In two types of fillers satisfying the above relationship, it is preferable that at least one of the signs (+, -) of Ra*(F1) and Ra*(F2), and Rb*(F2) and Rb*(F2) are opposite, as described above, but it is more preferable that both signs are opposite.

[0041] Furthermore, for two or more fillers (A), the content of each filler (e.g., the first filler and the second filler) is preferably 0.004% by mass or more and 0.4% by mass or less, based on the total amount of the first resin layer. When the content of each filler is 0.004% by mass or more, it is easy to create an appropriate metallic effect. Furthermore, when the content is 0.4% by mass or less, it is easy to prevent light from being reflected more than necessary by the first resin layer, reduce haze, and ensure the transparency of the laminated glass. From these viewpoints, the content of the filler (A) is more preferably 0.01% by mass or more, even more preferably 0.02% by mass or more, even more preferably 0.03% by mass or more, and more preferably 0.3% by mass or less, even more preferably 0.2% by mass or less, and even more preferably 0.1% by mass or less.

[0042] Furthermore, the ratio of the content of the second filler to the content of the first filler in the first resin layer (second filler / first filler) is preferably from 1 / 8 to 8 / 1 in mass ratio, more preferably from 1 / 4 to 4 / 1 in mass ratio, and even more preferably from 1 / 2 to 2 / 1 in mass ratio. By keeping the content ratio within the above range, it becomes easier to achieve a metallic feel that is an achromatic color with a strong gray impression.

[0043] The total content of the filler (A) in the first resin layer is preferably 0.01% by mass or more and 0.6% by mass or less, based on the total amount of the first resin layer. A total content of 0.01% by mass or more facilitates the creation of an appropriate metallic appearance. Furthermore, a total content of 0.6% by mass or less prevents unnecessary reflection of light in the first resin layer, reduces haze, and facilitates ensuring the transparency of the laminated glass. From these viewpoints, the content of the filler (A) is more preferably 0.02% by mass or more, even more preferably 0.04% by mass or more, even more preferably 0.06% by mass or more, and more preferably 0.5% by mass or less, even more preferably 0.35% by mass or less, and even more preferably 0.2% by mass or less.

[0044] (Colorant) The first resin layer may contain a colorant to form a colored layer. By containing a colorant in the first resin layer, it is possible to impart a color according to the colorant while maintaining the metallic appearance that gives the impression of a gray color due to light reflected from the filler (A). Therefore, by containing a colorant in the first resin layer, it is possible to create a colored metallic appearance with a heavy feel. The colorant may be dispersed in the resin in the first resin layer. Furthermore, it is preferable that the colorant be mixed into the first resin in a state separated from the filler (A), but it may also be mixed into the first resin layer in a state attached to the surface of the filler.

[0045] As the colorant, pigments, dyes, and the like that are incorporated into conventional interlayer films for laminated glass can be used. Pigments are preferred because they can effectively color the film even in small amounts. Examples of pigments include phthalocyanine, anthraquinone, perylene, azo compounds, carbon black, quinacridone, titanium oxide, diketopyrrolopyrrole, thioindigo, Ni complexes, perinone, isoindoline, quinophthalone, threne, dioxazine, pyrrocholine, calcium carbonate, and derivatives thereof. Among these, colorants with a color such as blue colorants or red colorants, i.e., colorants other than white colorants and black colorants, are preferred from the viewpoint of enhancing design. Furthermore, those that have high affinity with thermoplastic resins and are less likely to bleed out are preferred. Specifically, at least one selected from the group consisting of phthalocyanine pigments which are phthalocyanine or derivatives of phthalocyanine, anthraquinone pigments which are anthraquinone or derivatives of anthraquinone, perylene pigments which are perylene or derivatives of perylene, azo pigments which are azo compounds, and quinacridone pigments which are quinacridone or derivatives of quinacridone are more preferred. In the first resin layer, one colorant may be used alone, or two or more colorants may be used in combination.

[0046] When the first resin layer contains a colorant, the colorant content is preferably 0.0001% by mass or more and 0.2% by mass or less, based on the total amount of the first resin layer. By setting the colorant content within the above range, it is possible to achieve a moderate colored metallic effect while maintaining good transparency. The colorant content in the first resin layer is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, even more preferably 0.01% by mass or more, and more preferably 0.1% by mass or less, even more preferably 0.05% by mass or less, even more preferably 0.03% by mass or less, and particularly preferably 0.02% by mass or less.

[0047] However, the first resin layer may be substantially free of colorants. By substantially not containing a colorant, the transmitted light and reflected light of the first resin layer are more likely to reflect the hue of the filler (A). Therefore, a metallic feel can be achieved while suppressing coloration, making it easier to create a luxurious design. "Substantially not containing a colorant" means that no colorant is intentionally blended into the first resin layer. The specific colorant content in the first resin layer is, for example, less than 0.0001% by mass, preferably less than 0.00001% by mass, and most preferably 0% by mass.

[0048] [Optical Properties of First Resin Layer] The saturation Rc* of reflected light of the first resin layer in the visible light region (380 to 780 nm) is preferably 0 or more and 8.0 or less. When the saturation Rc* is 8.0 or less, the first resin layer can produce reflected light with a strong gray color, making it easier to produce a luxurious metallic feel. The saturation Rc* of the reflected light is more preferably 5.5 or less, and even more preferably 4.0 or less. From the viewpoint of obtaining reflected light with a stronger gray color, the lower the saturation Rc* of the reflected light, the better, and it is sufficient if it is 0 or more.

[0049] The saturation Tc* of the transmitted light in the visible light region (380 to 780 nm) of the first resin layer is preferably 0 or more and 8.0 or less. A saturation Tc* of 8.0 or less allows the transmitted light to have reduced coloring by the first resin layer. Therefore, for example, when observing the outdoors through the laminated glass from the indoor side, unnecessary hues are not imparted, resulting in a more luxurious laminated glass. The saturation Tc* of the transmitted light is more preferably 5.5 or less, and even more preferably 4.0 or less. From the viewpoint of suppressing the coloring of the transmitted light, the lower the saturation Tc* of the transmitted light, the better, and as described above, it is sufficient if it is 0 or more. However, from the viewpoint of enhancing the design by imparting a certain color, the saturation Tc* may be a certain value or more, and the saturation Tc* may be, for example, 1 or more, or 2 or more.

[0050] The haze of the first resin layer is preferably 12.0% or less, more preferably 11.0% or less, even more preferably 10.0% or less, and preferably 1.5% or more, more preferably 2.0% or more, and even more preferably 3.0% or more. When the haze of the first resin layer is 12.0% or less, light scattering does not occur more than necessary in the first resin layer, making it easier to improve transparency. When the haze is 1.5% or more, the first resin layer easily gives off a luxurious metallic feel. It is desirable that at least one of the saturation Rc* of reflected light, the saturation Tc* of transmitted light, and the haze of the first resin layer be within the above range, but it is preferable that all of these be within the above range. The optical properties (Rc*, Tc*, Haze) of the first resin layer are the values ​​of Rc*, Tc*, and Haze measured for a laminated glass prepared by bonding two reference glass plates together via the first resin layer. The laminated glass may be prepared by the method described in the Examples.

[0051] <Second Resin Layer> The interlayer film of the present invention preferably contains a resin layer (second resin layer) other than the first resin layer. The second resin layer preferably contains a colorant to form a colored layer. By containing a colorant, the second resin layer can be colored to a desired color, making it easier to impart a higher level of design. Furthermore, by containing a colorant in the second resin layer, light reflected by the filler (A) is absorbed by the second resin layer, preventing it from emitting from the second resin layer side of the interlayer film. Therefore, for example, when the interlayer film is viewed from the first resin layer side, the reflected light enhances the metallic effect, while when viewed from the second resin layer side, the metallic effect can be reduced. Therefore, for example, by arranging the first resin layer on the outdoor side (e.g., the exterior of an automobile) and the second resin layer on the indoor side (e.g., the interior of an automobile), the metallic effect can be enhanced when viewed from the outdoors, while providing a subdued impression when viewed from the indoors, thereby further enhancing the design.

[0052] (Colorant) The colorant used in the second resin layer may be a pigment or dye that is conventionally incorporated into interlayer films for laminated glass. The colorant may be dispersed in the resin that constitutes the second resin layer. Furthermore, a pigment is preferred because it can effectively color the interlayer film with a small amount of incorporation. Specific examples of pigments are as listed for the first resin layer. However, at least one pigment selected from phthalocyanine pigments, anthraquinone pigments, perylene pigments, azo pigments, quinacridone pigments, and carbon black is more preferred because of its high affinity with thermoplastic resins and resistance to bleed-out. Furthermore, a black colorant is preferred, with carbon black being particularly preferred, from the viewpoint of imparting a more luxurious feel and enhancing design. In the second resin layer, one colorant may be used alone, or two or more colorants may be used in combination.

[0053] The content of the colorant in the second resin layer is preferably 0.0001% by mass or more and 0.3% by mass or less. When the content is 0.0001% by mass or more, the light reflected by the filler (A) is sufficiently absorbed by the colorant, creating a sufficient metallic appearance when viewed from one side, while sufficiently suppressing the metallic appearance when viewed from the other side, creating a subdued impression. Furthermore, when the content is 0.3% by mass or less, excessive light absorption by the colorant is prevented, making it easier to ensure the transparency of the laminated glass. From these viewpoints, the content of the colorant is more preferably 0.001% by mass or more, even more preferably 0.005% by mass or more, even more preferably 0.01% by mass or more, and more preferably 0.1% by mass or less, even more preferably 0.08% by mass or less, and even more preferably 0.04% by mass or less.

[0054] However, the second resin layer may be a clear layer that does not substantially contain a colorant. When the second resin layer is a clear layer, the coloring by the filler (A) tends to be the color of the transmitted light as it is, making it easier to create a metallic feel with a strong gray impression. Note that "substantially not containing a colorant" means that no colorant is intentionally blended into the second resin layer. For example, the content of the colorant in the second resin layer is less than 0.0001% by mass, preferably less than 0.00001% by mass, and most preferably 0% by mass.

[0055] [Thermoplastic Resin] The resin constituting the first resin layer is preferably a thermoplastic resin. The resin constituting the second resin layer is preferably a thermoplastic resin. By containing a thermoplastic resin, the first resin layer or the second resin layer can easily function as an adhesive layer, and the adhesiveness to the laminated glass member or other layers constituting the interlayer film can be improved.

[0056] The thermoplastic resin in each resin layer is not particularly limited, but examples include polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ionomer resin, polyurethane resin, thermoplastic elastomer, acrylic resin, acrylic-vinyl acetate copolymer resin, polyvinyl alcohol resin, polyolefin resin, polyvinyl acetate resin, and polystyrene resin. The use of these resins facilitates ensuring adhesion to laminated glass components. Among these, polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ionomer resin, polyurethane resin, and thermoplastic elastomer are preferred. In the interlayer film of the present invention, the thermoplastic resin may be used alone or in combination of two or more. When two or more types are used in combination, the interlayer film may contain two or more types of thermoplastic resins in one resin layer (first or second resin layer), or different resin layers (first and second resin layers) may contain different types of thermoplastic resins. Among these, at least one selected from polyvinyl acetal resins and ethylene-vinyl acetate copolymer resins is preferred, and polyvinyl acetal resins are more preferred because they exhibit excellent adhesion to inorganic glass, particularly when used in combination with a plasticizer. Therefore, the resin in the first resin layer or the resins in the first and second resin layers is more preferably at least one selected from polyvinyl acetal resins and ethylene-vinyl acetate copolymer resins, and even more preferably a polyvinyl acetal resin.

[0057] The resin constituting each resin layer may be appropriately selected from the resins listed above. The resins constituting each resin layer may be different from each other, but are preferably the same. Therefore, the resins constituting both the first and second resin layers are preferably polyvinyl acetal resins or ethylene-vinyl acetate copolymer resins, and more preferably polyvinyl acetal resins.

[0058] (Polyvinyl Acetal Resin) The polyvinyl acetal resin is not particularly limited as long as it is a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol (PVA) with an aldehyde. The aldehyde is not particularly limited, but generally, an aldehyde having 1 to 10 carbon atoms is preferably used. The aldehyde having 1 to 10 carbon atoms is not particularly limited, and examples thereof include n-butyl aldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexyl aldehyde, n-octyl aldehyde, n-nonyl aldehyde, n-decyl aldehyde, formaldehyde, acetaldehyde, and benzaldehyde. These aldehydes may be used alone or in combination of two or more. Among the above, n-butylaldehyde, n-hexylaldehyde, and n-valeraldehyde are preferred, and n-butylaldehyde is more preferred. Therefore, the polyvinyl acetal resin is preferably a polyvinyl butyral resin.

[0059] Polyvinyl alcohol (PVA) can be obtained, for example, by saponifying a polyvinyl ester such as polyvinyl acetate. The degree of saponification of polyvinyl alcohol is generally 70 to 99.9 mol %. Polyvinyl acetal resins may be used singly or in combination of two or more. The average degree of polymerization of PVA is preferably 200 or more, more preferably 500 or more, even more preferably 1000 or more, and even more preferably 1500 or more. Increasing the average degree of polymerization above the lower limit improves the penetration resistance of laminated glass. Furthermore, the average degree of polymerization of PVA is preferably 5000 or less, more preferably 4000 or less, even more preferably 3500 or less, and even more preferably 2500 or less. The average degree of polymerization of polyvinyl alcohol is determined according to JIS K6726 "Testing Methods for Polyvinyl Alcohol."

[0060] The amount of hydroxyl groups in the polyvinyl acetal resin is preferably 15 mol% or more and preferably 38 mol% or less. By setting the amount of hydroxyl groups to 15 mol% or more, adhesiveness is likely to be improved and the penetration resistance of the laminated glass is likely to be improved. Furthermore, by setting the amount of hydroxyl groups to 38 mol% or less, the laminated glass is prevented from becoming too hard. From the viewpoint of adhesiveness to the laminated glass member, the amount of hydroxyl groups is more preferably 20 mol% or more, and even more preferably 25 mol% or more. Furthermore, the amount of hydroxyl groups is more preferably 35% or less, and even more preferably 33 mol% or less. When a polyvinyl butyral resin is used as the polyvinyl acetal resin, from the same viewpoint, the amount of hydroxyl groups is 15 mol% or more and preferably 38 mol% or less, more preferably 20 mol% or more, even more preferably 25 mol% or more, more preferably 35% or less, and even more preferably 33 mol% or less. The amount of hydroxyl groups in the polyvinyl acetal resin is the molar fraction calculated by dividing the amount of ethylene groups having hydroxyl groups by the total amount of ethylene groups in the main chain, and is expressed as a percentage. The amount of ethylene groups having hydroxyl groups can be measured, for example, in accordance with JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0061] The degree of acetalization of the polyvinyl acetal resin is preferably 47 mol% or more and preferably 85 mol% or less. The degree of acetalization is more preferably 55 mol% or more, even more preferably 60 mol% or more, and more preferably 80 mol% or less, even more preferably 75 mol% or less. Note that the term "degree of acetalization" refers to the degree of butyralization when the acetal group is a butyral group and the polyvinyl acetal resin (A) is a polyvinyl butyral resin.

[0062] The degree of acetalization is a molar fraction obtained by subtracting the amount of ethylene groups having hydroxyl groups and the amount of ethylene groups having acetyl groups from the total amount of ethylene groups in the main chain, and dividing the result by the total amount of ethylene groups in the main chain, and the percentage is expressed as the molar fraction. The degree of acetalization (degree of butyralization) may be calculated from the results of measurements made, for example, according to JIS K6728 "Testing Methods for Polyvinyl Butyral."

[0063] The degree of acetylation of the polyvinyl acetal resin is preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 10 mol% or less, and even more preferably 2 mol% or less. 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. The degree of acetylation is not particularly limited, but is preferably 0.01 mol% or more, more preferably 0.1 mol% or more. The degree of acetylation is a molar fraction calculated by dividing the amount of ethylene groups to which acetyl groups are bonded by the total amount of ethylene groups in the main chain, expressed as a percentage. The amount of ethylene groups to which acetyl groups are bonded can be measured, for example, in accordance with JIS K6728 "Test Methods for Polyvinyl Butyral."

[0064] (Ethylene-Vinyl Acetate Copolymer Resin) The ethylene-vinyl acetate copolymer resin may be a non-crosslinked ethylene-vinyl acetate copolymer resin or a high-temperature crosslinked ethylene-vinyl acetate copolymer resin. Furthermore, modified ethylene-vinyl acetate resins such as saponified ethylene-vinyl acetate copolymers and hydrolyzed ethylene-vinyl acetate can also be used as the ethylene-vinyl acetate copolymer resin. The ethylene-vinyl acetate copolymer resin preferably has a vinyl acetate content of 10 to 50 mass%, more preferably 20 to 40 mass%, as measured in accordance with JIS K 6730 "Test Methods for Ethylene-Vinyl Acetate Resins" or JIS K 6924-2:1997. By adjusting the vinyl acetate content to be equal to or greater than these lower limits, adhesion to laminated glass components is improved and the penetration resistance of the laminated glass is likely to be improved. Furthermore, by adjusting the vinyl acetate content to be equal to or less than these upper limits, the rupture strength of the interlayer film is increased, resulting in improved impact resistance of the laminated glass.

[0065] (Ionomer Resin) The ionomer resin is not particularly limited, and various ionomer resins can be used. Specific examples include ethylene-based ionomers, styrene-based ionomers, perfluorocarbon-based ionomers, telechelic ionomers, polyurethane ionomers, etc. Among these, ethylene-based ionomers are preferred because they improve the mechanical strength, durability, transparency, etc. of the laminated glass and have excellent adhesion to laminated glass members.

[0066] As the ethylene-based ionomer, an ionomer of an ethylene-unsaturated carboxylic acid copolymer is preferably used due to its excellent transparency and toughness. The ethylene-unsaturated carboxylic acid copolymer is a copolymer having at least ethylene-derived structural units and unsaturated carboxylic acid-derived structural units, and may also have structural units derived from other monomers. Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, maleic acid, etc., with acrylic acid and methacrylic acid being preferred, and methacrylic acid being particularly preferred. Examples of other monomers include acrylic acid esters, methacrylic acid esters, and 1-butene. The ethylene-unsaturated carboxylic acid copolymer preferably contains 75 to 99 mol % of ethylene-derived structural units and 1 to 25 mol % of unsaturated carboxylic acid-derived structural units, assuming that the total structural units of the copolymer are 100 mol %. The ionomer of an ethylene-unsaturated carboxylic acid copolymer is an ionomer resin obtained by neutralizing or crosslinking at least a portion of the carboxyl groups of the ethylene-unsaturated carboxylic acid copolymer with metal ions, and the degree of neutralization of the carboxyl groups is usually 1 to 90%, preferably 5 to 85%.

[0067] Examples of ion sources for the ionomer resin include alkali metals such as lithium, sodium, potassium, rubidium, and cesium, and polyvalent metals such as magnesium, calcium, and zinc, with sodium and zinc being preferred.

[0068] The method for producing the ionomer resin is not particularly limited, and the resin can be produced by a conventionally known production method. For example, when an ionomer of an ethylene-unsaturated carboxylic acid copolymer is used as the ionomer resin, for example, ethylene and an unsaturated carboxylic acid are radically copolymerized under high temperature and high pressure to produce the ethylene-unsaturated carboxylic acid copolymer. The ionomer of the ethylene-unsaturated carboxylic acid copolymer can then be produced by reacting the ethylene-unsaturated carboxylic acid copolymer with a metal compound containing the above-mentioned ion source.

[0069] (Polyurethane Resin) Examples of polyurethane resins include polyurethanes obtained by reacting an isocyanate compound with a diol compound, and polyurethanes obtained by reacting an isocyanate compound with a diol compound and a chain extender such as a polyamine. The polyurethane resin may also contain sulfur atoms. In this case, some or all of the diols may be selected from polythiols and sulfur-containing polyols. Polyurethane resins can improve adhesion to organic glass. Therefore, they are preferably used when the laminated glass member is made of organic glass.

[0070] (Thermoplastic Elastomer) Examples of thermoplastic elastomers include styrene-based thermoplastic elastomers and aliphatic polyolefins. The styrene-based thermoplastic elastomer is not particularly limited, and known elastomers can be used. Styrenic thermoplastic elastomers generally have a styrene monomer polymer block as a hard segment and a conjugated diene compound polymer block or a hydrogenated block thereof as a soft segment. Specific examples of styrene-based thermoplastic elastomers include styrene-isoprene diblock copolymers, styrene-butadiene diblock copolymers, styrene-isoprene-styrene triblock copolymers, styrene-butadiene / isoprene-styrene triblock copolymers, styrene-butadiene-styrene triblock copolymers, and hydrogenated products thereof. The aliphatic polyolefins may be saturated aliphatic polyolefins or unsaturated aliphatic polyolefins. The aliphatic polyolefins may be polyolefins containing a chain olefin as a monomer or polyolefins containing a cyclic olefin as a monomer. From the viewpoint of effectively improving the storage stability and sound insulation of the interlayer film, the aliphatic polyolefins are preferably saturated aliphatic polyolefins.Examples of the aliphatic polyolefin material include ethylene, propylene, 1-butene, trans-2-butene, cis-2-butene, 1-pentene, trans-2-pentene, cis-2-pentene, 1-hexene, trans-2-hexene, cis-2-hexene, trans-3-hexene, cis-3-hexene, 1-heptene, trans-2-heptene, cis-2-heptene, trans-3-heptene, cis-3-heptene, 1-octene, trans-2-octene, cis-2-octene, and trans-3- octene, cis-3-octene, trans-4-octene, cis-4-octene, 1-nonene, trans-2-nonene, cis-2-nonene, trans-3-nonene, cis-3-nonene, trans-4-nonene, cis-4-nonene, 1-decene, trans-2-decene, cis-2-decene, trans-3-decene, cis-3-decene, trans-4-decene, cis-4-decene, trans-5-decene, cis-5-decene, 4-methyl-1-pentene, and vinylcyclohexane.

[0071] (Plasticizer) The interlayer film may further contain a plasticizer. As described above, the interlayer film has one or more resin layers. Each resin layer (i.e., for example, the first resin layer or each of the first and second resin layers) may contain a plasticizer in addition to a thermoplastic resin. The inclusion of a plasticizer makes each resin layer flexible, thereby improving the flexibility and penetration resistance of the laminated glass. It also improves adhesion to laminated glass components. The inclusion of a plasticizer is particularly effective when a polyvinyl acetal resin is used as the thermoplastic resin. Therefore, it is more preferable that each resin layer, such as the first resin layer or the first and second resin layers, contain a polyvinyl acetal resin and a plasticizer. Examples of plasticizers include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, and phosphorus-based plasticizers such as organic phosphate ester plasticizers and organic phosphite ester plasticizers. Among these, organic ester plasticizers are preferred.

[0072] Examples of the organic ester plasticizer include 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, tetraethylene glycol di-2-ethylhexanoate, 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, 1,2-butylene glycol di-2-ethylbutyrate, and diethylene glycol di- Examples of suitable adipates include 2-ethyl butyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprylate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, dibutyl sebacate, oil-modified alkyd sebacic acid, a mixture of a phosphate ester and an adipate ester, and mixed adipates. Examples of mixed adipates include adipates prepared from two or more alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms. Among the above plasticizers, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly suitable.

[0073] The content of the plasticizer in each resin layer (for example, the first resin layer, or each of the first and second resin layers) is not particularly limited, but is preferably 10 parts by mass or more and 100 parts by mass or less relative to 100 parts by mass of the thermoplastic resin. When the plasticizer content is 10 parts by mass or more, the resin layer becomes moderately flexible, and penetration resistance, adhesion, etc. are improved. Furthermore, when the plasticizer content is 100 parts by mass or less, separation of the plasticizer from each resin layer is prevented. The content of the plasticizer in each resin layer is more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, even more preferably 35 parts by mass or more, and more preferably 70 parts by mass or less, even more preferably 63 parts by mass or less.

[0074] The first resin layer or each of the first and second resin layers is mainly composed of a resin or a resin and a plasticizer, and the total amount of the thermoplastic resin and the plasticizer in each resin layer is usually 70% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more but less than 100% by mass, based on the total amount of the resin layer. By making the total amount less than 100% by mass, the resin layer can contain additives such as a colorant and a filler (A).

[0075] [Other Additives] Each resin layer of the present invention may contain additives other than those described above, such as an ultraviolet absorber, an antioxidant, a light stabilizer, an adhesion modifier, a heat-shielding agent, a fluorescent brightening agent, a crystal nucleating agent, etc. As described above, the interlayer film of the present invention has one or more resin layers, and each resin layer may contain at least one selected from these additives as appropriate.

[0076] <Layer Structure> The layer structure of the interlayer film of the present invention will be described in more detail below. In the present invention, the interlayer film may be composed of a single first resin layer, or may be composed of two layers, such as the interlayer film 20 shown in FIG. 3 , including a first resin layer 21 and a second resin layer 22. The first resin layer 21 and the second resin layer 22 are laminated in the thickness direction. In the two-layer interlayer film 20, the first resin layer 21 forms one surface 20A (the surface facing the first resin layer) of the interlayer film, and the second resin layer 21 forms the other surface 20B (the surface facing the second resin layer) of the interlayer film, which respectively serve as bonding surfaces with the laminated glass members (first and second laminated glass members 31, 32) of the laminated glass 30. The surface of the first laminated glass member 31 is the surface of the laminated glass 30 facing the first resin layer (surface 30A), and the surface of the second laminated glass member 32 is the surface of the laminated glass 30 facing the second resin layer (surface 30B).

[0077] However, the interlayer film may have a plurality of first resin layers or a plurality of second resin layers. For example, a three-layer structure such as second resin layer / first resin layer / second resin layer may be formed by providing a plurality of second resin layers, or a plurality of first resin layers may be provided. Furthermore, the second resin layer and the first resin layer may be provided continuously, and may have a structure such as first resin layer / first resin layer / second resin layer or first resin layer / second resin layer / second resin layer. Furthermore, the interlayer film may have a structure of four or more layers.

[0078] (Sound insulation performance) The interlayer film may have multiple resin layers. When at least three resin layers are provided, the sound insulation performance may be imparted by a three-layer structure in which the central resin layer is a core layer and the layers on both sides of the core layer are skin layers. In this case, the interlayer film may contain appropriate resin layers in addition to the two skin layers and one core layer. Here, the core layer may be either the first resin layer or the second resin layer, but is preferably the second resin layer. Furthermore, the skin layer may be either the first or second resin layer, but it is preferable that at least one of them is the first resin layer. Here, the resins used for the skin layer and the core layer are both preferably polyvinyl acetal resin, and more preferably polyvinyl butyral resin.

[0079] As described above, both the skin layer and the core layer preferably contain a plasticizer. In this case, the content of the plasticizer in the core layer per 100 parts by mass of the thermoplastic resin is preferably greater than the content of the plasticizer in the skin layer per 100 parts by mass of the thermoplastic resin, and the difference in content is preferably 5 parts by mass to 60 parts by mass, more preferably 10 parts by mass to 50 parts by mass, and even more preferably 15 parts by mass to 35 parts by mass. Increasing the content of the plasticizer in the core layer facilitates improving sound insulation performance. Furthermore, the amount of hydroxyl groups in the polyvinyl acetal resin in the core layer is preferably lower than the amount of hydroxyl groups in the polyvinyl acetal resin in the skin layer, and the difference in hydroxyl group content is preferably 1 mol% to 20 mol%, more preferably 2 mol% to 15 mol%, and even more preferably 2 mol% to 10 mol%. Reducing the amount of hydroxyl groups in the core layer makes it easier to increase the plasticizer content and improve sound insulation performance.

[0080] (Barrier Layer) In the above description, the second resin layer has been described on the assumption that it is used as a clear layer or a colored layer, but it may also be provided with a function other than the above-mentioned clear layer or colored layer, and may be, for example, a barrier layer. The barrier layer is disposed between two resin layers (for example, between two first resin layers, between two second resin layers, or between the first resin layer and the second resin layer) and prevents components contained in a resin layer (such as a colorant or a plasticizer) from migrating to another resin layer.

[0081] When used as a barrier layer, the second resin layer may be a known resin film, such as a polyester film such as polyethylene terephthalate (PET) film, a polyolefin film, a polyamide film, a polyimide film, a polycarbonate film, or an acrylic resin film. Among these, it is preferable to use either an acrylic resin film or a PET film, with a PET film being more preferable. The acrylic resin used in the acrylic resin film is preferably an acrylic polymer containing a structural unit derived from a hydroxyl group-containing (meth)acrylate, and specific examples include polyhydroxypropyl methacrylate (HPMA resin) and polyhydroxyethyl methacrylate (HEMA resin).

[0082] Furthermore, the first resin layer does not need to be provided over the entire area of ​​the interlayer film, but may be provided over only a portion of the area. Similarly, the second resin layer does not need to be provided over the entire area of ​​the interlayer film, but may be provided over only a portion of the area. Furthermore, when a plurality of first resin layers are provided, only some of the first resin layers may be provided over only a portion of the area. Similarly, when a plurality of second resin layers are provided, only some of the second resin layers may be provided over only a portion of the area.

[0083] The interlayer film preferably has a second resin layer constituting a colored layer provided only in a partial region. For example, when the interlayer film has a laminated structure of a first resin layer / a second resin layer (clear layer) / a second resin layer (colored layer) / a second resin layer (clear layer), the second resin layer (colored layer) may be provided only in a partial region of the interlayer film. That is, a partial region may have a laminated structure of a first resin layer / a second resin layer (clear layer) / a second resin layer (colored layer) / a second resin layer (clear layer), and the remaining region may have a laminated structure of a first resin layer / a second resin layer (clear layer) / a second resin layer (clear layer). In this case, in a region where the second resin layer (colored layer) is not provided, the two second resin layers (clear layers) may be integrated to form a single second resin layer (clear layer). Furthermore, even in the case of a layer structure of, for example, first resin layer / second resin layer (colored layer) / second resin layer (clear layer), the second resin layer (colored layer) may be provided only in a partial region of the interlayer film. That is, a partial region may have a laminated structure of first resin layer / second resin layer (colored layer) / second resin layer (clear layer), and the remaining region may have a laminated structure of first resin layer / second resin layer (clear layer).

[0084] Furthermore, for example, the laminate may have a layer structure of second resin layer / first resin layer / second resin layer, with the first resin layer being provided only in a partial region, in which case a partial region may have a laminate structure of second resin layer / first resin layer / second resin layer, and the remaining region may have a structure consisting of second resin layer / second resin layer. In this case, in the region where the first resin layer is not provided, the two second resin layers may be integrated to form a single second resin layer.

[0085] Also, for example, in a laminate structure of the second resin layer (clear layer) / the first resin layer / the second resin layer (clear layer) / the second resin layer (colored layer) / the second resin layer (clear layer), the first resin layer and the second resin layer (colored layer) may be provided only in a partial region. That is, a partial region has a laminate structure of the second resin layer (clear layer) / the first resin layer / the second resin layer (clear layer) / the second resin layer (colored layer) / the second resin layer (clear layer), and the remaining region has a laminate structure of the second resin layer (clear layer) / the second resin layer (clear layer) / the second resin layer (clear layer). In this case, in the region where there is no first resin layer and no second resin layer (colored layer), two or three second resin layers (clear layers) may be integrated to form one second resin layer (clear layer).

[0086] The first and second resin layers may have a constant thickness or may have a variable thickness. For example, as described above, the first and second resin layers provided in a partial region of the interlayer film may have a cross-sectional shape in which the thickness decreases toward the region where the first and second resin layers are not provided.

[0087] The interlayer film may have a rectangular cross section and a constant thickness, but is not limited to a rectangular cross section and may have, for example, a wedge shape. A wedge-shaped interlayer film has a cross-sectional thickness that differs from one end to the other end, and may have a trapezoidal or triangular cross section. Furthermore, a wedge-shaped interlayer film has a thickness that changes from one end to the other, but the thickness does not need to change over the entire area; it may have a constant thickness in one area, and the thickness may change only in part.

[0088] [Thickness of each layer] The thickness of the first resin layer is preferably 0.1 mm or more and 2.5 mm or less, more preferably 0.2 mm or more and 2.0 mm or less, and even more preferably 0.25 mm or more and 1.5 mm or less. By adjusting the content of the filler (A) in the first resin layer within the above range and setting the thickness within these ranges, the interlayer film can easily improve design while ensuring transparency.

[0089] The thickness of the second resin layer is preferably 0.1 mm or more and 2.5 mm or less, more preferably 0.2 mm or more and 2.0 mm or less, and even more preferably 0.25 mm or more and 1.5 mm or less. By setting the thickness of the second resin layer within the above range, various functions can be imparted without making the thickness of the interlayer film larger than necessary. Furthermore, by using the second resin layer as a colored layer and adjusting the colorant content in the colored layer within the above range and setting the thickness within these ranges, the interlayer film can appropriately absorb light reflected by the first resin layer, thereby improving the transparency from the second resin layer side.

[0090] The thickness ratio of the first resin layer to the second resin layer is preferably 10:1 to 1:50. By setting the thickness ratio within this range, it is possible to improve the design while also ensuring transparency even when the second resin layer is used as a colored layer. From these viewpoints, the thickness ratio of the first resin layer to the second resin layer is more preferably 5:1 to 1:25, and even more preferably 1:1 to 1:10.

[0091] The thickness of the interlayer film is preferably 0.2 mm or more and 2.6 mm or less, more preferably 0.25 mm or more and 2.2 mm or less, and even more preferably 0.3 mm or more and 1.75 mm or less.

[0092] The thicknesses of the first and second resin layers and the intermediate film may vary as described above, and in such cases, the thicknesses of the first and second resin layers and the intermediate film described above refer to the thickness of the thickest portion of the first resin layer in the region where the first resin layer is present. Furthermore, when there are two or more first resin layers, the thickness of the first resin layer refers to the total thickness of the first resin layers, and the same applies to the second resin layer.

[0093] [Optical Properties of Interlayer Film] (Visible Light Reflectance (Rv)) The interlayer film of the present invention preferably has a visible light reflectance (Rv) of 5% or more, more preferably 7% or more, even more preferably 9% or more, and even more preferably 10% or more. An Rv of 5% or more makes it easier to achieve a luxurious metallic feel through reflected light. Furthermore, the visible light reflectance (Rv) is preferably 50% or less, more preferably 40% or less, even more preferably 30% or less, and even more preferably 20% or less. By setting the Rv to 50% or less, it is possible to prevent unnecessary reflection and unnecessary reduction in see-through properties.

[0094] (Saturation (Rc*)) The interlayer film of the present invention may have a saturation (Rc*) of reflected light of, for example, 20 or less, preferably 15 or less, more preferably 12 or less, and even more preferably 7.0 or less. The interlayer film of the present invention has a low saturation (Rc*) of reflected light, which makes it easier to impart a high-quality metallic feel with a strong gray color. The saturation (Rc*) is not particularly limited in terms of its lower limit, and may be 0 or more. However, in order to impart a metallic feel with a certain color, the saturation (Rc*) may be set to a certain value or more, for example, 1 or more, or 2 or more.

[0095] The visible light reflectance (Rv) and the saturation of reflected light (Rc*) of the interlayer film were measured from one side of a laminated glass produced by bonding two reference clear glass sheets together via the interlayer film. However, it is preferable to measure them from the same side as the side on which the spectral reflectance was measured. Therefore, as described below, when a second resin layer, which is a colored layer, is provided in addition to the first resin layer, it is preferable to use the values ​​(Rv1, Rc*1) measured from the first resin layer side. The reason for using the value of reflected light measured from the first resin layer side is that it is expected that reflected light will be observed mainly from the outdoor side of the laminated glass.

[0096] (Visible Light Transmittance (Tv)) The interlayer film of the present invention preferably has a visible light transmittance (Tv) of 1% or more and 90% or less, more preferably 3% or more and 85% or less, and even more preferably 6% or more and 80% or less. When a colored layer is provided as the second resin layer described below, the interlayer film of the present invention has a low visible light transmittance (Tv). When a colored layer is provided, the visible light transmittance (Tv) is preferably 1% or more and 50% or less, preferably 3% or more and 30% or less, and more preferably 6% or more and 20% or less. By setting the visible light transmittance (Tv) to 1% or more, a certain level of transparency can be ensured even when a colored layer is provided as the second resin layer. Furthermore, by setting the visible light transmittance (Tv) to 50% or less, the effect of providing a colored layer as the second resin layer can be more easily achieved. Furthermore, when the interlayer film of the present invention does not have a colored layer as the second resin layer described below, the visible light transmittance (Tv) is preferably 50% to 90%, more preferably 60% to 80%, and even more preferably 68% to 80%. By setting Tv to 50% or more, high transparency can be ensured. Furthermore, by setting Tv to 90% or less, when the interlayer film does not have a colored layer, it becomes easier to impart a luxurious metallic feel to the first resin layer.

[0097] (Saturation (Tc*)) The interlayer film of the present invention may have a saturation (Tc*) of transmitted light measured from the other surface of the interlayer film of the present invention of, for example, 35 or less, preferably 15 or less, more preferably 12 or less, and even more preferably 7.0 or less. The interlayer film of the present invention has a low saturation (Tc*), which prevents the laminated glass from appearing to have an excessively low tint when viewed from, for example, the interior of a vehicle, making it easier to impart a luxurious feel. Furthermore, the saturation (Tc*) is not particularly limited in terms of its lower limit, and it is sufficient that it is 0 or more. However, from the viewpoint of imparting a certain tint to the laminated glass when viewed from, for example, the interior of a vehicle, it may be, for example, 1 or more, or 3 or more.

[0098] The visible light transmittance (Tv) and saturation of transmitted light (Tc*) of the interlayer film were measured from one side of a laminated glass produced by bonding two reference clear glass sheets together via the interlayer film. It is preferable to measure the values ​​on the same side as the side on which the haze was measured. Therefore, as described below, when a second resin layer, which is a colored layer, is provided in addition to the first resin layer, it is preferable to use the values ​​(Tv2, Tc*2) measured from the second resin layer side. The reason for using the value of transmitted light measured from the second resin layer side is that it is expected that transmitted light will be observed mainly on the indoor side of the laminated glass.

[0099] The visible light reflectance (Rv) and visible light transmittance (Tv) can be measured using a spectrophotometer in accordance with JIS 3106 (2019). Chroma (Rc*, Tc*) can be calculated by measuring the a* (Ra* or Ta*) and b* (Rb* or Tb*) of reflected or transmitted light in the visible light region (380 to 780 nm) and then calculating c* = [(a*) ２ +(b*) ２ ] １／２ The visible light reflectance (Rv), the saturation of reflected light (Rc*), the visible light transmittance (Tv) and the saturation of transmitted light (Tc*) can be adjusted by the type and content of the filler (A), and the type and content of the colorant contained in the first resin layer and / or the second resin layer.

[0100] In a configuration in which the second resin layer 22, which is a colored layer, is provided in addition to the first resin layer 21 (see FIG. 3 ), the expression "measured from the first resin layer side" for each optical property (e.g., haze, spectral transmittance, Rv, Rc*, Tv, and Tc*) means that the property is measured from the surface 30A of the laminated glass on which the first resin layer 21 of the interlayer film is provided. Similarly, the expression "measured from the second resin layer side" means that the property is measured from the surface 30B of the laminated glass on which the second resin layer 22, which constitutes the colored layer, is provided. In this case, a layer other than the first resin layer 21 or the colored layer (e.g., a second resin layer (clear layer)) may be provided as appropriate outside the first resin layer 21 or the second resin layer 22 (colored layer). However, in the present invention, there are cases where both the one surface 20A side and the other surface 20B side are first resin layers (or second resin layers (colored layers)), such as first resin layer / second resin layer / first resin layer or second resin layer (colored layer) / first resin layer / second resin layer (colored layer). In such cases, for each optical property, measurements taken from any one surface may be referred to as "measured from the first resin layer side," and measurements taken from the other surface may be referred to as "measured from the second resin layer side." On the other hand, in a configuration such as first resin layer / second resin layer (colored layer) / first resin layer / second resin layer (colored layer), measurements taken from the surface of the laminated glass on the first resin layer side (i.e., the left side) may be referred to as "measured from the first resin layer side." Furthermore, measurements taken from the surface of the laminated glass on the second resin layer (i.e., the right side) may be referred to as "measured from the second resin layer side."

[0101] Furthermore, the reference clear glass plate used in the measurements of the above-mentioned haze, spectral transmittance, visible light reflectance (Rv), chroma of reflected light (Rc*), visible light transmittance (Tv), and chroma of transmitted light (Tc*) has a thickness of 2.5 mm and a visible light transmittance of 90.5% measured in accordance with JIS R 3106: 1998. Furthermore, the clear glass plate has a* = -0.6, b* = 0.2, and a haze of 0.2% or less, as obtained using CIE standard illuminant D65 and 10° visual field color matching functions specified in JIS Z 8781-1 (2012), JIS Z 8781-2 (2012), and JIS Z 8781-4 (2013). Furthermore, the interlayer film may have a region where the first resin layer is absent or the thicknesses of the first and second resin layers may vary. In such cases, the above-described haze, spectral transmittance, Rv, Tv, Rc*, and Rc* may be measured in the same region where the thickness of the first resin layer is greatest.

[0102] (Method for Manufacturing Interlayer Film) The interlayer film of the present invention is not particularly limited, but may be prepared by preparing a resin composition for forming each resin layer, molding the resin layer from the resulting resin composition, and laminating multiple resin layers in a multilayer structure. Each resin composition may be obtained, for example, by mixing a thermoplastic resin with a filler (A), a colorant, a plasticizer, and other additives, as needed. Here, in the first resin layer, the filler (A) is blended in addition to the thermoplastic resin. However, in order to improve dispersibility in the resin composition, for example, when a plasticizer is used, the filler (A) may be blended in the plasticizer and thoroughly dispersed therein before being mixed with the thermoplastic resin. In this case, a dispersant or the like may be added to the plasticizer as appropriate. Furthermore, in the second resin layer, a colorant may be blended in addition to the thermoplastic resin. In order to improve dispersibility in the resin composition, for example, when a plasticizer is used, the colorant may be blended in the plasticizer and thoroughly dispersed therein before being mixed with the thermoplastic resin. In this case, a dispersant or the like may be added to the plasticizer as appropriate. When an additive other than the filler (A) or the colorant is used, depending on the type of additive, the additive may be blended with a plasticizer and thoroughly dispersed in the plasticizer, and then mixed with the thermoplastic resin.

[0103] The interlayer film may be formed by extrusion molding, press molding, or the like. In extrusion molding, if the interlayer film is multilayered, it is preferable to prepare two or more extruders and attach multilayer feed blocks to the tips of the extruders to perform co-extrusion. Furthermore, if multiple resin layers are provided and two or more resin layers have the same composition, two or more resin layers having the same composition may be extruded from a single extruder. Furthermore, the thickness of each resin layer may vary in a direction perpendicular to the thickness direction. In such a case, the thickness may be varied, for example, by adjusting the amount of resin supplied. Alternatively, the interlayer film may be produced by preparing multiple resin layers, positioning the multiple resin layers between a pair of laminated glass components to obtain a laminate, and then thermocompression-bonding (press molding) the laminate, thereby producing the interlayer film while producing the laminated glass. Note that if the filler (A) has orientable anisotropy, such as when it has a flat shape, the longitudinal or planar direction of the filler (A) can be oriented along the planar direction of the interlayer film (each resin layer) by the above-mentioned press molding, extrusion molding, or the like.

[0104] <Laminated Glass> The present invention also provides laminated glass. The laminated glass comprises two laminated glass members (first and second laminated glass members) and an interlayer film disposed between these laminated glass members. The two laminated glass members are bonded via the interlayer film. One surface of the interlayer film is bonded to one laminated glass member, and the other surface is bonded to the other laminated glass member. The configuration of the interlayer film is as described above. The laminated glass may be produced by disposing the above-described interlayer film between two laminated glass members and integrating them by thermocompression bonding or the like. Alternatively, the laminated glass may be produced by preparing a plurality of resin layers, disposing the plurality of resin layers between a pair of laminated glass members to obtain a laminate, and integrating the laminate by thermocompression bonding or the like.

[0105] (Laminated Glass Member) Examples of the laminated glass member used in the laminated glass include glass plates. The glass plates may be either inorganic or organic glass, with inorganic glass being preferred. Examples of inorganic glass include, but are not limited to, clear glass, float glass, polished glass, figured glass, wired glass, striped glass, and green glass. Examples of organic glass generally used are what is called resin glass, and include, but are not limited to, organic glass made from resins such as polycarbonate, acrylic resin, acrylic copolymer resin, and polyester. The two laminated glass members may be made of the same material or different materials. For example, one may be inorganic glass and the other organic glass, but it is preferred that both laminated glass members be inorganic glass or organic glass. The thickness of each laminated glass member is, but is not limited to, approximately 0.1 to 15 mm, preferably 0.5 to 5 mm. The thicknesses of the laminated glass members may be the same or different, but are preferably the same.

[0106] The laminated glass preferably has a haze of 2.0% or more and 13.0% or less, and exhibits a flat reflectance in the spectral reflectance curve for wavelengths of 400 to 700 nm. By virtue of the above-described configuration, the laminated glass can provide a luxurious metallic appearance, enhancing design while also providing good transparency. The haze of the laminated glass, like the interlayer film described above, is preferably 12.0% or less, more preferably 11.0% or less, even more preferably 9.5% or less, and preferably 3.0% or more, more preferably 4.0% or more, and even more preferably 4.5% or less. The haze of the laminated glass may be measured from either side of the laminated glass. However, if the interlayer film includes a second resin layer, which is a colored layer, in addition to the first resin layer, the value (Haze 2) measured from the second resin layer side may be used.

[0107] From the same viewpoint as the interlayer film described above, the laminated glass preferably has an Rmax / Rmin ratio, which is the ratio of the maximum reflectance to the minimum reflectance in the spectral reflectance curve for a wavelength range of 400 to 700 nm, of 1.6 or less, more preferably 1.5 or less, even more preferably 1.4 or less, and even more preferably 1.35 or less. The lower the Rmax / Rmin of the laminated glass, the better, and it is sufficient that it is 1.0 or more. Furthermore, when a second resin layer serving as a colored layer is provided on the interlayer film, the Rmax / Rmin of the laminated glass is preferably 1.6 or less, more preferably 1.5 or less, and even more preferably 1.4 or less. On the other hand, when a second resin layer serving as a colored layer is not provided on the interlayer film, the Rmax / Rmin of the laminated glass becomes relatively small, preferably 1.4 or less, more preferably 1.35 or less, and even more preferably 1.3 or less.

[0108] Furthermore, similar to the interlayer film, the Rmin in the spectral reflectance curve of the laminated glass in the wavelength range of 400 to 700 nm is preferably 4% or more, more preferably 6% or more, and even more preferably 7% or more, and is preferably 50% or less, more preferably 40% or less, even more preferably 30% or less, and even more preferably 20% or less. The spectral reflectance curve may be obtained by measuring the spectral reflectance from either side of the laminated glass. However, if the interlayer film includes a second resin layer (a colored layer) in addition to the first resin layer, the spectral reflectance curve may be prepared using the spectral reflectance measured from the first resin layer side. Furthermore, the preferred ranges for the visible light reflectance (Rv), chroma (Rc*), visible light transmittance (Tv), and chroma (Tc*) of the laminated glass are the same as those for the interlayer film described above, and therefore, a description thereof will be omitted.

[0109] The laminated glass of the present invention can be used as window glass for various vehicles such as automobiles, aircraft, ships, and other vehicles, buildings, etc., but is preferably used as laminated glass for automobiles. The laminated glass for automobiles may be any of windshield glass (front glass), side glass, rear glass, and roof glass.

[0110] In various applications, window glass is generally used as a component for separating indoors from outdoors. When the interlayer film has a first resin layer 21 on one surface 20A of the interlayer film 20 and a second resin layer 22 composed of a colored layer and disposed on the other surface 20B, as shown in Fig. 3 , the surface 20A of the interlayer film on which the first resin layer 21 is disposed is preferably disposed on the outdoor side (i.e., the vehicle exterior side in an automobile), and the surface 20B on which the second resin layer 22 is disposed is preferably disposed on the indoor side (i.e., the vehicle exterior side in an automobile). In this case, a layer other than the first resin layer 21 and the colored layer (e.g., a second resin layer (clear layer)) may be appropriately disposed outside the first resin layer 21 and the second resin layer 22 (colored layer).

[0111] The present invention will be explained in more detail by way of examples, but the present invention is not limited to these examples in any way.

[0112] The measurement and evaluation methods in the present examples are as follows.

[0113] [Spectral reflectance from 400 to 700 nm] The spectral reflectance was measured from one side of the laminated glass using a spectrophotometer (Hitachi High-Technologies Corporation's "U-4100"). The measurement conditions were a scan speed of 300 nm / min and a slit width of 8 nm. From the obtained spectral reflectance, a spectral reflectance curve from wavelengths of 400 to 700 nm was obtained, and Rmax and Rmin were calculated. In the case of laminated glass having a first resin layer and a second resin layer, Rmax and Rmin were calculated using the spectral reflectance curve obtained by measurement from the side of the laminated glass facing the first resin layer.

[0114] [Rv1, Rv2] In accordance with JIS 3106 (2019), the visible light reflectance (Rv) was measured from one side of the laminated glass using a spectrophotometer (Hitachi High-Technologies Corporation's "U-4100") and designated as Rv1. For laminated glass having a first resin layer and a second resin layer, the visible light reflectance measured from the side of the laminated glass facing the first resin layer was designated as Rv1, and the visible light reflectance measured from the side of the laminated glass facing the second resin layer was designated as Rv2.

[0115] [Ra*1, Rb*1, Rc*1, Ra*2, Rb*2, Rc*2] Using a spectrophotometer (Hitachi High-Technologies Corporation's "U-4100"), the spectral reflectance was measured from one side of the laminated glass. The measurement conditions were a scan speed of 300 nm / min and a slit width of 8 nm. From the obtained spectral reflectance, chromaticity a* and b* were determined in accordance with JIS Z 8781 (2009) using a D65 light source and a 10° field of view. Furthermore, chroma c* was determined from a* and b*, and these were designated as Ra*1, Rb*1, and Rc*1, respectively. In addition, for laminated glass having a first resin layer and a second resin layer, a*, b*, and c* measured from the surface of the laminated glass facing the first resin layer were designated as Ra*1, Rb*1, and Rc*1, respectively, and a*, b*, and c* measured from the surface of the laminated glass facing the second resin layer were designated as Ra*2, Rb*2, and Rc*2, respectively.

[0116] [Tv1, Tv2] In accordance with JIS R 3212 (2015), a spectrophotometer ("U-4100" manufactured by Hitachi High-Technologies Corporation) was used to determine the visible light transmittance from one side of the laminated glass, and this was designated as Tv1. For laminated glass having a first resin layer and a second resin layer, the visible light transmittance measured from the side of the laminated glass facing the first resin layer was designated as Tv1, and the visible light transmittance measured from the side of the laminated glass facing the second resin layer was designated as Tv2.

[0117] [Ta*1, Tb*1, Tc*1, Ta*2, Tb*2, and Tc*3] Using a spectrophotometer (Hitachi High-Technologies Corporation's "U-4100"), the spectral transmittance was measured from one side of the laminated glass. The measurement conditions were a scan speed of 300 nm / min and a slit width of 8 nm. From the obtained spectral transmittance, a* and b* were calculated in accordance with JIS Z 8781 (2009) using a D65 light source and a 10° field of view. c* was also calculated from a* and b*, and these were designated as Ta*1, Tb*1, and Tc*1, respectively. In addition, for laminated glass having a first resin layer and a second resin layer, a*, b*, and c* measured from the surface of the laminated glass facing the first resin layer were designated as Ta*1, Tb*1, and Tc*1, respectively, and a*, b*, and c* measured from the surface of the laminated glass facing the second resin layer were designated as Ta*2, Tb*2, and Tc*2, respectively.

[0118] [Haze] The haze of the obtained laminated glass was measured from one side in accordance with JIS K6714 and designated as Haze 1. In addition, for laminated glass having a first resin layer and a second resin layer, the haze measured from the side of the laminated glass facing the first resin layer was designated as Haze 1, and the haze measured from the side of the laminated glass facing the second resin layer was designated as Haze 2.

[0119] [a* and b* of Reflected Light of Filler (A)] For each filler used in each Example and Comparative Example, an interlayer film and then a laminated glass were prepared as follows, and the a* and b* of reflected light were measured. A resin composition was obtained by adding 40 parts by mass of triethylene glycol di-2-ethylhexanoate and 0.05% by mass of filler (based on the total amount of the resin composition) to 100 parts by mass of polyvinyl butyral resin and mixing them, and the resulting composition was extrusion-molded to obtain an interlayer film with a thickness of 760 μm. Two sheets of reference glass were bonded together via the obtained interlayer film to obtain a laminated glass (laminated glass for measurement). The manufacturing conditions for the interlayer film and the laminated glass for measurement were the same as in Example 1. The polyvinyl butyral resin and triethylene glycol di-2-ethylhexanoate used were also the same as those used in Example 1. The spectral reflectance was measured from one side of the laminated glass for measurement, and the a* and b* were calculated from the obtained spectral reflectance to obtain the a* and b* of reflected light of each filler. The spectral reflectance and a* and b* were measured under the same conditions as those used to determine Ra*1 and Rb*1.

[0120] [Optical Properties of First Resin Layer (Rc*, Tc*, Haze)] Two sheets of reference glass were bonded together via the first resin layer prepared in each Example and Comparative Example to obtain laminated glass (laminated glass for measurement). The manufacturing conditions for the interlayer film and laminated glass for measurement were the same as those in Example 1. The polyvinyl butyral resin and triethylene glycol di-2-ethylhexanoate used were also the same as those used in Example 1. The spectral reflectance was measured from one side of the laminated glass for measurement, and a* and b* were calculated from the obtained spectral reflectance. The chroma c* was further calculated from a* and b*, and this was used as the chroma Rc* of the reflected light of the first resin layer. The spectral reflectance and a* and b* were measured under the same conditions as those used to determine Ra*1 and Rb*1. Furthermore, the spectral transmittance was measured using a spectrophotometer, a* and b* were calculated from the obtained spectral transmittance, and the chroma c* was further determined from a* and b*, and this was defined as the chroma Tc* of the transmitted light of the first resin layer. Furthermore, the haze of the obtained laminated glass for measurement was measured in accordance with JIS K6714, and this was defined as the haze of the first resin layer.

[0121] <Design evaluation> One surface of the laminated glass (the surface on the first resin layer side, if a second resin layer was present) was visually observed, and the design was evaluated according to the following evaluation criteria. A: A strong gray impression gave a luxurious metallic feel. B: The gray impression was somewhat weak, but the metallic feel was luxurious. C: Although a metallic feel was given, the gray impression was weak and the luxurious feel was lacking, or no metallic feel was given. <Transparency evaluation> The transparency when an external scene was viewed through the laminated glass from the other surface of the laminated glass (the surface on the second resin layer side, if a second resin layer was present) was evaluated according to the following evaluation criteria. A: The external scene could be clearly observed, and the transparency was excellent. B: The external scene could be observed fairly clearly, and the transparency was good. C: The external scene appeared blurred, and the transparency could not be said to be good.

[0122] The components used in the examples and comparative examples are as follows: (1) Thermoplastic resin PVB: polyvinyl butyral resin, acetalization degree 69 mol%, hydroxyl group amount 30 mol%, acetylation degree 1 mol%, average polymerization degree of PVA used in synthesis 1700 (2) Plasticizer 3GO: triethylene glycol di-2-ethylhexanoate (3) Filler (A) Oxide 1: SiO with a refractive index of 1.46 as the middle layer ２ The layer and the covering layer are TiO with a refractive index of 2.49. ２ The layer is a flat plate shape with a three-layer structure shown in FIG. 2, D50: 14 μm, thickness: 0.5 μm, aspect ratio: 2.8, a* of reflected light = 6.2, b* of reflected light = -7.9. Oxide 2: The middle layer is SiO with a refractive index of 1.46 ２ The layer and the covering layer are TiO with a refractive index of 2.49. ２ The layer is a flat plate shape of a three-layer structure shown in FIG. 2, D50: 14 μm, thickness: 0.5 μm, aspect ratio: 2.8, a* of reflected light = -8.7, b* of reflected light = 1.0. Oxide 3: The middle layer is SiO with a refractive index of 1.46 ２ The layer and the covering layer are TiO with a refractive index of 2.49. ２ The layer is a flat plate shape with a three-layer structure shown in FIG. 2, D50: 14 μm, thickness: 0.5 μm, aspect ratio: 2.8, a* of reflected light = -6.7, b* of reflected light = 8.2. Oxide 4: The middle layer is SiO with a refractive index of 1.46 ２The layer and the covering layer are TiO with a refractive index of 2.49. ２ 2, which is a three-layer structure shown in FIG. 2, D50: 14 μm, thickness: 0.5 μm, aspect ratio: 2.8, a* of reflected light = -6.6, b* of reflected light = 5.7 (Note: For oxides 1 to 4, the chromaticity a* and b* of reflected light were adjusted depending on the thickness of the coating layer.) Mica: "Iriodin 6163" manufactured by MERCK Corporation, plate-like mica (4) Colorant CB: Pigment Black 7 (CAS No. 1333-86-4), carbon black pigment PB15-1: Pigment Blue 15-1 (CAS No. 12239-87-1), copper phthalocyanine pigment, blue colorant PR147: Pigment Red 147 (CAS No. 68227-78-1), naphthol azo pigment PR202: Pigment Red 202 (CAS No. 3089-17-6), quinacridone pigment

[0123] [Example 1] (Preparation of Interlayer Film) Two types of fillers (A) were mixed and dispersed in a plasticizer according to the formulation in Table 1, and then added to an extruder together with polyvinyl butyral resin (PVB) and thoroughly kneaded to homogenize, thereby obtaining a resin composition for forming a first resin layer. The obtained resin composition was extruded at an extrusion temperature of 200°C to obtain an interlayer film consisting of a single first resin layer with a thickness of 760 μm. The interlayer film was an interlayer film consisting of a single resin layer, and the two types of fillers (A) were oriented so that their surface direction was aligned with the surface direction of the interlayer film.

[0124] (Preparation of Laminated Glass) Two sheets of clear glass, each measuring 100 mm long x 100 mm wide x 2.5 mm thick, were prepared. The standard clear glass described in the specification was used as the clear glass. The interlayer film obtained above was sandwiched between the two sheets of clear glass and pre-pressed using a vacuum bag method. The pre-pressed laminate was then held in an autoclave at a temperature of 140°C and a pressure of 1.2 MPa for 20 minutes, and then the temperature was lowered to 23°C and returned to atmospheric pressure to complete the full-pressure bonding, yielding a laminated glass in which two sheets of clear glass were bonded together by the interlayer film. The optical properties of the obtained laminated glass were measured, and the properties of the interlayer film and the laminated glass are shown in Table 1. The obtained laminated glass was also evaluated, and the results are shown in Table 1.

[0125] [Example 2] (Preparation of Interlayer Film) According to the formulation in Table 1, filler (A) was mixed and dispersed in a plasticizer, and then added to a co-extruder together with polyvinyl butyral resin (PVB). These were thoroughly mixed and kneaded in the co-extruder to form a uniform mixture, thereby obtaining a resin composition for forming a first resin layer. Furthermore, according to the formulation in Table 1, a colorant was mixed and dispersed in a plasticizer, and then added to the co-extruder together with polyvinyl butyral resin (PVB). These were thoroughly mixed and kneaded in the co-extruder to form a uniform mixture, thereby obtaining a resin composition for forming a second resin layer. The resin composition was co-extruded in the co-extruder at an extrusion temperature of 200°C to obtain an interlayer film consisting of a first resin layer with a thickness of 760 μm and a second resin layer with a thickness of 760 μm. The obtained interlayer film was then used to prepare a laminated glass in the same manner as in Example 1.

[0126] Examples 3, 5, and 6, Comparative Example 11 The same procedures as in Example 2 were carried out, except that the formulations of the resin compositions for forming the first resin layer and the second resin layer were changed as shown in Tables 1 and 3.

[0127] Examples 4 and 7, Comparative Examples 1 to 10 The same procedures as in Example 1 were carried out except that the formulation of the resin composition for forming the first resin layer was changed as shown in Tables 1 to 3.

[0128] Examples 8 to 15 Laminated glass was produced in the same manner as in Example 2, except that, when obtaining the resin composition for forming the first resin layer, a colorant was mixed with the plasticizer in addition to the filler (A) according to the formulations in Tables 1 and 2.

[0129]

[0130]

[0131] *phr is parts by mass relative to 100 parts by mass of PVB. *wt% is the content (% by mass) in the first resin layer or the second resin layer.

[0132] As shown in Tables 1 to 3, the interlayer films of Examples 1 to 15 had a first resin layer containing two types of filler (A). In the spectral reflectance curve for wavelengths of 400 to 700 nm, the reflectance was flat, as shown in FIG. 4, and the haze was 2.0% or more and 13.0% or less. This enabled them to achieve a luxurious metallic look while also improving transparency. In contrast, in Comparative Example 1, the first resin layer contained two types of filler (A). However, the two fillers (A) were similar in color and not complementary, and the reflectance was not flat in the spectral reflectance curve for wavelengths of 400 to 700 nm, as shown in FIG. 5. Therefore, although a metallic look was achieved, the color was relatively strong and the luxurious feel was not achieved. Furthermore, in Comparative Examples 2 to 11, although a certain metallic look was achieved, the use of only one type of filler (A) prevented the luxurious metallic look from being achieved. Furthermore, in Comparative Examples 5, 7, 10, and 11, the haze of the interlayer was high, and although the film had transparency, the scene was blurred and the see-through quality was not good.

[0133] Among the above examples, Examples 1, 4, and 7 did not have a second resin layer, and therefore had high visible light transmittance and excellent transparency. Furthermore, Example 7 had high saturations Rc* and Tc* in the first resin layer and high saturations Rc* and Tc* in the interlayer film, resulting in a slightly tinted metallic appearance. On the other hand, Examples 1 and 4 had low saturations Rc* and Tc* in the first resin layer and low saturations Rc* and Tc* in the interlayer film, resulting in a more grayish impression and a more luxurious metallic appearance.

[0134] Although Examples 2, 3, 5, 6, and 8 to 15 had a low visible light transmittance due to the inclusion of a second resin layer, sufficient transparency was ensured. Among these, Examples 2, 3, 5, and 6, like Examples 1 and 4, had a strong gray color impression and a luxurious metallic feel. On the other hand, Examples 8 to 15, because the first resin layer contained a colorant, maintained the gray color impression while imparting a heavy metallic feel with the color corresponding to the colorant of each Example. Furthermore, in Examples 2, 3, 9, and 12, the provision of a second resin layer meant that when the laminated glass was viewed from the second resin layer side (e.g., the interior of the vehicle), the metallic feel was hardly noticeable, while the external scene was relatively clear and transparency was good. Furthermore, in Examples 5, 6, 8, 10, 11, and 13 to 15, even when the laminated glass was viewed from the second resin layer side (for example, from the vehicle interior side), almost no metallic appearance was observed, while the outside scene was clear and the transparency was excellent.

[0135] REFERENCE SIGNS LIST 10 Interlayer 11, 12 Covering layer 20 Interlayer film for laminated glass 21 First resin layer 22 Second resin layer 30 Laminated glass 31 First laminated glass member 32 Second laminated glass member

Claims

1. An interlayer film for laminated glass, comprising a first resin layer, the first resin layer containing at least two types of filler (A), a haze of 2.0% or more and 13.0% or less, and a flat reflectance in a spectral reflectance curve of a wavelength of 400 to 700 nm.

2. The interlayer film for laminated glass according to claim 1, wherein the ratio of the maximum reflectance value to the minimum reflectance value in the spectral reflectance curve for a wavelength range of 400 to 700 nm is 1.0 or more and 1.4 or less.

3. The interlayer film for laminated glass according to claim 1, wherein the filler (A) has a* of reflected light in the range of -9.0 or more and 7.0 or less, and b* of reflected light in the range of -8.5 or more and 8.5 or less.

4. The interlayer film for laminated glass according to claim 1, wherein the filler (A) contains two or more types of fillers having complementary colors.

5. The interlayer film for laminated glass according to claim 1, wherein the absolute value of the sum of the a* of the reflected light for any two fillers (|Ra*(F1)+Ra*(F2)|) is 0 or more and 3.0 or less, and the absolute value of the sum of the b* of the reflected light (|Rb*(F1)+Rb*(F2)|) is 0 or more and 7.0 or less. (Here, the a* and b* of the first filler are Ra*(F1) and Rb*(F1), and the a* and b* of the second filler are Ra*(F2) and Rb*(F2).) 6. The interlayer film for laminated glass according to claim 1, wherein the at least two or more types of filler (A) each contain a metal oxide.

7. The interlayer film for laminated glass according to claim 1, wherein the first resin layer has a chroma Rc* of reflected light in the visible light region of 0 or more and 5.5 or less.

8. The interlayer film for laminated glass according to claim 1, wherein the chroma Tc* of transmitted light in the visible light region of the first resin layer is 0 or more and 5.5 or less.

9. The interlayer film for laminated glass according to claim 1, wherein the first resin layer satisfies at least one of the following requirements (1) to (3): (1) The chroma Rc* of reflected light in the visible light region is 0 or more and 4.0 or less. (2) The chroma Tc* of transmitted light in the visible light region is 0 or more and 4.0 or less. (3) The haze is 3.0% or more and 10.0% or less.

10. The interlayer film for laminated glass according to claim 1, wherein the first resin layer further contains a colorant.

11. The interlayer film for laminated glass according to claim 1, further comprising a second resin layer.

12. The interlayer film for laminated glass according to claim 11, wherein the second resin layer contains a colorant.

13. The interlayer film for laminated glass according to claim 12, wherein in a spectral reflectance curve of 400 to 700 nm measured from the first resin layer side, the ratio of the maximum reflectance value to the minimum reflectance value is 1.0 or more and 1.6 or less.

14. The interlayer film for laminated glass according to claim 1, which satisfies at least one of the following requirements (4) and (5): (4) The chroma Rc* of reflected light of the interlayer film for laminated glass is 0 or more and 7.0 or less. (5) The chroma Tc* of transmitted light of the interlayer film for laminated glass is 0 or more and 7.0 or less.

15. A laminated glass comprising: a first laminated glass component; a second laminated glass component; and the interlayer film for laminated glass according to any one of claims 1 to 14, wherein the interlayer film is disposed between the first laminated glass component and the second laminated glass component.

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