Intermediate film for laminated glass, and laminated glass

Abstract

The interlayer for laminated glass is provided with one or more resin layers, at least one resin layer contains a colorant, and the interlayer for laminated glass is obtained by bonding two transparent glass sheets having a thickness of 2.5 mm with the interlayer for laminated glass interposed therebetween. If the absolute value of the difference between the maximum value and the minimum value of L *, a *, and b * measured from one end to the other end is represented by [Delta] L *, [Delta] a *, and [Delta] b *, the value of [Delta] L * + [Delta] a * + [Delta] b * is 0.5 or more.

Description

Technical Field

[0001] The present invention relates to an interlayer film for laminated glass used in laminated glass. Background Art

[0002] Even if laminated glass is broken by external impact, glass fragments are less likely to fly around and are relatively safe, so it is widely used in window glass of various vehicles such as automobiles, railway vehicles, airplanes, and ships, and window glass of buildings, etc. As laminated glass, a laminated glass interlayer containing a resin component such as polyvinyl acetal resin and ethylene-vinyl acetate copolymer resin is widely known to be integrated between a pair of glasses.

[0003] Conventionally, regarding interlayer films for laminated glass, colored interlayer films are widely known in which the entire interlayer film or a portion of the interlayer film is colored by providing a colored layer on the entire interlayer film or a portion of the interlayer film. For example, in front windshield glass for automobiles, there is a case where a colored layer is provided on the upper portion of the glass as a shielding area. The shielding area has a lower transmittance than other portions, and is used to protect the driver and other passengers from direct sunlight (for example, see Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: International Publication No. 2018 / 225797 Summary of the invention

[0007] [Problems to be Solved by the Invention]

[0008] However, conventional colored interlayer films may have a color tone that changes from one end to the other end of the interlayer film, but sufficient research has not been conducted on how to change the color tone, and conventionally, a colored interlayer film having excellent design properties has not been sufficiently provided.

[0009] Therefore, an object of the present invention is to provide an interlayer film for laminated glass having high design properties.

[0010] [Technical means to solve the problem]

[0011] The present inventors have made sincere studies and have found that the design of the interlayer film for laminated glass can be improved by setting the change amount of L*, a*, b* or the change amount of visible light transmittance (Tv) in a specific direction of the interlayer film for laminated glass to a certain range, thereby completing the following invention. That is, the present invention provides the following [1] to

[20] .

[0012] [1] An interlayer film for laminated glass, comprising one or more resin layers, at least one of the resin layers containing a colorant, and

[0013] For the laminated glass obtained by bonding two pieces of transparent glass with a thickness of 2.5 mm with the above-mentioned laminated glass interposed by the intermediate film, if the absolute value of the difference between the maximum and minimum values ​​of L*, a*, and b* respectively measured from one end to the other end is set to ΔL*, Δa*, and Δb*, then the value of ΔL*+Δa*+Δb* is greater than 0.5.

[0014] [2] The interlayer film for laminated glass according to the above [1], which satisfies at least one of ΔL*≥Δa* and ΔL*≥Δb*.

[0015] [3] The interlayer film for laminated glass according to [1] above, which satisfies at least one of ΔL*<Δa* and ΔL*<Δb*.

[0016] [4] The interlayer film for laminated glass as described in the above [2], which satisfies ΔL*≥Δa* and ΔL*<Δb*, or satisfies ΔL*≥Δb* and ΔL*<Δa*.

[0017] [5] An interlayer film for laminated glass, comprising one or more resin layers, at least one of the resin layers containing a colorant, and

[0018] In a laminated glass obtained by bonding two sheets of 2.5 mm thick clear glass via the interlayer film for laminated glass, the absolute value of the difference between the maximum and minimum values ​​of the visible light transmittance (Tv) measured from one end to the other end is 0.1% or more.

[0019] [6] The interlayer film for laminated glass as described in [5] above, which has at least one of a region where the visible light transmittance (Tv) decreases from one end toward the other end and a region where the visible light transmittance (Tv) increases.

[0020] [7] The interlayer film for laminated glass as described in any one of [1] to [4] above, wherein in the laminated glass, the absolute value of the difference between the maximum and minimum values ​​of the visible light transmittance (Tv) measured from one end to the other end is 0.1% or more.

[0021] [8] The interlayer film for laminated glass as described in [7] above, which has at least one of a region where the visible light transmittance (Tv) decreases from one end toward the other end and a region where the visible light transmittance (Tv) increases.

[0022] [9] The interlayer film for laminated glass as described in any one of [1] to [8] above, wherein at least one of the one or more resin layers comprises at least one selected from the group consisting of a polyvinyl acetal resin and an ethylene-vinyl acetate copolymer resin.

[0023]

[10] The interlayer film for laminated glass according to the above [9], further comprising a layer other than the resin layer comprising at least one selected from the group consisting of a polyvinyl acetal resin and an ethylene-vinyl acetate copolymer resin.

[0024]

[11] An intermediate film for laminated glass as described in any one of [1] to

[10] above, comprising at least two resin layers having at least one of L*, a* and b* different from each other, wherein the L*, a* and b* are measured on a laminated glass for measurement obtained by bonding two sheets of transparent glass with a thickness of 2.5 mm with each resin layer interposed therebetween.

[0025]

[12] The interlayer film for laminated glass as described in any one of [1] to

[11] above, wherein the glass transition temperature of at least one of the one or two or more resin layers is 15° C. or higher.

[0026]

[13] The interlayer film for laminated glass as described in any one of [1] to

[12] above, wherein the glass transition temperature of at least one of the one or two or more resin layers is lower than 15°C.

[0027]

[14] The interlayer film for laminated glass as described in any one of [1] to

[13] above, wherein the area ratio of the region where the visible light transmittance (Tv) measured in the laminated glass is 60% or more is 30% or more.

[0028]

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

[14] , wherein the minimum value of the visible light transmittance (Tv) measured in the laminated glass is 50% or more.

[0029]

[16] The interlayer film for laminated glass as described in any one of [1] to

[15] above, wherein the minimum value of the visible light transmittance (Tv) measured in the laminated glass is 70% or more.

[0030]

[17] An intermediate film for laminated glass as described in any one of [1] to

[16] above, comprising at least one resin layer having a visible light transmittance (Tv) of less than 87%, wherein the visible light transmittance (Tv) is measured on a laminated glass obtained by bonding two sheets of transparent glass with a thickness of 2.5 mm with a resin layer interposed therebetween.

[0031]

[18] The interlayer film for laminated glass as described in any one of [1] to

[17] above, wherein the thickness is 2 mm or less.

[0032]

[19] The interlayer film for laminated glass as described in any one of [1] to

[18] above, wherein the content of the colorant is 0.00001 mass % to 7 mass %.

[0033]

[20] A laminated glass comprising the interlayer film for laminated glass according to any one of [1] to

[19] above, and a pair of laminated glass members.

[0034] The interlayer film for laminated glass is disposed between the pair of laminated glass members.

[0035] [Effects of the Invention]

[0036] According to the present invention, an interlayer film for laminated glass having high design properties can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] [ Figure 1 ] The upper side shows a cross-sectional view of an example of an intermediate film for laminated glass, and the lower side shows an example of a conceptual diagram of the Tv value of the intermediate film.

[0038] [ Figure 2 ] The upper side shows a cross-sectional view of an example of an intermediate film for laminated glass, and the lower side shows an example of a conceptual diagram of the Tv value of the intermediate film.

[0039] [ Figure 3 ] The upper side shows a cross-sectional view of an example of an intermediate film for laminated glass, and the lower side shows an example of a conceptual diagram of the Tv value of the intermediate film.

[0040] [ Figure 4 ] The upper side shows a cross-sectional view of an example of an intermediate film for laminated glass, and the lower side shows an example of a conceptual diagram of the Tv value of the intermediate film.

[0041] [ Figure 5 ] The upper side shows a cross-sectional view of an example of an intermediate film for laminated glass, and the lower side shows an example of a conceptual diagram of the Tv value of the intermediate film.

[0042] [ Figure 6 ] The upper side shows a cross-sectional view of an example of an intermediate film for laminated glass, and the lower side shows an example of a conceptual diagram of the Tv value of the intermediate film.

[0043] [ Figure 7 ] The upper side shows a cross-sectional view of an example of an intermediate film for laminated glass, and the lower side shows an example of a conceptual diagram of the Tv value of the intermediate film. DETAILED DESCRIPTION

[0044] Hereinafter, the present invention will be described in further detail using embodiments.

[0045] <Interlayer film for laminated glass>

[0046] The interlayer film for laminated glass of the present invention includes one or two or more resin layers, and at least one of the resin layers is a colored layer containing a colorant.

[0047] The interlayer film of the present invention is characterized in that, in a laminated glass obtained by bonding two sheets of 2.5 mm thick clear glass via the interlayer film, the interlayer film satisfies either of the following requirements (A) and (B).

[0048] Requirement (A): For laminated glass, when the absolute values ​​of the differences between the maximum and minimum values ​​of L*, a*, and b* measured from one end to the other are denoted by ΔL*, Δa*, and Δb*, the value of ΔL*+Δa*+Δb* is 0.5 or more.

[0049] Requirement (B): For laminated glass, the absolute value of the difference between the maximum value and the minimum value of the visible light transmittance (Tv) measured from one end to the other end is 0.1% or more.

[0050] <Requirement (A)>

[0051] In the present invention, if the value of ΔL*+Δa*+Δb* is less than 0.5, the change in color tone in the intermediate film becomes insufficient, and there is a situation where the designability cannot be fully improved. From the perspective of further improving the designability by making the intermediate film have a certain degree of color change, the value of ΔL*+Δa*+Δb* is preferably 0.6 or more, and more preferably 0.7 or more, and can be 0.8 or more, can be 0.9 or more, can be 1 or more, can be 1.1 or more, and can be 1.2 or more. In addition, from the perspective of further improving the designability, it is more preferably 1.5 or more, and more preferably 3 or more. In addition, in order to have a specific color matching pattern with a large color change, it is also preferably set to 10 or more.

[0052] In order to facilitate manufacturing, or to make the color change constant and further improve the design, the value of ΔL*+Δa*+Δb* is preferably 100 or less, more preferably 97 or less, and more preferably 75 or less. However, in order to relatively suppress the color change and give a more peaceful impression, the value of ΔL*+Δa*+Δb* may be reduced to a certain extent, for example, 30 or less, 20 or less, or 15 or less. In addition, the lower limit value and the upper limit value of the above requirement (A) may be any combination.

[0053] Here, the above-mentioned L*, a*, and b* values ​​are obtained for one side of the laminated glass using the CIE standard illuminant D65 and 10° viewing angle color matching function specified in JIS Z 8781-1 (2012), JIS Z 8781-2 (2012), and JIS Z 8781-4 (2013) for the spectral transmittance obtained using a spectrophotometer in accordance with JIS R3212 (2015).

[0054] Furthermore, the measurement can be performed at intervals of 50 mm from one end toward the other end. However, if the measurement is performed at intervals of 50 mm, when the number of measurement points is less than 20, the measurement interval can be adjusted so that the number of measurement points becomes 20. The detailed measurement conditions are described in detail in the examples described below.

[0055] The transparent glass used in obtaining the laminated glass has a thickness of 2.5 mm and a visible light transmittance of 90.5% measured in accordance with JIS R 3106:1998. The transparent glass has a*=-0.6, b*=0.2 obtained by using the CIE standard illuminant D65 and 10° viewing angle color matching functions specified in JIS Z 8781-1 (2012), JIS Z 8781-2 (2012), and JIS Z 8781-4 (2013), and a haze of 0.2% or less. The above transparent glass plate is also referred to as a reference transparent glass.

[0056] The direction from one end toward the other end of the intermediate film may be any direction along the surface direction of the intermediate film, preferably the TD (transverse direction). If the direction from one end toward the other end is the TD, when the intermediate film is manufactured by extrusion molding, the thickness of each resin layer can be easily changed from one end toward the other end. Therefore, it is easy to satisfy the above-mentioned requirements (A), (B) or the requirements (A-1), (A-2) and the like described below.

[0057] In the present invention, the interlayer film satisfying the requirement (A) preferably satisfies the following requirement (A-1) in one aspect.

[0058] Requirement (A-1): at least one of ΔL*≥Δa* and ΔL*≥Δb* is satisfied.

[0059] In the present invention, the change in color concentration in the interlayer film that satisfies the requirements of ΔL*≥Δa* or ΔL*≥Δb* is relatively dominant. The interlayer film that satisfies such requirements can improve the designability by making the chromaticity have a certain degree of uniformity and changing the color tone. In the interlayer film that satisfies the requirement (A-1), from the perspective of making the change in color concentration more dominant and improving the designability, it is more preferable to satisfy both the requirements of ΔL*≥Δa* and ΔL*≥Δb*.

[0060] In the case of ΔL*≥Δa*, the difference is preferably 0.2 or more, more preferably 1.5 or more, more preferably 5 or more, and more preferably 10 or more. In addition, from the perspective of giving a strong impression of design change by changing the color tone, the above difference can be set to be larger, for example, it can be set to 20 or more. In addition, from the perspective of design, in the case of ΔL*≥Δa*, their difference is preferably 80 or less, more preferably 70 or less, and more preferably 40 or less. Among them, in the case of a design that gives a peaceful impression, the above difference can be 30 or less. Furthermore, the lower limit and upper limit of the difference between these ΔL* and Δa* can be any combination.

[0061] In the case of ΔL*≥Δb*, the difference is preferably 0.2 or more, more preferably 1.5 or more, more preferably 5 or more, and more preferably 10 or more. In addition, from the perspective of giving a strong impression of design change by changing the color tone, the above difference can be set to a larger value, for example, it can be set to 20 or more. In addition, from the perspective of design, in the case of ΔL*≥Δb*, the difference is preferably 80 or less, more preferably 70 or less, and more preferably 40 or less. Among them, in the case of a design that gives a peaceful impression, the above difference can be 30 or less. Furthermore, the lower limit and upper limit of the difference between these ΔL* and Δb* can be any combination.

[0062] Furthermore, the interlayer film satisfying the requirement (A) preferably satisfies the following requirement (A-2) in one aspect.

[0063] Requirement (A-2): Satisfy at least one of ΔL*<Δa* and ΔL*<Δb*. In the interlayer satisfying the requirement of ΔL*<Δa* or ΔL*<Δb*, the change in hue is relatively dominant. The interlayer satisfying such requirement is easy to improve the design by making the color tonality have a certain degree of unity and changing the color. In the interlayer satisfying requirement (A-2), in order to make the change in hue more dominant, it is more preferable to satisfy both the requirements of ΔL*<Δa* and ΔL*<Δb*.

[0064] In the case of ΔL*<Δa*, the difference is preferably 0.2 or more, more preferably 0.5 or more, more preferably 2 or more, and more preferably 2.5 or more from the viewpoint of making the change in hue more dominant. In addition, in the case of ΔL*<Δa*, the difference is preferably 50 or less, more preferably 40 or less, and more preferably 20 or less from the viewpoint of giving a peaceful impression to the design. In addition, the lower limit and upper limit of the difference between ΔL* and Δa* may be any combination.

[0065] In the case of ΔL*<Δb*, the difference is preferably 0.2 or more, more preferably 0.5 or more, and more preferably 1.5 or more from the viewpoint of making the change in hue more dominant. In addition, in the case of ΔL*<Δb*, the difference is preferably 50 or less, more preferably 40 or less, more preferably 20 or less, and can be 10 or less from the viewpoint of giving a peaceful impression to the design. In addition, the lower limit and upper limit of the difference between ΔL* and Δb* can be any combination.

[0066] Only one of the requirements (A-1) and (A-2) may be satisfied, or both of the requirements (A-1) and (A-2) may be satisfied. That is, the interlayer film of the present invention may satisfy both ΔL*≥Δa* and ΔL*<Δb* or both ΔL*≥Δb* and ΔL*<Δa*. By satisfying both the requirements (A-1) and (A-2), the color concentration and the hue balance are well changed, thereby easily ensuring a high design property.

[0067] <Requirement (B)>

[0068] The interlayer film of one aspect of the present invention is as shown in requirement (B), and in the above-mentioned laminated glass, the absolute value of the difference between the maximum value and the minimum value of the visible light transmittance (Tv) measured from one end to the other end (hereinafter sometimes referred to as "ΔTv") is 0.1% or more. If ΔTv is less than 0.1%, the color concentration obtained by coloring with a colorant may not change appropriately from one end to the other end, and the design property may not be improved.

[0069] From the viewpoint of making the interlayer film have a certain degree of change in color density and further improving the designability, the value of ΔTv is preferably higher, preferably 0.3% or more, more preferably 0.5% or more, and may be 0.8% or more, or 1% or more. In addition, it is more preferably 1.5% or more, more preferably 2% or more, more preferably 3% or more, and more preferably 5% or more. In addition, in order to have a specific color pattern with a large change in color density, it can be set to 10% or more, for example.

[0070] In order to facilitate manufacturing and to further improve design properties by keeping the color change constant, the ΔTv value is preferably 90% or less, more preferably 80% or less, more preferably 70% or less, more preferably 50% or less, and more preferably 30% or less. However, in order to relatively suppress the change in color density and give a more peaceful impression, the ΔTv value may be reduced to a certain extent, for example, it may be set to 20% or less.

[0071] It should be noted that the lower limit value and the upper limit value of the above-mentioned ΔTv may be any combination.

[0072] The interlayer film of the present invention may satisfy either one of the requirements (B) and (A), but preferably satisfies both requirements from the viewpoint of making the design more favorable. By satisfying both requirements, the balance between the color concentration and the hue can be changed well, thereby further improving the design. Similarly, in addition to satisfying the requirements (A) and (B), the interlayer film of the present invention also preferably satisfies at least one of the requirements (A-1) and (A-2).

[0073] In the present invention, the requirements (A), (A-1), (A-2), (B) and the preferred values ​​of the respective requirements can be satisfied, for example, by varying the thickness of the colored layer from one end to the other end as described below. In addition, after providing two or more colored layers, the thickness of each colored layer can be varied from one end to the other end, thereby making it easier to further satisfy the requirements (A), (A-1), (A-2), (B) and the preferred values ​​of the respective requirements.

[0074] When the interlayer film of the present invention satisfies requirement (B), it is preferred that it has at least one of a region where the visible light transmittance (Tv) increases from one end toward the other end (hereinafter referred to as a "Tv increase region") or a region where the visible light transmittance (Tv) decreases (hereinafter referred to as a "Tv decrease region"). By having at least one of a Tv decrease region and a Tv increase region, the region where the color density changes will continue to a certain extent, and the design property can be easily improved.

[0075] Furthermore, the Tv increase area refers to the following area: as shown in the embodiment described below, when Tv is measured sequentially at measurement points at a certain interval (50 mm interval) from one end to the other end, the measured Tv is higher than the specific measurement point for more than 2 consecutive subsequent measurement points.

[0076] Similarly, the Tv reduction region refers to a region where, when Tv is measured sequentially at measurement points at predetermined intervals from one end toward the other end, the measured Tv is lower than that at a specific measurement point for two or more consecutive subsequent measurement points.

[0077] From the viewpoint of improving the design property by making the region with the color density change continue to a certain extent, it is more preferable that when Tv is measured at measurement points at a certain interval (50 mm interval) from one end toward the other end, the measured Tv is higher than the specific measurement point at the subsequent measurement points for more than 3 consecutive points, more preferably for more than 4 consecutive points, and even more preferably for more than 5 consecutive points. Similarly, it is more preferable that when Tv is measured at measurement points at a certain interval from one end toward the other end, the measured Tv is lower than the specific measurement point at the subsequent measurement points for more than 3 consecutive points, more preferably for more than 4 consecutive points, and even more preferably for more than 5 consecutive points.

[0078] There is no particular restriction on the difference between the maximum and minimum values ​​of the visible light transmittance (Tv) in each of the Tv increase region and the Tv decrease region. In terms of being able to impart a design with a change in color concentration, the difference between the maximum and minimum values ​​of the visible light transmittance (Tv) in each of the Tv increase region and the Tv decrease region may, for example, exceed 0%, preferably be 0.1% or more, may be 0.4% or more, may be 0.5% or more, may be 1% or more, may be 5% or more, may be 10% or more, may be 20% or more, may be 30% or more, may be 40% or more, may be 50% or more, may be 60% or more, may be 70% or more, and is usually 100% or less, preferably 90% or less. Furthermore, these lower limits and upper limits may be any combination.

[0079] In the present invention, from the viewpoint of design, it is preferred to have both Tv increased regions and Tv decreased regions. In addition, the number of Tv decreased regions or Tv increased regions is not particularly limited, and preferably the total number of Tv decreased regions and Tv increased regions is 2 or more, 3 or more, 5 or more, etc. In addition, from the viewpoint of facilitating the manufacture of the interlayer film, the total number of Tv decreased regions and Tv increased regions should not be too large, for example, 100 or less, preferably 50 or less, further more preferably 20 or less, further more preferably 10 or less, and further more preferably 8 or less. Furthermore, these lower limits and upper limits may be any combination.

[0080] The interlayer film of the present invention preferably has an area ratio of 30% or more in which the visible light transmittance measured in the laminated glass is 60% or more. In this way, if the area with a high Tv is larger than a certain area, the interlayer film can also be suitably used in applications requiring high transparency such as the front window of an automobile. The above-mentioned area ratio is preferably 40% or more, more preferably 50% or more, more preferably 60% or more, more preferably 70% or more, more preferably 80% or more, and more preferably 90% or more. In addition, the above-mentioned area ratio is preferably higher from the viewpoint of ensuring high transparency in a larger area, and it can be 100% or less. In terms of improving the transparency of the entire interlayer film, it is also preferably 100%. In addition, the above-mentioned area ratio may be less than a certain value, for example, it may be less than 99%, or it may be less than 95%. In addition, the lower limit and upper limit of these area ratios may be any combination.

[0081] When calculating the area ratio, Tv may be measured at a plurality of measurement points over the entire laminated glass, and the ratio of measurement points at which Tv is 60% or more among all the measurement points may be obtained as the area ratio.

[0082] In the case where Tv is substantially the same in the direction perpendicular to the direction from one end toward the other end (vertical direction), a plurality of Tv (e.g., 20 or more points) are measured at equal intervals from one end toward the other end of the laminated glass, and the ratio of the measuring points where Tv is 60% or more among all the measuring points can be obtained as the above-mentioned area ratio. Even in this measurement method, if Tv is substantially the same in the vertical direction, an accurate area ratio can be obtained.

[0083] The interlayer film of the present invention, as described above, can have a minimum value of visible light transmittance (Tv) measured when it is made into laminated glass, for example, of 1% or more, 10% or more, or 20% or more. The minimum value of Tv is preferably 50% or more, more preferably 60% or more, and more preferably 70% or more, from the viewpoint of easily ensuring a certain degree of transparency in the entire region of the interlayer film. The minimum value of visible light transmittance (Tv) is, for example, 97% or less, and from the viewpoint of improving the design of the interlayer film, it is preferably 90% or less, more preferably 85% or less, more preferably 83% or less, and more preferably 80% or less. The lower limit and upper limit of the minimum value of Tv can be any combination.

[0084] The maximum value of the visible light transmittance (Tv) measured for the laminated glass of the interlayer film of the present invention may be 100% or less, for example, 97% or less, or 90% or less. In addition, from the viewpoint of providing a colored layer on the entire interlayer film to improve the overall design of the interlayer film, the maximum value of the visible light transmittance (Tv) is preferably less than 87%, more preferably 85% or less, more preferably 83% or less, and more preferably 80% or less. In addition, in order to allow at least a portion to have good transparency, the maximum value of the visible light transmittance (Tv) of the present invention may be, for example, 45% or more, preferably 52% or more, more preferably 62% or more, and more preferably 72% or more. Furthermore, the lower limit and upper limit of the maximum values ​​of these Tv may be any combination.

[0085] The maximum and minimum values ​​of the visible light transmittance (Tv) mentioned here refer to the minimum and maximum values ​​of Tv measured from one end to the other end in the laminated glass made of the interlayer and two transparent glasses as described above.

[0086] The value (Cm) with the largest absolute value among the minimum and maximum values ​​of a* and the minimum and maximum values ​​of b* measured in the laminated glass of the intermediate film is preferably 1.7 or more, more preferably 5 or more, and more preferably 10 or more. As long as there is color, the values ​​of a* and b* are non-zero values. Therefore, if the absolute value of the above-mentioned a* or b* is set to be larger, a variety of colors can be used, which can easily improve the design. The above-mentioned Cm is not particularly limited, and it can be 60 or less, 50 or less, or 40 or less. Furthermore, any combination of the lower limit and upper limit of these Cm can be taken.

[0087] Furthermore, the minimum and maximum values ​​of a*, and the minimum and maximum values ​​of b* mentioned here refer to the minimum and maximum values ​​of a*, and the minimum and maximum values ​​of b* measured from one end to the other end in the laminated glass made of the intermediate film and two sheets of transparent glass as described above, respectively.

[0088] The intermediate film of the present invention may have one or more resin layers, preferably two or more resin layers. The two or more resin layers are resin layers stacked along the thickness direction of the intermediate film. In addition, among the one or more resin layers contained in the intermediate film, at least one resin layer is a colored layer containing a colorant. In the present invention, an intermediate film with higher design properties can be provided by having an intermediate film with a colored layer. In addition, by appropriately changing the thickness of the colored layer from one end to the other, an intermediate film that satisfies the above-mentioned requirements (A), (A-1), (A-2), (B), and the preferred values ​​of each requirement can be easily obtained.

[0089] The intermediate film of the present invention preferably has a plurality of resin layers, and at least two of the resin layers contain a colorant and at least two of the resin layers are set as colored layers. That is, the intermediate film of the present invention preferably has a plurality of resin layers, and at least two of the resin layers are colored layers. By providing two or more colored layers, it is easy to provide an intermediate film with higher design. When two or more resin layers are provided, it is preferred to appropriately change the thickness of each of the two or more colored layers from one end to the other end.

[0090] The average value of the thickness of each resin layer is not particularly limited, and is preferably 10 μm or more, more preferably 50 μm or more, more preferably 100 μm or more, and more preferably 150 μm or more. In addition, it is preferably 2000 μm or less, preferably 1500 μm or less, more preferably 1000 μm or less, more preferably 800 μm or less, and more preferably 500 μm or less. In addition, the lower limit and upper limit of the average value of these thicknesses can be any combination.

[0091] The average value of the thickness can be calculated from the average value of the thickness of each resin layer at each coordinate in the TD direction by continuously measuring the thickness.

[0092] In addition, the resin layer may include a colored layer, a transparent layer, etc., but all of them can be adjusted within the above range.

[0093] The ratio of the minimum thickness to the maximum thickness of the colored layer whose thickness changes from one end to the other end (minimum thickness / maximum thickness) is preferably 0.94 or less, more preferably 0.90 or less, more preferably 0.85 or less, and preferably 0.01 or more, more preferably 0.05 or more, and more preferably 0.1 or more. By setting the minimum thickness / maximum thickness within the above range, an intermediate film that satisfies the above-mentioned requirements (A), (A-1), (A-2), (B), and the preferred values ​​of each requirement can be easily obtained. In addition, the lower limit and upper limit of these ratios can be any combination.

[0094] Furthermore, each resin layer can be measured at 50 points, for example, at equal intervals from one end toward the other end, and the minimum and maximum values ​​of the 50 measurement points are set as the maximum and minimum values ​​of the thickness of each resin layer. In addition, the average value of the maximum and minimum values ​​of the thickness of each resin layer is set as the average value of the thickness of each resin layer.

[0095] As long as the thickness of one or more, preferably two or more, colored layers is changed, the thickness of all colored layers does not need to be changed from one end to the other. Therefore, the thickness of one or more colored layers contained in the interlayer film can be substantially uniform from one end to the other.

[0096] Furthermore, even if the thickness of the resin layer is designed to be uniform, it may not be completely uniform due to manufacturing errors, etc. Even if the thickness of the resin layer varies within the range of such manufacturing errors, if the thickness is not intentionally changed, the thickness is considered to be substantially uniform.

[0097] That is, in this specification, the term "substantially uniform thickness" means that it also includes the situation where the thickness varies due to manufacturing errors. Here, "substantially uniform thickness" specifically means that the ratio of the minimum value to the maximum value of the thickness (minimum value / maximum value) is, for example, 0.95 or more and 1.00 or less, preferably 0.97 or more and 1.00 or less, and more preferably 0.98 or more and 1.00 or less.

[0098] As described above, the number of resin layers stacked in the thickness direction may be 1 or more, preferably 2 or more, and may be 3 or more. The upper limit of the number of resin layers is not particularly limited, but is preferably 10, and more preferably 5, from the viewpoint of ease of production.

[0099] The number of colored layers in the resin layer may be 1 or more, as described above, and is preferably 2 or more. The upper limit of the number of colored layers is not particularly limited, but is preferably 8, and more preferably 4, from the viewpoint of ease of production.

[0100] In addition, the number of colored layers whose thickness changes from one end toward the other end may be 1 or more, preferably 2 or more, and may be 3 or more. In addition, the upper limit of the number of colored layers whose thickness changes from one end toward the other end is not particularly limited, but from the viewpoint of ease of manufacture, 6 is preferred, and 4 is more preferred.

[0101] In addition, the lower limit value and the upper limit value of each of the number of these resin layers and the number of coloring layers can be any combination.

[0102] The thickness of each resin layer may vary in a direction from one end to the other end, but the thickness may be substantially uniform in a direction perpendicular to the one direction (vertical direction). If the thickness is substantially uniform, the L*, a*, b*, and Tv of the interlayer film are substantially the same along the vertical direction. Furthermore, in the present invention, it is preferred that the one direction from one end to the other end is the TD direction, and the vertical direction is the direction perpendicular to the one direction and the thickness direction, which is the MD (machine direction).

[0103] When the interlayer film is applied to the curved glass described below, it stretches and curves, and the one direction and the like are also curved. The one direction and the perpendicular direction in the curved interlayer film are directions that curve in accordance with the curvature.

[0104] At least one of the resin layers of the interlayer film of the present invention may have a visible light transmittance (Tv) of less than 87%. Furthermore, the resin layer having a Tv of less than 87% is usually a colored layer. The interlayer film has a resin layer having a Tv of less than 87%, and the thickness of the resin layer having a Tv of less than 87% is changed from one end to the other end as described above, thereby making it easy to obtain an interlayer film that satisfies the requirements (A), (A-1), (A-2), and (B).

[0105] The interlayer film preferably has two or more resin layers with a Tv of less than 87%. Among them, the interlayer film is also preferably a state of having a resin layer with a Tv of less than 87% and a resin layer with a Tv of 87% or more. The resin layer with a Tv of 87% or more is typically a transparent layer substantially free of coloring agent. The upper limit of the visible light transmittance (Tv) of the resin layer with a Tv of 87% or more is not particularly limited, and it can be 100% or less, 95% or less, or 92% or less.

[0106] The Tv of the resin layer (typically the colored layer) having a Tv of less than 87% is preferably 85% or less, more preferably 80% or less, and more preferably 75% or less from the viewpoint of improving the design of the interlayer film. In addition, the Tv of the resin layer (typically the colored layer) having a Tv of less than 87% is preferably 0.5% or more, more preferably 5% or more, and more preferably 10% or more from the viewpoint of imparting a certain degree of transmittance to the interlayer film. The lower limit and upper limit of the Tv of these resin layers may be any combination.

[0107] The interlayer film preferably includes at least two resin layers that are different from each other in at least any one of L*, a*, and b*. By including such a resin layer, the interlayer film can easily satisfy the requirements (A), (A-1), (A-2), and (B).

[0108] Furthermore, the interlayer film preferably includes at least two resin layers having different Tv. By including such resin layers, the interlayer film can easily satisfy the requirements (A), (A-1), (A-2), and (B), and can especially easily satisfy the requirement (B).

[0109] In the case of having at least two resin layers in which at least any one of L*, a* and b* is different from each other, the sum of the absolute value of the difference in L*, the absolute value of the difference in a* and the absolute value of the difference in b* of the two resin layers is preferably 0.1 or more, more preferably 0.3 or more, more preferably 0.5 or more, more preferably 1 or more, and preferably 200 or less, more preferably 120 or less, more preferably 80 or less, and more preferably 60 or less. The interlayer film easily satisfies the requirements (A), (A-1), (A-2) and (B) when the sum of the above absolute values ​​is at least the above lower limit. The lower limit and upper limit of the sum of these absolute values ​​may be any combination.

[0110] In the case of an intermediate film having two resin layers with different L*, the difference in L* is preferably 0.05 or more, more preferably 0.15 or more, more preferably 0.25 or more, more preferably 0.5 or more, more preferably 1 or more, and preferably 120 or less, more preferably 100 or less, more preferably 80 or less, and more preferably 60 or less.

[0111] In the case of an intermediate film having two resin layers with different a*, the difference in a* is preferably greater than 0.05, more preferably greater than 0.15, more preferably greater than 0.25, more preferably greater than 0.5, more preferably greater than 1, and preferably less than 120, further more preferably less than 100, more preferably less than 80, and more preferably less than 60.

[0112] In addition, in the case of having two resin layers with different b* in the intermediate film, the difference in b* is preferably 0.05 or more, further more preferably 0.15 or more, more preferably 0.25 or more, more preferably 0.5 or more, more preferably 1 or more, and preferably 120 or less, further more preferably 100 or less, more preferably 80 or less, more preferably 60 or less.

[0113] Furthermore, in the intermediate film, when there are two resin layers with different Tv as described above, the difference in Tv is preferably 1% or more, further more preferably 3% or more, further more preferably 5% or more, further more preferably 10% or more, and preferably 86.5% or less, further more preferably 83% or less, further more preferably 80% or less.

[0114] It should be noted that the lower limit value and the upper limit value of each of the difference in L*, the difference in a*, the difference in b*, and the difference in Tv may be any combination.

[0115] In addition, the larger value (CL) of the absolute values ​​of a* and b* in each colored layer is preferably 0.5 or more, more preferably 1 or more, and more preferably 2 or more. In addition, the CL of the colored layer is not particularly limited, and may be 60 or less, for example, 50 or less, or 40 or less. By making the absolute value of a* or b* in the colored layer larger, the design of the interlayer film can be easily improved. In addition, the lower limit and upper limit of CL can be any combination.

[0116] The values ​​of visible light transmittance (Tv), L*, a*, and b* of each resin layer described above are obtained by cutting off the resin layer, pressing it to make a 760 μm thick resin film for evaluation, bonding two sheets of 2.5 mm thick transparent glass through the resin film, and measuring the obtained laminated glass for measurement. Here, the reference transparent glass can be used as the transparent glass.

[0117] In addition, the visible light transmittance (Tv) can be obtained by measuring the laminated glass for measurement in accordance with the above-mentioned JIS R3212 (2015). The values ​​of L*, a* and b* are obtained for one side of the laminated glass for measurement using the CIE standard illuminant D65 and 10° field of view color matching function specified in JIS Z 8781-1 (2012), JIS Z 8781-2 (2012), and JIS Z 8781-4 (2013) for the spectral transmittance obtained using a spectrophotometer in accordance with JIS R3212 (2015).

[0118] Figures 1 to 7 Specific examples of the laminated structure of the interlayer are shown. In each figure, the structure of the interlayer is shown on the upper side, and a conceptual diagram showing an example of the Tv value of the interlayer is shown on the lower side. In the conceptual diagram on the lower side, a dark color indicates a lower Tv value, and a light color indicates a higher Tv value, but the Tv value does not necessarily follow the conceptual diagram shown on the lower side of each figure, and the Tv value may also change according to a pattern other than the conceptual diagram.

[0119] Figures 1 to 5 The interlayer films 10A to 10E each have a two-layer structure, each having a structure in which a first resin layer 11 and a second resin layer 12 are stacked. Figure 1 to Figure 5 In the interlayer film shown, either the first resin layer 11 or the second resin layer 12 may contain a colorant to form a colored layer. It is preferred that both the first resin layer 11 and the second resin layer 12 contain a colorant to form a colored layer.

[0120] Among them, it is also preferable that one contains a colorant to form a colored layer, and the other forms a transparent layer substantially free of a colorant. In each interlayer film, the first resin layer 11 and the second resin layer 12 may have a portion with a varying thickness.

[0121] If further details are given, Figure 1 In the intermediate film 10A, the thickness of the first resin layer 11 decreases from one end 15A to the other end 15B, while the thickness of the second resin layer 12 increases from one end 15A to the other end 15B. The first and second resin layers 11 and 12 in the intermediate film 10A may have different Tv, L*, a*, and b*, for example, as described above. The thickness of each of the first and second resin layers 11 and 12 in the intermediate film 10A changes from one end 15A to the other end 15B, and accordingly, the Tv, L*, a*, and b* measured in the laminated glass described above also change.

[0122] Figure 1The thickness of the first and second resin layers 11 and 12 shown in the figure changes all the way from one end 15A to the other end 15B (that is, the thickness becomes smaller or the thickness becomes larger), but the thickness does not necessarily have to change all the way.

[0123] That is, the first and second resin layers 11 and 12 may have thicknesses that vary only in a portion from one end 15A to the other end 15B, and may have a substantially uniform thickness. Figure 2 As shown in the intermediate film 10B, the first and second resin layers 11 and 12 are provided with a substantially uniform thickness portion at one end 15A, and the substantially uniform thickness portion is connected to the thickness variation portion at the other end 15B. In addition, the thickness variation portion can be further connected to the substantially uniform thickness portion at the other end 15B.

[0124] The intermediate film can be Figure 3 As shown in the intermediate film 10C, the first resin layer 11 temporarily increases in thickness from one end 15A of the intermediate film 10C toward the other end 15B, and then decreases in thickness. In this case, the second resin layer 12 temporarily decreases in thickness from one end 15A of the intermediate film 10B toward the other end 15B, and then increases in thickness.

[0125] In this case, in the intermediate film 10C, the first and second resin layers 11 and 12 may have different Tv, L*, a*, and b* as described above, and the intermediate film 10C may change as follows: from one end 15A toward the other end 15B, the Tv, L*, a*, and b* measured in the above-mentioned laminated glass temporarily increase or decrease, and then decrease or increase.

[0126] exist Figure 3 In the illustrated embodiment, the first and second resin layers 11 and 12 have both a portion where the thickness decreases and a portion where the thickness increases from one end 15A toward the other end 15B. Figure 4 As shown in the intermediate film 10D, the thickness does not need to vary throughout the entire region from one end 15A to the other end 15B. That is, the first and second resin layers 11 and 12 may have portions with substantially uniform thickness. For example, Figure 4 As shown, in the first and second resin layers 11 and 12 , a portion where the thickness increases and a portion where the thickness decreases from one end 15A toward the other end 15B are connected via a portion where the thickness is substantially uniform.

[0127] In addition, Figure 5 As shown in the intermediate film 10E, the first and second resin layers 11 and 12 may repeat the portion with increased thickness and the portion with decreased thickness (or the portion with decreased thickness and the portion with increased thickness) from one end 15A of the intermediate film 10B toward the other end 15B. Figure 5In the illustrated interlayer film 10E, the thicker portion and the thinner portion are each repeated three times, but there is no particular limitation as long as each is repeated two or more times. However, from the viewpoint of ease of production, the number of repetitions may be set to about 10 times or less.

[0128] In having Figure 5 In the interlayer film 10E of the structure shown, the first and second resin layers 11 and 12 may have different visible light transmittances (Tv), L*, a*, and b* as described above. Thus, the interlayer film 10E repeats the parts where Tv, L*, a*, and b* increase and decrease (or decrease and increase) from one end 15A to the other end 15B in the laminated glass.

[0129] Furthermore, if Figure 5 As shown in FIG. 1 , in each resin layer, even when a portion with a larger thickness and a portion with a smaller thickness (or a portion with a smaller thickness and a portion with a larger thickness) are repeated, it is also possible to Figure 2 , 4 As shown, there is also a portion with substantially uniform thickness.

[0130] The intermediate film may have three or more resin layers, for example Figure 6 Like the intermediate film 10F of FIG. 1 , the intermediate film 10F includes first to fourth resin layers 11 to 14 , and a portion thereof (for example, the first to third resin layers 11 to 13 ) has a portion with a varying thickness.

[0131] Specifically, in the intermediate film 10F, the thickness of the first resin layer 11 increases temporarily from one end 15A to the other end 15B of the intermediate film 10F, and then decreases. The thickness of the second resin layer 12 decreases from one end 15A to the other end 15B, and the thickness of the third resin layer 13 increases from one end 15A to the other end 15B. In addition, the thickness of the fourth resin layer 14 is substantially uniform from one end 15A to the other end 15B.

[0132] In addition, any one, two, or three of the first to third resin layers 11 to 13 may be a colored layer. Furthermore, the first to third resin layers 11 to 13 that are not colored layers may be transparent layers. Similarly, the fourth resin layer 14 may be a colored layer or a transparent layer.

[0133] In the interlayer film 10F, the first to third resin layers 11 to 13 may have different Tv, L*, a*, and b*, for example, as described above. In this way, since the first to third resin layers 11 to 13 have different Tv, L*, a*, and b*, the interlayer film 10F in the laminated glass has different Tv, L*, a*, and b* from one end 15A toward the other end 15B.

[0134] Furthermore, in the above Figures 1 to 5 In the structure (two-layer structure) shown, the first and second resin layers 11 and 12 are described on the premise that Tv, L*, a*, and b* are all different from each other, but it is sufficient as long as at least one of Tv, L*, a*, and b* is different from each other. Therefore, in the above-mentioned laminated glass, any one of the different Tv, L*, a*, and b* of the interlayer film can change from one end 15A to the other end 15B.

[0135] Similarly, in Figure 6 In the structure shown (structure with three or more layers), the first to third resin layers 11 to 13 are also described on the premise that Tv, L*, a*, and b* are all different from each other, but it is sufficient that at least one of Tv, L*, a*, and b* is different from each other. Thus, in the above-mentioned laminated glass, any one of the different Tv, L*, a*, and b* of the interlayer film can change from one end 15A to the other end 15B.

[0136] In addition, the intermediate film can be Figure 7 As shown in FIG. 1 , a three-layered intermediate film is provided with first to third resin layers 11, 12, and 13. The three-layered intermediate film may be, for example, Figures 1 to 5 As shown in FIG. 1 , a third resin layer 13 having a substantially uniform thickness is further provided between the first and second resin layers 11 and 12 whose thickness varies from one end to the other end (see FIG. 1 ). Figure 7 ) of the intermediate film 10G. In this case, the third resin layer 13 may be a colored layer containing a colorant, or may be a transparent layer substantially free of a colorant. On the other hand, the first and second resin layers 11 and 12 are as described above.

[0137] Furthermore, in Figure 7 In the embodiment, the first and second resin layers 11 and 12 have the same structure as Figure 1 The structures of the first and second resin layers 11 and 12 shown in FIG. 1 are the same, but the structures of the first and second resin layers 11 and 12 are not limited to Figure 1 The structure shown can be Figure 2 to Figure 5 Any of the structures shown may also have Figures 2 to 5 Other than the structure shown.

[0138] In the case of a three-layer structure, although not shown in the figure, the first to third resin layers 11 to 13 may all be resin layers whose thickness changes from one end to the other end. For example, Figure 6 In the illustrated structure, the structure of the fourth resin layer 14 is omitted.

[0139] Furthermore, the intermediate film may have a laminated structure of 5 or more layers, for example, the functional film described below may be laminated on both sides. Figures 1 to 7The laminated structure of the resin layer described above is only an example, and the interlayer film is not limited to the above laminated structure.

[0140] Furthermore, in the laminated structure described above, each resin layer is arranged from one end to the other end, and the number of layers of the intermediate film from one end to the other end is the same. That is, each coloring layer can be arranged in the entire area of ​​the intermediate film. In addition, each resin layer can also be arranged in the entire area of ​​the intermediate film. Among them, a part of the resin layer can be arranged in a part of the area of ​​the intermediate film, so it is not necessary to arrange all the resin layers from one end to the other end, and the number of layers of the intermediate film can change between one end and the other end.

[0141] [Material of interlayer film]

[0142] The resin constituting each resin layer is preferably a thermoplastic resin. By using a thermoplastic resin for each resin layer of the intermediate film, the laminated glass components can be easily bonded via the intermediate film by thermocompression bonding. In addition, multiple resin layers can be easily manufactured by extrusion molding or the like.

[0143] (Thermoplastic resin)

[0144] As the thermoplastic resin used for the intermediate film, for example, (meth) acrylic resin, polyvinyl acetal resin, polyvinyl alcohol resin (PVA), polyurethane resin (PU, polyurethane resin), ethylene-vinyl acetate copolymer resin (EVA), ethylene-vinyl acetate copolymer saponification (EVOH), ethylene-methacrylic acid copolymer resin, ionomer resin, isobutylene resin, styrene-isoprene copolymer resin, styrene-butadiene copolymer resin, polyester resin, polyolefin resin, etc. In each resin layer, the thermoplastic resin can be used alone or in combination of two or more. In addition, when there are multiple resin layers, the thermoplastic resins of each resin layer can be the same in kind or different in kind.

[0145] As the thermoplastic resin, among the above, at least one of polyvinyl acetal resin and ethylene-vinyl acetate copolymer resin is preferably used, and polyvinyl acetal resin is more preferably used. By using polyvinyl acetal resin, the impact resistance of laminated glass can be easily improved, and the adhesion to laminated glass components can be easily improved.

[0146] The polyvinyl acetal resin is not particularly limited as long as it is a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol (PVA) with aldehyde.

[0147] The aldehyde is not particularly limited, and aldehydes having 1 to 10 carbon atoms are generally preferably used. The aldehyde having 1 to 10 carbon atoms is not particularly limited, and examples thereof include n-butyraldehyde, isobutyraldehyde, n-valeraldehyde, 2-ethylbutyraldehyde, n-hexanal, n-octanal, n-nonanal, n-decanal, formaldehyde, acetaldehyde, benzaldehyde, etc. These aldehydes may be used alone or in combination of two or more.

[0148] Among the above, n-butyraldehyde, n-hexanal, and n-valeraldehyde are preferred, and n-butyraldehyde is more preferred. Therefore, the polyvinyl acetal resin is preferably a polyvinyl butyral resin.

[0149] The polyvinyl acetal resin generally has an acetal group, a hydroxyl group, and an acetyl group in a side chain. The polyvinyl acetal resin may be an unmodified polyvinyl acetal resin or a modified polyvinyl acetal resin.

[0150] The modified polyvinyl acetal resin has a structure other than an acetal group, a hydroxyl group, and an acetyl group (modifying group), and preferably has a modifying group in a side chain. Examples of the modifying group include a polyalkylene oxide structure in a side chain, an alkyl group (e.g., having about 2 to 30 carbon atoms) other than an acetal group and an acetyl group in a side chain.

[0151] In the interlayer film, the polyvinyl acetal resin may be used alone or in combination of two or more.

[0152] When a plurality of resin layers are provided, the thermoplastic resins used in the respective resin layers may be the same in type or different in type.

[0153] In the intermediate film, the resin constituting at least one resin layer is preferably at least one of a polyvinyl acetal resin and an ethylene-vinyl acetate copolymer resin, and more preferably a polyvinyl acetal resin.

[0154] By using these resins, the thickness can be easily changed by extrusion molding, so it is suitable for manufacturing a coloring layer with a variable thickness. In addition, by using these resins, it is also possible to bond to a laminated glass member with a high adhesive force.

[0155] Therefore, the resin used for the colored layer whose thickness changes from one end to the other end or the resin layer constituting the surface layer is preferably at least one of polyvinyl acetal resin and ethylene-vinyl acetate copolymer resin, and more preferably polyvinyl acetal resin. Furthermore, the surface layer is a resin layer that becomes the bonding surface with the laminated glass member in the laminated glass.

[0156] When there are a plurality of resin layers, the resin constituting all the resin layers may be at least one of a polyvinyl acetal resin and an ethylene-vinyl acetate copolymer resin. In this case, it is more preferred that the resin constituting all the resin layers is a polyvinyl acetal resin.

[0157] In addition, when there are a plurality of resin layers, the resin constituting a part of the resin layers may be any one of the polyvinyl acetal resin and the ethylene-vinyl acetate copolymer resin, and the remaining resin layers may be resin layers other than the resin layers containing at least any one of the polyvinyl acetal resin and the ethylene-vinyl acetate copolymer resin (other resin layers). That is, the other resin layers may be resin layers containing resins other than the polyvinyl acetal resin and the ethylene-vinyl acetate copolymer resin.

[0158] When the intermediate film includes other resin layers, various functions can be imparted to the intermediate film. For example, the intermediate film may appropriately contain any of the functional films described below. The resin constituting the other resin layer is preferably a polyester resin such as polyethylene terephthalate.

[0159] The intermediate film preferably has one or more resin layers in which at least one resin layer is a resin layer having a glass transition temperature of 15° C. or higher (hereinafter sometimes referred to as a "high Tg resin layer"). When the intermediate film includes a high Tg resin layer, the intermediate film can be easily improved in terms of penetration resistance, workability, mechanical properties, etc., and can be suitably used as an intermediate film for laminated glass.

[0160] The glass transition temperature of the high Tg resin layer is preferably 20° C. or higher, more preferably 25° C. or higher, more preferably 30° C. or higher, and for example, 80° C. or lower, preferably 60° C. or lower, and more preferably 50° C. or lower. The lower limit and upper limit of the glass transition temperature may be any combination.

[0161] Furthermore, when the intermediate film is a single layer, the glass transition temperature can be obtained by using the intermediate film as a measurement sample and measuring the viscoelasticity using a viscoelasticity measuring device. In addition, when the intermediate film is a multilayer, each layer can be peeled off from the intermediate film, and a measurement sample is prepared from each layer, and the viscoelasticity is measured using a viscoelasticity measuring device.

[0162] Specifically, for example, it can be measured by the following measurement method.

[0163] The measured sample is stored in an environment with a room temperature of 23±2°C and a humidity of 25±5% for 12 hours. Next, the viscoelasticity is measured using a viscoelasticity measuring device (for example, the viscoelasticity measuring device "ARES-G2" manufactured by TA Instruments). A parallel plate with a diameter of 8 mm is used as a jig, and the measurement is performed in a shear mode, with the temperature lowered from 100°C to -20°C at a cooling rate of 3°C / min, and at a frequency of 1Hz and a strain of 1%. In the obtained measurement results, the peak temperature of the loss tangent is set to the glass transition temperature Tg (°C).

[0164] The intermediate film may be a resin layer (hereinafter referred to as a low Tg resin layer) in which at least one of the one or more resin layers has a glass transition temperature of less than 15°C. By having a low Tg resin layer in the intermediate film, the sound insulation of the intermediate film can be easily improved. From the viewpoint of improving the sound insulation, the glass transition temperature of the low Tg resin layer is preferably 10°C or less, more preferably 5°C or less, and more preferably 0°C or less. In addition, the glass transition temperature of the low Tg resin layer is not particularly limited, but from the viewpoint of improving the mechanical properties of the intermediate film, such as the bending rigidity, it is preferably above -20°C. Furthermore, any combination of the lower limit and upper limit values ​​of these glass transition temperatures may be used.

[0165] The glass transition temperature of the resin layer can be adjusted by appropriately adjusting the type of resin used in the resin layer, the composition of the resin, etc. For example, the glass transition temperature can be increased by increasing the amount of hydroxyl groups in the polyvinyl acetal resin.

[0166] The low Tg resin layer may be a colored layer, but is preferably a transparent layer that does not substantially contain a colorant and has high transparency.

[0167] When the interlayer film has a low Tg resin layer, it preferably contains a high Tg resin layer in addition to the low Tg resin layer. The interlayer film can improve the sound insulation by having both the high Tg resin layer and the low Tg resin layer, and can well maintain the mechanical strength, penetration resistance, and adhesion to the laminated glass member of the interlayer film.

[0168] That is, when the interlayer film has a multilayer structure, it is preferred that all resin layers be high Tg resin layers, or it is preferred that at least one resin layer be a high Tg resin layer and at least one resin layer be a low Tg resin layer.

[0169] For example, in the above Figures 1 to 5 In the case of a two-layer structure, both of the two resin layers can be set as high Tg resin layers, or one resin layer can be set as a high Tg resin layer and the other resin layer can be set as a low Tg resin layer. However, in the case of a two-layer structure, it is preferred that both are set as high Tg resin layers. In the case of a two-layer structure, since both resin layers become the surface layers bonded to the laminated glass component, by setting both resin layers as high Tg resin layers, the adhesion to the laminated glass component can be improved. In addition, the mechanical strength and penetration resistance of the interlayer film can also be well maintained.

[0170] Furthermore, if Figure 7 As shown, in the case of a three-layer structure, all three resin layers may be high Tg resin layers, or one or two resin layers may be high Tg resin layers and two or one resin layers may be low Tg resin layers.

[0171] In addition, when the interlayer film has three or more resin layers and has a low Tg resin layer, it is preferred to have a pair of high Tg resin layers and a low Tg resin layer disposed between the pair of high Tg resin layers. In this case, it is further preferred to dispose the high Tg resin layer on the surface layer and set it as the bonding surface with the laminated glass. With such a structure, the interlayer film can improve the sound insulation and well maintain the mechanical strength, penetration resistance, and adhesion to the laminated glass member of the interlayer film.

[0172] Therefore, in Figure 7 In the three-layer structure shown in FIG. 1 , the first and second resin layers 11 and 12 that will be the surface layers are high Tg resin layers, and the third resin layer 13 disposed between the surface layers is a low Tg resin layer. In this case, the third resin layer is preferably a transparent layer. On the other hand, at least one of the first and second resin layers 11 and 12 is preferably a colored layer, and more preferably both are colored layers. In addition, as described above, Figures 2 to 5 The same also applies to the case where a third resin layer is further provided between the first and second resin layers in the laminated structure shown.

[0173] In addition, for example Figure 6 In the four-layer structure shown, the first and fourth resin layers 11 and 14 serving as surface layers may be high Tg resin layers, and either or both of the first and third resin layers 12 and 13 disposed between the surface layers may be low Tg resin layers.

[0174] Furthermore, the resin layer that becomes the low Tg resin layer can be a layer thickness ratio of the low Tg resin layer thickness relative to the total layer thickness that is substantially uniform. In addition, when two or more resin layers are low Tg resin layers, the layer thickness ratio of the total thickness obtained by adding up the thicknesses of the low Tg resin layers relative to the total layer thickness can be substantially uniform. Therefore, when the intermediate film has a substantially uniform thickness, the low Tg resin layer (the total thickness in multiple cases) also has a substantially uniform thickness as described above. On the other hand, when the thickness of the intermediate film is uneven, for example, when the thickness changes from one end to the other end, the thickness of the low Tg resin layer can also change accordingly according to the changed thickness.

[0175] (Plasticizer)

[0176] When the resin used is a thermoplastic resin, each resin layer may further contain a plasticizer. When the resin layer contains a plasticizer, the interlayer film becomes soft, and as a result, the laminated glass also becomes soft. Furthermore, when the laminated glass component is an inorganic glass, the adhesion to the laminated glass component can also be improved. When a polyvinyl acetal resin is used as the thermoplastic resin, the plasticizer is particularly effective if it is contained in the resin layer containing the thermoplastic resin.

[0177] Examples of the plasticizer include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, and phosphorus plasticizers such as phosphate plasticizers and phosphite plasticizers. Among them, organic ester plasticizers are preferred, and triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferred.

[0178] The content of the plasticizer is not particularly limited, and is, for example, 10 parts by mass or more and 100 parts by mass or less, and preferably 20 parts by mass or more and 85 parts by mass or less, based on 100 parts by mass of the thermoplastic resin in each resin layer.

[0179] The content of the plasticizer in the high Tg resin layer can be set relatively low from the viewpoint of the handleability and mechanical strength of the intermediate film, for example, from 10 to 50 parts by mass, preferably from 20 to 45 parts by mass, and more preferably from 25 to 40 parts by mass, relative to 100 parts by mass of the thermoplastic resin.

[0180] The content of the plasticizer in the low Tg resin layer relative to 100 parts by mass of the thermoplastic resin may be greater than the content in the high Tg resin layer relative to 100 parts by mass of the thermoplastic resin from the viewpoint of improving the flexibility of the laminated glass and easily improving the penetration resistance or sound insulation. Specifically, it is 25 parts by mass to 100 parts by mass, more preferably 45 parts by mass to 95 parts by mass, and more preferably 50 parts by mass to 90 parts by mass.

[0181] Each resin layer is preferably a thermoplastic resin, or a thermoplastic resin and a plasticizer as the main component. Specifically, the total amount of the thermoplastic resin and the plasticizer is preferably 50% by mass or more, more preferably 60% by mass or more, and more preferably 65% ​​by mass or more and 100% by mass or less based on the total amount of each resin layer.

[0182] (Colorant)

[0183] When the resin layer is a colored layer, it contains a colorant, and the colorant is uniformly dispersed in the colored layer. By uniformly dispersing the colorant, the thickness is changed as described above, thereby easily satisfying the above-mentioned requirements (A), (A-1), (A-2), and (B). The colored layer may be the above-mentioned high Tg resin layer or a low Tg resin layer, and is preferably a high Tg resin layer.

[0184] The colorant used is not particularly limited, and pigments that have been previously mixed in the interlayer can be used, such as blue, yellow, red, green, purple, white, black, etc. Pigments can be used. Pigments, dyes, etc. can be used. The interlayer can be colored to a desired color by using a colorant. In addition, by containing a colorant, a*, b*, L*, and Tv of the resin layer can be adjusted. Specifically, by containing a colorant, the absolute values ​​of a* and b* can be increased. In addition, by containing a colorant, L* or Tv of the resin layer can also be reduced.

[0185] Examples of the pigment used for the interlayer film include carbon black, copper phthalocyanine pigments such as pigment blue, phthalocyanine pigments such as cobalt phthalocyanine pigments, anthraquinone pigments, perylene pigments, diketopyrrolopyrrole pigments, quinacridone pigments, perinone pigments, thioindigo pigments, isoindoline pigments, isoindolinone pigments, quinolinephthalone pigments, thionyl pigments, dioxazine pigments, indolizine pigments, fluorubine pigments, azo pigments, titanium oxide pigments, calcium carbonate pigments, metal oxide pigments, Ni complex pigments, and other metal complex pigments.

[0186] In addition, examples of dyes include azo dyes, cyanine dyes, triphenylmethane dyes, phthalocyanine dyes, anthraquinone dyes, naphthoquinone dyes, quinoneimine dyes, methine dyes, methine azo dyes, squarylium dyes, acridine dyes, styryl dyes, coumarin dyes, quinoline dyes, nitro dyes, etc. The dye may also be a disperse dye.

[0187] The pigments and dyes constituting the coloring agents may be directly mixed into the resin, or may be mixed into the resin after being made into ink, coloring agent or the like.

[0188] In addition, as a colorant, in addition to the above-mentioned pigments and dyes, a heat shielding agent in the interlayer film can also be used as a colorant. The heat shielding agent also blocks a certain amount of visible light, so the interlayer film can also meet the above-mentioned requirements (A), (A-1), (A-2), and (B) by containing a heat shielding agent.

[0189] As a heat shielding agent, typically, it is a material that can absorb infrared rays with a wavelength of 780nm or more, that is, heat rays. The heat shielding agent is composed of an inorganic material, and typically, heat shielding particles can be used. As a specific example, particles other than metal oxide particles such as metal oxide particles and lanthanum hexaboride (LaB6) particles can be listed. As metal oxide particles, tin oxide particles such as aluminum-doped tin oxide particles, indium-doped tin oxide particles, and antimony-doped tin oxide particles (ATO particles) can be listed; zinc oxide particles such as gallium-doped zinc oxide particles (GZO particles), indium-doped zinc oxide particles (IZO particles), aluminum-doped zinc oxide particles (AZO particles), tin-doped zinc oxide particles, and silicon-doped zinc oxide particles; titanium oxide particles such as niobium-doped titanium oxide particles; indium oxide particles such as tin-doped indium oxide particles (ITO particles); sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles (CWO particles), thallium-doped tungsten oxide particles, and rubidium-doped tungsten oxide particles. In addition, heat shielding particles other than these can also be used. The heat shielding agent can be used alone or in combination of two or more.

[0190] Among these, metal oxide particles are preferred due to their high heat ray shielding function, and at least one selected from ATO particles, GZO particles, ITO particles, and CWO particles is more preferred, and ITO particles or CWO particles are more preferred.

[0191] The preferred lower limit of the average particle size of the heat-insulating particles is 10 nm, and the more preferred lower limit is 20 nm, and the preferred upper limit is 100 nm, and the more preferred upper limit is 80 nm, and the more preferred upper limit is 50 nm. If the average particle size is above the above preferred lower limit, the shielding property of heat rays can be fully improved. In addition, if the average particle size is below the above preferred upper limit, it is not easy to excessively shield visible light due to the heat-insulating agent. Furthermore, "average particle size" means the volume average particle size. The average particle size can be measured using a particle size distribution measuring device ("UPA-EX150" manufactured by NIKKISO) or the like. In addition, any combination of the lower limit and upper limit values ​​of these average particle sizes can be taken.

[0192] As a colorant, among the above, it is preferred to use a pigment or a dye, and it is more preferred to use a pigment. By using any one of a pigment or a dye as a colorant, the values ​​of a*, b*, L*, and Tv can be greatly changed with a small amount used.

[0193] The content of the colorant in the entire interlayer film is, for example, 0.00001% by mass or more and 7% by mass or less based on the total amount of the interlayer film. By setting the content of the colorant to 0.00001% by mass or more, the interlayer film can be colored, and the above-mentioned requirements (A), (A-1), (A-2), and (B) can be satisfied. In addition, by setting the content to 7% by mass or less, excessive coloring can be prevented, and the colorant can be prevented from reducing various functional properties of the interlayer film.

[0194] The above content of the colorant in the entire interlayer film is preferably 0.00005 mass % or more, more preferably 0.0001 mass % or more, more preferably 0.0005 mass % or more, more preferably 0.001 mass % or more, and is preferably 5 mass % or less, more preferably 3 mass % or less, and more preferably 1 mass % or less.

[0195] When at least one of a pigment and a dye is used as a colorant, the lower limit of the content of the colorant selected from the pigment and the dye in the entire interlayer film is as described above, and the upper limit can be set lower than the above, for example, it can be set to 0.5 mass% or less, preferably 0.3 mass% or less, and more preferably 0.1 mass% or less. In addition, when at least a heat-insulating agent is used as a colorant, the upper limit of the content of the colorant composed of the heat-insulating agent is as described above, and the lower limit can be set higher than the above, for example, it can be set to 0.1 mass% or more, preferably 0.2 mass% or more, and more preferably 0.3 mass% or more. In addition, the lower limit and upper limit of the content of the colorant in the entire interlayer film can be any combination.

[0196] In addition, the content of the colorant in each colored layer is, for example, 0.00002% by mass or more and 10% by mass or less based on the total amount of each colored layer. By setting it to 0.00002% by mass or more, the above-mentioned requirements (A), (A-1), (A-2), and (B) can be satisfied by changing the thickness of the resin layer. In addition, by setting it to 5% by mass or less, excessive coloring can be prevented, and the colorant can be prevented from causing various functions and performance reductions in each resin layer.

[0197] The content of the colorant in each colored layer is preferably 0.0001 mass % or more, more preferably 0.0002 mass % or more, more preferably 0.002 mass % or more, and is preferably 8 mass % or less, more preferably 5 mass % or less, more preferably 3 mass % or less, and more preferably 1 mass % or less.

[0198] When at least one of a pigment and a dye is used as a colorant, the lower limit of the content of the colorant selected from the pigment and the dye in each coloring layer is as described above, and the upper limit can be set lower than the above, for example, it can be 0.6% by mass or less, preferably 0.4% by mass or less, and more preferably 0.2% by mass or less. In addition, when at least a heat-insulating agent is used as a colorant, the upper limit of the content of the colorant composed of the heat-insulating agent is as described above, and the lower limit can be set higher than the above, for example, it can be 0.1% by mass or more, preferably 0.2% by mass or more, and more preferably 0.4% by mass or more. The lower limit and upper limit of the content of the colorant in each of these coloring layers can be any combination.

[0199] When two or more colored layers are provided in the interlayer film, the content of the colorant in each resin layer may be the same as or different from each other.

[0200] In addition, the transparent layer is a layer that does not substantially contain a colorant and has high transparency. Furthermore, "substantially does not contain a colorant" means that a colorant that is inevitably mixed from other components such as a colored layer may be contained within a range that does not impair transparency. The visible light transmittance (Tv) of the transparent layer can be 87% or more as described above. The method for measuring the visible light transmittance (Tv) of the transparent layer is the same as the method for measuring the visible light transmittance (Tv) of each resin layer described above.

[0201] Each resin layer constituting the interlayer film may contain, in addition to plasticizers and colorants, known additives used in interlayer films. Specific examples of additives other than plasticizers include ultraviolet absorbers, antioxidants, light stabilizers, adhesion modifiers, fluorescent whitening agents, crystal nucleating agents, and the like.

[0202] The thickness of the intermediate film is not particularly limited, for example, it is 0.1 mm or more, preferably 0.2 mm or more, and more preferably 0.3 mm or more, and for example, it is 4 mm or less, preferably 3 mm or less, and more preferably 2 mm or less, more preferably 1.7 mm or less, more preferably 1.5 mm or less, and more preferably 1 mm or less. By making the thickness of the intermediate film above the lower limit, the impact resistance can be improved, and it is also easy to ensure the adhesion with the laminated glass components. On the other hand, by setting it below the upper limit, the thickness of the laminated glass can be prevented from becoming too thick. Furthermore, the thickness of the intermediate film is the average value of the total thickness of the intermediate film, and the average value of the thickness of each layer constituting the intermediate film can be calculated by adding up. In addition, the lower limit and upper limit of the thickness of these intermediate films can be combined in any way.

[0203] The intermediate film may be substantially uniform in thickness or uneven in thickness. For example, the above-mentioned thickness may change from one end toward the other end, or one end and the other end may have a thickness difference. When there is a thickness difference between one end and the other end, their thickness ratio is, for example, 0.5 or more and less than 0.95, preferably 0.6 or more and 0.9 or less. Furthermore, the thickness ratio is the value obtained by dividing the larger value of the thickness at one end and the other end by the smaller value. Furthermore, if the thickness of the intermediate film changes from one end toward the other end, even if the resin layer is not set as a multilayer, it is easy to meet the above-mentioned requirements (A), (A-1), (A-2), (B).

[0204] In the above description, the colorant is uniformly dispersed in each layer and the concentration of the colorant is substantially the same in the entire color layer. However, the concentration in the color layer may be uneven. If the concentration in the color layer is uneven, even if the thickness of the color layer does not change, it is easy to satisfy the above-mentioned requirements (A), (A-1), (A-2), and (B) by changing the colorant concentration inside the color layer from one end to the other end.

[0205] (Functional membrane)

[0206] The intermediate film may have a functional film. As the functional film, it may be composed of a resin layer, or may be composed of a layer other than the resin layer, or may be composed of a laminate of a resin layer and a layer other than the resin layer. Specifically, a coating film, a colored film, a heat reflective film, a barrier film, etc. may be cited.

[0207] Furthermore, the resin layer in the functional film may be the above-mentioned colored layer or a transparent layer. Furthermore, the colored layer in the functional film may be a colored layer with substantially uniform thickness or a colored layer with variable thickness. In addition, the colored layer may be provided in a partial region of the functional film in the manner of being provided in a partial region of the intermediate film. In the functional film, the colored layer may be provided together with the base film as described in the coating film or the colored film described below.

[0208] As the coating film, at least one side of the resin film (base film) can be listed as a coating film formed by a coating containing a colorant such as a pigment or dye. The resin used for the resin film can be listed as the above-mentioned thermoplastic resin, and resins other than the thermoplastic resin can also be used. As the resin used for the resin film, polyester resins such as polyethylene terephthalate are preferably used. In addition, pigments and dyes can be appropriately selected from the above-mentioned pigments and dyes. The coating film includes an adhesive resin component and a colorant, and can also be considered as the above-mentioned colored layer.

[0209] The colored film is a film formed by dispersing a colorant in a resin. The resin used in the resin film may include the above-mentioned thermoplastic resins, and resins other than thermoplastic resins may also be used. The resin used in the resin film is preferably a polyester resin such as polyethylene terephthalate. In addition, pigments and dyes may be appropriately selected from the above-mentioned pigments and dyes. The colored film may also be considered as the above-mentioned colored layer. In addition, the colored film may have a structure formed by laminating a colored layer on a substrate film.

[0210] Examples of the heat reflective film include a resin film with a metal foil, a multilayer laminated film in which a metal layer and a dielectric layer are formed on a resin film, a multilayer resin film, and a liquid crystal film, etc. These films have the ability to reflect infrared rays.

[0211] The resin film with metal foil comprises a resin film and a metal foil laminated on one side of the resin film. As the material of the resin film, the resins listed above as the thermoplastic resins can be used, and resins other than the resins listed above as the thermoplastic resins can also be used. As the material of the metal foil, aluminum, copper, silver, gold, palladium, and alloys thereof can be listed.

[0212] The multilayer laminated film having a metal layer and a dielectric layer formed on a resin film is a multilayer laminated film in which metal layers and dielectric layers are alternately laminated in an arbitrary number of layers on the resin film. Furthermore, in the multilayer laminated film having a metal layer and a dielectric layer formed on a resin layer, it is preferred that all the metal layers and the dielectric layers are alternately laminated, and there may be a structural portion in which the metal layers and the dielectric layers are not alternately laminated.

[0213] As a material of the resin film in the multilayer laminated film, the resins listed above as the thermoplastic resin may be used, and resins other than the resins listed above as the thermoplastic resin may also be used.

[0214] As the material of the metal layer in the multi-layer laminated film, the same materials as the material of the metal foil in the resin film with metal foil can be cited. In addition, a coating layer of metal or mixed oxide of metal can be given to both sides or one side of the metal layer. As the material of the coating layer, ZnO, Al2O3, Ga2O3, InO3, MgO, Ti, NiCr and Cu can be cited. In addition, as the material of the dielectric layer in the multi-layer laminated film, for example, indium oxide can be cited.

[0215] The multilayer resin film is a laminated film formed by laminating a plurality of resin films. As the material of the multilayer resin film, the same material as the material of the resin film in the multilayer laminated film can be cited. The number of laminations of the resin film in the multilayer resin film is more than 2, more than 3, or more than 5. The number of laminations of the resin film in the multilayer resin film can be less than 1000, less than 100, or less than 50. Furthermore, any combination of the lower limit and upper limit of these lamination numbers can be taken.

[0216] The multilayer resin film may be a multilayer resin film in which two or more thermoplastic resin layers having different optical properties (refractive index) are alternately or randomly stacked in any number of layers. Such a multilayer resin film is configured to obtain the desired infrared reflection performance.

[0217] Examples of the liquid crystal film include a film in which cholesteric liquid crystal layers reflecting light of an arbitrary wavelength are stacked in an arbitrary number of layers. Such a liquid crystal film is configured so as to obtain a desired infrared reflection performance.

[0218] The barrier film is a layer provided between two resin layers to prevent additives (such as colorants) contained in one resin layer from transferring to the other resin layer. The barrier film can be composed of a resin layer, and examples of the resin used for the barrier film include polyester resins and acrylic resins.

[0219] As the acrylic resin, an acrylic polymer containing a structural unit derived from a (meth)acrylate containing a hydroxyl group is preferred, and specifically, polyhydroxypropyl methacrylate (HPMA resin), polyhydroxyethyl methacrylate (HEMA resin), and the like are preferred.

[0220] As the polyester resin, polyethylene terephthalate, polyhydroxypropyl methacrylate, polyhydroxyethyl methacrylate are preferred, and polyethylene terephthalate (PET) is preferred. Polyethylene terephthalate may be a modified PET, and for example, cyclohexanedimethylene-modified PET (PETG) is preferred.

[0221] The resin used for the barrier layer may be used alone or in combination of two or more.

[0222] When the intermediate film has a functional film, it may include a resin layer other than the functional film in addition to the functional film, and may include a resin layer laminated on one or both sides of the functional film, preferably a resin layer laminated on both sides of the functional film. One resin layer may be laminated on one or both sides of the functional film, or two or more resin layers may be laminated.

[0223] Furthermore, as described above, the functional film may contain a colored layer, but it is generally difficult to change the thickness of the colored layer in the functional film, so the intermediate film may include a colored layer whose thickness changes from one end to the other end in addition to the functional film. Therefore, the resin layer laminated on one or both sides of the functional film may include a colored layer whose thickness changes from one end to the other end.

[0224] Specifically, in Figure 1 to Figure 5 In each of the laminated structures shown, a functional film may be further disposed between the first resin layer 11 and the second resin layer 12 .

[0225] (Method for producing interlayer film)

[0226] The manufacturing method of the intermediate film is not particularly limited, and the intermediate film is preferably formed by extrusion molding. Specifically, the resin constituting each resin layer, or a resin composition containing additives such as a plasticizer and a colorant in addition to the resin, is extruded to form each resin layer. In addition, when the intermediate film is a multilayer in the resin layer, it is preferably formed by a coextrusion method.

[0227] In the coextrusion, a coextruder equipped with a plurality of extruders and a multi-layer feed block may be used. The front end of each extruder of the coextruder may be connected to a multi-layer feed block via a molten resin delivery pipe or the like.

[0228] In the co-extruder, the resin or resin composition for forming each resin layer can be supplied from each extruder to the multi-layer feed block via a molten resin delivery pipe, etc., and the materials are merged in the multi-layer feed block to be co-extruded as a multi-layer intermediate film. At this time, the thickness of each resin layer can be adjusted by setting the gap width at each coordinate in the width direction (TD) of the flow path (e.g., slit) of each resin layer provided in the multi-layer feed block or / and the mold in accordance with the target thickness distribution.

[0229] In addition, in coextrusion, the gap width at each coordinate in the width direction (TD) of the die outlet can be adjusted as needed during extrusion molding to change the thickness of the intermediate film. In addition, as described below, in the case where a resin layer is formed by extruding it onto another resin layer or a functional film, or in the case where a resin layer is pre-made in order to be laminated on another resin layer or a functional film by lamination, when the resin layer is made, the gap width at each coordinate in the width direction (TD) of the die outlet can be similarly adjusted to change the thickness of the resin layer from one end to the other end.

[0230] When the interlayer film has multiple resin layers, it is not limited to coextrusion, and the interlayer film may be produced by extruding another resin layer onto a previously produced resin layer or by laminating previously produced resin layers.

[0231] In addition, when the intermediate film includes a functional film, the intermediate film can be manufactured by extruding the resin or resin composition used to form each resin layer onto one or both sides of the functional film. In addition, when a multi-layer resin layer is laminated on one or both sides of the functional film, coextrusion can also be utilized. In addition, the functional film can be laminated with a pre-made resin layer to obtain an intermediate film.

[0232] [Laminated glass]

[0233] The present invention further provides a laminated glass. The laminated glass comprises a first laminated glass member and a second laminated glass member, and an interlayer film disposed between the first laminated glass member and the second laminated glass member. The first laminated glass member and the second laminated glass member are bonded to each other via the interlayer film.

[0234] (First and second laminated glass components)

[0235] As the first and second laminated glass members used in the laminated glass, glass plates can be cited. The glass plates can be any of inorganic glass and organic glass, preferably inorganic glass. The inorganic glass is not particularly limited, and can be cited as transparent glass, float plate glass, tempered glass, tinted glass, polished plate glass, patterned glass, wired plate glass, ultraviolet absorbing plate glass, infrared reflecting plate glass, infrared absorbing plate glass, green glass, etc.

[0236] In addition, as organic glass, what is generally called resin glass is used, and various organic glass plates such as polycarbonate plate, (meth) acrylic plate such as polymethyl methacrylate plate, polyester plate such as acrylonitrile styrene copolymer plate, acrylonitrile butadiene styrene copolymer plate, polyethylene terephthalate plate, fluorine resin plate, polyvinyl chloride plate, chlorinated polyvinyl chloride plate, polypropylene plate, polystyrene plate, polysulfone plate, epoxy resin plate, phenolic resin plate, unsaturated polyester resin plate, polyimide resin plate, etc. can be listed. The organic resin plate can be appropriately subjected to surface treatment, etc.

[0237] The first and second laminated glass components may be made of the same material or different materials. For example, one may be inorganic glass and the other may be organic glass. Preferably, both the first and second laminated glass components are inorganic glass or organic glass.

[0238] The thickness of each glass plate used for the first and second laminated glass members is not particularly limited, and is, for example, about 0.1 to 15 mm, preferably 0.5 to 5 mm. The thickness of each glass plate may be the same or different from each other.

[0239] When the thickness of the first and second laminated glass members is different from each other, the difference in thickness can be 0.1 mm or more, preferably 0.2 mm. The difference in thickness between the first and second laminated glass members is not particularly limited, and can be, for example, 2 mm or less, preferably 1 mm or less.

[0240] The first and second laminated glass components may be flat glass or curved glass. Furthermore, when one of the first and second laminated glass components is flat glass, the other is also flat glass, and when one of the first and second laminated glass components is curved glass, the other is also curved glass.

[0241] For example, the bending radius of the curved glass in the longitudinal direction is preferably 4000 mm or more, more preferably 6000 mm or more, more preferably 8000 mm or more, and preferably 25000 mm or less, more preferably 20000 mm or less, and more preferably 15000 mm or less. The lower limit and upper limit of these bending radii may be any combination.

[0242] The method for producing laminated glass is not particularly limited, and laminated glass can be obtained by sandwiching an interlayer film between two laminated glass members and press-bonding them.

[0243] More specifically, an interlayer film is sandwiched between the first and second laminated glass components, and the interlayer film is passed through a squeeze roller or placed in a rubber bag for decompression and suction to remove the air remaining between the two glass components and the interlayer film. Thereafter, the interlayer film is pre-bonded at about 70 to 110°C to obtain a laminate. Next, the laminate is placed in an autoclave or pressed at about 120 to 150°C and a pressure of 1 to 1.5 MPa. Thus, a laminated glass can be obtained.

[0244] The intermediate film and laminated glass of the present invention can be used in various transportation vehicles such as automobiles, railway vehicles, airplanes, ships, and buildings. In addition, they can also be used as surface protection panels of various display devices such as liquid crystal displays and organic EL displays for display equipment purposes. The intermediate film and laminated glass can also be used for purposes other than these. The intermediate film and laminated glass are preferably intermediate films and laminated glasses for vehicles or buildings, and more preferably intermediate films and laminated glasses for vehicles.

[0245] Example

[0246] Hereinafter, the present invention will be described in further detail by way of examples, but the present invention is not limited to these examples at all.

[0247] The measuring methods and evaluation methods of various physical properties are as follows.

[0248] [Optical properties of laminated glass]

[0249] (L*, a*, b*, Tv)

[0250] For laminated glass, the spectral spectrum was measured using a spectrophotometer ("U-4100 (light source: deuterium lamp, 50W halogen lamp)" manufactured by Hitachi High-Technology) in accordance with JIS R3212 (2015). During the measurement, in order to make the integrating sphere receive only the parallel light transmitted through the laminated glass, the laminated glass was set on the optical path between the light source and the integrating sphere and offset from the integrating sphere by 13 cm in a manner parallel to the normal line of the optical axis, and the spectral transmittance was measured. In addition, the measurement conditions were set to a scanning speed of 300 nm / min and a slit width of 8 nm. Other measurement conditions were to use the CIE standard light source D65 specified in JIS Z 8781-1 (2012), JIS Z 8781-2 (2012), and JIS Z 8781-4 (2013) and a 10° field of view color matching function to measure L*, a*, and b*. In addition, the visible light transmittance (Tv) was also measured in accordance with JIS R3212 (2015). In addition, the measurement of L*, a*, b*, and Tv was performed by moving the laminated glass and measuring 21 measurement points at intervals of 50 mm from one end of the laminated glass to the other end along the TD direction at the center of the MD. During the measurement, the laminated glass can be cut into appropriate sizes as needed.

[0251] Furthermore, the ratio of the measurement points where Tv is 60% or more among all the measurement points of the laminated glass is obtained as the area ratio of the region where Tv is 60% or more. In addition, the number of regions where Tv decreases from one end to the other end and the number of regions where Tv increases are obtained according to the method described in the specification.

[0252] [Optical properties of each resin layer]

[0253] Regarding the optical properties of each resin layer (colored layer, transparent layer), each resin layer was cut from the interlayer, and a 760 μm thick resin film for evaluation was made from the cut material by press molding. Furthermore, the position of each layer can be identified by cross-sectional measurement using a microscope or elemental analysis of the cross section using EDX analysis.

[0254] The above-mentioned press molding is performed by pressing at 150°C and 100 kgf for 15 minutes. Two transparent glass sheets with a thickness of 2.5 mm are bonded together through the resin film for evaluation to obtain a laminated glass for measurement. The laminated glass for measurement is produced by the same method as in Example 1 described below. The transparent glass is the reference transparent glass described in the instruction manual.

[0255] Light was irradiated on one side of the laminated glass for measurement, and the L*, a*, and b* measured at a viewing angle of 10° on the other side of the laminated glass for measurement were set as the L*, a*, and b* of the resin layer. Similarly, the visible light transmittance (Tv) measured on the laminated glass for measurement was set as the Tv of the resin layer.

[0256] The conditions for irradiation of light and the conditions for measuring L*, a*, b* and Tv are the same as those described in the above-mentioned [Optical properties of laminated glass], and the three-point average of the measured values ​​measured at any position is set as the L*, a*, b* and Tv of the resin layer.

[0257] The components used in the following examples and comparative examples are as follows.

[0258] PVB1: polyvinyl acetal resin, average degree of polymerization 1700, hydroxyl content 30.3 mol%, acetalization degree 68.8 mol%, acetyl content 0.9 mol%

[0259] PVB2: polyvinyl acetal resin, average degree of polymerization 3000, hydroxyl content 23.8 mol%, acetalization degree 63.8 mol%, acetyl content 12.4 mol%

[0260] Plasticizer: Triethylene glycol di-2-ethylhexanoate (3GO)

[0261] Colorant 1: PB15-1 Pigment Blue 15-1 (Copper Phthalocyanine Pigment)

[0262] Colorant 2: PR202 Pigment Red 202 (Quinacridone Pigment)

[0263] Colorant 3: Pblack-7 Pigment Black 7 (Carbon Black)

[0264] Colorant 4: ITO tin-doped indium oxide particles (thermal insulation material)

[0265] Colorant 5: CWO cesium-doped tungsten oxide particles (thermal insulation material)

[0266] [Example 1]

[0267] (Production of interlayer film)

[0268] According to the composition of Table 1, the components are mixed to obtain a resin composition for the coloring layer (1) and a resin composition for the coloring layer (2). The resin composition for the coloring layer (1) is supplied to the first extruder. In addition, the resin composition for the coloring layer (2) is supplied to the second extruder. A co-extruder having a multi-layer feed block installed at the front end of the "first molten resin delivery pipe connected to the front end of the first extruder" and the "second molten resin delivery pipe connected to the front end of the second extruder" is used to obtain a two-layer structure intermediate film by co-extrusion. At this time, the resin flow paths of each layer just before the confluence in the feed block become Figure 1 The gap width at each coordinate in TD was set in the manner of the cross section shown. In addition, the colored layer (1) became the first resin layer 11, and the colored layer (2) became the second resin layer 12. The obtained interlayer film was cut so that the length in TD became 1000 mm and the length in MD became 1000 mm.

[0269] (Manufacturing of laminated glass)

[0270] Next, the cut interlayer film was sandwiched between a pair of transparent glasses (300 mm×150 mm) to obtain a laminated body. Furthermore, a plurality of pairs of transparent glasses were prepared so that the corresponding measurement locations could be measured, and the plurality of pairs of transparent glasses were bonded together via the interlayer film.

[0271] As the transparent glass, the reference transparent glass described in the instruction manual is used. The obtained laminate is put into a rubber bag, degassed at a vacuum degree of 2.6 kPa for 20 minutes, and then transferred to an oven in a degassed state, and further vacuum pressed at 90°C for 30 minutes to pre-press the laminate. The pre-pressed laminate is pressed for 20 minutes at 135°C and a pressure of 1.2 MPa in an autoclave to obtain a laminated glass. The optical properties of the obtained laminated glass are measured. The measurement results are shown in Tables 1 and 3. In addition, the optical properties, glass transition temperature, and thickness characteristics of each resin layer in the intermediate film are also shown in Table 1.

[0272] [Examples 2 and 3]

[0273] After changing the composition of the resin composition as shown in Tables 1 and 2, Figure 3 , Figure 1 The gap width at each coordinate of the TD of the flow path just before the resin layers in the mold merge is set in the manner shown in the cross section, and then the resin compositions are co-extruded to obtain an intermediate film of a two-layer structure. Using the obtained intermediate film, a laminated glass is prepared in the same manner as in Example 1, and the optical properties of the obtained laminated glass are measured. The measurement results are shown in Tables 1 and 4. In addition, the optical properties, glass transition temperature, and thickness characteristics of the resin layer in the intermediate film are also shown in Table 1.

[0274] [Examples 4, 6, 7, 9]

[0275] After changing the composition of the resin composition as shown in Tables 1 and 2, the gap width at each coordinate of the TD of each layer of the resin flow path just before the confluence in the feed block is set in a manner to become the cross-section of the diagram shown in Tables 1 and 2, and then the resin compositions are co-extruded to obtain an intermediate film with a two-layer structure. Furthermore, in Examples 4, 6, 7, and 9, as a laminated structure of a transparent layer and a colored layer, the first resin layer 11 is set as a transparent layer, and the second resin layer 12 is set as a colored layer. Using the obtained intermediate film, laminated glass is prepared in the same manner as in Example 1, and the optical properties of the obtained laminated glass are measured. The measurement results are shown in Tables 1, 2, 5, 7, and 8. In addition, the optical properties, glass transition temperature, and thickness characteristics of the resin layer in the intermediate film are also shown in Tables 1 and 2.

[0276] [Example 5]

[0277] According to the composition of Table 1, the components are mixed to obtain a resin composition for a transparent layer, a resin composition for a colored layer (1), a resin composition for a colored layer (2), and a resin composition for a colored layer (3), and these resin compositions are supplied to the first to fourth extruders. A co-extrusion device having a multi-layer feed block further installed at the front end of the "first to fourth molten resin delivery pipes connected to the front ends of the first to fourth extruders" is used to obtain a 4-layer structure intermediate film by co-extrusion. At this time, Figure 6 The gap width at each coordinate of the TD of each layer of resin flow path just before the confluence in the feed block is set in the manner of the cross section shown, and then the resin compositions are co-extruded to obtain an intermediate film with a 4-layer structure. Furthermore, in the intermediate film, the first resin layer 11 is set as a transparent layer, the second resin layer 12 is set as a colored layer (1), the third resin layer 13 is set as a colored layer (2), and the fourth resin layer 14 is set as a colored layer (3). Using the obtained intermediate film, laminated glass is prepared in the same manner as in Example 1, and the optical properties of the obtained laminated glass are measured. The measurement results are shown in Tables 1 and 6. In addition, the optical properties, glass transition temperature, and thickness characteristics of the resin layers in the intermediate film are also shown in Table 1.

[0278] [Example 8]

[0279] According to the composition of Table 1, the components are mixed to obtain a resin composition for a transparent layer, a resin composition for a colored layer (1), and a resin composition for a colored layer (2), and these resin compositions are supplied to the first to third extruders. Furthermore, as described in Table 2, two colorants (colorants 1, 4) are blended into the resin composition for the colored layer (1) in the amounts described in Table 2. A co-extrusion device having a multi-layer feed block further installed at the front end of the "first to third molten resin delivery pipes connected to the front ends of the first to third extruders" is used to obtain a three-layer structure intermediate film by co-extrusion. At this time, Figure 7 The gap width at each coordinate of the TD of each layer of resin flow path just before the confluence in the feed block is set in the manner of the cross section shown, and then the resin compositions are co-extruded to obtain an intermediate film with a three-layer structure. Furthermore, in the intermediate film, the first resin layer 11 is set as the colored layer (1), the second resin layer 12 is set as the colored layer (2), and the third resin layer 13 is set as the transparent layer. Using the obtained intermediate film, a laminated glass is prepared in the same manner as in Example 1, and the optical properties of the obtained laminated glass are measured. The measurement results are shown in Table 2. In addition, the optical properties, glass transition temperature, and thickness characteristics of the resin layers in the intermediate film are also shown in Table 2. Furthermore, the glass transition temperature of the colored layers (1) and (2) is 27°C, and the glass transition temperature of the transparent layer is -4°C.

[0280] [Comparative Example 1]

[0281] According to the composition of Table 2, the components were mixed to obtain a resin composition for a coloring layer. Next, the resin composition for a coloring layer was extruded so that the thickness was uniform along the TD to obtain an intermediate film of a single-layer structure. Using the obtained intermediate film, a laminated glass was prepared in the same manner as in Example 1, and the optical properties of the obtained laminated glass were measured. The measurement results are shown in Table 2. In addition, the optical properties, glass transition temperature, and thickness characteristics of the resin layer in the intermediate film are also shown in Table 2.

[0282] [Comparative Example 2]

[0283] According to the composition of Table 2, the components were mixed to obtain a resin composition for a transparent layer and a resin composition for a colored layer (1). Next, each resin composition was extruded in a manner that the thickness was uniform along the TD to obtain an intermediate film of a two-layer structure. Using the obtained intermediate film, a laminated glass was prepared in the same manner as in Example 1, and the optical properties of the obtained laminated glass were measured. The measurement results are shown in Table 2. In addition, the optical properties, glass transition temperature, and thickness characteristics of the resin layer in the intermediate film are also shown in Table 2.

[0284] Table 1

[0285]

[0286] Table 2

[0287]

[0288] In the following Tables 3 to 8, Tv, L*, a*, and b* at each representative measurement point are shown for Examples 1, 2, 4 to 7 in each of the Examples. In addition, the distance in each of the following Tables indicates the distance from one end.

[0289] Table 3

[0290] Example 1

[0291]

[0292] Table 4 Example 2

[0293]

[0294] Table 5

[0295] Example 4

[0296]

[0297] Table 6 Example 5

[0298]

[0299] Table 7 Example 6

[0300]

[0301] Table 8

[0302] Example 7

[0303]

[0304] As described above, the laminated glass made using the interlayer film of each embodiment has a value of ΔL*+Δa*+Δb* measured from one end to the other end of 0.5% or more, and the absolute value of the difference between the maximum and minimum values ​​of the visible light transmittance (Tv) is 0.1% or more, thereby providing excellent design properties.

[0305] In contrast, in Comparative Examples 1 and 2, the value of ΔL*+Δa*+Δb* measured from one end to the other is less than 0.5%, and the absolute value of the difference between the maximum and minimum values ​​of the visible light transmittance (Tv) is also less than 0.1%, so the design properties cannot be fully improved.

[0306] In addition, the interlayer film of Example 5 further satisfies the requirements of ΔL*<Δa* and ΔL*<Δb* (requirement (A-2)), and as a result, the change in hue is dominant, and a high degree of design can be ensured by making the color tonality have a certain degree of unity and changing the color. In addition, the Tv value is high as a whole, and Tv is 60% or more in all regions, so the usefulness in applications requiring high transparency is also high.

[0307] The interlayer films of Examples 4, 6 to 9 satisfy the requirements of ΔL*≥Δa* and ΔL*≥Δb* (requirement (A-1)), so the change in color concentration is dominant, and the design can be improved by making the chromaticity have a certain degree of uniformity and changing the color tone. Among them, in Examples 4, 6, and 7, the values ​​of ΔL*, Δb*, Δa*, and ΔTv are large, and the design can give a strong impression by color change, and there is also a region with a high Tv value within a sufficient range, which can be suitably used for window glass applications. In addition, in Examples 8 and 9, the Tv value is generally high, and Tv is 60% or more in all regions, so the usefulness in applications requiring high transparency is also high.

[0308] Furthermore, the interlayer films of Examples 1 to 3 satisfy both requirements (A-1) and (A-2), and as a result, high design properties can be ensured by changing the color density and hue with good hue balance. Among them, in Example 3, the values ​​of ΔL*, Δb*, Δa*, and ΔTv are large, and the interlayer films have a design property that can give a strong impression by color change, and also have a region with a high Tv value within a sufficient range, and can be suitably used for window glass applications, etc.

[0309] Description of the accompanying drawings

[0310] 10A~10G: Interlayer film for laminated glass

[0311] 11: First resin layer

[0312] 12: Second resin layer

[0313] 13: The third resin layer

[0314] 14: Fourth resin layer

[0315] 15A: One end

[0316] 15B: The other end

Claims

1. An interlayer film for laminated glass, comprising one or more resin layers, wherein at least one resin layer contains a colorant, For the laminated glass obtained by bonding two pieces of transparent glass with a thickness of 2.5 mm with an intermediate film therebetween, if the absolute values ​​of the differences between the maximum and minimum values ​​of L*, a*, and b* respectively measured from one end to the other end are set to ΔL*, Δa*, and Δb*, then the value of ΔL*+Δa*+Δb* is greater than 0.

5. 2 . The interlayer film for laminated glass according to claim 1 , which satisfies at least one of ΔL*≥Δa* and ΔL*≥Δb*. 3 . The interlayer film for laminated glass according to claim 1 , which satisfies at least one of ΔL*<Δa* and ΔL*<Δb*.

4. An interlayer film for laminated glass, comprising one or more resin layers, wherein at least one resin layer contains a colorant, For a laminated glass obtained by bonding two sheets of 2.5 mm thick clear glass via the interlayer film for laminated glass, the absolute value of the difference between the maximum and minimum values ​​of the visible light transmittance (Tv) measured from one end to the other end is 0.1% or more. 5 . The interlayer film for laminated glass according to claim 4 , comprising at least one of a region where the visible light transmittance (Tv) decreases from one end toward the other end and a region where the visible light transmittance (Tv) increases from one end toward the other end. 6 . The interlayer film for laminated glass according to claim 1 , wherein the absolute value of the difference between the maximum and minimum values ​​of the visible light transmittance (Tv) measured from one end to the other end of the laminated glass is 0.1% or more. 7 . The interlayer film for laminated glass according to claim 1 , wherein at least one of the one or more resin layers comprises at least one selected from the group consisting of a polyvinyl acetal resin and an ethylene-vinyl acetate copolymer resin. 8 . The interlayer film for laminated glass according to claim 7 , comprising a layer other than the resin layer comprising at least one selected from the group consisting of a polyvinyl acetal resin and an ethylene-vinyl acetate copolymer resin.

9. The interlayer film for laminated glass according to any one of claims 1 to 5, comprising at least two resin layers having at least any one of L*, a* and b* different from each other, wherein the L*, a* and b* are measured for a laminated glass for measurement obtained by bonding two sheets of transparent glass having a thickness of 2.5 mm with each resin layer interposed therebetween. 10 . The interlayer film for laminated glass according to claim 1 , wherein the glass transition temperature of at least one of the one or two or more resin layers is 15° C. or higher. 11 . The interlayer film for laminated glass according to claim 1 , wherein the glass transition temperature of at least one of the one or two or more resin layers is lower than 15° C. 12 . The interlayer film for laminated glass according to claim 1 , wherein, in the laminated glass, a region where the measured visible light transmittance (Tv) is 60% or more accounts for 30% or more in terms of area ratio. 13 . The interlayer film for laminated glass according to claim 1 , wherein the minimum value of the visible light transmittance (Tv) measured for the laminated glass is 50% or more. 14 . The interlayer film for laminated glass according to claim 1 , wherein the minimum value of the visible light transmittance (Tv) measured for the laminated glass is 70% or more.

15. The intermediate film for laminated glass as described in any one of claims 1 to 5, comprising at least one resin layer having a visible light transmittance (Tv) of less than 87%, wherein the visible light transmittance (Tv) is measured on a laminated glass obtained by bonding two sheets of transparent glass with a thickness of 2.5 mm with a resin layer interposed therebetween. 16 . The interlayer film for laminated glass according to claim 1 , which has a thickness of 2 mm or less. 17 . The interlayer film for laminated glass according to claim 1 , wherein a content of the colorant is 0.00001 mass % to 7 mass %.

18. A laminated glass comprising the interlayer film for laminated glass according to any one of claims 1 to 5, and a pair of laminated glass members, The interlayer film for laminated glass is disposed between the pair of laminated glass members.

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