Intermediate film for laminated glass, method for producing same, and laminated glass

Abstract

An intermediate film for laminated glass, which is provided with two or more resin layers, at least one resin layer having a glass transition temperature different from that of the other resin layer, and wherein x [mm] represents a seating point on a straight line from one end toward the other end, and x [mm] represents a seating point on the straight line from the one end toward the other end. The difference between the maximum value and the minimum value of the thickness ratio R (x) of the low-Tg resin layer having the lowest glass transition temperature from among the two or more resin layers to the entire interlayer for laminated glass is 8% or less.

Description

Technical Field

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

[0002] Laminated glass is safe because it rarely scatters glass fragments even if it is broken by external impact, and therefore is widely used as window glass for various vehicles such as automobiles, railway vehicles, aircraft, and ships, and window glass for buildings, etc. Laminated glass is widely known as a laminated glass obtained by sandwiching an interlayer film for laminated glass containing a resin component such as a polyvinyl acetal resin or an ethylene-vinyl acetate copolymer resin between a pair of glasses and integrating them.

[0003] Conventionally, in the case of an interlayer film for laminated glass, a sound insulation interlayer film is known in which a resin layer having a low glass transition temperature (low Tg resin layer) is provided in the interlayer film in order to improve the sound insulation property (for example, see Patent Document 1). In the sound insulation interlayer film, in general, a high Tg resin layer having a high glass transition temperature is provided in addition to the low Tg resin layer in order to ensure mechanical strength, adhesion to the laminated glass member, etc. In addition, it is widely known that the sound insulation interlayer film is generally molded by coextrusion.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2016-183077 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, in the past, it was difficult to make the thickness of the low Tg resin layer uniform along the width direction of the sound insulation interlayer during coextrusion, and there was a thickness error. If there was a thickness error in the width direction, the sound insulation performance of each area would fluctuate, making it difficult to fully improve the sound insulation performance of the interlayer as a whole.

[0009] Therefore, an object of the present invention is to provide an interlayer film for laminated glass that can suppress the variation in sound insulation performance in each region and thereby sufficiently improve the sound insulation performance.

[0010] Means for solving problems

[0011] As a result of intensive research, the inventors of the present application have found that the above-mentioned problems can be solved by improving the thickness accuracy of the low Tg resin layer during production so that the difference between the maximum and minimum values ​​of the thickness ratio R(x) of the low Tg resin layer to the entire interlayer film for laminated glass is less than a predetermined value, thereby completing the following invention. That is, the present invention provides the following [1] to

[21] .

[0012] [1] An interlayer film for laminated glass comprising two or more resin layers, wherein at least one of the resin layers has a glass transition temperature different from that of the other resin layers,

[0013] When the coordinate on the straight line from one end to the other end is marked as x [mm], the difference between the maximum and minimum values ​​of the thickness ratio R(x) of the low Tg resin layer having the lowest glass transition temperature among the two or more resin layers to the entire interlayer film for laminated glass is less than 8%.

[0014] [2] An interlayer film for laminated glass, which is divided into three equal parts from one end to the other end, wherein the absolute value of the difference between the maximum value and the minimum value of the primary resonance frequency in each region is 50 Hz or less, and the primary resonance frequency is measured by mechanical impedance measurement in accordance with ISO 16940:2008.

[0015] [3] An interlayer film for laminated glass, wherein the interlayer film is divided into three equal parts from one end to the other end, and the absolute value of the difference between the maximum value and the minimum value of the loss coefficient in each region is less than 0.1, wherein the loss coefficient is measured by mechanical impedance measurement in accordance with ISO 16940:2008.

[0016] [4] The interlayer film for laminated glass according to [1] above, wherein the standard deviation of the deviation ΔR(x) of the thickness ratio R(x) with respect to f(x) is 0.1% to 2%.

[0017] (where f(x) is a fitted straight line f(x)=ax+b calculated from the thickness ratio R(x) in the region of x=0.1X to 0.9X and the coordinate x when the total length of the straight line from one end to the other end is recorded as 1.0X. It should be noted that a and b are coefficients)

[0018] [5] The interlayer film for laminated glass according to [2] or [3], comprising two or more resin layers, at least one of the resin layers having a glass transition temperature different from that of the other resin layers,

[0019] The standard deviation of the deviation ΔR(x) of the thickness ratio R(x) with respect to f(x) is 0.1% or more and 2% or less.

[0020] (wherein R(x) is the thickness ratio of the low Tg resin layer having the lowest glass transition temperature among the two or more resin layers to the entire interlayer film for laminated glass when the coordinate on a straight line extending from one end toward the other end of the interlayer film is denoted by x [mm],

[0021] f(x) is a fitted straight line f(x)=ax+b calculated from the thickness ratio R(x) in the region of 0.1X to 0.9X and the coordinate x, when the total length of the straight line from one end to the other end is recorded as 1.0X. It should be noted that a and b are coefficients.)

[0022] [6] The interlayer film for laminated glass according to [1], [4] or [5] above, wherein the difference between the maximum value and the minimum value of the ratio R(x) is greater than 0%.

[0023] [7] The interlayer film for laminated glass according to [1], [4], [5] or [6] above, wherein the thickness ratio R(x) is within a range of 1% to 30%.

[0024] [8] The interlayer film for laminated glass according to any one of [1] to [7], comprising a wedge-shaped portion having a wedge angle of 0.1 mrad or more in cross section.

[0025] [9] The interlayer film for laminated glass according to [8] above, wherein the wedge-shaped portion has a portion where a wedge angle changes.

[0026]

[10] The interlayer film for laminated glass according to any one of [1] to [9], wherein the thickness is different at one end and the other end.

[0027]

[11] An intermediate film for laminated glass according to any one of [1] to

[10] above, comprising two or more resin layers, at least one of which has a glass transition temperature different from that of the other resin layers, and a low Tg resin layer having the lowest glass transition temperature among the two or more resin layers being arranged in a manner deviating from the center toward any surface side in the thickness direction.

[0028]

[12] An intermediate film for laminated glass according to any one of [1] to

[11] above, comprising two or more resin layers, at least one of which has a glass transition temperature different from that of the other resin layers, and a low Tg resin layer having the lowest glass transition temperature among the two or more resin layers being located at the center in the thickness direction.

[0029]

[13] An intermediate film for laminated glass according to any one of [1] to

[12] above, comprising two or more resin layers, at least one of which has a glass transition temperature different from that of the other resin layers, and two or more low-Tg resin layers, wherein the low-Tg resin layer is the resin layer having the lowest glass transition temperature among the two or more resin layers.

[0030]

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

[13] above, comprising a region containing a colorant.

[0031]

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

[14] , comprising at least one resin layer, wherein any one of the resin layers is a resin layer having a refractive index of 1.46 or more and a glass transition temperature of 15° C. or more.

[0032]

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

[14] , comprising at least one resin layer, wherein at least one surface of the interlayer film for laminated glass has a ten-point average roughness Rzjis94 of 10 μm or more.

[0033]

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

[14] , comprising at least one resin layer, any one of the resin layers being a resin layer having a refractive index of 1.46 or more and a glass transition temperature of 15° C. or more, and

[0034] At least one surface of the interlayer film for laminated glass has a ten-point average roughness Rzjis94 of 10 μm or more.

[0035]

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

[17] above, comprising at least one resin layer, wherein any one of the resin layers contains at least one resin selected from the group consisting of polyvinyl acetal resin and ethylene-vinyl acetate copolymer resin.

[0036]

[19] A method for producing an interlayer film for laminated glass, comprising producing the interlayer film for laminated glass according to any one of [1] to

[18] above by coextrusion.

[0037]

[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 components, wherein the interlayer film for laminated glass is arranged between the pair of laminated glass components.

[0038]

[21] The laminated glass according to

[20] above, wherein the laminated glass member is either bent glass or flat glass.

[0039] Effects of the Invention

[0040] According to the present invention, an interlayer film for laminated glass can be provided which can suppress the variation in sound insulation performance in each region and thus sufficiently improve the sound insulation performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] [ Figure 1 ] is a cross-sectional view showing an example of an intermediate film for laminated glass.

[0042] [ Figure 2 ] is a cross-sectional view showing an example of an intermediate film for laminated glass.

[0043] [ Figure 3 ] is a cross-sectional view showing an example of an intermediate film for laminated glass.

[0044] [ Figure 4 ] is a cross-sectional view showing an example of an intermediate film for laminated glass.

[0045] [ Figure 5 ] is a cross-sectional view showing an example of an intermediate film for laminated glass. DETAILED DESCRIPTION

[0046] Hereinafter, the present invention will be described in more detail using embodiments.

[0047] <Interlayer film for laminated glass>

[0048] In one aspect, the interlayer film for laminated glass of the present invention (hereinafter, also referred to as "interlayer film") comprises two or more resin layers, and at least one resin layer has a glass transition temperature different from that of the other resin layers. It should be noted that in the following description, in the above-mentioned interlayer film, the resin layer having the lowest glass transition temperature among the two or more resin layers is also referred to as "low Tg resin layer".

[0049] <Requirement (A)>

[0050] In one aspect, the interlayer film of the present invention satisfies the following requirement (A).

[0051] Requirement (A): When the coordinates on a straight line extending from one end to the other end are marked as x [mm], the difference between the maximum and minimum values ​​of the thickness ratio R(x) of the low Tg resin layer to the entire interlayer film (hereinafter also referred to as "ΔR(x)") is 8% or less.

[0052] In the interlayer film, when ΔR(x) is greater than 8%, it may be impossible to suppress the variation in the sound insulation performance of each region, and the sound insulation performance of the entire interlayer film may not be sufficiently improved.

[0053] From the viewpoint of improving the sound insulation performance, the above-mentioned ΔR(x) is preferably 7% or less, more preferably 6% or less, further preferably 5% or less, and further preferably 3.5% or less.

[0054] In addition, from the perspective of sound insulation performance, the lower ΔR(x) is, the better, and it can be above 0%. However, from the perspective of being able to produce with practical production efficiency during manufacturing, it is preferably greater than 0%, more preferably above 0.2%, further preferably above 0.4%, and even more preferably above 0.6%.

[0055] It should be noted that in this specification, the direction from one end of the intermediate film toward the other end is called the width direction, and the direction perpendicular to the width direction and the thickness direction of the intermediate film is called the longitudinal direction. Generally, the width direction is the direction consistent with the TD, and the longitudinal direction is the direction consistent with the MD, but there is no particular limitation. It should be noted that MD is the Machine Direction and is the direction consistent with the flow direction of the resin, and TD is the Transverse Direction.

[0056] It should be noted that the thickness of the intermediate film in the longitudinal direction may be substantially uniform. In addition, the intermediate film 10 is stretched and bent when applied to the curved glass described later, and the width direction and the like are also bent. The longitudinal and width directions in the curved intermediate film are bent in accordance with the bending, and the straight line from one end to the other end is also bent.

[0057] In the present invention, the difference between the maximum value and the minimum value of the thickness ratio R(x) can be reduced as described above by adjusting the thickness of the low Tg resin layer according to the thickness of the intermediate film. Specifically, if the thickness of the intermediate film is substantially uniform from one end to the other end, the thickness of the low Tg resin layer can be adjusted so that it is also substantially uniform. In addition, in the case where the thickness of the intermediate film changes from one end to the other end, such as a wedge-shaped intermediate film, the thickness of the low Tg resin layer can also be changed accordingly.

[0058] Generally, a multilayer interlayer film having a low Tg resin layer is formed by coextrusion, but in the case of coextrusion, the resins for each layer are combined in a feed block and extruded from a die (T die) while expanding in the TD (width direction). Here, in the case of a low Tg resin layer, the resin or resin composition of the low Tg resin layer and the resin or resin composition of the high Tg resin layer have different properties such as viscosity, and therefore, due to the difference in properties, when expanding in the width direction, one resin layer enters into another resin layer, which sometimes makes it difficult to make the thickness of the low Tg resin layer uniform in the width direction.

[0059] In the present invention, as described in the manufacturing method described later, after confirming the thickness of each resin layer actually obtained, the gap at each coordinate in the width direction (TD) can be adjusted at any position of the flow path such as the slit for each resin layer in the feed block or the multilayer mold, thereby adjusting the thickness of the low Tg resin layer so that it becomes uniform in accordance with the intermediate film having a uniform thickness. In this way, the thickness ratio R(x) can be reduced in the intermediate film having a substantially uniform thickness along the width direction.

[0060] Furthermore, in the case where the thickness of the interlayer varies as in the case of a wedge-shaped interlayer, the gap at each coordinate in the width direction (TD) can be adjusted at any portion of the flow path such as the slits for each resin layer in the feed block or the multilayer mold after confirming the thickness of each resin layer actually obtained, thereby finely varying the thickness of the low Tg resin layer in accordance with the thickness variation of the interlayer. Therefore, even in an interlayer whose thickness varies in the width direction, the thickness ratio R(x) can be reduced.

[0061] It should be noted that in the present invention, ΔR(x) can be measured as follows. That is, the thickness of the entire interlayer film for laminated glass and the thickness of the low Tg resin layer at each coordinate x [mm] from one end to the other end in the width direction are obtained at intervals of 5 cm, and the thickness ratio R(x) at each coordinate x [mm] is obtained. Then, the largest value among all the obtained thickness ratios R(x) is taken as the maximum value of the thickness ratio R(x), and the smallest value is taken as the minimum value of the thickness ratio R(x), and the difference between the maximum value and the minimum value is obtained, thereby ΔR(x) can be obtained.

[0062] Here, the thickness ratio R(x) is the ratio of the thickness of the low Tg resin layer to the thickness of the entire intermediate film expressed as a percentage. When there are two or more low Tg resin layers, the so-called "thickness of the low Tg resin layer" is the total thickness of all low Tg resin layers.

[0063] The thickness can be measured at any position in the longitudinal direction of the intermediate film, for example, at a position corresponding to the center position in the longitudinal direction.

[0064] The thickness data can be measured using a microscope. The thickness data of each resin layer, such as the thickness of the high Tg resin layer and the thickness data of the low Tg resin layer, can be measured using a microscope (e.g., a microscope "DSX500" manufactured by Orinpass or its equivalent). Specifically, the interlayer is cut in a direction perpendicular to the straight line from one end to the other end, thereby cutting out a cross section in the thickness direction at each coordinate x [mm]. The cross section is observed using a microscope, the boundary of each resin layer is determined, and the thickness of each resin layer at each coordinate x [mm] is calculated.

[0065] The thickness of the entire interlayer film can be obtained from the total thickness of all resin layers.

[0066] Among them, the calculation of the wedge angle described later can be implemented based on the thickness of the entire intermediate film measured and obtained using a known thickness measuring machine. As a thickness measuring machine used in the measurement of the thickness of the entire intermediate film, a contact thickness gauge measuring machine "TOF-4R" (manufactured by Yamamoto Electric Co., Ltd.) and the like can be cited. When using TOF-4R, the thickness is measured in the width direction at a conveying speed of 1 to 3 m / min. In addition, as a thickness measuring machine for the intermediate film after the above-mentioned intermediate film is made into laminated glass, a non-contact multilayer film measuring machine "OPTIGAUGE" (manufactured by Lumetriks Co., Ltd.) and the like can be cited.

[0067] In the present invention, when the requirement (A) is satisfied, the thickness ratio R(x) is preferably within a range of 1% or more and 30% or less. If the thickness ratio R(x) is 1% or more, sufficient sound insulation performance can be imparted to the interlayer film. In addition, if the thickness ratio R(x) is 30% or less, the interlayer film contains a resin layer other than the low Tg resin layer at a certain thickness or more, so that the penetration resistance, workability, mechanical strength, adhesion to the laminated glass member, etc. of the interlayer film can be improved. Therefore, it can be suitably used as an interlayer film for laminated glass.

[0068] From the viewpoint of sound insulation performance, the thickness ratio R(x) is more preferably 3% or more, more preferably 5% or more, more preferably 7% or more, more preferably 8% or more, more preferably 9% or more, and more preferably 10% or more. From the viewpoint of penetration resistance, operability, mechanical strength, etc., the thickness ratio R(x) is more preferably 28% or less, more preferably 26% or less, more preferably 24% or less, more preferably 22% or less, and more preferably 20% or less.

[0069] The above lower limit value and upper limit value may be any combination.

[0070] It should be noted that the phrase "the thickness ratio R(x) is within a predetermined range" means that both the maximum value and the minimum value of the thickness ratio R(x) are within the predetermined range.

[0071] <Requirement (B)>

[0072] In another aspect, the interlayer film of the present invention satisfies the following requirement (B).

[0073] Requirement (B): The absolute value of the difference between the maximum and minimum values ​​of the primary resonance frequency in each region divided into three equal parts from one end to the other end (hereinafter also referred to as "ΔPR") is less than 50 Hz, and the primary resonance frequency is measured by mechanical impedance measurement (MIM) in accordance with ISO16940:2008.

[0074] In the interlayer film, when ΔPR is larger than 50 Hz, it may be impossible to suppress the variation in the sound insulation performance of each region, and the sound insulation performance of the entire interlayer film may not be sufficiently improved.

[0075] From the viewpoint of sound insulation performance, the ΔPR is preferably 35 Hz or less, preferably 25 Hz or less, more preferably 20 Hz or less, further preferably 15 Hz or less, and further preferably 10 Hz or less.

[0076] In addition, from the perspective of sound insulation performance, the lower the ΔPR, the better, and it can be above 0 Hz. However, from the perspective of being able to produce with practical production efficiency during manufacturing, it is preferably greater than 0 Hz, more preferably above 0.1 Hz, more preferably above 0.5 Hz, further preferably above 1 Hz, and further preferably above 2 Hz.

[0077] ΔPR can be reduced by reducing the difference between the maximum and minimum values ​​of the thickness ratio R(x) of the low Tg resin layer in the interlayer film, and can be further reduced easily by reducing the standard deviation of the thickness ratio R(x) described later.

[0078] When the requirement (B) is satisfied, the primary resonance frequency may be, for example, within the range of 50 Hz to 250 Hz, preferably within the range of 75 Hz to 225 Hz, and more preferably within the range of 100 Hz to 200 Hz. If the primary resonance frequency is within a certain range, it is easy to properly exert the sound insulation performance. It should be noted that the so-called primary resonance frequency within the prescribed range means that the primary resonance frequencies measured by dividing the sound into three equal parts are all within the prescribed range.

[0079] It should be noted that the mechanical impedance measurement (MIM) in the above requirement (B) and the later-described requirement (C) is obtained by measuring the laminated glass produced by bonding two transparent glass plates via an interlayer according to ISO 16940:2008. In addition, the interlayer can be divided into three equal parts from one end to the other end (i.e., in the width direction), and the primary resonance frequency and loss factor in each area can be measured, and the absolute value of the difference between the maximum value and the minimum value of the measured primary resonance frequency and loss factor can be obtained. It should be noted that, regarding the transparent glass plates used in the mechanical impedance measurement, two transparent float glasses with a thickness of 2.0 mm, a width of 25 mm, and a length of 300 mm according to JIS R3202 are prepared.

[0080] The laminated glass used in the measurement can be produced as follows.

[0081] The intermediate film is sandwiched between two sheets of transparent float glass to obtain a laminate. The laminate is placed in a rubber bag and degassed at a vacuum degree of 2.6 kPa for 20 minutes. Then, it is moved into an oven in a degassed state, and further maintained at 90°C for 30 minutes, and vacuum pressurized to pre-press the laminate. Then, in an autoclave, the pre-pressed laminate is pressed for 20 minutes at 135°C and a pressure of 1.2 MPa to obtain a laminated glass. The obtained laminated glass is then left to stand in a room at 23°C and 30 RH% for 8 weeks. Mechanical impedance measurement (MIM) can be measured by the method described in the examples.

[0082] The primary resonance frequency and loss factor obtained by the above-mentioned measurement method are respectively regarded as the primary resonance frequency and loss factor of the interlayer film for laminated glass of the present invention.

[0083] <Requirement (C)>

[0084] In still another aspect, the interlayer film of the present invention satisfies the following requirement (C).

[0085] Requirement (C): The absolute value of the difference between the maximum and minimum values ​​of the loss coefficient (primary loss coefficient) in each area divided into three equal parts from one end to the other end (hereinafter also referred to as "ΔLF") is less than 0.1, and the loss coefficient is measured by mechanical impedance measurement (MIM) in accordance with ISO16940:2008.

[0086] In the interlayer film, when ΔLF is larger than 0.1, it may be impossible to suppress the variation in the sound insulation performance of each region, and the sound insulation performance of the interlayer film as a whole may not be sufficiently improved.

[0087] From the viewpoint of sound insulation performance, the above ΔLF is preferably 0.09 or less, more preferably 0.035 or less, further preferably 0.025 or less, and further preferably 0.015 or less.

[0088] In addition, from the perspective of sound insulation performance, ΔLF is as low as possible and can be greater than 0. However, from the perspective of enabling production with practical production efficiency during manufacturing, it is preferably greater than 0, more preferably greater than 0.001, further preferably greater than 0.002, and even more preferably greater than 0.003.

[0089] ΔLF can be reduced by reducing the difference between the maximum and minimum values ​​of the thickness ratio R(x) of the low Tg resin layer in the intermediate film, and can be further reduced easily by reducing the standard deviation of the thickness ratio R(x) described later.

[0090] When the requirement (C) is met, the above loss coefficient can be, for example, in the range of 0.15 to 0.50, preferably in the range of 0.2 to 0.45, and more preferably in the range of 0.24 to 0.40. If the primary resonance frequency is within a certain range, it is easy to properly exert the sound insulation performance. It should be noted that the so-called primary resonance frequency is within the prescribed range, which means that the primary resonance frequencies measured by three equal divisions are all within the prescribed range.

[0091] The interlayer film of the present invention may satisfy any one of the above requirements (A), (B), and (C), but preferably satisfies at least two of the requirements (A), (B), and (C). That is, it is preferred to satisfy both requirements (A) and (B), both requirements (A) and (C), or any one of the requirements (C) and (A). In addition, from the viewpoint of sound insulation performance, the interlayer film of the present invention more preferably satisfies all of the requirements (A), (B), and (C).

[0092] It should be noted that, when the interlayer film of the present invention satisfies at least one of the requirements (B) and (C), it is not necessary to provide two resin layers having different glass transition temperatures, it may include only one resin layer, or it may include two or more resin layers having the same glass transition temperature. In this case, one or more resin layers may be composed of the same material and performance as the resin layer used as the low Tg resin layer described later.

[0093] [Standard Deviation]

[0094] In the present invention, the standard deviation of the deviation ΔR(x) of the thickness ratio R(x) with respect to f(x) is preferably 0.1% or more and 2% or less.

[0095] f(x) can be obtained as follows.

[0096] First, the thickness ratio R(x) and the coordinate x are plotted as the Y-axis and the X-axis, respectively. Next, when the total length of the straight line from one end to the other end is recorded as 1.0X, the fitting linear straight line f(x)=ax+b is calculated by plotting the thickness ratio R(x) and the coordinate x in the region of x=0.1X~0.9X. It should be noted that a and b are coefficients, and the unit of the coordinate x is mm. In addition, the fitting linear straight line is obtained by the least squares method.

[0097] Here, the standard deviation represents the fluctuation of the thickness ratio R(x). If the standard deviation is 2% or less, the fluctuation of the thickness ratio R(x) is sufficiently reduced, and the sound insulation performance can be further improved. From the viewpoint of sound insulation performance, the standard deviation is more preferably 1.5% or less, more preferably 1.2% or less, and even more preferably 1%.

[0098] In addition, when the standard deviation is 0.1% or more, it is possible to prevent fluctuations from being suppressed more than necessary, and it is easy to improve production efficiency. From such a viewpoint, the standard deviation is more preferably 0.2% or more, and even more preferably 0.3% or more.

[0099] It should be noted that, in the above f(x), from the viewpoint of sound insulation performance, the absolute value of the value of a is preferably below a certain value, for example, below 12, preferably below 8, more preferably below 5.5, and further preferably below 2.5. The absolute value of the value of a may be above 0, but from the viewpoint of production efficiency, it may be above a certain value, for example, above 0.1, or above 0.2.

[0100] [Low Tg resin layer and high Tg resin layer]

[0101] In the present invention, the low Tg resin layer is a resin layer having the lowest glass transition temperature among two or more resin layers. The glass transition temperature of the low Tg resin layer is preferably lower than 15°C. By making the glass transition temperature of the low Tg resin layer lower than 15°C, it is easy to further improve the sound insulation performance of the intermediate film. 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 further preferably 0°C or less. In addition, the glass transition temperature of the second resin layer is not particularly limited, but from the viewpoint of making the mechanical properties such as the flexural rigidity of the intermediate film good, it is preferably above -20°C, and more preferably above -12°C.

[0102] In the present invention, the two or more resin layers contained in the interlayer film include a resin layer having a glass transition temperature higher than that of the low Tg resin layer (hereinafter also referred to as a “high Tg resin layer”).

[0103] The glass transition temperature of the high Tg resin layer is preferably 15° C. or higher. When the interlayer film has a high Tg resin layer having a glass transition temperature of 15° C. or higher, the penetration resistance, handling properties, mechanical properties, etc. of the interlayer film are easily improved, and the interlayer film can be suitably used as an interlayer film for laminated glass.

[0104] The glass transition temperature of the high Tg resin layer is preferably 20° C. or higher, more preferably 25° C. or higher, and is, for example, 80° C. or lower, preferably 60° C. or lower, and more preferably 50° C. or lower.

[0105] The glass transition temperature can be determined by peeling each layer from the interlayer film, preparing a measurement sample from each obtained layer, and measuring the viscoelasticity using a viscoelasticity measuring device by the following method.

[0106] 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 fixture, and the measurement is performed in a shear mode, at a cooling rate of 3°C / min from 100°C to -20°C, at a frequency of 1Hz and a strain of 1%. In the obtained measurement results, the peak temperature of the loss tangent is taken as the glass transition temperature Tg (°C).

[0107] The refractive index of each resin layer (low Tg resin layer and high Tg resin layer) contained in the intermediate film is preferably 1.46 or more, more preferably 1.465 or more, and more preferably 1.47 or more. If the refractive index is 1.46 or more, it is possible to prevent the position of the object viewed through the laminated glass from being offset from the actual position of the object. In terms of the refractive index, it is preferred to suppress the refractive index difference between it and the laminated glass member to be small. From this point of view, it is preferably 1.55 or less, and more preferably 1.53 or less.

[0108] The refractive indexes of the low Tg resin layer and the high Tg resin layer may be the same or different, and it is particularly preferred that the refractive index of the low Tg resin layer is lower than that of the high Tg resin layer.

[0109] [Layer structure of interlayer film]

[0110] The interlayer film may have a low Tg resin layer and a high Tg resin layer as described above, for example, it may be an interlayer film of a double-layer structure including one low Tg resin layer and one high Tg resin layer. In this case, both the high Tg resin layer and the low Tg resin layer may be the surface layer of the interlayer film. It should be noted that the so-called surface layer of the interlayer film becomes a bonding surface to be bonded to the laminated glass member in the laminated glass.

[0111] The interlayer film preferably has two or more layers of either the low Tg resin layer or the high Tg resin layer, and preferably has at least two or more layers of the high Tg resin layer. In addition, a configuration having two or more layers of the low Tg resin layer is also preferred.

[0112] Intermediate films such as Figure 1 As shown, the intermediate film 10A is preferably provided with two high Tg resin layers 12, 12 and one low Tg resin layer 11, wherein the low Tg resin layer 11 is provided between a pair of high Tg resin layers 12, 12. In this case, each high Tg resin layer 12, 12 can constitute the surface layer of the intermediate film and become a bonding surface with the laminated glass member described later.

[0113] In addition, if Figure 2As shown, the intermediate film is also preferably an intermediate film 10B, which has three high Tg resin layers 12 and two low Tg resin layers 11. In the intermediate film 10B, the high Tg resin layer 12, the low Tg resin layer 11, the high Tg resin layer 12, the low Tg resin layer 11 and the high Tg resin layer 12 are sequentially provided, and the high Tg resin layers 12, 12 can constitute the surface layer of the intermediate film.

[0114] Figure 1 , 2 In the interlayer films 10A and 10B shown, the high Tg resin layer 12 constitutes both surface layers of the interlayer film, and thus the interlayer film can be appropriately bonded to a laminated glass member.

[0115] The interlayer film is not limited to the layer structure described above, and may have a layer structure other than the above. Figure 1 , 2 In the embodiment, any one of the high Tg resin layer 12 and the low Tg resin layer 11 may be further provided between any one of the high Tg resin layer 12 and the low Tg resin layer 11. Figure 2 In the configuration, a high Tg resin layer may be further provided between at least one high Tg resin layer 12 and the low Tg resin layer 11 .

[0116] It should be noted that in Figure 1 , 2 In the figure, a method of an intermediate film (hereinafter also referred to as a "uniform film") is shown in which the overall thickness of the intermediate film is substantially uniform from one end 13A to the other end 13B of the intermediate film. However, in the case where the intermediate film is a non-uniform film, such as the case of a wedge-shaped intermediate film described later, the layer structure is the same as the layer structure described above.

[0117] In one embodiment, the intermediate film of the present invention can be an intermediate film (uniform film) with substantially uniform thickness. It should be noted that the so-called "substantially uniform thickness" is intended to include the situation where the thickness varies due to manufacturing errors. Specifically, if the ratio of the minimum value to the maximum value of the thickness (minimum value / maximum value) is greater than 0.93 and is about 1.00 or less, it can be included. It should be noted that the ratio of the minimum value to the maximum value of the above thickness is preferably greater than 0.95 and less than 1.00, preferably greater than 0.97 and less than 1.00, and more preferably greater than 0.98 and less than 1.00.

[0118] The interlayer film of the present invention may also be an interlayer film with uneven thickness, for example, an interlayer film with a thickness at one end different from that at the other end. In an interlayer film with a thickness at one end different from that at the other end, the ratio of the smaller thickness to the larger thickness between the thickness at one end and the thickness at the other end is preferably 0.1 to 0.93, more preferably 0.2 to 0.9, and further preferably 0.4 to 0.85.

[0119] The intermediate film having a thickness at one end different from that at the other end is preferably a wedge-shaped intermediate film. Figure 3 , 4 As shown, the intermediate film has a wedge-shaped cross-section whose thickness changes from one end 13A to the other end 13B.

[0120] [Wedge-shaped interlayer]

[0121] In the wedge-shaped interlayer film, the wedge angle α of the wedge-shaped portion is preferably 0.1 mrad or more. That is, the wedge-shaped interlayer film preferably has a wedge-shaped portion having a wedge angle α of 0.1 mrad or more in cross section. It should be noted that the cross section is parallel to the thickness direction and the width direction.

[0122] If the interlayer film has a wedge-shaped portion with a wedge angle α of 0.1 mrad or more, when used for a head-up display (HUD) as described later, the wedge-shaped portion of the cross section displays the HUD image, thereby easily reducing the reflection ghosting generated when the HUD image is displayed. From the viewpoint of reducing reflection ghosting, the wedge angle α is more preferably 0.12 mrad or more, further preferably 0.3 mrad or more, and further preferably 0.4 mrad or more. In addition, from the viewpoint of suppressing the formation of transmission ghosting due to light passing through the laminated glass, the wedge angle α is preferably set to a certain value or less, for example, 1.2 mrad or less, preferably 1.0 mrad or less, more preferably 0.8 mrad or less, and further preferably 0.6 mrad or less. It should be noted that the most suitable wedge angle α is different depending on the installation angle of the windshield and the viewer's viewpoint height, and can be adjusted to a wedge angle α suitable for various conditions.

[0123] The wedge-shaped interlayer can be Figure 3 As shown in the intermediate film 10C, the entire cross-section from one end 13A to the other end 13B is a wedge-shaped cross-section with a wedge angle of more than 0.1 mrad, or as shown in Figure 4 As shown in the intermediate film 10D, a portion from one end 13A to the other end 13B has a wedge-shaped cross section of 0.1 mrad or more.

[0124] It should be noted that, in the wedge-shaped interlayer film having a portion with a wedge-shaped cross section having a wedge angle of 0.1 mrad or more, the portion corresponding to the area displaying a head-up display (HUD) image when used for the below-described HUD application can be at least the portion with a wedge-shaped cross section having a wedge angle of 0.1 mrad or more.

[0125] When a portion from one end 13A to the other end 13B has a cross-sectional wedge shape of 0.1 mrad or more, the wedge angle α of the other portion may be less than 0.1 mrad, and the portion having substantially uniform thickness may be preferred. However, at least a portion of the other portion may have a cross-sectional wedge shape with a negative wedge angle α. It should be noted that the so-called negative wedge angle α means that the thickness decreases from the one end 13A toward the other end 13B.

[0126] It should be noted that, when a portion from one end 13A to the other end 13B becomes a wedge shape of greater than 0.1 mrad, the proportion of the portion becoming a wedge shape of greater than 0.1 mrad in the entire area from one end to the other end may be, for example, greater than 5% and less than 100%, preferably greater than 10% and less than 100%, more preferably greater than 20% and less than 100%, further preferably greater than 30% and less than 100%, further preferably greater than 50% and less than 100%.

[0127] The wedge-shaped interlayer film may have a portion where the wedge angle changes in at least one of the portions having a wedge-shaped cross section of 0.1 mrad or more. The wedge angle may change within a range of not less than the lower limit and not more than the upper limit.

[0128] When the wedge angle changes, the change can be evaluated to a degree that the difference between the maximum value of the wedge angle α and the minimum value of the wedge angle α substantially changes. Specifically, the difference between the maximum value of the wedge angle α and the minimum value of the wedge angle α may be 0.05 mrad or more and 1.5 mrad or less, preferably 0.1 mrad or more and 1.2 mrad or less, and more preferably 0.2 mrad or more and 1 mrad or less.

[0129] If the wedge-shaped interlayer film has a portion where the wedge angle substantially changes, even when the height position of the driver's eyes changes, for example, the most suitable wedge angle can be selected to suppress double reflections corresponding to each position. In addition, double reflections can be effectively suppressed for HUDs that display two or more images with different focal lengths, such as dual HUDs.

[0130] In addition, the wedge angle may change only to the extent of manufacturing error, but in such a case, it can be said that the wedge angle is substantially constant, for example, it can be changed within a range smaller than the above-mentioned lower limit.

[0131] It should be noted that, in this specification, the wedge angle α is a wedge angle measured by the following method.

[0132] After obtaining thickness data at intervals of 1 mm along the width direction using a thickness measuring machine, the thickness data is used as the vertical axis (y-axis), and the coordinates of the position along the width direction that makes one end 13A 0 are used as the horizontal axis (x-axis). At this time, in the area between the 41st point in the direction from one end 13A toward the other end 13B and the 41st point in the direction from the other end 13B toward the one end 13A, for a width of 80 mm centered on each point (= 81 points), a first-order fitting straight line is calculated based on the least squares method, and the angle formed by the first-order fitting straight line and the straight line of y=0 is used as the wedge angle at each position. It should be noted that the thickness measuring machine can use the thickness measuring machine exemplified above.

[0133] The thickness of the wedge-shaped intermediate film may increase from one end 13A toward the other end 13B as described above. Figure 3 , 4 As shown in the interlayer films 10C and 10D of the embodiment shown in FIG. 1 , the thickness of the low Tg resin layer 11 may also increase from one end 13A toward the other end 13B in accordance with the change in thickness of the interlayer film. If the thickness of the low Tg resin layer 11 is changed from one end 13A to the other end 13B in accordance with the change in thickness of the wedge-shaped interlayer film, even if the interlayer film is a wedge-shaped interlayer film, the value of ΔR(x) can be reduced, and the standard deviation can also be reduced.

[0134] [Position of low Tg resin layer in thickness direction]

[0135] In the intermediate film, the low Tg resin layer 11 may be, for example, Figure 1 As shown in FIG. 1 , the low Tg resin layer 11 is present at the center C in the thickness direction of the intermediate film. If the low Tg resin layer 11 is present at the center in the thickness direction, for example, Figure 1 The three-layer structure of the intermediate film 10A shown is symmetrical with the low Tg resin layer 11 as the center, so the production efficiency is improved. In addition, the thickness of the resin layer, that is, the high Tg resin layer 12, which exists on both sides can be maximized, so there is also an advantage that optical distortion is improved. Here, the so-called optical distortion refers to the distortion of the scenery when observing the scenery through the laminated glass using the above-mentioned intermediate film. It should be noted that when there are multiple low Tg resin layers, any one low Tg resin layer can exist in the center in the thickness direction.

[0136] In the interlayer film, the low Tg resin layer 11 may be arranged offset from the center to one of the surfaces in the thickness direction. If the low Tg resin layer 11 is arranged offset from the center position, there is an advantage that the sound insulation performance can be adjusted.

[0137] It should be noted that the so-called low Tg resin layer 11 is arranged offset from the center position, such as Figure 5 As shown in FIG. 1 , when the interlayer film has one low Tg resin layer 11, the center of the low Tg resin layer 11 is offset from the center C in the thickness direction. In addition, the so-called offset arrangement means that when there are multiple low Tg resin layers, for example, Figure 2 As shown, all low Tg resin layers are offset from the center C.

[0138] It should be noted that in this specification, whether the low Tg resin layer is present at the center in the thickness direction or is arranged to be offset from the center to any of the surfaces can be determined as follows: when the thickness of the entire interlayer film is taken as 100%, the distance X in the thickness direction from one surface of the interlayer film to the center of the low Tg resin layer is calculated as a ratio (%). If the distance X is 50%, it can be said that the low Tg resin layer is present at the center in the thickness direction, and if the distance X is 49% or less, it can be said that it is arranged to be offset from the center to any of the surfaces in the thickness direction.

[0139] It should be noted that the distance X can be calculated as follows: the value obtained by adding 50% of the average thickness of the low Tg resin layer to the total average thickness of all layers located on one surface side from a predetermined low Tg resin layer is calculated, and the ratio (%) of this value to the average thickness of the entire interlayer film is calculated. The ratio (%) can be rounded off to an integer value. In addition, when the distances from the low Tg resin layer to the two surfaces are different, the closer of the two surfaces can be regarded as the above-mentioned "one surface" in such a way that the ratio (%) does not exceed 50%.

[0140] The above distance X can also be said to be an index indicating the amount of deviation from the center position. The smaller it is compared to 50%, the greater the amount of deviation. The distance X when the low Tg resin layer deviates from the center in the thickness direction is not particularly limited, for example, it can be 5% or more and 49% or less, but it is preferably 10% or more and 40% or less. By making the distance X above the above lower limit, it is possible to prevent the low Tg resin layer from being arranged near the surface layer of the intermediate film. In addition, by setting it to less than 40%, it is easy to exert the effect obtained by arranging the low Tg resin layer to deviate from the center. It should be noted that in the case of having more than two low Tg resin layers, the distance X of all low Tg resin layers can be within the above range, but the distance X of at least one low Tg resin layer can also be within the above range. That is, one low Tg resin layer can be present at the center position in the thickness direction, and the other low Tg resin layers can be arranged to deviate from the center position in the thickness direction at the above distance X.

[0141] [Material of interlayer film]

[0142] As described above, the interlayer film of the present invention is formed of a plurality of resin layers. The resin constituting each resin layer is preferably a thermoplastic resin. By using a thermoplastic resin in each resin layer of the interlayer film, the laminated glass components can be easily bonded via the interlayer film by thermocompression bonding.

[0143] Examples of the thermoplastic resin used for the intermediate film include (meth)acrylic resins, polyvinyl acetal resins, polyvinyl alcohol resins (PVA), polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), ethylene-vinyl acetate copolymer saponified products (EVOH), ethylene-methacrylic acid copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, and styrene-butadiene copolymer resins.

[0144] Among the above, from the viewpoint of easy adjustment of the glass transition temperature and exerting sound insulation performance, the thermoplastic resin is preferably an ethylene-vinyl acetate copolymer resin, a polyvinyl acetal resin, and a (meth) acrylic resin, and more preferably an ethylene-vinyl acetate copolymer resin and a polyvinyl acetal resin, and among them, a polyvinyl acetal resin is further preferred. By using a polyvinyl acetal resin, it is easy to make the impact resistance of the laminated glass excellent and the adhesion to the laminated glass member good.

[0145] In each resin layer, the thermoplastic resin can be used alone or in combination with more than two kinds. In addition, when a plurality of resin layers are provided, the thermoplastic resin of each resin layer can be used with the same resin of the same kind, or with different kinds of resins, but preferably with the same resin of the same kind.

[0146] Therefore, the resins used for each low Tg resin layer and high Tg resin layer in the intermediate film are preferably ethylene-vinyl acetate copolymer resin, polyvinyl acetal resin or (meth) acrylic resin, more preferably polyvinyl acetal resin or ethylene-vinyl acetate copolymer resin, and further preferably polyvinyl acetal resin.

[0147] (Polyvinyl acetal resin)

[0148] The following describes the details of the polyvinyl acetal resin used in each resin layer. It should be noted that in the following description, the common structure of the polyvinyl acetal resin used in each resin layer is simply described as "polyvinyl acetal resin". The individual structure of the polyvinyl acetal resin used in the low Tg resin layer is described as "polyvinyl acetal resin (1)", and the individual structure of the polyvinyl acetal resin used in the high Tg resin layer is described as "polyvinyl acetal resin (2)".

[0149] Similarly, the thermoplastic resin used for the low Tg resin layer may be described as "thermoplastic resin (1)", and the thermoplastic resin used for the high Tg resin layer may be described as "thermoplastic resin (2)".

[0150] The polyvinyl acetal resin is not particularly limited as long as it is a polyvinyl acetal resin obtained by acetalizing polyvinyl alcohol with an aldehyde. It should be noted that in the following description, the polyvinyl alcohol used to obtain the polyvinyl acetal resin is sometimes described as PVA, and the PVA used to obtain the polyvinyl acetal resins (1) and (2) are described as PVA (1) and (2), respectively.

[0151] The average degree of polymerization of PVA is preferably 200 or more, more preferably 500 or more, further preferably 1000 or more, and further preferably 1500 or more. If the average degree of polymerization is above the lower limit, the penetration resistance of the laminated glass becomes higher. In addition, the average degree of polymerization of PVA is preferably 5000 or less, more preferably 4000 or less, and further preferably 3500 or less. If the above average degree of polymerization is below the upper limit, the molding of the interlayer film becomes easier.

[0152] In addition, it is preferred that the average degree of polymerization of PVA (1) is higher, and it is preferred that the average degree of polymerization of PVA (2) is lower. Therefore, it is preferred that the average degree of polymerization of PVA (1) is higher than the average degree of polymerization of PVA (2), and in this case, the difference between the average degree of polymerization of PVA (1) and the average degree of polymerization of PVA (2) is, for example, 100 or more and 1800 or less, preferably 200 or more and 1600 or less, and more preferably 400 or more and 1500 or less.

[0153] The average degree of polymerization of PVA (1) is preferably 2000 or more, more preferably 2100 or more. On the other hand, the average degree of polymerization of PVA (2) is preferably 2500 or less, more preferably 1900 or less.

[0154] The average degree of polymerization of polyvinyl alcohol can be determined by a method in accordance with JIS K6726 "Testing methods for polyvinyl alcohol".

[0155] The aldehyde is not particularly limited, and aldehydes having 1 to 10 carbon atoms are generally suitable. The aldehyde having 1 to 10 carbon atoms is not particularly limited, and examples thereof include n-butyl aldehyde, isobutyl aldehyde, n-pentyl aldehyde, 2-ethylbutyl aldehyde, n-hexyl aldehyde, n-octyl aldehyde, n-nonyl aldehyde, n-decyl aldehyde, formaldehyde, acetaldehyde, benzaldehyde, etc. These aldehydes may be used alone or in combination of two or more.

[0156] The number of carbon atoms in the acetal group contained in the polyvinyl acetal resin is not particularly limited, but is preferably 1 to 10, more preferably 3 to 5, further preferably 4 or 5, and particularly preferably 4. In addition, as a specific aldehyde, among the above, n-butyl aldehyde, n-hexyl aldehyde, and n-pentyl aldehyde are preferred, and n-butyl aldehyde is more preferred. Therefore, the polyvinyl acetal resin is preferably a polyvinyl butyral resin, and the polyvinyl acetal resins (1) and (2) are both polyvinyl butyral resins.

[0157] The polyvinyl acetal resin generally has an acetal group, a hydroxyl group, and an acetyl group in a side chain. The hydroxyl content (hydroxyl amount) of the polyvinyl acetal resin is, for example, 17 mol % to 38 mol %, preferably 20 mol % to 36 mol %.

[0158] The degree of acetalization of the polyvinyl acetal resin is, for example, 42 mol % or more and 85 mol % or less, and preferably 55 mol % or more and 80 mol % or less.

[0159] The degree of acetylation (the amount of acetyl groups) of the polyvinyl acetal resin is, for example, 0.01 mol % to 30 mol %, or preferably 0.1 mol % to 25 mol %.

[0160] To explain in more detail, the hydroxyl content (hydroxyl amount) of the polyvinyl acetal resin (1) used for the low Tg resin layer is preferably 17 mol% or more, more preferably 20 mol% or more, and, for example, 38 mol% or less, preferably 34 mol% or less. If the hydroxyl content is set to be above the lower limit, the adhesive force of the interlayer film will be further improved. In addition, from the viewpoint that the polyvinyl acetal resin (1) absorbs plasticizers and improves the sound insulation of laminated glass, it is more preferably 30 mol% or less, and further preferably 27 mol% or less. In addition, if the hydroxyl content of the polyvinyl acetal resin (1) is set to be 20 mol% or more, the reaction efficiency is high and the productivity is excellent.

[0161] The respective contents of hydroxyl groups of the polyvinyl acetal resin (polyvinyl acetal resin (2)) used for the high Tg resin layer are, for example, 20 mol% or more, preferably 25 mol% or more, and more preferably 28 mol% or more. If the above-mentioned hydroxyl content is set to be above the lower limit, the sound insulation can be maintained and the bending rigidity can be made higher. In addition, the respective contents of hydroxyl groups of the polyvinyl acetal resin (2) are preferably 38 mol% or less, more preferably 36 mol% or less, and further preferably 34 mol% or less. If the above-mentioned hydroxyl content is set to be below the above-mentioned upper limit, the polyvinyl acetal resin is easily precipitated during the synthesis of the polyvinyl acetal resin.

[0162] From the viewpoint of further improving the sound insulating property, the hydroxyl content of the polyvinyl acetal resin (1) is preferably lower than the hydroxyl content of the polyvinyl acetal resin (2).

[0163] When the content of hydroxyl groups of the polyvinyl acetal resin (1) is lower than the content of hydroxyl groups of the polyvinyl acetal resin (2), the absolute value of the difference in the content is, for example, 0.5 mol% or more, preferably 1 mol% or more. Thus, the sound insulation can be further improved. From such a viewpoint, the absolute value of the difference in the content of the hydroxyl groups is more preferably 3 mol% or more, and more preferably 5 mol% or more. In addition, the absolute value of the difference in the content of each hydroxyl group is preferably 20 mol% or less, and more preferably 10 mol% or less.

[0164] The hydroxyl content of the polyvinyl acetal resin is a value expressed as a percentage by dividing the amount of ethylene groups to which hydroxyl groups are bonded by the total amount of ethylene groups in the main chain. The amount of ethylene groups to which hydroxyl groups are bonded can be measured, for example, in accordance with JIS K6728 "Testing methods for polyvinyl butyral".

[0165] The acetalization degree of the polyvinyl acetal resin (1) used for the low Tg resin layer is preferably 47 mol% or more, more preferably 55 mol% or more, and further preferably 60 mol% or more. In addition, it is preferably 85 mol% or less, more preferably 80 mol% or less, and further preferably 75 mol% or less. If the above-mentioned acetalization degree is above the above-mentioned lower limit, the compatibility of the polyvinyl acetal resin (1) with the plasticizer becomes higher. If the acetalization degree of the polyvinyl acetal resin (1) is below the above-mentioned upper limit, the amount of residual aldehyde in the resin can be reduced. It should be noted that the so-called acetalization degree refers to the butyralization degree when the acetal group is a butyral group and the polyvinyl acetal resin (1) is a polyvinyl butyral resin.

[0166] The degree of acetalization (butyralization degree in the case of polyvinyl butyral resin) of the polyvinyl acetal resin (2) used for the high Tg resin layer is, for example, 42 mol% or more, preferably 55 mol% or more, more preferably 60 mol% or more, and further preferably 63 mol% or more. In addition, it is preferably 85 mol% or less, more preferably 80 mol% or less, and further preferably 75 mol% or less. If the above-mentioned degree of acetalization is above the above-mentioned lower limit, the compatibility of the polyvinyl acetal resin with the plasticizer becomes high. If the above-mentioned degree of acetalization is below the above-mentioned upper limit, the amount of residual aldehyde in the resin can be reduced.

[0167] The above-mentioned degree of acetalization is a value obtained by subtracting the amount of ethylene groups bonded with hydroxyl groups and the amount of ethylene groups bonded with acetyl groups from the total amount of ethylene groups in the main chain and dividing the obtained value by the total amount of ethylene groups in the main chain to obtain a molar fraction expressed as a percentage. The degree of acetalization (degree of butyralization) can be calculated from the results measured by a method in accordance with JIS K6728 "Testing methods for polyvinyl butyral".

[0168] The acetylation degree (acetyl group amount) of the polyvinyl acetal resin (1) used for the low Tg resin layer is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more. In addition, from the viewpoint that the compatibility of the polyvinyl acetal resin with the plasticizer is improved and a large amount of plasticizer can be easily mixed, the acetylation degree is more preferably 7 mol% or more, and particularly preferably 9 mol% or more. In addition, the acetylation degree of the polyvinyl acetal resin (1) is preferably 30 mol% or less, more preferably 25 mol% or less, further preferably 24 mol% or less, and further preferably 20 mol% or less. If the acetylation degree is set below the upper limit, the moisture resistance of the intermediate film and the laminated glass becomes higher.

[0169] The degree of acetylation of the polyvinyl acetal resin (2) used in the high Tg resin layer is preferably 15 mol% or less, more preferably 10 mol% or less, and further preferably 2 mol% or less. When the degree of acetylation is below the upper limit, the moisture resistance of the interlayer film and the laminated glass becomes high. In addition, the degree of acetylation of the polyvinyl acetal resin (2) is not particularly limited, but is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more.

[0170] The acetylation degree is a value expressed as a percentage of the molar fraction obtained by dividing the amount of ethylene groups bonded with acetyl groups by the total amount of ethylene groups in the main chain. The amount of ethylene groups bonded with acetyl groups can be measured, for example, in accordance with JIS K6728 "Testing methods for polyvinyl butyral".

[0171] Typically, the polyvinyl acetal resin may be an unmodified polyvinyl acetal resin, but may also be a modified polyvinyl acetal resin.

[0172] The modified polyvinyl acetal resin has a structure (modified group) other than an acetal group, a hydroxyl group and an acetyl group, and preferably has a modified group in a side chain. Examples of the modified group include a resin having a polyoxyalkylene structure in a side chain, and a resin having an alkyl group (e.g., having 2 to 30 carbon atoms) other than an acetal group and an acetyl group in a side chain.

[0173] (ethylene-vinyl acetate copolymer resin)

[0174] The ethylene-vinyl acetate copolymer resin used in each resin layer may be a non-crosslinked ethylene-vinyl acetate copolymer resin or a high temperature crosslinked ethylene-vinyl acetate copolymer resin. In addition, as the ethylene-vinyl acetate copolymer resin, a modified ethylene-vinyl acetate resin such as an ethylene-vinyl acetate copolymer saponified product or an ethylene-vinyl acetate hydrolyzate may be used.

[0175] The vinyl acetate content of the ethylene-vinyl acetate copolymer resin is preferably 10% by mass or more and 50% by mass or less, as measured in accordance with JIS K 6730 "Testing methods for ethylene-vinyl acetate resins". When the vinyl acetate content is greater than or equal to these lower limits, the adhesion to a glass plate or the like becomes good, and the penetration resistance of the laminated glass tends to become good. In addition, when the vinyl acetate content is less than or equal to these upper limits, the fracture strength of the interlayer film becomes high, and the impact resistance of the laminated glass becomes good.

[0176] The glass transition temperature of the resin layer containing the ethylene-vinyl acetate copolymer resin can be adjusted by, for example, the vinyl acetate content.

[0177] (Plasticizer)

[0178] Each resin layer may further contain a plasticizer when the resin used is a thermoplastic resin. By containing a plasticizer in the resin layer, the intermediate film becomes soft, and as a result, the laminated glass also becomes soft. In addition, when the laminated glass component is an inorganic glass, the adhesion to the laminated glass component can be improved. When polyvinyl acetal resin is used as the thermoplastic resin, it is particularly effective to contain a plasticizer in the resin layer containing the thermoplastic resin. Therefore, the low Tg resin layer preferably contains a plasticizer in addition to the polyvinyl acetal resin. In addition, the high Tg resin layer also preferably contains a plasticizer in addition to the polyvinyl acetal resin.

[0179] The following describes the details of the plasticizers used in each resin layer. It should be noted that in the following description, the plasticizers used in each resin layer are collectively described, but the plasticizer used in the low Tg resin layer is sometimes referred to as plasticizer (1). In addition, the plasticizer used in the high Tg resin layer is sometimes referred to as plasticizer (2).

[0180] As plasticizers used for each resin layer, for example, organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, and phosphorus plasticizers such as organic phosphate plasticizers and organic phosphite plasticizers can be cited. Among them, organic ester plasticizers are preferred. The above plasticizers are preferably liquid plasticizers. It should be noted that the so-called liquid plasticizer is a plasticizer that is liquid at room temperature (23° C.) and normal pressure (1 atmosphere).

[0181] As monobasic organic acid esters, esters formed by diols and monobasic organic acids can be mentioned. As diols, polyalkylene glycols in which each alkylene unit has 2 to 4 carbon atoms (preferably 2 or 3 carbon atoms) and the number of repeating alkylene units is 2 to 10 (preferably 2 to 4). In addition, as diols, monoalkylene glycols in which the number of carbon atoms is 2 to 4 (preferably 2 or 3 carbon atoms) and the number of repeating units is 1 can also be mentioned.

[0182] Specific examples of the diol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, and butylene glycol.

[0183] Examples of the monobasic organic acid include organic acids having 3 to 10 carbon atoms, and specific examples thereof include butyric acid, isobutyric acid, hexanoic acid, 2-ethylbutyric acid, 2-ethylpentanoic acid, heptanoic acid, n-octanoic acid, 2-ethylhexanoic acid, n-nonanoic acid, and decanoic acid.

[0184] Preferred monobasic organic acid esters include compounds represented by the following formula (1).

[0185]

[0186] In the above formula (1), R1 and R2 each represent an organic group having 2 to 10 carbon atoms, R3 represents an ethylene group, an isopropylene group or an n-propylene group, and p represents an integer of 3 to 10. In the above formula (1), R1 and R2 each preferably have 5 to 10 carbon atoms, more preferably 6 to 10 carbon atoms. The organic groups of R1 and R2 are preferably hydrocarbon groups, more preferably alkyl groups.

[0187] Specific examples of the glycol esters include ethylene glycol di-2-ethylbutyrate, 1,2-propylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, 1,2-butylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylbutyrate, diethylene glycol dioctanoate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dioctanoate, triethylene glycol di-2-ethylvalerate, triethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpropionate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, and tetraethylene glycol di-2-ethylbutyrate.

[0188] Examples of polybasic organic acid esters include ester compounds formed by dibasic organic acids having 4 to 12 carbon atoms, such as adipic acid, sebacic acid, and azelaic acid, and alcohols having 4 to 10 carbon atoms. The alcohols having 4 to 10 carbon atoms may have a linear, branched, or cyclic structure.

[0189] Specifically, dibutyl sebacate, dioctyl azelate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, di-(2-butoxyethyl) adipate, dibutyl carbitol adipate, mixed adipate, etc. may be mentioned. In addition, oil-modified sebacic acid alkyd resin, etc. may be mentioned. As mixed adipate, adipate made from two or more alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms may be mentioned.

[0190] Examples of the organic phosphoric acid plasticizer include phosphoric acid esters such as tributoxyethyl phosphate, isodecylphenyl phosphate, and triisopropyl phosphate.

[0191] The plasticizer may be used alone or in combination of two or more.

[0192] Among the above, the plasticizer is preferably selected from di-(2-butoxyethyl) adipate (DBEA), triethylene glycol di-2-ethylhexanoate (3GO), triethylene glycol di-2-ethylbutyrate (3GH) and triethylene glycol di-2-ethylpropionate, more preferably selected from triethylene glycol di-2-ethylhexanoate (3GO), triethylene glycol di-2-ethylbutyrate (3GH) and triethylene glycol di-2-ethylpropionate, further preferably selected from triethylene glycol di-2-ethylhexanoate and triethylene glycol di-2-ethylbutyrate, and particularly preferably triethylene glycol di-2-ethylhexanoate.

[0193] The content of the plasticizer in each resin layer is not particularly limited, and is, for example, 10 parts by mass or more and 100 parts by mass or less, and preferably 15 parts by mass or more and 90 parts by mass or less, based on 100 parts by mass of the thermoplastic resin.

[0194] To explain in more detail, in the low Tg resin layer, the content of the plasticizer (1) (hereinafter sometimes described as content (1)) is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 40 parts by mass or more, relative to 100 parts by mass of the thermoplastic resin (1). When the content (1) is equal to or more than the above lower limit, the flexibility of the interlayer film increases, the handling of the interlayer film becomes easier, and the sound insulation property is also easily improved. In addition, the content (1) is preferably further increased from the viewpoint of sound insulation property. From such a viewpoint, the content (1) is further preferably 50 parts by mass or more, and particularly preferably 55 parts by mass or more.

[0195] The content of the plasticizer (1) is preferably 100 parts by mass or less, more preferably 90 parts by mass or less, further preferably 85 parts by mass or less, particularly preferably 80 parts by mass or less, further preferably 75 parts by mass or less. If the content (1) is below the upper limit, the penetration resistance of the laminated glass is further improved.

[0196] In the high Tg resin layer, the content of the plasticizer (hereinafter sometimes referred to as "content (2)") is preferably 10 parts by mass or more relative to 100 parts by mass of the thermoplastic resin (2). If the content of the plasticizer is set to be greater than the above lower limit, the flexibility of the interlayer film increases, and the handling of the interlayer film becomes easier. From these viewpoints, the content (2) of the plasticizer is preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and particularly preferably 24 parts by mass or more.

[0197] The content (2) is preferably 60 parts by mass or less, more preferably 55 parts by mass or less, and even more preferably 50 parts by mass or less. When these contents are respectively below the above upper limits, mechanical properties such as flexural rigidity of the interlayer film become good.

[0198] In order to improve the sound insulation of laminated glass, the content (1) of the plasticizer in the low Tg resin layer is preferably the same as or greater than the content (2) of the plasticizer in the high Tg resin layer, and more preferably greater than the content (2).

[0199] In addition, when the content (1) is greater than the content (2), the absolute value of the difference is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more. As described above, if the absolute value of the difference in the content is increased, the sound insulation of the laminated glass can be further improved. In addition, the absolute value of the difference is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less.

[0200] In each resin layer (low Tg resin layer and high Tg resin layer), a thermoplastic resin, or a thermoplastic resin and a plasticizer are preferably used as the main components, and the total amount of the thermoplastic resin and the plasticizer is preferably 70 mass % or more and 100 mass % or less, more preferably 80 mass % or more and 100 mass % or less, and further preferably 90 mass % or more and 100 mass % or less, based on the total amount of each resin layer.

[0201] (Colorant)

[0202] Each resin layer contained in the intermediate film may contain a colorant. It should be noted that in the following description, the resin layer containing the colorant is sometimes referred to as a colored layer. The colorant can be uniformly dispersed in the colored layer. The colorant may be contained in at least one layer of the resin layer contained in the intermediate film, may be contained in any low Tg resin layer, may be contained in any high Tg resin layer, but is preferably contained in at least one layer of the high Tg resin layer.

[0203] For example, in Figure 1 , 3In the layer configurations shown in Figures 5 to 5, the colorant may be contained in the low Tg resin layer 11. Alternatively, the colorant may be contained in at least one of the high Tg resin layers 12, 12. In this case, the colorant is preferably contained in both of the high Tg resin layers 12, 12.

[0204] In addition, for example, Figure 2 In the layer configuration shown, the colorant may be contained in any one of the low Tg resin layers 11, 11, or in both of the low Tg resin layers 11, 11. In addition, the colorant may be contained in at least one of the high Tg resin layers 12, 12, 12, or in all of the high Tg resin layers 12, 12, 12.

[0205] In addition, the interlayer film may contain the colorant throughout the entire region or in a partial region. Figures 1 to 5 As shown, the intermediate film is provided over the entire region, but may be provided in a partial region of the intermediate film (not shown).

[0206] When the colored layer is provided in a part of the intermediate film, the colored layer is preferably a high Tg resin layer. By making the colored layer provided in a part of the intermediate film a high Tg resin layer, it is easy to make the difference (ΔR(x)) between the maximum and minimum values ​​of the thickness ratio of the low Tg resin layer less than a certain value.

[0207] It should be noted that, when the colored layer is provided in a partial region of the intermediate film, for example, Figures 1 to 5 In the layer structure shown, at least a part of the high Tg resin layer 12 may be a multilayer structure, and a part of the layers in the multilayer structure may be a colored layer.

[0208] The colorant used is not particularly limited, and pigments that have been used in the interlayer film in the past can be used, and blue, yellow, red, green, purple, white, black, etc. pigments can be used. Pigments, dyes, etc. can be used as pigments. By using a colorant in the interlayer film, the interlayer film can be colored in a desired color, and the design of the interlayer film can be improved.

[0209] Examples of pigments used in 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, perindigo pigments, isoindoline pigments, isoindolinone pigments, quinophthalone pigments, thionyl pigments, dioxadiazole pigments, oxadiazole pigments, thiocyanine pigments, oxadiazole ... Oxazine pigments, pyrrocoline pigments, fluorine red pigments, azo pigments, titanium oxide pigments, calcium carbonate pigments, metal oxide pigments, Ni complex pigments, other metal complex pigments, etc.

[0210] Examples of dyes include azo dyes, cyanine dyes, triphenylmethane dyes, phthalocyanine dyes, anthraquinone dyes, naphthoquinone dyes, quinoneimine dyes, methine dyes, azomethine dyes, Dyes, acridine dyes, styryl dyes, coumarin dyes, quinoline dyes, nitro dyes, etc. The dyes may also be disperse dyes.

[0211] The above-mentioned pigments and dyes constituting the coloring agent may be directly blended into the resin, or may be blended into the resin after being made into the form of ink, toner, or the like.

[0212] In addition, as a colorant, in addition to the above-mentioned pigments and dyes, substances used as heat shielding agents in the interlayer film can also be used as colorants. Heat shielding agents also block a certain amount of visible light, so the resin layer can also be colored by making the interlayer film contain heat shielding agents.

[0213] As a heat shielding agent, typically, it is a material that can absorb infrared rays with a wavelength of more than 780nm, that is, heat rays. The heat shielding agent is composed of an inorganic material, and typically, heat shielding particles are used. As a specific example, particles other than metal oxide particles such as metal oxide particles and lanthanum hexaboride (LaB6) particles can be cited. As metal oxide particles, tin oxide particles such as aluminum-doped tin oxide particles, indium-doped tin oxide particles, antimony-doped tin oxide particles (ATO particles), gallium-doped zinc oxide particles (GZO particles), indium-doped zinc oxide particles (IZO particles), aluminum-doped zinc oxide particles (AZO particles), tin-doped zinc oxide particles and silicon-doped zinc oxide particles 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, rubidium-doped tungsten oxide particles, etc. can be cited. 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.

[0214] Among them, metal oxide particles are preferred due to their high heat ray shielding function, at least one particle selected from ATO particles, GZO particles, ITO particles, and CWO particles is more preferred, and ITO particles or CWO particles are further preferred.

[0215] The preferred lower limit of the average particle size of the heat-insulating particles is 10 nm, the more preferred lower limit is 20 nm, the preferred upper limit is 100 nm, the more preferred upper limit is 80 nm, and the further 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 sufficiently improved. In addition, if the average particle size is below the above preferred upper limit, it is not easy to use the heat-insulating agent to shield visible light to a degree greater than necessary. It should be noted that the "average particle size" represents the volume average particle size. The average particle size can be measured using a particle size distribution measuring device ("UPA-EX150" manufactured by Nikkiso Co., Ltd.) or the like.

[0216] As the colorant, specifically, ITO, CWO, phthalocyanine pigments, and phthalocyanine dyes are preferably used. In addition, as the colorant, among the above, pigments and dyes are preferably used. As the colorant, by using any one of the pigments and dyes as the colorant, it is easy to color the intermediate film into a desired color with a small amount of use.

[0217] 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 appropriately colored. In addition, by setting the content of the colorant to 7% by mass or less, it is possible to prevent coloring to a degree greater than necessary and prevent various functions and performances of the interlayer film from being reduced due to the colorant.

[0218] The above content of the colorant in the entire interlayer film is preferably 0.00001 mass% or more, more preferably 0.0001 mass% or more, further preferably 0.001 mass% or more, further preferably 0.01 mass% or more, further preferably 0.1 mass% or more, and is preferably 6 mass% or less, more preferably 4 mass% or less, further preferably 2 mass% or less.

[0219] In addition, the content of the colorant in each resin layer containing the colorant is preferably 0.00005% by mass or more and 10% by mass or less based on the total amount of each resin layer. By setting it to 0.00005% by mass or more, the intermediate film can be appropriately colored by using the resin layer containing the colorant. In addition, by setting it to 10% by mass or less, it is possible to prevent coloring to a degree greater than necessary, and to prevent the various functions and performances of each resin layer from being reduced by the colorant. The content of the colorant in each resin layer containing the colorant is preferably 0.0001% by mass or more, more preferably 0.001% by mass or more, further preferably 0.01% by mass or more, further preferably 0.1% by mass or more, and more preferably 7% by mass or less, further preferably 5% by mass or less.

[0220] In addition, 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.

[0221] In addition, in the intermediate film, when a part of the resin layer contains a colorant, the other resin layer may be a layer that does not substantially contain a colorant. It should be noted that the so-called "substantially does not contain a colorant" means that the colorant inevitably mixed from other components such as the coloring layer may be contained, and the total amount of the resin layer is based on, for example, less than 0.00005% by mass, preferably less than 0.00001% by mass, and more preferably 0% by mass. In addition, even if the content of the colorant is 0.00005% by mass or more, as long as the function presented by containing the colorant is not impaired, for example, in an intermediate film having a mask layer containing a colorant, even if the colorant of the mask layer is mixed into other resin layers, as long as the design and transmittance of the function as the mask layer can be ensured.

[0222] (Ultraviolet light absorber)

[0223] Each resin layer constituting the intermediate film may further contain an ultraviolet absorber. More specifically, one or both of the low Tg resin layer and the high Tg resin layer may contain an ultraviolet absorber. In the case of the intermediate film, by making each resin layer contain an ultraviolet absorber, degradation can be prevented even when used for a long time in a light irradiation environment such as sunlight.

[0224] As the ultraviolet absorber, for example, a compound having a malonate skeleton, a compound having an oxalylanilide skeleton, a compound having a benzotriazole skeleton, a compound having a benzophenone skeleton, a compound having a triazine skeleton, a compound having a benzoate skeleton, a compound having a hindered amine skeleton, etc. can be used. Among them, a compound having a benzotriazole skeleton (benzotriazole-based compound) is preferred.

[0225] The ultraviolet absorber may be used alone or in combination of two or more.

[0226] The content of the ultraviolet absorber in each resin layer (for example, the low Tg resin layer and the high Tg resin layer) is preferably 0.01% by mass or more and 2% by mass or less based on the total amount of each resin layer. By setting it to 0.01% by mass or more, it is possible to appropriately prevent each resin layer from being degraded by ultraviolet rays contained in sunlight, and the durability can be improved. In addition, by setting it to 2% by mass or less, it is possible to prevent the resin layer from having a color tone due to the ultraviolet absorber, and it is also easy to exert an effect corresponding to the content.

[0227] The content of the ultraviolet absorber is more preferably 0.05% by mass or more and 1.5% by mass or less, and further preferably 0.1% by mass or more and 1% by mass or less.

[0228] (Antioxidant)

[0229] Each resin layer constituting the intermediate film may further contain an antioxidant. More specifically, one or both of the low Tg resin layer and the high Tg resin layer may contain an antioxidant. By making each resin layer of the intermediate film contain an antioxidant, the oxidative degradation of the intermediate film can be prevented, and the durability of the intermediate film can be improved. In addition, from the viewpoint of improving the durability of the intermediate film, one or both of the low Tg resin layer and the high Tg resin layer constituting the intermediate film may contain an antioxidant in addition to the ultraviolet absorber.

[0230] Examples of the antioxidant include phenolic compounds, phosphoric acid compounds, sulfur compounds, etc. The antioxidant prevents the resin film from oxidative degradation and improves durability. Among the above, phenolic compounds are suitable from the viewpoint of improving durability.

[0231] The phenolic compound may be, for example, 2,6-di-tert-butyl-p-cresol (BHT), butylated hydroxyanisole (BHA), 2,6-di-tert-butyl-4-ethylphenol, stearyl β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,2'-methylenebis-(4-methyl-6-butylphenol), 2,2'-methylenebis-(4-ethyl-6-tert-butylphenol), 4,4'-butylene-bis-(3-methyl-6-tert-butylphenol), 1,1,3-tri- (2-methyl-hydroxy-5-tert-butylphenyl) butane, tetrakis[methylene-3-(3',5'-butyl-4-hydroxyphenyl) propionate] methane, 1,3,3-tris-(2-methyl-4-hydroxy-5-tert-butylphenol) butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl) benzene, bis(3,3'-tert-butylphenol) butyrate and pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], etc.

[0232] Examples of the phosphoric acid compound include trisnonylphenyl phosphite, tridecyl phosphite, 2-ethyl-2-butylpropylidene-4,6-tri-tert-butylphenol phosphite, 9,10-dihydro-9-oxa-10-phosphaphenanthrene, tetrakis(tridecyl)isopropylidene diphenol diphosphite, and tris[2-tert-butyl-4-(3-tert-hydroxy-5-methylphenylthio)-5-methylphenyl]phosphite.

[0233] Examples of the sulfur-based compound include dialkylthiodipropionates such as dilauryl thiodipropionate, dimyristyl thiodipropionate, and distearyl thiodipropionate; and β-alkylmercaptopropionates of polyhydric alcohols such as pentaerythritol tetrakis(β-dodecylmercaptopropionate).

[0234] The antioxidant may be used alone or in combination of two or more.

[0235] The content of the antioxidant in each resin layer (for example, the low Tg resin layer and the high Tg resin layer) is preferably 0.01% by mass or more and 2% by mass or less based on the total amount of each resin layer. By setting it to 0.01% by mass or more, the oxidation degradation of the intermediate film can be appropriately prevented, and the durability can be improved. In addition, by setting it to 2% by mass or less, it is also easy to exert the effect corresponding to the content. The above content of the antioxidant is more preferably 0.04% by mass or more and 1.5% by mass or less, and further preferably 0.06% by mass or more and 1% by mass or less.

[0236] Each resin layer constituting the interlayer film may contain, in addition to the above-mentioned additives, known additives used for interlayer films as appropriate, specifically, light stabilizers, adhesion regulators, fluorescent whitening agents, crystal nucleating agents, and the like.

[0237] [Thickness of interlayer and each layer]

[0238] The thickness of the intermediate film is not particularly limited, and is, for example, 100 μm or more and 2500 μm or less, preferably 200 μm or more and 2000 μm or less, and more preferably 300 μm or more and 1500 μm or less. By setting the thickness of the intermediate film to be above the lower limit, the impact resistance can be improved, and it is also easy to ensure the adhesion with the laminated glass component. On the other hand, by setting it to be below the upper limit, the thickness of the laminated glass can be prevented from being thicker than necessary.

[0239] It should be noted that the thickness of the interlayer film is the thickness of the entire interlayer film. In addition, the thickness of the interlayer film, the low Tg resin layer and the high Tg resin layer described below are the average thickness of 20 points, and the thickness of each point can be measured using a microscope as described above.

[0240] The thickness of the low Tg resin layer is, for example, 30 μm or more and 500 μm or less. By making the thickness of the low Tg resin layer above the above lower limit, the sound insulation performance can be properly ensured. In addition, by setting it below the above upper limit, the thickness of the intermediate film can be prevented from increasing more than necessary. From these viewpoints, the thickness of the low Tg resin layer is preferably 50 μm or more and 300 μm or less, and more preferably 80 μm or more and 240 μm or less.

[0241] Two or more low-Tg resin layers may be provided in the interlayer film. In this case, the thickness of the low-Tg resin layer mentioned above is the total thickness of the low-Tg resin layers.

[0242] When two or more low-Tg resin layers are provided, the thicknesses of the plurality of low-Tg resin layers may be the same as or different from each other. For example, when two low-Tg resin layers are provided, the thickness of each low-Tg resin layer is, for example, 20 μm or more and 300 μm or less, preferably 25 μm or more and 180 μm or less, and more preferably 35 μm or more and 140 μm or less.

[0243] The thickness of the high Tg resin layer is, for example, 70 μm or more and 2000 μm or less. By making the thickness of the high Tg resin layer above the above lower limit, it is possible to impart appropriate mechanical strength, penetration resistance, etc. to the intermediate film. In addition, by setting it below the above upper limit, it is possible to prevent the thickness of the intermediate film from increasing more than necessary. From these viewpoints, the thickness of the high Tg resin layer is preferably 150 μm or more and 1500 μm or less, more preferably 200 μm or more and 1000 μm or less, and further preferably 300 μm or more and 800 μm or less.

[0244] The interlayer film may include two or more high Tg resin layers. In this case, the thickness of the high Tg resin layer mentioned above is the total thickness of the high Tg resin layers.

[0245] When two or more high Tg resin layers are provided, the thicknesses of the plurality of high Tg resin layers may be the same as or different from each other. For example, when two high Tg resin layers are provided, the thickness of each high Tg resin layer is, for example, 35 μm or more and 900 μm or less, preferably 75 μm or more and 700 μm or less, and more preferably 90 μm or more and 580 μm or less.

[0246] For example, when three high Tg resin layers are provided, the thickness of each high Tg resin layer is, for example, 30 μm to 700 μm, preferably 50 μm to 500 μm, and more preferably 70 μm to 400 μm.

[0247] In addition, the intermediate film is not particularly limited, and the length in the width direction from one end to the other end (hereinafter, sometimes referred to as "product width") is, for example, 300 mm or more, preferably 500 mm or more, and more preferably 600 mm or more. In addition, the upper limit of the product width is also not particularly limited, for example, 5000 mm or less, preferably 3000 mm or less, more preferably 2000 mm or less, and further preferably 1800 mm or less.

[0248] [Surface shape of interlayer film]

[0249] One or both surfaces of the intermediate film may have a concave-convex shape. The surface of the intermediate film is the surface in contact with the laminated glass component in the laminated glass. The ten-point average roughness of at least one surface of the intermediate film is preferably 10 μm or more. If the ten-point average roughness of the surface of the intermediate film is 10 μm or more, the degassing property is excellent, and bubbles are not easily generated on the surface of the intermediate film when the intermediate film is crimped to the laminated glass component. In addition, it is possible to prevent adhesion when the intermediate film is overlapped or rolled up, and further, it is possible to prevent optical deformation, etc. The ten-point average roughness is more preferably 15 μm or more, and further preferably 20 μm or more. In addition, from the viewpoint of making the degassing property good or suppressing optical deformation, the ten-point average roughness is preferably 95 μm or less, more preferably 80 μm or less, and further preferably 70 μm or less.

[0250] It should be noted that the ten-point average roughness is the ten-point average roughness (Rzjis94) measured in accordance with JIS B 0601-1994. As a measuring instrument for measuring the above-mentioned ten-point average roughness (Rzjis94), for example, "Surfcorder SE300" manufactured by Kosaka Laboratory Co., Ltd. can be used. More specifically, the above-mentioned ten-point average roughness (Rz) can be measured using a stylus needle with a tip radius of 2 μm and a tip angle of 60°, under the measurement conditions of a cutoff value of 2.5 mm, a reference length of 2.5 mm, a measurement length of 12.5 mm, a preliminary length of 2.5 mm, and a conveying speed of the stylus needle of 0.5 mm / sec, at 23°C and 30 RH%. In the case where a grooved embossing is imparted to the surface of the above-mentioned intermediate film, the above-mentioned ten-point average roughness (Rz) can be measured by conveying the stylus needle in a direction perpendicular to the line direction of the grooved lines.

[0251] The ten-point average roughness can be determined by measuring Rzjis94 at 10 points at equal intervals from one end to the other end and calculating the average value. It should be noted that only one surface of the surface of the intermediate film may have the above ten-point average roughness, and preferably both surfaces have the above ten-point average roughness.

[0252] The method for forming the uneven shape on the interlayer film is not particularly limited, and the uneven shape can be formed on the interlayer film obtained by the production method described below by, for example, a lip embossing method, an embossing roll method, a calender roll method, or the like.

[0253] (Method for producing interlayer film)

[0254] The method for manufacturing the intermediate film is not particularly limited, but 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 can be extruded to form each resin layer. In addition, the intermediate film of the present invention is more preferably manufactured by coextrusion.

[0255] In the coextrusion, a coextruder equipped with a plurality of extruders and a multilayer feed block may be used. In the coextruder, the front end of each extruder may be connected to the multilayer feed block via a molten resin delivery pipe or the like.

[0256] In the co-extruder, the resin or resin composition for forming each resin layer can be supplied from each extruder to a multi-layer feed block via a molten resin delivery pipe, etc., and merged in the multi-layer feed block to be co-extruded from a die (T die) as a multi-layer intermediate film. In addition, the resin or resin composition for forming each resin layer can be supplied from each extruder to a multi-layer die (M die) via a molten resin delivery pipe, etc., and merged in the multi-layer die and co-extruded.

[0257] In the present invention, the difference between the maximum and minimum values ​​of the thickness ratio R(x) of the low Tg resin layer is reduced, and they can be reduced by, for example, adjusting the gaps at each coordinate in the width direction (TD) of the flow path (e.g., slit) through which the resin or resin composition used to constitute the low Tg resin layer and the high Tg resin layer passes in coextrusion. As the slit, it can be, for example, a slit of each resin flow path provided in a feed block or a multilayer mold for the portion where each resin merges. In addition, by providing a concave-convex shape in which the gap changes in the width direction (TD) of each resin flow path, it is possible to present a portion where the resin is easy to flow and a portion where the resin is not easy to flow, so that even if the slit gaps of each resin confluence portion are uniform in the width direction (TD), the resin layer after the confluence can be adjusted.

[0258] Furthermore, when manufacturing a wedge-shaped intermediate film, the gap at the die outlet may be adjusted so as to be asymmetric in accordance with the wedge shape in the width direction.

[0259] [Laminated glass]

[0260] The present invention also provides a laminated glass. The laminated glass includes 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 may be bonded to each other via the interlayer film.

[0261] (1st and 2nd laminated glass components)

[0262] As the first and second laminated glass members used in the laminated glass, glass plates can be mentioned. The glass plates can be any glass of inorganic glass and organic glass, but are preferably inorganic glass. As inorganic glass, there are no particular restrictions, and examples thereof include transparent glass, float glass plates, tempered glass, tinted glass, polished glass plates, patterned glass, wired glass plates, wired glass plates, ultraviolet absorbing glass plates, infrared reflecting glass plates, infrared absorbing glass plates, and raw glass.

[0263] In addition, as organic glass, what is called resin glass is generally 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 can be mentioned. The organic resin plate can be appropriately surface treated.

[0264] The first and second laminated glass members may be made of the same material or other materials. For example, one may be inorganic glass and the other may be organic glass, but preferably, both the first and second laminated glass members are inorganic glass or organic glass.

[0265] The thickness of each glass plate used in 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 as or different from each other.

[0266] In addition, when the first and second laminated glass components have different thicknesses, the difference in thickness can be 0.1 mm or more, preferably 0.2 mm or more. In addition, the difference in thickness between the first and second laminated glass components is not particularly limited, for example, can be 2 mm or less, preferably 1 mm or less.

[0267] The first and second laminated glass members may be flat glass or curved glass. It should be noted that when one of the first and second laminated glass members is flat glass, the other is preferably flat glass, and when one is curved glass, the other is preferably curved glass.

[0268] In the case of curved glass, for example, the bending radius in the width direction is preferably 4000 mm or more, more preferably 6000 mm or more, further preferably 8000 mm or more, further preferably 10000 mm or more, and is preferably 25000 mm or less, more preferably 20000 mm or less, further preferably 15000 mm or less.

[0269] 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 bonding them by pressure.

[0270] More specifically, an intermediate film is sandwiched between the first and second laminated glass components, passed through a squeeze roller, or placed in a rubber bag and decompressed and sucked to degas the air remaining between the two glass components and the intermediate film. Then, pre-bonding is performed at about 70 to 110°C to obtain a laminate. Next, the laminate is placed in an autoclave or pressurized and pressure-bonded at about 120 to 150°C and a pressure of 1 to 1.5 MPa. By operating as described above, a laminated glass can be obtained.

[0271] The interlayer film and laminated glass of the present invention can be used in vehicles such as automobiles and railway vehicles, various transportation vehicles such as aircraft and ships, and buildings, etc. In addition, they can also be used in display device applications as surface protection panels of various display devices such as liquid crystal displays and organic EL displays. The interlayer film and laminated glass can also be used for applications other than these.

[0272] The interlayer film and the laminated glass are preferably interlayer films and laminated glass for vehicles or buildings, and more preferably interlayer films and laminated glass for vehicles.

[0273] In addition, the interlayer film and the laminated glass can be used for head-up display (HUD) applications in vehicle applications, etc. In HUD applications, for example, light from a HUD light source installed in the vehicle is irradiated to the laminated glass, and the light reflected on the laminated glass enters the eyes of the driver in the vehicle, etc., and is recognized as a HUD image. In HUD applications, from the viewpoint of easily reducing reflection ghosting, it is preferable to use a wedge-shaped interlayer film as the interlayer film.

[0274] Example

[0275] Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

[0276] The measuring methods and evaluation methods of various physical properties are as follows.

[0277] [Mechanical Impedance Measurement (MIM)]

[0278] Mechanical impedance measurement was performed on laminated glass obtained from the interlayer films involved in each embodiment and comparative example in accordance with ISO16940: 2008. The area was divided into three equal parts in the direction (TD) from one end to the other end, and the mechanical impedance measurement was performed at the center of each area. In addition, the measurement used laminated glass that had been placed in an environment of 23°C and 30RH% for 8 weeks.

[0279] Specifically, vibration was applied to the laminated glass for sound insulation evaluation using a vibration generator for vibration reduction test ("Vibrator G21-005D" manufactured by Shinken Co., Ltd.). The vibration characteristics thus obtained were amplified by a mechanical impedance measuring device ("XG-81" manufactured by Rion Co., Ltd.), and the vibration spectrum was analyzed using an FFT spectrum analyzer ("FFT Analyzer SA-01A2" manufactured by Rion Co., Ltd.), and the primary resonance frequency at 20°C and the loss factor at 20°C in each region were obtained. The maximum and minimum values, as well as the difference between the maximum and minimum values, are shown in Tables 2 and 3.

[0280] [Sound Transmission Loss (STL)]

[0281] In a reverberation chamber according to ISO10140-5 in which a first reverberation chamber as a sound source chamber and a second reverberation chamber as a sound receiving chamber are connected, the laminated glass obtained in each embodiment and comparative example is placed between the first reverberation chamber and the second reverberation chamber between the two reverberation chambers (sound source chamber, sound receiving chamber) connected according to ISO10140-5. Sound transmission loss was measured at 20°C using the sound transmission loss measuring device "Intensity Project SI-50, Martech Nerve Analizer SA-02" produced by Lyon. Specifically, the sound transmission loss (dB) was measured using the intensity method in accordance with JIS A1441-1. The center frequency was measured using a 1 / 3 octave band. Based on the measured sound transmission loss, evaluation was performed according to the following evaluation criteria. In addition, in this measurement, the sample which left it to stand for 8 weeks in the environment of 23 degreeC and 30RH% was used.

[0282] Evaluation was performed based on the STL value at 2500 Hz according to the following criteria.

[0283] A: 40.6dB or more

[0284] B: 40.3dB or more and less than 40.6dB

[0285] C: 40.1dB or more and less than 40.3dB

[0286] D: less than 40.1dB

[0287] [Example 1]

[0288] (Production of interlayer film)

[0289] In the first extruder, according to the formulation of A1 described in Table 1, 40 parts by mass of plasticizer, and the mass % of ultraviolet absorber and antioxidant described in Table 1 were added and kneaded to prepare resin compositions for layer 1 and layer 3. In addition, according to the formulation of A2 described in Table 1, 60 parts by mass of plasticizer, and the mass % of ultraviolet absorber and antioxidant described in Table 1 were added and kneaded to prepare resin compositions for layer 2.

[0290] In a co-extruder in which a multi-layer feed block is installed at the front end of a first molten resin delivery pipe connected to the front end of a first extruder and a second molten resin delivery pipe connected to the front end of a second extruder, a resin or a resin composition is delivered from the first and second extruders to a die (T die) via the feed block. Then, co-extrusion is performed while adjusting the amount of each resin composition extruded from the T die, thereby obtaining a Figure 1 As shown in FIG. 1 , an interlayer film having a low Tg resin layer (layer 2) is provided between a pair of high Tg resin layers (layers 1 and 3). At this time, in order to make the thickness of each layer roughly uniform, the gap width at each coordinate of TD was manually adjusted at the slit of the flow path immediately before the confluence of each resin provided in the feed block based on the difference between the target thickness distribution and the thickness distribution obtained by measurement.

[0291] The obtained intermediate film was embossed by an embossing roller method, and then cut in a manner that the product width (length in the longitudinal direction) was 1000 mm and the length in the width direction was 1000 mm to obtain the intermediate film of Example 1. For the obtained intermediate film, the thickness ratio R(x) of each coordinate [x(mm)] on TD was calculated according to the method described in the specification, and the maximum value, minimum value and difference ΔR(x) of the thickness ratio R(x) were obtained. Furthermore, the fitting straight line f(x)=ax+b was obtained, and the standard deviation was also calculated. In addition, the ten-point average roughness Rzjis94 of each surface of the intermediate film was also measured. Their results are shown in Table 2. It should be noted that the glass transition temperature of each layer constituting the intermediate film is shown in Table 1.

[0292] (Manufacturing of laminated glass)

[0293] The obtained intermediate film was sandwiched between two sheets of transparent float glass (for mechanical impedance measurement: 25 mm in length × 300 mm in width × 2.0 mm in thickness, for sound transmission loss measurement: 1000 mm in length × 1000 mm in width × 2.0 mm in thickness) to obtain a laminate. The laminate was placed in a rubber bag and degassed at a vacuum degree of 2.6 kPa for 20 minutes. Then, the laminate was moved into an oven in a degassed state and further kept at 90°C for 30 minutes to perform vacuum pressurization and pre-press the laminate. In an autoclave, the pre-pressed laminate was pressed for 20 minutes at 135°C and a pressure of 1.2 MPa to obtain a laminated glass. After the obtained laminated glass was allowed to stand for 8 weeks in a room at 23°C and 30 RH%, the mechanical impedance was measured. In addition, after the obtained laminated glass was allowed to stand for 8 weeks in a room at 23°C and 30 RH%, the sound transmission loss (STL) was also measured.

[0294] [Example 2]

[0295] The resin or resin composition was conveyed from the first and second extruders to the multilayer die (M die), and then co-extruded in the same manner as in Example 1 except that the slit gaps immediately before the resins merged inside the multilayer die were adjusted in the width direction (TD).

[0296] [Example 3]

[0297] The same procedure as in Example 1 was carried out except that protrusions were provided in the flow paths of the resins in the feed block and the heights of the protrusions were adjusted in the width direction (TD) so that the slit gaps immediately before the resins merged were uniform in the width direction (TD).

[0298] [Example 4]

[0299] The same operation as in Example 1 was performed except that the slit gap in the width direction (TD) in the feed block was changed.

[0300] [Example 5]

[0301] The same operation as in Example 1 was performed except that the slit gap in the width direction (TD) in the feed block was changed.

[0302] [Example 6]

[0303] The same operation as in Example 1 was performed except that the slit gap in the width direction (TD) in the feed block was changed.

[0304] [Examples 7, 8, 12]

[0305] The same procedure as in Example 3 was carried out except that the resin composition for the layer 2 was changed as described in Tables 1 and 2.

[0306] [Examples 9 and 13]

[0307] The same procedure as in Example 3 was carried out except that the resin compositions for layers 1 and 3 were changed as described in Tables 1 and 2.

[0308] [Examples 10 and 11]

[0309] The same procedure as in Example 4 was carried out except that the ratio of the flow rate of each resin in the feed block was changed so that the thickness of each resin layer would be as described in Table 2.

[0310] [Examples 14 to 16]

[0311] The same method as in Example 1 was carried out except that the wedge angle was set to the values ​​shown in Table 3 from one end to the other end and the die outlet gap was asymmetric with respect to the width direction (TD) to obtain Figure 3 The cross-sectional shape of the wedge-shaped intermediate membrane is shown.

[0312] [Example 17]

[0313] The same method as in Example 14 was used except that the wedge angle in the region from one end to a point of 700 mm from one end to the other end was the value shown in Table 3, and the wedge angle in the region from the point of 700 mm to the other end was 0 mrad, and extrusion was performed under the condition that the die outlet gap was asymmetric with respect to the width direction (TD). Figure 4 The cross-sectional shape of the wedge-shaped intermediate membrane is shown.

[0314] [Example 18]

[0315] The same method as in Example 14 was used except that the wedge angle was changed from 0.7 mrad to 0.2 mrad from one end to the other end and extrusion was performed under the condition that the die outlet gap was asymmetric with respect to the width direction (TD). The wedge angles listed in Table 3 are average wedge angles.

[0316] [Examples 19 and 20]

[0317] The same procedure as in Example 14 was carried out except that the thickness of each resin layer was changed as described in Table 3.

[0318] [Example 21]

[0319] As the feed block, a 5-layer feed block is used to have Figure 2The same procedure as in Example 1 was carried out except that the interlayer film was produced by adjusting the slit gap in the width direction (TD) in the feed block so as to have the laminated structure shown and the thickness of each layer was as described in Table 3.

[0320] [Comparative Example 1]

[0321] The same procedure as in Example 1 was performed except that the gap width at each coordinate in TD was not adjusted at the slit immediately before the resins of the feed block merged.

[0322] [Comparative Example 2]

[0323] In an extruder, 40 parts by mass of a plasticizer and the mass % of an ultraviolet absorber and an antioxidant as described in Table 1 were added and kneaded to 100 parts by mass of the resin according to the formulation of A1 described in Table 1 to prepare a resin composition for layer 1. The obtained resin composition was extruded from a T die to obtain an interlayer film consisting of a single resin layer. Laminated glass was prepared from the obtained interlayer film in the same manner as in Example 1 and evaluated in the same manner.

[0324] [Table 1]

[0325]

[0326] ※ Table 1 shows the average degree of polymerization, hydroxyl content (mol %), acetylation degree (mol %), and acetalization degree (mol %) of the polyvinyl butyral resin (PVB) used in each resin layer.

[0327] ※The mass % in Table 1 is based on the total amount of each resin layer, and the mass parts are the mass parts relative to 100 mass parts of the resin (polyvinyl butyral resin).

[0328] ※In Table 1, components other than resin are as follows.

[0329] Plasticizer: Triethylene glycol di-2-ethylhexanoate (3GO)

[0330] Ultraviolet light absorber: Trade name "Tinuvin 326", manufactured by BASF, benzotriazole compound

[0331] Antioxidant: 2,6-di-tert-butyl-p-cresol (BHT)

[0332] Colorants: Tin-doped indium oxide particles (ITO), cesium-doped tungsten oxide particles (CWO)

[0333] [Table 2]

[0334]

[0335] [Table 3]

[0336]

[0337] ※ The layer configurations in Tables 2 and 3 indicate that, when the interlayer film has a multilayer structure, layers 1 to 3 or layers 1 to 5 are laminated in this order.

[0338] ※It should be noted that the "wedge angle" shown in Tables 2 and 3 is the average value of the partial wedge angles measured at the portion where the wedge angle is 0.1 mrad or more.

[0339] As shown in the above examples, since the difference (ΔR(x)) between the maximum and minimum values ​​of the thickness ratio R(x) of the low Tg resin layer to the entire interlayer film becomes smaller, the absolute value (ΔPR) of the difference between the maximum and minimum values ​​of the primary resonance frequency and the absolute value (ΔLF) of the difference between the maximum and minimum values ​​of the loss factor measured by MIM become lower. Therefore, the fluctuation of the sound insulation performance in each area is suppressed, and the evaluation result obtained by the sound transmission loss becomes better.

[0340] In contrast, in Comparative Example 1, since the difference (ΔR(x)) between the maximum and minimum values ​​of the thickness ratio R(x) of the low Tg resin layer to the entire interlayer film is large, the fluctuation of the sound insulation performance in each region cannot be sufficiently suppressed, and the evaluation result obtained based on the sound transmission loss is poor. In addition, in Comparative Example 2, since it is a single-layer film without a low Tg resin layer, the sound insulation performance is insufficient.

[0341] Description of Reference Numerals

[0342] 10A~10E Interlayer film for laminated glass

[0343] 11 Low Tg resin layer

[0344] 12 High Tg resin layer

[0345] 13A One end

[0346] 13B The other end

[0347] C Center

[0348] X distance

[0349] α Wedge angle

Claims

1. An interlayer film for laminated glass, comprising two or more resin layers, wherein at least one resin layer has a glass transition temperature different from that of the other resin layers, When the coordinate on the straight line from one end to the other end is marked as x [mm], the difference between the maximum and minimum values ​​of the thickness ratio R(x) of the low Tg resin layer having the lowest glass transition temperature among the two or more resin layers to the entire interlayer film for laminated glass is less than 8%.

2. An interlayer film for laminated glass, which is divided into three equal parts from one end to the other end, and the absolute value of the difference between the maximum value and the minimum value of the primary resonance frequency in each region is 50 Hz or less, and the primary resonance frequency is measured by mechanical impedance measurement in accordance with ISO 16940:2008.

3. An interlayer film for laminated glass, wherein the interlayer film is divided into three equal parts from one end to the other end, and the absolute value of the difference between the maximum value and the minimum value of the loss coefficient in each region is 0.1 or less, wherein the loss coefficient is measured by mechanical impedance measurement in accordance with ISO 16940:2008.

4. The interlayer film for laminated glass according to claim 1, wherein a standard deviation of a deviation ΔR(x) of a thickness ratio R(x) to f(x) is 0.1% or more and 2% or less, in, f(x) is a fitted straight line f(x)=ax+b calculated from the thickness ratio R(x) and the coordinate x in the region of x=0.1X~0.9X when the total length of the straight line from one end to the other end is recorded as 1.0X; it should be noted that a and b are coefficients.

5. The interlayer film for laminated glass according to claim 2 or 3, comprising two or more resin layers, wherein at least one resin layer has a glass transition temperature different from that of the other resin layers. The standard deviation of the deviation ΔR(x) of the thickness ratio R(x) with respect to f(x) is 0.1% or more and 2% or less, in, R(x) is the thickness ratio of the low Tg resin layer having the lowest glass transition temperature among the two or more resin layers to the entire interlayer film for laminated glass, when the coordinate on a straight line extending from one end toward the other end of the interlayer film is denoted by x [mm], f(x) is a fitted straight line f(x)=ax+b calculated from the thickness ratio R(x) in the region of 0.1X to 0.9X and the coordinate x when the total length of the straight line from one end to the other end is recorded as 1.0X; it should be noted that a and b are coefficients. 6 . The interlayer film for laminated glass according to claim 1 , wherein the difference between the maximum value and the minimum value of the thickness ratio R(x) is larger than 0%. 7 . The interlayer film for laminated glass according to claim 1 , wherein the thickness ratio R(x) is within a range of 1% to 30%. 8 . The interlayer film for laminated glass according to claim 1 , comprising a wedge-shaped portion having a wedge angle of 0.1 mrad or more in cross section. 9 . The interlayer film for laminated glass according to claim 8 , wherein the wedge-shaped portion has a portion where a wedge angle changes. 10 . The interlayer film for laminated glass according to claim 1 , wherein the thickness is different between one end and the other end.

11. The interlayer film for laminated glass according to any one of claims 1 to 3, comprising two or more resin layers, at least one of which has a glass transition temperature different from that of the other resin layers, and a low Tg resin layer having the lowest glass transition temperature among the two or more resin layers is arranged to be offset from the center toward any one surface side in the thickness direction.

12. The interlayer film for laminated glass according to any one of claims 1 to 3, comprising two or more resin layers, at least one of which has a glass transition temperature different from that of the other resin layers, and a low Tg resin layer having the lowest glass transition temperature among the two or more resin layers is located at the center in the thickness direction.

13. The interlayer film for laminated glass according to any one of claims 1 to 3, comprising two or more resin layers, at least one of which has a glass transition temperature different from that of the other resin layers, and wherein the interlayer film comprises two or more low-Tg resin layers, wherein the low-Tg resin layer is a resin layer having the lowest glass transition temperature among the two or more resin layers. 14 . The interlayer film for laminated glass according to claim 1 , comprising a region containing a coloring agent.

15. The interlayer film for laminated glass according to any one of claims 1 to 3, comprising at least one resin layer, any of the resin layers being a resin layer having a refractive index of 1.46 or more and a glass transition temperature of 15°C or more, and At least one surface of the interlayer film for laminated glass has a ten-point average roughness Rzjis94 of 10 μm or more. 16 . The interlayer film for laminated glass according to claim 1 , comprising at least one resin layer, wherein any of the resin layers comprises at least one resin selected from the group consisting of a polyvinyl acetal resin and an ethylene-vinyl acetate copolymer resin. 17 . A method for producing an interlayer film for laminated glass, comprising producing the interlayer film for laminated glass according to claim 1 by coextrusion. 18 . A laminated glass comprising the interlayer film for laminated glass according to claim 1 and a pair of laminated glass members, wherein the interlayer film for laminated glass is arranged between the pair of laminated glass members. The laminated glass according to claim 18 , wherein the laminated glass member is any one of bent glass and flat glass.

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