Interlayer film for laminated glass, laminated film, and laminated glass structure

Abstract

The present disclosure provides an interlayer film for laminated glass that can suitably provide a laminated glass structure with good appearance and high safety. The present disclosure also provides a laminated film and a laminated glass structure using such an interlayer film for laminated glass. 【Solution means】An interlayer film for laminated glass containing a polyvinyl acetal resin and having a film exposed area calculated by a predetermined method of 90 area% or less.

Description

Technical Field

[0001] The present disclosure relates to an interlayer film for laminated glass, a laminated film, and a laminated glass structure.

Background Art

[0002] Conventionally, a laminated glass structure in which an interlayer film is interposed between two glass plates and integrated is widely known. Since the laminated glass structure is safe because glass fragments are less likely to scatter even when it is damaged by an external impact, it is widely used in, for example, vehicles such as automobiles, airplanes, ships, and buildings.

[0003] In recent years, there has been a demand for imparting various functions to the laminated glass structure. For example, a functional layer such as a dimming film may be disposed between two glass plates. Patent Document 1 discloses a laminated glass including an interlayer film and a dimming element encapsulated in the interlayer film between two glass plates.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] A laminated glass structure is generally manufactured through an autoclave process in which an intermediate film is placed between two glass plates and, after a preliminary degassing process, the glass plates and the intermediate film are pressed together under high-temperature and high-pressure conditions such as a temperature of about 130 to 140 °C and a pressure of about 1.3 MPa. However, when a functional layer such as a dimming film is further placed between the two glass plates, complex steps (thickness differences) are likely to occur because electronic wiring, shielding printing parts, etc. are provided in the functional layer, and pressure unevenness is also likely to occur during pressing. Therefore, air remains or foams between the intermediate film and the glass plate or the functional layer during pressing, resulting in insufficient transparency in the obtained laminated glass structure, distortion or wrinkles in the functional layer, and a poor appearance of the obtained laminated glass structure.

[0006] In a laminated glass structure having a functional layer such as a dimming film, for the purpose of protecting the edge portion of the functional layer from the external environment, a frame-shaped intermediate layer (also referred to as a gap filler) is placed around the functional layer, and a structure in which this is sandwiched between a pair of intermediate layers and further sandwiched between a pair of glass plates is generally adopted (see, for example, Patent Document 1, etc.). If a laminated glass structure having a functional layer is manufactured without using a gap filler from the viewpoint of improving work efficiency, etc., air remains or foams, resulting in a poor appearance in the laminated glass structure, and there are concerns that the impact resistance is likely to be lower than when using a gap filler.

[0007] In addition, since the functional layer is vulnerable to heat and pressure, when the glass plate and the intermediate film having the functional layer are pressed together under normal high-temperature and high-pressure conditions, the functional layer may deteriorate or become deactivated. In particular, when the functional layer contains guest-host liquid crystal (also referred to as GHLC), liquid crystal unevenness occurs in the obtained laminated glass structure due to the pressure and temperature changes during pressing, making it unsuitable for practical use. On the other hand, if an attempt is made to perform the pressing at a low temperature, air remains or foams easily, and in this case too, a laminated glass structure suitable for practical use cannot be obtained.

[0008] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide an interlayer film for laminated glass that can suitably provide a laminated glass structure having a good appearance and high safety. Another object of the present disclosure is also to provide a laminated film and a laminated glass structure using such an interlayer film for laminated glass.

Means for Solving the Problems

[0009] While variously studying an interlayer film for laminated glass, the present inventors have found that when the interlayer film for laminated glass contains a polyvinyl acetal resin and the film exposed area calculated by a predetermined method is within a predetermined range, air remaining and foaming during pressure bonding with a glass plate or the like can be suppressed without going through an autoclave process under high temperature and high pressure conditions, and a laminated glass structure having a good appearance can be efficiently obtained. Further, when a functional layer is laminated on the interlayer film for laminated glass to obtain a laminated glass structure, the laminated glass structure can effectively exhibit the effects derived from the functional layer. For example, even when a GHLC film is used as the functional layer and the interlayer film for laminated glass is laminated on the GHLC film, the obtained laminated glass structure can suitably exhibit the functions derived from the GHLC film without losing the functions, and the liquid crystal unevenness is sufficiently suppressed. Thus, the present inventors have completed the interlayer film for laminated glass and the like of the present disclosure. That is, the present disclosure relates to the following interlayer film for laminated glass.

[0010] The present disclosure 1 is an interlayer film for laminated glass containing a polyvinyl acetal resin and having a film exposed area calculated by the following method of 90 area% or less. <Method for Calculating Film Exposed Area> As a sample, prepare one piece of an interlayer film for laminated glass with a length of 30 cm and a width of 15 cm, and hold it for 4 hours under constant temperature conditions of 23°C and 28% RH. Separately, prepare two pieces of float plate glass with a length of 30 cm, a width of 15 cm, and a thickness of 3 mm, which complies with JIS R3202 (2011). Then, laminate the glass and the sample so that the tin surface of the glass is in contact with the sample and the sample is disposed between the two pieces of glass. The obtained laminate is temporarily pressure-bonded using a heating roll at 170°C. The temporarily pressure-bonded laminate is placed in an autoclave and heated to 90°C at 2°C / min. When the temperature reaches 40°C during heating, the pressure is set to 0.1 MPa. After reaching 90°C, hold for 20 minutes and cool down at a rate of 2°C / min. When the temperature drops to 40°C, return the pressure to normal pressure. The obtained optical laminate is left standing in an environment at a temperature of -18°C ± 0.6°C for 16 hours, and then the optical laminate fixed at an inclination angle of 45 degrees is struck 72 times per minute with a hammer in which a spring screw is adjusted so that the impact force at the top dead center of the stroke is 10.5 ± 0.5 kg. The striking is performed so that the hammer hits the optical laminate horizontally. The above-mentioned striking is performed a total of 130 times, 13 times (stroke 150 mm) at intervals of 11.5 mm in the horizontal direction and 10 times (stroke 90 mm) at intervals of 9 mm in the vertical direction from the lower part of the optical laminate. After the striking, take an image of the optical laminate and analyze the area ratio (area %) of the sample surface where the glass has peeled off and is exposed from the optical laminate. Disclosure 2 is the interlayer film for laminated glass according to Disclosure 1, wherein the polyvinyl acetal resin has a weight average molecular weight of 220,000 to 310,000. Disclosure 3 is the interlayer film for laminated glass according to Disclosure 1 or 2, further containing a plasticizer. Disclosure 4 is the interlayer film for laminated glass according to Disclosure 3, wherein the plasticizer is at least one selected from the group consisting of triethylene glycol-di-2-ethylhexanoate, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, and derivatives in which a part of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups. The present disclosure 5 is an interlayer film for laminated glass according to any one of the present disclosures 1 to 4, having a creep compliance at 90 °C of 6.0×10 -5 Pa -1 or more. The present disclosure 6 is an interlayer film for laminated glass according to any one of the present disclosures 1 to 5, wherein at least one surface of the interlayer film for laminated glass has an uneven shape. The present disclosure 7 is a laminated film having a structure in which an interlayer film for laminated glass according to any one of the present disclosures 1 to 6 and a functional layer are laminated. The present disclosure 8 is a laminated film according to the present disclosure 7, having a structure in which the functional layer is sandwiched between a first interlayer film and a second interlayer film, and at least one of the first interlayer film and the second interlayer film is an interlayer film for laminated glass according to any one of the present disclosures 1 to 6. The present disclosure 9 is a laminated film according to the present disclosure 7 or 8, wherein the functional layer is at least one selected from the group consisting of a dimming film, a display element film, and a solar cell element. The present disclosure 10 is a laminated film according to any one of the present disclosures 7 to 9, wherein the functional layer is a dimming film, and the dimming film includes at least one selected from the group consisting of a polymer dispersed liquid crystal (PDLC), a guest-host liquid crystal (GHLC), a suspended particle device (SPD), an electrochromic device, and an electrophoretic film device. The present disclosure 11 is a laminated glass structure having a structure in which a laminated film according to any one of the present disclosures 7 to 10 is sandwiched between a pair of glass plates. The present disclosure 12 is a laminated glass structure according to the present disclosure 11, which is produced without using a gap filler.

Advantages of the Invention

[0011] According to the present disclosure, it is possible to provide an interlayer film for laminated glass that can suitably provide a laminated glass structure with good appearance and high safety. Further, according to the present disclosure, it is also possible to provide a laminated film and a laminated glass structure using such an interlayer film for laminated glass.

Brief Description of the Drawings

[0012]

Figure 1

Mode for Carrying Out the Invention

[0013] 〔Interlayer Film for Laminated Glass〕 The interlayer film for laminated glass of the present disclosure contains a polyvinyl acetal resin, and the film exposed area calculated by the above-described method is 90 area% or less. This film exposed area is preferably 88 area% or less, and more preferably 85 area% or less. Note that the lower limit of the film exposed area is 0 area%. Here, as the float plate glass, for example, clear glass (product name: "float plate glass") manufactured by Misato Glass Co., Ltd. is used, and as the autoclave, a constant temperature and pressure device "HP-55-MAH-H14" manufactured by Kyo Shin Engineering Co., Ltd. is used. The hammer has a length of 313 mm from the rotation axis to the striking surface, and the striking surface consists of protrusions with a diameter of Φ30 mm and a length of 20 mm. Image taking and analysis of the image taking photograph (referred to as image analysis) are performed, for example, as follows.

[0014] (Image Taking) ·Device: 3D micro X-ray CT for animal hospitals "StellaScan AX" manufactured by Rigaku Corporation ·Measurement Conditions Tube voltage: 80 kV Tube current: CT / Live 250 μA FOV: 30 mm Capture size: Large Exposure time: 2.5 min Magnification: 1.67 times Pixel size: 83.2 μm / pixel

[0015] In addition, after the impact, the above optical laminate is put into a bag with a chuck for preventing glass scattering, and the entire bag is used for image taking. At this time, a spacer or the like for fixing the measurement position may be used. The bag is fixed so that the entire striking surface is included in the X-ray irradiation portion during measurement with the above device, and the measurement is performed by setting it to Binning1 under the above conditions. After the measurement is completed, an image is obtained by performing reconstruction in the entire range.

[0016] (Image analysis) Using the Avizo 3D Pro 2023.1.1 (manufactured by Thermo Fisher Scientific) and the open-source image analysis software Fiji (ImageJ) for image analysis software, the images obtained as described above are analyzed according to the following procedure.

[0017] (i) Image cropping Using Avizo 3D Pro 2023.1.1, apply "Crop Editer" to the acquired images and adjust so that regions within at least 10 mm from the ends of the test pieces and regions not including the unimpacted regions are extracted. The size of the cropped image is, for example, x = 1600, y = 496, z = 900. The XZ cross-section shall be a cross-section parallel to the surface of the above optical laminate (i.e., a cross-section perpendicular to the thickness direction).

[0018] (ii) Extraction of test pieces Apply "Interactive Thresholding" to the image in (i) above (i.e., the image cropped in (i) above) and adjust the threshold so that the test pieces (i.e., the regions of the glass sheet and the interlayer film for the cover glass) are extracted. Subsequently, apply "Closing" and "Remove Small Spots" to remove noise from the extracted regions. The conditions for each analysis module are, for example, as follows. · Interactive Thresholding Intensity Range: 16000 - 65535 · Closing Size: 3 Other conditions shall be the initial values. · Remove Small Spots Size: 1000 Other conditions shall be the initial values.

[0019] (iii) Division of the front and back regions of the test piece Apply "Invert" to the image in (ii) above to invert the extraction area. Subsequently, apply "Separate Objects" to divide the area with the test piece as the boundary. The conditions for each analysis module are as follows, for example. ·Invert Set as the initial value. ·Separate Objects Marker Extent: 20 Set other conditions as the initial values.

[0020] (iv) Extraction of the image edge in the XZ cross-section Apply "Add a new label field" of "Segmentation Editer" to the image in (i) above to create a new label. After creation, switch the screen display to the XZ cross-section. Then, select the entire area in the first and last images of the slice position, and then apply "Add" of "SELECTION" to extract only the image edge in the XZ cross-section.

[0021] (v) Identification of the front and back areas of the test piece Apply "OR Image" to the image in (iii) above and add the extraction area of the image in (iv) above to the extraction area of the image in (iii). Subsequently, apply "Labeling" and "Dilation" to identify the front area and the back area of the test piece, respectively. The conditions for each analysis module are as follows, for example. ·Labeling Set as the initial value. ·Dilation Size: 1 Set other conditions as the initial values.

[0022] (vi) Extraction of the glass piece Apply "Interactive Thresholding" to the image in (i) above and adjust the threshold value so that the glass piece is extracted. Subsequently, apply "Remove Small Spots" to remove noise from the extraction area. The conditions for each analysis module are as follows, for example. ·Interactive Thresholding Intensity Range: 26000 - 65535 ·Remove Small Spots Size: 10 Other conditions shall be the initial values.

[0023] (vii) Glass piece volume analysis of the test piece surface area Apply "Interactive Thresholding" to the image in (v) above to extract the surface area of the test piece. Subsequently, apply "AND Image" to extract the overlapping area with the extraction area in (vi) above. Then, apply "Label Analysis" to analyze the volume (voxel) of each glass piece extraction area. The conditions for each analysis module shall be as follows, for example. ·Interactive Thresholding Intensity Range: 1 - 1 ·Label Analysis Shall be the initial value.

[0024] (viii) Calculation of the film exposed area ratio of the test piece surface area Using Fiji, apply "Threshold" and "Subtract" to the image obtained in (vii) above to extract the glass area of the test piece and set the luminance value of that area to "1". Subsequently, apply "Reslice" and "Zprojection" to change the orientation of the image and convert it into a 2D image with the luminance values integrated. Then, apply "Threshold" to extract the intermediate film area for the glass. Thereafter, apply "Set Measurements" and "Measure" to measure the film exposed area. The conditions for each analysis module shall be as follows, for example. ·Threshold (first one) Lower threshold level: 1 Upper threshold level: 65535 ·Subtract Value: 254 · Reslice Start at: Top · Z projection Start slice: 1 Stop slice: 496 Projection type: Sum Slices · Threshold (second) Lower threshold level: 0 Upper threshold level: 0 · Set Measurements Check Area And calculate the film exposure area ratio from the obtained film exposure area using the following formula: Film exposure area ratio (%) = Film exposure area (pixel) / {Image size x (pixel) × Image size z (pixel)} × 100 It is calculated based on. The resolution is the value specified by the device.

[0025] (ix) Glass piece volume analysis of the back region of the test piece "Interactive Thresholding" was applied to the image in (v) above to extract the back region of the test piece. Subsequently, "AND Image" was applied to extract the region overlapping with the extraction region in (vi) above. Then, "Label Analysis" was applied to analyze the volume (voxel) of each glass piece extraction region. The conditions for each analysis module are as follows, for example. · Interactive Thresholding Intensity Range: 2 - 2 · Label Analysis Use the initial value.

[0026] (x) Glass piece extraction from the back region of the test piece Apply "Interactive Thresholding" to the image in (v) above to extract the surface area of the test piece. Subsequently, apply "AND Image" to extract the area overlapping with the extraction area in (vi) above. Then, apply "Export Data As..." to output the extracted image. The conditions for each analysis module are, for example, as follows. ·Interactive Thresholding Intensity Range: 2 - 2

[0027] (xi) Calculation of the film exposed area ratio of the back area of the test piece Using Fiji, apply "Threshold" and "Subtract" to the image obtained in (x) above to extract the glass area of the test piece and set the luminance value of that area to "1". Subsequently, apply "Reslice" and "Zprojection" to change the orientation of the image and convert it into a two-dimensional image with the luminance values integrated. Then, apply "Threshold" to extract the intermediate film area for glass. After that, apply "Set Measurements" and "Measure" to measure the film exposed area. The conditions for each analysis module are, for example, as follows. ·Threshold (the first one) Lower threshold level: 1 Upper threshold level: 65535 ·Subtract Value: 254 ·Reslice Start at: Top ·Zprojection Start slice: 1 Stop slice: 496 Projection type: Sum Slices ·Threshold (the second one) Lower threshold level: 0 Upper threshold level: 0 ·Set Measurements Check Area Then, from the obtained film exposed area, the film exposed area ratio is calculated using the following formula: Film exposed area ratio (%) = Film exposed area (pixel) / {Image size x (pixel) × Image size z (pixel)} × 100 based on this formula.

[0028] Here, for example, by appropriately adjusting the amount of hydroxyl groups contained in the polyvinyl acetal resin, the metal salt content (such as the content of the Mg-based adhesion regulator described later, etc.), the weight average molecular weight of the polyvinyl acetal resin, the stereoregularity, the surface roughness of the interlayer film for laminated glass, etc., the exposed area of the interlayer film for laminated glass can be easily adjusted within the above range. Usually, ordinary interlayer films for laminated glass may contain magnesium (Mg) salts such as magnesium acetate, magnesium propionate, magnesium butyrate, magnesium 2-ethylbutyrate, magnesium 2-ethylhexanoate, magnesium octylate, magnesium decanoate, magnesium neodecanoate, and magnesium salts of carboxylic acids having 1 to 16 carbon atoms as adhesion regulators. However, the interlayer film for laminated glass of the present disclosure preferably does not contain these Mg-based adhesion regulators. Specifically, in 100% by mass of the total amount of the interlayer film for laminated glass of the present disclosure, the content of the Mg-based adhesion regulator is preferably less than 1% by mass, and more preferably less than 0.5% by mass.

[0029] The interlayer film for laminated glass may be a single-layer film having a single-layer structure or a multi-layer film having a multi-layer structure. When the interlayer film for laminated glass has a plurality of layers, the plurality of layers may have the same configuration as each other or different configurations. For example, in the plurality of layers, the types and contents of the constituent materials (e.g., thermoplastic resins) may be the same as each other or different. When the interlayer film for laminated glass is a multi-layer film, at least one of its layers contains a polyvinyl acetal resin, and it is preferable that the film exposed area is within the above range when only this layer is used as a sample and subjected to the above method. Among them, it is more preferable that at least one of the multi-layer films contains a polyvinyl acetal resin, and the film exposed area is within the above range when the entire multi-layer film is used as a sample and subjected to the above method. Incidentally, when the interlayer film for laminated glass has a plurality of layers, the number thereof is not particularly limited, but for example, it is 2 layers or 3 layers.

[0030] The interlayer film for laminated glass preferably has a creep compliance at 90 °C of 6.0×10 -5 Pa -1 or more per layer. Since such an interlayer film has high fluidity under bonding conditions, for example, a laminated glass structure can be preferably provided without disposing a gap filler around the functional layer. That is, when the interlayer film and the functional layer are disposed between a pair of glass plates and crimped, delamination of the layer interface, residual air, and foaming are sufficiently suppressed. Further, for example, even when this crimping is performed under low-temperature conditions, residual air and foaming are sufficiently suppressed. Further, for example, even when this crimping is performed under low-pressure conditions, residual air and foaming are sufficiently suppressed. Therefore, the obtained laminated glass structure can be more excellent in transparency and have a better appearance.

[0031] The above creep compliance is more preferably 8.0×10 -5 Pa -1 or more, still more preferably 1.0×10 -4 Pa -1 or more, and even more preferably 1.3×10 -4 Pa -1The above is particularly preferred. The upper limit of the above creep compliance is 1.0×10 -3 Pa -1 or less, preferably 7.0×10 -4 Pa -1 or less, more preferably 5.0×10 -4 Pa -1 or less. More particularly, the above creep compliance is 6.0×10 -5 Pa -1 or more and 1.0×10 -3 Pa -1 or less, preferably 6.0×10 -5 Pa -1 or more and 7.0×10 -4 Pa -1 or less, more preferably 6.0×10 -5 Pa -1 or more and 5.0×10 -4 Pa -1 or less, still more preferably 8.0×10 -5 Pa -1 or more and 5.0×10 -4 Pa -1 or less, even more preferably 1.0×10 -4 Pa -1 or more and 5.0×10 -4 Pa -1 or less, particularly preferably 1.3×10 -4 Pa -1 or more and 5.0×10 -4 Pa -1 or less, most preferably.

[0032] The creep compliance at 90 °C per layer above is determined as follows. <Measurement method of creep compliance> As a measuring device, the dynamic viscoelasticity measuring system "MCR702e MultiDrive" manufactured by Anton Paar (purchased in 2023) is used. Using this measuring device, a circular sample with a diameter of 8 mm and a thickness of 0.76 mm made from one layer of the intermediate film is applied with a shear stress of 400 Pa at a measuring temperature of 90°C for 15 minutes to obtain the creep compliance J(t). The value of the obtained creep compliance J(t) at the 10-minute mark is taken as the value of the "creep compliance at 90°C per layer".

[0033] Here, when the thickness of the sample (intermediate film) to be measured is less than 0.76 mm, several such samples can be stacked and subjected to press molding or the like to make the thickness of the samples uniform. If the physical properties of the sample change due to hot pressing, it may be measured at the original thickness without pressing. Also, when the thickness of the sample is greater than 0.76 mm, the thickness may be made uniform by press molding or the like, or it may be measured at the original thickness. From the perspective of measurement accuracy, the measured thickness of the sample is preferably 0.3 mm or more and preferably 3 mm or less.

[0034] When setting the sample in the measuring device, in order to sufficiently press-bond the sample and the jig, the gap at room temperature is set to a pressure of 5 - 10 N, and then it is heated to 140°C with the gap fixed. Two minutes after reaching 140°C, the temperature reduction to the measuring temperature is started. After holding for 2 minutes after reaching the measuring temperature, the measurement of the creep compliance is started. As the measuring jig, a stainless-steel parallel plate with a diameter of 8 mm is used.

[0035] When the interlayer film for laminated glass is a multilayer film, it is preferable that at least one layer thereof satisfies the above creep compliance value. Further, as will be described later, when the interlayer film for laminated glass is laminated on a functional layer to form a laminate or a laminated glass structure, for example, considering the adhesion between the glass plate and the interlayer film for laminated glass, it is preferable that the layer adjacent to the glass plate among the layers constituting the interlayer film for laminated glass satisfies the above creep compliance value. Further, considering the adhesion between the interlayer film for laminated glass and the functional layer, it is preferable that the layer adjacent to the functional layer among the layers constituting the interlayer film for laminated glass satisfies the above creep compliance value, and it is more preferable that all layers satisfy the above creep compliance value.

[0036] The interlayer film for laminated glass preferably has a glass transition temperature (Tg) of -10°C or higher. When Tg is within this range, the penetration resistance and impact resistance are further improved. Tg is more preferably 0°C or higher, still more preferably 10°C or higher, and particularly preferably 15°C or higher. Tg is also preferably 50°C or lower. When Tg is within this range, the adhesion to a glass plate or the like tends to be better. Tg is more preferably 40°C or lower, and still more preferably 30°C or lower.

[0037] The Tg of the interlayer film for laminated glass is determined by viscoelasticity measurement. Specifically, it is determined as follows, for example. <Measurement Method of Tg> The test piece to be measured is stored in an environment of room temperature 23 ± 2°C and humidity 25 ± 5% for 12 hours. Then, using a viscoelasticity measuring device "ARES-G2" manufactured by TA Instruments, the viscoelasticity is measured. A parallel plate with a diameter of 8 mm is used as a jig, and the temperature is decreased from 100°C to -20°C at a temperature decreasing rate of 3°C / min in a shear mode, and the measurement is performed under the conditions of a frequency of 1 Hz 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).

[0038] The interlayer film for laminated glass contains a polyvinyl acetal resin. That is, the interlayer film for laminated glass has a resin layer containing a polyvinyl acetal resin. Such an interlayer film for laminated glass has good adhesiveness to various adherends (such as functional layers and glass plates, etc.). By using such an interlayer film, a laminated glass structure excellent in impact resistance and the like can be provided. Further, by adjusting the weight average molecular weight, glass transition temperature of the resin, and / or intermolecular interaction, etc. of the polyvinyl acetal resin used, it becomes easy to adjust the above-mentioned creep compliance per layer within a predetermined range. When the interlayer film for laminated glass is a multilayer film, it is preferable that at least the layer satisfying the above creep compliance value is the above resin layer. In addition, each component contained in the interlayer film for laminated glass may be used alone as only one kind, or two or more kinds may be used in combination. Hereinafter, the polyvinyl acetal resin will be described in detail.

[0039] The polyvinyl acetal resin is obtained by acetalizing polyvinyl alcohol with an aldehyde. Each raw material of the polyvinyl acetal resin may be used alone as only one kind, or two or more kinds may be used in combination.

[0040] The aldehyde is not particularly limited. For example, aldehydes having 1 to 10 carbon atoms are preferably used. The aldehydes having 1 to 10 carbon atoms are not particularly limited. For example, n-butyl aldehyde, isobutyl aldehyde, n-valeraldehyde, 2-ethylbutyl aldehyde, n-hexyl aldehyde, n-octyl aldehyde, n-nonyl aldehyde, n-decyl aldehyde, formaldehyde, acetaldehyde, and benzaldehyde, etc. can be mentioned. Among these, the above aldehyde is preferably n-butyl aldehyde, n-hexyl aldehyde, or n-valeraldehyde, and n-butyl aldehyde is more preferable. Therefore, the polyvinyl acetal resin is preferably a polyvinyl butyral resin.

[0041] Polyvinyl alcohol can be obtained, for example, by saponifying a polyvinyl ester such as polyvinyl acetate. The degree of saponification of polyvinyl alcohol is generally 70 to 99.9 mol%.

[0042] The average degree of polymerization of polyvinyl alcohol is preferably from 1000 to 3000. By using such polyvinyl alcohol, the polyvinyl acetal resin is likely to have a preferable weight average molecular weight as described later. The average degree of polymerization of polyvinyl alcohol is more preferably from 1100 to 2500, still more preferably from 1200 to 2000, and particularly preferably from 1300 to 1700.

[0043] As the polyvinyl alcohol, two or more polyvinyl alcohols having different average degrees of polymerization may be used. In this case, it is preferable to produce a polyvinyl acetal resin using a mixture of two or more polyvinyl alcohols as a raw material.

[0044] When using two or more polyvinyl alcohols, for example, as the polyvinyl alcohol, it is preferable to use a first polyvinyl alcohol having an average degree of polymerization of 1500 or more and a second polyvinyl alcohol having an average degree of polymerization of 1200 or less. The average degree of polymerization of the first polyvinyl alcohol is preferably from 1500 to 3500, more preferably from 1600 to 2500, and still more preferably from 1600 to 2000. Also, the average degree of polymerization of the second polyvinyl alcohol is preferably from 200 to 1200, more preferably from 300 to 900, and still more preferably from 400 to 850.

[0045] When the first polyvinyl alcohol and the second polyvinyl alcohol are used in combination, their blending ratios are not particularly limited. For example, based on 100% by mass of the total amount of the first polyvinyl alcohol and the second polyvinyl alcohol, the blending amount of the second polyvinyl alcohol is preferably 1 to 50% by mass, more preferably 3 to 40% by mass, still more preferably 5 to 35% by mass, and particularly preferably 10 to 30% by mass.

[0046] The average degree of polymerization of polyvinyl alcohol is determined by a method in accordance with JIS K6726 (1994) "Test Methods for Polyvinyl Alcohol". When two or more types of polyvinyl alcohol are used as raw materials, the average degree of polymerization of polyvinyl alcohol can be estimated by calculation from the average degree of polymerization of each polyvinyl alcohol.

[0047] The polyvinyl acetal resin preferably has a weight-average molecular weight of 100,000 to 300,000. Thereby, the adhesiveness of the intermediate film to various adherends and the penetration resistance of the laminated glass structure are further improved. Further, by using a polyvinyl acetal resin having a weight-average molecular weight within the above range, it becomes easier to adjust the creep compliance per layer of the intermediate film within the above-described range. The lower limit of the weight-average molecular weight of the polyvinyl acetal resin is more preferably 180,000 or more, still more preferably 210,000 or more, and particularly preferably 220,000 or more. The upper limit of the weight-average molecular weight of the polyvinyl acetal resin is more preferably 280,000 or less, still more preferably 260,000 or less, and particularly preferably 250,000 or less. The range of the weight-average molecular weight of the polyvinyl acetal resin is more preferably 180,000 to 280,000, still more preferably 210,000 to 260,000, and particularly preferably 220,000 to 250,000.

[0048] The weight-average molecular weight of the polyvinyl acetal resin is determined, for example, by the following measurement method using gel permeation chromatography. <Measurement Method of Molecular Weight> The polyvinyl acetal resin is dissolved in an N-methyl-2-pyrrolidone solution to which lithium bromide is added so as to be 10 mM to obtain a solution having a polyvinyl acetal resin concentration of 0.05% by mass. The obtained solution is filtered using a syringe filter (manufactured by Merck, Millex-LH 0.45 μm), and then the molecular weight is measured using gel permeation chromatography (manufactured by Waters, e2690). Then, the weight-average molecular weight (Mw) is calculated using a molecular weight calibration curve prepared with a monodisperse polystyrene standard sample. As a column, Shodex GPC KF-806L (manufactured by Showa Denko KK) is used, and as an eluent, an N-methyl-2-pyrrolidone solution added with lithium bromide to a concentration of 10 mM is used.

[0049] The hydroxyl group content of the polyvinyl acetal resin is preferably 15 mol% or more. Thereby, the adhesiveness of the intermediate film to various adherends is likely to be good, and the resulting laminated glass structure is excellent in terms of penetration resistance and the like. The hydroxyl group content of the polyvinyl acetal resin is preferably 38 mol% or less. Thereby, the flexibility of the intermediate film becomes good, and it is possible to prevent the resulting laminated glass structure from becoming too hard. Further, when the hydroxyl group content of the polyvinyl acetal resin is within the above range, the generation of bubbles during use in a high-temperature environment is sufficiently suppressed, and the high-temperature heat resistance of the intermediate film is further improved. The lower limit of the above hydroxyl group content is more preferably 20 mol% or more, and still more preferably 25 mol% or more. The upper limit of the above hydroxyl group content is more preferably 35% or less, and still more preferably 33 mol% or less.

[0050] Even when using polyvinyl butyral resin as the polyvinyl acetal resin, from the same viewpoint, the lower limit of the hydroxyl group content is preferably 15 mol% or more, more preferably 20 mol% or more, and still more preferably 25 mol% or more. The upper limit of the hydroxyl group content of the polyvinyl butyral resin is preferably 38 mol% or less, more preferably 35% or less, and still more preferably 33 mol% or less.

[0051] The hydroxyl group content of the polyvinyl acetal resin is a value obtained by dividing the amount of ethylene groups to which hydroxyl groups are bonded by the total amount of ethylene groups in the main chain and expressing the molar fraction as a percentage. The amount of ethylene groups to which hydroxyl groups are bonded can be measured, for example, in accordance with JIS K6728 (1977) "Test Methods for Polyvinyl Butyral".

[0052] The degree of acetalization of the polyvinyl acetal resin is preferably 47 mol% or more, more preferably 55 mol% or more, and still more preferably 60 mol% or more. The degree of acetalization of the polyvinyl acetal resin is also preferably 85 mol% or less, more preferably 80 mol% or less, and still more preferably 75 mol% or less. When the acetal group is a butyral group and the polyvinyl acetal resin is a polyvinyl butyral resin, the degree of acetalization means the degree of butyralization.

[0053] The degree of acetalization of the polyvinyl acetal resin is a value obtained by dividing, by the total amount of ethylene groups in the main chain, the value obtained by subtracting the amount of ethylene groups to which a hydroxyl group is bonded and the amount of ethylene groups to which an acetyl group is bonded from the total amount of ethylene groups in the main chain, and is expressed as a percentage of the molar fraction. The degree of acetalization can be calculated from the results measured by a method conforming to JIS K6728 (1977), "Test Methods for Polyvinyl Butyral".

[0054] The degree of acetylation of the polyvinyl acetal resin is preferably 30 mol% or less. Thereby, the moisture resistance of the interlayer film is improved. The upper limit of the degree of acetylation is more preferably 20 mol% or less, still more preferably 10 mol% or less, and particularly preferably 2 mol% or less. The lower limit of the degree of acetylation is not particularly limited, but is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more.

[0055] The degree of acetylation of the polyvinyl acetal resin is a value obtained by dividing, by the total amount of ethylene groups in the main chain, the molar fraction obtained by dividing the amount of ethylene groups to which an acetyl group is bonded, and is expressed as a percentage. The amount of ethylene groups to which an acetyl group is bonded can be measured, for example, in accordance with JIS K6728 (1977), "Test Methods for Polyvinyl Butyral".

[0056] The polyvinyl acetal resin is preferably an unmodified polyvinyl acetal resin, but a modified polyvinyl acetal resin may also be used. A modified polyvinyl acetal resin has a structure other than an acetal group, a hydroxyl group, and an acetyl group (a modifying group), and preferably has the modifying group in a side chain. Examples of the modifying group include those having a polyalkylene oxide structure in the side chain, those having an alkyl group other than an acetal group and an acetyl group (for example, having about 2 to 30 carbon atoms) in the side chain, and the like. The modification amount is not particularly limited, but is, for example, about 0.1 mol% or more and about 10 mol%. The modification amount represents the ratio of the functional group to all vinyl monomer units constituting the polyvinyl acetal resin.

[0057] The interlayer film for laminated glass may further contain a thermoplastic resin other than the polyvinyl acetal resin. Examples of the thermoplastic resin other than the polyvinyl acetal resin include (meth)acrylic resins, polyvinyl alcohol resins, polyurethane resins (PU), ethylene-vinyl acetate copolymer resins (EVA), saponified ethylene-vinyl acetate copolymers (EVOH), ethylene-methacrylic acid copolymer resins, ionomer resins, isobutylene resins, styrene-isoprene copolymer resins, and styrene-butadiene copolymer resins. However, it is preferable that the main component of the resin constituting the interlayer film for laminated glass is a polyvinyl acetal resin. Specifically, in 100% by mass of the total amount of the resin components constituting the resin layer of the interlayer film for laminated glass (when the interlayer film includes multiple resin layers, each resin layer), the polyvinyl acetal resin is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 90% by mass or more, and most preferably 100% by mass. That is, it is most preferable that the resin constituting the interlayer film for laminated glass is only a polyvinyl acetal resin.

[0058] The polyvinyl acetal resin is preferably produced by a production method including, for example, a mixing step of mixing polyvinyl alcohol and an aldehyde, and an aging step of aging the mixture obtained in the mixing step. The acetalization of polyvinyl alcohol proceeds by the above mixing step and aging step, and thus a polyvinyl acetal resin is obtained. In addition, when producing a thermoplastic resin such as a polyvinyl acetal resin, the intermolecular interaction can be adjusted by changing the reaction conditions and aging conditions.

[0059] In the above mixing step, polyvinyl alcohol and an aldehyde may be mixed according to a conventional method. Further, a catalyst such as an acid catalyst for promoting the acetalization reaction may be added in addition to polyvinyl alcohol and an aldehyde. For example, an aldehyde may be added to a mixture obtained by adding an acid catalyst to polyvinyl alcohol under low temperature conditions of about 0 to 40°C. Further, when two or more kinds of polyvinyl alcohol are used in combination (for example, when two or more kinds of polyvinyl alcohol having different molecular weights are used), the two or more kinds of polyvinyl alcohol may be mixed with an aldehyde.

[0060] In the above aging step, for example, after adding a catalyst such as an acid catalyst to the mixture (reaction mixture) obtained by the above mixing step, it is heated to the aging temperature and held at the aging temperature for a certain period of time. After the reaction mixture is held at the aging temperature for a certain period of time, it is appropriately cooled and then neutralized, and thereafter, washing with water, drying, etc. may be performed as necessary.

[0061] Examples of the acid catalyst that can be added in the above mixing step and aging step include inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, boric acid, and sulfuric acid. Further, in the above aging step, the concentration of the acid catalyst is preferably adjusted to about 0.5% by mass or more and 5% by mass or less, and more preferably adjusted to about 1% by mass or more and 2.5% by mass or less.

[0062] The aging temperature in the above aging process may be relatively low. For example, it is preferably 40°C or higher and 60°C or lower, more preferably 35°C or higher and 60°C or lower, and even more preferably 40°C or higher and 57°C or lower. The time to maintain at the above aging temperature (aging time) may be longer than a certain time. For example, it is preferably 75 minutes or longer and 180 minutes or shorter, more preferably 90 minutes or longer and 150 minutes or shorter, and even more preferably 100 minutes or longer and 140 minutes or shorter. When the aging temperature and aging time are respectively within the above ranges, it is presumed that the hydroxyl groups are likely to be uniformly distributed in the polyvinyl acetal resin molecule, and thereby, it is considered that the low molecular weight components are reduced and the molecular weight distribution becomes smaller.

[0063] (Plasticizer) The interlayer film for laminated glass preferably further contains a plasticizer. That is, the above resin layer preferably further contains a plasticizer. When the interlayer film for laminated glass further contains a plasticizer in addition to the polyvinyl acetal resin, the interlayer film becomes more flexible, and the adhesiveness of the interlayer film to various adherends and the penetration resistance of the laminated glass structure obtained using the interlayer film are further improved. In addition, by adjusting the type and content of the plasticizer, it becomes easier to adjust the above creep compliance per layer of the interlayer film within a predetermined range.

[0064] Examples of the plasticizer include, for example, organic ester plasticizers; organic phosphate plasticizers such as organic phosphoric acid ester plasticizers and organic phosphorous acid ester plasticizers; organic ether plasticizers such as polyalkylene glycol-based plasticizers; alcohol-based plasticizers; etc. Among these, the plasticizer is preferably an organic ester plasticizer and / or an organic ether-based plasticizer.

[0065] Preferred examples of the organic ester plasticizer include monobasic organic acid esters and polybasic organic acid esters.

[0066] Examples of the monobasic organic acid ester include esters of glycol and monobasic organic acid. The glycol is preferably a polyalkylene glycol or a monoalkylene glycol. The number of carbon atoms of each alkylene unit constituting the polyalkylene glycol and the monoalkylene glycol is preferably 2 to 4, more preferably 2 or 3. In the polyalkylene glycol, the number of repeating alkylene units is preferably 2 to 10, more preferably 2 to 4. Specific examples of the glycol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, butylene glycol and the like. Examples of the monobasic organic acid include organic acids having 3 to 10 carbon atoms, specifically, for example, butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptanoic acid, n-octylic acid, 2-ethylhexanoic acid, n-nonanoic acid and decylic acid and the like.

[0067] Specific examples of the monobasic organic acid ester include, for example, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethylbutyrate, 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, and the like.

[0068] Examples of the polybasic organic acid ester include, for example, ester compounds of a dibasic organic acid having 4 to 12 carbon atoms and an alcohol having 4 to 10 carbon atoms. Examples of the dibasic organic acid having 4 to 12 carbon atoms include adipic acid, sebacic acid, azelaic acid, and the like. The alcohol having 4 to 10 carbon atoms may be linear, may have a branched structure, or may have a cyclic structure.

[0069] Specific examples of the polybasic organic acid esters include, for example, dibutyl sebacate, dioctyl azelate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, diisononyl adipate, heptyl nonyl adipate, dibutyl carbitol adipate, mixed adipic acid esters, etc. The polybasic organic acid esters may also be oil-modified alkyds of sebacic acid, etc. Examples of the mixed adipic acid esters include adipic acid esters prepared from two or more alcohols selected from the group consisting of alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms.

[0070] The organic ester plasticizer is not limited to the complete esters of the above-mentioned esters, and may be a partial ester. The organic ester plasticizer may be, for example, a partial ester of a glycol and a monobasic organic acid, or a partial ester of a dibasic organic acid and an alcohol. Specific examples include, for example, triethylene glycol-mono-2-ethylhexanoate, etc.

[0071] The organic ester plasticizer may also be a partial ester of a trivalent or higher alcohol such as glycerin and a monobasic organic acid. The number of carbon atoms of the monobasic organic acid is preferably, for example, 3 to 24, more preferably 6 to 18. Specific examples include, for example, mono- or diesters of glycerin and stearic acid, mono- or diesters of glycerin and 2-ethylhexanoic acid, etc.

[0072] Among the above-mentioned organic ester plasticizers, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferably used.

[0073] Preferred examples of the organic phosphorus plasticizers include organic phosphate plasticizers, organic phosphite plasticizers, etc. Specific examples of the organic phosphorus plasticizers include phosphate esters such as tributoxyethyl phosphate, isodecyl phenyl phosphate, and triisopropyl phosphate, etc.

[0074] Preferred examples of the organic ether plasticizer include polyalkylene glycol plasticizers. Examples of the polyalkylene glycol plasticizer include polyoxyalkylene compounds having a polyoxyalkylene structure, specifically, polyhydric alcohol compounds such as glycols; ester compounds of glycols and monobasic or polybasic organic acids; ether compounds of monohydric or polyhydric alcohols and polyoxyalkylene; and the like. Here, examples of the glycol include polyoxyalkylene glycols and their derivatives, and examples of the polyoxyalkylene include polyoxyethylene, polyoxypropylene, polyoxybutylene, random copolymers or block copolymers thereof, and the like. The polyoxyalkylene compound may be a polyhydric alcohol compound, an ester compound, an ether compound, or other compounds as described above.

[0075] Examples of the polyoxyalkylene compound include polyoxyalkylene or its derivatives. More specifically, polyoxyalkylene glycols composed of polyoxyalkylene, ether compounds of polyoxyalkylene and polyhydric alcohols, and the like can be mentioned. These may all have hydroxyl groups at all terminals, or a part or all of the terminal hydroxyl groups may be derivatives in which a hydrogen atom is substituted with an alkyl group or an acyl group. The number of carbon atoms of the alkyl group and the acyl group is not particularly limited, but may be about 1 to 8, preferably 1 to 4.

[0076] Examples of the polyoxyalkylene glycol include polyoxyethylene polyoxypropylene glycols such as polyethylene glycol (polyoxyethylene glycol), polypropylene glycol (polyoxypropylene glycol), poly(ethylene oxide / propylene oxide) block copolymer, poly(ethylene oxide / propylene oxide) random copolymer, and polyoxybutylene glycols such as polytetramethylene glycol.

[0077] Examples of ether compounds of polyoxyalkylene and polyhydric alcohol include ether compounds of polyhydric alcohols such as glycerol, diglycerol, trimethylolpropane, erythritol, pentaerythritol, and bisphenol A with polyoxyalkylene. Specifically, examples include polyoxyethylene glyceryl ether, polyoxypropylene glyceryl ether, polyoxyethylene diglyceryl ether, polyoxypropylene diglyceryl ether, polyoxyalkylene pentaerythritol ether, and the like. Further, examples of derivatives in which some or all of the hydrogen atoms of the terminal hydroxyl group are substituted with an alkyl group or an acyl group include the above-mentioned polyoxyalkylene glycols and derivatives in which some or all of the hydrogen atoms of the terminal hydroxyl group of the ether compound are substituted with an alkyl group or an acyl group. Specifically, examples include polyoxyethylene glycol monomethyl ether, polyoxyethylene glycol dimethyl ether, polyoxypropylene glycol monomethyl ether, polyoxypropylene glycol dimethyl ether, polyoxyethylene polyoxypropylene glycol monomethyl ether, polyoxyethylene polyoxypropylene glycol dimethyl ether, polyoxyethylene glycol monobutyl ether, polyoxypropylene glycol monobutyl ether, polyoxyethylene polyoxypropylene monobutyl ether, and the like.

[0078] Among the above-mentioned polyoxyalkylene compounds, compounds having a polyoxyethylene structure, a polyoxypropylene structure, or a polyoxyethylene polyoxypropylene structure are preferred. Among them, compounds having a polyoxypropylene structure or a polyoxyethylene polyoxypropylene structure are more preferred. Specifically, the polyoxyalkylene compound is preferably polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, or a derivative in which some of the hydrogen atoms of their terminal hydroxyl groups are substituted with an alkyl group.

[0079] Preferred examples of the alcohol-based plasticizer include various polyhydric alcohols such as butanediol, hexanediol, trimethylolpropane, pentaerythritol, etc. Among these, trimethylolpropane is preferred.

[0080] Among the above-described compounds, the plasticizer is preferably at least one selected from the group consisting of triethylene glycol-di-2-ethylhexanoate (3GO), polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, and derivatives in which a part of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups, and 3GO is more preferred.

[0081] When the resin layer further contains a plasticizer, the content of the plasticizer (when two or more are included, the total amount thereof) is preferably 10 parts by mass or more with respect to 100 parts by mass of the thermoplastic resin contained in the resin layer (one layer). Thereby, the intermediate film becomes moderately flexible, and the adhesiveness of the intermediate film to various adherends and the penetration resistance of the laminated glass structure are further improved. The content of the plasticizer with respect to 100 parts by mass of the thermoplastic resin is more preferably 15 parts by mass or more, further preferably 30 parts by mass or more, particularly preferably 35 parts by mass or more. The content of the plasticizer is also preferably 100 parts by mass or less with respect to 100 parts by mass of the thermoplastic resin. Thereby, separation of the plasticizer from the intermediate film is sufficiently prevented. The content of the plasticizer with respect to 100 parts by mass of the thermoplastic resin is more preferably 70 parts by mass or less, further preferably 60 parts by mass or less, particularly preferably 50 parts by mass or less, and most preferably 45 parts by mass or less.

[0082] (Other additives) The interlayer film for laminated glass may also appropriately contain known additives that can be used in combination with polyvinyl acetal resins and the like. That is, for example, the resin layer may contain known additives. Examples of additives other than plasticizers include ultraviolet absorbers, heat insulating agents, coloring agents, infrared absorbers, antioxidants, light stabilizers, adhesion adjusters, fluorescent brighteners, crystal nucleating agents, and the like. Each additive may be used alone or in combination of two or more kinds.

[0083] (Ultraviolet absorber) When the interlayer film for laminated glass contains an ultraviolet absorber, degradation of the functional layer due to ultraviolet rays is sufficiently suppressed. For example, it is preferable that the resin layer included in at least one of the interlayer films for laminated glass further contains an ultraviolet absorber.

[0084] The ultraviolet absorber is not particularly limited, and examples thereof include compounds having a malonic acid ester structure, compounds having an oxalic acid anilide structure, compounds having a benzotriazole structure, compounds having a benzophenone structure, compounds having a triazine structure, compounds having a benzoate structure, compounds having a hindered amine structure, compounds having an indole structure, and the like. Among these, from the viewpoint of excellent compatibility with thermoplastic resins and weather resistance, the ultraviolet absorber is preferably a compound having a benzotriazole structure. Examples of the compound having a benzotriazole structure include Tinuvin 234, Tinuvin 326, Tinuvin 327, Tinuvin 640, Tinuvin 928 (manufactured by BAF); Eversorb 88, Eversorb 109 (manufactured by Everlight Chemical), etc., which are commercially available.

[0085] When the resin layer contains an ultraviolet absorber, the content of the ultraviolet absorber (the total amount when two or more kinds are included) is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, based on 100% by mass of the total amount of the materials constituting the resin layer (one layer). The content of the ultraviolet absorber is also preferably 5% by mass or less, more preferably 3% by mass or less, based on 100% by mass of the total amount of the materials constituting one layer of the resin layer.

[0086] (Heat insulation agent) When the interlayer film for laminated glass contains a heat insulation agent, deterioration of the functional layer due to heat is sufficiently suppressed. For example, it is preferable that the resin layer of the polyvinyl acetal resin further contains a heat insulation agent. Further, the polyvinyl acetal resin may have a layer made of a heat insulation agent (for example, a layer made of the following heat insulation particles) or a layer containing a heat insulation agent separately from or in addition to the resin layer.

[0087] The heat insulation agent is a material that can absorb infrared rays (also referred to as heat rays) of 780 nm or more. Specifically, the heat insulation agent is preferably heat insulation particles. The heat insulation particles are made of an inorganic material, and specific examples thereof include metal oxide particles and particles other than metal oxide particles such as lanthanum hexaboride (LaB6) particles. Examples of the metal oxide particles include tin oxide particles such as aluminum-doped tin oxide particles, indium-doped tin oxide particles, and antimony-doped tin oxide particles (ATO particles); zinc oxide particles such as gallium-doped zinc oxide particles (GZO particles), indium-doped zinc oxide particles (IZO particles), aluminum-doped zinc oxide particles (AZO particles), tin-doped zinc oxide particles, and silicon-doped zinc oxide particles; titanium oxide particles such as niobium-doped titanium oxide particles; indium oxide particles such as tin-doped indium oxide particles (ITO particles); sodium-doped tungsten oxide particles, cesium-doped tungsten oxide particles (CWO particles); tungsten oxide particles such as thallium-doped tungsten oxide particles and rubidium-doped tungsten oxide particles; and the like. Further, heat insulation particles other than these may be used. Among these, from the viewpoint of high heat ray shielding function, the heat insulation agent is preferably metal oxide particles, more preferably at least one selected from the group consisting of ATO particles, GZO particles, ITO particles, and CWO particles, and ITO particles and / or CWO particles are more preferable.

[0088] The average particle diameter of the heat shielding particles preferably has a lower limit of 10 nm or more, more preferably 20 nm or more. When the average particle diameter is in such a range, the heat ray shielding property by the heat shielding particles is further enhanced. Also, the average particle diameter of the heat shielding particles preferably has an upper limit of 100 nm or less, more preferably 80 nm or less, and still more preferably 50 nm or less. When the average particle diameter is in such a range, it becomes difficult to shield visible light by the heat shielding particles. Here, the "average particle diameter" refers to the volume average particle diameter. The average particle diameter can be measured using a particle size distribution measuring device (such as "UPA-EX150" manufactured by Nikkiso Co., Ltd.).

[0089] The heat shielding agent may also be an organic material or an organic-inorganic composite material (also referred to as a shielding compound) capable of absorbing infrared rays, and these are also near-infrared absorbing agents. The near-infrared absorbing agent has an absorption maximum in the near-infrared region, and the absorption maximum exhibits the maximum absorption among the absorption maxima existing in the wavelength region of 380 nm to 2500 nm. Specifically, the near-infrared absorbing agent has the maximum absorption in a wavelength region of 720 nm or more, preferably 750 nm or more and 2000 nm or less.

[0090] The heat shielding compound is preferably at least one selected from the group consisting of phthalocyanine compounds, naphthalocyanine compounds, and anthracyanine compounds. The phthalocyanine compound is phthalocyanine or a phthalocyanine derivative having a phthalocyanine skeleton, and preferably contains a metal atom therein. The naphthalocyanine compound is naphthalocyanine or a naphthalocyanine derivative having a naphthalocyanine skeleton, and preferably contains a metal atom therein. The anthracyanine compound is anthracyanine or an anthracyanine derivative having an anthracyanine skeleton, and preferably contains a metal atom therein. In the phthalocyanine compound, naphthalocyanine compound, and anthracyanine compound, the metal atom serves as the central metal of each of the naphthalocyanine skeleton, naphthalocyanine skeleton, and anthracyanine skeleton.

[0091] Among the above, the heat shielding compound is more preferably at least one selected from the group consisting of phthalocyanine compounds and naphthalocyanine compounds, and still more preferably a phthalocyanine compound. Further, as the above metal atom, a vanadium atom is preferable. Therefore, as the heat shielding compound, a phthalocyanine compound containing a vanadium atom is particularly preferable. The vanadium atom generally exists in a state where an oxygen atom is bonded (V=O). Further, it is also preferable to use tungsten oxide particles and a phthalocyanine compound in combination as the heat shielding agent, and it is more preferable to use CWO particles and a phthalocyanine compound in combination.

[0092] When the resin layer contains a heat shielding agent, the content of the heat shielding agent (when two or more are included, the total amount thereof) is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, and still more preferably 0.15% by mass or more, based on 100% by mass of the total amount of the materials constituting the resin layer (one layer). The content of the heat shielding agent is also preferably 1.5% by mass or less, more preferably 1.2% by mass or less, and still more preferably 0.9% by mass or less, based on 100% by mass of the total amount of the materials constituting one layer of the resin layer.

[0093] (Colorant) When the interlayer film for laminated glass contains a colorant, the laminated glass structure obtained using the interlayer film is favorably colored in a desired color tone, enhancing the design property. For example, it is preferable that the above resin layer of the interlayer film for laminated glass further contains a colorant. Examples of the colorant include pigments or dyes, etc., and both a pigment and a dye may be used in combination. There are also colorants classified into both pigments and dyes.

[0094] Examples of the pigment include perylene compounds, threne compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, perinone compounds, phthalocyanine compounds, indanthrene compounds, indigo compounds, isoindolinone compounds, nickel complex compounds, methine compounds, azomethine compounds, dioxazine, azo compounds, and carbon black, etc.

[0095] Examples of the dye include perylene compounds, threne compounds, quinacridone compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, perinone compounds, phthalocyanine compounds, indanthrene compounds, indigo compounds, isoindolinone compounds, nickel complex compounds, methine compounds, azomethine compounds, dioxazine, and azo compounds.

[0096] When the resin layer contains a colorant, the content of the colorant (the total amount when two or more kinds are included) is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, and still more preferably 0.001% by mass or more in 100% by mass of the total amount of the materials constituting the resin layer (one layer). The content of the dye is also preferably 0.15% by mass or less, more preferably 0.12% by mass or less in 100% by mass of the total amount of the materials constituting one layer of the resin layer.

[0097] When the interlayer film for laminated glass contains a pigment as a colorant in particular, the content of the pigment (the total amount when two or more kinds are included) is preferably 0.0001% by mass or more, more preferably 0.01% by mass or more, and still more preferably 0.02% by mass or more in 100% by mass of the total amount of the materials constituting the resin layer (one layer). The content of the pigment is also preferably 0.15% by mass or less, more preferably 0.12% by mass or less in 100% by mass of the total amount of the materials constituting one layer of the resin layer. Note that the pigment that can be contained in the interlayer film may be only one kind, or two or more kinds, or three or more kinds, or ten or less kinds, or five or less kinds.

[0098] When the interlayer film for laminated glass contains a dye as a coloring agent in particular, the content of the dye (when two or more kinds are contained, the total amount thereof) is preferably 0.00001% by mass or more, more preferably 0.0001% by mass or more, and still more preferably 0.001% by mass or more, based on 100% by mass of the total amount of the materials constituting the resin layer (one layer). The content of the dye is also preferably less than 0.015% by mass, more preferably 0.01% by mass or less, based on 100% by mass of the total amount of the materials constituting one resin layer. Note that the dye that can be contained in the interlayer film may be only one kind, two or more kinds, three or more kinds, ten or less kinds, or five or less kinds.

[0099] (Thickness) The thickness of the interlayer film for laminated glass is not particularly limited, but the layer thickness of the interlayer film (when it is a multilayer film, it means the total thickness) is preferably 100 μm or more, more preferably 200 μm or more, and still more preferably 300 μm or more. By having a certain thickness or more, the remaining air and foaming during the pressure bonding with the glass plate are further sufficiently suppressed.

[0100] Also, the film thickness (total thickness) of the interlayer film for laminated glass is preferably 2000 μm or less, more preferably 1300 μm or less, still more preferably 1000 μm or less, and particularly preferably 800 μm or less. By having a certain thickness or less, for example, it is possible to prevent the laminated glass structure obtained using the interlayer film from becoming unnecessarily thick.

[0101] Preferably, the thickness of the layer satisfying the above creep compliance value occupies a certain proportion or more of the total thickness of the interlayer film for laminated glass. Thereby, the remaining air and foaming during the pressure bonding with the glass plate are further sufficiently suppressed. For example, when the interlayer film for laminated glass is a multilayer film, when the film thickness (total thickness) of the interlayer film for laminated glass is taken as 100%, the thickness of the layer satisfying the above creep compliance value is preferably 10 to 100%, more preferably 30 to 100%, still more preferably 50 to 100%, particularly preferably 75 to 100%, and most preferably 100%.

[0102] In addition, when a laminated glass structure is formed using the above-mentioned interlayer film for laminated glass as described later, the thickness of the layer (the total thickness when two or more such layers are included) satisfying the above creep compliance value is preferably 10 to 50%, more preferably 20 to 40%, based on 100% of the total thickness of the laminated glass structure.

[0103] (concave-convex shape) At least one surface of the interlayer film for laminated glass preferably has a concave-convex shape. More specifically, it is preferable that at least one surface of the interlayer film has a plurality of concave portions and a plurality of convex portions, and it is more preferable that both surfaces of the interlayer film have a plurality of concave portions and a plurality of convex portions. Further, when the interlayer film for laminated glass is a multilayer film, it is preferable that one or both surfaces of the outermost layer of the interlayer film have a concave-convex shape.

[0104] The concave portion preferably has a groove shape with a continuous bottom. The groove shape with a continuous bottom is also referred to as a "scratched line shape". Therefore, the surface of the interlayer film for laminated glass preferably has a scratched line-shaped concave portion, and it is more preferable that both surfaces of the interlayer film have a scratched line-shaped concave portion. For example, when attempting to preliminarily bond a glass plate and an interlayer film with a rubber bag to obtain a laminated glass structure, the ends are temporarily bonded first, and it may be difficult for the air near the center to escape. However, when the surface of the interlayer film has a scratched line-shaped concave portion, the air near the center can also escape easily, so the adhesiveness during preliminary bonding is improved.

[0105] At least one surface of the interlayer film for laminated glass preferably has a plurality of groove-shaped recesses. In this case, it is preferable that the plurality of groove-shaped recesses are arranged in parallel. Among them, it is more preferable that the adjacent groove-shaped recesses are regularly arranged in parallel. When pressing the laminated film in which the interlayer film is laminated between a pair of glass plates, the ease of air escape (also referred to as degassing property) is closely related to the connectivity and smoothness of the bottoms of the recesses on the surface of the interlayer film. By making the concavo-convex shape of at least one surface of the interlayer film into a shape in which adjacent groove-shaped recesses are regularly arranged in parallel, the connectivity of the bottoms is improved and the degassing property is further improved.

[0106] The interval Sm between adjacent groove-shaped recesses is preferably 100 μm or more and preferably 500 μm or less. When the interval Sm of the groove-shaped recesses is within this range, more excellent degassing property is exhibited. The lower limit of the interval Sm of the groove-shaped recesses is more preferably 160 μm or more, and the upper limit is more preferably 350 μm or less, and still more preferably 250 μm or less. The interval Sm of the groove-shaped recesses is obtained by observing the first surface and the second surface (observation range: 20 mm × 20 mm) of the interlayer film using an optical microscope (manufactured by SONIC, "BS-D8000III"), measuring the interval between adjacent recesses, and then calculating the average value of the shortest distances between the bottommost parts of adjacent recesses.

[0107] The regularly arranged groove-shaped recesses are preferably such that adjacent groove-shaped recesses are arranged in parallel at equal intervals, but the intervals between all adjacent groove-shaped recesses do not have to be equal. The groove-shaped recesses do not have to have a continuous groove shape at the bottom, and may have a dividing wall in a part of the bottom. Also, as long as the adjacent recesses are arranged in parallel regularly, the groove shape at the bottom does not have to be linear. For example, the groove shape at the bottom may be wavy or zigzag.

[0108] In an intermediate film having an uneven shape on at least one surface, the surface roughness (RzJIS94) of the surface having the uneven shape is preferably 10 to 80 μm. When the surface roughness is within this range, the intermediate film can exhibit excellent degassing properties. The above surface roughness is more preferably 20 to 65 μm, and even more preferably 20 to 50 μm.

[0109] The surface roughness (RzJIS94) can be measured in accordance with JIS B0601 (1994). Here, when the concave portion of the uneven shape on the surface is in the form of a scored line, the measurement is performed in the vertical direction so as to cross the direction in which the concave portions in the scored line direction are continuous. For example, as a measuring instrument, "Surfcorder SE300" manufactured by Kosaka Laboratory Ltd. etc. is used, the cut-off value at the time of measurement is 2.5 mm, the reference length is 2.5 mm, the measurement length is 12.5 mm, the preliminary length is 2.5 mm, the feed rate of the stylus is 0.5 mm / second, and the stylus shape is one with a tip radius of 2 μm and a tip angle of 60°. Also, the environment at the time of measurement is 23°C and 30RH%. The intermediate film to be measured is measured after being left standing in the environment at the time of measurement for 3 hours or more.

[0110] Also, in an intermediate film having an uneven shape on at least one surface, the surface roughness (Rc) of the surface having the uneven shape is preferably 10 to 40 μm. When the surface roughness is within this range, the intermediate film can exhibit excellent degassing properties. The above surface roughness (Rc) is more preferably 15 to 35 μm, and even more preferably 19 to 30 μm. Note that the surface roughness (Rc) can be measured in accordance with JIS B0601 (2013).

[0111] The intermediate film for laminated glass can be manufactured by, for example, extrusion molding or press molding, etc., but it is preferably manufactured by extrusion molding. Also, as a method for forming an uneven shape on the surface of the intermediate film, for example, an embossing roll method, a calendar roll method, a profile extrusion method, a melt fracture method, etc. can be mentioned. Among them, the embossing roll method is preferably adopted.

[0112] 〔Laminated film〕 The laminated film of the present disclosure has a structure in which the interlayer film for laminated glass of the present disclosure described above and a functional layer are laminated. For example, the laminated film of the present disclosure has a structure in which a functional layer is sandwiched between a first interlayer film and a second interlayer film, and at least one of the first interlayer film and the second interlayer film is the interlayer film for laminated glass of the present disclosure described above. The first interlayer film and the second interlayer film may have the same configuration as each other or may be different. Further, it is preferable that both the first interlayer film and the second interlayer film are the interlayer film for laminated glass of the present disclosure described above.

[0113] The functional layer is preferably located between the first interlayer film and the second interlayer film. The functional layer is not particularly limited as long as it is a layer having a predetermined function, but is preferably a functional film. The functional film is preferably, for example, a dimming film, a display element film, a hologram film, or an optical film, and examples of the optical film include a polarizing film, a retardation film, and an antireflection film. The functional layer may also be a solar cell element as described later. Thus, the form in which the functional layer is at least one selected from the group consisting of a dimming film, a display element film, and a solar cell element is one of the preferred forms of the laminated film of the present disclosure.

[0114] The functional film is more preferably a film provided with electronic components such as a dimming film and a display element film, and still more preferably a dimming film or a display element film. That is, it is preferable that the functional layer is at least one selected from the group consisting of a dimming film and a display element film.

[0115] Generally, films with electronic components tend to have their functions degraded or deactivated when autoclaves under high-temperature and high-pressure conditions are applied. In particular, when autoclaves under high-temperature and high-pressure conditions are applied to GHLC films, their functions tend to be degraded or deactivated, and color unevenness occurs in the resulting laminated glass structure due to heat shrinkage caused by pressure application and temperature changes during pressure bonding, making it unsuitable for practical use. However, by using the interlayer film for laminated glass of the present disclosure, the laminated glass structure can be preferably manufactured even by an autoclave at a low temperature. Therefore, functional layers such as GHLC films can be incorporated into the laminated glass structure without deactivation. Therefore, the laminated glass structure provided with the laminated film of the present disclosure can effectively exhibit the functions derived from the functional layer and sufficiently suppress the occurrence of color unevenness. In addition, since electronic wirings, shielding printed portions, etc. are provided on the film with electronic components, complex steps (thickness differences) are likely to occur. Therefore, air remaining or foaming is likely to occur between the interlayer film and the glass plate or the functional layer during pressure bonding. However, in the present disclosure, even when pressure bonding is performed at a low temperature, such air remaining and foaming are sufficiently suppressed. Therefore, the resulting laminated glass structure has excellent transparency and good appearance. In addition, a laminated glass structure (for example, window glass) incorporated with a dimming film or a display element film has high added value such as excellent designability.

[0116] A dimming film is a film-like member provided with a dimming element. Specifically, the dimming film preferably includes two resin films and a dimming layer disposed between the two resin films. Since the surfaces of the dimming film having such a configuration that are in contact with the first interlayer film and the second interlayer film respectively are made of a resin material, the adhesiveness to these interlayer films can be improved.

[0117] The resin film used for the dimming film is not particularly limited. For example, polyester resin films such as polyethylene terephthalate (PET) film and polyethylene naphthalate (PEN) film; (meth)acrylic resin film; triacetyl cellulose (TAC) film; polyether sulfone (PES) resin film; polyimide resin film; etc. may be mentioned. Among these, from the viewpoint of handleability and the like, the resin film is preferably a polyester resin film, and more preferably a PET film. In addition, a conductive layer constituting an electrode may be provided on the surface on the dimming layer side of each of the two resin films.

[0118] The dimming layer is one in which the visible light transmittance changes by switching the application and non-application of voltage between the conductive layers provided on each of the two resin films. Preferred examples of the dimming layer include, for example, liquid crystal layers such as polymer dispersed liquid crystal (also abbreviated as PDLC) and guest host liquid crystal (also abbreviated as GHLC); suspension particle devices (also abbreviated as SPD) including a resin matrix and a light adjustment suspension dispersed in the resin matrix; electrochromic material layers; electrophoresis layers including electrophoresis particles and a dispersant for dispersing the electrophoresis particles; etc. Therefore, the dimming film preferably includes at least one selected from the group consisting of PDLC, GHLC, SPD, electrochromic devices, and electrophoresis film devices. That is, the above functional layer preferably includes at least one dimming film selected from the group consisting of PDLC films, GHLC films, SPD films, electrochromic films, and electrophoresis film devices.

[0119] The display element film is a film-like member provided with a display element. Specifically, the display element film preferably includes a resin film and a display element mounted on the resin film, and more preferably includes two resin films and a display element disposed between the two resin films. The display element film having such a configuration can improve the adhesiveness to the first intermediate film and the second intermediate film. Note that, as the resin film used for the display element film, the resin film described above regarding the light control film can be appropriately selected and used. Further, a conductive layer constituting an electrode may be provided on the surface on the display element side of the resin film constituting the display element film.

[0120] The film provided with an electronic component is not limited to the light control film and the display element film, and may be other functional films. In other functional films, the electronic component may be mounted on the resin film in the same manner as the light control film and the display element film, but an aspect in which the electronic component is disposed between a pair of resin films is preferable.

[0121] Here, the GHLC film is a film-like member provided with GHLC (Guest-Host Liquid Crystal). Specifically, the GHLC film preferably includes two resin films and a GHLC layer disposed between the two resin films. The GHLC layer is composed of, for example, a liquid crystal composition in which a dichroic dye is dissolved as a guest in a host liquid crystal. Since the dichroic dye has a uniaxial light absorption axis and absorbs only light vibrating in the direction of the light absorption axis, the GHLC film provided with the GHLC layer can change the orientation of the dichroic dye in accordance with the movement of the liquid crystal by an electric field and control the direction of the light absorption axis, thereby changing the transmission state of the liquid crystal layer.

[0122] In the above laminate film, when a GHLC film is used as the functional layer, a spacer may be disposed between two resin films constituting the GHLC film in order to control the thickness (cell gap) of the GHLC layer. The spacer is not particularly limited, and for example, it may be a bead spacer or may be formed from a photoresist, for example, in a cylindrical shape. The shape of the spacer is not particularly limited, and examples include a spherical shape, a cylindrical shape, or a prismatic shape.

[0123] The functional layer may also be a solar cell element. By using a solar cell element as the functional layer, the laminated glass structure of the present disclosure can provide laminated glass for building-integrated photovoltaics (BIPV for short). The solar cell element is not particularly limited as long as it is a solar cell element used for BIPV. Examples include crystalline or thin-film silicon-based solar cell elements; compound semiconductor-based solar cell elements such as CIS, CIGS, CdTe, and GaAs; organic solar cell elements such as dye-sensitized, organic thin-film, and perovskite; and the like.

[0124] The above laminate film can be manufactured, for example, by thermocompression bonding a first intermediate film, a functional layer, and a second intermediate film. Further, when incorporating the above laminate film into the laminated glass structure, thermocompression bonding may be performed by first thermocompression bonding the first intermediate film, the functional layer, and the second intermediate film to form a laminate film, and then bonding the laminate film to a glass plate to form the laminated glass structure. Further, before pressing, the first intermediate film, the functional layer, and the second intermediate film are disposed between two glass plates, and when pressing the glass plate and the above laminate film together, the first intermediate film, the functional layer, and the second intermediate film may be pressed together.

[0125] [Laminated glass structure] The laminated glass structure of the present disclosure has a structure in which the laminated film of the present disclosure described above is sandwiched between a pair of glass plates. For example, the laminated glass structure includes a first glass plate, a first intermediate film, a functional layer, a second intermediate film, and a second glass plate in this order. The laminated glass structure may further have one or two or more arbitrary layers between each layer, or may have two or more functional layers as described later.

[0126] (Glass plate) The laminated glass structure has a first glass plate and a second glass plate. Each glass plate may be, for example, either inorganic glass or organic glass, but inorganic glass is preferred. Note that the first glass plate and the second glass plate may be made of the same type of material as each other, or may be made of different materials. For example, one of the first glass plate and the second glass plate may be inorganic glass and the other may be organic glass, but it is preferable that both the first glass plate and the second glass plate are inorganic glass or organic glass.

[0127] The inorganic glass is not particularly limited, and examples thereof include clear glass, float plate glass, tempered glass, colored glass, polished plate glass, patterned plate glass, wired glass, wired glass, ultraviolet absorption plate glass, infrared reflection plate glass, infrared absorption plate glass, green glass, and the like.

[0128] As the organic glass, what is generally called resin glass is used. Examples thereof include (meth)acrylic plates such as polycarbonate plates and polymethyl methacrylate plates, acrylonitrile styrene copolymer plates, acrylonitrile butadiene styrene copolymer plates, polyester plates such as polyethylene terephthalate plates, fluororesin plates, polyvinyl chloride plates, chlorinated polyvinyl chloride plates, polypropylene plates, polystyrene plates, polysulfone plates, epoxy resin plates, phenolic resin plates, unsaturated polyester resin plates, polyimide resin plates, and other various organic glass plates. The resin plate may be appropriately subjected to surface treatment or the like.

[0129] The thickness of each glass plate is not particularly limited, but for example, it is preferably about 0.1 to 15 mm, more preferably 0.5 to 5 mm. The thicknesses of the first glass plate and the second glass plate may be the same as each other or different from each other.

[0130] Other members may be attached to each glass plate as necessary. For example, a functional member may be attached to at least one of the first glass plate and the second glass plate. In this case, various functions are imparted to the glass plate. The other members are preferably members constituting, for example, an electronic device or an optical member, and more preferably members constituting a display device. Examples of the display device include a liquid crystal display device, an organic EL display device, an LED display device, and a segment display device, and among them, a liquid crystal display device is preferable. The display device includes, for example, a display panel in which a display layer such as a liquid crystal layer or an organic EL layer, a light emitting element, etc. are provided on a glass plate as a substrate, but the glass plate as the substrate may be used as the first glass plate and / or the second glass plate. Each glass plate may also have various functional layers laminated thereon, such as a functional film described later; a conductive layer constituting an electrode, a sensor, etc.; an antireflection layer; a hard coat layer; etc.

[0131] (Layer structure) The laminated glass structure includes a pair of intermediate films (i.e., the first intermediate film and the second intermediate film) that sandwich a functional layer between a pair of glass plates (i.e., the first glass plate and the second glass plate). For example, it is preferable that the first intermediate film is adhered to the first glass plate and the functional layer to join them, and the second intermediate film is adhered to the second glass plate and the functional layer to join them. Thereby, the pair of glass plates, the pair of intermediate films, and the functional layer are integrated. The layer structure in such a mode is represented by G1 / F1 / Z / F2 / G2 (see FIG. 1). G1 represents the first glass plate, G2 represents the second glass plate, F1 represents the first intermediate film, F2 represents the second intermediate film, and Z represents the functional layer, respectively. FIG. 1 is a schematic diagram showing an example of the layer structure of the laminated glass structure.

[0132] In the above description, an embodiment in which two intermediate films and one functional layer are provided between a pair of glass plates has been exemplified. However, three or more intermediate films and two or more functional layers may be provided between a pair of glass plates. In this case, it is preferable that the intermediate films and the functional layers are alternately arranged, and it is preferable that intermediate films are arranged at positions closest to each glass plate. For example, when three or more intermediate films and two or more functional layers are provided between a pair of glass plates, the layer structure of the laminated glass structure is preferably G1 / F3 / Z1 / F4 / Z2 / F5 / G2. Z1 and Z2 represent functional layers, which may be the same or different. F3, F4, and F5 represent intermediate films, which may be the same or different. At least one of F3, F4, and F5 is the intermediate film for laminated glass of the present disclosure.

[0133] 〔Method for manufacturing a laminated glass structure〕 The laminated glass structure of the present disclosure is preferably manufactured by a method in which the above-mentioned laminated film is disposed between a pair of glass plates and these are bonded together by pressure bonding to obtain a laminated glass structure. When the first intermediate film is used as described above, delamination of the layer interface, residual air, and foaming can be sufficiently suppressed. In the above manufacturing method, it is also possible to produce by pressure bonding the glass plate and the laminated film without disposing a gap filler on the outer periphery of the functional layer.

[0134] In the above manufacturing method, first, a first glass plate, a second glass plate, and the above-mentioned laminated film disposed between these glass plates or each member (each intermediate film and functional layer) constituting the above-mentioned laminated film are prepared.

[0135] As described above, a functional member may be attached to at least one of the first glass plate and the second glass plate. However, it is preferable that the functional member be attached to the glass plate before being integrated into the laminated glass structure. Therefore, as at least one of the first glass plate and the second glass plate used in the above manufacturing method, a glass plate to which a functional member is attached may be prepared. For example, as described above, when the glass plate constitutes a substrate of a display device, a display device may be prepared as at least one of the first glass plate and the second glass plate.

[0136] Next, in the above manufacturing method, it is preferable to dispose the laminated film between the first glass plate and the second glass plate and bond them together to obtain a laminated glass structure. Also, it is preferable to dispose each member (i.e., each intermediate film and functional layer) constituting the laminated film between the first glass plate and the second glass plate and bond them together to obtain a laminated glass structure in which the laminated film is incorporated. Here, each member constituting the laminated film may be disposed according to the layer structure of the resulting laminated glass structure. For example, they may be disposed between the first glass plate and the second glass plate in the order of the first intermediate film, the functional layer, and the second intermediate film.

[0137] The above bonding (also referred to as pre-bonding or main bonding) may be performed in a two-step process of performing pre-bonding followed by main bonding, or may be performed in one step, but it is preferable to perform it in two steps. The pre-bonding may be performed by a vacuum bag, a ring bag, a nipper roll, or other pressing machines. The main bonding is preferably performed in an autoclave, but may also be performed by other pressing machines. When bonding in one step, it is preferable to bond with a vacuum bag or a ring bag, but it may also be performed by other pressing machines.

[0138] In the above manufacturing method, the lamination may be performed under low-temperature conditions according to the heat resistance of the functional layer. Since the interlayer film for laminated glass of the present disclosure has excellent fluidity, even if a laminated glass structure is manufactured by laminating under low temperature or low pressure, the obtained laminated glass structure can exhibit high safety. Note that by performing the lamination under low-temperature conditions or low-pressure conditions, deterioration or deactivation of the functional layer can be sufficiently prevented. Further, even when a functional member or the like is attached to the glass plate, deterioration or deactivation of the member can be sufficiently prevented.

[0139] From the viewpoint of more reliably preventing deterioration or deactivation of the functional layer or the like, the temperature at the time of performing the lamination is preferably 110°C or lower, more preferably 100°C or lower. Further, from the viewpoint of further preventing the generation and foaming of residual air, the temperature at the time of performing the lamination is preferably 60°C or higher, more preferably 70°C or higher.

[0140] Similarly, from the viewpoint of more reliably preventing deterioration or deactivation of the functional layer or the like, the pressure at the time of performing the lamination is preferably 1.2 MPa or lower, more preferably 0.8 MPa or lower. The lower limit value of the pressure at the time of performing the lamination is not particularly limited. For example, when performing the lamination under pressure such as in an autoclave, it is preferably 0.05 MPa or higher, more preferably 0.1 MPa or higher.

[0141] The time for performing the lamination at the above temperature and / or pressure is not particularly limited, but for example, it is preferably 1 to 120 minutes, more preferably 5 to 60 minutes.

[0142] In the above manufacturing method, as described above, it is preferable to perform preliminary adhesion (also referred to as preliminary lamination or temporary crimping) before the above lamination. Thereby, a decrease in transmittance and a decrease in adhesive strength that may occur in the autoclave process under low-temperature conditions can be sufficiently suppressed.

[0143] Depending on the type of the functional layer or the like, from the viewpoint of further preventing deterioration or deactivation, the preliminary adhesion may be performed under low-temperature conditions, or the preliminary adhesion may be performed under low-temperature and low-pressure conditions. In that case, for example, the temperature at the time of performing the preliminary adhesion is preferably 110°C or lower, more preferably 100°C or lower. Further, from the viewpoint of further preventing the generation and foaming of residual air, the temperature at the time of performing the preliminary adhesion is preferably 60°C or higher, more preferably 70°C or higher. The pressure at the time of performing the preliminary adhesion is preferably 0.6 MPa or lower. Further, when performing the preliminary adhesion under a negative pressure such as when using a vacuum back, the pressure at the time of performing the preliminary adhesion is preferably 0.3 MPa or lower, more preferably 0.095 MPa or lower, and still more preferably 0.09 MPa or lower. The pressure when performing the preliminary adhesion under pressure is also preferably 0.01 MPa or higher, more preferably 0.05 MPa or higher.

[0144] The time for performing the preliminary adhesion at the above temperature and / or pressure is not particularly limited, but for example, it is preferably 0 to 60 minutes, more preferably 0 to 30 minutes.

[0145] (Use) The laminated glass structure of the present disclosure can be used for various applications. For example, the laminated glass structure of the present disclosure can be used for vehicles such as automobiles and trains, various vehicles such as ships and airplanes, various buildings such as buildings, condominiums, single-family houses, halls, and gymnasiums, machine tools such as cutting and grinding machines, and construction machines such as shovels and cranes, as window glass, and for partitions inside various vehicles and various buildings. Among them, the laminated glass structure is preferably used for vehicle applications such as automobiles and trains or building applications. Thus, both the laminated glass for vehicles and the laminated glass for buildings composed of the laminated glass structure of the present disclosure are those found by the present inventors. The laminated glass structure is particularly preferably used for window glass for vehicles or BIPV, and particularly preferably used for window glass for vehicles. The window glass for vehicles is preferably the front glass, side glass, rear glass, or roof glass of an automobile or a train.

[0146] The laminated glass structure of the present disclosure is also preferably used for various display applications. For example, window glass, partitions, etc. using the laminated glass structure may be used as a display. Further, the laminated glass structure of the present disclosure can also be used as a cover glass for various displays. For example, the laminated glass structure may be applied to in-vehicle displays and the like.

Examples

[0147] The present disclosure will be described in more detail by way of examples and the like, but the present disclosure is not limited by these examples in any way. Unless otherwise specified, "parts" represents "parts by mass" and "%" represents "% by mass". The weight average molecular weight of the resin, the Tg of the film, and the creep compliance at 90 °C per layer of the film were determined according to the methods described above. The film exposed area was also determined according to the method described above (As the float plate glass, clear glass (product name: "float plate glass") manufactured by Misawa Glass Co., Ltd. was used, and image shooting and image analysis were performed under the above conditions.).

[0148] <Materials, etc.> Each material or member used in the preparation example is as follows. (1) Glass plate Clear glass (product name: "float plate glass") manufactured by Misawa Glass Co., Ltd., thickness 3 mm

[0149] (2) Thermoplastic resin Preparation Example A1 (Resin 1) Into a reactor equipped with a stirring device, 1800 ml of ion-exchanged water, 150 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%), and 50 g of polyvinyl alcohol B (average degree of polymerization 800, saponification degree 99 mol%) were added, and the mixture was heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Next, this solution was cooled and adjusted to a temperature of 40 °C. Then, 30% hydrochloric acid was added as a catalyst so that the hydrochloric acid concentration became 0.9% by mass. After adjusting the temperature to 20 °C, n-butylaldehyde was added with stirring so that it became 15 mol%. Thereafter, the solution was adjusted to 13 °C, and when n-butylaldehyde was added so that it became 54.7 mol%, white particulate polyvinyl butyral resin was precipitated. 20 minutes after the second addition of n-butylaldehyde, 30% hydrochloric acid was added so that the hydrochloric acid concentration became 1.1% by mass, and then the temperature was raised to 48 °C and aged at a aging temperature of 48 °C for 2 hours. Next, the solution was cooled, neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain Resin 1 (polyvinyl butyral resin, hydroxyl group amount 30.9 mol%, acetalization degree 68.1 mol%, acetylation degree 0.99 mol%, weight average molecular weight 245000).

[0150] Preparation Example A2 (Resin 2) Into a reactor equipped with a stirring device, 1800 ml of ion-exchanged water and 200 g of polyvinyl alcohol A (average degree of polymerization 1700, saponification degree 99 mol%) were added, and the mixture was heated and dissolved with stirring to obtain a polyvinyl alcohol solution. Next, 30% hydrochloric acid was added to this solution as a catalyst so that the hydrochloric acid concentration became 0.2% by mass. After adjusting the temperature to 15 °C, n-butylaldehyde was added with stirring so that it became 10 mol%. Thereafter, when n-butylaldehyde was added so that it became 60 mol%, white particulate polyvinyl butyral resin was precipitated. 10 minutes after the precipitation, 30% hydrochloric acid was added so that the hydrochloric acid concentration became 1.8% by mass, and then the temperature was raised to 53 °C and aged at a aging temperature of 53 °C for 2 hours. Next, the solution was cooled and neutralized, and then the polyvinyl butyral resin was washed with water and dried to obtain Resin 2 (polyvinyl butyral resin, hydroxyl group content 31.5 mol%, acetalization degree 67.8 mol%, acetylation degree 0.7 mol%, weight average molecular weight 267,000).

[0151] Preparation Example A3 (Resin 3) Instead of aging at the aging temperature of 53°C for 2 hours for Resin 2, it was aged at the aging temperature of 63°C for 2 hours. Otherwise, in the same manner as Resin 1, Resin 3 (polyvinyl butyral resin, hydroxyl group content 30.1 mol%, acetalization degree 69.2 mol%, acetylation degree 0.67 mol%, weight average molecular weight 262,000) was obtained.

[0152] (3) Plasticizer 3GO: Triethylene glycol - bis-(2-ethylhexanoate), manufactured by Sekisui Chemical Co., Ltd., molecular weight 402

[0153] (4) Intermediate film for laminated glass Preparation Example B1 (Film 1) To 100 parts of Resin 1, 40 parts of plasticizer (3GO) was mixed to obtain a resin composition. The obtained resin composition was fed into a twin-screw extruder and embossed using an embossing roll. A film-like Film 1 with a thickness of 760 μm was produced. For the obtained Film 1, the film exposed area, Tg, creep compliance J(t) at 90°C, and surface roughness (RzJIS94, Rc) were measured. The results are shown in Table 1.

[0154] Preparation Example B2 (Film 2) A film-like Film 2 with a thickness of 760 μm was produced in the same manner as Preparation Example B1, except that Resin 2 was used instead of Resin 1. For the obtained Film 2, the film exposed area, Tg, creep compliance J(t) at 90°C, and surface roughness (RzJIS94, Rc) were measured. The results are shown in Table 1.

[0155] Preparation Example B3 (Film 3) A film-like membrane 3 having a thickness of 760 μm was prepared in the same manner as in Preparation Example B1, except that Resin 3 was used instead of Resin 1. The exposed membrane area, Tg, creep compliance J(t) at 90° C., and surface roughness (RzJIS94, Rc) of the obtained membrane 3 were measured. The results are shown in Table 1.

[0156] (5) Evaluation test Using samples of 30 cm length × 30 cm width cut out from each of the films obtained above, laminated glass was produced as follows, and an impact resistance test was carried out. The results are shown in Table 1.

[0157] <Making laminated glass> Each sample is kept at a constant temperature of 23°C and 28% RH for 4 hours. Separately, two float glass sheets measuring 30 cm long x 30 cm wide x 3 mm thick and conforming to JIS R3202 (2011) are prepared. Then, the glass and the sample are laminated so that the tin surface of the glass contacts the sample and the sample is disposed between the two pieces of glass. The obtained laminate is temporarily pressed using a heated roll at 170°C. The temporarily pressed laminate is placed in an autoclave and heated to 90°C at 2°C / min. When the temperature reaches 40°C during heating, the pressure is set to 0.1 MPa. After reaching 90°C, the temperature is held for 20 minutes and cooled at 2°C / min. When the temperature is cooled to 40°C, the pressure is returned to normal pressure. In this way, a laminated glass is produced.

[0158] <Impact resistance test> Using each of the laminated glasses prepared as described above, an impact resistance test was carried out at -20°C in accordance with JIS R3212 (1998). In the impact resistance test, the presence or absence of penetration was checked, and cases where there was no penetration were judged as "Good", and cases where there was penetration were judged as "Poor". Furthermore, when there was no penetration (judged as "Good"), the size of the part where the film peeled off in the part of the impact surface where the steel ball fell was measured, and judged according to the following criteria. ◎: No peeling ○: The size of the peeled area is less than 1 cm ×: The size of the peeled area is 1 cm or more

[0159] [Table 1] [Explanation of symbols]

[0160] 10: Laminated glass structure G1, G2: Glass plates F1, F2: Intermediate film Z: Functional layer

Claims

1. It contains a polyvinyl acetal resin and a plasticizer, at least one surface has an uneven shape, and the film exposed area calculated by the following method is 90 area% or less, The creep compliance at 90 °C per layer is 6.0×10−5 Pa−1 or more and 1.0×10−3 Pa−1 or less, The amount of hydroxyl groups in the polyvinyl acetal resin is 30.9 mol% or more, The plasticizer is at least one selected from the group consisting of triethylene glycol-di-2-ethylhexanoate, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, and derivatives in which a part of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups An interlayer film for laminated glass, characterized in that. <Calculation method of film exposed area> As a sample, prepare one laminated glass interlayer film with a length of 30 cm and a width of 15 cm, and hold it for 4 hours under constant temperature conditions of 23 °C and 28% RH. Separately, prepare two float glass plates with a length of 30 cm, a width of 15 cm, and a thickness of 3 mm, and conforming to JIS R3202 (2011). Then, laminate the glass and the sample so that the tin surface of the glass is in contact with the sample and the sample is placed between the two glasses. The obtained laminate is temporarily pressure-bonded using a heating roll at 170 °C. The temporarily pressure-bonded laminate is placed in an autoclave and heated to 90 °C at 2 °C / min. When the temperature reaches 40 °C during heating, the pressure is set to 0.1 MPa. After holding for 20 minutes after reaching 90 °C, the temperature is lowered at a rate of 2 °C / min. When the temperature is lowered to 40 °C, the pressure is returned to normal pressure. The obtained optical laminate is left standing in an environment at a temperature of -18 °C ± 0.6 °C for 16 hours, and then the optical laminate fixed at an inclination angle of 45 degrees is struck 72 times per minute with a hammer in which the spring screw is adjusted so that the impact force at the top dead center of the stroke is 10.5 ± 0.5 kg. The striking is performed so that the hammer hits the optical laminate horizontally. The above-mentioned striking is performed a total of 130 times at intervals of 11.5 mm in the horizontal direction (stroke 150 mm) and 10 times at intervals of 9 mm in the vertical direction (stroke 90 mm) from the lower part of the optical laminate. After the impact is completed, an image of the optical laminate is taken, and the film exposed area (area %) of the sample where the glass has peeled off and is exposed from the optical laminate is analyzed.

2. The polyvinyl acetal resin has a weight average molecular weight of 220,000 to 310,000 The interlayer film for laminated glass according to claim 1, characterized in that.

3. It contains a polyvinyl acetal resin and a plasticizer, at least one surface has an uneven shape, and the film exposed area calculated by the following method is 90 area % or less, The creep compliance at 90 ° C. per layer is 8.0 × 10−5 Pa−1 or more and 1.0 × 10−3 Pa−1 or less, The polyvinyl acetal resin has a weight average molecular weight of 245,000 or more and 280,000 or less, The plasticizer is at least one selected from the group consisting of triethylene glycol-di-2-ethylhexanoate, polyoxyethylene polyoxypropylene glycol, polyoxypropylene glyceryl ether, polyoxypropylene diglyceryl ether, and derivatives in which a part of the hydrogen atoms of the terminal hydroxyl groups are substituted with alkyl groups The interlayer film for laminated glass, characterized in that. <Calculation method of film exposed area> As a sample, prepare one interlayer film for laminated glass with a length of 30 cm and a width of 15 cm, and hold it for 4 hours under constant temperature conditions of 23 ° C and 28% RH. Separately, prepare two float glass plates with a length of 30 cm, a width of 15 cm, and a thickness of 3 mm, and conforming to JIS R3202 (2011). Then, laminate the glass and the sample so that the tin surface of the glass is in contact with the sample and the sample is disposed between the two glasses. The obtained laminate is temporarily pressure-bonded using a heating roll at 170 ° C. The temporarily pressure-bonded laminate is placed in an autoclave and heated to 90 ° C at 2 ° C / min. When the temperature reaches 40 ° C during heating, the pressure is set to 0.1 MPa. After holding for 20 minutes after reaching 90 ° C, the temperature is decreased under the condition of 2 ° C / min. When the temperature has decreased to 40 ° C, the pressure is returned to normal pressure. The obtained optical laminate is left standing for 16 hours in an environment at a temperature of -18 ° C ± 0.6 ° C, and then the optical laminate fixed at an inclination angle of 45 degrees is struck 72 times per minute with a hammer in which the spring screw is adjusted so that the impact force at the top dead center of the stroke is 10.5 ± 0.5 kg. The impact is performed such that the hammer hits the optical laminate horizontally. The impact is performed 130 times in total, 13 times (stroke 150 mm) at intervals of 11.5 mm in the lateral direction and 10 times (stroke 90 mm) at intervals of 9 mm in the longitudinal direction, starting from the lower part of the optical laminate. After the impact, an image of the optical laminate is taken, and the film exposure area (area %) of the sample where the glass has peeled off and is exposed from the optical laminate is analyzed.

4. The creep compliance at 90 °C per layer is 8.0 × 10−5 Pa －１ or more The interlayer film for laminated glass according to claim 1, characterized in that...

5. The creep compliance at 90 °C per layer is 8.0 × 10−5 Pa−1 or more The interlayer film for laminated glass according to claim 3, characterized in that...

6. At least one surface of the interlayer film for laminated glass has an uneven shape The interlayer film for laminated glass according to claim 1, characterized in that...

7. The laminated film has a structure in which the interlayer film for laminated glass according to any one of claims 1 to 6 and a functional layer are laminated. The laminated film is characterized in that...

8. The functional layer is sandwiched between a first interlayer film and a second interlayer film, and at least one of the first interlayer film and the second interlayer film is the interlayer film for laminated glass according to any one of claims 1 to 6. The laminated film according to claim 7, characterized in that...

9. The functional layer is at least one selected from the group consisting of a dimming film, a display element film, and a solar cell element. The laminated film according to claim 7, characterized in that...

10. The functional layer is a dimming film, and the dimming film includes at least one selected from the group consisting of polymer-dispersed liquid crystal (PDLC), guest-host liquid crystal (GHLC), suspended particle device (SPD), electrochromic device, and electrophoretic film device. The laminated film according to claim 7, characterized in that...

11. The laminated glass structure has a structure in which the laminated film according to claim 7 is sandwiched between a pair of glass plates. The laminated glass structure is characterized in that...

12. It is produced without using a gap filler. The laminated glass structure according to claim 11, characterized in that...

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