Layered film, laminated glass, and layered film production method

Abstract

This layered film has: a first intermediate layer that is for laminated glass and contains a thermoplastic resin; and a printed layer adjacent to the surface of the first intermediate layer. The printed layer contains a cured product of a curable ink, and the average degree of cure of the printed layer is at least 80%.

Description

Laminated film, laminated glass, and method for manufacturing laminated film

[0001] This disclosure relates to laminated films, laminated glass, and methods for manufacturing laminated films.

[0002] In recent years, the design demands for laminated glass have become increasingly diverse. For example, in automotive applications, there is a growing need and concept to apply designs to laminated glass to match the body design or body color. Similarly, in architectural applications, there continues to be a demand for decorative elements on laminated glass for exterior or interior use. Furthermore, there is consideration being given to embedding dimming films, sensors, antennas, electronic display media, or solar cells within the laminated glass.

[0003] To enhance the functionality of laminated glass, it is known to form a printed layer in the interlayer. The printed layer may be, for example, an image-supporting layer or a conductive layer. The image-supporting layer may be, for example, a colored layer or an emissive layer. The image-supporting layer may have a desired design pattern. For example, Patent Document 1 discloses an image-supported interlayer sheet obtained by inkjet printing colored ink onto at least one surface of an interlayer sheet.

[0004] The printed layer, for example, contains a cured product of a curable ink and is formed on the surface of the intermediate layer. The intermediate layer and the printed layer constitute a laminated film. Laminated glass with a laminated film is generally manufactured by the following method: A laminated film is sandwiched between a first glass substrate and a second glass substrate and pre-bonded to obtain a laminate. Next, the laminate is placed in an autoclave and the components are pressed together under high temperature and high pressure. The autoclave treatment is carried out, for example, at a temperature of 120°C to 140°C and a pressure of 1.0 MPa to 1.5 MPa.

[0005] Japan Special Table No. 2007-501722

[0006] Traditionally, heat treatments such as autoclaving could cause wrinkles in the printed layer, resulting in appearance defects.

[0007] One embodiment of the present disclosure provides a technology that can suppress defects in the appearance of the printed layer caused by heat treatment.

[0008] As a result of diligent research, the inventors have found that the above-mentioned appearance defects are caused by insufficient curing of the curable ink. The inventors have solved the above problem by increasing the curing rate of the printed layer. This disclosure provides the following [1] to

[16] . [1] A laminated film having a first intermediate layer for laminated glass containing a thermoplastic resin, and a printed layer adjacent to the surface of the first intermediate layer, wherein the printed layer contains a cured product of a curable ink, and the average curing rate of the printed layer is 80% or more. [2] The laminated film according to [1], wherein the printed layer has a first surface adjacent to the first intermediate layer and a second surface facing the opposite direction from the first surface, and the absolute value of the difference between the curing rate of the first surface and the curing rate of the second surface is 10% or less. [3] The laminated film according to [1] or [2], wherein the printed layer has a first surface adjacent to the first intermediate layer and a second surface facing the opposite direction from the first surface, and the laminated film has a second intermediate layer containing a thermoplastic resin, the second intermediate layer being adjacent to the second surface of the printed layer. [4] The laminated film according to any one of [1] to [3], wherein the thickness of the printed layer is 1 μm or more and 50 μm or less. [5] The laminated film according to any one of [1] to [4], wherein the curable ink is an ultraviolet curable ink. [6] The laminated film according to any one of [1] to [5], wherein the average curing rate of the printed layer is 90% or more. [7] The laminated film according to any one of [1] to [6], wherein the thermoplastic resin is at least one of polyvinyl acetal, ethylene vinyl acetate, polyurethane, and polyolefin. [8] The laminated film according to [7], wherein the thermoplastic resin is polyvinyl acetal. [9] The printed layer has a first surface in contact with the first intermediate layer and a second surface facing the opposite direction from the first surface, and the laminated film comprises a third intermediate layer adjacent to the second surface of the printed layer, wherein the third intermediate layer has a shear storage modulus at 140°C that is higher than that of the first intermediate layer, as described in [1] or [2].

[10] The laminated film according to [9], wherein the printed layer has a second intermediate layer containing a thermoplastic resin, the second intermediate layer is positioned on the opposite side from the first intermediate layer with respect to the third intermediate layer, and the third intermediate layer has a shear storage modulus at 140°C that is higher than that of the second intermediate layer.

[11] Laminated glass comprising the laminated film according to any one of [1] to

[10] , and a first glass substrate and a second glass substrate sandwiching the laminated film.

[12] A method for manufacturing a laminated film, comprising printing a curable ink on the surface of a substrate, and curing the curable ink on the substrate to form a cured layer with a thickness of 10 μm or less, wherein a printed layer is formed by laminating a plurality of cured layers by alternately performing the printing of the curable ink and the formation of the cured layer multiple times.

[13] The method for manufacturing a laminated film according to

[12] , wherein the thickness of the printed layer is 1 μm or more and 50 μm or less.

[14] The method for manufacturing a laminated film according to

[12] or

[13] , wherein the curable ink is printed by plate printing.

[15] The method for manufacturing a laminated film according to

[12] or

[13] , wherein the curable ink is printed by plateless printing.

[16] The method for manufacturing a laminated film according to

[15] , wherein the plateless printing is inkjet printing.

[0009] According to one embodiment of the present disclosure, it is possible to suppress defects in the appearance of the printed layer caused by heat treatment.

[0010] Figure 1 shows an example of a method for manufacturing a laminated film. Figure 2 shows an example of the FT-IR spectrum of a curable ink. Figure 3 shows an example of the FT-IR spectrum of a printed layer. Figure 4 is a cross-sectional view showing a first example of a laminated film. Figure 5 is a cross-sectional view showing a first example of laminated glass. Figure 6 is a cross-sectional view showing a second example of a laminated film. Figure 7 is a cross-sectional view showing a second example of laminated glass. Figure 8 is a cross-sectional view showing a third example of a laminated film. Figure 9 is a cross-sectional view showing a third example of laminated glass. Figure 10 is a micrograph of the printed layer of Example 3 described in Table 1.

[0011] The embodiments for implementing this disclosure will be described below with reference to the drawings. In each drawing, identical or similar components will be denoted by the same reference numeral, and their descriptions may be omitted. In the specification, the "~" indicating a numerical range means that the numbers written before and after it are included as the lower and upper limits. The lower and upper limits can be combined in any way. The numerical range includes the rounded range.

[0012] As shown in Figure 1, a printed layer 20 may be formed on the intermediate layer 10 for laminated glass. The printed layer 20 is, for example, an image-supporting layer or a conductive layer. The image-supporting layer is, for example, a colored layer or an emissive layer. The image-supporting layer has a desired design pattern. The design pattern is set according to the application. The conductive layer forms, for example, a dimmable film, a sensor, an antenna, an electronic display medium, or at least part of an electrical circuit such as a solar cell.

[0013] The printed layer 20 includes, for example, a cured product of a curable ink 21. The printed layer 20 and the intermediate layer 10 constitute the laminated film 2. Laminated glass comprising the laminated film 2 is generally manufactured by the following method: The laminated film 2 is sandwiched between a first glass substrate and a second glass substrate and pre-bonded to obtain a laminate. Next, the laminate is placed in an autoclave and the components are pressed together under high temperature and high pressure. The autoclave treatment is carried out, for example, at a temperature of 120°C to 140°C and a pressure of 1.0 MPa to 1.5 MPa.

[0014] The intermediate layer 10 preferably contains a thermoplastic resin to improve adhesion. The thermoplastic resin is not particularly limited, but for example, it includes at least one selected from polyvinyl acetal, ethylene vinyl acetate, polyurethane, and polyolefin. The thermoplastic resin preferably contains polyvinyl acetal.

[0015] The inventors of the present invention have identified a problem in which wrinkles occur in the printed layer 20 due to heat treatment such as autoclave processing, resulting in a poor appearance, and have found that this problem is caused by insufficient curing of the curable ink 21. It is thought that if the curing rate of the printed layer 20 is too low, the intermediate layer 10, which has been softened by the heat treatment, drags the printed layer 20, causing the printed layer 20 to twist and wrinkle. The inventors of the present invention have solved the above problem by increasing the curing rate of the printed layer 20. Increasing the curing rate of the printed layer 20 can be done, for example, by performing printing and curing of the curable ink 21 alternately multiple times, as shown in Figure 1.

[0016] In this embodiment, the substrate on which the curable ink 21 is printed is the intermediate layer 10, but it is not limited to the intermediate layer 10. Alternatively, the printed layer 20 may be formed on a substrate other than the intermediate layer 10, and then the printed layer 20 may be transferred from the substrate to the intermediate layer 10 to form the printed layer 20 on the intermediate layer 10. The intermediate layer 10 may be any of the first intermediate layer 10A, the second intermediate layer 10B, and the third intermediate layer 10C, which will be described later.

[0017] The method for manufacturing the laminated film 2 is as shown in Figure 1 and comprises the following (A) and (B): (A) A curable ink 21 is printed on the surface of a substrate such as an intermediate layer 10. (B) The curable ink 21 is cured on the substrate to form a cured layer 22.

[0018] The printing method for the curable ink 21 is not particularly limited, as will be described later, and may be plated printing or plateless printing. The printing method for the curable ink 21 is preferably inkjet printing. Inkjet printing is an example of plateless printing.

[0019] The inkjet printer 100 is equipped with a print head 110, which has nozzles 111. The nozzles 111 eject curable ink 21 using a piezoelectric element or the like. Multiple nozzles 111 may be provided for each color of curable ink 21. The print head 110 moves relative to the surface of the substrate while ejecting curable ink 21 from the nozzles 111 onto the surface of the substrate. Either the print head 110 or the substrate may move, or both may move.

[0020] The curing type of the curable ink 21 is not particularly limited, as will be described later, but is preferably an ultraviolet curing type. In this case, the inkjet printer 100 is equipped with an ultraviolet light source 120. The ultraviolet light source 120 irradiates the curable ink 21 printed on the surface of the substrate with ultraviolet light. The ultraviolet light source 120 may move together with the print head 110 as shown in Figure 1, or it may not move, although this is not shown.

[0021] The ultraviolet light source 120 irradiates the curable ink 21 with ultraviolet light from the side opposite to the intermediate layer 10. The ultraviolet light is attenuated as it passes through the curable ink 21. Therefore, the curing rate of the curable ink 21 may vary depending on the direction of ultraviolet irradiation. If the intermediate layer 10 is transparent, the ultraviolet light source 120 can also irradiate the curable ink 21 with ultraviolet light through the intermediate layer 10.

[0022] The method for manufacturing the laminated film 2 involves forming the printed layer 20 by alternately performing (A) and (B) multiple times. In other words, the method for manufacturing the laminated film 2 involves forming the printed layer 20 by alternately performing the printing of the curable ink 21 and the formation of the cured layer 22 multiple times. The printed layer 20 is made up of multiple cured layers 22 laminated together. By alternately performing the printing of the curable ink 21 and the formation of the cured layer 22 multiple times, a printed layer 20 with a higher average curing rate can be formed compared to performing it only once. Furthermore, a printed layer 20 with less variation in the curing rate in the thickness direction of the printed layer 20 can be formed.

[0023] The number of layers of the cured layer 22 is equal to the number of times the curable ink 21 is printed and the cured layer 22 is formed, i.e., equal to the number of cycles. Preferably, the number of layers of the cured layer 22 is 2 or more. The more layers of the cured layer 22 there are, the higher the average curing rate and the smaller the variation in curing rate of the printed layer 20 obtained. Preferably, the number of layers of the cured layer 22 is 3 or more. However, from the viewpoint of shortening the formation time of the printed layer 20, the number of layers of the cured layer 22 is preferably 5 or less.

[0024] The thickness of each cured layer 22 is preferably 10 μm or less. When the thickness of each cured layer 22 is 10 μm or less, the curing reaction of the curable ink 21 is likely to proceed. For example, ultraviolet light easily reaches the entire ultraviolet-curable ink, and the curing reaction of the ultraviolet-curable ink is likely to proceed. Alternatively, heat easily reaches the entire thermosetting ink, and the curing reaction of the thermosetting ink is likely to proceed. From the viewpoint of improving the curing rate of the printed layer 20, the thinner the thickness of each cured layer 22 is, the more preferable it is. The thickness of each cured layer 22 is more preferably 5 μm or less, and still more preferably 2 μm or less. However, from the viewpoint of shortening the formation time of the printed layer 20, the thickness of each cured layer 22 may be 0.5 μm or more. The plurality of cured layers 22 may have the same thickness, or may have different thicknesses.

[0025] The thickness of the printed layer 20 is equal to the sum of the thicknesses of the plurality of cured layers 22 constituting the printed layer 20. The thickness of the printed layer 20 is preferably 1 μm or more. When the coating thickness of the curable ink 21 is 30 μm or more, it is difficult for ultraviolet light or heat to reach the entire curable ink 21. According to the present embodiment, since printing of the curable ink 21 and formation of the cured layers 22 are alternately performed a plurality of times, even when the thickness of the printed layer 20 is 30 μm or more, the curing rate of the printed layer 20 can be sufficiently increased. When the printed layer 20 is an image-bearing layer, a deeper color can be expressed as the thickness of the image-bearing layer increases. From the viewpoint of thinning the laminated film 2, the thickness of the printed layer 20 may be 50 μm or less.

[0026] The average curing rate Rave of the printed layer 20 is preferably 80% or more. The average curing rate Rave of the printed layer 20 is calculated using the following formula (1). (1) Rave = (S1 - S2) / S1 × 100. S1 is the area of the first peak P1 of the curable ink 21 measured by FT-IR (Fourier transform infrared spectroscopy) (see FIG. 2). S2 is the area of the second peak P2 of the printed layer 20 measured by FT-IR (see FIG. 3). In FIGS. 2 and 3, the horizontal axis represents wave number (cm －１ −1), and the vertical axis represents absorbance. Absorbance is a dimensionless quantity.

[0027] The first peak P1 and the second peak P2 are peaks derived from carbon-carbon double bonds and are peaks at the same wavenumber. The wavenumber of the first peak P1 and the second peak P2 is, for example, 809 cm －１ . It should be noted that the wavenumber of the first peak P1 and the second peak P2 only needs to be a wavenumber derived from carbon-carbon double bonds, and 809 cm －１ is not limitative, and for example may be 1668 cm －１ .

[0028] As the curing reaction of the curable ink 21 proceeds, cleavage of the carbon-carbon double bonds progresses, and the area of the peak derived from the carbon-carbon double bonds decreases. Therefore, S2 is smaller than S1. S1 and S2 are measured with a commercially available Fourier transform infrared spectrophotometer, for example, Frontier spectrophotometer (trade name, manufactured by Perkin Elmer). The peak background may be removed using software attached to a commercially available Fourier transform infrared spectrophotometer.

[0029] The measurement sample for S1 is the curable ink 21 before curing. On the other hand, the measurement sample for S2 is the entire print layer 20 in the thickness direction. The print layer 20 may be peeled off in advance from a base material such as the intermediate layer 10. For the peeling, for example, a microtome may be used. It should be noted that the measurement sample for S1 does not have to be the actually used curable ink 21, and may be a curable ink estimated from the composition of the print layer 20.

[0030] If the average curing rate Rave of the print layer 20 is 80% or more, the print layer 20 is sufficiently hard. Therefore, the print layer 20 is hardly dragged by thermal deformation of the intermediate layer 10. Accordingly, the occurrence of wrinkles in the print layer 20 can be suppressed. For example, the occurrence of wrinkles in an image carrying layer can be suppressed, and perspective distortion of a design pattern can be reduced. Further, the occurrence of wrinkles in a conductive layer can be suppressed, and short-circuiting of an electric circuit can be inhibited. From the viewpoint of suppressing the occurrence of wrinkles, the higher the average curing rate Rave of the print layer 20 is, the more preferable it is. The average curing rate Rave of the print layer 20 is more preferably 90% or more. The average curing rate Rave of the print layer 20 only needs to be 100% or less.

[0031] Furthermore, if the curable ink 21 is an ultraviolet-curable ink, the average curing rate Rave of the printed layer 20 hardly changes due to autoclave treatment. Therefore, the average curing rate Rave of the printed layer 20 may be measured after the manufacture of the laminated glass.

[0032] The printed layer 20 has a first surface 20a adjacent to the intermediate layer 10 and a second surface 20b facing the opposite direction from the first surface 20a. The absolute value of the difference between the hardening rate R1 of the first surface 20a and the hardening rate R2 of the second surface 20b (|R1-R2|) is preferably 10% or less. If |R1-R2| is 10% or less, the variation in the hardening rate in the thickness direction of the printed layer 20 is small, and the entire thickness direction of the printed layer 20 is hard. Therefore, the printed layer 20 is hardly affected by the thermal deformation of the intermediate layer 10. Thus, the occurrence of wrinkles in the printed layer 20 can be limited.

[0033] The curing rate R1 of the first surface 20a is calculated using the following formula (2): (2) R1 = (S1 - S3) / S1 × 100. S1 is the area of ​​the first peak P1 of the curable ink 21 measured by FT-IR. S3 is the area of ​​the third peak of the first surface 20a measured by FT-IR. The first peak P1 and the third peak are peaks originating from double bonds between carbons and are peaks of the same wavenumber. The measurement sample of S3 is a part of the thickness direction of the printed layer 20, and the distance from the first surface 20a is 10% or less of the thickness of the printed layer 20.

[0034] The curing rate R2 of the second surface 20b is calculated using the following formula (3): (3) R2 = (S1 - S4) / S1 × 100. S1 is the area of ​​the first peak P1 of the curable ink 21 measured by FT-IR. S4 is the area of ​​the fourth peak of the second surface 20b measured by FT-IR. The first peak P1 and the fourth peak are peaks originating from double bonds between carbons and are peaks of the same wavenumber. The measurement sample for S4 is a part of the thickness direction of the printed layer 20, and the distance from the second surface 20b is 10% or less of the thickness of the printed layer 20.

[0035] A smaller |R1-R2| is more preferable. |R1-R2| is more preferably 8% or less, and still more preferably 5% or less. |R1-R2| only needs to be 0% or more. |R1-R2| is most preferably 0%. Note that when |R1-R2| is greater than 0%, either R1 or R2 may be larger. For example, the magnitude relationship between R1 and R2 can change depending on the irradiation direction of ultraviolet rays.

[0036] In a plan view, the area of the printed layer 20 is preferably 1 mm ２ or more. Here, the term "plan view" refers to viewing from a direction perpendicular to the second surface 20b. When an opening pattern is formed in the printed layer 20, the area of the printed layer 20 does not include the area of the opening. The larger the area of the printed layer 20, the greater the stress that acts on the printed layer 20 due to thermal deformation of the intermediate layer 10. Since the printed layer 20 of the present embodiment is sufficiently hard, even when the area of the printed layer 20 in a plan view is 1 mm ２ or more, the occurrence of wrinkles in the printed layer 20 can be suppressed. In a plan view, the area of the printed layer 20 is more preferably 100 mm ２ or more, still more preferably 300 mm ２ or more. In a plan view, the area of the printed layer 20 only needs to be equal to or less than the area of the laminated glass, and is preferably 90000 mm ２ or less.

[0037] A ratio of the area of the printed layer 20 to the area of the intermediate layer 10 in a plan view is preferably 1% or more, more preferably 5% or more, and still more preferably 10% or more. Further, the ratio of the area of the printed layer 20 to the area of the intermediate layer 10 in a plan view is preferably 95% or less, and more preferably 90% or less.

[0038] When at least a part of the printed layer 20 has a linear shape in a plan view, the minimum value of the line width of the printed layer 20 is preferably 100 mm or less. The smaller the minimum value of the line width of the printed layer 20, the lower the rigidity of the printed layer 20. Since the printed layer 20 of the present embodiment is sufficiently hard, even when the minimum value of the line width of the printed layer 20 is 100 mm or less, the occurrence of wrinkles in the printed layer 20 can be suppressed. The minimum value of the line width of the printed layer 20 is more preferably 50 mm or less. The minimum value of the line width of the printed layer 20 is preferably 1 mm or more.

[0039] As shown in Figure 4, the laminated film 2A has a first intermediate layer 10A and a printed layer 20. The printed layer 20 is adjacent to the surface of the first intermediate layer 10A. As shown in Figure 5, the laminated glass 3A includes a first glass substrate 5 and a second glass substrate 6 in addition to the laminated film 2A. The first glass substrate 5 and the second glass substrate 6 may be either inorganic glass or organic glass, but inorganic glass is preferable from the viewpoint of scratch resistance. The inorganic glass is preferably tempered glass. The tempered glass may be either air-cooled tempered glass or chemically tempered glass.

[0040] Laminated glass 3A is obtained by sandwiching a laminated film 2A between a first glass substrate 5 and a second glass substrate 6 to create a laminate, then placing the laminate in an autoclave and pressing the components together under high temperature and pressure. During the autoclave process, the first intermediate layer 10A softens and adheres to both the first glass substrate 5 and the second glass substrate 6. The printed layer 20 is adjacent to the second glass substrate 6 as shown in Figure 5. The second glass substrate 6 may be placed on the outdoor side or the indoor side of the first glass substrate 5.

[0041] As shown in Figure 6, the laminated film 2B has a second intermediate layer 10B in addition to the first intermediate layer 10A and the printed layer 20. The printed layer 20 is adjacent to the surface of the first intermediate layer 10A. The printed layer 20 has a first surface 20a adjacent to the first intermediate layer 10A and a second surface 20b facing the opposite direction from the first surface 20a. The second intermediate layer 10B, like the first intermediate layer 10A, contains a thermoplastic resin. The second intermediate layer 10B is positioned on the opposite side of the printed layer 20 from the first intermediate layer 10A and is adjacent to the second surface 20b of the printed layer 20.

[0042] The method for laminating the second intermediate layer 10B is not particularly limited, and any known method may be used, for example, a lamination method may be used. For example, the second intermediate layer 10B can be laminated by extruding a thermoplastic resin onto the laminated film 2A shown in Figure 4. Alternatively, the second intermediate layer 10B can be laminated by press molding a film-like thermoplastic resin onto the laminated film 2A shown in Figure 4.

[0043] The printed layer 20 may be formed on either the first intermediate layer 10A or the second intermediate layer 10B. The first intermediate layer 10A may be laminated onto a laminated film composed of the second intermediate layer 10B and the printed layer 20. Furthermore, the first intermediate layer 10A and the second intermediate layer 10B may not be integrated until immediately before being sandwiched between the first glass substrate 5 and the second glass substrate 6, and may be integrated during autoclave processing.

[0044] As shown in Figure 7, the laminated glass 3B comprises a first glass substrate 5 and a second glass substrate 6 in addition to the laminated film 2B. The laminated glass 3B is obtained by sandwiching the laminated film 2B between the first glass substrate 5 and the second glass substrate 6 to form a laminate, and then placing the laminate in an autoclave and pressing the components together under high temperature and high pressure. During the autoclave process, the first intermediate layer 10A softens and adheres to the first glass substrate 5, and the second intermediate layer 10B softens and adheres to the second glass substrate 6.

[0045] As shown in Figure 7, the second intermediate layer 10B is placed between the printed layer 20 and the second glass substrate 6. Compared to the case without the second intermediate layer 10B, the adhesive strength between the printed layer 20 and the second glass substrate 6 can be improved. The second glass substrate 6 may be placed on the outdoor side or the indoor side of the first glass substrate 5.

[0046] As shown in Figure 8, the laminated film 2C has a third intermediate layer 10C in addition to the first intermediate layer 10A and the printed layer 20. The printed layer 20 is adjacent to the surface of the first intermediate layer 10A. The printed layer 20 has a first surface 20a adjacent to the first intermediate layer 10A and a second surface 20b facing the opposite direction from the first surface 20a. The third intermediate layer 10C is adjacent to the second surface 20b of the printed layer 20 and has a shear storage modulus at 140°C that is higher than that of the first intermediate layer 10A. The shear storage modulus is measured in accordance with JIS K7244-10:2005.

[0047] The method for laminating the third intermediate layer 10C is not particularly limited, and any known method may be used, for example, a lamination method may be used. For example, the third intermediate layer 10C can be laminated by extruding a thermoplastic resin onto the laminated film 2A shown in Figure 4. Alternatively, the third intermediate layer 10C can be laminated by press molding a film-like thermoplastic resin onto the laminated film 2A shown in Figure 4.

[0048] The printed layer 20 may be formed on either the first intermediate layer 10A or the third intermediate layer 10C. The first intermediate layer 10A may be laminated onto a laminated film composed of the third intermediate layer 10C and the printed layer 20. Furthermore, the first intermediate layer 10A and the third intermediate layer 10C may not be integrated until immediately before being sandwiched between the first glass substrate 5 and the second glass substrate 6, and may be integrated during autoclave processing.

[0049] As shown in Figure 8, the laminated film 2C may further have a second intermediate layer 10B. The second intermediate layer 10B is positioned on the opposite side from the printed layer 20 with respect to the third intermediate layer 10C. The second intermediate layer 10B contains a thermoplastic resin, similar to the first intermediate layer 10A. The third intermediate layer 10C has a higher shear storage modulus at 140°C than the second intermediate layer 10B.

[0050] The method for laminating the second intermediate layer 10B is not particularly limited, and any known method may be used, for example, a lamination method may be used. For example, the second intermediate layer 10B can be laminated by laminating a thermoplastic resin on the third intermediate layer 10C by extrusion molding. Alternatively, the second intermediate layer 10B can be laminated by laminating a film-like thermoplastic resin on the third intermediate layer 10C by press molding.

[0051] Furthermore, the second intermediate layer 10B and the third intermediate layer 10C may not be integrated until immediately before being sandwiched between the first glass substrate 5 and the second glass substrate 6, and may be integrated during the autoclave process.

[0052] As shown in Figure 9, the laminated glass 3C comprises a first glass substrate 5 and a second glass substrate 6 in addition to the laminated film 2C. The laminated glass 3C is obtained by sandwiching the laminated film 2C between the first glass substrate 5 and the second glass substrate 6 to form a laminate, and then placing the laminate in an autoclave and pressing the components together under high temperature and high pressure.

[0053] During autoclave treatment, the first intermediate layer 10A softens and adheres to the first glass substrate 5, and the second intermediate layer 10B softens and adheres to the second glass substrate 6. Although not shown in the figures, if the second intermediate layer 10B is absent, the third intermediate layer 10C is adjacent to the second glass substrate 6. However, if the second intermediate layer 10B is present, the shear storage modulus of the second intermediate layer 10B at 140°C is lower than that of the third intermediate layer 10C, making it more easily deformable and thus more likely to adhere to the second glass substrate 6.

[0054] As described above, the third intermediate layer 10C is adjacent to the second surface 20b of the printed layer 20 and has a shear storage modulus at 140°C that is higher than that of the first intermediate layer 10A. Therefore, the third intermediate layer 10C can restrain the printed layer 20 so that wrinkles do not occur in the printed layer 20. To enhance this effect, it is effective to improve the adhesion between the printed layer 20 and the third intermediate layer 10C, and it is effective to apply the curable ink 21 to the third intermediate layer 10C to form the printed layer 20.

[0055] The third intermediate layer 10C may contain a different thermoplastic resin than the first intermediate layer 10A and the second intermediate layer 10B. On the other hand, the first intermediate layer 10A and the second intermediate layer 10B may contain the same thermoplastic resin. The combination of thermoplastic resins is not particularly limited, but preferably the first intermediate layer 10A and the second intermediate layer 10B contain at least one selected from polyvinyl acetal, ethylene vinyl acetate, polyurethane, and polyolefin, and the third intermediate layer 10C contains polyethylene terephthalate. More preferably, the first intermediate layer 10A and the second intermediate layer 10B contain polyvinyl acetal, and the third intermediate layer 10C contains polyethylene terephthalate.

[0056] The details of the printing layer 20 and the intermediate layer 10 constituting the laminated film 2 will be described below in this order. [Printing Layer] The printing layer 20 is not particularly limited, but for example, it is an image-supporting layer. The image-supporting layer is, for example, a coloring layer or an emissive layer. The image-supporting layer has a desired design pattern and forms an image. The image-supporting layer preferably contains a coloring material. Either a pigment or a dye may be used as the coloring material, but the use of a dye is preferred. As pigments and dyes, blue, yellow, red, green, purple, white, black, and other pigments can be used. The coloring material may be colored by selective absorption of visible light, but is not limited to such coloring materials, and it is also preferable to use an emissive material, known as a fluorescent material, which emits visible light when irradiated with excitation light. Note that the fluorescent material (emissive material) may be a material that emits phosphorescence when irradiated with excitation light. The maximum emission wavelength of the excitation light (maximum excitation wavelength) is not particularly limited, but is preferably 420 nm or less, more preferably 410 nm or less, and even more preferably 408 nm or less. Furthermore, a wavelength of 300 nm or higher is preferred, 350 nm or higher is more preferred, and 380 nm or higher is even more preferred. By setting the maximum emission wavelength of the excitation light to be above the lower limit and below the upper limit, the light-emitting material can efficiently emit visible light in response to the excitation light.

[0057] Examples of luminescent materials that can be used in the light-emitting layer include lanthanide complexes, luminescent materials having a terephthalate ester structure, luminescent materials having a naphthalimide skeleton, luminescent materials having a coumarin skeleton, and luminescent materials having a quinoline skeleton. The luminescent material may be used alone or in combination of two or more types. By combining multiple luminescent materials with different emission wavelengths, it is possible to display not only monochromatic images but also images with various colors. Among the above, lanthanide complexes and luminescent materials having a terephthalate ester structure are preferred, and luminescent materials having a terephthalate ester structure are more preferred.

[0058] The compound having a terephthalate ester structure is preferably a compound having a terephthalate skeleton. Compounds having a terephthalate skeleton are typically colorless and can make the light-emitting layer colorless and transparent unless irradiated with excitation light. The colorant may be used alone in the printing layer 20, or two or more may be used in combination.

[0059] Compounds having a terephthalate skeleton include compounds having a diterephthalate ester structure, such as compounds having the structure represented by formula (4) below or compounds having the structure represented by formula (5) below. These may be used individually or in combination of two or more.

[0060]

[0061] In the above formula (4), R １ R represents an organic group, and x is 1, 2, 3, or 4. From the viewpoint of increasing the transparency of the printed layer 20, x is preferably 1 or 2, more preferably has a hydroxyl group at the 2nd or 5th position of the benzene ring, and even more preferably has hydroxyl groups at both the 2nd and 5th positions of the benzene ring. １The organic group is preferably a hydrocarbon group, more preferably a hydrocarbon group having 1 to 10 carbon atoms, even more preferably a hydrocarbon group having 1 to 5 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 3 carbon atoms. When the number of carbon atoms of the hydrocarbon group is 10 or less, the fluorescent material having the terephthalate skeleton can be easily dispersed or dissolved in the ink. The hydrocarbon group is preferably an alkyl group. In the above formula (4), the two R １ They may be the same as each other, or they may be different.

[0062] Examples of compounds having the structure represented by the above formula (4) include diethyl-2,5-dihydroxyterephthalate and dimethyl-2,5-dihydroxyterephthalate. Among these, diethyl-2,5-dihydroxyl terephthalate ("Diethyl 2,5-dihydroxyterephthalate" manufactured by Aldrich) is preferred as the compound having the structure represented by the above general formula (4).

[0063] In the above formula (5), R ２ represents an organic group, R ３ and R ４ represents a hydrogen atom or an organic group, and y is 1, 2, 3, or 4. The above R ２ The organic group is preferably a hydrocarbon group, more preferably a hydrocarbon group having 1 to 10 carbon atoms, even more preferably a hydrocarbon group having 1 to 5 carbon atoms, and particularly preferably a hydrocarbon group having 1 to 3 carbon atoms. When the number of carbon atoms of the hydrocarbon group is less than or equal to the above upper limit, the fluorescent material having the terephthalate skeleton can be easily dispersed or dissolved in the ink. The hydrocarbon group is preferably an alkyl group. In formula (5), the two R １ These may be the same or different. In the above general formula (5), NR ３ R ４ R is an amino group. ３ and R ４ Each of these is preferably an independent hydrocarbon group having 1 to 10 carbon atoms, or a hydrogen atom. The hydrocarbon group is more preferably having 1 to 5 carbon atoms, and even more preferably a hydrocarbon group having 1 to 3 carbon atoms. Also, R３ and R ４ The hydrocarbon groups are preferably all alkyl groups. ３ and R ４ They may bond to form a ring. ３ and R ４ The total number of carbon atoms is preferably 2 to 6, more preferably 2 to 5, when a ring is formed. Examples of rings include azetidine. In the above general formula (5), y is preferably 2. In formula (5), there are two or more NR in one molecule. ３ R ４ If there are two or more NR ３ R ４ These elements may be the same or different from each other. Preferred examples of compounds having the structure represented by the above general formula (5) include diethyl-2,5-diaminoterephthalate (for example, manufactured by Aldrich), dimethyl-2,5-bis(dimethylamino)terephthalate, and diethyl-2,5-bis(azetidine-1-yl)terephthalate.

[0064] The printed layer 20 contains a cured product of the curable ink 21. The printing method for the curable ink 21 may be either plateless printing or plated printing, and is not particularly limited, but examples include screen printing, inkjet printing, flexographic printing, and offset printing. Among these, screen printing and inkjet printing are preferred.

[0065] The printed layer 20 may be formed on the entire surface of the substrate such as the intermediate layer 10 by so-called solid printing, but it is preferable that the printed layer 20 is printed in a predetermined pattern such as a picture, design, icon, character, or a combination thereof, and formed on a part of the substrate surface.

[0066] When the printing layer 20 is an image-supporting layer, the curable ink 21 preferably contains a colorant, and more preferably contains a dye. The curable ink 21 may be an aqueous ink using water as the solvent, a solvent ink using an organic solvent, or an ink that does not use a solvent. The curable ink 21 may also preferably contain a binder resin. The colorant can be properly held by the binder resin. As the binder resin, any known resin used in inks may be used, and it may be a thermoplastic resin, or a curable resin such as an active energy ray curable resin or a thermosetting resin, but among these, an active energy ray curable resin, and especially an ultraviolet curable resin, is preferred. By using an ultraviolet curable resin, the curable ink 21 can be an ultraviolet curable ink.

[0067] Furthermore, it is preferable that the curable ink 21 is an active energy ray curable ink that hardens upon irradiation with active energy rays. Examples of active energy rays include visible light, ultraviolet light, infrared light, X-rays, alpha rays, beta rays, and gamma rays. It is even more preferable that the curable ink 21 is an ultraviolet-curable ink that hardens upon irradiation with ultraviolet light. In addition, it is preferable that the curable ink 21 contains a binder resin, and that the binder resin is a curable resin.

[0068] UV-curable inks preferably contain a polymerizable compound that can be cured by irradiation with ultraviolet light as a binder resin, which is a curable resin. While any known polymerizable compound used in UV-curable inks may be used, acrylate compounds are preferred. The acrylate compound is a compound having a (meth)acryloyl group; it may be a monofunctional acrylate compound having one (meth)acryloyl group, but it is preferable to include a polyfunctional acrylate compound having at least two (meth)acryloyl groups. Using a polyfunctional acrylate compound facilitates proper curing of the printed layer 20.

[0069] The polyfunctional acrylate compound may be either a diacrylate compound having two (meth)acryloyl groups or a polyfunctional acrylate compound having three or more (meth)acryloyl groups, but the latter is more preferred. When a polyfunctional acrylate compound having three or more (meth)acryloyl groups is used, the printed layer 20 becomes a crosslinked body having a three-dimensional network structure. As a result, the mechanical strength of the printed layer 20 is increased. In addition, the material constituting the printed layer 20 becomes less likely to migrate to the intermediate layer 10, etc.

[0070] Furthermore, UV-curable inks may contain, in addition to colorants and binder resins, other known components used in inks. For example, they may contain conventional UV-curable ink components such as sensitizers, dispersants, leveling agents, defoamers, surface modifiers, and photopolymerization initiators. UV-curable inks may also be solvent-free, but may contain organic solvents or other solvents as needed.

[0071] If the printed layer 20 is a conductive layer, the curable ink 21 is preferably a conductive ink. While general conductive inks can be used, it is preferable that the ink be UV-curable.

[0072] [Intermediate Layer] The intermediate layer 10 may be any of the first intermediate layer 10A, the second intermediate layer 10B, and the third intermediate layer 10C. The intermediate layer 10 may be used as a substrate for forming the printed layer 20. The intermediate layer 10 may also serve as an adhesive layer for bonding the printed layer 20 to the first glass substrate 5 or the second glass substrate 6. Therefore, it is preferable that the intermediate layer 10 be placed on at least one side of the laminated film 2, and more preferably on both sides of the laminated film 2.

[0073] The intermediate layer 10 is a resin layer containing a resin. Preferably, the resin in the intermediate layer 10 is a thermoplastic resin. The inclusion of a thermoplastic resin in the intermediate layer 10 facilitates its function as an adhesive layer, resulting in good adhesion to the glass substrate. While not particularly limited, examples of thermoplastic resins include polyvinyl acetal resin, ethylene-vinyl acetate copolymer resin, ionomer resin, polyurethane resin, thermoplastic elastomer, acrylic resin, acrylic-vinyl acetate copolymer resin, polyvinyl alcohol resin, polyolefin resin, polyvinyl acetate resin, and polystyrene resin. Using these resins makes it easier to ensure adhesion to the glass substrate. The thermoplastic resin may be used alone or in combination of two or more. Among the above, at least one selected from polyvinyl acetal resin and ethylene-vinyl acetate copolymer resin is preferred, and polyvinyl acetal resin is more preferred in that it exhibits excellent adhesion to glass when used in combination with a plasticizer.

[0074] When the laminated film 2 has multiple intermediate layers 10, the resin constituting each intermediate layer 10 may be appropriately selected from the resins listed above. Furthermore, the resins constituting each intermediate layer 10 may be different from each other, but it is preferable that they be the same. When the laminated film 2 has a first intermediate layer 10A and a second intermediate layer 10B, the resins used in both the first intermediate layer 10A and the second intermediate layer 10B are preferably at least one selected from polyvinyl acetal resin and ethylene-vinyl acetate copolymer resin, with polyvinyl acetal resin being more preferable.

[0075] (Polyvinyl acetal resin) The polyvinyl acetal resin is not particularly limited as long as it is obtained by acetalizing polyvinyl alcohol (PVA) with an aldehyde. The aldehyde is not particularly limited, but generally, aldehydes having 1 to 10 carbon atoms are preferably used. The aldehydes having 1 to 10 carbon atoms are not particularly limited, and examples include n-butyraldehyde, isobutyraldehyde, n-barrelaldehyde, 2-ethylbutyraldehyde, n-hexylaldehyde, n-octylaldehyde, n-nonylaldehyde, n-decylaldehyde, formaldehyde, acetaldehyde, benzaldehyde, etc. These aldehydes may be used alone or in combination of two or more. Among those mentioned above, n-butyraldehyde, n-hexylaldehyde, and n-valeraldehyde are preferred, with n-butyraldehyde being more preferred. Therefore, polyvinyl butyral resin is preferred as the polyvinyl acetal resin.

[0076] Polyvinyl alcohol (PVA) is obtained by saponifying a polyvinyl ester, such as polyvinyl acetate. The degree of saponification of polyvinyl alcohol is generally 70 to 99.9 mol%. Polyvinyl acetal resin may be used alone or in combination of two or more types. The average degree of polymerization of PVA is preferably 200 or higher, more preferably 500 or higher, even more preferably 1000 or higher, and even more preferably 1500 or higher. Setting the average degree of polymerization above the lower limit increases the puncture resistance of the laminated glass. Alternatively, the average degree of polymerization of PVA is preferably 5000 or lower, more preferably 4000 or lower, even more preferably 3500 or lower, and even more preferably 2500 or lower. The average degree of polymerization of polyvinyl alcohol is determined by a method in accordance with JIS K6726 "Test Method for Polyvinyl Alcohol".

[0077] The shear storage modulus of the intermediate layer 10 at 140°C is 6 × 10⁻⁶. ４From the viewpoint of achieving a Pa or higher load capacity, the weight-average molecular weight (Mw) of the polyvinyl acetal is preferably 220,000 or higher. Furthermore, an Mw of 220,000 or higher can improve the impact resistance of the polyvinyl acetal. The Mw of the polyvinyl acetal is more preferably 230,000 or higher, even more preferably 240,000 or higher, and even more preferably 260,000 or higher. Furthermore, the Mw of the polyvinyl acetal is preferably 310,000 or lower. An Mw of 310,000 or lower can more effectively suppress the scattering of glass constituting the laminated glass. The Mw of the polyvinyl acetal is more preferably 305,000 or lower, even more preferably 300,000 or lower, and even more preferably 290,000 or lower.

[0078] The weight-average molecular weight (Mw) of polyvinyl acetal is measured by gel permeation chromatography. The above weight-average molecular weight can be measured by the following method: The sample to be measured is dissolved to a concentration of 0.05% by mass in an N-methyl-2-pyrrolidone solution to which lithium bromide has been added to a concentration of 10 mM, and filtered using a syringe filter (Merck Millex-LH 0.45 μm). After filtration, the measurement is performed using gel permeation chromatography (Waters e2690), and the molecular weight is calculated using a molecular weight calibration curve prepared with monodisperse polystyrene standard samples. In addition, a Shodex GPC KF-806L column (Resonac Holdings Co., Ltd.) is used, and an N-methyl-2-pyrrolidone solution to which lithium bromide has been added to a concentration of 10 mM is used as the eluent.

[0079] The hydroxyl group content of the polyvinyl acetal resin is preferably 15 mol% or more, and more preferably 38 mol% or less. A hydroxyl group content of 15 mol% or more facilitates good adhesion and improves the penetration resistance of the laminated glass. Furthermore, a hydroxyl group content of 38 mol% or less prevents the laminated glass from becoming too hard. From the viewpoint of adhesion to the glass substrate, the above hydroxyl group content is more preferably 20 mol% or more, and even more preferably 25 mol% or more. Furthermore, the above hydroxyl group content is more preferably 35% or less, and even more preferably 33 mol% or less. When polyvinyl butyral resin is used as the polyvinyl acetal resin, from a similar viewpoint, the hydroxyl group content is 15 mol% or more, more preferably 38 mol% or less, more preferably 20 mol% or more, even more preferably 25 mol% or more, more preferably 35% mol% or less, and even more preferably 33 mol% or less. The amount of hydroxyl groups in polyvinyl acetal resin is the mole fraction obtained by dividing the amount of ethylene groups to which hydroxyl groups are attached by the total amount of ethylene groups in the main chain, expressed as a percentage. The amount of hydroxyl groups in polyvinyl acetal resin is calculated using the following formula (6): (6) Amount of hydroxyl groups in polyvinyl acetal [mol%] = 100 - (Degree of acetalization [mol%] + Degree of acetylation [mol%]).

[0080] The degree of acetalization of the above polyvinyl acetal resin is preferably 47 mol% or more, and more preferably 85 mol% or less. More preferably 55 mol% or more, even more preferably 60 mol% or more, even more preferably 80 mol% or less, and even more preferably 75 mol% or less. Note that the degree of acetalization refers to the degree of butyralization when the acetal group is a butyral group and the polyvinyl acetal resin (A) is a polyvinyl butyral resin.

[0081] The degree of acetalization described above is a value expressed as a percentage of the mole fraction obtained by dividing the total amount of ethylene groups in the main chain (the difference between the total amount of ethylene groups in the main chain and the amount of ethylene groups to which hydroxyl groups and ethylene groups are to which acetyl groups are attached) by the total amount of ethylene groups in the main chain. The degree of acetalization (or butyralization) can be measured by NMR (Nuclear Magnetic Resonance). The method for measuring the degree of acetalization will be described later, together with the method for measuring the degree of acetylation.

[0082] The degree of acetylation of the polyvinyl acetal resin is preferably 30 mol% or less, more preferably 20 mol% or less, even more preferably 10 mol% or less, and even more preferably 2 mol% or less. When the degree of acetylation is below the above upper limit, the moisture resistance of the laminated film 2 and laminated glass is increased. Furthermore, although the degree of acetylation is not particularly limited, it is preferably 0.01 mol% or more, and more preferably 0.1 mol% or more. The degree of acetylation is a value expressed as a percentage of the mole fraction obtained by dividing the amount of ethylene groups to which acetyl groups are bonded by the total amount of ethylene groups in the main chain. The degree of acetylation can be measured by NMR, similar to the degree of acetalization. The measurement conditions for the degree of acetalization and the degree of acetylation are as follows: Using a nuclear magnetic resonance (NMR) spectrometer (Bruker, product name "AVANCE III HD"), a 400 MHz spectrometer is used. １ 1H-NMR measurement will be performed. Polyvinyl acetal will be dissolved in deuterated dimethyl sulfoxide (DMSO-d6) to prepare a solution containing 1% by mass of polyvinyl acetal as the measurement sample. １ The chemical shift on the horizontal axis of the 1H-NMR spectrum is expressed in ppm, and the chemical shift of DMSO-d6 is set to 2.49 ppm. １ From the heights of multiple peaks in the 1H-NMR spectrum of polyvinyl acetal, the total amount of ethylene groups in the main chain, the amount of ethylene groups to which hydroxyl groups are attached, and the amount of ethylene groups to which acetyl groups are attached can be determined, respectively. This allows for the determination of the degree of acetylation and the degree of acetalization, respectively.

[0083] (Ethylene-vinyl acetate copolymer resin) The ethylene-vinyl acetate copolymer resin may be a non-crosslinked type ethylene-vinyl acetate copolymer resin or a high-temperature crosslinked type ethylene-vinyl acetate copolymer resin. In addition, ethylene-vinyl acetate modified resins such as ethylene-vinyl acetate copolymer saponified products and hydrolyzed products of ethylene-vinyl acetate can also be used as the ethylene-vinyl acetate copolymer resin. The vinyl acetate content of the ethylene-vinyl acetate copolymer resin is preferably 10% to 50% by mass, more preferably 20% to 40% by mass, as measured in accordance with JIS K6730 "Test method for ethylene-vinyl acetate resin" or JIS K6924-2:1997. Setting the vinyl acetate content above these lower limits improves adhesion to glass and improves the penetration resistance of laminated glass. Setting the vinyl acetate content below these upper limits increases the breaking strength of the laminated film 2 and improves the impact resistance of laminated glass.

[0084] (Plasticizer) If the intermediate layer 10 contains a thermoplastic resin, it is preferable that it further contains a plasticizer. That is, it is preferable that the intermediate layer 10 contains both a thermoplastic resin and a plasticizer. The intermediate layer 10 becomes flexible by containing a plasticizer, and as a result, the laminated film 2 also becomes flexible. This also improves the flexibility of the laminated glass and improves its resistance to penetration. Furthermore, it becomes possible to exhibit high adhesion to the glass substrate.

[0085] The plasticizer is particularly effective when included in the intermediate layer 10 when polyvinyl acetal resin is used as the thermoplastic resin. Therefore, it is more preferable that the intermediate layer 10 contains both polyvinyl acetal resin and a plasticizer. Examples of plasticizers include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, and phosphorus-based plasticizers such as organic phosphate ester plasticizers and organic phosphite ester plasticizers. Among these, organic ester plasticizers are preferred.

[0086] Organic ester plasticizers include, for example, triethylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethyl butyrate, 1,3-propylene glycol di-2-ethyl butyrate, 1,4-butylene glycol di-2-ethyl butyrate, 1,2-butylene glycol di-2-ethyl butyrate, diethylene glycol di- Examples include 2-ethyl butyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethyl butyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethyl butyrate, diethylene glycol dicapriate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, triethylene glycol di-2-ethyl butyrate, dihexyl adipate, dioctyl adipate, hexylcyclohexyl adipate, diisononyl adipate, heptylnonyl adipate, dibutyl sebacate, oil-modified alkyd sebacate, mixtures of phosphate esters and adipic acid esters, and mixed adipic acid esters. Examples of mixed adipic acid esters include adipic acid esters made from two or more alcohols selected from alkyl alcohols having 4 to 9 carbon atoms and cyclic alcohols having 4 to 9 carbon atoms. Among the plasticizers mentioned above, triethylene glycol-di-2-ethylhexanoate (3GO) is particularly preferred.

[0087] The content of the plasticizer in the intermediate layer 10 is not particularly limited, but is preferably 10 parts by mass or more and 100 parts by mass or less per 100 parts by mass of thermoplastic resin. When the plasticizer content is 10 parts by mass or more, the laminated film 2 becomes moderately flexible. As a result, the penetration resistance of the laminated glass is improved. Also, when the plasticizer content is 100 parts by mass or less, separation of the plasticizer from the intermediate layer 10 is prevented. The plasticizer content is more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, even more preferably 35 parts by mass or more, and even more preferably 70 parts by mass or less, and even more preferably 63 parts by mass or less.

[0088] The intermediate layer 10 is mainly composed of resin, or resin and plasticizer. The total amount of thermoplastic resin and plasticizer in the intermediate layer 10 is usually 70% by mass or more and 100% by mass or less, preferably 80% by mass or more and 100% by mass or less, and more preferably 90% by mass or more and 100% by mass or less, when the total amount of the intermediate layer 10 is considered to be 100% by mass. However, as the intermediate layer 10 generally contains additives as described later, the total amount of thermoplastic resin and plasticizer may be less than 100% by mass.

[0089] The intermediate layer 10 may appropriately contain various additives such as heat shielding agents, ultraviolet absorbers, antioxidants, and light stabilizers.

[0090] The thickness of the intermediate layer 10 is not particularly limited, but for example, it is 0.05 mm or more and 1.0 mm or less, preferably 0.1 mm or more and 0.8 mm or less, and more preferably 0.2 mm or more and 0.5 mm or less. By setting the thickness of the intermediate layer 10 within the above range, the printed layer 20 can be properly supported by the intermediate layer 10 without making the thickness of the laminated film 2 unnecessarily large, and the laminated film 2 can be easily bonded to the glass substrate.

[0091] The thickness of the laminated film 2 is not particularly limited, but for example, it is 0.3 mm or more and 2 mm or less, preferably 0.4 mm or more and 1.5 mm or less, and more preferably 0.5 mm and 1.2 mm or less. By setting the thickness of the laminated film 2 to be above the lower limit and below the upper limit, the laminated film 2 can be suitably applied to laminated glass.

[0092] The details of laminated glass are described below. [Laminated Glass] Laminated glass has a laminated film 2, a first glass substrate 5, and a second glass substrate 6. The first glass substrate 5 and the second glass substrate 6 are arranged with the laminated film 2 in between. Glass plates can be used as the first glass substrate 5 and the second glass substrate 6. The glass plates can be either inorganic glass or organic glass, but inorganic glass is preferred. Inorganic glass is not particularly limited, but examples include clear glass, float glass, polished glass, patterned glass, wired glass, reinforcing glass, green glass, etc. As for organic glass, what is generally called resin glass is used, and is not particularly limited, but examples include organic glass composed of resins such as polycarbonate, acrylic resin, acrylic copolymer resin, and polyester. The two glass plates may be made of the same material or different materials. For example, one may be inorganic glass and the other may be organic glass, but it is preferable that both glass plates are inorganic glass or organic glass. Furthermore, the thickness of each glass plate is not particularly limited, but is, for example, about 0.1 mm to 15 mm, preferably 0.5 mm to 5 mm. The thicknesses of each glass plate may be the same or different, but it is preferable that they be the same.

[0093] The method for manufacturing laminated glass is not particularly limited. For example, a laminated film 2 is sandwiched between a first glass substrate 5 and a second glass substrate 6, and the air remaining between the glass substrate and the laminated film 2 is removed by passing it through a pressing roll or by placing it in a rubber bag and applying reduced pressure and suction. Then, a laminate is obtained by pre-bonding at approximately 70°C to 110°C. Next, the laminate is placed in an autoclave or pressed to bond it at a temperature of approximately 120°C to 140°C and a pressure of 1.0 MPa to 1.5 MPa. In this way, laminated glass can be obtained.

[0094] Laminated glass can be used as a glass structure, such as window glass, in various fields. For example, it can be used in vehicles such as automobiles, railway cars, aircraft, and ships, as well as in architectural applications. Among these, its use in various vehicle applications, such as automobiles, is particularly preferable. When used in automobiles, it can be used for the windshield, side windows, rear windows, and roof windows. When used in automobiles, it is preferable that the laminated glass has a curved surface that follows the body lines of the automobile.

[0095] Laminated glass is preferable for applications requiring high design quality because it can support images within the glass structure. For example, when used in automotive windows, it allows for decoration to match the body design and color. It is also preferable for use in architectural applications as decorative glass for exterior or interior finishes. Furthermore, electrical circuits can be embedded within the glass structure instead of images.

[0096] Furthermore, as described above, when the printed layer 20 contains a light-emitting material, the laminated glass is preferably used together with a light source device that emits excitation light. The light source device is not particularly limited, but when the laminated glass is used in vehicle applications, it is preferably placed inside the vehicle, for example. When used in building applications, the light source device may be placed inside the building or outside the building.

[0097] Examples will be described below, but the technology of this disclosure is not limited in any way by the following examples. Examples 1 and 2 below are examples, and Example 3 below is a comparative example.

[0098] [Example 1] (Formation of Laminated Film) A 0.4 mm thick resin film was prepared as the first and second intermediate layers, consisting of 100 parts by mass of PVB (polyvinyl butyral resin, average degree of polymerization 1700, hydroxyl group content 30.5 mol%, degree of acetylation 1 mol%, degree of acetalization 68.5 mol%) and 40 parts by mass of a plasticizer (3GO: triethylene glycol-di-2-ethylhexanoate). A printed layer was formed on one side of the prepared resin film for the first intermediate layer using ultraviolet-curable ink (Mimaki LH120, manufactured by Mimaki Engineering Co., Ltd.). The printed layer was formed by alternately printing the ultraviolet-curable ink and forming the cured layer multiple times using an inkjet printer, as shown in Figure 1. The thickness of each cured layer was as shown in Table 1. The ultraviolet irradiation intensity was 3 W / cm². ２ The printed layer had five straight lines, each 130 mm long and spaced 10 mm apart, with line widths of 0.1 mm, 1 mm, 3 mm, 5 mm, and 10 mm. Subsequently, a resin film for a second intermediate layer was laminated onto the printed layer using a lamination method to obtain a laminated film with a structure similar to that shown in Figure 6, measuring 15 cm in length, 15 cm in width, and 0.8 mm in thickness.

[0099] (Formation of Laminated Glass) The obtained laminated film (interlayer for laminated glass) was sandwiched between two inorganic glass substrates (15 cm long x 15 cm wide x 2.5 mm thick) to obtain a laminate. This laminate was placed in a rubber bag, and the inside of the rubber bag was degassed at a vacuum of 2.6 kPa for 20 minutes. Then the rubber bag was moved into an oven and held at 90°C for another 30 minutes. After that, the laminate was removed from the rubber bag and placed in an autoclave, where the components of the laminate were pressed together at a temperature of 135°C and a pressure of 1.2 MPa for 20 minutes. This resulted in obtaining laminated glass having a structure similar to that shown in Figure 7.

[0100] [Example 2] In Example 2, a laminated film was prepared in the same manner as in Example 1, except that the thickness of each hardened layer, the number of hardened layers, and the thickness of the printed layer were changed, and then laminated glass was produced.

[0101] [Example 3] In Example 3, a laminated film was prepared in the same manner as in Example 1, except that the printing of the curable ink and the formation of the cured layer were performed only once, and the thickness of the printed layer was changed, and laminated glass was then produced.

[0102] [Evaluation] The printed layers of the laminated glass obtained in Examples 1 to 3 were visually observed, and their appearance was evaluated according to the following evaluation criteria. The evaluation results are shown in Table 1. -Evaluation Criteria- A: No wrinkles are formed in the printed layer. B: Wrinkles are formed in the printed layer.

[0103]

[0104] As shown in Table 1, in Examples 1 and 2, unlike Example 3, a printed layer consisting of multiple cured layers was formed by alternately performing printing with UV-curable ink and forming a cured layer multiple times. Therefore, in Examples 1 and 2, the average curing rate Rave of the printed layer was improved compared to Example 3, and the occurrence of wrinkles in the printed layer was suppressed. In Example 3, as shown in Figure 10, the occurrence of wrinkles in the printed layer 20 could not be suppressed.

[0105] The laminated film, laminated glass, and method for manufacturing the laminated film described above have been explained, but this disclosure is not limited to the embodiments described above. Various changes, modifications, substitutions, additions, deletions, and combinations are possible within the scope of the claims. These also naturally fall within the technical scope of this disclosure.

[0106] This application claims priority based on Japanese Patent Application No. 2025-055349, filed with the Japan Patent Office on March 28, 2025, and the entire contents of Japanese Patent Application No. 2025-055349 are incorporated herein by reference.

[0107] 2. Laminated film 10. Intermediate layer 10A. First intermediate layer 10B. Second intermediate layer 10C. Third intermediate layer 20. Printing layer 21. Curable ink 22. Cured layer

Claims

1. A laminated film comprising: a first intermediate layer for laminated glass containing a thermoplastic resin; and a printed layer adjacent to the surface of the first intermediate layer, wherein the printed layer contains a cured product of a curable ink, and the average curing rate of the printed layer is 80% or more.

2. The laminated film according to claim 1, wherein the printed layer has a first surface adjacent to the first intermediate layer and a second surface facing the opposite direction from the first surface, and the absolute value of the difference between the curing rate of the first surface and the curing rate of the second surface is 10% or less.

3. The laminated film according to claim 1 or 2, wherein the printed layer has a first surface adjacent to the first intermediate layer and a second surface facing the opposite direction from the first surface, and the laminated film has a second intermediate layer containing a thermoplastic resin, the second intermediate layer being adjacent to the second surface of the printed layer.

4. The laminated film according to claim 1 or 2, wherein the thickness of the printed layer is 1 μm or more and 50 μm or less.

5. The laminated film according to claim 1 or 2, wherein the curable ink is an ultraviolet-curable ink.

6. The laminated film according to claim 1 or 2, wherein the average curing rate of the printed layer is 90% or more.

7. The laminated film according to claim 1 or 2, wherein the thermoplastic resin is at least one selected from polyvinyl acetal, ethylene vinyl acetate, polyurethane, and polyolefin.

8. The laminated film according to claim 7, wherein the thermoplastic resin is polyvinyl acetal.

9. The laminated film according to claim 1 or 2, wherein the printed layer has a first surface in contact with the first intermediate layer and a second surface facing the opposite direction from the first surface, and the laminated film comprises a third intermediate layer adjacent to the second surface of the printed layer, wherein the shear storage modulus at 140°C is higher than that of the first intermediate layer.

10. The laminated film according to claim 9, wherein the printed layer has a second intermediate layer containing a thermoplastic resin, the second intermediate layer is positioned on the opposite side from the printed layer with respect to the third intermediate layer, and the third intermediate layer has a shear storage modulus at 140°C that is higher than that of the second intermediate layer.

11. Laminated glass comprising a laminated film according to claim 1 or 2, and a first glass substrate and a second glass substrate sandwiching the laminated film.

12. A method for manufacturing a laminated film, comprising: printing a curable ink onto the surface of a substrate; curing the curable ink on the substrate to form a cured layer with a thickness of 10 μm or less; and forming a printed layer by alternately performing the printing of the curable ink and the formation of the cured layer multiple times to laminate a plurality of the cured layers.

13. The method for manufacturing a laminated film according to claim 12, wherein the thickness of the printed layer is 1 μm or more and 50 μm or less.

14. The method for manufacturing a laminated film according to claim 12 or 13, wherein the curable ink is printed by plate printing.

15. The method for manufacturing a laminated film according to claim 12 or 13, wherein the curable ink is printed by plateless printing.

16. The method for manufacturing a laminated film according to claim 15, wherein the plateless printing is inkjet printing.

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