Laminated glass and functional layer

Abstract

To improve the appearance of laminated glass that has a light-extracting function. [Solution] This laminated glass includes a first glass plate having a main surface, a second glass plate arranged in the direction normal to the main surface, and a first interlayer, a functional layer, and a second interlayer laminated between the first and second glass plates in the direction normal to the main surface, wherein the functional layer includes a light extraction layer that extracts light incident from the side to the main surface side, and when placed in an environment of 130°C for 1 hour, the first shrinkage rate in a first direction intersecting the direction normal to the main surface, and the second shrinkage rate in a second direction intersecting the direction normal to the main surface and the first direction, respectively, are both 5% or less.

Description

Technical Field

[0001] The present invention relates to laminated glass and functional layers.

Background Art

[0002] For example, Patent Document 1 discloses laminated glass having a light extraction function. This laminated glass includes two glass plates and at least one polymer intermediate layer film between the two glass plates, and a functional layer containing light-scattering particles is applied to at least one surface of the polymer intermediate layer film.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to improve the appearance of laminated glass having a light extraction function.

Means for Solving the Problems

[0005] The laminated glass according to one aspect of the present invention includes a first glass plate having a main surface, a second glass plate disposed in the normal direction of the main surface, a first intermediate film, a functional layer, and a second intermediate film laminated in the normal direction of the main surface between the first glass plate and the second glass plate. The functional layer includes a light extraction layer that extracts light incident from the side to the main surface side. When placed in an environment of 130°C for 1 hour, the first shrinkage rate in a first direction intersecting the normal direction of the main surface and the second shrinkage rate in a second direction intersecting each of the normal direction of the main surface and the first direction are both 5% or less.

Effects of the Invention

[0006] According to the present invention, the appearance of laminated glass having a light extraction function can be improved. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic cross-sectional view showing a first example of laminated glass according to the embodiment. [Figure 2] This is a schematic cross-sectional view showing a second example of laminated glass according to the embodiment. [Figure 3] This is a schematic cross-sectional view showing how light is guided by laminated glass according to the embodiment. [Figure 4] This is a schematic cross-sectional view of the light extraction layer of the laminated glass according to the embodiment. [Figure 5] This is a schematic cross-sectional view of a recess in the light extraction layer of the laminated glass according to the embodiment. [Figure 6] This is a schematic top view showing a first example of a recess in the light extraction layer of laminated glass according to the embodiment. [Figure 7] This is a schematic top view showing a second example of a light extraction layer recess in laminated glass according to the embodiment. [Figure 8] This is a schematic top view showing the functional layer in the measurement of the first and second shrinkage rates. [Figure 9] This is a schematic cross-sectional view of the IX-IX line in Figure 8. [Figure 10] This figure shows the detailed configuration of the functional layer of the laminated glass according to Example 1. [Figure 11] This figure shows the detailed configuration of the functional layer of the laminated glass according to Example 2. [Figure 12] This figure shows the detailed configuration of the functional layer of the laminated glass in the comparative example. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described in detail below with reference to the drawings. In each drawing, the same reference numerals are used for the same components, and redundant explanations are omitted as appropriate.

[0009] The embodiments shown below illustrate laminated glass that embodies the technical concept of the present invention, and the present invention is not limited to the embodiments shown below. Furthermore, the size and positional relationships of the components shown in the drawings may be exaggerated for clarity of explanation. "Placement" is not limited to direct contact, but also includes indirect placement, for example, via other components.

[0010] In the diagrams shown below, a Cartesian coordinate system with X, Y, and Z axes is used to represent direction. The X, Y, and Z axes are approximately orthogonal to each other. The direction in which the arrow representing the X axis points is denoted as the +X side, and the opposite direction is denoted as the -X side. The direction in which the arrow representing the Y axis points is denoted as the +Y side, and the opposite direction is denoted as the -Y side. The direction in which the arrow representing the Z axis points is denoted as the +Z side, and the opposite direction is denoted as the -Z side.

[0011] In the drawings shown below, the Z-direction along the Z-axis of the first glass plate in the laminated glass according to the embodiment corresponds to the normal direction of the main surface. The X-direction along the X-axis corresponds to a first direction intersecting the normal direction of the main surface. The Y-direction along the Y-axis corresponds to a second direction intersecting the normal direction of the main surface and the first direction, respectively. In this specification, these are referred to as the first direction X, the second direction Y, and the normal direction Z.

[0012] In the drawings shown below, the first direction X corresponds to the TD (Transport Direction) direction, which is the axial direction of the roller around which the elongated sheet containing the functional layer of the laminated glass according to the embodiment is traversed when manufacturing the functional layer of the laminated glass according to the embodiment. The second direction Y corresponds to the MD (Machine Direction) direction, which is used to transport the elongated sheet containing the functional layer.

[0013] In this specification, the +Z direction is referred to as "up", and the -Z direction is referred to as "down". Viewing an object from the +Z direction is called a top view. However, the above direction expressions only represent relative positional relationships for the purpose of explanation and do not limit the direction of the embodiments. Also, in this specification, "height" and "thickness" mean the length of an object in the Z direction.

[0014] [Embodiment] Referring to FIGS. 1 to 3, the configuration of the laminated glass according to the embodiment will be described. FIG. 1 is a schematic cross-sectional view showing a first example of the laminated glass 100 according to the embodiment. FIG. 2 is a schematic cross-sectional view showing a second example of the laminated glass 100. FIG. 3 is a schematic cross-sectional view showing the state of light guiding by the laminated glass 100. Note that FIGS. 1 to 3 show the cross-section of the laminated glass 100 along the YZ plane.

[0015] As shown in FIGS. 1 and 2, the laminated glass 100 according to the embodiment includes a first glass plate 31 having a main surface 100a, a second glass plate 32 disposed in the normal direction Z of the main surface 100a, and a first intermediate film 21, a functional layer 10, and a second intermediate film 22 laminated and disposed in the normal direction of the main surface 100a between the first glass plate 31 and the second glass plate 32. The functional layer 10 includes a light extraction layer 11 that extracts light incident from the side toward the main surface 100a side.

[0016] The laminated glass 100 is a functional laminated glass in which the functional layer 10 is sandwiched between the first glass plate 31 and the second glass plate 32. In the examples shown in FIGS. 1 and 2, the first glass plate 31 and the functional layer 10 are adhered by the first intermediate film 21. The second glass plate 32 and the functional layer 10 are adhered by the second intermediate film 22.

[0017] In the first example shown in Figure 1, the functional layer 10 includes a base layer 131 placed on the light extraction layer 11 via an adhesive layer (not shown), a base layer 132 placed below the light extraction layer 11, and an adhesive layer 122 placed between the light extraction layer 11 and the base layer 132. The first interlayer 21 is placed between the base layer 131 and the first glass plate 31. The second interlayer 22 is placed between the base layer 132 and the second glass plate 32. The base layer 131 is the base material on which the light extraction layer 11 is formed. The base layer 132 is bonded to the light extraction layer 11 via the adhesive layer 122.

[0018] In the second example shown in Figure 2, the functional layer 10 includes an adhesive layer 122 positioned beneath the light extraction layer 11. The first interlayer 21 is positioned between the first glass plate 31 and the light extraction layer 11. The second interlayer 22 is positioned between the adhesive layer 122 and the second glass plate 32. The light extraction layer 11 is bonded to the second glass plate 32 via the adhesive layer 122 and the second interlayer 22.

[0019] In the examples shown in Figures 1 to 3, the light extraction layer 11 includes a recess 12. As shown in Figure 3, the laminated glass 100 guides light Lt emitted from a light source LS located to the side of the laminated glass 100, for example on the -Y side, and incident from the side of the functional layer 10, from the -Y side to the +Y side. The laminated glass 100 can extract the guided light Lt to the main surface 100a side, for example on the +Z side, through the recess 12.

[0020] More specifically, in the example shown in Figure 3, the light source LS is, for example, an LED (Light Emitting Diode) device. Multiple LED devices are arranged in a line in the first direction X. Light Lt incident from the light source LS onto the first glass plate 31 is guided while repeatedly reflecting within the first glass plate 31 or between the first glass plate 31 and the second glass plate 32. A portion of the guided light Lt is reflected by the first inclined surface ISa of the recess 12 of the light extraction layer 11 and emitted towards the main surface 100a side of the laminated glass 100. Note that in Figure 3, a portion of the light Lt emitted from the light source LS is represented by an arrow.

[0021] The first glass plate 31, the second glass plate 32, the first interlayer 21, the second interlayer 22, and the functional layer 10 are transparent to visible light. Visible light refers to light having a wavelength of 400 nm to 780 nm. The total light transmittance of the laminated glass 100 may be 60% or more, preferably 70% or more, and more preferably 80% or more. Here, total light transmittance refers to the transmittance to visible light. Total light transmittance can be measured, for example, using a haze meter in accordance with JIS K 7361-1.

[0022] In the manufacturing process of laminated glass 100, the first glass plate 31 and the second glass plate 32, the first interlayer 21 and the second interlayer 22, and the functional layer 10 are pressed together at a predetermined temperature, for example, 100°C to 150°C. The resulting laminated glass 100 may be further subjected to heating and pressurizing treatment in an autoclave. When these heating and pressurizing treatments are performed, the first interlayer 21 and the second interlayer 22 melt and become an adhesive when the first glass plate 31 and the second glass plate 32, the first interlayer 21 and the second interlayer 22, and the functional layer 10 are laminated and integrated. The first interlayer 21 and the second interlayer 22 act as an adhesive, bonding the first glass plate 31 and the second glass plate 32 to the functional layer 10.

[0023] In the manufacturing process of laminated glass with light extraction capabilities, wrinkles may occur in the functional layer of the laminated glass when it is heated and pressurized at a predetermined temperature. These wrinkles in the functional layer are visible through the light-transmitting first and 22nd glass plates. Therefore, the appearance of the laminated glass deteriorates when wrinkles occur in the functional layer.

[0024] As a result of diligent research, the inventors have revealed that when laminated glass is heated and pressurized at a predetermined temperature, the wrinkles described above occur due to the difference in shrinkage rates between the light extraction layer and the adhesive layer that constitute the functional layer of the laminated glass. Furthermore, the inventors have revealed that the temperature at which the heating and pressurizing treatment is performed is the dominant factor in the occurrence of wrinkles.

[0025] In view of the above, in the laminated glass 100 according to this embodiment, when the functional layer 10 is placed in an environment of 130°C for 1 hour, the first shrinkage rate in the first direction X and the second shrinkage rate in the second direction Y are both 5% or less. Furthermore, the functional layer 10 according to this embodiment includes a light extraction layer 11 that extracts light Lt incident from the side to the first interlayer 21. When placed in an environment of 130°C for 1 hour, the first shrinkage rate in the first direction X intersecting the normal direction of the first interlayer 21, and the second shrinkage rate in the second direction Y intersecting the normal direction of the first interlayer 21 and the first direction X are both 5% or less. By satisfying this condition, the difference in shrinkage rates between the light extraction layer 11 and the adhesive layer 122 constituting the functional layer 10 is reduced. By reducing the difference in shrinkage rates between the light extraction layer 11 and the adhesive layer 122, wrinkles in the functional layer 10 are reduced. By reducing wrinkles in the functional layer 10, the appearance of the laminated glass 100 having a light extraction function can be improved in this embodiment.

[0026] The following describes in detail the first glass plate 31, the second glass plate 32, the first interlayer 21, the second interlayer 22, and the functional layer 10 of the laminated glass 100 according to this embodiment.

[0027] (First glass plate 31 and second glass plate 32) The first glass plate 31 and the second glass plate 32 may each be made of glass. The first glass plate 31 and the second glass plate 32 may each have the same composition or different compositions. The thickness of the first glass plate 31 and the second glass plate 32 may each be, for example, 50 μm or more and 50 mm or less.

[0028] Examples of glass materials that make up the first glass plate 31 and the second glass plate 32 include soda-lime glass, alkali-free glass, borosilicate glass, and aluminosilicate glass. The first glass plate 31 and the second glass plate 32 may be subjected to chemical strengthening, physical strengthening, hard coating, etc., in order to improve their durability.

[0029] (First interlayer 21 and second interlayer 22) The configurations of the first interlayer 21 and the second interlayer 22, such as the material, mechanical properties, and optical properties, can be appropriately set according to the purpose. In the first example shown in Figure 1 and the second example shown in Figure 2, the first interlayer 21 and the second interlayer 22 are adhesive layers composed of an adhesive. The first interlayer 21 and the second interlayer 22 may have the same configuration or they may have different configurations.

[0030] The first interlayer 21 and the second interlayer 22 are each composed of any suitable adhesive. In one embodiment, the first interlayer 21 and the second interlayer 22 are composed of an adhesive having softness that absorbs vibration transmission. The storage modulus of the first interlayer 21 and the second interlayer 22 at 23°C is, for example, 1.0 × 10⁵ (Pa) or less, for example, 1.0 × 10⁵ (Pa) or less, 9.5 × 10⁴ (Pa) or less, 9.0 × 10⁴ (Pa) or less, 8.5 × 10⁴ (Pa) or less, 8.0 × 10⁴ (Pa) or less, 7.5 × 10⁴ (Pa) or less, or 7.0 × 10⁴ (Pa) or less, and 1.0 × 10³ (Pa) or more, 5.0 × 10³ (Pa) or more, 1.0 × 10⁴ (Pa) or more, or 5.0 × 10⁴ (Pa) or more. Preferably, the pressure is between 5.0 × 10³ (Pa) and 9.0 × 10⁴ (Pa), and more preferably between 1.0 × 10⁴ (Pa) and 8.5 × 10⁴ (Pa).

[0031] Any suitable adhesive can be used as the adhesive constituting the first interlayer 21 and the second interlayer 22, as long as it has the characteristics described above. Typical adhesives include acrylic adhesives, i.e., acrylic adhesive compositions. The acrylic adhesive composition is as described above. However, the adhesive constituting the first interlayer 21 and the second interlayer 22 preferably does not contain heterocyclic (meth)acrylate as a comonomer. Furthermore, the weight-average molecular weight Mw of the base polymer in the adhesive composition is preferably 2,000,000 or less, and more preferably 5,000 to 1,600,000. Details of the first interlayer 21 and the second interlayer 22, or the acrylic adhesive compositions constituting the first interlayer 21 and the second interlayer 22, are described, for example, in Japanese Patent Application Publication No. 2016-190996, and the description in said publication is incorporated herein by reference.

[0032] The thickness of the first interlayer 21 and the second interlayer 22 is preferably 5 μm to 300 μm, and more preferably 10 μm to 200 μm. If the thicknesses of the first interlayer 21 and the second interlayer 22 are within this range, shock can be mitigated, especially during lateral vibrations.

[0033] In laminated glass 100, the first interlayer 21 and the second interlayer 22 may be formed from polyvinyl butyral (PVB), ethylene-vinyl acetate copolymer resin (EVA), or ionomer resin, or an adhesive may be applied to their surfaces, or they may be formed from other resin materials. The first interlayer 21 and the second interlayer 22 are preferably transparent and have high transmittance.

[0034] (Functional layer 10) In the functional layer 10, each of the multiple recesses 12 included in the light extraction layer 11 has a first inclined surface ISa and a second inclined surface ISb. The first inclined surface ISa directs a portion of the light guided through the laminated glass 100 towards the main surface 100a by total internal reflection (TIR). The second inclined surface ISb is located on the opposite side from the first inclined surface ISa. Typically, the first inclined surface ISa is the inclined surface on the light source side, and the second inclined surface ISb is the inclined surface on the opposite side from the light source.

[0035] The inclination angle of the first inclined surface ISa is gentler, or in other words, smaller, than the inclination angle of the second inclined surface ISb. The recess 12 is, for example, an air cavity filled with air. The recess 12 reflects light incident on the first inclined surface ISa. The laminated glass 100 can extract the light reflected by the first inclined surface ISa of the recess 12 from the main surface 100a side.

[0036] The following will provide a detailed explanation of the multiple recesses 12 with reference to Figures 4 to 7. Figure 4 is a schematic top view showing the light extraction layer 11 of the laminated glass 100. Figure 5 is a schematic cross-sectional view of the recesses 12 in the light extraction layer 11 of the laminated glass 100. Figure 6 is a schematic top view showing a first example of the recesses 12 in the light extraction layer 11 of the laminated glass 100. Figure 7 is a schematic top view showing a second example of the recesses 12 in the light extraction layer 11 of the laminated glass 100.

[0037] In a top view, the ratio of the total area of ​​recesses to the area of ​​the optical laminate (occupancy rate) is preferably 1% to 80%. The upper limit of the occupancy rate may be, for example, 50% or less, 45% or less, 30% or less, 10% or less, or 5% or less. The smaller the occupancy rate, the higher the transmittance or the lower the haze of the light extraction layer 11 that can be obtained. For example, when the occupancy rate is 50%, a light extraction layer 11 with a haze of 30% can be obtained. On the other hand, the upper limit of the occupancy rate can be set according to the desired light extraction function. The occupancy rate may be uniform throughout the light extraction layer 11, or it may be configured to increase as the distance from the light source increases. A uniform configuration has the advantage of being suitable for mass production by the roll-to-roll or roll-to-sheet method. A configuration in which the occupancy rate increases with distance from the light source has the advantage that the brightness does not decrease even when the distance from the light source increases.

[0038] As shown in Figure 4, the multiple recesses 12 are spaced apart. The arrangement of the recesses 12 may or may not have periodicity or regularity in at least one direction. From the viewpoint of mass production, it is preferable that the arrangement of the recesses 12 be uniform throughout the entire light extraction layer 11. In the example shown in Figure 4, multiple recesses 12 having substantially the same shape and a curved surface convex in the same direction are periodically arranged throughout the entire light extraction layer 11 in the first direction X and the second direction Y. In this case, the pitch Py of the recesses 12 in the second direction Y is preferably 10 μm or more and 500 μm or less, and the pitch Px in the first direction X is preferably 10 μm or more and 500 μm or less. In the example shown in Figure 4, there are further recesses 12 arranged with a 1 / 2 pitch offset in each of the first direction X and the second direction Y.

[0039] The arrangement of the recesses 12 can be appropriately set according to the purpose, the shape of the light extraction layer 11, the desired light distribution, etc. For example, the recesses 12 may be periodically arranged in a direction having a predetermined angle with respect to the second direction Y, or periodically arranged in a direction having a predetermined angle with respect to the first direction X. The predetermined angle with respect to the direction perpendicular to the first direction X or the second direction Y can be appropriately set according to the purpose, the shape of the light extraction layer 11, the desired light distribution, etc.

[0040] The plurality of recesses 12 shown in Figure 4 have recesses 12 that are periodically spaced apart in the first direction X and the second direction Y, but the plurality of recesses 12 may have, for example, groove-shaped, or triangular prism-shaped recesses that extend in the first direction X.

[0041] Next, the shape of the recess 12 will be described. As shown in Figure 4, in a top view, the first inclined surface ISa forms a curved surface that is convex to the -Y side. Since the light emitted from each of the multiple LED devices spreads in the second direction Y, having a curved surface that is convex towards the light source side allows the first inclined surface ISa to act uniformly on the light. The curved surface of the first inclined surface ISa that is convex towards the light source side can be represented, for example, by a quartic curve.

[0042] As shown in Figure 5, the cross-sectional shape of the recess 12 is, for example, triangular. The inclination angle θa of the first inclined surface ISa is, for example, 10° to 70°. If the inclination angle θa is less than 10°, the controllability of light distribution may be insufficient, and the light extraction efficiency may be insufficient. On the other hand, if the inclination angle θa exceeds 70°, for example, it may become difficult to process the shaping film that constitutes the light extraction layer 11. The inclination angle θb of the second inclined surface ISb is, for example, 50° to 100°. If the inclination angle θb is less than 50°, stray light may be generated in an unintended direction. If the inclination angle θb exceeds 100°, for example, it may become difficult to process the shaping film that constitutes the light extraction layer 11. As shown in Figures 6 and 7, the length L of the recess 12 in the first direction X is preferably 10 μm to 500 μm. The width W of the recess 12 in the second direction Y is preferably 1 μm to 100 μm. The length L is, for example, twice or more the width W. The height H is preferably 1 μm or more and 100 μm or less.

[0043] Depending on the processing accuracy when forming the shaped film having the recess 12 having the top view shape shown in Figure 6, the recess 12 having the top view shape shown in Figure 7 may be formed. Even in such cases, the top view shape of the recess 12 can be characterized by its length L and width W.

[0044] The light extraction layer 11 can be made of any suitable material, as long as the recess 12 described above is formed. Typically, the light extraction layer 11 can be made of a material with high transmittance to visible light. Examples of such materials include acrylic resins such as polymethyl methacrylate (PMMA), polycarbonate (PC) resins, cycloolefin resins, and glass (e.g., quartz glass, alkali-free glass, borosilicate glass).

[0045] The recess 12 can be formed by any suitable method. For example, as in the first example shown in Figure 1, when the light extraction layer 11 is formed on the substrate layer 131, the recess 12 can be formed by coating the surface of a film made of the above material with lacquer, embossing an optical pattern corresponding to the recess 12 on the film surface containing the lacquer, and then curing the lacquer. Such a method is described, for example, in Japanese Patent Publication No. 2013-524288, the description of which is incorporated herein by reference.

[0046] The thickness of the light extraction layer 11 is preferably 5 μm to 200 μm, more preferably 5 μm to 150 μm, and even more preferably 5 μm to 100 μm. As shown in the second example in Figure 2, when the light extraction layer 11 is composed of a single shaped film, the thickness of the light extraction layer 11 may be, for example, 100 μm to 130 μm.

[0047] The light extraction layer 11 is not limited to a configuration that extracts light to the main surface 100a side by recesses 12. For example, the light extraction layer 11 may be a porous layer with voids inside. A porous layer as the light extraction layer 11 can extract light incident from the side to the main surface 100a side by scattering it in the voids. Details of the specific configuration and formation method of the porous layer are described, for example, in International Publication No. 2019 / 151073. The description in said publication is incorporated herein by reference. Alternatively, the light extraction layer 11 may extract light incident from the side to the main surface 100a side by light-scattering particles provided inside.

[0048] In the laminated glass 100 according to the first example shown in Figure 1, the base layer 131 and base layer 132 are both composed of, for example, polyethylene terephthalate (PET). However, at least one of the base layer 131 and base layer 132 may be composed of cycloolefin polymer (COP). The thickness of each of the base layer 131 and base layer 132 is, for example, 20 μm or more and 40 μm or less. In addition, in the laminated glass 100 according to the first example, the light extraction layer 11 is composed of, for example, an acrylic resin. In the first example, the shrinkage rates of the light extraction layer 11 in the first direction X and the second direction Y are, for example, 5% or more, 10% or more, 15% or more, and 40% or less. The shrinkage rates of the base layer 131 and base layer 132 in the first direction X and the second direction Y are both 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, and 0.5% or less. The lower limit is, for example, 0% and 0.1%.

[0049] In the laminated glass of the second example shown in Figure 2, the light extraction layer 11 is composed of, for example, polyethylene terephthalate (PET) in both parts. However, at least one of the light extraction layers 11 may be composed of cycloolefin polymer (COP). In the second example, the shrinkage rates of the light extraction layer 11 in the first direction X and the second direction Y are 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, and 0.5% or less, respectively. The lower limits are, for example, 0% and 0.1%.

[0050] The adhesive layer 122 of the laminated glass 100 in the first example shown in Figure 1 and the second example shown in Figure 2 is composed of an acrylic resin. The thickness of the adhesive layer 122 is, for example, 47 μm.

[0051] In this embodiment, the functional layer 10 is thinner than the first glass plate 31 and the second glass plate 32. The thickness of the functional layer 10 is, for example, 1000 μm or less, 800 μm or less, 600 μm or less, 500 μm or less, 400 μm or less, and 300 μm or less, with lower limits of 10 μm or more, 100 μm or more, and 200 μm or more.

[0052] [Examples and Comparative Examples] Examples and comparative examples will be described below in detail. However, the present invention is not limited in any way by these examples.

[0053] In the examples and comparative examples, the first and second shrinkage rates of the functional layer 10, as well as the wrinkle formation, were evaluated when the functional layer 10, sandwiched between two glass plates 30 (Optiwhite manufactured by Nippon Sheet Glass Co., Ltd.), was placed in an environment of 130°C for one hour. Furthermore, in evaluating the first and second shrinkage rates of the functional layer 10, both the "overall shrinkage rate," which represents the first and second shrinkage rates of the entire functional layer 10 made up of multiple layers, and the "individual shrinkage rate of each layer," which represents the individual first and second shrinkage rates of each of the multiple layers constituting the functional layer 10, were evaluated.

[0054] (Method for measuring the first and second contraction rates) The methods for measuring the first and second shrinkage rates will be described with reference to Figures 8 and 9. Figure 8 is a schematic top view showing the functional layer 10 in the measurement of the first shrinkage rate ΔTD and the second shrinkage rate ΔMD. Figure 9 is a schematic cross-sectional view of the line IX-IX in Figure 8.

[0055] In Figure 8, the first measurement point P1, the second measurement point P2, the third measurement point P3, and the fourth measurement point P4 are measurement points for measuring the first shrinkage rate ΔTD and the second shrinkage rate ΔMD. As shown in Figure 9, in measuring the first shrinkage rate ΔTD and the second shrinkage rate ΔMD, the functional layer 10 was sandwiched between a pair of Teflon® sheets 40 to prevent unwanted adhesion between the two glass plates 30 and the functional layer 10.

[0056] Figures 8 and 9 show an example in which one functional layer 10 is placed between two glass plates 30 for measurement. However, when measuring the first and second shrinkage rates of the functional layer 10, two or more functional layers 10 may be placed between the two glass plates 30, and the first and second shrinkage rates of the two or more functional layers 10 may be measured in parallel.

[0057] In measuring the first shrinkage rate ΔTD, the first length TD1 from the first measurement point P1 to the second measurement point P2 and the second length TD2 from the third measurement point P3 to the fourth measurement point P4 were measured in the functional layer 10 after being placed in a 130°C environment for 1 hour. In measuring the second shrinkage rate ΔMD, the third length MD1 from the first measurement point P1 to the third measurement point P3 and the fourth length MD2 from the second measurement point P2 to the fourth measurement point P4 were measured in the functional layer 10 after being placed in a 130°C environment for 1 hour. The measurements of the first shrinkage rate ΔTD and the second shrinkage rate ΔMD were performed with reference to JIS K7133.

[0058] Based on the measurement results for the first length TD1, second length TD2, third length MD1, and fourth length MD2, the first shrinkage rate ΔTD was calculated using equation (1) and the second shrinkage rate ΔMD was calculated using equation (2). ΔTD=[{(TD1-TD2)+(TD3-TD4)} / 2-TD0] / TD0...(1) ΔMD=[{(MD1-MD2)+(MD3-MD4)} / 2-MD0] / MD0 (2)

[0059] In equation (1), the first initial length TD0 is the measured value of {(TD1-TD2)+(TD3-TD4)} / 2 at room temperature, for example, 25°C. In equation (2), the second initial length MD0 is the measured value of {(MD1-MD2)+(MD3-MD4)} / 2 at room temperature, for example, 25°C. In the above example, the average value of two points was used to measure the first shrinkage rate ΔTD and the second shrinkage rate ΔMD, but it is not necessary to use the average value, and the average value of three or more points may also be used.

[0060] Table 1 shows the first shrinkage rate ΔTD and second shrinkage rate ΔMD of acrylic substrates manufactured by Toyo Kohan Co., Ltd. and PET Lumirror manufactured by Toray Industries, Inc., which can be used in the functional layers in Examples 1, 2, and Comparative Examples shown below, when exposed to a 130°C environment for 1 hour. As shown in Table 1, when exposed to a 130°C environment for 1 hour, the first shrinkage rate ΔTD of PET is smaller than that of the acrylic substrate, and the second shrinkage rate ΔMD of PET is smaller than that of the acrylic substrate. Furthermore, for PET, both the first shrinkage rate ΔTD and the second shrinkage rate ΔMD are 5% or less, while for acrylic substrates, both the first shrinkage rate ΔTD and the second shrinkage rate ΔMD are greater than 5%. [Table 1]

[0061] (Example 1) Figure 10 shows the detailed configuration of the functional layer 10 of the laminated glass 100 according to Example 1. The functional layer 10 of the laminated glass 100 according to Example 1 includes, in order from the +Z side to the -Z side, a base layer 131, an adhesive layer 1310, a shaping support layer 111A, a shaping layer 112, an adhesive layer 1221, an adhesive support layer 1222A, an adhesive layer 1320, and a base layer 132. The configuration of the functional layer 10 in Example 1 corresponds to the configuration of the functional layer 10 in the first example of laminated glass 100 shown in Figure 1.

[0062] The base layer 131 was composed of PET Lumirror manufactured by Toray Industries, Inc., with a thickness of 40 μm. The adhesive layer 1310 was composed of an acrylic adhesive manufactured by Tomoegawa Paper Co., Ltd.

[0063] The shaping support layer 111A is composed of an acrylic substrate manufactured by Toyo Kohan Co., Ltd. and has a thickness of 40 μm. The shaping layer 112 is composed of an acrylic ultraviolet curing resin and has a thickness of 15 μm. The shaping support layer 111A and the shaping layer 112 constitute the light extraction layer 11 in the first example.

[0064] The adhesive layer 1221 is composed of an acrylic ultraviolet-curing adhesive and has a thickness of 7 μm. The adhesive support layer 1222A is composed of an acrylic substrate manufactured by Toyo Kohan and has a thickness of 40 μm. The adhesive layer 1221 and the adhesive support layer 1222A constitute the adhesive layer 122 in the first example.

[0065] The adhesive layer 1320 was composed of an acrylic adhesive manufactured by Tomoegawa Paper Co., Ltd. The base material layer 132 was composed of PET Lumirror manufactured by Toray Industries, Inc., with a thickness of 40 μm.

[0066] In the functional layer 10 of Example 1, the light extraction layer 11 and the adhesive layer 122 were sandwiched between PET, which has a smaller first shrinkage rate ΔTD and a smaller second shrinkage rate ΔMD compared to the acrylic substrate. From another perspective, the functional layer 10 of Example 1 included a substrate layer 131 placed on top of the light extraction layer 11 and a substrate layer 132 placed below the light extraction layer 11.

[0067] (Example 2) Figure 11 shows the detailed configuration of the functional layer 10 of the laminated glass 100 according to Example 2. The functional layer 10 of the laminated glass 100 according to Example 1 includes, in order from the +Z side to the -Z side, a shaping support layer 111B, a shaping layer 112, an adhesive layer 1221, and an adhesive support layer 1222B. The configuration of the functional layer 10 in Example 2 corresponds to the configuration of the functional layer 10 in the laminated glass 100 according to the second example shown in Figure 2.

[0068] The shaping support layer 111B is composed of PET Lumirror manufactured by Toray Industries, Inc. and has a thickness of 40 μm. The shaping layer 112 is composed of an acrylic ultraviolet curing resin and has a thickness of 15 μm. The shaping support layer 111B and the shaping layer 112 constitute the light extraction layer 11 in the second example.

[0069] The adhesive layer 1221 is composed of an acrylic UV-curing adhesive and has a thickness of 7 μm. The adhesive support layer 1222B is composed of PET Lumirror manufactured by Toray Industries and has a thickness of 40 μm. The adhesive layer 1221 and the adhesive support layer 1222B constitute the adhesive layer 122 in the second example.

[0070] In the functional layer 10 of Example 2, the shaping support layer 111B that supports the shaping layer 112 in the light extraction layer 11 is made of PET, which has both a smaller first shrinkage rate ΔTD and a smaller second shrinkage rate ΔMD compared to an acrylic substrate. Also in the functional layer 10 of Example 2, the adhesive support layer 1222B that supports the adhesive layer 1221 in the adhesive layer 122 is made of PET, which has both a smaller first shrinkage rate ΔTD and a smaller second shrinkage rate ΔMD compared to an acrylic substrate.

[0071] (Comparative example) Figure 12 shows the detailed configuration of the functional layer 10 of the laminated glass according to the comparative example. The functional layer 10 of the laminated glass according to the comparative example includes, in order from the +Z side to the -Z side, a shaping support layer 111A, a shaping layer 112, an adhesive layer 1221, and an adhesive support layer 1222A.

[0072] The shaping support layer 111A is composed of an acrylic substrate manufactured by Toyo Kohan Co., Ltd. and has a thickness of 40 μm. The shaping layer 112 is composed of an acrylic ultraviolet curing resin and has a thickness of 15 μm. The shaping support layer 111A and the shaping layer 112 constitute the light extraction layer 11 in the comparative example.

[0073] The adhesive layer 1221 is composed of an acrylic UV-curing adhesive and has a thickness of 7 μm. The adhesive support layer 1222A is composed of an acrylic substrate manufactured by Toyo Kohan and has a thickness of 40 μm. The adhesive layer 1221 and the adhesive support layer 1222A constitute the adhesive layer 122 in the comparative example.

[0074] (Evaluation results) Table 2 shows the first and second shrinkage rates of the functional layer 10, as well as the evaluation results of wrinkle formation, when the functional layer 10 in Example 1, Example 2, and the comparative example was placed in an environment of 130°C for 1 hour. [Table 2]

[0075] As shown in Table 2, in Example 1, the first shrinkage rate ΔTD and second shrinkage rate ΔMD of the base layer including base layer 131 and base layer 132, the adhesive layer 122, and the light extraction layer 11 were evaluated as "individual shrinkage rates of each layer". In Example 2, the first shrinkage rate ΔTD and second shrinkage rate ΔMD of the adhesive layer 122 and the light extraction layer 11 were evaluated as "individual shrinkage rates of each layer". In the comparative example, the first shrinkage rate ΔTD and second shrinkage rate ΔMD of the adhesive layer 122 and the light extraction layer 11 were evaluated as "individual shrinkage rates of each layer".

[0076] As shown in Table 2, in both Example 1 and Example 2, both the first shrinkage rate ΔTD and the second shrinkage rate ΔMD were smaller compared to the comparative example. Furthermore, in both Example 1 and Example 2, both the first shrinkage rate ΔTD and the second shrinkage rate ΔMD of the functional layer 10 were 5% or less. On the other hand, wrinkles occurred in the comparative example, whereas no wrinkles occurred in either Example 1 or Example 2. Thus, it was found that in laminated glass 100 having the functional layer 10 according to Example 1 and Example 2, wrinkles in the functional layer 10 were reduced and the appearance was improved. In other words, it was found that when placed in an environment of 130°C for 1 hour, having both the first shrinkage rate ΔTD and the second shrinkage rate ΔMD at 5% or less reduces wrinkles in the functional layer 10 and improves the appearance of the laminated glass 100.

[0077] Furthermore, in Example 1, when placed in an environment of 130°C for 1 hour, the first shrinkage rate ΔTD and the second shrinkage rate of the light extraction layer 11 were both greater than 5%, and the first shrinkage rate ΔTD and the second shrinkage rate ΔMD of the base layer 131 were both 5% or less. Therefore, it was found that satisfying this condition reduces wrinkles in the functional layer 10 and improves the appearance of the laminated glass 100. Also, in Example 1, the first shrinkage rate ΔTD and the second shrinkage rate ΔMD of the base layer 132 were both 5% or less. Therefore, it was found that even under conditions where both the first shrinkage rate ΔTD and the second shrinkage rate ΔMD of the base layer 132 are 5% or less, wrinkles in the functional layer 10 are reduced and the appearance of the laminated glass 100 is improved.

[0078] In this embodiment, either the base layer 131 or the base layer 132 may be placed above or below the light extraction layer 11. However, if the light extraction layer 11 and the adhesive layer 122 are sandwiched between the base layer 131 and the base layer 132, the shrinkage of the light extraction layer 11 and the adhesive layer 122 is reduced, and the difference in shrinkage rates between the light extraction layer 11 and the adhesive layer 122 is reduced. By reducing the difference in shrinkage rates between the light extraction layer 11 and the adhesive layer 122, wrinkles in the functional layer 10 are reduced, and the appearance of the laminated glass 100 is improved. Therefore, it is preferable that the base layer 131 is placed above the light extraction layer 11 and the base layer 132 is placed below the light extraction layer 11. In other words, it is preferable that the base layers be placed both above and below the light extraction layer 11.

[0079] It is preferable that the base layer 131 or base layer 132 is composed of polyethylene terephthalate (PET), which has a low shrinkage rate. By constructing the base layer 131 or base layer 132 with polyethylene terephthalate (PET), the difference in shrinkage rates between the light extraction layer 11 and the adhesive layer 122 is reduced. This reduces wrinkles in the functional layer 10 and improves the appearance of the laminated glass 100.

[0080] Furthermore, in Example 2, when placed in an environment of 130°C for 1 hour, both the first shrinkage rate ΔTD and the second shrinkage rate ΔMD of the light extraction layer 11 were 5% or less. Therefore, it was found that satisfying this condition reduces wrinkles in the functional layer 10 and improves the appearance of the laminated glass 100.

[0081] Examples 1 and 2 have a light extraction layer 11 that extracts light Lt from the main surface 100a via recesses 12. Therefore, it was found that in laminated glass 100 having a light extraction layer 11 that extracts light Lt from the main surface 100a via recesses 12, when placed in an environment of 130°C for 1 hour, both the first shrinkage rate ΔTD and the second shrinkage rate ΔMD are 5% or less, thereby reducing wrinkles in the functional layer 10 and improving the appearance. However, the light extraction layer 11 is not limited to one that includes recesses 12, and may be a porous layer or may contain particles that have light-scattering properties.

[0082] The light extraction layer 11 is preferably composed of polyethylene terephthalate (PET), which has a low shrinkage rate. By including polyethylene terephthalate (PET) in the composition of the light extraction layer 11, the shrinkage of the light extraction layer 11 is reduced. This reduces wrinkles in the functional layer 10 and improves the appearance of the laminated glass 100.

[0083] The ordinal numbers, quantities, and other figures used in the description of the embodiments are all illustrative to specifically illustrate the technology of the present invention, and the present invention is not limited to these illustrative figures. Furthermore, the connection relationships between the components are illustrative to specifically illustrate the technology of the present invention, and do not limit the connection relationships that realize the functions of the present invention.

[0084] The laminated glass according to this embodiment has the function of extracting light from a light source and can improve the appearance, so it can be suitably used in applications where design is to be added by light. For example, laminated glass can be used in windows. Examples of windows include windows in buildings, windows or sunroofs in vehicles such as automobiles, and windows for viewing the inside of box-shaped products. In such applications, for example, when the light source is turned off, the laminated glass functions as a normal window, and when the light source is turned on, the entire laminated glass emits light uniformly, or a predetermined design, such as a pattern, design, letters, or picture, can be displayed on the laminated glass.

[0085] Examples of the present invention are as follows: <1> The laminated glass comprises a first glass plate having a main surface, a second glass plate arranged in the direction normal to the main surface, and a first interlayer, a functional layer, and a second interlayer laminated between the first and second glass plates in the direction normal to the main surface, wherein the functional layer includes a light extraction layer that extracts light incident from the side to the main surface side, and when placed in an environment of 130°C for 1 hour, the first shrinkage rate in a first direction intersecting the direction normal to the main surface, and the second shrinkage rate in a second direction intersecting the direction normal to the main surface and the first direction, respectively, are both 5% or less. <2> The functional layer further includes a substrate layer disposed above or below the light extraction layer, wherein when placed in an environment of 130°C for 1 hour, the first shrinkage rate and the second shrinkage rate of the light extraction layer are both greater than 5%, and the first shrinkage rate and the second shrinkage rate of the substrate layer are both 5% or less. <1> This is the laminated glass described above. <3> The substrate layer is disposed both above and below the light extraction layer, <2> This is the laminated glass described above. <4> The substrate layer is composed of polyethylene terephthalate, <2> or the above <3> This is the laminated glass described above. <5> When placed in an environment of 130°C for 1 hour, the first shrinkage rate and the second shrinkage rate of the light extraction layer are both 5% or less. <1> This is the laminated glass described above. <6> The light extraction layer is composed of polyethylene terephthalate, <5> This is the laminated glass described above. <7> The light extraction layer extracts the light through the recess, <1> From the above <6> It is laminated glass as described in one of the following. <8> A functional layer is disposed between a first glass plate and a second glass plate, respectively, via a first interlayer and a second interlayer, wherein the functional layer includes a light extraction layer that extracts light incident from the side to the first interlayer, and when placed in an environment of 130°C for one hour, the first shrinkage rate in a first direction intersecting the normal direction of the first interlayer, and the second shrinkage rate in a second direction intersecting the normal direction of the first interlayer and the first direction, are both 5% or less. [Explanation of Symbols]

[0086] 10 Functional Layers 11 Light extraction layer 12 recesses 21 First Interlayer 22 Second Interlayer 30 Two glass plates 31. First glass plate 32. Second glass plate 40 Teflon sheets 100 Laminated glass 100a main surface 111A, 111B Shaped support layer 112 Forming layer 122 Adhesive layer 131, 132 Base material layer 1221 Adhesive layer 1222A, 1222B Adhesive support layer 1310, 1320 adhesive layer H Height ISa First Incline ISb 2nd slope L Length LS light source Lt light MD1 Third Length MD2 4th length P1 1st measurement point P2 2nd measurement point P3 3rd measurement point P4 4th measurement point Px, Py pitch TD1 First length TD2 Second Length W width X 1st direction Y Second direction Z normal direction θa, θb Tilt angle ΔTD 1st contraction rate ΔMD second contraction rate

Claims

1. A first glass plate having a main surface, A second glass plate is arranged in the direction normal to the main surface, The first glass plate and the second glass plate include a first interlayer, a functional layer, and a second interlayer, which are laminated in the direction normal to the main surface. The aforementioned functional layer is It includes a light extraction layer that extracts light incident from the side to the main surface side, Laminated glass in which, when placed in an environment of 130°C for one hour, the first shrinkage rate in a first direction intersecting the normal direction of the main surface, and the second shrinkage rate in a second direction intersecting both the normal direction of the main surface and the first direction, are both 5% or less.

2. The functional layer further includes a substrate layer disposed above or below the light extraction layer, When placed in an environment of 130°C for 1 hour, The first and second shrinkage rates of the light extraction layer are both greater than 5%. The laminated glass according to claim 1, wherein the first shrinkage rate and the second shrinkage rate of the substrate layer are both 5% or less.

3. The laminated glass according to claim 2, wherein the substrate layer is disposed both above and below the light extraction layer.

4. The laminated glass according to claim 2 or 3, wherein the base layer comprises polyethylene terephthalate.

5. The laminated glass according to claim 1, wherein when placed in an environment of 130°C for one hour, the first shrinkage rate and the second shrinkage rate of the light extraction layer are both 5% or less.

6. The laminated glass according to claim 5, wherein the light extraction layer is composed of polyethylene terephthalate.

7. The laminated glass according to claim 1, wherein the light extraction layer extracts light through a recess.

8. A functional layer disposed between a first glass plate and a second glass plate, with a first interlayer and a second interlayer in between, The aforementioned functional layer is It includes a light extraction layer that extracts light incident from the side to the first interlayer, A functional layer in which, when placed in an environment of 130°C for one hour, the first shrinkage rate in a first direction intersecting the normal direction of the first interlayer, and the second shrinkage rate in a second direction intersecting both the normal direction of the first interlayer and the first direction, are both 5% or less.

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