TWI786225B - thin glass laminate - Google Patents

Abstract

The present invention provides a thin glass laminate capable of preventing breakage due to bending of the thin glass and having excellent bending durability. The thin glass laminate of the present invention has a resin film and a thin glass arranged at least above the resin film; the thickness of the thin glass is 30 μm to 150 μm, and at least a part of the end surface of the thin glass is extended downward and outward. Beveled and/or curved surfaces. In one embodiment, at the upper end of the thin glass, at least a part of the end surface is constituted by the slope or curved surface extending downward and outward.

Description

thin glass laminate

The present invention relates to a thin glass laminate.

Background of the invention Conventionally, glass laminates composed of glass materials and resin films such as optical films are often used in components that constitute image display devices, such as substrates for display elements, sealing materials for organic EL elements, and front protection plates. In recent years, image display devices have become lighter and thinner, and there is a tendency to require flexibility. Therefore, a glass laminate made of thinner glass materials is required. Originally, glass materials are difficult to handle due to their fragility, but the problem becomes more pronounced as the thickness becomes thinner. In particular, in the case of a glass laminate in which the glass material is arranged on the outermost layer, there is a problem that cracks are likely to occur when it is bent (especially when the glass material side is bent into a convex shape). It is generally known that when the glass is bent, once a wedge-shaped depression occurs, the stress will concentrate there. However, even if the wedge-shaped depressions can be reduced, a complete smooth surface cannot be obtained in principle.

prior art literature patent documents Patent Document 1: Japanese Patent No. 4122139

Summary of the invention The problem to be solved by the invention The present invention is made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a thin glass laminate which can prevent damage due to bending of the thin glass by virtue of the smoothness and shape of the end surface of the thin glass and is excellent in bending durability. .

Means for Solving the Problems The thin glass laminate of the present invention includes a resin film and a thin glass arranged at least above the resin film; the thickness of the thin glass is 30 μm to 150 μm, and at least a part of the end surface of the thin glass is Consists of slopes and/or curved surfaces extending downward and outward. In one embodiment, at the upper end of the thin glass, at least a part of the end surface is constituted by the slope or curved surface extending downward and outward. In one embodiment, at least a part of the end surface of the thin glass is formed by the slope extending downward and outward, and the angle _θ1 formed by the upper surface of the thin glass and the slope extending downward and outward is greater than 90° and is within Below 140°. In one embodiment, at least a part of the end surface of the thin glass has an upwardly curved surface that protrudes outward as the curved surface, and the upwardly curved surface is a junction A located at (curved surface height h1)×3/4 of the curved surface. A curved surface with an angle θ ₂ greater than 90° with the upper surface of the thin glass. In one embodiment, the angle θ ₂ is greater than 90° and less than 140°. In one embodiment, the thin glass further has a downwardly curved surface protruding outward as the curved surface on at least a part of its end surface. In one embodiment, at least a part of the end surface of the thin glass is composed of the inclined surface and/or the curved surface, and a vertical surface. In one embodiment, in the thin glass, a height H1 of a portion of the end surface formed by the inclined surface extending downward and outward or the curved surface is 0.1% or more with respect to the thickness of the thin glass. In one embodiment, the ratio (H1:H2) of the height H1 of the portion of the end surface formed by the slope or the curved surface extending downward and outward to the height H2 of the portion of the end surface formed by the vertical surface (H1:H2) is 1:9. ~9.99:0.01. In one embodiment, the arithmetic average surface roughness Ra of the end surface of the thin glass is 150 nm or less. In one embodiment, the 10-point average roughness Rz of the end surface of the thin glass is 500 nm or less. In one embodiment, the above-mentioned resin film is arranged so as to protrude from the thin glass. In one embodiment, the height difference between the resin film and the thin glass is 200 μm or less in a cross-sectional view. In one embodiment, the resin film is an optical film. In one embodiment, the optical film is a polarizing plate. In one embodiment, the resin film has a transparent conductive layer. In one embodiment, the thin glass and the resin film are laminated through an adhesive. According to another aspect of this invention, the manufacturing method of the said thin glass laminated body is provided. The manufacturing method includes: laminating thin glass and a resin film to form a laminate A, cutting the laminate A to a predetermined size, and grinding the end surface of the cut laminate B by polishing.

Invention effect According to the present invention, since at least a part of the end surface of the thin glass is formed of a slope or a curved surface, a thin glass laminate in which the thin glass is not easily broken and has excellent bending durability can be provided.

form for carrying out the invention A. Overall configuration of thin glass laminates The thin glass laminate of the present invention includes a resin film and a thin glass arranged at least above the resin film; in the thin glass, at least a part of the end surface of the thin glass is composed of a slope and/or a curved surface extending downward and outward. The thin glass laminate of the present invention has an inclined surface or a curved surface extending downward and outward on at least a part of the end surface of the thin glass, so that the thin glass is less likely to be broken and has excellent bending durability. We think that this is because when the thin glass laminate is bent, the external force applied to the thin glass laminate can be dispersed by the slope or curved surface extending downward and outward, thereby reducing the local load. And this effect is more pronounced when the end faces contain curved surfaces. Hereinafter, a typical configuration of the thin glass laminate of the present invention will be specifically described with reference to FIGS. 1 to 6 .

Fig. 1 is a schematic cross-sectional perspective view of a thin glass laminate according to an embodiment of the present invention. Fig. 2 is an enlarged cross-sectional view of an end portion of the thin glass laminate shown in Fig. 1 . The thin glass laminate 100 of this embodiment includes a resin film 10 and a thin glass 20 arranged on at least one surface (upper side) of the resin film 10 . The thin glass 20 includes a slope 21 extending downward and outward on at least a part of the end surface of the thin glass 20 . In one embodiment, the thin glass 20 and the resin film 10 can be laminated through any suitable adhesive or adhesive (not shown). In addition, the surface of the resin film 10 on which the thin glass 20 is placed should be covered entirely by the thin glass 20 (that is, the ends of the resin film 10 and the ends of the thin glass 20 should coincide). In addition, in this specification, for the sake of convenience, the thin glass 20 side (the upper side of the paper) of the thin glass laminate 100 is regarded as the upper side, and the resin film 10 side (the lower side of the paper) is regarded as the lower side, but the method of using the thin glass laminate Not subject to this restriction.

The angle _θ1 formed by the upper surface 23 of the thin glass 20 and the slope 21 extending downward and outward is preferably greater than 90°, more preferably greater than 90° and less than 150°, more preferably greater than 90° and less than 140°, more preferably 92°~140°. If it is in the said range, the above-mentioned effects of the present invention will be more remarkable. The above-mentioned thin glass may also have a plurality of slopes extending downward and outward with different slopes. In one embodiment, the thin glass may further have a slope (not shown) extending downward and inward. For example, at the lower end of the thin glass 20, at least a part of the end surface may be formed with a slope extending downward and inward. The angle θ ₁ ′ formed by the lower surface of the thin glass and the inclined surface extending downward and inward is preferably greater than 90°, more preferably greater than 90° and less than 150°, more preferably 92°-140°.

Fig. 3 is a schematic cross-sectional perspective view of a thin glass laminate according to an embodiment of the present invention. Fig. 4 is an enlarged cross-sectional view of an end portion of the thin glass laminate shown in Fig. 3 . In the thin glass laminate 100 ′ of this embodiment, the thin glass 20 includes a curved surface 22 in at least a part of the end surface of the thin glass 20 . As shown in the figure, the curved surface 22 should be configured to be convex outward. In addition, the curved surface constituting the end surface of the thin glass 20 may be a curved surface with a fixed curvature, or may be a collection of curved surfaces defined with arbitrary curvatures (that is, may have a plurality of curved surfaces with different curvatures). Hereinafter, in this specification, a curved surface composed of a single continuous curve with a constant curvature in cross-sectional view is referred to as a "single curved surface". Therefore, "a collection of surfaces defined by arbitrary curvature" can also be renamed "a collection of surfaces".

In one embodiment, the thin glass 20 has a curved surface 22 on at least a part of its end surface at (the height h1 of the curved surface 22)×3/4 (based on the edge 22b under the curved surface 22, the height is h1×3/4 4) and the angle θ ₂ formed by the junction surface A of the thin glass and the upper surface 23 of the thin glass is larger than 90° (the curved surface described below is referred to as "upward curved surface"). The angle θ ₂ is preferably greater than 90° and less than 150°, more preferably greater than 90° and less than 140°, more preferably 92°-140°. If it is within the range, the effect of the present invention is remarkable.

Fig. 5 is a schematic cross-sectional view of a thin glass laminate according to an embodiment of the present invention. Fig. 6 is an enlarged cross-sectional view of an end portion of the thin glass laminate shown in Fig. 5 . In the thin glass laminate 100" of this embodiment, the thin glass 20 includes an upward curved surface 22 and a downward curved surface 24 on at least a part of the end surface of the thin glass 20. The downward curved surface 24 means that the curved surface 24 is located at (the height of the curved surface 24 h1')×1/4 (based on the lower edge 24b of the curved surface 24, the height is h1'×1/4) and the angle θ ₃ formed by the lower surface 25 of the thin glass is larger than 90°. The angle θ ₃ is preferably greater than 90° and less than 150°, more preferably 92° to 140°. As long as it is in the above range, the bending resistance can be maintained. The downward curved surface is preferably convex outward.

In one embodiment, as shown in FIGS. 1-6 , at the upper end of the thin glass 20 , at least a part of the end surface is composed of a slope 21 or a curved surface 22 (preferably an upward curved surface) extending downward and outward. In the above-mentioned embodiment, the upper end edges 21a, 22a of the inclined surface 21 or the curved surface 22 extending downward and outward are in contact with the upper surface 23 of the thin glass. According to the above configuration, a thin glass laminate that is less prone to breakage can be obtained with a reduced local load on the upper end of the thin glass, which is a portion that is fragile and receives a greater external force when bent.

In one embodiment, as shown in FIGS. 1 to 6 , at least a part of the end surface of the thin glass 20 is composed of an inclined surface and/or a curved surface extending downward and outward, and a vertical surface 25 . In addition, the vertical surface 25 refers to a surface slightly perpendicular to the upper surface 23 of the resin film 10, and the angle formed by the vertical surface 25 and the upper surface 23 is preferably 85°-95°, more preferably 85°-90°. This is the allowable range due to the thin thickness of the glass. In one embodiment, as shown in FIGS. 1 and 3 , above the thin glass 20 , the end surface is composed of an inclined surface 21 or an upwardly curved surface 22 extending downward and outward; below, the end surface is composed of a vertical surface 25 . In another embodiment, as shown in FIG. 5 , the thin glass 20 has an upwardly curved surface 22 , a vertical surface 25 , and a downwardly curved surface 24 sequentially from above. The end surface of the thin glass only needs to be composed of a slope or a curved surface extending downward and outward, and a vertical surface. In this way, it is not necessary to reduce the amount of glass material, and the effect caused by the formation of the slope or curved surface extending downward and outward can be exerted. A thin glass laminate with superior bending durability. In addition, the resin film can also be configured to protrude or indent from the thin glass. In this case, there will be a height difference between the resin film and the thin glass under section view, and the height difference should be small. The height difference between the resin film and the thin glass is preferably 200 μm or less, more preferably 100 μm or less.

The plan view shape of the thin glass (and the thin glass laminate) may be any and appropriate shape. The angle formed by two adjacent sides of the thin glass in plan view may be right angle or non-right angle. Also, two adjacent sides can also be connected by a curve. In addition, the top view shape of the thin glass can be defined by a straight line, a curved line with arbitrary and appropriate curvature, or both a straight line and a curved line. Thin glass can also be circular. This is because the bending resistance of the glass is not restricted by the shape of the face as long as it is within the appropriate range of the end face of the present invention.

In the present invention, on the whole circumference of the thin glass, as mentioned above, its end surface may have an inclined surface or curved surface (preferably an upward curved surface), and a part of the thin glass may have an inclined surface extending downward and outward on its end surface as described above. Or a curved surface (preferably an upward curved surface). In addition, when the thin glass laminate is rectangular, its four sides may have slopes or curved surfaces (preferably upward curved surfaces) extending downward and outward as described above, and the opposite set of sides may have downward and outward extension as described above. The slope or curved surface (preferably an upward curved surface). When the end faces of the opposite set of sides have a slope or a curved surface (preferably an upward curved surface) extending downward and outward, the side is preferably a curved side. In addition, the thin glass 20 may have both an inclined surface and a curved surface extending downward and outward on one end surface.

In the thin glass, the height H1 of the portion formed by the slope or the curved surface extending downward and outward is preferably 0.1% or more, more preferably 10% or more, more preferably 20% or more, and more preferably 40% of the thickness of the thin glass. %above. In one embodiment, the upper limit of H1 is 100%. In another embodiment, H1 is preferably less than 100%, more preferably less than 99.9%, more preferably less than 90%, and more preferably less than 80%. If it is within the above range, a thin glass laminate that is not easily damaged can be obtained. "The height H1 of the portion of the end surface formed by the slope or curved surface extending downward and outward" means the sum of the heights of the slope and the curved surface extending downward and outward. In addition, the portion other than the portion where the end surface is formed of a slope or a curved surface extending downward and outward may be a portion where the end surface is formed of a vertical surface.

The ratio (H1:H2) of the height H1 of the part of the end surface formed by the slope or curved surface extending downward to the height H2 of the part of the end surface formed by the vertical surface (that is, the height of H1 subtracted from the thickness of the thin glass) should be 1 :9~10:0, more preferably 1:9~9.99:0.01, more preferably 2:8~9:1, more preferably 4:6~6:4. If it is within the above range, a thin glass laminate that is not easily damaged can be obtained.

The radius of curvature of the curved surface is preferably 50 μm to 1500 μm, more preferably 50 μm to 1000 μm. If it is within the above range, a thin glass laminate that is not easily damaged can be obtained. The above-mentioned surface can be defined as a single one, or it can be composed of any set of curvatures.

The fan-shaped central angle α including the curves constituting the above-mentioned curved surface (1 curved surface) is preferably 5°-95°, more preferably 10°-90°, more preferably 30°-90°. If it is within the above range, a thin glass laminate that is not easily damaged can be obtained.

The thickness of the above-mentioned thin glass is preferably 30 μm to 150 μm, most preferably 50 μm to 100 μm. Within the above range, a thin glass laminate excellent in flexibility can be produced without impairing the physical properties (hardness, CTE, barrier properties, etc.) of the thin glass.

The thickness of the said resin film can be set to arbitrary and appropriate thickness depending on a use. The thickness of the resin film is, for example, 10 μm to 500 μm, preferably 30 μm to 200 μm.

The lower limit of the ratio of the thickness of the resin film to the thickness of the thin glass (thickness of the resin film/thickness of the thin glass) is preferably 0.2 or more. Within the above-mentioned range, scattering of thin glass can be prevented. The upper limit of the ratio of the thickness of the resin film to the thickness of the thin glass (thickness of the resin film/thickness of the thin glass) is preferably 5 or less. If it is within the above-mentioned range, even when the thin glass is bent into a convex shape, it can withstand the stress applied to the glass surface. The ratio of resin film thickness to thin glass thickness (resin film thickness/thin glass thickness) is preferably 0.3~3. If it is within the above range, even if the thin glass is broken when handling the thin glass laminate, the breakage of the thin glass can be prevented.

The said thin glass laminate may contain arbitrary and appropriate other layers. For example, arbitrary and appropriate other layers may be disposed on the surface of the thin glass opposite to the resin film. Such a layer may be a layer having a thickness of 100 μm or less, and a specific example may be a protective film temporarily placed to prevent foreign matter from adhering or contaminating the thin glass surface. In addition, the glass surface may also contain functional layers such as transparent electrodes, antireflection layers, and antifouling layers. The thickness of the functional layer is preferably 1 μm or less.

In one embodiment, the thin glass laminate is configured such that no other layer is disposed on the surface of the thin glass opposite to the resin film (that is, configured with the thin glass as the outermost layer). The thin glass laminate formed with thin glass on the outermost layer tends to be easily damaged, especially when the side of the thin glass is bent to protrude. However, the thin glass laminate of the present invention even with thin glass on the Constructed from the outermost layer, the bending durability is still good.

B. Thin glass The shape of the above-mentioned thin glass is generally plate-like. Thin glass is classified according to composition, for example, soda lime glass, boric acid glass, aluminosilicate glass, quartz glass, etc. Moreover, the classification according to the alkaline component includes non-alkali glass and low-alkali glass. The content of alkali metal components (such as Na ₂ O, K ₂ O, Li ₂ O) in the above-mentioned thin glass is preferably not more than 15% by weight, more preferably not more than 10% by weight.

The total light transmittance of the above-mentioned thin glass at a wavelength of 550 nm should be above 90%. The refractive index n _g of the above-mentioned thin glass at a wavelength of 550 nm is preferably 1.4~1.6.

The average thermal expansion coefficient of the above-mentioned thin glass is preferably 10ppm°C ^-1 ~0.5ppm°C ^-1 , more preferably 7ppm°C ^-1 ~0.5ppm°C ^-1 .

The density of the above-mentioned thin glass is preferably 2.3g/cm ³ ~3.0g/cm ³ , more preferably 2.3g/cm ³ ~2.7g/cm ³ .

The arithmetic mean surface roughness Ra of the end surface of the thin glass is preferably not more than 150 nm, more preferably not more than 130 nm, more preferably not more than 110 nm. The lower limit of the arithmetic average surface roughness Ra of the end surface of the above-mentioned thin glass is, for example, 10 nm or more.

The 10-point average roughness Rz of the end surface of the thin glass is preferably not more than 500 nm, more preferably not more than 450 nm, more preferably not more than 400 nm. The lower limit of the 10-point average roughness Rz of the end surface of the thin glass is, for example, 200 nm or more.

Arbitrary and appropriate methods can be used for the forming method of the above-mentioned thin glass. Representatively speaking, the above-mentioned thin glass can be formed into a thin plate by melting a mixture containing main raw materials such as silica or alumina, defoaming agents such as mirabilite or antimony oxide, and reducing agents such as carbon at a temperature of 1400 ° C to 1600 ° C. It is produced after cooling. Examples of thin plate forming methods for the above-mentioned thin glass include an orifice downdraw method, an overflow melting method, and a float method. Thin glass formed into a plate by these methods can be thinned or smoothed, so it can be chemically polished with a solvent such as hydrofluoric acid as needed.

As the above-mentioned thin glass, a commercially available product may be used as it is, or a commercially available thin glass may be ground to a desired thickness and used. Examples of commercially available thin glass include "7059", "1737" or "EAGLE2000" manufactured by Corning Incorporated, "AN100" manufactured by AGC, "NA-35" manufactured by NH Techno Glass, and "OA-10" manufactured by Nippon Electric Glass. ", "D263" or "AF45" manufactured by SCHOTT Co., Ltd., etc.

C. Resin film In one embodiment, an optical film is used as the resin film. Examples of optical films include polarizers (optical films with a polarizing function), retardation plates, isotropic films, and the like. The resin film may have a single-layer structure or a multi-layer structure.

Arbitrary and appropriate materials can be used for the material which comprises the said resin film. Materials constituting the above-mentioned resin film include polyvinyl alcohol (PVA) resins, polyolefin resins, cyclic olefin resins, polycarbonate resins, cellulose resins, polyester resins, and polyamide resins. , Polyimide-based resins, polyether-based resins, polystyrene-based resins, (meth)acrylic-based resins, (meth)urethane-based acrylate resins, polyester-based resins, acetate-based resins, Epoxy resins, silicone resins, polyarylate resins, polysulfide resins, polyetherimide resins, epoxy resins, urethane resins, silicone resins, etc.

The elastic modulus of the above resin film at 23°C is preferably 1.5GPa~10GPa, more preferably 1.8GPa~9GPa, more preferably 1.8GPa~8GPa. If it is the said range, the effect of protecting a thin glass is high, and the thin glass laminated body which is hard to break can be obtained. In addition, the elastic modulus of the present invention can be measured by a tensile test.

In one embodiment, the resin film has a transparent conductive layer. The resin film with a transparent conductive layer is formed by disposing the transparent conductive layer on the resin film. The transparent conductive layer can be, for example, a metal oxide layer, a metal layer, a layer containing a conductive polymer, a layer containing metal nanowires, a layer composed of a metal mesh, and the like.

D. Protective film In one embodiment, a protective film may be disposed on the outer surface of the thin glass. This protective film temporarily protects the thin glass to prevent foreign matter etc. from adhering to the thin glass. The material constituting the protective film can be exemplified by polyethylene, polyvinyl chloride, polyethylene terephthalate, polyvinyl dichloride, polypropylene, polyvinyl alcohol, polyester, polycarbonate, polystyrene, polypropylene Nitrile, ethylene vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-methacrylic acid copolymer, nylon, cellophane, silicone resin, etc.

E. Manufacturing method of thin glass laminate In one embodiment, the above-mentioned thin glass laminate can be formed by laminating thin glass and a resin film to form a laminate A, and after cutting the laminate A to a predetermined size, the end (end surface) of the laminate B obtained by cutting is ) to be ground.

In one embodiment, the above-mentioned laminate A is formed by laminating the above-mentioned resin film and the above-mentioned thin glass through an adhesive. Arbitrary and appropriate adhesives can be used for the said adhesive agent. Examples of the above-mentioned adhesive include adhesives containing the following resins: resins having cyclic ether groups such as epoxy groups, glycidyl groups, and oxetanyl groups, acrylic resins, and polysiloxane resins. UV curable adhesives should be used.

In another embodiment, the above laminate A can be formed by applying a resin solution to thin glass.

Arbitrary and appropriate methods can be adopted for the cutting method of the said laminated body A. The cutting method can be, for example, a method of cutting using a milling (fullback), UV laser, water jet, end mill, or the like.

The length of the crack on the end surface of the laminate B is preferably 10 μm to 300 μm, more preferably 10 μm to 200 μm. The crack length refers to the maximum value of the length component in the direction perpendicular to the crack end face when the laminate B is viewed from above.

The grinding method of the end face of the above-mentioned laminated body B is preferably polishing. Polishing is a method in which the abrasive cloth touches the end surface of the laminate B for relative movement, and when the abrasive cloth is relatively moved, a slurry containing free abrasive grains is supplied to the surface to be processed to grind the end surface. In the present invention, the end surface having the slope and/or the curved surface extending downward and outward as described above can be formed by polishing.

The end face of the laminate B is preferably ground in a state where the laminate B is sandwiched between another plate of glass or resin. In this way, on the surface of the thin glass, the slurry enters the upper part of the thin glass by abutting the abrasive cloth on the glass surface side, then the abutment effect caused by the abrasive cloth can be reduced on the resin film side of the thin glass, so that it can be well formed. The end surface of the inclined surface and/or curved surface extending downward and outward as described above.

The abrasive cloth used for polishing should use nylon brush. The diameter of the brush should be 0.1mm~0.5mm, more preferably 0.1mm~0.3mm.

As the free abrasive grains, for example, cerium oxide, silicon oxide, indium oxide, etc. can be used. In particular, the use of cerium oxide will cause a substitution reaction between the silicon component of the glass and cerium, so it is suitable for cutting while dissolving the glass. The particle size of the above-mentioned free abrasive particles is preferably about 1 μm to 5 μm.

The amount of grinding during polishing is preferably 300 μm or less, preferably 200 μm or less, more preferably 100 μm or less. If the target grinding amount is too large, it may not be possible to obtain a thin glass laminate of the desired shape; for example, there may be problems such as peeling of the interface between the resin layer and the glass due to the use of a nylon brush.

In the thin glass laminate obtained by polishing the above laminate B, the arithmetic average roughness Ra of the glass portion is preferably 150 nm or less, more preferably 130 nm, more preferably 110 nm or less. The lower limit of the arithmetic average roughness Ra of this glass part is 10 nm or more, for example. Also, the 10-point average roughness Rz of the glass portion is preferably not more than 500 nm, more preferably not more than 450 nm, more preferably not more than 400 nm. The lower limit of the 10-point average roughness Rz of the glass portion is, for example, 200 nm or more. Example

The following examples illustrate the present invention in detail, but the present invention is not limited to these examples. The evaluation methods in Examples and Comparative Examples are as follows.

[Manufacturing example 1] Fabrication of a thin glass/resin film laminate (laminate A) Thin glass/resin film is produced by laminating resin film on thin glass with a thickness of 100 μm (manufactured by NEC Glass Co., Ltd., trade name “OA-10”) through an adhesive (epoxy UV-curable adhesive, thickness: 10 μm) Laminated body (laminated body A). As the resin film, a film formed by laminating a polarizer with a thickness of 5 μm and an acrylic film with a thickness of 40 μm was used. Moreover, this resin film is laminated|stacked acrylic-type film so that it may oppose thin glass.

[Example 1] The above-mentioned laminate A was cut with a cutting device (manufactured by SHODA TECHTRON CO., trade name "CCM-550A type") to obtain a laminate B. The cutting condition is that the two ends of the sample are fixed, using a diamond abrasive knife with a diameter of 200mm, serial number #325, and cutting at a speed of 3000rpm and a speed of 40mm/min (size: 60mm×120mm). Next, 15 sheets of the laminate B were laminated, sandwiched above and below it with plate glass (60mm×120mm) with a thickness of 500 μm, and the four sides of the peripheral part were polished with a polishing device (manufactured by SHODA TECHTRON CO., trade name "BPM-380C") End surface treatment was performed to obtain a thin glass laminate. In this end surface treatment, a 6-inch-diameter-long roller made of a nylon brush with a diameter of 0.2 mm is rotated (rotational speed: 900 rpm, brush contact amount: 5 mm) and abrasive liquid is supplied to the end surface with the nylon brush. grind. The polishing solution is a polishing solution containing cerium oxide particles (particle size: 2μm~3μm) in water. The final polishing amount was set to 100 μm.

[Example 2] After bonding a surface protection film (manufactured by Nitto Denko Co., Ltd., RP207) to the thin glass surface of the laminate A, it was cut in the same manner as in Example 1, and then polished to obtain a thin glass laminate.

[Comparative example 1] The laminated body A was cut with UV laser (wavelength 355nm, pulse width 15ps, speed 1000mm/s, scanning times 100 times) to obtain a thin glass laminated body.

[Comparative example 2] Roughly cut the laminated body A with a cutting machine, and then laminate 15 pieces with a rotary cutter (MISUMI company, XAL series superhard end mill (square end mill) 2 blades / length 3D type) End surface treatment was performed to obtain a thin glass laminate. As for the cutting conditions, the cutting amount was set to 0.5 mm, the rotation speed was 25000 rpm, and the speed was 1500 mm/s, and the cutting was performed.

[Comparative example 3] The laminated body A was cut with a cutting device (manufactured by SHODA TECHTRON CO., CCM-550A type) to obtain a thin glass laminated body. The cutting condition is that the two ends of the sample are fixed, and the cutting is carried out at the speed of 3000rpm and the speed of 40mm/min with a diamond abrasive knife with a diameter of 200mm and the serial number #325.

(Evaluation) The thin glass laminates obtained in Examples and Comparative Examples (Example 2 is a thin glass laminate obtained after peeling off the protective film) were used for the following evaluations. The results are listed in Table 1. (1) Shape evaluation Use SEM to observe the cross-section of the thin glass laminate to determine the shape of the end surface (whether there is a curved surface formed above the thin glass; the curvature of the curved surface; the junction A located at (curved surface height h1)×3/4 in the curved surface Angle θ ₂ formed with the top of the thin glass). In addition, in the thin glass laminates of Comparative Examples 1 to 3, no curved surface was formed on the end surface of the thin glass, and the angle formed between the upper surface and the vertical surface was 90°. In addition, the arithmetic mean surface roughness Ra and the arithmetic mean surface roughness Ra of the end face of the thin glass were measured by AFM (field of view: 50 μm□). (2) Bending Strength For a thin glass laminate (size: 60 mm×110 mm), a two-point bending test was performed by bending the long side, and the distance between two points at the time of rupture was measured. The distance between two points means the distance between one end and the other end in the longitudinal direction, that is, the distance shortened as the thin glass laminate is bent when the thin glass laminate is bent starting from the center in the longitudinal direction. Also, the narrower the distance between two points, the higher the bending strength.

[Table 1]

As is clear from Table 1, by forming a predetermined curved surface on the end surface of the thin glass, a thin glass laminate excellent in bending durability can be obtained.

100, 100', 100": thin glass laminate 10: thin glass 20: resin film 21: slope 21a, 22a: upper edge 22: (upward) curved surface 22b, 24b: lower edge 23: upper surface of thin glass 24: downward Curved surface 25: vertical surface, underside of thin glass (Figure 6) A, B: Junction surface h1: Height of curved surface 22 h1': Height of curved surface 24 H1: Height H2 of the part of the end surface formed by the slope or curved surface extending downward and outward : Height of the part of the end surface composed of vertical planes θ ₁ ~ θ ₃ : Angle α: Central angle of fan

Fig. 1 is a schematic cross-sectional perspective view of a thin glass laminate according to an embodiment of the present invention. Fig. 2 is an enlarged cross-sectional view of an end portion of a thin glass laminate according to an embodiment of the present invention. Fig. 3 is a schematic cross-sectional perspective view of a thin glass laminate according to an embodiment of the present invention. Fig. 4 is an enlarged end sectional view of a thin glass laminate according to an embodiment of the present invention. Fig. 5 is a schematic cross-sectional perspective view of a thin glass laminate according to an embodiment of the present invention. Fig. 6 is an enlarged cross-sectional view of an end portion of a thin glass laminate according to an embodiment of the present invention.

100': thin glass laminate

10: Resin film

20: thin glass

22: (upward) surface

Claims (18)

A thin glass laminate comprising a resin film and thin glass disposed at least above the resin film; the thickness of the thin glass is 30 μm to 150 μm, and the ratio of the thickness of the resin film to the thickness of the thin glass (resin film thickness/ Thin glass thickness) is 0.2~5, at least a part of the end surface of the thin glass is composed of a slope and/or a curved surface extending downward and outward, and the thin glass includes an upward curved surface and a curved surface at least a part of the end surface of the thin glass Downwardly curved surface, and with the lower edge of the downwardly curved surface as the reference, the angle θ3 formed by the joint surface at the height h1'×1/ ₄ of the downwardly curved surface and the bottom of the thin glass is greater than 90° and within 150° the following. The thin glass laminate according to claim 1, wherein at the upper end of the thin glass, at least a part of the end surface is formed by the inclined surface and/or curved surface extending downward and outward. The thin glass laminate according to claim 1 or 2, wherein at least a part of the end surface of the thin glass is formed by the inclined surface extending downward and outward, and the angle formed by the upper surface of the thin glass and the inclined surface extending downward and outward θ ₁ is greater than 90° and less than 140°. The thin glass laminate according to claim 1, wherein at least a part of the end surface of the thin glass has an outwardly convex upward curved surface as the curved surface, and the upward curved surface is located at (curved surface height h1)×3/4 of the curved surface A curved surface where the angle θ ₂ formed by the junction A at the place and the top of the thin glass is greater than 90°. The thin glass laminate according to claim 4, wherein the angle θ ₂ is greater than 90° and not more than 140°. The thin glass laminate according to claim 4 or 5, wherein the thin glass further has a downwardly curved surface protruding outward as the curved surface on at least a part of its end surface. The thin glass laminate according to claim 1 or 2, wherein at least a part of the end surface of the thin glass is composed of the inclined surface extending downward and outward, and/or the curved surface, and a vertical surface. The thin glass laminate according to claim 1 or 2, wherein in the thin glass, the height H1 of the portion of the end surface formed by the inclined surface extending downward and outward or the curved surface is 0.1% or more relative to the thickness of the thin glass. The thin glass laminate according to claim 7, wherein the ratio of the height H1 of the portion of the end surface formed by the slope or the curved surface extending downward and outward to the height H2 of the portion of the end surface formed by the vertical surface (H1:H2 ) is 1:9~9.99:0.01. The thin glass laminate according to claim 1 or 2, wherein the arithmetic mean surface roughness Ra of the end faces of the thin glass is 150 nm or less. The thin glass laminate according to claim 1 or 2, wherein the 10-point average roughness Rz of the end faces of the thin glass is 500 nm or less. The thin glass laminate according to claim 1 or 2, wherein the resin film is arranged to protrude from the thin glass. Such as the thin glass laminated body of claim 1 or 2, which is Here, the height difference between the resin film and the thin glass is 200 μm or less. The thin glass laminate according to claim 1 or 2, wherein the resin film is an optical film. The thin glass laminate according to Claim 14, wherein the aforementioned optical film is a polarizing plate. The thin glass laminate according to claim 14, wherein the resin film has a transparent conductive layer. The thin glass laminate according to claim 1 or 2, wherein the thin glass and the resin film are laminated through an adhesive. A method for manufacturing a thin glass laminate, which is used to manufacture the thin glass laminate according to any one of Claims 1 to 17, the aforementioned manufacturing method comprising: laminating thin glass and a resin film to form a laminate A, and laminating the laminate After the body A is cut to a predetermined size, the end face of the cut laminate B is ground by polishing.

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