JP2022058310A - Manufacturing methods for glass substrates, glass laminates, display devices, electronic devices, and glass laminates - Google Patents

Abstract

[Problem] To provide a glass substrate and a glass laminate having good bending resistance. [Solution] A glass substrate 10 has a first surface 1A, a second surface 1B opposing the first surface, and a side surface 1C, a thickness of 15 μm to 100 μm, and a maximum height Sz of the side surface 1C of 1.5 μm or less. [Selected Figure] Figure 1

Description

The present disclosure relates to a glass substrate, a glass laminate using the glass substrate, a display device and an electronic device, and a method for manufacturing the glass laminate.

Conventionally, in the display device, a cover member made of glass or resin has been used for the purpose of protecting the display device. This cover member protects the display device from impacts and scratches, and is required to have strength, impact resistance, scratch resistance, and the like. The glass cover member has features such as high surface hardness and scratch resistance, and high transparency, and the resin cover member has features such as light weight and resistance to breakage. Further, in general, the thicker the cover member, the higher the function of protecting the display device from impact, and the material and thickness of the cover member are appropriately selected and used from the viewpoint of weight, cost, size of the display device, and the like.

In recent years, flexible displays such as foldable displays, rollable displays, and bendable displays have been actively developed, and among them, foldable displays, that is, foldable display devices have been developed.

In a display device that can be bent, since the cover member also needs to bend in accordance with the movement of the display device, a cover member that can be bent is applied. In the case of a resin cover member, a film of polyimide or polyamide-imide which has been made colorless and transparent by devising a chemical structure has been developed (see, for example, Patent Document 1). Further, in the case of a cover member made of glass, a cover member such as ultra-thin glass (UTG) that can be bent by thinning the glass is under study (for example, a patent). See Document 2). Among the glasses, the one with particularly high bending resistance is called chemically strengthened glass, and by incorporating the stress that expands on the glass surface, minute scratches generated on the glass surface are prevented from becoming large during bending. This makes the glass hard to break.

Japanese Unexamined Patent Publication No. 2019-137864 Japanese Unexamined Patent Publication No. 2018-188335

However, since chemically strengthened glass is difficult to cut, when a cover member is manufactured using chemically strengthened glass, the glass substrate is first cut to a desired size, and then the cut glass base is used. There is a problem that the material needs to be chemically strengthened, the subsequent manufacturing process cannot proceed without cutting a large glass base material, and the productivity is low.

Further, even if the chemically strengthened glass can be cut, when the chemically strengthened glass is cut, the compressive stress layer formed on the surface of the chemically strengthened glass does not exist on the cut surface of the glass substrate. Therefore, there is a problem that the strength of the cut surface of the glass substrate is lowered. In this case, the bending resistance is lowered.

The present disclosure has been made in view of the above circumstances, and an object of the present disclosure is to provide a glass base material and a glass laminate having good bending resistance.

One embodiment of the present disclosure has a first surface, a second surface facing the first surface, and a side surface, the thickness is 15 μm or more and 100 μm or less, and the maximum height Sz of the side surface is. Provided is a glass substrate having a size of 1.5 μm or less.

The glass substrate in the present disclosure is cracked or broken when the operation of bending the glass substrate by 180 ° is repeated 200,000 times so that the distance between the opposing short sides of the glass substrate is 12 mm. It is preferable that there is no such thing.

The glass substrate in the present disclosure is preferably chemically strengthened glass.

In the glass substrate in the present disclosure, in the potassium concentration distribution in the thickness direction of the side surface, each region divided into ten equal parts in the thickness direction is directed from the first surface side to the second surface side. In order, when the first to tenth regions are used, it is preferable that the average value of the potassium concentration in the first region is higher than the average value of the potassium concentration in the fifth region. In the above case, the ratio of the average value of the potassium concentration in the fifth region to the average value of the potassium concentration in the first region is preferably in the range of 0 to 0.7.

The glass substrate in the present disclosure is preferably used for a flexible display.

Another embodiment of the present disclosure provides a glass laminate comprising the above-mentioned glass substrate and resin layers arranged on at least one of the first surface side and the second surface side of the glass substrate. ..

In the glass laminate in the present disclosure, the thickness of the resin layer is preferably 5 μm or more and 60 μm or less.

In the glass laminate in the present disclosure, the composite elastic modulus of the resin layer is preferably 4.7 GPa or more.

In the glass laminate in the present disclosure, it is preferable that the resin layer contains at least one selected from the group consisting of a polyimide resin, an epoxy resin, polyester, polyurethane and an acrylic resin.

The glass laminate in the present disclosure may further have a second resin layer that covers the side surface of the glass substrate.

In the glass laminate in the present disclosure, the second resin layer contains at least one selected from the group consisting of a polyimide resin, an epoxy resin, polyester, polyurethane and an acrylic resin, or a polymerizable compound. It is preferable to contain a cured product of the containing resin composition.

Another embodiment of the present disclosure provides a display device comprising a display panel and the above-mentioned glass substrate or the above-mentioned glass laminate arranged on the observer side of the display panel.

Another embodiment of the present disclosure provides an electronic device comprising the display device described above.

Other embodiments of the present disclosure include a preparatory step of preparing a glass substrate having a thickness of 15 μm or more and 100 μm or less and being chemically tempered glass, and at least one of the first surface side and the second surface side of the glass substrate. Provided is a method for producing a glass laminate, which comprises a resin layer forming step of forming a resin layer on one side, and a cutting step of cutting the glass substrate and the laminate having the resin layer after the resin layer forming step. do.

The method for producing a glass laminate in the present disclosure preferably includes a processing step of processing the cut surface of the glass substrate so that the maximum height Sz of the cut surface of the glass substrate is 1.5 μm or less. ..

The method for producing a glass laminate in the present disclosure can further include a second resin layer forming step of covering the side surface of the glass substrate with the second resin layer after the cutting step.

In the present disclosure, it is possible to provide a glass base material and a glass laminate having good bending resistance.

It is a schematic cross-sectional view which illustrates the glass base material in this disclosure. It is a schematic cross-sectional view which illustrates the glass base material in this disclosure. It is a schematic perspective view which illustrates the glass base material in this disclosure. It is a graph which exemplifies the profile of the concentration distribution of potassium. It is a schematic diagram for demonstrating a U-shaped bending test. It is a schematic sectional drawing illustrating the glass laminated body in this disclosure. It is a schematic sectional drawing illustrating the glass laminated body in this disclosure. It is a schematic sectional drawing illustrating the glass laminated body in this disclosure. It is a schematic sectional drawing illustrating the glass laminated body in this disclosure. It is a schematic sectional drawing illustrating the glass laminated body in this disclosure. It is a schematic sectional drawing illustrating the glass laminated body in this disclosure. It is a schematic sectional drawing illustrating the glass laminated body in this disclosure. It is a schematic cross-sectional view which illustrates the display device in this disclosure. It is a process drawing which illustrates the manufacturing method of the glass laminate in this disclosure. It is a process drawing which illustrates the manufacturing method of the glass laminate in this disclosure. It is a color image of the non-contact surface / layer cross-sectional shape measurement system of the glass base material of the comparative example. It is a color image of the non-contact surface / layer cross-sectional shape measurement system of the glass base material of the Example. It is explanatory drawing explaining the measuring method of the maximum height Sz.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings and the like. However, the present disclosure can be implemented in many different embodiments and is not construed as being limited to the description of the embodiments exemplified below. Further, in order to clarify the explanation, the drawings may schematically show the width, thickness, shape, etc. of each part as compared with the actual form, but this is just an example and the interpretation of the present disclosure is limited. It's not something to do. Further, in the present specification and each figure, the same elements as those described above with respect to the above-mentioned figures may be designated by the same reference numerals, and detailed description thereof may be omitted as appropriate.

In the present specification, in expressing the aspect of arranging another member on one member, when the term "above" or "below" is simply used, the member should be in contact with the member unless otherwise specified. Including the case where another member is arranged directly above or directly below, and the case where another member is arranged above or below one member via another member. Further, in the present specification, when expressing the mode of arranging another member on the surface of a certain member, when simply expressing "on the surface side" or "on the surface", unless otherwise specified, the certain member is used. It includes both the case where another member is arranged directly above or directly below the member so as to be in contact with the member, and the case where another member is arranged above or below one member via another member.

Hereinafter, the glass substrate, the glass laminate, the display device, the electronic device, and the method for manufacturing the glass laminate in the present disclosure will be described in detail.

A. Glass base material The glass base material in the present disclosure has a first surface (hereinafter, may be referred to as a first main surface) and a second surface facing the first main surface (hereinafter, referred to as a second main surface). In some cases) and a side surface, the thickness is not more than a predetermined value, and the maximum height Sz of the side surface is not more than a predetermined value.

FIG. 1 is a schematic cross-sectional view showing an example of a glass substrate in the present disclosure. As shown in FIG. 1, the glass base material 1 has a first main surface 1A, a second main surface 1B facing the first main surface 1A, and a side surface 1C, and has a predetermined thickness. The maximum height Sz of the side surface 1C is equal to or less than a predetermined value.

Since the glass substrate in the present disclosure has a thickness of a predetermined value or less and is thin, it has high flexibility and can enhance bending resistance. On the other hand, the glass base material tends to generate microcracks during processing, and particularly tends to generate microcracks at the edges of the glass base material during cutting processing of the glass base material. If there are microcracks in the glass substrate, cracks are likely to occur starting from these microcracks. Further, when chemically strengthened glass is used as the glass base material, bending resistance and impact resistance can be improved, but even in this case, when a large glass base material made of chemically strengthened glass is cut and processed, it is possible to improve the bending resistance and impact resistance. Since the compressive stress layer formed on the surface of the chemically strengthened glass does not exist on the cut surface, that is, the side surface of the glass substrate, the strength is lowered on the side surface of the glass substrate.

On the other hand, in the present disclosure, since the maximum height Sz of the side surface of the glass base material is equal to or less than a predetermined value, the smoothness of the side surface of the glass base material is high and microcracks on the side surface of the glass base material are reduced. As a result, the strength of the side surface of the glass substrate can be increased. Therefore, when the glass base material is bent, cracking from the side surface of the glass base material can be suppressed, and bending resistance can be improved. Further, the impact resistance at the end portion of the glass base material can be enhanced.

Therefore, in the present disclosure, it is possible to use a glass base material having good bending resistance. Therefore, the glass substrate in the present disclosure can be bent and can be used in a wide variety of display devices, for example, as a member for a foldable display.

In addition, in this specification, the "side surface" of a glass base material means all the surfaces other than the 1st main surface and the 2nd main surface of a glass base material. Further, for example, when the glass base material is chamfered, the side surface of the glass base material may have a chamfered portion. Specifically, as shown in FIG. 2, the side surface 1C of the glass substrate 1 can have a side surface portion 2a and a chamfered portion 2b.

The thickness of the glass substrate is 15 μm or more and 100 μm or less, more preferably 20 μm or more and 90 μm or less, and further preferably 25 μm or more and 80 μm or less. When the thickness of the glass substrate is as thin as the above range, good flexibility can be obtained and sufficient hardness can be obtained. In addition, curling of the glass substrate can be suppressed. Further, it is preferable in terms of weight reduction of the glass base material.

The maximum height Sz of the side surface of the glass substrate is 1.5 μm or less, preferably 1.0 μm or less. As the maximum height Sz of the side surface of the glass base material is within the above range, the smoothness of the side surface of the glass base material is high, so that cracking of the glass base material can be suppressed when the glass base material is bent. , Flexibility can be improved. Furthermore, the impact resistance at the end of the glass substrate can be improved. On the other hand, the maximum height Sz of the side surface of the glass substrate is preferably 0.005 μm or more. This is because when Sz is less than 0.005 μm, it may be difficult to cover the end portion due to poor adhesion. Therefore, the maximum height Sz of the side surface of the glass substrate is preferably in the range of 0.005 μm to 1.5 μm.

Here, the maximum height Sz is a value measured according to ISO 25178. The maximum height Sz can be measured using a non-contact surface shape measuring device of the optical interference method. As the optical interference type non-contact surface shape measuring device, for example, a non-contact surface / layer cross-sectional shape measuring system VertScan2.0 R5500GML-A150-AC manufactured by Ryoka System Co., Ltd. can be used. The details of the method for measuring the maximum height Sz will be described in the section of Examples described later.
It should be noted that Sz in the present disclosure is a parameter for evaluating surface roughness, and is effective as an evaluation of a substance having an irregular surface texture as compared with Rz or the like representing line roughness.

The shape of the glass substrate is usually a rectangular parallelepiped and a hexahedron. Further, for example, even when the glass base material is chamfered, the shape of the glass base material is usually rectangular parallelepiped and can be regarded as being substantially hexahedron. In this case, the glass substrate has two main surfaces (first main surface and second main surface) and four side surfaces. In such a case, the maximum height Sz of at least one of the four sides of the glass substrate may be within a predetermined range.

Above all, it is preferable that the maximum height Sz of the two facing side surfaces out of the four side surfaces of the glass substrate is within a predetermined range. For example, as shown in FIGS. 3A and 3B, when the glass base material 1 is bent, the glass base material 1 is likely to be cracked at the bent portion F1 of the glass base material 1. Therefore, when the maximum height Sz of the two side surfaces substantially parallel to the bending direction D1 of the glass base material 1 among the four side surfaces of the glass base material is within the above range, the glass base material is bent. It is possible to suppress the occurrence of cracks in the bent portion and improve the bending resistance.

Further, when the shape of the glass base material in a plan view is rectangular, it is preferable that the maximum height Sz of the two opposite side surfaces of the four side surfaces of the glass base material is in the above range. For example, as shown in FIGS. 3A and 3B, when the glass base material 1 is bent, it is easy to bend the glass base material 1, so that the bending direction D1 of the glass base material 1 is substantially parallel to the long side direction of the glass base material. In many cases. Therefore, if the maximum height Sz of the two opposing side surfaces of the four side surfaces of the glass base material is within the above range, the bent portion of the glass base material is not cracked when the glass base material is bent. It can be suppressed and the bending resistance can be improved.

Further, for the above-mentioned reasons, it is preferable that the maximum height Sz of the two side surfaces substantially parallel to the bending direction of the glass base material is within the above range among the four side surfaces of the glass base material.

In particular, it is preferable that the maximum height Sz of all four sides of the glass substrate is in a predetermined range. When the glass base material is bent, the cracking of the glass base material can be further suppressed, and the bending resistance can be further improved. Furthermore, the impact resistance at the end of the glass substrate can be improved.

The glass constituting the glass substrate is not particularly limited, but chemically strengthened glass is particularly preferable. Chemically tempered glass has better impact resistance and bending resistance than non-tempered glass. Further, chemically strengthened glass is preferable in that it has excellent mechanical strength and can be made thinner accordingly.

Chemically strengthened glass is glass whose mechanical properties have been strengthened by a chemical method by partially exchanging sodium ions with potassium ions in the vicinity of the surface of the glass, and has a compressive stress layer on the surface. That is, chemically strengthened glass is a glass in which a large amount of potassium is present on the surface and a compressive stress is applied to the surface.

Examples of the method for confirming chemically strengthened glass include a method of measuring the concentration distribution of potassium in the depth direction from the surface of the glass. Specifically, in the chemically strengthened glass, in the concentration distribution of potassium in the thickness direction of the side surface of the glass base material, each region formed by dividing the glass base material into ten equal parts in the thickness direction is divided from the first main surface side of the glass base material. When the first region to the tenth region are set in the order toward the second main surface side, it is preferable that the glass has an average value of potassium concentration of 2.0 or more in the first region.

Here, "the order from the first surface side to the second surface side" means that the area has a smaller number from the first surface side, that is, from the first surface side to the first area, the first area. It means that there are two regions and a third region.

Here, in the glass substrate, the concentration distribution of potassium in the thickness direction of the side surface can be measured by, for example, energy dispersive X-ray analysis (EDX). Specifically, when measuring the concentration distribution of potassium by energy dispersive X-ray analysis (EDX) in the thickness direction with respect to the side surface of the glass substrate, X-MaxN manufactured by Oxford Instruments Co., Ltd. is used. By using this, EDX mapping can be performed with respect to the thickness direction of the side surface of the glass substrate at an acceleration voltage of 10 kV, and the potassium concentration can be quantified.

Further, the average value of the potassium concentration in the first region can be obtained by the following method based on the potassium concentration distribution in the thickness direction of the side surface of the glass substrate obtained by the above method.

First, in the concentration distribution of potassium in the thickness direction of the side surface of the glass base material, each region divided into ten equal parts in the thickness direction is directed from the first main surface side to the second main surface side of the glass base material. In order, the first region to the tenth region are used. Then, the arithmetic average value of the measured values of the potassium concentration every 0.2 μm in the thickness direction in the first region is taken as the average value of the potassium concentration in the first region.

As described above, the shape of the glass substrate is usually a rectangular parallelepiped and a hexahedron. Further, for example, even when the glass base material is chamfered, the shape of the glass base material is usually rectangular parallelepiped and can be regarded as being substantially hexahedron. In this case, the glass substrate has two main surfaces (first main surface and second main surface) and four side surfaces. In the present disclosure, when the glass substrate is chemically tempered glass, it is chemically tempered glass having a compressive stress layer obtained by chemically strengthening only two main surfaces (first main surface and second main surface). Is preferable. That is, when the glass base material is chemically tempered glass, it is preferably two-sided tempered glass.

Generally, when the glass base material is a two-sided tempered glass, the compressive stress layer does not exist on the side surface of the glass base material, so that the strength is lowered on the side surface of the glass base material. On the other hand, in the present disclosure, since the maximum height Sz of the side surface of the glass base material is equal to or less than a predetermined value, the smoothness of the side surface of the glass base material is high and microcracks on the side surface of the glass base material are reduced. As a result, the strength of the side surface of the glass substrate can be increased. Therefore, when the glass base material is bent, cracking from the side surface of the glass base material can be suppressed, and bending resistance can be improved. Further, the impact resistance at the end portion of the glass base material can be enhanced.
Therefore, when the glass base material is two-sided tempered glass, high impact resistance and bending resistance can be achieved at the same time by setting the maximum height Sz of the side surface of the glass base material to a predetermined value or less.

In the present specification, "two-sided tempered glass" refers to chemically strengthened glass having a compressive stress layer in which only two main surfaces (first main surface and second main surface) of a glass plate are chemically strengthened. A chemically strengthened glass having a compressive stress layer obtained by chemically strengthening the entire surface of a glass plate (all six surfaces if the glass base material is rectangular) is referred to as "six-sided tempered glass". The two-sided tempered glass can be obtained, for example, by subjecting a glass substrate to a chemical strengthening treatment and then cutting it to a desired size. On the other hand, the six-sided tempered glass can be obtained, for example, by subjecting a glass substrate to a chemical strengthening treatment.

When the glass substrate is a two-sided tempered glass, in the glass substrate, the potassium concentration of the first main surface and the second main surface is higher than the potassium concentration in the central portion in the thickness direction of the side surface.

In the above case, the potassium concentration on the first main surface and the second main surface of the glass substrate is not particularly limited and is appropriately set according to the required characteristics. Similarly, the potassium concentration in the central portion of the side surface of the glass substrate in the thickness direction is not particularly limited and is appropriately set according to the required characteristics. For example, the potassium concentration in the central portion of the side surface of the glass substrate in the thickness direction may be zero.

When the glass substrate is a two-sided tempered glass, in the glass substrate, each region formed by dividing the potassium concentration distribution on the side surface of the glass substrate into ten equal parts in the thickness direction is formed. When the first to tenth regions are in order from the first main surface side to the second main surface side of the glass substrate, the average value of the potassium concentration in the first region is the fifth region. It is higher than the average value of potassium concentration.

In the above case, the ratio of the average value of the potassium concentration in the fifth region to the average value of the potassium concentration in the first region is preferably 0.7 or less, even if it is 0.5 or less. good. The lower limit is 0 or more. If the above ratio is in the above range, it can be said that the glass base material is two-sided tempered glass. As described above, the present disclosure is useful when the glass substrate is a two-sided tempered glass, and when the above ratio is within the above range, the maximum height Sz of the side surface of the glass substrate is set to a predetermined value or less. Therefore, both high impact resistance and bending resistance can be achieved at the same time.

In the above case, the potassium concentration in each region from the first region to the tenth region is not particularly limited and is appropriately set according to the required characteristics.

Here, as described above, in the glass substrate, the concentration distribution of potassium in the thickness direction of the side surface can be measured by, for example, energy dispersive X-ray analysis (EDX).

The average value of the potassium concentration in the first region and the average value of the potassium concentration in the fifth region are as follows, based on the potassium concentration distribution in the thickness direction of the side surface of the glass substrate obtained by the above method. It can be obtained by the method of. First, in the concentration distribution of potassium in the thickness direction of the side surface of the glass base material, each region divided into ten equal parts in the thickness direction is directed from the first main surface side to the second main surface side of the glass base material. In order, the first region to the tenth region are used. Then, the arithmetic average value of the measured values of the potassium concentration every 0.2 μm in the thickness direction in the first region is taken as the average value of the potassium concentration in the first region. Further, the arithmetic average value of the measured values of the potassium concentration every 0.2 μm in the thickness direction in the fifth region is taken as the average value of the potassium concentration in the fifth region.

For example, FIGS. 4A and 4B show an example of a profile of the potassium concentration distribution in the thickness direction of the side surface of the glass substrate. In the profile of the potassium concentration distribution shown in FIGS. 4 (a) and 4 (b), each region divided into ten equal parts in the thickness direction of the glass base material is divided into two main surfaces from the first main surface side of the glass base material. The first region 3A to the tenth region 3J are sequentially set toward the surface side. At this time, the average value of the potassium concentration in the first region 3A and the average value of the potassium concentration in the fifth region 3E are obtained. When the glass base material is two-sided tempered glass, for example, the concentration distribution of potassium as shown in FIGS. 4A and 4B can be obtained. On the other hand, when the glass base material is 6-sided tempered glass, for example, the concentration distribution of potassium as shown in FIG. 4C can be obtained.

Examples of the glass constituting the chemically strengthened glass base material include aluminosilicate glass, soda lime glass, borosilicate glass, lead glass, alkaline barium glass, and aluminohousilicate glass.

Examples of commercially available chemically strengthened glass base materials include Gorilla Glass manufactured by Corning, Dragontrail manufactured by AGC, and chemically strengthened glass manufactured by Shot.

The glass substrate in the present disclosure preferably has bending resistance. Specifically, the bending resistance of the glass substrate can be evaluated by performing a U-shaped bending test described below.

The U-shaped bending test is performed as follows. First, a test piece of a glass substrate having a size of 20 mm × 100 mm is prepared. Next, as shown in FIG. 5A, the short side portion 1P of the glass substrate 1 and the short side portion 1Q facing the short side portion 1P are fixed portions 100A and 100B arranged in parallel. Fix each. As shown in FIG. 5A, the fixed portion 100B is slidable in the horizontal direction. Next, as shown in FIG. 5B, the glass base material 1 is bent in a U shape by moving the fixing portion 100B so as to be close to the fixing portion 100A. Further, as shown in FIG. 5C, by moving the fixing portion 100B, the facing 2 fixed by the fixing portions 100A and 100B of the glass base material 1 until the glass base material 1 is cracked or broken. The interval d between the two short sides 1P and 1Q is gradually reduced. At this time, a bending test is performed so that the bent portion 1R of the glass base material 1 does not protrude from the lower ends of the fixed portions 100A and 100B. For example, when the distance d between the two short side portions 1P and 1Q facing each other is 10 mm, the outer diameter of the bent portion 1R is regarded as 10 mm.

In the U-shaped bending test, the distance d between the opposite short side portions 1P and 1Q of the glass base material 1 when the glass base material is cracked or broken is preferably 10 mm or less, and more preferably 8 mm or less. Is preferable, and particularly preferably 5 mm or less. It should be noted that the smaller the distance d between the opposite short side portions 1P and 1Q of the glass base material 1, the higher the bending resistance.

The bending resistance of the glass substrate can also be evaluated by performing a dynamic bending test. The dynamic bending test is a test in which the glass base material is repeatedly bent by setting the interval d between the opposite short side portions 1P and 1Q of the glass base material 1 to a predetermined value in the above U-shaped bending test.

In the above dynamic bending test, when the operation of bending the glass base material by 180 ° is repeated 200,000 times so that the distance d between the opposite short side portions 1P and 1Q of the glass base material 1 is 12 mm, the glass base material is used. It is preferable that the glass does not crack or break.
Further, the bending resistance can be improved by reducing the thickness of the glass base material.

For example, when the thickness of the glass substrate is 81 μm or more and 100 μm or less, in the above dynamic bending test, the glass substrate is 180 so that the distance d between the opposite short side portions 1P and 1Q of the glass substrate 1 is 12 mm. ° It is preferable that the glass substrate does not crack or break when the bending operation is repeated 200,000 times.

Further, for example, when the thickness of the glass base material is 50 μm or more and 81 μm or less, in the above dynamic bending test, the glass base material has a gap d between the opposite short side portions 1P and 1Q of the glass base material 1 of 10 mm. It is preferable that the glass substrate does not crack or break when the operation of bending 180 ° is repeated 200,000 times.

Further, for example, when the thickness of the glass base material is 50 μm or less, in the above dynamic bending test, the glass base material is 180 so that the distance d between the opposite short side portions 1P and 1Q of the glass base material 1 is 8 mm. ° It is preferable that the glass substrate does not crack or break when the bending operation is repeated 200,000 times.

The method for producing the glass substrate in the present disclosure is not particularly limited as long as it is a method capable of setting the maximum height Sz of the side surface of the glass substrate to a predetermined value or less, but among them, the chemical strengthening treatment and the cutting process are performed. It is preferable to carry out in order. For example, in the case of manufacturing a member for a display device using a glass base material, by adopting such a process order, it is possible to proceed with the subsequent manufacturing process without cutting a large glass base material, and production is possible. Efficiency can be increased.

In the method for producing a glass base material, it is preferable to process the cut surface of the glass base material so that the maximum height Sz of the cut surface of the glass base material is not more than a predetermined value. When processing the cut surface of the glass base material, for example, the glass base material may be cut so that the maximum height Sz of the cut surface of the glass base material is equal to or less than a predetermined value, or the glass base material may be cut. While cutting the material, the cut surface of the glass substrate may be processed so that the maximum height Sz of the cut surface of the glass substrate is equal to or less than a predetermined value, or the glass substrate may be processed after the glass substrate is cut. The cut surface of the glass substrate may be processed so that the maximum height Sz of the cut surface of the material is equal to or less than a predetermined value. Specific examples thereof include a method in which the glass substrate is cut by a scribing, the cut surface of the glass substrate is polished with abrasive paper, and the cut surface is further polished with diamond abrasive grains. The particle size of the abrasive material of the polishing paper is preferably, for example, 30 μm or less, and particularly preferably 15 μm. Further, the polishing material of the polishing paper is not particularly limited. The particle size of the diamond abrasive grains is, for example, preferably 3 μm or less, and particularly preferably 1 μm.

The glass substrate in the present disclosure can be used, for example, as a cover member of a display device. Specifically, the glass substrate in the present disclosure covers a display device used in electronic devices such as smartphones, tablet terminals, wearable terminals, personal computers, televisions, digital signage, public information displays (PIDs), and in-vehicle displays. It can be used as a member. Above all, the glass substrate in the present disclosure can be preferably used for flexible displays such as foldable displays, rollable displays and bendable displays, and can be preferably used for foldable displays.

B. Glass Laminate The glass laminate in the present disclosure includes the above-mentioned glass base material and a resin layer arranged on at least one of the first main surface side and the second main surface side of the glass base material.

FIG. 6 is a schematic cross-sectional view showing an example of the glass laminate in the present disclosure. As shown in FIG. 6, the glass laminate 10 has a glass base material 1 having a predetermined thickness and a resin layer 11 arranged on the first main surface 1A side of the glass base material 1.

FIG. 7 is a schematic cross-sectional view showing another example of the glass laminate in the present disclosure. As shown in FIG. 7, the glass laminate 10 includes a glass base material 1 having a predetermined thickness, a resin layer 11 arranged on the first main surface 1A side of the glass base material 1, and a glass base material 1. It has a resin layer 12 arranged on the second main surface 1B side.

Since the glass laminate in the present disclosure has the above-mentioned glass base material, bending resistance can be improved.

On the other hand, since the glass base material has a thickness of a predetermined value or less and is thin, there is a concern that it is easily broken and has low impact resistance. On the other hand, in the glass laminate in the present disclosure, the resin layer is arranged on at least one of the first main surface side and the second main surface side of the glass base material, so that an impact is applied to the glass laminate. At that time, the resin layer absorbs the impact, the cracking of the glass substrate can be suppressed, and the impact resistance can be enhanced. Further, the resin layer can suppress the scattering of the glass even if the glass base material is damaged.

Therefore, in the present disclosure, a glass laminate having good bending resistance and impact resistance can be obtained. Furthermore, even if the glass base material in the glass laminate is damaged, the risk of damaging the human body can be reduced, and the glass laminate can be made highly safe.

Therefore, the glass laminate in the present disclosure can be bent and can be used in a wide variety of display devices, for example, as a member for a foldable display.

Hereinafter, each configuration of the glass laminate in the present disclosure will be described.

1. 1. Glass base material The glass base material in the present disclosure has a first main surface, a second main surface facing the first main surface, and a side surface, and the thickness is equal to or less than a predetermined value. The maximum height Sz of is not more than a predetermined value.

Since the glass substrate is the same as that described in the above section "A. Glass substrate", the description thereof is omitted here.

2. 2. Resin layer The resin layer in the present disclosure is a layer arranged on at least one of the first main surface side and the second main surface side of the glass substrate. The resin layer can also function as a shock absorbing layer having shock absorbing properties and a shatterproof layer that suppresses shattering of glass when the glass base material is broken.

In the present specification, when the glass laminate in the present disclosure is used in the display device, the resin layer arranged on the observer side of the glass base material is referred to as a surface side resin layer, and the surface side of the glass base material. The resin layer arranged on the surface side opposite to the resin layer may be referred to as a back surface side resin layer.

(1) Characteristics of the resin layer The resin layer preferably has shock absorption. Specifically, the composite elastic modulus of the resin layer is preferably 4.7 GPa or more, and more preferably 5.7 GPa or more. When the composite elastic modulus of the resin layer is within the above range, cracking of the glass substrate due to impact can be suppressed, and impact resistance and scratch resistance can be improved.

The upper limit is 40 GPa or less, preferably 20 GPa or less, and particularly preferably 15 GPa or less. Specifically, it is preferably in the range of 40 GPa to 4.7 GPa, particularly preferably in the range of 5.7 GPa to 20 GPa, and particularly preferably in the range of 5.7 GPa to 15 GPa.

Further, according to the method for measuring the composite elastic modulus described later, since the composite elastic modulus of the glass substrate is about 40 GPa, the composite elastic modulus of the resin layer is preferably, for example, 40 GPa or less, preferably 20 GPa or less. It is more preferable to have.

Here, the composite elastic modulus of the resin layer shall be calculated using the contact projection area _Ap obtained when measuring the indentation hardness ( _HIT ) of the resin layer. The "indentation hardness" is a value obtained from the load-displacement curve from the load to the unloading of the indenter obtained by the hardness measurement by the nanoindentation method. The composite elastic modulus of the resin layer is the elastic modulus including the elastic deformation of the resin layer and the elastic deformation of the indenter.

The measurement of indentation hardness (HIT) shall be performed using "TI950 _{TriboIndenter} " manufactured by BRUKER Co., Ltd. for the measurement sample. Specifically, first, a block in which a glass laminate cut out to 1 mm × 10 mm is embedded with an embedding resin is prepared, and a uniform thickness of 50 nm or more without holes or the like is produced from this block by a general section preparation method. Cut out a section of 100 nm or less. "Ultra Microtome EM UC7" (manufactured by Leica Microsystems, Inc.) or the like can be used for preparing the sections. Then, the remaining block from which a uniform section having no holes or the like is cut out is used as a measurement sample.

Next, in the cross section obtained by cutting out the section in such a measurement sample, a Berkovich indenter (triangular pyramid, TI-0039 manufactured by BRUKER) was used as the indenter under the following measurement conditions in a resin layer. Push vertically to the center of the cross section for 10 seconds up to a maximum pushing load of 25 μN. Here, in order to avoid the influence of the glass base material and the influence of the side edge of the resin layer, the Berkovich indenter is 500 nm away from the interface between the glass base material and the resin layer on the center side of the resin layer, and the resin layer is formed. It shall be pushed into the portion of the resin layer 500 nm away from both ends on the center side of the resin layer.

If an arbitrary layer such as a functional layer is present on the surface of the resin layer opposite to the surface on the glass substrate side, the interface between the arbitrary layer and the resin layer is also on the center side of the resin layer. It shall be pushed into the portion of the resin layer separated by 500 nm. After that, after holding it constant and relaxing the residual stress, it is unloaded over 10 seconds, the maximum load after relaxation is measured, and the maximum load _{P max} (μN) and the contact projected area Ap (nm ² ) are measured. ) And _{P max} / Ap to calculate the indentation hardness ( _HIT ). The contact projection area is a contact projection area in which the curvature of the indenter tip is corrected by the Oliver-Charr method using fused silica (5-00098 manufactured by BRUKER Co., Ltd.) as a standard sample.

The indentation hardness ( _HIT ) shall be the arithmetic mean value of the values obtained by measuring at 10 points. If any of the measured values deviates by ± 20% or more from the arithmetic mean value, the measured value shall be excluded and remeasurement shall be performed. Whether or not any of the measured values deviates by ± 20% or more from the arithmetic mean value is determined by (AB) / B × 100 when the measured value is A and the arithmetic mean value is B. Judgment shall be made based on whether the required value (%) is ± 20% or more. The indentation hardness ( _HIT ) can be adjusted by the type of resin contained in the resin layer described later.

(Measurement condition)
・ Load speed: 2.5 μN / sec ・ Holding time: 5 seconds ・ Load unloading speed: 2.5 μN / sec ・ Measurement temperature: 25 ° C

The composite elastic modulus _Er of the resin layer is obtained by the following mathematical formula (1) using the contact projection area _Ap obtained when measuring the indentation hardness. For the composite elastic modulus, the indentation hardness is measured at 10 points, the composite elastic modulus is obtained each time, and the obtained composite elastic modulus is used as the arithmetic mean value of the obtained 10 points.

(In the above formula (1), _Ap is the contact projected area, _Er is the composite elastic modulus of the resin layer, and S is the contact rigidity.)

(2) Thickness of the resin layer The thickness of the resin layer is not particularly limited as long as it can obtain flexibility and shock absorption, and is preferably 5 μm or more and 60 μm or less, for example. It is more preferably 10 μm or more and 50 μm or less, and further preferably 15 μm or more and 40 μm or less. By making the thickness of the resin layer relatively thin so as to be within the above range, flexibility can be enhanced, cracking of the resin layer can be suppressed when the glass laminate is bent, and bending resistance can be suppressed. Can be maintained.

Here, the thickness of the resin layer is measured from a cross section in the thickness direction of the glass laminate observed by a transmission electron microscope (TEM), a scanning electron microscope (SEM), or a scanning transmission electron microscope (STEM). It can be an average value of the thicknesses of any 10 points obtained in the above. Unless otherwise specified, the same method can be used for measuring the thickness of other layers of the glass laminate.

(3) Material of resin layer (a) Resin The resin contained in the resin layer is not particularly limited as long as it can obtain a resin layer having transparency and shock absorption, but among them, A resin satisfying the above-mentioned composite elastic modulus is preferable. Specific examples thereof include polyimide resins, epoxy resins, polyesters, polyurethanes, acrylic resins and the like. These resins may be used alone or in combination of two or more.

In the present specification, the polyimide resin means a polymer having an imide bond in the main chain. Examples of the polyimide-based resin include polyimide, polyamide-imide, polyesterimide, and polyetherimide.
Hereinafter, polyimide and polyamide-imide will be described as examples.

(I) Polyimide Polyimide is obtained by reacting a tetracarboxylic acid component with a diamine component. It is preferable to obtain polyamic acid by polymerization of a tetracarboxylic acid component and a diamine component and imidize it. The imidization may be carried out by chemical imidization, thermal imidization, or a combination of chemical imidization and thermal imidization.

The polyimide is not particularly limited as long as it satisfies the above-mentioned composite elastic modulus and has transparency, and for example, the structural unit represented by the following general formula (1) is 10 mol% or more and 100 mol% or less, and The structural unit represented by the following general formula (2) is contained in (100-x) mol% (where x is the molar% of the structural unit represented by the above general formula (1)), and the weight average molecular weight is 100. It is preferably 000 or more. The polyimide has a tetracarboxylic acid residue having a specific structure containing a parabiphenylene group having a dihedral angle twisted in the main chain via an ester bond, and a diamine residue having an aromatic ring or an aliphatic ring. Moreover, by having a specific weight average molecular weight, it is easy to improve the balance between the composite elastic coefficient and the bending resistance.

(In the general formulas (1) and (2), R ¹ to R ⁴ independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and at least one of R ¹ and R ² and R ³ are represented. And at least one of ^R4 represents an alkyl group having 1 to 6 carbon atoms; A represents a tetravalent group which is a tetracarboxylic acid residue having an aromatic ring or an aliphatic ring, and B represents an aromatic ring. Represents a divalent group that is a diamine residue having a family ring or an aliphatic ring.)

Here, the tetracarboxylic acid residue means a residue obtained by removing four carboxyl groups from the tetracarboxylic acid, and represents the same structure as the residue obtained by removing the acid dianhydride structure from the tetracarboxylic acid dianhydride. .. Further, the diamine residue means a residue obtained by removing two amino groups from diamine.

In the general formula (1), at least one of R ¹ and R ² and at least one of R ³ and R ⁴ represent an alkyl group having 1 to 6 carbon atoms. The alkyl group having 1 to 6 carbon atoms may be a linear or branched alkyl group, for example, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, or i-. Examples thereof include a butyl group, a t-butyl group, an n-pentyl group, and an n-hexyl group. From the viewpoint of solvent solubility, it is preferably an alkyl group having 1 to 4 carbon atoms, more preferably an alkyl group having 1 to 2 carbon atoms, and more preferably a methyl group. Further, among them, from the viewpoint of solvent solubility, it is preferable that R ¹ and R ² and R ³ and R ⁴ represent a methyl group.

In the general formula (1), B represents a divalent group which is a diamine residue having an aromatic ring or an aliphatic ring. The diamine residue having an aromatic ring or an aliphatic ring can be a residue obtained by removing two amino groups from a diamine having an aromatic ring or a diamine having an aliphatic ring.

Specific examples of the diamine having an aromatic ring and the diamine having an aliphatic ring include those described in JP-A-2019-132930 and JP-A-2019-1989. These can be used alone or in combination of two or more.

In the above general formula (2), A represents a tetravalent group which is a tetracarboxylic acid residue having an aromatic ring or an aliphatic ring, and B is a diamine residue having an aromatic ring or an aliphatic ring. Represents a divalent group. Since B in the general formula (2) may be the same as B in the general formula (1), the description thereof is omitted here. B in the general formula (1) and B in the general formula (2) may be the same or different from each other.

The tetracarboxylic acid residue in A of the general formula (2) is a residue obtained by removing the acid dianhydride structure from the tetracarboxylic acid dianhydride having an aromatic ring, or a tetracarboxylic acid dianhydride having an aliphatic ring. It can be a residue obtained by removing the acid dianhydride structure from the anhydride.

Specific examples of the tetracarboxylic dianhydride having an aromatic ring and the tetracarboxylic dianhydride having an aliphatic ring are described in, for example, JP-A-2019-132930 and JP-A-2019-1989. Can be mentioned. These can be used alone or in combination of two or more.

The polyimide preferably contains 10 mol% or more and 100 mol% or less of the structural unit represented by the general formula (1). From the viewpoint of solubility in a solvent, the polyimide more preferably contains 15 mol% or more, more preferably 25 mol% or more, and 50 mol% or more of the structural unit represented by the above general formula (1). Is particularly preferred.

On the other hand, from the viewpoint of improving the surface hardness and transparency, the polyimide may contain a copolymerization component, and the polyimide may contain 95 mol% or less of the structural unit represented by the general formula (1), 90 mol% or less. The following may be contained, and 80 mol% or less may be contained.

Further, the polyimide may contain (100-x) mol% of the structural unit represented by the general formula (2) (where x is the molar% of the structural unit represented by the general formula (1)). preferable. From the viewpoint of solubility in a solvent, the polyimide contains 85 mol% or less, more preferably 75 mol% or less, and 50 mol% or less of the structural unit represented by the above general formula (2). Is particularly preferred.

When the polyimide contains 100 mol% of the structural unit represented by the general formula (1), the structural unit represented by the general formula (2) is 0 mol%, that is, not contained. The structural unit represented by the above general formula (2) may be 0 mol%, but may be contained as a copolymerization component from the viewpoint of improving surface hardness and transparency, and polyimide is the above general. The structural unit represented by the formula (2) may be contained in an amount of 5 mol% or more, 10 mol% or more, or 20 mol% or more.

From the viewpoint of improving transparency and surface hardness, at least one of the tetravalent group which is a tetracarboxylic acid residue of A and the divalent group which is a diamine residue of B is aromatic. A group comprising a group ring and in which (i) a fluorine atom, (ii) an aliphatic ring, and (iii) an aromatic ring are linked to each other with a sulfonyl group or an alkylene group which may be substituted with fluorine. It is preferable to include at least one selected from. When the polyimide contains at least one selected from a tetracarboxylic acid residue having an aromatic ring and a diamine residue having an aromatic ring, the molecular skeleton becomes rigid, the orientation is enhanced, and the surface hardness is improved, but the polyimide is rigid. The aromatic ring skeleton tends to have an absorption wavelength extending to a long wavelength, and the transmittance in the visible light region tends to decrease.

On the other hand, when the polyimide contains (i) a fluorine atom, the transparency is improved in that the electronic state in the polyimide skeleton can be made difficult to transfer charge. Further, when the polyimide contains (ii) an aliphatic ring, transparency is improved in that the transfer of charges in the skeleton can be inhibited by breaking the conjugation of π electrons in the polyimide skeleton. Further, when the polyimide contains a structure in which (iii) aromatic rings are linked to each other with a sulfonyl group or an alkylene group which may be substituted with fluorine, the π-electron conjugation in the polyimide skeleton is cut off to charge the charge in the skeleton. Transparency is improved in that it can inhibit movement.

Among them, at least one of the tetravalent group which is the tetracarboxylic acid residue of A and the divalent group which is the diamine residue of B is from the viewpoint of improving the transparency and the surface hardness. , The aromatic ring and the fluorine atom are preferably contained, and the divalent group which is the diamine residue of B preferably contains the aromatic ring and the fluorine atom.

In the polyimide, the diamine residue having the aromatic ring or the aliphatic ring in B in the general formulas (1) and (2) is trans. -Cyclohexanediamine residue, polyimide-1,4-bismethylenecyclohexanediamine residue, 4,4'-diaminodiphenylsulfone residue, 3,4'-diaminodiphenylsulfone residue, 2,2-bis (4-amino) Phenyl) propane residue, 3,3'-bis (
Trifluoromethyl) -4,4'-[(1,1,1,3,3,3-hexafluoropropane-2,2-diyl) bis (4,1-phenyleneoxy)] dianiline residue, 2, 2-Bis [3- (3-aminophenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane residue, 2,2-bis [4- (4-aminophenoxy) phenyl]- Must be at least one divalent group selected from the group consisting of 1,1,1,3,3,3-hexafluoropropane residues and a divalent group represented by the following general formula (3). Is preferable.

In particular, from the viewpoint of achieving both transparency and surface hardness, 4,4'-diaminodiphenyl sulfone residue, 3,4'-diaminodiphenyl sulfone residue, 2,2-bis (4-aminophenyl) propane residue, And, it is preferable that it is at least one divalent group selected from the group consisting of the divalent group represented by the following general formula (3), and the divalent group represented by the following general formula (3). Is more preferable. As the divalent group represented by the following general formula ( ³ ), it is more preferable that R5 and R6 are perfluoroalkyl groups, and among them, a perfluoroalkyl group having ¹ or more and 3 or less carbon atoms is preferable. It is more preferably a trifluoromethyl group or a perfluoroethyl group. Further, as the alkyl group in R5 and R6 in the following general ^formula ( ³ ), an alkyl group having 1 or more carbon atoms and 3 or less carbon atoms is preferable, and a methyl group or an ethyl group is more preferable.

(In the general formula (3), R ⁵ and R ⁶ independently represent a hydrogen atom, an alkyl group, or a perfluoroalkyl group.)

In polyimide, the tetracarboxylic acid residue having an aromatic ring or an aliphatic ring in A in the above general formula (2) is cyclohexanetetracarboxylic, among others, from the viewpoint of transparency, bending resistance and surface hardness. Acid dianhydride residue, cyclopentanetetracarboxylic acid dianhydride residue, dicyclohexane-3,4,3', 4'-tetracarboxylic acid dianhydride residue, cyclobutanetetracarboxylic acid dianhydride residue, Pyromerutic acid dianhydride residue, 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride residue, 2,2', 3,3'-biphenyltetracarboxylic acid dianhydride residue, 2 , 3,3', 4'-biphenyltetracarboxylic acid dianhydride residue, 4,4'-(hexafluoroisopropylidene) diphthalic acid anhydride residue, 3,4'-(hexafluoroisopropyridene) diphthalic acid Consists of anhydride residues, 3,3'-(hexafluoroisopropylidene) diphthalic acid anhydride residues, 4,4'-oxydiphthalic acid anhydride residues, and 3,4'-oxydiphthalic acid anhydride residues. It is preferably a tetravalent group of at least one selected from the group.

In A in the above general formula (2), it is preferable to contain 50 mol% or more, more preferably 70 mol% or more, and further preferably 90 mol% or more of these suitable residues in total.

As A in the above general formula (2), pyromellitic acid dianhydride residue, 3,3', 4,4'-biphenyltetracarboxylic acid dianhydride residue, from the viewpoint of improving the surface hardness. And a group of tetracarboxylic acid residues suitable for improving rigidity, such as at least one selected from the group consisting of 2,2', 3,3'-biphenyltetracarboxylic acid dianhydride residues. It is preferable to include A). Further, as A in the above general formula (2), cyclohexanetetracarboxylic acid dianhydride residue, cyclopentanetetracarboxylic acid dianhydride residue, dicyclohexane-3,4 are used from the viewpoint of improving transparency. , 3', 4'-tetracarboxylic acid dianhydride residue, cyclobutane tetracarboxylic acid dianhydride residue, 2,3,3', 4'-biphenyltetracarboxylic acid dianhydride residue, 4,4' -(Hexafluoroisopropyridene) diphthalic acid anhydride residue, 3,4'-(hexafluoroisopropyridene) diphthalic acid anhydride residue, 3,3'-(hexafluoroisopropyridene) diphthalic acid anhydride residue, Tetracarboxylic acid residue suitable for improving transparency, such as at least one selected from the group consisting of 4,4'-oxydiphthalic acid anhydride residues and 3,4'-oxydiphthalic acid anhydride residues. It is preferable to include a group (Group B). Group A and Group B may be mixed and used.

When group A and group B are mixed, a tetracarboxylic acid residue group (group A) suitable for improving the rigidity and a tetracarboxylic acid residue group (group B) suitable for improving transparency are used. ) To 1 mol of the tetracarboxylic acid residue group (group B) suitable for improving transparency, the tetracarboxylic acid residue group (group) suitable for improving the rigidity. A) is preferably 0.05 mol or more and 9 mol or less, more preferably 0.1 mol or more and 5 mol or less, and further preferably 0.3 mol or more and 4 mol or less.

Among them, from the viewpoint of improving surface hardness and transparency, the above group B includes 4,4'-(hexafluoroisopropyridene) diphthalic acid anhydride residue and 3,4'-(hexa) containing a fluorine atom. Fluoroisopropylidene) It is preferable to use at least one of diphthalic acid anhydride residues.

The content ratio of each repeating unit in the polyimide and the content ratio (mol%) of each tetracarboxylic acid residue and each diamine residue can be obtained from the molecular weight of the charged material at the time of producing the polyimide. Further, the content ratio (mol%) of each tetracarboxylic acid residue and each diamine residue in the polyimide is determined by high performance liquid chromatography, gas chromatograph mass spectrometer, and NMR for the decomposition product of the polyimide obtained in the same manner as described above. , Elemental analysis, XPS / ESCA and TOF-SIMS.

From the viewpoint of good bending resistance, the polyimide preferably has a weight average molecular weight of 100,000 or more in terms of polystyrene in gel permeation chromatography. From the viewpoint of bending resistance, the weight average molecular weight may be 120,000 or more, 140,000 or more, or 160,000 or more. On the other hand, the weight average molecular weight is preferably 270,000 or less because bubble defects are unlikely to occur. Further, from the viewpoint of solubility, the weight average molecular weight may be 250,000 or less, 230,000 or less, or 210,000 or less.

The weight average molecular weight of polyimide can be measured by gel permeation chromatography (GPC). Specifically, polyimide is used as an N-methylpyrrolidone (NMP) solution having a concentration of 0.1% by mass, and a 30 mmol% LiBr-NMP solution having a water content of 500 ppm or less is used as a developing solvent. 8120, column used: GPC LF-804 manufactured by SHODEX), measurement is performed under the conditions of a sample injection amount of 50 μL, a solvent flow rate of 0.4 mL / min, and 37 ° C. The weight average molecular weight is determined based on a polystyrene standard sample having the same concentration as the sample.

(Ii) Polyamide-imide The polyamide-imide is not particularly limited as long as it satisfies the above-mentioned composite elastic modulus and has transparency, but is, for example, a polyimide structural unit including a structural unit represented by the following formula (4). , It is preferable to contain a polyamide structural unit including a structural unit represented by the following formula (5).

(In formula (5), X represents a divalent group which is a dicarboxylic acid residue having an aromatic ring.)

Sufficient transparency is provided by the polyamide-imide containing a polyimide structural unit containing the structural unit represented by the above formula (4) and a polyamide structural unit containing the structural unit represented by the above formula (5). It is possible to obtain a resin layer having a high composite elastic modulus and bending resistance. In the above-mentioned polyamideimide, a polyimide constituent unit having a tetracarboxylic acid residue having a specific structure and a specific diamine residue containing a parabiphenylene group whose two-sided angle is twisted via an ester bond in the main chain is further fragrant. It contains a dicarboxylic acid residue having a group ring and introduces a polyamide constituent unit that promotes intermolecular interaction by hydrogen bonding. By giving the main chain structure of the polymer a twist of the aromatic ring, it is possible to suppress the intermolecular energy transition that occurs in the π-conjugated polymer, and while achieving sufficient transparency, the amide bond site and the polyimide It is presumed that by introducing an ester bond site into the structural unit, the intermolecular force due to hydrogen bond formation can be enhanced, and a resin layer having a high composite elastic coefficient and bending resistance can be obtained.

Further, the above-mentioned polyamide-imide has good bending resistance even in a high humidity environment. In the above-mentioned polyamide-imide, the amide bond site and the ester bond site in the polyimide constituent unit form a hydrogen bond, so that hydrogen bond with water can be suppressed even in a high humidity environment, so that it can withstand a high humidity environment. It is presumed that the deterioration of the flexibility is suppressed and the bending resistance is improved.

Further, since the polyamide-imide contains the structural unit represented by the above formula (4), the solubility in a solvent is good even if the constitutional unit represented by the above formula (4) is contained.

(Polyimide constituent unit)
The polyimide structural unit is a structural unit obtained by reacting a tetracarboxylic acid component with a diamine component, and examples thereof include the structural unit represented by the general formula (2) described in the section of polyimide.

The structural units represented by the above formula (4) are tetracarboxylic dianhydride represented by the following formula (4-1) and 2,2-bis (trifluoromethyl) -4,4-diaminobiphenyl. Can be obtained by reacting.

The content ratio of the structural unit represented by the above formula (4) may be 100 mol% with respect to the total of the polyimide structural units in the polyamide-imide. Further, the polyimide structural unit may contain another polyimide structural unit different from the structural unit represented by the above formula (4). The content ratio of the structural unit represented by the above formula (4) is preferably 50 mol% or more, more preferably 60 mol% or more, still more preferably 70 mol, based on the total of the polyimide structural units in the polyamide-imide. % Or more, preferably 100 mol% or less, and may be 90 mol% or less. When the content ratio of the structural unit represented by the above formula (4) is within the above range, it is possible to have a high composite elastic modulus and bending resistance while having sufficient transparency. It contains other polyimide structural units that are different from the structural units represented by the above formula (4) in order to improve the balance between transparency, composite elastic modulus and bending resistance, and to add further characteristics. May be good.

The content ratio of the tetracarboxylic acid dianhydride residue represented by the above formula (4-1) to the total of the tetracarboxylic acid residues contained in the polyimide constituent unit in the polyamide-imide is preferably 50 mol%. The above is more preferably 60 mol% or more, still more preferably 70 mol% or more, preferably 100 mol% or less, and may be 90 mol% or less. When the content ratio of the tetracarboxylic dianhydride residue represented by the above formula (4-1) is in the above range, it is possible to have a high composite elastic modulus and bending resistance while having sufficient transparency. can. Others different from the tetracarboxylic dianhydride residue represented by the above formula (4-1) in order to improve the balance between transparency, composite elastic modulus and bending resistance, and to add further properties. It may contain a tetracarboxylic dianhydride residue.

As another polyimide structural unit that may be included in the polyimide structural unit, for example, among the structural units represented by the general formula (2), the structural unit represented by the above formula (4) is Different polyimide building blocks can be mentioned. In the structural unit represented by the general formula (2), A and B may be the same or different in each structural unit. That is, in the structural unit represented by the general formula (2), A and B may be independently contained in one type or two or more types.

In the structural unit represented by the general formula (2), A represents a tetravalent group which is a tetracarboxylic acid residue having an aromatic ring or an aliphatic ring. As A, for example, a tetravalent group represented by the following formulas (a1) to (a7), and a part or all of hydrogen atoms in the tetravalent group represented by these formulas are fluorogroups and methyl. Examples thereof include a tetravalent group substituted with one or more substituents selected from the group consisting of a group, a methoxy group, a trifluoromethyl group, or a trifluoromethoxy group.

(In equations (a1) to (a7), * represents a bond, Q ^a is a single bond, -O-, -S-, -CH _2- , -CH (CH ₃ )-, -C (CH). ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, -SO _2- , -Ph-, -Ph-Q ^a2 -Ph-, -Q ^a2 -Ph-Q ^a2- , -Q ^a2- Ph-Ph-Q ^{a2-, -Q a2-Ph-Q a2-Ph-Q a2-, or a fluorene group. Ph represents a phenylene group and Q a2 represents -O- , -S-} , -CH. _2- , -CH (CH ₃ )-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, or -SO _2- )

The bonding position of ^Qa to each ring may be independently set to the ortho position or the meta position with respect to one of the two carboxy groups bonded to each ring. The binding position of ^Qa2 to each ring is preferably the meta-position or the para-position with respect to the phenylene group, and more preferably the para-position.

In the structural unit represented by the general formula (2), as A, among the tetravalent groups represented by the above formulas (a1) to (a7), as in the above formulas (a1) to (a3). In the case of a structure containing an aromatic ring, tetravalent groups represented by the above formulas (a1) and (a2) are preferable from the viewpoint of imparting transparency and solubility in a solvent. Further, it is preferable to have a bendable structure between the aromatic rings, and the Q ^a in the above formula (a2) is -O-, -S-, -CH _2- , -CH (CH). ₃ )-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -SO _2- , -Q ^{a2-Ph-Q a2- (Q a2 is -O-} , -S-,- It is preferably CH _2- , -CH (CH ₃ )-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, or -SO _2- ). Furthermore, since the transparency is improved when the fluorine atom is contained, the Q ^a is -C (CF ₃ ) _2- , -Q ^a2 -Ph-Q ^a2- (Q ^a2 is -C (CF ₃ ). ) _2- ) is preferable, and -C (CF ₃ ) _2- ) is more preferable as ^Qa from the viewpoint of the composite elastic modulus.

Further, in the structural unit represented by the general formula (2), as A, among the tetravalent groups represented by the above formulas (a1) to (a7), the above formulas (a4) to (a7). As described above, when an aliphatic ring is contained, it is preferable because it has an aliphatic structure and is excellent in transparency and solubility. Among them, the tetravalent group represented by the structure (a4), (a5), or (a6) having few bending portions is preferable from the viewpoint of improving the composite elastic modulus, and among them, the tetravalent group represented by (a4) is preferable. Group is preferred.

In the structural unit represented by the general formula (2), B represents a divalent group which is a diamine residue having an aromatic ring or an aliphatic ring. As B, for example, a divalent group represented by the following formulas (b1) to (b6), and a part or all of hydrogen atoms in the divalent group represented by these formulas are fluorogroups and methyl. Examples thereof include a divalent group substituted with one or more substituents selected from the group consisting of a group, a methoxy group, a trifluoromethyl group, or a trifluoromethoxy group.

(In equations (b1) to (b6), * represents a bond, Q ^b is a single bond, -O-, -S-, -CH _2- , -CH (CH ₃ )-, -C (CH). ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, -SO _2- , -Ph-, -Ph-Q ^b2 -Ph-, -Q ^b2 -Ph-Q ^b2- , -Q ^b2- Ph-Ph-Q ^b2- , -Q ^b2 -Ph-Q ^b2- , or Ph-Q ^b2- , or a fluorene group. Ph represents a phenylene group and Q ^b2 represents -O-, -S-, -CH. _2- , -CH (CH ₃ )-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , -CO-, or -SO _2- )

The binding position of Q ^b to each ring is preferably the meta-position or the para-position, and more preferably the para-position, independently of the amino group bonded to each ring. The binding position of Q ^b2 to each ring is preferably the meta-position or the para-position with respect to the phenylene group, and more preferably the para-position.

In the structural unit represented by the general formula (2), B is a phenylene skeleton from the viewpoint of transparency and maintenance of composite elastic modulus among the divalent groups represented by the above formulas (b1) to (b6). It is preferable to have a molecular structure in which the π-conjugation between phenylene groups is cleaved, and it is more preferable to contain fluorine.

As a molecular structure in which the π-conjugation between phenylene groups is cleaved, in the divalent group represented by the above formula (b2), Q ^b is -O-, -S-, -CH _2- , -CH (CH). ₃ )-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , or -SO _2- , preferably -C (CF ₃ ) _2- or -SO _2- . Is preferable.

Further, in the structural unit represented by the general formula (2), B is selected from the group consisting of divalent groups represented by the general formula (3) from the viewpoint of transparency and maintenance of the composite elastic modulus. It is preferably a divalent group of at least one. As the divalent group represented by the above general ^formula ( ³ ), it is more preferable that R5 and R6 are a methyl group or a trifluoromethyl group from the viewpoint of transparency, and trifluoro from the viewpoint of transparency. It is even more preferable that it is a methyl group.

Further, the polyimide structural unit different from the structural unit represented by the above formula (4) may be a structural unit represented by the following formula (6).

(In formula (6), B'represents a divalent group which is a diamine residue having an aromatic ring or an aliphatic ring, and is a 2,2-bis (trifluoromethyl) -4,4-diaminobiphenyl residue. It is different from the group.)

In the above formula (6), B'represents a diamine residue having an aromatic ring or an aliphatic ring, which is different from the 2,2-bis (trifluoromethyl) -4,4-diaminobiphenyl residue, and is described above. It may be the same as B in the general formula (5).

When the polyimide constituent unit contains other polyimide constituent units, it may contain the constituent unit represented by the following formula (7), the constituent unit represented by the following formula (8), or a combination thereof. preferable. When the structural unit represented by the following formula (7), the structural unit represented by the following formula (8), or a combination thereof is contained, the transparency is improved and the solubility in a solvent is enhanced. preferable. Above all, when the constituent unit represented by the following formula (7) is contained, it is more preferable from the viewpoint of improving transparency while maintaining a high composite elastic modulus.

The structural unit represented by the above formula (7) can be obtained by reacting cyclobutanetetracarboxylic dianhydride with 2,2-bis (trifluoromethyl) -4,4-diaminobiphenyl. The structural unit represented by the above formula (8) is a reaction between 4,4'-(hexafluoroisopropylidene) diphthalic acid anhydride and 2,2-bis (trifluoromethyl) -4,4-diaminobiphenyl. Can be obtained.

The total content ratio of the other polyimide constituent units, which is different from the constituent units represented by the above formula (4), may be 0 mol% with respect to the total of the polyimide constituent units in the polyamide-imide, but is included. In the case, it is preferably 5 mol% or more, may be 10 mol% or more, preferably 50 mol% or less, still more preferably 40 mol% or less, still more preferably 30 mol% or less. When the total content ratio of the other polyimide constituent units is within the above range, high transparency can be imparted and the composite elastic modulus becomes good.

Above all, when the structural unit represented by the above formula (7), the structural unit represented by the above formula (8), or a combination thereof is contained, the above formula is relative to the total of the polyimide structural units in the polyamide-imide. The total content ratio of the structural unit represented by (7) and the structural unit represented by the above formula (8) is preferably 5 mol% or more, may be 10 mol% or more, and is preferably 50. It is mol% or less, more preferably 40 mol% or less, still more preferably 30 mol% or less. If the total content ratio of the structural unit represented by the above formula (7) and the structural unit represented by the above formula (8) is within the above range, high transparency can be imparted and the composite elastic modulus is good. Become.

(Polyamide constituent unit)
The polyamide structural unit is a structural unit obtained by reacting a dicarboxylic acid component and a diamine component, and examples thereof include a structural unit represented by the following general formula (9).

(In the general formula (9), X represents a divalent group which is a dicarboxylic acid residue having an aromatic ring, and B represents a divalent group which is a diamine residue having an aromatic ring or an aliphatic ring. show.)

Here, the dicarboxylic acid residue refers to a residue obtained by removing two carboxyl groups from a dicarboxylic acid, and represents the same structure as a residue obtained by removing two carboxyl group groups from a dicarboxylic acid chloride. Further, the diamine residue means a residue obtained by removing two amino groups from diamine.

The polyamide structural unit in the polyamide-imide contains the structural unit represented by the above formula (5) as an essential component. The structural unit represented by the above formula (5) includes one type or two or more types in the polyamide structural unit.

The structural unit represented by the above formula (5) can be obtained by reacting a dicarboxylic acid component having an aromatic ring with 2,2-bis (trifluoromethyl) -4,4-diaminobiphenyl. Examples of the dicarboxylic acid component include a dicarboxylic acid and a dicarboxylic acid chloride, and it is preferable to use a dicarboxylic acid chloride from the viewpoint of reactivity.

The structural unit represented by the above formula (5) is at least one in which X in the above formula (5) is selected from the group consisting of the structures represented by the following formulas (x1) to (x3). Is preferable. It is possible to obtain a resin layer having a high composite elastic modulus while having sufficient transparency. Further, not only the 1,4-phenylene group represented by the following formula (x1) but also a 1,3-phenylene group may be used.

(In equation (x3), L is -O-, -S-, -CH _2- , -CH (CH ₃ )-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , or. -CO-, * represents a bond.)

In X in the above formula (5), in the structures represented by the above formulas (x1) to (x3), the above formula (x1) or the above formula (x1) or the formula from the viewpoint of improving the high composite elastic modulus and the bending resistance. The structure represented by (x2) is more preferable, and the structure represented by the above formula (x2) is even more preferable.

The content ratio of the constituent units represented by the above formula (5) may be 100 mol% with respect to the total of the polyamide constituent units in the polyamide-imide. Further, the polyamide constituent unit may further contain another polyamide constituent unit different from the constituent unit represented by the above formula (5). The content ratio of the structural unit represented by the above formula (5) is preferably 80 mol% or more, more preferably 85 mol% or more, still more preferably 90 mol, with respect to the total of the polyamide constituent units in the polyamide-imide. % Or more, preferably 100 mol% or less, and may be 95 mol% or less. When the content ratio of the structural unit represented by the above formula (5) is within the above range, the balance between transparency and composite elastic modulus is good.

From the viewpoint of the balance between transparency and composite elastic modulus, X in the above formula (5) is the above formula (x1) to () with respect to the total of the structural units represented by the above formula (5) in the polyamide-imide. The total content of one or more selected from the group consisting of the structure represented by x3) may be 100 mol%, 80 mol% or more and 100 mol% or less, and further 90 mol% or more and 100 mol% or less. It is preferably 95 mol% or more and 100 mol% or less.

The polyamide structural unit may contain other polyamide structural units different from the structural unit represented by the above formula (5), for example, the structural unit represented by the general formula (9). Among them, a polyamide structural unit different from the structural unit represented by the above formula (5) can be mentioned. In the structural unit represented by the general formula (9), X and B may be the same or different in each structural unit. That is, in the structural unit represented by the general formula (9), X and B may be independently contained in one type or two or more types. In the general formula (9), X may be the same as X in the structural unit represented by the above formula (5), and B may be the same as B in the structural unit represented by the general formula (5). May be.

As another polyamide constituent unit, which may be contained in the polyamide constituent unit and is different from the constituent unit represented by the above formula (5), X is used in the above general formula (9) from the viewpoint of transparency. Is at least one selected from the group consisting of the structures represented by the above formulas (x1) to (x3), and B is a divalent group represented by the above formula (b2) in which Q ^b is , -O-, -S-, -CH _2- , -CH (CH ₃ )-, -C (CH ₃ ) _2- , -C (CF ₃ ) _2- , or -SO _2- , or In the divalent group represented by the above general formula (3), R ⁵ and R ⁶ are preferably hydrogen atoms or methyl groups, and in the divalent group represented by the above formula (b2), Q ^b . Is -C (CF ₃ ) _2- or -SO _2- , or in the divalent group represented by the above general formula (3), R ⁵ and R ⁶ are methyl groups. Preferably, in the divalent group represented by the above formula (b2), it is more preferable that Q ^b is −C (CF ₃ ) ₂ −.

(Polyamide-imide)
The content ratio of the polyamide structural unit including the structural unit represented by the above formula (5) is the polyimide structural unit including the structural unit represented by the above formula (4) and the structural unit represented by the above formula (5). It is preferably 10 mol% or more, further preferably 30 mol% or more, still more preferably 40 mol% or more, still more preferably 50 mol% or more, and preferably 50 mol% or more, based on the total of the polyamide constituent units contained therein. It is 80 mol% or less, more preferably 70 mol% or less, still more preferably 60 mol% or less. When the content ratio of the polyamide structural unit including the structural unit represented by the above formula (5) is within the above range, the composite elastic modulus of the resin layer and the bending resistance at room temperature can be easily improved, and the polyamide-imide solvent can be used. Solubility and bending resistance under high temperature and high humidity tend to be good.

The content ratio of the dicarboxylic acid residue X having an aromatic ring in the above formula (5) is preferably 10 mol% or more with respect to the total of the tetracarboxylic acid residue and the dicarboxylic acid residue in the polyamideimide resin. More preferably 30 mol% or more, further preferably 40 mol% or more, still more preferably 50 mol% or more, preferably 80 mol% or less, still more preferably 70 mol% or less, still more preferably 60. It is less than mol%. When the content ratio of the dicarboxylic acid residue X having an aromatic ring in the above formula (5) is within the above range, the composite elastic modulus of the resin layer and the bending resistance at room temperature can be easily improved, and the polyamide-imide can be easily improved. The solubility in a solvent and the bending resistance under high temperature and high humidity tend to be good.

Further, the polyamide-imide may have a structure different from the polyimide structural unit and the polyamide structural unit in a part thereof. In the polyamide-imide, the total of the polyimide structural unit including the structural unit represented by the above formula (4) and the polyamide structural unit including the structural unit represented by the above formula (5) is 95 of all the structural units of the polyamide-imide. % Or more, more preferably 98% or more, and even more preferably 100%.

The structure different from the polyimide structural unit and the polyamide structural unit includes, for example, a structural unit in which the tetracarboxylic acid component is not completely imidized and has a partially polyamic acid structure, and a tricarboxylic acid such as trimellitic acid anhydride. Examples thereof include polyamide-imide constituent units containing acid residues.

The content ratio (mol%) of ^each structural unit and each residue in the polyamide-imide can be measured by using 1H-NMR, and can also be obtained from the charging ratio of the raw materials at the time of producing the polyamide-imide. Further, the structure of polyamide-imide can be carried out by using NMR, various mass spectrometry and the like. Regarding the structure and content ratio of each residue in polyamide-imide, for example, polyamide-imide is decomposed with an alkaline aqueous solution or supercritical methanol, and the obtained decomposition product is subjected to high performance liquid chromatography or gas chromatograph mass spectrometer. , NMR, elemental analysis, XPS / ESCA and TOF-SIMS.

The weight average molecular weight of the polyamide-imide is preferably 50,000 or more, more preferably 100,000 or more, still more preferably 150,000 or more, preferably 1,000,000 or less, and more preferably. It is 500,000 or less, more preferably 300,000 or less. When the weight average molecular weight of the polyamide-imide resin is within the above range, appearance defects such as cracks and whitening are unlikely to occur after firing, it is easy to obtain a resin layer with good transparency, and it is high during synthesis, varnish preparation, and resin layer formation. Viscosity is suppressed and the resin layer is easily formed.

The method for measuring the weight average molecular weight of polyamide-imide can be the same as the method for measuring the weight average molecular weight of the above-mentioned polyimide.

(B) Additives The resin layer can further contain additives, if necessary. Additives include, for example, UV absorbers, light stabilizers, antioxidants, inorganic particles, silica fillers for smooth winding, surfactants to improve film formation and defoaming properties, and adhesion improvement. Agents and the like can be mentioned.

When the resin layer contains an ultraviolet absorber, deterioration of the resin layer due to ultraviolet rays can be suppressed. Above all, when the resin layer contains polyimide, it is possible to suppress the color change of the resin layer containing polyimide with time. Further, in a display device including a glass laminate, deterioration of members arranged on the display panel side of the glass laminate, such as a polarizing element, due to ultraviolet rays can be suppressed.

Examples of the ultraviolet absorber contained in the resin layer include a triazine-based ultraviolet absorber, a benzophenone-based ultraviolet absorber such as a hydroxybenzophenone-based ultraviolet absorber, and a benzotriazole-based ultraviolet absorber.

Specific examples of benzophenone-based ultraviolet absorbers such as triazine-based ultraviolet absorbers and hydroxybenzophenone-based ultraviolet absorbers, and benzotriazole-based ultraviolet absorbers include those described in JP-A-2019-132930, for example. can.

As the ultraviolet absorber, a triazine-based ultraviolet absorber, a hydroxybenzophenone-based ultraviolet absorber, and a benzotriazole-based ultraviolet absorber are preferably used.

Further, the ultraviolet absorber is preferably a polymer or an oligomer. This is because it is possible to suppress the bleed-out of the ultraviolet absorber when the glass laminate is repeatedly bent. Examples of such an ultraviolet absorber include a polymer or oligomer having a triazine skeleton, a benzophenone skeleton, or a benzotriazole skeleton, and specifically, a (meth) acrylate having a benzotriazole skeleton or a benzotriazole skeleton. It is preferably obtained by thermally copolymerizing methyl methacrylate (MMA) at an arbitrary ratio.

The content of the ultraviolet absorber in the resin layer is not particularly limited, but is preferably 1% by mass or more and 6% by mass or less, and more preferably 2% by mass or more and 5% by mass or less. If the content of the UV absorber is too small, the effect of the UV absorber may not be sufficiently obtained. Further, if the content of the ultraviolet absorber is too large, the resin layer may be remarkably colored or the strength of the resin layer may be lowered.

(4) Method for Forming Resin Layer As a method for forming the resin layer, for example, a method of applying a resin composition on a glass substrate can be mentioned. The coating method is not particularly limited as long as it can be coated with a desired thickness. For example, a gravure coating method, a gravure reverse coating method, a gravure offset coating method, a spin coating method, a roll coating method, a reverse roll coating method, etc. General coating methods such as a blade coating method, a dip coating method, and a screen printing method can be mentioned. Further, as a method for forming the resin layer, a transfer method in which the resin layer is transferred to one surface of the glass substrate or a method in which a film-shaped resin layer is bonded to one surface of the glass substrate via an adhesive layer is used. You can also do it.

The adhesive layer has transparency. Specifically, the total light transmittance of the adhesive layer is preferably 85% or more, more preferably 88% or more, and even more preferably 90% or more.

Examples of the adhesive used for the adhesive layer include a pressure-sensitive adhesive such as OCA (Optical Clear Adhesive) and a photosensitive adhesive.

The thickness of the adhesive layer is preferably 1 μm or more and 100 μm or less, for example. If the adhesive layer is too thick, the bending resistance may be impaired. On the other hand, if the thickness of the adhesive layer is too thin, the adhesiveness cannot be guaranteed and the adhesive layer may be peeled off.

Hereinafter, a case where the resin layer contains polyimide or polyamide-imide will be described as an example.

(I) Method for forming a resin layer containing polyimide As a method for forming a resin layer containing polyimide, for example, a method of applying a polyimide varnish containing polyimide and an organic solvent on a glass substrate and drying it, and a method of forming the resin layer. Examples thereof include a method in which a polyimide precursor composition containing a polyimide precursor (polyamic acid) and an organic solvent is applied onto a glass substrate, and then the polyimide precursor is imidized by heat treatment or chemical treatment. In the former method, the heating conditions of the film forming process can be relaxed. On the other hand, in the latter method, since the solubility of the polyimide is not restricted, the choice of the chemical structure of the polyimide can be increased.

Among them, the following manufacturing method is mentioned as a preferable manufacturing method from the viewpoint that bubble defects are less likely to occur and a resin layer having good thickness uniformity can be easily obtained.

The method for forming the resin layer containing polyimide is a polyimide varnish containing polyimide and an organic solvent, and the content ratio of the polyimide is 6% by mass or more and 15% by mass or less in the polyimide varnish, 25. A preparation step for preparing a polyimide varnish having a viscosity at ° C. of 1,000 cps or more and 50,000 cps or less, a coating step of applying the polyimide varnish on a glass substrate, and a first step of drying the coating film at a temperature of 140 ° C. or lower. It is preferable to have one drying step and a second drying step of heating the coating film after drying at a temperature of 200 ° C. or higher.

When the polyimide is well dissolved in the organic solvent, the heating conditions of the film forming process can be relaxed. Therefore, it is preferable to form the resin layer by using a polyimide varnish in which the polyimide is dissolved in the organic solvent. When the polyimide has a specific amount or more of a structural unit containing a tetracarboxylic acid residue having a specific structure including a parabiphenylene group having a dihedral angle twisted in the main chain via an ester bond, it is easily dissolved in an organic solvent. .. When the polyimide has a solvent solubility such that it dissolves in an organic solvent at 25 ° C. in an amount of 6% by mass or more, the method for forming the resin layer can be preferably used.

According to the above method for forming the resin layer, the polyimide content in the varnish can be increased to a sufficient concentration, and the varnish can be adjusted to a desired viscosity range, so that bubble defects are less likely to occur and the thickness is uniform. Can obtain a good resin layer.

The organic solvent is not particularly limited as long as the polyimide can be dissolved, and for example, an aprotic polar solvent, a water-soluble alcohol solvent, or the like can be used. Among them, it contains nitrogen atoms such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphoramide, and 1,3-dimethyl-2-imidazolidinone. Organic solvent; it is preferable to use γ-butyrolactone or the like. Further, the organic solvent can be used as one kind or a mixed solvent of two or more kinds.

For the method of forming the resin layer containing the polyimide, for example, the methods described in JP-A-2019-1989 and JP-A-2019-182974 can be referred to.

(Ii) Method for Forming Resin Layer Containing Polyamideimide The method for forming the resin layer containing polyamide-imide is not particularly limited, and for example, polyamide containing polyamide-imide and an organic solvent on a glass substrate. Examples thereof include a method of applying imide varnish and drying it.

The method for producing the polyamideimide is not particularly limited, but for example, the tetracarboxylic acid dianhydride represented by the above formula (4-1) and the tetracarboxylic acid dianhydride having an aromatic ring or an aliphatic ring as required. It has one or more tetracarboxylic acid dianhydrides including the product, 2,2-bis (trifluoromethyl) -4,4-diaminobiphenyl and, if necessary, an aromatic ring or an aliphatic ring. A step of obtaining a polyimide precursor (polyamic acid) by reacting with one or more kinds of diamines containing diamine, and the obtained polyimide precursor (polyamic acid) and a dicarboxylic acid having an aromatic ring. Through a step of obtaining a polyamide-polyimide precursor (polyamic acid) copolymer by reacting with an acid component and a step of imidizing the obtained polyamide-polyimide precursor (polyamic acid) copolymer. Can be manufactured.

The organic solvent contained in the polyamide-imide varnish can be the same as the organic solvent contained in the above-mentioned polyimide varnish.

The method for applying the polyamide-imide varnish is not particularly limited as long as it can be applied to a desired thickness. For example, a gravure coating method, a gravure reverse coating method, a gravure offset coating method, a spin coating method, a roll coating method, etc. General coating methods such as a reverse roll coating method, a blade coating method, a dip coating method, and a screen printing method can be mentioned. Further, a transfer method can also be used as a method for forming the coating film of the polyamide-imide varnish.

After applying the polyamide-imide varnish, for example, the solvent in the coating film is dried at a temperature of 150 ° C. or lower, preferably 30 ° C. or higher and 120 ° C. or lower, until the coating film becomes tack-free.

The drying time may be appropriately adjusted according to the thickness of the coating film, the type of solvent, the drying temperature, etc., and is preferably 5 minutes or more and 60 minutes or less, preferably 10 minutes or more and 40 minutes or less. If the drying time is too long, the efficiency of forming the resin layer may decrease. On the other hand, if the drying time is too short, the appearance of the obtained resin layer may be affected by the rapid drying of the solvent.

The method for drying the solvent is not particularly limited as long as the solvent can be dried at the above temperature, and for example, an oven, a drying oven, a hot plate, infrared heating, or the like can be used.

The drying step may include a first drying step of drying the coating film and a second drying step of heating the coating film at a high temperature after drying. The heating temperature in the second drying step is preferably, for example, 150 ° C. or higher. From the viewpoint of bending resistance, it is preferable to remove the residual solvent in the resin layer as much as possible.

3. 3. Second Resin Layer The glass laminate in the present disclosure may further have a second resin layer that covers the side surface of the glass substrate. For example, in FIGS. 8 and 9, the second resin layer 13 is arranged on the side surface 1C of the glass substrate 1.

In the glass laminate in the present disclosure, the strength of the side surface of the glass substrate can be increased by covering the side surface of the glass substrate with the second resin layer. Further, when the second resin layer is directly arranged on the side surface of the glass base material, the microcracks on the side surface of the glass base material can be filled by the second resin layer, and the side surface of the glass base material can be filled. The strength of the glass can be increased. Therefore, when the glass laminate is bent, cracking from the side surface of the glass base material can be suppressed, and the bending resistance can be further improved. Furthermore, the impact resistance at the end of the glass substrate can be enhanced.

The second resin layer preferably has shock absorption. Specifically, the composite elastic modulus of the second resin layer can be the same as the composite elastic modulus of the resin layer.

The method for measuring the composite elastic modulus of the second resin layer can be the same as the composite elastic modulus of the resin layer.

The thickness of the second resin layer is not particularly limited as long as it can obtain flexibility and shock absorption, and is preferably 1 μm or more and 200 μm or less, preferably 10 μm or more and 100 μm. The following is more preferable. When the thickness of the second resin layer is within the above range, cracking of the glass base material can be suppressed when the glass laminate is bent, and bending resistance can be improved. Furthermore, the impact resistance at the end of the glass substrate can be improved.

Further, for example, as shown in FIG. 10, when the thickness of the resin layer 11 is T1 and the thickness of the second resin layer 13 is T2, the ratio of T1 to T2 (T1 / T2) is, for example, 0. It is preferably 0.01 or more and 5.0 or less, more preferably 0.1 or more and 4.0 or less, and further preferably 0.5 or more and 3.5 or less. When the thickness ratio is within the above range, cracking of the glass base material can be suppressed when the glass laminate is bent, and bending resistance can be improved. Furthermore, the impact resistance at the end of the glass substrate can be improved.

Here, the thickness of the second resin layer is a cross section in the thickness direction of the glass laminate observed by a transmission electron microscope (TEM), a scanning electron microscope (SEM), or a scanning transmission electron microscope (STEM). It can be the average value of the thickness of any 10 points obtained by measuring from.

The degree of coverage of the side surface of the glass substrate by the second resin layer is particularly high as long as it is possible to increase the strength of the side surface of the glass substrate by coating the side surface of the glass substrate with the second resin layer. Not limited. For example, the entire side surface of the glass substrate may be coated with the second resin layer, or a part of the side surface of the glass substrate may be coated with the second resin layer.

The arrangement of the second resin layer is not particularly limited as long as the second resin layer covers the side surface of the glass base material. For example, the shape of the glass base material is rectangular parallelepiped and hexahedral. In some cases, at least one of the four sides of the glass substrate may be coated with the second resin layer. That is, in this case, of the four side surfaces of the glass substrate, one side surface may be coated with the second resin layer, or the two side surfaces may be coated with the second resin layer. One side surface may be coated with the second resin layer, or the four side surfaces may be coated with the second resin layer. Above all, it is preferable that all four sides of the glass substrate are covered with the second resin layer. When the glass laminate is bent, cracking of the glass base material can be suppressed and bending resistance can be improved. Furthermore, the impact resistance at the end of the glass substrate can be improved.

The second resin layer is not particularly limited as long as it covers the side surface of the glass base material, and may be integrally with another layer of the glass laminate, and is separate from the other layers. It may be a layer of.

The fact that the second resin layer is integrated with the other layer means that the second resin layer and the other layer are continuously formed as one layer.

When the second resin layer is integrated with another layer, examples of the other layer include a functional layer described later. For example, as shown in FIG. 11, when a functional layer such as a hard coat layer 14 is arranged on the surface side of the resin layer 11 (surface side resin layer) opposite to the glass base material 1, the second resin layer 13 May be integrated with a functional layer such as the hard coat layer 14.

The material of the second resin layer can be the same as the material used for the resin layer. Further, as the material of the second resin layer, the material used for the functional layer described later can also be used. When the second resin layer is integrated with the functional layer, the second resin layer contains the same material as the functional layer.

The method for forming the second resin layer is appropriately selected depending on the form of the second resin layer and the like.

For example, when the second resin layer is not integral with the other layer, the method for forming the second resin layer is not particularly limited as long as it can cover the side surface of the glass substrate, and the glass base is not particularly limited. A method of applying the resin composition to the side surface of the material can be mentioned. The coating method is not particularly limited as long as it can be applied to the side surface of the glass substrate with a desired thickness, and examples thereof include a spray coating method, a dip coating method, and a method using a dispenser.

On the other hand, for example, when the second resin layer is integrated with the functional layer, the second resin layer is formed at the same time as the formation of the functional layer. Examples of the method for forming the functional layer and the second resin layer include a method of applying the resin composition to one main surface and side surface of the glass substrate. Examples of the coating method include a spin coating method, a die coating method, a spray coating method, a dip coating method and the like. Further, in this case, as a method for forming the functional layer and the second resin layer, a transfer method for transferring the functional layer and the second resin layer to one main surface and side surface of the glass substrate, or one of the glass substrates. It is also possible to use a method of adhering a resin film to the main surface and the side surface via an adhesive layer. The specific method can be the same as the method for forming the functional layer described later.

4. Functional layer The glass laminate in the present disclosure may further have a functional layer on the surface side of the surface side resin layer opposite to the glass substrate.

Examples of the functional layer include a hard coat layer, a protective layer, an antireflection layer, an antiglare layer and the like.

Further, the functional layer may be a single layer or may have a plurality of layers. Further, the functional layer may be a layer having a single function, or may have a plurality of layers having different functions from each other. For example, the glass laminate in the present disclosure may have a hard coat layer and a protective layer as functional layers in order from the resin layer side.

(1) Hard Coat Layer As shown in FIG. 12, for example, the glass laminate in the present disclosure further has a hard coat layer 14 on the surface side of the resin layer 11 (surface side resin layer) opposite to the glass base material 1. be able to.
The hard coat layer is a member for increasing the surface hardness. By arranging the hard coat layer, scratch resistance can be improved.

(A) Characteristics of hard coat layer Here, the "hard coat layer" is a member for increasing the surface hardness, and specifically, in the configuration in which the glass laminate in the present disclosure has a hard coat layer, JIS When the pencil hardness test specified in K 5600-5-4 (1999) is performed, it means a hardness of "H" or higher.

When the glass laminate in the present disclosure has a hard coat layer on the surface side opposite to the glass substrate of the surface side resin layer, the pencil hardness of the surface of the glass laminate on the hard coat layer side is H or more. Is preferable, 2H or more is more preferable, and 3H or more is further preferable.

Here, the pencil hardness is measured by the pencil hardness test specified in JIS K5600-5-4 (1999). Specifically, using a test pencil specified by JIS-S-6006, a pencil hardness test specified by JIS K5600-5-4 (1999) was performed on the surface of the glass laminate on the hard coat layer side to scratch the surface. It can be done by evaluating the highest pencil hardness that does not have a mark. The measurement conditions can be an angle of 45 °, a load of 750 g, a speed of 0.5 mm / sec or more and 1 mm / sec or less, and a temperature of 23 ± 2 ° C. As the pencil hardness tester, for example, a pencil scratch coating film hardness tester manufactured by Toyo Seiki Co., Ltd. can be used.

(B) Structure of Hard Court Layer The hard coat layer may be a single layer or may have a multi-layer structure of two or more layers. When the hard coat layer has a multi-layer structure, in order to improve the surface hardness and to have a good balance between bending resistance and elastic modulus, the hard coat layer includes a layer for satisfying the pencil hardness and the above-mentioned layer for satisfying the pencil hardness. It is preferable to have a layer for satisfying the bending resistance (a layer for satisfying the scratch resistance) when the U-shaped bending test is repeatedly performed.

(C) Material of hard coat layer As the material of the hard coat layer, for example, an organic material, an inorganic material, an organic-inorganic composite material, or the like can be used.

Above all, the material of the hard coat layer is preferably an organic material. Specifically, the hard coat layer preferably contains a cured product of a resin composition containing a polymerizable compound. The cured product of the resin composition containing the polymerizable compound can be obtained by subjecting the polymerizable compound to a polymerization reaction by a known method using a polymerization initiator, if necessary.

(I) Polymerizable compound A polymerizable compound has at least one polymerizable functional group in the molecule. As the polymerizable compound, for example, at least one of a radically polymerizable compound and a cationically polymerizable compound can be used.

The radically polymerizable compound is a compound having a radically polymerizable group. The radically polymerizable group contained in the radically polymerizable compound may be any functional group capable of causing a radical polymerization reaction, and is not particularly limited, and examples thereof include a group containing a carbon-carbon unsaturated double bond. Examples thereof include a vinyl group and a (meth) acryloyl group. When the radically polymerizable compound has two or more radically polymerizable groups, these radically polymerizable groups may be the same or different from each other.

The number of radically polymerizable groups contained in one molecule of the radically polymerizable compound is preferably two or more, and more preferably three or more, from the viewpoint of improving the hardness of the hard coat layer.

As the radically polymerizable compound, a compound having a (meth) acryloyl group is preferable from the viewpoint of high reactivity, and for example, urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, and melamine ( Polyfunctional (meth) acrylate monomer having several (meth) acryloyl groups in a molecule called meth) acrylate, polyfluoroalkyl (meth) acrylate, silicone (meth) acrylate, etc. and having a molecular weight of hundreds to thousands. And oligomers can be preferably used, and polyfunctional (meth) acrylate polymers having two or more (meth) acryloyl groups in the side chains of the acrylate polymer can also be preferably used. Among them, a polyfunctional (meth) acrylate monomer having two or more (meth) acryloyl groups in one molecule can be preferably used. By including the cured product of the polyfunctional (meth) acrylate monomer in the hard coat layer, the hardness of the hard coat layer can be improved, and the adhesion can be further improved. Further, a polyfunctional (meth) acrylate oligomer or polymer having two or more (meth) acryloyl groups in one molecule can also be preferably used. By including the cured product of the polyfunctional (meth) acrylate oligomer or the polymer in the hard coat layer, the hardness and bending resistance of the hard coat layer can be improved, and the adhesion can be further improved.

In addition, in this specification, (meth) acryloyl represents each of acryloyl and methacryloyl, and (meth) acrylate represents each of acrylate and methacrylate.

Specific examples of the polyfunctional (meth) acrylate monomer include those described in JP-A-2019-132930. Among them, those having 3 or more and 6 or less (meth) acryloyl groups in one molecule are preferable from the viewpoint of high reactivity, improvement of the hardness of the hard coat layer, and adhesion, for example, pentaerythritol. Triacrylate (PETA), Dipentaerythritol Hexaacrylate (DPHA), Pentaerythritol Tetraacrylate (PETTA), Dipentaerythritol Pentaacrylate (DPPA), Trimethylol Propantri (meth) Acrylate, Trypentaerythritol Octa (Meta) Acrylate, Tetrapentaerythritol deca (meth) acrylates and the like can be preferably used, and in particular, pentaerythritol tri (meth) acrylates, dipentaerythritol penta (meth) acrylates, and dipentaerythritol hexaacrylates, which are PO, EO, or At least one selected from those modified with caprolactone is preferable.

The resin composition may contain a monofunctional (meth) acrylate monomer as a radically polymerizable compound in order to adjust hardness, viscosity, improve adhesion and the like. Specific examples of the monofunctional (meth) acrylate monomer include those described in JP-A-2019-132930.

The cationically polymerizable compound is a compound having a cationically polymerizable group. The cationically polymerizable group contained in the cationically polymerizable compound may be any functional group capable of causing a cationic polymerization reaction, and is not particularly limited, and examples thereof include an epoxy group, an oxetanyl group, and a vinyl ether group. When the cationically polymerizable compound has two or more cationically polymerizable groups, these cationically polymerizable groups may be the same or different from each other.

The number of cationically polymerizable groups contained in one molecule of the cationically polymerizable compound is preferably two or more, and more preferably three or more, from the viewpoint of improving the hardness of the hard coat layer.

Further, as the cationically polymerizable compound, a compound having at least one of an epoxy group and an oxetanyl group as a cationically polymerizable group is preferable, and a compound having at least one of an epoxy group and an oxetanyl group in one molecule is preferable. Is more preferable. A cyclic ether group such as an epoxy group or an oxetanyl group is preferable because the shrinkage associated with the polymerization reaction is small. Further, among the cyclic ether groups, compounds having an epoxy group are easily available, compounds having various structures are easily available, the durability of the obtained hard coat layer is not adversely affected, and compatibility with radically polymerizable compounds is easily controlled. There is an advantage. Further, among the cyclic ether groups, the oxetanyl group has a higher degree of polymerization than the epoxy group and has low toxicity, and when the obtained hard coat layer is combined with a compound having an epoxy group, it is contained in the coating film. There are advantages such as increasing the network formation rate obtained from the cationically polymerizable compound and forming an independent network without leaving an unreacted monomer in the film even in a region mixed with the radically polymerizable compound.

Examples of the cationically polymerizable compound having an epoxy group include polyglycidyl ether of a polyhydric alcohol having an alicyclic ring, or a cyclohexene ring or cyclopentene ring-containing compound with an appropriate oxidizing agent such as hydrogen peroxide or peracid. Alicyclic epoxy resin obtained by epoxidation; polyglycidyl ether of aliphatic polyhydric alcohol or its alkylene oxide adduct, polyglycidyl ester of aliphatic long chain polybasic acid, homopolymer of glycidyl (meth) acrylate, An aliphatic epoxy resin such as a copolymer; a glycidyl ether produced by reacting bisphenols such as bisphenol A, bisphenol F and hydrogenated bisphenol A, or derivatives such as alkylene oxide adducts and caprolactone adducts thereof with epichlorohydrin. And novolak epoxy resin and the like, and examples thereof include glycidyl ether type epoxy resin derived from bisphenols.

Specific examples of the alicyclic epoxy resin, the glycidyl ether type epoxy resin, and the cationically polymerizable compound having an oxetanyl group can be mentioned, for example, those described in JP-A-2018-104682.

The cured product of the resin composition containing the polymerizable compound contained in the hard coat layer includes a Fourier transform infrared spectrophotometer (FTIR), a thermal decomposition gas chromatograph device (GC-MS), and a decomposition product of the polymer. , High-speed liquid chromatography, gas chromatograph mass spectrometer, NMR, elemental analysis, XPS / ESCA, TOF-SIMS and the like can be used for analysis.

(Ii) Polymerization Initiator The resin composition may contain a polymerization initiator, if necessary. As the polymerization initiator, a radical polymerization initiator, a cationic polymerization initiator, a radical, a cationic polymerization initiator and the like can be appropriately selected and used. These polymerization initiators are decomposed by at least one of light irradiation and heating to generate radicals or cations to promote radical polymerization and cation polymerization. In some cases, the polymerization initiator is completely decomposed and does not remain in the hard coat layer.

Specific examples of the radical polymerization initiator and the cationic polymerization initiator include those described in JP-A-2018-104682.

(Iii) Particles The hard coat layer preferably contains inorganic or organic particles, and more preferably contains inorganic fine particles. The hardness can be improved by containing the particles in the hard coat layer.

Examples of the inorganic particles include metal oxides such as silica (SiO ₂ ), aluminum oxide, zirconia, titania, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, and cerium oxide. Examples thereof include particles, metal fluoride particles such as magnesium fluoride and sodium fluoride, metal particles, metal sulfide particles, and metal nitride particles. Among them, metal oxide particles are preferable, at least one selected from silica particles and aluminum oxide particles is more preferable, and silica particles are even more preferable. This is because excellent hardness can be obtained.

Further, the inorganic particles have at least a reactive functional group having a photoreactivity capable of forming a covalent bond by cross-linking the inorganic particles with each other or with at least one of the polymerizable compounds on the surface of the inorganic particles. It is preferable that it is a reactive inorganic particle contained in a part of the above. The hardness of the hard coat layer can be further improved by performing a cross-linking reaction between the reactive inorganic particles or between the reactive inorganic particles and at least one of the radically polymerizable compound and the cationically polymerizable compound.

The reactive inorganic particles are coated with an organic component at least a part of the surface thereof, and have a reactive functional group introduced by the organic component on the surface. As the reactive functional group, for example, a polymerizable unsaturated group is preferably used, and more preferably a photocurable unsaturated group. Examples of the reactive functional group include an ethylenically unsaturated bond such as a (meth) acryloyl group, a vinyl group and an allyl group, and an epoxy group.

The reactive silica particles are not particularly limited, and conventionally known particles can be used. Examples thereof include the reactive silica particles described in JP-A-2008-165040. Examples of commercially available products of the reactive silica particles include those manufactured by Nissan Chemical Industries, Ltd .; MIBK-SD, MIBK-SDMS, MIBK-SDL, MIBK-SDZL, and JGC Catalysts and Chemicals Co., Ltd .; V8802, V8803 and the like.

Further, the silica particles may be spherical silica particles, but are preferably atypical silica particles. Spherical silica particles and atypical silica particles may be mixed. In the present specification, the atypical silica particles mean silica particles having a potato-like random unevenness on the surface. Since the surface area of the atypical silica particles is larger than that of the spherical silica particles, the inclusion of such atypical silica particles increases the contact area with the resin component and the like, and makes the hardness of the hard coat layer more excellent. Can be.

Whether or not the particles are atypical silica particles can be confirmed by observing the cross section of the hardcourt layer with an electron microscope.

The average particle size of the inorganic particles is preferably 5 nm or more, more preferably 10 nm or more, from the viewpoint of improving hardness. If the average particle size of the inorganic particles is too small, it is difficult to produce the particles, and the particles may easily aggregate with each other. Further, the average particle size of the inorganic particles is preferably 200 nm or less, more preferably 100 nm or less, and further preferably 50 nm or less from the viewpoint of transparency. If the average particle size of the inorganic particles is too large, large irregularities may be formed on the hard coat layer and haze may increase.

Here, the average particle size of the inorganic particles can be measured by observing the cross section of the hard coat layer with an electron microscope, and the average particle size of 10 arbitrarily selected particles is taken as the average particle size. The average particle size of the atypical silica particles is the average value of the maximum value (major axis) and the minimum value (minor axis) of the distance between two points on the outer periphery of the atypical silica particles that appeared by observing the cross section of the hard coat layer with a microscope. be.

The hardness of the hardcourt layer can be controlled by adjusting the size and content of the inorganic particles. For example, the content of the silica particles is preferably 25 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the polymerizable compound.

(Iv) Ultraviolet absorber The hard coat layer may contain an ultraviolet absorber. Deterioration of the resin layer due to ultraviolet rays can be suppressed. Above all, when the resin layer contains polyimide, it is possible to suppress the color change of the resin layer containing polyimide with time. Further, in a display device including a glass laminate, deterioration of members arranged on the display panel side of the glass laminate, such as a polarizing element, due to ultraviolet rays can be suppressed.

The ultraviolet absorber contained in the hard coat layer preferably has a peak absorption wavelength of 300 nm or more and 390 nm or less, more preferably 320 nm or more and 370 nm or less, and more preferably 330 nm or more and 370 nm or less. More preferred. Such an ultraviolet absorber can efficiently absorb ultraviolet rays in the UVA region, while inhibiting the curing of the hard coat layer by shifting the absorption wavelength of the initiator for curing the hard coat layer to 250 nm and the peak wavelength. This is because a hard coat layer having an ultraviolet absorbing ability can be formed without causing the above.

Among the ultraviolet absorbers, it is preferable that the peak of the absorption wavelength is 380 nm or less because coloring by the ultraviolet absorber can be suppressed.
The absorbance of the ultraviolet absorber can be measured using, for example, an ultraviolet-visible near-infrared spectrophotometer (for example, JASCO Corporation V-7100).

The ultraviolet absorber may be the same as the ultraviolet absorber used for the resin layer.
Above all, from the viewpoint of suppressing deterioration of the resin layer by ultraviolet rays, one or more ultraviolet absorbers selected from the group consisting of hydroxybenzophenone-based ultraviolet absorbers and benzotriazole-based ultraviolet absorbers are preferable, and hydroxybenzophenone-based ultraviolet rays are preferable. More preferably, one or more UV absorbers selected from the group consisting of absorbers.

Specific examples of the hydroxybenzophenone-based ultraviolet absorber include those described in JP-A-2019-132930.
As the hydroxybenzophenone-based ultraviolet absorber, a 2-hydroxybenzophenone-based ultraviolet absorber is preferable, and one or more selected from the group consisting of benzophenone-based ultraviolet absorbers having the following general formula (A) is more preferable. preferable. It is possible to suppress deterioration of the resin layer due to ultraviolet rays and improve durability.

(In the general formula (A), X ¹ and X ² independently represent a hydroxyl group, −OR ^a , or a hydrocarbon group having 1 to 15 carbon atoms, and Ra is ^a hydrocarbon having 1 to 15 carbon atoms. Represents a group.)

In the general formula ( ^A ), the hydrocarbon groups having 1 to 15 carbon atoms in X ¹ , X ² and Ra are methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group and octyl. Examples thereof include a group, a dodecyl group, an allyl group, a benzyl group and the like. Each of the aliphatic hydrocarbon groups having 3 or more carbon atoms may be linear or branched. The hydrocarbon group preferably has 1 to 12 carbon atoms, and more preferably 1 to 8 carbon atoms. The hydrocarbon group is preferably an aliphatic hydrocarbon group, and more preferably a methyl group or an allyl group, from the viewpoint of easily improving transparency.
From the viewpoint of easily improving durability, it is preferable that X ¹ and X ² are independently hydroxyl groups or −OR ^a .

Among the ones or more selected from the group consisting of benzophenone-based ultraviolet absorbers having the general formula (A), 2,2', 4,4'-tetrahydroxybenzophenone, 2,2'-dihydroxy-4, It is preferably at least one selected from the group consisting of 4'-dimethoxybenzophenone and 2,2'-dihydroxy-4,4'-diallyloxybenzophenone, preferably 2,2', 4,4'-tetrahydroxy. More preferably, it is at least one selected from the group consisting of benzophenone and 2,2'-dihydroxy-4,4'-dimethoxybenzophenone.
Specific examples of the benzotriazole-based ultraviolet absorber include those described in JP-A-2019-132930.

As the benzotriazole-based ultraviolet absorber, 2- (2-hydroxyphenyl) benzotriazoles are preferable, and one or more selected from the group consisting of benzotriazole-based ultraviolet absorbers having the following general formula (B). It is more preferable to have. It is possible to suppress deterioration of the resin layer due to ultraviolet rays and improve durability.

(In the general formula (B), Y ¹ , Y ² and Y ³ independently represent a hydrogen atom, a hydroxyl group, −OR ^b , or a hydrocarbon group having 1 to 15 carbon atoms, and R ^b is a carbon atom. Represents a hydrocarbon group of number 1 to 15, where at least one of Y ¹ , Y ² and Y ³ represents a hydroxyl group, —OR ^b , or a hydrocarbon group having ¹ to 15 carbon atoms. Represents a hydrogen atom or a halogen atom.)

In the general formula (B), the hydrocarbon groups having 1 to 15 carbon atoms in Y ¹ , Y ² , Y ³ and R ^b are methyl group, ethyl group, propyl group, butyl group, pentyl group and hexyl group. , Heptyl group, octyl group, dodecyl group and the like. Each of the aliphatic hydrocarbon groups having 3 or more carbon atoms may be linear or branched. The hydrocarbon group preferably has 1 to 12 carbon atoms, and more preferably 1 to 8 carbon atoms. The hydrocarbon group is preferably an aliphatic hydrocarbon group, preferably a linear or branched alkyl group, and above all, a methyl group, a t-butyl group, or t-, from the viewpoint of easily improving transparency. It is preferably a pentyl group, an n-octyl group, or a t-octyl group.

^In the general formula (B), examples of the halogen atom in Y4 include a chlorine atom, a fluorine atom, a bromine atom and the like, and a chlorine atom is preferable.

In the general formula (B), it is preferable that Y ¹ and Y ³ are hydrogen atoms and Y ² is a hydroxyl group or −OR ^b , and 2- (2-hydroxy-4-octyloxyphenyl) -2H. More preferably, it is one or more selected from the group consisting of -benzotriazole and 2- (2,4-dihydroxyphenyl) -2H-benzotriazole. It is possible to suppress deterioration of the resin layer due to ultraviolet rays and improve durability.

The content of the ultraviolet absorber in the hard coat layer is preferably, for example, 10% by mass or less, and more preferably 7% by mass or less, from the viewpoint of suppressing haze caused by mixing the ultraviolet absorber. preferable. Further, from the viewpoint of suppressing deterioration of the resin layer due to ultraviolet rays and improving durability, the content of the ultraviolet absorber in the hard coat layer is preferably 1% by mass or more and 6% by mass or less, preferably 2% by mass. It is more preferably 5% by mass or less.

(V) Antifouling agent The hardcoat layer may contain an antifouling agent. Antifouling property can be imparted to the glass laminate.

The antifouling agent is not particularly limited, and examples thereof include a silicone-based antifouling agent, a fluorine-based antifouling agent, and a silicone-based and fluorine-based antifouling agent. Further, the antifouling agent may be an acrylic antifouling agent. As the antifouling agent, one type may be used alone, or two or more types may be mixed and used.

The hard coat layer containing a silicone-based antifouling agent or a fluorine-based antifouling agent is hard to get fingerprints (not noticeable) and has good wiping property. Further, when a silicone-based antifouling agent or a fluorine-based antifouling agent is contained, the surface tension at the time of applying the curable resin composition for the hard coat layer can be lowered, so that the leveling property is good and the obtained hard coat layer can be obtained. The appearance of is good.

Further, the hard coat layer containing a silicone-based antifouling agent has good slipperiness and scratch resistance. In a display device provided with a glass laminate having a hard coat layer containing such a silicone-based antifouling agent, the slipperiness when contacted with a finger, a pen, or the like is improved, so that the tactile sensation is improved.

The antifouling agent preferably has a reactive functional group in order to enhance the durability of the antifouling performance. When the antifouling agent does not have a reactive functional group, the glass laminate is hard when the glass laminate is laminated, regardless of whether the glass laminate is in the form of a roll or a sheet. When the antifouling agent is transferred to the surface opposite to the surface on the coat layer side and another layer is attached or applied to the surface opposite to the surface on the hard coat layer side of the glass laminate, the other Layer may be peeled off, and further, other layers may be easily peeled off when repeatedly bent. On the other hand, when the antifouling agent has a reactive functional group, the performance sustainability of the antifouling performance becomes good.

The number of reactive functional groups contained in the antifouling agent may be 1 or more, preferably 2 or more. By using an antifouling agent having two or more reactive functional groups, excellent scratch resistance can be imparted to the hardcoat layer.

Further, the antifouling agent preferably has a weight average molecular weight of 5000 or less. The weight average molecular weight of the antifouling agent can be measured by gel permeation chromatography (GPC).

The antifouling agent may be uniformly dispersed in the hardcoat layer, but from the viewpoint of obtaining sufficient antifouling property with a small amount of addition and suppressing a decrease in the strength of the hardcoat layer, the antifouling agent is placed on the surface side of the hardcoat layer. It is preferable that they are unevenly distributed.

As a method of unevenly distributing the antifouling agent on the surface side of the hard coat layer, for example, at the time of forming the hard coat layer, the coating film of the curable resin composition for the hard coat layer is dried and before being cured. By heating to reduce the viscosity of the resin component contained in the coating film to increase the fluidity, the antifouling agent is unevenly distributed on the surface side of the hard coat layer, or an antifouling agent with low surface tension is used. Examples thereof include a method in which the antifouling agent is floated on the surface of the coating film without applying heat when the coating film is dried, and then the coating film is cured so that the antifouling agent is unevenly distributed on the surface side of the hard coat layer.

The content of the antifouling agent is preferably 0.01 parts by mass or more and 3.0 parts by mass or less with respect to 100 parts by mass of the resin component. If the content of the antifouling agent is too small, it may not be possible to impart sufficient antifouling property to the hardcoat layer, and if the content of the antifouling agent is too large, the hardness of the hardcoat layer may decrease. be.

(Vi) Other Additives The hardcourt layer may further contain additives, if desired. The additive is appropriately selected depending on the function to be imparted to the hard coat layer, and is not particularly limited. For example, an inorganic or organic particle for adjusting the refractive index, an infrared absorber, an antiglare agent, or an antifouling agent. , Antistatic agents, colorants such as blue pigments and purple pigments, leveling agents, surfactants, lubricants, various sensitizers, flame retardant agents, adhesive additives, polymerization inhibitors, antioxidants, light stabilizers, Examples include surface modifiers.

(D) Thickness of hard coat layer The thickness of the hard coat layer may be appropriately selected depending on the material of the hard coat layer, the function of the hard coat layer, and the use of the glass laminate. For example, when the material of the hard coat layer is an organic material, the thickness of the hard coat layer is preferably 2 μm or more and 50 μm or less, more preferably 3 μm or more and 30 μm or less, and 5 μm or more and 20 μm or less. It is more preferably 6 μm or more and 10 μm or less. Further, for example, when the material of the hard coat layer is an inorganic material, the thickness of the hard coat layer can be about several tens of nm. When the thickness of the hard coat layer is within the above range, sufficient hardness can be obtained as the hard coat layer, and a glass laminate having good bending resistance can be obtained.

(E) Method for forming a hard coat layer The method for forming a hard coat layer is appropriately selected depending on the material of the hard coat layer and the like, and for example, curing for a hard coat layer containing the above polymerizable compound and the like on the above resin layer. Examples thereof include a method of applying and curing the sex resin composition, a vapor deposition method, a sputtering method and the like.

The curable resin composition for a hard coat layer contains a polymerizable compound, and may further contain a polymerization initiator, particles, an ultraviolet absorber, a solvent, an additive and the like, if necessary.

The method for applying the curable resin composition for a hard coat layer on the resin layer is not particularly limited as long as it can be applied to a desired thickness, for example, a gravure coat method, a gravure reverse coat method, or a gravure offset. General coating methods such as a coating method, a spin coating method, a roll coating method, a reverse roll coating method, a blade coating method, a dip coating method, and a screen printing method can be mentioned. Further, a transfer method can also be used as a method for forming a coating film of the resin composition for a hard coat layer.

The coating film of the curable resin composition for the hard coat layer is dried as necessary to remove the solvent. Examples of the drying method include vacuum drying, heat drying, and a method of combining these drying methods. For example, it can be dried by heating at a temperature of 30 ° C. or higher and 120 ° C. or lower for 10 seconds or longer and 180 seconds or lower.

As a method for curing the coating film of the curable resin composition for the hard coat layer, it is appropriately selected depending on the polymerizable group of the polymerizable compound, and for example, at least one of light irradiation and heating can be used.

Ultraviolet rays, visible rays, electron beams, ionizing radiation and the like are mainly used for light irradiation. In the case of ultraviolet curing, for example, ultraviolet rays emitted from light rays such as an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, a xenon arc, and a metal halide lamp can be used. The irradiation amount of the energy radiation source can be, for example, about 50 mJ / cm ² or more and 5000 mJ / cm ² or less as the integrated exposure amount at the ultraviolet wavelength of 365 nm.

When heating, for example, the treatment can be performed at a temperature of 40 ° C. or higher and 120 ° C. or lower. Further, the reaction may be carried out by leaving it at room temperature (25 ° C.) for 24 hours or more.

Further, as a method for forming the hard coat layer, a hard coat film in which the hard coat layer is arranged on one surface of the base material layer is used, and a method of bonding the hard coat film on the resin layer via an adhesive layer is used. You can also do it. In this case, the adhesive layer and the hard coat film having the base material layer and the hard coat layer can be arranged in this order on the surface side of the resin layer opposite to the glass base material.

The adhesive layer has transparency. Specifically, the total light transmittance of the adhesive layer is preferably 85% or more, more preferably 88% or more, and even more preferably 90% or more.

Examples of the adhesive used for the adhesive layer include a pressure-sensitive adhesive such as OCA (Optical Clear Adhesive) and a photosensitive adhesive.

The thickness of the adhesive layer is preferably 1 μm or more and 100 μm or less, for example. If the adhesive layer is too thick, the bending resistance may be impaired. On the other hand, if the thickness of the adhesive layer is too thin, the adhesiveness cannot be guaranteed and the adhesive layer may be peeled off.

(2) Protective Layer The glass laminate in the present disclosure may further have a protective layer on the surface side of the surface-side resin layer opposite to the glass substrate.

The protective layer is transparent. Specifically, the total light transmittance of the protective layer is preferably 85% or more, more preferably 88% or more, and further preferably 90% or more.

The protective layer is not particularly limited as long as it has transparency, and may contain, for example, a resin. The resin used for the protective layer is not particularly limited as long as it is a resin capable of obtaining a transparent protective layer, and a general resin can be used.

As a method of arranging the protective layer on the resin layer, for example, a method of using a protective film as the protective layer and attaching the protective film to the resin layer via an adhesive layer, a method of forming a protective layer on the resin layer, etc. Can be mentioned.

The adhesive layer may be the same as the adhesive layer described in the section of the hard coat layer.

5. Other Structures The glass laminate in the present disclosure may have other layers, if necessary, in addition to the above-mentioned layers. Examples of the other layer include a primer layer, a decorative layer and the like.

(1) Primer layer The glass laminate in the present disclosure may have a primer layer between the glass base material and the resin layer. The primer layer can improve the adhesion between the glass substrate and the resin layer.

The material of the primer layer is not particularly limited as long as it is a material capable of enhancing the adhesion between the glass base material and the resin layer, and examples thereof include resin. Examples of the resin include (meth) acrylic resin, urethane resin, (meth) acrylic urethane copolymer, vinyl chloride-vinyl acetate copolymer, polyester, butyral resin, chlorinated polypropylene, chlorinated polyethylene, epoxy resin, and silicone. Examples include resin. These resins may be used alone or in combination of two or more.

The thickness of the primer layer may be any thickness as long as it can enhance the adhesion between the glass substrate and the resin layer, and can be, for example, 0.1 μm or more and 10 μm or less, preferably 0.2 μm. It can be 5 μm or less.

Examples of the method for forming the primer layer include a method of applying a primer layer composition on a glass substrate. As the coating method, for example, general gravure coating method, gravure reverse coating method, gravure offset coating method, spin coating method, roll coating method, reverse roll coating method, blade coating method, dip coating method, screen printing method and the like are used. The coating method can be mentioned. Further, a transfer method can also be used as a method for forming the primer layer.

(2) Decorative layer The glass laminate in the present disclosure has a decorative layer between the glass base material and the surface side resin layer, or on the surface side opposite to the surface side resin layer of the glass base material. May be.

The decorative layer contains a colorant and a binder resin. The binder resin contained in the decorative layer is not particularly limited, and a resin used for a general decorative layer can be used. The colorant contained in the decorative layer is not particularly limited, and a known colorant used for a general decorative layer can be used.
The decorative layer is usually placed on a portion of the glass substrate. Further, the decorative layer may have a pattern shape.
The thickness of the decorative layer is not particularly limited, but can be, for example, 5 μm or more and 40 μm or less.

6. Characteristics of Glass Laminate The glass laminate in the present disclosure preferably has a total light transmittance of, for example, 80% or more, more preferably 85% or more, and further preferably 88% or more. Due to the high total light transmittance as described above, a glass laminate having good transparency can be obtained.

Here, the total light transmittance of the glass laminate can be measured according to JIS K7361-1, and can be measured by, for example, a haze meter HM150 manufactured by Murakami Color Technology Laboratory.

The haze of the glass laminate in the present disclosure is, for example, preferably 2.0% or less, more preferably 1.5% or less, still more preferably 1.0% or less. With such a low haze, it is possible to obtain a glass laminate having good transparency.

Here, the haze of the glass laminate can be measured according to JIS K-7136, and can be measured by, for example, a haze meter HM150 manufactured by Murakami Color Technology Laboratory.

The glass laminate in the present disclosure preferably has bending resistance. Specifically, when the above-mentioned U-shaped bending test is performed on the glass laminate, the distance between the facing short sides of the glass laminate when the glass laminate cracks or breaks is 10 mm or less. It is preferably present, and more preferably 5 mm or less.

In the U-shaped bending test, when the resin layer is arranged on only one of the first main surface side and the second main surface side of the glass substrate, the glass laminate is arranged so that the glass substrate is on the outside. The glass laminate may be folded so that the glass substrate is on the inside, but in either case, it is preferable to have the above-mentioned bending resistance.

Further, when the above-mentioned dynamic bending test is performed on the glass laminated body, the glass laminated body is repeatedly bent 200,000 times so that the distance between the opposing short sides of the glass laminated body is 12 mm. It is preferable that the glass laminate does not crack or break.

7. Applications of the glass laminate The glass laminate in the present disclosure can be used as a member arranged on the observer side of the display panel in the display device. The glass laminate in the present disclosure can be used for display devices used in electronic devices such as smartphones, tablet terminals, wearable terminals, personal computers, televisions, digital signage, public information displays (PIDs), and in-vehicle displays. .. Above all, the glass laminate in the present disclosure can be preferably used for a flexible display such as a foldable display, a rollable display, and a bendable display, and can be preferably used for a foldable display.

When the glass laminate in the present disclosure is arranged on the surface of the display device, the glass is glass when the resin layer is arranged on only one of the first main surface side and the second main surface side of the glass base material. The surface on the substrate side may be arranged so that the surface on the display panel side and the surface on the resin layer side are on the outside, so that the surface on the resin layer side is on the display panel side and the surface on the glass substrate side is on the outside. It may be arranged.

The method of arranging the glass laminate on the surface of the display device in the present disclosure is not particularly limited, and examples thereof include a method via an adhesive layer. As the adhesive layer, a known adhesive layer used for adhering the glass laminate can be used.

C. Display device The display device in the present disclosure includes a display panel and the above-mentioned glass substrate or the above-mentioned glass laminate arranged on the observer side of the display panel.

FIG. 13 is a schematic cross-sectional view showing an example of the display device in the present disclosure, and is an example including the above-mentioned glass laminate. As shown in FIG. 13, the display device 20 includes a display panel 21 and a glass laminate 10 arranged on the observer side of the display panel 21. In the display device 20, the glass laminate 10 is used as a member arranged on the surface of the display device 20, and the adhesive layer 22 is arranged between the glass laminate 10 and the display panel 21.

The glass base material and the glass laminate in the present disclosure can be the same as the above-mentioned glass base material and the glass laminate.

Examples of the display panel in the present disclosure include display panels used in display devices such as liquid crystal displays, organic EL display devices, and LED display devices.

The display device in the present disclosure may have a touch panel member between the display panel and the glass base material or the glass laminate.

The display device in the present disclosure is preferably a flexible display. Above all, the display device in the present disclosure is preferably foldable. That is, the display device in the present disclosure is more preferably a foldable display. Since the display device in the present disclosure has the above-mentioned glass base material or glass laminate, it has excellent impact resistance and bending resistance, and is suitable as a flexible display and further as a foldable display.

D. Electronic Equipment The electronic equipment in the present disclosure includes the above-mentioned display device.

The electronic device in the present disclosure is not particularly limited as long as it is provided with the above-mentioned display device, and is, for example, a smartphone, a tablet terminal, a wearable terminal, a personal computer, a television, a digital signage, or a public information display (PID). ), In-vehicle display and the like.

E. Method for manufacturing a glass laminate The method for manufacturing a glass laminate in the present disclosure includes a preparatory step for preparing a glass substrate having a thickness of a predetermined value or less and being chemically tempered glass, and a first main step of the glass substrate. A resin layer forming step of forming a resin layer on at least one of a surface side and a second main surface side, and a cutting step of cutting the laminated body having the glass base material and the resin layer after the resin layer forming step. Have.

14 (a) to 14 (c) are process diagrams showing an example of the method for manufacturing a glass laminate in the present disclosure. First, as shown in FIG. 14A, a preparatory step for preparing a glass substrate 1 having a thickness of not more than a predetermined value and being chemically tempered glass is performed. Next, as shown in FIG. 14B, a resin layer forming step of forming the resin layer 11 on the first main surface 1A side of the glass base material 1 is performed. Subsequently, as shown in FIG. 14 (c), a cutting step of cutting the laminated body 10A having the glass base material 1 and the resin layer 11 is performed.

In the method for producing the glass laminate shown in FIGS. 14A to 14C, the resin layer 11 is formed only on the first main surface 1A side of the glass substrate 1 in the resin layer forming step. However, as shown in FIGS. 15A to 15C, the resin layer 11 is formed on the first main surface 1A side of the glass base material 1 in the resin layer forming step, and the second main surface of the glass base material 1 is formed. The resin layer 12 may be formed on the surface 1B side.

Conventionally, in the method for producing a glass laminate, it is difficult to cut the chemically strengthened glass. Therefore, first, the glass base material is cut to a desired size, and then the cut glass base material is chemically strengthened. After that, a resin layer was formed on the glass substrate. Therefore, the manufacturing process could not proceed without cutting the large glass base material, and the productivity was low.

On the other hand, in the method for producing a glass laminate in the present disclosure, a resin layer is formed on a glass substrate which is chemically tempered glass, and then the glass substrate and the laminate of the resin layer are cut, so that a large-scale chemical is used. The manufacturing process can be advanced without cutting the tempered glass, and the productivity can be improved.

Hereinafter, each step in the method for manufacturing a glass substrate in the present disclosure will be described.
1. 1. Preparation step In the preparation step in the present disclosure, a glass substrate having a thickness of not more than a predetermined value and being chemically tempered glass is prepared.
Since the thickness of the glass substrate has been described in the above section "A. Glass substrate", the description thereof is omitted here.

The chemically strengthened glass constituting the glass substrate is not particularly limited, and may be, for example, 6-sided tempered glass or 2-sided tempered glass, but 6-sided tempered glass is usually used. Since other points of the glass constituting the glass substrate can be the same as those described in the above section "A. Glass substrate", the description thereof is omitted here.

The glass substrate may be in the form of a single leaf or in the form of a roll.
The size of the glass substrate is not particularly limited, but a large glass substrate is preferable. Examples of the large glass base material include a multi-chamfering glass base material for multi-chamfering a display device member, a roll-shaped glass base material, and the like.

2. 2. Resin layer forming step In the resin layer forming step in the present disclosure, a resin layer is formed on at least one of the first main surface side and the second main surface side of the glass substrate.
Since the resin layer and the method for forming the resin layer are described in the above section “B. Glass laminate 2. Resin layer”, the description thereof is omitted here.

3. 3. Cutting Step In the cutting step in the present disclosure, after the resin layer forming step, the glass substrate and the laminate having the resin layer are cut.

When cutting the glass base material and the resin layer, for example, the glass base material and the resin layer may be cut in separate steps, or the glass base material and the resin layer may be cut in a single cutting process. Further, when the glass base material and the resin layer are cut in separate steps, the cutting methods of the glass base material and the resin layer may be the same or different. When the resin layer is formed only on one of the first main surface side and the second main surface side of the glass base material, the resin layer is usually cut in the order of cutting the glass base material and the resin layer. After that, the glass substrate is cut.

When the glass base material and the resin layer are cut in separate steps, examples of the method for cutting the glass base material include a method of cutting by scribe, a chemical etching method, and a laser cutting method. Further, a cutting method by mechanical scribe using a cutter "SOLID-D" manufactured by Samsung Diamond Industry Co., Ltd. can be used.

When cutting the glass substrate and the resin layer in separate steps, for example, a method of cutting with a screen, a method of cutting with an ultrasonic cutter, a UV laser, a CO ₂ laser, or the like is used as the cutting method of the resin layer. Examples include the laser cutting method used, and the cutting method using a punching blade. Further, a cutting method by mechanical scribe using a cutter "SOLID-D" manufactured by Samsung Diamond Industry Co., Ltd. can be used.

When the glass base material and the resin layer are cut by a single cutting process, examples of the method for cutting the glass base material and the resin layer include a method of cutting by scribe.

4. Processing Step The method for manufacturing a glass laminate in the present disclosure preferably includes a processing step for processing the cut surface of the glass substrate so that the maximum height Sz of the cut surface of the glass substrate is equal to or less than a predetermined value. .. When the maximum height Sz of the cut surface of the glass substrate is not more than a predetermined value, the bending resistance can be improved as described in the above section "A. Glass substrate". Further, the impact resistance at the end portion of the glass laminate can be improved.

In the method for producing a glass laminate in the present disclosure, a processing step may be performed during the cutting step, or a processing step may be performed after the cutting step. Specifically, when processing the cut surface of the glass base material, the glass base material may be cut so that the maximum height Sz of the cut surface of the glass base material is equal to or less than a predetermined value, or the glass base material may be cut. While cutting the material, the cut surface of the glass substrate may be processed so that the maximum height Sz of the cut surface of the glass substrate is equal to or less than a predetermined value, or the glass substrate may be processed after the glass substrate is cut. The cut surface of the glass substrate may be processed so that the maximum height Sz of the cut surface of the material is equal to or less than a predetermined value.

More specifically, a method of cutting the glass base material and the resin layer with a scribing, polishing the cut surface of the glass base material with abrasive paper, and further polishing with diamond abrasive grains can be mentioned. The particle size of the abrasive material of the polishing paper is preferably, for example, 30 μm or less, and particularly preferably 15 μm. Further, the polishing material of the polishing paper is not particularly limited. The particle size of the diamond abrasive grains is, for example, preferably 3 μm or less, and particularly preferably 1 μm.

5. Second Resin Layer Forming Step The method for producing a glass laminate in the present disclosure may further include a second resin layer forming step of covering the side surface of the glass substrate with the second resin layer after the cutting step. can.
By covering the side surface of the glass base material with the second resin layer, the bending resistance can be improved as described in the above-mentioned "A. Glass base material" section. Further, the impact resistance at the end portion of the glass laminate can be improved.
Since the second resin layer and the method for forming the second resin layer are described in the above section "B. Glass laminate 3. Second resin layer", the description thereof is omitted here.

6. Functional layer forming step In the method for manufacturing a glass laminate in the present disclosure, after the resin layer forming step, a functional layer forming step of forming a functional layer on the surface side of the surface side resin layer opposite to the glass substrate is performed. May be good.

The functional layer forming step may be performed before the cutting step or after the cutting step, but is preferably performed before the cutting step from the viewpoint of improving productivity. When the functional layer forming step is performed before the cutting step, the laminated body having the glass base material, the resin layer and the functional layer is cut in the cutting step.
Since the functional layer and the method for forming the functional layer are described in the above section "B. Glass laminate 4. Functional layer", the description thereof is omitted here.

7. Other Steps In the method for producing a glass laminate in the present disclosure, a primer layer forming step of forming a primer layer on a surface of a glass substrate on which a resin layer is formed may be performed before the resin layer forming step. In this case, in the above-mentioned cutting step, the laminate having the glass base material, the primer layer and the resin layer is cut. Since the primer layer and the method for forming the primer layer are described in the above section "B. Glass laminate 5. Other configurations", the description thereof is omitted here.

Further, in the method for producing a glass laminate in the present disclosure, a decorative layer forming step of forming a decorative layer on one surface of a glass substrate may be performed before the resin layer forming step. In this case, in the above-mentioned cutting step, the laminated body having the glass base material, the decorative layer and the resin layer is cut. Since the decorative layer and the method for forming the decorative layer have been described in the above section "B. Glass laminate 5. Other configurations", the description thereof is omitted here.

The present disclosure is not limited to the above embodiment. The above embodiment is an example, and any object having substantially the same structure as the technical idea described in the claims of the present disclosure and having the same effect and effect is the present invention. Included in the technical scope of the disclosure.

Hereinafter, the present disclosure will be further described with reference to Examples and Comparative Examples.
[Comparative Example 1]
The glass substrate was cut, chamfered, and chemically strengthened in that order. First, untempered glass having a thickness of 70 μm and a size of 200 mm × 200 mm was prepared and cut by scribe to a size of 20 mm × 100 mm. After that, the cut surface of the glass substrate was polished and chamfered. Next, the glass substrate was chemically strengthened to obtain a six-sided tempered glass.

[Comparative Example 2]
The glass substrate was cut and chemically strengthened in order. Six-sided tempered glass was obtained in the same manner as in Comparative Example 1 except that the cut surface of the glass substrate was not chamfered in Comparative Example 1.

[Comparative Example 3]
The glass substrate was chemically strengthened and cut in order. First, a glass substrate having a size of 200 mm × 200 mm and a thickness of 70 μm was chemically strengthened to obtain a six-sided tempered glass. Next, a two-sided tempered glass was obtained by cutting with a picosecond laser at a pulse energy of 80 μJ and an oscillation frequency of 150 kHz so as to have a size of 20 mm × 100 mm from the central portion of the glass substrate.

[Comparative Example 4]
The glass substrate was chemically strengthened and cut in order. In Comparative Example 3, the glass substrate was cut in the same manner as in Comparative Example 3 except that the cutting conditions by the picosecond laser were set to a pulse energy of 9 μJ and an oscillation frequency of 300 kHz.

[Comparative Example 5]
The glass substrate was slimmed, cut, chamfered, and chemically strengthened in that order. Six-sided tempered glass was obtained in the same manner as in Comparative Example 1 except that the 70 μm-thick untempered glass was slimmed to a thickness of 60 μm before cutting.

[Comparative Example 6]
The glass substrate was chemically strengthened and cut in order. In Comparative Example 3, the glass substrate was cut in the same manner as in Comparative Example 3 except that the method for cutting the glass substrate was a method of scribe cutting at a pushing amount of 0.1 mm and a speed of 20 mm / sec.

[Comparative Example 7]
The glass substrate was cut in the same manner as in Comparative Example 6 except that a glass substrate having a thickness of 14 μm was used.

[Comparative Example 8]
The glass substrate was cut in the same manner as in Comparative Example 6 except that a glass substrate having a thickness of 110 μm was used.

[Example 1]
Chemical strengthening and cutting (special polishing) of the glass substrate were performed in order. The glass substrate was scribed in the same manner as in Comparative Example 6. Then, the cut surface of the glass substrate was polished with a polishing paper containing an abrasive having a particle size of 15 μm, and then polished with diamond abrasive grains having a particle size of 1 μm. In this specification, the process from scribe to polishing is referred to as special polishing.

[Example 2]
Chemical strengthening and cutting (special polishing) of the glass substrate were performed in order. In Example 1, the glass substrate was cut and the cut surface of the glass substrate was polished in the same manner as in Example 1 except that the glass substrate, which was a 6-sided tempered glass that was not chamfered, was used. ..

[Example 3]
A glass substrate was obtained in the same manner as in Example 2 except that the polishing time was 0.9 times that of Example 2.

[Example 4]
A glass substrate was obtained in the same manner as in Example 2 except that the polishing time was 1.1 times that of Example 2.

[Example 5]
Chemical strengthening and cutting (special polishing) of the glass substrate were performed in order. First, a glass having a size of 200 mm × 200 mm and a thickness of 70 μm was slimmed to 60 μm and chemically strengthened to obtain a six-sided tempered glass. After that, two-sided tempered glass was obtained by sequentially performing cutting (special polishing) in the same manner as in Example 1.

[Example 6]
The glass substrate was cut and the cut surface of the glass substrate was polished in the same manner as in Example 1 except that the chemical strengthening method was changed so that the CS value and the CT value were set to the values shown in Table 1.

[Example 7]
A 70 μm-thick chemically strengthened glass substrate chemically strengthened to the CS and CT values shown in Table 1 was screened using a cutter (“SOLID-D” manufactured by Samsung Diamond Industry Co., Ltd.) and then broken. I cut it by doing.

[Example 8]
A 50 μm-thick chemically strengthened glass substrate chemically strengthened to the CS and CT values shown in Table 1 was screened using a cutter (“SOLID-D” manufactured by Samsung Diamond Industry Co., Ltd.) and then broken. I cut it by doing.

[Example 9]
A 30 μm-thick chemically strengthened glass substrate chemically strengthened to the CS and CT values shown in Table 1 was screened using a cutter (“SOLID-D” manufactured by Samsung Diamond Industry Co., Ltd.) and then broken. I cut it by doing.

[Evaluation 1]
(1) Surface compressive stress value (CS) and internal tensile stress (CT) of chemically strengthened glass
For the glass substrate, the surface compressive stress value and the internal tensile stress were measured from the first main surface or the second main surface using a refractometer type glass surface stress meter FSM-6000LE manufactured by Luceo.

(2) Maximum height Sz
The maximum height Sz of the side surface of the glass substrate was measured using a non-contact surface / layer cross-sectional shape measurement system VertScan2.0 R5500GML-A150-AC manufactured by Ryoka System Co., Ltd. Various parameters were obtained based on ISO 25178, measurements were performed at arbitrary 10 points, and their arithmetic mean values were obtained. The measurement conditions were as follows.
・ Measurement area: 0.02 mm x 0.02 mm
・ Objective lens: 50x ・ Length measurement mode: Wave
-Wavelength filter: 530white
-Height analysis mode: pv mode

The measurement is performed by the following method.
As shown in FIG. 18, first, the glass base material 101 is fixed by sandwiching it between two jigs 100 and 100 on the stage S. Next, the lens 102 including the light source is arranged so as to be directly above the side surface of the glass base material 101. The inclination of the stage S is adjusted so that the direction of the light from the light source is perpendicular to the stage S. Finally, by adjusting the height of the stage S, the distance between the lens 102 and the side surface of the glass base material 101 is adjusted to focus, and then the measurement is performed.

Further, for the glass substrates of Comparative Examples 3 and 6 and Example 4, color images acquired by using the non-contact surface / layer cross-sectional shape measurement system VertScan2.0 R5500GML-A150-AC manufactured by Ryoka System Co., Ltd. are shown. 16 (a) to (b) and FIG. 17 are shown.

(3) U-shaped bending test The above-mentioned U-shaped bending test was performed on a glass substrate. Then, the distance d between the two opposing short sides of the glass substrate when the glass substrate was cracked or broken was measured. The results of the U-shaped bending test were evaluated according to the following criteria.
A: The maximum distance d when the glass substrate is cracked or broken is 5 mm or less.
B: The maximum distance d when the glass substrate is cracked or broken is more than 5 mm and 10 mm or less.
C: The maximum distance d when the glass substrate is cracked or broken is more than 10 mm.

(4) Dynamic bending test The above-mentioned dynamic bending test was performed on the glass substrate, and the bending resistance of the glass substrate was evaluated.
At this time, the distance d between the two opposing short sides of the glass substrate was set to 10 mm. The results of the dynamic bending test were evaluated according to the following criteria.
A: The glass substrate does not break even after 200,000 times B: The glass substrate does not break even after 20,000 times C: The glass substrate breaks after 20,000 times or less

(5) Impact test (pen drop test)
An impact test was performed on the glass substrate. First, an optical adhesive film (OCA) having a thickness of 50 μm and a PET film having a thickness of 100 μm were bonded to a glass substrate in this order to prepare a test laminate. The test laminate was placed on the metal plate so that the PET film side of the test laminate was in contact with the metal plate having a thickness of 30 mm. Next, the pen was dropped onto the test laminate from the predetermined test height with the tip of the pen facing down with respect to the end of the test laminate. Here, the end portion of the test laminate indicates a region within 5 mm from the end portion of the glass substrate.

As the pen, Bren 0.5BAS88-BK (weight 12 g, pen tip 0.5 mmφ) manufactured by Zebra was used. Then, at the end of the glass substrate, the maximum test height at which the glass substrate was not cracked was measured. The larger the value, the higher the impact resistance.

The results of the impact test were evaluated according to the following criteria.
A: The maximum test height at which the glass substrate did not crack is 3 cm or more.
B: The maximum test height at which the glass substrate was not cracked is less than 3 cm.

(6) Production efficiency (number of sheets processed)
Regarding the method for producing the glass substrate, the production efficiency was evaluated according to the following criteria. The number of processed sheets per fixed time in Comparative Example 1 was used as a reference value. Here, the number of processed sheets means the number of samples completed within a predetermined time (5 hours). When counting the number of processed sheets, the sample with broken glass is not included. The definition of glass breakage is that two or more samples are separated, although they are completed.
A: The number of processed sheets per fixed time is 3 times or more of the reference value.
B: The number of processed sheets per fixed time is 1 times or less of the reference value.

Generally, when the glass base material is a two-sided tempered glass, the compressive stress layer does not exist on the side surface of the glass base material, so that the strength is lowered on the side surface of the glass base material. On the other hand, as shown in Table 1, even in the case of two-sided tempered glass, when the maximum height Sz of the side surface of the glass substrate is not more than a predetermined value (Examples 1 to 9), bending resistance It was confirmed that the properties and the impact resistance at the edges of the glass substrate were good. Further, even in the case of the two-sided tempered glass, when the maximum height Sz of the side surface of the glass substrate is not more than a predetermined value (Examples 1 to 9), the case of the six-sided tempered glass (Comparative Examples 1 to 9). It was confirmed that the same degree of bending resistance as 2) can be obtained.

[Comparative Example 9]
(Formation of primer layer)
The 6-sided tempered glass obtained in Comparative Example 1 was used. The following composition for a primer layer was coated on the glass substrate and dried at 80 ° C. for 3 minutes and at 150 ° C. for 60 minutes to form a primer layer having a thickness of 1 μm.

<Composition for primer layer>
・ Bisphenol A type solid epoxy resin (jER1256B40 manufactured by Mitsubishi Chemical) 28 parts by mass ・ Bisphenol A novolak type solid epoxy resin (jER157S65B80 manufactured by Mitsubishi Chemical) 5 parts by mass ・ 2-ethyl-4-methylimidazole (manufactured by Tokyo Chemical Industry) 1 mass Parts / solvent (MEK) 11 parts by mass

(Formation of resin layer)
With reference to Synthesis Example 1 of WO2014 / 046180, a tetracarboxylic dianhydride represented by the following chemical formula was synthesized.

Dehydrated N, N-dimethylacetamide (DMAc) (1833.2 g) and 2,2'-bis (trifluoromethyl) benzidine (TFMB) (138.48 g) were dissolved in a 5 L separable flask. The solution was added and the tetracarboxylic acid dianhydride (TMPBPTME) (176.70 g) represented by the above chemical formula was gradually added to a place where the temperature was controlled to 30 ° C. so that the temperature rise was 2 ° C. or lower. It was charged and stirred with a mechanical stirrer for 30 minutes. Pyromytzic acid dianhydride (PMDA) (64.20 g) was gradually added thereto in several portions so that the temperature rise was 2 ° C. or lower, and the polyimide precursor solution (solid) in which the polyimide precursor was dissolved was added. Minutes 18% by mass) was synthesized. The molar ratio of TMPBPTME to PMDA (TMPBPTME: PMDA) of the tetracarboxylic dianhydride used in the polyimide precursor was 90:10. The weight average molecular weight of the polyimide precursor was 75,000.

The above-mentioned polyimide precursor solution (2162 g) cooled to room temperature was added to a 5 L separable flask under a nitrogen atmosphere. Dehydrated N, N-dimethylacetamide (432 g) was added thereto, and the mixture was stirred until uniform. Next, the catalyst pyridine (6.622 g) and acetic anhydride (213.67 g) were added and stirred at room temperature for 24 hours to synthesize a polyimide solution.

N, N-dimethylacetamide (DMAc) (2000 g) was added to the obtained polyimide solution, and the mixture was stirred until uniform. Next, the polyimide solution was divided into 3 equal parts in a 5 L beaker and transferred, and isopropyl alcohol (3500 g) was gradually added to each beaker to obtain a white slurry. The above slurry was transferred onto a Büchner funnel, filtered, then flushed with isopropyl alcohol (9000 g in total) for washing, and then filtered. The process was repeated three times, dried at 110 ° C. using a vacuum dryer, and polyimide (polyimide). Polyimide powder) was obtained. The weight average molecular weight of the polyimide measured by GPC was 100,000.

N, N-dimethylacetamide (DMAc) was added to the polyimide so that the solid content concentration of the polyimide was 12% by mass to prepare a polyimide varnish (resin composition) having 12% by mass of the polyimide in the varnish. The viscosity of the polyimide varnish (resin composition) (solid content concentration 12% by mass) at 25 ° C. was 15000 cps.

The polyimide varnish (resin composition) is applied onto the primer layer to a predetermined thickness and dried at 80 ° C. for 5 minutes, 150 ° C. for 10 minutes, and 230 ° C. for 30 minutes to obtain a resin having a thickness of 20 μm. Formed a layer.

[Comparative Example 10]
In Comparative Example 9, the primer layer and the primer layer were placed on the glass substrate in the same manner as in Comparative Example 9, except that the 6-sided tempered glass obtained in Comparative Example 2 was used and the thickness of the resin layer was 5 μm. A resin layer was formed.

[Example 10]
First, a glass substrate having a size of 200 mm × 200 mm and a thickness of 70 μm is prepared, the cut surface of the glass substrate is polished and chamfered, and then the glass substrate is chemically strengthened to obtain a size. A 6-sided tempered glass having a thickness of 200 mm × 200 mm and a thickness of 70 μm was obtained. Next, the primer layer and the resin layer were formed on the glass substrate in this order under the same primer layer composition, resin composition, and coating conditions as in Comparative Example 9. Next, the resin layer and the primer layer were cut with an ultrasonic cutter so as to have a size of 100 mm × 20 mm, and the glass substrate was scribed at a pushing amount of 0.1 mm and a speed of 20 mm / sec. Then, the cut surface of the glass substrate was polished with a polishing paper containing an abrasive having a particle size of 15 μm, and then polished with diamond abrasive grains having a particle size of 1 μm.

[Example 11]
In Example 10, a primer layer and a resin layer were formed on the glass substrate in the same manner as in Example 10 except that the resin layer was formed as described below, and the resin layer, the primer layer and the glass substrate were formed. It was cut and the cut surface of the glass substrate was polished.

(Formation of resin layer)
A resin composition (manufactured by Byron UR-4800 Toyobo Co., Ltd.) containing a urethane-modified copolymerized polyester resin was formed on a glass substrate to a predetermined thickness to form a resin layer having a thickness of 20 μm.
The drying conditions for forming the resin layer were 100 ° C. for 3 minutes.

[Example 12]
First, a glass having a size of 200 mm × 200 mm and a thickness of 70 μm was slimmed to 60 μm and chemically strengthened to obtain a six-sided tempered glass having a size of 200 mm × 200 mm and a thickness of 60 μm. A glass laminate was obtained in the same manner as in Example 10 except that the obtained glass was used and the thickness of the resin layer was 25 μm.

[Example 13]
In Example 12, a glass laminate was obtained in the same manner as in Example 12 except that the resin layer was formed as described below.

(Formation of resin layer)
A polyurethane resin composition was formed into a film having a predetermined thickness on a glass substrate to form a resin layer having a thickness of 15 μm. The drying conditions for forming the resin layer were 100 ° C. for 10 minutes.

[Example 14]
In Example 10, a glass laminate was obtained in the same manner as in Example 10 except that the tempered glass obtained in Example 8 was used and the thickness of the resin layer was set to 20 μm.

[Example 15]
In Example 10, a glass laminate was obtained in the same manner as in Example 10 except that the tempered glass obtained in Example 9 was used and the thickness of the resin layer was 25 μm.

[Example 16]
After forming the primer layer shown in Comparative Example 9 on the tempered glass substrate obtained in Example 8, the resin composition having the following composition was applied and dried at 70 ° C. to evaporate the solvent. Next, a resin layer having a thickness of 30 μm was formed by irradiating with ultraviolet rays at an integrated light intensity of 500 mJ / cm ² , and a glass laminate was obtained.
(Resin composition)
-Acrylate monomer: 100 parts by mass-Silica particles (average particle diameter 30 to 50 nm): 50 parts by mass-Photopolymerization initiator: 4 parts by mass-Solvent (MEK): 100 parts by mass

[Evaluation 2]
(1) Composite elastic modulus The composite elastic modulus of the resin layer was measured by the above-mentioned method for measuring the composite elastic modulus of the resin layer.

(2) Maximum height Sz
For the glass laminate, the maximum height Sz of the side surface of the glass substrate was measured in the same manner as in Example 1.

(3) U-shaped bending test The above-mentioned U-shaped bending test was performed on the glass laminate. Then, the distance d between the two opposing short sides of the glass laminate was measured when the glass laminate was not cracked or broken. The results of the U-shaped bending test were evaluated according to the following criteria.
A: The minimum distance d when the glass laminate is not cracked or broken is 5 mm or less.
B: The minimum distance d when the glass laminate is not cracked or broken is more than 5 mm and 10 mm or less.
C: The minimum distance d when the glass laminate is not cracked or broken is more than 10 mm.

(4) Dynamic bending test The above-mentioned dynamic bending test was performed on the glass laminate to evaluate the bending resistance of the glass laminate. At this time, the distance d between the two opposing short sides of the glass laminate was set to 10 mm. Further, the glass laminate was bent so that the resin layer was on the inside and the glass base material was on the outside. The results of the dynamic bending test were evaluated according to the following criteria.
A: The glass substrate is not broken even after 200,000 times, and the resin layer is not cracked. B: The glass substrate is not broken even after 20,000 times, and the resin layer is not cracked. C: The glass substrate was broken or the resin layer was cracked after 20,000 times or less.

(5) Impact test (pen drop test)
An impact test was performed on the glass laminate. First, an optical adhesive film (OCA) having a thickness of 50 μm and a PET film having a thickness of 100 μm were laminated in this order on the surface of the glass base material of the glass laminate to prepare a test laminate. The test laminate was placed on the metal plate so that the PET film side of the test laminate was in contact with the metal plate having a thickness of 30 mm.

Next, the pen was dropped onto the test laminate from the predetermined test height with the tip of the pen facing down with respect to the end of the test laminate. Here, the end portion of the test laminate indicates a region within 5 mm from the end portion of the glass substrate.

As the pen, Bren 0.5BAS88-BK (weight 12 g, pen tip 0.5 mmφ) manufactured by Zebra was used. Then, at the end of the glass laminate, the maximum test height at which the glass substrate was not cracked was measured. The larger the value, the higher the impact resistance. The results of the impact test were evaluated according to the following criteria.
A: The maximum test height at which the glass substrate did not crack is 11 cm or more.
B: The maximum test height at which the glass substrate was not cracked was 7 cm or more and less than 11 cm.
C: The maximum test height at which the glass substrate did not crack is less than 7 cm.

(6) Production efficiency (number of sheets processed)
Regarding the method for producing the glass laminate, the production efficiency was evaluated according to the following criteria. The number of processed sheets per fixed time in Comparative Example 6 was used as a reference value. Here, the number of processed sheets means the number of samples completed within a predetermined time (5 hours). When counting the number of processed sheets, the sample with broken glass is not included. The definition of glass breakage is that two or more samples are separated, although they are completed.
A: The number of processed sheets per fixed time is 3 times or more of the reference value.
B: The number of processed sheets per fixed time is 1 times or less of the reference value.

From Table 2, even when the glass substrate is a two-sided tempered glass in the glass laminate, when the maximum height Sz of the side surface of the glass substrate is not more than a predetermined value, the bending resistance and the glass laminate are shown. It was confirmed that the impact resistance at the end was good. Even when the glass base material is two-sided tempered glass, when the maximum height Sz of the side surface of the glass base material is not more than a predetermined value (Examples 6 to 9), the case of six-sided tempered glass (comparison). It was confirmed that the same degree of bending resistance as in Examples 7 to 8) was obtained.

[Reference example]
The concentration distribution of potassium was measured on the side surfaces of various glass substrates by energy dispersive X-ray analysis (EDX) in the thickness direction. Specifically, using X-MaxN manufactured by Oxford Instruments, EDX mapping was performed with respect to the thickness direction of the side surface of the glass substrate at an acceleration voltage of 10 kV, and the potassium concentration was quantified. Then, in the concentration distribution of potassium in the thickness direction of the side surface of the obtained glass base material, each region divided into ten equal parts in the thickness direction is divided into equal parts from the first main surface side to the second main surface side of the glass base material. The average value of the potassium concentration in the 1st region, the 2nd region and the 5th region was obtained in the order from the 1st region to the 10th region. The average value of the potassium concentration in each region was the arithmetic mean value of the measured values every 0.2 μm in the thickness direction. The results are shown in Table 3.

[Sample creation procedure]
-Small the area including the edge of the glass to about 1.0 cm.
-Epoxy cold embedding resin is used for embedding.
-Glass is polished using a Tegrapol-35 mechanical polishing device manufactured by Marumoto Struas.
Final polishing conditions: Diamond abrasive grain 1 μm
・ Pt sputtering is performed after polishing is completed.

The 6-sided tempered glass of Reference Example 3 is the same as the 6-sided tempered glass obtained in Comparative Example 1 above. Further, the two-sided tempered glass of Reference Example 4 is the same as the two-sided tempered glass obtained in Examples 1 to 4, and the two-sided tempered glass of Reference Example 8 is obtained in Example 5 above. It is the same as the two-sided tempered glass. Further, the tempered glass of Reference Example 9 is the same as the two-sided tempered glass obtained in Example 9.

From Table 3, if the ratio of the average value of the potassium concentration in the fifth region to the average value of the potassium concentration in the first region is 0.7 or less, it can be said that the glass substrate is two-sided tempered glass. It was confirmed that.

1 ... Glass base material 1A ... First main surface of glass base material 1B ... Second main surface of glass base material 1C ... Side surface of glass base material 10 ... Glass laminate 11, 12 ... Resin layer 13 ... Second resin layer 14… Hard coat layer 20… Display device 21… Display panel

Claims (17)

It has a first surface, a second surface facing the first surface, and a side surface.
A glass substrate having a thickness of 15 μm or more and 100 μm or less, and a maximum height Sz of the side surface of 1.5 μm or less. The first aspect of the present invention, wherein cracking or breaking does not occur when the operation of bending the glass base material by 180 ° is repeated 200,000 times so that the distance between the opposing short sides of the glass base material is 12 mm. Glass substrate. The glass substrate according to claim 1 or 2, which is chemically tempered glass. The first to tenth regions of the potassium concentration distribution in the thickness direction of the side surface are divided into ten equal parts in the thickness direction in the order from the first surface side to the second surface side. The glass substrate according to claim 3, wherein the average value of the potassium concentration in the first region is higher than the average value of the potassium concentration in the fifth region when the region is used. The glass substrate according to claim 4, wherein the ratio of the average value of the potassium concentration in the fifth region to the average value of the potassium concentration in the first region is in the range of 0 to 0.7. The glass substrate according to any one of claims 1 to 5, which is used for a flexible display. The glass substrate according to any one of claims 1 to 6, and the glass substrate.
A resin layer arranged on at least one of the first surface side and the second surface side of the glass substrate, and
A glass laminate. The glass laminate according to claim 7, wherein the thickness of the resin layer is 5 μm or more and 60 μm or less. The glass laminate according to claim 7 or 8, wherein the composite elastic modulus of the resin layer is 4.7 GPa or more. The glass according to any one of claims 7 to 9, wherein the resin layer contains at least one selected from the group consisting of a polyimide resin, an epoxy resin, polyester, polyurethane and an acrylic resin. Laminate. The glass laminate according to any one of claims 7 to 10, further comprising a second resin layer covering the side surface of the glass substrate. The second resin layer contains at least one selected from the group consisting of a polyimide resin, an epoxy resin, polyester and polyurethane, or contains a cured product of a resin composition containing a polymerizable compound. Item 11. The glass laminate according to Item 11. Display panel and
The glass substrate according to any one of claims 1 to 6, or the glass substrate according to any one of claims 7 to 12, which is arranged on the observer side of the display panel. Glass laminate and
Display device. An electronic device comprising the display device according to claim 13. A preparatory step for preparing a glass substrate having a thickness of 15 μm or more and 100 μm or less and being chemically tempered glass.
A resin layer forming step of forming a resin layer on at least one of the first surface side and the second surface side of the glass substrate,
After the resin layer forming step, a cutting step of cutting the glass base material and the laminate having the resin layer, and
A method for manufacturing a glass laminate. The method for producing a glass laminate according to claim 15, further comprising a processing step of processing the cut surface of the glass substrate so that the maximum height Sz of the cut surface of the glass substrate is 1.5 μm or less. The method for producing a glass laminate according to claim 15, further comprising a second resin layer forming step of covering the side surface of the glass substrate with the second resin layer after the cutting step.

Images