JP2022169387A - laminate - Google Patents

Abstract

To enhance a tolerance to a pressing force at an end part of a glass film in a laminate.SOLUTION: A laminate includes a base material film, a glass film, and a first adhesion part adhering the base material film and the glass film. In a plan view, a side face defining an external periphery of the glass film is located further inside than a side face defining an external periphery of the base material film. The first adhesion part has an indentation elasticity modulus of 1×108 Pa or more at 25°C.SELECTED DRAWING: Figure 1A

Description

The present invention relates to a laminate used for, for example, a display panel of a flat panel display (FPD).

Generally, a laminate of a glass film and a supporting substrate is produced by laminating a supporting substrate and a glass film having the same width. However, it is difficult to stack sheets of the same size without any deviation. Slight misalignment inevitably occurs during lamination. For example, in the case of a laminate that is rectangular in plan view, the edge of the glass film protrudes on one of the four sides. On the side where the edge of the glass film protrudes, there is a problem that the glass film is likely to break due to the pressure of the edge.

On the other hand, in Patent Document 1, a display device includes a cover glass; a cover adhesive member arranged under the cover glass; a display panel arranged under the cover adhesive member; and a back plate arranged under the display panel. The display device includes at least one bending region where the cover glass, the cover adhesive member, the display panel and the back plate can be bent, and the cover adhesive member covers at least one side surface of the cover glass. ing.

Patent Document 2 discloses a bendable laminate in which a first film layer, an optical film layer, an adhesive layer, and a second film layer are laminated in this order, and the position of the end of the adhesive layer proposes a laminate that is, at least in part, outside the position of the edge of said optical film layer.

In Patent Document 3, a first glass substrate including one surface and the other surface and the side surface facing each other in the thickness direction is arranged to cover and contact the side surface of the first glass substrate, and the a first functional coating layer including one surface and the other surface facing each other and a side surface, the first functional coating layer exposing the one surface of the first glass substrate, and the first functional coating The one surface of the layer is proposed as a protective member for a display device located on the extended surface of the one surface of the first glass substrate.

Korean Patent Publication No. 1020190078226 JP 2019-199081 A Korean Patent Publication No. 1020200090292

Even if the edge of the glass film does not protrude, if the adhesive portion or adhesive portion interposed between the glass film and the supporting substrate does not have sufficient hardness, the edge of the glass film will not be able to withstand pressure. The glass film is fragile, and the problem that the edge of the glass film is easily broken cannot be solved. It is considered that this is because the adhesive portion or adhesive portion is deformed by the force that presses the edge of the glass film, and the strain at the edge of the glass film increases.

One aspect of the present disclosure is a laminate that includes a base film, a glass film, and a first bonding portion that bonds the base film and the glass film, wherein the glass film is The side surface defining the outer periphery of the base film is located inside the side surface defining the outer periphery of the base film, and the indentation elastic modulus at 25 ° C. of the first adhesive portion is 1 × ¹⁰ Pa or more. .

According to the present disclosure, the resistance to pressure of the edge of the glass film of the laminate is increased.

1A and 1B are a schematic cross-sectional view and a plan view, respectively, showing the configuration of a laminate according to an embodiment of the present disclosure; FIG. FIG. 4A is a cross-sectional schematic diagram (a) and a plan view (b) shows the configuration of a laminate according to another embodiment of the present disclosure. FIG. 4 is an illustration of the previous step of the method of measuring the adhesive force between the bond and the glass film; FIG. 4 is an illustration of the subsequent steps of the method for measuring the adhesive force between the adhesive portion and the glass film; FIG. 10 is a diagram showing contact points between the ball and the central portion when obtaining the allowable load; It is a figure which shows the contact point of a ball|bowl and an edge part when calculating|requiring an allowable load. 1 is a plan view showing the configuration of a long laminate according to an embodiment of the present disclosure; FIG. FIG. 3B is a cross-sectional view of the long laminate taken along line bb of FIG. 3A; It is explanatory drawing which shows an example of the process of obtaining a singulated glass integrated sheet. FIG. 3 is a plan view showing an arrangement example of glass films in the singulated glass-integrated sheet. FIG. 4 is an explanatory diagram showing an example of a process for obtaining a long laminate; FIG. 6B is an explanatory diagram showing an example of a process following the process shown in FIG. 6A; It is explanatory drawing which shows an example of the process by which a laminated body is singulated from a long laminated body. FIG. 4 is an explanatory diagram of an example of a bending inspection method; FIG. 11 is an explanatory diagram of another example of the bending inspection method;

Hereinafter, laminates, long laminates, manufacturing methods thereof, and bend inspection methods according to embodiments of the present disclosure will be sequentially described. However, the laminate, the long laminate, the manufacturing method thereof, and the bending inspection method according to the present disclosure are not limited to the following embodiments.

Also, although the term “parallel” is used from time to time, it is not necessarily strictly parallel, and one and the other deviate from a parallel arrangement to the extent that they have an angle of, for example, less than 10° (or less than 5°). may Similarly, although the term "perpendicular" is used from time to time, it is not necessarily strictly perpendicular, and one and the other are at an angle of, for example, 80° or more and 100° or less (or 95° or more and 95° or less). may deviate from being perpendicular to

In addition, when referring to the drawings, the shape or size of each component in each drawing is not shown to the same scale as in reality. The relative relationships of these dimensions are shown schematically and exaggerated to clarify the characteristics of each component.

[Laminate]
A laminate according to an embodiment of the present disclosure is, for example, an optical laminate used for a display panel of a flat panel display (FPD). The FPD is not particularly limited, but typically refers to a thin image display device such as a liquid crystal display device or an organic EL display device.

The laminate includes a substrate film, a glass film, and a first bonding portion that bonds the substrate film and the glass film. The base film may be any film that can support the glass film, and has light transmittance to transmit predetermined light.

In a plan view, the side surface defining the outer periphery of the glass film (simply referred to as the side surface of the glass film) is positioned inside the side surface defining the outer periphery of the base film (simply referred to as the side surface of the base film). To position.

Planar view means viewing the glass film or the substrate film from the normal direction of the glass film or the substrate film. The meaning of planar view is the same below.

In other words, the outer circumference of the base film protrudes from the outer circumference of the glass film over the entire circumference. Positioning the perimeter of the glass film, which is weak in strength, inside the perimeter of the base film increases the resistance to pressure from the edges of the glass film. It is considered that this is because the base film can receive the force that presses the edge of the glass film on its surface, and the base film can relax the stress applied to the glass film by pressing over a wider area.

However, the indentation elastic modulus at 25° C. of the first bonding portion is set to 1×10 ⁸ Pa or more. This remarkably improves the resistance to pressure of the edge of the glass film. From the viewpoint of further significantly improving the resistance to pressure of the edge of the glass film, the indentation elastic modulus at 25° C. of the first adhesive portion may be set to 5×10 ⁸ Pa or more, or even 1×10 ⁹ Pa or more. good.

A significant improvement in the resistance to pressure of the edge of the glass film is, for example, the ratio of the allowable load at the edge of the laminate to the allowable load at the center of the laminate (hereinafter referred to as "load ratio (edge/center) ) can be evaluated. When the indentation modulus of elasticity at 25° C. of the first adhesive portion is set to 1×10 ⁸ Pa or more, the load ratio (end portion/central portion) can be set to 0.9 or more.

In plan view, the separation distance from the side surface (periphery) of the glass film to the side surface (periphery) of the base film (hereinafter also referred to as "separation distance G1") is not particularly limited, but may be, for example, 10 mm or less. good. From the viewpoint of suppressing an increase in size of the laminate, the separation distance G1 may be 1 mm or less, 800 μm or less, 500 μm or less, or 300 μm or less. On the other hand, the distance G1 may be 20 μm or more, or may be 50 μm or more, from the viewpoint of receiving the force that presses the edge of the glass film on a larger surface of the base film and relaxing the stress due to pressing over a wider area. , is preferably greater than 50 μm.

If the indentation elastic modulus at 25° C. of the first adhesive portion is less than 1×10 ⁸ Pa, it becomes difficult to sufficiently improve the resistance to pressure of the edges of the glass film. It is considered that this is because the first adhesive portion is deformed by the force pressing the edge of the glass film, and the effect of the surface of the base film receiving the force pressing the edge of the glass film is canceled. In order to remarkably improve the resistance to pressure on the edges of the glass film, it is important to give the first adhesive portion sufficient hardness, that is, to give the first adhesive portion a sufficient indentation elastic modulus. be. Since the first adhesive part has sufficient hardness, the force pressing the end is smoothly transmitted to the base film directly below the pressing point, and the stress applied to the glass film is stably relaxed, and the glass film It is considered that the strain at the end of the is suppressed.

From the viewpoint of further improving the resistance to pressure on the edge of the glass film, the storage elastic modulus at 25° C. of the first adhesive portion may be 1 GPa or more, further 3 GPa or more. On the other hand, from the viewpoint of giving the laminate an appropriate flexibility required for FPD applications, the storage elastic modulus at 25° C. of the first adhesive portion may be 20 GPa or less, or 10 GPa or less. The storage modulus can be determined by dynamic viscoelasticity measurement.

In a laminate (usually, a laminate obtained by separating a long laminate into pieces), the substrate film and the glass film may each have a rectangular shape. Rectangular typically means a square or rectangular shape, but need not be strictly square or rectangular. For example, the corners may be R-chamfered and rounded, or the corners may be C-chamfered. Also, the four sides may not be straight lines, and may be formed by lines having some bends or irregularities.

In the laminate, a second adhesive portion may be arranged on the side surface defining the outer periphery of the glass film. At least a portion (preferably all) of the side surfaces of the glass film may be covered with the second adhesive portion. This further increases the resistance to pressure on the edge of the glass film. The indentation elastic modulus at 25° C. of the second adhesive portion is not particularly limited, but may be, for example, ±30% of the indentation elastic modulus at 25° C. of the first adhesive portion.

In a plan view, a separation distance (hereinafter also referred to as "separation distance G2") from the side surface defining the outer periphery of the second bonding portion (also referred to simply as the side surface of the second bonding portion) to the side surface of the glass film; The separation distance G1 from the side surface of the glass film to the side surface of the base film may be the same. That is, at least part of the side surface of the second adhesive portion may be flush with the side surface of the base film from the main surface of the glass film on the side of the first adhesive portion toward the opposite main surface thereof. At this time, in plan view, the maximum thickness of the second adhesive portion from the side surface of the glass film has the same length as the separation distance G1. As a result, the strength of the protruding portion of the base film in the laminate is improved, and the handleability of the laminate is improved.

The side surface of the second adhesive portion may be flush with the side surface of the base film from the main surface of the glass film on the side of the base film to the main surface on the opposite side. In other words, the entire side surface of the second adhesive portion may be flush with the side surface of the base film. In this case, the side surfaces of the laminate can be made flush from one side to the other side in the thickness direction of the laminate. That is, the thickness in plan view of the second adhesive portion covering the corner portion where the main surface of the glass film opposite to the first adhesive portion side and the side surface of the glass film intersect is the same length as the separation distance G1. have. As a result, the strength of the protruding portion of the base film is further improved, and the thickness of the laminate as a whole becomes uniform. Normally, even if a bonding portion is formed at such a corner portion, the bonding portion is damaged and the bonding portion at the corner portion does not have a sufficient thickness. On the other hand, in the present embodiment, the thickness of the second adhesive portion at the corner portion can be made equal to the separation distance G1 by adopting, for example, a manufacturing method to be described later.

The base film may be a resin film made of resin. The resin constituting the resin film may be a thermoplastic resin or a thermosetting resin. Examples of thermoplastic resins include, but are not limited to, polyether sulfone resins; polycarbonate resins; acrylic resins; polyester resins such as polyethylene terephthalate resin and polyethylene naphthalate resin; polyolefin resins; polyimide resins; polyamide resins; polyimide amide resins; polyarylate resins; polysulfone resins; Examples of the thermosetting resin include, but are not particularly limited to, epoxy-based resins, urethane-based resins, silicone-based resins, and the like.

The base film may further contain any appropriate amount of additive depending on the purpose. Additives include, for example, diluents, antioxidants, modifiers, surfactants, dyes, pigments, discoloration inhibitors, UV absorbers, softeners, stabilizers, plasticizers, antifoaming agents, reinforcing agents, and the like. mentioned.

The thickness of the base film may be, for example, 1 μm or more and 60 μm or less, may be 5 μm or more and 50 μm or less, or may be 10 μm or more and 40 μm or less.

The storage elastic modulus of the base film at 25° C. is not particularly limited, but may be, for example, 1.5 GPa or more and 10 GPa or less, may be 1.8 GPa or more and 9 GPa or less, or may be 1.8 GPa or more and 8 GPa or less. good. If it is such a range, the effect which supports and protects a glass film will be high, and the productivity of a laminated body will improve more in the manufacturing method of a laminated body. The storage modulus can be determined by dynamic viscoelasticity measurement. Polyethylene terephthalate (PET) resin is preferable as the resin constituting such a base film.

A glass film is a thin glass plate with a uniform thickness. The composition of the glass constituting the glass film is not particularly limited, but examples thereof include soda-lime glass, boric acid glass, aluminosilicate glass, and quartz glass. The glass may be alkali-free glass or low-alkali glass. The total content of alkali metal components (eg, Na ₂ O, K ₂ O, Li ₂ O) in the glass is, for example, 15% by mass or less, and may be 10% by mass or less.

The thickness of the glass film is, for example, 100 μm or less, and may be 10 μm or more and 60 μm or less.

The density of the glass film is, for example, 2.3 g/cm ³ or more and 3.0 g/cm ³ or less, and may be 2.3 g/cm ³ or more and 2.7 g/cm ³ or less.

A glass film is manufactured by any suitable method. Typically, a glass film is made by melting a mixture containing a main raw material such as silica or alumina, an antifoaming agent such as mirabilite or antimony oxide, and a reducing agent such as carbon at a temperature of 1400° C. or higher and 1600° C. or lower. It is produced by cooling after molding into a film. Examples of methods for forming the glass film include a slot down draw method, a fusion method, a float method, and the like. The glass film obtained by these methods may be chemically polished with a solvent such as hydrofluoric acid, if necessary, in order to further thin the plate or improve the smoothness of the surface and edges.

The surface of the glass film may be subjected to surface treatment such as corona treatment, plasma treatment, coupling treatment, etc. in order to improve adhesion with the first adhesive portion.

The first adhesive portion is formed with a first adhesive. The first adhesive portion is formed by curing the first adhesive. The first adhesive portion has substantially no fluidity. In addition, in this disclosure, a distinction is made between an adhesive and a pressure-sensitive adhesive. The adhesive is non-curable and has fluidity. The indentation elastic modulus at 25° C. of the adhesive part formed by the adhesive may be, for example, 1×10 ⁶ Pa or less. The storage elastic modulus at 25° C. of the adhesive part formed by the adhesive may be, for example, 10 MPa or less.

The first adhesive is first applied to the base film. Next, the substrate film and the glass film are bonded together via the coating film of the first adhesive. The first adhesive is then cured to form the first bond. The thickness of the first adhesive portion is, for example, 0.1 μm or more and 10 μm or less, and may be 0.5 μm or more and 5 μm or less.

The first adhesive is not particularly limited, and any appropriate adhesive can be used. Examples of the first adhesive include adhesives containing a resin having a cyclic ether group such as an epoxy group, a glycidyl group, or an oxetanyl group, an acrylic resin, a silicone resin, or the like. The first adhesive is preferably UV curable. When the first adhesive that forms the first adhesive portion is an ultraviolet curing type, it is possible to further increase the productivity of the laminate in the method for producing the laminate.

The second adhesive portion is formed with a second adhesive. The second adhesive portion is formed by curing the second adhesive. The second adhesive portion has substantially no fluidity. The second adhesive is preferably UV curable. When the second adhesive that forms the second adhesive portion is an ultraviolet curing type, it is possible to further increase the productivity of the laminate in the method for producing the laminate. The first adhesive and the second adhesive may be adhesives having the same composition.

The adhesive force between the first adhesive portion and the glass film may be, for example, 0.1 N/mm or more, or 1 N/mm or more. With such an adhesive force, when an object collides with the glass film, peeling at the interface between the glass film and the first adhesive portion can be suppressed to a higher degree.

At least part of the main surface of the glass film opposite to the first adhesive portion side may be coated with a surface coat layer having various functions, or may be coated via an arbitrary adhesive portion or adhesive portion. It may be laminated with another base film or film member. Also, the main surface (back surface) of the base film on the side opposite to the first adhesive portion side may be laminated with an arbitrary film member via an arbitrary adhesive portion or adhesive portion.

An arbitrary film member may be an optical film or a separator described later. The optical film is not particularly limited, but includes, for example, a polarizing plate, a retardation plate, an isotropic film, and the like. Materials constituting the optical film include, for example, polyvinyl alcohol-based resins, polyolefin-based resins, cyclic olefin-based resins, polycarbonate-based resins, cellulose-based resins, polyester-based resins, polyvinyl alcohol-based resins, polyamide-based resins, polyimide-based resins, Polyether-based resins, polystyrene-based resins, (meth)acrylic-based resins, (meth)acrylic urethane-based resins, polysulfone-based resins, acetate-based resins, epoxy-based resins, silicone-based resins, and the like can be mentioned. The optical film may be a metal film, a metal oxide film such as an ITO film, or a laminated film of a metal film and a resin film.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings as appropriate. In each drawing, the shape and size of each component are not necessarily represented to the same scale. In the drawings, like components are referenced using like numerals.

FIG. 1A is a cross-sectional schematic diagram (a) and a plan view (b) showing the configuration of a laminate 10 according to one embodiment. The laminate 10 includes a base film 100 , a glass film 200 , and a first bonding portion 300 that bonds the base film 100 and the glass film 200 together. In plan view, the side surface (periphery) of the glass film 200 is located inside the side surface (periphery) of the base film 100 over the entire circumference. In plan view, the separation distance G1 between the side surface of the glass film 200 and the side surface of the base film 100 is set to be larger than 50 μm, for example. The indentation elastic modulus of the first adhesive portion 300 at 25° C. is set to 1×10 ⁸ Pa or more. In this configuration, the force pressing the edge of the glass film 200 from the normal direction can be received by the surface of the base film 100 . The glass film 200 is firmly adhered to the base film 100 by the first adhesion part 300 .

When the laminate 10 is viewed from above, the base film 100 and the glass film 200 each have a rectangular shape, but this is only an example. The four corners C2 of the base film 100 may be rounded by R-chamfering, or may be C-chamfered. The four sides do not necessarily have to be straight lines.

A second adhesive portion 310 may be arranged on the side surface of the glass film 200 as in the laminate 10A shown in FIG. 1B. The entire side surface of the glass film 200 may be covered with the second adhesive portion 310 as shown in FIG. 1B(b).

The side surface of the second adhesive portion 310 is flush with the side surface of the base film 100 from the main surface of the glass film 200 on the side of the base film 100 to the main surface on the opposite side (G1=G2). Therefore, the maximum thickness of the second adhesive portion 310 in the direction in which the side surface of the glass film 200 and the side surface of the base film 100 are separated from each other in plan view (the direction of the line segment L1 shown in FIG. 1B(b)) is the glass film 200 and the side of the base film 100 is the same as the distance G1. The thickness of the second adhesive portion 310 covering the corner portion (C3) where the main surface of the glass film 200 opposite to the first adhesive portion 300 side and the side surface of the glass film 200 intersect has the same length as the separation distance G1. have. As a result, the side surfaces defining the outer circumference of the laminate 10A are flush from one side to the other side in the thickness direction over the entire circumference.

The second adhesive portion 310 may be formed with the first adhesive together with the first adhesive portion 300 . In this case, the first adhesive and the second adhesive are adhesives having the same composition. The first adhesive creeps up and hardens to form the second adhesive portion 310 .

<Physical property measurement method 1>
(1) Indentation Elasticity Modulus (1-1) Adhesion Portion The indentation elasticity moduli of the first adhesion portion and the second adhesion portion can be measured by a nanoindentation method in accordance with ISO14577. Specifically, first, the first adhesive or the second adhesive is applied to the surface of a film having a smooth surface that has been subjected to mold release treatment to form a coating film. After that, a film having a smooth surface which is similarly subjected to a release treatment is attached to the coating film, and the coating film is cured to form an adhesive portion having a thickness of 3 μm or more sandwiched between the pair of films. After that, one of the films is peeled off and used as a test piece (sample). Alternatively, the base film may be peeled off from the laminate to expose the first adhesive portion and the second adhesive portion to prepare a test piece (sample). The indentation depth of the indenter may be 100 nm or less, and the sample thickness of 3 μm or more is sufficient.

The obtained test piece is set in a measuring device (for example, Triboindenter manufactured by HYSITRON INCORPORATED used in Examples and Comparative Examples described later), and the indentation modulus at 25° C. is determined under the following measurement conditions. Measurement may be performed 5 times or more and an average value may be obtained.

Measurement conditions Sample size: 10mm x 10mm
Indenter: Concial (spherical indenter: curvature radius 10 μm)
Measurement method: Single indentation measurement Measurement temperature: 25°C
Indentation depth of indenter: 100 nm
Analysis: "Oliver and Pharr analysis" based on load-displacement curves

(1-2) Adhesive Portion When measuring the indentation elastic modulus of a fluid adhesive portion, a test piece (sample) is prepared by the following procedure. First, a pressure-sensitive adhesive is applied to the surface of a film having a smooth surface that has been subjected to release treatment to form a coating film. After that, a film having a smooth surface that has also undergone a release treatment on the surface is attached to the coating film, and if necessary, UV irradiation (crosslinking process) is performed, and a 25 μm thick adhesive sandwiched between the pair of films is applied. form a part. After that, one of the films is peeled off and used as a test piece (sample). Using this test piece, the indentation modulus at 25° C. is determined in the same manner as for the bonded portion. Measurement may be performed 5 times or more and an average value may be obtained.

(2) Storage Elastic Modulus (2-1) Base Film The storage elastic modulus of the base film can be measured as a tensile storage elastic modulus in accordance with JIS K 7244-1:1998. Specifically, first, the base film is cut into a predetermined size to prepare a test piece. Using this test piece, a dynamic viscoelasticity measuring device (for example, a multi-function dynamic viscoelasticity measuring device “DMS6100” manufactured by Hitachi High-Tech Science Co., Ltd.) was used to measure viscoelasticity under the following conditions. Determine the tensile storage modulus at °C. Measurement may be performed 5 times or more and an average value may be obtained.

Measurement conditions Temperature range: -100 to 200°C
Heating rate: 2°C/min
Mode: Tensile Sample width: 10mm
Distance between chucks: 20mm
Frequency: 10Hz
Strain amplitude: 10 μm
Atmosphere: Air (250 ml/min)
Data acquisition interval: 0.5 min (every 1°C)

(2-2) Adhesion Portion The storage modulus of the first adhesion portion and the second adhesion portion can be measured as the tensile storage modulus in the same manner as the substrate film. Specifically, first, the first adhesive or the second adhesive is formed into a film and cured to prepare a cured film having a thickness of about 20 μm. This film is cut into a predetermined size to prepare a test piece. Using this test piece, viscoelasticity is measured in the same manner as the base film, and the tensile storage modulus at 25°C is determined. Measurement may be performed 5 times or more and an average value may be obtained.

(2-3) Adhesive Portion The storage elastic modulus of the adhesive layer formed from the adhesive can be measured in torsion mode according to JIS K 7244-1:1998. Specifically, a coating film of an adhesive is sandwiched between parallel plates, and a dynamic viscoelasticity measuring device (for example, "Advanced Rheometric Expansion System (ARES)" manufactured by Rheometric Scientific) is used to measure viscoelasticity under the following conditions. is measured to determine the storage modulus at 25°C. Measurement may be performed 5 times or more and an average value may be obtained.

Measurement conditions Deformation mode: Torsion Measurement frequency: 1Hz
Measurement temperature: -40°C to +150°C
Temperature rise: 5°C/min

(3) Adhesive strength The adhesive strength between the first adhesive portion and the glass film was measured using a surface/interface property analyzer "SAICAS DN-20" manufactured by Daipla-Wintes Co., Ltd. under the following conditions and methods. Measure. As shown in FIG. 2A, the surface/interface property analysis device 41 includes a blade 42 having the following characteristics, and a moving device and a pressure measuring section (not shown). Blade 42 is movable. The blade 42 has a cutting edge 43 formed at the tip.

Characteristics of blade 42 Material of blade 42: Single crystal diamond Width of blade edge 43: 1 mm
Rake angle of cutting edge 43: 10°

First, as shown in FIG. 2A, the laminate 10 is set in the measuring device 41. Then, as shown in FIG. The cutting edge 43 is pushed into the base film 100 while being moved to one side of the horizontal direction D1 (corresponding to the surface direction of the laminate 10) so as to be inclined with respect to the vertical direction D2 (corresponding to the thickness direction of the laminate 10). , to cut the base film 100 with the cutting edge 43 . The horizontal velocity is 10 μm/sec and the vertical velocity is 0.5 μm/sec.

After cutting the base film 100 with the cutting edge 43 , the cutting edge 43 is also cut into the first adhesive portion 300 as shown in FIG. 2B. When the cutting edge 43 reaches the interface between the first adhesive portion 300 and the glass film 200, the cutting edge 43 is horizontally moved to the one side. Thereby, the first adhesive part 300 is peeled off from the glass film 200 . The peel strength at this time is measured as the adhesive strength between the first adhesive portion 300 and the glass film 200 .

The adhesive force between the first adhesive portion 300 and the separator, which will be described later, can be similarly measured by replacing the glass film with the separator. However, when measuring the adhesive force between the first adhesive portion 300 and the separator, the cutting edge 43 is pushed into the separator to cut into the separator. When the cutting edge 43 reaches the interface between the separator and the first adhesive portion 300, the cutting edge 43 is horizontally moved to the one side, and the peel strength when the first adhesive portion 300 is peeled from the separator is measured as the adhesive force. .

(4) Load ratio (end/center)
First, an indentation test is performed to measure the permissible load at the edge and central portion of the laminate. Place the laminate with the base film side down on a horizontal table (for example, the weighing pan of the digital scale "SH-5000" manufactured by A&D Co., Ltd. used in Examples and Comparative Examples described later). . A ballpoint pen (for example, an oil-based ballpoint pen "BK407 Black" manufactured by Pentel Co., Ltd. (ball diameter 0.7 mm) used in Examples and Comparative Examples described later) A ball with a diameter of 0.7 mm at the tip of the glass film side is pressed. At this time, the permissible load of the end portion and the central portion where the glass film does not crack at two or more points is measured in units of 50 g. Next, the allowable load at the end is divided by the allowable load at the center to calculate the load ratio (end/center).

The laminate was manually pressed with a ballpoint pen held vertically, and the load when cracks occurred at two or more points was read in units of 50 g. The load increase rate should be controlled to approximately 50 g/sec. For example, when the load at which cracks occur at two or more points exceeds 450 g and is less than 500 g, the allowable load is 450 g, and when it exceeds 500 g and is less than 550 g, the allowable load is 500 g.

FIG. 2C is a diagram showing the arrangement of contact points P between the ball at the tip of the ballpoint pen and the central portion 10M when determining the allowable load of the central portion 10M of the laminate 10 in the indentation test. FIG. 2D is a diagram showing the arrangement of the contact points P between the ball at the tip of the ballpoint pen and the end portion 10T when determining the allowable load (b) of the end portion 10T of the laminate 10 in the indentation test. In five or more laminates 10, the same measurement may be performed at arbitrary three points in the end portion 10T and the central portion 10M, and the average may be calculated.

The central portion 10M of the laminated body 10 refers to a circular region with a radius of 20 mm centered on the center C of the laminated body 10 . The three points in the central portion 10M of the laminate 10 may be arbitrarily selected so as not to overlap each other.

The end portion 10T of the laminate 10 refers to a region of the glass film 200 where the distance g from the side surface (periphery) of the glass film 200 is 0.3 mm or less. The three points of the end portion 10T of the laminate 10 may be arbitrarily selected so as to be separated from each other as much as possible.

[Long laminate]
A long laminate according to an embodiment of the present disclosure has a plurality of laminates already described. In other words, the long laminate is an intermediate when manufacturing a plurality of laminates. A plurality of individualized laminates are obtained by dividing one long laminate.

The long laminate may be completed in a rolled state. The long laminate may be unwound from a rolled state and supplied to other processes in a roll-to-roll manner. The long laminate may be unwound from a roll and fed to a dividing process that singulates the long laminate. The intermediate body before being completed as a long laminate may also be handled in a rolled state. The intermediate may be unwound from a rolled state and supplied to a process for obtaining a long laminate in a roll-to-roll manner.

The roll-to-roll method is one method for handling a long laminate or an intermediate before being completed as a long laminate. The roll-to-roll method includes a process of unwinding a long laminate or intermediate from a rolled state, and winding the long laminate or intermediate into a roll. In the roll-to-roll method, an unwinding section for unwinding the long laminate or the intermediate and a winding section for winding the long laminate or the intermediate are used.

The long laminate includes a long base film, a long separator having a plurality of openings arranged along the longitudinal direction, a plurality of glass films arranged inside the plurality of openings, and a base film. and a first bonding portion for bonding the separator and bonding the base film and the plurality of glass films. The side surface defining the outer circumference of the glass film and the inner wall of the opening of the separator are separated from each other. Therefore, when dividing the long laminated body into a plurality of individualized laminated bodies, the first adhesive part intervening between the side surface of the glass film and the inner wall of the opening of the separator and the base film are cut. do it. Cutting the first adhesive portion and the base film together is easier than cutting the glass film, the first adhesive portion, and the base film together.

The long base film is made of the same material as the base film of the above-described individualized laminate, except that the size and shape are different. A part of the long base film becomes the base film of the laminated body.

The plurality of glass films are made of the same material as the glass films included in the above-described individualized laminate. The plurality of glass films may all be the same, or different glass films may be arranged at different locations on the long base film.

The first adhesive portion provided on the long base film is made of the same material as the first adhesive portion provided on the above-described individualized laminate. A first adhesive is first applied to a long base film. Next, the substrate film, the glass film and the separator are bonded together via the coating film of the first adhesive. The first adhesive is then cured to form the first bond. The first adhesive is, for example, an ultraviolet curing type.

The adhesive strength between the first adhesive portion and the separator may be 0.1 N/mm or more, or may be 0.5 N/mm or more.

A long separator having a plurality of openings arranged along the longitudinal direction is formed, for example, by partially cutting a separator having no long openings at a plurality of locations. The longitudinal directions of the long separator and the long base film are generally parallel. The separator without elongated openings is not particularly limited, but for example, a material similar to the resin film exemplified as the base film can be arbitrarily selected and used. The thickness of the separator may be the same as or different from that of the base film. The thickness of the separator may be the same as or different from the thickness of the glass film. When the thickness of the separator is Ts and the thickness of the glass film is Tg, 0.8≦Ts/Tg≦1.2 may be satisfied. Moreover, when the thickness of the base film is Tf, 0.8≦Tf/Tg≦2 may be satisfied.

The heat shrinkage rate of the separator at 90° C. may be 1.0% or less, or may be 0.5% or less. By reducing the heat shrinkage rate of the separator, it becomes easier to secure the distance between the side surface of the glass film and the inner wall of the opening of the separator (hereinafter also referred to as "distance G3") regardless of temperature conditions.

<Physical property measurement method 2>
(5) Thermal Shrinkage A separator is cut into a size of 100 mm in the longitudinal direction and 100 mm in the width direction to obtain a test piece. The initial dimensions in the longitudinal direction and width direction of this test piece are measured at 25° C. using an image measuring machine “QVA606-PRO_AE10” manufactured by Mitutoyo Corporation. Next, the test piece is heated at 90° C. for 30 minutes, cooled to room temperature, and then measured again at 25° C. for the lengthwise and widthwise dimensions (post-heating dimensions) of the test piece. The thermal contraction rates in the longitudinal direction and in the width direction are calculated from the following formulas, and the larger value is adopted. Measurement may be performed 5 times or more and an average value may be obtained.
Heat shrinkage rate (%) = {(initial dimension - dimension after heating) / (initial dimension)} x 100

The heat shrinkage rate at 90° C. of the carrier film, which will be described later, can also be measured in the same manner. The heat shrinkage rate of the carrier film at 90° C. may be 1.0% or less, or may be 0.5% or less.

A distance G3 between the side surface of the glass film and the inner wall of the opening of the separator may be 0.5 mm or more, or may be 1 mm or more. By setting the separation distance G3 to 0.5 mm or more, it becomes possible to sufficiently secure the separation distance G1 between the side surface of the glass film and the side surface of the base film in the individualized laminate.

However, since the distance G1 between the side surface of the glass film and the side surface of the base film may be, for example, 20 μm or more, or 50 μm or more, the distance between the side surface of the glass film and the inner wall of the opening of the separator is excessively wide. There is no need to secure G3. The separation distance G3 may be, for example, 1.6 mm or less, or 1 mm or less.

A second adhesive portion may be arranged on the side surface of the glass film. All of the side surfaces of the glass film may be covered with the second adhesive portion. For example, a second adhesive portion may be filled between the side surface of the glass film and the inner wall of the opening of the separator. The second bond may be formed with the first adhesive together with the first bond. In this case, the first adhesive and the second adhesive are adhesives having the same composition. 1 adhesive creeps up and hardens to form a second bond.

FIG. 3A is a plan view showing the configuration of a long laminate 10C according to one embodiment, and FIG. 3B is a cross-sectional view of the long laminate 10C taken along line bb in FIG. 3A. A long separator 400 is laminated on a long base film with a first adhesive portion 300 interposed therebetween. A long separator is formed by partially cutting out a plurality of locations from a long separator having no opening and having the same size (width) as the base film. The arrangement, number, etc. of the openings formed in the separator are not limited to the illustrated example, and can be set as appropriate. The side surface of the glass film 200 and the inner wall of the opening of the separator 400 are separated from each other, and the second adhesive portion 310 is integrally formed with the first adhesive portion 300 in the gap between them.

Also in the long laminate, at least part of the main surface of the glass film opposite to the first adhesive portion side may be coated with a surface coat layer having various functions, or any adhesive portion or It may be laminated with another base film or film member via an adhesive portion. Also, the main surface (back surface) of the base film on the side opposite to the first adhesive portion side may be laminated with an arbitrary film member via an arbitrary adhesive portion or adhesive portion. The optional film member may be the optical film described above.

The long laminate may be a long laminate with a carrier film laminated with a long carrier film. The long laminate with a carrier film includes a first adhesive portion interposed between the long laminate, the carrier film, the main surface of the separator and the plurality of glass films on the side opposite to the base film side, and the carrier film. may have A 1st adhesion part is formed of a 1st adhesive. The first adhesive may be non-curable or fluid.

The long laminated body may be a long laminated body with a film member laminated with any long film member. The long laminate with a film member is a second adhesive interposed between the long laminate, the film member, the main surface (back surface) of the base film opposite to the plurality of glass films, and the film member. or a third adhesive portion. Any film member may be the optical film described above, or may be a separator.

The first adhesive and the second adhesive forming the first adhesive portion and the second adhesive portion may have fluidity, and the indentation elastic modulus at 25° C. is, for example, 1×10 ⁶ Pa or less. good too. Moreover, the storage elastic modulus at 25° C. of the first adhesive portion (first adhesive) and the second adhesive portion (second adhesive) may be, for example, 10 MPa or less. In this case, the long laminate can be peeled off from the carrier film and the first adhesive portion. Also, the third adhesive portion may be formed in the same manner as the first adhesive portion or the second adhesive portion, for example, using the materials exemplified for the first adhesive portion or the second adhesive portion.

The types of the first adhesive and the second adhesive are not particularly limited, and examples include acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinyl Pyrrolidone-based adhesives, polyacrylamide-based adhesives, cellulose-based adhesives, and the like can be used. For each adhesive, for example, base polymer, cross-linking agent, additives (e.g., tackifier, coupling agent, polymerization inhibitor, cross-linking retarder, catalyst, plasticizer, softener, filler, colorant, metal Powders, UV absorbers, light stabilizers, antioxidants, antidegradants, surfactants, antistatic agents, surface lubricants, leveling agents, corrosion inhibitors, particles of inorganic or organic materials (metal compound particles (metal oxide particles, etc.), resin particles, etc.)), but are not limited to these.

The long carrier film is not particularly limited, but for example, the same material as the resin film exemplified as the base film can be arbitrarily selected and used. The thickness of the carrier film may be the same as or different from that of the base film. The thickness of the carrier film may be the same as or different from the thickness of the glass film. When the thickness of the carrier film is Tcf and the thickness of the glass film is Tg, 0.8≦Tcf/Tg≦2 may be satisfied.

The handleability of a long laminate with a carrier film is generally governed by the flexural rigidity of the carrier film. Therefore, the bending stiffness of the carrier film at 25°C may be greater than the bending stiffness of the glass film at 25°C. In this case, the handleability of the long laminate is improved. However, the flexural rigidity of the carrier film and the glass film is measured using test pieces of the carrier film and the glass film having the same width, respectively. The numerical value of the bending stiffness varies depending on the width of the test piece.

<Physical property measurement method 3>
(6) Bending stiffness The bending stiffness of the carrier film is calculated by the following formula.
Bending stiffness=E×bh ³ /12
(In the formula, E is the tensile modulus (Pa) of the carrier film at 25°C, b is the width (m) of the test piece, and h is the thickness (m) of the test piece.)

The tensile elastic modulus E (Pa) of the carrier film can be measured with an autograph (for example, a precision universal testing machine manufactured by Shimadzu Corporation).

[Long Laminate and Method for Producing Laminate]
Next, an example of a method for manufacturing a long laminate (hereinafter referred to as "manufacturing method A") will be described.
Manufacturing method A can generally be classified into four stages.
The first step is to prepare a sheet integrated with singulated glass.
The second step is to prepare the second raw material sheet.
The third step is to prepare a long laminate with a carrier film from the singulated glass-integrated sheet and the second raw material sheet.
The fourth step is to further process the long laminate with the carrier film.

<First stage>
The first stage has a first step of preparing a first raw material sheet. The first raw material sheet is a laminate in which a long carrier film and a long separator are pasted together at the first adhesive portion. At this point, the elongate separator does not have a plurality of openings. That is, the separator contained in the first raw material sheet is the raw material of the separator having a plurality of openings.

The first step is not particularly limited, but may be performed by a roll-to-roll method. That is, the first step may include unwinding the first raw material sheet wound into a roll by the unwinding section. The unwound first raw material sheet is supplied to subsequent processes.

Following the first step, a second step is performed to form slits extending to the first adhesive portion so as to surround a plurality of portions to be peeled arranged along the longitudinal direction of the separator. The method of forming the slits is not particularly limited, but they can be formed, for example, by a half-cutting technique using a laser. In the roll-to-roll method, slits may be formed in a portion of the first raw material sheet while it is being unwound and being conveyed or when conveyance is stopped. The raw material sheet that has undergone the second step may be once wound into a roll by the winding unit, or may be further wound after undergoing subsequent processes.

Following the second step, a third step of removing a plurality of portions to be peeled from the inside of the slit to form a plurality of openings arranged in the separator along the longitudinal direction and exposing the first adhesive portion from each opening is performed. will be The first adhesive portion is made of a fluid first adhesive, and the plurality of portions to be peeled can be peeled off from the first adhesive portion.

Following the third step, a plurality of glass films having a size smaller than the openings in a plan view are arranged inside the openings. At that time, the glass film is arranged so that the side surface (periphery) of the glass film and the inner wall of the opening of the separator are separated from each other. Thereby, the glass film is attached to the carrier film via the first adhesive portion. As a result, a singulated glass-integrated sheet is obtained.

The present disclosure also relates to, for example, the singulated glass-integrated sheet obtained in the first step of the manufacturing method of the above example. The singulated glass integrated sheet includes a long carrier film, a long separator having a plurality of openings arranged along the longitudinal direction, a plurality of glass films arranged inside the plurality of openings, and a carrier. a first adhesive portion interposed between the film and the separator and interposed between the carrier film and the plurality of glass films. However, the side surface defining the outer circumference of the glass film and the inner wall of the opening of the separator are separated from each other. That is, inside the plurality of openings of the separator, a plurality of glass films having a size smaller than the openings in a plan view are arranged so that the side surfaces of the glass films and the inner walls of the openings of the separator are separated from each other.

FIG. 4 is an explanatory view showing an example of the process for obtaining the singulated glass-integrated sheet. The process progresses sequentially in the direction of the arrows in FIG. 4 in a roll-to-roll manner. FIG. 4( a ) schematically shows at least part of the process of the first step, which may include unwinding the first raw material sheet 456 wound into a roll by the unwinding section 1 . The first raw material sheet 456 is a laminate in which a long carrier film 500 and a long separator 400 are adhered together by the first adhesive portion 600 . The unwound first raw material sheet 456 is supplied to the subsequent second step.

FIG. 4(b) schematically shows at least part of the process of the second step, showing how the slit S is formed by the half-cutting device 2 using a laser. The slit is formed to describe a rectangular opening. A region surrounded by the slit S is the part to be peeled 410 .

FIG. 4(c) schematically shows at least a part of the process of the third step, showing how the portion to be peeled 410 is peeled and removed to form the opening OP. For example, the part to be peeled 410 can be peeled by pushing up the upstream end of the part to be peeled 410 from below the carrier film 500 and pulling the floating upstream end.

FIG. 4(d) schematically shows at least part of the process of the fourth step, in which a plurality of glass films 200 smaller in size than the opening OP are formed inside the formed opening OP in plan view. It shows how they are arranged. As shown in the schematic cross-sectional view, the glass film 200 is arranged such that a gap SP is formed between its side surface (periphery) and the inner wall of the opening OP of the separator 400 . At this time, the distance between the side surface of the glass film 200 and the inner wall of the opening of the separator 400 is controlled to be, for example, 0.5 mm or more (for example, 0.5 mm or more and 1.6 mm or less). Thereby, the singulated glass integrated sheet 2456 is obtained. The singulated glass integration sheet 2456 may press the glass film 200 against the first adhesive portion 600 through the nip between the pair of nip rollers 3a and 3b. After that, the singulated glass-integrated sheet 2456 may be wound into a roll by the winding unit 4, as shown in FIG. 4(e).

The illustrated example shows an example in which the longitudinal direction of the rectangular glass film 200 and the MD direction of the long carrier film are parallel, but the relationship between the longitudinal direction of the glass film 200 and the MD direction is not limited to this. .

FIG. 5 is a plan view showing an arrangement example of the glass films 200 on the singulated glass integrated sheet 2456. As shown in FIG. FIG. 5( a ) is of the same type as the singulated glass integrated sheet shown in FIG. 4 . FIG. 5B shows an example in which the longitudinal direction of the rectangular glass film 200 and the TD direction of the long carrier film are parallel. FIG. 5(c) shows an example in which the longitudinal direction of the rectangular glass film 200 and the TD direction of the long carrier film are inclined at a predetermined angle.

In the case of an optical laminate used for a flexible flat panel display (FPD) display panel or the like, the glass film is required to be rolled or bent. When the direction in which the glass film is rolled or bent (that is, the circumferential direction of the peripheral surface formed when the glass film is rolled or bent) is the first direction, the first direction and the MD direction are the same. The arrangement direction of the glass film in the singulated glass integrated sheet may be determined so as to be parallel (the first direction and the TD direction are perpendicular).

The second to fourth steps of the manufacturing method A will be described below with reference to the drawings. FIG. 6A is an explanatory diagram showing part of an example of the process for obtaining the long laminate 10D (10C). FIG. 6B is an explanatory diagram showing part of an example of a process for obtaining a long laminate 10C following the process shown in FIG. 6A. In addition, in FIGS. 6A and 6B , processes that can be omitted are surrounded by rectangles drawn with dashed lines that are R-chamfered.

<Second stage>
The second stage has a fifth step of preparing a second raw material sheet 130 having a long base film 100 and a first adhesive 300 a applied to the base film 100 . For example, the base film 100 is unwound from a long base film 100 wound in a roll, and the first adhesive 300a is continuously applied to the unwound portion.

The method of applying the first adhesive 300a includes air doctor coating, blade coating, knife coating, reverse coating, transfer roll coating, gravure roll coating, kiss coating, cast coating, spray coating, slot orifice coating, calender coating, and electric coating. Coating methods such as dye coating, dip coating, and die coating; letterpress printing methods such as flexographic printing, direct gravure printing methods, intaglio printing methods such as offset gravure printing methods, lithographic printing methods such as offset printing methods, screen printing methods, etc. A printing method such as a stencil printing method can be used.

The thickness of the coating film of the first adhesive 300a is, for example, 0.5 μm or more and 20 μm or less, may be 1 μm or more and 15 μm or less, or may be 3 μm or more and 10 μm or less.

By forming a sufficiently thick coating film of the first adhesive 300a in the fifth step, part of the first adhesive 300a can be used for forming the second adhesive portion 310 in the subsequent process. In this case, the operation of separately using the second adhesive 310a in subsequent processes can be omitted.

<Third stage>
The third step has a sixth step of laminating the singulated glass integration sheet 2456 and the second raw material sheet 130 . The glass film 200 (and the separator 400) of the singulated glass integrated sheet 2456 is attached to the second raw material sheet 130 via the coating film of the first adhesive 300a.

When the coating film of the first adhesive 300a is sufficiently thick, for example, 5 μm or more and 10 μm or less, a part of the first adhesive 300a is used as the second adhesive 310a on the side surface (periphery) of the glass film 200. and the inner wall of the opening OP of the separator 400 (see FIG. 4D) to cover the side surface of the glass film 200 .

When part of the first adhesive 300a does not act as the second adhesive 310a, before the sixth step (that is, before laminating the singulated glass integrated sheet 2456 and the second raw material sheet 130) A step of filling the gap SP between the side surface (periphery) of the glass film 200 and the inner wall of the opening OP of the separator 400 with the second adhesive 310a to cover the side surface of the glass film 200 may be further performed.

When the first adhesive 300a is a UV curable adhesive, the laminate of the singulated glass integrated sheet 2456 and the second raw material sheet 130 is subjected to a UV irradiation step. In this case, the second adhesive 310a, which is separately used as necessary, also uses a UV curable adhesive. However, the first adhesive 300a may be cured by other methods. By UV irradiation, the first adhesive portion 300 is formed from the first adhesive 300a, and the second adhesive portion 310 is formed from the second adhesive 310a.

The first adhesive 300a has an adhesive force between the first adhesive portion 300 and the glass film 200 and an adhesive force between the first adhesive portion 300 and the separator 400, both of which are, for example, 0.1 N/mm or more. is selected so that

By the sixth step, a long laminated body 10C including the base film 100, the separator 400, the first adhesive portion 300, and the plurality of glass films 200 bonded to the first adhesive portion 300 is formed. At this stage, the carrier film 500 is stuck to the glass film 200 via the first adhesive portion 600 . That is, a long laminate 10D with a carrier film is obtained. After that, the carrier film-attached long laminate 10D may be wound into a roll as an optional step.

<Fourth stage>
The fourth step is to further process the carrier film-attached long laminate 10D. For example, a seventh step of peeling off the carrier film 500 and the first adhesive portion 600 from the long laminate 10D with the carrier film to obtain the long laminate 10C is performed. After the seventh step, an eighth step is performed in which laminated bodies separated into pieces for each glass film are cut out from the long laminated body along predetermined cutting lines.

After the seventh step and before the eighth step, the ninth A step of forming the surface coating layer 700 on at least a part of the main surface of the glass film 200 opposite to the first bonding portion 300 side is performed. good too. Further, on the main surface of the glass film 200 opposite to the first adhesive portion 300 side, an arbitrary base film 100A selected from the base films described above is attached via an arbitrary adhesive portion or adhesive portion 300A. A ninth B step of stacking may be performed.

Examples of the surface coat layer 700 include an anti-fingerprint coat layer, a hard coat layer, an antireflection layer, an antiglare layer, an antifouling layer, an antisticking layer, a hue adjustment layer, an antistatic layer, an easy adhesion layer, and an ingredient deposition prevention layer. layers, shock absorbing layers, shatterproof layers, and the like. The surface coat layer can be composed of various materials, and the anti-fingerprint coat layer includes, for example, fluorine resin, silicone resin, and the like. Other surface coating layers are formed of, for example, acrylic coating agents, melamine coating agents, urethane coating agents, epoxy coating agents, silicone coating agents, inorganic coating agents, and the like. Coating agents include silane coupling agents, colorants, dyes, pigments, fillers, surfactants, plasticizers, antistatic agents, surface lubricants, leveling agents, antioxidants, light stabilizers, UV absorbers, Additives such as polymerization inhibitors and antifouling agents may be included.

Before the eighth step, an arbitrary adhesive portion or adhesive portion (second adhesive portion or third adhesive portion) is formed on the main surface (back surface) of the base film 100 opposite to the first adhesive portion 300 side. A tenth step of laminating an arbitrary film member may be performed via the substrate. The tenth step may be performed before the seventh step or after the seventh step. Any film member may be the optical film described above, or may be a separator. The film member laminated on the back surface is selected according to the application of the laminate. One film member or two or more film members may be laminated on the back surface.

In the eighth step of singulating the laminate along a predetermined cutting line from the long laminate, the cutting line includes at least the first portion and may further include the second portion. FIG. 7 is an explanatory view showing an example of the process of singulating the laminate from the long laminate 10C.

The first portion LA is set in a region between the side surface of the glass film 200 and the inner wall of the opening of the separator 400 so as to be spaced apart from the side surface of the glass film 200 and surround the glass film 200 . Since the first portion LA of the cutting line is set in a region where the fragile glass film 200 is not cut, cutting is very easy.

The second portion LB is set to a portion that does not cross the glass film 200 from one end to the other end in the width direction of the long laminate 10C (FIG. 7(a)). By cutting the long laminate 10C along the second portion LB, a large sheet 10E including a plurality of glass films 200 (nine in the illustrated example) is formed (FIG. 7(b)). The length of the large sheet 10E is arbitrarily selected in consideration of ease of handling. After that, the large-sized sheet 10E is cut along the first portion LA, and the individualized laminate 10 is cut out from the large-sized sheet 10E (FIG. 7(c)).

Any cutting method may be used for the step of obtaining the individualized laminate (that is, the step of cutting the long laminate), but the long laminate or large sheet is cut along the cutting line with a laser. It is desirable that the method of cutting is quick and accurate. The type of laser is not particularly limited, but semiconductor lasers, gas lasers such as CO ₂ lasers, and the like can be used.

A bending test may be performed at any timing after the sixth step. In the bending inspection, the presence or absence of cracks in the glass film 200 is checked.

[Method for inspecting bending of long laminate]
In the bending inspection method, for example, one surface of the long laminate is conveyed at an embrace angle of 150 ° or more along the peripheral surface of a guide member (first guide member) having a peripheral surface with a radius of curvature of 5 mm or less. You may have a process. According to such a bending inspection method, the bending inspection of a plurality of glass films included in the long laminate can be performed continuously while the long laminate is being transported, which is efficient. That is, unlike the conventional art, it is not necessary to perform bending inspection of the glass film of the laminated body that has been separated into pieces for each laminated body, which can greatly save labor and time.

Also here, by setting the indentation elastic modulus of the first adhesive portion at 25° C. to 1×10 ⁸ Pa or more, it is possible to further reduce the probability that the glass film contained in the long laminate will break in the bending inspection method. .

It is desirable that no cracks occur in any of the glass films contained in the long laminate itself in the bending test. For example, if the probability of occurrence of cracks is 30% or less, or even 20% or less on a number basis, it may be considered that cracks do not actually occur.

A guide member having a peripheral surface with a curvature radius of 5 mm or less may be, for example, a roller with a radius of 5 mm or less. The length of the roller having a radius of 5 mm or less in the direction of the rotation axis may be greater than or equal to the length of the long laminate in the lateral direction (width direction). In this case, the roller itself, which is the guide member, bends (slightly curves), and there is a possibility that the peripheral surface of the central portion of the roller in the axial direction cannot come into contact with the long laminate with sufficient pressure. On the other hand, by using the backup roller, it is possible to suppress bending of the roller, which is the first guide member.

The guide member may be a plate member having a peripheral surface with a radius of curvature of 5 mm or less on the end face. Such a plate-like member has, on its end face, a peripheral surface similar to a part of the peripheral surface of the roller with a radius of curvature of 5 mm or less. On the other hand, the end face of the plate member is less likely to bend or curve like a roller. Therefore, the central portion in the axial direction of the peripheral surface of the guide member and the long laminated body can always be brought into contact with each other with sufficient pressure.

Here, the "axis of the peripheral surface" refers to a set of centers of curvature radii that regulate the curvature of the peripheral surface. The "embracing angle" corresponds to the central angle of the arc when the portion of the peripheral surface of the guide member that contacts the long laminated body is viewed from the direction of the axis of the peripheral surface. For example, when a plurality of rolls are used as guide members, the embrace angle corresponds to the bending angle of the long laminate from roll to roll.

In the bending inspection method, the other surface of the long laminate conveyed by the guide member as described above is further placed on the peripheral surface of another guide member (second guide member) having a peripheral surface with a curvature radius of 5 mm or less. It may have a step of conveying along and at an embrace angle of 150° or more. When performing this step, the long laminate is sequentially bent in both one side and the other side directions with a large curvature. Also here, if the probability of occurrence of cracks is 30% or less, or even 20% or less based on the number, it may be considered that cracks do not actually occur.

The glass film may be a glass film that is used by being rolled or bent. The glass film may be rolled or bent at any timing by the user. The glass film may be a glass film that is used by being rolled or bent in a predetermined direction (the direction of rolling or bending is predetermined). When the direction in which the glass film is rolled or bent (that is, the circumferential direction of the peripheral surface formed when the glass film is rolled or bent) is the first direction, the first direction and the first and second It may be parallel to the circumferential direction of the peripheral surface of the guide member. That is, the glass film may be a glass film that is used by being rolled or bent so as to be convex or concave in the normal direction of the peripheral surfaces of the first and second guide members. The glass film may be, for example, a front plate for a display panel that is used by being rolled or bent in the first direction. According to the bending inspection method according to the present embodiment, the bending resistance of such a glass film can be evaluated easily and efficiently.

The bend inspection method may be incorporated into the long laminate manufacturing method. That is, the step of bend inspection may be part of the steps of the manufacturing method. For example, the method for manufacturing a long laminate is a step of transporting one surface of the long laminate along the peripheral surface of a first guide member having a peripheral surface with a radius of curvature of 5 mm or less at an embrace angle of 150° or more. may include When the glass film is used by being rolled or bent in the first direction, the first direction may be parallel to the circumferential direction of the first guide member. That is, the glass film may be a glass film that is used by being rolled or bent so as to be convex or concave in the normal direction of the peripheral surface of the first guide member. In the case of manufacturing method A, the step of bend inspection may be performed at any timing as long as it is after the sixth step.

In the method for manufacturing a long laminate, the other surface of the long laminate conveyed by the first guide member is held along the peripheral surface of the second guide member having a peripheral surface with a radius of curvature of 5 mm or less. It may have a step of conveying at an angle of 150° or more. When the glass film is used by being rolled or bent in the first direction, the first direction and the circumferential direction of the circumferential surface of the second guide member may be parallel. That is, the glass film may be a glass film that is used by being rolled or bent so as to be convex or concave in the normal direction of the peripheral surface of the second guide member. In the bending test, when the long laminate is sequentially bent to one side and the other side and then wound into a roll, it is desirable that the glass film is wound inward.

The first direction may be parallel to the longitudinal direction (MD direction) of the long laminate, or may be inclined with respect to the MD direction.

FIG. 8 shows how the long laminated body 10C is conveyed along the peripheral surface of the roller 5 having a radius of 5 mm or less, which is a guide member. FIG. 8(a) is a plan view of the long laminated body 10C viewed from the normal direction, and FIG. 8(b) is a cross-sectional view of the guide member 5 and the backup roller 6 viewed along line bb. The first direction, which is the direction in which the glass film is rolled or bent, is parallel to the MD direction. The roller 5 is supported by a backup roller 6 so as to receive the pressing force from the long laminate 10C.

FIG. 9 shows how the long laminated body 10C is conveyed along the peripheral surface 7s having a radius of 5 mm or less of the plate member 7, which is a guide member. 9(a) is a plan view of the long laminated body 10C viewed from the normal direction, and FIG. 9(b) is a cross-sectional view of the guide member 7 viewed along line bb. Point 7c is the center of the radius of curvature of peripheral surface 7s. The first direction, which is the direction in which the glass film is rolled or bent, is inclined with respect to the MD direction and parallel to the circumferential direction of the circumferential surface 7s.

Note that the long laminate to be subjected to the bending inspection method is not limited to the long laminate described in the present embodiment. Any long laminate containing a glass film can be subjected to the bend inspection method, and the bendability of the glass film can be inspected. Specifically, in the bending inspection method, one surface of an arbitrary long laminate is conveyed at an embrace angle of 150° or more along the peripheral surface of a first guide member having a peripheral surface with a radius of curvature of 5 mm or less. It may be an inspection method having steps. In such an inspection method, the other side of any long laminate conveyed by the first guide member is further held along the peripheral surface of the second guide member having a peripheral surface with a radius of curvature of 5 mm or less. It may have a step of conveying at an angle of 150° or more. Also here, the glass film is a glass film that is used by being rolled or bent in the first direction, and the first direction is parallel to the circumferential directions of the circumferential surfaces of the first guide member and the second guide member. There may be.

Among them, the bend inspection method according to the present disclosure is suitable when any long laminate includes a plurality of glass films arranged along the longitudinal direction. This is because the bendability of all or most of a plurality of glass films can be efficiently inspected in a series of steps. The plurality of glass films may be attached to the long base film by the adhesive portion. However, from the viewpoint of suppressing the peeling of the glass film from the base film during transportation, the glass film and the base film are bonded to each other at a bonding portion such as the above-described first bonding portion or second bonding portion. It is desirable to be In that case, it is desirable that the adhesive force between the adhesive portion and the glass film is, for example, 0.1 N/mm or more.

[Example]
EXAMPLES The present invention will be specifically described below based on examples and comparative examples, but the present invention is not limited to the following examples.

<<Examples 1 to 5>>
The following materials were prepared.
(Base film)
A polyethylene terephthalate (PET) film (“Diafoil S100 (registered trademark)” manufactured by Mitsubishi Chemical Corporation) having a thickness of 50 μm was prepared.

(glass film)
An ultra-thin glass sheet ("G-leaf (registered trademark)" manufactured by Nippon Electric Glass Co., Ltd.) having a thickness of 30 μm was prepared. The glass film had a rectangular shape in plan view and a size of 30 mm×120 mm.

(Adhesive A)
An epoxy adhesive composition (adhesive A) was prepared by blending the following materials.
Alicyclic epoxy resin (“Celoxide 2021P” manufactured by Daicel Co., Ltd., epoxy equivalent 128 to 133 g / eq.) 70 parts by mass Trifunctional aliphatic epoxy resin (“EHPE3150” manufactured by Daicel Co., Ltd., epoxy equivalent 170 to 190 g / eq.) ) 5 parts by mass oxetane resin ("Aron oxetane" manufactured by Toagosei Co., Ltd.) 19 parts by mass Silane coupling agent (3-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd. "KBM-403") 4 parts by mass Part Photoacid generator (triarylsulfonium salt, San-Apro Co., Ltd. "CPI101A") 2 parts by mass

[Formation of laminate]

The adhesive layer A was applied to a glass film to form a coating film, and then the substrate film was attached to the coating film. Thereafter, the coating film was irradiated with ultraviolet rays from the glass film side to cure the coating film, and a 3 μm-thick adhesive portion was formed between the glass film and the substrate film to obtain a laminate. However, the laminate was formed so that the side surface of the glass film was located inside the side surface of the base film when the laminate was viewed from above. By changing the size of the base film, the separation distance G1 from the side surface of the glass film to the side surface of the base film was changed. Table 1 shows the separation distance G1 in Examples 1 to 5.

<Evaluation>

A pressure-sensitive adhesive was prepared by the following procedure, a pressure-sensitive adhesive portion was formed on a substrate film as a substitute for another film member, and the laminate was adhered to the pressure-sensitive adhesive portion to prepare a sample for evaluation. That is, the sample simulates a product in which a laminate including a substrate film, a glass film, and an adhesive portion for bonding these is laminated with another film member (such as an optical film).

(adhesive)
The following materials were blended, and the blend was irradiated with ultraviolet rays for polymerization to obtain a base polymer composition (polymerization rate: about 10%).
Lauryl acrylate (LA) 43 parts by mass 2-ethylhexyl acrylate (2EHA) 44 parts by mass 4-hydroxybutyl acrylate (4HBA) 6 parts by mass N-vinyl-2-pyrrolidone (NVP) 7 parts by mass BASF Corporation "Irgacure 184 (registered Trademark)” 0.015 parts by mass

Separately, an acrylic oligomer was prepared by the following procedure. First, the following materials were mixed and stirred at 70° C. for 1 hour in a nitrogen atmosphere to obtain a polymerization solution.
Dicyclopentanyl methacrylate (DCPMA) 60 parts by mass Methyl methacrylate (MMA) 40 parts by mass α-thioglycerol 3.5 parts by mass Toluene 100 parts by mass

0.2 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) was added to the polymerization liquid, and the mixture was reacted at 70°C for 2 hours, then heated to 80°C and reacted for 2 hours. After that, the reaction solution was heated to 130° C. to remove the toluene, the chain transfer agent and the unreacted monomer by drying to obtain a solid acrylic oligomer. The acrylic oligomer had a weight average molecular weight of 5,100. The glass transition temperature (Tg) was 130°C.

Based on 100 parts by mass of the base polymer composition, 0.07 parts by mass of 1,6-hexanediol diacrylate (HDDA), 1 part by mass of an acrylic oligomer, and a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd. "KBM403" ) was added, and these were uniformly mixed to prepare an adhesive.

The pressure-sensitive adhesive was applied to the surface of a base film whose surface was subjected to a release treatment to form a coating film, and then the base film whose surface was similarly subjected to a release treatment was attached to the coating film. Next, the coating film was irradiated with ultraviolet rays to form a 25 μm-thick adhesive portion sandwiched between the pair of base films. After that, one base film was peeled off to obtain an adhesive portion formed on the base film.

[Preparation of sample]
The base film side of the laminate composed of the base film, the glass film, and the adhesive portion interposed therebetween is attached to the adhesive portion formed on the above another base film, and the load ratio ( Samples were prepared for indentation testing to determine edge/center).

The permissible load (W1) at the edge and the permissible load (W2) at the center of the laminate were measured by the method described above, and the W1/W2 ratio was calculated as the load ratio (edge/central).

Next, the indentation elastic modulus (E) of the bonded portion was measured by the method described above using a separately prepared test piece of the bonded portion. In addition, the indentation modulus (E) was similarly measured for the adhesive portion formed on the base film.

Next, using a laminate composed of a substrate film, a glass film, and an adhesive portion interposed therebetween, the adhesive strength between the adhesive portion and the glass film was measured by the method described above. As a result, the adhesive strength was 1 N/mm.

The evaluation results of Examples 1 to 5 are shown in Table 1 together with the evaluation results of Comparative Examples 1 to 3 described later. In Table 1, laminates A1-A5 correspond to Examples 1-5, and laminates B1-B3 correspond to Comparative Examples 1-3. The symbols in the table represent the following.
E: indentation modulus (Pa)
W1: Allowable load at the end (g)
W2: Permissible load at the center (g)
W1/W2: load ratio (end/center)

《比較例１》
基材フィルム上に形成された粘着部にガラスフィルムを直接貼り付けたサンプルを作製し、既述の方法で、積層体の端部の許容荷重（Ｗ１）および中央部の許容荷重（Ｗ２）を測定し、荷重比（端部／中央部）（Ｗ１／Ｗ２）を算出した。

<<Comparative example 1>>
A sample was prepared by directly attaching the glass film to the adhesive portion formed on the base film, and the allowable load (W1) at the end of the laminate and the allowable load (W2) at the center were measured by the method described above. It was measured and the load ratio (end/center) (W1/W2) was calculated.

<<Comparative Example 2>>
A laminate was formed in the same manner as in Examples, except that the size of the base film was reduced and the side surface of the glass film was positioned 100 µm outside the side surface of the base film when the laminate was viewed in plan. , was similarly evaluated.

<<Comparative Example 3>>
(Adhesive B)
An acrylic adhesive composition (adhesive B) was prepared by blending the following materials. A laminate was formed in the same manner as in Example 4, except that the adhesive B was used, and evaluated in the same manner.
4-hydroxybutyl acrylate (functional group-containing (meth) acrylic ester monomer manufactured by Osaka Organic Chemical Industry Co., Ltd.) 75 parts by mass N-(2-hydroxyethyl) acrylamide (amide group-containing vinyl monomer manufactured by KJ Chemicals Co., Ltd.) 25 Parts by mass Photopolymerization initiator (BASF "Irgacure 819") 0.5 parts by mass

In Comparative Example 1, the permissible load (W1) at the edge and the permissible load (W2) at the center were both very low, and the glass film cracked at a load of 450 g or less than 500 g. This is probably because the pressure-sensitive adhesive portion is soft and the pressing load is small, so the force pressing against the glass film is not relieved, and the distortion occurring in the glass film increases.

In Comparative Example 2, the allowable load (W2) at the central portion is sufficiently large, but the allowable load (W1) at the end portions is insufficient. As a result, the load ratio (end/center) indicated by W1/W2 is less than 0.9. This is because the edges of the glass film protrude from the base film, and the base film cannot sufficiently support the edges of the glass film.

In Comparative Example 3, the indentation elasticity modulus of the adhesion portion was less than 1×10 ⁸ Pa, although the adhesion portion had a much higher indentation elasticity modulus than the adhesion portion. Both the load (W1) and the allowable load (W2) of the central portion are insufficient.

On the other hand, in Examples 1 to 5, both the allowable load (W1) at the end and the allowable load (W2) at the center are sufficiently large, and the load ratio (end/center) indicated by W1/W2 is maintained above 0.9. By comparing Examples 1 to 5, it can be understood that the distance G1 from the side surface of the glass film to the side surface of the base film is desirably 50 μm or more, and more desirably 100 μm or more.

INDUSTRIAL APPLICABILITY The present disclosure can contribute to improving the performance of optical laminates used for display panels of flat panel displays (FPDs), for example.

10, 10B: Laminated body 10C, 10D: Long laminated body 10M: Central part 10T: End part 10E: Large sheet 100: Base film 130: Second raw material sheet 200: Glass film 300: First adhesive part 300a: Second 1 Adhesive 310: Second Adhesive Part 456: First Raw Material Sheet 400: Separator 410: Part to be Peeled 500: Carrier Film 600: First Adhesive Part 2456: Single Glass Integrated Sheet L1: Line Segment LA: First Part LB: Second part 1: Unwinding part 2: Half cut device 3a, 3b: Nip roller 4: Winding part S: Slit C1, C2: Corner G1, G2, G3: Separation distance C3: Corner part P: Contact Point OP: opening 5: roller 6: backup roller 7: plate member 7s: peripheral surface 7c: center of curvature radius of peripheral surface 7s

Claims (11)

a base film;
glass film,
a first bonding portion that bonds the base film and the glass film;
A laminate comprising
In plan view, the side surface defining the outer periphery of the glass film is located inside the side surface defining the outer periphery of the base film,
The laminate, wherein the indentation elastic modulus at 25° C. of the first adhesive portion is 1×10 ⁸ Pa or more. The laminate according to claim 1, wherein the glass film has a thickness of 100 µm or less. The ratio of the allowable load at the end of the laminate to the allowable load at the center of the laminate is 0.9 or more,
The permissible load was measured by placing the laminate on a horizontal table and applying three points from the glass film side to each of the end portion and the central portion of the laminate with a diameter of 0.7 mm at the tip of the ballpoint pen from the vertical direction. 3. The laminate according to claim 1, wherein the load is measured in units of 50 g at which the glass film does not crack at two or more points when pressed with a ball. 4. The laminate according to any one of claims 1 to 3, wherein the distance from the side surface of the glass film to the side surface of the base film is greater than 50 μm in plan view. The laminate according to any one of claims 1 to 4, wherein the first adhesive that forms the first adhesive portion is an ultraviolet curing type. The laminate according to any one of claims 1 to 5, wherein a second adhesive portion is arranged on the side surface of the glass film. 7. The laminate according to claim 6, wherein the second adhesive forming the second adhesive part is an ultraviolet curing type. 8. The laminate according to claim 7, wherein said first adhesive and said second adhesive are adhesives having the same composition. In plan view, the separation distance from the side surface defining the outer periphery of the second adhesive portion to the side surface of the glass film and the separation distance from the side surface of the glass film to the side surface of the base film are the same. The laminate according to any one of claims 6 to 8. 10. The method according to claim 9, wherein the side surface of the second adhesive portion is flush with the side surface of the base film from the main surface of the glass film on the side of the base film to the opposite main surface thereof. laminate. The laminate according to any one of claims 1 to 10, wherein the adhesive force between said first adhesive portion and said glass film is 0.1 N/mm or more.

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