CN117222521A

CN117222521A - Laminate body

Info

Publication number: CN117222521A
Application number: CN202280031315.5A
Authority: CN
Inventors: 矢野孝伸; 朝比奈太郎
Original assignee: Nitto Denko Corp
Current assignee: Nitto Denko Corp
Priority date: 2021-04-27
Filing date: 2022-04-26
Publication date: 2023-12-12
Also published as: WO2022230892A1; KR20240001321A; JP2022169387A

Abstract

A laminate comprising a base film, a glass film, and a first adhesive portion for adhering the base film and the glass film, wherein the side surface defining the outer periphery of the glass film is positioned further inside than the side surface defining the outer periphery of the base film in a plan view, and the first adhesive portion has a press-in elastic modulus of 1 x 10 at 25 DEG C ⁸ Pa or more.

Description

Laminate body

Technical Field

The present invention relates to a laminate of display panels, for example, for Flat Panel Displays (FPDs).

Background

In general, a laminate of a glass film and a support substrate is produced by laminating a support substrate and a glass film having the same width. However, it is difficult to laminate sheets of the same size without any offset at all. A slight offset must be generated at the time of lamination. For example, in the case of a laminate having a rectangular shape in plan view, the end portions of the glass film protrude on either one of four sides. The edge of the glass film from which the end portion protrudes has a problem that the glass film is easily broken by pressing the end portion.

On the other hand, patent document 1 proposes a display device including: cover glass; a cover adhesive member disposed at a lower portion of the cover glass; a display panel disposed at a lower portion of the cover adhesive member; and a back plate disposed at a lower portion of the display panel, wherein the cover adhesive member covers at least one side surface of the cover glass in at least one bending region where the cover glass, the cover adhesive member, the display panel, and the back plate are bendable.

Patent document 2 proposes 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, wherein the position of the end portion of the adhesive layer is located outside the position of the end portion of the optical film layer at least in part.

Patent document 3 proposes a protective member for a display device, which includes: a first glass substrate including one surface and the other surface and the side surfaces facing each other in the thickness direction; and a first functional coating layer disposed so as to cover and contact the side surface of the first glass substrate, including one surface facing each other in the thickness direction, another surface, and a side surface, the first functional coating layer exposing the one surface of the first glass substrate, the one surface of the first functional coating layer being located on an extended surface of the one surface of the first glass substrate.

Prior art literature

Patent literature

Patent document 1: korean laid-open patent publication No. 1020190078226

Patent document 2: japanese patent laid-open No. 2019-199081

Patent document 3: korean laid-open patent publication No. 1020200090292

Disclosure of Invention

Problems to be solved by the invention

Even in the case where the end portion of the glass film does not protrude, if the adhesion portion or the bonding portion between the glass film and the support substrate does not have sufficient hardness, the end portion of the glass film is fragile with respect to pressing, and the problem that the end portion of the glass film is easily broken cannot be solved. This is considered to be because the adhesive portion or the bonding portion is deformed by the force pressing the end portion of the glass film, and the strain of the end portion of the glass film becomes large.

Means for solving the problems

One aspect of the present disclosure relates to a laminate including a base film, a glass film, and a first adhesive portion for adhering the base film and the glass film, wherein a side surface defining an outer periphery of the glass film is located inside a side surface defining the outer periphery of the base film in a plan view, and a press-in elastic modulus of the first adhesive portion at 25 ℃ is 1×10 ⁸ Pa or more.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present disclosure, the end portion of the glass film included in the laminate has high resistance to pressing.

The novel features of the invention, both as to its organization and content, together with further objects and features thereof, are best understood from the following detailed description when read with the accompanying drawings.

Drawings

Fig. 1A is a schematic cross-sectional view (a) and a plan view (b) showing the structure of a laminate according to an embodiment of the present disclosure.

Fig. 1B is a schematic cross-sectional view (a) and a plan view (B) showing the structure of a laminate according to another embodiment of the present disclosure.

Fig. 2A is an explanatory diagram of a procedure before a method for measuring the adhesion force between the adhesion portion and the glass film.

Fig. 2B is an explanatory view of a procedure after the method of measuring the adhesion force between the adhesion portion and the glass film.

Fig. 2C is a diagram showing the contact point between the ball and the center portion when the allowable load is obtained.

Fig. 2D is a diagram showing the contact points between the balls and the end portions when the allowable load is obtained.

Fig. 3A is a plan view showing the structure of an elongated laminate according to an embodiment of the present disclosure.

Fig. 3B is a cross-sectional view of the elongated laminate at line B-B of fig. 3A.

Fig. 4 is an explanatory diagram showing an example of a process for obtaining a monolithic glass body sheet.

Fig. 5 is a plan view showing an example of arrangement of glass films in a monolithic glass integrated sheet.

Fig. 6A 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 subsequent to the process shown in fig. 6A.

Fig. 7 is an explanatory diagram showing an example of a process of singulating a laminate from a long laminate.

Fig. 8 is an explanatory view of an example of the bending inspection method.

Fig. 9 is an explanatory view of another example of the bending inspection method.

Detailed Description

The laminate, the long laminate, the method for manufacturing the same, and the method for inspecting bending according to the embodiment of the present disclosure will be described in order. However, the laminate, the long laminate, the methods for manufacturing the same, and the bending inspection method of the present disclosure are not limited to the following embodiments.

In addition, although the term "parallel" is often used, it is not necessarily strictly parallel, and one and the other may deviate from a parallel arrangement to such an extent that they have an angle of, for example, less than 10 ° (or less than 5 °). Similarly, although the term "vertical" is often used, it is not necessarily strictly vertical, and one and the other may deviate from the vertical arrangement to such an extent that they have an angle of, for example, 80 ° or more and 100 ° or less (or 95 ° or more and 95 ° or less).

In the case of referring to the drawings, the shapes and sizes of the respective constituent elements are not shown in the same scale as the actual ones. The relative relationship between these dimensions is schematically and emphasized in order to clarify the characteristics of the respective constituent elements.

[ laminate ]

The laminate of an embodiment of the present disclosure is an optical laminate for a display panel of a Flat Panel Display (FPD), for example. The FPD is not particularly limited, and typically refers to a thin image display device such as a liquid crystal display device or an organic EL display device.

The laminate is provided with a base film, a glass film, and a first adhesive portion for adhering the base film to the glass film. The base film may be any film that can support a glass film, and has a light transmittance that transmits predetermined light.

The side surface defining the outer periphery of the glass film (also simply referred to as the side surface of the glass film) is located further inside than the side surface defining the outer periphery of the base film (also simply referred to as the side surface of the base film) in a plan view.

The plane view means that the glass film and the substrate film are viewed from the normal direction of the glass film or the substrate film. The meaning of the plan view is the same as below.

In other words, the outer periphery of the base film extends from the outer periphery of the glass film over the entire periphery. By positioning the outer periphery of the glass film having weak strength inside the outer periphery of the base film, the resistance of the end portion of the glass film to pressing is increased. This is considered to be because the base material film can receive the force pressing the end portion of the glass film on the surface, and the base material film can alleviate the stress applied to the glass film by the pressing over a larger area.

However, the press-in elastic modulus of the first adhesive portion at 25℃was set to 1X 10 ⁸ Pa or more. This significantly improves the resistance of the end portion of the glass film to pressing. From the viewpoint of more significantly improving the resistance of the end portion of the glass film to pressing, the press-in elastic modulus of the first adhesive portion at 25℃may be set to 5X 10 ⁸ Pa or more, further set to 1×10 ⁹ Pa or more.

The significant improvement in the resistance to pressing of the end portions of the glass film can be evaluated, for example, by the ratio of the allowable load of the end portions of the laminate to the allowable load of the central portion of the laminate (hereinafter, also referred to as "load ratio (end portion/central portion)"). The pressing elastic modulus at 25 ℃ of the first bonding part is setIs set to 1 multiplied by 10 ⁸ In the case of Pa or more, the load ratio (end portion/center portion) can be set to 0.9 or more.

The separation distance (hereinafter also referred to as "separation distance G1") from the side surface (outer periphery) of the glass film to the side surface (outer periphery) of the base film in plan view is not particularly limited, and may be, for example, 10mm or less. From the viewpoint of suppressing the increase in the size of the laminate, the separation distance G1 may be 5mm or less or 3mm or less, may be 1mm or less or 800 μm or less, may be 500 μm or less, or may be 300 μm or less. On the other hand, from the viewpoint of receiving a force pressing the end portion of the glass film with a larger surface of the base film and relaxing the stress generated by the pressing with a larger area, the separation distance G1 may be 20 μm or more, or may be 50 μm or more, and preferably be more than 50 μm.

If the modulus of elasticity of the first adhesive portion at 25 ℃ is less than 1X 10 ⁸ Pa makes it difficult to sufficiently improve the resistance of the end portion of the glass film to pressing. This is considered to be because the first adhesive portion is deformed by the force pressing the end portion of the glass film, and the effect of the base material film receiving the force pressing the end portion of the glass film on the surface is canceled. In order to significantly improve the resistance of the end portion of the glass film to pressing, it is important to make the first adhesive portion have a sufficient hardness, that is, to make the first adhesive portion have a sufficient pressing elastic modulus. It is considered that the first adhesive portion has a sufficient hardness, so that the force pressing the end portion is smoothly transmitted to the base film directly below the pressing point, thereby stably relaxing the stress applied to the glass film and suppressing the strain at the end portion of the glass film.

In order to further improve the resistance of the end portion of the glass film to pressing, the storage modulus of the first adhesive portion at 25 ℃ may be 1GPa or more, and further 3GPa or more. On the other hand, from the viewpoint of imparting the laminate with moderate flexibility required for the FPD application, the storage modulus of the first adhesive portion at 25 ℃ may be 20GPa or less, or 10GPa or less. The storage modulus can be determined by performing dynamic viscoelasticity measurement.

In the laminate (typically, a laminate obtained by singulating a long laminate), the base film and the glass film may each be rectangular. Rectangular typically refers to a square or rectangular shape, but need not be exactly square or rectangular. For example, R-chamfering may be performed on the diagonal portion to form a rounded corner, or C-chamfering may be performed on the diagonal portion. The four sides may be formed of a line having some curvature or concavity and convexity, instead of a straight line.

In the laminate, the second adhesive portion may be disposed on a side surface defining the outer periphery of the glass film. At least a part (preferably all) of the side surface of the glass film may be covered with the second adhesive portion. Thus, the resistance of the end portion of the glass film to pressing becomes further high. The press-fitting elastic modulus of the second adhesive portion at 25 ℃ is not particularly limited, and may be, for example, a value of ±30% with respect to the press-fitting elastic modulus of the first adhesive portion at 25 ℃.

The separation distance (hereinafter, also referred to as "separation distance G2") from the side surface defining the outer periphery of the second adhesive portion (also referred to as "side surface of the second adhesive portion") to the side surface of the glass film may be the same as the separation distance G1 from the side surface of the glass film to the side surface of the base material film in plan view. That is, at least a part of the side surface of the second adhesive portion may be coplanar with the side surface of the base film from the main surface of the glass film on the first adhesive portion side toward the opposite side. At this time, the maximum thickness of the second adhesive portion from the side surface of the glass film in plan view has the same length as the separation distance G1. This improves the strength of the protruding portion of the base film in the laminate, and improves the operability of the laminate.

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

The base film may be a resin film made of a resin. The resin constituting the resin film may be a thermoplastic resin or a thermosetting resin. The thermoplastic resin is not particularly limited, and examples thereof include polyethersulfone resins; a polycarbonate resin; an acrylic resin; polyester resins such as polyethylene terephthalate resins and polyethylene naphthalate resins; a polyolefin resin; cycloolefin resins such as norbornene resins; polyimide resin; a polyamide resin; polyimide amide-based resins; polyarylate-based resins; polysulfone-based resin; polyetherimide resins, and the like. The thermosetting resin is not particularly limited, and examples thereof include epoxy resins, polyurethane resins, silicone resins, and the like.

The base film may further contain an appropriate amount of any additive according to the purpose. Examples of the additives include diluents, anti-aging agents, modifiers, surfactants, dyes, pigments, anti-discoloration agents, ultraviolet absorbers, softeners, stabilizers, plasticizers, antifoaming agents, and reinforcing agents.

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

The storage modulus of the base film at 25℃is not particularly limited, and may be, for example, 1.5GPa to 10GPa, 1.8GPa to 9GPa, or 1.8GPa to 8 GPa. If the amount is within such a range, the effect of supporting the glass film and protecting the glass film is high, and in the method for producing a laminate, the productivity of the laminate is further improved. The storage modulus can be determined by performing dynamic viscoelasticity measurement. As a resin constituting such a base film, polyethylene terephthalate (PET) resin is preferable.

The glass film is a thin glass plate having a uniform thickness. The composition of the glass constituting the glass film is not particularly limited, and examples thereof include soda lime glass, boric acid glass, aluminosilicate glass, quartz glass, and the like. The glass may be alkali-free glass or low alkali glass. Alkali metal component of glass (e.g., na ₂ O、K ₂ O、Li ₂ The total content of O) is, for example, 15 mass% or less, or 10 mass% or less.

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

The density of the glass film is, for example, 2.3g/cm ³ Above and 3.0g/cm ³ Hereinafter, the concentration may be 2.3g/cm ³ Above and 2.7g/cm ³ The following is given.

The glass film may be manufactured by any suitable method. Typically, the glass film is produced by melting a mixture containing a main 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 ℃ to 1600 ℃ and then cooling the molten mixture after forming the molten mixture into a film. Examples of the method for forming the glass film include a slot draw method, a fusion method, and a float method. The glass film obtained by these methods may be subjected to chemical polishing with a solvent such as hydrofluoric acid, if necessary, in order to further reduce the thickness and to improve the smoothness of the surface and the end portions.

In order to improve the adhesion to the first adhesion portion, the surface of the glass film may be subjected to a surface treatment such as corona treatment, plasma treatment, or coupling treatment.

The first adhesive portion is formed of a first adhesive. The first adhesive portion is formed by curing the first adhesive. The first adhesive portion has substantially no fluidity. In the present disclosure, the adhesive and the binder are distinguished. The adhesive is non-curable and has fluidity. The adhesive portion formed of the adhesive may have a press-in elastic modulus at 25℃of, for example, 1X 10 ⁶ Pa or below. The storage modulus of the adhesive portion formed of the adhesive at 25 ℃ may be, for example, 10MPa or less.

The first adhesive is first applied to the substrate film. Then, the base film and the glass film are bonded with the coating film of the first adhesive interposed therebetween. Thereafter, the first adhesive is cured to form a first adhesive portion. 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, or may be 0.5 μm or more and 3 μm or less. The larger the thickness of the first adhesive portion, the larger the adhesive force between the base material film and the glass film tends to be. The first adhesive may also be applied to the glass film. The substrate film and the glass film may be bonded to each other with the coating film of the first adhesive on the substrate film side and the coating film of the first adhesive on the glass film side interposed therebetween. In this case, the adhesion of the first adhesion portion tends to be further improved. In other words, when the first adhesive is applied to both the base film and the glass film, even if the first adhesive portion having the same thickness as that in the case where the first adhesive is applied only to the base film is formed, a higher adhesive force can be obtained.

The first adhesive is not particularly limited, and any suitable adhesive may be used. Examples of the first adhesive include adhesives containing resins having cyclic ether groups such as epoxy groups, glycidyl groups, and oxetane groups, acrylic resins, and silicone resins. The first adhesive is preferably ultraviolet curable. In the case where the first adhesive forming the first adhesive portion is ultraviolet curable, the productivity of the laminate can be further improved in the method for manufacturing the laminate.

The second adhesive portion is formed of 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 ultraviolet curable. In the case where the second adhesive forming the second adhesive portion is ultraviolet curable, the productivity of the laminate can be further improved in the method for manufacturing the laminate. The first adhesive and the second adhesive may be adhesives having the same composition. In other words, the second adhesive portion may be formed of the first adhesive. If the first adhesive is applied to the base film and the glass film, and the base film and the glass film are bonded to each other with the coating film of the first adhesive on the base film side and the coating film of the first adhesive on the glass film side interposed therebetween, the second adhesive portion in a good state is easily formed.

The adhesion force between the first adhesion portion and the glass film may be, for example, 0.1N/mm or more, or 0.2N/mm or more, or 0.5N/mm or more, or 1N/mm or more. By setting the adhesion force as described above, peeling at the interface between the glass film and the first adhesion portion can be more highly suppressed when the object collides with the glass film.

At least a part of the main surface of the glass film on the side opposite to the first adhesive portion side may be covered with a surface coating having various functions, or may be laminated with another base film or film member via any adhesive portion or adhesive portion. 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.

Any of the film members may be an optical film, a separator described later, or a release liner (or carrier film). The optical film is not particularly limited, and refers to, for example, a polarizing plate, a retardation plate, an isotropic film, and the like. Examples of the material constituting the optical film include 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 polyurethane-based resins, polysulfone-based resins, acetate-based resins, epoxy-based resins, and silicone-based resins. The optical film may be a metal film, an oxide metal film such as an ITO film, or a laminate film of a metal film and a resin film.

Embodiments of the present disclosure will be described below with reference to the drawings. In the drawings, the shapes and sizes of the constituent members are not necessarily shown to the same scale. In the drawings, the same constituent elements are referred to by the same reference numerals.

Fig. 1A is a schematic cross-sectional view (a) and a plan view (b) showing the structure of a laminate 10 according to an embodiment. The laminate 10 includes a base film 100, a glass film 200, And a first bonding portion 300 for bonding the base film 100 and the glass film 200. The side surface (outer periphery) of the glass film 200 is located inside the side surface (outer periphery) of the base film 100 over the entire periphery 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, for example, greater than 50 μm in plan view. The press-in elastic modulus of the first adhesive part 300 at 25 ℃ is set to be 1×10 ⁸ Pa or more. In this structure, the force pressing the end portion 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 bonded to the base film 100 by the first bonding portion 300.

The base film 100 and the glass film 200 are rectangular in plan view of the laminate 10, but this is merely an example, and for example, four corners C1 of the glass film 200 and/or four corners C2 of the base film 100 may be rounded by R-chamfering or C-chamfering in plan view. The four sides need not necessarily be straight lines.

As in the laminate 10A shown in fig. 1B, the second adhesive portion 310 may be disposed on the side surface of the glass film 200. As shown in fig. 1B (B), the entire side surface of the glass film 200 may be covered with the second adhesive portion 310.

The side surface of the second adhesive portion 310 is coplanar with the side surface of the base material film 100 from the main surface of the glass film 200 on the base material film 100 side to the main surface on the opposite side thereof (g1=g2). Therefore, the maximum thickness of the second bonding portion 310 in the direction in which the side surface of the glass film 200 separates from the side surface of the base film 100 in a plan view (the direction of the line segment L1 shown in fig. 1B) has the same length as the separation distance G1 between the side surface of the glass film 200 and the side surface of the base film 100. The thickness of the second adhesive portion 310 covering the corner (C3) where the main surface of the glass film 200 opposite to the first adhesive portion 300 and the side surface of the glass film 200 intersect also has the same length as the separation distance G1. As a result, the side surfaces defining the outer periphery of the laminate 10A are coplanar from one side to the other side in the thickness direction over the entire periphery.

The second adhesive portion 310 may be formed of the first adhesive together with the first adhesive portion 300. In this case, the first adhesive and the second adhesive have the same composition, and for example, the first adhesive before curing is applied to the base film in a thicker manner, and the first adhesive climbs up to the side surface of the glass film 200 and is cured to form the second adhesive portion 310.

< method for measuring physical Properties 1>

(1) Modulus of elasticity under pressure

(1-1) adhesive portion

The modulus of elasticity in press of the first adhesive portion and the second adhesive portion can be measured by nanoindentation according to ISO 14577. Specifically, first, a first adhesive or a second adhesive is applied to a surface of a film having a smooth surface, the surface of which has been subjected to a mold release treatment, to form a coating film. Then, a film having a smooth surface, which has been subjected to a mold release treatment as described above, is bonded to the coating film, and the coating film is cured to form a bonded portion having a thickness of 3 μm or more sandwiched between the pair of films. Then, one of the films was 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, thereby producing a test piece (sample). The pressing depth of the pressing head may be 100nm or less, and it is sufficient that the thickness of the sample is 3 μm or more.

The obtained test piece was set in a measuring apparatus (for example, a triboindenoster made of HYSITRON INCORPORATED used in examples and comparative examples described later), and the indentation elastic modulus at 25℃was obtained under the following measurement conditions. The measurement may be performed 5 times or more to obtain an average value.

Measurement conditions

Sample size: 10mm by 10mm

Pressure head: concial (spherical indenter: radius of curvature 10 μm)

The measuring method comprises the following steps: single press-in assay

Measuring temperature: 25 DEG C

Depth of press-in of press head: 100nm of

Analysis: load-displacement curve based "Oliver and Pharr resolution"

(1-2) adhesive portion

In the case of measuring the press-in elastic modulus of the adhesive portion having fluidity, a test piece (sample) was produced in the following procedure. First, an adhesive is applied to a surface of a film having a smooth surface, the surface of which has been subjected to a mold release treatment, to form a coating film. Then, a film having a smooth surface, which has been subjected to a mold release treatment as well, was bonded to the coating film, and ultraviolet irradiation (crosslinking process) was performed as needed, to form a bonded portion having a thickness of 25 μm sandwiched between the pair of films. Then, one of the films was peeled off and used as a test piece (sample). Using this test piece, the press-in elastic modulus at 25 ℃ was obtained in the same manner as the bonded portion. The measurement may be performed 5 times or more to obtain an average value.

(2) Storage modulus

(2-1) adhesive portion

The storage modulus of the first adhesive portion and the second adhesive portion may be in accordance with JIS K7244-1: 1998 as tensile storage modulus. Specifically, first, the first adhesive or the second adhesive is formed into a film shape and cured, and a cured film having a thickness of about 20 μm is produced. The film was cut into a predetermined size to prepare test pieces. Using this test piece, viscoelasticity was measured using a dynamic viscoelasticity measuring apparatus (for example, a multifunctional dynamic viscoelasticity measuring apparatus "DMS6100" manufactured by hitachi high technology, ltd.) under the following conditions, and the tensile storage modulus at 25 ℃ was obtained. The measurement may be performed 5 times or more to obtain an average value.

Measurement conditions

Temperature range: 100-200 DEG C

Heating rate: 2 ℃/min

Mode: stretching

Sample width: 10mm of

Distance between chucks: 20mm of

Frequency: 10Hz

Strain amplitude: 10 μm

Atmosphere: atmosphere (250 ml/min)

Data acquisition interval: 0.5min (every 1 ℃ C.)

(2-2) adhesive portion

The storage modulus of the adhesive layer formed of the adhesive may be in accordance with JIS K7244-1: 1998, in torsional mode. Specifically, the adhesive coating film was sandwiched between parallel plates, and the viscoelasticity was measured using a dynamic viscoelasticity measuring apparatus (for example, "Advanced Rheometric ExpansionSystem (ARES)", manufactured by Rheometric Scientific corporation) under the following conditions to obtain the storage modulus at 25 ℃. The measurement may be performed 5 times or more to obtain an average value.

Measurement conditions

Deformation mode: torsion

Measuring frequency: 1Hz

Measuring temperature: -40 to +150 DEG C

Temperature rise: 5 ℃/min

(3) Adhesive force

The adhesion between the first adhesive part and the glass film was measured using a surface/interface physical property analyzer "saicsin-20" manufactured by daiplawindows corporation, under the following conditions and by the following method. As shown in fig. 2A, the surface/interface physical property analysis device 41 includes a blade 42 having the following characteristics, a moving device not shown, and a pressure measuring unit. The blade 42 is movable. The blade 42 includes a cutting edge 43 formed at the distal end.

Characteristics of the blade 42

The material of the blade 42: single crystal diamond

Width of the cutting edge 43: 1mm of

Nose angle of nose 43: 10 degree

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

After cutting the blade edge 43 into the base film 100, as shown in fig. 2B, the blade edge 43 is also cut into the first adhesive part 300. When the edge 43 reaches the interface between the first adhesive part 300 and the glass film 200, the edge 43 is horizontally moved to the above-described side. Thereby, the first adhesive part 300 is peeled from the glass film 200. The peel strength at this time was measured as the adhesion force between the first adhesive part 300 and the glass film 200.

The adhesion force between the first adhesion part 300 and the separator, which will be described later, may be measured in the same manner by replacing the glass film with the separator. However, when the adhesive force between the first adhesive part 300 and the diaphragm is measured, the blade edge 43 is pushed into the diaphragm, and the blade edge 43 is cut into the diaphragm. When the edge 43 reaches the interface between the separator and the first adhesive part 300, the edge 43 is horizontally moved to the above side, and the peel strength of the first adhesive part 300 when peeled from the separator is measured as the adhesive force.

(4) Load ratio (end/center)

First, the allowable load of the end portions and the center portion of the laminate was measured by the press-in test. The laminate is placed on a horizontal table with the substrate film side facing downward (for example, a weighing tray called "SH-5000" by the name of A & D, which is used in examples and comparative examples, which will be described later). Balls having a diameter of 0.7mm from the tip end portion of a ballpoint pen for the vertical direction (for example, an oily ballpoint pen "BK407 black" (ball diameter of 0.7 mm) manufactured by PANTONE corporation used in examples and comparative examples described later) press 3 points of the end portion and the central portion of the laminate from the glass film side. In this case, the allowable load at the end and center of the glass film where no crack was generated was measured at 2 points or more in 50g units. Next, the allowable load at the end portion is divided by the allowable load at the center portion, and the load ratio (end portion/center portion) is calculated.

The pressing of the laminate was manually performed by standing the ballpoint pen vertically, and the load when cracking occurred at 2 points or more was read in 50g units. The rate of increase of the load may be controlled to be approximately 50g/1 second. For example, when the load at which a crack is generated at 2 points or more exceeds 450g and is less than 500g, the allowable load is 450g, and when the load exceeds 500g and is less than 550g, the allowable load is 500g.

Fig. 2C is a diagram showing the arrangement of the contact point P between the ball at the ball pen tip and the central portion 10M when the allowable load of the central portion 10M of the laminated body 10 is obtained in the press-in test. Fig. 2D is a diagram showing the arrangement of the contact point P between the ball at the tip of the ballpoint pen and the end portion 10T when the allowable load (b) of the end portion 10T of the laminated body 10 is obtained in the press-in test. In the laminate 10 of five or more, the same measurement may be performed at any 3 points at the end portions 10T and the central portion 10M, and an average value may be calculated.

The central portion 10M of the laminate 10 is an in-circle region having a radius of 20mm centered on the center C of the laminate 10. The 3 points of the central portion 10M of the laminated body 10 may be arbitrarily selected so as not to overlap with each other.

The end 10T of the laminate 10 is a region of the glass film 200 having a distance g of 0.3mm or less from the side surface (outer periphery) of the glass film 200. The 3 points at the end 10T of the laminate 10 may be arbitrarily selected so as to be separated from each other as much as possible.

[ Long laminate ]

An elongated laminate according to an embodiment of the present disclosure has a plurality of the above-described laminates. In other words, the long laminate is an intermediate in the case of manufacturing a plurality of laminates. By dividing one long laminate, a plurality of individual laminates can be obtained.

The long laminate may be completed in a state wound in a roll shape. The long laminate may be unwound from a state wound into a roll, and supplied to another process in a roll-to-roll manner. The long laminate may be unwound from a state wound in a roll shape and supplied to a dividing process for dividing the long laminate into individual sheets. The intermediate before completion of the long laminate may be processed in a state of being wound into a roll. The intermediate may be unwound from a state wound into a roll, and supplied to a process for obtaining a long laminate in a roll-to-roll manner.

The roll-to-roll method is one of the methods for processing a long laminate or an intermediate before completion of the long laminate. The roll-to-roll system includes a process of unwinding a long laminate or intermediate from a state wound into a roll, or winding a long laminate or intermediate into a roll. In the roll-to-roll system, an unwinding section for unwinding the long laminate or intermediate and a winding section for winding the long laminate or intermediate are used.

The long laminate is provided with: a long base film; a long diaphragm having a plurality of openings arranged along a longitudinal direction; a plurality of glass films disposed inside the plurality of openings, respectively; and a first bonding portion bonding the base film to the separator and bonding the base film to the plurality of glass films. The side surface defining the outer periphery of the glass film is separated from the inner wall of the opening of the diaphragm. Therefore, when dividing the long laminate into a plurality of individual laminates, the first adhesive portion and the base film interposed between the side surface of the glass film and the inner wall of the opening of the separator may be cut. The first adhesive portion is easily cut together with the base film, as compared with cutting the glass film, the first adhesive portion, and the base film together. For example, a sheet equivalent to a sheet used as a release liner for various sheets can be used as the separator. Here, the separator may also be referred to as a spacer, a frame sheet, or the like.

The long base film is made of the same material except that the size and shape thereof are different from those of the base film provided in the monolithic laminated body. A part of the long base film is called a base film of the monolithic laminate.

The plurality of glass films are made of the same material as the glass films included in the monolithic laminated body. The plurality of glass films may be all the same, or different glass films may be disposed at different positions of the long base film.

The first adhesive portion provided in the long base film is made of the same material as the first adhesive portion provided in the singulated laminate. The first adhesive is first applied to the elongated substrate film. Then, the base film, the glass film, and the separator are bonded to each other with the coating film of the first adhesive interposed therebetween. Thereafter, the first adhesive is cured to form a first adhesive portion. The first adhesive is, for example, ultraviolet curable.

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

The long diaphragm having the plurality of openings aligned in the longitudinal direction is formed by partially cutting out a plurality of portions of the long diaphragm having no openings, for example. The long separator and the long base film are generally parallel in their longitudinal directions. The separator having no opening is not particularly limited, and 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 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 set to Ts and the thickness of the glass film is set to Tg, the ratio of Ts/Tg to Tg is 0.8.ltoreq.1.2. In addition, when the thickness of the base film is Tf, 0.8.ltoreq.Tf/Tg.ltoreq.2 may be satisfied. In the case of 1.0< Ts/Tg, particularly in the case of 3.0. Ltoreq.ts/Tg, the separator is relatively thick with respect to the glass film, and therefore, the difficulty of the operation of adhering the glass film to the base film via the first adhesive tends to be high. In view of easy work, high adhesion of the glass film, particularly the end portion, and good appearance of the first adhesion portion or the second adhesion portion, ts/Tg is preferably not more than 4.0. On the other hand, in the case where Ts/Tg <1.0, for example, in the case where Ts/Tg is 0.3 or less, since the separator is relatively thin with respect to the glass film, the glass film protrudes from the frame of the separator. Therefore, minute cracks may occur in the glass film, particularly at the end portions thereof, during the operation. From the viewpoint of suppressing cracking of the glass film, it is preferably 0.5.ltoreq.Ts/Tg.

The heat shrinkage of the separator at 90 ℃ may be 1.0% or less, may be 0.5% or less, may be 0.4% or less, or may be 0.35% or less. By reducing the thermal shrinkage rate of the separator, a separation distance (hereinafter, also referred to as "separation distance G3") between the side surface of the glass film and the inner wall of the opening of the separator is easily ensured regardless of the temperature conditions. In addition, since the strain of the first bonding portion for bonding the separator and the glass film to the base material film is reduced, the bonding force of the first bonding portion is also advantageously improved.

< method for measuring physical Properties 2>

(5) Heat shrinkage rate

The separator was cut into a size of 100mm in the longitudinal direction and 100mm in the width direction, and test pieces were produced. The initial dimensions of the test piece in the longitudinal and width directions were measured at 25℃using an image measuring machine "QVA-PRO_AE10" manufactured by Sanfeng, inc. Then, the test piece was heated at 90℃for 30 minutes, cooled to room temperature, and then the dimensions (heated dimensions) of the test piece in the longitudinal direction and the width direction were measured again at 25 ℃. The heat shrinkage in the longitudinal direction and the width direction were calculated from the following expressions, respectively, and the larger value was used. The measurement may be performed 5 times or more to obtain an average value.

Heat shrinkage (%) = { (initial size-heated size)/(initial size) } ×100

The heat shrinkage of the carrier film at 90℃may be measured in the same manner as described below. The heat shrinkage of the carrier film at 90 ℃ may be 1.0% or less, or 0.5% or less, or 0.4% or less, or 0.35% or less, or 0.2% or less, or 0.1% or less. In this way, the strain of the first bonding portion for bonding the glass film to the base film is reduced, and thus the bonding strength of the first bonding portion is advantageously improved.

The separator and the substrate film may have an MD direction and a TD direction. In the case where the MD direction and the TD direction are present, the heat shrinkage rate in one direction may be larger than that in the other direction. In this case, the larger heat shrinkage ratio is preferably within the above range.

The separation distance G3 between the side surface of the glass film and the inner wall of the opening of the diaphragm may be 0.5mm or more, or 1mm or more. By setting the separation distance G3 to 0.5mm or more, the separation distance G1 between the side surface of the glass film and the side surface of the base film can be sufficiently ensured in the laminated body to be singulated.

However, the separation 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, and thus, the separation distance G3 between the side surface of the glass film and the inner wall of the opening of the separator does not need to be ensured too widely. However, from the viewpoint of forming the second adhesive portion in a good state and facilitating singulation, the separation distance G3 may be made larger, for example, 1mm or more or 2mm or more. In addition, from the viewpoint of suppressing breakage of the end portion of the glass film, it is preferable that the separation distance G3 is not excessively large. The separation distance G3 may be, for example, 10mm or less, 8mm or less, 6mm or less, 5mm or less, 1.6mm or less, or 1mm or less.

The second adhesive portion may be disposed on a side surface of the glass film. The entire side surface of the glass film may be covered with the second adhesive portion. For example, the second adhesive portion may be filled between the side surface of the glass film and the inner wall of the opening of the diaphragm. The second adhesive portion may be formed of the first adhesive together with the first adhesive portion. In this case, the first adhesive and the second adhesive have the same composition, and for example, the first adhesive before curing is applied to the base film in a thicker manner, and the first adhesive climbs up to the side surface of the glass film and is cured to form the second adhesive portion.

Fig. 3A is a plan view showing the structure of an elongated laminate 10C according to an embodiment, and fig. 3B is a cross-sectional view of the elongated laminate 10C taken along line B-B in fig. 3A. A long separator 400 is laminated on the long base film via the first adhesive portion 300. The long separator is formed by partially cutting out a plurality of portions from a long separator having the same size (width) as the base film and having no openings. The arrangement, number, and the like of the openings formed in the separator are not limited to the example of the drawing, and may be appropriately set. The side surface of the glass film 200 is separated from the inner wall of the opening of the diaphragm 400, and the second bonding portion 310 is integrally formed with the first bonding portion 300 in a gap therebetween.

In the long laminate, at least a part of the main surface of the glass film on the side opposite to the first adhesive portion side may be covered with a surface coating having various functions, or may be laminated with another base film or film member via any adhesive portion or adhesive portion. 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. Any of the film members 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 may have a long laminate, a carrier film, and a first adhesive portion between the carrier film and a main surface of the separator and the plurality of glass films on the opposite side of the substrate film side. The first adhesive portion is formed of a first adhesive. The first binder may be non-curable or may have fluidity.

The long laminate may be a long laminate with a film member laminated with any film member of a long strip. The long laminate with the film member may include the long laminate, the film member, and a second adhesive portion or a third adhesive portion interposed between the film member and a main surface (back surface) of the base film on the side opposite to the plurality of glass films. Any of the film members may be the optical film, the separator, or the carrier film.

The first and second adhesives forming the first and second adhesive portions may have fluidity, and the modulus of elasticity under pressing at 25℃may be, for example, 1X 10 ⁶ Pa or below. The storage modulus of the first adhesive portion (first adhesive) and the second adhesive portion (second adhesive) at 25 ℃ may be, for example, 10MPa or less. In this case, the long laminate can be peeled from the carrier film and the first adhesive portion. The third adhesive portion may be formed of a material exemplified as the first adhesive portion or the second adhesive portion in the same manner as the first adhesive portion or the second adhesive portion.

The types of the first adhesive and the second adhesive are not particularly limited, and for example, an acrylic adhesive, a rubber adhesive, a silicone adhesive, a urethane adhesive, a vinyl alkyl ether adhesive, a polyvinylpyrrolidone adhesive, a polyacrylamide adhesive, a cellulose adhesive, and the like can be used. Each binder may contain, for example, a base polymer, a crosslinking agent, an additive (for example, a tackifier, a coupling agent, a polymerization inhibitor, a crosslinking inhibitor, a catalyst, a plasticizer, a softener, a filler, a colorant, a metal powder, an ultraviolet absorber, a light stabilizer, an antioxidant, an anti-deterioration agent, a surfactant, an antistatic agent, a surface lubricant, a leveling agent, an anticorrosive agent, particles of an inorganic or organic material (metal compound particles (metal oxide particles, etc.), resin particles, etc.), but is not limited thereto.

The long carrier film is not particularly limited, and for example, a material similar to 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 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 support film is Tcf and the thickness of the glass film is Tg, tcf/Tg of 0.8.ltoreq.2 can be satisfied.

The operability of the long laminate with carrier film is substantially governed by the bending rigidity of the carrier film. Therefore, the bending rigidity of the carrier film at 25 ℃ can be larger than that of the glass film at 25 ℃. In this case, the operability of the long laminate is improved. Wherein the bending rigidity of the carrier film and the glass film was measured using test pieces having the same width of the carrier film and the glass film, respectively. The value of the bending rigidity varies depending on the width of the test piece.

< method for measuring physical Properties 3>

(6) Flexural rigidity

The bending rigidity of the carrier film was calculated by the following formula.

Bending stiffness=e×bh ³ /12

(wherein E is the tensile elastic modulus (Pa) of the support film at 25 ℃, 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 or separator can be measured by an Autograph (for example, a precision universal tester manufactured by shimadzu corporation).

[ Long laminate and method for producing laminate ]

Next, an example of a method for producing the long laminate (hereinafter, referred to as "production method a") will be described.

The manufacturing method a can be roughly divided into four stages.

The first stage is a stage of preparing a monolithic glass integrated sheet.

The second stage is a stage of preparing a second raw material sheet.

The third stage is a stage of preparing a long laminate with a carrier film from the monolithic glass integrated sheet and the second raw material sheet.

The fourth stage is a stage of further processing the elongated laminate with carrier film.

< first stage >

The first stage includes a first step of preparing a first raw material sheet. The first raw material sheet is a laminate obtained by bonding a long carrier film and a long separator to each other by a first adhesive section. At this time, the long diaphragm is in a state of not having a plurality of openings. That is, the separator included in the first raw material sheet is a raw material of a separator having a plurality of openings.

The first step is not particularly limited, and may be performed in a roll-to-roll manner. That is, the first step may include unwinding the first raw sheet wound in a roll shape by the unwinding section. The first raw material sheet after being unwound is supplied to a subsequent process.

Next, a first step is performed in which a slit reaching the first adhesive portion is formed in the separator so as to include a plurality of planned-to-peel portions aligned in the longitudinal direction. The method of forming the slit is not particularly limited, and may be formed by, for example, a half-cut technique using a laser. In the roll-to-roll system, a slit may be formed in a part of the first raw material sheet during the process of unwinding and conveying or when conveying is stopped. The raw material sheet subjected to the second step may be once wound into a roll shape by the winding section, or may be further subjected to a subsequent process and then wound.

Next, a second step is performed in which a plurality of planned stripping portions are removed from the inside of the slit, and a plurality of openings aligned in the longitudinal direction are formed in the separator so that the first adhesive portions are exposed from the openings. The first adhesive portion is formed of a first adhesive agent having fluidity, and the plurality of predetermined portions to be peeled are peelable from the first adhesive portion.

Next, a third step of disposing a plurality of glass films having a smaller size than the openings in a plan view on the inner sides of the plurality of openings. At this time, the glass film is disposed such that a side surface (outer periphery) of the glass film is separated from an inner wall of the opening of the diaphragm. Thereby, the glass film is adhered to the carrier film via the first adhesive portion. As a result, a monolithic glass integrated sheet can be obtained.

The present disclosure also relates to a monolithic glass integrated sheet obtained in the first stage of the manufacturing method of the above example, for example. The monolithic glass integrated sheet comprises: a long carrier film; a long diaphragm having a plurality of openings arranged along a longitudinal direction; a plurality of glass films disposed inside the plurality of openings, respectively; and a first adhesive portion interposed between the carrier film and the separator and between the carrier film and the plurality of glass films. However, the side surface defining the outer periphery of the glass film is separated from the inner wall of the opening of the diaphragm. That is, a plurality of glass films smaller in size than the openings in plan view are disposed inside the plurality of openings of the separator so that the side surfaces of the glass films are separated from the inner walls of the openings of the separator.

Fig. 4 is an explanatory diagram showing an example of a process for obtaining a monolithic glass body sheet. The process proceeds in a roll-to-roll fashion in the direction of the arrow in fig. 4. Fig. 4 (a) schematically shows at least a part of the first step, and may include unwinding a first raw material sheet 456 wound in a roll shape by an unwinding unit 1. The first raw material sheet 456 is a laminate obtained by bonding the long carrier film 500 and the long separator 400 by the first adhesive portion 600. The first raw material sheet 456 after being unwound is supplied to a subsequent second step.

Fig. 4 (b) schematically shows a process of at least a part of the second step, and shows a case where the slit S is formed by the half-cutting device 2 using a laser. The slit is formed in such a manner as to depict a rectangular opening. The region surrounded by the slit S is the planned peeling section 410.

Fig. 4 (c) schematically shows a process of at least a part of the third step, and shows a case where the predetermined portion 410 to be peeled is peeled and removed to form the opening OP. The planned stripping section 410 can be stripped, for example, by pushing up the upstream end of the planned stripping section 410 from below the carrier film 500 and pulling the floating upstream end.

Fig. 4 (d) schematically shows a process of at least a part of the fourth step, and shows a case where a plurality of glass films 200 having a smaller size than the opening OP in a plan view are disposed inside the opening OP formed. As shown in the cross-sectional schematic view, the glass film 200 is configured such that a gap SP is formed between a side surface (outer periphery) thereof and an inner wall of the opening OP of the diaphragm 400. At this time, the separation distance between the side surface of the glass film 200 and the inner wall of the opening of the diaphragm 400 is controlled to be, for example, 0.5mm or more (for example, 0.5mm or more and 1.6mm or less). Thereby, the monolithic glass integrated sheet 2456 can be obtained. The monolithic glass integrated sheet 2456 may press the glass film 200 against the first adhesive portion 600 by sandwiching the glass film by the pair of sandwiching rollers 3a and 3 b. Thereafter, as shown in fig. 4 (e), the monolithic glass integrated sheet 2456 may be wound into a roll shape by the winding portion 4.

In the example shown in the figure, the rectangular glass film 200 has an example in which the longitudinal direction of the rectangular glass film 200 is parallel to the MD direction of the long carrier film, 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 example of arrangement of the glass film 200 in the monolithic glass body 2456. Fig. 5 (a) is of the same type as the monolithic glass body sheet shown in fig. 4. Fig. 5 (b) shows an example in which the longitudinal direction of the rectangular glass film 200 is parallel to the TD direction of the long carrier film. Fig. 5 (c) shows an example in which the longitudinal direction of the rectangular glass film 200 is inclined at a predetermined angle to the TD direction of the long carrier film.

In the case of an optical laminate used for a display panel or the like of a flexible Flat Panel Display (FPD), a glass film is required to be curled or bent. When the direction in which the glass film is curled or bent (that is, the circumferential direction of the circumferential surface formed when the glass film is curled or bent) is set to the first direction, the arrangement direction of the glass films in the monolithic glass integrated sheet may be determined so that the first direction is parallel to the MD direction (the first direction is perpendicular to the TD direction).

Hereinafter, the second to fourth stages of the manufacturing method a will be described with reference to the drawings. Fig. 6A is an explanatory diagram showing a part of an example of a process for obtaining the long laminate 10D (10C). Fig. 6B is an explanatory diagram showing a part of an example of a process for obtaining the long laminate 10C after the process shown in fig. 6A. In fig. 6A and 6B, the process that can be omitted is R-chamfered and surrounded by four sides drawn with broken lines.

< second stage >

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

Examples of the application method of the first adhesive 300a include application methods such as air knife application, blade application, doctor blade application, reverse application, transfer roll application, gravure roll application, contact application (kiss coating), casting application, spray application, slit orifice application (slot orifice coating), calender application, electrodeposition application, dip application, and die application; relief printing methods such as flexography, direct gravure printing methods, gravure printing methods such as offset gravure printing methods, lithographic printing methods such as offset printing methods, and stencil printing methods such as screen printing methods.

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

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

< third stage >

The third step includes a sixth step of laminating the monolithic glass integrated sheet 2456 and the second raw material sheet 130. The glass film 200 (and the separator 400) of the monolithic glass integrated sheet 2456 is adhered to the second raw material sheet 130 via the coating film of the first adhesive 300 a.

When the coating film of the first adhesive 300a is sufficiently thick, for example, is formed to be 5 μm or more and 10 μm or less, a part of the first adhesive 300a as the second adhesive 310a intrudes into the gap SP (see fig. 4 d) between the side surface (outer periphery) of the glass film 200 and the inner wall of the opening OP of the separator 400, and covers the side surface of the glass film 200.

Further, a coating film of the first adhesive 300a may be formed on the side of the monolithic glass integrated sheet 2456 on which the glass film 200 is disposed. The thickness is, for example, 0.5 μm or more and 5 μm or less, or 0.5 μm or more and 3 μm or less. When the first adhesive is also applied to the glass film 200 side of the monolithic glass integrated sheet 2456, high adhesion between the monolithic glass integrated sheet 2456 and the base sheet 100 can be obtained even if the first adhesive portion is relatively thin. This is also associated with the second adhesive portion forming a good state at the gap SP between the side surface (outer periphery) of the glass film 200 and the inner wall of the opening OP of the diaphragm 400. The thickness of the first adhesive portion is, for example, 0.1 μm or more and 10 μm or less, or may be 0.5 μm or more and 5 μm or less, or may be 0.5 μm or more and 3 μm or less, or may be 0.5 μm or more and 1 μm or less.

If a part of the first adhesive 300a does not function as the second adhesive 310a, a step of filling the second adhesive 310a in the gap SP between the side surface (outer periphery) of the glass film 200 and the inner wall of the opening OP of the separator 400 and covering the side surface of the glass film 200 may be further performed before the sixth step (i.e., before the monolithic glass integrated sheet 2456 and the second raw material sheet 130 are laminated).

When the first adhesive 300a is a UV curable adhesive, the UV irradiation step is performed on the laminate of the individual glass integrated sheet 2456 and the second raw material sheet 130. In this case, the second adhesive 310a used as needed may be a UV curable adhesive. However, the curing of the first adhesive 300a may be performed by other methods. The first adhesive 300a and the second adhesive 310a form the first adhesive 300 and the second adhesive 310a, respectively, by UV irradiation.

The first adhesive 300a is selected so that the adhesion between the first adhesive 300 and the glass film 200 and the adhesion between the first adhesive 300 and the separator 400 are each 0.1N/mm or more, for example.

Through the sixth step, the long laminate 10C including the base film 100, the separator 400, the first adhesive portion 300, and the plurality of glass films 200 adhered to the first adhesive portion 300 is formed. At this stage, the carrier film 500 is adhered to the glass film 200 via the first adhesive portion 600. That is, the long laminate 10D with the carrier film can be obtained. The long laminate 10D with carrier film may be wound into a roll shape as an optional step after that.

< fourth stage >

The fourth stage is a stage of further processing the long laminate with carrier film 10D. For example, a seventh step of peeling the carrier film 500 and the first adhesive portion 600 from the carrier film-attached long laminate 10D to obtain a long laminate 10C is performed. After the seventh step, an eighth step of cutting out the laminated body, which is singulated for each glass film, from the long laminated body along a predetermined cutting line is performed.

After the seventh step and before the eighth step, a 9A step of forming the surface coating 700 on at least a part of the main surface of the glass film 200 on the side opposite to the first bonding portion 300 may be performed. Further, the 9B-th step of laminating an arbitrary base film 100A selected from the above base films on the main surface of the glass film 200 on the opposite side of the first bonding portion 300 via an arbitrary bonding portion or bonding portion 300A may be performed.

Examples of the top coat 700 include a fingerprint-resistant coating, a hard coat, an antireflection layer, an antiglare layer, an antifouling layer, an anti-sticking layer, a hue adjustment layer, an antistatic layer, an easy-to-adhere layer, a component deposition preventing layer, an impact absorbing layer, and a scattering preventing layer. The surface coating may be composed of various materials, for example, the fingerprint resistant coating includes, for example, a fluororesin, a silicone resin, or the like. The other surface coating layer is formed of, for example, an acrylic coating agent, a melamine coating agent, a polyurethane coating agent, an epoxy coating agent, a silicone coating agent, an inorganic coating agent, or the like. The coating agent may contain additives such as silane coupling agents, colorants, dyes, pigments, fillers, surfactants, plasticizers, antistatic agents, surface lubricants, leveling agents, antioxidants, light stabilizers, ultraviolet absorbers, polymerization inhibitors, antifouling materials, and the like.

Before the eighth step, a tenth step of laminating an arbitrary film member on the main surface (back surface) of the base film 100 on the opposite side of the first adhesive portion 300 side with an arbitrary adhesive portion or adhesive portion (second adhesive portion or third adhesive portion) interposed therebetween may be performed. The tenth step may be performed before the seventh step or after the seventh step. Any of the film members may be the optical film or the separator. The film member to be laminated on the back surface is selected according to the use of the laminate. The film member to be laminated on the back surface may be one or two or more.

In the eighth step of singulating the laminate from the long laminate along a predetermined cutting line, the cutting line may include at least a first portion and may include a second portion. Fig. 7 is an explanatory diagram showing an example of a process of singulating a 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 diaphragm 400 in such a manner as to be separated from the side surface of the glass film 200 and to surround the glass film 200. The first portion LA of the cutting line is set in a region where the glass film 200 that is easily broken is not cut, and thus cutting is very easy.

The second portion LB is set at a portion that does not cross the glass film 200 from one end to the other end in the width direction of the long laminated body 10C (fig. 7 (a)). By cutting the elongated laminated body 10C along the second portion LB, a large sheet 10E including a plurality of glass films 200 (9 in the illustrated example) is formed (fig. 7 (b)). The length of the large sheet 10E may be arbitrarily selected in consideration of ease of handling. Thereafter, the large sheet 10E is cut along the first portion LA, and the laminated body 10, which is singulated, is cut out from the large sheet 10E (fig. 7 (c)).

Any cutting method can be used in the step of obtaining the singulated laminate (i.e., the step of cutting the long laminate), but from the viewpoint of rapidity and accuracy, a method of cutting the long laminate or the large sheet along the cutting line by a laser is preferable. The type of laser is not particularly limited, and semiconductor laser and CO can be used ₂ A gas laser such as laser light, and the like.

After the sixth step, the bending inspection may be performed at any time. In the bending test, it was confirmed whether or not the glass film 200 had cracks.

[ method of inspecting bending of elongated laminate ]

The bending inspection method may include, for example, a step of conveying one surface of the long laminate at an angle of 150 ° or more along the peripheral surface of the guide member (first guide member) having a peripheral surface with a radius of curvature of 5mm or less. According to such a bending inspection method, the bending inspection of the plurality of glass films included in the long laminate can be continuously performed while conveying the long laminate, and therefore the efficiency is high. That is, it is not necessary to perform bending inspection of the glass film of the laminated body, which is formed by dividing each laminated body into individual laminated bodies, as in the conventional technique, and labor and time can be significantly saved.

Here, the pressing elastic modulus of the first adhesive portion at 25℃is 1X 10 ⁸ Pa or more, the probability of breakage of the glass film included in the long laminate can be further reduced in the bending inspection method.

In the bending test, it is preferable that all glass films contained in the long laminate itself do not crack. For example, when the probability of occurrence of a crack is 30% or less, and further 20% or less based on the number, it is considered that a crack is not actually generated.

The guide member having a peripheral surface with a radius of curvature of 5mm or less may be a roller with a radius of 5mm or less, for example. The length of the rotation axis of the roller having a radius of 5mm or less may be equal to or longer than the length of the long laminate in the short side direction (width direction). In this case, the roller itself as the guide member is deflected (slightly curved), and there is a possibility that the peripheral surface of the central portion in the axial direction of the roller and the long laminated body may not be in contact with each other with sufficient pressure. On the other hand, by using the backup roller, deflection of the roller as the first guide member can be suppressed.

The guide member may be a plate-like member having a peripheral surface with a radius of curvature of 5mm or less on the end surface. The plate-like member has a peripheral surface on an end surface thereof, the peripheral surface being similar to a part of the peripheral surface of the roller having a radius of curvature of 5mm or less. On the other hand, the end surface of the plate-like member is less likely to be bent or curved like a roller. Therefore, the center portion of the peripheral surface of the guide member in the axial direction can always be in contact with the long laminate with a sufficient pressure.

Here, the "axis of the peripheral surface" refers to a set of centers of curvature radius that restricts curvature of the peripheral surface. The "included angle" corresponds to the center angle of the circular arc when the portion of the peripheral surface of the guide member in contact with the long laminate is viewed from the direction of the axis of the peripheral surface. For example, in the case of using a plurality of reels as the guide member, the included angle corresponds to the bending angle of the long laminate from the reel to the reel.

The bending inspection method may further include a step of conveying the other surface of the long laminate conveyed by the guide member as described above at an angle of 150 ° or more along the peripheral surface of another guide member (second guide member) having a peripheral surface with a radius of curvature of 5mm or less. In this step, the long laminate is sequentially bent in two directions, one and the other, with a large curvature. Here, when the probability of occurrence of cracks is 30% or less, and further 20% or less based on the number, it is considered that cracks are not actually generated.

The glass film may be a rolled or bent glass film. The glass film may also be curled or bent by the user at any time. The glass film may be a glass film that is curled or bent in a predetermined direction and used (the direction of curling or bending is predetermined). If the direction in which the glass film is curled or bent (that is, the circumferential direction of the circumferential surface formed when the glass film is curled or bent) is set to the first direction, the first direction may be parallel to the circumferential direction of the circumferential surfaces of the first guide member and the second guide member. That is, the glass film may be a glass film that is curled or bent so as to protrude or recess in the normal direction of the peripheral surfaces of the first guide member and the second guide member. The glass film may be, for example, a front panel for a display panel that is used by being curled or bent in the first direction. According to the bending inspection method of the present embodiment, the bending resistance of such a glass film can be easily and efficiently evaluated.

The bending inspection method may also be incorporated into the method of manufacturing the elongated laminate. That is, the bending inspection step may be a part of the manufacturing method step. For example, the method of producing the long laminate may include a step of conveying one surface of the long laminate at an angle of 150 ° or more along the peripheral surface of the first guide member having a peripheral surface with a radius of curvature of 5mm or less. In the case where the glass film is a glass film that is used by being curled 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 curled or bent so as to protrude or recess in the normal direction of the peripheral surface of the first guide member. In the case of the manufacturing method a, the bending inspection step may be performed at an arbitrary timing after the sixth step.

The method for producing a long laminate may further include a step of conveying the other surface of the long laminate conveyed by the first guide member at an angle of 150 ° or more along the peripheral surface of the second guide member having a peripheral surface with a radius of curvature of 5mm or less. In the case where the glass film is a glass film that is used by being curled or bent in the first direction, the first direction may be parallel to the circumferential direction of the peripheral surface of the second guide member. That is, the glass film may be a glass film that is curled or bent so as to protrude or recess in the normal direction of the peripheral surface of the second guide member. In the bending test, when the long laminate is wound in a roll shape after being bent to one side and the other side in order, it is preferable to wind the glass film so that the glass film faces 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 a case where the long laminate 10C is conveyed along the peripheral surface of the roller 5 having a radius of 5mm or less as a guide member. Fig. 8 (a) is a plan view seen from the normal direction of the long laminate 10C, and fig. 8 (b) is a cross-sectional view of the guide member 5 and the support roller 6, seen along line b-b. The direction in which the glass film is curled or bent, i.e., the first direction, is parallel to the MD direction. The roller 5 is supported by a support roller 6 to receive a pressing force from the long laminate 10C.

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

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 including a glass film is the object of the bending inspection method, and the bending property of the glass film can be inspected. Specifically, the bending inspection method may be an inspection method including a step of conveying one surface of an arbitrary long laminate at an angle of 150 ° or more along the peripheral surface of the first guide member having a peripheral surface with a radius of curvature of 5mm or less. The inspection method may further include a step of conveying the other surface of the arbitrary long laminate conveyed by the first guide member at an angle of 150 ° or more along the peripheral surface of the second guide member having a peripheral surface with a radius of curvature of 5mm or less. Here, the glass film may be a glass film that is curled or bent in a first direction, and the first direction may be parallel to the circumferential direction of the circumferential surfaces of the first guide member and the second guide member.

Among them, in the case where an arbitrary long laminate includes a plurality of glass films aligned in the longitudinal direction, the bending inspection method of the present disclosure is preferable. This is because all or most of the glass films can be efficiently inspected for flexibility through a series of steps. The plurality of glass films may be adhered to the long base film via the adhesive portion. However, from the viewpoint of suppressing peeling of the glass film from the base film during conveyance, it is preferable to bond the glass film to the base film by using the bonding portion such as the first bonding portion or the second bonding portion described above. In this case, the adhesion between the adhesion portion and the glass film is preferably 0.1N/mm or more, for example.

Examples (example)

The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the examples.

Examples 1 to 5

The following materials were prepared.

(substrate film)

A polyethylene terephthalate (PET) film (DIAFOIL S100 (registered trademark) manufactured by Mitsubishi chemical Co., ltd.) having a thickness of 50 μm was prepared.

(glass film)

An ultra-thin plate glass (G-leaf (registered trademark) manufactured by Nitro Kagaku Co., ltd.) having a thickness of 30 μm was prepared. The glass film was rectangular in shape in plan view and had dimensions of 30mm by 120mm.

(adhesive A)

An epoxy adhesive composition (adhesive a) was prepared by blending the following materials.

70 parts by mass of an alicyclic epoxy resin (CELLOXIDE 2021P, manufactured by Kagaku Kogyo Co., ltd., epoxy equivalent of 128 to 133 g/eq.)

5 parts by mass of 3-functional aliphatic epoxy resin (EHPE 3150, manufactured by Kagaku Kogyo Co., ltd., epoxy equivalent weight: 170 to 190 g/eq.)

19 parts by mass of an OXETANE resin (ARON OXETANE, manufactured by Toyama Co., ltd.)

4 parts by mass of a silane coupling agent (3-glycidoxypropyl trimethoxysilane, "KBM-403" manufactured by Xinyue chemical Co., ltd.)

2 parts by mass of a photoacid generator (triarylsulfonium salt, "CPI101A" manufactured by SAN-APRO Co., ltd.)

[ formation of laminate ]

The adhesive layer a is applied to the glass film to form a coating film, and then the base film is bonded to the coating film. Then, ultraviolet rays were irradiated from the glass film side to the coating film, and the coating film was cured to form a bonded portion having a thickness of 3 μm between the glass film and the base film, thereby obtaining a laminate. However, the laminate is formed such that the side surface of the glass film is positioned further inward than the side surface of the base film when the laminate is viewed from above. By changing the size of the base material film, the separation distance G1 from the side surface of the glass film to the side surface of the base material film is changed. The separation distances G1 in examples 1 to 5 are shown in table 1.

< evaluation >

An adhesive was prepared in the following manner, and an adhesive portion was formed on a base film as a substitute for other film members, and the laminate was stuck to the adhesive portion to prepare a sample for evaluation. That is, the sample simulates a product in which a laminate including a base film, a glass film, and an adhesive portion to which the base film, the glass film, and the adhesive portion are adhered are laminated with other film members (optical films, etc.).

(adhesive)

The following materials were blended, and the complex was irradiated with ultraviolet rays to polymerize, thereby obtaining a base polymer composition (polymerization rate: about 10%).

Lauryl Acrylate (LA) 43 parts by mass

44 parts by mass of 2-ethylhexyl acrylate (2 EHA)

6 parts by mass of 4-hydroxybutyl acrylate (4 HBA)

7 parts by mass of N-vinyl-2-pyrrolidone (NVP)

0.015 part by mass of IRGACURE184 (registered trademark) manufactured by BASF corporation

In addition, an acrylic oligomer was prepared according to the following procedure. First, the following materials were mixed and stirred at 70℃for 1 hour under a nitrogen atmosphere to obtain a polymerization solution.

60 parts by mass of dicyclohexyl methacrylate (DCPMA)

40 parts by mass of Methyl Methacrylate (MMA)

3.5 parts by mass of alpha-thioglycerol

Toluene 100 parts by mass

To the polymerization solution, 0.2 parts by mass of 2,2' -Azobisisobutyronitrile (AIBN) was added, followed by reaction at 70℃for 2 hours, and then the temperature was raised to 80℃for 2 hours. Thereafter, the reaction solution was heated to 130℃and dried to remove toluene, chain transfer agent and unreacted monomers, thereby obtaining a solid acrylic oligomer. The weight average molecular weight of the acrylic oligomer was 5100. The glass transition temperature (Tg) was 130 ℃.

To 100 parts by mass of the base polymer composition, 0.07 part by mass of 1, 6-hexanediol diacrylate (HDDA), 1 part by mass of an acrylic oligomer, and 0.3 part by mass of a silane coupling agent (KBM 403, made by singe chemical industry co., ltd.) were added, and these were uniformly mixed to prepare an adhesive.

The adhesive is applied to the surface of the substrate film having the release treatment on the surface thereof to form a coating film, and then the substrate film having the release treatment on the surface thereof is bonded to the coating film. Subsequently, the coating film was irradiated with ultraviolet light to form a 25 μm thick adhesive portion sandwiched between a pair of base films. Then, one of the base films was peeled off to obtain an adhesive portion formed on the base film.

[ preparation of sample ]

A sample for press-in test for determining a load ratio (end portion/center portion) was prepared by adhering a base film side of a laminate composed of a base film, a glass film, and an adhesive portion interposed therebetween to an adhesive portion formed on the other base film.

By the above method, the allowable load (W1) at the end portion and the allowable load (W2) at the center portion of the laminate are measured, and the W1/W2 ratio is calculated as the load ratio (end portion/center portion).

Next, using a test piece of the adhesive part prepared separately, the indentation elastic modulus (E) of the adhesive part was measured by the above method. The indentation elastic modulus (E) was also measured in the same manner for the adhesive portion formed on the base film.

Next, using a laminate composed of a base film, a glass film, and an adhesive portion interposed therebetween, the adhesive force between the adhesive portion and the glass film was measured by the above method. As a result, the adhesion was 1N/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 to A5 correspond to examples 1 to 5, and laminates B1 to B3 correspond to comparative examples 1 to 3. The symbols in the table represent the following.

E: modulus of elasticity under pressure (Pa)

W1: allowable load of end (g)

W2: allowable load (g) of the center portion

W1/W2: load ratio (end/center)

TABLE 1

Comparative example 1

A sample having a glass film directly adhered to an adhesive portion formed on a base film was prepared, and by the above method, the allowable load (W1) at the end portion and the allowable load (W2) at the center portion of the laminate were measured, and the load ratio (end portion/center portion) (W1/W2) was calculated.

Comparative example 2

A laminate was formed in the same manner as in example except that the size of the base film was reduced so that the side surface of the glass film was positioned 100 μm outside the side surface of the base film in a plan view of the laminate.

Comparative example 3

(adhesive B)

The following materials were blended to prepare an acrylic adhesive composition (adhesive B). A laminate was formed in the same manner as in example 4, except that the adhesive B was used, and evaluation was performed in the same manner.

75 parts by mass of 4-hydroxybutyl acrylate (functional group-containing (meth) acrylate monomer manufactured by Osaka organic chemical Co., ltd.)

25 parts by mass of N- (2-hydroxyethyl) acrylamide (an amide group-containing vinyl monomer manufactured by KJ chemical Co., ltd.)

0.5 part by mass of a photopolymerization initiator (IRGACURE 819, manufactured by BASF corporation)

In comparative example 1, the allowable load (W1) at the end portion and the allowable load (W2) at the center portion were very low, and the glass film was cracked under a load of less than 450g or 500 g. This is considered to be because the adhesion portion is soft and the press-in load is small, and therefore the force pressing the glass film is not relaxed, and the strain generated in the glass film increases.

In comparative example 2, the allowable load (W2) at the center portion was sufficiently large, but the allowable load (W1) at the end portion was insufficient. As a result, the load ratio (end/center) expressed as W1/W2 was less than 0.9. This is because the end portion of the glass film protrudes from the base film, and therefore the base film cannot sufficiently support the end portion of the glass film.

In comparative example 3, although the adhesive portion having a press-in elastic modulus much larger than that of the adhesive portion was formed, since the press-in elastic modulus of the adhesive portion was smaller than 1×10 ⁸ Pa, therefore, the allowable load (W1) at the end portion and the allowable load (W2) at the center portion are insufficient.

On the other hand, in examples 1 to 5, the allowable load (W1) at the end portion and the allowable load (W2) at the center portion were both sufficiently large, and the load ratio (end portion/center portion) expressed by W1/W2 was maintained at 0.9 or more. In comparative examples 1 to 5, it is understood that the separation distance G1 from the side surface of the glass film to the side surface of the base film is preferably 50 μm or more, and more preferably 100 μm or more.

Examples 6 to 10

The following materials were prepared to produce a long laminate.

(substrate film)

The same substrate film as in example 1 was used except for the size. Specifically, a 50m long polyethylene terephthalate (PET) film (DIAFOILS 100 (registered trademark) manufactured by Mitsubishi chemical corporation) having a width of 450mm and a thickness of 50 μm was prepared.

(Carrier film)

A50 m long, 450mm wide polyethylene terephthalate (PET) film (DIAFOILS 100 (registered trademark) manufactured by Mitsubishi chemical corporation) having a predetermined thickness (38 μm or 125 μm) shown in Table 2 was prepared. Table 2 shows the tensile elastic modulus (25 ℃) of the carrier film, the heat shrinkage at 90℃and the bending rigidity.

(diaphragm)

In examples 6 to 8 and 10, a polyethylene terephthalate (PET) film (DIAFOILS 100 (registered trademark) manufactured by Mitsubishi chemical Co., ltd.) having a length of 50m, a width of 450mm and a thickness of 25 μm was prepared. In example 9, an acrylic resin film having a length of 50m, a width of 450mm and a thickness of 40 μm was prepared. The acrylic resin film is formed by forming methacrylic resin particles having glutarimide ring units into a film shape by extrusion molding, and then stretching the film. Table 2 shows the tensile elastic modulus (25 ℃) of the separator, the heat shrinkage at 90℃and the bending rigidity.

(glass film)

A plurality of ultra-thin plate glasses (G-leaf (registered trademark) manufactured by Nitro Kabushiki Kaisha) having a thickness of 30 μm were prepared. The glass film was rectangular in shape in plan view and had dimensions of 65mm by 150mm.

(adhesive A)

The same epoxy adhesive composition (adhesive a) as used in examples 1 to 5 was prepared. The first adhesive portion formed of the adhesive a had a press-in elastic modulus of 5GPa.

(adhesive)

In examples 6 to 8 and 10, an adhesive used in RP207 manufactured by Nito electric company was used. That is, in examples 6 to 8 and 10, a laminate of a carrier film (38 μm) and an adhesive portion (20 μm) was used, which was obtained by peeling a release liner from RP 207.

In example 9, 90 parts by mass of Butyl Acrylate (BA), 10 parts by mass of Acrylic Acid (AA), 0.2 part by mass of 2,2' -azobisisobutyronitrile as a polymerization initiator, and 234 parts by mass of ethyl acetate were added, and the mixture was slowly stirred while introducing nitrogen gas, and the mixture was kept at 63 ℃ for polymerization for about 7 hours to prepare an acrylic polymer (a) solution (30 mass%). The weight average molecular weight of the acrylic polymer (A) was 60 ten thousand, and Tg was-50 ℃. An acrylic adhesive was prepared by diluting an acrylic polymer (a) solution (30 mass%) with ethyl acetate to 20 mass%, adding 11 parts by mass of an epoxy crosslinking agent (tetra d-C, mitsubishi gas chemical Co., ltd.) as a crosslinking agent to 100 parts by mass (solid content) of the acrylic polymer, and mixing and stirring the mixture at a temperature of around 25 ℃ for about 1 minute. An acrylic adhesive was applied to one side of the carrier film (125 μm), and heated at 140℃for 60 seconds to form an adhesive portion having a thickness of 20. Mu.m.

[ formation of long laminate ]

< first stage >

In the first stage, a monolithic glass integrated sheet is prepared.

First, a first raw material sheet is prepared. The first raw material sheet is a laminate obtained by bonding a long carrier film and a long separator to each other by a first adhesive section. Specifically, an adhesive was applied to a carrier film (PET film) having a thickness shown in table 2 in a roll-to-roll manner, and then a separator (PET film) having a thickness shown in table 2 was stuck to the carrier film to form a first raw material sheet. In the first raw material sheet, the thickness of the adhesive portion formed of the adhesive was 20 μm.

Next, slits reaching the adhesive portions are formed in the separator so as to surround the plurality of planned-to-peel portions aligned in the longitudinal direction. The slit is formed by a half-cut technique using a laser.

Next, the plurality of planned stripping portions are removed from the inside of the slit, and a plurality of openings aligned in the longitudinal direction are formed in the separator. The size of the opening is 75mm by 160mm. The adhesive portion is exposed from each opening. The spacing between the openings was 30mm in both the MD and TD directions.

Next, a plurality of glass films (size 65mm×150 mm) are arranged inside the plurality of openings in plan view. At this time, the separation distance G3 between the side surface (outer periphery) of the glass film and the inner wall of the opening of the diaphragm was 5mm. Thus, a monolithic glass integrated sheet having 4×5 glass films (total 20 glass films) in a part of the carrier film was obtained in a roll-to-roll manner.

< second stage >

In the second stage, a second sheet of raw material is prepared.

The second raw material sheet is a laminate having a long base film and a first adhesive applied to the base film. Specifically, the adhesive a was applied to a base film (PET film) having a thickness shown in table 2 in a roll-to-roll manner. The thickness of the coating film of the adhesive A is shown in Table 2 (3 μm or 6 μm).

< third stage >

In the third stage, a long laminate with a carrier film is prepared from the monolithic glass integrated sheet and the second raw material sheet. Specifically, the monolithic glass integrated sheet and the second raw material sheet are laminated, and the glass film and the separator of the monolithic glass integrated sheet are bonded to the second raw material sheet with the coating film of the adhesive a interposed therebetween.

In example 10, a coating film of adhesive a was formed at a thickness of 1 μm on the side of the monolithic glass integrated sheet where the glass film was disposed. A part of the adhesive a as a second adhesive intrudes into a gap between a side surface (outer periphery) of the glass film and an inner wall of the opening of the diaphragm to cover the side surface of the glass film.

The adhesive a is a UV curable adhesive. Therefore, the laminate of the monolithic glass integrated sheet and the second raw material sheet is irradiated with UV light, and the adhesive a is cured, thereby forming a first adhesive portion and a second adhesive portion.

< fourth stage >

In the fourth step, the carrier film and the adhesive portion are peeled from the long laminate with the carrier film to obtain a long laminate, and the laminate, which is singulated for each glass film, is cut from the long laminate along a predetermined cutting line.

The cutting line was set in a region between the side surface of the glass film and the inner wall of the opening of the diaphragm so as to be separated from the side surface of the glass film by 2.5mm and to surround the glass film.

< evaluation >

The thickness of the first adhesive portion was measured, and the adhesion force between the base material film (first adhesive portion) and the glass film and the adhesion force between the base material film (first adhesive portion) and the separator were measured by the above-described method.

Further, the end of each of the 20 laminated bodies after singulation was observed for the presence or absence of adhesion failure, and the laminated body in which the end of each of the glass films did not float from the base film was regarded as a good product. Table 2 shows that the ratio of the acceptable products is 70% or more, 30% or more and less than 70% is denoted as Δ, and less than 30% is denoted as x.

Further, the appearance (presence or absence of cracks) of the glass film ends of the 20 laminated bodies after singulation was observed, and the laminated bodies without cracks were regarded as acceptable products. Table 2 shows that the ratio of the acceptable products is 70% or more, 30% or more and less than 70% is denoted as Δ, and less than 30% is denoted as x. In table 2, laminates A6 to a10 correspond to examples 6 to 10.

TABLE 2

The adhesion force between the glass film and the first adhesion portion of the separator tends to be as follows: as a result, the larger the thickness of the adhesive a applied to the base film, the more stable the adhesive force becomes. In addition, by reducing the heat shrinkage rate of the carrier film or increasing the bending rigidity, the adhesive force tends to be significantly improved. In addition, by applying the adhesive a not only on the substrate film side but also on the glass film side, the adhesive force is more stable. This is presumably because a good second adhesion portion was formed. On the other hand, the following tendency is exhibited: if the thermal shrinkage rate of the separator becomes large, the adhesion decreases.

Examples 11 to 13

A long laminate was produced in the same manner as in example 6, and the laminate was singulated and evaluated, except that the carrier film used in example 9 (A9) was used as the carrier film and the thickness of the separator was changed.

Example 14

A long laminate was produced in the same manner as in example 13, except that a coating film of the adhesive a was formed at a thickness of 1 μm on the side of the monolithic glass integrated sheet where the glass film was disposed, and the laminate was singulated and evaluated in the same manner as in example 9.

Comparative example 3

A long laminate was produced in the same manner as in example 14, and the laminate was singulated and evaluated, except that a plurality of glass films were arranged side by side on the adhesive portion of the base film without using a separator, to produce a singulated glass integrated sheet.

The results of examples 11 to 14 and comparative example 3 are shown in Table 3. In table 3, laminates a11 to a14 correspond to examples 11 to 14, and laminate B3 corresponds to comparative example 3.

TABLE 3

If the thickness of the separator is larger than the thickness of the glass film (30 μm), the laminate, a part of which is singulated, has poor adhesion, but a substantially good evaluation result is obtained. However, by applying the adhesive a not only on the substrate film side but also on the glass film side, such adhesion failure does not occur. In the laminate B3 of comparative example 3, the glass film was not surrounded by the separator, and the end of the glass film was not prepared, so that a laminate having a crack at the end was seen everywhere during the manufacturing process.

Industrial applicability

The present disclosure can contribute to the higher performance of an optical laminate used for a display panel such as a Flat Panel Display (FPD).

While the invention has been described with reference to presently preferred embodiments, such disclosure should not be construed in a limiting sense. Various modifications and alterations will no doubt become apparent to those skilled in the art to which the present invention pertains upon reading the foregoing disclosure. It is therefore intended that the appended claims be interpreted as including all such alterations and modifications as fall within the true spirit and scope of the invention.

Description of the reference numerals

10. 10B: laminate body

10C, 10D: elongated laminate

10M: central portion

10T: end portion

10E: large sheet

100: substrate film

130: second raw material tablet

200: glass film

300: a first adhesive part

300a: first adhesive

310: second adhesive part

456: first raw material sheet

400: diaphragm

410: scheduled peeling part

500: carrier film

600: first adhesive part

2456: monolithic glass integrated sheet

L1: line segment

LA: first part

LB: second part

1: unwinding part

2: half cutting device

3a, 3b: clamping roller

4: winding part

S: slit(s)

C1, C2: corner portion

G1, G2, G3: separation distance

And C3: corner portion

P: contact point

OP: an opening

5: roller

6: supporting roller

7: plate-like member

7s: peripheral surface

7c: center of radius of curvature of the peripheral surface 7s

Claims

1. A laminate, comprising:

a base material film;

a glass film; and

a first bonding portion that bonds the base film and the glass film,

wherein,

the side surface defining the outer periphery of the glass film is positioned further inside than the side surface defining the outer periphery of the base film in a plan view,

the first adhesive part has a press-in elastic modulus of 1×10 at 25deg.C ⁸ Pa or more.

2. The laminate of claim 1, wherein,

the thickness of the glass film is 100 μm or less.

3. The laminate according to claim 1 or 2, wherein,

the ratio of the allowable load of the end portion of the laminate to the allowable load of the central portion of the laminate is 0.9 or more,

the allowable load is a load measured in 50g units, in which when the laminate is placed on a horizontal table and 3 points of each of the end portion and the central portion of the laminate are pressed from the vertical direction by a ball having a diameter of 0.7mm at the tip portion of a ballpoint pen from the glass film side, no crack is generated at 2 points or more in the glass film.

4. The laminate according to claim 1 to 3,

the separation distance from the side surface of the glass film to the side surface of the base film is greater than 50 μm in a plan view.

5. The laminate according to claim 1 to 4,

the first adhesive forming the first adhesive portion is ultraviolet curable.

6. The laminate according to claim 1 to 5,

a second adhesive portion is disposed on the side surface of the glass film.

7. The laminate of claim 6, wherein,

the second adhesive forming the second adhesive portion is ultraviolet curable.

8. The laminate of claim 7, wherein,

the first adhesive and the second adhesive are adhesives having the same composition.

9. The laminate according to any one of claim 6 to 8, wherein,

the separation distance from the side surface defining the outer periphery of the second adhesive portion to the side surface of the glass film is the same as the separation distance from the side surface of the glass film to the side surface of the base material film in a plan view.

10. The laminate of claim 9, wherein,

the side surface of the second adhesive portion is coplanar with the side surface of the base film from the main surface of the glass film on the base film side to the main surface on the opposite side.

11. The laminate according to any one of claim 1 to 10, wherein,

the adhesion force between the first adhesion part and the glass film is more than 0.1N/mm.