KR20220127153A - Laminate - Google Patents

Abstract

The present invention relates to a laminate which includes a substrate, a colored layer, and a flattening layer, wherein the substrate is thin glass having a thickness of 100 μm or less, and the colored layer and the flattening layer are in direct contact with the substrate. An objective of the present invention is to provide a laminate having good flexibility, having excellent light transmittance in a portion where the colored layer is not formed, and capable of suppressing discoloration of the colored layer when the laminate is viewed diagonally.

Description

Laminate {LAMINATE}

The present invention relates to a laminate and a method for manufacturing the laminate. The present invention further relates to a front plate comprising a laminate.

Electronic products, such as an image display apparatus, are provided with a touch sensor in many cases. In the image display device provided with a touch sensor, in order to prevent the trace part etc. of a touch sensor from being visible from a user, it has been proposed to provide a bezel (shielding part) (Unexamined-Japanese-Patent No. 2015-076095; Patent Document 1) .

As the bezel, for example, a laminate in which a colored layer is formed on a light-transmitting base material is used in many cases. Conventionally, a method of forming a colored layer on a substrate by silk screen printing has been used as a method for producing a laminate. In this regard, in recent years, a method of forming a colored layer on a substrate by a photolithography method has been developed and used.

Although the laminate obtained by the photolithography method has a small thickness and good shielding properties, the flexibility of the laminate and the translucency of the portion where the colored layer is not formed (transmission of the base material) were not sufficient. Moreover, when the laminated body was seen from the diagonal direction, the color of a colored layer may change and look. Moreover, as a method of using the photolithography method, first, a separation layer is formed on a support body, and a protective layer is formed as needed. A separation layer has a function which makes it easy to peel a support body in a later transcription|transfer process. Then, a colored layer is formed on the separation layer (or on the protective layer to be formed as necessary). Then, after transferring a colored layer to a to-be-adhered body through a bonding layer, the support body is peeled and removed. Since these steps are carried out, the number of steps is relatively large, and economical efficiency is sometimes not good.

An object of the present invention is to provide a laminate that has good flexibility, is excellent in light transmittance in a portion where the colored layer is not formed, and can suppress discoloration of the colored layer when the laminate is viewed from a diagonal direction. Another object of the present invention is to provide a method for manufacturing a laminate in which the laminate can be manufactured by a relatively small number of steps.

This invention provides the following laminated body, a front plate, and the manufacturing method of a laminated body.

[1] comprising a base material, a colored layer, and a planarization layer,

The substrate is a thin glass having a thickness of 100 μm or less,

The colored layer and the planarization layer are in direct contact with the substrate.

[2] The laminate according to [1], wherein the colored layer is formed on the entire periphery of the substrate.

[3] The laminate according to [1] or [2], wherein an area ratio of the colored layer to the substrate in a plan view is 1% or more and 50% or less.

[4] A front plate comprising the laminate according to any one of [1] to [3].

[5] The method for producing the laminate according to [1], comprising:

A pressure-sensitive adhesive layer forming step of forming a pressure-sensitive adhesive layer on a support;

The bonding process of bonding a base material together on the said support body via the said adhesive layer;

A colored layer forming step of forming a colored layer on the side opposite to the pressure-sensitive adhesive layer side of the substrate by a photolithography method;

A planarization layer forming step of forming a planarization layer on the colored layer side of the substrate;

Peeling process of peeling the said support body and the said adhesive layer

A method of manufacturing a laminate comprising a.

[6] The method for producing a laminate according to [5], wherein the pressure-sensitive adhesive layer is peeled off in an environment in which the temperature is -30°C or higher and 30°C or lower.

[7] The method for producing a laminate according to [5] or [6], wherein the width of the substrate is wider than that of the support.

ADVANTAGE OF THE INVENTION According to this invention, it can provide the laminated body which has favorable flexibility, is excellent in the light transmittance of the part in which the colored layer is not formed, and can suppress discoloration of the colored layer when the laminated body is viewed from a diagonal direction. Moreover, according to this invention, the manufacturing method of the laminated body which can manufacture the said laminated body with comparatively small number of processes can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing which shows typically an example of the laminated body of this invention.
It is a schematic plan view which shows typically an example of the laminated body of this invention.
It is a schematic sectional drawing which shows typically an example of the laminated body of this invention.
It is a schematic sectional drawing which shows typically the manufacturing method of the flexible optical laminated body of this invention.
It is a figure which shows the evaluation result of the discoloration of the colored layer of Example 1. FIG.
It is a figure which shows the evaluation result of the discoloration of the colored layer of Comparative Example 1. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, although embodiment of this invention is described referring drawings, this invention is not limited to the following embodiment. In all the drawings below, scales are appropriately adjusted to facilitate understanding of each component, and the scale of each component shown in the drawings does not necessarily coincide with the scale of the actual component.

<Laminate>

A laminate according to an aspect of the present invention includes a base material, a colored layer, and a planarization layer, the base material is made of thin glass having a thickness of 100 µm or less, and the colored layer and the planarization layer are in direct contact with the base material. According to the present invention, the base material is a thin glass having a thickness of 100 µm or less, and the colored layer and the planarization layer are formed in direct contact with the base material, so that the flexibility is good and the light transmittance of the part where the colored layer is not formed is good. great. In addition, since the laminate of the present invention does not have a separation layer and a bonding layer having irregularities on the surface, the occurrence of irregularities on the surface of the planarization layer is suppressed, and discoloration of the colored layer when the laminate is viewed from a diagonal direction is reduced. can be suppressed

The laminate will be described with reference to FIG. 1 . The laminate 10 shown in FIG. 1 is laminated|stacked on the base material 1, the colored layer 2 and the planarization layer 3 contacting directly.

The shape of the laminate 10 in plan view (hereinafter also referred to as plan view shape) may be, for example, a square shape, preferably a rectangular shape having a long side and a short side, and more preferably a rectangular shape. to be. Each layer constituting the layered product 10 may have an R-processed part, a notch process, or a hole-processing in-plane in a plan view. In this specification, planar view means viewing from the thickness direction (stacking direction) of a layer.

Although the thickness of the laminated body 10 is not specifically limited, For example, 60 micrometers or less may be sufficient, Preferably it is 50 micrometers or less, More preferably, it is 40 micrometers or less, More preferably, it is 35 micrometers or less. The thickness of the laminated body 10 is 30 micrometers or more normally.

When the planar shape of the laminate 10 is a rectangle, the length of the long side may be, for example, 10 mm or more and 500 mm or less, preferably 50 mm or more and 300 mm or less, more preferably 100 mm or more and 200 mm or less. The length of the short side is, for example, 5 mm or more and 400 mm or less, preferably 20 mm or more and 300 mm or less, more preferably 40 mm or more and 200 mm or less, and still more preferably 60 mm or more and 180 mm or less. .

The laminated body 10 is excellent in the light transmission property of the part in which the colored layer 2 is not formed. The light transmittance of the laminate 10 can be expressed by the total light transmittance. As for the laminated body 10, the total light transmittance of the part in which the colored layer 2 is not formed may be 80 % or more, for example, 92 % or more may be sufficient as it, Preferably it is 92.5 % or more, More preferably, 93 % or more. % or more. Moreover, a total light transmittance can be measured based on JISK7361-1:1997. For example, total light transmittance can be measured according to the procedure described in the column of the Example mentioned later.

The layered product 10 may have a yellowness (according to ASTM E313-73. Hereinafter, also referred to as yellowness for simplicity) of a portion where a colored layer is not formed, for example, 2.3 or less, preferably 2.2. Hereinafter, more preferably, it is 2.1 or less, More preferably, it is 2.0 or less. Yellowness can be measured according to the procedure described in the column of Examples to be described later.

The laminate 10 is bendable. Being bendable means that it can be bent without generating cracks. The optical laminate 100 may be bent with the flattening layer 3 side as at least either one of the inner and the outer sides, preferably bendable with the flattening layer 3 side inside, more preferably Even when repeated bending is performed so that the flattening layer 3 side is turned inside and the bending radius is 2 mm, there is a tendency that cracks are less likely to occur. In this specification, the bending|flexion includes the form of bending in which a curved surface is formed in a bending part. The form of bending WHEREIN: The radius of curvature of the bent inner surface is not specifically limited. Further, the bending includes a form of refraction in which the refraction angle of the inner surface is greater than 0° and less than 180°, and a form of folding in which the radius of curvature of the inner surface is close to zero or the refraction angle of the inner surface is 0°.

The laminate 10 is excellent in flexibility. The flexibility of the laminate 10 can be evaluated by the bending life. The laminate 10 may have a bending life of, for example, 50,000 times or more, preferably 100,000 times, when the laminate 10 is repeatedly bent with the flattening layer 3 side inside to have a bending radius of 2 mm. It is more than 200,000 times, More preferably, it is 200,000 times or more. The bending life of the laminate 10 can be measured according to the procedure described in the column of Examples to be described later.

Since the wiring of a touch sensor, an electrode, etc. can shield the laminated body 10, it is suitable for the image display apparatus which has a touch sensor. An image display apparatus is not specifically limited, For example, an organic electroluminescent (organic EL) display apparatus, an inorganic electroluminescent (inorganic EL) display apparatus, a liquid crystal display apparatus, an electroluminescent display apparatus, etc. are mentioned. The laminated body 10 can be arrange|positioned in the image display apparatus in the state bonded by the polarizing plate. A linear polarizing plate may be sufficient as a polarizing plate, and the circularly polarizing plate in which the retardation layer was laminated|stacked on the linear polarizing plate may be sufficient as it. Moreover, since the laminated body 10 is bendable, it is suitable for a flexible display.

[write]

The substrate is thin glass (hereinafter, also referred to as thin glass for simplicity) having a thickness of 100 µm or less. Moreover, in this invention, the glass whose thickness is 100 micrometers or less is called thin glass. When the base material is thin glass having a thickness of 100 µm or less, unevenness is suppressed on the surface of the planarization layer, and discoloration of the colored layer when the laminate is viewed from a diagonal direction can be suppressed.

The thickness of the thin glass is preferably 90 µm or less, more preferably 80 µm or less, still more preferably 70 µm or less, and particularly preferably 60 µm or less from the viewpoint of improving the flexibility and light transmittance of the laminate. and more particularly preferably 50 µm or less. The thickness of the thin glass is usually 10 µm or more, preferably 20 µm or more, and more preferably 30 µm or more from the viewpoint of improving the impact resistance of the laminate.

As the thin glass, it is preferable to use chemically strengthened glass excellent in strength and light transmittance. By using chemically strengthened glass, the impact resistance of the laminate can be improved while maintaining flexibility (flexibility). Chemically strengthened glass can be obtained by chemical ion exchange treatment of glass. The strength of the glass surface can be improved by partially replacing sodium ions and lithium ions on the glass surface with potassium ions having a larger ionic radius by chemical ion exchange treatment. By the formation of a thin compressive stress layer, the surface strength is improved. Examples of the glass used for chemically strengthened glass include aluminosilicate glass, soda-lime glass, borosilicate glass, lead glass, alkali barium glass, and aluminoborosilicate glass.

The chemical ion exchange treatment can be performed by immersing the glass in an ion replacement solution heated to a melting point or higher, or directly applying a paste-like ion replacement solution to the glass. Examples of the ion replacement solution include those based on potassium nitrate, potassium carbonate, potassium hydrogencarbonate, potassium phosphate, potassium sulfate, and potassium hydroxide. Especially, potassium nitrate (330 degreeC) is preferable at the point which melting|fusing point is lower than melting|fusing point (normally 500 degreeC or more and 600 degrees C or less) of glass, and handling is easy.

An etching process may be performed before a chemical ion exchange process, and you may perform thin film formation of glass. The etching treatment may be performed using hydrofluoric acid or a mixture of hydrofluoric acid or this, an aqueous ammonium fluoride solution and an organic acid such as formic acid, acetic acid, propionic acid and the like as a chemical treatment solution. Using these, etching can be performed by spraying, dipping, or the like. The etching treatment may be performed using an inert gas containing fluorine as the etching gas, for example, He gas or Ar gas containing at least one type of CF ₄ , C ₃ F ₈ , C ₂ F ₆ , XeF ₂ , or the like. . Specifically, etching can be performed by plasmaizing an inert gas containing fluorine diluted with He gas or Ar gas under atmospheric pressure to liberate fluorine from fluorocarbons.

[Colored layer]

The colored layer 2 can function as a light-shielding layer patterned on one side of the base 1 . The colored layer 2 is formed so as to form a non-display area of an image display device, for example. The colored layer 2 may be formed, for example, on at least a part of the periphery on the base material 1 , and preferably, as shown in FIG. 2 , in a plan view of the laminate 10 , the perimeter on the base material 1 . is formed in the whole of By forming the colored layer 2 around the periphery of the base material 1, the colored layer 2 is visually recognized like a picture frame, so that designability can be improved.

In the planar view of the laminated body 10, the width|variety of the colored layer 2 is not specifically limited, What is necessary is just to select suitably according to the size, a use, a design, etc. of the laminated body 10. As shown in FIG. In Fig. 2, the width Wa of the colored layer 2 on the short side of the laminate 10 may be, for example, 0.1 mm or more and 50 mm or less, preferably 1 mm or more and 20 mm or less, more Preferably they are 2 mm or more and 10 mm or less. The width Wb of the colored layer 2 on the long side of the laminate 10 may be, for example, 0.1 mm or more and 50 mm or less, preferably 1 mm or more and 20 mm or less, more preferably 2 mm or more and 10 mm or less.

In a planar view of the laminate 10, the area ratio of the colored layer to the base material may be, for example, 1% or more and 50% or less, 30% or less, 20% or less, or 10% or less, for example.

The colored layer 2 may be formed as a single layer of a thin film. The thickness of the colored layer 2 may be, for example, 3 µm or less, preferably 2.5 µm or less, more preferably from the viewpoint of reducing the step difference on the flattening layer 3 side of the laminate 10. It is 2.0 micrometers or less, More preferably, it is 1.5 micrometers or less. The thickness of the colored layer 2 may be, for example, 0.5 µm or more, and is preferably 0.7 µm or more, and more preferably 1 µm or more from the viewpoint of improving light-shielding properties. When the colored layer 2 has a tapered portion as will be described later, the thickness of the colored layer 2 may be the maximum thickness of the colored layer 2 .

The optical density of the colored layer 2 may be, for example, 1.5 or more, preferably 1.8 or more, more preferably from the viewpoint of minimizing light leakage at the boundary between the display area and the non-display area of the image display device. Preferably it is 2.5 or more, More preferably, it is 3 or more, Especially preferably, it is 3.5 or more, Especially preferably, it is 4.0 or more. The optical density of the colored layer 2 can be measured, for example, with an optical density meter (product name: 361T, manufactured by X-rite). Specifically, first, a sample in which a colored layer is formed on a substrate is set in a measuring device, and a light source disposed on the colored layer is turned on. Then, the colored layer of the sample is focused, and the upper light source is turned off. Next, the light source for measurement located on the base material side of a sample is turned on, and optical density is measured using the colored layer as a measurement area|region. The optical density is obtained by the following formula when the intensity of light incident on the colored layer 2 is I ₀ and the intensity of transmitted light after passing through the colored layer 2 is I:

Optical density = log ₁₀ [I ₀ /I]

can be calculated accordingly.

As shown in FIG. 3 , the colored layer 2 may have a tapered end in the cross-sectional shape in the thickness direction. When the colored layer 2 has the tapered portion 2a, the level difference on the surface of the laminate 10 on the flattening layer 3 side tends to become small. The colored layer 2 can have the width T of the tapered portion 2a, that is, the width from the inner end of the colored layer 2 to the point at which the maximum thickness H is 2 µm or less. The colored layer 2 has an optical density of 5 or more, preferably 6 or more, at a point 2 μm away from the area of the tapered portion 2a, and a maximum thickness H of, for example, 0.5 μm or more and 3.0 μm or less. can

The colored layer 2 may be comprised of a colored resin composition. The colored resin composition may be, for example, a resin in which a pigment is dispersed, a binder resin, a polymerizable compound, a polymerizable initiator, a composition comprising an additive, or the like, or a photocurable (thermosetting) resin composition comprising a pigment.

The colored resin composition may be, for example, a black resin composition, preferably a photocurable black resin composition. As a pigment, a black pigment may be sufficient, for example, Carbon black, a graphite, a metal oxide, an organic black pigment etc. are mentioned as the example. Examples of the organic black pigment include aniline black, lactam black, and perylene black series. As an additive, an adhesion promoter, a photo-crosslinking sensitizer, a hardening accelerator, surfactant, a dispersing agent, antioxidant, a ultraviolet absorber, a thermal polymerization inhibitor, a leveling agent etc. are mentioned, for example. The additive may include alone or a combination of two or more. The photocurable black resin composition may be a composition capable of forming a colored layer having an optical density of 3.8 or more per 1 μm.

The colored layer 2 may be a thin film formed by photolithography. The photolithography method can be formed, for example, by applying a photocurable black resin composition onto the substrate 1, and then exposing and developing the photocurable black resin composition. For exposure, an exposure light source that emits light having a wavelength of 250 nm or more and 450 nm, for example, a mercury vapor arc, a carbon arc, a Xe arc, or the like can be used. The laminate of the present invention is different from the conventional manufacturing method using a photolithography method in which a colored layer is formed on a support having a separation layer, then transferred to an adherend through a bonding layer, and then the support is peeled off. Alternatively, since it is obtained by a manufacturing method using a photolithography method for forming a colored layer directly on a substrate, it has an advantage that it can be manufactured by a manufacturing method with fewer steps than a conventional manufacturing method.

[flattened layer]

The planarization layer 3 is formed on the entire surface of the base material 1 and the colored layer 2 , and can have functions such as planarization of the surface step by the colored layer 2 , refractive index control, and a protective layer.

The planarization layer 3 may be an organic film, an inorganic film, or an organic-inorganic hybrid film. When the planarization layer 3 is an organic film, the planarization layer 3 is formed of a composition for forming a planarization layer including, for example, a thermoplastic resin such as a polyacrylate-based resin, a polyimide-based resin, or a polyester-based resin. can do. When the planarization layer 3 is an inorganic film, the planarization layer 3 can be formed of, for example, silazane, silica, or an inorganic film or metal film having light transmittance. The inorganic membrane may contain an inorganic filler. The inorganic filler may be spherical nanoparticles capable of improving light transmittance. As the organic-inorganic hybrid film, a dispersed organic-inorganic hybrid composite material such as siloxane or silsesquioxane can be used.

The thickness of the planarization layer 3 may be, for example, 1 μm or more and 2.5 μm.

The planarization layer 3 can be replaced with an adhesive layer or an adhesive bond layer. The pressure-sensitive adhesive layer and the adhesive layer may be formed of a pressure-sensitive adhesive (PSA) composition and an optically transparent adhesive (OCA) composition, respectively. The pressure-sensitive adhesive layer may be formed of, for example, a pressure-sensitive adhesive composition comprising an acrylic copolymer and a crosslinking agent, or a pressure-sensitive adhesive composition comprising a urethane (meth)acrylate resin, a (meth)acrylate ester monomer and a photoinitiator. can be formed. The thickness of an adhesive layer and an adhesive bond layer may be 1 micrometer or more and 50 micrometers or less, for example.

<Front panel>

Another aspect of the present invention is a front plate including the laminate of the present invention. The front plate may contain only the laminate of the present invention, or may contain a layer different from the laminate of the present invention. As another layer, the resin film etc. for improving a hard-coat layer, an abrasion-resistance layer, and impact resistance are mentioned, for example. Since the laminate of the present invention has good light transmission properties and can suppress discoloration of the colored layer when viewed from a diagonal direction, it is suitable for a front plate. When the laminate is disposed in the image display device as the front plate, the front plate is disposed on the viewer side of the image display element. It is preferable that a front plate has a hard-coat layer, an abrasion-resistant layer, a resin film, etc. on the visual recognition side of a laminated body. It is preferable that the laminated body 10 is arrange|positioned so that it may become the base material 1 and the colored layer 2 (or the planarization layer 3) in order from the visual recognition side of an image display element.

When the front plate of the present invention contains the laminate of the present invention and a resin film for enhancing impact resistance, the substrate 1, the colored layer 2 (or the planarization layer) in order from the visual recognition side of the image display element (3)), it is preferable to arrange|position so that it may become the said resin film.

When a front plate has a hard-coat layer, hardness can be improved more by providing a hard-coat layer in at least one surface of a laminated body. The hard-coat layer may be formed in one surface of a base film, and may be formed in both surfaces. When the image display device on which the front plate is arranged is a touch panel type image display device, since the surface of the front plate becomes a touch surface, the front plate which has a hard-coat layer is used preferably. By providing a hard-coat layer, hardness and scratch resistance can be improved. The hard coat layer is, for example, a cured layer of ultraviolet curable resin. Examples of the ultraviolet curable resin include (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, and epoxy resins. The hard-coat layer may contain the additive in order to improve hardness. The additive is not limited, and inorganic fine particles, organic fine particles, or a mixture thereof may be mentioned. The thickness of a hard-coat layer may be 0.1 micrometer or more and 30 micrometers or less, for example, Preferably they are 1 micrometer or more and 20 micrometers or less, More preferably, they are 5 micrometers or more and 15 micrometers or less.

It is also preferable that an abrasion-resistant layer is formed on the visual recognition side of a hard-coat layer in order to improve abrasion resistance or prevent contamination by sebum etc. The front plate may have an abrasion-resistant layer, and the abrasion-resistant layer may be a layer constituting the visual side surface of the front plate. The wear-resistant layer may include a structure derived from a fluorine compound. As a fluorine compound, it has a silicon atom, and the compound which has a hydrolysable group like an alkoxy group and a halogen in a silicon atom is preferable. A coating film can be formed by a hydrolysable group dehydration-condensation reaction, and the adhesiveness of an abrasion-resistant layer can be improved by reacting with active hydrogen on the surface of a base material. Moreover, since a fluorine compound can provide water repellency when it has a perfluoroalkyl group or a perfluoropolyether structure, it is preferable. Particularly preferred are fluorine-containing polyorganosiloxane compounds having a perfluoropolyether structure and a long-chain alkyl group having 4 or more carbon atoms. It is also preferable to use two or more types of compounds as a fluorine compound. Further, preferred fluorine compounds to be included are fluorine-containing organosiloxane compounds containing an alkylene group having 2 or more carbon atoms and a perfluoroalkylene group.

The thickness of the wear-resistant layer is, for example, 1 nm or more and 20 nm or less. Moreover, the abrasion-resistant layer has water repellency, and a water contact angle is about 110-125 degrees, for example. The contact angle hysteresis and the sliding angle measured by the sliding method are about 3 to 20 degrees and about 2 to 55 degrees, respectively. In addition, the wear-resistant layer is a silanol condensation catalyst, antioxidant, rust inhibitor, ultraviolet absorber, light stabilizer, fungicide, antibacterial agent, bioadhesion inhibitor, deodorant, pigment, flame retardant, antistatic agent, in the range that does not impair the effects of the present invention. You may contain various additives, such as an inhibitor.

A primer layer may be provided between the abrasion-resistant layer and the hard coat layer. As a primer agent, there exist primer agents, such as an epoxy compound of an ultraviolet curing type, a thermosetting type, a moisture curing type, or a two-component curing type, for example. Moreover, as a primer agent, a polyamic acid may be used and it is also preferable to use a silane coupling agent. The thickness of the primer layer is, for example, 0.001 to 2 µm.

As a method of obtaining a laminate comprising an abrasion-resistant layer and a hard coat layer, a primer layer is formed by applying, drying, and curing a primer agent as necessary on the hard coat layer, followed by a composition containing a fluorine compound (abrasion-resistant layer). It can be formed by apply|coating and drying the composition for coating. Examples of the coating method include a dip coating method, a roll coating method, a bar coating method, a spin coating method, a spray coating method, a die coating method, and a gravure coating method. Moreover, it is also preferable to perform hydrophilization treatment, such as plasma treatment, corona treatment, or ultraviolet treatment, to an applied surface before apply|coating a primer agent or the composition for abrasion-resistant layer coating.

As a resin film, if it is a resin film which can transmit light, it will not be limited. For example, triacetyl cellulose, acetyl cellulose butyrate, ethylene-vinyl acetate copolymer, propionyl cellulose, butyryl cellulose, acetyl propionyl cellulose, polyester, polystyrene, polyamide, polyetherimide, poly(meth)acryl , polyimide, polyethersulfone, polysulfone, polyethylene, polypropylene, polymethylpentene, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polyvinyl acetal, polyether ketone, polyether ether ketone, polymethyl (meth ) acrylate, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, and a film formed of a polymer such as polyamideimide. These polymer|macromolecule can be used individually or in mixture of 2 or more types. When the laminate is used for a flexible display, a resin film formed of a polymer such as polyimide, polyamide, or polyamideimide, which has excellent flexibility, can be configured to have high strength and high transparency, is preferably used. In addition, in this specification, "(meth)acryl" means that either an acryl or methacryl may be sufficient. "(meth)", such as (meth)acrylate, has the same meaning. The thickness of the resin film is, for example, 10 µm or more and 500 µm or less, and preferably 20 µm or more and 100 µm or less.

It is preferable that the elastic modulus in temperature 25 degreeC is 5000 Mpa or more, and, as for the resin film for improving impact resistance, it is more preferable that it is 5500 Mpa or more.

<Method for producing laminated body>

Another aspect of this invention is the manufacturing method of a laminated body. The manufacturing method of a laminated body is demonstrated, referring FIG. The manufacturing method of the laminate includes a pressure-sensitive adhesive layer forming step of forming the pressure-sensitive adhesive layer 22 on the support 21 ( FIG. 4(a) ), and a substrate ( The bonding process of bonding 1) [FIG.4(b)], and the colored layer formation process of forming the colored layer 2 by the photolithographic method on the opposite side to the adhesive layer 22 of the base material 1. Fig. 4(c)], the planarization layer forming step of forming the planarization layer 3 on the colored layer 2 side of the substrate 1 (Fig. 4(d)), the support body 21 and the pressure-sensitive adhesive layer A peeling process (FIG. 4(e)) of peeling (22) from the base material 1 and obtaining the laminated body 10 is included. The production method of the present invention forms a conventional colored layer on a support having a separation layer, and then transfers it to an adherend through a bonding layer, and then peels and removes the support, unlike the production method on the substrate. Since the colored layer is directly formed, it is advantageous in that the number of steps is small compared to the conventional manufacturing method.

As a support body, a glass plate, a resin plate, and a metal plate can be used, for example. The pressure-sensitive adhesive layer can be composed of a pressure-sensitive adhesive composition mainly containing a resin such as (meth)acrylic type, rubber type, urethane type, ester type, silicone type, or polyvinyl ether type. Especially, the adhesive composition which uses (meth)acrylic-type resin excellent in transparency, weather resistance, heat resistance, etc. as a base polymer is preferable. An active energy ray hardening type or a thermosetting type may be sufficient as an adhesive composition.

As a (meth)acrylic-type resin (base polymer) used for an adhesive composition, For example, (meth)acrylic acid butyl, (meth)acrylate methyl, (meth)acrylate ethyl, (meth)acrylate hexyl, (meth)acrylate octyl, One or two types of (meth)acrylic acid esters such as (meth)acrylic acid lauryl, (meth)acrylic acid isooctyl, (meth)acrylic acid isodecyl, (meth)acrylic acid 2-ethylhexyl, (meth)acrylic acid isobornyl Polymers or copolymers having the above as monomers are preferably used.

It is preferable to copolymerize a polar monomer with a base polymer. Examples of the polar monomer include (meth)acrylic acid, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid hydroxyethyl, (meth)acrylamide, N,N-dimethylaminoethyl (meth)acrylate, The monomer which has a carboxy group, a hydroxyl group, an amide group, an amino group, an epoxy group, etc. like glycidyl (meth)acrylate is mentioned.

Although the adhesive composition may contain only the said base polymer, normally, it further contains a crosslinking agent. Examples of the crosslinking agent include those that form a metal carboxylate salt between a carboxyl group and a divalent or higher metal ion; A polyamine compound that forms an amide bond with a carboxy group; A polyepoxy compound or polyol that forms an ester bond with a carboxy group; As the polyisocyanate compound, those that form an amide bond with a carboxy group are exemplified. Especially, a polyisocyanate compound is preferable.

The active energy ray-curable pressure-sensitive adhesive composition has a property of being cured by irradiation with active energy rays such as ultraviolet rays or electron beams, has adhesiveness even before irradiation with active energy rays, and can adhere to an adherend such as a film, and is irradiated with active energy rays It is a pressure-sensitive adhesive composition having a property that can be cured by the adhesion, such as adjustment.

It is preferable that an active energy ray hardening-type adhesive composition is an ultraviolet curable type. In addition to a base polymer and a crosslinking agent, an active energy ray hardening-type adhesive composition contains an active energy ray polymeric compound further. Moreover, you may make it contain a photoinitiator, a photosensitizer, etc. as needed.

As an active-energy-ray-polymerizable compound, For example, (meth)acrylate monomer which has at least 1 piece(s) acryloyloxy group in a molecule|numerator; (meth)acrylic compounds such as (meth)acryloyloxy group-containing compounds such as (meth)acrylate oligomers obtained by reacting two or more functional group-containing compounds and having at least two (meth)acryloyloxy groups in the molecule can be heard

The pressure-sensitive adhesive composition includes fine particles for imparting light scattering properties, beads (resin beads, glass beads, etc.), glass fibers, resins other than the base polymer, tackifiers, fillers (metal powders and other inorganic powders, etc.), antioxidants, ultraviolet rays It may contain additives such as absorbents, dyes, pigments, colorants, defoamers, corrosion inhibitors, and photopolymerization initiators.

An adhesive layer can be formed by apply|coating, for example, an organic solvent dilution liquid of the said adhesive composition on a base material, and drying it. When an active energy ray hardening-type adhesive composition is used, it can be set as the hardened|cured material which has a desired degree of hardening by irradiating an active energy ray to the formed adhesive layer.

As for the adhesive which comprises an adhesive layer, the adhesive which has low-temperature peelability is preferable. The pressure-sensitive adhesive layer composed of the pressure-sensitive adhesive having low-temperature releasability is, for example, -30°C or higher and 30°C or lower, preferably -5°C or higher and 5°C or lower, from the substrate.

The thickness of an adhesive layer may be 2 micrometers or more and 100 micrometers or less, for example, Preferably they are 3 micrometers or more and 50 micrometers or less, More preferably, they are 5 micrometers or more and 30 micrometers or less.

An adhesive layer can be prepared as an adhesive sheet. The pressure-sensitive adhesive sheet is, for example, by dissolving or dispersing the pressure-sensitive adhesive composition in an organic solvent such as toluene or ethyl acetate to prepare a pressure-sensitive adhesive solution, and forming a layer made of the pressure-sensitive adhesive on the release film subjected to the release treatment in the form of a sheet, It can be produced by the method of bonding another peeling film together on the adhesive layer, etc. Each layer can be bonded together by the method of bonding the adhesive sheet which peeled one peeling film to one layer, then peeling the other peeling film, and bonding the other layer together.

An adhesive layer formation process WHEREIN: When an adhesive layer is an adhesive sheet, peeling removes one peeling film, and the exposed surface can be bonded together with a support body. Then, in a bonding process, one peeling film can be peeled and removed, and a base material can be bonded together to the exposed surface. The above-mentioned thin glass can be used as a base material.

In a colored layer forming process, a colored layer is formed by the photolithographic method on the surface on the opposite side to the adhesive layer of a base material. In the photolithography method, as mentioned above, an active energy ray-curable resin composition is apply|coated on a base material, the coating film of the photosensitive resin composition is exposed, it can develop then, and can bake after that.

In the planarization layer forming step, a planarization layer can be formed on the formed colored layer. When the planarization layer is an organic film, as described above, it can be formed by applying the composition for forming a planarization layer on a base material on the colored layer side and baking.

In a peeling process, a support body and an adhesive layer are peeled and removed from a base material. Peeling can be performed by adjusting the temperature at the time of peeling, for example to -30 degreeC or more and 30 degrees C or less, Preferably, -5 degreeC or more and 5 degrees C or less, when an adhesive layer is an adhesive which has low-temperature peelability.

From a viewpoint of making it easy to peel and remove a support body and an adhesive layer from a base material, it is preferable to use the base material whose width|variety is wider than the support body. When the substrate and the support are rectangular, a substrate in which either the width of the long side or the width of the short side of the substrate is wider than the width of the support by, for example, 1 mm or more, preferably 5 mm or more can be used.

(Example)

Hereinafter, the present invention will be described in more detail by way of Examples. In the examples, "%" and "parts" are mass % and parts by mass, unless otherwise noted.

[Evaluation of discoloration of colored layer]

The laminate was placed on a base made of a white acrylic resin so that the side of the base material or the side of the separation layer faced upward with respect to the colored layer. Illuminate the laminate with a fluorescent lamp (45 W) and observe the discoloration of the portion with the colored layer when viewed from a diagonal direction with respect to the laminate (specifically, an angle of 60 degrees with respect to the horizontal direction) while rotating the fluorescent lamp reflecting unit while rotating the laminate. did.

No discoloration: Appears to be the same color as the area without the colored layer.

Discolored oil: It looks different from the part without the colored layer.

[Evaluation of bending life]

A colored polyimide film (thickness 125 µm; product name: UPILEX-S, manufactured by Ube Industries, Ltd.) was prepared. Corona-treated on the surface of the flattening layer side of a laminated body, and one surface of a colored polyimide film. After bonding the laminated body and the corona-treated surfaces of the colored polyimide film with a roll bonding device through an adhesive layer, the colored polyimide film was laser cut according to the size of the thin glass to prepare a sample for evaluation.

Then, a 2.0R jig and plate were mounted on a bending tester (Covotech, environmental bending evaluation machine), and the evaluation sample was fixed to the plate using a double-sided adhesive tape so that the substrate side was the upper surface with respect to the colored layer. With respect to the colored layer, bending was repeated at a bending speed of 1 Hz and a bending radius of 2.0 mm with the base material side inside, until cracks were generated in the laminate or reached 200,000 times. The judgment criteria are as follows.

A: Cracks do not occur even if the number of bending is 200,000 times.

B: Cracks occur when the number of bending is 100,000 or more and less than 200,000.

C: Cracks occur when the number of bending is 50,000 or more and less than 100,000.

D: Cracks occur when the number of bending is less than 50,000.

[Measurement of total light transmittance and yellowness]

Measurement was performed using a spectrophotometer (KONICA MINOLTA, INC., CN-3700A).

[Production Example 1: Preparation of adhesive]

A mixed solution of 80 parts of ethyl acetate, 70 parts of butyl acrylate, 20 parts of methyl acrylate, and 1.0 parts of acrylic acid is introduced into a reactor equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, and the air in the apparatus is replaced with nitrogen gas to oxygen Without including, the internal temperature was raised to 55 ℃. Then, the total amount of the solution which melt|dissolved 0.2 part of radical polymerization initiator in 10 parts of acetone was added. 1 hour after addition of the radical polymerization initiator, while continuously adding acetone to the reactor at an addition rate of 17.3 parts/hour so that the concentration of the acrylic resin excluding the monomer becomes 35%, the reaction mixture is kept at an internal temperature of 54 to 56°C for 12 hours, and finally acetic acid Ethyl was added and it adjusted so that the density|concentration of an acrylic resin might be set to 20 %.

The weight average molecular weight Mw of the obtained acrylic resin was 1.5 million, and Mw/Mn was 5.0.

Obtained acrylic resin: 100 parts (non-volatile content), Colonate L: 0.5 part, and KBM-403: 0.5 part were mixed. Ethyl acetate was added so that solid content concentration might be 10 %, and the adhesive composition was obtained.

The obtained adhesive composition was apply|coated to the release-treated surface of the polyethylene terephthalate film (38 micrometers in thickness) by which the release process was carried out so that the thickness after drying might be set to 25 micrometers using the applicator. The application layer was dried at 100 degreeC for 1 minute, and the film provided with an adhesive layer was obtained. Then, on the adhesive layer, the other polyethylene terephthalate film (38 micrometers in thickness) by which the mold release process was carried out was pasted together. Thereafter, it was cured for 7 days under conditions of a temperature of 23°C and a relative humidity of 50%RH.

[Production Example 2: Preparation of a composition for forming a colored layer (black)]

[Ink component] Acetylene black 15 mass % polyester 75 mass % dimethyl glutarate 2.5 mass % succinic acid 2 mass % isophorone 5.5 mass %

[curing agent] aliphatic polyisocyanate 75 mass % ethyl acetate 25 mass %

[solvent] isophorone

[Preparation method] 10 parts by mass of a curing agent and 10 parts by mass of a solvent were added and stirred with respect to 100 parts by mass of the ink component to obtain a composition for forming a colorant-containing layer (black).

[Production Example 3: Preparation of a composition for forming a planarization layer (transparent)]

[Ink component] Polyester 90 mass % glutaric acid dimethyl ester 2.5 mass % succinic acid 2 mass % isophorone 5.5 mass %

[curing agent] aliphatic polyisocyanate 75 mass % ethyl acetate 25 mass %

[solvent] isophorone

[Preparation method] With respect to 100 parts by mass of the ink component, 10 parts by mass of a curing agent and 10 parts by mass of a solvent were added and stirred to obtain a composition for forming a protective layer.

<Example 1>

The adhesive produced in manufacture example 1 was apply|coated on the support body (a glass plate, long side 165mm x short side 131mm x thickness 1.1mm), and the adhesive layer was formed. The thin glass (Schott company make, thickness 30 micrometers, long side 167 mm x short side 133 mm, chemical strengthening treatment, and surface-polishing) was bonded through the adhesive layer on a support body through the adhesive layer. Then, on the surface of the thin glass opposite to the pressure-sensitive adhesive layer side, using the above-described composition for forming a colored layer, a colored layer is patterned by a photolithography method so as to have a tapered shape having a thickness of 1.4 μm after drying, A colored layer was formed over the entire periphery of the substrate. The width of the colored layer on the long side and the short side in plan view was both 5 mm, and the area ratio of the colored layer to the base material was 6.6%. Next, the composition for forming a planarization layer was applied to the colored layer side of the thin glass and thermosetted to form a planarization layer (thickness on the colored layer: 2 µm). The support body and the adhesive layer were peeled and removed at the temperature of 0 degree|times, and the laminated body of Example 1 which has the laminated constitution of a planarization layer / colored layer / thin glass was obtained. The colored layer and the planarization layer were in direct contact with the thin glass. As shown in FIG. 5, the color change was not recognized in evaluation of the discoloration of a colored layer in the laminated body. In Fig. 5, in the fluorescent lamp reflecting portion, it is understood that there is no difference in appearance, since it is not possible to distinguish between the presence of the colored layer and the absence of the colored layer. A result is shown in Table 1. Moreover, the photolithographic method includes the composition application|coating process for colored layer formation, an exposure process, a developing process, and a thermosetting process.

<Comparative Example 1>

As in Synthesis Example 1 of US11180585, an acrylic resin was coated on a support (glass plate) to form a separation layer (thickness: 300 nm). Then, on the separation layer, the composition of Example 1 in JP-A-2016-014877 was coated to form a protective layer (thickness: 1.5 µm). On the protective layer, the above-described composition for forming a colored layer was applied to a thickness of 1.4 µm after drying, and the colored layer was formed on the entire periphery of the substrate by patterning by photolithography. The width of the colored layer on the long side and the short side in plan view was both 5 mm, and the area ratio of the colored layer to the base material was 6.6%. Then, on the protective layer and the colored layer, the composition for forming a planarization layer was applied and cured to form a planarization layer (thickness on the colored layer: 2 µm). Next, a peelable thermoplastic resin film was laminated on the planarization layer. After peeling and removing the support, the thin glass used in Example 1 was bonded through an adhesive layer (Adeka Acools KR series, manufactured by ADEKA, thickness: 1.5 μm), and the thermoplastic resin film was peeled off, and the flattening layer/colored layer/ A laminate of Comparative Example 1 having a layer structure of a protective layer/separation layer/adhesive layer/thin glass was obtained. As shown in FIG. 6, the color change was recognized in evaluation of the discoloration of a colored layer in the laminated body. In Fig. 6, in the fluorescent lamp reflective portion, it is understood that there is a difference in appearance due to the distinction between the presence of the colored layer and the absence of the colored layer, and there is a boundary therebetween. A result is shown in Table 1.

<Comparative Example 2>

In Comparative Example 1, instead of the adhesive layer (thickness: 1.5 µm), flattening was carried out in the same manner as in Comparative Example 1 except that the pressure-sensitive adhesive layer (thickness: 25 µm) of Example 6 of JP-A-2020-60708 was used. A laminate of Comparative Example 2 having a layer structure of layer/colored layer/protective layer/separation layer/adhesive layer/thin glass was obtained. A result is shown in Table 1.

[Table 1]

1: Base 2: Colored layer
2a: tapered part 3: planarization layer
10: laminate 21: support
22: adhesive layer H: maximum thickness of colored layer
T: width of taper
Wa: the width of the colored layer on the short side
Wb: the width of the colored layer on the long side

Claims (7)

It includes a substrate (基材), a colored layer and a planarization layer,
The substrate is a thin glass having a thickness of 100 μm or less,
The colored layer and the planarization layer are in direct contact with the substrate. The method of claim 1,
The said colored layer is formed in the whole peripheral part of the said base material, The laminated body. 3. The method of claim 1 or 2,
The laminated body whose area ratio with respect to the said base material of the said colored layer in a planar view is 1 % or more and 50 % or less. A front plate comprising the laminate according to claim 1 or 2 . A method for producing the laminate according to claim 1, comprising:
A pressure-sensitive adhesive layer forming step of forming a pressure-sensitive adhesive layer on a support;
The bonding process of bonding a base material together on the said support body via the said adhesive layer;
A colored layer forming step of forming a colored layer on the side opposite to the pressure-sensitive adhesive layer side of the substrate by a photolithography method;
A planarization layer forming step of forming a planarization layer on the colored layer side of the substrate;
Peeling process of peeling the said support body and the said adhesive layer
A method of manufacturing a laminate comprising a. 6. The method of claim 5,
The manufacturing method of the laminated body which peels the said adhesive layer in the environment whose temperature is -30 degreeC or more and 30 degrees C or less. 7. The method of claim 5 or 6,
The width of the substrate is wider than the support, the manufacturing method of the laminate.

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