TW202323027A - Multi-layer structure - Google Patents

Abstract

A multi-layer structure according to the present invention comprises a support body made of resin, an adhesive layer laminated on the support body, a metal layer laminated on the adhesive layer, and a glass layer laminated on the metal layer. The thickness of the glass layer is 10-300 [mu]m, and when the elastic modulus of the adhesive layer at 60 DEG C is denoted by x [MPa], and the amount of moisture contained in the support body is denoted by y [[mu]g/cm2], y ≤ 3333.3x is satisfied.

Description

multilayer structure

field of invention The present invention relates to multilayer structures.

Background of the invention A multilayer structure in which two or more layers are laminated is known. As an example, a multilayer structure in which a silver reflective layer is laminated on a thin glass layer (glass film) can be mentioned. The thickness of the multilayer structure is, for example, within a range of 10 to 200 μm. The multilayer structure is obtained, for example, from a glass roll formed by the down-draw method. Implement Technical Documents First patent documents

Patent Document 1: Japanese Patent Laid-Open No. 2013-231744

Summary of the invention ＜Problem to be solved by the invention＞ However, if the multilayer structure is placed in a high-temperature environment, it may cause poor appearance due to the influence of heat.

The present invention has been made in view of the above points, and an object of the present invention is to provide a multilayer structure that is less likely to have a defective appearance even when placed in a high-temperature environment. method used to solve the problem

This multilayer structure has a support made of resin, an adhesive layer laminated on the support, a metal layer laminated on the adhesive layer, and a glass layer laminated on the metal layer, and the thickness of the glass layer is 10 μm. When the above 300 μm is defined as x [MPa] for the elastic modulus at 60° C. of the adhesive layer and y [μg/cm ² ] for the amount of moisture contained in the support, y≦3333.3x is satisfied. ＜Efficacy of Invention＞

According to the disclosed technology, it is possible to provide a multilayer structure that is less prone to appearance defects even if placed in a high-temperature environment.

Detailed Description of the Preferred Embodiment Hereinafter, specific embodiments will be described with reference to the drawings. In each drawing, the same components are assigned the same symbols, and overlapping descriptions may be omitted.

FIG. 1 is a cross-sectional view illustrating a multilayer structure according to this embodiment. As shown in FIG. 1 , the multilayer structure 1 has a support 10 , an adhesive layer 20 , a resin layer 30 , a metal layer 40 , an adhesive layer 50 , and a glass layer 60 . The adhesive layer 20 , the resin layer 30 , the metal layer 40 , the adhesive layer 50 , and the glass layer 60 are sequentially laminated on the upper surface 10 a of the support body 10 . In addition, the resin layer 30 and the adhesive agent layer 50 are provided as needed.

The planar shape of the multilayer structure 1 (the shape viewed from the direction normal to the upper surface 10 a of the support body 10 ) is, for example, a rectangle. However, it is not limited thereto, and the planar shape of the multilayer structure 1 can be a circle, an ellipse, a combination thereof, or other appropriate shapes.

The multilayer structure 1 can be used as a mirror, for example. In the multilayer structure 1, the thickness of the glass layer 60 is not less than 10 μm and not more than 300 μm. In the multilayer structure 1 , the thickness of the glass layer 60 is thin, and the distance between the surface of the glass layer 60 and the metal layer 40 is extremely short. Therefore, in the multilayer structure 1 , it is possible to solve the problem of the conventional plate glass in which images appear double, and to express a clear image.

Here, materials and the like of each part of the multilayer structure 1 will be described.

[Support] The support body 10 is made of resin, and supports the glass layer 60 and the like. The thickness of the support body 10 can be, for example, about 1 mm to 5 mm. Examples of the material of the support body 10 include resins such as polycarbonate and polypropylene.

Glass or metal can be used as the support body 10 , but since glass and metal are heavy, the weight of the multilayer structure 1 as a whole increases and the handleability deteriorates. By using the support body 10 made of resin, the weight of the multilayer structure 1 can be reduced, and the handleability of the multilayer structure 1 can be improved. From the viewpoint of further improving handleability, the weight per unit area of the support body 10 is preferably 8 kg/m ² or less. In addition, by using the support body 10 made of resin, the multilayer structure 1 having flexibility can be realized. For example, the multilayer structure 1 can be pasted along a curved surface.

[Adhesive layer] The adhesive layer 20 is stacked on the support body 10 . In the example of FIG. 1 , the adhesive layer 20 is provided between the support body 10 and the resin layer 30, but when the multilayer structure 1 does not have the resin layer 30, the adhesive layer 20 is provided between the support body 10 and the metal layer 40. between. Any appropriate adhesive is used as the adhesive layer 20 . As a material of the adhesive layer 20, an acrylic adhesive, a silicone adhesive, a rubber adhesive, etc. are mentioned, for example. The thickness of the adhesive layer 20 is not particularly limited, and is, for example, about 5 μm or more and 500 μm or less.

[Resin layer] The resin layer 30 is laminated on the support body 10 via the adhesive layer 20 . The resin layer 30 is composed of one layer or a plurality of layers. When the resin layer 30 is formed of a plurality of layers, it is preferable to laminate them through an adhesive layer having an adhesive function. The total thickness of the resin layer 30 may be 20 μm to 1000 μm from the viewpoint of flexibility, preferably 25 μm to 500 μm, more preferably 50 μm to 200 μm. When the resin layer 30 is comprised by one layer, the thickness of the resin layer 30 can be the range of 20 micrometers or more and 150 micrometers or less, for example.

Examples of the material for the resin layer 30 include polyester resins such as polyethylene terephthalate resins and polyethylene naphthalate resins, and cycloolefin resins such as norbornene resins. , polyether resin, polycarbonate resin, acrylic resin, polyolefin resin, polyimide resin, polyamide resin, polyimide amide resin, polyarylate resin, Polyurethane-based resins, polyetherimide-based resins, cellulose-based resins, urethane-based resins, etc.

The resin layer 30 is provided as needed, and the effect of improving the handleability of the multilayer structure 1 is exhibited by providing the resin layer 30 .

[Metal layer] The metal layer 40 is laminated on the adhesive layer 20 via the resin layer 30 . In the case where the multilayer structure 1 does not have the resin layer 30 , the metal layer 40 is directly laminated on the adhesive layer 20 . The metal layer 40 is a layer that reflects visible light incident through the glass layer 60 and the adhesive layer 50 . The material of the metal layer 40 is preferably a material with a high reflectance of visible light, and examples thereof include aluminum, silver, and silver alloys. The thickness of the metal layer 40 is not particularly limited, and is, for example, about 10 nm to 500 nm. The metal layer 40 can be formed on the resin layer 30 by, for example, sputtering, vapor deposition, plating, or the like.

In addition, the metal layer 40 may be formed under the glass layer 60 by, for example, sputtering, vapor deposition, or plating. In this case, the adhesive layer 50 is unnecessary.

[Adhesive layer] The adhesive layer 50 is formed of a material with high visible light transmittance. The thickness of the adhesive layer 50 is, for example, not less than 0.1 μm and not more than 25 μm. As the adhesive layer 50, for example, acrylic adhesives, silicone adhesives, rubber adhesives, ultraviolet curable acrylic adhesives, ultraviolet curable epoxy adhesives, thermosetting epoxy adhesives, Thermosetting melamine adhesives, thermosetting phenol adhesives, ethylene vinyl acetate (EVA) interlayers, polyvinyl butyral (PVB) interlayers, etc.

In addition, in this specification, an adhesive means the layer which has adhesiveness at normal temperature, and adheres to a to-be-adhered body with light pressure. Therefore, even when the to-be-attached body adhered to the adhesive is peeled off, the adhesive maintains a practical adhesive force. On the other hand, an adhesive means a layer interposed between substances and capable of bonding substances. Therefore, when peeling off the to-be-adhered body stuck to an adhesive agent, an adhesive agent does not have practical adhesive force.

[Glass Layer] The glass layer 60 is laminated on the metal layer 40 via the adhesive layer 50 . The glass layer 60 is not particularly limited, and an appropriate layer can be employed according to the purpose. The glass layer 60 is classified by composition, and examples thereof include soda lime glass, boric acid glass, aluminosilicate glass, and quartz glass. Moreover, according to the classification based on an alkali component, non-alkali glass and low-alkali glass are mentioned. The content of alkali metal components (for example, Na ₂ O, K ₂ O, Li ₂ O) in the glass is preferably 15% by weight or less, more preferably 10% by weight or less.

The thickness of the glass layer 60 is preferably 10 μm or more in consideration of the surface hardness, airtightness, and corrosion resistance of glass. In addition, since the glass layer 60 is desired to have film-like flexibility, the thickness of the glass layer 60 is preferably 300 μm or less. The thickness of the glass layer 60 is more preferably from 20 μm to 200 μm, particularly preferably from 30 μm to 150 μm.

The light transmittance of the glass layer 60 at a wavelength of 550 nm is preferably 85% or more. The refractive index of the glass layer 60 at a wavelength of 550 nm is preferably 1.4 to 1.65. The density of the glass layer 60 is preferably 2.3 g/cm ³ to 3.0 g/cm ³ , more preferably 2.3 g/cm ³ to 2.7 g/cm ³ .

The method for forming the glass layer 60 is not particularly limited, and an appropriate method can be employed according to the purpose. Typically, the glass layer 60 can be formed into a thin plate by melting a mixture containing main raw materials such as silicon dioxide and alumina; defoaming agents such as mirabilite and antimony oxide; and reducing agents such as carbon at a temperature of about 1400°C to 1600°C. After shape, cool to make. As a molding method of the glass layer 60 , for example, an orifice downdraw method, a fusion method, a float method, etc. may be mentioned. The glass layer shaped into a plate by these methods may be chemically polished with a solvent such as hydrofluoric acid as needed in order to reduce the thickness of the plate and improve smoothness.

In addition, functional layers such as an antifouling layer, an antireflection layer, a conductive layer, a reflective layer, and a decorative layer may be provided on the upper surface of the glass layer 60 (the surface on which the adhesive layer 50 is not formed).

[Influence of Water Contained in Support] Since the support 10 is a resin, it contains water. The amount of water contained in the resin differs depending on the material, and is, for example, the value shown in Table 1. Table 1 is an example of the amount of moisture contained in the resin, as measured by the inventors. Of course, resins not shown in Table 1 also contain a predetermined amount of water. [Table 1]

The inventors found that if a multilayer structure whose support is a resin is used in a high temperature environment (for example, 60° C.), moisture contained in the resin penetrates into the adhesive layer and becomes air bubbles, deteriorating the appearance of the multilayer structure.

The deterioration of the appearance of the multilayer structure in a high-temperature environment (for example, 60° C.) is considered to be due to the following mechanism. First, the elastic modulus of the adhesive layer decreases due to heating, and the moisture contained in the support pushes away the adhesive near the surface and easily penetrates into the adhesive layer, and the moisture that penetrates into the adhesive layer vaporizes to generate air bubbles. Furthermore, air bubbles in the adhesive layer cause minute irregularities on the surfaces of the resin layer and the metal layer that are located on the side of the glass layer relative to the adhesive layer. Thus, the reflection on the surface of the metal layer becomes uneven to deteriorate the appearance of the multilayer structure.

Therefore, in the multilayer structure 1 , measures are taken to prevent moisture contained in the support body 10 from migrating to the adhesive layer 20 . This will be described below.

The inventors considered that in order to prevent the moisture contained in the support body 10 from moving to the adhesive layer 20, a low water-absorbing resin should be used as the material of the support body 10, and even if the material of the adhesive layer 20 is used in a high-temperature environment (for example, 60°C) adhesives that also have a high modulus of elasticity are effective. That is, it is considered that in a high-temperature environment (for example, 60° C.), if the elastic modulus of the adhesive layer 20 is high, the adhesive layer 20 is hard, so it is possible to prevent moisture from entering the adhesive layer from the interface between the adhesive layer 20 and the support body 10. 20's interior, experiments were carried out.

The inventors prepared a plurality of samples of the multilayer structure in which the amount of moisture contained in the support body 10 and the elastic modulus of the adhesive layer 20 were changed, and after storage at 60° C. for 12 hours, they visually inspected and examined whether the damage was caused by air bubbles. The appearance of the multilayer structure deteriorated. In addition, the planar shape of the sample of the multilayer structure used in the experiment was rectangular, and was set at 297 mm in length and 210 mm in width. In addition, the thickness of the resin layer 30 was 20 μm, the thickness of the metal layer 40 was 50 nm, the thickness of the adhesive layer 50 was 2 μm, and the thickness of the glass layer 60 was 100 μm.

In addition, the measurement of the moisture content contained in the support body 10 was performed by the Karl Fischer method. In addition, the elastic modulus of the adhesive layer 20 was measured by the nanoindentation method using a nanoindenter (Triboindenter manufactured by Hysitron Inc.). The elastic modulus was measured by a single indentation method at 60° C. using a conical (spherical indenter: radius of curvature: 10 μm) under the measurement conditions of an indentation depth of about 2 μm.

The experimental results are shown in FIG. 2 . Fig. 2 is a graph showing the relationship between the elastic modulus [MPa] of the adhesive layer and the water content [μg/cm ² ] of the support at 60°C. In FIG. 2 , ○ is a sample in which the appearance of the multilayer structure is not deteriorated due to bubbles, and × is a sample in which the appearance of the multilayer structure is deteriorated due to bubbles.

From the results shown in FIG. 2 , it can be said that the appearance of the multilayer structure does not deteriorate as long as it is on the arrow side of the inclined straight line in FIG. 2 . That is, when the elastic modulus of the adhesive layer 20 at 60° C. is x [MPa] and the amount of water contained in the support 10 is y [μg/cm ² ], y≦3333.3x is satisfied, then Deterioration of the appearance of the multilayer structure due to moisture contained in the support body 10 can be suppressed.

However, the modulus of elasticity of the adhesive layer 20 is preferably 0.1 MPa or more. When the modulus of elasticity of the adhesive layer 20 is 0.1 MPa or more, it is possible to suppress the occurrence of fine irregularities on the surface of the metal layer 40 due to scratches or the like. Moreover, when the elastic modulus of the adhesive layer 20 is 0.1 MPa or more, handling in the manufacturing process of the multilayer structure 1 becomes easy.

In addition, the amount of water contained in the support body 10 is preferably 1500 μg/cm ² or less. When the amount of moisture contained in the support body 10 is 1500 μg/cm ² or less, it is suitable from the viewpoint of being able to suppress deterioration of the appearance of the multilayer structure due to moisture.

In addition, suitable low water-absorbing resins used as the material of the support body 10 include, for example, polycarbonate and polypropylene shown in Table 1, but are not limited thereto. Moreover, as a method of increasing the elastic modulus of the adhesive layer 20, methods, such as raising the crosslinking density of a monomer, raising the glass transition temperature of a monomer, using a polyfunctional monomer, etc. are mentioned, for example.

As mentioned above, although preferred embodiment etc. were described in detail, it is not limited to the above-mentioned embodiment etc., Various deformation|transformation and substitution can be added to the said embodiment etc. without deviating from the range described in the claim.

This international application claims priority based on Japanese Patent Application No. 2021-157512 filed on September 28, 2021, and uses all the contents of Japanese Patent Application No. 2021-157512 in this international application.

1: multi-layer structure 10: Support body 10a: above 20: Adhesive layer 30: resin layer 40: metal layer 50: Adhesive layer 60: glass layer

FIG. 1 is a cross-sectional view illustrating a multilayer structure according to this embodiment. Fig. 2 is a graph showing the relationship between the elastic modulus [MPa] of the adhesive layer and the water content [μg/cm ² ] of the support at 60°C.

Claims (5)

A multilayer structure comprising: a resin support, an adhesive layer laminated on the support, a metal layer laminated on the adhesive layer, and a glass layer laminated on the metal layer, the glass layer When the thickness is 10 μm or more and 300 μm or less, when the elastic modulus of the adhesive layer at 60°C is x [MPa], and the amount of moisture contained in the support is y [μg/cm ² ], y is satisfied ≦3333.3x. The multi-layer structure as claimed in claim 1, The modulus of elasticity of the adhesive layer is 0.1 MPa or more. The multilayer structure according to claim 1 or 2, wherein the water contained in the support is 1500 μg/cm ² or less. The multilayer structure according to any one of claims 1 to 3, A resin layer is laminated between the adhesive layer and the metal layer. The multilayer structure according to any one of claims 1 to 4, An adhesive layer is laminated between the metal layer and the glass layer.

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