JP-2026075881-A - Laminate, method for manufacturing the same, and anti-reflective film

Abstract

[Problem] To provide a laminate having a titanium oxide film that does not damage the substrate surface and has excellent manufacturing efficiency and anti-reflective performance, a method for manufacturing the same, and an anti-reflective film. [Solution] The laminate 1 comprises a substrate 2, a protective layer 3, and a titanium oxide film 4 in order toward one side in the thickness direction. The titanium oxide film 4 contains crystals in which a group of Ti₂O₃ diffraction spots appear in the electron diffraction pattern observed with a transmission electron microscope, and its refractive index when incident with light of a wavelength of 550 nm is greater than 2.50 and less than or equal to 2.80. [Selection Diagram] Figure 1

Inventors

• 林 雄二郎
• 中島 一裕
• 荻田 拓哉
• 杉本 皓輔
• 長命 翔太

Assignees

• 日東電工株式会社

Dates

Publication Date

20260511

Application Date

20241023

Claims (7)

1. The substrate, protective layer, and titanium oxide film are arranged in order toward one side in the thickness direction. The titanium oxide film contains crystals in which a group of Ti₂O₃ diffraction spots appear in the electron diffraction pattern observed with a transmission electron microscope. A laminate in which the refractive index when incident on light with a wavelength of 550 nm is greater than 2.50 and less than or equal to 2.80.
2. The laminate according to claim 1, wherein the refractive index exceeds 2.68.
3. A method for manufacturing a laminate according to claim 1, The first step is to prepare the aforementioned substrate, A second step involves forming the protective layer on one side in the thickness direction of the substrate, A method for manufacturing a laminate, comprising a third step of forming the titanium oxide film on one side of the thickness direction of the protective layer using high-power impulse magnetron sputtering (HiPIMS) at a film formation temperature of 70°C or higher.
4. The method for manufacturing a laminate according to claim 3, wherein the third step is carried out with the film formation temperature set to 100°C or higher.
5. The method for manufacturing a laminate according to claim 3 or 4, wherein the second and third steps are carried out using a roll-to-roll method.
6. The laminate according to claim 1 or 2 and a low refractive index layer having a refractive index smaller than that of the titanium oxide film are provided sequentially toward one side in the thickness direction, The titanium oxide film is an anti-reflective film with a high refractive index.
7. The anti-reflective film according to claim 6, comprising two or more alternating laminates consisting of the high refractive index layer and the low refractive index layer.

Description

This invention relates to a laminate, a method for manufacturing the same, and an anti-reflective film. In image display devices such as liquid crystal displays and organic EL displays, an anti-reflective film is placed on the outermost surface of the display screen to prevent reflection of ambient light. Such an anti-reflective film comprises a transparent substrate film and an anti-reflective layer including a high refractive index layer and a low refractive index layer. As a high refractive index layer used in such anti-reflective films, a rutile-type titanium oxide ( TiO₂ ) film deposited at room temperature by high-power magnetron impulse sputtering (HiPIMS) has been proposed (see, for example, Non-Patent Document 1). Aiempanakit et al. Surface & Coatings Technology, 205 (2011) 4828-4831. Figure 1 shows one embodiment of the laminate of the present invention.Figures 2A to 2C show one embodiment of the method for manufacturing a laminate according to the present invention. Figure 2A shows the first step of preparing a substrate, Figure 2B shows the second step of forming a protective layer on one side of the substrate in the thickness direction, and Figure 2C shows the third step of forming a titanium oxide film on one side of the protective layer in the thickness direction.Figure 3 shows one embodiment of the anti-reflective film of the present invention.Figure 4 shows another embodiment of the anti-reflective film of the present invention. 1. Laminate One embodiment of the laminate of the present invention will be described with reference to Figure 1. As shown in Figure 1, the laminate 1 has a film shape (including a sheet shape) with a predetermined thickness. Furthermore, the laminate 1 extends in a plane direction perpendicular to the thickness direction, and one surface in the thickness direction and the other surface in the thickness direction of the laminate 1 are flat. The laminate 1 comprises a base material 2, a protective layer 3, and a titanium oxide film 4, arranged sequentially on one side in the thickness direction. Specifically, as shown in Figure 1, the laminate 1 comprises a base material 2, a protective layer 3 disposed on one side of the base material 2 in the thickness direction, and a titanium oxide film 4 disposed on one side of the protective layer 3 in the thickness direction. <Base material> The base material 2 is the bottom layer of the laminate 1. The base material 2 comprises a transparent resin film 21 and a cured resin layer 22 in order toward one side in the thickness direction. Specifically, the base material 2 comprises a transparent resin film 21 and a cured resin layer 22 disposed on one side of the transparent resin film 21 in the thickness direction. More specifically, the base material 2 comprises, for example, a transparent resin film 21 and a cured resin layer 22 disposed on one side of the transparent resin film 21 in the thickness direction. The base material 2 preferably consists of a transparent resin film 21 and a cured resin layer 22 disposed on one side of the transparent resin film 21 in the thickness direction. Specifically, the base material 2 preferably consists of a transparent resin film 21 and a cured resin layer 22 disposed on one side of the transparent resin film 21 in the thickness direction. The total light transmittance (JIS K-7105) when light with a wavelength of 550 nm is incident on the substrate 2 is, for example, 80% or more, preferably 85% or more, more preferably 88% or more, even more preferably 90% or more, and also, for example, 100% or less. The thickness of the base material 2 is not particularly limited, but from the viewpoint of strength and handling, it is, for example, 10 μm or more, preferably 30 μm or more, more preferably 50 μm or more, and also, for example, 200 μm or less, preferably 150 μm or less, more preferably 100 μm or less. The transparent resin film 21 is a transparent, flexible resin film. Examples of materials for the transparent resin film 21 include cellulose resin, polyester resin, (meth)acrylic resin (acrylic resin and/or methacrylic resin), olefin resin, polycarbonate resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, polystyrene resin, norbornene resin, and polyvinyl alcohol resin. Examples of polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Examples of polyolefin resins include polyethylene, polypropylene, and cycloolefin polymer (COP). Examples of cellulose resins include triacetylcellulose (TAC). The materials for the transparent resin film 21 can be used individually or in combination of two or more. The transparent resin film 21 can be, for example, a cellulose resin film, from the viewpoint of transparency, heat resistance, and mechanical strength. Preferably, a triacetylcellulose (TAC) film is used. The total light transmittance (JIS K-7105) when light with a wavelength of 550 nm is