Resin laminate

Abstract

The invention provides a resin laminate having relatively high surface hardness and high transparency. The resin laminate has a hard resin layer and a substrate layer. The hard resin layer is formed by a curing resin composition with multi-functional (methyl)acryloyl monomers as an essential ingredient, has a three-dimensional cross-linking structure and a thickness of 25 [mu]m-250[mu]m. The substrate layer is formed by a monolayer thermoplastic resin or two or more layers of a multi-layer thermoplastic resin. An independent tensile elasticity modulus of the hard resin layer is 2.000-4,000 MPa; and a total light transmittance is over 90%. Besides, a ratio (t1 / t2) of a total thickness (t1) of the substrate layer to the thickness (t2) of the hard resin layer is 0.25-10; and a scratch hardness of the resin laminate is over 40 g.

Description

technical field [0001] The present invention relates to a resin laminate having excellent surface hardness, transparency, and molding processability, and particularly to a resin laminate suitable for a display panel as a transparent multilayer sheet. Background technique [0002] In electronic equipment such as digital cameras and mobile phones, as substrates of liquid crystal displays, etc., or as protective plates for protecting the surface of liquid crystal displays from scratches, contamination, etc., acrylic, polycarbonate, poly Laminates made of thermoplastic resins such as ethylene phthalate. These laminated resins have excellent optical properties and are less likely to be broken than glass, so they have come to be widely used in fields where glass has been conventionally used in recent years. However, thermoplastic resins such as acrylic, polycarbonate, and polyethylene terephthalate have disadvantages in that surface hardness, abrasion resistance, and scratch resi...

AI Technical Summary

Problems solved by technology

[0005] However, in the examples shown as specific examples of these methods, pencils are made by using polyethylene terephthalate films and cellulose triacetate films, which are inherently harder than polycarbonate resins, as substrates. Hardness ranges from 4H to 6H. Although this effect is confirmed, pencil hardness cannot be achieved with only a thin hard coat layer, so a hard base layer and auxiliary functions of inorganic materials are required

Therefore, these base layers and inorganic materials become important factors that hinder transparency, and are not suitable for display devices such as liquid crystal displays.

[0006] In addition, an attempt has been made to form a two-layer coating film with a specific film thickness on a polycarbonate resin substrate using polycarbonate resin, which is a resin with low pencil hardness. Formate acrylate, polyfunctional oligomers, polyfunctional monomers, monofunctional monomers, and ultraviolet curable resins with a specific number of functional groups, but the maximum pencil hardness in this technology is 4H, which is not sufficient (see Patent Document 7)

[0007] In addition, the above-mentioned Patent Document 7 evaluates the scratch hardness measured by the pencil method based on JIS K5600-5-4, and the thermoplastic resin layer is laminated with a hard coat layer and a hard resin layer. The nature and thickness of the layer are affected by the thermoplastic resin as the underlying layer, and plastic deformation and elastic deformation due to dents occur, making it difficult to distinguish whether the surface is only dents or scratches caused by scratches at first glance.

In addition, depending on the material of the hard resin layer, cracks may occur due to deformation due to unexpected dents, and it is difficult to measure the accurate surface hardness only by measuring the hardness of the pencil.

In addition, when used as a protective plate for liquid crystal displays, etc. as described above, it is necessary to consider protection from scratches caused by stronger metals and minerals in daily life, so soft pencils are used compared with metals and minerals. There may be differences in the wear resistance and scratch resistance in actual daily life in the judgment made by the method.

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