Laminated polyester film and antireflection film

Abstract

Provided is a laminated polyester film which is inhibited from causing interference fringes when used as the base film of an antireflection film and which is excellent in the adhesion, particularly moist heat resistant tight adhesion, to a hard coat layer made by using a radiation-curable resin. A laminated polyester film which comprises a layer (S) made by using a polyester and a layer (C) containing a polyester resin (A) having a fluorene skeleton, wherein the moist heat resistant adhesion index of the surface of the layer (C) is 3 to 5.

Description

technical field [0001] The present invention relates to a laminated polyester film that suppresses interference fringes when used as an antireflection film base material and has good adhesion to a hard coat agent containing an active ray-curable resin, and is laminated on at least one side thereof with a use-activated film. Anti-reflection film with hard coating made of radiation-curable resin. Background technique [0002] A laminated film in which a hard coat layer is provided on the film surface is widely used for an antireflection film, a film for a touch panel, a film for a name brand, and the like. [0003] In recent years, the market for flat panel displays (FPDs) represented by liquid crystal displays (LCDs), plasma displays (PDPs), and organic electroluminescence displays (organic ELs) has expanded significantly, and the requirements for larger screens and higher precision have increased. , It is also becoming more and more strongly demanded to provide functions co...

AI Technical Summary

Problems solved by technology

However, if necessary, corona discharge treatment is applied to the polyester film before the end of the crystal orientation, the coating is easy to adhere to the paint, and after drying, stretching and heat treatment are carried out to complete the method of crystal orientation, that is, the online coating method ( In-line coating process), although the aqueous dispersion of high refractive index resin is required, the high refractive index resin often has a hard chemical structure, and a large amount of highly hydrophilic sulfonate must be used for water dispersion of the resin group, so there is a problem with the adhesion under high temperature and high humidity environment

In addition, because resins copolymerized with fluorene groups generally have a high glass transition temperature, there is poor stretchability, resulting in poor coatability in the line coating method, or fine cracks are generated in the easy-adhesion layer so that the film Problems such as poor haze

[0007] In addition, studies have been conducted to increase the refractive index of the easily-adhesive layer by providing an easily-adhesive layer containing high-refractive-index metal oxide particles such as titanium oxide particles on a polyester film (Patent Document 2). In the in-line coating method, problems such as surface scattering caused by particle protrusions, agglomerated particles or voids at the interface between particles and the binder are prone to occur, resulting in poor film haze.

[0008] In addition, research has also been carried out to place an easily-adhesive layer containing a water-soluble titanium chelate compound or a zirconium compound on a polyester film to increase the refractive index of the easily-adhesive layer (Patent Document 3), but titanium or zirconium The content of these chelate compounds is low, and it is necessary to add a large amount of chelate compounds to increase the refractive index. In addition, metal chelate compounds decompose during heat treatment, and the decomposed products are generated in the easy-adhesion layer depending on conditions. Impurities, etc., may degrade the quality when forming an anti-reflection film

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