In general, glass has been employed for various kinds of purposes, owing to excellent light transmittance, gas barrier properties, dimensional stability, and so forth. Glass has been employed not only for windowpanes for buildings, automobiles, and trains, but also for flat displays in which high-performance glass is employed, represented by CRT displays, liquid crystal displays, plasma displays, organic EL displays, field emission displays, and so forth. However, glass has disadvantages such as easily breaking and scattering upon breaking. This problem is marked in the flat display field where there is great demand for reducing the thickness of glass. As the thickness of the entire flat display is reduced, the display glass employed therein has been reduced, leading to a problem that glass is easily broken at the time of the flat display being used.
Various kinds of proposals have been made for preventing glass from breaking and scattering due to breaking, by applying a film formed of thermoplastic resin onto the glass.
For example, Japanese Unexamined Patent Application Publication No. 6-190997 discloses that applying a multi-layer laminated film formed of a polyethylene terephthalate layer and a sebacic acid copolymerization—polyethylene terephthalate layer onto the surface of glass can markedly prevent glass from damage and scattering.
However, while the method according to Japanese Unexamined Patent Application Publication No. 6-190997 has effects to prevent glass from scattering, on the other hand, this causes crystallization and consequently a hazy appearance over time, since the glass transition temperature of the sebacic acid copolymerization—polyethylene terephthalate layer forming the multi-layer laminated film is low, thereby bringing about a state wherein transmission of visible light deteriorates. In addition, while the method according to Japanese Unexamined Patent Application Publication No. 6-190997 improves tear resistance of a film, this has little effect on improving impact resistance and preventing the glass itself from breaking. Accordingly, the method according to Japanese Unexamined Patent Application Publication No. 6-190997 cannot be employed for a glass protecting film for a flat display which requires continuous high transmittance of visible light and also needs to prevent glass damage itself.
USPTO Backgrounds
USPTO Backgrounds