Stock material or miscellaneous articles – Structurally defined web or sheet – Continuous and nonuniform or irregular surface on layer or...
Patent
1996-11-01
1998-06-30
Watkins, III, William P.
Stock material or miscellaneous articles
Structurally defined web or sheet
Continuous and nonuniform or irregular surface on layer or...
428141, 428156, 359483, 359493, 359580, 359581, 359582, 359601, G02B 110, B32B 5402, B32B 326
Patent
active
057731268
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a composite film suitable for use, for example, as a surface film for various displays, such as CRT displays, liquid crystal displays, and plasma displays, as a cover film for optical lenses, such as transparent plastics, sunglasses, eyeglass lenses, and finder lenses for cameras and for various instruments and gauges, as a surface antireflection film for window glasses of automobiles, electric railcars and the like, and as a protective film for the surface of a polarizing plate (film) on the back light side of liquid crystal displays.
More particularly, the present invention relates to a composite film excellent in both surface slip properties and surface protective properties.
A conventional polarizing film is generally formed by adsorbing iodine or a dichroic dye onto a stretched and aligned film for a polarizing membrane to prepare a polarizing membrane having a polarizing property and providing a protective film on both surfaces of the polarizing membrane.
A film of polyvinyl alcohol or a derivative thereof is used as the polarizing membrane, while a non-aligned film of a cellulose acetate resin or an acrylic resin is used as the protective film for the polarizing membrane. The protective film is formed by lamination of a film or by coating of a liquid resin. Further, sealing of a polarizing film into a protective film in a bag form has also been proposed in the art.
The polarizing film thus obtained is used mainly in liquid crystal display members and, further, in decorative members and films for removing reflected light. In particular, a polarizing film using a polyvinyl alcohol-iodine membrane as the polarizing membrane with a triacetyl cellulose film (hereinafter often referred to as a "TAC film") being used as the protective film has been extensively used because it has excellent optical properties, exhibits high polarization in a wide wavelength range, and, at the same time, is excellent in brightness and contrast.
Further, in the above polarizing film, a hard coat layer is further provided on the TAC film as the protective film in order to further improve the scratch resistance and chemical resistance of the surface of the film.
The polarizing film bearing the above hard coat layer has acceptable properties as a final product. It, however, has various problems, to be solved, associated with production process and some performance requirements.
For example, in the actual production process, as compared with the lamination of a TAC film onto a polarizing membrane followed by coating of a hard coat layer, the lamination of a TAC film with a hard coat layer coated thereon is preferred from the viewpoint of producing products having a higher quality in a better yield with a higher efficiency.
However, when a hard coat layer, which inherently has high smoothness, is formed by coating on the TAC film, both the surface of the hard coat layer and the back surface of the TAC film are smooth, offering good adhesion. Therefore, the film with a hard coat layer formed thereon has very poor surface slip properties.
When the film with the above hard coat layer coated thereon is rolled, uneven deformation called "crater" or "pyramid" is created in a part of the film, which is causative of an inefficient process and a lowered yield.
The creation of "craters" and "pyramids" is known to be attributable to mutual adhesion between films during winding. In order to prevent such a problem, a method has been proposed wherein a hard coat layer is formed from a coating liquid containing an extender pigment, such as silica, and/or organic polymer beads to render the surface of the coating matte. This method, however, is disadvantageous in that a part of the matting material precipitates on the surface of the hard coat layer, resulting in deteriorated chemical resistance and that since the matting material cannot be evenly dispersed in the coating liquid, an even coating cannot be formed and, in the case of curing of the coating by ultraviolet irradiation, a har
REFERENCES:
patent: 4318958 (1982-03-01), Piatt
patent: 4473277 (1984-09-01), Brown
patent: 4485123 (1984-11-01), Troue
patent: 4568598 (1986-02-01), Bilkadi et al.
patent: 4604297 (1986-08-01), Liu
patent: 4694218 (1987-09-01), Chao
patent: 5124184 (1992-06-01), Wong
patent: 5178955 (1993-01-01), Aharoni et al.
patent: 5387463 (1995-02-01), Nakamura et al.
patent: 5425848 (1995-06-01), Haisma et al.
patent: 5456747 (1995-10-01), Ibbotson
Nakai Yasuo
Noritake Yugo
Sakamoto Toru
Dai Nippon Printing Co. Ltd.
Watkins III William P.
LandOfFree
Composite film having a surface slip property does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Composite film having a surface slip property, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Composite film having a surface slip property will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1856807