Stock material or miscellaneous articles – Coated or structually defined flake – particle – cell – strand,... – Particulate matter
Patent
1995-11-21
1998-05-12
Le, H. Thi
Stock material or miscellaneous articles
Coated or structually defined flake, particle, cell, strand,...
Particulate matter
427221, 427301, 427340, 428407, B32B 516, B05D 700
Patent
active
057502587
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to crosslinked resin-coated silica fine particles suitable for controlling the thickness of a liquid crystal layer of a liquid crystal display device, and a process for the production thereof.
TECHNICAL BACKGROUND
A liquid crystal display device is typical of flat panel displays, and owing to its low dissipation power and low-voltage drive, it is widely used as a display device for various machines such as an electronic desk calculator, a television set, a computer and a word processor. The display panel of the liquid crystal display device is formed, for example, by attaching two transparent substrates provided with necessary elements such as transparent electrodes, oriented films, etc., with a sealing material while spacing them at a predetermined distance, to form a liquid crystal cell, and injecting a liquid crystal in the liquid crystal cell. A predetermined surface of one of the above two transparent substrates (surface to form an inner wall of the liquid crystal cell) is provided, in advance, with dispersed spacers, for example, by wet-spraying, for forming a liquid crystal layer having an intended thickness while spacing the two transparent substrates from each other at predetermined value of a distance (cell gap).
For obtaining a liquid crystal display device having excellent display characteristics, not only it is necessary to prevent an eluted component from the spacers from affecting the liquid crystal, but also it is required not to cause local variability on the distance between the two transparent substrates.
The spacer material that can satisfy the above requirements includes silica fine particles formed by hydrolyzing-polycondensing silicon alkoxide to form seed particles and growing these seed particles by a predetermined method (see JP-A-4-240112, JP-A-62-269933 and JP-A-63-73225). Since having a high purity, these silica fine particles are almost free from affecting a liquid crystal with its eluted component when brought into contact with the liquid crystal. Further, each silica fine particle has high particle diameter accuracy, and the CV value (coefficient of variability) of silica fine particles produced under the same conditions is low, so that the two transparent substrates can be spaced from each other substantially uniformly when the silica fine particles are used as a spacer. Since, however, all the spacers of silica fine particles disclosed in the above Japanese Laid-open Publications are not calcined, these spacers have a problem in that they undergo cracking under heat and pressure applied when a sealing material is cured.
Further, the above silica fine particles have suitable properties as a spacer for a liquid crystal display device. However, when these silica fine particles are used as a spacer for a liquid crystal display device, part of the silica fine particles move during the process of injecting a liquid crystal into liquid crystal cell, and in this movement, the oriented film is sometimes impaired thereby causing orientation nonuniformity. Further, a liquid crystal which adheres to a periphery of the liquid crystal cell at the time of injection of the liquid crystal is generally removed by ultrasonic cleaning. In this ultrasonic cleaning, however, part of the silica fine particles move, so that the oriented film is impaired to have orientation nonuniformity. For producing a liquid crystal display device having high display characteristics with high productivity, it is therefore necessary to prevent the substantial movement of the spacer when the injection of a liquid crystal and the ultrasonic cleaning are carried out after the formation of the liquid crystal cell.
As a spacer which does not cause the substantial movement after the formation of the liquid crystal cell, there is a spacer formed by surface-coating silica fine particles with a commercially available synthetic resin powder. Specifically, there is known a spacer formed by allowing silica fine particles to adsorb a commercially available synthetic resin pow
REFERENCES:
patent: 4137367 (1979-01-01), Sample et al.
patent: 4225650 (1980-09-01), Van Brederode et al.
patent: 4233366 (1980-11-01), Sample et al.
patent: 4724167 (1988-02-01), Evans et al.
patent: 5008305 (1991-04-01), Kennan et al.
patent: 5013585 (1991-05-01), Shimizu et al.
patent: 5035803 (1991-07-01), Cohen
patent: 5153068 (1992-10-01), Kohara et al.
patent: 5182173 (1993-01-01), Swei
patent: 5194333 (1993-03-01), Ohnaka et al.
Adachi Tatsuhiko
Fujino Ken-ichi
Nakayama Norihiro
Sakai Kazuhiko
Le H. Thi
Ube Nitto Kasei Co., Ltd.
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