JPS61215525A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To completely prevent a light leakage phenomenon by applying a thermosetting resin contg. a block coloring agent to a sealing material to enclose a surroundings and an inside part of two sheets of glass plates. CONSTITUTION:The titled element can completely prevent the light leakage phenomenon when the sealing material is visible to the black color and especially the surface of the element makes to lighten under a light source of a fluorescent lamp. The compounding amount of the coloring agent is limitted to 3-25pts.wt. on the basis of 100pts.wt. the thermosetting resin. The coloring agent comprises the mixture contg. equal parts of carbon black powders, an anthraquinone type blue coloring matter having 630nm the max. adsorping wavelength, an azo type reddish violet coloring matter having 560nm the max. adsorping wavelength and an azo type yellow coloring matter having 410nm the max. adsorping wavelength. The sealing part 3 is formed on the inner part of the glass plate 2 by a screen printing method and then another glass plate 3 is adhered with the glass plate 2 and is cured by a heat followed by filling the liquid crystal cell 4 between the glass plates 2, and 3 to prepare the titled element.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a liquid crystal display element.

Conventional technology In recent years, the use of liquid identification devices has increased significantly due to their ability to be made thinner and consume less power. be.

Conventionally, the structure of a liquid crystal display element used in this type of general liquid crystal display device is as shown in FIGS. Inside, a sealing part 3 is formed by dispersing insulating powder with an appropriate particle size in a thermosetting resin, and the sealing part 3 is formed between two glass plates 2.
The liquid crystal 4 is filled in the minute gap created when the two are bonded together. In this case, the material used for the seal portion 3 is a transparent resin such as epoxy resin or phenol resin in which glass fiber powder, alumina powder, or the like is dispersed.

Problems to be Solved by the Invention According to the above-mentioned conventional configuration, the resin of the sealing part 3 is transparent or has a slightly milky white color due to glass fiber powder or alumina powder, so the surface illuminance of the liquid crystal display element is particularly low. When displaying with a light source such as a fluorescent lamp shining from behind in order to increase the size of the image, there is a problem in that the seal portion 3 becomes ``handled by light''. Therefore, when increasing the screen size, it is necessary to increase the area of the glass plate 2 constituting the liquid crystal display element, and in order to maintain a uniform gap between the two glass plates 2, it is necessary to increase the area of the glass plate 2 that constitutes the liquid crystal display element. It is necessary to form a large number of seal portions 3 in a lattice-like pattern inside the screen, and this portion remains as a non-display area, resulting in a problem that it becomes very difficult to see. As a countermeasure for this, with the same pattern as the seal part 3,
Attempts have been made to form a black coating on the outside of the two glass plates 2. However, in this case, the reduction in "light leakage" can be reduced when viewed from the front, but as the viewing angle is widened,
Since light passes through only a portion of the thickness of the glass plate 2, no fundamental countermeasure has been taken.

Means for Solving the Problems In order to solve the above problems, the liquid crystal display element of the present invention includes:
As a sealing member for sealing the periphery and inside of two glass plates, for 100 parts by weight of thermosetting resin,
The structure is such that it contains 3 to 25 parts by weight of a black coloring agent.

Function In the liquid crystal display element having the above structure, since the sealing member exhibits a black color, all "light leakage" can be prevented, especially when the surface is brightened and viewed using a light source such as a fluorescent lamp. The reason why the coloring agent content was limited to 3 to 25 parts by weight is because if the coloring agent content is less than 3 parts by weight, the sealing member will not be sufficiently colored, and as a result, light will pass through. Moreover, if the amount exceeds 25 parts by weight, the adhesive strength as a sealing member will decrease significantly. In addition, as this coloring agent, carbon black juveniles and maximum absorption wavelength 630
An anthraquinone gastric pigment having a maximum absorption wavelength of 560 rv, an azo red-purple pigment having a maximum absorption wavelength of 410 ni, and an equal mixture of an azo yellow pigment having a maximum absorption wavelength of 410 ni can be used.

Example Embodiments of the present invention will be described below with reference to FIG.

FIG. 1 shows the relationship between the light transmittance and adhesive strength of the seal portion of a liquid crystal display element in an example of the present invention, in comparison with a comparative example and a conventional example. The structure of the liquid crystal display element is similar to the conventional example shown in FIGS. 2 and 3.

First, a first example will be described. As a sealing member, 100 parts by weight of epoxy resin (Epikote 815), 15 parts by weight of curing agent (triethyluane), 15 parts by weight of carbon black powder, 5 parts by weight of glass fiber powder ( Using a mixture of 2 parts by weight of granules (10μ-), a seal portion 3 was formed on the inner surface of one glass plate 2 by screen printing in the same pattern as shown in FIG. After bonding the other glass plate 3 together, it was thermally cured at 150°C for 60 minutes. Next, the minute gap (approximately 11
μ+e) was filled with liquid crystal 4 to obtain a liquid crystal display element.

A drive circuit (not shown) was connected to this liquid crystal display element, and the light transmittance of the seal portion 3 was measured while the illuminance of the fluorescent lamp behind it was maintained at 35,000 L x. Furthermore, after this, the peeling strength of the seal portion 3 of this liquid crystal display element was measured.

Next, as a second example, the content of carbon black powder was set at 25 parts by weight, and as a first comparative example, the content of carbon black powder was set at 2.5 parts by weight. A comparative example in which the carbon black powder content was 30 parts by weight, and a conventional example in which no carbon black powder was used at all were manufactured in exactly the same manner as in the first example except for the carbon black powder content. Each of these samples was measured and evaluated in the same manner as in the first example.

As a result, as shown in FIG. 1, especially in the case of the second example, no light was transmitted at all. Further, the first comparative example had a problem in transmittance, and the second comparative example had a problem in beering strength. In FIG. 1, the solid line indicates the transmittance, and the broken line indicates the Bierig intensity.

Effects of the Invention As described above, according to the present invention, by a simple process of mixing a black coloring agent with a thermosetting resin, it is possible to completely prevent the light leakage phenomenon, which has been present in the past.
Furthermore, as a ripple effect, it becomes possible to broaden the visual field and improve image quality.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the relationship between the amount of carbon black added and the light transmittance and adhesive strength of the sealing part in Examples, Comparative Examples, and Conventional Examples of the present invention, and Fig. 2 is a front view of the liquid crystal display element. , FIG. 3 is a sectional view of the same. 2...Glass plate, 3...Sealing member representative Hiroshi MorimotoFigure 1Figure 2

Claims (1)

[Claims] A liquid crystal display element using a sealing member for sealing the periphery and the inside of 1 or 2 glass plates containing 3 to 25 parts by weight of a black coloring agent based on 100 parts by weight of a thermosetting resin. .