JPH01142617A - Cell for liquid crystal display element and its production - Google Patents

Abstract

PURPOSE:To enhance impact resistance and to improve contrast by adhering two sheets of substrates provided with transparent electrodes and oriented films by positioning the surfaces provided with the transparent electrodes and the oriented films to the inner side, then sealing a liquid crystal into the spacing between the films so that the adhesion is effected by adhesive points of <=60mu diameter including spacers and of a specific density. CONSTITUTION:The dotty adhesive agents which contain the spherical or rod- shaped spacers consisting of an inorg. or org. material and have a prescribed height are disposed on at least either of two sheets of the transparent substrates on which the transparent electrodes and insulating films are provided. The size of the adhesive points after sticking of the cell for the display element formed by sticking another transparent substrate to said substrate is specified to <=60mu in average and the number of the adhesive points is specified to 0.3-300 pieces/mm<2> in average. The display element panel which is uniform in the cell spacing and for which the ferroelectric liquid crystal having excellent shock resistance and the good contrast is used is thereby obtd.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention provides a means for firmly adhering two substrates with uniform gaps, and is particularly useful for large-sized substrates. Liquid crystal display elements require a gap of several microliters, and strings require a particularly narrow gap.
It is something that I thought about when I was at the front office of Repize.

(Prior Art) In recent years, display elements using nematic liquid crystals have come to be used in various fields such as watches, word processors, and pocket televisions.

However, the currently mainstream TN (twisted nematic) Fj1 element or 5TN (super twisted nematic) type element has a slow response time of several milliseconds or more and poor viewing angle characteristics, making it difficult for new applications. There are limits to the field. In contrast, the next display element using ferroelectric liquid crystal, which is a smectic liquid crystal but has spontaneous polarization and exhibits a high-speed response of several microseconds to several tens of microseconds, has recently attracted attention (N.C. Clark). and Niss T. Ragapal, Applied Physics Letters, 36 (/I) pt Tata (/Pro), etc.). However, in order to exhibit the above-mentioned high-speed response, the cell gap of the ferroelectric liquid crystal element panel must be as thin as μμ from the /μ door.

Furthermore, does ferroelectric liquid crystal have properties closer to crystals than nematic liquid crystal? The problem with this is that just touching the center of the flannel slightly will destroy the alignment of the liquid crystal, and it will not return to its original state like a nematic liquid crystal.In other words, it has poor shock resistance. .

In view of these points, as disclosed in Japanese Patent Application Laid-Open No. 6/-/6λ30, a non-photosensitive polyimide-based organic polymer material is used as a photoresist using a photoresist agent. By turning or using a material that is itself patterned from a photosensitive polyimide-based organic polymer precursor, it is possible to set the cell gap with relative precision. However, the liquid crystal cell produced by this method has almost no impact resistance, which causes considerable problems in handling.

(Objective of the present invention) The present invention uses a ferroelectric liquid crystal to fc′l? In dog size,
It is an object of the present invention to provide a cell for a display element having uniform gaps and strong adhesion, thereby having strong impact resistance and high contrast.

(Summary of the Invention) The present invention provides nine transparent substrates each having a transparent electrode and an insulating film on their surfaces, each having a predetermined height including a spherical or rod-shaped spacer made of an inorganic or organic substance on at least one of nine transparent substrates. In the display element cell, the size of the bonding points after bonding is 60 μm or less on average, and the number of bonding points is 0°3 on average. Ferroelectric liquid crystal with uniform cell gap, excellent shock resistance, and good contrast by changing JOO1/F12 to JOO1/F12? This provides a user-friendly display element channel.

(Detailed Description of the Invention) The printing method used for printing the sealing material of the present invention is a letterpress method. As a printing method, there is a planographic method in addition to the letterpress method of the present invention, but it is difficult to coat the sealing material thickly and requires overlapping, which is troublesome. The size of the adhesive spots in the present invention is preferably 60μ or less in diameter and 3μ or more, preferably 4tOμ or less! μ or more.

The density of bonding points is 0. j pieces/attack 2 to J 00
(A value between i1/ and 2 is preferable.) If the size of the bonding point becomes large, although the impact resistance is improved, it may induce alignment defects in the liquid crystal or reduce the contrast.

If the thickness is less than 3μ, the adhesive effect will be reduced and it will be very difficult to provide adhesive points using letterpress printing. From the standpoint of impact resistance, it is better to have a higher density of bonding points; however, if the density is greater than 300/2 rugs, the contrast will deteriorate.

In providing the bonding points, a printing method is preferred, and a letterpress printing method is particularly preferred. The printing plate used in letterpress printing is preferably a resin plate whose shape can be easily controlled. It is preferable that the tip of the convex portion has a diameter of 4 cOμ or less, but it may be triangular with a depression at the apex.

Since the adhesive used in the present invention involves a printing process, it is necessary to use an adhesive with a long pot life. For example, an epoxy adhesive such as Structobond Examples of adhesives and UV-curable adhesives include the Aronix series manufactured by Toagosei Co., Ltd.

In order to set the cell gap, it is necessary to knead a current or rod-shaped spacer into this adhesive. Examples of spacers include spherical alumina oxide, plastic, and rod-shaped glass. Examples of inorganic materials include Alfit made by Showa Denko Co., Ltd. and P made by Nippon Electric Glass Co., Ltd.
F series, Catalysts & Chemicals Industries cotton balls, etc.

As an organic substance, Micro/
Nippon Leu, Nippon Shokubai Kagaku Co., Ltd.'s Epostor, Toshiba Silicone Co., Ltd.'s Tospearl, and the like.

Further, when the size of the substrate becomes larger than 10 tm, the above-mentioned spacers may be appropriately dispersed in the display area in order to further improve the uniformity of the cell gap.

Although the adhesive in the present invention has a dot shape, stripe shapes may also be used.

The width of the stripes is preferably 60 μm or less, and short strips are preferably disposed intermittently. It is preferable that the density of the stripe-like particles be λ pieces/n or more.

The substrate used in the present invention is not particularly limited as long as it is transparent and has transparent polarization, but glass and plastic films are usually preferred. On the substrate on which the electrodes are provided, it is necessary to provide a precise alignment film for aligning the ferroelectric liquid crystal. Such alignment films include - for boat fishing, polyimide, polyamide, polyetheramide, polyvinyl alcohol-A/, polyx stel, polyether sulfone, polysulfone, nylon, polycarbonate,
Insulating polymer thin films such as cellulose derivatives or plasma polymerized films are preferably used.

Further, an inorganic thin film such as SiO2 may be used as necessary. For these thin films, it is desirable to perform a rubbing treatment on at least one of the two substrates to improve the alignment of the liquid crystal.

The present invention will be explained below based on examples.

Example 1 Polyimide L manufactured by Hitachi Chemical Co., Ltd. was applied as an alignment film on a transparent electrode made of ITO (indium, tin oxide) in advance.
Apply Xr≠oo, bake at 32j0C for 7 hours, ft/
A rubbing process was performed on a glass plate having a thickness of . As a spacer on this substrate, an adhesive made of Nippon Shokubai Kagaku Co., Ltd.'s Eposter〇p2Of was kneaded,
I printed approximately 70 dots/tx 2 of Structbond X71Ltori manufactured by Mitsui Toatsu Co., Ltd. with a diameter of about/7 μm using letterpress printing.

Similarly, for the other substrate, an alignment film was applied on the transparent electrode and rubbed, the adhesive was printed, and a companion substrate was attached. Heat curing treatment for adhesive? After application, the cell gap was measured and found to be 0.200.

The distance was 78m, which was relatively good. Note that the size of the bonding point after cell creation was 30 μm in diameter. This cell is sealed with ferroelectric liquid crystal C3lotlflOO0C manufactured by Chisso Corporation,
o, r Cool at a cooling rate of 0c/min. This cell exhibited a uniform orientation, and no substantial coloring unevenness occurred. In the center of this cell is r, 'yy ball money! ! When dropped from a height of α, no disturbance of orientation occurred and good shock resistance was exhibited.

Claims (2)

[Claims] (1) In a cell for a liquid crystal display element, in which two substrates provided with a transparent electrode and an alignment film are glued together with a gap provided with the side provided with the transparent electrode and alignment film inside, and a liquid crystal is filled in the gap. , the adhesive is made of an adhesive containing spacers, the diameter is 60μ or less, and 0.3 pieces/mm^2 to 300 pieces/m
A cell for a liquid crystal display device, characterized in that the cell is formed by bonding points having a density of m^2. (2) On at least one alignment film of two substrates provided with transparent electrodes and alignment films, adhesive containing spacers is placed in dots of 0.3 pieces/mm^2 to 300 pieces/mm^2. After forming it by resin letterpress printing method to a density of
A method for manufacturing a cell for a liquid crystal display device, characterized by creating bonding points smaller than μ and sealing liquid crystal between substrates.