JPH01113733A - Liquid crystal display element - Google Patents

Abstract

PURPOSE:To easily prevent UV rays and to improve the heat resistance, wear resistance and durability of an element by dispersing the fine particles of a UV nontransmittable inorg. system having a prescribed grain size to the inside of either of the high-molecular oriented films disposed on the inside front face side of transparent glass substrates and the high-molecular protective films formed on the outside surfaces of the transparent glass substrates disposed at need. CONSTITUTION:Electrode layers 2, 2A are formed on the inside surfaces of a pair of the transparent glass substrates 1, 1A of the liquid crystal display element. The high-molecular oriented films 3, 3A and a liquid crystal layer 4 are disposed on the inside surfaces of the electrode layers 2, 2A. The high- molecular protective films 7 are formed on the outside surfaces at need. The fine particles 6 of the UV nontransmittable inorg. system having 0.01-1mum grain size are dispersed into either of the high-molecular oriented films 3, 3A or the protective films 7 of this liquid crystal display element. The UV rays are easily prevented and the heat resistance, wear resistance and durability of the liquid crystal display element are improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a liquid crystal display element, and more specifically, the present invention relates to a liquid crystal display element, and more specifically, a liquid crystal display element that is inexpensive and simple, has durability against ultraviolet rays, and has excellent heat resistance and abrasion resistance. Regarding elements.

[Prior Art] As shown in FIG. 6, a protective filter 71 used in a conventional liquid crystal display element for preventing ultraviolet rays has an adhesive layer containing a predetermined amount of an ultraviolet absorber such as a benzophenone type or a metal chelate type. There are known films or sheets having the following properties (Japanese Utility Model Publication No. 56-28568 and Japanese Utility Model Publication No. 56-28569).

Furthermore, as a conventional liquid crystal panel having ultraviolet ray resistance, a structure is known in which a thin film made of ceric oxide containing silicon monoxide of a predetermined thickness is formed on the outer or inner surface of a substrate to block the transmission of ultraviolet rays. (Special Publication No. 56-19609).

[Problems to be solved by the invention] When using the above-mentioned former protective film or sheet,
A process for forming this ultraviolet protection filter is required, which poses problems in terms of yield and cost. Furthermore, it is often difficult to apply these films uniformly and without bubbles to curved substrates or large III-plates having large curvatures.

Furthermore, when forming the latter thin film for blocking ultraviolet transmission, its abrasion resistance is low and durability is poor, and it is often difficult to form this thin film in the case of a large-area substrate.

The present invention has been made in view of the above points, and an object of the present invention is to provide a liquid crystal display element that can inexpensively and easily prevent ultraviolet rays and has excellent heat resistance, abrasion resistance, and durability.

[Means for Solving the Problems] The liquid crystal display element of the first invention includes a pair of glass substrates, at least one of which is transparent, a pair of electrode layers formed on the inner surfaces of the pair of glass substrates, a pair of polymer alignment films formed on the surfaces of the pair of electrode layers and arranged to face each other; a liquid crystal layer formed between the pair of polymer alignment films;
A liquid crystal display element comprising: a polymer alignment film disposed at least on the inner surface side of the transparent glass substrate, and a polymer disposed as necessary and formed on the outer surface of the transparent glass substrate, F. It is characterized in that ultrafine inorganic particles that do not transmit ultraviolet light and have a particle size of 0.01 to 1 μm are dispersed inside at least one of the protective films.

That is, the liquid crystal display element of the first invention uses a glass substrate as a transparent substrate. In this device, the ultrafine particles may be dispersed inside a polymer alignment film formed on the inner surface of only the transparent glass substrate, that is, the glass substrate on the incident light side, or may be dispersed inside a polymer alignment film formed on the inner surface of only the glass substrate on the incident light side, or both of the glass substrates of the pair. It may be dispersed inside a polymer alignment film or the like disposed on the inner surface side of the glass substrate. Further, the ultrafine particles may be dispersed only in the polymer alignment film, only in the polymer protective film, or in both. Among these, the former is preferred because it is advantageous in terms of process and has high durability.

These ultrafine particles are made of an inorganic material that does not transmit ultraviolet rays. That is, it scatters, reflects or absorbs ultraviolet rays. Particularly preferred is one that excludes ultraviolet rays of 0.4 to 0.45 μm or less, which are harmful to liquid crystals. Also, this material has a light transmission range with a lower limit of 0.4 to 0.45 μm and an upper limit of at least 0.
．． Preferably, the thickness is 8 μm. With this material, we can list the ones shown in the table, especially 0.45 μm
It is preferable to use a material that does not transmit light of the following wavelengths, such as titanium dioxide, thallous chloride, thallous bromide, or silver bromide. Also, the particle size of these ultrafine particles is 0.01~
It is 1 μm. Generally, when a colorless and transparent substance is made into a powder with a particle size of approximately 1 μm, it becomes white due to light scattering. Powder of a substance with a high refractive index scatters more light and increases its whiteness.

However, if the particle size is 1/10 or less of the wavelength of light, for example, the scattering will be small and the transparency (hereinafter referred to as "margin") will be high. When ultrafine particles with a particle size in the above range are dispersed in a colorless and transparent polymer alignment film such as polyimide, transparency is not lost and ultraviolet rays of 0.4 to 0.45 μm or less, which are harmful to liquid crystals, can be eliminated. can.

The first invention uses a pair of glass substrates, at least one of which is transparent, but the second invention uses a pair of resin 'IIJ substrates, at least one of which is transparent, the pair of electrode layers, and the liquid crystal layer. In the liquid crystal display element comprising: the transparent resin +! ! 1. Dispersing the ultrafine particles within at least one of one substrate, a polymer alignment film that is optionally arranged on at least the inner surface of the transparent resin substrate, and the polymer protective film. It is characterized by

That is, in this second invention, a resin substrate is used as the substrate, and the ultrafine particles can be dispersed even inside this transparent resin substrate, which is arranged on the incident light side. The ultrafine particles can be dispersed not only inside the polymer alignment film or the polymer protective film, but also in two or three of them.

The ultrafine particles used in this invention are also the same as those described in the first invention.

[Example] The present invention will be explained below with reference to Examples.

(Example 1) In the liquid crystal display element of this example, a transparent glass substrate 1.1Δ is used as the substrate, and the ultrafine particles 6 are formed by a pair of polymer alignment films 3.
．． It is distributed in 3A. This explanatory new view is shown in FIG.

This liquid crystal display element includes a pair of glass substrates 1.1A, a pair of electrode layers 2.2Δ, a pair of polymer alignment films 3.3A, a liquid crystal layer 4, and an inner end surface of the outer periphery of the glass substrate 1.1A. It consists of a sealed seal member 5 and a spacer (not shown).

The glass substrate 1.1A is transparent and made of soda glass. A pair of electrode layers 2.2A are formed on the inner surface of a negative pair of glass substrates 1.1A. This electrode layer 2.2
A is composed of ITO (indium-tin-oxide). The polymer alignment film 3.3A is formed on the surfaces of the pair of electrode layers 2.2Δ and is arranged to face each other. This alignment film 3.3A is made of polyimide 31 and ultrafine particles 6 dispersed in this polymer 31,
The film thickness is 500 to 2000 people. The ultrafine powder 6 is
It is made of titanium dioxide, an inorganic material that does not transmit ultraviolet light. As shown in Table 1, this titanium dioxide has a light transmission range of 0.45 to 6 μm and a refractive index of 2.61. The particle size of the ultrafine particles 6 is about 0.03 μm (300 people). The ultrafine particles 6 are dispersed in both of the pair of polymer alignment films 3.3A. The concentration of the ultrafine particles 6 is about 1% by volume with respect to the total volume of the alignment film, and the density is such that light does not enter directly inside but always collides with the particles.

The liquid crystal layer 4 is made of liquid crystal (rZL I-1565J, rZ
L [-1940J, etc.), and its thickness is approximately 7 μm. The sealing member 4 is made of epoxy adhesive, and the spacer (not shown) is made of polystyrene beads.

Orientation It! in which the fine particles 6 are dispersed! J3.3A is a method in which 4.0 g of titanium dioxide ultrafine particles ([T
itanium Oxide P25'', manufactured by Nippon Aerosil Co., Ltd.), and printed it on the glass substrate 1 using a letterpress.
．． It was formed by printing on 1A, firing at 30Q°C, and then rubbing.

The spectral characteristics (transmittance) of this liquid crystal display element (example amount) are shown in FIG. This transmittance was measured using a spectrophotometer. As shown in FIG. 2, in this liquid crystal display element, in a liquid crystal display element manufactured in the same manner without adding ultrafine particles 6 (comparative example amount), approximately 220 to 40
It exhibits large transmittance at 0 μm, that is, in the ultraviolet region.

- In the six-line liquid crystal display element, the transmittance of 400 μm or less is extremely small, so it is possible to prevent UV deterioration of the liquid crystal. Furthermore, since the particle size of the fine particles used in the product of this example is small and its M is small, transparency is not lost.

Next, a weather test was conducted using a Sunshine Weather-Ometer, and the changes in current value over time were examined, and the results are shown in FIG. According to this result, due to the deterioration of the liquid crystal, the current consumption of the comparative example decreased from 1.9 mA to 6.7 mA after 1000 hours.
mA. - For this example product, after the same time 3.8
It only increased to 0mA. The weather resistance of the liquid crystal display element of this example is significantly improved compared to the conventional one.

Further, in this example, the ultrafine particles could be easily dispersed within the resin film.

(Example 2) Curved glass substrate for door mirror (curvature radius 100100Q
Next, an alignment film was formed using a spin code in the same manner as in Example 1, and the same study was conducted. As a result, as in Example 1, the deterioration of the liquid crystal was smaller than that of the conventional product.

It should be noted that the present invention is not limited to those shown in the above-mentioned embodiments, but can be modified in various ways within the scope of the present invention depending on the purpose and use.

That is, ultrafine ultrafine particles t that are non-transparent to ultraviolet rays are formed on the polymer protective film (resin protective film) 7 disposed on the outer surface of the transparent substrate disposed on the incident light side, as shown in FIG. It can be dispersed internally. This film is then placed on the outer surface of the glass substrate via an adhesive. Moreover, these ultrafine particles can also be incorporated into the adhesive. It can also be used as a protective film or a protective film, and in the case of a protective film, it can be mixed into the adhesive. These ultrafine particles are deposited on a transparent resin glass substrate 6 as shown in FIG.
can be dispersed inside the In this case, it is necessary to adjust the additive amount to avoid clouding. As a method for dispersing and forming the ultrafine particles, when molding these films or resin substrates, the particles can be uniformly kneaded and molded by extrusion or the like.

[Effects of the Invention] The present invention provides at least one polymer alignment film disposed on the inner surface side of a transparent glass substrate, and at least one of a polymer protective film disposed if necessary. When using a resin IJM board, this resin%
A UV-impermeable particle having a particle size of 0.01 to 1 μm is placed inside at least one of a polymer alignment film and a polymer protective film, which are arranged on the inner circumferential surface of the resin substrate. It is characterized by dispersing inorganic ultrafine particles.

Therefore, in this liquid crystal display element, ultraviolet rays can be easily prevented at a low cost, so the durability of the liquid crystal (liquid crystal display element) can be increased, and transparency can be ensured by preventing clouding, so the liquid crystal display element can be protected from ultraviolet rays easily. Function is not hindered either.

Furthermore, since this display element uses chemically stable inorganic ultrafine particles, it is possible to improve the heat resistance and abrasion resistance of the alignment film and the like. In particular, when predetermined ultrafine particles are dispersed in the resin alignment film, this abrasion resistance is improved, so that large visible scratches are less likely to occur when rubbed. In addition, the grain size is generally 1/1 of the thickness of the oriented film.
Since it is as small as 10 or less, this alignment film is flat like the conventional one. Also, in this case, a large radius of curvature (for example, 1001
It is extremely easy to deal with curved substrates or large-area substrates with 00O. In this case, the refractive index of the alignment film can be adjusted by adjusting the amount of ultrafine particles dispersed in the alignment film.
The optimum film thickness for minimizing light reflection can also be made thinner than in the past.

[Brief explanation of the drawing]

FIG. 1 is an explanatory cross-sectional view of a liquid crystal display element that is an alternative to the first embodiment. FIG. 2 is a graph showing the relationship between wavelength and transmittance of the liquid crystal display element in Example 1. FIG. 3 is a graph showing the relationship between time and current of the liquid crystal display element according to Example 1, and showing the results of a weather resistance test. FIG. 4 is an explanatory cross-sectional view of a liquid crystal display element having a protective film in which ultrafine particles are dispersed. FIG. 5 is an explanatory cross-sectional view of a liquid crystal display element having a resin substrate in which ultrafine particles are dispersed. 6th
The figure is an explanatory cross-sectional view of a conventional liquid crystal display element. 1... Substrate 2... Electrode layer 3... Alignment film 4... Liquid crystal layer 5... Seal member
6... Ia-free ultrafine particles 7... Protective film Figure 1

Claims (6)

[Claims] (1) A pair of glass substrates, at least one of which is transparent, a pair of electrode layers formed on the inner surfaces of the pair of glass substrates, and a pair of electrode layers formed on the surfaces of the pair of electrode layers and arranged to face each other. In a liquid crystal display element comprising a pair of polymer alignment films, and a liquid crystal layer formed between the pair of polymer alignment films, the polymer alignment film disposed at least on the inner surface side of the transparent glass substrate. Inside at least one of the film and a polymeric protective film arranged as necessary and formed on the outer surface of the transparent glass substrate, particles having a particle size of 0.01 to
A liquid crystal display element characterized by dispersing inorganic ultrafine particles that are opaque to ultraviolet rays and having a diameter of 1 μm. (2) The particle size of UV-impermeable inorganic ultrafine particles is 0.
．． The liquid crystal display element according to claim 1, which has a thickness of 1 μm or less. (3) The liquid crystal display element according to claim 1, wherein the ultraviolet-opaque inorganic ultrafine particles are titanium dioxide, thallous chloride, thallous bromide, or silver bromide. (4) A pair of resin substrates, at least one of which is transparent, a pair of electrode layers formed on the inner surfaces of the pair of resin substrates, and a liquid crystal layer formed between the pair of electrode layers. In the liquid crystal display element, at least the transparent resin substrate, a polymer alignment film arranged as necessary and formed on the inner surface of the transparent resin substrate, and an optionally arranged polymer alignment film formed on the inner surface of the transparent resin substrate At least one of the polymer protective films formed on the outer surface of the substrate contains particles with a particle size of 0.0.
A liquid crystal display element characterized by dispersing inorganic ultrafine particles that are opaque to ultraviolet rays and have a diameter of 1 to 1 μm. (5) The liquid crystal display element according to claim 4, wherein the inorganic ultrafine particles that do not transmit ultraviolet rays have a particle size of 0.1 μn or less. (6) The liquid crystal display element according to claim 4, wherein the inorganic ultrafine particles that do not transmit ultraviolet light are titanium dioxide, thallous chloride, thallous bromide, or silver bromide.