JPH0580343A - Spherical spacer for stn type liquid crystal display element and stn type liquid crystal display element formed by using such spacer - Google Patents

Abstract

PURPOSE:To obtain the STN type liquid crystal display element which is constituted to decrease the fluctuations in the spacing (gap) between substrate members and to obviate the generation of bubbles at the time of a low temp. and forms a bright image without having defects of the displayed image. CONSTITUTION:The spherical spacers 8 for the liquid crystal display element have the value of K defined by equation (I) within a 750 to 1500kgf/mm<2> range at 20 deg.C and the recovery rate after compression displacement is in a 30 to 80% range at 20 deg.C. In the equation, F, S are respectively the load value (kgf) and compression displacement (mm) at 10% compression displacement of the spherical spacers and R is the radius (mm) of the spacers.

Description

Detailed Description of the Invention

[0001]

The present invention relates to STN (Super Twisted)
The present invention relates to a spherical spacer for a Nematic) type liquid crystal display element and an STN type liquid crystal display element using the same.

[0002]

2. Description of the Related Art Conventional TN (Twisted Nematic)
A typical example of a mode liquid crystal display element is shown in FIG.

In this liquid crystal display device, a pair of substrate members 7 and 9, a spacer 8 and a nematic liquid crystal 11 arranged in the gap t for keeping a gap (hereinafter referred to as a gap) t therebetween constant, and a gap t. It has a sealing member 10 filled in the periphery and polarizing sheets 12 and 13 provided on the surfaces of the respective substrate members 7 and 9.

The substrate members 7 and 9 are made of glass (ITO) (Indium-Tin-O) on one side of the transparent substrates 1 and 4.
xide) films and the like are patterned to form the transparent electrodes 2 and 5, and the transparent electrodes 2 and 5 and the transparent substrate 1,
The surface of 4 is covered with alignment control films 3 and 6 such as a polyimide film. The orientation control films 3 and 6 are subjected to orientation control processing by rubbing.

The spacer 8 is made of aluminum oxide,
It is formed of an inorganic spacer such as silicon oxide or a synthetic resin such as benzoguanamine or polystyrene polymer. For example, inorganic spacers are disclosed in JP-A-63-73225 and JP-A-1-59974, and synthetic resin spacers are disclosed in JP-A-60-200228 and JP-A-1-293316. Etc.

The liquid crystal display device having such a structure is usually manufactured as follows.

Spacers 8 are sprinkled on the orientation control film 3 of the one substrate member 7, and a sealing resin is applied to the peripheral portion of the other substrate member 9 by printing or the like. Next, the pair of substrate members 7, 9 are stacked so that the orientation control films 3, 6 face each other, and pressure is applied to heat and cure the sealing resin to fix the pair of substrate members 7, 9 to each other. Next, the gap between the pair of substrate members 7 and 9 is filled with the nematic liquid crystal 11 through the holes provided in the seal member 10, and the polarizing sheets 12 and 13 are provided on the outer surfaces of the transparent substrates 1 and 4, respectively.
To arrange.

[0008]

However, when the inorganic spherical spacer is used as the spacer for the STN type liquid crystal display element, the gap t has a small variation, but bubbles are generated in the element at low temperature. Then, the bubbles at a low temperature modulate the alignment of the liquid crystal, and the quality of the displayed image is remarkably deteriorated. The reason for this is considered to be that the liquid crystal 11 contracts at a low temperature, whereas the inorganic spherical spacer 8 has a low stretchability, and therefore the change in the gap t is small, which reduces the pressure in the element.

On the other hand, when a plastic spherical spacer is used, since the spacer 8 has high elasticity, the gap t becomes smaller as the liquid crystal 11 shrinks at a low temperature, so that the above bubble does not occur. This causes a large variation in t.

As described above, both the inorganic spherical spacers and the plastic spherical spacers have drawbacks when used in the STN type liquid crystal display device.

Further, in the conventional TN type liquid crystal display element, the allowable range of the variation of the gap t for preventing color unevenness is ± 0.2 to ± 0.3 μm. However, in the STN type liquid crystal display element, which has been widely used recently, the birefringence effect is utilized by setting the twist angle of the liquid crystal molecules to 180 ° or more, so that the gap t is allowed to prevent uneven color. The range is extremely strict with less than ± 0.1 μm. For this reason, it is very difficult to reduce the variation in the gap t without causing foaming at low temperature in the conventional liquid crystal display element assembling technology.

In order to solve such a problem, a method of mixing and using a plurality of kinds of spacers having different hardness is disclosed in, for example, JP-A-63-104022 and JP-A-64-91117. It is proposed in Kaihei 2-34820, JP-A-2-89026 and the like.

However, although such a method has a certain effect in solving the problem, it is inconvenient in operation because it requires the spacers to be dispersed in two or more times, resulting in an industrial problem. Difficult to implement.

The present invention is intended to solve the above-mentioned problems of the prior art all at once, and an object of the present invention is to make the variation of the gap as small as possible and to prevent foaming at a low temperature. Provided is a spherical spacer for a liquid crystal display element, and an STN liquid crystal display element using the same. Still another object of the present invention is to use STN type spherical spacers which are easy to operate and industrially advantageous without the need to mix and use a plurality of kinds of spacers and STs using the same.
An object is to provide an N-type liquid crystal display device.

[0015]

The spherical spacer for an STN type liquid crystal display device of the present invention has a K defined by the following formula (A).
Value is in the range of 750 kgf / mm ^{2 to} 1500 kgf / mm ² , and the recovery rate after compression deformation is 30% to 80% at 20 ° C.
The above-mentioned object is achieved thereby.

[0016]

[Equation 2] K = (3 / √2) ・ F ・ S ^-3/2・ R ^-1/2
(A) where F and S are the load value (kgf) and the compressive displacement (mm) at 10% compressive deformation of the spherical spacer, respectively.
R is the radius (mm) of the spacer.

The STN type liquid crystal display element of the present invention comprises the above-mentioned spacer, and thereby the above-mentioned object is achieved.

Next, the above K value will be described.

According to Rounder-Uhlifitz Theory of Physics, "Theory of Elasticity" (published in 1972, Tokyo Book), page 42, when two elastic spheres having radii R and R'contact with each other with a predetermined compressive force, h is given by the following equation.

H = F ^2/3 [D ² (1 / R + 1 / R ′)] ^1/3 (1) D = (3/4) [(1-σ ² ) / E + (1-σ ' ² ) / E'] (2) where h is the difference between R + R 'and the center of both spheres, F is the compressive force, E and E'are the elastic moduli of the two elastic spheres, and σ , Σ'represents the Poisson's ratio of the elastic sphere.

On the other hand, when replacing the sphere with a rigid plate and compressing from both sides, if R '→ ∞, E >>E', then the following equation is approximately obtained.

F = (2 ^1/2 / 3) (S ^3/2 ) (E · R ^1/2 ) (1-σ ² ) ... (3) Here, S represents the amount of compressive deformation. By modifying this equation, the following equation can be easily obtained.

[0023] ^{K = (3/2 1/2) · F} · S -3/2 · R -1/2 ... (4) Therefore, the formula represents a K value: K = (3 / √2) · F · S ⁻³ / ² · R ^−1/2 (5) is obtained.

The K value universally and quantitatively represents the hardness of the sphere. By using this K value, it becomes possible to express the suitable hardness of the spacer quantitatively and uniquely.

The K value is 750 kgf / mm ^{2 to} 1500 kg
By using a spacer within the range of f / mm ² , when producing an STN type liquid crystal display element, foaming does not occur at low temperature, and a gap is formed between both substrates by a pressure press. At this time, gap control can be easily performed. More preferred K value is 850
is ^{kgf / mm 2 ~1300kgf / mm 2} .

When a spacer having a K value of more than 1500 kgf / mm ² is used, there is a drawback that the surface of the liquid crystal alignment film is scratched when the STN type liquid crystal display element is manufactured. When the temperature decreases, the spacer is less likely to be compressed and deformed due to the contraction of the liquid crystal, and thus bubbles are generated in the liquid crystal cell due to the reduced pressure. K value is 750kg
When a spacer having a thickness of less than f / mm ² is used, the gap is difficult to control because the spacer is too soft.

By the way, it is not possible to completely express the material mechanical properties of a suitable spacer only by defining the suitable hardness of the spacer used in the STN type liquid crystal display element.

Another important property is that the recovery rate after compressive deformation, which is a value indicating the elasticity of the spacer, is within a predetermined range. The elasticity or elasto-plasticity of the spherical spacer can be quantitatively and uniquely expressed by defining the recovery rate after compressive deformation. In the spacer used in the present invention, the recovery rate after compression deformation of the spacer is preferably in the range of 30% to 80% at 20 ° C. A particularly preferable recovery rate after compressive deformation is in the range of 40% to 70%.

When a spacer having a recovery rate of more than 80% is used, the spacer deformed by compression easily elastically recovers when the pressure is removed after the gap between both substrates is released by a pressure press in the liquid crystal cell manufacturing process. However, a situation may occur in which the gap of the taken out liquid crystal cell is disturbed.

When a spacer having a recovery rate of less than 30% is used, when the pressure is locally applied excessively when the gap between the substrates is formed by the pressure press, the spacer is in a state of being compressed and deformed. Therefore, there is a problem in that the gap at that portion is not restored, which may cause unevenness in the gap.

As the spacer of the present invention, an inorganic spherical spacer or a synthetic resin spherical spacer may be used as long as it satisfies the above K value and recovery rate.

From the viewpoint that the K value and recovery rate can be easily adjusted within the above range, a spacer composed of a hybrid of an inorganic substance and an organic substance is particularly preferable.

For example, inorganic / organic hybrid fine particles obtained by impregnating inorganic porous fine particles with a polymerizable organic monomer and then polymerizing this monomer can be mentioned. Further, organic / inorganic hybrid fine particles obtained by a so-called sol-gel method in which a metal alkoxide is impregnated in an organic porous fine particle and then the metal alkoxide is hydrolyzed to form a metal oxide can be mentioned.

Preferred inorganic porous fine particles used for preparing the above-mentioned inorganic / organic hybrid fine particles include
Examples thereof include porous fine particles such as silicon oxide, aluminum oxide, titanium oxide and zirconium oxide. Regarding the manufacturing method, Japanese Patent Publication No. 2-61406 and Japanese Patent Laid-Open No. 3-6
An example thereof is disclosed in Japanese Patent No. 5518.

As the polymerizable organic monomer, crosslinkable monomers such as divinylbenzene, polyfunctional acrylic ester, diallyl phthalate and triallyl isocyanurate are preferably used.

As the organic porous fine particles used for the preparation of the above organic / inorganic hybrid fine particles, porous crosslinked plastic fine particles are suitable, and the production method thereof is described in JP-B-58-45658 and JP-B-61-28.
Examples thereof are disclosed in Japanese Patent Publication No. 099, Japanese Patent Publication No. 61-36919 and Japanese Patent Publication No. 63-59462.

Specific examples of such organic porous fine particles include epoxy resin, phenol resin, melamine resin, unsaturated polyester resin, divinylbenzene polymer, divinylbenzene-polyfunctional acrylic acid ester copolymer, diallyl phthalate polymer. Examples thereof include porous fine particles made of a crosslinkable polymer such as a polymer, a triallyl cyanurate polymer, and a benzoguanamine polymer. Particularly preferred materials are divinylbenzene polymer and divinylbenzene-
It is a porous fine particle of a polyfunctional acrylic acid ester copolymer and a diallyl phthalate polymer.

Aluminum alkoxide, silyl alkoxide, titanium alkoxide, and zirconium alkoxide are preferably used as the metal alkoxide. Specifically, trimethyl aluminum alkoxide, triethyl aluminum alkoxide, triisopropyl aluminum alkoxide, tri-n-propyl aluminum alkoxide, triisobutyl aluminum alkoxide, tri-n-butyl aluminum alkoxide, tri-n-pentyl aluminum alkoxide, tri-n. -Heptyl aluminum alkoxide; trimethylsilyl alkoxide, triethylsilyl alkoxide, triisopropylsilyl alkoxide, tri-
n-propylsilylalkoxide, triisobutylsilylalkoxide, tri-n-butylsilylalkoxide, tri-n-pentylsilylalkoxide, tri-n
-Heptylsilyl alkoxide; trimethyltitanium alkoxide, triethyltitanium alkoxide, triisopropyltitanium alkoxide, tri-n-propyltitanium alkoxide, triisobutyltitanium alkoxide, tri-n-butyltitanium alkoxide, tri-n-heptyltitanium alkoxide,
Tri-n-hexyl titanium alkoxide; trimethyl zirconium alkoxide, triethyl zirconium alkoxide, triisopropyl zirconium alkoxide, tri-n-propyl zirconium alkoxide,
Triisobutyl zirconium alkoxide, tri-n-
Butyl zirconium alkoxide, tri-n-heptyl zirconium alkoxide, tri-n-hexyl zirconium alkoxide, etc. are mentioned.

The spacer of the present invention may be colored. An example of a colored spacer is, for example, JP-A-57 / 57.
No. 189117, No. 63-89890, No. 1-144021, No. 1-144.
No. 429 is disclosed.

The reason for using colored spheres is as follows.

In the liquid crystal display element, when a voltage is applied between the transparent electrodes, the liquid crystal undergoes an optical change to form an image. In contrast, the spacer does not show an optical change due to its application. Therefore, in the dark portion when the image is displayed, the uncolored spacer may be visually recognized as a bright spot, and as a result, the display contrast of the image may be reduced.

The spherical spacer of the present invention may have adhesiveness. Examples of the spherical spacer having adhesiveness are, for example, Japanese Utility Model Laid-Open No. 51-22453 and Japanese Patent Laid-Open No. 63-4.
4631, JP-A-63-94224, JP-A-63-200126, JP-A-1-247154.
It is disclosed in Japanese Patent Laid-Open No. 1-247155 and Japanese Patent Laid-Open No. 1-247155.

The reason why the spherical spacer having adhesiveness is used in the liquid crystal display element is to positively prevent the inconvenient phenomenon that the spacer moves in the gap between the substrate members and damages the alignment control film as described above. ..

The spherical spacer of the present invention may have conductivity. Examples of the spherical spacer having conductivity are described in, for example, JP-A-61-277104 and JP-A-61-1.
No. 277105, JP-A No. 63-190204, and the like. The reason why the spherical spacer having conductivity is used is to electrically connect a predetermined portion between the electrode substrate pair of the liquid crystal display element.

The particle size of the present invention is preferably in the range of 0.1 μm to 100 μm, more preferably in the range of 0.5 μm to 50 μm, and particularly preferably in the range of 1 μm to 20 μm.

Next, a method of measuring the K value and the recovery rate after compression deformation will be described.

(A) K value measuring method and conditions (i) Measuring method At room temperature, spacers are scattered on a steel plate having a smooth surface, and one spacer is selected from them. next,
Using a micro compression tester (PCT-200 type, manufactured by Shimadzu Corporation), the spacer is compressed by the smooth end surface of a diamond cylinder with a diameter of 50 μm. At this time, the compression load is electrically detected as an electromagnetic force, and the compression displacement is electrically detected as a displacement by the differential transformer.

Then, the relationship between compression displacement and load as shown in FIG. 2 is obtained. From FIG. 2, the load value and the compressive displacement at 10% compressive deformation of the spacer are obtained, and the relationship between the K value and the compressive strain as shown in FIG. 3 is obtained from these values and the equation (5).

However, the compressive strain is a value obtained by dividing the compressive displacement by the particle size of the spacer and expressed in%.

(Ii) Compression speed A constant load speed compression method was used. 0.27 grams weight per second (gr
The load increased at the rate of f).

(Iii) Test load Maximum 10 grf.

(B) Method of measuring recovery rate after compressive deformation and conditions (i) Method of measuring At room temperature, spacers are scattered on a steel sheet having a smooth surface, and one spacer is selected from them. next,
Using a micro compression tester (PCT-200 type, manufactured by Shimadzu Corporation), the spacer is compressed by the smooth end surface of a diamond cylinder with a diameter of 50 μm. At this time, the compression load is electrically detected as an electromagnetic force, and the compression displacement is electrically detected as a displacement by the differential transformer.

Then, as shown in FIG. 4, after compressing the spacer to the reversal load value (shown by curve (a) in FIG. 4), the load is decreased conversely (curve (b) in FIG. 4). ). At this time, the relationship between the load and the compressive displacement is measured.
However, the end point of unloading is 0, not 0.
Set the origin load value to 1 g or more. The recovery rate is defined by the ratio (L ₂ / L ₁ ) of the displacement L ₁ to the reversal point and the displacement difference L ₂ from the reversal point to the point where the origin load value is taken, expressed in%.

(Ii) Measurement conditions Reverse load value 1 grf Origin load value 0.1 grf Compression rate under load and unload 0.27 grf / sec Measuring chamber temperature 20 ° C. The liquid crystal display device of the present invention is different from the above spherical spacers. The same structure as that shown in FIG. 1 can be used.

[0055]

[Function] The spherical spacer for a liquid crystal display device has a K value defined by the above formula (A) of 750 kgf / mm ^{2 to} 1500 kgf / mm ²
And the recovery rate after compression deformation at 20 ° C
Within the range of 30% to 80%, the hardness and elasticity of the spacer can be set within a preferable range for the STN type liquid crystal display element, and therefore, the variation in the gap between the substrate members of the element can be reduced, Further, it is possible to provide an STN type liquid crystal display element in which foaming does not occur at low temperature.

[0056]

EXAMPLES The present invention will be described in detail below based on examples.

Example 1 Porous plastic particles composed of a styrene-divinylbenzene copolymer having an average particle size of 6.98 μm and a standard deviation of 0.25 μm.
A container A containing 10 g and a container B containing 1 g of tetraethoxysilane are connected and connected to a vacuum pump. The container B was degassed at -760 mmHg for 20 minutes at the melting point of tetraethoxysilane (-85 ° C) and then returned to room temperature. Degassing of container B was performed at -760 mmHg at room temperature for 60 minutes. afterwards,
The containers A and B were connected in a vacuum state, the tetraethoxysilane vapor was transferred to the container A, and the porous plastic particles were coated with tetraethoxysilane.

After the particles were separated by filtration, the particles were mixed with 50 ml of methanol.
Washed twice. Next, tetraethoxysilane-containing porous particles and 6N hydrochloric acid were added to another container, and a condensate of a metal oxide was formed inside the porous structure of the particles while being irradiated with ultrasonic waves while being cooled.

The organic / inorganic hybrid spacer thus obtained has an average particle size of 7.03 μm and a standard deviation of
It was 0.27 μm. The compression test of this spacer was performed using a micro compression tester (manufactured by Shimadzu Corporation). as a result,
The K value at a compression strain of 10% was 1150 kgf / mm ² .
Also, the recovery rate after compressive deformation when the reversal load is 1 grf is 58.
%Met.

On the other hand, a transparent conductive film of indium oxide-tin oxide having a thickness of about 500 Å was formed on a glass plate having a thickness of 0.7 mm by a low temperature sputtering method, and then a predetermined electrode pattern was formed by photolithography. .. Next, an alignment agent was applied onto this and then baked to form an alignment control film, and an alignment treatment was performed. Next, this one
A glass substrate for a liquid crystal display device was obtained by cutting into a size of cm × 12.5 cm.

An epoxy adhesive mixed with a glass fiber spacer was printed around the glass substrate with a width of 1 mm by screen printing.

After arranging one glass substrate horizontally, the spacer obtained above was scattered from above by pressurized nitrogen gas and uniformly dropped onto the glass substrate. The spraying time was adjusted so that the spacer spraying density on the glass substrate was about 100 particles / mm ² .

Another glass substrate was superposed on the glass substrate on which the spacers were scattered, and then a load of 1 kgf / cm ² was applied by a pressing machine so that the entire glass substrate was uniformly applied. At the same time, this was heated at a temperature of 160 ° C. for 20 minutes to cure the surrounding epoxy adhesive.

After the inside of the cell thus prepared was sucked to form a vacuum, the STN type liquid crystal was injected into the inside from the pore portion provided in a part of the peripheral seal portion. The gap between the upper and lower substrates of the STN type liquid crystal cell thus produced was measured with a liquid crystal cell gap measuring device (TFM-120AFT type manufactured by Oak Manufacturing Co., Ltd.), and the gap value was in the range of 6.97 ± 0.05 μm.

Polarizing sheets were applied to the upper and lower surfaces of the liquid crystal cell, and the polarizing sheets were attached so that the color tone of the reflected light applied to the liquid crystal cell was yellowish green. At this time, no color unevenness was observed in the yellow-green background color. As a result of connecting a power source to the STN type liquid crystal display element thus produced and lighting it, good display performance was obtained.

Example 2 10 g of porous particles made of titanium oxide (TiO ₂ ) having an average particle size of 6.95 μm and a standard deviation of 0.28 μm were placed in the bottom of a container equipped with a dropping funnel, and tetramethylolmethane tetraacrylate was added to the dropping funnel. A mixed solution of 1 g, 1 g of divinylbenzene and 0.02 g of benzoyl peroxide was added. Container-760mm
After degassing with Hg for 30 minutes, the stopper of the dropping funnel was opened and the above monomer mixture was slowly added dropwise to impregnate the titanium oxide porous fine particles.

After the particles were separated by filtration, the particles were transferred to another container equipped with a stirrer and a cooling pipe, and 100 ml of a 5% polyvinyl alcohol aqueous solution was added to the container to thoroughly stir them to uniformly disperse the particles. This was heated at 85 ° C. for 12 hours with stirring at 300 rpm in a nitrogen stream to completely polymerize the above-mentioned monomer impregnated into the titanium oxide porous particles. The obtained particles were thoroughly washed with hot water to remove polyvinyl alcohol.

The inorganic / organic hybrid spacer thus obtained has an average particle size of 7.00 μm and a standard deviation of
It was 0.30 μm.

The K value at a compressive strain of 10% of this spacer was 1250 kgf / mm ² . Recovery rate after compression deformation is 65
%Met.

The gap value of the STN type liquid crystal cell prepared in the same manner as in Example 1 except that this spacer was used is
The range was 6.95 ± 0.07 μm.

Further, in the same manner as in Example 1, no color unevenness was observed in the state where the polarizing sheet was attached, and the display state in the lighting state was good.

Comparative Example 1 Average particle size of benzoguanamine polymer 6.98 μm,
Example 1 except that a spacer having a standard deviation of 0.25 μm was used.
An STN type liquid crystal display device was obtained in the same manner as in.

The K value at a compressive strain of 10% of the spacer used was 600 kgf / mm ² . The recovery rate after compression deformation of the spacer was 13%.

The gap value of the STN type liquid crystal cell is 6.92 ± 0.
It was in the range of 07 μm.

When a polarizing sheet was attached in the same manner as in Example 1, color unevenness was observed in the background color, and the display state in the lit state was poor.

Comparative Example 2 30% by weight of triallyl isocyanurate and 70% by weight of diallyl phthalate were subjected to suspension polymerization and then classified to obtain a spacer having an average particle size of 7.03 μm and a standard deviation of 0.26 μm.
K value at 10% compressive strain of this spacer is 240 kgf
It was / mm ² . The recovery rate of the spacer after compression deformation was 12%.

The STN type liquid crystal cell produced in the same manner as in Example 1 except that this spacer was used had a gap value of 6.
The range was 89 ± 0.03 μm.

When a polarizing sheet was attached in the same manner as in Example 1, color unevenness was observed in the background color and the display state in the lit state was poor.

Comparative Example 3 Polystyrene average particle size 6.98 μm, standard deviation 0.2
An STN type liquid crystal display device was obtained in the same manner as in Example 1 except that a spacer of 5 μm was used.

The K value at a compressive strain of 10% of the spacer used was 105 kgf / mm ² . The recovery rate after compression deformation of the spacer was not measurable.

The gap value of the STN type liquid crystal cell is 6.75 ± 0.
It was in the range of 07 μm.

When a polarizing sheet was attached in the same manner as in Example 1, color unevenness was observed in the background color, and the display state in the lit state was poor.

Comparative Example 4 Average particle size 7.05 μm of benzoguanamine polymer
Example 1 except that a spacer having a standard deviation of 0.25 μm was used.
An STN type liquid crystal display device was obtained in the same manner as in.

The K value at a compressive strain of 10% of the spacer used was 620 kgf / mm ² . The recovery rate after compression deformation of the spacer was 13%.

The gap value of the STN type liquid crystal cell is 6.88 ± 0.
It was in the range of 05 μm.

When a polarizing sheet was attached in the same manner as in Example 1, color unevenness was recognized in the background color, and the display state in the lit state was poor.

Comparative Example 5 Average particle size of silicon dioxide 7.01 μm, standard deviation 0.1
An STN type liquid crystal display device was obtained in the same manner as in Example 1 except that a 9 μm spacer was used.

The K value at a compressive strain of 10% of the spacer used was 5000 kgf / mm ² . The recovery rate after compression deformation of the spacer was 85%.

The gap value of the STN type liquid crystal cell is 6.99 ± 0.
It was in the range of 10 μm.

When a polarizing sheet was attached in the same manner as in Example 1, color unevenness was observed in the background color, and the display state in the lit state was poor.

[0091]

As described above, according to the present invention, the STN
It is possible to provide a spacer having physical properties suitable as a spacer of a liquid crystal display device. Therefore, as seen when the inorganic spherical spacer is used, foaming does not occur at a low temperature to induce modulation of the alignment characteristics of the liquid crystal and the quality of the displayed image is not deteriorated. Further, as seen when the plastic spherical spacer is used, the definition of the displayed image is not deteriorated by causing the dimension of the liquid crystal layer gap of the liquid crystal display element to be disturbed. Therefore, according to the present invention, it is possible to obtain the STN type liquid crystal display element which can obtain a clear image without a defect in the displayed image.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a general liquid crystal display element.

FIG. 2 is a graph showing a relationship between a load and a compressive displacement of a spacer.

FIG. 3 is a graph showing the relationship between the K value and the compressive strain of the spacer.

FIG. 4 is a diagram illustrating a method of measuring a recovery rate of a spacer after compression deformation.

[Explanation of symbols]

 1, 4 Transparent substrate 2, 5 Transparent electrode 3, 6 Alignment control film 7, 9 Substrate member 8 Spacer 10 Sealing member 11 Liquid crystal 12, 13 Polarizing sheet

Claims (2)

[Claims] 1. The value of K defined by the following formula (A) is in the range of 750 kgf / mm ^{2 to} 1500 kgf / mm ² at 20 ° C., and the recovery rate after compression deformation is 30% to 80% at 20 ° C. %
Spherical spacer for STN type liquid crystal display device within the range. [Equation 1] K = (3 / √2) ・ F ・ S ^-3/2・ R ^-1/2
(A) where F and S are the load value (kgf) and the compressive displacement (mm) at 10% compression deformation of the spherical spacer,
R is the radius (mm) of the spacer. 2. The spacer according to claim 1 is used,
STN type liquid crystal display device.