JP2000171810A - Spacer for liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spacer for a liquid crystal display device which enables homogeneous display, prevents the occurrence of impact unevenness and prevents the occurrence of abnormal alignment during energization or by static electricity. SOLUTION: This spacer is >=0.45 to <=1 in the ratio L2/L1 of the length L1 (μm) of a range where the line of a height 3 H horizontal to a base line overlaps the graph in a grain size distribution analysis and likewise a length L2 (μm) of a range where the line of the height 75 H horizontal to the base line overlaps the graph when the height of the maximum value of the graph is defined as 100 H and the base line as 0 H. In addition, the standard deviation of the grain size distribution is >=1.0 μm. Further, the spacer has the nonionic hydrophilic unit (I) expressed by formula on its surface. In the equation, R1 denotes a 1-18C alkylene group, an acyl group, etc., R2 denotes a 2-4C alkylene group; (x) denotes a number from >=1 to <=100.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacer for a liquid crystal display device, and more particularly, to a large liquid crystal display device which has a high cell gap uniformity to enable uniform display without unevenness, and which is shocked after completion. The present invention relates to a spacer for a liquid crystal display device and a liquid crystal display device, which prevent the occurrence of unevenness due to a change in cell gap caused thereby and also prevent the abnormal alignment of the liquid crystal which occurs upon energization or impact.

[0002]

2. Description of the Related Art A liquid crystal display has a structure as shown in FIG. A transparent electrode 3 patterned in a predetermined shape and an alignment film 4 covering the transparent electrode 3 are provided on the upper and lower surfaces of the glass substrate 2, and a liquid crystal material 5 is injected between the two glass substrates. The periphery of the substrate is sealed with a sealant 6. In order to keep the distance between the liquid crystal cells constant, the spacers 7 are uniformly dispersed, and the distance between the liquid crystal cells is generally 1 to 30 μm. Polarizing plates 1 are provided on both outer sides of the glass substrate.

A liquid crystal has a shutter function of passing or blocking light from a backlight by controlling a voltage applied to an electrode on a glass substrate. The gap (cell gap) between the glass substrates is uniform. Otherwise, display unevenness occurs because the light transmittance becomes non-uniform. In order to realize a high-quality display, it is necessary that the cell gap is uniform and a uniform display is possible. Also,
Even if there is no non-uniformity at first, display non-uniformity (hereinafter referred to as “impact non-uniformity”) also occurs when a cell gap change is induced by an impact or the like, and it is necessary to prevent this. Further, with the increase in size of the panel, impact unevenness tends to be much more likely to occur, and it is becoming more important to prevent such unevenness at the same time. Such characteristics are basically different to some extent in generally commercialized liquid crystal display devices such as TN, STN, MIM, TFT, and recently commercialized in-plane switching TFT. Is the same as

[0004] Conventionally, resin spacers, silica spacers, and resin / silica hybrid spacers have been used as spacers for liquid crystal display devices. These spacers are obtained by synthesizing a spacer having a wide particle size distribution in advance and then performing a precise classification operation to narrow the particle size distribution, and a spacer obtained by synthesizing the particle size distribution at the stage of synthesis such as seed polymerization. The narrow ones are divided into those obtained directly. However, the former spacer, in which the classification operation is performed, has a disadvantage that it is difficult to generate impact unevenness, but has a drawback that the cell gap uniformity is inferior.On the other hand, the latter spacer that directly synthesizes a narrow particle size distribution by seed polymerization or the like. Have good cell gap uniformity and enable uniform display, but on the other hand, have a disadvantage that impact unevenness is likely to occur, and both are inadequate to achieve both performances .

It is also known that in a TN or STN liquid crystal panel, an abnormal compounding region easily occurs within a range of several μm from the spacer due to an interfacial interaction between the liquid crystal and the spacer when a voltage is applied. The abnormal alignment region is often induced by static electricity or the like generated during energization or when the protective film is removed, and there is a problem that the region expands with energization time. Further, there is also a known problem that an abnormal alignment region is generated like a line between spacers even when no voltage is applied. Since the abnormal alignment region is observed as so-called light leakage, when it occurs, the contrast of the liquid crystal display device is reduced. A so-called aging operation (annealing step) of the liquid crystal panel is performed in the production of the liquid crystal panel for the purpose of eliminating the abnormal alignment region, but there is a problem that the production efficiency is reduced.

[0006]

Means for Solving the Problems The present inventors have realized that a spacer having a specific particle size distribution pattern and having a specific nonionic hydrophilic unit on the surface enables uniform display in a liquid crystal display device. In addition, it has been found that it is possible to prevent the occurrence of unevenness due to a change in the cell gap that occurs after the application of an impact, and to prevent the occurrence of abnormal orientation around the spacer or between spacers due to electricity or static electricity.

That is, according to the present invention, when the height of the maximum value is set to 100H and the base line is set to 0H in the particle size distribution analysis graph, the length of the range where the line having a height of 3H horizontal to the base line overlaps the graph is set. L1 (μm), and the length L2 (μm) of the range where a line of height 75H, which is also horizontal to the base line, overlaps the graph.
m), the ratio L2 / L1 is 0.45 or more and 1 or less, the standard deviation of the particle size distribution is 1.0 μm or less, and at least the surface of the formula (I) R ¹ O− (R ² O) _x − (I (Wherein, R ¹ is an alkyl group having 1 to 18 carbon atoms, an alkenyl group, an aryl group, an alkylaryl group, an aralkyl group,
It represents an acyl group, an alkylcarbamoyl group or an arylcarbamoyl group. R ² represents a linear or branched alkylene group having 2 to 4 carbon atoms, and may be substituted with a hydroxy group or a halogen group. x represents a number from 1 to 100, and x
R ² may be the same or different. The present invention provides a spacer for a liquid crystal display device having a nonionic hydrophilic unit represented by the formula (1), a method for producing the same, and a liquid crystal display device using the spacer.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The particle size distribution analysis graph shows how many particles are present in each range when all the particles of the spacer are divided at regular intervals by a certain range of particle sizes. This is expressed as a percentage (%, hereinafter referred to as particle size distribution probability) with respect to the number of particles, and the vertical axis represents the particle size distribution probability and the horizontal axis represents the particle size divided into a particle size distribution graph.
Each constant particle size range divided at this time is called the resolution of this graph.

FIG. 1 schematically shows the relationship between these numerical values. Note that the particle size distribution analysis graph is originally represented by a columnar graph, but FIG. 1 is shown as a line graph for easy viewing.

As shown in FIG. 1, the vertical axis represents the particle size distribution probability,
The height of the maximum value of the particle size distribution graph obtained by taking the particle size divided on the horizontal axis is defined as 100H, and the baseline is defined as 0H. Using this as a reference for the height, a length L1 (μm) of a range where a line having a height of 3H horizontal to the base line overlaps the graph is set. Similarly, let L2 be the length of the range where the line of height 75H that is horizontal to the baseline overlaps the graph.

Further, based on a line having a height of 85H, which is horizontal to the base line, the length of the range overlapping with the graph as in the case of L1 and L2 is obtained based on a line having a height of L3 and a height of 50H. The length obtained is L4.

Further, when the height of the maximum value is 100H and the base line is 0H, the point P2 on the largest particle size side within the range where the line of height 3H horizontal to the base line overlaps the graph is shown.
Similarly, the slope of the line connecting the point P1 on the largest particle size side in the range where the line of height 75H horizontal to the base line overlaps the graph is K12, meaning that the value does not consider the direction of the slope. The absolute value is shown as abs (K12).

The resolution of the measured data in the particle size distribution analysis graph is within 0.02 μm. When there are two or more ranges where the lines of each height overlap the graph, the sum of the lengths is set to a length such as L1. Here, “when there are two or more ranges where the lines of each height overlap the graph” appears as a distribution showing bimodality, for example, the bimodal distribution shown in FIG. There are two ranges where the height 75H overlaps the graph.

That is, as shown in FIG. 2, when the small particle size side of the portion where the line of height 75H overlaps the graph is l 2 and the large particle size side is m 2, the sum of the lengths is defined as L 2. Do "
L2 is the sum of l2 and m2. On the other hand, since "the portion where the line having a height of 75H horizontal to the base line overlaps the graph and the average particle size is larger" is only m2, M2 = m2. Similarly, L3 is also the sum of l3 and m3.

The precise definition of L1 and L2 in the original columnar graph of the particle size distribution analysis graph can be shown in enlarged views in FIGS. 3 and 4, respectively. In the columnar graphs of FIGS. 3 and 4, each fixed particle size range, which is divided for analysis, that is, the width of one column is the resolution of this graph. Further, since L1 and M1 are the lengths of the range where the line of height 3H horizontal to the base line overlaps the graph, it is exactly as shown in FIG. Similarly, L2 and M2 are exactly as shown in FIG. In addition, L3 and L4 have the same definition as L1 and L2 except that the height of a line horizontal to the baseline is different.

Next, the measuring method and conditions for the particle size distribution analysis will be described. 0.03 g of the spacer was previously treated with sodium dodecyl sulfate (hereinafter referred to as “filtration”) to remove fine particles.
(Abbreviated as SDS) in a 0.4% by weight aqueous solution to prepare a spacer dispersion. Switch on the particle size analyzer (Coulter Multisizer II, manufactured by Coulter Counter Co., Ltd.) and leave it for at least 30 minutes to stabilize it and complete the particle size correction. The measurement aperture has a sample passage hole of 50 μm, and the number of measurement is set to 500,000.

Next, the above-mentioned spacer dispersion liquid is set in a particle size measuring instrument, and adjusted so that an attached concentration gauge indicates 5%.
If the concentration is insufficient, increase the amount of spacer. If the concentration is excessive, dilute with the above SDS aqueous solution. When the concentration is reached,
First, to set the range width of the NARROW range, measure the particle size of about 1000 to 10,000 particles in the FULL range. Move the right and left cursors of the NARROW range setting to the particle size at which the height of the particle size distribution showed the maximum value in this preliminary measurement, and then move the right cursor move button 13 times to the right and the left cursor move button 12 times to the left. Press to set the range width of the NARROW range. For example,
With the above method, the range width of the NARROW range is set to 5.197 μm
When set to 8.340 μm, the measurement resolution is 0.0123 μm. However, if the sample aperture of the measurement aperture is 50 μm, noise will increase sharply below 1.5 μm.
Be careful that the lower limit of the ARROW range does not fall below 1.5μm. Next, switch to the NARROW range and perform this measurement.
Measure the particle size of 10,000 pieces. Next, this measurement data is analyzed in the attached analysis software (COULTER MULTISIZER particle size distribution analysis program VER.MD.1.1) in the 256-channel analysis mode, and the particle size distribution probability is calculated. L1 and L2 are calculated from the particle size distribution analysis values according to the above definition.

In the spacer for a liquid crystal display device of the present invention, the ratio L2 / L1 of L1 and L2 defined as described above must be in the range of 0.45 or more and 1 or less. When L2 / L1 is within the above range, both high cell gap uniformity and impact non-uniformity prevention can be achieved. In the spacer of the present invention, the ratio L3 / L1 of L1 and L3 is preferably in the range of 0.2 or more and 1 or less, and the ratio L4 / L1 of L1 and L4 is preferred.
Is preferably in the range of 0.6 or more and 1 or less. Also M
It is preferable that the ratio M2 / M1 of 1 to M2 is in the range of 0.3 or more and 1 or less. Further, it is preferable that abs (K12) is 3 (% / μm) or more.

The spacer for a liquid crystal display device having the above-mentioned particle size distribution pattern defined in the present invention has a sharply rising particle size distribution probability on the large particle size side. The standard deviation of the particles on the diameter side is small.
In an actual liquid crystal display device, the glass substrate is supported not by all the particles but by the particles on the large particle size side. Therefore, even in a distribution having the same standard deviation as the entire distribution, by satisfying the above conditions, it is possible to reduce the deviation in the particle diameter of the large particle diameter portion that effectively supports the glass substrate. A liquid crystal display device using such a spacer has a high cell gap uniformity and enables a uniform display even on a wide screen of a large panel.

In addition, since the range having a height of 75 H or more on the large particle size side is sufficiently wide and has a sufficient supporting force against compression due to impact, the change in cell gap caused by impact is small and large panels can be used. Can be sufficiently prevented. According to the definition of the present invention, a distribution pattern having a plurality of peaks may be included in the range, but also in this case, the impact unevenness is prevented for the above-described reason.

Further, the spacer of the present invention needs to have a nonionic hydrophilic unit represented by the above formula (I) on at least the surface. R ¹ in the formula (I) has the above-mentioned meaning, but from the viewpoint of the alignment abnormality prevention performance and the reactivity,
The preferred number of carbon atoms is from 6 to 16, more preferably from 10 to 14. R ² has the above-mentioned meaning, but is preferably an ethylene group from the viewpoint of preventing abnormal alignment. X has the above-mentioned meaning, but is preferably a number of 1 or more and 50 or less. By having this nonionic hydrophilic unit, it is possible to prevent the occurrence of abnormal orientation around the spacer or between the spacers due to electricity or static electricity, thereby realizing a display with high contrast.

The specific particle size distribution pattern of the present invention and the composition of the spacer having a nonionic hydrophilic unit on its surface are not particularly limited, but resins such as resin spacers and resin / silica hybrid spacers are used. Is preferable, and a resin spacer is particularly preferable.

The method of obtaining polymer fine particles having a nonionic hydrophilic unit represented by the above formula (I) on the surface includes a method of polymerizing using a monomer having a specific nonionic hydrophilic unit, a method of polymerizing using a monomer having a specific nonionic hydrophilic unit, Surface treatment of fine particles having a specific group with a specific compound, and a method of impregnating a polymer fine particle with a monomer having a specific nonionic hydrophilic unit and polymerizing the same. It is disclosed in JP-A-118421.

Further, in order to impart the particle size distribution pattern of the present invention, for example, polymer fine particles having a wide particle size distribution are synthesized in advance by suspension polymerization, dispersion polymerization, or the like using the above-described method. Spacers obtained by narrowing the particle size distribution by performing a classification operation, or a plurality of spacers consisting of resin microspheres having a bimodal distribution synthesized by seed polymerization, etc., each standard deviation of the particle size is 1.0 μm or less, preferably 0.5 μm or less, each average particle size difference is preferably 0.005 μm to 1.0 μm, more preferably 0.01 μm to 0.5 μm, particularly preferably 0.01 μm
For example, a method of mixing several points of m to 0.1 μm at a specific ratio may be used.

[0025]

EXAMPLES In the following examples, "parts" indicate parts by weight.

Reference Example (Production of seed polymer particles) 10 parts of polyvinylpyrrolidone (molecular weight: 40,000), Perex
A solution prepared by dissolving 3 parts of OT-P (manufactured by Kao Corporation, anionic surfactant) and 0.48 parts of azobisisobutyronitrile in 340 parts of methanol was heated to 60 ° C. under a nitrogen stream while stirring, and then stirred. Under the same conditions, 32 parts of styrene were added, and the mixture was kept at the same temperature for 24 hours to obtain polymer particles. The average size of these particles is 1.
The standard deviation of the particle size distribution was 0.045 μm.

Comparative Example 1 300 parts of ion-exchanged water and 2.88 parts of sodium lauryl sulfate were added to 1.69 parts of the dried seed polymer particles obtained in Reference Example, and the mixture was uniformly dispersed to prepare a seed polymer particle dispersion. on the other hand,
75 parts of ethanol and benzoyl peroxide were added to 150 parts of a monomer mixture consisting of 90 parts of divinylbenzene (purity: 81%), 40 parts of ethylene glycol dimethacrylate (NK ester 1G, manufactured by Shin-Nakamura Kogyo KK) and 20 parts of acrylonitrile. .
In a solution prepared by dissolving 34 parts, 750 parts of ion-exchanged water and 6.75 parts of sodium lauryl sulfate were mixed to prepare a monomer / polymerization initiator dispersion.

Then, 305 parts of the monomer / polymerization initiator dispersion subjected to ultrasonic treatment was added to 305 parts of the seed polymer particle dispersion four times at 120 minute intervals four times while stirring at 40 ° C. 120 minutes after the last addition of the monomer / polymerization initiator dispersion, the dispersion mixture was added to polyvinyl alcohol (GH-17; saponification degree 8).
6.5-89 mol%, 1% by Nippon Synthetic Chemical Industry Co., Ltd.) and polyvinylpyrrolidone (manufactured by BASF Corporation, LUVISKOL K-3)
0) Add 324 parts of 1% aqueous solution and stir under nitrogen
Polymerization was performed at 80 ° C. for 14 hours. The obtained polymer fine particles were washed with ion-exchanged water and a solvent, then isolated and dried. The average particle size of these particles was 6.57 μm, the standard deviation was 0.186 μm, and the particle size distribution and L2 / L1, L3 / L1, L4
/ L1, M2 / M1 and abs (K12).

The particles were used as a spacer for a liquid crystal display device, and the cell size was about 13.4 inches diagonally and the number of dots was 800 × 60.
An STN liquid crystal display device having a cell gap of 6.54 μm was prepared. When a scanning voltage was applied to this display device and its display characteristics were observed, high-quality display excellent in uniformity was obtained over the entire surface, but unevenness occurred when an impact was applied. When a voltage was applied, an abnormally oriented region was generated around the spacer.

Here, the impact was given by the following method. That is, the liquid crystal display device is set upright on the floor with one long side down, and at this time, a rubber rod having a diameter of 1 cm and a length longer than the long side is installed on the floor in parallel with the long side in contact with the floor. I do. The distance between the liquid crystal display and the rubber rod is 90 (height) of the height of the liquid crystal display (short side).
%, And adjust the position so that the rubber bar is always present in the entire area extending vertically on the floor from both ends of the long side in contact with the floor. The impact is given by repeating the tilting of the liquid crystal display device toward the rubber bar 50 times. The same applies to the following examples and comparative examples.

[0031]

[Table 1]

Example 1 In Comparative Example 1, the amount of the dry seed polymer particles obtained in Reference Example was 1.551 parts, 1.608 parts, 1.667 parts, 1.721 parts, 1.
778 parts and 1.837 parts, respectively. The monomers used were 70 parts of divinylbenzene (purity 81%) and ethylene glycol dimethacrylate (NK ester 1 manufactured by Shin-Nakamura Kogyo Co., Ltd.).
G) In the same manner as in Comparative Example 1 except that 10 parts and 30 parts of polyethylene glycol monomethacrylate (PE-90 manufactured by NOF Corporation) were used, the average particle diameter was 6.760 μm, and 6.
680 μm, 6.600 μm, 6.530 μm, 6.460 μm, 6.390
μm polymer fine particles were obtained. Further, 30 parts of each of the polymer fine particles was dispersed in 150 parts of chloroform, 28 parts of pyridine was added, 58 parts of n-myristoyl chloride was added dropwise in a nitrogen atmosphere under ice cooling, and the mixture was further reacted at 55 ° C. for 14 hours to carry out an esterification reaction. Was completed. After adding 54 parts of ethanol to the reaction mixture to decompose excess n-myristoyl chloride, the mixture was purified by filtration, washed with a solvent, isolated and dried to obtain polymer fine particles having their surfaces esterified.

Next, the fine particles having their surfaces esterified are mixed at a weight ratio of 36/25/16/9/4/1 to obtain particles having an average particle size of 6.66 μm and a standard deviation of 0.208 μm. Was. The particles had a particle size distribution and L2 / L1 shown in Table 2.
, L3 / L1, L4 / L1, M2 / M1 and abs (K12).

Using these particles as a spacer for a liquid crystal display device, the cell size is about 13.4 inches diagonally and the number of dots is 640 × 48.
An STN liquid crystal display device having a cell gap of 6.65 μm was prepared. When a scanning voltage was applied to this display device and its display characteristics were visually observed, high-quality display excellent in uniformity was obtained over the entire surface, and no unevenness was generated even when an impact was applied. Further, no abnormal alignment region was generated even when a voltage was applied.

[0035]

[Table 2]

Example 2 Using the same liquid crystal display device spacer as in Example 1, a TFT type liquid crystal display device having a cell size of about 13.4 inches, a dot number of 800 × 600, and a cell gap of 6.65 μm was prepared.
When a display voltage was applied to this display device and its display characteristics were observed, a high-quality display excellent in uniformity was obtained over the entire surface, and no unevenness was generated even when an impact was applied. Further, no abnormal alignment region was generated even when a voltage was applied.

Embodiment 3 Using the same spacer for a liquid crystal display device as in Embodiment 1, a lateral electric field drive type TFT liquid crystal display device having a cell size of about 13.4 inches, a dot number of 800 × 600, and a cell gap of 6.65 μm was used. Created. When a display voltage was applied to this display device and its display characteristics were observed, a high-quality display excellent in uniformity was obtained over the entire surface, and no unevenness was generated even when an impact was applied. Further, no abnormal alignment region was generated even when a voltage was applied.

Example 4 Using the same spacer for a liquid crystal display device as in Example 1, a TN type liquid crystal display device having a cell size of about 10.4 inches, a number of dots of 640 × 480, and a cell gap of 6.65 μm was prepared. When a display voltage was applied to this display device and its display characteristics were observed, a high-quality display excellent in uniformity was obtained over the entire surface, and no unevenness was generated even when an impact was applied. Also,
No abnormal alignment region was generated even when voltage was applied.

Example 5 In Comparative Example 1, the amount of the dry seed polymer particles obtained in Reference Example was 1.501 parts, 1.551 parts, 1.608 parts, 1.663 parts, 1.
The average particle diameter was 6.835 μm, 6.760 μm, 6.680 μm, and 6.60 μm, respectively, except that 713 parts and 1.765 parts were changed and the monomers used were the same as in Example 1.
Polymer fine particles of 5 μm, 6.540 μm and 6.475 μm were obtained. Further, 30 parts of each of the polymer fine particles was used in Example 1
In the same manner as in the above, esterification was performed with n-myristoyl chloride to obtain polymer fine particles having the respective surfaces esterified.

Next, these particles whose surfaces were esterified were mixed at a weight ratio of 6/5/4/3/2/2 to obtain particles having an average particle size of 6.70 μm and a standard deviation of 0.215 μm. . The particles had a particle size distribution and L2 / L1 shown in Table 3.
, L3 / L1, L4 / L1, M2 / M1 and abs (K12).

Using these particles as a spacer for a liquid crystal display device, the cell size was about 13.4 inches diagonally and the number of dots was 800 × 60.
An STN type liquid crystal display device having a cell gap of 6.70 μm was prepared. When a display voltage was applied to this display device and its display characteristics were observed, a high-quality display excellent in uniformity was obtained over the entire surface, and no unevenness was generated even when an impact was applied. Further, no abnormal alignment region was generated even when a voltage was applied.

[0042]

[Table 3]

Comparative Example 2 In Example 1, the amount of the dried seed polymer particles obtained in Reference Example was 1.446 parts, 1.518 parts, 1.586 parts, 1.652 parts, and 1.
Except for changing to 721 parts and 1.786 parts, respectively, the average particle diameter was 6.920 μm, 6.810 μm,
Polymer fine particles of 6.710 μm, 6.620 μm, 6.530 μm, and 6.450 μm were obtained. Furthermore, each of the polymer fine particles is 30
The parts were esterified with n-myristoyl chloride in the same manner as in Example 1 to obtain polymer fine particles whose surfaces were esterified.

Next, these particles whose surfaces were esterified were mixed at a weight ratio of 1/2/3/3/2/1 to obtain particles having an average particle size of 6.67 μm and a standard deviation of 0.208 μm. Was. The particles had a particle size distribution and L2 / L shown in Table 4.
1, L3 / L1, L4 / L1, M2 / M1, and abs (K12)
Had.

These particles were used as a spacer for a liquid crystal display device, and the cell size was about 13.4 inches diagonally and the number of dots was 800 × 60.
A super twist type liquid crystal display device having a cell gap of 6.64 μm was prepared. When a scanning voltage was applied to this display device and its display characteristics were observed, no unevenness occurred even when an impact was applied, and no abnormal alignment region occurred even when the voltage was applied. Sex was inadequate.

[0046]

[Table 4]

Comparative Example 3 In Comparative Example 1, the amount of the dry seed polymer particles obtained in Reference Example was 1.446 parts, 1.518 parts, 1.586 parts, 1.652 parts, and 1.
In the same manner as in Comparative Example 1 except that the amounts were changed to 721 parts and 1.786 parts, respectively, the average particle diameter was 6.760 μm, 6.680 μm,
Polymer fine particles of 6.600 μm, 6.530 μm, 6.460 μm, and 6.390 μm were obtained. Next, these fine particles were mixed in a weight ratio of 36 /
By mixing at a ratio of 25/16/9/4/1, particles having an average particle size of 6.67 μm and a standard deviation of 0.226 μm were obtained. The particles had the particle size distribution shown in Table 5 and L2 / L1, L3 / L1,
It had L4 / L1, M2 / M1 and abs (K12).

The particles were used as a spacer for a liquid crystal display, and the cell size was about 13.4 inches diagonally and the number of dots was 800 × 60.
A super twist type liquid crystal display device having a cell gap of 6.64 μm was prepared. When a display voltage was applied to this display device and its display characteristics were observed, a high-quality display excellent in uniformity was obtained over the entire surface, and no unevenness was generated even when an impact was applied. However, when a voltage was applied, an abnormal orientation region was generated around the spacer.

[0049]

[Table 5]

Comparative Example 4 An average particle size of 6.57 was obtained in the same manner as in Comparative Example 1 except that the monomers used were changed to those used in Example 1.
A particle having a standard deviation of 0.186 μm was obtained. Further, 30 parts of the polymer fine particles were esterified with n-myristoyl chloride in the same manner as in Example 1 to obtain polymer fine particles having a surface esterified. The particles had the average particle size, particle size distribution and L2 / L1, L3 / L1, L4 / L1, M2 / M1, and abs (K12) shown in Table 6.

Using these particles as a spacer for liquid crystal display, the cell size is about 13.4 inches diagonally and the number of dots is 800 × 600.
A super twist type liquid crystal display device having a cell gap of 6.64 μm was produced. When a scanning voltage was applied to this display device and its display characteristics were observed, a high-quality display with excellent uniformity was obtained over the entire surface, and no abnormal alignment region was generated even when the voltage was applied. When an impact was applied, unevenness occurred.

[0052]

[Table 6]

[0053]

According to the spacer for a liquid crystal display device of the present invention, in a liquid crystal display device using the same, a decrease in display contrast is suppressed by preventing abnormal alignment of liquid crystal, and a uniform display is achieved. Can also prevent the occurrence of unevenness due to the change in cell gap caused by the above.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a particle size distribution analysis graph.

FIG. 2 is a diagram schematically showing a particle size distribution analysis graph having a bimodal distribution.

FIG. 3 is an enlarged view of the particle diameter distribution analysis graph in the original columnar graph near the height 3H.

FIG. 4 is an enlarged view near a height of 75H of a particle size distribution analysis graph in an original columnar graph.

FIG. 5 is a cross-sectional view illustrating an example of a liquid crystal display device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polarizer 2 Glass substrate 3 Transparent electrode 4 Alignment film 5 Liquid crystal material 6 Sealant 7 Spacer

Continued on the front page (72) Inventor Yasuhiro Yoneda 1334 Minato, Wakayama-shi, Wakayama Pref.

Claims (4)

[Claims] In the particle size distribution analysis graph, when the height of the maximum value is 100H and the baseline is 0H, the length L1 (μm ), Also height 75 horizontal to the baseline
Ratio L2 of length L2 (μm) in the range where line H overlaps the graph
/ L1 is not less than 0.45 and not more than 1, and the standard deviation of the particle size distribution is not more than 1.0 μm, and at least the surface has the formula (I) R ¹ O− (R ² O) _x − (I) R ¹ is an alkyl group having 1 to 18 carbon atoms, an alkenyl group, an aryl group, an alkylaryl group, an aralkyl group,
It represents an acyl group, an alkylcarbamoyl group or an arylcarbamoyl group. R ² represents a linear or branched alkylene group having 2 to 4 carbon atoms, and may be substituted with a hydroxy group or a halogen group. x represents a number from 1 to 100, and x
R ² may be the same or different. A spacer for a liquid crystal display device having a nonionic hydrophilic unit represented by the formula: 2. The spacer for a liquid crystal display device according to claim 1, comprising a spacer containing a resin. 3. A plurality of groups each having a particle size distribution with a standard deviation of 1.0 μm or less, and having at least a nonionic hydrophilic unit represented by the above formula (I) on the surface, and having different average particle sizes. 3. The method for producing a spacer for a liquid crystal display device according to claim 1, wherein the fine particles are mixed. 4. A liquid crystal display device using the spacer according to claim 1.