JP3433190B2 - Fine particles, spacer for liquid crystal display element, liquid crystal display device, fine particle manufacturing apparatus and fine particle manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to fine particles, a spacer for a liquid crystal display element, a liquid crystal display device, a fine particle manufacturing apparatus, and a fine particle manufacturing method.

[0002]

2. Description of the Related Art Liquid crystal display devices are widely used in personal computers, portable electronic devices and the like. In such a liquid crystal display element, a spacer is arranged in the liquid crystal display cell in order to keep the gap between the two bonded transparent electrode substrates constant.

[0003]

In such a liquid crystal display device, it is known that the alignment of liquid crystal molecules becomes irregular at the interface between the liquid crystal and the spacer, which deteriorates the display quality. In particular, in a liquid crystal display element using a super twisted nematic liquid crystal (STN liquid crystal) or a thin film transistor (TFT) which has been widely used recently, such an abnormal alignment phenomenon of the liquid crystal is often taken up as a problem.

When such abnormal orientation of the liquid crystal occurs, brightly shining regions called light leakage are observed around the spacers. When the area of such light leakage is large and the number thereof is large, white light leakage is mixed in a wide area of the screen that should originally be a black background, the contrast of the liquid crystal display screen is lowered, and the display quality is significantly deteriorated. Let

Further, in a normally black mode liquid crystal display element, a predetermined spacer, which is a portion to be displayed in black (dark) color when the voltage is OFF, is illuminated by an incident light from the outside, and a liquid crystal display is displayed. This may reduce the contrast of the screen and significantly reduce the display quality.

Further, in recent years, liquid crystal display elements for mobile applications and touch panel applications have been increasing. Vibrations are transmitted to the panel and a large impact force is applied to the liquid crystal display element. At this time, distortion occurs in the glass substrate,
The spacers incorporated to keep the gap of the liquid crystal layer uniform move. Then, the spacers, which are uniformly arranged on the entire liquid crystal display surface, become non-uniform, and the display quality is significantly deteriorated.

An object of the present invention is to obtain novel fine particles which are useful as a spacer by suppressing the abnormal orientation of the liquid crystal display device.

[0008]

The present invention relates to fine particles formed of core fine particles, wherein the core fine particles are formed of a polymer, and the core fine particles are subjected to a low temperature plasma treatment in an organic gas atmosphere. According to the present invention, the present invention relates to a fine particle having a plasma synthesis layer formed on the surface of the core fine particle, a spacer for a liquid crystal display element using the fine particle, a liquid crystal display device using the spacer, and a method for producing the fine particle.

Further, the present invention is a fine particle production apparatus for forming fine particles from core fine particles, wherein the fine particle production apparatus comprises a reaction vessel, a rotating machine for rotating the reaction vessel, a decompressor and a high frequency generator. The core fine particles are charged into the reaction vessel, the core fine particles are formed of a polymer, the pressure inside the reaction vessel is reduced by the decompressor, and an organic gas is fed into the reaction vessel. Introduced, plasma is generated in the reaction vessel by the high frequency from the high frequency generator, by the rolling of the reaction vessel of the core fine particles and the low temperature plasma treatment of the core fine particles in the organic gas atmosphere, The present invention relates to a fine particle manufacturing apparatus in which a plasma synthesis layer is formed on the surface of the core fine particles.

The present inventor made various kinds of fine particles as trials and studied in order to obtain fine particles useful as a spacer for a liquid crystal display device.

As a result, the inventor of the present invention can obtain fine particles in which a plasma synthesis layer is formed on the surface of such core fine particles by subjecting the core fine particles formed of the polymer to low temperature plasma treatment in an organic gas atmosphere. Found.

Further, the present inventor found out that such fine particles are extremely useful as a spacer for a liquid crystal display element by suppressing abnormal orientation of the liquid crystal display element, and arrived at the present invention.

In the present invention, the plasma synthesis layer is formed on the surface of the core fine particles by the low temperature plasma treatment of the predetermined core fine particles in the organic gas atmosphere.

In the plasma synthesis layer, organic gas molecules are excited by a low temperature plasma treatment or ionized to become a chemically active species, and the chemically active species cause a chemical reaction which is difficult by ordinary thermal excitation. It is formed with various compositions derived from organic gas.

According to the fine particles of the present invention, since the plasma synthesis layer is formed on the surface of the predetermined core fine particles by a chemical reaction which is difficult by ordinary thermal excitation, the adhesion between the core fine particles and the plasma synthesis layer is improved. And excellent coverage of the plasma synthesis layer.

Further, according to the fine particles of the present invention, the plasma synthesis layer is formed so that the active groups such as hydroxyl groups on the surface of the predetermined core fine particles are sufficiently covered. Suppress abnormal orientation of the element,
Excellent adhesion to polyimide film.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described.
The plasma used in the present invention is a gas in which atoms and molecules are ionized into electrons and ions, and low temperature plasma is a gas discharge phenomenon under low pressure.

In the low temperature plasma, the gas molecules inside are repeatedly ionized, dissociated, or excited and deactivated, and contain the same number of free electrons as the ions, and are electrically neutral as a whole.

The collision of these chemical species causes various chemical changes on the surface of the core fine particles. By utilizing this, the surface of the core fine particles can be plasma-treated. Although called low temperature, the temperature of free electrons defined by kinetic energy is typically about 20,000 to 30,000K.

On the other hand, since the temperature of the chemical species such as ions and radicals is on the order of several hundreds of degrees Celsius, and under a low pressure, the temperature of the processed material is practically room temperature, which is a preferable processing condition. Can be done.

In the present invention, the fine particles which are the basis for the plasma treatment are called core fine particles. Such core fine particles can be used regardless of whether they are organic polymer fine particles or inorganic polymer fine particles.

Core fine particles of an organic polymer include acrylic acid ester type polymers, styrene type polymers, nylon type polymers, urethane type polymers, polyethylene type polymers, polyester type polymers and polyvinyl acetate ethylene type polymers. It can be formed from at least one polymer selected from the group consisting of

The core fine particles formed from these polymers have a three-dimensional network structure, are not thermoplastic, and are insoluble in organic solvents. The fine particles formed from such core fine particles are printed by polyimide baking (25
At 0 ° C.), the gap controllability is unlikely to be impaired.

In the present invention, core-shell type hybrid fine particles using at least one material of organic polymers and inorganic polymers can also be used as core fine particles. In such a case, at least one of an organic polymer and an inorganic polymer can be used for the core-shell type core portion or shell portion.

The organic gas used in the present invention is not particularly limited as long as it is a substance that reacts with plasma.

Examples of the organic gas include aliphatic hydrocarbons such as hexane and aromatic hydrocarbons such as hexane.
Toluene, naphthalene, etc., vinyl group-containing monomers, methyl methacrylate, styrene, divinylbenzene, etc., long-chain aliphatic alcohols, dodecanol (lauryl alcohol), etc., long-chain aliphatic phenols, nonylphenol, etc. As the amine, aniline or the like can be used, and as the unsaturated aliphatic hydrocarbon, at least one organic gas selected from the group consisting of 1-octene and the like can be used.

The organic gas according to the present invention is sent into the reaction vessel in the form of gas, and is subjected to plasma treatment while being in contact with the core fine particles. Gasification of organic matter is performed by heating, etc.
It can also be performed under reduced pressure.

In the present invention, various low temperature plasma conditions such as temperature and pressure can be adopted without particular limitation.

In the present invention, an apparatus for producing fine particles can be used to form fine particles from core fine particles. This fine particle manufacturing apparatus includes a reaction container, a rotating machine for rotating the reaction container, a decompressor, and a high-frequency generator.

In such an apparatus for producing fine particles, core fine particles are put into a reaction vessel, and the inside of the reaction vessel is decompressed by a decompressor. Further, in such an apparatus, an organic gas is introduced into the reaction container, and plasma is generated in the reaction container by the high frequency wave from the high frequency generator. Furthermore, in such an apparatus, the core fine particles are tumbled by the rotation of the reaction vessel and the low temperature plasma treatment of the core fine particles in an organic gas atmosphere forms a plasma synthesis layer on the surface of the core fine particles to produce fine particles.

Such an apparatus can be manufactured by modifying a rotary evaporator. Further, such an apparatus can be produced by using a glass ball mill as a reaction container and providing an appropriate pressure reducer and high frequency generator.

In such an apparatus, the core fine particles can be tumbled during the low temperature plasma treatment of the core fine particles according to the present invention in the organic gas atmosphere, and the surfaces of the core fine particles to be treated are constantly replaced. The surface of the core is uniformly subjected to low-temperature plasma treatment, coalescence of the core particles is prevented, and a uniform plasma synthesis layer is formed on the surface of the core particles.

Further, in such a device, 13.56 MHz
Plasma can be generated at a high frequency such as, and the core fine particles can be uniformly irradiated with plasma. In addition,
The leak rate of such a device is 5 × 10 ml / min ⁻³ (ST
P: standard state) can be the following.

In the present invention, in the actual production of fine particles by plasma treatment, in order to make the plasma irradiation of the core fine particles more efficient, the rolling and stirring efficiency of the core fine particles is increased, and a ball mill type plasma irradiation apparatus is used. Good to do by.

An example of the low temperature plasma treatment according to the present invention will be given below. In advance, dry nitrogen is caused to flow under reduced pressure in the reaction vessel of the glass ball mill system of the graft polymerization apparatus to keep the core fine particles in a dry state.

The core fine particles are kept in a stirred state in a reaction vessel (reaction chamber, ball mill). Then, the organic gas is turned into steam under heating or reduced pressure and introduced into the reaction chamber. At this time, the piping as the introduction path is set slightly higher than the heating temperature of the organic gas to prevent the organic gas from condensing.
The organic gas is plasma-treated on the surface of the core fine particles to form a plasma synthesis layer, and a coating film made of the plasma synthesis layer is formed on the surface of the core fine particles.

An organic gas is introduced, a voltage is immediately applied to the plasma generator, and plasma is emitted in the reaction vessel.
The core fine particles and the organic gas receive the energy of the plasma to start the synthesis of the coating film. Plasma synthesis is performed by causing plasma emission while rolling and stirring the fine particles for a certain period of time so that all core fine particles are uniformly surface-coated.

In order to suppress the abnormal orientation in the liquid crystal display device, the hydroxyl group or the like existing on the surface of the conventional spacer is chemically modified with a reactive monomer, or the hydroxyl group is utilized to acetalize, urethanize and ester. It is conceivable that the liquid crystal regulating force on the spacer surface is weakened and the abnormal alignment of the liquid crystal is prevented by modifying it by a chemical reaction selected from the chemical formulas or by coating it with a polymer of various monomers.

However, according to the study by the present inventor,
It has been found that with such a technique, it is difficult to specify the proportion of hydroxyl groups and the like existing on the surface of the spacer, and as a result, the regulation force of the liquid crystal becomes unstable.

That is, in such a technique, the hydroxyl group is derived from polyvinyl alcohol used as a dispersion medium in the case of a synthetic resin spacer, or is derived from a silanol bond in the case of a silica spacer. Is also formed secondarily, and the number of hydroxyl groups cannot be controlled.

In the fine particles and spacers of the present invention, a plasma synthesis layer of vinyl monomer or the like, which cannot be obtained by a conventional chemical modification method, is formed as a coating layer on the surface of the core fine particles to suppress the liquid crystal regulating force of hydroxyl groups and the like. can do.

The plasma treatment method has long been known as a surface treatment method for fibers or powders of a specific type (for example, acrylamide treatment for increasing hydrophilicity of carbon black) (for example, Coloring Materials Association Magazine 1990). Year, 63 volumes, 3
No., pp. 163-170, Kinki University, Seijiro Ito).

However, the plasma treatment used in the present invention is
This is a low-temperature plasma treatment method in which the core fine particles and the organic gas are mixed under reduced pressure, plasma is generated in the reaction vessel, and a plasma synthesis layer of the organic gas is formed on the surface of the core fine particles.

With the fine particles of the present invention, the plasma synthesis layer formed on the surface of the core fine particles functions as a functional surface coating layer (shell).

Such a functional surface coating layer is capable of imparting to the fine particles a variety of highly functional properties which cannot be obtained by the conventional method for forming a polymerized coating film, and a liquid crystal cell in-plane spacer for a liquid crystal display device is provided. It is especially important as the required characteristics.

The functional surface coating layer is a spacer surface that does not disturb the alignment of the liquid crystal before and after applying a voltage to the liquid crystal display cell (a liquid crystal cell spacer of an abnormal alignment preventing function), and a liquid crystal is rubbed on the polyimide film rubbed surface. Surface to which cell spacers can be fixed (fixing function type liquid crystal cell spacers),
When the liquid crystal display element is in normally black mode, the cell spacer surface is darkened to prevent light from shining through the cell spacer. A light-shielding surface (liquid crystal cell spacer of light-shielding function), dry spraying, wet spraying, etc. With any spraying method, the spacers can be sprayed as primary fine particles to provide a trouble-free surface.

In the present invention, in order to impart one or more of these functions, the plasma treatment conditions,
In particular, the organic gas or the like used can be selected.

The fine particles of the present invention can be used as a spacer for a liquid crystal display element arranged in a pair of liquid crystal display cells, and a spacer for maintaining a predetermined space between the pair of substrates. It can be used as a spacer in a liquid crystal display device having a liquid crystal interposed between the respective substrates.

When the fine particles of the present invention are used as a spacer for a liquid crystal display element, that is, a liquid crystal cell spacer, the fine particles preferably have a spherical shape.
An average particle size of 15 μm is good. The reason is that in order to obtain a thin liquid crystal layer, it is preferable to use a spacer for a liquid crystal display element having an average particle diameter as small as possible. However, when fine particles having an average particle diameter in this range are used, the chiral pitch (spiral step shape) of the liquid crystal is used. This is because a clear image can be obtained based on the pitch of 360 ° rotation). Moreover, more preferably, the average particle diameter of the fine particles is 3 to 10 μm.

The present invention will be described in more detail with reference to the drawings. The fine particles of the present invention can be produced using a fine particle producing apparatus as shown in FIG. FIG. 1 is a schematic view of an apparatus for producing fine particles as an example of the present invention.

The fine particles of one example of the present invention are fine particles formed from core fine particles 1 as shown in FIG. In the present invention, the core fine particles 1 are formed of a polymer. The fine particles of an example of the present invention have core fine particles 1 and a plasma synthesis layer on the surface of the core fine particles 1, and a plasma is formed on the surface of the core fine particles 1 by the low temperature plasma treatment of the core fine particles 1 in an organic gas atmosphere. A composite layer is formed.

The fine particle production apparatus 2 as shown in FIG. 1 is an example of an apparatus for forming fine particles from the core fine particles 1, and includes a reaction vessel 3, a rotating machine 4 for rotating the reaction vessel 3, a decompressor 5, a high frequency wave. And a generator 6. For the rotating machine 4, a suitable rotating means such as a bearing can be used.

In the fine particle production apparatus 2, the core fine particles 1 are put into the reaction container 3. The core fine particles 1 are formed of a polymer.

The pressure inside the reaction vessel 3 is reduced by the pressure reducer 4, and the organic gas 7 is introduced into the reaction vessel 3. Plasma is also generated in the reaction vessel 3 by the high frequency from the high frequency generator 6.

A plasma synthesis layer is formed on the surface of the core fine particles 1 by rolling of the core fine particles 1 by rotation of the reaction vessel 3 and low-temperature plasma treatment of the core fine particles 1 in the atmosphere of the organic gas 7.

The fine particle production apparatus 2 includes electrodes 8, 9, 10 for irradiating the reaction container 3 with a high frequency wave from the high frequency generator 6, and a pressure gauge 1 for measuring the pressure in the reaction container 3.
1. Argon, steam and oxygen gas inlets 12, 13 and 14 respectively supplied to the reaction vessel 3 when necessary
Is provided.

[0057]

[Preparation of core fine particles]

(Core fine particles 1) 5% aqueous solution of polyvinyl alcohol [GH-17 manufactured by Nippon Synthetic Chemical Industry Co., Ltd., saponification degree 87%] 8
1 g of monomethoxyhydroquinone and benzoyl peroxide (manufactured by NOF Corporation, recrystallized with acetone) in 500 g
0 g and pentaerythritol tetraacrylate 15
After being mixed with 00 g at 40 to 43 ° C. in the air with sufficient stirring, the mixture was added and dispersed into fine particles by stirring.

Thereafter, these were polymerized under nitrogen at 80 ° C. for 5 hours. After sufficiently washing the obtained polymer fine particles with water,
A classification operation was performed. Particles having an average particle diameter of 6.0 μm and a standard deviation of 0.3 μm were collected and dried to obtain core fine particles 1.

(Core Fine Particles 2) Trimethylolpropane trimethacrylate was used in place of the pentaerythritol tetraacrylate used in the preparation of the core fine particles 1 and the average particle diameter was 15 μm and the standard deviation was 0.65 μm by the same operation. Core fine particles 2 were obtained.

(Core fine particles 3) To 650 g of pure water whose temperature had been adjusted to 1 ° C. in advance, 75 g of tetramethoxysilane at 5 ° C. was gently added to obtain a state in which tetramethoxysilane and pure water were separated into upper and lower two layers. Then, the mixture was stirred while cooling until the temperature of the upper layer tetramethoxysilane reached 1 ° C.

0.35 g of butyl alcohol in 14 g of pure water
And 0.3 g of ammonia water having a concentration of 28% were added, and 0.75 g of an anionic surfactant (sodium octylnaphthalene sulfonate) was added thereto to prepare a surfactant mixed solution whose temperature was adjusted to 5 ° C.

This surfactant mixed solution was gradually added to this lower layer over 1 hour while stirring the lower layer separated into the upper and lower two layers of the tetramethoxysilane solution.

Subsequently, stirring was continued for 2 hours to prepare a dispersion liquid of polyorganosiloxane particles. The particles obtained are then filtered off, washed with alcohol and dried at 100 ° C. for 2 hours.
After drying for an hour, core fine particles 3 having an average particle diameter of 5.6 μm and a particle diameter variation coefficient of 1.2% were obtained.

[Production of Fine Particles] (Example 1) (Liquid Crystal Cell Spacer with Abnormal Alignment Prevention Function, Part 1) The fine particle manufacturing apparatus shown in FIG. 1 was used. A glass ball mill was used as the reaction vessel. Also, a high frequency generator (Samco Co., Ltd., graft polymerization device Model)
Plasma is generated by the high frequency (13.56 MHz) of PT-501). The leak amount of the device is 5 × 10
^-3 mL / min (STP: standard state).

In a 1 L glass flask, 50 g of the core fine particles 1 and 350 g of a glass ball mixture of 2 mm and 15 mm (mixing weight ratio 1: 1) were placed, and the degree of vacuum in the reaction tank was 0.03 torr ( 4 Pa, below 1 torr ≈ 13
The pressure was reduced to 3 Pa) and the flask was kept at a rotation speed of 50 RPM for 12 hours.

In an organic gas supply tank, 5 g of hexane was put in advance at room temperature, the valve was opened, and the vacuum degree in the reaction tank was adjusted to be constant at 0.2 Torr (27 Pa). Then, a voltage was applied, the power value was set to 50 W, and plasma treatment was performed for 60 minutes. The emission color in the plasma state was white.

After the treatment, the white core fine particles 1 had turned pale yellow. When the particle size was measured with a Coulter counter, the average particle size was 6.1 μm and the standard deviation was 0.32.
It was found that the plasma synthesis layer having a thickness of 0.1 μm was coated with hexane.

(Example 2) (Liquid Crystal Cell Spacer of Abnormal Alignment Prevention + Fixing Function, Part 1) As in Example 1, 50 g, 2 mm and 15 mm of core fine particles 1 were placed in a 1 L glass flask. 350 g of a glass ball mixture (mixing weight ratio 1: 1) was added, and the degree of vacuum in the reaction tank was reduced to 0.03 torr (4 Pa).
The flask was kept at 0 RPM for 12 hours.

Styrene was previously added to the organic gas supply tank in advance.
0 g was charged, the liquid temperature was heated to 50 ° C., the valve was opened, the degree of vacuum in the reaction vessel was adjusted to be constant at 0.2 Torr (27 Pa), a voltage was applied to the plasma generator, and the power value was changed. Plasma treatment was performed at 50 W for 60 minutes. The emission color in the plasma state was pink.

After the treatment, the white core fine particles 1 had turned pale yellow. As a result of the particle size measurement, the coated fine particles were
The average particle size is 6.1 μm and the standard deviation is 0.31 μm,
It was found that the plasma synthesis layer of styrene was 0.1 μm thick.

(Example 3) (Liquid Crystal Cell Spacer of Abnormal Alignment Prevention Function, Part 2) Similar to Example 1, 50 g of core fine particles 2, 2 mm and 15 mm glass balls were placed in a 1 L glass flask. 350 g of a mixture (mixing weight ratio 1: 1) was added, and the degree of vacuum in the reaction vessel was reduced to 0.03 Torr (4 Pa).
The flask was kept at 0 RPM for 12 hours.

Divinylbenzene (manufactured by Nissei Chemical Industry Co., Ltd., purity 97%, m + p type) was previously stored in an organic gas supply tank.
5g, the liquid temperature was heated to 50 ° C., the valve was opened, the degree of vacuum in the reaction tank was adjusted to be constant at 0.2 Torr (27 Pa), a voltage was applied to the plasma generator, and the power value was changed. At 50 W for 60 minutes for plasma treatment. The emission color in the plasma state was pink.

After the treatment, the white core fine particles 2 had turned pale yellow. As a result of the particle size measurement, the coated fine particles were
The average particle size is 15.2 μm, the standard deviation is 0.65 μm, and the plasma synthesis layer of divinylbenzene is 0.2
It was found to be μm thick.

(Embodiment 4) (Liquid Crystal Cell Spacer of Abnormal Alignment Prevention Function, Part 3) In the same manner as in Embodiment 1, 50 g of core fine particles 3 and glass balls of 2 mm and 15 mm were placed in a 1 L glass flask. 350 g of a mixture (mixing weight ratio 1: 1) was added, and the degree of vacuum in the reaction vessel was reduced to 0.03 Torr (4 Pa).
The flask was kept at 0 RPM for 12 hours.

10 g of 1-octene was placed in an organic gas supply tank in advance, the liquid temperature was heated to 80 ° C., the valve was opened,
The degree of vacuum in the reaction tank was adjusted to be constant at 0.2 Torr (27 Pa), a voltage was applied to the plasma generator, the power value was set to 50 W, and plasma treatment was performed for 60 minutes. The emission color in the plasma state was white.

After the treatment, the white core fine particles 3 had turned pale yellow. As a result of the particle size measurement, the coated fine particles are
The average particle size is 5.7 μm, the standard deviation is 0.075 μm, and the plasma synthesis layer of 1-octene is 0.1 μm.
Was found to be thick.

(Embodiment 5) (Liquid Crystal Cell Spacer for Preventing Abnormal Alignment + Fixing Function, Part 2) In the same manner as in Embodiment 1, 50 g of the core fine particles 2 was placed in a 1 L glass flask and the reaction vessel The degree of vacuum inside is 0.0
The pressure was reduced to 3 Torr (4 Pa) and kept for 12 hours.

10 g of methyl methacrylate was placed in an organic gas supply tank in advance, the liquid temperature was heated to 80 ° C., the valve was opened, and the degree of vacuum in the reaction tank was 0.2 Torr (27 P).
It was adjusted to be constant in a), a voltage was applied to the plasma generator, the power value was set to 50 W, and plasma treatment was performed for 60 minutes. The emission color in the plasma state was white.

After the treatment with methylmethacrylate, the white fine particles had turned pale yellow. As a result of particle size measurement,
It was found that the coated fine particles had an average particle diameter of 15.2 μm and a standard deviation of 0.31 μm, and the plasma synthesis layer of methyl methacrylate had a thickness of 0.2 μm.

(Example 6) (Light-shielding property + liquid crystal cell spacer of abnormal alignment preventing type) As in Example 1, 50 g of the core fine particles 1 was placed in a 1 L glass flask and placed in a reaction vessel. Vacuum degree 0.0
The pressure was reduced to 3 Torr (4 Pa) and kept for 12 hours.

An aniline was previously added to the organic gas supply tank in an amount of 1
0 g was added, the liquid temperature was heated to 80 ° C., the valve was opened, the degree of vacuum in the reaction tank was adjusted to be constant at 0.2 Torr (27 Pa), and further oxygen was supplied from another pipe into the reaction layer. Open the valve so that the degree of vacuum is 0.5 Torr (67 Pa), apply a voltage to the plasma generator, and set the power value to 50 W.
And plasma treatment was performed for 60 minutes. The emission color in the plasma state was white.

After the treatment, the white fine particles had turned dark blue. As a result of particle size measurement, it was found that the coated fine particles had an average particle size of 6.1 μm and a standard deviation of 0.31 μm, and the plasma synthesis layer of aniline had a thickness of 0.1 μm.

(Example 7) (Liquid Crystal Cell Spacer of Abnormal Alignment Prevention Function, Part 4) As in Example 1, 50 g of the core fine particles 3 was placed in a 1 L glass flask and placed in a reaction tank. The vacuum degree of 0.
The pressure was reduced to 03 Torr (4 Pa) and kept for 12 hours.

Toluene was previously added to the organic gas supply tank in advance.
0 g was charged, the liquid temperature was heated to 80 ° C., the valve was opened, the degree of vacuum in the reaction vessel was adjusted to be constant at 0.2 Torr (27 Pa), a voltage was applied to the plasma generator, and the power value was changed. Plasma treatment was performed at 50 W for 60 minutes. The emission color in the plasma state was white.

After the treatment, the white fine particles had turned pale yellow. As a result of measuring the particle size, it was found that the coated fine particles had an average particle size of 6.6 μm and a standard deviation of 0.06 μm, and the plasma synthesis layer of 1-octene had a thickness of 0.1 μm.

Comparative Examples 1 to 3 The core fine particles 1 to 3 were used as they were.

[Test Example] Examples 1 to 7 and Comparative Examples 1 to 3
The fine particles obtained in 1. were evaluated for the occurrence of abnormal alignment in a liquid crystal display element and the adhesion to a polyimide film. Each evaluation method is shown below, and the results are shown in Table 1.

(Evaluation of Abnormal Orientation in Liquid Crystal Display Element) Using fine particles, an STN type liquid crystal display element having a substrate size of 50 mm × 50 mm and a cell gap of 6.0 μm was prepared, and cell evaluation was performed as follows. .

First, a voltage of AC2V was applied to the liquid crystal display element to evaluate the cell display characteristics in the initial state (abnormal orientation 1). Then, a voltage of 20V was applied to the liquid crystal display element, and then a further 2V was applied. The voltage was applied, and the cell display characteristics in the voltage applied state were evaluated (abnormal orientation 2).

(Evaluation of adhesiveness) 30 mm square, 0.9 mm
Thick ITO (indium tin oxide) film-forming glass substrate solution for polyimide film formation (NISSAN SE-351
0) is evenly coated with a spin coater, dried and then 250
Baking was carried out at ℃ for 1 hour. A 0.1 wt% isopropyl alcohol dispersion liquid of the test fine particles was dropped on the polyimide surface with a dropper, naturally dried and then baked at 160 ° C. for 1 hour to prepare a sample.

The sticking property was evaluated as a sticking rate, and the sample was blown with air [air blowing conditions: dry air 4 kgf / c.
m ² (392 kPa, 1 kgf / cm ² ≈98 kPa) pressure, spraying time 60 seconds, nozzle-substrate distance 1
cm, spray angle 45 °], and the residual rate of the number of particles before and after spraying was examined and expressed.

[0092]

[Table 1]

The blackness of the fine particles of Example 6 and Comparative Example 1 in the liquid crystal display cell shown in FIG. 2 was evaluated. The evaluation methods are shown below, and the results are shown in Table 2.

(Evaluation of Blackness) 1% by weight of fine particles was dispersed in ethylene glycol with an ultrasonic cleaner, and the dispersion liquid was filled in the glass cell shown in FIG.
-500 (manufactured by Dainippon Ink Mfg. Co., Ltd.) was measured with each filter.

FIG. 2 is a sectional view of an example of a liquid crystal display cell according to the present invention. In the liquid crystal display cell 21 of FIG. 2, a dispersion liquid 24 in which fine particles 23 are dispersed is filled between two glass substrates 22a and 22b. The thickness of the glass substrate is 0.8
mm, the distance between the glass substrates is 2 mm.

[0096]

[Table 2]

[0097]

EFFECTS OF THE INVENTION According to the fine particles of the present invention, a plasma synthesis layer is formed on the surface of a predetermined core fine particle by a chemical reaction that is difficult with ordinary thermal excitation. And the coverage of the plasma synthesis layer.

Further, according to the fine particles of the present invention, the plasma synthesis layer is formed to such an extent that the active groups such as hydroxyl groups on the surface of the predetermined core fine particles are sufficiently covered. Suppress abnormal orientation of the element,
Excellent adhesion to polyimide film.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an apparatus for producing fine particles according to an example of the present invention.

FIG. 2 is a sectional view of an example of a liquid crystal display cell according to the present invention.

[Explanation of symbols]

1-core fine particles 2 Fine particle manufacturing equipment 3 reaction vessels 4 rotating machines 5 pressure reducer 6 high frequency generator 7 organic gas 8, 9, 10 electrodes 11 pressure gauge 12, 13, 14 Gas inlet 21 Liquid crystal display cell 22a, 22b glass substrates 23 Fine particles 24 dispersion

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C08J 7/00

Claims (8)

(57) [Claims] 1. Fine particles formed of core fine particles, wherein the core fine particles are formed of a polymer, and the core fine particles are formed on a surface of the core fine particles by low-temperature plasma treatment in an organic gas atmosphere. A fine particle characterized in that a plasma synthesis layer is formed. 2. The core fine particles are acrylic acid ester-based polymers, styrene-based polymers, nylon-based polymers, urethane-based polymers, polyethylene-based polymers, polydimethylsiloxane-based polymers, polyester-based polymers and poly-based polymers. The fine particles according to claim 1, wherein the fine particles are formed of at least one polymer selected from the group consisting of vinyl acetate ethylene-based polymers. 3. The organic gas is hexane, toluene,
The fine particles according to claim 1 or 2, characterized by comprising at least one organic substance selected from the group consisting of naphthalene, methyl methacrylate, styrene, divinylbenzene, dodecanol, nonylphenol, aniline and phenylenediamine. 4. A spacer for a liquid crystal display element, which is arranged in a liquid crystal display cell, wherein the spacer for a liquid crystal display element comprises the fine particles according to any one of claims 1 to 3. A spacer for a liquid crystal display element. 5. The spacer for a liquid crystal display device according to claim 4, wherein the fine particles have an average particle diameter of 1 to 15 μm. 6. A liquid crystal display device, comprising: a pair of substrates; spacers for maintaining a predetermined space between the substrates; and liquid crystals interposed between the substrates, wherein the spacers are provided. Or a spacer for a liquid crystal display element as described in 5 above. 7. A fine particle production apparatus for forming fine particles from core fine particles, the fine particle production apparatus comprising a reaction vessel, a rotating machine for rotating the reaction vessel, a decompressor and a high frequency generator. Cage,
The core fine particles are charged into the reaction vessel, the core fine particles are formed of a polymer, the pressure inside the reaction vessel is reduced by the pressure reducer, an organic gas is introduced into the reaction vessel, the high frequency Plasma is generated in the reaction vessel by the high frequency from the generator, by the rolling of the core fine particles by the rotation of the reaction vessel and the low temperature plasma treatment of the core fine particles in the organic gas atmosphere,
A fine particle manufacturing apparatus, wherein a plasma synthesis layer is formed on the surface of the core fine particles. 8. When forming fine particles from the core fine particles, the core fine particles are formed of a polymer, and the core fine particles are subjected to low-temperature plasma treatment in an organic gas atmosphere to perform plasma synthesis on the surfaces of the core fine particles. A method for producing fine particles, which comprises forming a layer.