JP2690885B2 - Ferroelectric liquid crystal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] TECHNICAL FIELD The present invention relates to two opposing substrates.
Ferroelectric liquid crystal is enclosed between the plates and
In the area where the dielectric liquid crystal is present, the two substrates are epoxy.
Induction that is fixed via xy-based bead-shaped powder adhesive
The present invention relates to an electric liquid crystal element. Ferroelectric liquid crystal has a fast response speed
And has bistability (memory property) due to interface effects, etc.
Large display device with excellent properties and large display capacity
Is expected to be applied. However, realization of a large display element
In order to achieve uniform control of the substrate spacing of about 2 μm,
Direction uniformity, improved contrast ratio, short writing time
Some problems such as reduction must be solved. Especially,
In ferroelectric liquid crystals, the uniformity of molecular orientation is
Compared with TN liquid crystal, it is less affected by alignment film and alignment treatment.
Scoop, display contrast ratio, response speed, bistable
Performance (memory performance), which has a large effect on many characteristics.
It is an essential element. In this sense, the present invention is particularly concerned with μm
For ferroelectric liquid crystal devices with uniform substrate spacing
And eliminates micro-orientation defects (zig-zag dislocation)
And a technique for improving bistability (memory property). [Outline of the Invention] [0003]
In a dielectric liquid crystal device, a small alignment defect in the ferroelectric liquid crystal
Set the number density of zig-zag dislocations to an appropriate range
Set and obtain the maximum contrast ratio of lighting and non-lighting
Maximum drive frequency f_maxThe fluctuation range of and
Applied voltage ± V_hThe contrast ratio starts changing
Dynamic frequency f_minAppropriate frequency range overlapping with the fluctuation range of
By setting to, epoxy-based beaded powder adhesive
Alignment Defects in Ferroelectric Liquid Crystals in the Vicinity of Temperature
Ferroelectric liquid crystal element with excellent bistability and
I got Further, such a ferroelectric liquid crystal device is manufactured.
As a method to do this, the liquid crystal is smeared from the smectic A phase.
Simultaneously with slow cooling when cooling to Rusmectic C phase
The liquid crystal should be aligned by applying an appropriate voltage to
And found. [0005] 2. Description of the Related Art Ferroelectric liquid crystal elements are transparent electrode films for driving.
And alignment film for aligning liquid crystal molecules are formed on the surface of glass plate
The two substrates are placed facing each other at regular intervals, and the gap
It is configured by enclosing a liquid crystal in. By the way, in recent years, chiral smectic C
Ferroelectric liquid crystal element using ferroelectric liquid crystal exhibiting phase
It was developed (see, for example, Japanese Patent Laid-Open No. 56-107216). You
That is, p-decyloxybenzylidene-p'-amino-
2-methylbutyl cinnamate, p-hexyloxyben
Dilidene-p'-amino-2-chloropropylcinname
Liquid crystal substance having chiral smectic C phase
, The liquid crystal molecule arrangement has a spiral layer structure. This spiral
Two substrates facing each other with a gap narrower than the cycle
When a ferroelectric liquid crystal is injected in between, the liquid crystal molecules have a helical structure.
It disappears and the bistable state (me
Molybdenum). That is, the ferroelectricity of liquid crystal molecules
The bistable state is applied to each other at high speed by applying a voltage
It is switched and driven, but even if the voltage is removed
Note that the liquid crystal molecules hold either stable position.
It has a property. Another known example is Japanese Patent Laid-Open No. 57-2.
Using an adhesive that is encapsulated as in the 9031 publication
There is a technology to bond and fix lath plates. However, this
Adhesives have low adhesive strength and adversely affect the liquid crystal, which is preferable.
It wasn't good. [0008] By the way, chirals
Realization of bistable state of liquid crystal material with mectic C phase
In order to keep the two substrates constant at intervals of several μm or less.
It is indispensable to have it, but there is no distortion or
To reduce the gap length between the substrates due to
Was difficult. For example, on the surface of the first substrate
Disperse spacer particles with the same diameter as the gap length
Stack the second substrate with irregularities for
In the case of adhesion, after applying pressure heating heat adhesion of the second substrate
Spacer particles are destroyed in the convex part, and in the concave part
As a result of spacer particles being released from the first substrate,
It is difficult to achieve uniform substrate spacing. In view of such circumstances, the present invention uses two substrates.
Can be arranged in parallel with a gap as narrow as possible
It is intended to provide a cell structure. [0011] The present inventor has used two substrates.
Can be placed very precisely in parallel with a gap as narrow as possible
The following structure of ferroelectric liquid crystal device is proposed.
You. One of them is related to the improvement of ferroelectric liquid crystal devices.
Therefore, a pair of sealing materials are used to sandwich the ferroelectric liquid crystal.
Keeps the distance between the two substrates arranged facing each other
Spacer particles dispersed in the substrate gap for
It exists at the interface between the ferroelectric liquid crystal and the substrate and aligns the liquid crystal molecules.
Substrate gap in a ferroelectric liquid crystal device consisting of an alignment film
Epoxy blended with latent curing agent dispersed in
Bonding two substrates with a bead-shaped powder adhesive
It is. Hereinafter, the ferroelectric liquid crystal device proposed in the present application will be described.
explain about. Figure 7 shows a partial breakdown of the basic structure of the proposed example.
It is a sectional perspective view. In the figure, 1 and 3 are transparent electrodes
Glass (not shown) and alignment film 7 formed on the surface
With the substrate, these two substrates 1 and 3 are evenly distributed
Heat-resistant spherical or polygonal fine particles (hereinafter
The gap length of the substrate is defined by 2)
And a sealing material disposed on the periphery of the substrate 1.
4 and epoxy compound containing a latent curing agent mixed and dispersed
Heat-bonded by a powdered powder adhesive 8 to the opposite side
It is constructed into a ferroelectric liquid crystal device in the attracted state.
You. The epoxy-based bead-shaped powder adhesive 8 is pressed.
It becomes a blurred shape, and there is distortion and warpage
Cushion to prevent the spacer particles from being destroyed
Function as well as the opposing substrate
Since it works to pull it toward the board, the board space is
It is just uniform. Phenolic curing as a latent curing agent
Agents, especially diglycidyl ethers of bisphenols
Is a polycondensation product and polyphenol compound, especially bisphenol.
When using an adduct with an enol, use an epoxy resin
It is well compatible and develops high adhesive strength. In addition, the alignment film becomes dirty.
It is effective in preventing dyeing and destruction. A chiral smect is added to such a cell structure.
Injecting a ferroelectric liquid crystal having a strong C phase causes a spacer
Forcibly in the gap between the particle 2 and the epoxy-based beaded powder adhesive 8.
The electric liquid crystal flows in to fill the space and apply an external force to the cell.
Spacer particles 2 and epoxy-based beaded powder
The adhesive 8 keeps a certain distance, and
As a harmful substance, the flow of the ferroelectric liquid crystal is blocked. Also
And, spacer particles 2 and epoxy-based beaded powder
Adhesive 8 is a material that does not affect the behavior of ferroelectric liquid crystal
It is selected from among the
It is small and does not affect the display screen.
Absent. Next, a method of manufacturing the above-mentioned ferroelectric liquid crystal device
Will be described with reference to FIG. Transparent electrode 9 and alignment film 7
The glass substrate 1 on which the film is formed is oriented horizontally with the side of the alignment film facing the surface.
The heat-sealable sealing material 4 around the cell thickness.
Apply to a uniform thickness. This sealing material 4
Equivalent to the target cell thickness on the substrate surface in the enclosed area
Spacer particles 2 with diameter and larger than target cell thickness
A latent type hardener containing a diameter that is close to the seal thickness.
Disperse the poxy-based bead-shaped powder adhesive 8 '(Fig.
(A)). Next, with the orientation film surface 7 side facing down, the other substrate 3
Overlaid with the sealing material 4 of the lower substrate 1 and epoxy type beads
Two substrates 1 and 3 for a certain period of time with a powder adhesive 8 '
They are arranged in parallel with a space (Fig. (B)). In such a state, the upper and lower two substrates
Apply pressure P to 1 and 3 to seal material 4 and latent hard
Agent-containing epoxy-based bead-shaped powder adhesive 8'softens
When heated to temperature, sealant 4 and epoxy beads
The powdery adhesive powder 8'begins to soften. Epoxy beads
The powder adhesive 8 ′ receives the pressure P evenly, and the glass substrate 1
It is flattened and crushed while welding across 3
You. In this way, the upper glass substrate 3 becomes the spacer particles.
When contacted with 2, the two substrates 1 and 3 are spacer particles.
While being supported by 2 and matching the diameter of the spacer particles 2
The movement is stopped in a parallel state while keeping a distance (Fig.
(C)). At this time, the glass substrates 1 and 3 have some irregularities.
Even if there is (usually about 20 to 30 μm), press while heating.
By bonding them together, the distance between the glass substrates is constant.
Maintained at intervals. That is, the unevenness of about 20 to 30 μm
Is corrected. If heating is continued in such a state, it will become flat.
2 pieces of crushed epoxy-based bead-shaped powder adhesive 8
It is cured in a state of being welded to the substrates 1 and 3. This
The two substrates 1 and 3 inside by the spacer particles 2.
The sealing material 4 and the epoxy resin
A state in which a force attracted by the powder adhesive 8 is received.
It is fixed in the state to form a cell. The epoxy-based bead-shaped powder adhesive 8 is also pressed.
It acts as a cushion during the wearing process and has a swelling base
The spacer particles 2 are ground and destroyed by the convex portions of the plate.
To prevent Further, the epoxy type bead-shaped powder adhesive 8 is
Since it contains a latent curing agent, it does not cause contamination during the curing reaction.
No reaction gas is generated and therefore the alignment film is not deteriorated.
No. As a result, a ferroelectric liquid crystal device with a good contrast ratio
Is obtained. Furthermore, the epoxy-based beaded powder adhesive 8
As it is chemically stable, the liquid crystal will not change even if it is used for a long time.
It has excellent service life without deterioration of quality. As described above, according to the present invention, 2
The target gap value between the substrates 1 and 3 is also changed to the diameter.
The two substrates are latent with the spacer particles dispersed.
By using an epoxy-based bead-shaped powder adhesive containing a hardener
Since it was applied, many epoxy beaded powder adhesives
In many places, stress is applied to the inside of the
The gap can be defined by the laser particles, and
Not only able to form parallel and parallel cell structures
Liquid crystal objects that maintain a certain gap even when subjected to an external force
Flow under the quality can be prevented. In addition,
Spacer particles and epoxy-based beaded powder adhesive
Because it is more specified, a small gap is created regardless of the substrate area.
Can be held constant, and further phenolic curing
Since the agent is used, pollutant gas is not emitted and the alignment of the liquid crystal is disturbed.
There is an effect that is not. The ferroelectric liquid crystal has a high response speed,
Immediately having bistability (memory property) due to interface effects
It is suitable for large display elements with large display capacity.
Use is expected. By the way, in the ferroelectric liquid crystal element,
The part where the ferroelectric liquid crystal exists to bond the two substrates together
Around the epoxy-based beaded powder adhesive
Occurrence of minute alignment defects (zig-zag dislocation)
If there is such a small orientation defect, bistability (
Of the ferroelectric liquid crystal element over the entire surface.
The problem of not being able to drive evenly
It was clarified by the lighters. In the present specification, such a problem is also solved.
Erase, ferroelectric liquid crystal orientation and bistability (memory
Ferroelectric liquid crystal suitable for large-sized display devices.
A device and a method of manufacturing the device are also disclosed. The epoxy-based bead-shaped powder adhesive of
Proposal that can reduce minute alignment defects that occur in the periphery
An example will be described. That is, the first proposal example
Two substrates facing each other relating to an electric liquid crystal element
The ferroelectric liquid crystal is enclosed between the
The two substrates are epoxied in the part where the electric liquid crystal is present.
Ferroelectrics fixed via a bead-shaped powder adhesive
Liquid crystal element, the minute alignment defect in the ferroelectric liquid crystal
Number density of zig-zag dislocation is 15 / 0.16mm
^TwoBelow, and the maximum contrast of lighting and non-lighting
Maximum drive frequency f that can obtain the ratio_maxFluctuation range and half selection
Voltage applied at times ± V_hThe contrast ratio starts changing
Drive frequency f_minOverlap with fluctuation range of 2kHz or less
It is characterized by being configured in. The second proposal is a ferroelectric liquid crystal device.
And a ferroelectric liquid crystal is used.
In the manufacturing method of the liquid crystal element, the part where the liquid crystal exists
With epoxy-based beaded powder adhesive
The substrate is bonded and the liquid crystal is coated from the smectic A phase.
When cooling to the Iral smectic C phase, if slowly cooled
At the same time, a voltage of 2 to 8 V is applied to orient the liquid crystal.
It is characterized by the following. In the ferroelectric liquid crystal device according to the present invention
Is a ferroelectric liquid crystal having a helical molecular alignment structure.
It is preferably a mectic liquid crystal. Against voltage
This is because the response speed is high and the image is clear. Ferroelectric liquid
The crystal is p-decyloxybenzylidene described above.
-P'-amino-2-methylbutyl cinnamate, p-
Hexyloxybenzylidene-p'-amino-2-chloro
In addition to propylcinnamate, some of the inventors have proposed
"Technical Report of the Television Society" (ED917 IPD10
4-1, February 3, 1986)
Those of are also suitable. [0028] Embedded image Where R₁: R_TwoAre shown in the following table.
In addition, C in the table^*Represents an asymmetric carbon (chiral group). [0030] [Table 1][0031] [Table 2]Further, Trepearl AD (manufactured by Toray Industries, Inc.
The product name) is especially used as an epoxy beaded powder adhesive.
It is excellent. In the case of ferroelectric liquid crystal, the substrate interval is 1 to 3
Most preferably, it is μm. In the present invention, an epoxy-based beaded powder
The powder adhesive has a spherical shape, and after bonding, the two substrates 1 and 3
It is preferable that the spherical shape is pressed by the pressure of
New This is because the alignment film and the conductive film are not damaged. Also book
In the liquid crystal electro-optical element of the invention, an epoxy-based bead shape
The existence ratio of powder adhesive is 100 cm^Two0.1 to 50 per
It is preferably in the mg range. Too few contact
If you don't show the strength to wear, and on the other hand there are too many
Because it becomes. In the present invention, the substrate is preferably glass
It is. This is because it has excellent transparency and hardness. What
The substrate may be a plastic plate. Safe or
This is because it has the characteristic of being light. Plastic plate
Is polymethylmethacrylate, polycarbonate, etc.
Those having excellent transparency are preferable. Plastic board
The surface that is exposed to the outside air is
Mosquito, epoxy silane, organic polysiloxane, cross-linked poly
A hard coat layer such as acrylate is provided
Is preferred. In the present invention, at least the upper plate is also included.
Use a non-oriented or uniaxially oriented film for (one substrate)
May be used. The reason for this is the panel (display)
When the surface is curved in a convex shape, even when viewed from an angle
This is because the rainbow pattern cannot be seen. Uniaxial orientation is vertical
It may be horizontal. The degree of orientation is such that the draw ratio is about 1.5 to 7 times.
Any degree will do. Preferably 5 to 6 times
It is. Regarding the film, in the case of non-oriented film
Acetate film is also a stretched resin
May be any known one, but preferably polyethylene.
The use of lentephthalate film. Fusion
It has a high point and is stable on liquid crystal, etc., and can be used for a long time.
This is because that. On top of that, the cost is low.
You. The thickness of the film should be as thick as the panel can
It can be of any thickness. Next, a conductive film is provided on the film surface.
It is necessary to be. To give a charge to the liquid crystal
You. The conductive film may be any known one, but is preferably
Is composed of indium oxide and tin oxide. this
The film is deposited in an oxidizing atmosphere by metal deposition, sputtering, or
Plating (including ion assist method)
Can be formed. Then, an alignment film is formed on the conductive film.
You. Next, an alignment treatment for gradually cooling while applying a voltage
On the uniformity of the orientation of ferroelectric liquid crystals using the theoretical method
Report the experimental results. (A) Evaluation method for uniformity of orientation Alignment uniformity is mainly determined by optical observation with a polarizing microscope.
I went. In addition, it is considered that it is strongly affected by the uniformity of orientation.
The obtained drive characteristics were also measured at the same time. Driving characteristics are shown in Fig. 1.
Apply an actual drive waveform that repeats lighting and non-lighting as shown.
Then, the following two driving frequencies were measured. However,
Drive waveform is voltage, bias is fixed, only drive frequency
It was variable. V_s= 20 volts V_h= 10V 1/4 bias V_n= 5 volts f_max: Maximum contrast ratio of lighting and non-lighting is obtained
Maximum drive frequency f_min: Voltage applied at half selection ± V_hIn the contrast
Drive frequency at which f_max~ F_minCan be driven when the voltage is fixed
It is considered to indicate the frequency range. Actual ferroelectricity
In order for the liquid crystal element panel to be fully driven,
F in elementary_maxMinimum value of and f_minAnd the maximum value of f_maxMaximum value of ≫f_minMinimum value of The condition is that (B) Orientation uniformity improvement experiment (Experiment 1) [Initial orientation] For the experiment, 640 × 4 manufactured under the conditions shown in Table 3
00-dot, A4 size ferroelectric liquid crystal element panel is used
Was. As shown in Table 3, the initial orientation is PI double-sided rubbing.
went. Align the alignment state in the initial alignment process with a polarizing microscope.
Observing, the area around the epoxy-based bead-shaped powder adhesive
Many micro-orientation defects (zig-zag dislocation) were found in
Was. At this time, f_max, F_minAnd that
Adjust the relationship between the driving area and the average number of fine alignment defects (n).
The result is shown in Figure 2. [0040] [Table 3] In Table 3, SmA is smecty.
Phase A, SmC^*Represents the chiral smectic C phase
You. The average number n of minute alignment defects and the driving frequency range are
It can be seen that there is the following correlation.   The part with few micro-orientation defects responds at high frequency.
Wide drive frequency range.   In the part where there are many fine alignment defects, f_maxIs falling
The driveable area is narrowed. (Experiment 2) To improve the uniformity of orientation
In addition, a method of applying a DC voltage simultaneously with slow cooling was used. First
After the initial alignment treatment, apply smectic A phase SmA (60 ℃)
After standing for about 1 hour, it was gradually cooled while applying a voltage. Experiment
Change the applied DC voltage under the slow cooling condition of 10 ℃ / hr.
And investigate the uniformity of orientation from optical observation and drive characteristics
Was. The following five values were selected for the applied voltage. Applied voltage: 2V, 4V, 6V, 8V, 16V After that, the applied voltage was fixed at 4V and the slow cooling condition was 5 ° C / h.
The effects at r, 10 ° C / hr and 20 ° C / hr were investigated. Measurement
The measurement is performed for 12 points in the ferroelectric liquid crystal element panel.
Was. [Results] Application under slow cooling conditions of 10 ° C./hr
Diagram showing changes in drive characteristics and alignment state when voltage is changed
3, shown in FIG. 4 and FIG. Figure 3 shows f_max, F_minTo
The average value and the variation of the values measured at 12 points are calculated for each DC voltage.
FIG. Figure 4 shows DC voltage and micro-orientation
Shows the relationship with the average number of. FIG. 5 shows f_maxVariety of
Range of g and f_minShows the range of variation of
The overlapping area is indicated by diagonal lines. From these results
I understand.   When no voltage is applied and only slow cooling is performed, f_maxIs 14kHz ≧ f_max≧ 7.6kHz Distributed in_minIs 12.2kHz ≧ f_min≧ 6.0 kHz Distributed. f_maxThe variation range of f is f_minRose
Overlaps the range of luck and the entire ferroelectric liquid crystal element panel
It cannot be driven under a single driving condition.   F as the applied voltage is increased to 4V_max, F_min
The range of fluctuations in is narrowed, and drive characteristics approach uniformity.
It is shown that. The orientation state at this time is f_max, F
_minIn order to reduce the variation in
A decrease in pitting was observed.   When the applied voltage is further increased, f_maxThe upper limit of
The range of variation gradually spreads down. The orientation is
Micro-orientation defects reappear, and at 16V, epoxy
Black inversion area appears around the bead-shaped powder adhesive
Was.   As is clear from FIG. 5, at 4V, f_maxWhen
f_minThe overlapping area of the variation area of is the smallest.   Slow cooling conditions of 5 ° C / hr while applying 4V DC voltage,
F at 10 ℃ / hr and 20 ℃ / hr_max, F_minRose
The appearance of luck is shown in FIG. Overlap at 10 ℃ / hr
Area is minimized, indicating that optimal slow cooling conditions exist.
doing. Summarizing the above results, [1] 4V, 10 ° C / hr voltage value and slow cooling conditions
As a result, a uniform alignment state was obtained. However, the driving at this time
The dynamic characteristic is that the entire surface of the ferroelectric liquid crystal device panel is not completely
It is not a characteristic that it can be driven independently, but it is almost satisfactory
The characteristics could be obtained. [2] Reduction of fine alignment defects and application of driving characteristics
Very uniform correspondence, minute alignment defects and driving characteristics
Suggests that there is a close relationship with. [3] Epoxy resin used to bond two substrates
Occurrence of minute alignment defects around the powdered adhesive
Was seen. [Discussion] Uniformization of driving characteristics and minute alignment defects
It was found from the above experiment that the decrease in
Was. Also, when examining the reversal process due to the pulse, a minute orientation
The drive characteristics are very small, because the part that does not completely reverse remains in the defect.
It shows that the orientation defects are different inside and outside. this
The point is K. Nakagawa et al. Turn off in the inside and outside regions of minute alignment defects
It seems to correspond to the indication that the set voltage is different.
Will be Micro-orientation defects, as Clark et al. Point out,
The alignment state is different between the inside and the outside with a small alignment defect.
It is highly possible that Clark et al.
Alignment defects are loca such as bending of two different layers.
l existing at the boundary of the layer structure (LLS)
I have. From this point of view, fine alignment defects at 4 V or less
Is reduced and absorbed in one orientation state is the layer bend.
LLS structure such as Ding is stable against the polarity of the voltage
LLS grows and unstable LLS is absorbed.
You could think so. In addition, minute alignment defects are
Considering that it often occurs around the powdered powder adhesive
Then, due to the effect of the epoxy side surface, the orientation state becomes
If it shows an LLS structure that is different from the orientation state of the side region,
It seems to be there. In addition, the fine alignment defect is 4 V or more.
It also has the property of starting to increase again. [Summary] Driving the entire surface under the same driving conditions
In order to make the molecular orientation uniform, especially to reduce micro-orientation defects.
Is an important issue. In this experiment, it is clear from Fig. 5
The value of the applied DC voltage during slow cooling is 2 to 8 volts.
When f_max, F_minThe range of variations in
Drive conditions for the entire ferroelectric liquid crystal device panel.
It turned out to be uniform. Also, at this time,
Maximum drive frequency f that can obtain the maximum contrast ratio of lighting
_maxFluctuation range and voltage applied at half-selection ± V_hAnd
Drive frequency f at which the trust ratio begins to change_minFluctuation range
It is clear from Fig. 4 that the overlap with and is less than 2 kHz.
As described above, small alignment defects (zig-zag di
The number density of slocation is 15 / 0.16mm^TwoBe less than
For example, the driving conditions for the entire ferroelectric liquid crystal element panel are
It turned out to be almost uniform. Furthermore, as is clear from FIG.
If the gradual cooling condition is 5 to 20 ° C / hr, the same as above
It was found that the driving conditions for the entire channel were almost uniform.
Was. Especially, 4V DC voltage is applied under the slow cooling condition of 10 ℃ / hr.
When added, it has the smallest number of micro-orientation defects,
It was found that a uniform alignment state with less roughness was obtained.
Was. Also, not only DC voltage but also AC voltage can be used.
It is possible. [0048] BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. [Example 1] Transparent electrode film and rubbing on the surface
Forming an alignment film made of polyimide film
Epoxy bead-like powder adhered to the peripheral area of the outside air
Apply the agent to a thickness of about 7 μm to form a seal part.
Epoxy-based bead-shaped powder adhesive with a diameter of 5.5 μm
(The composition will be described later) and alumina with a diameter of 2 μm
Fine particles to the desired density (for example, epoxy-based bead-like powder)
80 pieces / mm for both adhesive and alumina fine particles^Twobelow
Density, ie 15 / 0.16mm^TwoDisperse at the following density).
Put the lower substrate on top of this and pressure (eg 0.3-5 kg / cm
^Two) Is added and heated (for example, 80 to 200 ° C). this
The cell structure in which the substrates are fixed in parallel at intervals of 2 μm
You can get a structure. A ferroelectric chiral smect is added to the completed cell.
Tick liquid crystal (for example, p-deci
Roxybenzylidene-p'-amino-2-methylbutyl
(Cinnamate) is heated and poured as smectic A phase
Entered. The smectic A phase is chiral smecty
When cooling to C phase, slow cooling at 5 to 20 ° C / hr
At times, a voltage of 2 to 8 V is applied to orient the liquid crystal uniformly.
I let you. In this way, a ferroelectric liquid crystal element was produced.
However, small alignment defects (zig-zag disl
The number density of ocation) is 15 / 0.16mm^TwoIt was below.
In addition, the maximum contrast ratio of lighting and non-lighting is obtained.
Large driving frequency f_maxFluctuation range and applied at half selection
Voltage ± V_hDrive frequency at which the contrast ratio begins to change
f_minThe overlap with the fluctuation range of
The frequency range was less than 2 kHz. Further, this ferroelectric liquid crystal element is driven to drive light.
When the contrast ratio when transmitting and when blocking light is measured, 5.
5 to 6.5 could be obtained. This is a big enough
It is a trust ratio, and the orientation state is not disturbed. Next, a concrete example of the epoxy-based bead-shaped powder adhesive
A few examples are given. Part 1 Epoxy resin "Epicoat" 828 20g and "Epicor
20 "to 1001 (both are trade names made of oiled shell epoxy)
g in a 300 cc poly cup and add the surfactant "Emulgit
4 g of To 9 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was added.
Bisphenol A type diglycidyl ether and bisphenol
The latent curing agent "Epicure" which is an adduct of Nol A
4g (approx. 171N (trade name of Yuka Shell Epoxy))
0.12 eq.), Heat the whole to 95 ° C, and scrape quickly.
All were made into a transparent compatible solution. Stirrer equipped with a Teflon plate blade at its tip
Set the container in the container and keep it at a temperature of 50 ° C and 800 rpm.
It was agitated. Add 6cc of water at 50 ℃ in a syringe, and add 40
Repeat the operation of stirring for 4 times 4 times, using a total of 24 cc of water,
Emulsify the above epoxy resin and Epocure 171N mixture
Was. 0.44 equivalents of piperazine in this emulsion
Add a hardening liquid diluted with 32cc of water and stir gently
Homogenized. Allow to stand for 6 days at 25 ° C with an average particle size of about 6 μm
Partially cured spherical particles were obtained. 95 wt% within 5.5 ± 2 μm
Wet classification (hydraulic method) was performed to obtain a particle size distribution that allows particles to enter.
Silica sol "Snowtex" N (Japan
1 wt% of solids based on solid content based on particles
%, And stir for 30 minutes to allow the silica sol to adsorb to the particles.
I let you. After suction filtration, the resultant was dried under reduced pressure at room temperature. Slide glass
Disperse 0.5mg of the above particles evenly in a 15mm square
Cover with the same slide glass and press down with clips
Put it in a hot air dryer at 170 ℃ for 2 hours to cure it.
I understood. After that, the splitting strength was taken out from the dryer and measured.
Was 40 kg / 15 mm. Part 2 40g of "Epicoat" 828 and phenol latent curing agent
"Epicure" 171N 12g (about 0.26 equivalent) and interface
Activator "Neugen" (manufactured by Daiichi Kogyo Seiyaku) EA 137 4g
Transfer to a 300cc poly cup and heat mix at 95 ° C to clear.
Made into a compatible solution. 1 except that the emulsification temperature is room temperature
This was emulsified in a similar manner. 0.3 in this emulsion
Add an equivalent amount of piperazine diluted with 32 cc of water to the curing liquid.
Gently stir to homogenize. Gently stir about 1 to 3 rpm at 25 ° C.
While leaving for 4 days, the partial hardness of the average particle size 6.5 μm
The spheroidized particles were obtained. 5.5 μm ± 2 μm as in 1
Wet classification so that 95 wt% of particles will enter,
Silica sol "Snowtex" N was adsorbed at a solid content of 1 wt%
I let you. The splitting strength after drying under reduced pressure was 35 kg / 15 mm. Part 3 With a phenolic curing agent contained in epoxy resin adhesive particles
The following are used, and all have a good contrast.
Got the ratio. METHYLON 75/08 G-E Company RESIMENE P97 Monsanto VARCOM 1281B VALCOM Super Becca site 1001 Reichhold Japan Hitachin 4010, 4020 Hitachi Chemical [0058] Embedded imageExample 2 Uniaxially oriented poly with a thickness of 100 μm
Ethylene terephthalate film (stretching ratio 5.5 times)
On one surface under high vacuum (2 x 10^-2Toor),
And gold loaded in a tungsten boat under oxygen atmosphere
Evaporation source consisting of metal indium and metal tin (metal tin 12
% By weight) was vacuum deposited by resistance heating. Obtained guidance
The thickness of the electrolytic film was 850Å. Then acid for 20 minutes at 150 ° C
Heat treated to make a transparent film with a sheet resistance of 50Ω.
Was. Then, an alignment film made of polyimide is formed and a rubbing process is performed.
I understood. The film thus obtained is used as an upper plate.
Used as an epoxy cured particle (average particle diameter 2 μm)
Used as a pacer, the epoxy-based beaded form of Part 1 of Example 1
Use a powder adhesive as an adhesive and harden it at 150 ° C at 2 μm intervals.
Chemically bonded. Ferroelectric chiral smear in completed cell
The stictic liquid crystal is heated and poured as a smectic A phase
Entered. The smectic A phase is chiral smecty
When cooling to C phase, slow cooling at 5 to 20 ° C / hr
At times, a voltage of 2 to 8 V is applied to orient the liquid crystal uniformly.
I let you. Then, a liquid crystal display cell was prepared as shown in FIG.
However, small alignment defects (zig-zag disl
The number density of ocation) is 15 / 0.16mm^TwoIt was below.
In addition, the maximum contrast ratio of lighting and non-lighting is obtained.
Large driving frequency f_maxFluctuation range and applied at half selection
Voltage ± V_hDrive frequency at which the contrast ratio begins to change
f_minThe overlap with the fluctuation range of
The frequency range was less than 2 kHz. Also, the conductive film or film should not be scratched.
Also, even if the surface is curved, a rainbow pattern does not occur, which is unprecedented.
A good liquid crystal cell was obtained. Reference Example 1 As a comparative example, a B-stage epoxy containing an amine-based curing agent
Fabrication of ferroelectric liquid crystal electro-optical element using resin particles
Then I measured the contrast ratio. Then the contrast
The ratio has dropped to 3.0-4.0, and the orientation is disturbed.
I found out that B-stage Epo containing amine curing agent
As the xy resin particles, Mitsui Toatsu Co., Ltd.
Lactobond "X-7479-50 is heated at 90 ° C for 30 minutes to remove B
It is then crushed and classified to a particle size of 7 μm.
Random particles of irregular shape were used. In the above embodiment, the space is
The spherical particles and epoxy resin adhesive particles are formed in a spherical shape.
However, the same effect can be obtained by using ellipsoidal spheres and polyhedral particles.
Needless to say. In addition, in the above-mentioned first embodiment
In general, the substrate is made of glass, but it is hard and heat resistant.
The same action can be obtained by using the polymer resin plate material. [0065] INDUSTRIAL APPLICABILITY The present invention relates to a ferroelectric liquid crystal and a liquid crystal sandwiched between the ferroelectric liquid crystal and the ferroelectric liquid crystal.
Two sheets are placed facing each other with a sealing material to hold
The board and the board are distributed and distributed in order to keep the board space constant.
Spacer particles that have been placed and the liquid formed on the substrate
An alignment film for orienting crystals and applying a voltage to the liquid crystal
In a ferroelectric liquid crystal device consisting of driving means for
The two substrates are distributed in the space between the substrates,
Epoxy resin-based particles containing a conventional curing agent
Are joined in a dot-like manner with a linear adhesive, and the ferroelectric liquid
Density of micro-orientation defects (zig-zag dislocation) in crystals
15 degrees / 0.16 mm^TwoBelowLighted and unlit
Maximum drive frequency f that gives the maximum contrast ratio _max of
Variation range and voltage applied at half selection ± V _h In the contra
Drive frequency f at which the strike ratio begins to change _min Overlap with fluctuation range
Less than 2 kHzSince it was configured as follows,
Produce an effect. That is, for a large number of epoxy resin adhesive particles
In many places, stress is applied to the inner side,
The spacing can be defined by the pacer particles, and the inherent strain of the substrate
Can only be forced to form parallel cell structures
Instead, the liquid crystal maintains a certain gap even when subjected to external force.
It is possible to prevent the lower side of the substance from flowing. Also the substrate
The gap between the two is controlled by spacer particles and epoxy resin adhesive particles.
To maintain a constant small gap regardless of the substrate area.
It can be held and realizes a large area LCD panel.
Can be Furthermore, using a phenolic curing agent
Since there is no pollutant gas, the alignment of the liquid crystal is not disturbed.
There is also an effect.In addition, the minute alignment defect in the ferroelectric liquid crystal
Number density of zig-zag dislocation is 15 / 0.16mm
^Two Maximum contrast below and lit and unlit
Maximum drive frequency f for which the ratio is obtained _max Fluctuation range and half selection
Voltage applied at time ± V _h The contrast ratio starts changing
Drive frequency f _min Overlap with fluctuation range is less than 2kHz
The entire ferroelectric liquid crystal element panel
The driving conditions can be made almost uniform.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a drive characteristic measurement waveform diagram. FIG. 2 is a diagram showing the relationship between the number of minute alignment defects and the drivable frequency region. FIG. 3 is a diagram showing a variation of an average value of f _max and f _min and a variation thereof due to a DC voltage. FIG. 4 is a diagram showing a relationship between an average number of micro-orientation defects and a DC voltage. FIG. 5 is a diagram showing the relationship between the uniformity of drive characteristics and the DC voltage. FIG. 6 is a diagram showing a relationship between uniformity of drive characteristics and slow cooling conditions. FIG. 7 is a partially cutaway perspective view of a ferroelectric liquid crystal device of the present invention. FIG. 8 is a diagram showing a manufacturing process of the present invention. [Explanation of reference numerals] 1, 3 ... Substrate 2 ... Spacer particles 4 ... Sealing material 7 ... Alignment film 8 ... Epoxy bead-shaped powder adhesive

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Koji Iwasa               563 Takatsuka Nitta, Matsudo City, Chiba Seiko Den               Child industry Takatsuka office (72) Inventor Sadayuki Shimoda               563 Takatsuka Nitta, Matsudo City, Chiba Seiko Den               Child industry Takatsuka office (72) Inventor Masaaki Taguchi               563 Takatsuka Nitta, Matsudo City, Chiba Seiko Den               Child industry Takatsuka office (72) Inventor Koichiro Oka               1-1-1 Sonoyama, Otsu City, Shiga Prefecture Toray               Shiga Works Co., Ltd.

Claims (1)

(57) [Claims] Ferroelectric liquid crystal, two substrates which are arranged to face each other with a sealing material for sandwiching the liquid crystal, spacer particles which are dispersedly arranged at the substrate gap to keep the substrate gap constant, and on the substrate In a ferroelectric liquid crystal device formed by an alignment film for orienting the liquid crystal and a driving means for applying a voltage to the liquid crystal, the two substrates are dispersedly arranged at a substrate interval. The particles are bonded in a dot-like manner with a particulate adhesive containing an epoxy resin as a main component containing a type curing agent, and fine alignment defects (zig-zag dislocatio) in the ferroelectric liquid crystal are bonded.
number density of n) is Ri der 15 /0.16Mm ² or less, and, the lighting, the maximum contrast ratio of the non-lighting can be obtained most
Variation range of large drive frequency f _max and application at half selection
Driving frequency where the contrast ratio starts to change with voltage ± V _h
A ferroelectric liquid crystal device characterized in that the overlap with the f _min fluctuation range is configured to be 2 kHz or less . 2. 2. The ferroelectric liquid crystal device according to claim 1, wherein the particulate adhesive material has a spherical shape pressed by the pressure of two substrates. 3. The existence ratio of the particulate adhesive is 0.1 per 100 cm ^{2 of the} substrate.
2. The ferroelectric liquid crystal device according to claim 1, which is in the range of 50 mg. 4. The ferroelectric liquid crystal device according to claim 1, wherein the distance between the two substrates is 1 to 3 μm, and the average particle diameter of the particulate adhesive is within 5.5 ± 2 μm. 5. The ferroelectric liquid crystal device according to claim 1, wherein the latent curing agent is a phenolic compound.