JP3474117B2 - Liquid crystal cell manufacturing method and liquid crystal cell manufacturing apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal cell manufacturing method and a liquid crystal cell manufacturing apparatus, and more specifically, a liquid crystal injection port into which liquid crystal is injected is sealed with an ultraviolet curable resin (hereinafter referred to as "UV curable resin"). And a liquid crystal cell manufacturing apparatus for manufacturing the liquid crystal cell.

[0002]

2. Description of the Related Art Generally, a liquid crystal cell used for a display element or the like is prepared by injecting liquid crystal between two glass substrates and then sealing the liquid crystal injection port into which the liquid crystal is injected with a sealing material. Manufactured by. A UV curable resin that is cured by irradiation with ultraviolet rays has been used as the sealing material.

This type of UV curable resin has a very short reaction time as compared with a thermosetting resin such as an epoxy resin, and since it does not use a curing agent or the like, it adversely affects the liquid crystal such as deterioration of the liquid crystal. It is possible to obtain a liquid crystal cell which is relatively less affected and which is more reliable than in the case of sealing with the thermosetting resin.

[0004]

However, in the above-mentioned conventional method of sealing the liquid crystal injection port with a UV curable resin, the resin does not cure unless it is irradiated with ultraviolet light, so that light in a wide wavelength range including ultraviolet light is applied to the resin. Although it is irradiated and cured, ultraviolet rays have a property of deteriorating the liquid crystal which is an organic substance, so that when the irradiation time of light becomes long, the deterioration and decomposition of the liquid crystal due to the ultraviolet rays becomes remarkable, As a result, when the liquid crystal cell is incorporated into an electronic component or the like and driven, display unevenness occurs, display quality deteriorates, and the reliability of the liquid crystal cell deteriorates.

On the other hand, when the light irradiation time is short, the surface of the resin is cured, but since the resin is not sufficiently cured to the deep portion, an uncured portion remains, and as a result, the uncured portion penetrates into the liquid crystal. It is mixed as an impurity in the liquid crystal cell. That is, the curing of the resin proceeds by a polymerization reaction using a molecule excited by light energy as a polymerization initiator, but when the irradiation time of light is short, the resin surface is cured, but the polymerization reaction in the deep portion of the resin is insufficient. Therefore, the uncured portion remains in the resin, and thus the uncured portion penetrates into the liquid crystal and is mixed as an impurity in the liquid crystal cell, resulting in display unevenness due to the mixing of impurities, resulting in display quality. And the reliability of the liquid crystal cell is reduced, as described above.

The present invention has been made in view of the above problems, and provides a liquid crystal cell manufacturing method and a liquid crystal cell manufacturing apparatus capable of obtaining a liquid crystal cell having excellent characteristics and reliability as a display element. The purpose is to do.

[0007]

Considering the current production technology, in order to prevent the liquid crystal from leaking out from the viewpoint of workability and quality, the resin should be cured to seal the liquid crystal injection port. Is still considered the most preferred method.

Therefore, the inventor of the present application first studied the mechanism of the hardening phenomenon and obtained the following findings. That is, when the resin is irradiated with light, the polymerization reaction is generally initiated by the polymerization initiator excited by light energy from the resin surface, and the resin surface is cured in the direction of the interface with the liquid crystal, that is, in the resin deep part. It is thought to progress.

However, since the resin surface is in contact with air, when the light energy is small, the polymerization initiator excited by the light energy temporarily binds to oxygen in the air to cause so-called oxygen inhibition. As a result, the resin surface is not cured and becomes a "sticky" so-called tack state. on the other hand,
When a large amount of light is irradiated to the resin, the polymerization energy required for the polymerization of the resins becomes larger than the binding energy with oxygen, and the polymerization of the resins progresses, and the resin surface eliminates the tack state and cures. To do. That is, for example, when the light energy is small and the light is applied to the resin for only a short time, the tack state is not resolved and the resin surface is not cured, but even light with a small energy does not remove the resin for a long time. If irradiation is continued, a large amount of light energy will be applied to the resin, and the resin surface will also be cured.

On the other hand, since the deep portion of the resin is not in contact with air, oxygen inhibition does not occur, and the polymerization reaction proceeds in the deep portion of the resin even when the resin is irradiated with light having low energy.
The resin deep part is easily cured.

When the resin is irradiated with light in this way, when the light energy is small and the light irradiation time is short, the resin surface is not cured due to oxygen inhibition, and only the resin deep portion is cured.
On the other hand, when the resin is irradiated with light for a certain long time, a large amount of light energy is applied to the resin even if the energy is small, and the energy of the bond with oxygen in the air is higher than that of the bond energy. The polymerization energy required for polymerizing the resins becomes larger. Therefore, in this case, after the resin deep portion where oxygen inhibition does not occur is cured, the resin surface is also cured by eliminating the tack state. However, since the light energy is applied to the resin over a long period of time, the inventors have also found that the liquid crystal cell is locally disturbed in display.

Further, as a result of further earnest studies by the inventor of the present application, when light having large energy is present in a low wavelength region of 380 nm or less in the wavelength range of ultraviolet rays, and when the resin is irradiated with light in such a wavelength region. It was found that it adversely affects the liquid crystal. That is, when the resin having such a large energy is irradiated for a long time, the liquid crystal deteriorates and decomposes, which adversely affects the liquid crystal.

[0013] However, since the light <br/> sectional been 380nm or more longer wavelengths shielding the following wavelength 380nm is irradiated to the resin, the light energy of such a wavelength is small, tuck state of the resin surface by oxygen inhibition as described above Occurs. Therefore, long-time irradiation is required to completely cure the resin by a sufficient polymerization reaction necessary for sealing, and in that case, the liquid crystal of the liquid crystal cell, which is an organic substance, is deteriorated and decomposed.

Further, when the resin is irradiated with light having a large energy including a low wavelength region of 380 nm or less, the polymerization energy required for polymerizing the resins is larger than the binding energy with oxygen in the air. Although oxygen inhibition does not occur and the resin surface cures, the energy required for the polymerization reaction is absorbed and blocked by the cured resin surface, and as a result, the progress of the polymerization reaction at the resin deep part is extremely reduced, and the resin deep part Is hard to cure. That is, when the irradiation time is short, the polymerization reaction in the deep portion of the resin becomes insufficient, and the uncured portion remains in the resin, and the uncured portion penetrates into the liquid crystal, resulting in deterioration of display quality.

On the other hand, when the resin having the above-mentioned large energy is irradiated for a long time, the deterioration and decomposition of the liquid crystal becomes remarkable,
Irradiating the resin with such high-energy light adversely affects the liquid crystal in any case.

Therefore, in order to prevent the deterioration of the liquid crystal and to completely cure the resin efficiently , the resin is irradiated with light in the wavelength range of 380 nm or more in which the wavelength of 380 nm or less is blocked without adversely affecting the liquid crystal. Then, after hardening the resin deep portion, it is necessary to irradiate the resin with light in a wide wavelength range including a wavelength range of 380 nm or less to quickly cure the resin surface in a short time.

The present invention has been made on the basis of such findings, and a method of manufacturing a liquid crystal cell according to the present invention comprises a liquid crystal injection step of injecting a liquid crystal between two transparent substrates, and the liquid crystal injection step. In a method for manufacturing a liquid crystal cell, the method including a step of sealing the liquid crystal injected in step 1 with a sealing material made of an ultraviolet curable resin, wherein the step of sealing has a wavelength range of 380 nm or more in which a wavelength of 380 nm or less is blocked. After performing a first irradiation process of irradiating the sealing material with a light having a wavelength of 380 nm or less, a wide wavelength range light including a wavelength range of 380 nm or less is subjected to the first irradiation process.
The second irradiation treatment for irradiating the encapsulant in a time shorter than the irradiation time is performed, and the first irradiation treatment is the surface or surface layer of the encapsulant in contact with air. The deeper portion of the encapsulant that is in a non-contact state with air than is hardened, and the second irradiation process further includes a step of contacting the air with the deeper portion of the encapsulant that is in a non-contact state with air. It is characterized in that the surface or surface layer of the stopper is cured.

According to the above-mentioned manufacturing method, in the first irradiation process, light having a wavelength range of 380 nm or more in which the wavelength of 380 nm or less having a small light energy is blocked is applied to the encapsulant made of an ultraviolet curable resin. Therefore, the polymerization initiator binds with oxygen in the air to cause oxygen inhibition, and the surface of the encapsulant is in a “sticky” tack state, but the deep part of the encapsulant does not cause oxygen inhibition, and thus the desired polymerization occurs. The reaction proceeds and cures. Further, in the second irradiation treatment than is irradiated with light of a wide wavelength range including a wavelength range 380 nm, to cure even surface or surface layer of the sealing material. Moreover, the second irradiation treatment first
Sealing material in a shorter time than the irradiation time in the irradiation treatment of 1.
By irradiating and in which hardening the surface or surface layer than the deep of the sealing material in the air and a non-contact state of the sealing material
Because, without adversely affecting the liquid crystal, it is possible to produce an excellent liquid crystal cell in the display characteristics and reliability.

Further, the liquid crystal cell manufacturing apparatus according to the present invention is
And conveying means for sealing material made of an ultraviolet curing resin is transported to a liquid crystal cell that has been applied to the predetermined portion, a first illumination for irradiating the sealing material of the liquid crystal cell carried by said transport means
Means and the irradiation time by the first irradiation means is shorter than
A second irradiation unit that irradiates the encapsulant for a period of time; and a filter unit that blocks light in the wavelength range of 380 nm or less among the light emitted from the first irradiation unit. I am trying.

According to the above liquid crystal cell manufacturing apparatus, liquid crystal cells having excellent characteristics and reliability as a display element can be continuously and efficiently mass-produced.

[0021] Also, the first irradiation means, by provided a plurality in the filter means and the counter-shaped, passing through the filter means for blocking light of a wavelength range 380 nm 380
A large amount of light having a wavelength range of nm or more is applied to the liquid crystal cell, and the deep part of the sealing material can be easily cured.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a manufacturing process diagram showing an embodiment of a method for manufacturing a liquid crystal cell according to the present invention, and FIG. 2 is a diagram showing an outline of a manufacturing procedure for a liquid crystal cell.

First, two glass substrates of the same size as the transparent substrates (first and second glass substrates 2a and 2b).
Is prepared, a transparent electrode is formed on the upper surface of the first glass substrate 2a by a known method, and a predetermined alignment treatment is performed. Then, in the sealing material application step 1 of FIG. 1, a substantially frame-shaped pattern formed on the upper surface of the first glass substrate 2a is thermally cured with an epoxy resin or the like by a screen printing method as shown in FIG. 2 (I). A resin is applied to form the seal layer 3.

Next, in the thermocompression bonding step 4 of FIG.
The second glass substrate 2b shown in (II) is stacked on the sealing layer 3 as shown in FIG. 2 (III), and pressed with a heating press so that the cell gap becomes a predetermined value. 2a and the second glass substrate 2b are bonded together via the seal layer 3 to form the liquid crystal injection port 5.

Next, the thermosetting resin forming the seal layer 3 is subjected to a predetermined heat treatment to completely cure the seal layer 3, and then the process proceeds to the liquid crystal injection step 6 of FIG. Thus, a desired liquid crystal such as a tran (diphenylacetylene) -based or ester-based liquid crystal is injected from the liquid crystal injection port 5.
Next, in a sealing material applying step 7 of FIG. 1, as shown in FIG. 2 (IV), a UV curable resin such as a modified acrylic resin is applied as a sealing material 8 to the liquid crystal injection port 5 and its periphery by a dispenser, In the subsequent sealing step 9 (FIG. 1), the resin is irradiated with light energy to cure the sealing material 8, thereby manufacturing a liquid crystal cell.

By the way, in the present embodiment, in the sealing step 9, the wavelength of 380 nm or shorter is blocked 38.
After performing a first irradiation process of irradiating the resin with a light having a wavelength range of 0 nm or more, a second irradiation process of irradiating the resin with a light of a wide wavelength range including a wavelength range of 380 nm or less There is.

As described above, the first irradiation treatment is performed at 380 nm or less.
The reason why the resin is irradiated with light having a wavelength range of 380 nm or more in which the lower wavelength is blocked is as follows.

A high pressure mercury lamp as an irradiation means is shown in FIG.
As shown in FIG. 3, the light having large energy having a peak in the wavelength range near 360 nm in the low wavelength region has a bad influence on the liquid crystal such as deterioration and decomposition of the liquid crystal. It is understood that there is. Therefore, it is necessary to block the sealing material 8 from being irradiated with light in a wavelength range that adversely affects the liquid crystal for a long time. Therefore, in the first irradiation processing, a wavelength of 380 nm or less is used.
It was decided to irradiate only the light having a wavelength range of 380 nm or more whose length was cut off .

Next, in the sealing step 9, the second irradiation process is performed in addition to the first irradiation process for the following reason.

As described above, in order to prevent the liquid crystal from being adversely affected, it is necessary to irradiate using light having a wavelength range of 380 nm or more in which a wavelength of 380 nm or less is blocked .
The wavelength range in which wavelengths below 380 nm are blocked is 380 nm
Since the energy of the above light is small, the deep resin portion that is not in contact with the air is cured by the polymerization reaction by light irradiation, but the resin surface cannot eliminate the tack state due to oxygen inhibition. In addition, when the light is irradiated for a long time, a large amount of light is emitted.
Is applied to accelerate the curing of the resin surface, but the heat energy of light deteriorates and decomposes the liquid crystal, causing local disorder in the liquid crystal display. Therefore, in the present embodiment, in order to quickly cure the resin surface or surface layer after the resin deep portion is cured, light of a wide wavelength range including an ultraviolet wavelength range of 380 nm or less with large energy is used in the first irradiation treatment. After the completion, the resin was irradiated. And in this case,
Since only the resin surface or surface layer needs to be cured,
The irradiation time is short, and it is possible to avoid adversely affecting the liquid crystal.

As described above, in this embodiment, the wavelength range in which the wavelength of 380 nm or less is cut off is 38 in the first irradiation process.
The UV curable resin as the encapsulant 8 is irradiated with light having a wavelength of 0 nm or more to cure the resin deep part which is in non-contact with the air or the surface layer of the encapsulant in contact with air. A deep portion of the encapsulant that is not in contact with air by irradiating the UV curable resin with light in a wide wavelength range including 380 nm or less in the second irradiation process.
Rather than curing the resin surface or surface layer in contact with air.

The light energy and the irradiation time are 1 to 10 minutes when a high pressure mercury lamp is used as the irradiation means and the light energy is set to 1000 mJ / cm ² or less in the first irradiation process. It is desirable to set the light energy to 500 m for the second irradiation process.
When it is set to J / cm ² or less, it is desirable to set the irradiation time to about 10 seconds.

When such a liquid crystal cell is manufactured by a batch method (batch method), the first irradiation treatment is performed as shown in FIG.
It can be easily performed by using an ultraviolet cut filter having a filter characteristic as shown in (hereinafter referred to as "UV cut filter").

That is, as shown in FIG. 4, UV having a filter characteristic capable of blocking light in the low wavelength region of 380 nm or less.
A cut filter is manufactured, and then, as shown in FIG. 5A, a liquid crystal cell 11 coated with a sealing material 8 is arranged below a high pressure mercury lamp 10 arranged in a furnace. Furthermore, the two UV filters 12a, 1 having the above filter characteristics
2b are connected, and the two UV cut filters 12a, 1
2b is interposed between the high pressure mercury lamp 10 and the liquid crystal cell 11.

Next, the high pressure mercury lamp 10 is turned on to irradiate the liquid crystal cell 11 with light from the high pressure mercury lamp 10.
As a result, as shown by broken lines (arrows A and B), the UV cut filters 12a and 12b block light in the low wavelength region of 380 nm or less, which adversely affects the liquid crystal, and as shown by solid lines (arrow C). Only light in the long wavelength region of 380 nm or more that does not adversely affect the liquid crystal is in the liquid crystal cell 11
And the resin deep portion that is not in contact with air is cured.

After the hardening treatment of the resin deep portion is performed in this way, as shown in FIG. 5B, the UV cut filters 12a and 12b are moved in the arrow D direction and the arrow E direction, respectively. The filters 12a and 12b are removed from the furnace and the 380 from the high pressure mercury lamp 10 is removed.
The liquid crystal cell 11 can be easily manufactured by irradiating the liquid crystal cell 11 with light in a wide wavelength range including a wavelength range of nm or less for a short time to cure the resin surface.

Next, a liquid crystal cell manufacturing apparatus for continuously conveying and manufacturing the liquid crystal cell will be described.

FIG. 6 is an internal structural view showing the outline of the present liquid crystal cell manufacturing apparatus. The liquid crystal cell manufacturing apparatus is a belt conveyor 1 for sequentially transporting a large number of liquid crystal cells 11 in the direction of arrow F.
3 (conveying means), the first and second high pressure mercury lamps 14a and 14b (irradiating means) for irradiating the sealing material 8 of the liquid crystal cell 11 conveyed by the belt conveyor 13, and the first high pressure mercury lamp. 380 of the light emitted from 14a
UV cut filter 1 that blocks light in the wavelength range below nm
5 (filter means), the first and second high-pressure mercury lamps 14a and 14b, and the continuous furnace 16 having the UV cut filter 15 therein. Further, the first high-pressure mercury lamp 14a includes the UV cut filter 15 And the UV
A plurality of rows are provided above the cut filter 15.

In the liquid crystal cell manufacturing apparatus configured as described above, the light from the first high pressure mercury lamp 14a is UV.
Since the cut filter 15 blocks light in the low wavelength region of 380 nm or less, it blocks wavelengths of 380 nm or less.
Further , light in the wavelength range of 380 nm or more is applied to the liquid crystal cell 11 on the belt conveyor 13. Then, the polymerization reaction proceeds using the light energy from the plurality of first high-pressure mercury lamps 14a as a polymerization initiator, and the liquid crystal cell 11 becomes the belt conveyor 1
Due to 3, the deep portion of the resin as the sealing material 8 is completely cured while passing below the plurality of first high pressure mercury lamps 14a. Then, when the liquid crystal cell 11 is conveyed below the second high-pressure mercury lamp 14b by the belt conveyor 13, the liquid crystal cell 11 receives the liquid from the second high-pressure mercury lamp 14b.
The surface of the resin that is the sealing material 8 is cured by being irradiated with light including a wavelength range of 80 nm or less, and the liquid crystal injection port 5 is sealed to complete the liquid crystal cell 11.

Thus, according to the present liquid crystal cell manufacturing apparatus,
By simply transporting the liquid crystal cell 11 on the belt conveyor 13,
The first irradiation process and the second irradiation process can be continuously executed, and the liquid crystal cells 11 can be mass-produced with a simple device. Moreover, the first high pressure mercury lamp 14
Since a is provided in plural so as to face the UV cut filter 15, it blocks light in the low wavelength region of 380 nm or less.
The liquid crystal cell 11 is irradiated with a large amount of light having a wavelength range of 380 nm or more that has passed through the UV cut filter 15, whereby a desired polymerization reaction proceeds in the resin deep portion, and the resin deep portion can be easily cured. .

The present invention is not limited to the above embodiment. Although a thermosetting resin such as an epoxy resin is used as the material (sealing material) of the seal layer 3 in the above-described embodiment, a UV curable resin is used because the sealing material is treated so as to be completely cured before liquid crystal injection. In particular, in this case, since the sealing material can be hardened in a short time, it is possible to further improve the productivity.

[0043]

EXAMPLES Next, examples of the present invention will be specifically described.

The inventor of the present application uses three kinds of liquid crystal materials and three kinds of encapsulating materials to produce five kinds of liquid crystal cells in which these liquid crystal materials and encapsulating materials are combined, and for each liquid crystal cell, The test piece of the present invention example subjected to the first and second irradiation treatments, the test piece of the comparative example subjected to only the first irradiation treatment, and the comparative example (conventional example) subjected to the second irradiation treatment only. Each of the test pieces of No. 1 was addressed to a total of 15 test pieces in a batch manner.

That is, first, the width is 50 mm and the length is 100 m.
Two glass substrates 2a and 2b having a thickness of m and a thickness of 1.1 mm are prepared. For one glass substrate (first glass substrate 2a), a transparent electrode is formed on the upper surface and a predetermined alignment treatment is performed. After the application, epoxy resin was applied to the substantially frame-shaped pattern formed on the upper surface of the first glass substrate 2a by screen printing to form the seal layer 3.

Next, the second glass substrate 2b is placed on the seal layer 3 of the first glass substrate 2a and pressed by a heating press so that the cell gap becomes about 8 μm. Then, the second glass substrate 2b and the second glass substrate 2b were bonded together via the seal layer 3 to form the liquid crystal injection port 5.

Next, a desired liquid crystal is injected from the liquid crystal injection port 5 by a vacuum injection method, and the liquid crystal is supplied to the space portion (empty cell portion) defined by the seal layer 3 and the two glass substrates 2a and 2b. did. In this embodiment, the liquid crystal is 2
One type of tolan-based liquid crystal (tran type liquid crystal A, tolan type liquid crystal B) and one type of ester type liquid crystal were used. More specifically, the tran liquid crystal A is an inexpensive general-purpose TN.
(Twisted Nematic) type liquid crystal is used, low voltage TN type liquid crystal which is sensitive to ultraviolet ray is used as the tolan type liquid crystal B, and ultraviolet ray is sensitive as the ester type liquid crystal and has a large capacity display. Suitable low voltage STN
(Super Twisted Nematic) type liquid crystal was used.

Next, a modified acrylic resin was applied as the sealing material 8 to the liquid crystal injection port 5 and its periphery of each test piece. Specifically, the maximum length is 10 mm and the maximum thickness is 1 mm.
The modified acrylic resin was applied to the liquid crystal injection port 5 and its periphery with a dispenser in an elliptical shape so as to have a size of mm. Here, as the modified acrylic resin, LPD-173 (manufactured by Nippon Loctite Co., Ltd.) is used for the tolan type liquid crystal A, and LP is used for the tolan type liquid crystal B and the ester type liquid crystal.
D-173 (Nippon Loctite) or 30Y-27
4-4 (manufactured by ThreeBond Co., Ltd.) was used.

Then, the UV cut filters 12a, 12
The test piece is irradiated with the high-pressure mercury lamp 10 through b for 90 seconds for the first irradiation treatment, and then the high-pressure mercury lamp 10 is irradiated again for 10 seconds on the test piece with the UV cut filters 12a and 12b removed. Then, the second irradiation treatment was performed, thereby producing the test piece of the example of the present invention.

Further, only the first irradiation treatment and the second irradiation treatment were carried out to produce test pieces of comparative examples.

As a high pressure mercury lamp, HHL-40
00 / C-OS (Oak Seisakusho) was used.

Then, an initial current value was measured and a reliability test (a humidity resistance test, a high temperature storage test, a high temperature operation test) was performed on each of the test pieces.

Initial current value is voltage 3V, frequency 32Hz
Underneath, static driving was performed. It should be noted that this initial current value is a measure of how much impurities are mixed in the liquid crystal to affect the display drive, and it is generally considered that the lower the value, the smaller the amount of impurities. .

Of the reliability tests, the humidity resistance test was conducted at a temperature of 80 ° C. and a humidity of 90%, and after standing for 240 hours, evaluation was made based on whether or not the liquid crystal display was disturbed.
In the high temperature storage test, the room temperature of the laboratory was set at 95 ° C, and 240
After being left for a time, it was evaluated whether or not the liquid crystal display was disturbed. In the high temperature operation test, the room temperature in the laboratory was set to 70 ° C., and after leaving it for 240 hours, it was evaluated whether or not the liquid crystal display was disturbed.

Tables 1 to 5 show the experimental results of the 15 test pieces produced in this experiment.

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

[Table 3]

[0059]

[Table 4]

[0060]

[Table 5] In Tables 1 to 5, Examples 1 to 5 show experimental results when a liquid crystal cell was manufactured by the manufacturing method of the present invention, and Comparative Example 11
-Comparative example 15 shows an experimental result when only the first irradiation treatment is performed, and Comparative examples 21 to 25 show an experimental result when only the second irradiation treatment is performed. Also, during the reliability test, ○ indicates that the display was not disturbed and good results were obtained, △ indicates that the display was locally slightly disturbed, and × indicates the display disorder. Is partially recognized and is judged to be defective.

As is clear from Tables 1 to 5, when the liquid crystal material and the sealing material are the same, the initial current value of the comparative example exceeds the initial current value of the example in all cases.

That is, Comparative Examples 11 to 15 have a wavelength of 380 nm.
Since only the first irradiation treatment that blocks light in the following wavelength range is performed, the light energy is small, and therefore the uncured material in the resin is mixed into the liquid crystal by the time the polymerization required for sealing is completed. . In addition, Comparative Examples 21 to 25 perform only the second irradiation process of irradiating light in a wide wavelength range including a wavelength range of 380 nm or less, so that the resin surface is rapidly cured by light having large energy, and as a result, In the deep part of the resin, the polymerization reaction does not proceed easily, and the uncured material remains, and the uncured material is mixed in the liquid crystal. Further, as described above, in Comparative Examples 11 to 15 and Comparative Examples 21 to 25, the amount of impurities mixed in the liquid crystal is large, and thus it is considered that the initial current value is increased as compared with Examples 1 to 5.

On the other hand, in Examples 1 to 5, Comparative Example 11
15 to 15 and Comparative Examples 21 to 25, the amount of impurities is less mixed, so that the initial current value is also low, and is superior to Comparative Examples 11 to 15 and Comparative Examples 21 to 25 from the viewpoint of low power consumption. I understand.

As is clear from Tables 3 and 5, when the ester-based liquid crystal is used as the liquid crystal material, the increase in the initial current value is very small. Is likely to be less affected by impurities.

Further, in the reliability test, in Comparative Examples 11 to 15 in which only the first irradiation treatment was performed, the humidity resistance test and the high temperature operation test were good, but in the high temperature storage test, the local display was performed. The turbulence was slightly recognized. It is considered that this is because light irradiation for a long time is required to completely cure the resin surface, and the influence of heat energy due to light adversely affects the display of the liquid crystal.

In Comparative Examples 21 to 25 in which only the second irradiation treatment was performed, the humidity resistance test was good, but in the high temperature storage test and the high temperature operation test, the display was partially disturbed, which was good. No results were obtained. That is, since the encapsulating material 8 is constantly irradiated with light including a low wavelength region of 380 nm or less in the encapsulation step 9, the resin surface cures quickly and easily, but the cured resin surface causes the resin to polymerize. Since the polymerization energy required for the absorption of the resin is difficult, the resin deep portion is hard to cure, and as a result, the liquid crystal cell 11 must be irradiated with the ultraviolet light for a certain long time.
It is considered that this causes deterioration and decomposition of the liquid crystal which is an organic substance.

On the other hand, in Examples 1 to 5, good results were obtained also in the reliability test, and liquid crystal cells having excellent reliability could be obtained without deterioration of display quality such as display unevenness. Was confirmed.

Since the ester type liquid crystal is not easily affected by the mixing of impurities, the initial current value of the comparative example shows only a slight increase in the initial current value of the example as described above. In the test, the same result as that of the tran liquid crystal was obtained. This is a low voltage STN used for ester liquid crystal
It is conceivable that the shaped liquid crystal has a property of being deteriorated under the influence of a slight amount of heat or ultraviolet rays, or having a property of impairing the stability of the display operation due to the inclusion of a slight amount of impurities.

Therefore, regardless of the type of liquid crystal material, by performing the first and second irradiation treatments as in the embodiment of the present invention, a liquid crystal cell having excellent display characteristics and reliability can be obtained. It was confirmed that it was possible.

[0070]

As described above in detail, in the method for manufacturing a liquid crystal cell according to the present invention, a liquid crystal injecting step of injecting a liquid crystal between two transparent substrates and a liquid crystal injected in the liquid crystal injecting step are irradiated with ultraviolet rays. production method smell of a liquid crystal cell including a sealing step of sealing with a sealing material made of the cured resin Te, sealing step, 380 N
After performing a first irradiation process of irradiating the sealing material with light having a wavelength range of 380 nm or more in which a wavelength of m or less is blocked,
The first wavelength of light in a wide wavelength range including a wavelength range of 380 nm or less
A second irradiation process for irradiating the sealing material in a shorter time than the irradiation time in the elevation processing on, were or, the first irradiation treatment,
From the surface or surface layer of the sealing tape in contact with the air to cure the deep sealing material in a non-contact state with air, a further, second
In the irradiation treatment of, since the surface or surface layer of the encapsulant that is in contact with air is hardened more than the deep part of the encapsulant that is not in contact with air, only the encapsulant is applied without adversely affecting the liquid crystal. The liquid crystal cell can be efficiently cured, and thus display quality such as display unevenness does not deteriorate, and a liquid crystal cell having excellent display characteristics and reliability can be manufactured.

Further, the liquid crystal cell manufacturing apparatus according to the present invention is
A transport means for transporting the liquid crystal cell coated with a sealing material made of an ultraviolet curable resin at a predetermined position, a first irradiating means for irradiating the liquid crystal cell transported by the transport means, and a first irradiating means. Teru
Irradiate the encapsulant in a shorter time than the irradiation time by the irradiation means.
That a second illumination means, among the light emitted from the first irradiation means is provided with the filter means for blocking light of a wavelength region 380 nm, a liquid crystal having excellent to the display characteristics and reliability The cells can be mass-produced with a simple device.

[0072] Also, the first irradiation means, by provided a plurality in the filter means and the counter-shaped, passing through the filter means for blocking light of a wavelength range 380 nm 380
A large amount of light having a wavelength range of nm or more is applied to the liquid crystal cell, and the deep part of the sealing material can be easily cured.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram showing an embodiment of a method of manufacturing a liquid crystal cell according to the present invention.

FIG. 2 is a diagram showing an outline of a manufacturing procedure of a liquid crystal cell.

FIG. 3 is a characteristic diagram showing spectral characteristics of a high pressure mercury lamp.

FIG. 4 is a diagram for explaining a procedure for manufacturing a liquid crystal cell by a batch method.

FIG. 5 is a characteristic diagram showing a filter characteristic of a UV cut filter.

FIG. 6 is a schematic view showing an embodiment of a liquid crystal cell manufacturing apparatus according to the present invention.

[Explanation of symbols]

2a glass substrate (transparent substrate) 2b glass substrate (transparent substrate) 6 Liquid crystal injection process 9 Sealing process 11 Liquid crystal cell 13 Belt conveyor (conveying means) 14a First high-pressure mercury lamp (irradiation means) 14b Second high-pressure mercury lamp (irradiation means) 15 UV cut filter (filter means)

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) G02F 1/1341

Claims (4)

(57) [Claims] 1. A liquid crystal injecting step of injecting liquid crystal between two transparent substrates, and a sealing step of encapsulating the liquid crystal injected in the liquid crystal injecting step with an encapsulant made of an ultraviolet curable resin. In the method for manufacturing a liquid crystal cell, in the encapsulation step, a wavelength of 380 nm or less is blocked.
After performing a first irradiation process of irradiating the sealing material with a light having a wavelength range of 80 nm or more, a wide wavelength range of light including a wavelength range of 380 nm or less is irradiated in the first irradiation process.
A method of manufacturing a liquid crystal cell, which comprises performing a second irradiation treatment of irradiating the sealing material in a time shorter than the time . 2. The first irradiation treatment cures a deep portion of the encapsulant which is in non-contact with air more than a surface or a surface layer of the encapsulant in contact with air, and the second irradiation. The method for producing a liquid crystal cell according to claim 1, wherein the treatment cures a surface or a surface layer of the encapsulant that is in contact with air rather than a deep portion of the encapsulant that is not in contact with air. 3. A transport means for transporting a liquid crystal cell coated with a sealant made of an ultraviolet curable resin at a predetermined location, and a first means for irradiating the sealant for the liquid crystal cell transported by the transport means . Irradiation means and irradiation by the first irradiation means
Of the light emitted from the second irradiation means for irradiating the sealing material in a time shorter than the time and the light emitted from the first irradiation means,
A liquid crystal cell manufacturing apparatus comprising: a filter unit that blocks light in a wavelength range of 380 nm or less. 4. The liquid crystal cell manufacturing apparatus according to claim 3, wherein a plurality of the first irradiation means are provided so as to face the filter means.