JP3214303B2 - Manufacturing method of liquid crystal element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a liquid crystal element, and more particularly to a sealing agent for a liquid crystal cell for sealing a liquid crystal between a pair of opposing electrode substrates and an adhesive bead for spot bonding the pair of electrode substrates. The present invention relates to a method for manufacturing a liquid crystal element having a curing step.

[0002]

2. Description of the Related Art Conventionally, a method of curing a liquid crystal cell sealant and an adhesive bead for bonding a pair of electrode substrates is performed by superposing and aligning the pair of electrode substrates, and then distorting the electrode substrates due to thermal expansion during heating. While suppressing the entire surface of the electrode substrate with a pressure of 0.1 to 5.0 kg / cm ² to suppress
A method of curing in an oven set at 0 to 200 ° C. was common.

As a pressing method for suppressing the distortion of the electrode substrate at this time, for example, a pressing method using a weight that applies a load to the entire surface of the electrode substrate or a pressing jig using air pressure, spring load, or the like is used. There are methods.

[0004]

However, since a pressurizing jig using a weight, air pressure, and spring load for suppressing the distortion of the electrode substrate has a large heat capacity, it is necessary to set the jig in an oven set at, for example, 160 ° C. It takes about 3 hours for the temperature of the electrode substrate in the supplied air pressure jig to reach 150 ° C. As described above, curing with a temperature profile with a very low temperature rising rate has the following problems.

(1) Before the hot melt type adhesive bead is sufficiently melted, the curing reaction between the curing agent in the adhesive bead and the epoxy adhesive proceeds, and so-called wetting does not occur at the interface with the electrode substrate. , Sufficient adhesive strength cannot be obtained. In such a state, the impact resistance may be reduced particularly in the ferroelectric liquid crystal element.

(2) It takes about 1 to cure the sealant for the liquid crystal cell.
A heat treatment at 50 ° C. for about 1 hour is required, but the above-described conventional curing method requires a heat treatment time for curing (about 1 hour), a temperature rise time (about 3 hours), and a cooling time. In addition, a long processing time is required from the loading of the electrode substrate to the removal of the electrode substrate.

Further, in a conventional curing method in which an electrode substrate is placed in a pressing jig and put into an oven, a large pressing jig and an oven are used for pressing and heating a large-area electrode substrate. Is required, which increases the cost.

Accordingly, an object of the present invention is to provide a method of manufacturing a liquid crystal element capable of improving the adhesive strength of an adhesive bead and shortening the curing time of a sealant for a liquid crystal cell.

[0009]

In order to achieve the above-mentioned object, the present invention provides a first step of preparing a plurality of paired electrode substrates, and a step of preparing each of the plurality of paired electrode substrates. A second step of attaching a liquid crystal cell sealing material for enclosing liquid crystal between the pair of electrode substrates on one of the pair of electrode substrates, and an adhesive bead for bonding the pair of electrode substrates; A third step of bonding the pair of electrode substrates to each other after the second step;
After the step, a fourth step of sequentially arranging and laminating a heating element via a buffer and a heat plate on both surfaces of each of the pair of electrode substrates bonded to each other, and after the fourth step, Each of the plurality of stacked pair of electrode substrates, the plurality of buffer materials, the plurality of heat plates and the plurality of heating elements are integrally pressed to cause the plurality of heating elements to generate heat, And a fifth step of curing the liquid crystal cell sealing material and the adhesive beads.

[0010]

[0011]

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic sectional view showing a step of curing a sealant and an adhesive bead in a method for manufacturing a liquid crystal element according to an embodiment of the present invention.

As shown in FIG. 1, a buffer 2a, a heat plate 3a, a planar heating element 4, and a heat plate 4 are provided between a plurality of pairs of electrode substrates 1a and 1b provided in multiple stages in order from the bottom. 3b and a cushioning material 2b are provided. The heat plate 3a and the planar heating element 4 are formed slightly larger than the electrode substrates 1a and 1b.
a, 2b and the heat plate 3b are connected to the electrode substrates 1a, 1b.
It is formed in substantially the same size as.

The uppermost electrode substrate 1a, 1
Above b, a metal material 5 for receiving air pressure made of aluminum or the like, which is pressurized by air pressure via the buffer material 2a, the heat plate 3a, the heating element 4, the heat plate 3b, and the buffer material 2b is placed. Is done. The metal material 5 has a uniform thickness and can transmit the received air pressure uniformly to the electrode substrates 1a and 1b.

Further, the lowermost electrode substrates 1a, 1
b, the buffer 2a, the heat plate 3a, the heating element 4, the heat plate 3b, the buffer 2
b is installed.

A pair of electrode substrates 1a,
1b, on at least one of the opposing surfaces,
A liquid crystal cell sealant 7 containing a one-part type thermosetting epoxy adhesive for enclosing the liquid crystal cell with itself, and a hot melt type containing a thermosetting epoxy adhesive for spot bonding the electrode substrates 1a and 1b. Adhesive bead 8 is attached.

The cushioning members 2a and 2b are formed thinly.
It is provided to equalize the pressing force of the air pressure received by each of the electrode substrates 1a and 1b.

The heat plates 3a and 3b are for uniformly transferring the heat generated by the planar heating element 4 disposed between the heat plates 3a and 3b to the electrode substrates 1a and 1b. It is formed with.

As described above, in the step of curing the liquid crystal cell sealant and the adhesive bead in the method of manufacturing a liquid crystal element according to the embodiment of the present invention, the electrode substrates 1 bonded together are used.
While pressurizing a and 1b with air pressure, the heat generated by each heating element 4 is transferred to each of the electrode substrates 1a and 1b via the heat plates 3a and 3b and the cushioning materials 2a and 2b, and the liquid crystal cell sealant 7 and The adhesive bead 8 is cured.

Since the cushioning members 2a and 2b are formed to be thin and the heat plates 3a and 3b have good heat conductivity, the heating elements 4
Can be transferred to the electrode substrates 1a and 1b with almost no loss of heat.

Next, an embodiment of the present invention will be described in detail.

[0023]

【Example】

(Embodiment 1) In the curing step of the liquid crystal cell sealant and the adhesive bead, the pair of electrode substrates 1a and 1b
A liquid crystal cell sealant (for example, manufactured by Mitsui Toatsu Chemical Co., Ltd.) on a glass substrate (sheet thickness: 1.1 mm, size: 300 mm × 320 mm) constituting
Product name: Print Structbond XN-21-F)
Then, an adhesive bead having an average particle size of about 5.6 μm (for example, trade name: Trepearl Type III, manufactured by Toray Industries, Inc.) is 1 mm thick.
Sprayed at an average density of 170 pieces per ² .

A spacer having an average particle size of about 1.04 μm (for example, manufactured by Catalyst Kasei Kogyo Co., Ltd., on the other glass substrate (having a thickness of 1.1 mm) constituting the pair of electrode substrates 1 a and 1 b) (Silica microbeads) were applied at an average density of 300 per mm ² .

Then, the two glass substrates were bonded to form a pair of electrode substrates 1a and 1b.

As shown in FIG. 1, a cushioning material (eg, manufactured by Bridgestone Corporation, trade name: Everlight Scott Felt, thickness: 1 mm) 2a provided on the press table 6 and a heat plate (plate thickness: A 1 mm aluminum plate) 3a, a planar heating element (for example, Sakicon 230, manufactured by Sakaguchi Electric Heat Co., Ltd.)
Watt density: 1 W / cm ² ) 4, heat plate (plate thickness is 3
mm aluminum plate) 3b, cushioning material (same as cushioning material 2a)
The lowermost electrode substrates 1a and 1b are placed on the uppermost electrode substrates 1a and 1b, and a similar buffer is provided between the plurality of electrode substrates 1a and 1b disposed between the lowermost electrode substrates 1a and 1b. A material 2a, a heat plate 3a, a heating element 4, a heat plate 3b, and a buffer 2b are provided, and a similar buffer 2a, heat plate 3a, and a heating element 4 provided on the uppermost electrode substrates 1a and 1b. , Heat plate 3b, cushioning material 2
A metal material (aluminum plate having a plate pressure of 8 mm) 5 which receives an air pressure is placed on b.

These are set in an air pressurized jig (not shown), and pressurized by air pressure (1 kg / cm ² ) on each of the electrode substrates 1 a and 1 b, and each heating element 4 is energized. To generate heat.

At this time, the heat generated by the heating element 4 is adjusted by a connected temperature sensor (not shown) and a temperature controller (not shown) so that the temperature of the heat plate 3b in contact with the plate is maintained at 160 ° C. I do.

The heat generated by each heating element 4 is transmitted to each of the electrode substrates 1a and 1b via the heat plates 3a and 3b and the cushioning members 2a and 2b, respectively, so that the temperature of the electrode substrates 1a and 1b becomes 1
It took 10-15 minutes to reach 50 ° C. afterwards,
After holding the electrode substrates 1a and 1b at 150 ° C. for one hour, the power supply to the heating element 4 is turned off to allow natural cooling, and then the electrode substrates 1a and 1b and the like are taken out of the jig (not shown). .

Then, the electrode substrates 1a and 1b are set at 35 mm.
After cutting into corners, the adhesive strength of the adhesive bead 8 was measured by a shearing method. Table 1 shows the measurement results indicating the adhesive strength of the adhesive bead 8 at this time.

[0031]

[Table 1] In order to compare the adhesive strength of the adhesive bead 8 according to the present embodiment with the adhesive strength of the adhesive bead in the curing step of the conventional liquid crystal cell sealant and the adhesive bead, the following comparison was made. Made a sample.

This comparative sample was prepared by laminating a pair of electrode substrates formed in the same manner as in Example 1 described above, alternately laminating the electrode substrates and the buffer material, and setting them in an oven. Then, after pressurizing with air pressure (1 kg / cm ² ) using an air pressurizing jig,
Keep at 0 ° C.

In this case, the temperature of the electrode substrate is 150 ° C.
It took about 3 hours to reach. Then, this 150
After holding at a temperature of 1 ° C. for 1 hour, the electrode substrate is naturally cooled, and the electrode substrate is taken out.

Then, this electrode substrate was cut into a 35 mm square, and the adhesive strength of the adhesive bead was similarly measured by a shearing method. Table 2 shows the measurement results indicating the adhesive strength of the adhesive bead at this time.

[0035]

[Table 2] As is clear from this comparison result, Example 1 shown in Table 1 was used.
In the adhesive bead described above, the heat generated by the heating element 4 is generated by the electrode substrates 1a, 1 via the heat plate 3a and the cushioning materials 2a, 2b.
b, the heat is directly transferred to the entire surface of the electrode substrate 1.
Since the temperature distributions a and 1b are uniform and the temperature rise time is short, a stable and strong adhesive strength (shear strength) is obtained for each sample.

On the other hand, in the case of the adhesive bead formed by the conventional curing process prepared for comparison shown in Table 2, the temperature is higher on the outside than on the inside of the electrode substrate due to heating in an oven (the temperature distribution is low). Since the temperature rise time is too slow, there is a part with extremely low adhesive strength, and the measurement of the adhesive strength (shear strength) of the sample (Sample Nos. 1 and 2 in Table 2) is not sufficient. It was possible, and the average value of the adhesive strength (shear strength) of each sample was lower than that of Example 1.
In addition, the average value of the adhesive strength of the adhesive bead according to the conventional process shown in Table 2 is a value only for those for which the adhesive strength (shear strength) could be measured.

(Embodiment 2) In this embodiment, as shown in FIG. 1, a liquid crystal cell is formed by screen printing on one glass substrate (plate thickness: 1.1 mm) constituting each pair of electrode substrates 1a and 1b. Sealant (for example, product name: Structbond XN-21-F, manufactured by Mitsui Toatsu Chemicals Co., Ltd.), and then an adhesive bead (for example, having an average particle size of about 5.6 μm)
Toray Corp., trade name: Trepearl Type III) was sprayed at an average density of 80 pieces per 1 mm ² .

Further, a spacer having an average particle size of about 1.04 μm (for example, a product of Catalyst Kasei Kogyo Co., Ltd., on the other glass substrate (having a thickness of 1.1 mm) constituting each pair of electrode substrates 1a and 1b) : Silica microbeads) at an average density of 300 per mm ² .

Then, the two glass substrates were bonded to form a pair of electrode substrates 1a and 1b.

Then, after curing the electrode substrates 1a and 1b in the same manner as in Example 1, a pyrimidine-based ferroelectric liquid crystal having the following phase transition temperature is injected, and as shown in FIG. The liquid crystal panel 10 was created.

[0041] Then, the liquid crystal panel 10 on which the electric mounting according to the present embodiment described above is performed and the electrode substrate bonded by the conventional liquid crystal cell sealing agent and the adhesive bead curing method of the first embodiment,
A shock resistance test with a liquid crystal panel of a comparative sample prepared by injecting the above-described ferroelectric liquid crystal and performing electrical mounting was performed using a 50 G
Was performed by a drop test.

As a result of this drop test (impact resistance test), no disturbance was found in the orientation of the liquid crystal of the liquid crystal panel 10 according to the present embodiment. However, as shown in FIG. The alignment of the liquid crystal located on both sides 11a and 11b (shaded portions) was disturbed.

As described above, the curing step of the liquid crystal cell sealant and the adhesive bead according to the present embodiment shortens the curing time and increases the adhesive strength of the adhesive bead to improve the impact resistance of the liquid crystal element. Performance can be improved.

Further, without using the heat plates 3a, 3b, the heating element 4 is provided on the pair of electrode substrates 1a, 1b with the cushioning material 2.
The electrode substrates 1a and 1b may be heated through the electrodes a and 2b.

[0045]

As described above, according to the present invention,
After the heating elements are respectively arranged and laminated on both sides of each of the plurality of paired electrode substrates via a buffer and a heat plate, a plurality of each pair of electrode substrates and a plurality of buffer Simultaneously pressurize a plurality of heat plates and a plurality of heating elements, generate heat from the plurality of heating elements, and cure the sealing material for liquid crystal cells and adhesive beads to uniformly heat the entire surface of the electrode substrate. And the heating time can be shortened.

Therefore, by obtaining a sufficient adhesive strength of the adhesive bead, it is possible to enhance the impact resistance of the liquid crystal element to be produced, and to shorten the curing treatment time, thereby improving the liquid crystal element. Manufacturing efficiency can be improved.

Further, since it is only necessary to use a heating element corresponding to a large-sized electrode substrate, equipment such as a large oven for heating the electrode substrate as in the related art is not required, and cost is reduced. Reduction can be achieved.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a curing step of a liquid crystal cell sealant and an adhesive bead according to an embodiment of the present invention.

FIG. 2 is a diagram schematically showing the disorder of the orientation of liquid crystal in a drop test of a liquid crystal panel prepared for a comparative sample.

[Explanation of symbols]

 1a, 1b Electrode substrate 2a, 2b Buffer material 3a, 3b Heat plate 4 Heating element 5 Metal material 7 Liquid crystal cell sealant 8 Adhesive bead 10 Liquid crystal panel

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G02F 1/1339

Claims (4)

(57) [Claims] (1)A first method of preparing a plurality of paired electrode substrates;
Process and For each of the plurality of pairs of electrode substrates, the pair of electrode substrates
Liquid crystal is sealed between the pair of electrode substrates on one of the electrodes.
Sealing material for a liquid crystal cell for entering, and the pair of electrodes
A second step of mounting an adhesive bead for bonding the substrate; After the second step, the plurality of each pair of electrode substrates is removed.
A third step of laminating each, After the third step, each of the plurality of the
On both sides of a pair of electrode substrates, buffer material and heat plate
Fourth step of arranging and stacking heating elements via
When, After the fourth step, a pair of the plurality of stacked electrodes are stacked.
Polar substrate, the plurality of cushioning materials, the plurality of heat presses.
And the plurality of heating elements are pressed together to form the plurality of heating elements.
By causing the heating elements to generate heat, the liquid crystal cell sealing material and
A fifth step of curing the adhesive beads.
To A method for manufacturing a liquid crystal element, comprising: 2. The method according to claim 1, wherein the heating element is formed in a planar shape and has a size corresponding to the electrode substrate. 3. The method according to claim 1, wherein the sealant includes a one-component thermosetting epoxy adhesive. 4. The method according to claim 1, wherein the adhesive beads are of a hot melt type including a thermosetting epoxy adhesive for spot bonding the pair of electrode substrates.