JPH08136905A - Substrate for liquid crystal display panel and its production - Google Patents

Abstract

PURPOSE: To provide a method for producing a substrate for a liquid crystal display panel having excellent gas permeation resistance and good surface smoothness with an inexpensive and simple method. CONSTITUTION: This process for producing the substrate for the liquid crystal display panel consists of a stage for applying a UV curing resin 22 on a base maternal film or sheet 1b having a smooth surface, a stage for forming a UV curing resin film or sheet by irradiating the UV curing resin with UV rays (33 to 35) to cure the resin, a stage for forming laminated films or sheets 6 by holding both surfaces of the film 5 having a gas barrier property with two sheets of the UV curing resin films or sheets via the UV curing resin films or sheets and a stage for irradiating the laminated films or sheets with UV rays to cure and sticking these films or sheets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display panel substrate and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a substrate for a liquid crystal display panel, a glass substrate has been conventionally used in many cases, but the use of a plastic substrate is gradually increasing as the liquid crystal display panel is incorporated into a portable device. . The plastic substrate has advantages over the glass substrate such as lighter weight, flexibility and superior impact resistance, but on the other hand, it has a disadvantage that the surface smoothness is inferior to the glass substrate.

The surface of the liquid crystal display panel substrate which is in contact with the liquid crystal material is required to have liquid crystal resistance and smoothness. In particular, in the case of the super twisted nematic (STN) method in which the twist angle of the liquid crystal is 180 ° or more, extremely high accuracy is required for the distance between the substrates (cell gap), and even slight irregularities on the substrate surface cause a display contrast. Lead to a decline. Therefore, the surface smoothness required for the STN type liquid crystal display panel substrate is a center line average surface roughness (Ra) value of 0.5 μm or less, preferably 0.2 μm or less, and more preferably 0.1 μm. It is said that

As a method for manufacturing a plastic liquid crystal substrate, a solution casting method or a melt extrusion method is usually used. However, a single layer film or sheet formed by these manufacturing methods has a high degree of accuracy as described above. It is extremely difficult to realize the surface smoothness of. Therefore, various proposals have been made to improve the smoothness of the substrate surface.

For example, Japanese Patent Laid-Open No. 4-308815 proposes to use a thermal transfer roll or an excimer laser in order to reduce the surface roughness pitch of the plastic flexible substrate on the side in contact with the liquid crystal layer. Has been done. However, with such a method, it is difficult to evenly smooth the entire substrate even if the unevenness of the partial substrate can be flattened to some extent.

Further, in Japanese Patent Laid-Open No. 5-57831, a base material layer made of a resin such as polycarbonate or polymethylmethacrylate molded by a casting method or an extrusion method, a gas permeable resin layer, and a cured crosslinkable resin are formed. After casting a resin solution for forming a resin layer on a lower layer on which layers and the like are laminated, the residual solvent amount is 5 to 10
Proposals have been made such as drying to 0% by weight, contacting a pressure-bonding material having a surface roughness of 0.5 μm or less on the semi-dried film, and drying and curing. In this case, in addition to the problem that the drying step is required twice, it is inefficient because it is dried and cured while the pressure-bonding material is kept in contact. On the other hand, if the pressure-bonding material is peeled off and then dried, There is a problem that the surface smoothness is lowered during peeling and drying.

For these methods, Japanese Patent Laid-Open No. 5-162
No. 228, a liquid of an active energy ray-curable resin composition is supplied into a gap between a base material sheet and a smoothing template material having a smooth surface so that these are sandwiched between the above two layers. Then, it has been proposed to cure the active energy ray-curable resin composition by irradiation with active energy rays. This method can be evaluated as a substrate having good transferability on a flat surface and good surface smoothness because curing can be performed while the smoothing template material is kept in contact with the base material sheet and the smoothing template material. It is extremely difficult to maintain a constant gap.

The second problem of the plastic substrate as compared with the glass substrate is that it does not have sufficient shielding properties against gases such as oxygen and water vapor. Polycarbonate (PC), polyether sulfone (PES), polyarylate (PAr) and other materials used as substrate materials all have high gas permeability, so liquid crystal panels using these as substrates can be used for long periods of time. If so, bubbles may be generated in the liquid crystal layer, which may cause display defects. For the purpose of preventing this, a gas barrier layer made of a material having a gas barrier property, for example, a thin film of polyvinyl alcohol (PVA) or polyvinylidene chloride is provided.

The substrate provided with such a gas barrier layer has a structure in which a gas barrier layer is formed on the outside (one side or both sides) of a base film or sheet, and the gas barrier layer is sandwiched inside the base film or sheet. There is a so-called "sandwich" type. In the former case, the surface hardness, heat resistance and solvent resistance of the gas barrier layer are low,
It is necessary to further form a protective layer such as a hard coat on it. On the other hand, for example, JP-A-61-1512
The latter "sandwich" type disclosed in Japanese Patent Laid-Open No. 8 and Japanese Patent Laid-Open No. 61-69027 has an advantage that a surface protective layer is not necessarily required.

In the method of manufacturing a substrate as described above, it is necessary to further form a new protective layer on the film or sheet as the base material in order to smooth the surface and improve the gas barrier property. This means that when considering the manufacturing process of the entire substrate,
A two-step process of forming a base film or sheet and forming a protective layer is required, which causes a cost increase.

Further, in the case where the protective layer is made of a material having a hardness and an elastic modulus different from those of the base material, if the protective layer is formed on only one side of the substrate, the substrate may be deformed such as warped during processing.
Not preferred. However, if the protective layers are provided on both sides of the substrate, the cost will be further increased.

The above-mentioned "sandwich" type substrate having a structure in which the gas barrier layer is sandwiched between two substrate films is an effective method from the viewpoint of preventing deformation during processing. The problem is that most of the materials used for the gas barrier layer have low adhesion to the base film. Therefore, at the time of bonding, it is necessary to interpose an adhesive layer between both layers as shown in FIG. 2, and steps of applying, drying and curing the adhesive are added, which eventually leads to an increase in manufacturing cost.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a substrate for a liquid crystal display panel which has excellent gas permeation resistance and good surface smoothness. It is to provide an inexpensive and simple manufacturing method.

[0014]

The present invention according to claim 1 has a structure in which two ultraviolet curable resin films or sheets are laminated and integrated on both sides of a film having a gas barrier property. The gist of this is a panel substrate.

The present invention according to claim 2 comprises the step of applying an ultraviolet curable resin on a base material film or sheet having a smooth surface, and irradiating the ultraviolet curable resin with ultraviolet rays to cure the ultraviolet curable resin film or A step of forming a sheet, a step of sandwiching both sides of a film having a gas barrier property with the two ultraviolet curable resin films or sheets through the ultraviolet curable resin film or sheet, and forming a laminated film or sheet; The gist of the invention is a method for producing a substrate for a liquid crystal display panel, which comprises a step of irradiating the laminated film or sheet with ultraviolet rays, curing and adhering.

In the present invention, the film having a gas barrier property is not particularly limited in its kind, but for example, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer or a graft polymer thereof may be used. , Polyvinyl butyral, polyacrylonitrile, vinylidene halide polymers such as polyvinylidene chloride, polytetrafluoroethylene and polytrifluoromonochloroethylene.

The thickness of the film having a gas barrier property formed from the above resin is appropriately set depending on the application and the kind of the above resin, but is generally 5 to 30.
Those having a size of about μm are preferably used.

The type of the ultraviolet curable resin used in the present invention is not particularly limited, but it is necessary that the ultraviolet curable resin has a certain degree of transparency in view of its use as a substrate for a liquid crystal display panel.
When formed into a film or sheet, the total light transmittance of the film or sheet is 60% or more, more preferably 80% or more. In addition, since the substrate is exposed to a high temperature of about 100 to 150 ° C. in the manufacturing process of the liquid crystal display panel substrate, particularly in the process of forming the alignment film and the transparent conductive film, heat resistance that can withstand these temperatures. is necessary.

Examples of the UV-curable resin include photopolymerizable prepolymers such as urethane acrylate, polyester acrylate, epoxy acrylate and polyol acrylate, and one or more (meth) acryloyloxy groups in the molecule, such as 2-hydroxy. Ethyl acrylate, 2-hydroxybutyl acrylate, benzyl acrylate, phenoxyethyl acrylate, tetraethylene glycol diacrylate, tripropylene glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate,
A photopolymerization system including a photopolymerizable monomer such as pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, and a photopolymerization initiator can be used.

The thickness of the film or sheet formed from the above ultraviolet curable resin is appropriately set depending on the application, but generally, a thickness of about 15 to 500 μm is preferably used.

The substrate film used in the step of forming the above ultraviolet curable resin film or sheet has a center line average surface roughness of 0.5 μm or less, and examples of materials constituting these include: Polycarbonate,
Examples thereof include polymethylmethacrylate, polyethersulfone, polysulfone, polyarylate, polyetheretherketone, polyamide, polyimide, polyester, cellulose triacetate, polyetherimide, phenoxyurethane, and epoxy resin.

In the present invention according to claim 2, the method of laminating and laminating the ultraviolet curable resin film or sheet and the film having a gas barrier property can be arbitrarily selected and implemented, but the ultraviolet curable resin is preferable to other plastic films. Considering that it has adhesiveness, in the step of forming an ultraviolet curable resin film or sheet, the irradiation amount of ultraviolet rays is set so that the ultraviolet curable resin film or sheet is in a semi-cured state that can retain its shape. And a step of forming a laminated film or sheet by sandwiching the base film or sheet between the two sheets of the film having gas barrier properties via the above-mentioned semi-cured UV-curable resin film or sheet, From the step of irradiating the laminated film or sheet connected to The method for manufacturing a substrate for a liquid crystal display panel according to the present invention does not particularly require a step of bonding the ultraviolet curable resin film or sheet and a film having a gas barrier property using an adhesive, so that the manufacturing process can be simplified. In addition, various effects such as enhancing the optical performance of the obtained liquid crystal display panel substrate can be exhibited.

As described above, in the step of forming a laminated film or sheet, at least one of the two UV-curable resin films or sheets is in a semi-cured state (state in which it is not completely cured) capable of retaining its shape. To form a laminated film or sheet, and irradiate the laminated film or sheet with ultraviolet rays to cure the laminated film or sheet, whereby the resulting liquid crystal display panel substrate can be more firmly bonded.

FIG. 1 shows a sectional view of an example of the liquid crystal display panel substrate of the present invention according to claim 1. As shown in the drawing, the ultraviolet curable resin film or sheet 2a without an adhesive is used. It is firmly bonded directly to the film having a gas barrier property due to the photocurability of 2b.

The liquid crystal display panel substrate and the method of manufacturing the same according to the present invention have a gas barrier property when applied to an electric device which is used only in an environment in which proper air conditioning is performed and humidity resistance is not required. Without using the film having, a UV curable resin film or sheet obtained by applying a UV curable resin on a base film or sheet having a smooth surface, irradiating the UV curable resin with ultraviolet rays, and curing the same. It can be used as a substrate for a liquid crystal display panel obtained by laminating the base material film or sheet so that they are located on the outer side, irradiating with ultraviolet rays, and curing. The liquid crystal display panel substrate satisfies all the liquid crystal display panel substrate suitability of the liquid crystal display panel substrate of the present invention having good surface smoothness except the gas barrier property.

Further, the above-mentioned method for producing a substrate for a liquid crystal display panel comprises a step of applying an ultraviolet curable resin on a base material film or sheet having a smooth surface, and irradiating the ultraviolet curable resin with ultraviolet rays to cure the ultraviolet ray and curing the ultraviolet rays. A step of forming a cured resin film or sheet, a step of laminating the two ultraviolet curable resin films or sheets so that the base film or sheet is located outside, respectively, to form a laminated film or sheet; As a method for producing a substrate for a liquid crystal display panel, which comprises a step of irradiating a film or sheet with ultraviolet rays, curing and adhering the substrate, the substrate for a liquid crystal display panel of the present invention has an excellent substrate for a liquid crystal display panel. The process is simplified, and therefore, the effect of reducing the manufacturing cost can be directly maintained.

[0027]

According to the present invention, as described above, an ultraviolet curable resin film or sheet is formed by applying an ultraviolet curable resin on a base film or sheet having a smooth surface having a center line average surface roughness of 0.5 μm or less. Therefore, the surface in contact with the liquid crystal effectively transfers the surface of the base film or sheet having the above-mentioned smooth surface and is formed into a smooth surface, so that the surface smoothness sufficient as a substrate for an STN liquid crystal display panel is obtained. Have.

According to a second aspect of the present invention, the surface in contact with the liquid crystal has sufficient surface smoothness as a substrate for STN type liquid crystal display panel, and the ultraviolet curable resin film or the ultraviolet curable resin film on both sides of the film having gas barrier property. Sheets are laminated and attached by an extremely simple method by light irradiation without adding a new thin layer formation or adhesive coating process, so liquid crystal display with excellent long-term reliability due to excellent gas barrier properties. It is possible to manufacture a panel substrate.

Further, unlike the conventional method in which a base film is laminated on a film having a gas barrier property with an adhesive,
By directly laminating the ultraviolet curable resin film or sheet and the film having a gas barrier property, it is possible to simplify the process and reduce the manufacturing cost. The reliability of the obtained liquid crystal display panel substrate is also superior to that of the conventional method. In addition, since the structure of the liquid crystal display panel substrate is symmetrical with respect to the thickness direction of the substrate, there is no problem such as curling of the substrate during processing, and the handling property in the post process is also good. .

[0030]

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

(Embodiment 1) FIG. 3 is a schematic view of steps showing an example of a method for manufacturing a liquid crystal display panel substrate of the present invention according to claim 2. In the figure, 1a and 1b are base films or sheets having smooth surfaces, and ultraviolet curable resins 21 and 22 are supplied from the ultraviolet curable resin supply tanks 23 and 24 onto the base film or sheets 1a and 1b. , The doctor blades 31, 32 are used for coating. Then
The applied ultraviolet curable resin is used in the ultraviolet irradiation device 3
Ultraviolet rays are irradiated by 3, 34 and cured to form ultraviolet curable resin films or sheets 3a, 3b.
Reference numeral 5 is a film having a gas barrier property, and the laminated film or sheet 6 is sandwiched between the two base film or sheets 1a and 1b by the pinch roll 41 through the ultraviolet curable resin film or sheets 3a and 3b. It is formed. Further, the laminated film or sheet 6
Is irradiated with ultraviolet rays by the ultraviolet irradiation device 35 and cured to be cured with the ultraviolet curable resin film or sheet 3a, 3b.
The film 5 having gas barrier properties is firmly attached.

In this example, the base film has a thickness of 50 μm.
m, the surface roughness of 0.02 μm polyester film (manufactured by Teijin Ltd., trade name: Tetron OX) 1a and 1b, respectively, and urethane acrylate (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: UV-7000B) 40 is supplied thereon. 40 parts by weight of a bifunctional acrylic monomer (Osaka Organic Synthesis Co., Ltd., trade name: Biscoat # 700), 20 parts by weight of pentaerythritol tetraacrylate, 1 part by weight of a polymerization initiator (produced by Merck, trade name: Darocur 1173). The ultraviolet curable resin 2a, 2b made of
mJ / cm ² of ultraviolet light was irradiated the ultraviolet curable resin 2
By curing Nos. 1 and 22, semi-cured UV curable resin films 3a and 3b having a thickness of 42 μm were obtained.

The above two ultraviolet curable resin films 3a,
An ethylene-vinyl alcohol copolymer having a gas barrier property with a thickness of 15 μm between 3b (molar ratio 50:50).
The film 5 is supplied, and both sides of the gas barrier film 5 are sandwiched between the base polyester films 1a and 1b via the ultraviolet curable resin films 3a and 3b, and the pinch roll 41 forms the laminated film 6. . Then, the total amount of light is 500 m by the irradiation device 35.
J / cm ² ultraviolet rays were applied to firmly bond the ultraviolet curable resin films or sheets 3a and 3b to the film 5 having gas barrier properties. Finally, the base polyester films 1a and 1b on both sides were peeled and removed to obtain a liquid crystal display panel substrate having a thickness of 100 μm.

The surface roughness of the obtained liquid crystal display panel substrate was measured by a non-contact three-dimensional surface roughness meter, and the center line average surface roughness (Ra) was 0.1 μm or less. In addition, the light transmittance of the liquid crystal display panel substrate is 90% or more, the oxygen transmittance is ² cc / atm · m ² · day, and the retardation value is 5 nm or less, which shows good optical characteristics as a liquid crystal display panel substrate. Had. Next, a heat resistance test (70 ° C. × 500) of the obtained liquid crystal display panel substrate
Time) and a humidity resistance test (60 ° C. × 90% RH × 500 hours). As a result of both of the above-mentioned tests, in any of the tests, no defect in appearance such as peeling occurred on the substrate.

Example 2 The same polyester film as in Example 1 was used for the base films 1a and 1b, and an epoxy acrylate (manufactured by Somar Co., trade name: CN1) was used.
04) 45 parts by weight, isobornyl acrylate (Kyoeisha Chemical Co., Ltd., trade name: Light acrylate IB-XA) 3
0 parts by weight, trimethylolpropane triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name: Biscoat # 29)
5) UV curable resin 2 comprising 25 parts by weight and 1 part by weight of a polymerization initiator (manufactured by Merck & Co., trade name: Darocur 1173)
1 and 22 are applied, and then ultraviolet irradiation devices 33 and 34
Thus, the ultraviolet curable resins 21 and 22 were cured by irradiating ultraviolet rays in the same manner as in Example 1 to obtain semi-cured films 3a and 3b having a thickness of 150 μm. The above two laminated films 3
A polyvinylidene chloride film 5 having a gas barrier property and having a thickness of 18 μm is supplied from between a and 3b, and the both surfaces of the gas barrier film 5 are provided with the base polyester film 1a through the ultraviolet curable resin films 3a and 3b. 1b, and the pinch roll 41 forms the laminated film 6.

Next, the total amount of light 5
Ultraviolet rays of 00 mJ / cm ² were applied to firmly bond the ultraviolet curable resin films or sheets 3a and 3b to the film 5 having gas barrier properties. Finally, the base polyester films 1a and 1b on both sides are peeled and removed to a thickness of 100.
A substrate for liquid crystal display panel having a thickness of μm was obtained.

The surface roughness of the obtained liquid crystal display panel substrate was measured by a non-contact three-dimensional surface roughness meter, and the value of the center line average surface roughness (Ra) was 0.1 μm or less. Further, the liquid crystal display panel substrate has a light transmittance of 85% or more, a retardation value of 15 nm or less, and an oxygen transmittance of 3.2 cc / atm · m ² · day, which has good optical characteristics and a gas barrier as a liquid crystal display panel substrate. Had sex.

(Embodiment 3) FIG. 4 is a schematic view of steps showing an example of a method for manufacturing a liquid crystal display panel substrate of the present invention without interposing a film having a gas barrier property. In the figure, 1
a and 1b are base films or sheets having a smooth surface, and ultraviolet curable resins 21 and 22 are supplied from the ultraviolet curable resin supply tanks 23 and 24 onto the base film or sheets 1a and 1b, and a doctor blade 31, 32
Applied by. Next, the applied ultraviolet curable resin is irradiated with ultraviolet rays by the ultraviolet irradiation devices 33 and 34 and cured to form ultraviolet curable resin films or sheets 3a and 3b. The two UV curable resin films or sheets 3a and 3b are laminated by a pinch roll 41 so that the base film or sheets 1a and 1b are located outside, respectively, to form a laminated film or sheet 10, which is irradiated with ultraviolet rays, When cured, a liquid crystal display panel substrate is manufactured.

In this example, the base films 1a and 1b are
Using the same polyester film as in Example 1,
Apply the same UV curable resin 2a, 2b as in Example 1, and then
Then, with the high pressure mercury lamps (400w) 33 and 34,
Integrated light intensity 450 mJ / cm ²Same ultraviolet rays as in Example 1
Irradiate under one condition to cure the UV curable resins 21 and 22.
50 μm thick semi-cured UV curable resin film 3
a and 3b were obtained.

Two pieces of the ultraviolet curable resin film 3a,
3b is laminated so that the base films 1a and 1b are located outside, respectively, to form a laminated film, which is irradiated with ultraviolet rays under the same conditions as in Example 1 so that the ultraviolet curable resins 21 and 22 described above are irradiated.
Was cured and both were firmly adhered. Finally, the base polyester films 1a and 1b on both sides are peeled and removed to have a thickness of 1
A substrate for a liquid crystal display panel of 00 μm was obtained.

The surface roughness of the obtained liquid crystal display panel substrate was measured by a non-contact three-dimensional surface roughness meter, and the center line average surface roughness (Ra) was 0.1 μm or less. Further, the light transmittance of the liquid crystal display panel substrate was 90% or more and the retardation value was 5 nm or less, which had good optical characteristics and gas barrier properties as a liquid crystal display panel substrate. Next, a heat resistance test (70 ° C. × 500 hours) and a humidity resistance test (60 ° C. × 90%) of the obtained liquid crystal display panel substrate
RH × 500 hours). As a result of both of the above-mentioned tests, in any of the tests, no defect in appearance such as peeling occurred on the substrate.

(Example 4) As the base films 1a and 1b, the same polyester film as in Example 1 was used, and an epoxy acrylate (manufactured by Somar Co., trade name: CN1) was used.
04) 45 parts by weight, isobornyl acrylate (Kyoeisha Chemical Co., Ltd., trade name: Light acrylate IB-XA) 3
0 parts by weight, trimethylolpropane triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name: Biscoat # 29)
5) UV curable resin 2 comprising 25 parts by weight and 1 part by weight of a polymerization initiator (manufactured by Merck & Co., trade name: Darocur 1173)
1 and 22 are applied, and then ultraviolet irradiation devices 33 and 34
The ultraviolet curable resins 21 and 22 were cured by irradiating ultraviolet rays having an integrated light amount of 250 mJ / cm ² respectively to obtain semi-cured films 3 a and 3 b having a thickness of 150 μm.

Two sheets of the above ultraviolet curable resin film 3a,
3b is laminated so that the base films 1a and 1b are located outside, respectively, to form a laminated film, which is irradiated with ultraviolet rays under the same conditions as in Example 1 so that the ultraviolet curable resins 21 and 22 described above are irradiated.
Was cured and both were firmly adhered. Finally, the base polyester films 1a and 1b on both sides are peeled and removed to a thickness of 3
A substrate for a liquid crystal display panel of 00 μm was obtained.

The surface roughness of the obtained liquid crystal display panel substrate was measured by a non-contact three-dimensional surface roughness tester, and the center line average surface roughness (Ra) was 0.1 μm or less. Further, the liquid crystal display panel substrate had a light transmittance of 85% or more and a retardation value of 15 nm or less, and had good optical properties and gas barrier properties as a liquid crystal display panel substrate.

(Comparative Example 1) As the film 5 having a gas barrier property, the same film as in Example 1 was used, and the thickness 3 was set on both sides thereof.
A 5 μm polyether sulfone film was directly laminated to obtain a liquid crystal display panel substrate having a thickness of 85 μm. The light transmittance of the obtained liquid crystal display panel substrate is 90% or more,
Retardation value is 5nm or less, oxygen transmission rate is 2cc
It was / atm · m ² · day, but as a result of carrying out a heat resistance test at 70 ° C. × 500 hours and a humidity resistance test at 60 ° C. × 90% RH × 500 hours, peeling occurred at the edge of the substrate.

[0046]

As described above, the present invention applies an ultraviolet curable resin to a base film or sheet having a smooth surface having a center line average surface roughness of 0.5 μm or less to form an ultraviolet curable resin film or sheet. Is formed, the surface in contact with the liquid crystal is effectively transferred to the surface of the base film or sheet having the above-mentioned smooth surface to form a smooth surface.
It has sufficient surface smoothness as an N-type liquid crystal display panel substrate.

According to a second aspect of the present invention, the surface in contact with the liquid crystal has a surface smoothness sufficient as a substrate for an STN liquid crystal display panel, and the ultraviolet curable resin film or the ultraviolet curable resin film is provided on both sides of a film having a gas barrier property. Sheets are laminated and laminated by an extremely simple method by light irradiation without adding a new thin film layer formation or adhesive coating process. Therefore, a liquid crystal display panel with excellent gas barrier properties and high long-term reliability The substrate can be manufactured.

Further, unlike the conventional method in which a base film is laminated on a film having a gas barrier property with an adhesive,
By directly laminating the ultraviolet curable resin film or sheet and the film having a gas barrier property, it is possible to simplify the process and reduce the manufacturing cost. The reliability of the obtained liquid crystal display panel substrate is also superior to that of the conventional method.

Further, since the structure of the liquid crystal display panel substrate is symmetrical with respect to the thickness direction of the substrate, there is no problem such as curling of the substrate at the time of processing, and the handling property in the subsequent process is also improved. It is good.

[0050]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a liquid crystal display panel substrate of the present invention according to claim 1.

FIG. 2 is a cross-sectional view showing an example of an existing liquid crystal display panel substrate in which a transparent film or sheet and a film having a gas barrier property are bonded together using an adhesive layer.

FIG. 3 is a schematic diagram of a step showing an embodiment of a method for manufacturing a liquid crystal display panel substrate of the present invention according to claim 2.

FIG. 4 is a schematic view of a step showing an embodiment of a method for producing a substrate for a liquid crystal display panel of the present invention without interposing a film having a gas barrier property.

[Explanation of symbols]

 1a, b Base film or sheet 21, 22 UV curable resin 23, 24 UV curable resin supply tank 3a, 3b UV curable resin film or sheet 31, 32 Doctor knife 33-35 UV irradiation device 41 Pinch roll 5 Having gas barrier property Film 6 Laminated film or sheet 7a, 7b Transparent film or sheet 8 Film having gas barrier properties 9a, 9b Adhesive layer 10 Laminated film or sheet

Claims (2)

[Claims] 1. A substrate for a liquid crystal display panel, which has a structure in which two ultraviolet curable resin films or sheets are laminated and integrated on both sides of a film having a gas barrier property. 2. A step of applying an ultraviolet curable resin on a base film or sheet having a smooth surface, a step of irradiating the ultraviolet curable resin with ultraviolet rays and curing the resin to form an ultraviolet curable resin film or sheet, A step of forming a laminated film or sheet by sandwiching both surfaces of a film having a gas barrier property with the ultraviolet curable resin film or sheet with the ultraviolet curable resin film or sheet interposed therebetween, and forming an ultraviolet ray on the laminated film or sheet. The method for producing a substrate for a liquid crystal display panel, which comprises a step of irradiating, curing, and adhering.