JP4505864B2 - Manufacturing method of transfer type color filter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a color filter built in a color filter liquid crystal display device or the like. More specifically, the present invention relates to a transfer color filter manufacturing method.
[0002]
[Prior art]
[0003]
In recent years, with the development of personal computers, particularly with the development of portable personal computers, the demand for color liquid crystal display devices tends to increase. However, cost reduction is required for further spread.
Conventionally, various methods have been tried in order to reduce the cost of the color filter incorporated in the color liquid crystal display device.
The first method is a pigment dispersion method. In this method, first, a photosensitive resin layer in which a pigment is dispersed is formed on a substrate, and this is patterned to obtain a single color pattern of the color filter layer. By repeating this process a predetermined number of times, for example, color filter layers of three colors of red (R), green (G), and blue (B) are formed.
[0004]
The second method is a staining method. In this dyeing method, an aqueous polymer material, which is a material to be dyed, is first formed on a glass substrate, this is patterned, and the resulting pattern is immersed in a dyeing bath and colored in a color filter layer monochromatic pattern Get. By repeating this process three times, a color filter layer of three colors of red (R), green (G), and blue (B) is formed.
The third method is an electrodeposition method. In this method, first, a transparent electrode is patterned on a substrate and immersed in an electrodeposition coating liquid composed of a pigment, a resin, an electrolytic solution, and the like to obtain a colored color filter layer monochromatic pattern. This process is repeated three times, and then fired to form three color filter layers of red (R), green (G), and blue (B).
[0005]
The fourth method is a printing method. In this method, an ink in which a pigment is dispersed in a thermosetting resin is printed on a substrate to obtain a colored color filter layer monochromatic pattern. This process is repeated three times, and then fired to form three color filter layers of red (R), green (G), and blue (B).
However, when a color filter for a liquid crystal display device is manufactured, even if the above-described various methods are used, if the color filter is manufactured by means of directly forming the color filter layer on the substrate, the cost is sufficiently high. It cannot be handled.
[0006]
Therefore, in order to sufficiently cope with the cost, for example, a transfer sheet using a thin metal plate having a thermal expansion coefficient almost the same as that of a glass substrate used for a color filter as a transfer base material is used to simplify the manufacturing process. A method of manufacturing a color filter has been proposed. In this method, a color filter layer is once formed on a transfer substrate, and then the color filter layer is transferred onto a glass substrate.
[0007]
According to this method, the surface of the obtained color filter is highly smooth, and the step of repeatedly forming a predetermined number of colors such as red (R), green (G), and blue (B) is performed on the glass substrate. In contrast, it is performed separately on the transfer substrate. Therefore, it can be said that it is preferable in terms of production efficiency as a whole process for producing a color filter for a liquid crystal display device because a troublesome process for producing a color filter can be performed in a process separate from the color filter production line for the glass substrate.
[0008]
On the other hand, in recent years, with the advancement of liquid crystal display devices, liquid crystal display devices having a larger size, for example, from a size of 5 inches diagonal to 8 inches, 10 inches, 12 inches, and 14 inches are gradually put into practical use. It has come to be.
Until now, in order to efficiently produce such a liquid crystal display device, a method of manufacturing a liquid crystal display device of these sizes on a single glass substrate in a multi-face has been taken.
For example, the manufacture of a liquid crystal display device having a diagonal size of 8 inches has four faces on a glass substrate of about 300 × 400 mm square, and the manufacture of a liquid crystal display device having a diagonal size of 10 inches is about 400 × 500 mm square glass. The four-sided substrate and the 12-inch diagonal liquid crystal display device are manufactured on the six-sided glass substrate of about 550 × 650 mm square, that is, the size of the glass substrate for manufacturing the liquid crystal display device. As the size of diagonal inches increases, the size gradually increases.
[0009]
In the same way, in the manufacturing method of the transfer type color filter which simplifies the manufacturing process using the transfer sheet as the glass substrate for manufacturing the liquid crystal display device is enlarged, for example, 12 inches diagonal. When manufacturing a color filter for a liquid crystal display device, a color sheet is transferred to a neighboring glass substrate of about 550 × 650 mm square using six transfer sheets of about 12 inches diagonal to each adjacent position. A method of forming a filter layer is employed.
[0010]
At this time, when the transfer sheet on the first surface having a diagonal of about 12 inches is pressed against the glass substrate through the adhesive, the adhesive extends, so that the excess adhesive protrudes from the peripheral portion of the transfer sheet. Excess adhesive protruding from the peripheral portion of the transfer sheet on the first surface is completely removed, and the transfer sheet on the second surface is pressed to an adjacent position with high accuracy. However, conventionally used adhesives are water-insoluble, and excess adhesive that has protruded has been removed using an organic solvent.
This manufacturing process using an organic solvent is not preferable in terms of work safety, health, and environmental effects.
[0011]
In addition, the conventional adhesive is applied to the opposite surfaces of both the transfer sheet and the glass substrate, both are heated, and when the adhesive is in a semi-dried state, the transfer sheet and the glass substrate are brought into close contact with each other and pressed, and then irradiated with ultraviolet rays. Went to cure the adhesive.
In such a heating method, even if the transfer base material of the transfer sheet and the glass substrate have substantially the same thermal expansion coefficient, the expansion speed of the two is different. A difference in size occurs between the glass substrate and the glass substrate, and a change occurs in the overall size of the transferred color filter pattern. For this reason, there has been a problem in terms of size when bonding with the counter panel constituting the liquid crystal display device.
[0012]
[Problems to be solved by the invention]
The problem in the present invention is that when a color filter layer formed on a transfer sheet is transferred onto a glass substrate to produce a transfer type color filter, the transfer sheet is brought into close contact with the glass substrate via an adhesive and pressed. Can be removed without using an organic solvent to remove the excess adhesive, and the transfer sheet coated with the adhesive and the glass substrate can be pressed and adhered without heating. It is an object of the present invention to provide a transfer type color filter manufactured using a filter adhesive. Another object of the present invention is to provide a liquid crystal display device using the transfer type color filter.
[0013]
[Means for Solving the Problems]
In the present invention, a transfer sheet composed of a transfer substrate, a release layer, a color filter layer, a light shielding layer, and the like is bonded to a predetermined position of a substrate through an adhesive, and the transfer substrate is cured after the adhesive is cured. In the transfer type color filter manufactured by removing the color filter layer and the light-shielding layer, etc. onto a substrate, the photosensitive agent-free solvent mainly comprising a resin, a dilution monomer, and a photosensitizer as the adhesive A color-type adhesive for a color filter, wherein the resin is manufactured using an adhesive for a color filter whose resin is an acrylic copolymer having an ethylenically unsaturated group and a carboxyl group is there.
[0014]
In the transfer type color filter according to the present invention, the acrylic copolymer of the adhesive has a molecular weight of 1 to 100 × 10 ³ , a double bond equivalent of 3 × 10 ³ or less, and a carboxyl group has a resin acid value. It is a transfer type color filter characterized by being an acrylic copolymer of 50-150.
[0015]
The present invention also provides the transfer type color filter according to the invention, wherein the acrylic copolymer of the adhesive contains at least 5% by weight of a thermosetting component.
[0016]
The present invention also provides the transfer type color filter according to the invention, wherein the dilution monomer has a boiling point of 200 ° C. or higher.
[0017]
The present invention also provides the transfer type color filter according to the above invention, wherein the substrate is a substrate on which a driving element TFT is formed.
[0018]
The present invention also provides a liquid crystal display device using the transfer type color filter according to the above invention.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a transfer type color filter according to the present invention will be described in detail based on an embodiment thereof.
[0020]
The color filter adhesive used in the production of the transfer type color filter according to the present invention is a photosensitive solvent-free color filter adhesive mainly composed of a resin, a dilution monomer, and a photosensitizer, wherein the resin is ethylene. Although it is an acrylic copolymer having a polymerizable unsaturated group and a carboxyl group, a thermosetting component, an additive and the like are used as necessary.
[0021]
The acrylic copolymer having an ethylenically unsaturated group and a carboxyl group preferably has a double bond equivalent of 3 × 10 ³ or less from the viewpoint of sensitivity, and the carboxyl group has a resin acid value from the viewpoint of solubility. A range of 50 to 150 is preferred. When the acid value is 50 or less, the solubility is lowered, and the adhesive cannot be completely removed and remains in the periphery of the transfer sheet on the glass substrate.
On the other hand, when the acid value is 150 or more, there is a problem that the peripheral portion of the transfer sheet cannot be obtained due to swelling when the adhesive is removed. The molecular weight of the acrylic copolymer is preferably in the range of 1 to 100 × 10 ³ , and the sensitivity is lowered when the molecular weight is 1 × 10 ³ or less, and the alkali solubility is lowered when the molecular weight is 100 × 10 ³ or more. .
[0022]
The acrylic copolymer of the color filter adhesive may be an acrylic copolymer of a monomer having a glycidyl group and an ethylenically unsaturated group such as glycidyl methacrylate (GMA) and an ethylenically unsaturated group such as acrylic acid. And a monomer having a carboxyl group and then an acid anhydride such as phthalic anhydride or tetrahydrophthalic anhydride, or an acrylic monomer having an ethylenically unsaturated group and a carboxyl group such as acrylic acid. A resin obtained by adding a monomer having a glycidyl group and an ethylenically unsaturated group, such as GMA, to the system copolymer.
In addition, phenolic novolac resin, cresol novolac resin, bisphenol type epoxy resin, etc., after adding carboxylic acid having ethylenically unsaturated group such as acrylic acid, phthalic anhydride and tetrahydrophthalic anhydride are also added. Can be used.
[0023]
As the dilution monomer for the color filter adhesive, it is preferable that the boiling point is 200 ° C. or higher so as not to cause foaming at the time of curing, and the adhesive can be diluted to an appropriate viscosity in accordance with the operation at the time of bonding and pressing. It ’s fine.
For example, a polyfunctional monomer such as dipentaerythritol hexa (meth) acrylate, a trifunctional monomer such as pentaerythritol tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1.6 Bifunctional monomers such as hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, phenoxyethyl (meth) acrylate, tricyclodecyl (meth) acrylate, isobornyl (meth) acrylate , Monofunctional monomers such as lauryl (meth) acrylate, hydroxyethyl (meth) acrylate, 2-acryloyloxyethyl monophthalate, and polyols having two or more hydroxyl groups Compound, an isocyanate compound and a hydroxyl group (meth) urethane acrylate, epoxy acrylate consisting of acrylate resins can be used in combination as appropriate.
[0024]
The photosensitizer for the color filter adhesive is not particularly limited, and includes benzophenone, diethylaminobenzophenone, methyl benzoylbenzoate, benzoin isopropyl ether, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, Benzyl dimethyl ketal, thioxanthone, diethyl thioxanthone, 2-methyl {4- (methylthio) phenyl} -2-morpholino-1-propanone, etc., and the addition amount thereof is 0.1% relative to the total amount of resin and dilution monomer. -20 parts by weight is preferred.
[0025]
Additives include polymerization inhibitors such as hydroquinone and hydroquinone monomethyl ether, adhesion imparting agents such as silane coupling agents and titanium coupling agents, and thermosetting components such as epoxy resins, polyols and melamine resins. Of these, when there are few thermosetting components, many carboxylic acid groups remain in the cured resin and the water resistance is lowered. The addition amount is preferably ½ equivalent or more with respect to the carboxylic acid in the acrylic copolymer.
[0026]
In the color filter adhesive used in the production of the transfer type color filter according to the present invention, an excess of the adhesive on the periphery of the transfer sheet can be removed by liquid phase treatment with an alkaline aqueous solution. Therefore, the influence of organic solvents on work safety, health, and environment is eliminated.
In addition, the transfer sheet and glass substrate coated with the color filter adhesive can be brought into close contact with each other and heated at room temperature without heating, resulting in a dimensional difference between the transfer sheet transfer substrate and the glass substrate. It will not be.
Furthermore, since the transfer sheet and the glass substrate are brought into close contact with each other and pressed immediately after the color filter adhesive is dropped onto the transfer sheet, it is possible to prevent the occurrence of white spots due to adhesion of foreign matters during the process.
[0027]
FIGS. 1A to 1C are explanatory views showing a multi-faceted state in which a transfer type color filter is manufactured by bonding a plurality of transfer sheets (16) to a glass substrate (4).
FIG. 1 (a) shows a transfer sheet (16) having a diagonal of about 12 inches, for example, and the shaded portion (22) is a color filter layer (11) transferred to a glass substrate (4), and a light shielding layer (12). Shows the area.
[0028]
An adhesive is dropped on the transfer sheet (16) on the first surface on which a release layer, a color filter layer, a light-shielding layer, etc. are formed in advance on a transfer substrate, for example, on a glass substrate (4) of approximately 550 × 650 mm square. When pressed through the adhesive, the adhesive spreads, so that the excess adhesive protrudes from the peripheral portion of the transfer sheet.
FIG. 1 (b) shows a state in which excess adhesive protrudes from the peripheral portion of the transfer sheet. The adhesive (15 ′) where the dot portion protrudes and the chain line (17) indicate the second and subsequent surfaces. The transfer position of the transfer sheet is shown.
[0029]
Next, the area of the color filter layer and the light shielding layer indicated by the hatched portion (22) is irradiated with light, the adhesive in this area is cured, and the light that protrudes from the peripheral portion of the transfer sheet on the first surface is not irradiated. Remove the adhesive (15 '). This is for the purpose of accurately pressing the transfer sheet on the second and subsequent surfaces to a predetermined position.
In FIG. 1 (c), after the protruding adhesive (15 ') is removed, the transfer substrate and the release layer of the transfer sheet are peeled off, and the color filter layer and light shielding layer regions indicated by the hatched portion (22) are transferred. Shows the state.
[0030]
Thereafter, in the same manner, the transfer sheet on the second surface to the sixth surface is pressed to transfer the area of the color filter layer and the light shielding layer, and the transfer mold has six faces on a glass substrate (4) of approximately 550 × 650 mm square. A color filter is formed.
[0031]
2 (a) to 2 (f) are explanatory views showing the steps of manufacturing a transfer type color filter in cross section.
FIG. 2A shows a transfer sheet (16) in which a release layer (14), a color filter layer (11), a light shielding layer (12) and the like are already formed on a transfer substrate (13).
The color filter layer (11) is formed by an arbitrary method such as a pigment dispersion method or a dyeing method, and has a pixel shape, for example, red (R), green (G), blue (B). The three primary colors.
[0032]
First, as shown in FIG. 2B, the color filter adhesive (15) is dropped onto the transfer sheet (16) on the first surface.
Next, as shown in FIG. 2 (c), for example, the glass sheet (4) of approximately 550 × 650 mm square is aligned and pressed (40) from above and below to transfer the sheet (16) and the glass substrate (4). Is adhered through the adhesive layer (15).
Then, the excess protruding adhesive (15 ′) is spread on the peripheral portion of the transfer sheet (16) on the first surface.
[0033]
Subsequently, as shown in FIG. 2 (d), a photomask (70) is overlapped and light irradiation (60) is performed on the transfer area of the color filter layer (11) and the light-shielding layer (12), and the adhesive in this area is applied. The layer (15) is cured.
Next, as shown in FIG. 2 (e), the transfer substrate (13) and the release layer (14) are peeled off, and the adhesive (15 ′) protruding to the peripheral portion of the transfer sheet (16) on the first surface. ) Is removed using an alkaline aqueous solution, and as shown in FIG. 2 (f), the color filter layer (11) and the light shielding layer (12) are disposed on the first surface of the glass substrate (4) of approximately 550 × 650 mm square. A transfer type color filter to which is transferred is obtained.
[0034]
Since the six-sided transfer sheet (16) having a diagonal of about 12 inches is attached to the approximately 550 × 650 mm square glass substrate (4), only this first surface is transferred at this stage. Subsequently, the same operation is performed to obtain a transfer type color filter having six faces attached to a glass substrate (4) of approximately 550 × 650 mm square.
[0035]
【Example】
Examples of the present invention will be specifically described below.
<Example 1>
(Preparation of transfer sheet)
First, 42 alloys (nickel weight%, remaining iron) having a thickness of 0.11 mm were used as a transfer substrate. 6 wt% polyvinyl alcohol was applied and formed to a thickness of 5 to 10 μm by a dip coater method, and then dried in an atmosphere at 150 ° C. to obtain a release layer.
On this release layer, a red acrylic pigment-dispersed photosensitive material having the following composition was applied with a reverse coater, dried and then irradiated with light through a photomask having a predetermined pattern, developed with an alkaline developer, washed with water, and washed at 150 ° C. for 5 hours. Dried for minutes.
In the same manner, green, blue, and black acrylic pigment dispersed photosensitive materials were used to form a color filter layer and a light shielding layer at predetermined positions to obtain a transfer sheet.
[0036]
The composition of the acrylic pigment dispersion used is based on the following formulation.
A: 10 parts by weight of pigment The pigment is indicated by a color index (CI) number.
Red: C.I. I. Red pigment 177
Green: C.I. I. Green pigment 36 and C.I. I. Yellow pigment 139
Blue: C.I. I. Blue pigment 15
Black: C.I. I. Black pigment 7
B: Anionic acrylic copolymer having the following composition: 10 parts by weight Methyl methacrylate 2 parts by weight Methacrylic acid 1 part by weight Hydroxy methacrylate 2 parts by weight Butyl methacrylate 2 parts by weight Cyclohexyl acrylate 3 parts by weight C: Multifunctional acrylic monomer 10 parts by weight Aronix M-300 (Toagosei Chemical Industry Co., Ltd.)
D: Photopolymerization initiator 0.5 parts by weight Irgagua 907 (Ciba Geigy)
E: 120 parts by weight of organic solvent
(Preparation of photosensitive solvent-free adhesive)
A polymer having a molecular weight of 20 × 10 ³ was obtained by using ADVN (manufactured by Otsuka Chemical Co., Ltd.) with 40 g of GMA, 60 g of methyl methacrylate (MMA) and 200 g of acetone in a nitrogen atmosphere. The polymer solution was reacted with 20 g of acrylic acid and 0.2 g of benzyldimethylamine, reacted with 25 g of tetrahydrophthalic anhydride, precipitated and precipitated with cyclohexane, and dried to obtain 130 g of a white powder. The powder resin had a molecular weight of 35 × 10 ³ and an acid value of 100.
50 g of this resin, 50 g of TMP3A, 40 g of hydroxyethyl methacrylate, 40 g of 1,6-hexanediol dimethacrylate, 10 g of biscoat # 2000 (manufactured by Osaka Organic Chemical), 10 g of 1-hydroxycyclohexyl phenyl ketone, 0.1 g of methoquinone, glycidoxypropyltri 10 g of methoxysilane and 15 g of bisphenol A diglycidyl ether were added and dissolved to obtain a photosensitive solventless adhesive.
[0038]
(Production of transfer type color filter)
The photosensitive solventless adhesive was dropped on the transfer sheet. Immediately after the dripping, the adhesive surface of the glass substrate is put on the dripped adhesive and pressed with a pressure of 1 to 5 kg / cm ² with a roll press to spread the adhesive uniformly between the transfer sheet and the glass substrate. I let you.
At this time, the protrusion generated by the overlap of the light shielding layer and the color filter layer serves as a spacer, so that the distance between the color filter layer and the glass substrate is constant at the portion where both face each other. The thickness of the color filter layer is about 1.3 μm, and the amount of protrusion of the protrusion from the color filter layer is about 0.4 μm. Thereby, the film thickness of the adhesive layer spread between the color filter layer and the glass substrate is made uniform.
[0039]
Next, the adhesive is cured by irradiating UV light at 200 mJ / cm ² from the back side of the glass substrate through a photomask that shields the region other than the color filter layer (11) to be transferred and the light shielding layer (12). The metal sheet and the release layer of the material were peeled together. Then, the protruding adhesive was removed using an alkaline aqueous solution.
Subsequently, post-baking was performed to obtain a transfer type color filter in which the color filter layer and the light shielding layer were transferred onto the glass substrate.
A similar operation was performed using a transfer sheet on the second surface at an adjacent position on the glass substrate from which the protruding adhesive was removed, but the transfer was satisfactory.
[0040]
The composition of the alkaline aqueous solution used is based on the following formulation.
Na ₂ CO ₃ ... 5 parts by weight NaOH ... 1 part by weight H ₂ O ... 200 parts by weight
【The invention's effect】
In the present invention, a transfer sheet composed of a transfer substrate, a release layer, a color filter layer, a light shielding layer, and the like is bonded to a predetermined position of a substrate via an adhesive, and the transfer substrate is peeled after the adhesive is cured. In addition, when producing a transfer type color filter by transferring a color filter layer and a light-shielding layer to a substrate, a photosensitive solvent-free color mainly composed of a resin, a dilution monomer, and a photosensitizer is used as an adhesive. Since the adhesive for a filter is manufactured using the adhesive for a color filter, which is an acrylic copolymer having an ethylenically unsaturated group and a carboxyl group, the transfer sheet is attached to the glass substrate via the adhesive. By sticking and pressing, it becomes a transfer type color filter that uses an alkaline aqueous solution instead of an organic solvent to remove the excess adhesive that protrudes.
For this reason, the manufacturing process of the transfer type color filter using this color filter adhesive is preferable in terms of work safety, health, and environmental effects.
Moreover, it becomes a transfer type color filter using the adhesive for color filters which can be made to adhere | attach and press without heating the transfer sheet and glass substrate which apply | coated the adhesive agent. For this reason, the transfer type color filter using this color filter adhesive does not cause a dimensional difference between the transfer substrate of the transfer sheet and the glass substrate.
[0042]
In the present invention, the acrylic copolymer is an acrylic copolymer having a molecular weight of 1 to 100 × 10 ³ , a double bond equivalent of 3 × 10 ³ or less, and a carboxyl group having a resin acid value of 50 to 150. It becomes a transfer type color filter using the adhesive for color filters which has favorable sensitivity and favorable alkali solubility.
In the present invention, since the acrylic copolymer contains at least 5% by weight or more of a thermosetting component, a transfer type color filter using an adhesive for color filters having good water resistance is obtained.
Moreover, since the boiling point of a dilution monomer is 200 degreeC or more, this invention becomes a transfer type color filter using the adhesive for color filters which does not raise | generate a foam etc. at the time of hardening.
[0043]
In the present invention, since the substrate is a substrate on which the driving element TFT is formed, the transfer type color filter is obtained by transferring the color filter onto the substrate on which the driving element TFT is formed.
[0044]
Further, the present invention provides a liquid crystal display device incorporating the transfer type color filter.
[Brief description of the drawings]
FIGS. 1A to 1C are explanatory diagrams showing a state of multiple imposition.
FIGS. 2A to 2F are explanatory views showing, in cross section, a process for manufacturing a transfer type color filter according to the present invention. FIGS.
[Explanation of symbols]
4 ... Glass substrate 11 ... Color filter layer 12 ... Light shielding layer 13 ... Transfer base material 14 ... Release layer 15 ... Photosensitive solventless adhesive 15 '... Extruding adhesive 16 ... Transfer sheet 17 ... Transfer sheet is pressed Planned position 22: Color filter layer and light shielding layer (pixel region)
40 ... Press 60 ... Light irradiation 70 ... Photomask R ... Red color filter layer G ... Green color filter layer B ... Blue color filter layer

Claims (1)

A transfer sheet composed of a transfer substrate, a release layer, a color filter layer, a light shielding layer, and the like is bonded to a predetermined position of the substrate via an adhesive, and after the adhesive is cured, the transfer substrate is peeled off, In a method for producing a transfer type color filter produced by transferring the color filter layer, the light shielding layer, etc. to a substrate, a photosensitive solventless type mainly comprising a resin, a dilution monomer and a photosensitizer as the adhesive A color filter adhesive, wherein the resin is an acrylic copolymer having an ethylenically unsaturated group and a carboxyl group ,
The acrylic copolymer of the adhesive is an acrylic copolymer having a molecular weight of 1 to 100 × 10 ³ , a double bond equivalent of 3 × 10 ³ or less, and a carboxyl group having a resin acid value of 50 to 150. A manufacturing method of a transfer type color filter.

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