JPH05281412A - Manufacture of color filter and production apparatus therefor - Google Patents

Abstract

PURPOSE:To provide the process for manufacture for producing the color filters having colored ink films having excellent smoothness under a relatively small pressurizing force or at a relatively high speed and the apparatus for production to be used for embodiment of such process. CONSTITUTION:This process for manufacture and the apparatus for manufacture are the process of supporting the rear surface of a light transmissive substrate 11 with a heating surface plate 24 in order to smooth the colored ink film surface 13 stuck on one surface of the light transmissive substrate, pressurizing and smoothing the ink film surface while pressing the ink film surface with a heating roller 25 via a thin resin film and heating the ink film, then peeling the resin film from the entire surface of the smoothed ink film and are provided with the apparatus for peeling the resin film by using a peeling roller 35 moving the film at a relatively high speed.

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 color filter used in, for example, a liquid crystal display device and an apparatus for manufacturing the same, and in particular, it is attached directly or through another layer on the transparent substrate. Method for smoothing various patterned colored color ink coatings, and apparatus for performing the same.

[0002]

2. Description of the Related Art In the structure of a color liquid crystal display device, a color filter is arranged on one surface side across a liquid crystal layer. A printing method is one of the methods for manufacturing this color filter. This printing method is a method of printing a colored color ink dispersed in a pigment and a resin solvent in a dot shape or a stripe shape on the surface of a transparent glass substrate, and is a manufacturing method with low cost and high mass productivity. ..

That is, in this printing method, a desired pattern of red (R), green (G), and blue (B) colored inks is printed on a transparent glass substrate by an intaglio offset printing machine equipped with a pressure transfer blanket. -Print in a striped pattern. A cross section of the printed and dried state is shown in FIG. First, the glass substrate
A black light blocking layer 12 is applied to the surface of 11 in a matrix. Next, mainly in a group of regions without the light blocking layer 12,
The transfer blanket is moved while being rotated to print the red colored ink film R in a stripe shape. Subsequently, a green colored ink film G and then a blue colored ink film B are printed on the adjacent region group having no light blocking layer. In this way, in the state where the colored ink coatings 13 of the three primary colors are printed on the glass substrate, as shown in the figure, the coating surface has an arc shape within the pixels of each color. That is, the film thickness is minimum near the boundary of each colored ink film, and is maximum in the central portion.

If this is left as it is, color unevenness may occur and a high quality color liquid crystal display cannot be obtained. Therefore, it is necessary to smooth the surface 13a of the colored color ink coating 13 as shown in FIG. Conventionally, as one of the methods for smoothing the surface of such an ink film, the surface of the colored ink film is polished and smoothed with a lapping film containing fine particles as disclosed in JP-A-61-3122. There is a way. Another method is disclosed in Japanese Patent Laid-Open No. 63-216028.
As disclosed in Japanese Patent Laid-Open Publication No. Hei 1-167807, there is a method in which a roller made of rubber or a mirror-finished metal is heated and pressed to crush the convex portion of the colored ink film to smooth it. Furthermore, there is a method in which the colored ink coating side of the color filter is applied directly or through a film that is hard to adhere to these to a flat plate or a flat platen, and pressure is applied from the glass substrate side with a pressing roller or platen to smooth the surface. ,
JP-A-2-251816 or JP-A-62-162
It is disclosed in Japanese Patent No. 280805.

[0005]

The latter method out of the above has the advantage that a substantially uniform pressure is applied to the entire surface of the colored ink film surface, and the entire surface is likely to be uniformly smoothed.
However, since the pressing pressure is applied through the glass substrate on which the colored ink film is formed, it is necessary to keep the pressing force to a relatively small pressure within the range where the glass substrate is not damaged. In particular, when pressure is applied by the press roller, the glass substrate is likely to be damaged, so it is necessary to keep the pressure to a lower level. The method of applying pressure by applying a flat surface plate on the glass substrate is convenient because it does not easily damage the substrate, but the pressing force to obtain the necessary and sufficient crushing amount over the entire surface is a large value. I will end up. Therefore, according to these methods, as shown in FIG. 3, gaps that cannot be crushed easily remain between the color ink coatings. When such a gap is left, when assembled as a liquid crystal display device, voids or bubbles are formed on the bonding surface with another substrate such as a thin glass plate for electrode formation or a polarizing plate glass, or glass is parallel and even. Sticking becomes impossible. Also, directly or over the color ink film adhered to the filter substrate.
If an ITO film (indium-tin oxide film), which is a transparent conductive film, is formed by sputtering, etc., if the surface of the colored ink film has irregularities, the film formed by sputtering will be insufficient in the thick part of the film. Or the wire is likely to be broken without forming a sputtered film. Thus, the manufacturing and characteristics of the color liquid crystal display device are likely to be hindered. Furthermore, the light diffusion phenomenon due to the unevenness of the surface of the colored ink coating film impairs the transparency and causes other optical loss and the like.

To completely eliminate such a gap between the colored ink coatings, a higher pressing pressure is required, or a considerably long pressing time is required. that is,
This is a problem in terms of production efficiency such as complicated temperature control and viscosity control of the colored ink film. In addition, interposing a film that does not easily adhere between the surface plate and the colored ink coating,
Although effective in itself, the air present in the recesses between the colored ink coatings is likely to remain locally, and the air bubbles cause cavities in the colored ink coatings, or the surface has irregularities.
Alternatively, it is considered that streaky irregularities are likely to occur due to excessive air discharge. Thus, while the conventional manufacturing method and manufacturing apparatus have considerable advantages,
There are points to be improved as described above.

The present invention provides a manufacturing method for manufacturing a color filter having a colored ink film having a relatively small pressing force or a relatively high speed and an excellent smoothness, and a manufacturing apparatus used for carrying out the method. The purpose is to

[0008]

According to the present invention, a step of smoothing a surface of a colored color ink film adhered to one surface of a transparent substrate is performed by using a heating platen on the rear surface of the transparent substrate. Of the color filter that supports the ink film surface and presses the heating roller through the thin resin film on the ink film surface to pressurize and smooth the ink film while heating, and then peel the resin film from the entire surface of the ink film surface. It is a manufacturing method.

The color filter manufacturing apparatus of the present invention further includes a heating platen for mechanically supporting the back surface side of the light-transmissive substrate having a colored color ink film adhered on one surface thereof, and a heating platen for the heating platen. A heating roller arranged so as to face the substrate supporting portion so as to rotate while heating and pressurizing the ink film on the substrate surface; and an ink film on the substrate surface supported by the heating platen and the heating roller. It is characterized in that it is provided with a means for supplying a thin resin film and a film peeling means for peeling the resin film adhering to the ink coating on the surface of the substrate.

[0010]

According to the color filter manufacturing method and manufacturing apparatus of the present invention, it is possible to obtain a color ink film surface having excellent smoothness with a relatively small pressure. In particular, though the resin film is used, since this film is extremely thin compared to the thickness of the light-transmitting substrate, it is substantially equivalent to directly heating and pressurizing the color ink film with a heating roller, and the color ink film is almost the same. It can be pressed and crushed while being heated directly near the softening point. Therefore, thermal efficiency is good, and relatively small pressure is sufficient, so that the processing speed can be increased and the mass productivity is excellent. Further, the resin film is positioned obliquely to the surface of the color ink film to be smoothed, rolled by a heating roller, and after the smoothing of the entire surface is finished, the ink is peeled off from the entire surface of the smoothed ink film surface. High-precision smooth color ink coating surface can be obtained without leaving air bubbles in the coating film, unevenness due to the bubbles, or wrinkles or streaky traces.

[0011]

Embodiments will be described below with reference to the drawings.
The same parts are denoted by the same reference numerals.

In the embodiment shown in FIGS. 1 to 6, first, a light shielding layer 12 made of chromium is formed on one surface of a transparent glass substrate 11 having a side of 30 cm and a thickness of 1.1 mm. Formed into a shape. Next, after cleaning the substrate surface, using an intaglio offset printing machine, using a colored ink mainly composed of an epoxy resin varnish containing a pigment and a solvent,
A striped colored ink film 13 was printed on the substrate surface using an intaglio according to a concave cell pattern. The colored ink film 13 was formed by sequentially printing three primary colors of red (R), green (G), and blue (B). Then, since each of the colored ink coatings R, G, and B has viscoelasticity, a portion in the vicinity of the center, which is slightly biased toward the rear end side in the printing direction, has a mountain-like shape. The film thickness near the top is 4 to 5 μm.

After forming this colored ink film 13, 10
The solvent was removed by drying at a temperature in the range of 0 to 150 ° C. at which thermal curing of the colored ink film did not occur. The amount of the solvent removed is 60% or more, and more preferably 80% or more of the amount of the solvent initially added to the colored ink. This solvent removal amount is 60
If it is at most%, bubbles may flow in due to foaming due to evaporation of the solvent when the colored ink film is smoothed later, so the above range was made.

Next, the printed and dried glass substrate of the color filter was inserted into a smoothing processing device 20 for smoothing the surface of the colored ink film and smoothed. The smoothing processing device 20 has a feed device 24 having a servo motor 22 and a ball screw 23 mounted on a base 21, and a heating platen 24 placed on the feed device. Above the position where the heating platen 14 passes, a heating roller for heating and pressing is provided.
25 are installed. Further, a resin film supply device 26 is provided, and between the heating platen 24 and the heating roller 25,
The resin film 27 can be supplied as shown by the arrow Fd.

A heating heater 28 is embedded in the heating platen 24, and a vacuum suction chuck (not shown) is further provided. The heating roller 25 also has a built-in heater so that it can be moved up and down. This heating roller 25
Has a diameter of 12 cm and a surface JIS-A hardness of 80,
It is a silicon rubber having a surface roughness Ra of 0.1 μm or less.
The hardness of the roller surface depends on the hardness of the resin component in the colored ink coating, but is preferably 40 or more and 90 or less. When the hardness is lower than 40, it becomes difficult to smooth the surface roughness of the ink film to 0.1 μm or less. If the hardness is higher than 90, the glass substrate is likely to be damaged. The resin film 27 has a thickness in the range of 30 to 80 μm, for example, 50 μm on the lower surface in the figure of a film 29 made of polyethylene terephthalate (hereinafter referred to as PET).
Silicone type release agent 30 which is hard to adhere to colored ink film
It is applied to a thickness of not more than μm, for example, a thickness of several thousand angstroms. The film supply device 26 is a resin film 27.
In order to automatically supply the heat roller 25, a film feed roll 31 made of practic, on which an unused resin film 27 is wound, is installed diagonally above and to the left of the heating roller 25. Between the film feed roll 31 and the heating roller 25, an ion blow device 32 for removing foreign matter adhering to the film.
A suction device 33 and a meandering prevention roller 34 are provided. These constitute a resin film supply section. The film feed roll 31 is provided with a reverse rotation drive device, a braking mechanism, a powder brake, etc., which are not shown, and is controlled by the control device. And heating roller
On the right side of the figure of 25, a movable film peeling roller 35,
A guide roller 36, a movable film tension roller 37, a meandering prevention roller 38, and a film winding roll 39 are provided. A resin film is hung on each of these rollers as shown in the drawing, and is conveyed. The winding roll 39 has
Similarly, a torque motor and a braking mechanism are provided and controlled by the controller.

Therefore, first, the surface of the heating platen 24 is set to 85-1.
The temperature of the heating roller 25 was set to a temperature in the range of 85 to 100 ° C. Then, as shown in FIG. 1, the glass substrate 11 having the colored color ink film 13 printed thereon is vacuum-adsorbed on the heating platen 25 with the colored ink film facing upward and preheated as shown by an arrow Fe. Advanced. Until the heating platen 24 reaches below the heating roller 25, the roller 25 and the film peeling roller 35.
Is in the upper position. The heating platen 24 is a heating roller.
At a time point A (see FIG. 6, the same applies hereinafter) near the front of 25, the take-up roll 39 is rotationally driven to move the resin film.
27 moves to the right in the figure. Thereby, the unused release agent side of the resin film faces the colored ink coating 13 to be smoothed.

Next, at the time B when the heating platen 24 reaches below the heating roller 25, as shown in FIG. 2, the heating roller 25 and the film peeling roller 35 descend from the original position indicated by the dotted line, From the time point C, the heating roller 25 crushes the colored ink film 13 with a predetermined pressure as shown by the arrow Fa and rotates and moves as shown by the arrow Fb to smooth it. Colored ink coating 13 is about 9
It is heated to 0 ° C, softened and smoothed. In the meantime, the resin film 27 moves to the right in the figure along with the movement of the heating platen 24 and the rotation of the heating roller 25. Appropriate tension is applied to the resin film 27 by the feed roll 31 and the winding roll 39 to absorb the thermal expansion of the film.
On the side of the feed roll 31, the resin film 27 is inclined with respect to the surface of the colored ink film 13 to be smoothed so that the bubbles are pushed backward, that is, toward the feed roll side, and the smoothed ink film is also formed. The surface is kept in intimate contact until the entire surface is smoothed.

Then, as shown in FIG. 3, the colored ink film 13 on the glass substrate is smoothed. This state is enlarged and shown in FIG. The resin film 27 is interposed between the colored ink film 13 and the heating roller 25, and the striped colored ink film is continuously smoothed in the pattern direction, that is, in the direction of the arrow Fc in the longitudinal direction. .. In this smoothing step, the resin film 27 is inclined at a predetermined angle with respect to the surface of the colored ink coating film to be smoothed, whereby the air present in the recesses of the colored ink coating film 13 is smoothly extruded. While being heated, the ink film is smoothed by the heating roller 25. The angle between the surface of the colored ink film to be smoothed and the resin film may be 5 degrees or more and 80 degrees or less. Heating roller 25
After the smoothing, the resin film 27 is kept on the surface of the smoothed colored ink coating 13a, so that the colored ink coating surface is kept warm and does not cause temperature unevenness. In the process, no wrinkles or streaky traces were formed on the coating surface. The pressing force (linear pressure) applied by the heating roller 25 was 10 to 15 Kg / cm, and the feed rate was in the range of 5 to 8 cm / min.

Next, the colored ink film 13 on the glass substrate surface
After the entire surface has been smoothed, the film peeling roller 35 is pushed up as shown by the arrow Ff and the film pulling roller 37 is moved from the original position shown by the dotted line to the arrow Fg as shown in FIG. As shown in the drawing, the resin film 27 is moved to the upper left direction and the colored ink film surface 13a is moved.
Was strongly pulled obliquely upward from one end to the other end on the heating roller side, and peeled from the entire surface of the smoothed ink film surface. The tension roller may not be moved and used, but the take-up roll 39 may be strongly rotated in the forward direction to apply a strong tension to the resin film to separate the resin film, thereby controlling the resin film. When the peeling speed of this resin film is in the range of 2 to 50 seconds per 1 m of the direction of peeling of the colored ink coating surface, no streaky traces remain on the smoothed colored ink coating surface, Good results have been obtained.

In this way, at the time point G after the resin film is peeled off, the film tension roller 37 is returned to its original position and the heating roller 25 and the film peeling roller 35 are raised as shown in FIG. The smoothing process of the color filter on the subsequent heating platen 24 is performed. Such an operation is automatically controlled by a well-known sequence control device using a microcomputer. Then, mass production can be performed at a relatively high processing speed. In this way, the glass substrate 11 of the color filter after the smoothing treatment was removed from the heating platen 24 and heated at 200 to 250 ° C. for several hours to thermally cure the colored ink film. The smoothed color ink coating 13 had a thickness of 2.8 μm. An ITO film to be a counter electrode of a liquid crystal display device was formed on the colored ink film directly or through an overcoat layer. According to the present invention, since the smoothness of the colored ink film is extremely good,
Good optical and electrical properties were obtained even when the ITO film was directly deposited without the bar coat layer.

In the embodiment shown in FIG. 7, the heating platen 24 is fixed without moving and is placed above the heating roller 24.
Rotate 25 to move the colored ink coating 13 on the glass substrate.
Is a device for smoothing. The resin film 27 is positioned obliquely with respect to the surface to be smoothed, and the film peeling roller 35 is positioned on the extension of the surface of the colored ink film and is in contact with the surface after smoothing. It remains as it is. Then, after the entire surface smoothing process is completed, the film peeling roller 35 and the pulling roller 37 are instantaneously moved as shown by the dotted line in the same manner as in the above-described embodiment, and the resin film is moved to one end of the colored ink film surface. To the other end on the heating roller side, it is configured to be pulled obliquely and to be peeled off instantly.

The pattern of the colored ink film is not limited to the stripe pattern, and may be a regular array pattern in which the pixels of each color are rectangular. In that case, the heating roller is rotated in the longitudinal direction of the color pixels to smooth it. Moreover, it is desirable to peel the resin film in that direction. Alternatively, it may be a pattern of square or circular color pixels. In that case, the film can be smoothed and peeled in any direction.

[0023]

As described above, according to the present invention,
A color filter having a colored color ink coating having excellent smoothness can be manufactured with a relatively small pressure. In particular, though it is through the resin film, it is extremely thin, so that it is substantially equivalent to pressing the ink film while directly heating the ink film with the heating roller. As a result, the ink film is pressed and crushed while being efficiently heated to near the softening point, so that the thermal efficiency is good and a relatively small pressing force is sufficient, so that the processing speed can be increased. Therefore, it is excellent in mass productivity. In addition, the resin film is positioned diagonally to the surface of the ink film to be smoothed and smoothed with a heating roller, and after smoothing the entire surface, the resin film is pulled diagonally and peeled from the entire surface of the smoothed ink film surface. By doing so, air bubbles in the ink film and unevenness due to it,
Alternatively, a wrinkle-like or streak-like trace is not left and a highly accurate smooth ink film surface can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic side view showing a state of an initial stage of a smoothing process according to an embodiment of the present invention.

FIG. 2 is a schematic side view showing a state in a step subsequent to FIG.

FIG. 3 is a schematic side view showing a state in a step subsequent to FIG.

FIG. 4 is an enlarged perspective view of an essential part in the step of FIG.

5 is a schematic side view showing a state in a step subsequent to FIG.

FIG. 6 is a diagram showing a continuous operation of each member in the steps shown in FIGS.

FIG. 7 is a schematic side view showing another embodiment of the present invention.

FIG. 8 is an enlarged cross-sectional view showing a state after printing the coloring ink of a general color filter.

FIG. 9 is an enlarged cross-sectional view showing a state in which the colored ink film is smoothed.

[Explanation of symbols]

11 ... Translucent substrate, 13 ... Colored color ink film, 24 ... Heating platen, 25 ... Heating roller, 26 ... Resin film transport device, 27
… Resin film, 35… Film peeling roller, 37… Film pulling roller.

Claims (5)

[Claims] 1. A step of depositing a colored color ink coating on one surface of a transparent substrate directly or through another layer, a step of drying the colored color ink coating after that, and a step of subsequently forming the colored color ink coating. In the method for producing a color filter, which comprises pressurizing while heating to smooth the ink coating surface, the step of smoothing the colored color ink coating surface is performed by heating the back surface side of the transparent substrate with a heating platen. Mechanically supporting and pressing a heating roller through the thin resin film on the ink film surface to pressurize and smooth the ink film while heating, and then peel the resin film. Color filter manufacturing method. 2. The resin film is arranged so as to be pressed by a heating roller while keeping an oblique direction with respect to the surface of the colored color ink film to be smoothed, and is kept in contact with the smoothed surface of the ink film. The method for producing a color filter according to claim 1, wherein the surface of the color filter is peeled off after smoothing the entire surface. 3. The method for producing a color filter according to claim 1, wherein the speed of peeling the resin film from the entire surface of the smoothed ink film surface is in the range of 2 seconds to 50 seconds per 1 m in the peeling direction. 4. A heating platen for mechanically supporting a back surface side of a transparent substrate having a colored color ink film adhered to one surface thereof directly or via another layer, and a substrate support of the heating platen. A heating roller which is arranged so as to face the substrate and rotates while heating and pressurizing the ink film on the substrate surface; and an ink film on the substrate surface supported by the heating platen and a heating roller. An apparatus for manufacturing a color filter, comprising: a means for supplying a thin resin film between them; and a film peeling means for peeling the resin film adhering to the ink film on the substrate surface. 5. The resin film supply means includes a first roller for keeping an oblique direction with respect to the ink film surface to be smoothed on the substrate, and the film peeling means removes the resin film from the ink film surface after smoothing. The color filter manufacturing apparatus according to claim 4, further comprising a second roller that peels in an oblique direction with respect to the ink film surface.