JPH06238876A - Thin film printer - Google Patents

Abstract

PURPOSE:To provide a thin film printer in which a uniform thin film having no unevenness such as streak is accurately formed on a printing matter. CONSTITUTION:A thin film printer supplies printing liquid onto anilox roll 3 by a liquid supply unit, forms a uniform printing liquid film on the roll 3 by a doctor roll 2 having elasticity, moves part of the film onto a press plate 5 having a predetermined pattern, and then transfer prints the film of a desired pattern on a platelike printing matter 6 fixed onto a print table. The roll 3 of the printer is obtained by covering a surface of a metal roll with ceramics, then polishing it, engraving predetermined cells on the surface with a laser light ray, then further polishing the surface to set unevenness of cell capacity to be formed to + or -10% or less and setting a hardness of the surface to l000Hv or more.

Description

Detailed Description of the Invention

[0001]

The present invention relates to various kinds of liquid crystal alignment films, liquid crystal color filters, liquid crystal color filter flattening films, liquid crystal insulating films, liquid crystal encapsulating seals, liquid crystal pattern forming photoresist films, and the like. Print a thin film on the substrate,
The present invention relates to a thin film forming apparatus for forming.

[0002]

2. Description of the Related Art Conventionally, an alignment film for a liquid crystal display element, an insulating film,
To form various functional thin films such as a conductive film and a photoresist for pattern formation, a thin film forming apparatus as shown in FIG. 1 shown in JP-A-60-135920 is used. In this apparatus, first, the printing liquid is dropped on the anilox roll 3 by the dispenser 1. Since a large number of concave cells are provided on the surface of the anilox roll 3, the printing liquid can be held. The supplied printing liquid is kneaded between the anilox roll 3 and the doctor roll 2. The doctor roll 2 is pressed against the elastic anilox roll 3 to form a uniform liquid film on the anilox roll 3. This liquid film moves onto the printing plate 5 by contact rotation with the printing plate 5 having a predetermined convex portion attached to the plate cylinder 4. The plate-shaped object 6 to be printed, which is fixed on the printing table 7 in advance, moves from the position A in FIG. 1 to the position B in FIG. 1 while contacting the printing plate. 5 is transferred onto the printing medium 6 in a desired pattern shape. By such a method, for example, a thin film is formed on the liquid crystal display element. However, in recent years, liquid crystal elements and the like have been made larger, have higher gradation, and have higher definition, and therefore, higher precision of thin films formed on the elements has been required. Particularly in the case of the alignment film, the unevenness of the film and the streaks directly appear as the display unevenness, and thus the conventional thin film printing apparatus cannot sufficiently cope with the problem. As a result of intensive studies on the mechanism of the thin film printing apparatus, the present inventors have found that the accuracy of the cell capacity formed on the anilox roll has a great influence on the accuracy of the liquid film formed directly. The anilox roll of the conventional device mechanically presses the prototype die into the roll,
It was made by making recesses by mechanical engraving, which was repeatedly pressed several times until cells were formed on the entire roll surface, then plating hard chrome on the surface, and finally polishing the plated surface. For this reason, the accuracy of the cell capacity formed during pressure processing is not sufficient, or the cell structure is deformed or the cell wall is roughened due to uneven chrome plating, and the accuracy of the resulting cell capacity is reduced. There was a problem that the accuracy of the thin film formed was not sufficient because the accuracy was not sufficient to meet the required accuracy of the liquid film.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, in which the amount of printing liquid formed on an anilox roll is kept constant, and a thin film having a desired thickness is formed on a material to be printed. The present invention provides a thin film printing apparatus that can be formed with high precision.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a printing liquid is supplied onto an anilox roll by a liquid supply device, and a uniform printing liquid film is formed on the anilox roll by a doctor roll having elasticity. In a thin film printing apparatus for transferring and printing a printing liquid film having a desired pattern on a plate-shaped printing medium fixed on a printing table after moving a part of the film onto a printing plate having a predetermined pattern, The anilox roll is coated with ceramic on the surface of a metal roll and polished, and after engraving a predetermined cell on the surface with a laser beam, the surface is further polished to reduce the variation in the cell capacity formed on the surface.
The present invention relates to an anilox roll thin film printing apparatus having a surface hardness of 10% or less and a surface hardness of 1000 Hv or more.

According to the present invention, the surface of a metal roll is coated with ceramic and then polished, a predetermined cell is engraved on the surface with a laser beam, and then the surface is polished to suppress variations in cell capacity formed on the surface to ± 10% or less. And the surface hardness is 10
Anilox rolls of 00Hv or above are used.
The anilox roll mentioned here is a roll that has cells for holding the printing liquid on the surface and transfers the printing liquid to the printing plate. The cell is a concave depression formed on almost the entire surface of the anilox roll and has a diameter of generally 20 to 100 μm if it is expressed as an equivalent diameter. The reason why the equivalent diameter is used here is that there are various cell shapes such as a square, a circle, a rhombus, and a hexagon. Also, the reason that the equivalent diameter has a range is to change the size of the cell used depending on the film thickness to be formed. The accuracy of this cell volume is very important for forming a uniform thin film. For example, if the variation in cell volume is ± 10% or more, streaks and unevenness will be visually observed in the alignment film after coating. On the other hand, if the variation in cell capacity is less than ± 10%,
Streaks and unevenness become less noticeable. Although there are subtle points in the visual observation of streaks and unevenness due to individual differences, even in the case of a skilled observer, the variation in cell capacity is ± 10%.
If it is within the range, the thin film formed will be uniform and no streaks or unevenness will be observed, so the variation in cell capacity is ± 10%.
It is necessary to stay within. To measure the variation in cell capacity, apply a fixed amount of printing liquid to the surface of the anilox roll and evaluate the application area, or apply the printing liquid to the anilox roll surface and hold it on a fixed area after doctor cutting. The amount of printing liquid is washed out and evaluated with a color meter. It is considered necessary to provide a total of six or more cell capacitance variation measurement points at both ends and the center, but it is not specified because it depends on the roll size.

The surface hardness of the roll is 1000 Vv or more in Vickers hardness. The roll surface hardness is related to the wear rate, and if the surface hardness is low, the wear progresses and the variation in cell capacity expands, and as a result, streaks and unevenness are observed. This is because when the surface hardness is 1000 Hv or more, there is almost no abrasion during application and the change in cell capacity does not matter.

In order to manufacture an anilox roll that achieves these conditions, ceramic is formed on the roll surface, then polished, formed on the polished surface by a laser pulse controlled in position, and again formed as necessary after cell formation. A method of polishing the surface is effective. As the ceramic in this case,
Oxides such as Cr ₂ O ₃ , TiO ₂ , and Al ₂ O ₃ , TiN,
Si ₃ N ₄ , nitride such as AlN, CrC, TiC, Si
It is preferable to use a carbide such as C. As a method of forming ceramics, a thermal spraying method using a plasma jet,
There is a method such as a CVD method using plasma or the like, but it is not specified as long as a ceramic having a theoretical density of 80% or more can be formed. Further, a metal or another ceramic may be formed between the ceramic and the base metal in order to maintain the adhesiveness and the thermal expansion matching. After the ceramic layer is formed on the surface layer, the surface is preferably mirror-polished, and a concave cell is engraved on the surface by a laser beam whose position is controlled by a computer or the like. By this engraving, it is possible to form the concave cell with high accuracy. The ceramic surface after laser engraving is polished again.

[0008]

【Example】

Example 1 A roll was prepared by shrink-fitting a stainless steel shaft into a thick carbon steel pipe for machine structure. A ceramic layer of Cr ₂ O ₃ is formed on the surface of this roll by plasma jet spraying,
The surface was polished to a surface roughness Ra of 0.05 μm or less. At this time, the thickness of the ceramic layer was about 200 μm, and the surface hardness was 1250 Hv. A laser beam controlled by a computer was applied to this ceramic layer to engrave the cell, and the surface was polished again. The variation in cell capacity at this time was ± 7%, and this roll was incorporated into the thin film printing apparatus shown in FIG. 1 as an anilox roll. In this thin film printer, a polyimide resin liquid L for a liquid crystal alignment film is used as a printing liquid.
Using Q-1800 (trade name of Hitachi Chemical Co., Ltd.),
A 280 × 320 mm pattern was formed on a 300 × 400 mm glass substrate with 15Ω / □ ITO and dried on a hot plate at 50 ° C. When this pattern portion was observed with the light emitted from a white fluorescent lamp, no streaks or unevenness was observed.

Comparative Example 1 A roll was prepared by shrink-fitting a stainless steel shaft on a thick carbon steel for machine structural use. After polishing the surface of this roll, cells were engraved using an engraving die. Next, after pretreatment such as degreasing of the surface, hard chrome plating was performed and the surface was polished to obtain an anilox roll. This anilox roll has a cell capacity variation of ± 15% and a surface hardness of 70.
It was 0 Hv. This roll was incorporated into the thin film printing apparatus shown in FIG. 1 as an anilox roll. In this thin film printer, a polyimide resin liquid L for a liquid crystal alignment film is used as a printing liquid.
Using Q-1800, 300 Ω 400 mm 15Ω / □
A 280 × 320 mm pattern was formed on a glass substrate with ITO and dried on a hot plate at 50 ° C.
When observing this pattern part with a white fluorescent lamp,
A horizontal streak slightly entering the direction perpendicular to the printing direction was observed.

[0010]

EFFECT OF THE INVENTION By using the anilox roll of the present invention, it is possible to form a uniform thin film with no unevenness such as streaks on the object to be printed with high precision.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a thin film forming apparatus.

[Explanation of symbols]

 1 Dispenser 2 Doctor 3 Anilox Roll 4 Plate Cylinder 5 Printing Plate 6 Printing Substrate 7 Printing Table

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takao Nakagawa 4-13-1, Higashimachi, Hitachi City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Yamazaki Plant (72) Inventor Toyoichi Ueda Nishishinjuku 2-chome, Shinjuku-ku, Tokyo 1-1 Hitachi Hitachi Chemical Co., Ltd. (72) Inventor Kiyoshi Nakanishi 312 Chikusacho, Hanamigawa-ku, Chiba-shi, Chiba Nakan Corporation

Claims (1)

[Claims] 1. A liquid supply device supplies a printing liquid onto an anilox roll, and a doctor roll having elasticity forms a uniform printing liquid film on the anilox roll. A part of this liquid film is formed into a predetermined pattern. In a thin film printing device that transfers and prints a printing liquid film of a desired pattern onto a plate-shaped printing medium fixed on a printing table after moving it to a printing plate, an anilox roll is made of ceramic on the metal roll surface. An anilox roll in which after coating and polishing, engraving a predetermined cell on the surface with a laser beam, and further polishing the surface to reduce the variation in cell capacity formed on the surface to ± 10% or less and to set the surface hardness to 1000 Hv or more. Thin film printing equipment.