JPH10119455A - Printing blanket, its manufacture, and manufacture of color filter using the blanket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacturing method of a blanket, capable of printing an alignment mark and a describing line simultaneously while satisfying printing characteristics, required to respective printings, and realize the reduction of cost of the blanket. SOLUTION: The surface rubber layer of a printing blanket includes at least an alignment mark printing zone and a line describing printing zone while the alignment mark printing zone thereof is provided with a hardness greater than that of the line describing printing zone. The printing blanket is manufactured by a method wherein the part in the surface rubber layer, which corresponds to the alignment mark printing zone, is heated locally. On the other hand, a color filter is made by a method wherein the alignment mark and the line describing part of a color filter layer, a black matrix layer and the like are printed simultaneously by offset printing employing a blanket for printing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing blanket used for printing a color filter and the like, a method for manufacturing the same, and a method for manufacturing a color filter using the blanket.

[0002]

2. Description of the Related Art A liquid crystal display used as a display device in place of a cathode ray tube or the like realizes color display using a color filter. This color filter is, for example, red (R) patterned for each pixel,
A green (G) and blue (B) color filter layer and a light-shielding black matrix layer are formed on a transparent substrate.

At present, as a method for producing a color filter layer or a black matrix layer, a photolithography method in which a photoresist colored with a pigment or the like is applied to a transparent substrate, and is patterned by exposure and development is mainly used. However, this method can form a pattern with high dimensional accuracy,
Since a large amount of expensive photoresist is required, the number of manufacturing steps is complicated and complicated, and the yield is low, there is a problem that the manufacturing cost of the color filter increases.

In recent years, it has been studied to manufacture a color filter by printing an ink colored with a pigment or the like on a transparent substrate by a printing method such as intaglio offset printing.
A printing method such as an intaglio offset printing method is promising as a method capable of realizing cost reduction of a color filter because of a simple manufacturing process and excellent mass productivity.

[0005]

In the production of a color filter by a printing method, in order to obtain a color filter having excellent image quality, it is necessary to accurately adjust the printing position when printing is repeated for a plurality of inks. Therefore, a mark for adjusting the printing position is formed on the transparent substrate. This is generally called an alignment mark. The alignment mark is, for example, about 30 μm in line width and 0.5 m in length.
It is formed of a cross-shaped pattern of about mx 0.5 mm in width, and is formed at four corners of the transparent substrate.

[0006] The alignment marks are required to be formed with extremely high dimensional accuracy so that printing alignment can be performed with high accuracy. For this reason, a photolithography method capable of forming a pattern with higher dimensional accuracy than the printing method is used for the production thereof, and the effect of reducing the cost of the color filter has been impaired. On the other hand, recent improvements in printing technology have provided offset printing machines and blankets capable of high-precision printing, and therefore, attempts have been made to use a printing method for producing alignment marks. Further, for the purpose of reducing the number of printing steps and increasing the accuracy of printing alignment, printing an alignment mark simultaneously with a color filter layer and a black matrix layer has been attempted.

In general, when an alignment mark is formed by a printing method, for example, as shown in FIG. 1, an image area 2 (in FIG. 1) on the surface of a printing plate 1 to be printed, such as a color filter layer. , The area where the alignment mark 4 is printed is provided outside the area where the stripe pattern is formed (so-called effective plate surface 3).

However, when an image portion provided in the effective plate surface of the printing plate and an alignment mark provided outside the effective plate surface are simultaneously printed, the characteristics required for the blanket in each printing are different. This causes problems such as poor printing. That is, when printing a color filter layer or a black matrix layer, (1) the printing accuracy indicating the deviation between the design value and the printing position is within ± 20 μm in the rotation direction of the blanket with respect to the blanket; (2) Excellent ink receiving characteristics from the printing plate and suppression of the occurrence of pinholes; (3) Excellent ink transfer characteristics to the transparent substrate, that is, complete transfer of ink and piling (4) Excellent linearity,
It is required that a pattern having excellent surface flatness can be formed.

On the other hand, when printing an alignment mark, the blanket is required to have (i) extremely high printing accuracy, and (ii) a pattern recognition of the shape of the alignment mark by an image reader. That is, although it is not particularly required to suppress pinholes and piling or to flatten the pattern surface, since the pattern formed by printing is subjected to pattern recognition by an image reader, it has extremely high printing accuracy, and It is necessary to form a sharp pattern without rounding the edge of the ink film.

As described above, the characteristics required for the blanket are different between the alignment mark and the image portions such as the color filter layer and the black matrix layer, whereas the conventional blanket has uniform surface properties. Therefore, it is difficult to satisfy all the characteristics required for both at the same time. As a method of simultaneously printing the alignment mark and the image portion while satisfying the characteristics required for each, Japanese Patent Application Laid-Open No. 3-61574 discloses a method of (a) forming a concave portion of an intaglio corresponding to printing of an alignment mark. The method of making it deeper than the concave portion of the intaglio corresponding to the printing of the image area, or (b) making the blanket area corresponding to the alignment mark print area thicker than the blanket area corresponding to the print area of the image area It has been disclosed.

However, in the above method (a), the transfer amount of the alignment mark ink is increased, and the number of pinholes is reduced. However, the cohesive force of the ink is increased, and the shape of the alignment mark is rounded. You will not be able to recognize. In the method (b), the amount of blanket distortion increases in the alignment mark printing area, and the printing accuracy decreases.

Japanese Patent Application Laid-Open No. 5-19116 discloses that
There is disclosed a blanket in which hardness, surface roughness and wettability with ink of a surface rubber layer are specified. However, since the physical properties of the surface rubber layer in the above publication are optimized for the characteristics required for printing of the image portion, there is a possibility that a printing failure occurs in the alignment mark. Therefore, for the image portion, a pattern excellent in linearity and surface flatness can be printed without generating pinholes and piling, and the alignment mark has extremely high printing accuracy and a sharp edge. For example, there is a demand for a blanket that can print a pattern suitable for pattern recognition.

SUMMARY OF THE INVENTION An object of the present invention is to provide a printing blanket capable of simultaneously printing an alignment mark and an image portion while satisfying the required printing characteristics, and a method of manufacturing the same. Another object of the present invention is to produce a color filter having excellent image quality,
Another object of the present invention is to provide a method for manufacturing a color filter that can realize low cost.

[0014]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, in a blanket having a surface rubber layer on the outermost surface, the surface rubber layer has at least an alignment mark printed. Including an area and an image area printing area, the alignment mark printing area,
When the hardness is higher than the image area printing area, a new fact that a printing blanket that can simultaneously print the alignment mark and the image area while simultaneously satisfying the required printing characteristics is obtained. And completed the present invention.

In the blanket of the present invention, the surface rubber layer in the alignment mark printing area has a hardness (JIS) higher than the surface rubber layer in the image area printing area.
Preferably, A) is 5 to 55 greater. The hardness (JIS A) of the surface rubber layer in the image area printing area is 20 to
Preferably it is 70. The method for manufacturing a printing blanket of the present invention includes the steps of locally heating a portion corresponding to an alignment mark printing region in the surface rubber layer formed on the outermost surface of the blanket, and setting the hardness of the portion to an image area. It is characterized in that it is made larger than a part corresponding to a printing area.

According to the method of manufacturing a color filter of the present invention, after the alignment mark and one of the plurality of types of ink layers are simultaneously printed on the transparent substrate, the method further comprises the steps of: In the method of manufacturing a color filter for printing the remaining ink layer, the printing blanket of the present invention is used to print an alignment mark in an alignment mark printing area of a surface rubber layer formed on the outermost surface of the blanket. Then, a plurality of types of ink layers are printed in the printing area printing area.

According to the above-described method of manufacturing a color filter, an ink layer corresponding to an alignment mark and one of a plurality of types of ink layers (ie, an image portion such as a color filter layer or a black matrix layer) are formed. Can be simultaneously printed while satisfying the required printing characteristics. Therefore, printing alignment can be realized with high accuracy, and a color filter having excellent printing accuracy can be manufactured at low cost.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The printing blanket of the present invention comprises:
It has a surface rubber layer at least on the outermost surface,
For example, it is constituted by providing a surface rubber layer on one or a plurality of support layers provided with a porous elastic layer as necessary. The surface rubber layer includes at least two regions, an alignment mark printing region and an image portion printing region, and a portion corresponding to the alignment mark printing region has a hardness (JI) higher than a portion corresponding to the image portion printing region.
SA) is set to be larger by 5 to 55, preferably 10 to 40, more preferably 15 to 25. If the difference in hardness is less than the above range, it is difficult to simultaneously satisfy the printing characteristics required for each of the alignment mark and the image area.

The hardness (JIS A) of the portion corresponding to the image printing area in the surface rubber layer of the printing blanket of the present invention is usually 20 in accordance with the characteristics of the ink used for printing and the printing conditions. ~ 70, preferably 30 ~ 6
0, more preferably in the range of 35 to 45. If the hardness of the portion corresponding to the image area printing region is lower than the above range, the portion may be deformed during printing, and the printing accuracy of the image area may be reduced. On the other hand, when the hardness exceeds the above range, the transferability of the ink to a printing substrate such as a transparent substrate is reduced, and there is a possibility that piling may occur.

The hardness (JIS A) of the portion corresponding to the alignment mark printing area in the surface rubber layer is determined by the properties of the ink used for printing, printing conditions, etc., and the hardness of the portion corresponding to the image area printing area. Usually 25, depending on the hardness
~ 75, preferably 35-65, more preferably 40-
It is set in the range of 50. If the hardness of the portion corresponding to the alignment mark printing area is lower than the above range, the printing accuracy of the alignment mark may be insufficient. On the other hand, if the hardness exceeds the above range, there is a problem that the ink is sticky and the shape of the alignment mark is disturbed, or the ink is not transferred at all. The part of the surface rubber layer corresponding to the alignment mark printing area is
Piling tends to occur as the hardness increases, but the ink receiving characteristics and printing accuracy are improved, and the cohesive force is also reduced due to the reduced amount of ink transfer, and the shape of the alignment mark is not rounded. There is an advantage that an alignment mark suitable for recognition can be formed.

The printing blanket of the present invention has a flatness of the surface of an ink film (for example, an ink film of a color filter layer ink or a black matrix layer ink printed on a transparent substrate) printed on a substrate. It is preferable that the surface of the surface rubber layer is smooth in order to further improve the surface roughness. Specifically, for example, it is appropriate that the surface rubber layer has a surface roughness of 1 μm or less, preferably 0.5 μm or less in ten-point average roughness (Rz).

For the surface rubber layer, rubbers such as natural rubber, chloroprene rubber (CR), urethane rubber, acrylic rubber, acrylonitrile-butadiene rubber (NBR), polysulfide rubber, and silicone rubber are used. In particular, a blanket using a silicone rubber for the surface rubber layer has an effect that a pattern with sharp edges can be produced because the ink is not separated between the blanket and a substrate such as a transparent substrate. This effect is remarkable in printing fine patterns such as a color filter layer and a black matrix layer.

The above-mentioned silicone rubber can be used in various known forms, for example, kneadable rubber rubber, liquid rubber such as RTV silicone rubber, and LIM silicone rubber which can be injection-molded. . Silicone oil, silicone gel or the like may be appropriately blended with the silicone rubber for the purpose of adjusting the hardness.

The support layer of the blanket may be any as long as it has a flat surface. For example, a plastic film such as polyethylene, polyethylene terephthalate (PET), polyether sulfone (PES), polycarbonate (PC), polyimide (PI), etc. In addition to a metal plate of aluminum, stainless steel, or the like, a laminate of base fabrics impregnated with rubber paste can be used.

The elastic layer optionally provided in the support layer is formed by vulcanizing a foamed rubber obtained by compounding a foaming agent or a rubber paste containing a water-soluble powder such as salt, and then washing with water. A sponge-like rubber or the like obtained by dissolving the powder is used. The expansion ratio of the elastic layer is set in consideration of the blanket hardness and printing characteristics. Next, a method for manufacturing a printing blanket of the present invention will be described.

The method for producing a blanket according to the present invention comprises the steps of: laminating a preformed and vulcanized surface rubber layer on a support of the blanket; or applying a coating liquid for the surface rubber layer, followed by drying. After vulcanizing the surface rubber layer, of the surface rubber layer, a portion corresponding to the alignment mark printing region is locally heated so that the hardness of the portion is higher than the portion corresponding to the printing region of the image area. It is characterized in that it is increased.

As a method of locally heating a portion of the surface rubber layer corresponding to the alignment mark printing region, for example, heating is performed using an infrared heater, an ultraviolet heater, a hot blaster, a blow lamp, or the like, or heat is generated on the surface rubber layer. There is a method of pressing against the body. The heating conditions are not particularly limited, because they vary depending on the desired hardness at the site, the hardness of the rubber surface rubber layer before heating, and the like, but, for example, at a temperature of 40 to 150 ° C. for 1 to 600 minutes. What is necessary is just to heat. In addition, IR spot heater (for example, model number “HYS-
20W "), the hardness can be adjusted in an extremely fine range with a radius of about 0.1 to 2 mm, and the hardness of the rubber layer can be easily adjusted by adjusting the irradiation time. Also, it is possible to prevent the hardness from increasing in an area other than the alignment mark printing area.

As a method of making the hardness of the portion corresponding to the alignment mark printing area of the surface rubber layer larger than the hardness of the portion corresponding to the image area printing area, for example, in addition to the above method, for example, Examples include a method of providing a partition in a mold for forming a layer and casting rubber having different hardness, and a method of irradiating a portion corresponding to an alignment mark printing region with ultraviolet rays, an electron beam, or the like.

Next, a method for manufacturing the color filter of the present invention will be described. The method of manufacturing a color filter according to the present invention includes the steps of: performing offset printing using the printing blanket of the present invention described above, by using an alignment mark and one of ink layers (for example, red (R) and green) of a plurality of types of ink layers.
(G) and a color filter layer composed of three colors of blue (B) and, if necessary, one layer selected from a layer containing a black matrix layer) on the transparent substrate at the same time. Is to print the remaining ink layer of the ink layers.

An example of the method for manufacturing the color filter of the present invention will be described below. First, a black matrix layer and an alignment mark are simultaneously printed on a transparent substrate using a printing plate on which a pattern corresponding to a black matrix layer and a pattern corresponding to an alignment mark are formed. Next, a color filter layer is sequentially printed for each color on the transparent substrate on which the black matrix layer and the alignment mark are formed, to obtain a color filter. Note that the color filter layer may be printed at the same time as the alignment mark.

Although various methods can be adopted for the offset printing, the intaglio offset printing method is particularly preferably used from the viewpoints of printing accuracy, linearity of the printing line, uniformity of the ink film thickness, and the like. Hereinafter, a method of manufacturing a color filter by the intaglio offset printing method will be described. For example, soda-lime glass,
Non-alkali glass, quartz glass, low alkali glass,
Glass such as low expansion glass; resins such as fluororesin, polycarbonate resin, polyethersulfone resin, and polymethacrylic resin; metals such as stainless steel, copper, and low expansion alloy invar are used. Above all, it is preferable to use soft glass such as quartz glass or soda lime glass in order to reproduce a fine pattern with high accuracy.

The depth of the concave portion of the intaglio plate is not particularly limited because it varies depending on the printing object such as a color filter layer, a black matrix layer, and an alignment mark, but is usually 1 to 15 μm, preferably 5 to 10 μm. It is set appropriately within the range. The transparent substrate has a wavelength of 400 to 700 n.
Those having high transmittance to light of m are preferable, for example, non-alkali glass, soda lime glass, glass substrates such as low alkali glass, polyether, polysulfone,
A film such as polyarylate is preferably used.

The ink used for forming the color filter layer is a vehicle containing a binder resin and a colorant. The binder resin is transparent, heat-resistant, light-resistant,
It is preferable to have excellent properties such as solvent resistance, chemical resistance, adhesiveness to a transparent substrate, dispersibility of a coloring agent, and the like. For example, polyester-melamine resin, melamine resin, epoxy resin, epoxy-melamine resin, etc. Can be used. These resins are used alone or in combination of two or more. Further, a curing catalyst such as an acid catalyst may be appropriately blended in the resin for the purpose of adjusting the curing speed of the resin.

The colorant used in the color filter layer ink may be, for example, an anthraquinone red pigment, a halogenated phthalocyanine green pigment,
A phthalocyanine blue pigment is appropriately selected and used. For the purpose of adjusting the spectral characteristics of the color filter layer, yellow inks such as disazo, isoindoline and isoindolinone are used for red ink and green ink, and dioxazine violet is used for blue ink. Pigments may be incorporated respectively.

The ink used to form the black matrix layer is a vehicle containing a binder resin and a colorant, and the same binder resin as described above can be used as the binder resin. Examples of the colorant include black pigments such as carbon black, iron oxide (iron black), titanium black, and iron sulfate. The amount of the coloring agent is appropriately set according to the optical density (OD value) of the black matrix layer, the printing suitability of the ink, and the like. The optical density of the black matrix layer is 2.3 or more (visible light transmittance of about 0.5% or less), preferably 3.0 or more (visible light transmittance of 0.1% or less). Is appropriate.

The ink for the color filter layer and the ink for the black matrix layer are mixed with the above-mentioned binder resin, colorant, and, if necessary, a solvent and extender, and mixed with a mixer such as a three-roll or kneader. It is prepared by mixing. The viscosity of the ink is preferably low. Specifically, the viscosity is 10 to 30,0.
Suitably, it is 00 poise (P), preferably 500 to 10,000 poise.

The ink for forming the alignment mark is prepared in the same manner as the black matrix layer ink and the color filter layer ink except that carbon black or the like is used as a coloring agent. The black matrix layer ink and the color filter layer ink printed on the transparent substrate are preferably subjected to a flattening treatment in an uncured or semi-cured state, respectively.

After printing on the surface of the transparent substrate, the ink for the color filter layer, the ink for the black matrix layer, and the ink for the alignment mark are usually used in an amount of 180 to 25.
30 to 180 minutes at 0 ° C, preferably 200 to 230 ° C
By heating and drying for 50 to 80 minutes. Thus, a color filter is obtained.

[0039]

The present invention will be described below with reference to examples and comparative examples. Examples 1-3 and Comparative Example 1 960 g of RTS liquid silicone rubber base material "TSE3450A" manufactured by Toshiba Silicone Co., Ltd. and curing agent "TS"
96 g of E3450B, 180 g of a main component of RTV liquid silicone rubber (gel) “YE5818A” and 18 g of a curing agent “YE5818B”, and 60 g of a silicone oil “TSF451-1000” manufactured by the company were mixed. The mixture thus obtained is coated on a support layer made of polyethylene terephthalate (PET) and dried to form a surface rubber layer having a thickness of 0.55 mm, and then vulcanized at room temperature (23 ° C.) for 20 hours. did.

Next, a portion corresponding to the alignment mark printing area in the surface rubber layer is locally heated by an infrared spot heater (the above-mentioned “HYS-20W”).
The hardness of the site is adjusted to the value shown in Table 1,
An offset blanket for printing was obtained. Irradiation with infrared rays was performed under the conditions of an irradiation distance of 20 mm and an irradiation time of 1 to 40 minutes, depending on the desired hardness.

Example 4 and Comparative Example 2 600 g of the main component "KE1603A" of RTV liquid silicone rubber and the curing agent "KE16" manufactured by Shin-Etsu Chemical Co., Ltd.
03B ”600g and the company's retarder“ N ”
o. 3 ", forming a surface rubber layer and locally heating an alignment mark printing area in the same manner as in Examples 1 to 3 and Comparative Example 1 except that 2.1 g was mixed and applied onto the support layer. Thus, an offset blanket for printing was obtained.

Example 5 and Comparative Example 3 1200 g of "TSE3402A" as the main ingredient of RTV liquid silicone rubber and "TSE3" manufactured by Toshiba Silicone Co., Ltd.
402B "120g and the company's retarder" M
E75 "(0.84 g) was mixed and coated on the support layer, and 2
Except that vulcanization was performed at 3 ° C. for 44 hours, formation of a surface rubber layer and local heating of an alignment mark printing area were performed in the same manner as in Examples 1 to 3 and Comparative Example 1 to obtain a printing offset blanket. .

In the printing blankets obtained in Examples 1 to 5 and Comparative Examples 1 to 3, the hardness of the portion corresponding to the image area printing region and the portion corresponding to the alignment mark printing region in the surface rubber layer. (JIS A)
Is as shown in Table 1 below. Example 6 and Comparative Example 4 A millable silicone rubber “K” manufactured by Shin-Etsu Chemical Co., Ltd.
E575U ”100 parts by weight, vulcanizing agent“ C
-1 "and 1 part by weight were mixed and kneaded. Next, a surface rubber layer having a thickness of 0.55 mm was formed on the same support layer as the above example using the silicone rubber, subjected to primary vulcanization at 180 ° C. for 30 minutes, and further at 200 ° C. for 120 to 180 minutes. Secondary vulcanization was performed.

Next, a portion corresponding to the alignment mark printing area in the surface rubber layer was subjected to the same conditions as in Examples 1 to 5 and Comparative Examples 1 to 3 using the infrared spot heater described above. And locally heated. In the printing blankets of Example 6 and Comparative Example 4, the hardness (JI) of the portion corresponding to the image portion printing region and the portion corresponding to the alignment mark printing region in the surface rubber layer was determined.
SA) is as shown in Table 2 below.

<< Printing Test >> Using the printing blankets obtained in the above Examples 1 to 6 and Comparative Examples 1 to 4, a portion of the surface rubber layer corresponding to the image printing area and an alignment mark Printing was simultaneously performed for both the portion corresponding to the printing region and the printing characteristics in each region were evaluated.

In the printing test, a polyester resin, an anthraquinone red pigment and butyl carbitol acetate were kneaded to adjust the steady flow viscosity to 1,000 poise (P) and the yield value to 10,000 dyn · cm. The used ink was used. For the measurement of the viscosity and the yield value, a liquid meter “MR-500” manufactured by Rheology Co., Ltd. was used.

The printing test was performed by intaglio offset printing using a normal offset printing machine. The intaglio used for printing had a concave portion formed on the surface of the soda lime glass substrate. Among the concave portions, the concave portion corresponding to the image portion was a stripe pattern having a line width of 110 μm and a depth of 8 μm. . On the other hand, the concave portion corresponding to the alignment mark has a line width of 30 μm and a depth of 8 μm, and has a vertical shape of 50 μm.
The cross was 0 μm and 500 μm wide. The transparent substrate, which is a printing substrate, has a size of 300 mm × 370 mm (10.
5 mm) and soda-lime glass having a thickness of 1.1 mm.

<< Evaluation of Printing Characteristics >> The printing characteristics of the image portion and the alignment marks were evaluated for each of the above Examples and Comparative Examples. (Ink acceptability of image printing area) Under the conditions of a blanket moving speed of 300 mm / sec and a receiving speed of 10 mm / sec, the above ink is transferred from the intaglio recess to the blanket and further transferred to the transparent substrate. Was. With respect to the ink film (image area) formed on the transparent substrate, the number of occurrences of pinholes (so-called white spots) per transparent substrate surface (average value on the transparent substrate 90 surface) was determined. The acceptability of the ink at a portion corresponding to the image area printing area was evaluated. In addition, the evaluation of the acceptability of the ink is as follows.
This was performed only when the ink was completely transferred from the blanket to the transparent substrate.

(Transferability of Ink in Print Area of Image Area) In a portion of the surface rubber layer of the blanket corresponding to the print area of the image area, transfer of the ink from the blanket to the transparent substrate was visually confirmed. Was evaluated for complete metastasis. (Shape of Edge of Image Area) Among the ink films formed on the transparent substrate, the edge of the ink film corresponding to the image area was observed in a range of 1,000 μm in length using an optical microscope. . If the flow of the edge was within ± 5 μm, the pattern of the image area was determined to be a straight line.

(Cross-sectional shape of ink film in image area) The surface shape of the ink film corresponding to the image area was observed using a scanning laser microscope (Model No. 1LM21 manufactured by Lasertec). If the cross section of the ink film was semi-cylindrical and there were no extreme irregularities, it was determined to be good. (Ink transferability of alignment mark printing area) In the part corresponding to the alignment mark printing area in the blanket surface rubber layer, the transfer of ink from the blanket to the transparent substrate is visually checked, and the ink is completely transferred. Was evaluated.

(Printing Accuracy of Alignment Mark) The deviation of the printing position of the alignment mark printed on the transparent substrate from the design value was measured. For the measurement, S-mic manufactured by Sokia Corporation was used. In addition, for the alignment marks for which pattern recognition was not possible, printing accuracy could not be measured. (Possibility of Pattern Recognition) The propriety of pattern recognition for the alignment mark was evaluated using an image reader ("Artwork HG" manufactured by OMRON Corporation). The print shape of the alignment mark was evaluated based on whether or not pattern recognition was possible.

Of the above evaluation items, the transferability of the ink in the printing area of the image area, the shape of the edge of the image area, and the cross-sectional shape of the ink film in the image area were all good.
Tables 1 and 2 show the evaluation results of the ink acceptability of the image printing area, the ink transferability of the alignment mark printing area, the printing accuracy of the alignment mark, and the possibility of pattern recognition.

[0053]

[Table 1]

[0054]

[Table 2]

As is clear from the above table, Examples 1 to 3 were used.
Showed that pattern recognition was possible and the printing accuracy of the alignment marks was sufficiently high. On the other hand, in Comparative Example 1 in which the hardness of the image area printing region A and the hardness of the alignment mark printing region B are the same, there was a problem that the pattern recognition of the alignment mark was impossible. Further, from the results of Example 4 and Comparative Example 2, Example 5 and Comparative Example 3, or Example 6 and Comparative Example 4, even when the hardness in the image area printing region is different from those of Examples 1 to 3, the alignment is not affected. When the hardness of the mark printing area B was set to be higher than the hardness of the image area printing area A, the result that the printing accuracy of the alignment mark was improved was obtained.

Therefore, by using the blankets of Examples 1 to 6, the color filter layers of three colors of red, green and blue and the black matrix layer can be formed with extremely high printing accuracy, that is, the printing position can be adjusted with high accuracy. Can be formed together. Further, the alignment mark can be produced by a printing method in the same manner as the color filter layer and the black matrix layer. Therefore, a color filter having excellent image quality can be manufactured at low cost.

[0057]

As described above in detail, according to the present invention, in the production of a color filter or the like that requires precise printing, excellent printing accuracy can be obtained and a great reduction in cost can be realized. it can.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a printing plate used in the present invention.

[Brief description of reference numerals]

 4 Alignment mark

Claims (5)

[Claims] 1. A blanket having a surface rubber layer on the outermost surface, wherein the surface rubber layer includes at least an alignment mark printing area and an image area printing area, and the alignment mark printing area is the image area printing area. A printing blanket characterized by having a higher hardness than the printing blanket. 2. The alignment mark printing area is
Hardness of the surface rubber layer (JIS
2. A printing blanket according to claim 1, wherein A) is 5 to 55 greater. 3. The printing blanket according to claim 1, wherein the hardness (JIS A) of the surface rubber layer corresponding to the image area printing area is 20 to 70. 4. A portion corresponding to an alignment mark printing region of the surface rubber layer formed on the outermost surface of the blanket is locally heated, and the hardness of the portion is adjusted to a portion corresponding to an image portion printing region. A method for producing a printing blanket, characterized in that the printing blanket is made larger. 5. A color for simultaneously printing an alignment mark and one of a plurality of ink layers on a transparent substrate, and then printing a remaining ink layer of the plurality of ink layers. In the method of manufacturing a filter, using the printing blanket according to any one of claims 1 to 3, of the surface rubber layer formed on the outermost surface of the blanket, an alignment mark is printed in an alignment mark printing area. And printing a plurality of types of ink layers in an image printing area.