JPH06347637A - Printing method - Google Patents

Abstract

PURPOSE:To obtain a color filter pattern print in which ink is surely repelled by a partition pattern and surely wets a substrate of a light transparent part to obtain uniform light transmissivity, blotting to adjacent light transparent part, is suppressed and freed from defective pixel. CONSTITUTION:(1) The printing is performed with a printing ink having surface tension between the critical surface tension of the partition pattern and the critical surface tension of a printed surface of a gap. (2) The critical surface tension is set to <35 dyne, and the critical surface tension of the printed surface of the gap to >=35 dyne, and the critical surface tension + or -5 dyne <= the critical surface tension of the ink <= the critical surface tension of the printed surface of the gap + or -5 dyne. (3) The partition contains a fluorine-based water-repellent and oil-repellent agent. (4) A color pattern is a color filter for liquid crystal. (5) A method for printing the color pattern is an ink-jet recording method.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for printing a color pattern, and more particularly to a method for printing a color filter used for manufacturing a display element such as liquid crystal.

[0002]

2. Description of the Related Art Color filters for display elements such as liquid crystals are
It can be obtained by forming a three-primary-color pixel pattern of R (red), G (green), and B (blue) on a transparent substrate.

As a method of forming a three-primary-color pixel pattern, a method of obtaining a pattern formed by a conventional photolithographic method by dyeing or an electrodeposition method using patterned electrodes is generally used, but the process is complicated and the manufacturing cost is high. It had the drawback of being expensive.

As a low-cost manufacturing method, a conventional printing method using a printing plate, an ink jet method, etc. are known. However, it is necessary to prevent the pixels from spreading during printing and improve the pattern accuracy. . Specifically, JP-A-59
Japanese Patent Laid-Open No. 75205/1975 proposes a method of printing a light-transmitting portion with an inkjet method using a diffusion prevention pattern having poor wettability and a dye made of a material having good wettability. No pattern printing was obtained. Further, Japanese Patent Laid-Open No. 62-106407 proposes an ink that is difficult to wet the partition wall as an ink, but similarly, with the disclosed contents, color pattern printing with sufficient accuracy is insufficient. Furthermore, JP-A-4-12300
5, JP-A-4-123006 and JP-A-4
JP-A-123007 proposes a method of stacking a photosensitive layer and a silicone rubber layer and selectively forming a water-repellent or oil-repellent layer by exposure and development to enable printing with less blurring.

[0005]

In the above-mentioned method of the prior art, depending on the combination of the partition pattern (black matrix) and the printing ink, the printing accuracy due to bleeding may be insufficient, or the partial wetting of the ink may be insufficient. It has a defect that defective pixels are generated.

The problem to be solved by the present invention is to provide a printing method in which the ink is reliably repelled by the partition, and the substrate of the transmissive portion is surely wetted with the ink to cause less bleeding and less defective pixels. It is in.

[0007]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, have solved the present invention.

That is, the present invention provides the following printing method in order to solve the above problems. (1) A method for printing a color pattern in a gap between partition patterns, which comprises printing with a printing ink having a surface tension between the critical surface tension of the partition pattern and the critical surface tension of the printing surface of the gap. .

(2) The critical surface tension of the partition pattern is 35
The value is less than dyne, the critical surface tension of the printed surface of the gap is 35 dyne or more, and the surface tension of the ink has a difference of 5 dyne or more from the critical surface tension of the printed surface of the partition and the gap. The printing method of 1).

(3) The printing method according to (1) or (2), wherein the partition pattern contains a fluorine-based water / oil repellent agent.

(4) The printing method according to (1), (2) or (3), wherein the color pattern is a color filter for liquid crystal.

(5) The above-mentioned (1), wherein the color pattern printing method is an ink jet recording method.
The printing method of (2), (3) or (4).

According to the method of the present invention, printing is performed using an ink having a surface tension between the critical surface tension of the partition pattern and the critical surface tension of the gap (light transmitting portion) surrounded by the partition. Thus, it is possible to reliably print the space surrounded by the partition which is the light transmitting portion.

If the critical surface tension of the partition is less than 35 dynes,
When the critical surface tension of the printed surface of the gap is 35 dynes or more and the surface tension of the ink has a difference of 5 dynes or more from the critical surface tension of the partition and the printed surface of the gap, there is no bleeding and no unevenness. Pixels can be obtained.

The partition pattern can be produced by a known method such as a gravure printing method, a photoresist method, a thermal transfer method, etc. However, the binder having a low polarity should be selected as much as possible in selecting the binder for forming the partition pattern used in the printing method of the present invention. Resins are preferred. In the partition manufacturing method by the photoresist method, even a general photoresist can be used, but in order to further lower the critical surface tension, a photosensitive layer and a silicone rubber layer are laminated and a water / oil repellent layer is formed by exposure / development. Alternatively, a fluorine-based or silicone-based water-repellent or oil-repellent agent may be added to the resist in advance.

Specific examples of the partitioning resin are as follows, but the partitioning resin is not limited to these, and it is preferable that the critical surface tension is as low as possible from the viewpoint of ink repellency.

[0017]

[Table 1]

These resins are used in combination of one or more kinds, and in some cases, resins having a critical surface tension of 35 dyne / cm or more can be combined.

When the resin alone has a high critical surface tension and the ink repellency is insufficient, the critical surface tension may be lowered by adding a silicone or fluorine-based water / oil repellent agent.

A black colorant such as a pigment such as carbon black or titanium black or a black dye can be used for coloring the partition.

When a resin of 35 dyne / cm or more is combined or colored, the critical surface tension after forming the partition wall is preferably less than 35 dyne / cm.

The material having a critical surface tension of 35 dyne or more in the space surrounded by the partition (light transmitting portion) may be at least on the surface which comes into contact with the ink, and specific examples include those shown in Table 2 below. The most preferable light transmissive member is glass in terms of transparency and uniformity, but is not limited to these.

[0023]

[Table 2]

The ink used in the present printing method may be either water-based or oil-based ink, but it is necessary that the ink composition has a difference of 5 dyne or more from the critical surface tension of the printing surface of the partition and the gap. That is, in the case of an ink having a surface tension which does not differ from the critical surface tension of the partition by more than 5 dynes, the partition effect of the partition is poor, and the ink easily flows into other adjacent gaps, and conversely, the printed surface of the gap is opposite. In the case of an ink having a surface tension within 5 dyne from the critical surface tension of No. 3, the wetting of the gap becomes insufficient and the printing uniformity is lost. Known ink compositions can be used for these ink compositions.

The water-based ink that can be used in the printing method of the present invention contains water as a main component, a colorant and a water-soluble resin, and if necessary, a water-soluble organic solvent and various auxiliaries.

The colorant includes a pigment and a water-soluble dye, and the water-soluble dye can be selected from acid dyes, basic dyes, direct dyes, reactive dyes, disperse dyes, food dyes and the like. Examples of the pigment include, but are not limited to, monoazo-based, disazo-based, phthalocyanine-based, and quinacridone-based organic pigments.

The water-soluble organic solvent of the above water-based ink prevents nozzle clogging due to evaporation of water, makes the gap (light transmitting portion) surrounded by the partition even, and delays evaporation to form an ink film. May be used for the purpose of homogenizing, specifically, glycols such as ethylene glycol, diethylene glycol, polyethylene glycol, glycerin; ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, Glycol ethers such as ethylene glycol monophenyl ether; pyrrolidones such as N-methyl-2-pyrrolidone; alkanolamines such as triethanolamine; methanol,
Alcohols such as ethanol and isopropyl alcohol; dimethyl sulfoxide and the like.

These water-soluble organic solvents may be used alone or in combination in consideration of the drying property on the filter medium, nozzle clogging, dye solubility, pigment dispersibility, etc., and may be used in the ink composition. It is desirable to use as little as possible.

Since the water is stable in the dissolution of the dye, it is necessary to use water having a purity of ion-exchanged water or higher in order to prevent the nozzles from being clogged with heavy metal ions in ink jet recording.

The water-soluble resin of the above water-based ink is polyvinyl alcohol, polyvinylpyrrolidone, gelatin, casein, glue, polyacrylic acid, shellac, styrene-acrylic acid copolymer, styrene-maleic anhydride copolymer, glycidyl methacrylate-. Ammonium salts such as acrylic acid copolymers, alkali metal salts, polyamine sulfone, polyvinylamine, polyvinylpyridine, polyethyleneimine, polyethyleneimine-epichlorohydrin reaction products, polyamide-polyamine resins or acid neutralized products thereof, and light There are curable photosensitive resins, oligomers, and monomers. Specifically, a photosensitive resin based on a water-soluble resin such as gelatin, casein, mulberry, or a water-soluble group such as glycol or carboxylate is introduced. Glycidylme Acrylate, does not cellulose derivatives, although there is a polyurethane polymethacrylate derivatives limited thereto.

As auxiliary agents, alkali metal hydroxides, pH adjusting agents such as alkanolamines, antibacterial / antifungal agents, sequestering agents, pigment dispersants, surfactants and the like are used as necessary. You may.

The surface tension of the oil-based ink that can be used in the printing method of the present invention is almost the same as the surface tension of the organic solvent used when no surfactant is used. It is necessary to have a surface tension having a difference of 5 dyne or more from the critical surface tension of the surface, specifically, aliphatic alcohols such as methanol, ethanol and propanol, ketones such as dimethyl ketone and methyl ethyl ketone, and glycols. , Nitrogen ethers such as glycol ethers, glycol esters, amides, amino alcohols, morpholine and pyridine, and the like, and it is also possible to use two or more kinds in combination. However, an aliphatic hydrocarbon compound having a small surface tension, a naphthene-based hydrocarbon, a low-polarity solvent such as a fluorine-based solvent or a silicone-based solvent is not preferable because it wets the partition too well.

The binder resin for the oil-based ink can be used without particular limitation as long as it is soluble in the organic solvent. Specific examples thereof include acrylic resin, styrene acrylic resin, phenol resin, terpene phenol resin, epoxy resin, modified epoxy resin, polyester resin, vinyl chloride-based resin, petroleum resin, and rosin ester, but are not limited thereto. However, two or more kinds can be mixed and used at the same time.

As the colorant for the oil-based ink, oil-soluble dyes such as monoazo type, disazo type, metal complex salt type, anthraquinone type, phthalocyanine type, triallylmethane type, etc. which have been conventionally used in various coloring fields, carbon black. Examples thereof include inorganic pigments such as titanium oxide, zinc oxide, and zinc sulfide, and organic pigments such as monoazo pigments, disazo pigments, phthalocyanine pigments, and quinacridone pigments, but are not limited thereto.

In order to improve the adhesiveness of the ink film printed with the above oil-based ink, the ink is provided with phthalic acid ester, sebacic acid ester, stearic acid ester, phosphoric acid ester, citric acid ester, adipic acid ester,
You may use plasticizers, such as a maleic acid ester and a trimellitic acid ester.

The printing method of the present invention is most effective when the color pattern is a color filter for liquid crystal.

The printing method in which the color pattern printing method is an ink jet recording method is advantageous in terms of printing accuracy and cost. In the inkjet recording method, droplets that are close to the nozzle diameter are generally ejected and the dots spread further on the printing surface. Therefore, the nozzle diameter of the inkjet recording device used is smaller than the size of the gap (light transmitting portion) of the color pattern. Need to be small.

[0038]

EXAMPLES Next, the present invention will be described more specifically with reference to examples. In the following examples, "part" represents "part by weight".

(Ink Example 1) 8 parts of pigment (R: Brilliant carmine 6B, G: phthalocyanine green, B: phthalocyanine blue), resin (polyvinylpyrrolidone,
K value = 15) 5 parts, diethylene glycol 1 part, "Solspers 27000" (ICI Dispersant) 1 part, ethanol 10 parts, ion-exchanged water 75 parts were mixed and dispersed in a ball mill for 24 hours, and then 0. Filtration was performed using a 5 micron membrane filter to obtain RGB inks for jet printers. At this time, the surface tensions of the inks were 43 dynes for all three colors.

(Ink Example 2) Dye (R: CI Solvent Red 132, G: CI Solvent Blue 67)
And Solvent Yellow 89, B: C.I. I. Solvent Blue 67) 4 parts, Dynal BR-113
(Mitsubishi Rayon Co., Ltd. acrylic resin, molecular weight about 3000
0) 12.0 parts, KR-216 (Shin-Etsu Chemical Co., Ltd. silicone resin, polymerization degree of about 300) 2.0 parts, Epicron 1050 (Dainippon Ink and Chemicals Co., Ltd. epoxy resin)
4.0 parts, diethyl sebacate 1.5 parts, methyl ethyl ketone 54.5 parts, and methanol 18.0 parts were thoroughly stirred and dissolved, and then the solution was filtered using a 0.5 micron membrane filter. An RGB jet printer ink was obtained. At this time, the surface tensions of the inks were 27 dynes for all three colors.

Example 1 On a glass having a critical surface tension of 55 dynes, a line width of 20 μm and a pitch of 11 made of a silicone resin having a critical surface tension of 24 dynes was used by a resist method.
A partition pattern having a thickness of 0 μm and a thickness of 2 μm was formed. Next, by using a continuous ink jet recording apparatus having a nozzle diameter of 60 microns, printing is carried out alternately on the light transmitting part surrounded by the partition in the order of RGB with the water-based ink having the surface tension of 44 dyne of the above ink example 1. As a result, a color filter having a uniform light transmitting portion and no bleeding to the adjacent light transmitting portion was obtained.

Comparative Example 1 A partition pattern of polyethylene terephthalate having a critical surface tension of 43 dyne and having a line width of 20 μm, a pitch of 110 μm and a thickness of 2 μm was formed on a glass having a critical surface tension of 55 dyne by a resist method. . Next, using a continuous type ink jet recording apparatus having a nozzle diameter of 60 microns, printing was carried out alternately on the light transmitting portion surrounded by the partition in the order of RGB with the aqueous ink having the surface tension of 44 dynes of the above ink example 1. As a result, in the obtained color filter, the light transmitting portion was partially non-uniform and bleeding to the adjacent light transmitting portion was partially seen.

(Example 2) A line width 10 made of poly (1,2-butadiene) resin containing a fluorine-based oil repellent having a critical surface tension of 18 dynes by a resist method on Mylar (polyethylene terephthalate) having a critical surface tension of 43 dynes. By forming a partition pattern of micron, pitch 60 micron, thickness 2 micron, and using a continuous type ink jet recording apparatus with a nozzle diameter of 30 micron, the above inks are alternately printed in the order of RGB on the light transmission part surrounded by the partition. As a result of printing with the oil-based ink having a surface tension of 27 dynes of Example 2, a color filter having a uniform light transmitting portion and no bleeding to the adjacent light transmitting portion was obtained.

(Comparative Example 1) A mylar (polyethylene terephthalate) having a critical surface tension of 43 dynes, a line width of 10 μm, a pitch of 60 μm, and a thickness, made of polydimethylsiloxane (silicone resin) having a critical surface tension of 28 dynes, were formed by a resist method. A partition pattern of 2 microns was formed. Next, by using a continuous ink jet recording apparatus having a nozzle diameter of 30 microns, printing was performed on the light-transmitting portion surrounded by the partition in the order of RGB in turn with the oil ink of surface tension 27 dynes of the above ink example 2. As a result, the obtained color filter has a uniform light transmitting portion,
Bleed to adjacent light transmitting parts was partially seen.

[0045]

According to the printing method of the present invention, the ink is surely repelled by the partition pattern, and the substrate of the light transmitting portion is surely wetted with the ink, and uniform light transmission is obtained.
In addition, it is possible to obtain a color filter pattern print which is free from bleeding in adjacent light transmitting portions and has no defective pixels.

Claims (5)

[Claims] 1. A method of printing a color pattern in a gap of a partition pattern, wherein printing is performed using a printing ink having a surface tension between the critical surface tension of the partition pattern and the critical surface tension of the printing surface of the gap. A printing method characterized by. 2. The critical surface tension of the partition pattern is less than 35 dyne, the critical surface tension of the printed surface of the gap is 35 dyne or more, and the surface tension of the ink is the critical surface of the printed surface of the partition pattern and the gap. The printing method according to claim 1, wherein the difference from the tension is 5 dyne or more. 3. The printing method according to claim 2, wherein the partition pattern contains a fluorine-based water and oil repellent agent. 4. The printing method according to claim 1, 2 or 3, wherein the color pattern is a color filter for liquid crystal. 5. The printing method according to claim 1, 2, 3, or 4, wherein the color pattern printing method is an ink jet recording method.