JP2008297494A - Inkjet ink and color filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet ink with which the flatness of a drawn image is satisfactory, and to provide a color filter in which the flatness of a picture element part is satisfactory and variation in color density in the picture element part is suppressed. <P>SOLUTION: The solid content and viscosity upon the concentration of inkjet ink satisfy prescribed relation. Namely, the inkjet ink comprises, a pigment, a dispersant and a solvent, and in which viscosity when being concentrated till the solid content reaches 40 mass% is ≤10 Pa s at 25°C and viscosity when being concentrated till the solid content reaches 70 mass% is ≥10 Pa s at 25°C. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an inkjet ink and a color filter.

  In recent years, with the development of personal computers, particularly large-screen liquid crystal televisions, the demand for liquid crystal displays, especially color liquid crystal displays, has been increasing. However, since the color liquid crystal display is expensive, there is an increasing demand for cost reduction, and in particular, there is a high demand for cost reduction for a color filter having high specific gravity.

  In such a color filter, it is usually provided with coloring patterns of three primary colors of red (R), green (G), and blue (B), and electrodes corresponding to the respective pixels of R, G, and B are turned on, By turning it off, the liquid crystal operates as a shutter, and light passes through each of the R, G, and B pixels, and color display is performed.

  As a conventional manufacturing method, for example, a staining method can be mentioned. In this dyeing method, first, a water-soluble polymer material, which is a dyeing material, is formed on a glass substrate, patterned into a desired shape by a photolithography process, and then the obtained pattern is immersed in a dyeing bath. To get a colored pattern. By repeating this three times, R, G, and B color filter layers are formed.

  Another method is a pigment dispersion method. In this method, a photosensitive resin layer in which a pigment is dispersed is first formed on a substrate, and this is patterned to obtain a monochromatic pattern. Further, this process is repeated three times to form R, G, and B color filter layers.

  Still other methods include an electrodeposition method, a method in which a pigment is dispersed in a thermosetting resin, R, G, and B are printed three times, and then the resin is thermoset.

  However, in any method, in order to color three colors of R, G, and B, it is necessary to repeat the same process three times, which causes a problem that the cost is high, and the yield decreases because the same process is repeated. There is a problem of doing.

  As a method of manufacturing a color filter that solves these problems, a method of forming a colored layer (pixel portion) by spraying colored ink by an inkjet method has been proposed (Patent Document 1). Here, when ink having good wettability with respect to the glass substrate is used, a method of printing a convex portion that is a boundary in advance with a substance with poor wettability with respect to the ink, or poor wettability with respect to the glass. In the case of using ink, a method is disclosed in which a pattern is formed in advance with a material having good wettability with ink, and the ink is fixed. However, controlling the glass substrate and the convex portion that forms the boundary to have ink affinity and ink repellency is effective in controlling color mixing between pixels and ink wettability, but the shape of the pixel portion itself is convex. There is a problem that the flatness of the pixel portion cannot be obtained due to the shape or the concave shape. In such a case, there arises a problem that the color density in the pixel varies and the display quality of the image is remarkably deteriorated.

  Patent Document 2 discloses a method for obtaining a flatness of a pixel portion by providing a flattening layer in the pixel portion. The above document describes a method of exposing from the substrate side, adjusting the degree of curing of the planarization layer according to the thickness of the pixel portion, and imparting flatness, but regarding variations in color density within the pixel portion, Nothing has been resolved. Patent Document 3 discloses a method of forming a film-like protective layer by transfer, but similarly, variations in color density in the pixel portion are not eliminated.

  Patent Document 4 discloses an ink having a color pigment and an extender pigment as an ink that imparts flatness to a pixel portion. In the above-mentioned document, the mass ratio between the resin and the pigment, the mass ratio between the colored pigment and the extender pigment, and the solid content in the ink are also mentioned. However, when the present inventors made an additional examination of the above document, it was found that sufficient flatness could not be obtained. Patent Document 5 discloses a method of imparting flatness while adjusting the density in the pixel portion using dark and light inks. However, the process becomes complicated and sufficient flatness cannot be obtained.

  Moreover, a method for obtaining flatness by controlling the dry state of the pixel portion is disclosed (Patent Documents 6, 7, and 8). Patent Document 6 describes that the flatness of the pixel portion can be obtained by exposing the ink before drying. Patent Document 7 describes a method of drying at a higher temperature as the viscosity of the ink is higher. Furthermore, Patent Document 8 describes a method of adjusting the drying condition according to the shape of the pixel. However, the methods of Patent Documents 6 and 7 do not provide sufficient flatness, and the method of Patent Document 8 is impractical when considering actual production.

  Further, Patent Documents 9 and 10 disclose a color filter in which the end of the pixel portion has a thickness of 80% or more of the highest portion, but does not disclose any means for obtaining flatness.

  Furthermore, Patent Document 11 discloses a method of repeating ink ejection and drying many times in order to prevent ink from overflowing from a recess surrounded by a partition wall and mixing with other pixels. Although the above method can prevent color mixing in the pixel portion and at the same time improve the flatness of the pixel portion, the process becomes complicated and is not suitable for actual manufacturing.

In addition, the ink for color filters is excellent in straightness and stability when ejected from the head, and the landed ink droplets can easily spread to every corner of the entire ink layer forming area and can be dried more efficiently. An ink-jet ink for a color filter containing a specific solvent is also known as the ink (see, for example, Patent Document 12).
JP 59-75205 A JP-A-8-304619 JP-A-10-197719 JP-A-9-132740 JP 2004-177867 A Japanese Patent Laid-Open No. 11-142641 JP 2002-372613 A JP 2003-266003 A JP 2002-148429 A JP 2002-156520 A JP 2004-325736 A JP 2006-284752 A

  However, when the inkjet ink described in Patent Document 12 is used, although there is an effect with respect to wetting and spreading of the inkjet ink, a sufficient effect is not always obtained with respect to improving the flatness of the image.

  The present invention has been made in view of the above, and includes an inkjet ink in which the flatness of a drawn image is good, and a color filter in which the flatness of the pixel portion is good and variation in color density in the pixel portion is suppressed. It aims at providing and makes it a subject to achieve this objective.

As a result of intensive studies, the present inventor obtained the knowledge that the above problem can be solved when the solid content and the viscosity when the ink-jet ink is concentrated satisfy a predetermined relationship, and the present invention has been completed based on the knowledge.
That is, specific means for solving the above-described problems are as follows.
<1> Including a pigment, a dispersant, and a solvent, when the viscosity is 10 Pa · s or less at 25 ° C. until the solid content is 40% by mass, and the solid content is 70% by mass. It is an inkjet ink having a viscosity of 10 Pa · s or more at 25 ° C.

<2> The viscosity when concentrated until the solid content is 40% by mass is 10 Pa · s or less at 25 ° C., and the viscosity when concentrated until the solid content is 60% by mass is 10 Pa · s or more at 25 ° C. It is an inkjet ink as described in <1>.
<3> The inkjet ink according to <1> or <2>, further containing a curable component.
<4> The inkjet ink according to any one of <1> to <3>, wherein the solid content is 15 to 30% by mass.

<5> The inkjet ink according to any one of <1> to <4>, wherein 80% or more of the total mass of the solvent is a solvent having a boiling point of 230 ° C. or more.

<6> The inkjet ink according to any one of <1> to <5>, wherein the viscosity at 20 ° C. is 30 mPa · s or less.
<7> The inkjet ink according to any one of <1> to <6>, which is used for producing a color filter.
<8> The inkjet ink according to any one of <1> to <7>, wherein the pigment includes a red, green, or blue pigment.

<9> A color filter using the inkjet ink according to any one of <1> to <8>.
<10> The color filter according to <9>, wherein the contrast is 7000 or more.

  ADVANTAGE OF THE INVENTION According to this invention, the color filter with which the flatness of the drawn image was favorable and the flatness of a pixel part was favorable, and the dispersion | variation in the color density in a pixel part was suppressed can be provided.

Hereinafter, the inkjet ink (hereinafter also simply referred to as “ink”) and the color filter of the present invention will be described in detail.
<Inkjet ink>
The ink-jet ink of the present invention includes a pigment, a dispersant, and a solvent. When the solid content is concentrated to 40% by mass, the viscosity is 10 Pa · s or less at 25 ° C. and the solid content reaches 70% by mass. The viscosity when concentrated is 10 Pa · s or more at 25 ° C. Here, solid content means the content rate in the inkjet ink of the component (solid content) remove | excluding the solvent from inkjet ink.
With the above configuration, the flatness of the image when the image is formed using the inkjet ink can be improved.
When an image is formed using an ink-jet ink having a viscosity of more than 10 Pa · s at 25 ° C. when concentrated to a solid content of 40% by mass, the cross-sectional shape of the formed image is a remarkably concave shape. As a result, the flatness of the image deteriorates. On the other hand, when an image is formed using an inkjet ink having a viscosity of less than 10 Pa · s at 25 ° C. when concentrated until the solid content becomes 70% by mass, the cross-sectional shape of the formed image is a prominent convex shape As a result, the flatness of the image deteriorates.
The cause of the change in pixel irregularities during the ink drying process has not been clarified in detail, but the application of droplets to the non-absorbent substrate and the coffee ring phenomenon that occurs during the subsequent drying process It is estimated that the timing of selective volatilization of the solvent from the surrounding area, increase in liquid viscosity due to volatilization, and decrease in fluidity of liquid due to increase in viscosity (sometimes called pinning) has a complex effect. However, in order to maintain a flat shape that is neither convex nor concave, it has been found that it is most important to design the viscosity during ink concentration within the ink concentration viscosity range of the present invention.

  Moreover, it is preferable that the inkjet ink of this invention is an inkjet ink for color filters used for preparation of a color filter. Accordingly, when a color filter is manufactured using the inkjet ink, the flatness of the pixel portion can be improved, and variations in color density in the pixel portion can be suppressed. As a result, a color filter excellent in display quality without unevenness can be manufactured.

(Relationship between solid content and viscosity when ink-jet ink is concentrated)
Here, the relationship between the solid content and the viscosity when the inkjet ink is concentrated will be described with reference to the graph of FIG.
As the ink is concentrated (ie, the solvent is removed from the ink) and the amount of solids in the ink is increased, the viscosity of the ink increases monotonically as shown by the polygonal lines 10, 12, 14, and 16. .
As described above, in the present invention, the viscosity when concentrated until the solid content is 40% by mass is 10 Pa · s or less at 25 ° C., and the viscosity when concentrated until the solid content is 70% by mass is 25. It is necessary to be 10 Pa · s or more at ° C. That is, in FIG. 1, the broken lines 10 and 12 are the behaviors of the inkjet ink included in the present invention, and the broken lines 14 and 16 are the behaviors of the inkjet ink not included in the present invention.
As indicated by the broken lines 10 and 12, the ink of the present invention has a solid content in the ink of 40 to 70% by mass (preferably 40 to 60% by mass) when concentrated to a viscosity of 10 Pa. ).

In the present invention, examples of the method for concentrating the ink-jet ink until a desired solid content amount include the following methods.
That is, about 4 g of ink was poured into a 10 cm × 15 cm stainless steel bat, spread thinly over the entire surface of the bat, and 70 mass% or more at 100 ° C. for 15 minutes in an explosion-proof dry oven with sufficient wind flow in the cabinet. After the ink is dried until the solid content becomes, the solid content of the dry ink is accurately measured (in the case of a normal solvent, the solid content is dried to 100% (that is, the solid content ratio is 1)). This ink is collected in a glass bottle, and an ink solvent is added according to the following formulas 1 and 2, and the mixture is stirred for 30 minutes or more until uniform to dilute the ink solids, and concentrated until the desired solids are obtained. Is possible.
It is also possible to obtain a dry ink by drying for 8 hours under conditions of 5 mmHg (0.67 kPa) and 45 ° C. In particular, in the case of a heat-effective ink containing an epoxy group-containing monomer or a thermal polymerization initiator as a monomer or a curing agent, concentration is performed under the latter conditions.

Addition amount of solvent to make ink concentrated to 40% by mass of solid content
= Dry ink mass x Dry ink solid content ratio x 6 ÷ 4 ··· (Equation 1)
Addition amount of solvent to make ink concentrated to 70 mass% solid content
= Dry ink mass x Dry ink solid content ratio x 3 ÷ 7 (Expression 2)

  The viscosity of the concentrated ink (concentrated ink) can be measured using a viscoelasticity measuring apparatus STRESSTECH manufactured by REOLOGICA Instruments AB under the conditions of a concentrated ink temperature of 25 ° C. and a frequency of 1 Hz.

From the viewpoint of more effectively obtaining the effects of the present invention, the ink-jet ink of the present invention has a viscosity of 10 Pa · s or less when concentrated to a solid content of 40% by mass, and a solid content of 60% by mass. The viscosity when concentrated to% is preferably 10 Pa · s or more.
Further, the solid content before concentration of the inkjet ink of the present invention is 15 to 30% by mass from the viewpoints of ink ejection stability, wettability to the base material, prevention of overflow onto the partition walls, and the like. Preferably, it is 18-25 mass%.
Further, the viscosity before concentration of the ink-jet ink of the present invention is preferably 30 mPa · s or less at 20 ° C. from the viewpoint of ink ejection stability, wettability to the substrate, and the like, and 25 mPa · s. The following is more preferable.

  In addition, the viscosity of the ink before concentration can be measured with an E-type viscometer manufactured by Tokyo Keiki Co., Ltd. under the condition of an ink temperature of 20 ° C.

The inkjet ink of the present invention includes a pigment, a dispersant, and a solvent. The inkjet ink of the present invention may further contain a curable component, a polymerization initiator, a surfactant, other additives, and the like.
Hereinafter, each component contained in the ink of the present invention will be described in detail.

(Pigment)
The ink-jet ink of the present invention contains at least one pigment as a colorant.
As the pigment, known pigments such as organic pigments and inorganic pigments can be used, but various organic pigments are suitable because sufficient transmission density, light resistance, adhesion to the substrate, and other various resistances are required. It is. Specific examples of the pigment include, for example, compounds classified as pigments in the color index (CI; issued by The Society of Dyers and Colorists), and JP-A-2005-17716 [0038] to The pigment described in [0054], the pigment described in JP 2004-361447 A [0068] to [0072], and the colorant described in JP 2005-17521 A [0080] to [0088] are suitable. Can be used. By containing the pigment, the storage stability of the pixel is improved, and the viscosity of the concentrated ink can be appropriately adjusted.
The content of the pigment in the present invention is not particularly limited, but from the viewpoint of preparing the ink of the present invention so that the relationship between the solid content and the viscosity when concentrated is the aforementioned relationship, the desired hue and concentration From the viewpoint of obtaining an ink, the proportion of the pigment in the ink solid content is preferably 10% by mass or more, more preferably 12 to 70% by mass, more preferably 15 to 60% by mass, and particularly preferably 20 to 50% by mass.

The pigment in the inkjet ink of the present invention preferably contains a red, green, or blue pigment. Thereby, the red pixel, the green pixel, and the blue pixel of the color filter can be suitably formed using the ink of the present invention.
The pigment in the ink for forming a red pixel preferably contains at least one kind of red pigment, but is not limited to a form using only one kind of red pigment, and a mixed system in which two or more kinds of red pigments are combined. A form used as a pigment or a form using a combination of a red pigment and another color pigment as a mixed pigment is also suitable. Examples of such combinations include C.I. I. In pigment red 254, C.I. I. Pigment red 177, C.I. I. Pigment red 224, C.I. I. Pigment yellow 139, C.I. I. Pigment yellow 150, or C.I. I. A combination with Pigment Violet 23 is mentioned.

The pigment in the ink for forming the green pixel preferably contains at least one kind of green pigment, but is not limited to a form using only one kind of green pigment, and a mixed system in which two or more kinds of green pigments are combined. A form used as a pigment, or a form using a combination of a green pigment and another color pigment as a mixed pigment is also suitable. As such a combination, for example,
C. I. In Pigment Green 36, C.I. I. Pigment yellow 150, C.I. I. Pigment yellow 139, C.I. I. Pigment yellow 185, C.I. I. Pigment yellow 138 or C.I. I. And a combination with Pigment Yellow 180.

  The pigment in the ink for forming a blue pixel preferably contains at least one kind of blue pigment, but is not limited to a form using only one kind of blue pigment, and a mixed system in which two or more kinds of blue pigments are combined. A form used as a pigment or a form using a combination of a blue pigment and another color pigment is also suitable. Examples of such combinations include C.I. I. In Pigment Blue 15: 6, C.I. I. Pigment violet 23 or C.I. I. A combination with Pigment Blue 60 is mentioned.

  Next, the C.I. I. Pigment red 254, C.I. I. Pigment green 36, C.I. I. The preferable range of the content of Pigment Blue 15: 6 will be described. C. I. Pigment Red 254 is preferably 30% by mass or more, particularly preferably 50% by mass or more from the viewpoint of color purity. C. I. From the viewpoint of color purity, the pigment green 36 is preferably 50% by mass or more, and particularly preferably 60% by mass or more. C. I. Pigment Blue 15: 6 is preferably 80% by mass or more, particularly preferably 90% by mass or more from the viewpoint of color purity.

Since the particle diameter of the pigment used in the present invention affects the viscosity of the concentrated ink, it is preferable to select the primary particle diameter of the pigment so that the particle diameter can be appropriately adjusted. Specifically, in order to adjust the concentrated ink viscosity at 40% by mass or 70% by mass, a pigment having a small primary particle diameter is selected, and the concentrated ink viscosity at 40% by mass or 70% by mass is decreased. In order to adjust in the direction, a method of selecting a pigment having a large primary particle diameter of the pigment is effective.
The pigment used in the present invention preferably has a number average particle diameter of 0.001 to 0.2 μm, more preferably 0.01 to 0.1 μm, and particularly preferably 0.02 to 0.05 μm.
If the number average particle diameter of the pigment is less than the above range, the viscosity of the concentrated ink may increase. In this case, a depression is formed in the center of the pixel (concave shape), the flatness is deteriorated, and the surface of the particle The energy becomes large and it becomes difficult to keep the dispersion state stable. If the number average particle diameter of the pigment exceeds the above range, the viscosity of the concentrated ink may decrease. In this case, the center of the pixel swells (convex shape), flatness deteriorates, and the polarization due to the pigment is eliminated. There is a problem that occurs.

Moreover, in this invention, an inorganic pigment or an extender can be used as needed. By using an inorganic pigment or extender, the thickness of the pixel can be adjusted appropriately, the viscosity of the ink and the remaining ink can be adjusted appropriately, and the hardness, shape, and durability of the pixel can be improved.
Specific examples of inorganic pigments or extender pigments include titanium oxide, barium sulfate, calcium carbonate, zinc white, lead sulfate, yellow lead, zinc yellow, red rose (red iron (III) oxide), cadmium red, ultramarine blue, bitumen, and oxidation. Examples thereof include chrome green, cobalt green, amber, titanium black, synthetic iron black, and carbon black. The amount of the extender pigment can be appropriately adjusted according to the purpose, but it is preferably in the range of 1% by mass to 70% by mass and more preferably in the range of 5% by mass to 50% by mass with respect to the total pigment.

  Moreover, when forming the pattern of a black matrix layer using the inkjet ink of this invention on the board | substrate of a color filter, a black pigment with high light-shielding property is mix | blended in inkjet ink. As the black pigment having a high light shielding property, for example, an inorganic colorant such as carbon black or iron trioxide, or an organic colorant such as cyanine black can be used.

The pigment is desirably used as a dispersion. This dispersion can be prepared by dispersing, using a known disperser, a composition obtained by previously mixing the pigment, a dispersant and a solvent described later. At this time, a small amount of resin may be added in order to impart dispersion stability of the pigment. Moreover, it is also possible to prepare by adding and dispersing a composition obtained by mixing the pigment and the dispersant in advance to the monomer described later. The disperser used for dispersing the pigment is not particularly limited. For example, a kneader described in Kazuzo Asakura, “Encyclopedia of Pigments”, first edition, Asakura Shoten, 2000, page 438, Known dispersing machines such as a roll mill, an atrider, a super mill, a dissolver, a homomixer, and a sand mill can be used. Further, fine grinding may be performed using frictional force by mechanical grinding described on page 310 of the document.
Since the dispersion state of the pigment in the pigment dispersion affects the viscosity of the concentrated ink, it is preferable to appropriately adjust the dispersion state. Specifically, in order to adjust the concentrated ink viscosity at 40% by mass or 70% by mass, the pigment dispersion time is increased and the concentrated ink viscosity at 40% by mass or 70% by mass is decreased. In order to adjust, a method of shortening the pigment dispersion time is effective. The dispersion time is preferably in the range of 0.5 to 40 hours, more preferably in the range of 1 to 10 hours, and most preferably in the range of 2 to 6 hours.
When the dispersion time exceeds this range, the viscosity of the concentrated ink may increase. In this case, a depression is formed in the center of the pixel (concave shape), and the flatness is deteriorated. If the dispersion time is less than this range, the viscosity of the concentrated ink may be lowered. In this case, the center of the pixel swells (convex shape), and the flatness deteriorates.

(Dispersant)
The ink of the present invention contains at least one dispersant in order to obtain pigment dispersion stability.
Since the dispersant affects the viscosity of the concentrated ink, it is preferable to adjust the amount of the dispersant appropriately. Specifically, in order to adjust the concentrated ink viscosity at 40% by mass or 70% by mass, the amount of dispersant added is increased, and the concentrated ink viscosity at 40% by mass or 70% by mass is decreased. In order to adjust the ratio, it is effective to reduce the amount of the dispersant.
The amount used is preferably 0.1 to 10% by mass, more preferably 0.1 to 9% by mass, and more preferably 0.1 to 8% by mass with respect to the total mass of the inkjet ink. A range is particularly preferred. By containing the dispersant in the above range, when the ink of the present invention is concentrated, the relationship between the solid content and the viscosity can be the aforementioned relationship.
Examples of the dispersant include a hydroxyl group-containing carboxylic acid ester, a salt of a long chain polyaminoamide and a high molecular weight acid ester, a salt of a high molecular weight polycarboxylic acid, a salt of a long chain polyaminoamide and a polar acid ester, a high molecular weight unsaturated ester, Molecular copolymer, modified polyurethane, modified polyacrylate, polyether ester type anionic activator, naphthalene sulfonic acid formalin condensate salt, aromatic sulfonic acid formalin condensate, polyoxyethylene alkyl phosphate ester, polyoxyethylene nonylphenyl Ether, stearylamine acetate, pigment derivatives and the like can be used.

As specific examples of the dispersant, examples described in paragraphs [0021] to [0023] of JP-A-2005-15672 can be used as preferred examples of the present invention.
Other dispersants used in the present invention include those described in JP 2004-339330 A [0060] to [0094] and those described in JP 2004-339331 A [0051] to [0070]. “Dispersant comprising a polymer having a main chain structure in which at least diisocyanates and / or triisocyanates are polymerized as a monomer unit and not including a polyether chain”.
These dispersants may be used alone or in combination of two or more. In the present invention, it is particularly preferable to use a combination of a pigment derivative and a polymer dispersant.

(solvent)
The ink of the present invention contains various solvents for the purpose of dissolving or dispersing various additives used in the present invention.
As the solvent, “Chemical Handbook Application Edition 3rd revision, Maruzen Co., Ltd., issued on August 15, 1985”, “Solvent Pocket Book, Ohm Co., Ltd., issued June 20, 1989”, “Solvent Handbook, Solvents described in “Kodansha Co., Ltd., issued on August 10, 1982” can be used.
JP 2004-220036 [0066] and [0092] to [0096], JP 2006-284752 [0082] to [0089], JP 2006-299090 [0024] to [0029]. JP-A-2006-345449 [0019], WO04-7626, JP-A-2006-83362 [0024], JP-A-2005-234045 [0063] to [0067], JP-A-369365 [ [0014] to [0026], JP 2006-163306 PR [0053], JP 2000-310706 [0031] to [0037] can be suitably used.

As the main solvent of the ink for inkjet color filters, it is preferable to use a high boiling point solvent having a boiling point of 160 ° C to 300 ° C. If the boiling point of the main solvent is 160 ° C. or higher, the phenomenon of ink sticking at the nozzle tip of the print head can be more effectively prevented, and the ink discharge performance can be improved. In addition, since the volatilization after landing on the substrate becomes slower, the pixel shape can be controlled more easily. On the other hand, if the boiling point of the main solvent is 300 ° C. or less, the solvent is less likely to remain in the pixel, and sufficient hardness, strength, and solvent resistance as a color filter can be obtained more effectively. In a process or a subsequent process, a phenomenon that causes a decrease in voltage holding ratio due to cracking, reticulation, or elution of impurities can be more effectively prevented.
Further, from the viewpoint of maintaining the in-plane uniformity of the pixel shape when producing the color filter, the solvent contained in the ink of the present invention is 80% of the total mass (the mass of all solvent components in the ink). The above is more preferably a solvent (solvent type) having a boiling point of 230 ° C. or higher.

  Examples of the solvent having a boiling point of 230 ° C. or higher include cyclohexylbenzene, 2,6-dimethylnaphthalene, biphenyl, 1-chloronaphthalene, undecanol, n-decanol, diethyl adipate, isoamyl benzoate, butyl benzoate, propyl benzoate, Methyl cinnamate, dibutyl oxalate, ethylene carbonate, 1,3-octylene glycol, diethylene glycol, triglycol dichloride, tripropylene glycol, 1,4-butanediol, propylene carbonate, 1,5-pentanediol, caprylic acid Catechol, isoquinoline, diisopropanolamine, imidazole, quinoline, diethanolamine, dicyclohexylamine, N, N-dibutylaniline, triamylamine, and monohydric polyhydric alcohol Ether or diether, polyethers, monomethyl ether acetate, include the higher boiling point 230 ° C. Of the derivatives such as diacetate.

  Among these, polyhydric alcohol derivatives having a boiling point of 230 ° C. or more are most preferable from the viewpoints of material solubility, safety, pigment dispersion stability, dischargeability, inkjet head non-corrosiveness, and the like. Specific examples of polyhydric alcohol derivatives having a boiling point of 230 ° C. or higher include diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, dipropylene glycol monobutyl ether, and tripropylene glycol. Monomethyl ether, tripropylene glycol monoethyl ether, tripropylene glycol monopropyl ether, diethylene glycol monopropyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monomethyl ether acetate, triethylene glycol monoethyl ether acetate, triethylene glycol monopropyl ether acetate The , Dipropylene glycol monopropyl ether acetate, dipropylene glycol monobutyl ether acetate, tripropylene glycol monomethyl ether acetate, tripropylene glycol monoethyl ether acetate, tripropylene glycol monopropyl ether acetate, diethylene glycol dibutyl ether, triethylene glycol diethyl ether, triethylene glycol Ethylene glycol dipropyl ether, dipropylene glycol dibutyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, tripropylene glycol dipropyl ether, diethylene glycol diacetate, dipropylene glycol diacetate, 1,3-butanediol diacetate Examples include 1,4-butanediol diacetate, 1,5-pentanediol diacetate, 1,6-hexanediol diacetate, ethylene glycol monophenyl ether, glycerin-1,3-diacetate, and glycerin triacetate. .

Further, from the viewpoint of maintaining the in-plane uniformity of the pixel shape when producing a color filter, the solvent contained in the ink of the present invention is 40% of the total mass (mass of all solvent components in the ink). The above is preferably a solvent (solvent type) having a boiling point of 270 ° C. or higher.
Examples of the solvent having a boiling point of 270 ° C. or higher include dodecylbenzene, 1-bromonaphthalene, ethyl cinnamate, isoamyl salicylate, benzyl salicylate, diethyl tartrate, diethyl phthalate, dimethyl phthalate, dibutyl maleate, glycerin, triethylene glycol, Examples include trimethylolethane, trimethylolpropane, p-octylphenol, 2-naphthol, nonylphenyl, dioctylamine, sulfolane, and polyhydric alcohol derivatives having a boiling point of 270 ° C. or higher.

  Among these, polyhydric alcohol derivatives having a boiling point of 270 ° C. or higher are more preferable from the viewpoints of material solubility, safety, pigment dispersion stability, dischargeability, and non-corrosiveness of the inkjet head. Specific examples of polyhydric alcohol derivatives having a boiling point of 270 ° C. or higher include triethylene glycol monobutyl ether, tripropylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, tetraethylene glycol monoethyl ether, tetraethylene glycol monopropyl ether, tetra Ethylene glycol monobutyl ether, tetrapropylene glycol monomethyl ether, tetrapropylene glycol monoethyl ether, tetrapropylene glycol monopropyl ether, tetrapropylene glycol monobutyl ether, triethylene glycol monobutyl ether acetate, tripropylene glycol monobutyl ether acetate, tetraethylene glycol monomethyl ether A Tate, tetraethylene glycol monoethyl ether acetate, tetraethylene glycol monopropyl ether acetate, tetraethylene glycol monobutyl ether acetate, tetrapropylene glycol monomethyl ether acetate, tetrapropylene glycol monoethyl ether acetate, tetrapropylene glycol monopropyl ether acetate, tetrapropylene Glycol monobutyl ether acetate, triethylene glycol dibutyl ether, tripropylene glycol dibutyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol dipropyl ether, tetraethylene glycol dibutyl ether, tetrapropylene Glycol dimethyl ether, tetrapropylene glycol diethyl ether, tetrapropylene glycol dipropyl ether, tetrapropylene glycol dibutyl ether, triethylene glycol diacetate, tripropylene glycol diacetate, 1,7-heptanediol diacetate, 1,8-octanediol diester An acetate etc. can be mentioned.

The ink of the present invention may contain an alkane solvent as a kind of solvent.
Here, the alkane solvent is a saturated hydrocarbon solvent, and is composed of a linear aliphatic saturated hydrocarbon, a branched aliphatic saturated hydrocarbon, or an alicyclic saturated hydrocarbon. By including an alkane-based solvent, the viscosity and surface tension of the ink can be reduced appropriately, and the wettability of the ink itself is improved, so that the landed ink droplets reach every corner of the entire pixel formation area. Wet and spread easily. As a result, even when the substrate is diversified, it is possible for the ink that has landed to the narrow part of the black matrix to spread out and prevent pixel color loss and luminance reduction. As the alkane solvent used in the present invention, a mixture of two or more kinds may be used.

  The surface tension of the alkane-based solvent is preferably 28 mN / m or less at 20 ° C., and more preferably 27.5 mN / m or less from the viewpoint that the landed ink droplets easily spread to every corner. When two or more types of alkane solvents are used as a mixture, even if one type is outside the above range, it is preferably used if the surface tension of the mixed solvent is within the above range.

  Also, the viscosity of the alkane solvent is preferably 2.5 mPa · s or less at 20 ° C., and more preferably 2 mPa · s or less, from the viewpoint that the landed ink droplets are easily spread to every corner. When two or more types of alkane solvents are used in combination, one type is preferably used as long as the viscosity of the mixed solvent is in the above range even if it is outside the above range.

  In addition, the boiling point of the alkane solvent is 100 ° C. to 260 ° C., more preferably 120 ° C. to 255 ° C., particularly 170 ° C. to 220 ° C. To preferred. When two or more types of alkane solvents are used in combination, even if one type is outside the above range, it is preferably used as long as the boiling point of the mixed solvent is within the above range.

  Moreover, it is preferable that the alkane solvent has 8 to 14 carbon atoms because the landed ink droplets are easily spread to every corner. n-octane, n-nonane, n-decane, n-undecane, n-dodecane, isododecane, n-tridecane, n-tetradecane, 2-methylheptane, 3-methylheptane, 2,2-dimethylhexane, 2,5 -Dimethylhexane, 2,2,3-trimethylpentane, 2,2,4-trimethylpentane, 2,2,2,6,6-pentamethylheptane, 2-methyloctane, etc., especially n-decane , N-dodecane is preferably used.

  As said solvent, this may be used independently and 2 or more may be mixed and used. A small amount of a solvent having a boiling point of 160 ° C. or less may be used in combination. By using together a small amount of a solvent having a boiling point of 160 ° C. or less, the solubility of the material may be improved or the effect of lowering the ink viscosity may be obtained. The amount of the solvent having a boiling point of 160 ° C. or lower can be appropriately selected, but is preferably suppressed to 50% by mass or less, more preferably 20% by mass or less of the total solvent.

(Curing component)
The inkjet ink of the present invention preferably contains at least one curable component (hereinafter also referred to as “monomer”).
As the curable component (monomer), a monomer having two or more polymerizable groups (hereinafter sometimes referred to as a bifunctional or higher functional monomer) is preferable.
The curable component (monomer) is not particularly limited as long as it can be polymerized by active energy rays and / or heat, but it has 3 or more polymerizable groups from the viewpoint of film strength and solvent resistance. More preferable is a monomer (hereinafter sometimes abbreviated as a tri- or higher functional monomer).

The type of the polymerizable group is not particularly limited, but an acryloyloxy group, a methacryloyloxy group, an epoxy group, and an oxetanyl group are particularly preferable.
Specific examples of the polymerizable monomer include epoxy group-containing monomers described in JP-A-2001-350012 [0061] to [0065], acrylate monomers, methacrylate monomers described in JP-A-2002-371216 [0016], Oxetanyl group-containing as described in JP-A No. 2001-220526, JP-A No. 2001-310937, JP-A No. 2003-341217 [0021] to [0084], JP-A No. 2004-91556 [0022] to [0058] And monomers described in “Reactive Monomer Market Outlook” published by CMC Publishing Co., Ltd.

  As acrylate monomer and methacrylate monomer, trimethylolpropane triacrylate, trimethylolpropane PO (propylene oxide) modified triacrylate, trimethylolpropane EO (ethylene oxide) modified triacrylate, trimethylolpropane trimethacrylate, pentaerythritol as trifunctional monomer A triacrylate is mentioned. Examples of tetrafunctional or higher functional monomers and oligomers include pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, and the like. Can do.

  Examples of the epoxy group-containing monomer include bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated bisphenol A type epoxy resin, bisphenol S type epoxy resin, diphenyl ether type epoxy resin, hydroquinone type epoxy resin, naphthalene type epoxy resin, Biphenyl type epoxy resin, fluorene type epoxy resin, phenol novolac type epoxy resin, orthocresol novolac type epoxy resin, trishydroxyphenylmethane type epoxy resin, trifunctional type epoxy resin, tetraphenylolethane type epoxy resin, dicyclopentadiene phenol type Epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol A nucleated polyol type epoxy resin, polypropylene glycol type epoxy resin , Glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, glyoxal type epoxy resins, alicyclic epoxy resins, and the like heterocyclic epoxy resin.

  More specifically, bisphenol A type epoxy resins such as trade name Epicoat 828 (manufactured by Yuka Shell Epoxy), bisphenol F type epoxy resins such as trade name YDF-175S (manufactured by Tohto Kasei Co., Ltd.), trade name YDB-715 Brominated bisphenol A type epoxy resins (made by Toto Kasei Co., Ltd.), bisphenol S type epoxy resins such as trade name EPICLON EXA1514 (Dainippon Ink Chemical Co., Ltd.), trade name YDC-1312 (made by Toto Kasei Co., Ltd.), etc. Hydroquinone type epoxy resin, Naphthalene type epoxy resin such as trade name EPICLON EXA4032 (manufactured by Dainippon Ink & Chemicals), Biphenyl type epoxy resin such as trade name Epicoat YX4000H (manufactured by Yuka Shell Epoxy), Trade name Epicoat 157S70 (oil) Shell Epoxy ) Phenol novolac epoxy resin such as bisphenol A type epoxy resin, trade name Epicoat 154 (manufactured by Yuka Shell Epoxy), trade name YDPN-638 (manufactured by Tohto Kasei Co., Ltd.), trade name YDCN-701 Cresol novolac type epoxy resin such as Kasei Co., Ltd., dicyclopentadiene phenol type epoxy resin such as EPICLON HP-7200 (produced by Dainippon Ink and Chemicals), Epicoat 1032H60 (produced by Yuka Shell Epoxy), etc. Trishydroxyphenylmethane type epoxy resin, trifunctional epoxy resin such as trade name VG3101M80 (manufactured by Mitsui Chemicals), tetraphenylolethane type epoxy resin such as trade name Epicoat 1031S (manufactured by Yuka Shell Epoxy), trade name Denako Tetrafunctional epoxy resin such as EX-411 (manufactured by Nagase Kasei Kogyo Co., Ltd.), hydrogenated bisphenol A type epoxy resin such as trade name ST-3000 (manufactured by Toto Kasei Co., Ltd.), trade name Epicoat 190P (manufactured by Yuka Shell Epoxy Co., Ltd.) ), Glycidyl ester type epoxy resins such as trade name YH-434 (manufactured by Toto Kasei Co., Ltd.), glyoxal type epoxy resins such as trade name YDG-414 (manufactured by Tohto Kasei Co., Ltd.), and brand name Epolide GT Examples include alicyclic polyfunctional epoxy compounds such as -401 (manufactured by Daicel Chemical Industries), and heterocyclic epoxy resins such as triglycidyl isocyanate (TGIC). Further, if necessary, a trade name Neotote E (manufactured by Toto Kasei Co., Ltd.) can be mixed as an epoxy reactive diluent.

  From the viewpoint of preparing the ink of the present invention so as to reduce the viscosity of the ink, promote the polymerization reaction of the pixel portion, and the relationship between the solid content and the viscosity when concentrated is the aforementioned relationship, a monofunctional monomer or bifunctional monomer is used. Monomers may be used in combination as appropriate. When these monofunctional monomers and bifunctional monomers are used in combination, the effect of reducing the viscosity when concentrated is obtained. Examples of these monofunctional monomers and bifunctional monomers include monofunctional epoxy group-containing monomers described in paragraph No. [0065] of JP-A No. 2001-350012, and paragraph Nos. 0015 to of JP-A No. 2002-371216. And monofunctional or bifunctional acrylate monomers and methacrylate monomers described in 0016, and monofunctional or bifunctional monomers described in “Market Prospects of Reactive Monomers” published by CMC Publishing Co., Ltd.

  Further, from the viewpoint of preparing the ink of the present invention so that the relationship between the solid content and the viscosity when the film is supplemented and the adhesion with the substrate is concentrated and concentrated, the above-mentioned relationship is obtained. A highly polar monomer such as a functional monomer or urethane acrylate, an oligomer, or the like may be used. When these polyfunctional monomers, highly polar monomers, and oligomers are used, an effect of increasing the viscosity when the ink is concentrated can be obtained. There is no restriction | limiting in particular as a preferable polyfunctional monomer, a highly polar monomer, and an oligomer, A general purpose thing can be used. For example, dipentaerythritol hexaacrylate, isocyanuric acid EO-modified diacrylate, isocyanuric acid EO-modified triacrylate, ε-caprolactone-modified tris (acryloxyethyl) isocyanurate, urethane acrylate (for example, Allonics M-1000, manufactured by Toagosei Co., Ltd.) -1200, M-1210, M-1600), polyester acrylate (for example, Allonics M-6100, M-6200, M-6250, M-6500, M-7500, M-7100, M-7300K, M-8030, manufactured by Toa Gosei Co., Ltd.) M-8060, M-8100, M-8530, M-8560, M-9050), and the like.

  The amount of the monomer used is preferably 20% by mass or more, more preferably 30% by mass or more, and further preferably 40% by mass or more in the ink solid content. When the amount of the monomer used is 20% by mass or more, the pixel portion is sufficiently polymerized, so that scratches due to insufficient film strength of the pixel portion are less likely to occur or when a transparent conductive film is applied. Such effects as preventing cracks and reticulation from occurring, improving the solvent resistance when providing the alignment film, and reducing the voltage holding ratio are obtained. Here, the solid content of the ink for specifying the blending ratio includes all components except the solvent, and liquid polymerizable monomers and the like are also included in the solid content.

The oxetanyl group-containing monomer is described in detail in the above-mentioned JP-A No. 2003-341217, paragraph numbers 0021 to 0084, and the compounds described therein can be suitably used in the present invention.
A compound having an oxetanyl group described in JP-A-2004-91556 can also be used in the present invention. This is described in detail in paragraphs 0022 to 0058.

  Hereinafter, specific examples of the compound having an oxetanyl group will be given, but the present invention is not limited thereto.

  These compounds having an oxetane group are preferably added in a proportion of 0.1 to 70% by mass, more preferably 0.5 to 60% by mass, and still more preferably 1 to 50% by mass with respect to the curable composition. be able to. Moreover, the oxetane compound which can be used for this invention may use only 1 type, or may use 2 or more types together.

(Binder resin)
In the present invention, a binder resin can be used from the viewpoint of preparing the ink of the present invention so that the relationship between the solid content and the viscosity when concentrated is the above-described relationship. By using the binder resin, it is possible to increase the viscosity when the ink is concentrated, and to obtain the effect of preparing the ink of the present invention so that the relationship between the solid content and the viscosity when concentrated is the above-described relationship. Specifically, in order to adjust the concentrated ink viscosity at 40% by mass or 70% by mass, the amount of binder added is increased. Increase the molecular weight of the binder. A binder having a linear structure is used. Etc. are effective. On the other hand, in order to adjust the concentrated ink viscosity at 40% by mass or 70% by mass, the amount of binder added is decreased. Reduce the molecular weight of the binder. A binder having many branched structures is used. Etc. are effective.
As the binder resin, a binder resin that is simply dried and solidified such that it is composed only of a resin that does not have polymerization reactivity may be used. Specifically, epoxy resin, diallyl phthalate resin, silicone resin, phenol resin, unsaturated polyester resin, polyimide resin, polyurethane resin, melamine resin, urea resin, ionomer resin, ethylene ethyl acrylate resin, acrylonitrile acrylate styrene copolymer resin, Acrylonitrile styrene resin, acrylonitrile chlorinated polyethylene styrene copolymer resin, ethylene vinyl acetate resin, ethylene vinyl alcohol copolymer resin, acrylonitrile butadiene styrene copolymer resin, vinyl chloride resin, chlorinated polyethylene resin, polyvinylidene chloride resin, cellulose acetate resin, fluorine Resin, polyoxymethylene resin, polyamide resin, polyarylate resin, thermoplastic polyurethane elastomer, polyetheretherketone resin Polyether sulfone resin, polyethylene, polypropylene, polycarbonate resin, polystyrene, polystyrene maleic acid copolymer resin, polystyrene acrylic acid copolymer resin, polyphenylene ether resin, polyphenylene sulfide resin, polybutadiene resin, polybutylene terephthalate resin, acrylic resin, methacrylic resin, Examples thereof include methylpentene resin, polylactic acid, polybutylene succinate resin, butyral resin, formal resin, polyvinyl alcohol, polyvinyl pyrrolidone, ethyl cellulose, carboxymethyl cellulose, gelatin, and copolymer resins thereof. These should be appropriately selected in consideration of film strength, ink viscosity, residual ink viscosity, pigment dispersion stability, thermal stability, non-coloring property, water resistance, and chemical resistance.

The addition amount of the binder resin is preferably in the range of 0 to 70% by mass, more preferably in the range of 0 to 30% by mass, and particularly preferably in the range of 0 to 20% by mass with respect to the solid content. The molecular weight of the binder resin is preferably in the range of 1,000 to 1,000,000, more preferably in the range of 5,000 to 100,000, and particularly preferably in the range of 10,000 to 50,000. . The binder resin may be used by being dissolved in a solvent, or may be used by being dispersed in a solvent. When used by dispersing in a solvent, the average particle size of the binder resin to be dispersed is preferably 1.0 μm or less, and more preferably 0.1 μm or less. When the average particle size of the binder resin to be dispersed is 1.0 μm or less, clogging at the head can be more effectively prevented, and the transparency and smoothness of the film can be further improved.
In addition, the binder resin may increase the viscosity of the ink, and it is also preferable not to use it essentially.

  In addition, in order to impart sufficient strength, durability, and adhesion to the coating film, a binder resin that can cure the pixel by a polymerization reaction after forming a pixel pattern on the substrate by an inkjet method is used. Preferably, it can be polymerized and cured, such as a photo-curable binder resin that can be polymerized and cured by visible light, ultraviolet light, electron beam, etc., or a thermosetting binder resin that can be polymerized and cured by heating. Binder resin can be used.

(1) Photo-curing binder resin In photo-curing resin (photo-curing binder resin) that can be polymerized and cured by light such as ultraviolet rays and electron beams, film formability and adhesion to the surface to be coated are imparted. For the purpose, a polymer having a relatively high molecular weight can be included. The term “relatively high molecular weight” as used herein means that the molecular weight is higher than that of so-called monomers and oligomers. As a polymer having a relatively high molecular weight, any of a polymer having no polymerization reactivity per se and a polymer having a polymerization reactivity per se may be used, and a combination of two or more types may be used. May be.

As the polymer having no polymerization reactivity, for example, a copolymer comprising two or more of the following monomers can be used: acrylic acid, methacrylic acid, methyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, 2- Hydroxyethyl methacrylate, benzyl acrylate, benzyl methacrylate, styrene, polystyrene macromonomer, and polymethyl methacrylate macromonomer.
More specifically, methacrylic acid / benzyl methacrylate copolymer, methacrylic acid / benzyl methacrylate / styrene copolymer, benzyl methacrylate / styrene copolymer, benzyl methacrylate macromonomer / styrene copolymer, benzyl methacrylate / styrene macromonomer A copolymer etc. can be illustrated.

As a polymer having polymerization reactivity itself, it is polymerized by the action of other components such as a photopolymerization initiator activated by light irradiation or by being irradiated with light. Those that induce a reaction can be used.
Various ethylenic double bond-containing compounds themselves have polymerization reactivity and can be used as photocurable resins. Conventionally, a prepolymer blended in a UV curable resin composition used in various fields such as inks, paints, and adhesives can be used as a polymer having a relatively high molecular weight in the present invention. Conventionally known prepolymers include radical polymerization type prepolymers, cationic polymerization type prepolymers, thiol / ene addition type prepolymers, and any of them may be used.

  Among these, radical polymerization type prepolymers are most easily available on the market, such as ester acrylates, ether acrylates, urethane acrylates, epoxy acrylates, amino resin acrylates, acrylic resin acrylates, unsaturated polyesters. Examples can be given.

The molecular weight of the ethylenic double bond-containing compound used as a polymer having a polymerization reactivity per se is such that the viscosity of the ink of the present invention is not too high to adversely affect the ejection properties from the ejection head. The molecular weight is preferably 100,000 or less, more preferably 70,000 or less, and particularly preferably 50,000 or less.
The polymer having a relatively high molecular weight can be usually blended at a ratio of 1 to 50% by mass with respect to the total solid content of the ink.

(2) Thermosetting binder resin As the thermosetting binder resin, a combination of a compound having two or more thermosetting functional groups in one molecule and a curing agent is usually used, and a catalyst capable of further promoting a thermosetting reaction. May be added. An epoxy group is preferably used as the thermosetting functional group. Moreover, you may use further the polymer which has no polymerization reactivity in itself.
As a compound having two or more thermosetting functional groups in one molecule, an epoxy compound having two or more epoxy groups in one molecule is usually used. An epoxy compound having two or more epoxy groups in one molecule is an epoxy compound having two or more, preferably 2 to 50, more preferably 2 to 20 epoxy groups in one molecule (referred to as an epoxy resin). Is included). The epoxy group should just be a structure which has an oxirane ring structure, for example, can show a glycidyl group, an oxyethylene group, an epoxycyclohexyl group, etc. Examples of the epoxy compound include known polyvalent epoxy compounds that can be cured by carboxylic acid. Examples of such an epoxy compound include “Epoxy resin handbook” edited by Masaki Shinbo, published by Nikkan Kogyo Shimbun (Showa 62). These can be used widely.
As an epoxy compound, in order to impart solvent resistance and heat resistance to the cured film, to increase the crosslink density of the polymer having a relatively high molecular weight and the cured film, or to improve the inkjet ejection performance by lowering the viscosity In addition, it is preferable to use a compound having a relatively low molecular weight in combination.

  The epoxy compound which is a polymer having a relatively high molecular weight (hereinafter sometimes referred to as “binder epoxy compound”) is represented by at least the structural unit represented by the following formula (1) and the following formula (2). A polymer composed of structural units and having two or more glycidyl groups can be used.

(In formula (1), R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ² is a hydrocarbon group having 1 to 12 carbon atoms.)

(In the formula (2), R ³ is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.)
The structural unit represented by the formula (1) is derived from a monomer represented by the following formula (3).

(In the formula (3), R ¹ and R ² have the same meanings as R ¹ and R ² in the formula (1).)

By using the monomer represented by the formula (3) as a constituent unit of the binder epoxy compound, sufficient hardness and transparency can be imparted to the pixel formed from the ink of the present invention. In the formula (3), R ² is a hydrocarbon group having 1 to 12 carbon atoms, and may be any of a linear aliphatic, alicyclic, and aromatic hydrocarbon group, and an additional structure, For example, it may contain a double bond, a side chain of a hydrocarbon group, a side chain of a spiro ring, an intra-ring bridged hydrocarbon group, or the like.

  Specific examples of the monomer represented by the formula (3) include methyl (meth) acrylate, ethyl (meth) acrylate, i-propyl (meth) acrylate, n-propyl (meth) acrylate, and i-butyl (meth). Acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, Examples thereof include para-t-butylcyclohexyl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and phenyl (meth) acrylate.

In formula (3), R ¹ is preferably hydrogen or a methyl group, and R ² is preferably an alkyl group having 1 to 12 carbon atoms. Among them, a methyl group and a cyclohexyl group are particularly preferable. Preferable examples of the monomer represented by the above formula (3) include methyl methacrylate (MMA) and cyclohexyl methacrylate (CHMA).

  The structural unit represented by the formula (2) in the polymer is derived from a monomer represented by the following formula (4).

(In the formula (4), R ³ has the same meaning as R ³ in Formula (2).)

The monomer represented by the formula (4) is used for introducing an epoxy group (epoxy reaction point) into the polymer.
In the formula (4), R ³ is preferably hydrogen or a methyl group. Specific examples of the monomer represented by the formula (4) include glycidyl (meth) acrylate, and glycidyl methacrylate (GMA) is particularly preferable.

  The polymer may be a random copolymer or a block copolymer. Further, the polymer may contain a main chain constituent unit other than the formula (1) or the formula (2) as long as the performance required for each detail of the color filter, such as hardness and transparency, can be ensured. Good. Specific examples of such a monomer include acrylonitrile and styrene.

  The content of the structural unit of formula (1) and the structural unit of formula (2) in the binder epoxy compound is derived from the monomer that derives the structural unit of formula (1) and the structural unit of formula (2). When expressed in terms of the charged mass ratio to the monomer (the monomer that derives the formula (1): the monomer that induces the formula (2)), it is in the range of 10:90 to 90:10. preferable. If the amount of the structural unit of the formula (1) is larger than the above ratio 10:90, the phenomenon that the reaction point of curing decreases and the crosslinking density decreases can be more effectively prevented, while the formula (2) If the amount of the structural unit is less than the above ratio 90:10, it is possible to more effectively prevent the phenomenon that the bulky skeleton is reduced and the curing shrinkage is increased.

The weight average molecular weight of the binder epoxy compound is preferably 3,000 or more, particularly 4,000 or more, when expressed in terms of polystyrene-converted weight average molecular weight. When the molecular weight of the binder epoxy compound is 3,000 or more, physical properties such as strength and solvent resistance required for pixels as details of the color filter can be further improved.
In addition, since the ink of the present invention is used in an ink jet system, the binder epoxy compound preferably has a weight average molecular weight of 20,000 or less, more preferably 15,000 or less when expressed in terms of polystyrene-converted weight average molecular weight. It is particularly preferred. If the molecular weight is 20,000 or less, the increase in viscosity is less likely to occur, the stability of the ejection amount when ejecting from the ejection head and the straightness in the ejection direction can be further improved, and the stability of long-term storage is improved. It can be improved further.

  As the binder epoxy compound, it is particularly preferable to use a glycidyl methacrylate (GMA) / methyl methacrylate (MMA) copolymer having a polystyrene-reduced weight average molecular weight (Mw) in the above range. The GMA / MMA copolymer may contain other monomer components as long as the object of the present invention can be achieved.

(Polymerization initiator)
In the ink of the present invention, a polymerization initiator may be used in combination for the purpose of promoting the polymerization reaction of the monomer and the binder resin. The polymerization initiator can be selected according to the type of monomer and binder used in the ink and the polymerization route.

(1) Polymerization initiator suitable for acrylate (methacrylate) monomer and photo-curable binder resin As a polymerization initiator suitable for acrylate monomer, methacrylate monomer and photo-curable binder resin, polymerization of the pixel portion is performed by active energy rays. In such a case, a photopolymerization initiator is used. When the pixel portion is polymerized by heat, a thermal polymerization initiator is used. Examples of the photopolymerization initiator include those described in paragraphs [0079] to [0088] of JP-A-2006-28455, and preferred specific examples include 2-trichloromethyl-5- (p-styryl). Styryl) -1,3,4-oxadiazole and 2,4-bis (trichloromethyl) -6- [4 ′-(N, N-bisethoxycarbonylmethylamino) -3′-bromophenyl] -s -Triazines are mentioned.

  As the thermal polymerization initiator, generally known organic peroxide compounds and azo compounds can be used. As a result, the strength of the pixel portion can be improved. In addition to the thermal polymerization initiator, a curing catalyst such as imidazole can also be used. The organic peroxide compound and the azo compound can be used in combination of two or more in addition to the single use. Here, the organic peroxide is a derivative of hydrogen peroxide (H—O—O—H) and refers to an organic compound having —O—O— bond in the molecule.

  When classified by chemical structure, ketone peroxides, peroxyketals, hydroperoxides, dialkyl peroxides, diacyl peroxides, peroxyesters, peroxydicarbonates and the like can be mentioned. Specifically, 3,3 ′, 4,4′-tetra (t-butylperoxycarbonyl) benzophenone, benzoyl peroxide, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, t-butylperoxybenzoate, di-t-butylperoxybenzoate, di-t-butylperoxyisophthalate, t- Butyl peroxyacetate, t-hexyl peroxybenzoate, t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxylaurate, t-butyl peroxyisopropyl monocarbonate, t-butyl Peroxy-2-ethylhexyl monocarbonate, 2,5-bis (m-toluyl peroxy Hexane, 2,5-dimethyl-2,5-bis (benzoyl peroxy) hexane, t-hexyl peroxy isopropyl monocarbonate,

t-butylperoxyisobutyrate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-hexylperoxyisopropylmonocarbonate, 2,5-dimethyl-2,5-bis (2-ethylhexanoylperoxy) hexane, t-butylperoxy-2-ethylhexanoate, t-butylperoxymaleic acid, cyclohexanone peroxide, methylacetoacetate peroxide, methylhexanone peroxide, acetylacetone peroxide Oxide, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) -2-methylcyclohexane, 1,1-bis ( -Butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) butane, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane, diisopropylbenzene hydroperoxide, 1, 1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, t-butyl hydroperoxide and the like are preferable, such as 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane. Peroxyketal compounds, diacyl peroxide compounds such as benzoyl peroxide, and peroxyester compounds such as t-butyl peroxybenzoate are preferred.

  Examples of the azo compound include compounds described in paragraphs [0021] to [0023] of JP-A-5-5014. Among these compounds, a compound that has a decomposition temperature that is somewhat high and is stable at room temperature, is a compound that decomposes when heated to generate radicals and serves as a polymerization initiator. Among organic peroxide compounds or azo compounds (thermal polymerization initiators), those having a relatively high half-life temperature (preferably 50 ° C. or higher, more preferably 80 ° C. or higher) are used. The viscosity can be suitably configured without changing with time, and examples thereof include azobis (cyclohexane-1-carbonitrile) and the like as a preferable thermal polymerization initiator.

The content of the photopolymerization initiator and / or the thermal polymerization initiator suitable for the acrylate monomer, methacrylate monomer, and photocurable binder resin is preferably 0.1 to 10% by mass, more preferably based on the solid content. 0.3 to 5% by mass. If the content of the polymerization initiator is 0.1% by mass or more with respect to the monomer, the effect as the polymerization initiator can be sufficiently exerted, and if it is 5% by mass or less, the change with time of the viscosity of the inkjet ink Or coloration due to decomposition products of the polymerization initiator can be prevented.
These initiators can be used alone or in combination of two or more.

(2) Polymerization Initiator Suitable for Oxetanyl Group-Containing Monomer or Binder Resin Suitable polymerization initiators for the oxetanyl group-containing monomer or binder resin include compounds that generate an acid. The compound that generates an acid in the present invention represents a compound that generates an acid by light or heat after ink-jet coating. Application of carboxylic acid, sulfonic acid, phosphoric acid, phosphoric acid ester, sulfuric acid, sulfuric acid ester, sulfinic acid, hydrochloric acid, nitric acid, boric acid, trifluoroboric acid, boron complex, antimony derivative, hexafluorophosphoric acid, etc. Any material that generates Bronsted acid or Lewis acid by the action of light and / or heat in the later droplets can be used.
Among them, as an acid that can effectively cure the oxetane compound of the present invention by light and / or heat, hydrochloric acid, sulfonic acid, an acid having boron, or an acid having phosphorus is generated. Most preferably, it is most preferable to generate an acid having phosphorus.
As a specific compound for generating such an acid, as a photopolymerization initiator, for example, an organic halogenated compound, an oxydiazole compound, an organic boric acid compound, a disulfonic acid compound, an oxime ester compound, an onium salt compound, Among them, an onium hydrochloric acid generator such as an iodonium salt or a sulfonium salt is preferably used.

  Specific examples of the organic halogenated compound include Wakabayashi et al., “Bull Chem. Soc Japan” 42, 2924 (1969), US Pat. No. 3,905,815, Japanese Patent Publication No. 46-4605, JP 48-36281, JP 55-3070, JP 60-239736, JP 61-169835, JP 61-169837, JP 62-58241, JP 62 -212401, JP-A-63-70243, JP-A-63-298339, M.S. P. Hutt “Journal of Heterocyclic Chemistry” 1 (No 3), (1970) ”, and the oxazole compound and s-triazine compound substituted with a trihalomethyl group.

  Examples of the organic borate compound include JP-A-62-143044, JP-A-62-1050242, JP-A-9-188585, JP-A-9-188686, JP-A-9-188710, JP-A-2000. -131837, Japanese Patent Application Laid-Open No. 2002-107916, Japanese Patent No. 2764769, Japanese Patent Application No. 2000-310808, and Kunz, Martin “Rad Tech'98. Proceeding April 19-22, 1998, Chicago”. The organic borate described in JP-A-6-157623, JP-A-6-175564, JP-A-6-175561, or organic boron oxosulfonium complex, JP-A-6-175554 No. 6, JP-A-6-175553 Organoboron iodonium complexes described in JP-A-9-188710, organoboron phosphonium complexes described in JP-A-9-348710, JP-A-7-128785, JP-A-7-140589, JP-A-7- Specific examples include organoboron transition metal coordination complexes such as those described in Japanese Patent No. 306527 and Japanese Patent Laid-Open No. 7-292014.

  Examples of the disulfone compound include compounds described in JP-A No. 61-166544 and Japanese Patent Application No. 2001-132318.

  Examples of oxime ester compounds include J.M. C. S. Perkin II (1979) 1653-1660), J. MoI. C. S. Perkin II (1979) 156-162, Journal of Photopolymer Science and Technology (1995) 202-232, JP-A 2000-66385, compounds described in JP-A 2000-80068, JP-T 2004-534797 Compounds and the like.

  Examples of onium salt compounds include S.I. I. Schlesinger, Photogr. Sci. Eng. , 18, 387 (1974), T.A. S. Bal et al, Polymer, 21, 423 (1980), diazonium salts described in U.S. Pat. No. 4,069,055, ammonium salts described in JP-A-4-365049, U.S. Pat. No. 4,069, No. 055, No. 4,069,056, phosphonium salts described in European Patent Nos. 104 and 143, U.S. Pat. Nos. 339,049 and 410,201, JP Examples include iodonium salts described in JP-A No. -150848 and JP-A-2-296514.

  The iodonium salt that can be suitably used in the present invention is a diaryl iodonium salt, and is preferably substituted with two or more electron donating groups such as an alkyl group, an alkoxy group, and an aryloxy group from the viewpoint of stability. . More preferably, the alkoxy group is preferably substituted by 3 or more, and most preferably 4 or more. Further, as another preferable iodonium salt form having good curability by light, at least one of diaryls forms a part of chromophore having absorption at 300 nm or more. Alternatively, as a substituent, an iodonium salt having a functional group having absorption at 300 nm or more is preferable.

Examples of the sulfonium salt that can be suitably used in the present invention include European Patent Nos. 370,693, 390,214, 233,567, 297,443, 297,442, and U.S. Pat. 933,377, 161,811, 410,201, 339,049, 4,760,013, 4,734,444, 2,833,827, Germany Examples thereof include sulfonium salts described in the specifications of Patent Nos. 2,904,626, 3,604,580, and 3,604,581, and are preferably electron withdrawing groups from the viewpoint of stability. It is preferably substituted. The electron withdrawing group preferably has a Hammett value greater than zero. Preferred electron-withdrawing groups include halogen atoms and carboxylic acids.
Other preferred sulfonium salts are triarylsulfonium salts from the viewpoints of thermal decomposability, balance of stability, and photocurability when used in combination with sensitizers, such as halogen atoms and carboxyl groups. It is preferable to have at least one electron-withdrawing group, more preferably 2 or more, and most preferably 3 or more.

  In addition, as another preferable form of the sulfonium salt, a sulfonium salt in which one substituent of the triarylsulfonium salt has a coumarin or an anthraquinone structure and absorbs at 300 nm or more can be given. As another preferred sulfonium salt, the triarylsulfonium salt forms part of a chromophore in which at least one of the triaryls has an absorption at 300 nm or more. Alternatively, a triarylsulfonium salt having a functional group having absorption at 300 nm or more is preferable as a substituent.

  Moreover, as an onium salt compound, J.M. V. Crivello et al, Macromolecules, 10 (6), 1307 (1977), J. MoI. V. Crivello et al, J.A. Polymer Sci. , Polymer Chem. Ed. , 17, 1047 (1979), a selenonium salt described in C.I. S. Wen et al, Teh, Proc. Conf. Rad. Curing ASIA, p478 Tokyo, Oct (1988), and onium salts such as arsonium salts.

  The content of the polymerization initiator suitable for the oxetanyl group-containing monomer or binder resin of the present invention is preferably 0.1 to 30% by mass, more preferably based on the total solid content contained in the curable composition. It is 0.5-25 mass%, Most preferably, it is 1-20 mass%. Within this range, better sensitivity and a hardened part can be formed. Moreover, the compound which generate | occur | produces the said acid can be used 1 type or in mixture of 2 or more types.

(Curing agent)
In general, the epoxy group-containing monomer and the thermosetting binder resin are combined with a curing agent. As the curing agent, the curing agent and accelerator described in Chapter 3 of “Review Epoxy Resin Basics I” published on November 19, 2003, published by the Epoxy Resin Technology Association, can be suitably used. Carboxylic anhydride or polyvalent carboxylic acid can be used.
Specific examples of polyhydric carboxylic acid anhydrides include phthalic anhydride, itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenyl succinic anhydride, tricarballylic anhydride, maleic anhydride, hexahydrophthalic anhydride, dimethyltetrahydro anhydride Aliphatic or alicyclic dicarboxylic anhydrides such as phthalic acid, hymic anhydride, and nadic anhydride; fats such as 1,2,3,4-butanetetracarboxylic dianhydride and cyclopentanetetracarboxylic dianhydride Aromatic polycarboxylic dianhydrides; aromatic polycarboxylic anhydrides such as pyromellitic anhydride, trimellitic anhydride, and benzophenone tetracarboxylic anhydride; ester groups such as ethylene glycol bistrimellitic acid and glycerin tristrimellitic acid Containing acid anhydrides, particularly preferably aromatic poly It may be mentioned carboxylic acid anhydrides. Moreover, the epoxy resin hardening | curing agent which consists of a commercially available carboxylic acid anhydride can also be used suitably.

  Specific examples of the polyvalent carboxylic acid used in the present invention include aliphatic polyvalent carboxylic acids such as succinic acid, glutaric acid, adipic acid, butanetetracarboxylic acid, maleic acid, and itaconic acid; hexahydrophthalic acid, Aliphatic polycarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid, cyclopentanetetracarboxylic acid, and phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, trimellitic acid, Aromatic polyvalent carboxylic acids such as 1,4,5,8-naphthalenetetracarboxylic acid and benzophenonetetracarboxylic acid can be mentioned, and aromatic polyvalent carboxylic acids can be mentioned preferably.

  Moreover, it is preferable to use vinyl ether block carboxylic acid for polyvalent carboxylic acid which can be used for this invention. Specific examples include vinyl ether block carboxylic acids described in “Review Epoxy Resin Basics I” P193-194, JP2003-66223A, JP2004-339332A published by the Epoxy Resin Technology Association. . By blocking the carboxylic acid with vinyl ether, the addition reaction (esterification reaction) of the carboxylic acid and the epoxy compound gradually proceeds at room temperature, and the ink viscosity is prevented from increasing with time, and various solvents and epoxy monomers are used. The solubility in the epoxy resin is improved, and a uniform composition can be made. This vinyl ether block carboxylic acid is preferably used in combination with a thermal latent catalyst described later. By using in combination with the heat latent catalyst, the deblocking reaction is promoted during heating, and the film loss during heating is small, and a color filter with higher strength can be formed.

  These polyvalent carboxylic acid anhydrides and polyvalent carboxylic acids can be used singly or in combination of two or more. The compounding quantity of the hardening | curing agent used for this invention is the range of 1-100 mass parts normally per 100 mass parts of components (monomer and resin) containing an epoxy group, Preferably it is 5-50 mass parts. If the compounding quantity of a hardening | curing agent is 1 mass part or more, hardening can be advanced more and a tougher coating film can be formed. Moreover, if the compounding quantity of a hardening | curing agent is 100 mass parts or less, the adhesiveness with respect to the board | substrate of a coating film can be improved more, and a more uniform and smoother coating film can be formed.

(Thermal latent catalyst)
In the present invention, when an epoxy group-containing monomer and a thermosetting binder resin are used, a catalyst capable of accelerating the thermosetting reaction between acid and epoxy is added to improve the hardness and heat resistance of the pixel. Also good. As such a catalyst, a thermal latent catalyst that exhibits activity during heat curing can be used.

The heat-latent catalyst exhibits catalytic activity when heated, accelerates the curing reaction and gives good properties to the cured product, and is added as necessary. The thermal latent catalyst is preferably one that exhibits acid catalytic activity at a temperature of 60 ° C. or higher. As such, a compound obtained by neutralizing a protonic acid with a Lewis base, a compound obtained by neutralizing a Lewis acid with a Lewis base, Lewis Examples thereof include a mixture of an acid and a trialkyl phosphate, sulfonic acid esters, onium compounds and the like, and various compounds described in JP-A-4-218561 can be used. Specifically, (i) compounds obtained by neutralizing halogenocarboxylic acids, sulfonic acids, monophosphates and diesters with various amines such as ammonia, monomethylamine, triethylamine, pyridine, ethanolamine, or trialkylphosphine (B) compounds obtained by neutralizing Lewis acids such as BF ₃ , FeCl ₃ , SnCl ₄ , AlCl ₃ , ZnCl ₂ with the aforementioned Lewis base, (c) methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, etc. Examples include primary alcohols, ester compounds with secondary alcohols, (d) primary alcohols, secondary monoalcohol phosphate monoester compounds, and phosphate diester compounds. Examples of the onium compound include an ammonium compound [RNR ′] ⁺ X ⁻ , a sulfonium compound [RSR ′] ⁺ X ⁻ , an oxonium compound [ROR ′] ⁺ X ^{−, and the} like. Here, R and R ′ are alkyl, alkenyl, aryl, alkoxy and the like.

  The thermal latent catalyst is preferably a halogen-free acidic catalyst from the viewpoint of liquid crystal contamination. Specific examples of the halogen-free acidic catalyst include Nofure LC-1 and Nofure LC-2 (both trade names, manufactured by NOF Corporation).

(Surfactant)
As examples of the surfactant, the surfactants disclosed in JP-A-7-216276, paragraph [0021], JP-A-2003-337424, and JP-A-11-133600 are preferable. As mentioned. The content of the surfactant is preferably 5% by mass or less with respect to the total amount of the inkjet ink.

<Color filter>
The color filter of the present invention is formed using the above-described inkjet ink of the present invention.
The color filter of the present invention is manufactured by, for example, a manufacturing method in which a colored layer is formed by applying droplets of the inkjet ink of the present invention to a recess surrounded by a partition formed on a substrate by an inkjet method.
In addition, the color filter of the present invention preferably has a contrast of 7000 or more from the viewpoint of improving contrast when a liquid crystal display device is obtained and obtaining good display quality.

  A conventionally known method can be used as means for setting the contrast to 7000 or more. Specifically, a method using a pigment powder having a small primary particle size, for example, a method of obtaining a pigment particle having a small particle size by reprecipitation of a pigment dissolved in a solvent, and a longer dispersion time when the pigment is broken down. And a salt milling method. Of these, a method of increasing the dispersion time is advantageous in terms of cost and is preferable. In this case, in order to prevent the viscosity of the pigment dispersion from rapidly increasing in the middle of the dispersion step, it is more preferable to add a larger amount of the dispersant used for pigment dispersion than the usual amount used.

The method for producing a color filter of the present invention may be referred to as a step of forming pixels by applying the ink of the present invention described above to the recesses surrounded by the partition walls by the ink jet method (hereinafter referred to as “pixel forming step”). Preferably, the method further comprises a curing step of curing the formed at least one color pixel by irradiation of active energy rays, and a curing step of curing by heat after forming all pixels having a desired hue. If necessary, other steps such as baking can be provided.
Note that the partition walls are formed on the substrate in advance before the pixel forming step, and details of the method for forming the partition walls will be described later.

(Colored layer formation process)
In the colored layer forming step, droplets of the inkjet ink of the present invention are applied to the recesses between the partition walls (dark color separation walls) by the inkjet method to form a colored layer. This colored layer becomes a color pixel of red (R), green (G), blue (B), etc. constituting the color filter.
The colored layer is formed by injecting ink-jet ink for forming colored pixels (for example, RGB three-color pixel pattern) into the recesses surrounded by the partition formed on the substrate as described above. It can be formed to include the plurality of pixels described above.
As the ink jet method, known methods such as a method of thermally curing ink, a method of photocuring, and a method of ejecting droplets after forming a transparent image receiving layer on a substrate in advance can be used.
The shape of the color filter pattern is not particularly limited, and may be a general stripe shape, a lattice shape, or a delta array shape as a black matrix shape.

As an inkjet method, a method in which charged inkjet ink is continuously ejected and controlled by an electric field, a method in which ink is intermittently ejected using a piezoelectric element, and an ink is heated and intermittently ejected using its foam. Various methods such as a method can be adopted.
As the injection conditions of the ink-jet ink, it is preferable from the viewpoint of the injection stability that the ink-jet ink is heated to 30 to 60 ° C. and the ink viscosity is lowered for injection. Ink-jet inks generally have higher viscosities than aqueous inks, so the viscosity fluctuation range due to temperature fluctuations is large. It is important to keep the ink-jet ink temperature as constant as possible, since the viscosity variation directly affects the droplet size and the droplet ejection speed and easily causes image quality degradation.

As the ink jet head (hereinafter also simply referred to as a head), a known one can be applied, and a continuous type or a dot on demand type can be used. Among the dot-on-demand types, the thermal head is preferably a type having an operation valve as described in JP-A-9-323420 for discharging. As the piezo head, for example, the heads described in European Patent A277,703, European Patent A278,590 and the like can be used. Among these, the piezo head is more preferable because the influence of heat on the ink-jet ink can be reduced and the choice of usable solvents is wide. The head preferably has a temperature control function so that the temperature of the ink can be controlled. It is preferable to set the injection temperature so that the viscosity at the time of ejection is 5 to 25 mPa · s, and to control the ink temperature so that the fluctuation range of the viscosity is within ± 5%. Moreover, as a drive frequency, it is preferable to operate | move at 1-500 kHz. The shape of the nozzle does not necessarily need to be circular, and is not particular about the shape such as an ellipse or a rectangle. The nozzle diameter is preferably in the range of 10 to 100 μm. The nozzle opening itself is not necessarily a perfect circle. In this case, the nozzle diameter is assumed to be a circle equivalent to the area of the opening.
The color filter in the present invention is preferably in the form of a group composed of three colored layers by spraying RGB three-color inks.

  In the present invention, after removing the solvent contained in the droplets to form an ink remainder, the process of irradiating the ink remainder with active energy rays (hereinafter sometimes referred to as a first curing process) and / or. A colored layer may be formed by polymerizing the remaining ink in a step of heating the remaining ink (hereinafter sometimes referred to as a second curing step). Further, when the temperature at which thermal polymerization of the remaining ink starts is T ° C., preheating (hereinafter sometimes referred to as a preheating step) is performed at a temperature lower than T ° C., and the ink is contained in the droplets. After removing the solvent to form an ink residue, the ink residue is polymerized by a step of irradiating the ink residue with active energy rays and / or a step of heating the ink residue at a temperature of T ° C. or more to form a colored layer. May be.

Hereinafter, the first curing step, the second curing step, and the preheating step will be described.
-First curing step-
A step (first curing step) of irradiating and curing at least one colored layer formed in the colored layer forming step with active energy rays can be provided. In the first curing step, a cured colored layer can be formed by curing the inkjet ink of the present invention of each color including red (R), green (G), and blue (B). Curing may be performed each time a colored layer of one color is formed, or may be performed after forming a colored layer of a plurality of colors.

  Curing of the ink-jet ink according to the present invention such as R, G, B, etc. can be carried out by performing an exposure process that promotes polymerization curing using an energy source that emits an active energy ray in a wavelength region corresponding to the photosensitive wavelength of the ink. The

  Examples of the energy source include 400-200 nm ultraviolet light, far ultraviolet light, g-line, h-line, i-line, KrF excimer laser light, ArF excimer laser light, electron beam, X-ray, molecular beam, or ion beam. Those to which the above-mentioned polymerization initiator is sensitive can be appropriately selected and used. Specifically, a light source that emits actinic rays belonging to a wavelength region of 250 to 450 nm, preferably 365 ± 20 nm, for example, LD, LED (light emitting diode), fluorescent lamp, low pressure mercury lamp, high pressure mercury lamp, metal halide lamp, carbon arc lamp. , Xenon lamps, chemical lamps and the like. Preferred light sources include LEDs, high pressure mercury lamps, and metal halide lamps.

  The irradiation time of the active energy ray can be appropriately set according to the combination of the monomer and the polymerization initiator, and can be set to 1 to 30 seconds, for example.

-Second curing step-
In the method for producing a color filter of the present invention, a step (second curing step) of curing all the colored layers having a desired hue including red (R), green (G), and blue (B) by heat. Can be provided. As described above, by providing the first curing step and the second curing step, it is possible to achieve both the production efficiency of the color filter and the display characteristics. Moreover, you may make it harden | cure only by a 2nd hardening process.

  In this step, a colored layer and partition walls having a desired hue are formed, and after the first curing step, a heat treatment (so-called baking treatment) is further performed to cure by heat. That is, a substrate on which a colored layer and partition walls photopolymerized by light irradiation are formed is heated in an electric furnace, a drier or the like, or is irradiated with an infrared lamp and heated.

  The heating temperature and heating time at this time depend on the composition of the inkjet ink and the thickness of the colored layer, but generally from about 120 ° C. to about 250 ° C. from the viewpoint of ensuring sufficient solvent resistance, alkali resistance, and ultraviolet absorbance. It is preferable to heat at about 10 minutes to about 120 minutes.

In the method for producing a color filter using the inkjet ink of the present invention, a preheating step may be provided before the pixel portion is polymerized by exposure to active energy rays and / or heat treatment. The heating temperature in the preheating step is not particularly limited. However, when the temperature at which the thermal polymerization of the pixel portion starts is T ° C, a temperature that is lower than T ° C and does not cause the polymerization of the pixel portion is preferable, and is 50 ° C or higher. 100 degreeC or less is more preferable, and 60 degreeC or more and 90 degrees C or less are further more preferable. By including the above process, the evaporation of the solvent in the pixel portion is promoted, and the color filter can be efficiently produced. In addition, the viscosity of the remaining ink portion is reduced by heat, so that higher fluidity is obtained. Thus, it is possible to obtain a color filter having a highly flat pixel portion.
The preheating step is effective not only for ink that polymerizes by heat but also for ink that is polymerized by light as long as the remaining ink portion has fluidity as in the present invention. In the case of an ink that is polymerized by light, the temperature T at which the ink starts thermal polymerization is the temperature at which the photopolymerization initiator or the like is decomposed by heat to start the polymerization reaction, or the monomer itself is decomposed by heat to cause the polymerization reaction to occur. Mean temperature to start.
The time for the preheating step is not particularly limited, but it is preferably 1 to 5 minutes.

The temperature T can be obtained as follows.
Let T be the temperature at which ink polymerization is started by heating and the gelation of the ink is observed with respect to the ink viscosity before heating. More specifically, T is the heating temperature when the increase in ink viscosity after heating is 5 mPa · s or more.

  In the method for producing a color filter using the inkjet ink of the present invention, from the viewpoint of further suppressing the aggregation of pigments in the ink and the precipitation of various binders and maintaining the surface state of the pixels better, the colored layer forming step The preliminary heating step, the first curing step, and the second curing step are preferably performed within 24 hours, more preferably within 12 hours, and even more preferably within 6 hours.

(substrate)
As a substrate (permanent support) constituting the color filter of the present invention, it is possible to use a metal support, a metal bonded support, a glass substrate (for example, an alkali-free glass substrate), ceramic, a synthetic resin film, or the like. it can. Particularly preferably, a glass substrate (for example, an alkali-free glass substrate or the like) or a synthetic resin film having good transparency and dimensional stability can be used.

(Partition wall)
In the method for producing the color filter, a colored layer is formed by applying droplets of the inkjet ink of the present invention to a recess surrounded by a partition formed on a substrate by an inkjet method. Any partition may be used, but when a color filter is manufactured, a partition having a black matrix function and a light blocking effect is preferable. The partition walls can be produced by the same material and method as those of known black matrixes for color filters. For example, paragraph numbers [0021] to [0074] of JP 2005-3861 A, black matrices described in paragraph numbers [0012] to [0021] of JP 2004-240039 A, and JP 2006-17980 A. And the inkjet black matrix described in paragraphs [0009] to [0044] of JP-A No. 2006-10875.
Among the known production methods, it is preferable to use a photosensitive resin transfer material from the viewpoint of cost reduction. The photosensitive resin transfer material is a material in which at least a light-shielding resin layer is provided on a temporary support, and the resin layer having a light-shielding property can be transferred to the substrate by pressure bonding to the substrate.

The photosensitive resin transfer material is preferably formed using a photosensitive resin transfer material described in JP-A-5-72724, that is, an integral film. Examples of the constitution of the integral film include a temporary support / thermoplastic resin layer / intermediate layer / photosensitive resin layer (in the present invention, the “photosensitive resin layer” refers to a resin that can be cured by light irradiation, Is also referred to as a “light-shielding resin layer”, and when it is colored in a desired color, it is also referred to as a “colored resin layer”) / protective film laminated in this order.
Regarding the temporary support, the thermoplastic resin layer, the intermediate layer, the protective film, and the production method of the transfer material constituting the photosensitive resin transfer material, paragraphs [0023] to [0066] of JP-A-2005-3861 Those described are preferred.

  The partition wall may be subjected to ink repellent treatment to prevent color mixing of the inkjet ink. As for the ink repellent treatment, for example, (1) a method of kneading an ink repellent substance into a partition wall (for example, see JP-A-2005-36160), and (2) a method of newly providing an ink repellent layer (for example, a special method) (See Kaihei 5-241101), (3) A method of applying an ink repellency treatment to the partition walls formed on the substrate (see, for example, Japanese Patent Application Laid-Open No. 2002-62420), and (4) On the wall upper surface of the partition walls Examples thereof include a method of applying an ink repellent material (for example, see JP-A-10-123500). In particular, (3) a method of performing an ink repellent treatment with plasma on a partition formed on a substrate is preferable.

(Wettability variable layer)
In the present invention, as another method of selectively forming the wettability in a predetermined area of the substrate surface and forming an ink layer forming area having a higher ink affinity than the surrounding area, a transparent substrate of a color filter is used. On top of this, a wettability variable layer that changes wettability in the direction in which the ink affinity increases by the action of the photocatalyst is formed, and the wettability in a predetermined region on the surface of the wettability variable layer is selectively changed by exposure. Thus, a method of forming an ink layer forming region having higher ink affinity than the surroundings may be used. Specifically, it is described in detail in JP-A-2006-284552 [0134] to [0135].

(Overcoat layer)
After forming the color filter by forming the colored region (colored pixel) and the partition as described above, an overcoat layer can be formed so as to cover the entire surface of the pixel and the partition for the purpose of improving the durability.

The overcoat layer can protect the pixels such as R, G, and B and the partition walls and can flatten the surface. However, it is preferable not to provide from the point which the number of processes increases.
An overcoat layer can be comprised using resin (OC agent), and acrylic resin composition, an epoxy resin composition, a polyimide resin composition etc. are mentioned as resin (OC agent). Among them, an acrylic resin composition is desirable because it is excellent in transparency in the visible light region, and the resin component of the ink for ink for color filters usually has an acrylic resin as a main component and has excellent adhesion. Examples of the overcoat layer include those described in paragraphs [0018] to [0028] of JP-A No. 2003-287618, and commercially available overcoat agents such as Optomer SS6699G manufactured by JSR.

  The color filter of the present invention can be suitably applied to applications such as a portable terminal such as a television, a personal computer, a liquid crystal projector, a game machine, and a mobile phone, a digital camera, and a car navigation. In the color filter of the present invention, it is sufficient that at least one of color pixels such as red (R), green (G), and blue (B) is formed by the inkjet ink of the present invention.

<Display device>
The color filter of the present invention can be suitably used for display devices such as liquid crystal display devices, plasma display display devices, EL display devices, and CRT display devices. For the definition of display devices and explanation of each display device, refer to “Electronic Display Devices (Akio Sasaki, published by Industrial Research Institute 1990)”, “Display Devices (Junaki Ibuki, Industrial Books Co., Ltd.) Issue)).

  Among the display devices, a liquid crystal display device is particularly preferable. The liquid crystal display device is described in, for example, “Next-generation liquid crystal display technology (edited by Tatsuo Uchida, published by Kogyo Kenkyukai 1994)”. The liquid crystal display device to which the present invention can be applied is not particularly limited, and can be applied to various types of liquid crystal display devices described in, for example, the “next generation liquid crystal display technology”. Among these, the present invention is particularly effective for a color TFT liquid crystal display device. The color TFT liquid crystal display device is described in, for example, “Color TFT liquid crystal display (issued in 1996 by Kyoritsu Publishing Co., Ltd.)”. Further, the present invention can be applied to a liquid crystal display device with a wide viewing angle such as a lateral electric field driving method such as IPS and a pixel division method such as MVA. These methods are described, for example, on page 43 of "EL, PDP, LCD display-latest technology and market trends-(issued in 2001 by Toray Research Center Research Division)".

  In addition to the color filter, the liquid crystal display device includes various members such as an electrode substrate, a polarizing film, a retardation film, a backlight, a spacer, and a viewing angle compensation film. For example, “'94 Liquid Crystal Display Peripheral Materials and Chemicals Market (Kentaro Shima, CMC 1994)” and “2003 Liquid Crystal Related Markets Current Status and Future Prospects (Volume 2)” (Table Yoshiyoshi) Fuji Chimera Research Institute, published in 2003) ”.

  The display devices include ECB (Electrically Controlled Birefringence), TN (Twisted Nematic), IPS (In-Plane Asymmetric Vrist), FLC (Ferroelectric Liquid Crystral), OCB (OpticalBandyStic). Various display modes such as Aligned), HAN (Hybrid Aligned Nematic), and GH (Guest Host) can be adopted. It is characterized by using the color filter as described above, and it has no display unevenness when mounted on a TV or monitor, and can have a wide color reproduction range and a high contrast ratio. It can be suitably used for a large-screen display device or the like.

  The present invention will be described more specifically with reference to the following examples. The materials, reagents, ratios, equipment, operations, and the like shown in the following examples can be appropriately changed without departing from the scope of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. In the following examples, “%” and “parts” represent “mass%” and “parts by mass” unless otherwise specified, and the molecular weight indicates the weight average molecular weight.

[Example 1]
<< Preparation of inkjet ink >>
<Preparation of pigment dispersion for R (R1)>
C. I. Pigment Red 254 was blended with pigment dispersant 1 (compound 1 described later) and solvent (1,3-butanediol diacetate) (hereinafter abbreviated as 1,3-BGDA) as shown in Table 1 below. Thereafter, using a motor mill M-50 (manufactured by Eiger Japan), zirconia beads having a diameter of 0.65 mm were used and dispersed at a peripheral speed of 9 m / s for 4 hours to prepare an R pigment dispersion (R1).
<Preparation of other pigment dispersions>
In the pigment dispersion for R (R1), the pigment and other components were blended as shown in Table 1 below, and dispersion treatment was performed for the dispersion time as shown in Table 1 below. Similarly, R pigment dispersions (R2), (R3), (R4), (R5), (R6), G pigment dispersions (G1), (G2), and B pigment dispersions (B1) , (B2) were prepared.

<Preparation of inkjet ink>
A solvent (1,3-BGDA), a surfactant (the following structure 2), an inhibitor (phenothiazine), and a monomer (dipentaerythritol hexaacrylate; hereinafter also referred to as “DPHA”) are mixed until they are sufficiently dissolved. 1 pigment dispersions (R1) and (R2) were blended as shown in Table 2 below, and mixed sufficiently with stirring to prepare the inkjet ink of Example 1.

≪Inkjet ink viscosity measurement≫
When the ink-jet ink obtained above is concentrated to a viscosity at 20 ° C. after preparation (that is, before concentration) and to a solid content of 40% by mass, 50% by mass, 60% by mass, and 70% by mass. The viscosity at 25 ° C. was measured.

<Concentration of inkjet ink>
Concentration of the inkjet ink was performed by the following method.
About 4 g of ink was poured into a 10 cm × 15 cm stainless steel vat, spread thinly over the entire vat, and the ink was dried at 100 ° C. for 15 minutes in an explosion-proof dry oven with a sufficient flow of air in the cabinet. When this dry ink was dried up at 110 ° C. for 30 minutes and the solid content ratio was measured, the solid content ratio was 1 (that is, the solid content was 100%).
The solid content of the dried ink is recovered in a glass bottle, and the ink solid solvent is added according to the following formulas 1 and 2 and stirred for 30 minutes or more until uniform to dilute the ink solid content. Concentrated until

Addition amount of solvent to make ink concentrated to 40% by mass of solid content
= Dry ink mass x Dry ink solid content ratio x 6 ÷ 4 (Formula 1)
Addition amount of solvent to make ink concentrated to 70 mass% solid content
= Dry ink mass x Dry ink solid content ratio x 3 ÷ 7 (Equation 2)

<Viscosity measurement>
The viscosity of the ink before concentration was measured with an E-type viscometer manufactured by Tokyo Keiki Co., Ltd. at an ink temperature of 20 ° C.
The viscosity when concentrated was measured using a viscoelasticity measuring device STRESSTECH manufactured by REOLOGICA Instruments AB under conditions of an ink temperature of 25 ° C. and a frequency of 1 Hz.

≪Preparation of color filter≫
A color filter was produced using the obtained inkjet ink.
Specifically, a partition wall was formed on a substrate, a droplet of the ink jet ink prepared as described above was applied to a recess surrounded by the formed partition wall, and a colored layer was formed. Hereinafter, each step will be described.

<Formation of partition walls>
(Preparation of dark color composition for barrier rib formation)
The dark color composition K1 is first weighed in K pigment dispersion 1 and propylene glycol monomethyl ether acetate in the amounts shown in Table 3, mixed at a temperature of 24 ° C. (± 2 ° C.), stirred at 150 rpm for 10 minutes, and then Methyl ethyl ketone, binder 2, hydroquinone monomethyl ether, DPHA solution, 2,4-bis (trichloromethyl) -6- [4 '-(N, N-bisethoxycarbonylmethyl) amino-3' in the amounts shown in Table 3 -Bromophenyl] -s-triazine and Surfactant 1 are weighed out, added in this order at a temperature of 25 ° C. (± 2 ° C.), and stirred at 150 rpm for 30 minutes at a temperature of 40 ° C. (± 2 ° C.). It is done. In addition, the quantity of Table 3 is a mass part, and has the following composition in detail.

~ K pigment dispersion 1 ~
・ Carbon black (Nexex 35 manufactured by Degussa) ... 13.1%
Dispersant 1 (Compound 1 described above) 0.65%
-Polymer (Random copolymer of benzyl methacrylate / methacrylic acid = 72/28 molar ratio, molecular weight 37,000) ... 6.72%
・ Propylene glycol monomethyl ether acetate: 79.53%

~ Binder 2
・ Polymer (benzyl methacrylate / methacrylic acid = 78/22 molar ratio random copolymer, molecular weight 38,000) 27%
・ Propylene glycol monomethyl ether acetate 73%

~ DPHA solution ~
・ Dipentaerythritol hexaacrylate (containing polymerization inhibitor MEHQ 500ppm, Nippon Kayaku Co., Ltd., trade name: KAYARAD DPHA) 76%
・ Propylene glycol monomethyl ether acetate 24%

~ Surfactant 1 ~
・ The following structure 1 ・ ・ ・ 30%
・ Methyl ethyl ketone 70%

(Production of photosensitive transfer material)
On a 75 μm thick polyethylene terephthalate film temporary support, a coating solution for a thermoplastic resin layer having the following formulation C was applied and dried using a slit nozzle. Next, an oxygen barrier layer coating solution having the following formulation P1 was applied and dried. Furthermore, the dark color composition K1 described in Table 3 was applied and dried. Thus, on the temporary support, a thermoplastic resin layer having a dry film thickness of 6.0 μm, an oxygen blocking layer having a dry film thickness of 1.6 μm, and a photosensitive resin layer having a dry film thickness of 2.5 μm. Finally, a protective film (12 μm thick polypropylene film) was pressure-bonded.
Thus, a photosensitive transfer material K1 in which the temporary support, the thermoplastic resin layer, the oxygen blocking layer, and the black (K) photosensitive resin layer were integrated was produced.

-Coating solution for thermoplastic resin layer: Formulation C-
-Methanol ... 11.1 parts-Propylene glycol monomethyl ether ... 6.36 parts-Methyl ethyl ketone ... 52.4 parts-Methyl methacrylate / 2-ethylhexyl acrylate / benzyl methacrylate / methacrylic acid copolymer (copolymerization) Composition ratio (molar ratio) = 55 / 11.7 / 4.5 / 28.8, molecular weight = 100,000, Tg≈70 ° C.) 5.83 parts styrene / acrylic acid copolymer (copolymerization composition) Ratio (molar ratio) = 63/37, molecular weight = 10,000, Tg≈100 ° C.) 13.6 parts. Compound obtained by dehydration condensation of 2 equivalents of bisphenol A and pentaethylene glycol monomethacrylate (Shin Nakamura Chemical Co., Ltd.) ) BPE-500) ... 9.1 parts ・ Surfactant 1 ... 0.54 parts

-Oxygen barrier coating solution: Formulation P1-
PVA205 (polyvinyl alcohol, manufactured by Kuraray Co., Ltd., degree of saponification = 88%, degree of polymerization 550) 32.2 parts Polyvinylpyrrolidone (manufactured by BASF, K-30) 14.9 parts distillation Water: 524 parts, methanol: 429 parts

(Formation of partition walls)
A glass cleaner liquid adjusted to 25 ° C. is sprayed onto an alkali-free glass substrate with a shower for 20 seconds while being washed with a rotating brush having nylon bristles. After washing with pure water, silane coupling liquid (N-β (aminoethyl) A 0.3% aqueous solution of γ-aminopropyltrimethoxysilane (trade name: KBM603, Shin-Etsu Chemical Co., Ltd.) was sprayed for 20 seconds with a shower and washed with pure water. This substrate was heated at 100 ° C. for 2 minutes by a substrate preheating apparatus.
After peeling off the protective film of the photosensitive transfer material K1, a substrate heated at 100 ° C. for 2 minutes using a laminator (manufactured by Hitachi Industries, Ltd. (Lamic II type)), rubber roller temperature 130 ° C., linear pressure 100N / Cm, laminating at a conveyance speed of 2.2 m / min.
After peeling the temporary support, the exposure mask with the substrate and mask (quartz exposure mask with image pattern) standing upright with a proximity type exposure machine (manufactured by Hitachi Electronics Engineering Co., Ltd.) having an ultra high pressure mercury lamp. The distance between the surface and the photosensitive resin layer was set to 200 μm, and pattern exposure was performed with an exposure amount of 90 mJ / cm ² .
Next, pure water is sprayed with a shower nozzle to uniformly wet the surface of the photosensitive resin layer K1, and then a KOH developer (KOH, containing nonionic surfactant, trade name: CDK-1 ( (Fujifilm Arch) diluted 100 times with pure water) was subjected to shower development at 23 ° C. for 80 seconds and a flat nozzle pressure of 0.04 MPa to obtain a patterning image. Subsequently, ultrapure water was sprayed at a pressure of 9.8 MPa with an ultrahigh pressure washing nozzle to remove residues, and an image of matrix-like black (K) was obtained. Thereafter, the substrate is further post-exposed with 1000 mJ / cm ² light from the side of the resin layer with an ultrahigh pressure mercury lamp, and further 1000 mJ / cm with an ultrahigh pressure mercury lamp from the side opposite to the resin layer. Post-exposure was performed with the light of No. ² , and then heat treatment was performed at 220 ° C. for 30 minutes to form partition walls.

(Ink repellent plasma treatment of partition walls)
The substrate on which the barrier ribs were formed was subjected to ink repellent plasma treatment under the following conditions using a cathode coupling parallel plate type plasma treatment apparatus.
~ Conditions for ink repellent plasma treatment ~
・ Used gas: CF ₄
・ Gas flow rate: 80sccm
・ Pressure: 40 Pa
・ RF power: 50W
・ Processing time: 30 sec

<Formation of colored layer>
Next, on the substrate with the partition walls after the ink repellent plasma treatment, a desired density is applied to the concave portions (pixel portions) on the substrate partitioned by the partition walls by an inkjet head (SE-128, head temperature 28 ° C.) manufactured by Dimatix. Then, R ink 1 was discharged until a color filter having a red (R) colored pixel portion was produced. Both the partition walls and the pixels were completely cured by baking the color filter after image coloring in an oven at 220 ° C. for 30 minutes.

≪Evaluation≫
The following evaluation was performed about the color filter which has the colored pixel part of the obtained red (R). The evaluation results are shown in Table 4.

(Evaluation of flatness)
The shape of the pixel portion was observed using a non-contact type surface shape measuring apparatus New View 6K (manufactured by Zygo), and the profile of the surface shape was calculated. The lowest part was A, the highest part was B, and the flatness was evaluated according to the following criteria based on the height difference (B−A). If it is “◯” or “Δ”, it is practically acceptable.
~ Evaluation of flatness ~
○: B−A <0.3 μm
Δ: 0.3 ≦ B−A <0.6 μm
×: 0.6 μm ≦ BA

(Contrast evaluation)
Using a three-wavelength cold-cathode tube light source (LC22GD3 manufactured by Sharp Corporation) as a backlight unit and a diffusion plate installed, a color filter between two polarizing plates (POLAX-15N manufactured by Luceo Co., Ltd.) The Y value of the chromaticity of the light that passes when the polarizing plate is installed in parallel Nicols, and the Y value of the chromaticity of the light that passes when installed in crossed Nicols The contrast was obtained by dividing by. A color luminance meter (BM-5 manufactured by Topcon Co., Ltd.) was used for the measurement of chromaticity.

(Evaluation of uneven color)
The obtained color filter having a red (R) colored pixel portion was checked for density unevenness in one pixel with an optical microscope.
○: Color unevenness is not observed in both the reflected image and the transmitted image.
Δ: Reflection unevenness is not observed in the transmission image, but slight color unevenness is observed in the reflection image (within a practically allowable range).
X: Color unevenness is observed in the transmission image.

[Examples 2 to 5, Comparative Examples 1 to 4]
In Example 1, each ink was prepared in the same manner as in Example 1 except that the composition was changed as shown in Table 2 in the preparation of R ink 1, and a color filter was prepared. The viscosity of the ink was measured by the method, and the flatness, contrast, and color unevenness of the pixel portion of the color filter were evaluated.
The evaluation results are shown in Table 4.

As shown in Table 4, the viscosity when concentrated until the solid content is 40% by mass is 10 Pa · s or less at 25 ° C., and the viscosity when concentrated until the solid content is 70% by mass is 10 Pa at 25 ° C. -When the color filter was produced using the inkjet ink more than s (Examples 1-5), the cross-sectional shape (flatness) of the pixel part was favorable.
In addition, when the result of the viscosity measurement in Examples 1-5 and Comparative Examples 1-4 was plotted, it became the graph shown in FIG.

In addition, three color filters were also produced as follows.
That is, a Dimatix ink jet head (SE-128, head temperature 28 ° C.) is formed in the concave portion (pixel portion) on the substrate partitioned by the partition, on the substrate with the partition after the ink repellent plasma treatment in Example 1. When R ink 2, G ink 1 and B ink 1 are ejected to a desired density to produce a color filter, variation in color density within the pixel is suppressed, and a uniform and uniform color filter is produced. I was able to.

It is a graph for demonstrating the relationship between solid content and a viscosity when an inkjet ink is concentrated. It is a graph which shows the relationship between the amount of solid content and a viscosity when the inkjet ink in an Example and a comparative example is concentrated.

Explanation of symbols

10 Line 12 showing behavior of inkjet ink included in the present invention 14 Line 14 showing behavior of inkjet ink included in the present invention 16 Line 16 showing behavior of inkjet ink not included in the present invention Lines showing behavior

Claims (10)

  It contains a pigment, a dispersant, and a solvent. The viscosity when concentrated until the solid content is 40% by mass is 10 Pa · s or less at 25 ° C., and the viscosity when concentrated until the solid content is 70% by mass is 25. An ink-jet ink having a pressure of 10 Pa · s or more at a temperature.   The viscosity when concentrated until the solid content is 40% by mass is 10 Pa · s or less at 25 ° C., and the viscosity when concentrated until the solid content is 60% by mass is 10 Pa · s or more at 25 ° C. The inkjet ink according to 1.   Furthermore, the inkjet ink of Claim 1 or 2 containing a sclerosing | hardenable component.   The inkjet ink according to any one of claims 1 to 3, wherein the solid content is 15 to 30% by mass.   The inkjet ink according to any one of claims 1 to 4, wherein 80% or more of the total mass of the solvent is a solvent having a boiling point of 230 ° C or higher.   The inkjet ink according to any one of claims 1 to 5, which has a viscosity at 20 ° C of 30 mPa · s or less.   The inkjet ink according to claim 1, which is used for producing a color filter.   The inkjet ink according to any one of claims 1 to 7, wherein the pigment contains a red, green, or blue pigment.   A color filter using the inkjet ink according to claim 1.   The color filter according to claim 9, wherein the contrast is 7000 or more.

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